Series comparison

-[Qemu-devel] [PULL 00/12] Block layer patches
+[Qemu-devel] [PULL v3 00/35] Block layer patches
-The following changes since commit b98a66201dbc7cf3b962f4bb260f66100cc75578:
+The following changes since commit 281f327487c9c9b1599f93c589a408bbf4a651b8:
-  Merge remote-tracking branch 'remotes/palmer/tags/riscv-for-master-4.0-rc0-2' into staging (2019-03-19 12:55:02 +0000)
+  Merge remote-tracking branch 'remotes/vivier/tags/m68k-for-2.12-pull-request' into staging (2017-12-22 00:11:36 +0000)
-are available in the Git repository at:
+are available in the git repository at:
   git://repo.or.cz/qemu/kevin.git tags/for-upstream
-for you to fetch changes up to 59fba0aaee7438002d9803a86c888f21a1070cc8:
+for you to fetch changes up to 1a63a907507fbbcfaee3f622907ec244b7eabda8:
-  qemu-iotests: Treat custom TEST_DIR in 051 (2019-03-19 15:51:31 +0100)
+  block: Keep nodes drained between reopen_queue/multiple (2017-12-22 15:05:32 +0100)
 ----------------------------------------------------------------
-Block layer patches:
+Block layer patches
 - mirror: Fix early return from drain (could cause deadlocks)
 - vmdk: Fixed probing for version 3 images
 - vl: Fix to create migration object before block backends again (fixes
   segfault for block drivers that set migration blockers)
 - Several minor fixes, documentation and test case improvements
 ----------------------------------------------------------------
-Alberto Garcia (1):
+Doug Gale (1):
-      block: Make bdrv_{copy_on_read,crypto_luks,replication} static
+      nvme: Add tracing
-Kevin Wolf (3):
+Edgar Kaziakhmedov (1):
-      qcow2: Fix data file error condition in qcow2_co_create()
+      qcow2: get rid of qcow2_backing_read1 routine
       block: Silence Coverity in bdrv_drop_intermediate()
       qemu-iotests: Fix 232 for non-qcow2
-Lukáš Doktor (1):
+Fam Zheng (2):
-      qemu-iotests: Treat custom TEST_DIR in 051
+      block: Open backing image in force share mode for size probe
       block: Remove unused bdrv_requests_pending
-Markus Armbruster (1):
+John Snow (1):
-      vl: Fix to create migration object before block backends again
+      iotests: fix 197 for vpc
-Max Reitz (1):
+Kevin Wolf (27):
-      blockdev: Check @replaces in blockdev_mirror_common
+      block: Formats don't need CONSISTENT_READ with NO_IO
       block: Make bdrv_drain_invoke() recursive
       block: Call .drain_begin only once in bdrv_drain_all_begin()
       test-bdrv-drain: Test BlockDriver callbacks for drain
       block: bdrv_drain_recurse(): Remove unused begin parameter
       block: Don't wait for requests in bdrv_drain*_end()
       block: Unify order in drain functions
       block: Don't acquire AioContext in hmp_qemu_io()
       block: Document that x-blockdev-change breaks quorum children list
       block: Assert drain_all is only called from main AioContext
       block: Make bdrv_drain() driver callbacks non-recursive
       test-bdrv-drain: Test callback for bdrv_drain
       test-bdrv-drain: Test bs->quiesce_counter
       blockjob: Pause job on draining any job BDS
       test-bdrv-drain: Test drain vs. block jobs
       block: Don't block_job_pause_all() in bdrv_drain_all()
       block: Nested drain_end must still call callbacks
       test-bdrv-drain: Test nested drain sections
       block: Don't notify parents in drain call chain
       block: Add bdrv_subtree_drained_begin/end()
       test-bdrv-drain: Tests for bdrv_subtree_drain
       test-bdrv-drain: Test behaviour in coroutine context
       test-bdrv-drain: Recursive draining with multiple parents
       block: Allow graph changes in subtree drained section
       test-bdrv-drain: Test graph changes in drained section
       commit: Simplify reopen of base
       block: Keep nodes drained between reopen_queue/multiple
-Sam Eiderman (1):
+Thomas Huth (3):
-      vmdk: Support version=3 in VMDK descriptor files
+      block: Remove the obsolete -drive boot=on|off parameter
       block: Remove the deprecated -hdachs option
       block: Mention -drive cyls/heads/secs/trans/serial/addr in deprecation chapter
-Sergio Lopez (2):
+ qapi/block-core.json             |   4 +
-      mirror: Confirm we're quiesced only if the job is paused or cancelled
+ block/qcow2.h                    |   3 -
-      iotests: 153: Wait for an answer to QMP commands
+ include/block/block.h            |  15 +-
  include/block/block_int.h        |   6 +-
  block.c                          |  75 ++++-
  block/commit.c                   |   8 +-
  block/io.c                       | 164 +++++++---
  block/qcow2.c                    |  51 +--
  block/replication.c              |   6 +
  blockdev.c                       |  11 -
  blockjob.c                       |  22 +-
  hmp.c                            |   6 -
  hw/block/nvme.c                  | 349 +++++++++++++++++----
  qemu-io-cmds.c                   |   3 +
  tests/test-bdrv-drain.c          | 651 +++++++++++++++++++++++++++++++++++++++
  vl.c                             |  86 +-----
  hw/block/trace-events            |  93 ++++++
  qemu-doc.texi                    |  29 +-
  qemu-options.hx                  |  19 +-
  tests/Makefile.include           |   2 +
  tests/qemu-iotests/197           |   4 +
  tests/qemu-iotests/common.filter |   3 +-
 files changed, 1294 insertions(+), 316 deletions(-)
  create mode 100644 tests/test-bdrv-drain.c
-Vladimir Sementsov-Ogievskiy (2):
-      qapi: fix block-latency-histogram-set description and examples
-      blockjob: fix user pause in block_job_error_action
- qapi/block-core.json       | 10 +++---
- block.c                    |  7 ++--
- block/copy-on-read.c       |  2 +-
- block/crypto.c             |  2 +-
- block/mirror.c             | 16 ++++++++++
- block/qcow2.c              |  2 +-
- block/replication.c        |  2 +-
- block/vmdk.c               |  6 ++--
- blockdev.c                 | 55 +++++++++++++++++++-------------
- blockjob.c                 |  8 +++--
- vl.c                       | 15 +++++----
- tests/qemu-iotests/051     |  2 +-
- tests/qemu-iotests/153     | 12 +++----
- tests/qemu-iotests/153.out |  6 ++++
- tests/qemu-iotests/232     | 30 ------------------
- tests/qemu-iotests/232.out | 20 ------------
- tests/qemu-iotests/247     | 79 ++++++++++++++++++++++++++++++++++++++++++++++
- tests/qemu-iotests/247.out | 22 +++++++++++++
- tests/qemu-iotests/group   |  1 +
-files changed, 193 insertions(+), 104 deletions(-)
- create mode 100755 tests/qemu-iotests/247
- create mode 100644 tests/qemu-iotests/247.out

-[Qemu-devel] [PULL 05/12] block: Silence Coverity in bdrv_drop_intermediate()
+[Qemu-devel] [PULL v3 01/35] block: Formats don't need CONSISTENT_READ with NO_IO
-Coverity doesn't like that the return value of bdrv_check_update_perm()
+Commit 1f4ad7d fixed 'qemu-img info' for raw images that are currently
-stays unused only in this place (CID 1399710).
+in use as a mirror target. It is not enough for image formats, though,
 as these still unconditionally request BLK_PERM_CONSISTENT_READ.
-Even if checking local_err should be equivalent to checking ret < 0,
+As this permission is geared towards whether the guest-visible data is
-let's switch to using the return value to be more consistent (and in
+consistent, and has no impact on whether the metadata is sane, and
-case of a bug somewhere down the call chain, forgetting to assign errp
+'qemu-img info' does not read guest-visible data (except for the raw
-is more likely than returning 0 for an error case).
+format), it makes sense to not require BLK_PERM_CONSISTENT_READ if there
 is not going to be any guest I/O performed, regardless of image format.
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-Reviewed-by: Alberto Garcia <berto@igalia.com>
-Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
-Reviewed-by: Markus Armbruster <armbru@redhat.com>
 ---
- block.c | 7 +++----
+ block.c | 6 +++++-
-file changed, 3 insertions(+), 4 deletions(-)
+file changed, 5 insertions(+), 1 deletion(-)
 diff --git a/block.c b/block.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block.c
 +++ b/block.c
-@@ -XXX,XX +XXX,XX @@ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
+@@ -XXX,XX +XXX,XX @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
-     QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) {
+     assert(role == &child_backing || role == &child_file);
-         /* Check whether we are allowed to switch c from top to base */
-         GSList *ignore_children = g_slist_prepend(NULL, c);
+     if (!backing) {
--        bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
++        int flags = bdrv_reopen_get_flags(reopen_queue, bs);
--                               ignore_children, &local_err);
++
-+        ret = bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
+         /* Apart from the modifications below, the same permissions are
-+                                     ignore_children, &local_err);
+          * forwarded and left alone as for filters */
-         g_slist_free(ignore_children);
+         bdrv_filter_default_perms(bs, c, role, reopen_queue, perm, shared,
--        if (local_err) {
+@@ -XXX,XX +XXX,XX @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
--            ret = -EPERM;
-+        if (ret < 0) {
+         /* bs->file always needs to be consistent because of the metadata. We
-             error_report_err(local_err);
+          * can never allow other users to resize or write to it. */
-             goto exit;
+-        perm |= BLK_PERM_CONSISTENT_READ;
-         }
++        if (!(flags & BDRV_O_NO_IO)) {
 +            perm |= BLK_PERM_CONSISTENT_READ;
 +        }
          shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
      } else {
          /* We want consistent read from backing files if the parent needs it.
 --
-.20.1
+.13.6

-New patch
+[Qemu-devel] [PULL v3 02/35] iotests: fix 197 for vpc
+From: John Snow <jsnow@redhat.com>
+VPC has some difficulty creating geometries of particular size.
+However, we can indeed force it to use a literal one, so let's
+do that for the sake of test 197, which is testing some specific
+offsets.
+Signed-off-by: John Snow <jsnow@redhat.com>
+Reviewed-by: Eric Blake <eblake@redhat.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Lukáš Doktor <ldoktor@redhat.com>
+---
+ tests/qemu-iotests/197           | 4 ++++
+ tests/qemu-iotests/common.filter | 3 ++-
+files changed, 6 insertions(+), 1 deletion(-)
+diff --git a/tests/qemu-iotests/197 b/tests/qemu-iotests/197
+index XXXXXXX..XXXXXXX 100755
+--- a/tests/qemu-iotests/197
++++ b/tests/qemu-iotests/197
+@@ -XXX,XX +XXX,XX @@ echo '=== Copy-on-read ==='
+ echo
+ # Prep the images
++# VPC rounds image sizes to a specific geometry, force a specific size.
++if [ "$IMGFMT" = "vpc" ]; then
++    IMGOPTS=$(_optstr_add "$IMGOPTS" "force_size")
++fi
+ _make_test_img 4G
+ $QEMU_IO -c "write -P 55 3G 1k" "$TEST_IMG" | _filter_qemu_io
+ IMGPROTO=file IMGFMT=qcow2 IMGOPTS= TEST_IMG_FILE="$TEST_WRAP" \
+diff --git a/tests/qemu-iotests/common.filter b/tests/qemu-iotests/common.filter
+index XXXXXXX..XXXXXXX 100644
+--- a/tests/qemu-iotests/common.filter
++++ b/tests/qemu-iotests/common.filter
+@@ -XXX,XX +XXX,XX @@ _filter_img_create()
+         -e "s# log_size=[0-9]\\+##g" \
+         -e "s# refcount_bits=[0-9]\\+##g" \
+         -e "s# key-secret=[a-zA-Z0-9]\\+##g" \
+-        -e "s# iter-time=[0-9]\\+##g"
++        -e "s# iter-time=[0-9]\\+##g" \
++        -e "s# force_size=\\(on\\|off\\)##g"
+ }
+ _filter_img_info()
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 03/35] block: Make bdrv_drain_invoke() recursive
+This change separates bdrv_drain_invoke(), which calls the BlockDriver
+drain callbacks, from bdrv_drain_recurse(). Instead, the function
+performs its own recursion now.
+One reason for this is that bdrv_drain_recurse() can be called multiple
+times by bdrv_drain_all_begin(), but the callbacks may only be called
+once. The separation is necessary to fix this bug.
+The other reason is that we intend to go to a model where we call all
+driver callbacks first, and only then start polling. This is not fully
+achieved yet with this patch, as bdrv_drain_invoke() contains a
+BDRV_POLL_WHILE() loop for the block driver callbacks, which can still
+call callbacks for any unrelated event. It's a step in this direction
+anyway.
+Cc: qemu-stable@nongnu.org
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ block/io.c | 14 +++++++++++---
+file changed, 11 insertions(+), 3 deletions(-)
+diff --git a/block/io.c b/block/io.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/io.c
++++ b/block/io.c
+@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
+     bdrv_wakeup(bs);
+ }
++/* Recursively call BlockDriver.bdrv_co_drain_begin/end callbacks */
+ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
+ {
++    BdrvChild *child, *tmp;
+     BdrvCoDrainData data = { .bs = bs, .done = false, .begin = begin};
+     if (!bs->drv || (begin && !bs->drv->bdrv_co_drain_begin) ||
+@@ -XXX,XX +XXX,XX @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
+     data.co = qemu_coroutine_create(bdrv_drain_invoke_entry, &data);
+     bdrv_coroutine_enter(bs, data.co);
+     BDRV_POLL_WHILE(bs, !data.done);
++
++    QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {
++        bdrv_drain_invoke(child->bs, begin);
++    }
+ }
+ static bool bdrv_drain_recurse(BlockDriverState *bs, bool begin)
+@@ -XXX,XX +XXX,XX @@ static bool bdrv_drain_recurse(BlockDriverState *bs, bool begin)
+     BdrvChild *child, *tmp;
+     bool waited;
+-    /* Ensure any pending metadata writes are submitted to bs->file.  */
+-    bdrv_drain_invoke(bs, begin);
+-
+     /* Wait for drained requests to finish */
+     waited = BDRV_POLL_WHILE(bs, atomic_read(&bs->in_flight) > 0);
+@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs)
+         bdrv_parent_drained_begin(bs);
+     }
++    bdrv_drain_invoke(bs, true);
+     bdrv_drain_recurse(bs, true);
+ }
+@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
+     }
+     bdrv_parent_drained_end(bs);
++    bdrv_drain_invoke(bs, false);
+     bdrv_drain_recurse(bs, false);
+     aio_enable_external(bdrv_get_aio_context(bs));
+ }
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
+             aio_context_acquire(aio_context);
+             for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+                 if (aio_context == bdrv_get_aio_context(bs)) {
++                    /* FIXME Calling this multiple times is wrong */
++                    bdrv_drain_invoke(bs, true);
+                     waited |= bdrv_drain_recurse(bs, true);
+                 }
+             }
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
+         aio_context_acquire(aio_context);
+         aio_enable_external(aio_context);
+         bdrv_parent_drained_end(bs);
++        bdrv_drain_invoke(bs, false);
+         bdrv_drain_recurse(bs, false);
+         aio_context_release(aio_context);
+     }
+--
+.13.6

-[Qemu-devel] [PULL 04/12] vmdk: Support version=3 in VMDK descriptor files
+[Qemu-devel] [PULL v3 04/35] block: Call .drain_begin only once in bdrv_drain_all_begin()
-From: Sam Eiderman <shmuel.eiderman@oracle.com>
+bdrv_drain_all_begin() used to call the .bdrv_co_drain_begin() driver
 callback inside its polling loop. This means that how many times it got
 called for each node depended on long it had to poll the event loop.
-Commit 509d39aa22909c0ed1aabf896865f19c81fb38a1 added support for read
+This is obviously not right and results in nodes that stay drained even
-only VMDKs of version 3.
+after bdrv_drain_all_end(), which calls .bdrv_co_drain_begin() once per
 node.
-This commit fixes the probe function to correctly handle descriptors of
+Fix bdrv_drain_all_begin() to call the callback only once, too.
 version 3.
-This commit has two effects:
+Cc: qemu-stable@nongnu.org
-. We no longer need to supply '-f vmdk' when pointing to descriptor
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-       files of version 3 in qemu/qemu-img command line arguments.
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
-. This fixes the scenario where a VMDK points to a parent version 3
+---
-       descriptor file which is being probed as "raw" instead of "vmdk".
+ block/io.c | 3 +--
 file changed, 1 insertion(+), 2 deletions(-)
-Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com>
+diff --git a/block/io.c b/block/io.c
 Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
 Signed-off-by: Shmuel Eiderman <shmuel.eiderman@oracle.com>
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
 ---
  block/vmdk.c | 6 ++++--
 file changed, 4 insertions(+), 2 deletions(-)
 diff --git a/block/vmdk.c b/block/vmdk.c
 index XXXXXXX..XXXXXXX 100644
---- a/block/vmdk.c
+--- a/block/io.c
-+++ b/block/vmdk.c
++++ b/block/io.c
-@@ -XXX,XX +XXX,XX @@ static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
-             }
+         aio_context_acquire(aio_context);
-             if (end - p >= strlen("version=X\n")) {
+         bdrv_parent_drained_begin(bs);
-                 if (strncmp("version=1\n", p, strlen("version=1\n")) == 0 ||
+         aio_disable_external(aio_context);
--                    strncmp("version=2\n", p, strlen("version=2\n")) == 0) {
++        bdrv_drain_invoke(bs, true);
-+                    strncmp("version=2\n", p, strlen("version=2\n")) == 0 ||
+         aio_context_release(aio_context);
-+                    strncmp("version=3\n", p, strlen("version=3\n")) == 0) {
-                     return 100;
+         if (!g_slist_find(aio_ctxs, aio_context)) {
-                 }
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
-             }
+             aio_context_acquire(aio_context);
-             if (end - p >= strlen("version=X\r\n")) {
+             for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
-                 if (strncmp("version=1\r\n", p, strlen("version=1\r\n")) == 0 ||
+                 if (aio_context == bdrv_get_aio_context(bs)) {
--                    strncmp("version=2\r\n", p, strlen("version=2\r\n")) == 0) {
+-                    /* FIXME Calling this multiple times is wrong */
-+                    strncmp("version=2\r\n", p, strlen("version=2\r\n")) == 0 ||
+-                    bdrv_drain_invoke(bs, true);
-+                    strncmp("version=3\r\n", p, strlen("version=3\r\n")) == 0) {
+                     waited |= bdrv_drain_recurse(bs, true);
                      return 100;
                  }
              }
 --
-.20.1
+.13.6

-[Qemu-devel] [PULL 08/12] qemu-iotests: Fix 232 for non-qcow2
+[Qemu-devel] [PULL v3 05/35] test-bdrv-drain: Test BlockDriver callbacks for drain
-is marked as generic, but commit 12efe428c9e added code that assumes
+This adds a test case that the BlockDriver callbacks for drain are
-qcow2. What the new test really needs is backing files and support for
+called in bdrv_drained_all_begin/end(), and that both of them are called
-updating the backing file link (.bdrv_change_backing_file).
+exactly once.
 Split the non-generic code into a new test case 247 and make it work
 with qed, too.
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Reviewed-by: Eric Blake <eblake@redhat.com>
 ---
- tests/qemu-iotests/232     | 30 ---------------
+ tests/test-bdrv-drain.c | 137 ++++++++++++++++++++++++++++++++++++++++++++++++
- tests/qemu-iotests/232.out | 20 ----------
+ tests/Makefile.include  |   2 +
- tests/qemu-iotests/247     | 79 ++++++++++++++++++++++++++++++++++++++
+files changed, 139 insertions(+)
- tests/qemu-iotests/247.out | 22 +++++++++++
+ create mode 100644 tests/test-bdrv-drain.c
  tests/qemu-iotests/group   |  1 +
 files changed, 102 insertions(+), 50 deletions(-)
  create mode 100755 tests/qemu-iotests/247
  create mode 100644 tests/qemu-iotests/247.out
-diff --git a/tests/qemu-iotests/232 b/tests/qemu-iotests/232
+diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
 index XXXXXXX..XXXXXXX 100755
 --- a/tests/qemu-iotests/232
 +++ b/tests/qemu-iotests/232
@@ -XXX,XX +XXX,XX @@ run_qemu_info_block -blockdev driver=file,filename="$TEST_IMG",node-name=node0,a
  run_qemu_info_block -blockdev driver=file,filename="$TEST_IMG",node-name=node0,auto-read-only=on
  run_qemu_info_block -blockdev driver=file,filename="$TEST_IMG",node-name=node0
 -echo
 -echo "=== Try commit to backing file with auto-read-only ==="
 -echo
 -
 -TEST_IMG="$TEST_IMG.0" _make_test_img $size
 -TEST_IMG="$TEST_IMG.1" _make_test_img $size
 -TEST_IMG="$TEST_IMG.2" _make_test_img $size
 -TEST_IMG="$TEST_IMG.3" _make_test_img $size
 -TEST_IMG="$TEST_IMG.4" _make_test_img $size
 -
 -(cat <<EOF
 -{"execute":"qmp_capabilities"}
 -{"execute":"block-commit",
 - "arguments":{"device":"format-4", "top-node": "format-2", "base-node":"format-0", "job-id":"job0"}}
 -EOF
 -sleep 1
 -echo '{"execute":"quit"}'
 -) | $QEMU -qmp stdio -nographic -nodefaults \
 -    -blockdev file,node-name=file-0,filename=$TEST_IMG.0,auto-read-only=on \
 -    -blockdev qcow2,node-name=format-0,file=file-0,read-only=on \
 -    -blockdev file,node-name=file-1,filename=$TEST_IMG.1,auto-read-only=on \
 -    -blockdev qcow2,node-name=format-1,file=file-1,read-only=on,backing=format-0 \
 -    -blockdev file,node-name=file-2,filename=$TEST_IMG.2,auto-read-only=on \
 -    -blockdev qcow2,node-name=format-2,file=file-2,read-only=on,backing=format-1 \
 -    -blockdev file,node-name=file-3,filename=$TEST_IMG.3,auto-read-only=on \
 -    -blockdev qcow2,node-name=format-3,file=file-3,read-only=on,backing=format-2 \
 -    -blockdev file,node-name=file-4,filename=$TEST_IMG.4,auto-read-only=on \
 -    -blockdev qcow2,node-name=format-4,file=file-4,read-only=on,backing=format-3 |
 -    _filter_qmp
 -
  # success, all done
  echo "*** done"
  rm -f $seq.full
 diff --git a/tests/qemu-iotests/232.out b/tests/qemu-iotests/232.out
 index XXXXXXX..XXXXXXX 100644
 --- a/tests/qemu-iotests/232.out
 +++ b/tests/qemu-iotests/232.out
@@ -XXX,XX +XXX,XX @@ QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0,read
  QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0,auto-read-only=off: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
  node0: TEST_DIR/t.IMGFMT (file)
  QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
 -
 -=== Try commit to backing file with auto-read-only ===
 -
 -Formatting 'TEST_DIR/t.IMGFMT.0', fmt=IMGFMT size=134217728
 -Formatting 'TEST_DIR/t.IMGFMT.1', fmt=IMGFMT size=134217728
 -Formatting 'TEST_DIR/t.IMGFMT.2', fmt=IMGFMT size=134217728
 -Formatting 'TEST_DIR/t.IMGFMT.3', fmt=IMGFMT size=134217728
 -Formatting 'TEST_DIR/t.IMGFMT.4', fmt=IMGFMT size=134217728
 -QMP_VERSION
 -{"return": {}}
 -{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "job0"}}
 -{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "job0"}}
 -{"return": {}}
 -{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "waiting", "id": "job0"}}
 -{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "pending", "id": "job0"}}
 -{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "job0", "len": 134217728, "offset": 134217728, "speed": 0, "type": "commit"}}
 -{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "concluded", "id": "job0"}}
 -{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "null", "id": "job0"}}
 -{"return": {}}
 -{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}}
  *** done
 diff --git a/tests/qemu-iotests/247 b/tests/qemu-iotests/247
 new file mode 100755
 index XXXXXXX..XXXXXXX
 --- /dev/null
 +++ b/tests/qemu-iotests/247
@@ -XXX,XX +XXX,XX @@
 +#!/usr/bin/env bash
 +#
 +# Test for auto-read-only with commit block job
 +#
 +# Copyright (C) 2019 Red Hat, Inc.
 +#
 +# This program is free software; you can redistribute it and/or modify
 +# it under the terms of the GNU General Public License as published by
 +# the Free Software Foundation; either version 2 of the License, or
 +# (at your option) any later version.
 +#
 +# This program is distributed in the hope that it will be useful,
 +# but WITHOUT ANY WARRANTY; without even the implied warranty of
 +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 +# GNU General Public License for more details.
 +#
 +# You should have received a copy of the GNU General Public License
 +# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 +#
 +
 +# creator
 +owner=kwolf@redhat.com
 +
 +seq=`basename $0`
 +echo "QA output created by $seq"
 +
 +status=1    # failure is the default!
 +
 +_cleanup()
 +{
 +    _cleanup_test_img
 +    rm -f $TEST_IMG.[01234]
 +}
 +trap "_cleanup; exit \$status" 0 1 2 3 15
 +
 +# get standard environment, filters and checks
 +. ./common.rc
 +. ./common.filter
 +
 +# Requires backing files and .bdrv_change_backing_file support
 +_supported_fmt qcow2 qed
 +_supported_proto file
 +_supported_os Linux
 +
 +size=128M
 +
 +echo
 +echo "=== Try commit to backing file with auto-read-only ==="
 +echo
 +TEST_IMG="$TEST_IMG.0" _make_test_img $size
 +TEST_IMG="$TEST_IMG.1" _make_test_img $size
 +TEST_IMG="$TEST_IMG.2" _make_test_img $size
 +TEST_IMG="$TEST_IMG.3" _make_test_img $size
 +TEST_IMG="$TEST_IMG.4" _make_test_img $size
 +
 +(cat <<EOF
 +{"execute":"qmp_capabilities"}
 +{"execute":"block-commit",
 + "arguments":{"device":"format-4", "top-node": "format-2", "base-node":"format-0", "job-id":"job0"}}
 +EOF
 +sleep 1
 +echo '{"execute":"quit"}'
 +) | $QEMU -qmp stdio -nographic -nodefaults \
 +    -blockdev file,node-name=file-0,filename=$TEST_IMG.0,auto-read-only=on \
 +    -blockdev $IMGFMT,node-name=format-0,file=file-0,read-only=on \
 +    -blockdev file,node-name=file-1,filename=$TEST_IMG.1,auto-read-only=on \
 +    -blockdev $IMGFMT,node-name=format-1,file=file-1,read-only=on,backing=format-0 \
 +    -blockdev file,node-name=file-2,filename=$TEST_IMG.2,auto-read-only=on \
 +    -blockdev $IMGFMT,node-name=format-2,file=file-2,read-only=on,backing=format-1 \
 +    -blockdev file,node-name=file-3,filename=$TEST_IMG.3,auto-read-only=on \
 +    -blockdev $IMGFMT,node-name=format-3,file=file-3,read-only=on,backing=format-2 \
 +    -blockdev file,node-name=file-4,filename=$TEST_IMG.4,auto-read-only=on \
 +    -blockdev $IMGFMT,node-name=format-4,file=file-4,read-only=on,backing=format-3 |
 +    _filter_qmp
 +
 +# success, all done
 +echo "*** done"
 +rm -f $seq.full
 +status=0
 diff --git a/tests/qemu-iotests/247.out b/tests/qemu-iotests/247.out
 new file mode 100644
 index XXXXXXX..XXXXXXX
 --- /dev/null
-+++ b/tests/qemu-iotests/247.out
++++ b/tests/test-bdrv-drain.c
 @@ -XXX,XX +XXX,XX @@
-+QA output created by 247
++/*
 + * Block node draining tests
 + *
 + * Copyright (c) 2017 Kevin Wolf <kwolf@redhat.com>
 + *
 + * Permission is hereby granted, free of charge, to any person obtaining a copy
 + * of this software and associated documentation files (the "Software"), to deal
 + * in the Software without restriction, including without limitation the rights
 + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 + * copies of the Software, and to permit persons to whom the Software is
 + * furnished to do so, subject to the following conditions:
 + *
 + * The above copyright notice and this permission notice shall be included in
 + * all copies or substantial portions of the Software.
 + *
 + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 + * THE SOFTWARE.
 + */
 +
-+=== Try commit to backing file with auto-read-only ===
++#include "qemu/osdep.h"
 +#include "block/block.h"
 +#include "sysemu/block-backend.h"
 +#include "qapi/error.h"
 +
-+Formatting 'TEST_DIR/t.IMGFMT.0', fmt=IMGFMT size=134217728
++typedef struct BDRVTestState {
-+Formatting 'TEST_DIR/t.IMGFMT.1', fmt=IMGFMT size=134217728
++    int drain_count;
-+Formatting 'TEST_DIR/t.IMGFMT.2', fmt=IMGFMT size=134217728
++} BDRVTestState;
-+Formatting 'TEST_DIR/t.IMGFMT.3', fmt=IMGFMT size=134217728
++
-+Formatting 'TEST_DIR/t.IMGFMT.4', fmt=IMGFMT size=134217728
++static void coroutine_fn bdrv_test_co_drain_begin(BlockDriverState *bs)
-+QMP_VERSION
++{
-+{"return": {}}
++    BDRVTestState *s = bs->opaque;
-+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "job0"}}
++    s->drain_count++;
-+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "job0"}}
++}
-+{"return": {}}
++
-+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "waiting", "id": "job0"}}
++static void coroutine_fn bdrv_test_co_drain_end(BlockDriverState *bs)
-+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "pending", "id": "job0"}}
++{
-+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "job0", "len": 134217728, "offset": 134217728, "speed": 0, "type": "commit"}}
++    BDRVTestState *s = bs->opaque;
-+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "concluded", "id": "job0"}}
++    s->drain_count--;
-+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "null", "id": "job0"}}
++}
-+{"return": {}}
++
-+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}}
++static void bdrv_test_close(BlockDriverState *bs)
-+*** done
++{
-diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
++    BDRVTestState *s = bs->opaque;
 +    g_assert_cmpint(s->drain_count, >, 0);
 +}
 +
 +static int coroutine_fn bdrv_test_co_preadv(BlockDriverState *bs,
 +                                            uint64_t offset, uint64_t bytes,
 +                                            QEMUIOVector *qiov, int flags)
 +{
 +    /* We want this request to stay until the polling loop in drain waits for
 +     * it to complete. We need to sleep a while as bdrv_drain_invoke() comes
 +     * first and polls its result, too, but it shouldn't accidentally complete
 +     * this request yet. */
 +    qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000);
 +
 +    return 0;
 +}
 +
 +static BlockDriver bdrv_test = {
 +    .format_name            = "test",
 +    .instance_size          = sizeof(BDRVTestState),
 +
 +    .bdrv_close             = bdrv_test_close,
 +    .bdrv_co_preadv         = bdrv_test_co_preadv,
 +
 +    .bdrv_co_drain_begin    = bdrv_test_co_drain_begin,
 +    .bdrv_co_drain_end      = bdrv_test_co_drain_end,
 +};
 +
 +static void aio_ret_cb(void *opaque, int ret)
 +{
 +    int *aio_ret = opaque;
 +    *aio_ret = ret;
 +}
 +
 +static void test_drv_cb_drain_all(void)
 +{
 +    BlockBackend *blk;
 +    BlockDriverState *bs;
 +    BDRVTestState *s;
 +    BlockAIOCB *acb;
 +    int aio_ret;
 +
 +    QEMUIOVector qiov;
 +    struct iovec iov = {
 +        .iov_base = NULL,
 +        .iov_len = 0,
 +    };
 +    qemu_iovec_init_external(&qiov, &iov, 1);
 +
 +    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
 +    bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
 +                              &error_abort);
 +    s = bs->opaque;
 +    blk_insert_bs(blk, bs, &error_abort);
 +
 +    /* Simple bdrv_drain_all_begin/end pair, check that CBs are called */
 +    g_assert_cmpint(s->drain_count, ==, 0);
 +    bdrv_drain_all_begin();
 +    g_assert_cmpint(s->drain_count, ==, 1);
 +    bdrv_drain_all_end();
 +    g_assert_cmpint(s->drain_count, ==, 0);
 +
 +    /* Now do the same while a request is pending */
 +    aio_ret = -EINPROGRESS;
 +    acb = blk_aio_preadv(blk, 0, &qiov, 0, aio_ret_cb, &aio_ret);
 +    g_assert(acb != NULL);
 +    g_assert_cmpint(aio_ret, ==, -EINPROGRESS);
 +
 +    g_assert_cmpint(s->drain_count, ==, 0);
 +    bdrv_drain_all_begin();
 +    g_assert_cmpint(aio_ret, ==, 0);
 +    g_assert_cmpint(s->drain_count, ==, 1);
 +    bdrv_drain_all_end();
 +    g_assert_cmpint(s->drain_count, ==, 0);
 +
 +    bdrv_unref(bs);
 +    blk_unref(blk);
 +}
 +
 +int main(int argc, char **argv)
 +{
 +    bdrv_init();
 +    qemu_init_main_loop(&error_abort);
 +
 +    g_test_init(&argc, &argv, NULL);
 +
 +    g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all);
 +
 +    return g_test_run();
 +}
 diff --git a/tests/Makefile.include b/tests/Makefile.include
 index XXXXXXX..XXXXXXX 100644
---- a/tests/qemu-iotests/group
+--- a/tests/Makefile.include
-+++ b/tests/qemu-iotests/group
++++ b/tests/Makefile.include
-@@ -XXX,XX +XXX,XX @@
+@@ -XXX,XX +XXX,XX @@ gcov-files-test-thread-pool-y = thread-pool.c
-rw auto quick
+ gcov-files-test-hbitmap-y = util/hbitmap.c
-rw auto
+ check-unit-y += tests/test-hbitmap$(EXESUF)
-rw auto quick
+ gcov-files-test-hbitmap-y = blockjob.c
-+247 rw auto quick
++check-unit-y += tests/test-bdrv-drain$(EXESUF)
  check-unit-y += tests/test-blockjob$(EXESUF)
  check-unit-y += tests/test-blockjob-txn$(EXESUF)
  check-unit-y += tests/test-x86-cpuid$(EXESUF)
@@ -XXX,XX +XXX,XX @@ tests/test-coroutine$(EXESUF): tests/test-coroutine.o $(test-block-obj-y)
  tests/test-aio$(EXESUF): tests/test-aio.o $(test-block-obj-y)
  tests/test-aio-multithread$(EXESUF): tests/test-aio-multithread.o $(test-block-obj-y)
  tests/test-throttle$(EXESUF): tests/test-throttle.o $(test-block-obj-y)
 +tests/test-bdrv-drain$(EXESUF): tests/test-bdrv-drain.o $(test-block-obj-y) $(test-util-obj-y)
  tests/test-blockjob$(EXESUF): tests/test-blockjob.o $(test-block-obj-y) $(test-util-obj-y)
  tests/test-blockjob-txn$(EXESUF): tests/test-blockjob-txn.o $(test-block-obj-y) $(test-util-obj-y)
  tests/test-thread-pool$(EXESUF): tests/test-thread-pool.o $(test-block-obj-y)
 --
-.20.1
+.13.6

-New patch
+[Qemu-devel] [PULL v3 06/35] block: bdrv_drain_recurse(): Remove unused begin parameter
+Now that the bdrv_drain_invoke() calls are pulled up to the callers of
+bdrv_drain_recurse(), the 'begin' parameter isn't needed any more.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ block/io.c | 12 ++++++------
+file changed, 6 insertions(+), 6 deletions(-)
+diff --git a/block/io.c b/block/io.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/io.c
++++ b/block/io.c
+@@ -XXX,XX +XXX,XX @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
+     }
+ }
+-static bool bdrv_drain_recurse(BlockDriverState *bs, bool begin)
++static bool bdrv_drain_recurse(BlockDriverState *bs)
+ {
+     BdrvChild *child, *tmp;
+     bool waited;
+@@ -XXX,XX +XXX,XX @@ static bool bdrv_drain_recurse(BlockDriverState *bs, bool begin)
+              */
+             bdrv_ref(bs);
+         }
+-        waited |= bdrv_drain_recurse(bs, begin);
++        waited |= bdrv_drain_recurse(bs);
+         if (in_main_loop) {
+             bdrv_unref(bs);
+         }
+@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs)
+     }
+     bdrv_drain_invoke(bs, true);
+-    bdrv_drain_recurse(bs, true);
++    bdrv_drain_recurse(bs);
+ }
+ void bdrv_drained_end(BlockDriverState *bs)
+@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
+     bdrv_parent_drained_end(bs);
+     bdrv_drain_invoke(bs, false);
+-    bdrv_drain_recurse(bs, false);
++    bdrv_drain_recurse(bs);
+     aio_enable_external(bdrv_get_aio_context(bs));
+ }
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
+             aio_context_acquire(aio_context);
+             for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+                 if (aio_context == bdrv_get_aio_context(bs)) {
+-                    waited |= bdrv_drain_recurse(bs, true);
++                    waited |= bdrv_drain_recurse(bs);
+                 }
+             }
+             aio_context_release(aio_context);
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
+         aio_enable_external(aio_context);
+         bdrv_parent_drained_end(bs);
+         bdrv_drain_invoke(bs, false);
+-        bdrv_drain_recurse(bs, false);
++        bdrv_drain_recurse(bs);
+         aio_context_release(aio_context);
+     }
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 07/35] block: Don't wait for requests in bdrv_drain*_end()
+The device is drained, so there is no point in waiting for requests at
+the end of the drained section. Remove the bdrv_drain_recurse() calls
+there.
+The bdrv_drain_recurse() calls were introduced in commit 481cad48e5e
+in order to call the .bdrv_co_drain_end() driver callback. This is now
+done by a separate bdrv_drain_invoke() call.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ block/io.c | 2 --
+file changed, 2 deletions(-)
+diff --git a/block/io.c b/block/io.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/io.c
++++ b/block/io.c
+@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
+     bdrv_parent_drained_end(bs);
+     bdrv_drain_invoke(bs, false);
+-    bdrv_drain_recurse(bs);
+     aio_enable_external(bdrv_get_aio_context(bs));
+ }
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
+         aio_enable_external(aio_context);
+         bdrv_parent_drained_end(bs);
+         bdrv_drain_invoke(bs, false);
+-        bdrv_drain_recurse(bs);
+         aio_context_release(aio_context);
+     }
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 08/35] block: Unify order in drain functions
+Drain requests are propagated to child nodes, parent nodes and directly
+to the AioContext. The order in which this happened was different
+between all combinations of drain/drain_all and begin/end.
+The correct order is to keep children only drained when their parents
+are also drained. This means that at the start of a drained section, the
+AioContext needs to be drained first, the parents second and only then
+the children. The correct order for the end of a drained section is the
+opposite.
+This patch changes the three other functions to follow the example of
+bdrv_drained_begin(), which is the only one that got it right.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ block/io.c | 12 ++++++++----
+file changed, 8 insertions(+), 4 deletions(-)
+diff --git a/block/io.c b/block/io.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/io.c
++++ b/block/io.c
+@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs)
+         return;
+     }
++    /* Stop things in parent-to-child order */
+     if (atomic_fetch_inc(&bs->quiesce_counter) == 0) {
+         aio_disable_external(bdrv_get_aio_context(bs));
+         bdrv_parent_drained_begin(bs);
+@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
+         return;
+     }
+-    bdrv_parent_drained_end(bs);
++    /* Re-enable things in child-to-parent order */
+     bdrv_drain_invoke(bs, false);
++    bdrv_parent_drained_end(bs);
+     aio_enable_external(bdrv_get_aio_context(bs));
+ }
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
+     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+         AioContext *aio_context = bdrv_get_aio_context(bs);
++        /* Stop things in parent-to-child order */
+         aio_context_acquire(aio_context);
+-        bdrv_parent_drained_begin(bs);
+         aio_disable_external(aio_context);
++        bdrv_parent_drained_begin(bs);
+         bdrv_drain_invoke(bs, true);
+         aio_context_release(aio_context);
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
+     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+         AioContext *aio_context = bdrv_get_aio_context(bs);
++        /* Re-enable things in child-to-parent order */
+         aio_context_acquire(aio_context);
+-        aio_enable_external(aio_context);
+-        bdrv_parent_drained_end(bs);
+         bdrv_drain_invoke(bs, false);
++        bdrv_parent_drained_end(bs);
++        aio_enable_external(aio_context);
+         aio_context_release(aio_context);
+     }
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 09/35] block: Don't acquire AioContext in hmp_qemu_io()
+Commit 15afd94a047 added code to acquire and release the AioContext in
+qemuio_command(). This means that the lock is taken twice now in the
+call path from hmp_qemu_io(). This causes BDRV_POLL_WHILE() to hang for
+any requests issued to nodes in a non-mainloop AioContext.
+Dropping the first locking from hmp_qemu_io() fixes the problem.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ hmp.c | 6 ------
+file changed, 6 deletions(-)
+diff --git a/hmp.c b/hmp.c
+index XXXXXXX..XXXXXXX 100644
+--- a/hmp.c
++++ b/hmp.c
+@@ -XXX,XX +XXX,XX @@ void hmp_qemu_io(Monitor *mon, const QDict *qdict)
+ {
+     BlockBackend *blk;
+     BlockBackend *local_blk = NULL;
+-    AioContext *aio_context;
+     const char* device = qdict_get_str(qdict, "device");
+     const char* command = qdict_get_str(qdict, "command");
+     Error *err = NULL;
+@@ -XXX,XX +XXX,XX @@ void hmp_qemu_io(Monitor *mon, const QDict *qdict)
+         }
+     }
+-    aio_context = blk_get_aio_context(blk);
+-    aio_context_acquire(aio_context);
+-
+     /*
+      * Notably absent: Proper permission management. This is sad, but it seems
+      * almost impossible to achieve without changing the semantics and thereby
+@@ -XXX,XX +XXX,XX @@ void hmp_qemu_io(Monitor *mon, const QDict *qdict)
+      */
+     qemuio_command(blk, command);
+-    aio_context_release(aio_context);
+-
+ fail:
+     blk_unref(local_blk);
+     hmp_handle_error(mon, &err);
+--
+.13.6

-[Qemu-devel] [PULL 02/12] qcow2: Fix data file error condition in qcow2_co_create()
+[Qemu-devel] [PULL v3 10/35] qcow2: get rid of qcow2_backing_read1 routine
-We were trying to check whether bdrv_open_blockdev_ref() returned
+From: Edgar Kaziakhmedov <edgar.kaziakhmedov@virtuozzo.com>
 success, but accidentally checked the wrong variable. Spotted by
 Coverity (CID 1399703).
+Since bdrv_co_preadv does all neccessary checks including
+reading after the end of the backing file, avoid duplication
+of verification before bdrv_co_preadv call.
+Signed-off-by: Edgar Kaziakhmedov <edgar.kaziakhmedov@virtuozzo.com>
+Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
+Reviewed-by: Eric Blake <eblake@redhat.com>
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-Reviewed-by: Eric Blake <eblake@redhat.com>
-Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
 ---
- block/qcow2.c | 2 +-
+ block/qcow2.h |  3 ---
-file changed, 1 insertion(+), 1 deletion(-)
+ block/qcow2.c | 51 ++++++++-------------------------------------------
 files changed, 8 insertions(+), 46 deletions(-)
+diff --git a/block/qcow2.h b/block/qcow2.h
+index XXXXXXX..XXXXXXX 100644
+--- a/block/qcow2.h
++++ b/block/qcow2.h
+@@ -XXX,XX +XXX,XX @@ uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
+ }
+ /* qcow2.c functions */
+-int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
+-                  int64_t sector_num, int nb_sectors);
+-
+ int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
+                                      int refcount_order, bool generous_increase,
+                                      uint64_t *refblock_count);
 diff --git a/block/qcow2.c b/block/qcow2.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/qcow2.c
 +++ b/block/qcow2.c
-@@ -XXX,XX +XXX,XX @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
+@@ -XXX,XX +XXX,XX @@ static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs,
-             goto out;
+     return status;
-         }
+ }
-         data_bs = bdrv_open_blockdev_ref(qcow2_opts->data_file, errp);
--        if (bs == NULL) {
+-/* handle reading after the end of the backing file */
-+        if (data_bs == NULL) {
+-int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
-             ret = -EIO;
+-                        int64_t offset, int bytes)
-             goto out;
+-{
-         }
+-    uint64_t bs_size = bs->total_sectors * BDRV_SECTOR_SIZE;
 -    int n1;
 -
 -    if ((offset + bytes) <= bs_size) {
 -        return bytes;
 -    }
 -
 -    if (offset >= bs_size) {
 -        n1 = 0;
 -    } else {
 -        n1 = bs_size - offset;
 -    }
 -
 -    qemu_iovec_memset(qiov, n1, 0, bytes - n1);
 -
 -    return n1;
 -}
 -
  static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
                                          uint64_t bytes, QEMUIOVector *qiov,
                                          int flags)
  {
      BDRVQcow2State *s = bs->opaque;
 -    int offset_in_cluster, n1;
 +    int offset_in_cluster;
      int ret;
      unsigned int cur_bytes; /* number of bytes in current iteration */
      uint64_t cluster_offset = 0;
@@ -XXX,XX +XXX,XX @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
          case QCOW2_CLUSTER_UNALLOCATED:
              if (bs->backing) {
 -                /* read from the base image */
 -                n1 = qcow2_backing_read1(bs->backing->bs, &hd_qiov,
 -                                         offset, cur_bytes);
 -                if (n1 > 0) {
 -                    QEMUIOVector local_qiov;
 -
 -                    qemu_iovec_init(&local_qiov, hd_qiov.niov);
 -                    qemu_iovec_concat(&local_qiov, &hd_qiov, 0, n1);
 -
 -                    BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
 -                    qemu_co_mutex_unlock(&s->lock);
 -                    ret = bdrv_co_preadv(bs->backing, offset, n1,
 -                                         &local_qiov, 0);
 -                    qemu_co_mutex_lock(&s->lock);
 -
 -                    qemu_iovec_destroy(&local_qiov);
 -
 -                    if (ret < 0) {
 -                        goto fail;
 -                    }
 +                BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
 +                qemu_co_mutex_unlock(&s->lock);
 +                ret = bdrv_co_preadv(bs->backing, offset, cur_bytes,
 +                                     &hd_qiov, 0);
 +                qemu_co_mutex_lock(&s->lock);
 +                if (ret < 0) {
 +                    goto fail;
                  }
              } else {
                  /* Note: in this case, no need to wait */
 --
-.20.1
+.13.6

-[Qemu-devel] [PULL 03/12] qapi: fix block-latency-histogram-set description and examples
+[Qemu-devel] [PULL v3 11/35] block: Document that x-blockdev-change breaks quorum children list
-From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
+Removing a quorum child node with x-blockdev-change results in a quorum
 driver state that cannot be recreated with create options because it
 would require a list with gaps. This causes trouble in at least
 .bdrv_refresh_filename().
-There no @device parameter, only the @id one.
+Document this problem so that we won't accidentally mark the command
 stable without having addressed it.
-Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
-Reviewed-by: Eric Blake <eblake@redhat.com>
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Alberto Garcia <berto@igalia.com>
 ---
- qapi/block-core.json | 10 +++++-----
+ qapi/block-core.json | 4 ++++
-file changed, 5 insertions(+), 5 deletions(-)
+file changed, 4 insertions(+)
 diff --git a/qapi/block-core.json b/qapi/block-core.json
 index XXXXXXX..XXXXXXX 100644
 --- a/qapi/block-core.json
 +++ b/qapi/block-core.json
 @@ -XXX,XX +XXX,XX @@
+ # does not support all kinds of operations, all kinds of children, nor
+ # all block drivers.
  #
- # Manage read, write and flush latency histograms for the device.
++# FIXME Removing children from a quorum node means introducing gaps in the
 +# child indices. This cannot be represented in the 'children' list of
 +# BlockdevOptionsQuorum, as returned by .bdrv_refresh_filename().
 +#
  # Warning: The data in a new quorum child MUST be consistent with that of
  # the rest of the array.
  #
--# If only @device parameter is specified, remove all present latency histograms
-+# If only @id parameter is specified, remove all present latency histograms
- # for the device. Otherwise, add/reset some of (or all) latency histograms.
- #
- # @id: The name or QOM path of the guest device.
-@@ -XXX,XX +XXX,XX @@
- # [0, 10), [10, 50), [50, 100), [100, +inf):
- #
- # -> { "execute": "block-latency-histogram-set",
--#      "arguments": { "device": "drive0",
-+#      "arguments": { "id": "drive0",
- #                     "boundaries": [10, 50, 100] } }
- # <- { "return": {} }
- #
-@@ -XXX,XX +XXX,XX @@
- # not changed (or not created):
- #
- # -> { "execute": "block-latency-histogram-set",
--#      "arguments": { "device": "drive0",
-+#      "arguments": { "id": "drive0",
- #                     "boundaries-write": [10, 50, 100] } }
- # <- { "return": {} }
- #
-@@ -XXX,XX +XXX,XX @@
- #   write: [0, 1000), [1000, 5000), [5000, +inf)
- #
- # -> { "execute": "block-latency-histogram-set",
--#      "arguments": { "device": "drive0",
-+#      "arguments": { "id": "drive0",
- #                     "boundaries": [10, 50, 100],
- #                     "boundaries-write": [1000, 5000] } }
- # <- { "return": {} }
-@@ -XXX,XX +XXX,XX @@
- # Example: remove all latency histograms:
- #
- # -> { "execute": "block-latency-histogram-set",
--#      "arguments": { "device": "drive0" } }
-+#      "arguments": { "id": "drive0" } }
- # <- { "return": {} }
- ##
- { 'command': 'block-latency-histogram-set',
 --
-.20.1
+.13.6

-New patch
+[Qemu-devel] [PULL v3 12/35] nvme: Add tracing
+From: Doug Gale <doug16k@gmail.com>
+Add trace output for commands, errors, and undefined behavior.
+Add guest error log output for undefined behavior.
+Report invalid undefined accesses to MMIO.
+Annotate unlikely error checks with unlikely.
+Signed-off-by: Doug Gale <doug16k@gmail.com>
+Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ hw/block/nvme.c       | 349 ++++++++++++++++++++++++++++++++++++++++++--------
+ hw/block/trace-events |  93 ++++++++++++++
+files changed, 390 insertions(+), 52 deletions(-)
+diff --git a/hw/block/nvme.c b/hw/block/nvme.c
+index XXXXXXX..XXXXXXX 100644
+--- a/hw/block/nvme.c
++++ b/hw/block/nvme.c
+@@ -XXX,XX +XXX,XX @@
+ #include "qapi/visitor.h"
+ #include "sysemu/block-backend.h"
++#include "qemu/log.h"
++#include "trace.h"
+ #include "nvme.h"
++#define NVME_GUEST_ERR(trace, fmt, ...) \
++    do { \
++        (trace_##trace)(__VA_ARGS__); \
++        qemu_log_mask(LOG_GUEST_ERROR, #trace \
++            " in %s: " fmt "\n", __func__, ## __VA_ARGS__); \
++    } while (0)
++
+ static void nvme_process_sq(void *opaque);
+ static void nvme_addr_read(NvmeCtrl *n, hwaddr addr, void *buf, int size)
+@@ -XXX,XX +XXX,XX @@ static void nvme_isr_notify(NvmeCtrl *n, NvmeCQueue *cq)
+ {
+     if (cq->irq_enabled) {
+         if (msix_enabled(&(n->parent_obj))) {
++            trace_nvme_irq_msix(cq->vector);
+             msix_notify(&(n->parent_obj), cq->vector);
+         } else {
++            trace_nvme_irq_pin();
+             pci_irq_pulse(&n->parent_obj);
+         }
++    } else {
++        trace_nvme_irq_masked();
+     }
+ }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
+     trans_len = MIN(len, trans_len);
+     int num_prps = (len >> n->page_bits) + 1;
+-    if (!prp1) {
++    if (unlikely(!prp1)) {
++        trace_nvme_err_invalid_prp();
+         return NVME_INVALID_FIELD | NVME_DNR;
+     } else if (n->cmbsz && prp1 >= n->ctrl_mem.addr &&
+                prp1 < n->ctrl_mem.addr + int128_get64(n->ctrl_mem.size)) {
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
+     }
+     len -= trans_len;
+     if (len) {
+-        if (!prp2) {
++        if (unlikely(!prp2)) {
++            trace_nvme_err_invalid_prp2_missing();
+             goto unmap;
+         }
+         if (len > n->page_size) {
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
+                 uint64_t prp_ent = le64_to_cpu(prp_list[i]);
+                 if (i == n->max_prp_ents - 1 && len > n->page_size) {
+-                    if (!prp_ent || prp_ent & (n->page_size - 1)) {
++                    if (unlikely(!prp_ent || prp_ent & (n->page_size - 1))) {
++                        trace_nvme_err_invalid_prplist_ent(prp_ent);
+                         goto unmap;
+                     }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
+                     prp_ent = le64_to_cpu(prp_list[i]);
+                 }
+-                if (!prp_ent || prp_ent & (n->page_size - 1)) {
++                if (unlikely(!prp_ent || prp_ent & (n->page_size - 1))) {
++                    trace_nvme_err_invalid_prplist_ent(prp_ent);
+                     goto unmap;
+                 }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
+                 i++;
+             }
+         } else {
+-            if (prp2 & (n->page_size - 1)) {
++            if (unlikely(prp2 & (n->page_size - 1))) {
++                trace_nvme_err_invalid_prp2_align(prp2);
+                 goto unmap;
+             }
+             if (qsg->nsg) {
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_dma_read_prp(NvmeCtrl *n, uint8_t *ptr, uint32_t len,
+     QEMUIOVector iov;
+     uint16_t status = NVME_SUCCESS;
++    trace_nvme_dma_read(prp1, prp2);
++
+     if (nvme_map_prp(&qsg, &iov, prp1, prp2, len, n)) {
+         return NVME_INVALID_FIELD | NVME_DNR;
+     }
+     if (qsg.nsg > 0) {
+-        if (dma_buf_read(ptr, len, &qsg)) {
++        if (unlikely(dma_buf_read(ptr, len, &qsg))) {
++            trace_nvme_err_invalid_dma();
+             status = NVME_INVALID_FIELD | NVME_DNR;
+         }
+         qemu_sglist_destroy(&qsg);
+     } else {
+-        if (qemu_iovec_to_buf(&iov, 0, ptr, len) != len) {
++        if (unlikely(qemu_iovec_to_buf(&iov, 0, ptr, len) != len)) {
++            trace_nvme_err_invalid_dma();
+             status = NVME_INVALID_FIELD | NVME_DNR;
+         }
+         qemu_iovec_destroy(&iov);
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_write_zeros(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
+     uint64_t aio_slba = slba << (data_shift - BDRV_SECTOR_BITS);
+     uint32_t aio_nlb = nlb << (data_shift - BDRV_SECTOR_BITS);
+-    if (slba + nlb > ns->id_ns.nsze) {
++    if (unlikely(slba + nlb > ns->id_ns.nsze)) {
++        trace_nvme_err_invalid_lba_range(slba, nlb, ns->id_ns.nsze);
+         return NVME_LBA_RANGE | NVME_DNR;
+     }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_rw(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
+     int is_write = rw->opcode == NVME_CMD_WRITE ? 1 : 0;
+     enum BlockAcctType acct = is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ;
+-    if ((slba + nlb) > ns->id_ns.nsze) {
++    trace_nvme_rw(is_write ? "write" : "read", nlb, data_size, slba);
++
++    if (unlikely((slba + nlb) > ns->id_ns.nsze)) {
+         block_acct_invalid(blk_get_stats(n->conf.blk), acct);
++        trace_nvme_err_invalid_lba_range(slba, nlb, ns->id_ns.nsze);
+         return NVME_LBA_RANGE | NVME_DNR;
+     }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_io_cmd(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
+     NvmeNamespace *ns;
+     uint32_t nsid = le32_to_cpu(cmd->nsid);
+-    if (nsid == 0 || nsid > n->num_namespaces) {
++    if (unlikely(nsid == 0 || nsid > n->num_namespaces)) {
++        trace_nvme_err_invalid_ns(nsid, n->num_namespaces);
+         return NVME_INVALID_NSID | NVME_DNR;
+     }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_io_cmd(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
+     case NVME_CMD_READ:
+         return nvme_rw(n, ns, cmd, req);
+     default:
++        trace_nvme_err_invalid_opc(cmd->opcode);
+         return NVME_INVALID_OPCODE | NVME_DNR;
+     }
+ }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_del_sq(NvmeCtrl *n, NvmeCmd *cmd)
+     NvmeCQueue *cq;
+     uint16_t qid = le16_to_cpu(c->qid);
+-    if (!qid || nvme_check_sqid(n, qid)) {
++    if (unlikely(!qid || nvme_check_sqid(n, qid))) {
++        trace_nvme_err_invalid_del_sq(qid);
+         return NVME_INVALID_QID | NVME_DNR;
+     }
++    trace_nvme_del_sq(qid);
++
+     sq = n->sq[qid];
+     while (!QTAILQ_EMPTY(&sq->out_req_list)) {
+         req = QTAILQ_FIRST(&sq->out_req_list);
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_create_sq(NvmeCtrl *n, NvmeCmd *cmd)
+     uint16_t qflags = le16_to_cpu(c->sq_flags);
+     uint64_t prp1 = le64_to_cpu(c->prp1);
+-    if (!cqid || nvme_check_cqid(n, cqid)) {
++    trace_nvme_create_sq(prp1, sqid, cqid, qsize, qflags);
++
++    if (unlikely(!cqid || nvme_check_cqid(n, cqid))) {
++        trace_nvme_err_invalid_create_sq_cqid(cqid);
+         return NVME_INVALID_CQID | NVME_DNR;
+     }
+-    if (!sqid || !nvme_check_sqid(n, sqid)) {
++    if (unlikely(!sqid || !nvme_check_sqid(n, sqid))) {
++        trace_nvme_err_invalid_create_sq_sqid(sqid);
+         return NVME_INVALID_QID | NVME_DNR;
+     }
+-    if (!qsize || qsize > NVME_CAP_MQES(n->bar.cap)) {
++    if (unlikely(!qsize || qsize > NVME_CAP_MQES(n->bar.cap))) {
++        trace_nvme_err_invalid_create_sq_size(qsize);
+         return NVME_MAX_QSIZE_EXCEEDED | NVME_DNR;
+     }
+-    if (!prp1 || prp1 & (n->page_size - 1)) {
++    if (unlikely(!prp1 || prp1 & (n->page_size - 1))) {
++        trace_nvme_err_invalid_create_sq_addr(prp1);
+         return NVME_INVALID_FIELD | NVME_DNR;
+     }
+-    if (!(NVME_SQ_FLAGS_PC(qflags))) {
++    if (unlikely(!(NVME_SQ_FLAGS_PC(qflags)))) {
++        trace_nvme_err_invalid_create_sq_qflags(NVME_SQ_FLAGS_PC(qflags));
+         return NVME_INVALID_FIELD | NVME_DNR;
+     }
+     sq = g_malloc0(sizeof(*sq));
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_del_cq(NvmeCtrl *n, NvmeCmd *cmd)
+     NvmeCQueue *cq;
+     uint16_t qid = le16_to_cpu(c->qid);
+-    if (!qid || nvme_check_cqid(n, qid)) {
++    if (unlikely(!qid || nvme_check_cqid(n, qid))) {
++        trace_nvme_err_invalid_del_cq_cqid(qid);
+         return NVME_INVALID_CQID | NVME_DNR;
+     }
+     cq = n->cq[qid];
+-    if (!QTAILQ_EMPTY(&cq->sq_list)) {
++    if (unlikely(!QTAILQ_EMPTY(&cq->sq_list))) {
++        trace_nvme_err_invalid_del_cq_notempty(qid);
+         return NVME_INVALID_QUEUE_DEL;
+     }
++    trace_nvme_del_cq(qid);
+     nvme_free_cq(cq, n);
+     return NVME_SUCCESS;
+ }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_create_cq(NvmeCtrl *n, NvmeCmd *cmd)
+     uint16_t qflags = le16_to_cpu(c->cq_flags);
+     uint64_t prp1 = le64_to_cpu(c->prp1);
+-    if (!cqid || !nvme_check_cqid(n, cqid)) {
++    trace_nvme_create_cq(prp1, cqid, vector, qsize, qflags,
++                         NVME_CQ_FLAGS_IEN(qflags) != 0);
++
++    if (unlikely(!cqid || !nvme_check_cqid(n, cqid))) {
++        trace_nvme_err_invalid_create_cq_cqid(cqid);
+         return NVME_INVALID_CQID | NVME_DNR;
+     }
+-    if (!qsize || qsize > NVME_CAP_MQES(n->bar.cap)) {
++    if (unlikely(!qsize || qsize > NVME_CAP_MQES(n->bar.cap))) {
++        trace_nvme_err_invalid_create_cq_size(qsize);
+         return NVME_MAX_QSIZE_EXCEEDED | NVME_DNR;
+     }
+-    if (!prp1) {
++    if (unlikely(!prp1)) {
++        trace_nvme_err_invalid_create_cq_addr(prp1);
+         return NVME_INVALID_FIELD | NVME_DNR;
+     }
+-    if (vector > n->num_queues) {
++    if (unlikely(vector > n->num_queues)) {
++        trace_nvme_err_invalid_create_cq_vector(vector);
+         return NVME_INVALID_IRQ_VECTOR | NVME_DNR;
+     }
+-    if (!(NVME_CQ_FLAGS_PC(qflags))) {
++    if (unlikely(!(NVME_CQ_FLAGS_PC(qflags)))) {
++        trace_nvme_err_invalid_create_cq_qflags(NVME_CQ_FLAGS_PC(qflags));
+         return NVME_INVALID_FIELD | NVME_DNR;
+     }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_identify_ctrl(NvmeCtrl *n, NvmeIdentify *c)
+     uint64_t prp1 = le64_to_cpu(c->prp1);
+     uint64_t prp2 = le64_to_cpu(c->prp2);
++    trace_nvme_identify_ctrl();
++
+     return nvme_dma_read_prp(n, (uint8_t *)&n->id_ctrl, sizeof(n->id_ctrl),
+         prp1, prp2);
+ }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_identify_ns(NvmeCtrl *n, NvmeIdentify *c)
+     uint64_t prp1 = le64_to_cpu(c->prp1);
+     uint64_t prp2 = le64_to_cpu(c->prp2);
+-    if (nsid == 0 || nsid > n->num_namespaces) {
++    trace_nvme_identify_ns(nsid);
++
++    if (unlikely(nsid == 0 || nsid > n->num_namespaces)) {
++        trace_nvme_err_invalid_ns(nsid, n->num_namespaces);
+         return NVME_INVALID_NSID | NVME_DNR;
+     }
+     ns = &n->namespaces[nsid - 1];
++
+     return nvme_dma_read_prp(n, (uint8_t *)&ns->id_ns, sizeof(ns->id_ns),
+         prp1, prp2);
+ }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_identify_nslist(NvmeCtrl *n, NvmeIdentify *c)
+     uint16_t ret;
+     int i, j = 0;
++    trace_nvme_identify_nslist(min_nsid);
++
+     list = g_malloc0(data_len);
+     for (i = 0; i < n->num_namespaces; i++) {
+         if (i < min_nsid) {
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_identify(NvmeCtrl *n, NvmeCmd *cmd)
+     case 0x02:
+         return nvme_identify_nslist(n, c);
+     default:
++        trace_nvme_err_invalid_identify_cns(le32_to_cpu(c->cns));
+         return NVME_INVALID_FIELD | NVME_DNR;
+     }
+ }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_get_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
+     switch (dw10) {
+     case NVME_VOLATILE_WRITE_CACHE:
+         result = blk_enable_write_cache(n->conf.blk);
++        trace_nvme_getfeat_vwcache(result ? "enabled" : "disabled");
+         break;
+     case NVME_NUMBER_OF_QUEUES:
+         result = cpu_to_le32((n->num_queues - 2) | ((n->num_queues - 2) << 16));
++        trace_nvme_getfeat_numq(result);
+         break;
+     default:
++        trace_nvme_err_invalid_getfeat(dw10);
+         return NVME_INVALID_FIELD | NVME_DNR;
+     }
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
+         blk_set_enable_write_cache(n->conf.blk, dw11 & 1);
+         break;
+     case NVME_NUMBER_OF_QUEUES:
++        trace_nvme_setfeat_numq((dw11 & 0xFFFF) + 1,
++                                ((dw11 >> 16) & 0xFFFF) + 1,
++                                n->num_queues - 1, n->num_queues - 1);
+         req->cqe.result =
+             cpu_to_le32((n->num_queues - 2) | ((n->num_queues - 2) << 16));
+         break;
+     default:
++        trace_nvme_err_invalid_setfeat(dw10);
+         return NVME_INVALID_FIELD | NVME_DNR;
+     }
+     return NVME_SUCCESS;
+@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_admin_cmd(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
+     case NVME_ADM_CMD_GET_FEATURES:
+         return nvme_get_feature(n, cmd, req);
+     default:
++        trace_nvme_err_invalid_admin_opc(cmd->opcode);
+         return NVME_INVALID_OPCODE | NVME_DNR;
+     }
+ }
+@@ -XXX,XX +XXX,XX @@ static int nvme_start_ctrl(NvmeCtrl *n)
+     uint32_t page_bits = NVME_CC_MPS(n->bar.cc) + 12;
+     uint32_t page_size = 1 << page_bits;
+-    if (n->cq[0] || n->sq[0] || !n->bar.asq || !n->bar.acq ||
+-            n->bar.asq & (page_size - 1) || n->bar.acq & (page_size - 1) ||
+-            NVME_CC_MPS(n->bar.cc) < NVME_CAP_MPSMIN(n->bar.cap) ||
+-            NVME_CC_MPS(n->bar.cc) > NVME_CAP_MPSMAX(n->bar.cap) ||
+-            NVME_CC_IOCQES(n->bar.cc) < NVME_CTRL_CQES_MIN(n->id_ctrl.cqes) ||
+-            NVME_CC_IOCQES(n->bar.cc) > NVME_CTRL_CQES_MAX(n->id_ctrl.cqes) ||
+-            NVME_CC_IOSQES(n->bar.cc) < NVME_CTRL_SQES_MIN(n->id_ctrl.sqes) ||
+-            NVME_CC_IOSQES(n->bar.cc) > NVME_CTRL_SQES_MAX(n->id_ctrl.sqes) ||
+-            !NVME_AQA_ASQS(n->bar.aqa) || !NVME_AQA_ACQS(n->bar.aqa)) {
++    if (unlikely(n->cq[0])) {
++        trace_nvme_err_startfail_cq();
++        return -1;
++    }
++    if (unlikely(n->sq[0])) {
++        trace_nvme_err_startfail_sq();
++        return -1;
++    }
++    if (unlikely(!n->bar.asq)) {
++        trace_nvme_err_startfail_nbarasq();
++        return -1;
++    }
++    if (unlikely(!n->bar.acq)) {
++        trace_nvme_err_startfail_nbaracq();
++        return -1;
++    }
++    if (unlikely(n->bar.asq & (page_size - 1))) {
++        trace_nvme_err_startfail_asq_misaligned(n->bar.asq);
++        return -1;
++    }
++    if (unlikely(n->bar.acq & (page_size - 1))) {
++        trace_nvme_err_startfail_acq_misaligned(n->bar.acq);
++        return -1;
++    }
++    if (unlikely(NVME_CC_MPS(n->bar.cc) <
++                 NVME_CAP_MPSMIN(n->bar.cap))) {
++        trace_nvme_err_startfail_page_too_small(
++                    NVME_CC_MPS(n->bar.cc),
++                    NVME_CAP_MPSMIN(n->bar.cap));
++        return -1;
++    }
++    if (unlikely(NVME_CC_MPS(n->bar.cc) >
++                 NVME_CAP_MPSMAX(n->bar.cap))) {
++        trace_nvme_err_startfail_page_too_large(
++                    NVME_CC_MPS(n->bar.cc),
++                    NVME_CAP_MPSMAX(n->bar.cap));
++        return -1;
++    }
++    if (unlikely(NVME_CC_IOCQES(n->bar.cc) <
++                 NVME_CTRL_CQES_MIN(n->id_ctrl.cqes))) {
++        trace_nvme_err_startfail_cqent_too_small(
++                    NVME_CC_IOCQES(n->bar.cc),
++                    NVME_CTRL_CQES_MIN(n->bar.cap));
++        return -1;
++    }
++    if (unlikely(NVME_CC_IOCQES(n->bar.cc) >
++                 NVME_CTRL_CQES_MAX(n->id_ctrl.cqes))) {
++        trace_nvme_err_startfail_cqent_too_large(
++                    NVME_CC_IOCQES(n->bar.cc),
++                    NVME_CTRL_CQES_MAX(n->bar.cap));
++        return -1;
++    }
++    if (unlikely(NVME_CC_IOSQES(n->bar.cc) <
++                 NVME_CTRL_SQES_MIN(n->id_ctrl.sqes))) {
++        trace_nvme_err_startfail_sqent_too_small(
++                    NVME_CC_IOSQES(n->bar.cc),
++                    NVME_CTRL_SQES_MIN(n->bar.cap));
++        return -1;
++    }
++    if (unlikely(NVME_CC_IOSQES(n->bar.cc) >
++                 NVME_CTRL_SQES_MAX(n->id_ctrl.sqes))) {
++        trace_nvme_err_startfail_sqent_too_large(
++                    NVME_CC_IOSQES(n->bar.cc),
++                    NVME_CTRL_SQES_MAX(n->bar.cap));
++        return -1;
++    }
++    if (unlikely(!NVME_AQA_ASQS(n->bar.aqa))) {
++        trace_nvme_err_startfail_asqent_sz_zero();
++        return -1;
++    }
++    if (unlikely(!NVME_AQA_ACQS(n->bar.aqa))) {
++        trace_nvme_err_startfail_acqent_sz_zero();
+         return -1;
+     }
+@@ -XXX,XX +XXX,XX @@ static int nvme_start_ctrl(NvmeCtrl *n)
+ static void nvme_write_bar(NvmeCtrl *n, hwaddr offset, uint64_t data,
+     unsigned size)
+ {
++    if (unlikely(offset & (sizeof(uint32_t) - 1))) {
++        NVME_GUEST_ERR(nvme_ub_mmiowr_misaligned32,
++                       "MMIO write not 32-bit aligned,"
++                       " offset=0x%"PRIx64"", offset);
++        /* should be ignored, fall through for now */
++    }
++
++    if (unlikely(size < sizeof(uint32_t))) {
++        NVME_GUEST_ERR(nvme_ub_mmiowr_toosmall,
++                       "MMIO write smaller than 32-bits,"
++                       " offset=0x%"PRIx64", size=%u",
++                       offset, size);
++        /* should be ignored, fall through for now */
++    }
++
+     switch (offset) {
+-    case 0xc:
++    case 0xc:   /* INTMS */
++        if (unlikely(msix_enabled(&(n->parent_obj)))) {
++            NVME_GUEST_ERR(nvme_ub_mmiowr_intmask_with_msix,
++                           "undefined access to interrupt mask set"
++                           " when MSI-X is enabled");
++            /* should be ignored, fall through for now */
++        }
+         n->bar.intms |= data & 0xffffffff;
+         n->bar.intmc = n->bar.intms;
++        trace_nvme_mmio_intm_set(data & 0xffffffff,
++                                 n->bar.intmc);
+         break;
+-    case 0x10:
++    case 0x10:  /* INTMC */
++        if (unlikely(msix_enabled(&(n->parent_obj)))) {
++            NVME_GUEST_ERR(nvme_ub_mmiowr_intmask_with_msix,
++                           "undefined access to interrupt mask clr"
++                           " when MSI-X is enabled");
++            /* should be ignored, fall through for now */
++        }
+         n->bar.intms &= ~(data & 0xffffffff);
+         n->bar.intmc = n->bar.intms;
++        trace_nvme_mmio_intm_clr(data & 0xffffffff,
++                                 n->bar.intmc);
+         break;
+-    case 0x14:
++    case 0x14:  /* CC */
++        trace_nvme_mmio_cfg(data & 0xffffffff);
+         /* Windows first sends data, then sends enable bit */
+         if (!NVME_CC_EN(data) && !NVME_CC_EN(n->bar.cc) &&
+             !NVME_CC_SHN(data) && !NVME_CC_SHN(n->bar.cc))
+@@ -XXX,XX +XXX,XX @@ static void nvme_write_bar(NvmeCtrl *n, hwaddr offset, uint64_t data,
+         if (NVME_CC_EN(data) && !NVME_CC_EN(n->bar.cc)) {
+             n->bar.cc = data;
+-            if (nvme_start_ctrl(n)) {
++            if (unlikely(nvme_start_ctrl(n))) {
++                trace_nvme_err_startfail();
+                 n->bar.csts = NVME_CSTS_FAILED;
+             } else {
++                trace_nvme_mmio_start_success();
+                 n->bar.csts = NVME_CSTS_READY;
+             }
+         } else if (!NVME_CC_EN(data) && NVME_CC_EN(n->bar.cc)) {
++            trace_nvme_mmio_stopped();
+             nvme_clear_ctrl(n);
+             n->bar.csts &= ~NVME_CSTS_READY;
+         }
+         if (NVME_CC_SHN(data) && !(NVME_CC_SHN(n->bar.cc))) {
+-                nvme_clear_ctrl(n);
+-                n->bar.cc = data;
+-                n->bar.csts |= NVME_CSTS_SHST_COMPLETE;
++            trace_nvme_mmio_shutdown_set();
++            nvme_clear_ctrl(n);
++            n->bar.cc = data;
++            n->bar.csts |= NVME_CSTS_SHST_COMPLETE;
+         } else if (!NVME_CC_SHN(data) && NVME_CC_SHN(n->bar.cc)) {
+-                n->bar.csts &= ~NVME_CSTS_SHST_COMPLETE;
+-                n->bar.cc = data;
++            trace_nvme_mmio_shutdown_cleared();
++            n->bar.csts &= ~NVME_CSTS_SHST_COMPLETE;
++            n->bar.cc = data;
++        }
++        break;
++    case 0x1C:  /* CSTS */
++        if (data & (1 << 4)) {
++            NVME_GUEST_ERR(nvme_ub_mmiowr_ssreset_w1c_unsupported,
++                           "attempted to W1C CSTS.NSSRO"
++                           " but CAP.NSSRS is zero (not supported)");
++        } else if (data != 0) {
++            NVME_GUEST_ERR(nvme_ub_mmiowr_ro_csts,
++                           "attempted to set a read only bit"
++                           " of controller status");
++        }
++        break;
++    case 0x20:  /* NSSR */
++        if (data == 0x4E564D65) {
++            trace_nvme_ub_mmiowr_ssreset_unsupported();
++        } else {
++            /* The spec says that writes of other values have no effect */
++            return;
+         }
+         break;
+-    case 0x24:
++    case 0x24:  /* AQA */
+         n->bar.aqa = data & 0xffffffff;
++        trace_nvme_mmio_aqattr(data & 0xffffffff);
+         break;
+-    case 0x28:
++    case 0x28:  /* ASQ */
+         n->bar.asq = data;
++        trace_nvme_mmio_asqaddr(data);
+         break;
+-    case 0x2c:
++    case 0x2c:  /* ASQ hi */
+         n->bar.asq |= data << 32;
++        trace_nvme_mmio_asqaddr_hi(data, n->bar.asq);
+         break;
+-    case 0x30:
++    case 0x30:  /* ACQ */
++        trace_nvme_mmio_acqaddr(data);
+         n->bar.acq = data;
+         break;
+-    case 0x34:
++    case 0x34:  /* ACQ hi */
+         n->bar.acq |= data << 32;
++        trace_nvme_mmio_acqaddr_hi(data, n->bar.acq);
+         break;
++    case 0x38:  /* CMBLOC */
++        NVME_GUEST_ERR(nvme_ub_mmiowr_cmbloc_reserved,
++                       "invalid write to reserved CMBLOC"
++                       " when CMBSZ is zero, ignored");
++        return;
++    case 0x3C:  /* CMBSZ */
++        NVME_GUEST_ERR(nvme_ub_mmiowr_cmbsz_readonly,
++                       "invalid write to read only CMBSZ, ignored");
++        return;
+     default:
++        NVME_GUEST_ERR(nvme_ub_mmiowr_invalid,
++                       "invalid MMIO write,"
++                       " offset=0x%"PRIx64", data=%"PRIx64"",
++                       offset, data);
+         break;
+     }
+ }
+@@ -XXX,XX +XXX,XX @@ static uint64_t nvme_mmio_read(void *opaque, hwaddr addr, unsigned size)
+     uint8_t *ptr = (uint8_t *)&n->bar;
+     uint64_t val = 0;
++    if (unlikely(addr & (sizeof(uint32_t) - 1))) {
++        NVME_GUEST_ERR(nvme_ub_mmiord_misaligned32,
++                       "MMIO read not 32-bit aligned,"
++                       " offset=0x%"PRIx64"", addr);
++        /* should RAZ, fall through for now */
++    } else if (unlikely(size < sizeof(uint32_t))) {
++        NVME_GUEST_ERR(nvme_ub_mmiord_toosmall,
++                       "MMIO read smaller than 32-bits,"
++                       " offset=0x%"PRIx64"", addr);
++        /* should RAZ, fall through for now */
++    }
++
+     if (addr < sizeof(n->bar)) {
+         memcpy(&val, ptr + addr, size);
++    } else {
++        NVME_GUEST_ERR(nvme_ub_mmiord_invalid_ofs,
++                       "MMIO read beyond last register,"
++                       " offset=0x%"PRIx64", returning 0", addr);
+     }
++
+     return val;
+ }
+@@ -XXX,XX +XXX,XX @@ static void nvme_process_db(NvmeCtrl *n, hwaddr addr, int val)
+ {
+     uint32_t qid;
+-    if (addr & ((1 << 2) - 1)) {
++    if (unlikely(addr & ((1 << 2) - 1))) {
++        NVME_GUEST_ERR(nvme_ub_db_wr_misaligned,
++                       "doorbell write not 32-bit aligned,"
++                       " offset=0x%"PRIx64", ignoring", addr);
+         return;
+     }
+     if (((addr - 0x1000) >> 2) & 1) {
++        /* Completion queue doorbell write */
++
+         uint16_t new_head = val & 0xffff;
+         int start_sqs;
+         NvmeCQueue *cq;
+         qid = (addr - (0x1000 + (1 << 2))) >> 3;
+-        if (nvme_check_cqid(n, qid)) {
++        if (unlikely(nvme_check_cqid(n, qid))) {
++            NVME_GUEST_ERR(nvme_ub_db_wr_invalid_cq,
++                           "completion queue doorbell write"
++                           " for nonexistent queue,"
++                           " sqid=%"PRIu32", ignoring", qid);
+             return;
+         }
+         cq = n->cq[qid];
+-        if (new_head >= cq->size) {
++        if (unlikely(new_head >= cq->size)) {
++            NVME_GUEST_ERR(nvme_ub_db_wr_invalid_cqhead,
++                           "completion queue doorbell write value"
++                           " beyond queue size, sqid=%"PRIu32","
++                           " new_head=%"PRIu16", ignoring",
++                           qid, new_head);
+             return;
+         }
+@@ -XXX,XX +XXX,XX @@ static void nvme_process_db(NvmeCtrl *n, hwaddr addr, int val)
+             nvme_isr_notify(n, cq);
+         }
+     } else {
++        /* Submission queue doorbell write */
++
+         uint16_t new_tail = val & 0xffff;
+         NvmeSQueue *sq;
+         qid = (addr - 0x1000) >> 3;
+-        if (nvme_check_sqid(n, qid)) {
++        if (unlikely(nvme_check_sqid(n, qid))) {
++            NVME_GUEST_ERR(nvme_ub_db_wr_invalid_sq,
++                           "submission queue doorbell write"
++                           " for nonexistent queue,"
++                           " sqid=%"PRIu32", ignoring", qid);
+             return;
+         }
+         sq = n->sq[qid];
+-        if (new_tail >= sq->size) {
++        if (unlikely(new_tail >= sq->size)) {
++            NVME_GUEST_ERR(nvme_ub_db_wr_invalid_sqtail,
++                           "submission queue doorbell write value"
++                           " beyond queue size, sqid=%"PRIu32","
++                           " new_tail=%"PRIu16", ignoring",
++                           qid, new_tail);
+             return;
+         }
+diff --git a/hw/block/trace-events b/hw/block/trace-events
+index XXXXXXX..XXXXXXX 100644
+--- a/hw/block/trace-events
++++ b/hw/block/trace-events
+@@ -XXX,XX +XXX,XX @@ virtio_blk_submit_multireq(void *vdev, void *mrb, int start, int num_reqs, uint6
+ hd_geometry_lchs_guess(void *blk, int cyls, int heads, int secs) "blk %p LCHS %d %d %d"
+ hd_geometry_guess(void *blk, uint32_t cyls, uint32_t heads, uint32_t secs, int trans) "blk %p CHS %u %u %u trans %d"
++# hw/block/nvme.c
++# nvme traces for successful events
++nvme_irq_msix(uint32_t vector) "raising MSI-X IRQ vector %u"
++nvme_irq_pin(void) "pulsing IRQ pin"
++nvme_irq_masked(void) "IRQ is masked"
++nvme_dma_read(uint64_t prp1, uint64_t prp2) "DMA read, prp1=0x%"PRIx64" prp2=0x%"PRIx64""
++nvme_rw(char const *verb, uint32_t blk_count, uint64_t byte_count, uint64_t lba) "%s %"PRIu32" blocks (%"PRIu64" bytes) from LBA %"PRIu64""
++nvme_create_sq(uint64_t addr, uint16_t sqid, uint16_t cqid, uint16_t qsize, uint16_t qflags) "create submission queue, addr=0x%"PRIx64", sqid=%"PRIu16", cqid=%"PRIu16", qsize=%"PRIu16", qflags=%"PRIu16""
++nvme_create_cq(uint64_t addr, uint16_t cqid, uint16_t vector, uint16_t size, uint16_t qflags, int ien) "create completion queue, addr=0x%"PRIx64", cqid=%"PRIu16", vector=%"PRIu16", qsize=%"PRIu16", qflags=%"PRIu16", ien=%d"
++nvme_del_sq(uint16_t qid) "deleting submission queue sqid=%"PRIu16""
++nvme_del_cq(uint16_t cqid) "deleted completion queue, sqid=%"PRIu16""
++nvme_identify_ctrl(void) "identify controller"
++nvme_identify_ns(uint16_t ns) "identify namespace, nsid=%"PRIu16""
++nvme_identify_nslist(uint16_t ns) "identify namespace list, nsid=%"PRIu16""
++nvme_getfeat_vwcache(char const* result) "get feature volatile write cache, result=%s"
++nvme_getfeat_numq(int result) "get feature number of queues, result=%d"
++nvme_setfeat_numq(int reqcq, int reqsq, int gotcq, int gotsq) "requested cq_count=%d sq_count=%d, responding with cq_count=%d sq_count=%d"
++nvme_mmio_intm_set(uint64_t data, uint64_t new_mask) "wrote MMIO, interrupt mask set, data=0x%"PRIx64", new_mask=0x%"PRIx64""
++nvme_mmio_intm_clr(uint64_t data, uint64_t new_mask) "wrote MMIO, interrupt mask clr, data=0x%"PRIx64", new_mask=0x%"PRIx64""
++nvme_mmio_cfg(uint64_t data) "wrote MMIO, config controller config=0x%"PRIx64""
++nvme_mmio_aqattr(uint64_t data) "wrote MMIO, admin queue attributes=0x%"PRIx64""
++nvme_mmio_asqaddr(uint64_t data) "wrote MMIO, admin submission queue address=0x%"PRIx64""
++nvme_mmio_acqaddr(uint64_t data) "wrote MMIO, admin completion queue address=0x%"PRIx64""
++nvme_mmio_asqaddr_hi(uint64_t data, uint64_t new_addr) "wrote MMIO, admin submission queue high half=0x%"PRIx64", new_address=0x%"PRIx64""
++nvme_mmio_acqaddr_hi(uint64_t data, uint64_t new_addr) "wrote MMIO, admin completion queue high half=0x%"PRIx64", new_address=0x%"PRIx64""
++nvme_mmio_start_success(void) "setting controller enable bit succeeded"
++nvme_mmio_stopped(void) "cleared controller enable bit"
++nvme_mmio_shutdown_set(void) "shutdown bit set"
++nvme_mmio_shutdown_cleared(void) "shutdown bit cleared"
++
++# nvme traces for error conditions
++nvme_err_invalid_dma(void) "PRP/SGL is too small for transfer size"
++nvme_err_invalid_prplist_ent(uint64_t prplist) "PRP list entry is null or not page aligned: 0x%"PRIx64""
++nvme_err_invalid_prp2_align(uint64_t prp2) "PRP2 is not page aligned: 0x%"PRIx64""
++nvme_err_invalid_prp2_missing(void) "PRP2 is null and more data to be transferred"
++nvme_err_invalid_field(void) "invalid field"
++nvme_err_invalid_prp(void) "invalid PRP"
++nvme_err_invalid_sgl(void) "invalid SGL"
++nvme_err_invalid_ns(uint32_t ns, uint32_t limit) "invalid namespace %u not within 1-%u"
++nvme_err_invalid_opc(uint8_t opc) "invalid opcode 0x%"PRIx8""
++nvme_err_invalid_admin_opc(uint8_t opc) "invalid admin opcode 0x%"PRIx8""
++nvme_err_invalid_lba_range(uint64_t start, uint64_t len, uint64_t limit) "Invalid LBA start=%"PRIu64" len=%"PRIu64" limit=%"PRIu64""
++nvme_err_invalid_del_sq(uint16_t qid) "invalid submission queue deletion, sid=%"PRIu16""
++nvme_err_invalid_create_sq_cqid(uint16_t cqid) "failed creating submission queue, invalid cqid=%"PRIu16""
++nvme_err_invalid_create_sq_sqid(uint16_t sqid) "failed creating submission queue, invalid sqid=%"PRIu16""
++nvme_err_invalid_create_sq_size(uint16_t qsize) "failed creating submission queue, invalid qsize=%"PRIu16""
++nvme_err_invalid_create_sq_addr(uint64_t addr) "failed creating submission queue, addr=0x%"PRIx64""
++nvme_err_invalid_create_sq_qflags(uint16_t qflags) "failed creating submission queue, qflags=%"PRIu16""
++nvme_err_invalid_del_cq_cqid(uint16_t cqid) "failed deleting completion queue, cqid=%"PRIu16""
++nvme_err_invalid_del_cq_notempty(uint16_t cqid) "failed deleting completion queue, it is not empty, cqid=%"PRIu16""
++nvme_err_invalid_create_cq_cqid(uint16_t cqid) "failed creating completion queue, cqid=%"PRIu16""
++nvme_err_invalid_create_cq_size(uint16_t size) "failed creating completion queue, size=%"PRIu16""
++nvme_err_invalid_create_cq_addr(uint64_t addr) "failed creating completion queue, addr=0x%"PRIx64""
++nvme_err_invalid_create_cq_vector(uint16_t vector) "failed creating completion queue, vector=%"PRIu16""
++nvme_err_invalid_create_cq_qflags(uint16_t qflags) "failed creating completion queue, qflags=%"PRIu16""
++nvme_err_invalid_identify_cns(uint16_t cns) "identify, invalid cns=0x%"PRIx16""
++nvme_err_invalid_getfeat(int dw10) "invalid get features, dw10=0x%"PRIx32""
++nvme_err_invalid_setfeat(uint32_t dw10) "invalid set features, dw10=0x%"PRIx32""
++nvme_err_startfail_cq(void) "nvme_start_ctrl failed because there are non-admin completion queues"
++nvme_err_startfail_sq(void) "nvme_start_ctrl failed because there are non-admin submission queues"
++nvme_err_startfail_nbarasq(void) "nvme_start_ctrl failed because the admin submission queue address is null"
++nvme_err_startfail_nbaracq(void) "nvme_start_ctrl failed because the admin completion queue address is null"
++nvme_err_startfail_asq_misaligned(uint64_t addr) "nvme_start_ctrl failed because the admin submission queue address is misaligned: 0x%"PRIx64""
++nvme_err_startfail_acq_misaligned(uint64_t addr) "nvme_start_ctrl failed because the admin completion queue address is misaligned: 0x%"PRIx64""
++nvme_err_startfail_page_too_small(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the page size is too small: log2size=%u, min=%u"
++nvme_err_startfail_page_too_large(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the page size is too large: log2size=%u, max=%u"
++nvme_err_startfail_cqent_too_small(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the completion queue entry size is too small: log2size=%u, min=%u"
++nvme_err_startfail_cqent_too_large(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the completion queue entry size is too large: log2size=%u, max=%u"
++nvme_err_startfail_sqent_too_small(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the submission queue entry size is too small: log2size=%u, min=%u"
++nvme_err_startfail_sqent_too_large(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the submission queue entry size is too large: log2size=%u, max=%u"
++nvme_err_startfail_asqent_sz_zero(void) "nvme_start_ctrl failed because the admin submission queue size is zero"
++nvme_err_startfail_acqent_sz_zero(void) "nvme_start_ctrl failed because the admin completion queue size is zero"
++nvme_err_startfail(void) "setting controller enable bit failed"
++
++# Traces for undefined behavior
++nvme_ub_mmiowr_misaligned32(uint64_t offset) "MMIO write not 32-bit aligned, offset=0x%"PRIx64""
++nvme_ub_mmiowr_toosmall(uint64_t offset, unsigned size) "MMIO write smaller than 32 bits, offset=0x%"PRIx64", size=%u"
++nvme_ub_mmiowr_intmask_with_msix(void) "undefined access to interrupt mask set when MSI-X is enabled"
++nvme_ub_mmiowr_ro_csts(void) "attempted to set a read only bit of controller status"
++nvme_ub_mmiowr_ssreset_w1c_unsupported(void) "attempted to W1C CSTS.NSSRO but CAP.NSSRS is zero (not supported)"
++nvme_ub_mmiowr_ssreset_unsupported(void) "attempted NVM subsystem reset but CAP.NSSRS is zero (not supported)"
++nvme_ub_mmiowr_cmbloc_reserved(void) "invalid write to reserved CMBLOC when CMBSZ is zero, ignored"
++nvme_ub_mmiowr_cmbsz_readonly(void) "invalid write to read only CMBSZ, ignored"
++nvme_ub_mmiowr_invalid(uint64_t offset, uint64_t data) "invalid MMIO write, offset=0x%"PRIx64", data=0x%"PRIx64""
++nvme_ub_mmiord_misaligned32(uint64_t offset) "MMIO read not 32-bit aligned, offset=0x%"PRIx64""
++nvme_ub_mmiord_toosmall(uint64_t offset) "MMIO read smaller than 32-bits, offset=0x%"PRIx64""
++nvme_ub_mmiord_invalid_ofs(uint64_t offset) "MMIO read beyond last register, offset=0x%"PRIx64", returning 0"
++nvme_ub_db_wr_misaligned(uint64_t offset) "doorbell write not 32-bit aligned, offset=0x%"PRIx64", ignoring"
++nvme_ub_db_wr_invalid_cq(uint32_t qid) "completion queue doorbell write for nonexistent queue, cqid=%"PRIu32", ignoring"
++nvme_ub_db_wr_invalid_cqhead(uint32_t qid, uint16_t new_head) "completion queue doorbell write value beyond queue size, cqid=%"PRIu32", new_head=%"PRIu16", ignoring"
++nvme_ub_db_wr_invalid_sq(uint32_t qid) "submission queue doorbell write for nonexistent queue, sqid=%"PRIu32", ignoring"
++nvme_ub_db_wr_invalid_sqtail(uint32_t qid, uint16_t new_tail) "submission queue doorbell write value beyond queue size, sqid=%"PRIu32", new_head=%"PRIu16", ignoring"
++
+ # hw/block/xen_disk.c
+ xen_disk_alloc(char *name) "%s"
+ xen_disk_init(char *name) "%s"
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 13/35] block: Open backing image in force share mode for size probe
+From: Fam Zheng <famz@redhat.com>
+Management tools create overlays of running guests with qemu-img:
+  $ qemu-img create -b /image/in/use.qcow2 -f qcow2 /overlay/image.qcow2
+but this doesn't work anymore due to image locking:
+    qemu-img: /overlay/image.qcow2: Failed to get shared "write" lock
+    Is another process using the image?
+    Could not open backing image to determine size.
+Use the force share option to allow this use case again.
+Cc: qemu-stable@nongnu.org
+Signed-off-by: Fam Zheng <famz@redhat.com>
+Reviewed-by: Eric Blake <eblake@redhat.com>
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ block.c | 3 ++-
+file changed, 2 insertions(+), 1 deletion(-)
+diff --git a/block.c b/block.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block.c
++++ b/block.c
+@@ -XXX,XX +XXX,XX @@ void bdrv_img_create(const char *filename, const char *fmt,
+         back_flags = flags;
+         back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
++        backing_options = qdict_new();
+         if (backing_fmt) {
+-            backing_options = qdict_new();
+             qdict_put_str(backing_options, "driver", backing_fmt);
+         }
++        qdict_put_bool(backing_options, BDRV_OPT_FORCE_SHARE, true);
+         bs = bdrv_open(full_backing, NULL, backing_options, back_flags,
+                        &local_err);
+--
+.13.6

-[Qemu-devel] [PULL 11/12] blockdev: Check @replaces in blockdev_mirror_common
+[Qemu-devel] [PULL v3 14/35] block: Remove the obsolete -drive boot=on|off parameter
-From: Max Reitz <mreitz@redhat.com>
+From: Thomas Huth <thuth@redhat.com>
-There is no reason why the constraints we put on @replaces should be
+It's not working anymore since QEMU v1.3.0 - time to remove it now.
 limited to drive-mirror.  Therefore, move the sanity checks from
 qmp_drive_mirror() to blockdev_mirror_common() so they apply to
 blockdev-mirror as well.
-Signed-off-by: Max Reitz <mreitz@redhat.com>
+Signed-off-by: Thomas Huth <thuth@redhat.com>
-Reviewed-by: Eric Blake <eblake@redhat.com>
+Reviewed-by: John Snow <jsnow@redhat.com>
-Reviewed-by: Alberto Garcia <berto@igalia.com>
+Reviewed-by: Markus Armbruster <armbru@redhat.com>
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
 ---
- blockdev.c | 55 ++++++++++++++++++++++++++++++++----------------------
+ blockdev.c    | 11 -----------
-file changed, 33 insertions(+), 22 deletions(-)
+ qemu-doc.texi |  6 ------
 files changed, 17 deletions(-)
 diff --git a/blockdev.c b/blockdev.c
 index XXXXXXX..XXXXXXX 100644
 --- a/blockdev.c
 +++ b/blockdev.c
-@@ -XXX,XX +XXX,XX @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
+@@ -XXX,XX +XXX,XX @@ QemuOptsList qemu_legacy_drive_opts = {
-         sync = MIRROR_SYNC_MODE_FULL;
+             .type = QEMU_OPT_STRING,
              .help = "chs translation (auto, lba, none)",
          },{
 -            .name = "boot",
 -            .type = QEMU_OPT_BOOL,
 -            .help = "(deprecated, ignored)",
 -        },{
              .name = "addr",
              .type = QEMU_OPT_STRING,
              .help = "pci address (virtio only)",
@@ -XXX,XX +XXX,XX @@ DriveInfo *drive_new(QemuOpts *all_opts, BlockInterfaceType block_default_type)
          goto fail;
      }
-+    if (has_replaces) {
+-    /* Deprecated option boot=[on|off] */
-+        BlockDriverState *to_replace_bs;
+-    if (qemu_opt_get(legacy_opts, "boot") != NULL) {
-+        AioContext *replace_aio_context;
+-        fprintf(stderr, "qemu-kvm: boot=on|off is deprecated and will be "
-+        int64_t bs_size, replace_size;
+-                "ignored. Future versions will reject this parameter. Please "
-+
+-                "update your scripts.\n");
-+        bs_size = bdrv_getlength(bs);
+-    }
 +        if (bs_size < 0) {
 +            error_setg_errno(errp, -bs_size, "Failed to query device's size");
 +            return;
 +        }
 +
 +        to_replace_bs = check_to_replace_node(bs, replaces, errp);
 +        if (!to_replace_bs) {
 +            return;
 +        }
 +
 +        replace_aio_context = bdrv_get_aio_context(to_replace_bs);
 +        aio_context_acquire(replace_aio_context);
 +        replace_size = bdrv_getlength(to_replace_bs);
 +        aio_context_release(replace_aio_context);
 +
 +        if (replace_size < 0) {
 +            error_setg_errno(errp, -replace_size,
 +                             "Failed to query the replacement node's size");
 +            return;
 +        }
 +        if (bs_size != replace_size) {
 +            error_setg(errp, "cannot replace image with a mirror image of "
 +                             "different size");
 +            return;
 +        }
 +    }
 +
      /* pass the node name to replace to mirror start since it's loose coupling
       * and will allow to check whether the node still exist at mirror completion
       */
@@ -XXX,XX +XXX,XX @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp)
      }
      if (arg->has_replaces) {
 -        BlockDriverState *to_replace_bs;
 -        AioContext *replace_aio_context;
 -        int64_t replace_size;
 -
-         if (!arg->has_node_name) {
+     /* Other deprecated options */
-             error_setg(errp, "a node-name must be provided when replacing a"
+     if (!qtest_enabled()) {
-                              " named node of the graph");
+         for (i = 0; i < ARRAY_SIZE(deprecated); i++) {
-             goto out;
+diff --git a/qemu-doc.texi b/qemu-doc.texi
-         }
+index XXXXXXX..XXXXXXX 100644
 --- a/qemu-doc.texi
 +++ b/qemu-doc.texi
@@ -XXX,XX +XXX,XX @@ deprecated.
  @section System emulator command line arguments
 -@subsection -drive boot=on|off (since 1.3.0)
 -
--        to_replace_bs = check_to_replace_node(bs, arg->replaces, &local_err);
+-The ``boot=on|off'' option to the ``-drive'' argument is
 -ignored. Applications should use the ``bootindex=N'' parameter
 -to set an absolute ordering between devices instead.
 -
--        if (!to_replace_bs) {
+ @subsection -tdf (since 1.3.0)
--            error_propagate(errp, local_err);
--            goto out;
+ The ``-tdf'' argument is ignored. The behaviour implemented
 -        }
 -
 -        replace_aio_context = bdrv_get_aio_context(to_replace_bs);
 -        aio_context_acquire(replace_aio_context);
 -        replace_size = bdrv_getlength(to_replace_bs);
 -        aio_context_release(replace_aio_context);
 -
 -        if (size != replace_size) {
 -            error_setg(errp, "cannot replace image with a mirror image of "
 -                             "different size");
 -            goto out;
 -        }
      }
      if (arg->mode == NEW_IMAGE_MODE_ABSOLUTE_PATHS) {
 --
-.20.1
+.13.6

-[Qemu-devel] [PULL 07/12] vl: Fix to create migration object before block backends again
+[Qemu-devel] [PULL v3 15/35] block: Remove the deprecated -hdachs option
-From: Markus Armbruster <armbru@redhat.com>
+From: Thomas Huth <thuth@redhat.com>
-Recent commit cda4aa9a5a0 moved block backend creation before machine
+It's been marked as deprecated since QEMU v2.10.0, and so far nobody
-property evaluation.  This broke qemu-iotests 055.  Turns out we need
+complained that we should keep it, so let's remove this legacy option
-to create the migration object before block backends, so block
+now to simplify the code quite a bit.
-backends can add migration blockers.  Fix by calling
-migration_object_init() earlier, right before configure_blockdev().
+Signed-off-by: Thomas Huth <thuth@redhat.com>
+Reviewed-by: John Snow <jsnow@redhat.com>
-Fixes: cda4aa9a5a08777cf13e164c0543bd4888b8adce
+Reviewed-by: Markus Armbruster <armbru@redhat.com>
 Reported-by: Kevin Wolf <kwolf@redhat.com>
 Signed-off-by: Markus Armbruster <armbru@redhat.com>
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
 ---
- vl.c | 15 ++++++++-------
+ vl.c            | 86 ++-------------------------------------------------------
-file changed, 8 insertions(+), 7 deletions(-)
+ qemu-doc.texi   |  8 ------
  qemu-options.hx | 19 ++-----------
 files changed, 4 insertions(+), 109 deletions(-)
 diff --git a/vl.c b/vl.c
 index XXXXXXX..XXXXXXX 100644
 --- a/vl.c
 +++ b/vl.c
 @@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
-         exit(0);
+     const char *boot_order = NULL;
-     }
+     const char *boot_once = NULL;
+     DisplayState *ds;
-+    /*
+-    int cyls, heads, secs, translation;
-+     * Migration object can only be created after global properties
+     QemuOpts *opts, *machine_opts;
-+     * are applied correctly.
+-    QemuOpts *hda_opts = NULL, *icount_opts = NULL, *accel_opts = NULL;
-+     */
++    QemuOpts *icount_opts = NULL, *accel_opts = NULL;
-+    migration_object_init();
+     QemuOptsList *olist;
-+
+     int optind;
-     /*
+     const char *optarg;
-      * Note: we need to create block backends before
+@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
-      * machine_set_property(), so machine properties can refer to
--     * them.
+     cpu_model = NULL;
-+     * them, and after migration_object_init(), so we can create
+     snapshot = 0;
-+     * migration blockers.
+-    cyls = heads = secs = 0;
-      */
+-    translation = BIOS_ATA_TRANSLATION_AUTO;
-     configure_blockdev(&bdo_queue, machine_class, snapshot);
+     nb_nics = 0;
-@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
-                      machine_class->name, machine_class->deprecation_reason);
+@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
-     }
+         if (optind >= argc)
+             break;
--    /*
+         if (argv[optind][0] != '-') {
--     * Migration object can only be created after global properties
+-            hda_opts = drive_add(IF_DEFAULT, 0, argv[optind++], HD_OPTS);
--     * are applied correctly.
++            drive_add(IF_DEFAULT, 0, argv[optind++], HD_OPTS);
--     */
+         } else {
--    migration_object_init();
+             const QEMUOption *popt;
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
                  cpu_model = optarg;
                  break;
              case QEMU_OPTION_hda:
 -                {
 -                    char buf[256];
 -                    if (cyls == 0)
 -                        snprintf(buf, sizeof(buf), "%s", HD_OPTS);
 -                    else
 -                        snprintf(buf, sizeof(buf),
 -                                 "%s,cyls=%d,heads=%d,secs=%d%s",
 -                                 HD_OPTS , cyls, heads, secs,
 -                                 translation == BIOS_ATA_TRANSLATION_LBA ?
 -                                 ",trans=lba" :
 -                                 translation == BIOS_ATA_TRANSLATION_NONE ?
 -                                 ",trans=none" : "");
 -                    drive_add(IF_DEFAULT, 0, optarg, buf);
 -                    break;
 -                }
              case QEMU_OPTION_hdb:
              case QEMU_OPTION_hdc:
              case QEMU_OPTION_hdd:
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
              case QEMU_OPTION_snapshot:
                  snapshot = 1;
                  break;
 -            case QEMU_OPTION_hdachs:
 -                {
 -                    const char *p;
 -                    p = optarg;
 -                    cyls = strtol(p, (char **)&p, 0);
 -                    if (cyls < 1 || cyls > 16383)
 -                        goto chs_fail;
 -                    if (*p != ',')
 -                        goto chs_fail;
 -                    p++;
 -                    heads = strtol(p, (char **)&p, 0);
 -                    if (heads < 1 || heads > 16)
 -                        goto chs_fail;
 -                    if (*p != ',')
 -                        goto chs_fail;
 -                    p++;
 -                    secs = strtol(p, (char **)&p, 0);
 -                    if (secs < 1 || secs > 63)
 -                        goto chs_fail;
 -                    if (*p == ',') {
 -                        p++;
 -                        if (!strcmp(p, "large")) {
 -                            translation = BIOS_ATA_TRANSLATION_LARGE;
 -                        } else if (!strcmp(p, "rechs")) {
 -                            translation = BIOS_ATA_TRANSLATION_RECHS;
 -                        } else if (!strcmp(p, "none")) {
 -                            translation = BIOS_ATA_TRANSLATION_NONE;
 -                        } else if (!strcmp(p, "lba")) {
 -                            translation = BIOS_ATA_TRANSLATION_LBA;
 -                        } else if (!strcmp(p, "auto")) {
 -                            translation = BIOS_ATA_TRANSLATION_AUTO;
 -                        } else {
 -                            goto chs_fail;
 -                        }
 -                    } else if (*p != '\0') {
 -                    chs_fail:
 -                        error_report("invalid physical CHS format");
 -                        exit(1);
 -                    }
 -                    if (hda_opts != NULL) {
 -                        qemu_opt_set_number(hda_opts, "cyls", cyls,
 -                                            &error_abort);
 -                        qemu_opt_set_number(hda_opts, "heads", heads,
 -                                            &error_abort);
 -                        qemu_opt_set_number(hda_opts, "secs", secs,
 -                                            &error_abort);
 -                        if (translation == BIOS_ATA_TRANSLATION_LARGE) {
 -                            qemu_opt_set(hda_opts, "trans", "large",
 -                                         &error_abort);
 -                        } else if (translation == BIOS_ATA_TRANSLATION_RECHS) {
 -                            qemu_opt_set(hda_opts, "trans", "rechs",
 -                                         &error_abort);
 -                        } else if (translation == BIOS_ATA_TRANSLATION_LBA) {
 -                            qemu_opt_set(hda_opts, "trans", "lba",
 -                                         &error_abort);
 -                        } else if (translation == BIOS_ATA_TRANSLATION_NONE) {
 -                            qemu_opt_set(hda_opts, "trans", "none",
 -                                         &error_abort);
 -                        }
 -                    }
 -                }
 -                error_report("'-hdachs' is deprecated, please use '-device"
 -                             " ide-hd,cyls=c,heads=h,secs=s,...' instead");
 -                break;
              case QEMU_OPTION_numa:
                  opts = qemu_opts_parse_noisily(qemu_find_opts("numa"),
                                                 optarg, true);
 diff --git a/qemu-doc.texi b/qemu-doc.texi
 index XXXXXXX..XXXXXXX 100644
 --- a/qemu-doc.texi
 +++ b/qemu-doc.texi
@@ -XXX,XX +XXX,XX @@ The ``--net dump'' argument is now replaced with the
  ``-object filter-dump'' argument which works in combination
  with the modern ``-netdev`` backends instead.
 -@subsection -hdachs (since 2.10.0)
 -
-     if (qtest_chrdev) {
+-The ``-hdachs'' argument is now a synonym for setting
-         qtest_init(qtest_chrdev, qtest_log, &error_fatal);
+-the ``cyls'', ``heads'', ``secs'', and ``trans'' properties
-     }
+-on the ``ide-hd'' device using the ``-device'' argument.
 -The new syntax allows different settings to be provided
 -per disk.
 -
  @subsection -usbdevice (since 2.10.0)
  The ``-usbdevice DEV'' argument is now a synonym for setting
 diff --git a/qemu-options.hx b/qemu-options.hx
 index XXXXXXX..XXXXXXX 100644
 --- a/qemu-options.hx
 +++ b/qemu-options.hx
@@ -XXX,XX +XXX,XX @@ of available connectors of a given interface type.
  @item media=@var{media}
  This option defines the type of the media: disk or cdrom.
  @item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
 -These options have the same definition as they have in @option{-hdachs}.
 -These parameters are deprecated, use the corresponding parameters
 +Force disk physical geometry and the optional BIOS translation (trans=none or
 +lba). These parameters are deprecated, use the corresponding parameters
  of @code{-device} instead.
  @item snapshot=@var{snapshot}
  @var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
@@ -XXX,XX +XXX,XX @@ the raw disk image you use is not written back. You can however force
  the write back by pressing @key{C-a s} (@pxref{disk_images}).
  ETEXI
 -DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \
 -    "-hdachs c,h,s[,t]\n" \
 -    "                force hard disk 0 physical geometry and the optional BIOS\n" \
 -    "                translation (t=none or lba) (usually QEMU can guess them)\n",
 -    QEMU_ARCH_ALL)
 -STEXI
 -@item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
 -@findex -hdachs
 -Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
 -@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
 -translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
 -all those parameters. This option is deprecated, please use
 -@code{-device ide-hd,cyls=c,heads=h,secs=s,...} instead.
 -ETEXI
 -
  DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
      "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
      " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
 --
-.20.1
+.13.6

-New patch
+[Qemu-devel] [PULL v3 16/35] block: Mention -drive cyls/heads/secs/trans/serial/addr in deprecation chapter
+From: Thomas Huth <thuth@redhat.com>
+Looks like we forgot to announce the deprecation of these options in
+the corresponding chapter of the qemu-doc text, so let's do that now.
+Signed-off-by: Thomas Huth <thuth@redhat.com>
+Reviewed-by: John Snow <jsnow@redhat.com>
+Reviewed-by: Markus Armbruster <armbru@redhat.com>
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ qemu-doc.texi | 15 +++++++++++++++
+file changed, 15 insertions(+)
+diff --git a/qemu-doc.texi b/qemu-doc.texi
+index XXXXXXX..XXXXXXX 100644
+--- a/qemu-doc.texi
++++ b/qemu-doc.texi
+@@ -XXX,XX +XXX,XX @@ longer be directly supported in QEMU.
+ The ``-drive if=scsi'' argument is replaced by the the
+ ``-device BUS-TYPE'' argument combined with ``-drive if=none''.
++@subsection -drive cyls=...,heads=...,secs=...,trans=... (since 2.10.0)
++
++The drive geometry arguments are replaced by the the geometry arguments
++that can be specified with the ``-device'' parameter.
++
++@subsection -drive serial=... (since 2.10.0)
++
++The drive serial argument is replaced by the the serial argument
++that can be specified with the ``-device'' parameter.
++
++@subsection -drive addr=... (since 2.10.0)
++
++The drive addr argument is replaced by the the addr argument
++that can be specified with the ``-device'' parameter.
++
+ @subsection -net dump (since 2.10.0)
+ The ``--net dump'' argument is now replaced with the
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 17/35] block: Remove unused bdrv_requests_pending
+From: Fam Zheng <famz@redhat.com>
+Signed-off-by: Fam Zheng <famz@redhat.com>
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ include/block/block_int.h |  1 -
+ block/io.c                | 18 ------------------
+files changed, 19 deletions(-)
+diff --git a/include/block/block_int.h b/include/block/block_int.h
+index XXXXXXX..XXXXXXX 100644
+--- a/include/block/block_int.h
++++ b/include/block/block_int.h
+@@ -XXX,XX +XXX,XX @@ bool blk_dev_is_tray_open(BlockBackend *blk);
+ bool blk_dev_is_medium_locked(BlockBackend *blk);
+ void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes);
+-bool bdrv_requests_pending(BlockDriverState *bs);
+ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
+ void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in);
+diff --git a/block/io.c b/block/io.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/io.c
++++ b/block/io.c
+@@ -XXX,XX +XXX,XX @@ void bdrv_disable_copy_on_read(BlockDriverState *bs)
+     assert(old >= 1);
+ }
+-/* Check if any requests are in-flight (including throttled requests) */
+-bool bdrv_requests_pending(BlockDriverState *bs)
+-{
+-    BdrvChild *child;
+-
+-    if (atomic_read(&bs->in_flight)) {
+-        return true;
+-    }
+-
+-    QLIST_FOREACH(child, &bs->children, next) {
+-        if (bdrv_requests_pending(child->bs)) {
+-            return true;
+-        }
+-    }
+-
+-    return false;
+-}
+-
+ typedef struct {
+     Coroutine *co;
+     BlockDriverState *bs;
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 18/35] block: Assert drain_all is only called from main AioContext
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Fam Zheng <famz@redhat.com>
+---
+ block/io.c | 6 ++++++
+file changed, 6 insertions(+)
+diff --git a/block/io.c b/block/io.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/io.c
++++ b/block/io.c
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
+     BdrvNextIterator it;
+     GSList *aio_ctxs = NULL, *ctx;
++    /* BDRV_POLL_WHILE() for a node can only be called from its own I/O thread
++     * or the main loop AioContext. We potentially use BDRV_POLL_WHILE() on
++     * nodes in several different AioContexts, so make sure we're in the main
++     * context. */
++    assert(qemu_get_current_aio_context() == qemu_get_aio_context());
++
+     block_job_pause_all();
+     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 19/35] block: Make bdrv_drain() driver callbacks non-recursive
+bdrv_drained_begin() doesn't increase bs->quiesce_counter recursively
+and also doesn't notify other parent nodes of children, which both means
+that the child nodes are not actually drained, and bdrv_drained_begin()
+is providing useful functionality only on a single node.
+To keep things consistent, we also shouldn't call the block driver
+callbacks recursively.
+A proper recursive drain version that provides an actually working
+drained section for child nodes will be introduced later.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Fam Zheng <famz@redhat.com>
+---
+ block/io.c | 16 +++++++++-------
+file changed, 9 insertions(+), 7 deletions(-)
+diff --git a/block/io.c b/block/io.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/io.c
++++ b/block/io.c
+@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
+ }
+ /* Recursively call BlockDriver.bdrv_co_drain_begin/end callbacks */
+-static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
++static void bdrv_drain_invoke(BlockDriverState *bs, bool begin, bool recursive)
+ {
+     BdrvChild *child, *tmp;
+     BdrvCoDrainData data = { .bs = bs, .done = false, .begin = begin};
+@@ -XXX,XX +XXX,XX @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
+     bdrv_coroutine_enter(bs, data.co);
+     BDRV_POLL_WHILE(bs, !data.done);
+-    QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {
+-        bdrv_drain_invoke(child->bs, begin);
++    if (recursive) {
++        QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {
++            bdrv_drain_invoke(child->bs, begin, true);
++        }
+     }
+ }
+@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs)
+         bdrv_parent_drained_begin(bs);
+     }
+-    bdrv_drain_invoke(bs, true);
++    bdrv_drain_invoke(bs, true, false);
+     bdrv_drain_recurse(bs);
+ }
+@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
+     }
+     /* Re-enable things in child-to-parent order */
+-    bdrv_drain_invoke(bs, false);
++    bdrv_drain_invoke(bs, false, false);
+     bdrv_parent_drained_end(bs);
+     aio_enable_external(bdrv_get_aio_context(bs));
+ }
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
+         aio_context_acquire(aio_context);
+         aio_disable_external(aio_context);
+         bdrv_parent_drained_begin(bs);
+-        bdrv_drain_invoke(bs, true);
++        bdrv_drain_invoke(bs, true, true);
+         aio_context_release(aio_context);
+         if (!g_slist_find(aio_ctxs, aio_context)) {
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
+         /* Re-enable things in child-to-parent order */
+         aio_context_acquire(aio_context);
+-        bdrv_drain_invoke(bs, false);
++        bdrv_drain_invoke(bs, false, true);
+         bdrv_parent_drained_end(bs);
+         aio_enable_external(aio_context);
+         aio_context_release(aio_context);
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 20/35] test-bdrv-drain: Test callback for bdrv_drain
+The existing test is for bdrv_drain_all_begin/end() only. Generalise the
+test case so that it can be run for the other variants as well. At the
+moment this is only bdrv_drain_begin/end(), but in a while, we'll add
+another one.
+Also, add a backing file to the test node to test whether the operations
+work recursively.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ tests/test-bdrv-drain.c | 69 ++++++++++++++++++++++++++++++++++++++++++++-----
+file changed, 62 insertions(+), 7 deletions(-)
+diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
+index XXXXXXX..XXXXXXX 100644
+--- a/tests/test-bdrv-drain.c
++++ b/tests/test-bdrv-drain.c
+@@ -XXX,XX +XXX,XX @@ static BlockDriver bdrv_test = {
+     .bdrv_co_drain_begin    = bdrv_test_co_drain_begin,
+     .bdrv_co_drain_end      = bdrv_test_co_drain_end,
++
++    .bdrv_child_perm        = bdrv_format_default_perms,
+ };
+ static void aio_ret_cb(void *opaque, int ret)
+@@ -XXX,XX +XXX,XX @@ static void aio_ret_cb(void *opaque, int ret)
+     *aio_ret = ret;
+ }
+-static void test_drv_cb_drain_all(void)
++enum drain_type {
++    BDRV_DRAIN_ALL,
++    BDRV_DRAIN,
++};
++
++static void do_drain_begin(enum drain_type drain_type, BlockDriverState *bs)
++{
++    switch (drain_type) {
++    case BDRV_DRAIN_ALL:        bdrv_drain_all_begin(); break;
++    case BDRV_DRAIN:            bdrv_drained_begin(bs); break;
++    default:                    g_assert_not_reached();
++    }
++}
++
++static void do_drain_end(enum drain_type drain_type, BlockDriverState *bs)
++{
++    switch (drain_type) {
++    case BDRV_DRAIN_ALL:        bdrv_drain_all_end(); break;
++    case BDRV_DRAIN:            bdrv_drained_end(bs); break;
++    default:                    g_assert_not_reached();
++    }
++}
++
++static void test_drv_cb_common(enum drain_type drain_type, bool recursive)
+ {
+     BlockBackend *blk;
+-    BlockDriverState *bs;
+-    BDRVTestState *s;
++    BlockDriverState *bs, *backing;
++    BDRVTestState *s, *backing_s;
+     BlockAIOCB *acb;
+     int aio_ret;
+@@ -XXX,XX +XXX,XX @@ static void test_drv_cb_drain_all(void)
+     s = bs->opaque;
+     blk_insert_bs(blk, bs, &error_abort);
++    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort);
++    backing_s = backing->opaque;
++    bdrv_set_backing_hd(bs, backing, &error_abort);
++
+     /* Simple bdrv_drain_all_begin/end pair, check that CBs are called */
+     g_assert_cmpint(s->drain_count, ==, 0);
+-    bdrv_drain_all_begin();
++    g_assert_cmpint(backing_s->drain_count, ==, 0);
++
++    do_drain_begin(drain_type, bs);
++
+     g_assert_cmpint(s->drain_count, ==, 1);
+-    bdrv_drain_all_end();
++    g_assert_cmpint(backing_s->drain_count, ==, !!recursive);
++
++    do_drain_end(drain_type, bs);
++
+     g_assert_cmpint(s->drain_count, ==, 0);
++    g_assert_cmpint(backing_s->drain_count, ==, 0);
+     /* Now do the same while a request is pending */
+     aio_ret = -EINPROGRESS;
+@@ -XXX,XX +XXX,XX @@ static void test_drv_cb_drain_all(void)
+     g_assert_cmpint(aio_ret, ==, -EINPROGRESS);
+     g_assert_cmpint(s->drain_count, ==, 0);
+-    bdrv_drain_all_begin();
++    g_assert_cmpint(backing_s->drain_count, ==, 0);
++
++    do_drain_begin(drain_type, bs);
++
+     g_assert_cmpint(aio_ret, ==, 0);
+     g_assert_cmpint(s->drain_count, ==, 1);
+-    bdrv_drain_all_end();
++    g_assert_cmpint(backing_s->drain_count, ==, !!recursive);
++
++    do_drain_end(drain_type, bs);
++
+     g_assert_cmpint(s->drain_count, ==, 0);
++    g_assert_cmpint(backing_s->drain_count, ==, 0);
++    bdrv_unref(backing);
+     bdrv_unref(bs);
+     blk_unref(blk);
+ }
++static void test_drv_cb_drain_all(void)
++{
++    test_drv_cb_common(BDRV_DRAIN_ALL, true);
++}
++
++static void test_drv_cb_drain(void)
++{
++    test_drv_cb_common(BDRV_DRAIN, false);
++}
++
+ int main(int argc, char **argv)
+ {
+     bdrv_init();
+@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
+     g_test_init(&argc, &argv, NULL);
+     g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all);
++    g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain);
+     return g_test_run();
+ }
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 21/35] test-bdrv-drain: Test bs->quiesce_counter
+This is currently only working correctly for bdrv_drain(), not for
+bdrv_drain_all(). Leave a comment for the drain_all case, we'll address
+it later.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ tests/test-bdrv-drain.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
+file changed, 45 insertions(+)
+diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
+index XXXXXXX..XXXXXXX 100644
+--- a/tests/test-bdrv-drain.c
++++ b/tests/test-bdrv-drain.c
+@@ -XXX,XX +XXX,XX @@ static void test_drv_cb_drain(void)
+     test_drv_cb_common(BDRV_DRAIN, false);
+ }
++static void test_quiesce_common(enum drain_type drain_type, bool recursive)
++{
++    BlockBackend *blk;
++    BlockDriverState *bs, *backing;
++
++    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
++    bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
++                              &error_abort);
++    blk_insert_bs(blk, bs, &error_abort);
++
++    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort);
++    bdrv_set_backing_hd(bs, backing, &error_abort);
++
++    g_assert_cmpint(bs->quiesce_counter, ==, 0);
++    g_assert_cmpint(backing->quiesce_counter, ==, 0);
++
++    do_drain_begin(drain_type, bs);
++
++    g_assert_cmpint(bs->quiesce_counter, ==, 1);
++    g_assert_cmpint(backing->quiesce_counter, ==, !!recursive);
++
++    do_drain_end(drain_type, bs);
++
++    g_assert_cmpint(bs->quiesce_counter, ==, 0);
++    g_assert_cmpint(backing->quiesce_counter, ==, 0);
++
++    bdrv_unref(backing);
++    bdrv_unref(bs);
++    blk_unref(blk);
++}
++
++static void test_quiesce_drain_all(void)
++{
++    // XXX drain_all doesn't quiesce
++    //test_quiesce_common(BDRV_DRAIN_ALL, true);
++}
++
++static void test_quiesce_drain(void)
++{
++    test_quiesce_common(BDRV_DRAIN, false);
++}
++
+ int main(int argc, char **argv)
+ {
+     bdrv_init();
+@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
+     g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all);
+     g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain);
++    g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all);
++    g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain);
++
+     return g_test_run();
+ }
+--
+.13.6

-[Qemu-devel] [PULL 09/12] blockjob: fix user pause in block_job_error_action
+[Qemu-devel] [PULL v3 22/35] blockjob: Pause job on draining any job BDS
-From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
+Block jobs already paused themselves when their main BlockBackend
 entered a drained section. This is not good enough: We also want to
 pause a block job and may not submit new requests if, for example, the
 mirror target node should be drained.
-Job (especially mirror) may call block_job_error_action several
+This implements .drained_begin/end callbacks in child_job in order to
-times before actual pause if it has several in-flight requests.
+consider all block nodes related to the job, and removes the
 BlockBackend callbacks which are unnecessary now because the root of the
 job main BlockBackend is always referenced with a child_job, too.
-block_job_error_action will call job_pause more than once in this case,
-which lead to following block-job-resume qmp command can't actually
-resume the job.
-Fix it by do not increase pause level in block_job_error_action if
-user_paused already set.
-Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
 ---
- blockjob.c | 8 +++++---
+ blockjob.c | 22 +++++++++-------------
-file changed, 5 insertions(+), 3 deletions(-)
+file changed, 9 insertions(+), 13 deletions(-)
 diff --git a/blockjob.c b/blockjob.c
 index XXXXXXX..XXXXXXX 100644
 --- a/blockjob.c
 +++ b/blockjob.c
-@@ -XXX,XX +XXX,XX @@ BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
+@@ -XXX,XX +XXX,XX @@ static char *child_job_get_parent_desc(BdrvChild *c)
-                                         action);
+                            job->id);
-     }
+ }
-     if (action == BLOCK_ERROR_ACTION_STOP) {
--        job_pause(&job->job);
+-static const BdrvChildRole child_job = {
--        /* make the pause user visible, which will be resumed from QMP. */
+-    .get_parent_desc    = child_job_get_parent_desc,
--        job->job.user_paused = true;
+-    .stay_at_node       = true,
-+        if (!job->job.user_paused) {
+-};
-+            job_pause(&job->job);
+-
-+            /* make the pause user visible, which will be resumed from QMP. */
+-static void block_job_drained_begin(void *opaque)
-+            job->job.user_paused = true;
++static void child_job_drained_begin(BdrvChild *c)
-+        }
+ {
-         block_job_iostatus_set_err(job, error);
+-    BlockJob *job = opaque;
-     }
++    BlockJob *job = c->opaque;
-     return action;
+     block_job_pause(job);
  }
 -static void block_job_drained_end(void *opaque)
 +static void child_job_drained_end(BdrvChild *c)
  {
 -    BlockJob *job = opaque;
 +    BlockJob *job = c->opaque;
      block_job_resume(job);
  }
 -static const BlockDevOps block_job_dev_ops = {
 -    .drained_begin = block_job_drained_begin,
 -    .drained_end = block_job_drained_end,
 +static const BdrvChildRole child_job = {
 +    .get_parent_desc    = child_job_get_parent_desc,
 +    .drained_begin      = child_job_drained_begin,
 +    .drained_end        = child_job_drained_end,
 +    .stay_at_node       = true,
  };
  void block_job_remove_all_bdrv(BlockJob *job)
@@ -XXX,XX +XXX,XX @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,
      block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort);
      bs->job = job;
 -    blk_set_dev_ops(blk, &block_job_dev_ops, job);
      bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
      QLIST_INSERT_HEAD(&block_jobs, job, job_list);
 --
-.20.1
+.13.6

-New patch
+[Qemu-devel] [PULL v3 23/35] test-bdrv-drain: Test drain vs. block jobs
+Block jobs must be paused if any of the involved nodes are drained.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ tests/test-bdrv-drain.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++
+file changed, 121 insertions(+)
+diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
+index XXXXXXX..XXXXXXX 100644
+--- a/tests/test-bdrv-drain.c
++++ b/tests/test-bdrv-drain.c
+@@ -XXX,XX +XXX,XX @@
+ #include "qemu/osdep.h"
+ #include "block/block.h"
++#include "block/blockjob_int.h"
+ #include "sysemu/block-backend.h"
+ #include "qapi/error.h"
+@@ -XXX,XX +XXX,XX @@ static void test_quiesce_drain(void)
+     test_quiesce_common(BDRV_DRAIN, false);
+ }
++
++typedef struct TestBlockJob {
++    BlockJob common;
++    bool should_complete;
++} TestBlockJob;
++
++static void test_job_completed(BlockJob *job, void *opaque)
++{
++    block_job_completed(job, 0);
++}
++
++static void coroutine_fn test_job_start(void *opaque)
++{
++    TestBlockJob *s = opaque;
++
++    while (!s->should_complete) {
++        block_job_sleep_ns(&s->common, 100000);
++    }
++
++    block_job_defer_to_main_loop(&s->common, test_job_completed, NULL);
++}
++
++static void test_job_complete(BlockJob *job, Error **errp)
++{
++    TestBlockJob *s = container_of(job, TestBlockJob, common);
++    s->should_complete = true;
++}
++
++BlockJobDriver test_job_driver = {
++    .instance_size  = sizeof(TestBlockJob),
++    .start          = test_job_start,
++    .complete       = test_job_complete,
++};
++
++static void test_blockjob_common(enum drain_type drain_type)
++{
++    BlockBackend *blk_src, *blk_target;
++    BlockDriverState *src, *target;
++    BlockJob *job;
++    int ret;
++
++    src = bdrv_new_open_driver(&bdrv_test, "source", BDRV_O_RDWR,
++                               &error_abort);
++    blk_src = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
++    blk_insert_bs(blk_src, src, &error_abort);
++
++    target = bdrv_new_open_driver(&bdrv_test, "target", BDRV_O_RDWR,
++                                  &error_abort);
++    blk_target = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
++    blk_insert_bs(blk_target, target, &error_abort);
++
++    job = block_job_create("job0", &test_job_driver, src, 0, BLK_PERM_ALL, 0,
++                           0, NULL, NULL, &error_abort);
++    block_job_add_bdrv(job, "target", target, 0, BLK_PERM_ALL, &error_abort);
++    block_job_start(job);
++
++    g_assert_cmpint(job->pause_count, ==, 0);
++    g_assert_false(job->paused);
++    g_assert_false(job->busy); /* We're in block_job_sleep_ns() */
++
++    do_drain_begin(drain_type, src);
++
++    if (drain_type == BDRV_DRAIN_ALL) {
++        /* bdrv_drain_all() drains both src and target, and involves an
++         * additional block_job_pause_all() */
++        g_assert_cmpint(job->pause_count, ==, 3);
++    } else {
++        g_assert_cmpint(job->pause_count, ==, 1);
++    }
++    /* XXX We don't wait until the job is actually paused. Is this okay? */
++    /* g_assert_true(job->paused); */
++    g_assert_false(job->busy); /* The job is paused */
++
++    do_drain_end(drain_type, src);
++
++    g_assert_cmpint(job->pause_count, ==, 0);
++    g_assert_false(job->paused);
++    g_assert_false(job->busy); /* We're in block_job_sleep_ns() */
++
++    do_drain_begin(drain_type, target);
++
++    if (drain_type == BDRV_DRAIN_ALL) {
++        /* bdrv_drain_all() drains both src and target, and involves an
++         * additional block_job_pause_all() */
++        g_assert_cmpint(job->pause_count, ==, 3);
++    } else {
++        g_assert_cmpint(job->pause_count, ==, 1);
++    }
++    /* XXX We don't wait until the job is actually paused. Is this okay? */
++    /* g_assert_true(job->paused); */
++    g_assert_false(job->busy); /* The job is paused */
++
++    do_drain_end(drain_type, target);
++
++    g_assert_cmpint(job->pause_count, ==, 0);
++    g_assert_false(job->paused);
++    g_assert_false(job->busy); /* We're in block_job_sleep_ns() */
++
++    ret = block_job_complete_sync(job, &error_abort);
++    g_assert_cmpint(ret, ==, 0);
++
++    blk_unref(blk_src);
++    blk_unref(blk_target);
++    bdrv_unref(src);
++    bdrv_unref(target);
++}
++
++static void test_blockjob_drain_all(void)
++{
++    test_blockjob_common(BDRV_DRAIN_ALL);
++}
++
++static void test_blockjob_drain(void)
++{
++    test_blockjob_common(BDRV_DRAIN);
++}
++
+ int main(int argc, char **argv)
+ {
+     bdrv_init();
+@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
+     g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all);
+     g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain);
++    g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
++    g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain);
++
+     return g_test_run();
+ }
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 24/35] block: Don't block_job_pause_all() in bdrv_drain_all()
+Block jobs are already paused using the BdrvChildRole drain callbacks,
+so we don't need an additional block_job_pause_all() call.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ block/io.c              |  4 ----
+ tests/test-bdrv-drain.c | 10 ++++------
+files changed, 4 insertions(+), 10 deletions(-)
+diff --git a/block/io.c b/block/io.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/io.c
++++ b/block/io.c
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
+      * context. */
+     assert(qemu_get_current_aio_context() == qemu_get_aio_context());
+-    block_job_pause_all();
+-
+     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+         AioContext *aio_context = bdrv_get_aio_context(bs);
+@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
+         aio_enable_external(aio_context);
+         aio_context_release(aio_context);
+     }
+-
+-    block_job_resume_all();
+ }
+ void bdrv_drain_all(void)
+diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
+index XXXXXXX..XXXXXXX 100644
+--- a/tests/test-bdrv-drain.c
++++ b/tests/test-bdrv-drain.c
+@@ -XXX,XX +XXX,XX @@ static void test_blockjob_common(enum drain_type drain_type)
+     do_drain_begin(drain_type, src);
+     if (drain_type == BDRV_DRAIN_ALL) {
+-        /* bdrv_drain_all() drains both src and target, and involves an
+-         * additional block_job_pause_all() */
+-        g_assert_cmpint(job->pause_count, ==, 3);
++        /* bdrv_drain_all() drains both src and target */
++        g_assert_cmpint(job->pause_count, ==, 2);
+     } else {
+         g_assert_cmpint(job->pause_count, ==, 1);
+     }
+@@ -XXX,XX +XXX,XX @@ static void test_blockjob_common(enum drain_type drain_type)
+     do_drain_begin(drain_type, target);
+     if (drain_type == BDRV_DRAIN_ALL) {
+-        /* bdrv_drain_all() drains both src and target, and involves an
+-         * additional block_job_pause_all() */
+-        g_assert_cmpint(job->pause_count, ==, 3);
++        /* bdrv_drain_all() drains both src and target */
++        g_assert_cmpint(job->pause_count, ==, 2);
+     } else {
+         g_assert_cmpint(job->pause_count, ==, 1);
+     }
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 25/35] block: Nested drain_end must still call callbacks
+bdrv_do_drained_begin() restricts the call of parent callbacks and
+aio_disable_external() to the outermost drain section, but the block
+driver callbacks are always called. bdrv_do_drained_end() must match
+this behaviour, otherwise nodes stay drained even if begin/end calls
+were balanced.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ block/io.c | 12 +++++++-----
+file changed, 7 insertions(+), 5 deletions(-)
+diff --git a/block/io.c b/block/io.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/io.c
++++ b/block/io.c
+@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs)
+ void bdrv_drained_end(BlockDriverState *bs)
+ {
++    int old_quiesce_counter;
++
+     if (qemu_in_coroutine()) {
+         bdrv_co_yield_to_drain(bs, false);
+         return;
+     }
+     assert(bs->quiesce_counter > 0);
+-    if (atomic_fetch_dec(&bs->quiesce_counter) > 1) {
+-        return;
+-    }
++    old_quiesce_counter = atomic_fetch_dec(&bs->quiesce_counter);
+     /* Re-enable things in child-to-parent order */
+     bdrv_drain_invoke(bs, false, false);
+-    bdrv_parent_drained_end(bs);
+-    aio_enable_external(bdrv_get_aio_context(bs));
++    if (old_quiesce_counter == 1) {
++        bdrv_parent_drained_end(bs);
++        aio_enable_external(bdrv_get_aio_context(bs));
++    }
+ }
+ /*
+--
+.13.6

-[Qemu-devel] [PULL 06/12] iotests: 153: Wait for an answer to QMP commands
+[Qemu-devel] [PULL v3 26/35] test-bdrv-drain: Test nested drain sections
-From: Sergio Lopez <slp@redhat.com>
-There are various actions in this test that must be executed
-sequentially, as the result of it depends on the state triggered by the
-previous one.
-If the last argument of _send_qemu_cmd() is an empty string, it just
-sends the QMP commands without waiting for an answer. While unlikely, it
-may happen that the next action in the test gets invoked before QEMU
-processes the QMP request.
-This issue seems to be easier to reproduce on servers with limited
-resources or highly loaded.
-With this change, we wait for an answer on all _send_qemu_cmd() calls.
-Signed-off-by: Sergio Lopez <slp@redhat.com>
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
 ---
- tests/qemu-iotests/153     | 12 ++++++------
+ tests/test-bdrv-drain.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++
- tests/qemu-iotests/153.out |  6 ++++++
+file changed, 57 insertions(+)
 files changed, 12 insertions(+), 6 deletions(-)
-diff --git a/tests/qemu-iotests/153 b/tests/qemu-iotests/153
+diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
 index XXXXXXX..XXXXXXX 100755
 --- a/tests/qemu-iotests/153
 +++ b/tests/qemu-iotests/153
@@ -XXX,XX +XXX,XX @@ for opts1 in "" "read-only=on" "read-only=on,force-share=on"; do
              _img_info -U | grep 'file format'
          fi
      done
 -    _send_qemu_cmd $h "{ 'execute': 'quit', }" ""
 +    _send_qemu_cmd $h "{ 'execute': 'quit' }" ''
      echo
      echo "Round done"
      _cleanup_qemu
@@ -XXX,XX +XXX,XX @@ echo "Adding drive"
  _send_qemu_cmd $QEMU_HANDLE \
      "{ 'execute': 'human-monitor-command',
         'arguments': { 'command-line': 'drive_add 0 if=none,id=d0,file=${TEST_IMG}' } }" \
 -    ""
 +    'return'
  _run_cmd $QEMU_IO "${TEST_IMG}" -c 'write 0 512'
@@ -XXX,XX +XXX,XX @@ echo "== Closing an image should unlock it =="
  _send_qemu_cmd $QEMU_HANDLE \
      "{ 'execute': 'human-monitor-command',
         'arguments': { 'command-line': 'drive_del d0' } }" \
 -    ""
 +    'return'
  _run_cmd $QEMU_IO "${TEST_IMG}" -c 'write 0 512'
@@ -XXX,XX +XXX,XX @@ for d in d0 d1; do
      _send_qemu_cmd $QEMU_HANDLE \
          "{ 'execute': 'human-monitor-command',
             'arguments': { 'command-line': 'drive_add 0 if=none,id=$d,file=${TEST_IMG},readonly=on' } }" \
 -        ""
 +        'return'
  done
  _run_cmd $QEMU_IMG info "${TEST_IMG}"
@@ -XXX,XX +XXX,XX @@ _run_cmd $QEMU_IMG info "${TEST_IMG}"
  _send_qemu_cmd $QEMU_HANDLE \
      "{ 'execute': 'human-monitor-command',
         'arguments': { 'command-line': 'drive_del d0' } }" \
 -    ""
 +    'return'
  _run_cmd $QEMU_IO "${TEST_IMG}" -c 'write 0 512'
@@ -XXX,XX +XXX,XX @@ echo "Closing the other"
  _send_qemu_cmd $QEMU_HANDLE \
      "{ 'execute': 'human-monitor-command',
         'arguments': { 'command-line': 'drive_del d1' } }" \
 -    ""
 +    'return'
  _run_cmd $QEMU_IO "${TEST_IMG}" -c 'write 0 512'
 diff --git a/tests/qemu-iotests/153.out b/tests/qemu-iotests/153.out
 index XXXXXXX..XXXXXXX 100644
---- a/tests/qemu-iotests/153.out
+--- a/tests/test-bdrv-drain.c
-+++ b/tests/qemu-iotests/153.out
++++ b/tests/test-bdrv-drain.c
-@@ -XXX,XX +XXX,XX @@ Is another process using the image [TEST_DIR/t.qcow2]?
+@@ -XXX,XX +XXX,XX @@ static void aio_ret_cb(void *opaque, int ret)
- _qemu_img_wrapper commit -b TEST_DIR/t.qcow2.b TEST_DIR/t.qcow2.c
+ enum drain_type {
- {"return": {}}
+     BDRV_DRAIN_ALL,
- Adding drive
+     BDRV_DRAIN,
-+{"return": "OKrn"}
++    DRAIN_TYPE_MAX,
+ };
- _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
- can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+ static void do_drain_begin(enum drain_type drain_type, BlockDriverState *bs)
-@@ -XXX,XX +XXX,XX @@ Creating overlay with qemu-img when the guest is running should be allowed
+@@ -XXX,XX +XXX,XX @@ static void test_quiesce_drain(void)
+     test_quiesce_common(BDRV_DRAIN, false);
- _qemu_img_wrapper create -f qcow2 -b TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.overlay
+ }
- == Closing an image should unlock it ==
-+{"return": ""}
++static void test_nested(void)
++{
- _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
++    BlockBackend *blk;
- Adding two and closing one
++    BlockDriverState *bs, *backing;
-+{"return": "OKrn"}
++    BDRVTestState *s, *backing_s;
-+{"return": "OKrn"}
++    enum drain_type outer, inner;
++
- _qemu_img_wrapper info TEST_DIR/t.qcow2
++    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
-+{"return": ""}
++    bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
++                              &error_abort);
- _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
++    s = bs->opaque;
- can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
++    blk_insert_bs(blk, bs, &error_abort);
- Is another process using the image [TEST_DIR/t.qcow2]?
++
- Closing the other
++    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort);
-+{"return": ""}
++    backing_s = backing->opaque;
++    bdrv_set_backing_hd(bs, backing, &error_abort);
- _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
++
 +    for (outer = 0; outer < DRAIN_TYPE_MAX; outer++) {
 +        for (inner = 0; inner < DRAIN_TYPE_MAX; inner++) {
 +            /* XXX bdrv_drain_all() doesn't increase the quiesce_counter */
 +            int bs_quiesce      = (outer != BDRV_DRAIN_ALL) +
 +                                  (inner != BDRV_DRAIN_ALL);
 +            int backing_quiesce = 0;
 +            int backing_cb_cnt  = (outer != BDRV_DRAIN) +
 +                                  (inner != BDRV_DRAIN);
 +
 +            g_assert_cmpint(bs->quiesce_counter, ==, 0);
 +            g_assert_cmpint(backing->quiesce_counter, ==, 0);
 +            g_assert_cmpint(s->drain_count, ==, 0);
 +            g_assert_cmpint(backing_s->drain_count, ==, 0);
 +
 +            do_drain_begin(outer, bs);
 +            do_drain_begin(inner, bs);
 +
 +            g_assert_cmpint(bs->quiesce_counter, ==, bs_quiesce);
 +            g_assert_cmpint(backing->quiesce_counter, ==, backing_quiesce);
 +            g_assert_cmpint(s->drain_count, ==, 2);
 +            g_assert_cmpint(backing_s->drain_count, ==, backing_cb_cnt);
 +
 +            do_drain_end(inner, bs);
 +            do_drain_end(outer, bs);
 +
 +            g_assert_cmpint(bs->quiesce_counter, ==, 0);
 +            g_assert_cmpint(backing->quiesce_counter, ==, 0);
 +            g_assert_cmpint(s->drain_count, ==, 0);
 +            g_assert_cmpint(backing_s->drain_count, ==, 0);
 +        }
 +    }
 +
 +    bdrv_unref(backing);
 +    bdrv_unref(bs);
 +    blk_unref(blk);
 +}
 +
  typedef struct TestBlockJob {
      BlockJob common;
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
      g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all);
      g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain);
 +    g_test_add_func("/bdrv-drain/nested", test_nested);
 +
      g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
      g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain);
 --
-.20.1
+.13.6

-New patch
+[Qemu-devel] [PULL v3 27/35] block: Don't notify parents in drain call chain
+This is in preparation for subtree drains, i.e. drained sections that
 affect not only a single node, but recursively all child nodes, too.
 Calling the parent callbacks for drain is pointless when we just came
 from that parent node recursively and leads to multiple increases of
 bs->quiesce_counter in a single drain call. Don't do it.
 In order for this to work correctly, the parent callback must be called
 for every bdrv_drain_begin/end() call, not only for the outermost one:
 If we have a node N with two parents A and B, recursive draining of A
 should cause the quiesce_counter of B to increase because its child N is
 drained independently of B. If now B is recursively drained, too, A must
 increase its quiesce_counter because N is drained independently of A
 only now, even if N is going from quiesce_counter 1 to 2.
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
 ---
  include/block/block.h |  4 ++--
  block.c               | 13 +++++++++----
  block/io.c            | 47 ++++++++++++++++++++++++++++++++++-------------
 files changed, 45 insertions(+), 19 deletions(-)
 diff --git a/include/block/block.h b/include/block/block.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/block/block.h
 +++ b/include/block/block.h
@@ -XXX,XX +XXX,XX @@ void bdrv_io_unplug(BlockDriverState *bs);
   * Begin a quiesced section of all users of @bs. This is part of
   * bdrv_drained_begin.
   */
 -void bdrv_parent_drained_begin(BlockDriverState *bs);
 +void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore);
  /**
   * bdrv_parent_drained_end:
@@ -XXX,XX +XXX,XX @@ void bdrv_parent_drained_begin(BlockDriverState *bs);
   * End a quiesced section of all users of @bs. This is part of
   * bdrv_drained_end.
   */
 -void bdrv_parent_drained_end(BlockDriverState *bs);
 +void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore);
  /**
   * bdrv_drained_begin:
 diff --git a/block.c b/block.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block.c
 +++ b/block.c
@@ -XXX,XX +XXX,XX @@ static void bdrv_replace_child_noperm(BdrvChild *child,
                                        BlockDriverState *new_bs)
  {
      BlockDriverState *old_bs = child->bs;
 +    int i;
      if (old_bs && new_bs) {
          assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
      }
      if (old_bs) {
          if (old_bs->quiesce_counter && child->role->drained_end) {
 -            child->role->drained_end(child);
 +            for (i = 0; i < old_bs->quiesce_counter; i++) {
 +                child->role->drained_end(child);
 +            }
          }
          if (child->role->detach) {
              child->role->detach(child);
@@ -XXX,XX +XXX,XX @@ static void bdrv_replace_child_noperm(BdrvChild *child,
      if (new_bs) {
          QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
          if (new_bs->quiesce_counter && child->role->drained_begin) {
 -            child->role->drained_begin(child);
 +            for (i = 0; i < new_bs->quiesce_counter; i++) {
 +                child->role->drained_begin(child);
 +            }
          }
          if (child->role->attach) {
@@ -XXX,XX +XXX,XX @@ void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
      AioContext *ctx = bdrv_get_aio_context(bs);
      aio_disable_external(ctx);
 -    bdrv_parent_drained_begin(bs);
 +    bdrv_parent_drained_begin(bs, NULL);
      bdrv_drain(bs); /* ensure there are no in-flight requests */
      while (aio_poll(ctx, false)) {
@@ -XXX,XX +XXX,XX @@ void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
       */
      aio_context_acquire(new_context);
      bdrv_attach_aio_context(bs, new_context);
 -    bdrv_parent_drained_end(bs);
 +    bdrv_parent_drained_end(bs, NULL);
      aio_enable_external(ctx);
      aio_context_release(new_context);
  }
 diff --git a/block/io.c b/block/io.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/io.c
 +++ b/block/io.c
@@ -XXX,XX +XXX,XX @@
  static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
      int64_t offset, int bytes, BdrvRequestFlags flags);
 -void bdrv_parent_drained_begin(BlockDriverState *bs)
 +void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore)
  {
      BdrvChild *c, *next;
      QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) {
 +        if (c == ignore) {
 +            continue;
 +        }
          if (c->role->drained_begin) {
              c->role->drained_begin(c);
          }
      }
  }
 -void bdrv_parent_drained_end(BlockDriverState *bs)
 +void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore)
  {
      BdrvChild *c, *next;
      QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) {
 +        if (c == ignore) {
 +            continue;
 +        }
          if (c->role->drained_end) {
              c->role->drained_end(c);
          }
@@ -XXX,XX +XXX,XX @@ typedef struct {
      BlockDriverState *bs;
      bool done;
      bool begin;
 +    BdrvChild *parent;
  } BdrvCoDrainData;
  static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
@@ -XXX,XX +XXX,XX @@ static bool bdrv_drain_recurse(BlockDriverState *bs)
      return waited;
  }
 +static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent);
 +static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent);
 +
  static void bdrv_co_drain_bh_cb(void *opaque)
  {
      BdrvCoDrainData *data = opaque;
@@ -XXX,XX +XXX,XX @@ static void bdrv_co_drain_bh_cb(void *opaque)
      bdrv_dec_in_flight(bs);
      if (data->begin) {
 -        bdrv_drained_begin(bs);
 +        bdrv_do_drained_begin(bs, data->parent);
      } else {
 -        bdrv_drained_end(bs);
 +        bdrv_do_drained_end(bs, data->parent);
      }
      data->done = true;
@@ -XXX,XX +XXX,XX @@ static void bdrv_co_drain_bh_cb(void *opaque)
  }
  static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
 -                                                bool begin)
 +                                                bool begin, BdrvChild *parent)
  {
      BdrvCoDrainData data;
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
          .bs = bs,
          .done = false,
          .begin = begin,
 +        .parent = parent,
      };
      bdrv_inc_in_flight(bs);
      aio_bh_schedule_oneshot(bdrv_get_aio_context(bs),
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
      assert(data.done);
  }
 -void bdrv_drained_begin(BlockDriverState *bs)
 +static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent)
  {
      if (qemu_in_coroutine()) {
 -        bdrv_co_yield_to_drain(bs, true);
 +        bdrv_co_yield_to_drain(bs, true, parent);
          return;
      }
      /* Stop things in parent-to-child order */
      if (atomic_fetch_inc(&bs->quiesce_counter) == 0) {
          aio_disable_external(bdrv_get_aio_context(bs));
 -        bdrv_parent_drained_begin(bs);
      }
 +    bdrv_parent_drained_begin(bs, parent);
      bdrv_drain_invoke(bs, true, false);
      bdrv_drain_recurse(bs);
  }
 -void bdrv_drained_end(BlockDriverState *bs)
 +void bdrv_drained_begin(BlockDriverState *bs)
 +{
 +    bdrv_do_drained_begin(bs, NULL);
 +}
 +
 +static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent)
  {
      int old_quiesce_counter;
      if (qemu_in_coroutine()) {
 -        bdrv_co_yield_to_drain(bs, false);
 +        bdrv_co_yield_to_drain(bs, false, parent);
          return;
      }
      assert(bs->quiesce_counter > 0);
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
      /* Re-enable things in child-to-parent order */
      bdrv_drain_invoke(bs, false, false);
 +    bdrv_parent_drained_end(bs, parent);
      if (old_quiesce_counter == 1) {
 -        bdrv_parent_drained_end(bs);
          aio_enable_external(bdrv_get_aio_context(bs));
      }
  }
 +void bdrv_drained_end(BlockDriverState *bs)
 +{
 +    bdrv_do_drained_end(bs, NULL);
 +}
 +
  /*
   * Wait for pending requests to complete on a single BlockDriverState subtree,
   * and suspend block driver's internal I/O until next request arrives.
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
          /* Stop things in parent-to-child order */
          aio_context_acquire(aio_context);
          aio_disable_external(aio_context);
 -        bdrv_parent_drained_begin(bs);
 +        bdrv_parent_drained_begin(bs, NULL);
          bdrv_drain_invoke(bs, true, true);
          aio_context_release(aio_context);
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
          /* Re-enable things in child-to-parent order */
          aio_context_acquire(aio_context);
          bdrv_drain_invoke(bs, false, true);
 -        bdrv_parent_drained_end(bs);
 +        bdrv_parent_drained_end(bs, NULL);
          aio_enable_external(aio_context);
          aio_context_release(aio_context);
      }
 --
 .13.6

-[Qemu-devel] [PULL 01/12] mirror: Confirm we're quiesced only if the job is paused or cancelled
+[Qemu-devel] [PULL v3 28/35] block: Add bdrv_subtree_drained_begin/end()
-From: Sergio Lopez <slp@redhat.com>
+bdrv_drained_begin() waits for the completion of requests in the whole
 subtree, but it only actually keeps its immediate bs parameter quiesced
 until bdrv_drained_end().
-While child_job_drained_begin() calls to job_pause(), the job doesn't
+Add a version that keeps the whole subtree drained. As of this commit,
-actually transition between states until it runs again and reaches a
+graph changes cannot be allowed during a subtree drained section, but
-pause point. This means bdrv_drained_begin() may return with some jobs
+this will be fixed soon.
 using the node still having 'busy == true'.
-As a consequence, block_job_detach_aio_context() may get into a
-deadlock, waiting for the job to be actually paused, while the coroutine
-servicing the job is yielding and doesn't get the opportunity to get
-scheduled again. This situation can be reproduced by issuing a
-'block-commit' immediately followed by a 'device_del'.
-To ensure bdrv_drained_begin() only returns when the jobs have been
-paused, we change mirror_drained_poll() to only confirm it's quiesced
-when job->paused == true and there aren't any in-flight requests, except
-if we reached that point by a drained section initiated by the
-mirror/commit job itself.
-The other block jobs shouldn't need any changes, as the default
-drained_poll() behavior is to only confirm it's quiesced if the job is
-not busy or completed.
-Signed-off-by: Sergio Lopez <slp@redhat.com>
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
 ---
- block/mirror.c | 16 ++++++++++++++++
+ include/block/block.h | 13 +++++++++++++
-file changed, 16 insertions(+)
+ block/io.c            | 54 ++++++++++++++++++++++++++++++++++++++++-----------
 files changed, 56 insertions(+), 11 deletions(-)
-diff --git a/block/mirror.c b/block/mirror.c
+diff --git a/include/block/block.h b/include/block/block.h
 index XXXXXXX..XXXXXXX 100644
---- a/block/mirror.c
+--- a/include/block/block.h
-+++ b/block/mirror.c
++++ b/include/block/block.h
-@@ -XXX,XX +XXX,XX @@ typedef struct MirrorBlockJob {
+@@ -XXX,XX +XXX,XX @@ void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore);
-     bool initial_zeroing_ongoing;
+ void bdrv_drained_begin(BlockDriverState *bs);
-     int in_active_write_counter;
-     bool prepared;
+ /**
-+    bool in_drain;
++ * Like bdrv_drained_begin, but recursively begins a quiesced section for
- } MirrorBlockJob;
++ * exclusive access to all child nodes as well.
++ *
- typedef struct MirrorBDSOpaque {
++ * Graph changes are not allowed during a subtree drain section.
-@@ -XXX,XX +XXX,XX @@ static int mirror_exit_common(Job *job)
++ */
++void bdrv_subtree_drained_begin(BlockDriverState *bs);
-         /* The mirror job has no requests in flight any more, but we need to
++
-          * drain potential other users of the BDS before changing the graph. */
++/**
-+        assert(s->in_drain);
+  * bdrv_drained_end:
-         bdrv_drained_begin(target_bs);
+  *
-         bdrv_replace_node(to_replace, target_bs, &local_err);
+  * End a quiescent section started by bdrv_drained_begin().
-         bdrv_drained_end(target_bs);
+  */
-@@ -XXX,XX +XXX,XX @@ static int mirror_exit_common(Job *job)
+ void bdrv_drained_end(BlockDriverState *bs);
-     bs_opaque->job = NULL;
++/**
-     bdrv_drained_end(src);
++ * End a quiescent section started by bdrv_subtree_drained_begin().
-+    s->in_drain = false;
++ */
-     bdrv_unref(mirror_top_bs);
++void bdrv_subtree_drained_end(BlockDriverState *bs);
-     bdrv_unref(src);
++
+ void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
-@@ -XXX,XX +XXX,XX @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
+                     Error **errp);
-              */
+ void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
-             trace_mirror_before_drain(s, cnt);
+diff --git a/block/io.c b/block/io.c
+index XXXXXXX..XXXXXXX 100644
-+            s->in_drain = true;
+--- a/block/io.c
-             bdrv_drained_begin(bs);
++++ b/block/io.c
-             cnt = bdrv_get_dirty_count(s->dirty_bitmap);
+@@ -XXX,XX +XXX,XX @@ typedef struct {
-             if (cnt > 0 || mirror_flush(s) < 0) {
+     BlockDriverState *bs;
-                 bdrv_drained_end(bs);
+     bool done;
-+                s->in_drain = false;
+     bool begin;
-                 continue;
++    bool recursive;
-             }
+     BdrvChild *parent;
+ } BdrvCoDrainData;
-@@ -XXX,XX +XXX,XX @@ immediate_exit:
-     bdrv_dirty_iter_free(s->dbi);
+@@ -XXX,XX +XXX,XX @@ static bool bdrv_drain_recurse(BlockDriverState *bs)
+     return waited;
-     if (need_drain) {
+ }
-+        s->in_drain = true;
-         bdrv_drained_begin(bs);
+-static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent);
 -static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent);
 +static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
 +                                  BdrvChild *parent);
 +static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
 +                                BdrvChild *parent);
  static void bdrv_co_drain_bh_cb(void *opaque)
  {
@@ -XXX,XX +XXX,XX @@ static void bdrv_co_drain_bh_cb(void *opaque)
      bdrv_dec_in_flight(bs);
      if (data->begin) {
 -        bdrv_do_drained_begin(bs, data->parent);
 +        bdrv_do_drained_begin(bs, data->recursive, data->parent);
      } else {
 -        bdrv_do_drained_end(bs, data->parent);
 +        bdrv_do_drained_end(bs, data->recursive, data->parent);
      }
-@@ -XXX,XX +XXX,XX @@ static void coroutine_fn mirror_pause(Job *job)
+     data->done = true;
- static bool mirror_drained_poll(BlockJob *job)
+@@ -XXX,XX +XXX,XX @@ static void bdrv_co_drain_bh_cb(void *opaque)
  }
  static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
 -                                                bool begin, BdrvChild *parent)
 +                                                bool begin, bool recursive,
 +                                                BdrvChild *parent)
  {
-     MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
+     BdrvCoDrainData data;
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
          .bs = bs,
          .done = false,
          .begin = begin,
 +        .recursive = recursive,
          .parent = parent,
      };
      bdrv_inc_in_flight(bs);
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
      assert(data.done);
  }
 -static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent)
 +static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
 +                                  BdrvChild *parent)
  {
 +    BdrvChild *child, *next;
 +
-+    /* If the job isn't paused nor cancelled, we can't be sure that it won't
+     if (qemu_in_coroutine()) {
-+     * issue more requests. We make an exception if we've reached this point
+-        bdrv_co_yield_to_drain(bs, true, parent);
-+     * from one of our own drain sections, to avoid a deadlock waiting for
++        bdrv_co_yield_to_drain(bs, true, recursive, parent);
-+     * ourselves.
+         return;
-+     */
+     }
-+    if (!s->common.job.paused && !s->common.job.cancelled && !s->in_drain) {
-+        return true;
+@@ -XXX,XX +XXX,XX @@ static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent)
      bdrv_parent_drained_begin(bs, parent);
      bdrv_drain_invoke(bs, true, false);
      bdrv_drain_recurse(bs);
 +
 +    if (recursive) {
 +        QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
 +            bdrv_do_drained_begin(child->bs, true, child);
 +        }
 +    }
+ }
+ void bdrv_drained_begin(BlockDriverState *bs)
+ {
+-    bdrv_do_drained_begin(bs, NULL);
++    bdrv_do_drained_begin(bs, false, NULL);
++}
 +
-     return !!s->in_flight;
++void bdrv_subtree_drained_begin(BlockDriverState *bs)
 +{
 +    bdrv_do_drained_begin(bs, true, NULL);
  }
+-static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent)
++static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
++                                BdrvChild *parent)
+ {
++    BdrvChild *child, *next;
+     int old_quiesce_counter;
+     if (qemu_in_coroutine()) {
+-        bdrv_co_yield_to_drain(bs, false, parent);
++        bdrv_co_yield_to_drain(bs, false, recursive, parent);
+         return;
+     }
+     assert(bs->quiesce_counter > 0);
+@@ -XXX,XX +XXX,XX @@ static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent)
+     if (old_quiesce_counter == 1) {
+         aio_enable_external(bdrv_get_aio_context(bs));
+     }
++
++    if (recursive) {
++        QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
++            bdrv_do_drained_end(child->bs, true, child);
++        }
++    }
+ }
+ void bdrv_drained_end(BlockDriverState *bs)
+ {
+-    bdrv_do_drained_end(bs, NULL);
++    bdrv_do_drained_end(bs, false, NULL);
++}
++
++void bdrv_subtree_drained_end(BlockDriverState *bs)
++{
++    bdrv_do_drained_end(bs, true, NULL);
+ }
+ /*
 --
-.20.1
+.13.6

-New patch
+[Qemu-devel] [PULL v3 29/35] test-bdrv-drain: Tests for bdrv_subtree_drain
+Add a subtree drain version to the existing test cases.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ tests/test-bdrv-drain.c | 27 ++++++++++++++++++++++++++-
+file changed, 26 insertions(+), 1 deletion(-)
+diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
+index XXXXXXX..XXXXXXX 100644
+--- a/tests/test-bdrv-drain.c
++++ b/tests/test-bdrv-drain.c
+@@ -XXX,XX +XXX,XX @@ static void aio_ret_cb(void *opaque, int ret)
+ enum drain_type {
+     BDRV_DRAIN_ALL,
+     BDRV_DRAIN,
++    BDRV_SUBTREE_DRAIN,
+     DRAIN_TYPE_MAX,
+ };
+@@ -XXX,XX +XXX,XX @@ static void do_drain_begin(enum drain_type drain_type, BlockDriverState *bs)
+     switch (drain_type) {
+     case BDRV_DRAIN_ALL:        bdrv_drain_all_begin(); break;
+     case BDRV_DRAIN:            bdrv_drained_begin(bs); break;
++    case BDRV_SUBTREE_DRAIN:    bdrv_subtree_drained_begin(bs); break;
+     default:                    g_assert_not_reached();
+     }
+ }
+@@ -XXX,XX +XXX,XX @@ static void do_drain_end(enum drain_type drain_type, BlockDriverState *bs)
+     switch (drain_type) {
+     case BDRV_DRAIN_ALL:        bdrv_drain_all_end(); break;
+     case BDRV_DRAIN:            bdrv_drained_end(bs); break;
++    case BDRV_SUBTREE_DRAIN:    bdrv_subtree_drained_end(bs); break;
+     default:                    g_assert_not_reached();
+     }
+ }
+@@ -XXX,XX +XXX,XX @@ static void test_drv_cb_drain(void)
+     test_drv_cb_common(BDRV_DRAIN, false);
+ }
++static void test_drv_cb_drain_subtree(void)
++{
++    test_drv_cb_common(BDRV_SUBTREE_DRAIN, true);
++}
++
+ static void test_quiesce_common(enum drain_type drain_type, bool recursive)
+ {
+     BlockBackend *blk;
+@@ -XXX,XX +XXX,XX @@ static void test_quiesce_drain(void)
+     test_quiesce_common(BDRV_DRAIN, false);
+ }
++static void test_quiesce_drain_subtree(void)
++{
++    test_quiesce_common(BDRV_SUBTREE_DRAIN, true);
++}
++
+ static void test_nested(void)
+ {
+     BlockBackend *blk;
+@@ -XXX,XX +XXX,XX @@ static void test_nested(void)
+             /* XXX bdrv_drain_all() doesn't increase the quiesce_counter */
+             int bs_quiesce      = (outer != BDRV_DRAIN_ALL) +
+                                   (inner != BDRV_DRAIN_ALL);
+-            int backing_quiesce = 0;
++            int backing_quiesce = (outer == BDRV_SUBTREE_DRAIN) +
++                                  (inner == BDRV_SUBTREE_DRAIN);
+             int backing_cb_cnt  = (outer != BDRV_DRAIN) +
+                                   (inner != BDRV_DRAIN);
+@@ -XXX,XX +XXX,XX @@ static void test_blockjob_drain(void)
+     test_blockjob_common(BDRV_DRAIN);
+ }
++static void test_blockjob_drain_subtree(void)
++{
++    test_blockjob_common(BDRV_SUBTREE_DRAIN);
++}
++
+ int main(int argc, char **argv)
+ {
+     bdrv_init();
+@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
+     g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all);
+     g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain);
++    g_test_add_func("/bdrv-drain/driver-cb/drain_subtree",
++                    test_drv_cb_drain_subtree);
+     g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all);
+     g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain);
++    g_test_add_func("/bdrv-drain/quiesce/drain_subtree",
++                    test_quiesce_drain_subtree);
+     g_test_add_func("/bdrv-drain/nested", test_nested);
+     g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
+     g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain);
++    g_test_add_func("/bdrv-drain/blockjob/drain_subtree",
++                    test_blockjob_drain_subtree);
+     return g_test_run();
+ }
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 30/35] test-bdrv-drain: Test behaviour in coroutine context
+If bdrv_do_drained_begin/end() are called in coroutine context, they
+first use a BH to get out of the coroutine context. Call some existing
+tests again from a coroutine to cover this code path.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ tests/test-bdrv-drain.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++
+file changed, 59 insertions(+)
+diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
+index XXXXXXX..XXXXXXX 100644
+--- a/tests/test-bdrv-drain.c
++++ b/tests/test-bdrv-drain.c
+@@ -XXX,XX +XXX,XX @@ static void aio_ret_cb(void *opaque, int ret)
+     *aio_ret = ret;
+ }
++typedef struct CallInCoroutineData {
++    void (*entry)(void);
++    bool done;
++} CallInCoroutineData;
++
++static coroutine_fn void call_in_coroutine_entry(void *opaque)
++{
++    CallInCoroutineData *data = opaque;
++
++    data->entry();
++    data->done = true;
++}
++
++static void call_in_coroutine(void (*entry)(void))
++{
++    Coroutine *co;
++    CallInCoroutineData data = {
++        .entry  = entry,
++        .done   = false,
++    };
++
++    co = qemu_coroutine_create(call_in_coroutine_entry, &data);
++    qemu_coroutine_enter(co);
++    while (!data.done) {
++        aio_poll(qemu_get_aio_context(), true);
++    }
++}
++
+ enum drain_type {
+     BDRV_DRAIN_ALL,
+     BDRV_DRAIN,
+@@ -XXX,XX +XXX,XX @@ static void test_drv_cb_drain_subtree(void)
+     test_drv_cb_common(BDRV_SUBTREE_DRAIN, true);
+ }
++static void test_drv_cb_co_drain(void)
++{
++    call_in_coroutine(test_drv_cb_drain);
++}
++
++static void test_drv_cb_co_drain_subtree(void)
++{
++    call_in_coroutine(test_drv_cb_drain_subtree);
++}
++
+ static void test_quiesce_common(enum drain_type drain_type, bool recursive)
+ {
+     BlockBackend *blk;
+@@ -XXX,XX +XXX,XX @@ static void test_quiesce_drain_subtree(void)
+     test_quiesce_common(BDRV_SUBTREE_DRAIN, true);
+ }
++static void test_quiesce_co_drain(void)
++{
++    call_in_coroutine(test_quiesce_drain);
++}
++
++static void test_quiesce_co_drain_subtree(void)
++{
++    call_in_coroutine(test_quiesce_drain_subtree);
++}
++
+ static void test_nested(void)
+ {
+     BlockBackend *blk;
+@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
+     g_test_add_func("/bdrv-drain/driver-cb/drain_subtree",
+                     test_drv_cb_drain_subtree);
++    // XXX bdrv_drain_all() doesn't work in coroutine context
++    g_test_add_func("/bdrv-drain/driver-cb/co/drain", test_drv_cb_co_drain);
++    g_test_add_func("/bdrv-drain/driver-cb/co/drain_subtree",
++                    test_drv_cb_co_drain_subtree);
++
++
+     g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all);
+     g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain);
+     g_test_add_func("/bdrv-drain/quiesce/drain_subtree",
+                     test_quiesce_drain_subtree);
++    // XXX bdrv_drain_all() doesn't work in coroutine context
++    g_test_add_func("/bdrv-drain/quiesce/co/drain", test_quiesce_co_drain);
++    g_test_add_func("/bdrv-drain/quiesce/co/drain_subtree",
++                    test_quiesce_co_drain_subtree);
++
+     g_test_add_func("/bdrv-drain/nested", test_nested);
+     g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 31/35] test-bdrv-drain: Recursive draining with multiple parents
+Test that drain sections are correctly propagated through the graph.
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+---
+ tests/test-bdrv-drain.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++
+file changed, 74 insertions(+)
+diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
+index XXXXXXX..XXXXXXX 100644
+--- a/tests/test-bdrv-drain.c
++++ b/tests/test-bdrv-drain.c
+@@ -XXX,XX +XXX,XX @@ static void test_nested(void)
+     blk_unref(blk);
+ }
++static void test_multiparent(void)
++{
++    BlockBackend *blk_a, *blk_b;
++    BlockDriverState *bs_a, *bs_b, *backing;
++    BDRVTestState *a_s, *b_s, *backing_s;
++
++    blk_a = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
++    bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR,
++                                &error_abort);
++    a_s = bs_a->opaque;
++    blk_insert_bs(blk_a, bs_a, &error_abort);
++
++    blk_b = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
++    bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR,
++                                &error_abort);
++    b_s = bs_b->opaque;
++    blk_insert_bs(blk_b, bs_b, &error_abort);
++
++    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort);
++    backing_s = backing->opaque;
++    bdrv_set_backing_hd(bs_a, backing, &error_abort);
++    bdrv_set_backing_hd(bs_b, backing, &error_abort);
++
++    g_assert_cmpint(bs_a->quiesce_counter, ==, 0);
++    g_assert_cmpint(bs_b->quiesce_counter, ==, 0);
++    g_assert_cmpint(backing->quiesce_counter, ==, 0);
++    g_assert_cmpint(a_s->drain_count, ==, 0);
++    g_assert_cmpint(b_s->drain_count, ==, 0);
++    g_assert_cmpint(backing_s->drain_count, ==, 0);
++
++    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a);
++
++    g_assert_cmpint(bs_a->quiesce_counter, ==, 1);
++    g_assert_cmpint(bs_b->quiesce_counter, ==, 1);
++    g_assert_cmpint(backing->quiesce_counter, ==, 1);
++    g_assert_cmpint(a_s->drain_count, ==, 1);
++    g_assert_cmpint(b_s->drain_count, ==, 1);
++    g_assert_cmpint(backing_s->drain_count, ==, 1);
++
++    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b);
++
++    g_assert_cmpint(bs_a->quiesce_counter, ==, 2);
++    g_assert_cmpint(bs_b->quiesce_counter, ==, 2);
++    g_assert_cmpint(backing->quiesce_counter, ==, 2);
++    g_assert_cmpint(a_s->drain_count, ==, 2);
++    g_assert_cmpint(b_s->drain_count, ==, 2);
++    g_assert_cmpint(backing_s->drain_count, ==, 2);
++
++    do_drain_end(BDRV_SUBTREE_DRAIN, bs_b);
++
++    g_assert_cmpint(bs_a->quiesce_counter, ==, 1);
++    g_assert_cmpint(bs_b->quiesce_counter, ==, 1);
++    g_assert_cmpint(backing->quiesce_counter, ==, 1);
++    g_assert_cmpint(a_s->drain_count, ==, 1);
++    g_assert_cmpint(b_s->drain_count, ==, 1);
++    g_assert_cmpint(backing_s->drain_count, ==, 1);
++
++    do_drain_end(BDRV_SUBTREE_DRAIN, bs_a);
++
++    g_assert_cmpint(bs_a->quiesce_counter, ==, 0);
++    g_assert_cmpint(bs_b->quiesce_counter, ==, 0);
++    g_assert_cmpint(backing->quiesce_counter, ==, 0);
++    g_assert_cmpint(a_s->drain_count, ==, 0);
++    g_assert_cmpint(b_s->drain_count, ==, 0);
++    g_assert_cmpint(backing_s->drain_count, ==, 0);
++
++    bdrv_unref(backing);
++    bdrv_unref(bs_a);
++    bdrv_unref(bs_b);
++    blk_unref(blk_a);
++    blk_unref(blk_b);
++}
++
+ typedef struct TestBlockJob {
+     BlockJob common;
+@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
+                     test_quiesce_co_drain_subtree);
+     g_test_add_func("/bdrv-drain/nested", test_nested);
++    g_test_add_func("/bdrv-drain/multiparent", test_multiparent);
+     g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
+     g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain);
+--
+.13.6

-New patch
+[Qemu-devel] [PULL v3 32/35] block: Allow graph changes in subtree drained section
+We need to remember how many of the drain sections in which a node is
 were recursive (i.e. subtree drain rather than node drain), so that they
 can be correctly applied when children are added or removed during the
 drained section.
 With this change, it is safe to modify the graph even inside a
 bdrv_subtree_drained_begin/end() section.
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
 ---
  include/block/block.h     |  2 --
  include/block/block_int.h |  5 +++++
  block.c                   | 32 +++++++++++++++++++++++++++++---
  block/io.c                | 28 ++++++++++++++++++++++++----
 files changed, 58 insertions(+), 9 deletions(-)
 diff --git a/include/block/block.h b/include/block/block.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/block/block.h
 +++ b/include/block/block.h
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs);
  /**
   * Like bdrv_drained_begin, but recursively begins a quiesced section for
   * exclusive access to all child nodes as well.
 - *
 - * Graph changes are not allowed during a subtree drain section.
   */
  void bdrv_subtree_drained_begin(BlockDriverState *bs);
 diff --git a/include/block/block_int.h b/include/block/block_int.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/block/block_int.h
 +++ b/include/block/block_int.h
@@ -XXX,XX +XXX,XX @@ struct BlockDriverState {
      /* Accessed with atomic ops.  */
      int quiesce_counter;
 +    int recursive_quiesce_counter;
 +
      unsigned int write_gen;               /* Current data generation */
      /* Protected by reqs_lock.  */
@@ -XXX,XX +XXX,XX @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
      int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
      BdrvRequestFlags flags);
 +void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent);
 +void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent);
 +
  int get_tmp_filename(char *filename, int size);
  BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
                              const char *filename);
 diff --git a/block.c b/block.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block.c
 +++ b/block.c
@@ -XXX,XX +XXX,XX @@ static void bdrv_child_cb_drained_end(BdrvChild *child)
      bdrv_drained_end(bs);
  }
 +static void bdrv_child_cb_attach(BdrvChild *child)
 +{
 +    BlockDriverState *bs = child->opaque;
 +    bdrv_apply_subtree_drain(child, bs);
 +}
 +
 +static void bdrv_child_cb_detach(BdrvChild *child)
 +{
 +    BlockDriverState *bs = child->opaque;
 +    bdrv_unapply_subtree_drain(child, bs);
 +}
 +
  static int bdrv_child_cb_inactivate(BdrvChild *child)
  {
      BlockDriverState *bs = child->opaque;
@@ -XXX,XX +XXX,XX @@ const BdrvChildRole child_file = {
      .inherit_options = bdrv_inherited_options,
      .drained_begin   = bdrv_child_cb_drained_begin,
      .drained_end     = bdrv_child_cb_drained_end,
 +    .attach          = bdrv_child_cb_attach,
 +    .detach          = bdrv_child_cb_detach,
      .inactivate      = bdrv_child_cb_inactivate,
  };
@@ -XXX,XX +XXX,XX @@ const BdrvChildRole child_format = {
      .inherit_options = bdrv_inherited_fmt_options,
      .drained_begin   = bdrv_child_cb_drained_begin,
      .drained_end     = bdrv_child_cb_drained_end,
 +    .attach          = bdrv_child_cb_attach,
 +    .detach          = bdrv_child_cb_detach,
      .inactivate      = bdrv_child_cb_inactivate,
  };
@@ -XXX,XX +XXX,XX @@ static void bdrv_backing_attach(BdrvChild *c)
                      parent->backing_blocker);
      bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET,
                      parent->backing_blocker);
 +
 +    bdrv_child_cb_attach(c);
  }
  static void bdrv_backing_detach(BdrvChild *c)
@@ -XXX,XX +XXX,XX @@ static void bdrv_backing_detach(BdrvChild *c)
      bdrv_op_unblock_all(c->bs, parent->backing_blocker);
      error_free(parent->backing_blocker);
      parent->backing_blocker = NULL;
 +
 +    bdrv_child_cb_detach(c);
  }
  /*
@@ -XXX,XX +XXX,XX @@ static void bdrv_replace_child_noperm(BdrvChild *child,
          assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
      }
      if (old_bs) {
 +        /* Detach first so that the recursive drain sections coming from @child
 +         * are already gone and we only end the drain sections that came from
 +         * elsewhere. */
 +        if (child->role->detach) {
 +            child->role->detach(child);
 +        }
          if (old_bs->quiesce_counter && child->role->drained_end) {
              for (i = 0; i < old_bs->quiesce_counter; i++) {
                  child->role->drained_end(child);
              }
          }
 -        if (child->role->detach) {
 -            child->role->detach(child);
 -        }
          QLIST_REMOVE(child, next_parent);
      }
@@ -XXX,XX +XXX,XX @@ static void bdrv_replace_child_noperm(BdrvChild *child,
              }
          }
 +        /* Attach only after starting new drained sections, so that recursive
 +         * drain sections coming from @child don't get an extra .drained_begin
 +         * callback. */
          if (child->role->attach) {
              child->role->attach(child);
          }
 diff --git a/block/io.c b/block/io.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/io.c
 +++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
      assert(data.done);
  }
 -static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
 -                                  BdrvChild *parent)
 +void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
 +                           BdrvChild *parent)
  {
      BdrvChild *child, *next;
@@ -XXX,XX +XXX,XX @@ static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
      bdrv_drain_recurse(bs);
      if (recursive) {
 +        bs->recursive_quiesce_counter++;
          QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
              bdrv_do_drained_begin(child->bs, true, child);
          }
@@ -XXX,XX +XXX,XX @@ void bdrv_subtree_drained_begin(BlockDriverState *bs)
      bdrv_do_drained_begin(bs, true, NULL);
  }
 -static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
 -                                BdrvChild *parent)
 +void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
 +                         BdrvChild *parent)
  {
      BdrvChild *child, *next;
      int old_quiesce_counter;
@@ -XXX,XX +XXX,XX @@ static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
      }
      if (recursive) {
 +        bs->recursive_quiesce_counter--;
          QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
              bdrv_do_drained_end(child->bs, true, child);
          }
@@ -XXX,XX +XXX,XX @@ void bdrv_subtree_drained_end(BlockDriverState *bs)
      bdrv_do_drained_end(bs, true, NULL);
  }
 +void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent)
 +{
 +    int i;
 +
 +    for (i = 0; i < new_parent->recursive_quiesce_counter; i++) {
 +        bdrv_do_drained_begin(child->bs, true, child);
 +    }
 +}
 +
 +void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent)
 +{
 +    int i;
 +
 +    for (i = 0; i < old_parent->recursive_quiesce_counter; i++) {
 +        bdrv_do_drained_end(child->bs, true, child);
 +    }
 +}
 +
  /*
   * Wait for pending requests to complete on a single BlockDriverState subtree,
   * and suspend block driver's internal I/O until next request arrives.
 --
 .13.6

-[Qemu-devel] [PULL 12/12] qemu-iotests: Treat custom TEST_DIR in 051
+[Qemu-devel] [PULL v3 33/35] test-bdrv-drain: Test graph changes in drained section
-From: Lukáš Doktor <ldoktor@redhat.com>
-When custom TEST_DIR is specified the output includes it without leading
-'/':
-    $ TEST_DIR=/var/tmp ./check -file -qcow2 051
-    ....
--drive0 (NODE_NAME): json:{"backing": {"driver": "qcow2", "file":
-{"driver": "file", "filename": "TEST_DIR/t.qcow2"}}, "driver": "qcow2",
-"file": {"driver": "file", "filename": SNAPSHOT_PATH}} (qcow2,
-read-only)
-+drive0 (NODE_NAME): json:{"backing": {"driver": "qcow2", "file":
-{"driver": "file", "filename": "TEST_DIR/t.qcow2"}}, "driver": "qcow2",
-"file": {"driver": "file", "filename": "TEST_DIR/vl.ziHfeP"}} (qcow2,
-read-only)
-Let's remove it from the sed regexp.
-Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
 ---
- tests/qemu-iotests/051 | 2 +-
+ tests/test-bdrv-drain.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++
-file changed, 1 insertion(+), 1 deletion(-)
+file changed, 80 insertions(+)
-diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051
+diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
-index XXXXXXX..XXXXXXX 100755
+index XXXXXXX..XXXXXXX 100644
---- a/tests/qemu-iotests/051
+--- a/tests/test-bdrv-drain.c
-+++ b/tests/qemu-iotests/051
++++ b/tests/test-bdrv-drain.c
-@@ -XXX,XX +XXX,XX @@ TMPDIR=/nonexistent run_qemu -drive driver=null-co,snapshot=on
+@@ -XXX,XX +XXX,XX @@ static void test_multiparent(void)
- echo "info block" |
+     blk_unref(blk_b);
-     run_qemu -drive file="$TEST_IMG",snapshot=on,read-only=on,if=none,id=$device_id |
+ }
-     _filter_qemu_io |
--    sed -e 's#"/[^"]*/vl\.[A-Za-z0-9]\{6\}"#SNAPSHOT_PATH#g'
++static void test_graph_change(void)
-+    sed -e 's#"[^"]*/vl\.[A-Za-z0-9]\{6\}"#SNAPSHOT_PATH#g'
++{
++    BlockBackend *blk_a, *blk_b;
++    BlockDriverState *bs_a, *bs_b, *backing;
- # success, all done
++    BDRVTestState *a_s, *b_s, *backing_s;
 +
 +    blk_a = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
 +    bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR,
 +                                &error_abort);
 +    a_s = bs_a->opaque;
 +    blk_insert_bs(blk_a, bs_a, &error_abort);
 +
 +    blk_b = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
 +    bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR,
 +                                &error_abort);
 +    b_s = bs_b->opaque;
 +    blk_insert_bs(blk_b, bs_b, &error_abort);
 +
 +    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort);
 +    backing_s = backing->opaque;
 +    bdrv_set_backing_hd(bs_a, backing, &error_abort);
 +
 +    g_assert_cmpint(bs_a->quiesce_counter, ==, 0);
 +    g_assert_cmpint(bs_b->quiesce_counter, ==, 0);
 +    g_assert_cmpint(backing->quiesce_counter, ==, 0);
 +    g_assert_cmpint(a_s->drain_count, ==, 0);
 +    g_assert_cmpint(b_s->drain_count, ==, 0);
 +    g_assert_cmpint(backing_s->drain_count, ==, 0);
 +
 +    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a);
 +    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a);
 +    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a);
 +    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b);
 +    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b);
 +
 +    bdrv_set_backing_hd(bs_b, backing, &error_abort);
 +    g_assert_cmpint(bs_a->quiesce_counter, ==, 5);
 +    g_assert_cmpint(bs_b->quiesce_counter, ==, 5);
 +    g_assert_cmpint(backing->quiesce_counter, ==, 5);
 +    g_assert_cmpint(a_s->drain_count, ==, 5);
 +    g_assert_cmpint(b_s->drain_count, ==, 5);
 +    g_assert_cmpint(backing_s->drain_count, ==, 5);
 +
 +    bdrv_set_backing_hd(bs_b, NULL, &error_abort);
 +    g_assert_cmpint(bs_a->quiesce_counter, ==, 3);
 +    g_assert_cmpint(bs_b->quiesce_counter, ==, 2);
 +    g_assert_cmpint(backing->quiesce_counter, ==, 3);
 +    g_assert_cmpint(a_s->drain_count, ==, 3);
 +    g_assert_cmpint(b_s->drain_count, ==, 2);
 +    g_assert_cmpint(backing_s->drain_count, ==, 3);
 +
 +    bdrv_set_backing_hd(bs_b, backing, &error_abort);
 +    g_assert_cmpint(bs_a->quiesce_counter, ==, 5);
 +    g_assert_cmpint(bs_b->quiesce_counter, ==, 5);
 +    g_assert_cmpint(backing->quiesce_counter, ==, 5);
 +    g_assert_cmpint(a_s->drain_count, ==, 5);
 +    g_assert_cmpint(b_s->drain_count, ==, 5);
 +    g_assert_cmpint(backing_s->drain_count, ==, 5);
 +
 +    do_drain_end(BDRV_SUBTREE_DRAIN, bs_b);
 +    do_drain_end(BDRV_SUBTREE_DRAIN, bs_b);
 +    do_drain_end(BDRV_SUBTREE_DRAIN, bs_a);
 +    do_drain_end(BDRV_SUBTREE_DRAIN, bs_a);
 +    do_drain_end(BDRV_SUBTREE_DRAIN, bs_a);
 +
 +    g_assert_cmpint(bs_a->quiesce_counter, ==, 0);
 +    g_assert_cmpint(bs_b->quiesce_counter, ==, 0);
 +    g_assert_cmpint(backing->quiesce_counter, ==, 0);
 +    g_assert_cmpint(a_s->drain_count, ==, 0);
 +    g_assert_cmpint(b_s->drain_count, ==, 0);
 +    g_assert_cmpint(backing_s->drain_count, ==, 0);
 +
 +    bdrv_unref(backing);
 +    bdrv_unref(bs_a);
 +    bdrv_unref(bs_b);
 +    blk_unref(blk_a);
 +    blk_unref(blk_b);
 +}
 +
  typedef struct TestBlockJob {
      BlockJob common;
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
      g_test_add_func("/bdrv-drain/nested", test_nested);
      g_test_add_func("/bdrv-drain/multiparent", test_multiparent);
 +    g_test_add_func("/bdrv-drain/graph-change", test_graph_change);
      g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
      g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain);
 --
-.20.1
+.13.6

-New patch
+[Qemu-devel] [PULL v3 34/35] commit: Simplify reopen of base
+Since commit bde70715, base is the only node that is reopened in
+commit_start(). This means that the code, which still involves an
+explicit BlockReopenQueue, can now be simplified by using bdrv_reopen().
+Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Fam Zheng <famz@redhat.com>
+---
+ block/commit.c | 8 +-------
+file changed, 1 insertion(+), 7 deletions(-)
+diff --git a/block/commit.c b/block/commit.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/commit.c
++++ b/block/commit.c
+@@ -XXX,XX +XXX,XX @@ void commit_start(const char *job_id, BlockDriverState *bs,
+                   const char *filter_node_name, Error **errp)
+ {
+     CommitBlockJob *s;
+-    BlockReopenQueue *reopen_queue = NULL;
+     int orig_base_flags;
+     BlockDriverState *iter;
+     BlockDriverState *commit_top_bs = NULL;
+@@ -XXX,XX +XXX,XX @@ void commit_start(const char *job_id, BlockDriverState *bs,
+     /* convert base to r/w, if necessary */
+     orig_base_flags = bdrv_get_flags(base);
+     if (!(orig_base_flags & BDRV_O_RDWR)) {
+-        reopen_queue = bdrv_reopen_queue(reopen_queue, base, NULL,
+-                                         orig_base_flags | BDRV_O_RDWR);
+-    }
+-
+-    if (reopen_queue) {
+-        bdrv_reopen_multiple(bdrv_get_aio_context(bs), reopen_queue, &local_err);
++        bdrv_reopen(base, orig_base_flags | BDRV_O_RDWR, &local_err);
+         if (local_err != NULL) {
+             error_propagate(errp, local_err);
+             goto fail;
+--
+.13.6

-[Qemu-devel] [PULL 10/12] block: Make bdrv_{copy_on_read, crypto_luks, replication} static
+[Qemu-devel] [PULL v3 35/35] block: Keep nodes drained between reopen_queue/multiple
-From: Alberto Garcia <berto@igalia.com>
+The bdrv_reopen*() implementation doesn't like it if the graph is
 changed between queuing nodes for reopen and actually reopening them
 (one of the reasons is that queuing can be recursive).
-Signed-off-by: Alberto Garcia <berto@igalia.com>
+So instead of draining the device only in bdrv_reopen_multiple(),
 require that callers already drained all affected nodes, and assert this
 in bdrv_reopen_queue().
 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Fam Zheng <famz@redhat.com>
 ---
- block/copy-on-read.c | 2 +-
+ block.c             | 23 ++++++++++++++++-------
- block/crypto.c       | 2 +-
+ block/replication.c |  6 ++++++
- block/replication.c  | 2 +-
+ qemu-io-cmds.c      |  3 +++
-files changed, 3 insertions(+), 3 deletions(-)
+files changed, 25 insertions(+), 7 deletions(-)
-diff --git a/block/copy-on-read.c b/block/copy-on-read.c
+diff --git a/block.c b/block.c
 index XXXXXXX..XXXXXXX 100644
---- a/block/copy-on-read.c
+--- a/block.c
-+++ b/block/copy-on-read.c
++++ b/block.c
-@@ -XXX,XX +XXX,XX @@ static bool cor_recurse_is_first_non_filter(BlockDriverState *bs,
+@@ -XXX,XX +XXX,XX @@ BlockDriverState *bdrv_open(const char *filename, const char *reference,
   * returns a pointer to bs_queue, which is either the newly allocated
   * bs_queue, or the existing bs_queue being used.
   *
 + * bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
   */
  static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
                                                   BlockDriverState *bs,
@@ -XXX,XX +XXX,XX @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
      BdrvChild *child;
      QDict *old_options, *explicit_options;
 +    /* Make sure that the caller remembered to use a drained section. This is
 +     * important to avoid graph changes between the recursive queuing here and
 +     * bdrv_reopen_multiple(). */
 +    assert(bs->quiesce_counter > 0);
 +
      if (bs_queue == NULL) {
          bs_queue = g_new0(BlockReopenQueue, 1);
          QSIMPLEQ_INIT(bs_queue);
@@ -XXX,XX +XXX,XX @@ BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
   * If all devices prepare successfully, then the changes are committed
   * to all devices.
   *
 + * All affected nodes must be drained between bdrv_reopen_queue() and
 + * bdrv_reopen_multiple().
   */
  int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp)
  {
@@ -XXX,XX +XXX,XX @@ int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **er
      assert(bs_queue != NULL);
 -    aio_context_release(ctx);
 -    bdrv_drain_all_begin();
 -    aio_context_acquire(ctx);
 -
      QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
 +        assert(bs_entry->state.bs->quiesce_counter > 0);
          if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) {
              error_propagate(errp, local_err);
              goto cleanup;
@@ -XXX,XX +XXX,XX @@ cleanup:
      }
      g_free(bs_queue);
 -    bdrv_drain_all_end();
 -
      return ret;
  }
+@@ -XXX,XX +XXX,XX @@ int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp)
--BlockDriver bdrv_copy_on_read = {
+ {
-+static BlockDriver bdrv_copy_on_read = {
+     int ret = -1;
-     .format_name                        = "copy-on-read",
+     Error *local_err = NULL;
+-    BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags);
-     .bdrv_open                          = cor_open,
++    BlockReopenQueue *queue;
-diff --git a/block/crypto.c b/block/crypto.c
-index XXXXXXX..XXXXXXX 100644
++    bdrv_subtree_drained_begin(bs);
---- a/block/crypto.c
++
-+++ b/block/crypto.c
++    queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags);
-@@ -XXX,XX +XXX,XX @@ static const char *const block_crypto_strong_runtime_opts[] = {
+     ret = bdrv_reopen_multiple(bdrv_get_aio_context(bs), queue, &local_err);
-     NULL
+     if (local_err != NULL) {
- };
+         error_propagate(errp, local_err);
+     }
--BlockDriver bdrv_crypto_luks = {
++
-+static BlockDriver bdrv_crypto_luks = {
++    bdrv_subtree_drained_end(bs);
-     .format_name        = "luks",
++
-     .instance_size      = sizeof(BlockCrypto),
+     return ret;
-     .bdrv_probe         = block_crypto_probe_luks,
+ }
 diff --git a/block/replication.c b/block/replication.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/replication.c
 +++ b/block/replication.c
-@@ -XXX,XX +XXX,XX @@ static const char *const replication_strong_runtime_opts[] = {
+@@ -XXX,XX +XXX,XX @@ static void reopen_backing_file(BlockDriverState *bs, bool writable,
-     NULL
+         new_secondary_flags = s->orig_secondary_flags;
- };
+     }
--BlockDriver bdrv_replication = {
++    bdrv_subtree_drained_begin(s->hidden_disk->bs);
-+static BlockDriver bdrv_replication = {
++    bdrv_subtree_drained_begin(s->secondary_disk->bs);
-     .format_name                = "replication",
++
-     .instance_size              = sizeof(BDRVReplicationState),
+     if (orig_hidden_flags != new_hidden_flags) {
+         reopen_queue = bdrv_reopen_queue(reopen_queue, s->hidden_disk->bs, NULL,
                                           new_hidden_flags);
@@ -XXX,XX +XXX,XX @@ static void reopen_backing_file(BlockDriverState *bs, bool writable,
                               reopen_queue, &local_err);
          error_propagate(errp, local_err);
      }
 +
 +    bdrv_subtree_drained_end(s->hidden_disk->bs);
 +    bdrv_subtree_drained_end(s->secondary_disk->bs);
  }
  static void backup_job_cleanup(BlockDriverState *bs)
 diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
 index XXXXXXX..XXXXXXX 100644
 --- a/qemu-io-cmds.c
 +++ b/qemu-io-cmds.c
@@ -XXX,XX +XXX,XX @@ static int reopen_f(BlockBackend *blk, int argc, char **argv)
      opts = qopts ? qemu_opts_to_qdict(qopts, NULL) : NULL;
      qemu_opts_reset(&reopen_opts);
 +    bdrv_subtree_drained_begin(bs);
      brq = bdrv_reopen_queue(NULL, bs, opts, flags);
      bdrv_reopen_multiple(bdrv_get_aio_context(bs), brq, &local_err);
 +    bdrv_subtree_drained_end(bs);
 +
      if (local_err) {
          error_report_err(local_err);
      } else {
 --
-.20.1
+.13.6

The following changes since commit b98a66201dbc7cf3b962f4bb260f66100cc75578:

Merge remote-tracking branch 'remotes/palmer/tags/riscv-for-master-4.0-rc0-2' into staging (2019-03-19 12:55:02 +0000)

are available in the Git repository at:

git://repo.or.cz/qemu/kevin.git tags/for-upstream

for you to fetch changes up to 59fba0aaee7438002d9803a86c888f21a1070cc8:

qemu-iotests: Treat custom TEST_DIR in 051 (2019-03-19 15:51:31 +0100)

----------------------------------------------------------------
Block layer patches:

- mirror: Fix early return from drain (could cause deadlocks)
- vmdk: Fixed probing for version 3 images
- vl: Fix to create migration object before block backends again (fixes
  segfault for block drivers that set migration blockers)
- Several minor fixes, documentation and test case improvements

----------------------------------------------------------------
Alberto Garcia (1):
      block: Make bdrv_{copy_on_read,crypto_luks,replication} static

Kevin Wolf (3):
      qcow2: Fix data file error condition in qcow2_co_create()
      block: Silence Coverity in bdrv_drop_intermediate()
      qemu-iotests: Fix 232 for non-qcow2

Lukáš Doktor (1):
      qemu-iotests: Treat custom TEST_DIR in 051

Markus Armbruster (1):
      vl: Fix to create migration object before block backends again

Max Reitz (1):
      blockdev: Check @replaces in blockdev_mirror_common

Sam Eiderman (1):
      vmdk: Support version=3 in VMDK descriptor files

Sergio Lopez (2):
      mirror: Confirm we're quiesced only if the job is paused or cancelled
      iotests: 153: Wait for an answer to QMP commands

Vladimir Sementsov-Ogievskiy (2):
      qapi: fix block-latency-histogram-set description and examples
      blockjob: fix user pause in block_job_error_action

From: Sergio Lopez <slp@redhat.com>

While child_job_drained_begin() calls to job_pause(), the job doesn't
actually transition between states until it runs again and reaches a
pause point. This means bdrv_drained_begin() may return with some jobs
using the node still having 'busy == true'.

As a consequence, block_job_detach_aio_context() may get into a
deadlock, waiting for the job to be actually paused, while the coroutine
servicing the job is yielding and doesn't get the opportunity to get
scheduled again. This situation can be reproduced by issuing a
'block-commit' immediately followed by a 'device_del'.

To ensure bdrv_drained_begin() only returns when the jobs have been
paused, we change mirror_drained_poll() to only confirm it's quiesced
when job->paused == true and there aren't any in-flight requests, except
if we reached that point by a drained section initiated by the
mirror/commit job itself.

The other block jobs shouldn't need any changes, as the default
drained_poll() behavior is to only confirm it's quiesced if the job is
not busy or completed.

Signed-off-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/mirror.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/block/mirror.c b/block/mirror.c
index XXXXXXX..XXXXXXX 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -XXX,XX +XXX,XX @@ typedef struct MirrorBlockJob {
     bool initial_zeroing_ongoing;
     int in_active_write_counter;
     bool prepared;
+    bool in_drain;
 } MirrorBlockJob;
 
 typedef struct MirrorBDSOpaque {
@@ -XXX,XX +XXX,XX @@ static int mirror_exit_common(Job *job)
 
         /* The mirror job has no requests in flight any more, but we need to
          * drain potential other users of the BDS before changing the graph. */
+        assert(s->in_drain);
         bdrv_drained_begin(target_bs);
         bdrv_replace_node(to_replace, target_bs, &local_err);
         bdrv_drained_end(target_bs);
@@ -XXX,XX +XXX,XX @@ static int mirror_exit_common(Job *job)
     bs_opaque->job = NULL;
 
     bdrv_drained_end(src);
+    s->in_drain = false;
     bdrv_unref(mirror_top_bs);
     bdrv_unref(src);
 
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
              */
             trace_mirror_before_drain(s, cnt);
 
+            s->in_drain = true;
             bdrv_drained_begin(bs);
             cnt = bdrv_get_dirty_count(s->dirty_bitmap);
             if (cnt > 0 || mirror_flush(s) < 0) {
                 bdrv_drained_end(bs);
+                s->in_drain = false;
                 continue;
             }
 
@@ -XXX,XX +XXX,XX @@ immediate_exit:
     bdrv_dirty_iter_free(s->dbi);
 
     if (need_drain) {
+        s->in_drain = true;
         bdrv_drained_begin(bs);
     }
 
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn mirror_pause(Job *job)
 static bool mirror_drained_poll(BlockJob *job)
 {
     MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
+
+    /* If the job isn't paused nor cancelled, we can't be sure that it won't
+     * issue more requests. We make an exception if we've reached this point
+     * from one of our own drain sections, to avoid a deadlock waiting for
+     * ourselves.
+     */
+    if (!s->common.job.paused && !s->common.job.cancelled && !s->in_drain) {
+        return true;
+    }
+
     return !!s->in_flight;
 }
 
-- 
2.20.1

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

There no @device parameter, only the @id one.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qapi/block-core.json | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index XXXXXXX..XXXXXXX 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -XXX,XX +XXX,XX @@
 #
 # Manage read, write and flush latency histograms for the device.
 #
-# If only @device parameter is specified, remove all present latency histograms
+# If only @id parameter is specified, remove all present latency histograms
 # for the device. Otherwise, add/reset some of (or all) latency histograms.
 #
 # @id: The name or QOM path of the guest device.
@@ -XXX,XX +XXX,XX @@
 # [0, 10), [10, 50), [50, 100), [100, +inf):
 #
 # -> { "execute": "block-latency-histogram-set",
-#      "arguments": { "device": "drive0",
+#      "arguments": { "id": "drive0",
 #                     "boundaries": [10, 50, 100] } }
 # <- { "return": {} }
 #
@@ -XXX,XX +XXX,XX @@
 # not changed (or not created):
 #
 # -> { "execute": "block-latency-histogram-set",
-#      "arguments": { "device": "drive0",
+#      "arguments": { "id": "drive0",
 #                     "boundaries-write": [10, 50, 100] } }
 # <- { "return": {} }
 #
@@ -XXX,XX +XXX,XX @@
 #   write: [0, 1000), [1000, 5000), [5000, +inf)
 #
 # -> { "execute": "block-latency-histogram-set",
-#      "arguments": { "device": "drive0",
+#      "arguments": { "id": "drive0",
 #                     "boundaries": [10, 50, 100],
 #                     "boundaries-write": [1000, 5000] } }
 # <- { "return": {} }
@@ -XXX,XX +XXX,XX @@
 # Example: remove all latency histograms:
 #
 # -> { "execute": "block-latency-histogram-set",
-#      "arguments": { "device": "drive0" } }
+#      "arguments": { "id": "drive0" } }
 # <- { "return": {} }
 ##
 { 'command': 'block-latency-histogram-set',
-- 
2.20.1

From: Sam Eiderman <shmuel.eiderman@oracle.com>

Commit 509d39aa22909c0ed1aabf896865f19c81fb38a1 added support for read
only VMDKs of version 3.

This commit fixes the probe function to correctly handle descriptors of
version 3.

This commit has two effects:
    1. We no longer need to supply '-f vmdk' when pointing to descriptor
       files of version 3 in qemu/qemu-img command line arguments.
    2. This fixes the scenario where a VMDK points to a parent version 3
       descriptor file which is being probed as "raw" instead of "vmdk".

Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com>
Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Signed-off-by: Shmuel Eiderman <shmuel.eiderman@oracle.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/vmdk.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/block/vmdk.c b/block/vmdk.c
index XXXXXXX..XXXXXXX 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -XXX,XX +XXX,XX @@ static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
             }
             if (end - p >= strlen("version=X\n")) {
                 if (strncmp("version=1\n", p, strlen("version=1\n")) == 0 ||
-                    strncmp("version=2\n", p, strlen("version=2\n")) == 0) {
+                    strncmp("version=2\n", p, strlen("version=2\n")) == 0 ||
+                    strncmp("version=3\n", p, strlen("version=3\n")) == 0) {
                     return 100;
                 }
             }
             if (end - p >= strlen("version=X\r\n")) {
                 if (strncmp("version=1\r\n", p, strlen("version=1\r\n")) == 0 ||
-                    strncmp("version=2\r\n", p, strlen("version=2\r\n")) == 0) {
+                    strncmp("version=2\r\n", p, strlen("version=2\r\n")) == 0 ||
+                    strncmp("version=3\r\n", p, strlen("version=3\r\n")) == 0) {
                     return 100;
                 }
             }
-- 
2.20.1

Coverity doesn't like that the return value of bdrv_check_update_perm()
stays unused only in this place (CID 1399710).

Even if checking local_err should be equivalent to checking ret < 0,
let's switch to using the return value to be more consistent (and in
case of a bug somewhere down the call chain, forgetting to assign errp
is more likely than returning 0 for an error case).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
---
 block.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/block.c b/block.c
index XXXXXXX..XXXXXXX 100644
--- a/block.c
+++ b/block.c
@@ -XXX,XX +XXX,XX @@ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
     QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) {
         /* Check whether we are allowed to switch c from top to base */
         GSList *ignore_children = g_slist_prepend(NULL, c);
-        bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
-                               ignore_children, &local_err);
+        ret = bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
+                                     ignore_children, &local_err);
         g_slist_free(ignore_children);
-        if (local_err) {
-            ret = -EPERM;
+        if (ret < 0) {
             error_report_err(local_err);
             goto exit;
         }
-- 
2.20.1

From: Sergio Lopez <slp@redhat.com>

There are various actions in this test that must be executed
sequentially, as the result of it depends on the state triggered by the
previous one.

If the last argument of _send_qemu_cmd() is an empty string, it just
sends the QMP commands without waiting for an answer. While unlikely, it
may happen that the next action in the test gets invoked before QEMU
processes the QMP request.

This issue seems to be easier to reproduce on servers with limited
resources or highly loaded.

With this change, we wait for an answer on all _send_qemu_cmd() calls.

Signed-off-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/153     | 12 ++++++------
 tests/qemu-iotests/153.out |  6 ++++++
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/tests/qemu-iotests/153 b/tests/qemu-iotests/153
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/153
+++ b/tests/qemu-iotests/153
@@ -XXX,XX +XXX,XX @@ for opts1 in "" "read-only=on" "read-only=on,force-share=on"; do
             _img_info -U | grep 'file format'
         fi
     done
-    _send_qemu_cmd $h "{ 'execute': 'quit', }" ""
+    _send_qemu_cmd $h "{ 'execute': 'quit' }" ''
     echo
     echo "Round done"
     _cleanup_qemu
@@ -XXX,XX +XXX,XX @@ echo "Adding drive"
 _send_qemu_cmd $QEMU_HANDLE \
     "{ 'execute': 'human-monitor-command',
        'arguments': { 'command-line': 'drive_add 0 if=none,id=d0,file=${TEST_IMG}' } }" \
-    ""
+    'return'
 
 _run_cmd $QEMU_IO "${TEST_IMG}" -c 'write 0 512'
 
@@ -XXX,XX +XXX,XX @@ echo "== Closing an image should unlock it =="
 _send_qemu_cmd $QEMU_HANDLE \
     "{ 'execute': 'human-monitor-command',
        'arguments': { 'command-line': 'drive_del d0' } }" \
-    ""
+    'return'
 
 _run_cmd $QEMU_IO "${TEST_IMG}" -c 'write 0 512'
 
@@ -XXX,XX +XXX,XX @@ for d in d0 d1; do
     _send_qemu_cmd $QEMU_HANDLE \
         "{ 'execute': 'human-monitor-command',
            'arguments': { 'command-line': 'drive_add 0 if=none,id=$d,file=${TEST_IMG},readonly=on' } }" \
-        ""
+        'return'
 done
 
 _run_cmd $QEMU_IMG info "${TEST_IMG}"
@@ -XXX,XX +XXX,XX @@ _run_cmd $QEMU_IMG info "${TEST_IMG}"
 _send_qemu_cmd $QEMU_HANDLE \
     "{ 'execute': 'human-monitor-command',
        'arguments': { 'command-line': 'drive_del d0' } }" \
-    ""
+    'return'
 
 _run_cmd $QEMU_IO "${TEST_IMG}" -c 'write 0 512'
 
@@ -XXX,XX +XXX,XX @@ echo "Closing the other"
 _send_qemu_cmd $QEMU_HANDLE \
     "{ 'execute': 'human-monitor-command',
        'arguments': { 'command-line': 'drive_del d1' } }" \
-    ""
+    'return'
 
 _run_cmd $QEMU_IO "${TEST_IMG}" -c 'write 0 512'
 
diff --git a/tests/qemu-iotests/153.out b/tests/qemu-iotests/153.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/153.out
+++ b/tests/qemu-iotests/153.out
@@ -XXX,XX +XXX,XX @@ Is another process using the image [TEST_DIR/t.qcow2]?
 _qemu_img_wrapper commit -b TEST_DIR/t.qcow2.b TEST_DIR/t.qcow2.c
 {"return": {}}
 Adding drive
+{"return": "OKrn"}
 
 _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
 can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
@@ -XXX,XX +XXX,XX @@ Creating overlay with qemu-img when the guest is running should be allowed
 
 _qemu_img_wrapper create -f qcow2 -b TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.overlay
 == Closing an image should unlock it ==
+{"return": ""}
 
 _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
 Adding two and closing one
+{"return": "OKrn"}
+{"return": "OKrn"}
 
 _qemu_img_wrapper info TEST_DIR/t.qcow2
+{"return": ""}
 
 _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
 can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 Closing the other
+{"return": ""}
 
 _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
 
-- 
2.20.1

From: Markus Armbruster <armbru@redhat.com>

Recent commit cda4aa9a5a0 moved block backend creation before machine
property evaluation.  This broke qemu-iotests 055.  Turns out we need
to create the migration object before block backends, so block
backends can add migration blockers.  Fix by calling
migration_object_init() earlier, right before configure_blockdev().

Fixes: cda4aa9a5a08777cf13e164c0543bd4888b8adce
Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 vl.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/vl.c b/vl.c
index XXXXXXX..XXXXXXX 100644
--- a/vl.c
+++ b/vl.c
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
         exit(0);
     }
 
+    /*
+     * Migration object can only be created after global properties
+     * are applied correctly.
+     */
+    migration_object_init();
+
     /*
      * Note: we need to create block backends before
      * machine_set_property(), so machine properties can refer to
-     * them.
+     * them, and after migration_object_init(), so we can create
+     * migration blockers.
      */
     configure_blockdev(&bdo_queue, machine_class, snapshot);
 
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
                      machine_class->name, machine_class->deprecation_reason);
     }
 
-    /*
-     * Migration object can only be created after global properties
-     * are applied correctly.
-     */
-    migration_object_init();
-
     if (qtest_chrdev) {
         qtest_init(qtest_chrdev, qtest_log, &error_fatal);
     }
-- 
2.20.1

232 is marked as generic, but commit 12efe428c9e added code that assumes
qcow2. What the new test really needs is backing files and support for
updating the backing file link (.bdrv_change_backing_file).

Split the non-generic code into a new test case 247 and make it work
with qed, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/232     | 30 ---------------
 tests/qemu-iotests/232.out | 20 ----------
 tests/qemu-iotests/247     | 79 ++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/247.out | 22 +++++++++++
 tests/qemu-iotests/group   |  1 +
 5 files changed, 102 insertions(+), 50 deletions(-)
 create mode 100755 tests/qemu-iotests/247
 create mode 100644 tests/qemu-iotests/247.out

diff --git a/tests/qemu-iotests/232 b/tests/qemu-iotests/232
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/232
+++ b/tests/qemu-iotests/232
@@ -XXX,XX +XXX,XX @@ run_qemu_info_block -blockdev driver=file,filename="$TEST_IMG",node-name=node0,a
 run_qemu_info_block -blockdev driver=file,filename="$TEST_IMG",node-name=node0,auto-read-only=on
 run_qemu_info_block -blockdev driver=file,filename="$TEST_IMG",node-name=node0
 
-echo
-echo "=== Try commit to backing file with auto-read-only ==="
-echo
-
-TEST_IMG="$TEST_IMG.0" _make_test_img $size
-TEST_IMG="$TEST_IMG.1" _make_test_img $size
-TEST_IMG="$TEST_IMG.2" _make_test_img $size
-TEST_IMG="$TEST_IMG.3" _make_test_img $size
-TEST_IMG="$TEST_IMG.4" _make_test_img $size
-
-(cat <<EOF
-{"execute":"qmp_capabilities"}
-{"execute":"block-commit",
- "arguments":{"device":"format-4", "top-node": "format-2", "base-node":"format-0", "job-id":"job0"}}
-EOF
-sleep 1
-echo '{"execute":"quit"}'
-) | $QEMU -qmp stdio -nographic -nodefaults \
-    -blockdev file,node-name=file-0,filename=$TEST_IMG.0,auto-read-only=on \
-    -blockdev qcow2,node-name=format-0,file=file-0,read-only=on \
-    -blockdev file,node-name=file-1,filename=$TEST_IMG.1,auto-read-only=on \
-    -blockdev qcow2,node-name=format-1,file=file-1,read-only=on,backing=format-0 \
-    -blockdev file,node-name=file-2,filename=$TEST_IMG.2,auto-read-only=on \
-    -blockdev qcow2,node-name=format-2,file=file-2,read-only=on,backing=format-1 \
-    -blockdev file,node-name=file-3,filename=$TEST_IMG.3,auto-read-only=on \
-    -blockdev qcow2,node-name=format-3,file=file-3,read-only=on,backing=format-2 \
-    -blockdev file,node-name=file-4,filename=$TEST_IMG.4,auto-read-only=on \
-    -blockdev qcow2,node-name=format-4,file=file-4,read-only=on,backing=format-3 |
-    _filter_qmp
-
 # success, all done
 echo "*** done"
 rm -f $seq.full
diff --git a/tests/qemu-iotests/232.out b/tests/qemu-iotests/232.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/232.out
+++ b/tests/qemu-iotests/232.out
@@ -XXX,XX +XXX,XX @@ QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0,read
 QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0,auto-read-only=off: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
 node0: TEST_DIR/t.IMGFMT (file)
 QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
-
-=== Try commit to backing file with auto-read-only ===
-
-Formatting 'TEST_DIR/t.IMGFMT.0', fmt=IMGFMT size=134217728
-Formatting 'TEST_DIR/t.IMGFMT.1', fmt=IMGFMT size=134217728
-Formatting 'TEST_DIR/t.IMGFMT.2', fmt=IMGFMT size=134217728
-Formatting 'TEST_DIR/t.IMGFMT.3', fmt=IMGFMT size=134217728
-Formatting 'TEST_DIR/t.IMGFMT.4', fmt=IMGFMT size=134217728
-QMP_VERSION
-{"return": {}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "job0"}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "job0"}}
-{"return": {}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "waiting", "id": "job0"}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "pending", "id": "job0"}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "job0", "len": 134217728, "offset": 134217728, "speed": 0, "type": "commit"}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "concluded", "id": "job0"}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "null", "id": "job0"}}
-{"return": {}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}}
 *** done
diff --git a/tests/qemu-iotests/247 b/tests/qemu-iotests/247
new file mode 100755
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/tests/qemu-iotests/247
@@ -XXX,XX +XXX,XX @@
+#!/usr/bin/env bash
+#
+# Test for auto-read-only with commit block job
+#
+# Copyright (C) 2019 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# creator
+owner=kwolf@redhat.com
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+status=1	# failure is the default!
+
+_cleanup()
+{
+    _cleanup_test_img
+    rm -f $TEST_IMG.[01234]
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+# Requires backing files and .bdrv_change_backing_file support
+_supported_fmt qcow2 qed
+_supported_proto file
+_supported_os Linux
+
+size=128M
+
+echo
+echo "=== Try commit to backing file with auto-read-only ==="
+echo
+TEST_IMG="$TEST_IMG.0" _make_test_img $size
+TEST_IMG="$TEST_IMG.1" _make_test_img $size
+TEST_IMG="$TEST_IMG.2" _make_test_img $size
+TEST_IMG="$TEST_IMG.3" _make_test_img $size
+TEST_IMG="$TEST_IMG.4" _make_test_img $size
+
+(cat <<EOF
+{"execute":"qmp_capabilities"}
+{"execute":"block-commit",
+ "arguments":{"device":"format-4", "top-node": "format-2", "base-node":"format-0", "job-id":"job0"}}
+EOF
+sleep 1
+echo '{"execute":"quit"}'
+) | $QEMU -qmp stdio -nographic -nodefaults \
+    -blockdev file,node-name=file-0,filename=$TEST_IMG.0,auto-read-only=on \
+    -blockdev $IMGFMT,node-name=format-0,file=file-0,read-only=on \
+    -blockdev file,node-name=file-1,filename=$TEST_IMG.1,auto-read-only=on \
+    -blockdev $IMGFMT,node-name=format-1,file=file-1,read-only=on,backing=format-0 \
+    -blockdev file,node-name=file-2,filename=$TEST_IMG.2,auto-read-only=on \
+    -blockdev $IMGFMT,node-name=format-2,file=file-2,read-only=on,backing=format-1 \
+    -blockdev file,node-name=file-3,filename=$TEST_IMG.3,auto-read-only=on \
+    -blockdev $IMGFMT,node-name=format-3,file=file-3,read-only=on,backing=format-2 \
+    -blockdev file,node-name=file-4,filename=$TEST_IMG.4,auto-read-only=on \
+    -blockdev $IMGFMT,node-name=format-4,file=file-4,read-only=on,backing=format-3 |
+    _filter_qmp
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/247.out b/tests/qemu-iotests/247.out
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/tests/qemu-iotests/247.out
@@ -XXX,XX +XXX,XX @@
+QA output created by 247
+
+=== Try commit to backing file with auto-read-only ===
+
+Formatting 'TEST_DIR/t.IMGFMT.0', fmt=IMGFMT size=134217728
+Formatting 'TEST_DIR/t.IMGFMT.1', fmt=IMGFMT size=134217728
+Formatting 'TEST_DIR/t.IMGFMT.2', fmt=IMGFMT size=134217728
+Formatting 'TEST_DIR/t.IMGFMT.3', fmt=IMGFMT size=134217728
+Formatting 'TEST_DIR/t.IMGFMT.4', fmt=IMGFMT size=134217728
+QMP_VERSION
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "job0"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "job0"}}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "waiting", "id": "job0"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "pending", "id": "job0"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "job0", "len": 134217728, "offset": 134217728, "speed": 0, "type": "commit"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "concluded", "id": "job0"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "null", "id": "job0"}}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}}
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -XXX,XX +XXX,XX @@
 244 rw auto quick
 245 rw auto
 246 rw auto quick
+247 rw auto quick
-- 
2.20.1

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Job (especially mirror) may call block_job_error_action several
times before actual pause if it has several in-flight requests.

block_job_error_action will call job_pause more than once in this case,
which lead to following block-job-resume qmp command can't actually
resume the job.

Fix it by do not increase pause level in block_job_error_action if
user_paused already set.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 blockjob.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
                                         action);
     }
     if (action == BLOCK_ERROR_ACTION_STOP) {
-        job_pause(&job->job);
-        /* make the pause user visible, which will be resumed from QMP. */
-        job->job.user_paused = true;
+        if (!job->job.user_paused) {
+            job_pause(&job->job);
+            /* make the pause user visible, which will be resumed from QMP. */
+            job->job.user_paused = true;
+        }
         block_job_iostatus_set_err(job, error);
     }
     return action;
-- 
2.20.1

From: Alberto Garcia <berto@igalia.com>

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/copy-on-read.c | 2 +-
 block/crypto.c       | 2 +-
 block/replication.c  | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index XXXXXXX..XXXXXXX 100644
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -XXX,XX +XXX,XX @@ static bool cor_recurse_is_first_non_filter(BlockDriverState *bs,
 }
 
 
-BlockDriver bdrv_copy_on_read = {
+static BlockDriver bdrv_copy_on_read = {
     .format_name                        = "copy-on-read",
 
     .bdrv_open                          = cor_open,
diff --git a/block/crypto.c b/block/crypto.c
index XXXXXXX..XXXXXXX 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -XXX,XX +XXX,XX @@ static const char *const block_crypto_strong_runtime_opts[] = {
     NULL
 };
 
-BlockDriver bdrv_crypto_luks = {
+static BlockDriver bdrv_crypto_luks = {
     .format_name        = "luks",
     .instance_size      = sizeof(BlockCrypto),
     .bdrv_probe         = block_crypto_probe_luks,
diff --git a/block/replication.c b/block/replication.c
index XXXXXXX..XXXXXXX 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -XXX,XX +XXX,XX @@ static const char *const replication_strong_runtime_opts[] = {
     NULL
 };
 
-BlockDriver bdrv_replication = {
+static BlockDriver bdrv_replication = {
     .format_name                = "replication",
     .instance_size              = sizeof(BDRVReplicationState),
 
-- 
2.20.1

From: Max Reitz <mreitz@redhat.com>

There is no reason why the constraints we put on @replaces should be
limited to drive-mirror.  Therefore, move the sanity checks from
qmp_drive_mirror() to blockdev_mirror_common() so they apply to
blockdev-mirror as well.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 blockdev.c | 55 ++++++++++++++++++++++++++++++++----------------------
 1 file changed, 33 insertions(+), 22 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index XXXXXXX..XXXXXXX 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -XXX,XX +XXX,XX @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
         sync = MIRROR_SYNC_MODE_FULL;
     }
 
+    if (has_replaces) {
+        BlockDriverState *to_replace_bs;
+        AioContext *replace_aio_context;
+        int64_t bs_size, replace_size;
+
+        bs_size = bdrv_getlength(bs);
+        if (bs_size < 0) {
+            error_setg_errno(errp, -bs_size, "Failed to query device's size");
+            return;
+        }
+
+        to_replace_bs = check_to_replace_node(bs, replaces, errp);
+        if (!to_replace_bs) {
+            return;
+        }
+
+        replace_aio_context = bdrv_get_aio_context(to_replace_bs);
+        aio_context_acquire(replace_aio_context);
+        replace_size = bdrv_getlength(to_replace_bs);
+        aio_context_release(replace_aio_context);
+
+        if (replace_size < 0) {
+            error_setg_errno(errp, -replace_size,
+                             "Failed to query the replacement node's size");
+            return;
+        }
+        if (bs_size != replace_size) {
+            error_setg(errp, "cannot replace image with a mirror image of "
+                             "different size");
+            return;
+        }
+    }
+
     /* pass the node name to replace to mirror start since it's loose coupling
      * and will allow to check whether the node still exist at mirror completion
      */
@@ -XXX,XX +XXX,XX @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp)
     }
 
     if (arg->has_replaces) {
-        BlockDriverState *to_replace_bs;
-        AioContext *replace_aio_context;
-        int64_t replace_size;
-
         if (!arg->has_node_name) {
             error_setg(errp, "a node-name must be provided when replacing a"
                              " named node of the graph");
             goto out;
         }
-
-        to_replace_bs = check_to_replace_node(bs, arg->replaces, &local_err);
-
-        if (!to_replace_bs) {
-            error_propagate(errp, local_err);
-            goto out;
-        }
-
-        replace_aio_context = bdrv_get_aio_context(to_replace_bs);
-        aio_context_acquire(replace_aio_context);
-        replace_size = bdrv_getlength(to_replace_bs);
-        aio_context_release(replace_aio_context);
-
-        if (size != replace_size) {
-            error_setg(errp, "cannot replace image with a mirror image of "
-                             "different size");
-            goto out;
-        }
     }
 
     if (arg->mode == NEW_IMAGE_MODE_ABSOLUTE_PATHS) {
-- 
2.20.1

From: Lukáš Doktor <ldoktor@redhat.com>

When custom TEST_DIR is specified the output includes it without leading
'/':

$ TEST_DIR=/var/tmp ./check -file -qcow2 051
    ....
-drive0 (NODE_NAME): json:{"backing": {"driver": "qcow2", "file":
{"driver": "file", "filename": "TEST_DIR/t.qcow2"}}, "driver": "qcow2",
"file": {"driver": "file", "filename": SNAPSHOT_PATH}} (qcow2,
read-only)
+drive0 (NODE_NAME): json:{"backing": {"driver": "qcow2", "file":
{"driver": "file", "filename": "TEST_DIR/t.qcow2"}}, "driver": "qcow2",
"file": {"driver": "file", "filename": "TEST_DIR/vl.ziHfeP"}} (qcow2,
read-only)

Let's remove it from the sed regexp.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/051 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/051
+++ b/tests/qemu-iotests/051
@@ -XXX,XX +XXX,XX @@ TMPDIR=/nonexistent run_qemu -drive driver=null-co,snapshot=on
 echo "info block" |
     run_qemu -drive file="$TEST_IMG",snapshot=on,read-only=on,if=none,id=$device_id |
     _filter_qemu_io |
-    sed -e 's#"/[^"]*/vl\.[A-Za-z0-9]\{6\}"#SNAPSHOT_PATH#g'
+    sed -e 's#"[^"]*/vl\.[A-Za-z0-9]\{6\}"#SNAPSHOT_PATH#g'
 
 
 # success, all done
-- 
2.20.1

The following changes since commit 281f327487c9c9b1599f93c589a408bbf4a651b8:

Merge remote-tracking branch 'remotes/vivier/tags/m68k-for-2.12-pull-request' into staging (2017-12-22 00:11:36 +0000)

are available in the git repository at:

git://repo.or.cz/qemu/kevin.git tags/for-upstream

for you to fetch changes up to 1a63a907507fbbcfaee3f622907ec244b7eabda8:

block: Keep nodes drained between reopen_queue/multiple (2017-12-22 15:05:32 +0100)

----------------------------------------------------------------
Block layer patches

----------------------------------------------------------------
Doug Gale (1):
      nvme: Add tracing

Edgar Kaziakhmedov (1):
      qcow2: get rid of qcow2_backing_read1 routine

Fam Zheng (2):
      block: Open backing image in force share mode for size probe
      block: Remove unused bdrv_requests_pending

John Snow (1):
      iotests: fix 197 for vpc

Kevin Wolf (27):
      block: Formats don't need CONSISTENT_READ with NO_IO
      block: Make bdrv_drain_invoke() recursive
      block: Call .drain_begin only once in bdrv_drain_all_begin()
      test-bdrv-drain: Test BlockDriver callbacks for drain
      block: bdrv_drain_recurse(): Remove unused begin parameter
      block: Don't wait for requests in bdrv_drain*_end()
      block: Unify order in drain functions
      block: Don't acquire AioContext in hmp_qemu_io()
      block: Document that x-blockdev-change breaks quorum children list
      block: Assert drain_all is only called from main AioContext
      block: Make bdrv_drain() driver callbacks non-recursive
      test-bdrv-drain: Test callback for bdrv_drain
      test-bdrv-drain: Test bs->quiesce_counter
      blockjob: Pause job on draining any job BDS
      test-bdrv-drain: Test drain vs. block jobs
      block: Don't block_job_pause_all() in bdrv_drain_all()
      block: Nested drain_end must still call callbacks
      test-bdrv-drain: Test nested drain sections
      block: Don't notify parents in drain call chain
      block: Add bdrv_subtree_drained_begin/end()
      test-bdrv-drain: Tests for bdrv_subtree_drain
      test-bdrv-drain: Test behaviour in coroutine context
      test-bdrv-drain: Recursive draining with multiple parents
      block: Allow graph changes in subtree drained section
      test-bdrv-drain: Test graph changes in drained section
      commit: Simplify reopen of base
      block: Keep nodes drained between reopen_queue/multiple

Thomas Huth (3):
      block: Remove the obsolete -drive boot=on|off parameter
      block: Remove the deprecated -hdachs option
      block: Mention -drive cyls/heads/secs/trans/serial/addr in deprecation chapter

Commit 1f4ad7d fixed 'qemu-img info' for raw images that are currently
in use as a mirror target. It is not enough for image formats, though,
as these still unconditionally request BLK_PERM_CONSISTENT_READ.

As this permission is geared towards whether the guest-visible data is
consistent, and has no impact on whether the metadata is sane, and
'qemu-img info' does not read guest-visible data (except for the raw
format), it makes sense to not require BLK_PERM_CONSISTENT_READ if there
is not going to be any guest I/O performed, regardless of image format.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/block.c b/block.c
index XXXXXXX..XXXXXXX 100644
--- a/block.c
+++ b/block.c
@@ -XXX,XX +XXX,XX @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
     assert(role == &child_backing || role == &child_file);
 
     if (!backing) {
+        int flags = bdrv_reopen_get_flags(reopen_queue, bs);
+
         /* Apart from the modifications below, the same permissions are
          * forwarded and left alone as for filters */
         bdrv_filter_default_perms(bs, c, role, reopen_queue, perm, shared,
@@ -XXX,XX +XXX,XX @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
 
         /* bs->file always needs to be consistent because of the metadata. We
          * can never allow other users to resize or write to it. */
-        perm |= BLK_PERM_CONSISTENT_READ;
+        if (!(flags & BDRV_O_NO_IO)) {
+            perm |= BLK_PERM_CONSISTENT_READ;
+        }
         shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
     } else {
         /* We want consistent read from backing files if the parent needs it.
-- 
2.13.6

From: John Snow <jsnow@redhat.com>

VPC has some difficulty creating geometries of particular size.
However, we can indeed force it to use a literal one, so let's
do that for the sake of test 197, which is testing some specific
offsets.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Lukáš Doktor <ldoktor@redhat.com>
---
 tests/qemu-iotests/197           | 4 ++++
 tests/qemu-iotests/common.filter | 3 ++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/tests/qemu-iotests/197 b/tests/qemu-iotests/197
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/197
+++ b/tests/qemu-iotests/197
@@ -XXX,XX +XXX,XX @@ echo '=== Copy-on-read ==='
 echo
 
 # Prep the images
+# VPC rounds image sizes to a specific geometry, force a specific size.
+if [ "$IMGFMT" = "vpc" ]; then
+    IMGOPTS=$(_optstr_add "$IMGOPTS" "force_size")
+fi
 _make_test_img 4G
 $QEMU_IO -c "write -P 55 3G 1k" "$TEST_IMG" | _filter_qemu_io
 IMGPROTO=file IMGFMT=qcow2 IMGOPTS= TEST_IMG_FILE="$TEST_WRAP" \
diff --git a/tests/qemu-iotests/common.filter b/tests/qemu-iotests/common.filter
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/common.filter
+++ b/tests/qemu-iotests/common.filter
@@ -XXX,XX +XXX,XX @@ _filter_img_create()
         -e "s# log_size=[0-9]\\+##g" \
         -e "s# refcount_bits=[0-9]\\+##g" \
         -e "s# key-secret=[a-zA-Z0-9]\\+##g" \
-        -e "s# iter-time=[0-9]\\+##g"
+        -e "s# iter-time=[0-9]\\+##g" \
+        -e "s# force_size=\$on\\|off\$##g"
 }
 
 _filter_img_info()
-- 
2.13.6

This change separates bdrv_drain_invoke(), which calls the BlockDriver
drain callbacks, from bdrv_drain_recurse(). Instead, the function
performs its own recursion now.

One reason for this is that bdrv_drain_recurse() can be called multiple
times by bdrv_drain_all_begin(), but the callbacks may only be called
once. The separation is necessary to fix this bug.

The other reason is that we intend to go to a model where we call all
driver callbacks first, and only then start polling. This is not fully
achieved yet with this patch, as bdrv_drain_invoke() contains a
BDRV_POLL_WHILE() loop for the block driver callbacks, which can still
call callbacks for any unrelated event. It's a step in this direction
anyway.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
     bdrv_wakeup(bs);
 }
 
+/* Recursively call BlockDriver.bdrv_co_drain_begin/end callbacks */
 static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
 {
+    BdrvChild *child, *tmp;
     BdrvCoDrainData data = { .bs = bs, .done = false, .begin = begin};
 
     if (!bs->drv || (begin && !bs->drv->bdrv_co_drain_begin) ||
@@ -XXX,XX +XXX,XX @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
     data.co = qemu_coroutine_create(bdrv_drain_invoke_entry, &data);
     bdrv_coroutine_enter(bs, data.co);
     BDRV_POLL_WHILE(bs, !data.done);
+
+    QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {
+        bdrv_drain_invoke(child->bs, begin);
+    }
 }
 
 static bool bdrv_drain_recurse(BlockDriverState *bs, bool begin)
@@ -XXX,XX +XXX,XX @@ static bool bdrv_drain_recurse(BlockDriverState *bs, bool begin)
     BdrvChild *child, *tmp;
     bool waited;
 
-    /* Ensure any pending metadata writes are submitted to bs->file.  */
-    bdrv_drain_invoke(bs, begin);
-
     /* Wait for drained requests to finish */
     waited = BDRV_POLL_WHILE(bs, atomic_read(&bs->in_flight) > 0);
 
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs)
         bdrv_parent_drained_begin(bs);
     }
 
+    bdrv_drain_invoke(bs, true);
     bdrv_drain_recurse(bs, true);
 }
 
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
     }
 
     bdrv_parent_drained_end(bs);
+    bdrv_drain_invoke(bs, false);
     bdrv_drain_recurse(bs, false);
     aio_enable_external(bdrv_get_aio_context(bs));
 }
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
             aio_context_acquire(aio_context);
             for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
                 if (aio_context == bdrv_get_aio_context(bs)) {
+                    /* FIXME Calling this multiple times is wrong */
+                    bdrv_drain_invoke(bs, true);
                     waited |= bdrv_drain_recurse(bs, true);
                 }
             }
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
         aio_context_acquire(aio_context);
         aio_enable_external(aio_context);
         bdrv_parent_drained_end(bs);
+        bdrv_drain_invoke(bs, false);
         bdrv_drain_recurse(bs, false);
         aio_context_release(aio_context);
     }
-- 
2.13.6

bdrv_drain_all_begin() used to call the .bdrv_co_drain_begin() driver
callback inside its polling loop. This means that how many times it got
called for each node depended on long it had to poll the event loop.

This is obviously not right and results in nodes that stay drained even
after bdrv_drain_all_end(), which calls .bdrv_co_drain_begin() once per
node.

Fix bdrv_drain_all_begin() to call the callback only once, too.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
         aio_context_acquire(aio_context);
         bdrv_parent_drained_begin(bs);
         aio_disable_external(aio_context);
+        bdrv_drain_invoke(bs, true);
         aio_context_release(aio_context);
 
         if (!g_slist_find(aio_ctxs, aio_context)) {
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
             aio_context_acquire(aio_context);
             for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
                 if (aio_context == bdrv_get_aio_context(bs)) {
-                    /* FIXME Calling this multiple times is wrong */
-                    bdrv_drain_invoke(bs, true);
                     waited |= bdrv_drain_recurse(bs, true);
                 }
             }
-- 
2.13.6

This adds a test case that the BlockDriver callbacks for drain are
called in bdrv_drained_all_begin/end(), and that both of them are called
exactly once.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 tests/test-bdrv-drain.c | 137 ++++++++++++++++++++++++++++++++++++++++++++++++
 tests/Makefile.include  |   2 +
 2 files changed, 139 insertions(+)
 create mode 100644 tests/test-bdrv-drain.c

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/tests/test-bdrv-drain.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Block node draining tests
+ *
+ * Copyright (c) 2017 Kevin Wolf <kwolf@redhat.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "block/block.h"
+#include "sysemu/block-backend.h"
+#include "qapi/error.h"
+
+typedef struct BDRVTestState {
+    int drain_count;
+} BDRVTestState;
+
+static void coroutine_fn bdrv_test_co_drain_begin(BlockDriverState *bs)
+{
+    BDRVTestState *s = bs->opaque;
+    s->drain_count++;
+}
+
+static void coroutine_fn bdrv_test_co_drain_end(BlockDriverState *bs)
+{
+    BDRVTestState *s = bs->opaque;
+    s->drain_count--;
+}
+
+static void bdrv_test_close(BlockDriverState *bs)
+{
+    BDRVTestState *s = bs->opaque;
+    g_assert_cmpint(s->drain_count, >, 0);
+}
+
+static int coroutine_fn bdrv_test_co_preadv(BlockDriverState *bs,
+                                            uint64_t offset, uint64_t bytes,
+                                            QEMUIOVector *qiov, int flags)
+{
+    /* We want this request to stay until the polling loop in drain waits for
+     * it to complete. We need to sleep a while as bdrv_drain_invoke() comes
+     * first and polls its result, too, but it shouldn't accidentally complete
+     * this request yet. */
+    qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000);
+
+    return 0;
+}
+
+static BlockDriver bdrv_test = {
+    .format_name            = "test",
+    .instance_size          = sizeof(BDRVTestState),
+
+    .bdrv_close             = bdrv_test_close,
+    .bdrv_co_preadv         = bdrv_test_co_preadv,
+
+    .bdrv_co_drain_begin    = bdrv_test_co_drain_begin,
+    .bdrv_co_drain_end      = bdrv_test_co_drain_end,
+};
+
+static void aio_ret_cb(void *opaque, int ret)
+{
+    int *aio_ret = opaque;
+    *aio_ret = ret;
+}
+
+static void test_drv_cb_drain_all(void)
+{
+    BlockBackend *blk;
+    BlockDriverState *bs;
+    BDRVTestState *s;
+    BlockAIOCB *acb;
+    int aio_ret;
+
+    QEMUIOVector qiov;
+    struct iovec iov = {
+        .iov_base = NULL,
+        .iov_len = 0,
+    };
+    qemu_iovec_init_external(&qiov, &iov, 1);
+
+    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
+                              &error_abort);
+    s = bs->opaque;
+    blk_insert_bs(blk, bs, &error_abort);
+
+    /* Simple bdrv_drain_all_begin/end pair, check that CBs are called */
+    g_assert_cmpint(s->drain_count, ==, 0);
+    bdrv_drain_all_begin();
+    g_assert_cmpint(s->drain_count, ==, 1);
+    bdrv_drain_all_end();
+    g_assert_cmpint(s->drain_count, ==, 0);
+
+    /* Now do the same while a request is pending */
+    aio_ret = -EINPROGRESS;
+    acb = blk_aio_preadv(blk, 0, &qiov, 0, aio_ret_cb, &aio_ret);
+    g_assert(acb != NULL);
+    g_assert_cmpint(aio_ret, ==, -EINPROGRESS);
+
+    g_assert_cmpint(s->drain_count, ==, 0);
+    bdrv_drain_all_begin();
+    g_assert_cmpint(aio_ret, ==, 0);
+    g_assert_cmpint(s->drain_count, ==, 1);
+    bdrv_drain_all_end();
+    g_assert_cmpint(s->drain_count, ==, 0);
+
+    bdrv_unref(bs);
+    blk_unref(blk);
+}
+
+int main(int argc, char **argv)
+{
+    bdrv_init();
+    qemu_init_main_loop(&error_abort);
+
+    g_test_init(&argc, &argv, NULL);
+
+    g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all);
+
+    return g_test_run();
+}
diff --git a/tests/Makefile.include b/tests/Makefile.include
index XXXXXXX..XXXXXXX 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -XXX,XX +XXX,XX @@ gcov-files-test-thread-pool-y = thread-pool.c
 gcov-files-test-hbitmap-y = util/hbitmap.c
 check-unit-y += tests/test-hbitmap$(EXESUF)
 gcov-files-test-hbitmap-y = blockjob.c
+check-unit-y += tests/test-bdrv-drain$(EXESUF)
 check-unit-y += tests/test-blockjob$(EXESUF)
 check-unit-y += tests/test-blockjob-txn$(EXESUF)
 check-unit-y += tests/test-x86-cpuid$(EXESUF)
@@ -XXX,XX +XXX,XX @@ tests/test-coroutine$(EXESUF): tests/test-coroutine.o $(test-block-obj-y)
 tests/test-aio$(EXESUF): tests/test-aio.o $(test-block-obj-y)
 tests/test-aio-multithread$(EXESUF): tests/test-aio-multithread.o $(test-block-obj-y)
 tests/test-throttle$(EXESUF): tests/test-throttle.o $(test-block-obj-y)
+tests/test-bdrv-drain$(EXESUF): tests/test-bdrv-drain.o $(test-block-obj-y) $(test-util-obj-y)
 tests/test-blockjob$(EXESUF): tests/test-blockjob.o $(test-block-obj-y) $(test-util-obj-y)
 tests/test-blockjob-txn$(EXESUF): tests/test-blockjob-txn.o $(test-block-obj-y) $(test-util-obj-y)
 tests/test-thread-pool$(EXESUF): tests/test-thread-pool.o $(test-block-obj-y)
-- 
2.13.6

Now that the bdrv_drain_invoke() calls are pulled up to the callers of
bdrv_drain_recurse(), the 'begin' parameter isn't needed any more.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
     }
 }
 
-static bool bdrv_drain_recurse(BlockDriverState *bs, bool begin)
+static bool bdrv_drain_recurse(BlockDriverState *bs)
 {
     BdrvChild *child, *tmp;
     bool waited;
@@ -XXX,XX +XXX,XX @@ static bool bdrv_drain_recurse(BlockDriverState *bs, bool begin)
              */
             bdrv_ref(bs);
         }
-        waited |= bdrv_drain_recurse(bs, begin);
+        waited |= bdrv_drain_recurse(bs);
         if (in_main_loop) {
             bdrv_unref(bs);
         }
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs)
     }
 
     bdrv_drain_invoke(bs, true);
-    bdrv_drain_recurse(bs, true);
+    bdrv_drain_recurse(bs);
 }
 
 void bdrv_drained_end(BlockDriverState *bs)
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
 
     bdrv_parent_drained_end(bs);
     bdrv_drain_invoke(bs, false);
-    bdrv_drain_recurse(bs, false);
+    bdrv_drain_recurse(bs);
     aio_enable_external(bdrv_get_aio_context(bs));
 }
 
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
             aio_context_acquire(aio_context);
             for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
                 if (aio_context == bdrv_get_aio_context(bs)) {
-                    waited |= bdrv_drain_recurse(bs, true);
+                    waited |= bdrv_drain_recurse(bs);
                 }
             }
             aio_context_release(aio_context);
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
         aio_enable_external(aio_context);
         bdrv_parent_drained_end(bs);
         bdrv_drain_invoke(bs, false);
-        bdrv_drain_recurse(bs, false);
+        bdrv_drain_recurse(bs);
         aio_context_release(aio_context);
     }
 
-- 
2.13.6

The device is drained, so there is no point in waiting for requests at
the end of the drained section. Remove the bdrv_drain_recurse() calls
there.

The bdrv_drain_recurse() calls were introduced in commit 481cad48e5e
in order to call the .bdrv_co_drain_end() driver callback. This is now
done by a separate bdrv_drain_invoke() call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
 
     bdrv_parent_drained_end(bs);
     bdrv_drain_invoke(bs, false);
-    bdrv_drain_recurse(bs);
     aio_enable_external(bdrv_get_aio_context(bs));
 }
 
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
         aio_enable_external(aio_context);
         bdrv_parent_drained_end(bs);
         bdrv_drain_invoke(bs, false);
-        bdrv_drain_recurse(bs);
         aio_context_release(aio_context);
     }
 
-- 
2.13.6

Drain requests are propagated to child nodes, parent nodes and directly
to the AioContext. The order in which this happened was different
between all combinations of drain/drain_all and begin/end.

The correct order is to keep children only drained when their parents
are also drained. This means that at the start of a drained section, the
AioContext needs to be drained first, the parents second and only then
the children. The correct order for the end of a drained section is the
opposite.

This patch changes the three other functions to follow the example of
bdrv_drained_begin(), which is the only one that got it right.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs)
         return;
     }
 
+    /* Stop things in parent-to-child order */
     if (atomic_fetch_inc(&bs->quiesce_counter) == 0) {
         aio_disable_external(bdrv_get_aio_context(bs));
         bdrv_parent_drained_begin(bs);
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
         return;
     }
 
-    bdrv_parent_drained_end(bs);
+    /* Re-enable things in child-to-parent order */
     bdrv_drain_invoke(bs, false);
+    bdrv_parent_drained_end(bs);
     aio_enable_external(bdrv_get_aio_context(bs));
 }
 
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
         AioContext *aio_context = bdrv_get_aio_context(bs);
 
+        /* Stop things in parent-to-child order */
         aio_context_acquire(aio_context);
-        bdrv_parent_drained_begin(bs);
         aio_disable_external(aio_context);
+        bdrv_parent_drained_begin(bs);
         bdrv_drain_invoke(bs, true);
         aio_context_release(aio_context);
 
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
         AioContext *aio_context = bdrv_get_aio_context(bs);
 
+        /* Re-enable things in child-to-parent order */
         aio_context_acquire(aio_context);
-        aio_enable_external(aio_context);
-        bdrv_parent_drained_end(bs);
         bdrv_drain_invoke(bs, false);
+        bdrv_parent_drained_end(bs);
+        aio_enable_external(aio_context);
         aio_context_release(aio_context);
     }
 
-- 
2.13.6

Commit 15afd94a047 added code to acquire and release the AioContext in
qemuio_command(). This means that the lock is taken twice now in the
call path from hmp_qemu_io(). This causes BDRV_POLL_WHILE() to hang for
any requests issued to nodes in a non-mainloop AioContext.

Dropping the first locking from hmp_qemu_io() fixes the problem.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hmp.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/hmp.c b/hmp.c
index XXXXXXX..XXXXXXX 100644
--- a/hmp.c
+++ b/hmp.c
@@ -XXX,XX +XXX,XX @@ void hmp_qemu_io(Monitor *mon, const QDict *qdict)
 {
     BlockBackend *blk;
     BlockBackend *local_blk = NULL;
-    AioContext *aio_context;
     const char* device = qdict_get_str(qdict, "device");
     const char* command = qdict_get_str(qdict, "command");
     Error *err = NULL;
@@ -XXX,XX +XXX,XX @@ void hmp_qemu_io(Monitor *mon, const QDict *qdict)
         }
     }
 
-    aio_context = blk_get_aio_context(blk);
-    aio_context_acquire(aio_context);
-
     /*
      * Notably absent: Proper permission management. This is sad, but it seems
      * almost impossible to achieve without changing the semantics and thereby
@@ -XXX,XX +XXX,XX @@ void hmp_qemu_io(Monitor *mon, const QDict *qdict)
      */
     qemuio_command(blk, command);
 
-    aio_context_release(aio_context);
-
 fail:
     blk_unref(local_blk);
     hmp_handle_error(mon, &err);
-- 
2.13.6

From: Edgar Kaziakhmedov <edgar.kaziakhmedov@virtuozzo.com>

Since bdrv_co_preadv does all neccessary checks including
reading after the end of the backing file, avoid duplication
of verification before bdrv_co_preadv call.

Signed-off-by: Edgar Kaziakhmedov <edgar.kaziakhmedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.h |  3 ---
 block/qcow2.c | 51 ++++++++-------------------------------------------
 2 files changed, 8 insertions(+), 46 deletions(-)

diff --git a/block/qcow2.h b/block/qcow2.h
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -XXX,XX +XXX,XX @@ uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
 }
 
 /* qcow2.c functions */
-int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
-                  int64_t sector_num, int nb_sectors);
-
 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
                                      int refcount_order, bool generous_increase,
                                      uint64_t *refblock_count);
diff --git a/block/qcow2.c b/block/qcow2.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -XXX,XX +XXX,XX @@ static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs,
     return status;
 }
 
-/* handle reading after the end of the backing file */
-int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
-                        int64_t offset, int bytes)
-{
-    uint64_t bs_size = bs->total_sectors * BDRV_SECTOR_SIZE;
-    int n1;
-
-    if ((offset + bytes) <= bs_size) {
-        return bytes;
-    }
-
-    if (offset >= bs_size) {
-        n1 = 0;
-    } else {
-        n1 = bs_size - offset;
-    }
-
-    qemu_iovec_memset(qiov, n1, 0, bytes - n1);
-
-    return n1;
-}
-
 static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
                                         uint64_t bytes, QEMUIOVector *qiov,
                                         int flags)
 {
     BDRVQcow2State *s = bs->opaque;
-    int offset_in_cluster, n1;
+    int offset_in_cluster;
     int ret;
     unsigned int cur_bytes; /* number of bytes in current iteration */
     uint64_t cluster_offset = 0;
@@ -XXX,XX +XXX,XX @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
         case QCOW2_CLUSTER_UNALLOCATED:
 
             if (bs->backing) {
-                /* read from the base image */
-                n1 = qcow2_backing_read1(bs->backing->bs, &hd_qiov,
-                                         offset, cur_bytes);
-                if (n1 > 0) {
-                    QEMUIOVector local_qiov;
-
-                    qemu_iovec_init(&local_qiov, hd_qiov.niov);
-                    qemu_iovec_concat(&local_qiov, &hd_qiov, 0, n1);
-
-                    BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
-                    qemu_co_mutex_unlock(&s->lock);
-                    ret = bdrv_co_preadv(bs->backing, offset, n1,
-                                         &local_qiov, 0);
-                    qemu_co_mutex_lock(&s->lock);
-
-                    qemu_iovec_destroy(&local_qiov);
-
-                    if (ret < 0) {
-                        goto fail;
-                    }
+                BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
+                qemu_co_mutex_unlock(&s->lock);
+                ret = bdrv_co_preadv(bs->backing, offset, cur_bytes,
+                                     &hd_qiov, 0);
+                qemu_co_mutex_lock(&s->lock);
+                if (ret < 0) {
+                    goto fail;
                 }
             } else {
                 /* Note: in this case, no need to wait */
-- 
2.13.6

Removing a quorum child node with x-blockdev-change results in a quorum
driver state that cannot be recreated with create options because it
would require a list with gaps. This causes trouble in at least
.bdrv_refresh_filename().

Document this problem so that we won't accidentally mark the command
stable without having addressed it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 qapi/block-core.json | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index XXXXXXX..XXXXXXX 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -XXX,XX +XXX,XX @@
 # does not support all kinds of operations, all kinds of children, nor
 # all block drivers.
 #
+# FIXME Removing children from a quorum node means introducing gaps in the
+# child indices. This cannot be represented in the 'children' list of
+# BlockdevOptionsQuorum, as returned by .bdrv_refresh_filename().
+#
 # Warning: The data in a new quorum child MUST be consistent with that of
 # the rest of the array.
 #
-- 
2.13.6

From: Doug Gale <doug16k@gmail.com>

Add trace output for commands, errors, and undefined behavior.
Add guest error log output for undefined behavior.
Report invalid undefined accesses to MMIO.
Annotate unlikely error checks with unlikely.

Signed-off-by: Doug Gale <doug16k@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 hw/block/nvme.c       | 349 ++++++++++++++++++++++++++++++++++++++++++--------
 hw/block/trace-events |  93 ++++++++++++++
 2 files changed, 390 insertions(+), 52 deletions(-)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -XXX,XX +XXX,XX @@
 #include "qapi/visitor.h"
 #include "sysemu/block-backend.h"
 
+#include "qemu/log.h"
+#include "trace.h"
 #include "nvme.h"
 
+#define NVME_GUEST_ERR(trace, fmt, ...) \
+    do { \
+        (trace_##trace)(__VA_ARGS__); \
+        qemu_log_mask(LOG_GUEST_ERROR, #trace \
+            " in %s: " fmt "\n", __func__, ## __VA_ARGS__); \
+    } while (0)
+
 static void nvme_process_sq(void *opaque);
 
 static void nvme_addr_read(NvmeCtrl *n, hwaddr addr, void *buf, int size)
@@ -XXX,XX +XXX,XX @@ static void nvme_isr_notify(NvmeCtrl *n, NvmeCQueue *cq)
 {
     if (cq->irq_enabled) {
         if (msix_enabled(&(n->parent_obj))) {
+            trace_nvme_irq_msix(cq->vector);
             msix_notify(&(n->parent_obj), cq->vector);
         } else {
+            trace_nvme_irq_pin();
             pci_irq_pulse(&n->parent_obj);
         }
+    } else {
+        trace_nvme_irq_masked();
     }
 }
 
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
     trans_len = MIN(len, trans_len);
     int num_prps = (len >> n->page_bits) + 1;
 
-    if (!prp1) {
+    if (unlikely(!prp1)) {
+        trace_nvme_err_invalid_prp();
         return NVME_INVALID_FIELD | NVME_DNR;
     } else if (n->cmbsz && prp1 >= n->ctrl_mem.addr &&
                prp1 < n->ctrl_mem.addr + int128_get64(n->ctrl_mem.size)) {
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
     }
     len -= trans_len;
     if (len) {
-        if (!prp2) {
+        if (unlikely(!prp2)) {
+            trace_nvme_err_invalid_prp2_missing();
             goto unmap;
         }
         if (len > n->page_size) {
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
                 uint64_t prp_ent = le64_to_cpu(prp_list[i]);
 
                 if (i == n->max_prp_ents - 1 && len > n->page_size) {
-                    if (!prp_ent || prp_ent & (n->page_size - 1)) {
+                    if (unlikely(!prp_ent || prp_ent & (n->page_size - 1))) {
+                        trace_nvme_err_invalid_prplist_ent(prp_ent);
                         goto unmap;
                     }
 
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
                     prp_ent = le64_to_cpu(prp_list[i]);
                 }
 
-                if (!prp_ent || prp_ent & (n->page_size - 1)) {
+                if (unlikely(!prp_ent || prp_ent & (n->page_size - 1))) {
+                    trace_nvme_err_invalid_prplist_ent(prp_ent);
                     goto unmap;
                 }
 
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
                 i++;
             }
         } else {
-            if (prp2 & (n->page_size - 1)) {
+            if (unlikely(prp2 & (n->page_size - 1))) {
+                trace_nvme_err_invalid_prp2_align(prp2);
                 goto unmap;
             }
             if (qsg->nsg) {
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_dma_read_prp(NvmeCtrl *n, uint8_t *ptr, uint32_t len,
     QEMUIOVector iov;
     uint16_t status = NVME_SUCCESS;
 
+    trace_nvme_dma_read(prp1, prp2);
+
     if (nvme_map_prp(&qsg, &iov, prp1, prp2, len, n)) {
         return NVME_INVALID_FIELD | NVME_DNR;
     }
     if (qsg.nsg > 0) {
-        if (dma_buf_read(ptr, len, &qsg)) {
+        if (unlikely(dma_buf_read(ptr, len, &qsg))) {
+            trace_nvme_err_invalid_dma();
             status = NVME_INVALID_FIELD | NVME_DNR;
         }
         qemu_sglist_destroy(&qsg);
     } else {
-        if (qemu_iovec_to_buf(&iov, 0, ptr, len) != len) {
+        if (unlikely(qemu_iovec_to_buf(&iov, 0, ptr, len) != len)) {
+            trace_nvme_err_invalid_dma();
             status = NVME_INVALID_FIELD | NVME_DNR;
         }
         qemu_iovec_destroy(&iov);
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_write_zeros(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
     uint64_t aio_slba = slba << (data_shift - BDRV_SECTOR_BITS);
     uint32_t aio_nlb = nlb << (data_shift - BDRV_SECTOR_BITS);
 
-    if (slba + nlb > ns->id_ns.nsze) {
+    if (unlikely(slba + nlb > ns->id_ns.nsze)) {
+        trace_nvme_err_invalid_lba_range(slba, nlb, ns->id_ns.nsze);
         return NVME_LBA_RANGE | NVME_DNR;
     }
 
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_rw(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
     int is_write = rw->opcode == NVME_CMD_WRITE ? 1 : 0;
     enum BlockAcctType acct = is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ;
 
-    if ((slba + nlb) > ns->id_ns.nsze) {
+    trace_nvme_rw(is_write ? "write" : "read", nlb, data_size, slba);
+
+    if (unlikely((slba + nlb) > ns->id_ns.nsze)) {
         block_acct_invalid(blk_get_stats(n->conf.blk), acct);
+        trace_nvme_err_invalid_lba_range(slba, nlb, ns->id_ns.nsze);
         return NVME_LBA_RANGE | NVME_DNR;
     }
 
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_io_cmd(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
     NvmeNamespace *ns;
     uint32_t nsid = le32_to_cpu(cmd->nsid);
 
-    if (nsid == 0 || nsid > n->num_namespaces) {
+    if (unlikely(nsid == 0 || nsid > n->num_namespaces)) {
+        trace_nvme_err_invalid_ns(nsid, n->num_namespaces);
         return NVME_INVALID_NSID | NVME_DNR;
     }
 
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_io_cmd(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
     case NVME_CMD_READ:
         return nvme_rw(n, ns, cmd, req);
     default:
+        trace_nvme_err_invalid_opc(cmd->opcode);
         return NVME_INVALID_OPCODE | NVME_DNR;
     }
 }
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_del_sq(NvmeCtrl *n, NvmeCmd *cmd)
     NvmeCQueue *cq;
     uint16_t qid = le16_to_cpu(c->qid);
 
-    if (!qid || nvme_check_sqid(n, qid)) {
+    if (unlikely(!qid || nvme_check_sqid(n, qid))) {
+        trace_nvme_err_invalid_del_sq(qid);
         return NVME_INVALID_QID | NVME_DNR;
     }
 
+    trace_nvme_del_sq(qid);
+
     sq = n->sq[qid];
     while (!QTAILQ_EMPTY(&sq->out_req_list)) {
         req = QTAILQ_FIRST(&sq->out_req_list);
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_create_sq(NvmeCtrl *n, NvmeCmd *cmd)
     uint16_t qflags = le16_to_cpu(c->sq_flags);
     uint64_t prp1 = le64_to_cpu(c->prp1);
 
-    if (!cqid || nvme_check_cqid(n, cqid)) {
+    trace_nvme_create_sq(prp1, sqid, cqid, qsize, qflags);
+
+    if (unlikely(!cqid || nvme_check_cqid(n, cqid))) {
+        trace_nvme_err_invalid_create_sq_cqid(cqid);
         return NVME_INVALID_CQID | NVME_DNR;
     }
-    if (!sqid || !nvme_check_sqid(n, sqid)) {
+    if (unlikely(!sqid || !nvme_check_sqid(n, sqid))) {
+        trace_nvme_err_invalid_create_sq_sqid(sqid);
         return NVME_INVALID_QID | NVME_DNR;
     }
-    if (!qsize || qsize > NVME_CAP_MQES(n->bar.cap)) {
+    if (unlikely(!qsize || qsize > NVME_CAP_MQES(n->bar.cap))) {
+        trace_nvme_err_invalid_create_sq_size(qsize);
         return NVME_MAX_QSIZE_EXCEEDED | NVME_DNR;
     }
-    if (!prp1 || prp1 & (n->page_size - 1)) {
+    if (unlikely(!prp1 || prp1 & (n->page_size - 1))) {
+        trace_nvme_err_invalid_create_sq_addr(prp1);
         return NVME_INVALID_FIELD | NVME_DNR;
     }
-    if (!(NVME_SQ_FLAGS_PC(qflags))) {
+    if (unlikely(!(NVME_SQ_FLAGS_PC(qflags)))) {
+        trace_nvme_err_invalid_create_sq_qflags(NVME_SQ_FLAGS_PC(qflags));
         return NVME_INVALID_FIELD | NVME_DNR;
     }
     sq = g_malloc0(sizeof(*sq));
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_del_cq(NvmeCtrl *n, NvmeCmd *cmd)
     NvmeCQueue *cq;
     uint16_t qid = le16_to_cpu(c->qid);
 
-    if (!qid || nvme_check_cqid(n, qid)) {
+    if (unlikely(!qid || nvme_check_cqid(n, qid))) {
+        trace_nvme_err_invalid_del_cq_cqid(qid);
         return NVME_INVALID_CQID | NVME_DNR;
     }
 
     cq = n->cq[qid];
-    if (!QTAILQ_EMPTY(&cq->sq_list)) {
+    if (unlikely(!QTAILQ_EMPTY(&cq->sq_list))) {
+        trace_nvme_err_invalid_del_cq_notempty(qid);
         return NVME_INVALID_QUEUE_DEL;
     }
+    trace_nvme_del_cq(qid);
     nvme_free_cq(cq, n);
     return NVME_SUCCESS;
 }
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_create_cq(NvmeCtrl *n, NvmeCmd *cmd)
     uint16_t qflags = le16_to_cpu(c->cq_flags);
     uint64_t prp1 = le64_to_cpu(c->prp1);
 
-    if (!cqid || !nvme_check_cqid(n, cqid)) {
+    trace_nvme_create_cq(prp1, cqid, vector, qsize, qflags,
+                         NVME_CQ_FLAGS_IEN(qflags) != 0);
+
+    if (unlikely(!cqid || !nvme_check_cqid(n, cqid))) {
+        trace_nvme_err_invalid_create_cq_cqid(cqid);
         return NVME_INVALID_CQID | NVME_DNR;
     }
-    if (!qsize || qsize > NVME_CAP_MQES(n->bar.cap)) {
+    if (unlikely(!qsize || qsize > NVME_CAP_MQES(n->bar.cap))) {
+        trace_nvme_err_invalid_create_cq_size(qsize);
         return NVME_MAX_QSIZE_EXCEEDED | NVME_DNR;
     }
-    if (!prp1) {
+    if (unlikely(!prp1)) {
+        trace_nvme_err_invalid_create_cq_addr(prp1);
         return NVME_INVALID_FIELD | NVME_DNR;
     }
-    if (vector > n->num_queues) {
+    if (unlikely(vector > n->num_queues)) {
+        trace_nvme_err_invalid_create_cq_vector(vector);
         return NVME_INVALID_IRQ_VECTOR | NVME_DNR;
     }
-    if (!(NVME_CQ_FLAGS_PC(qflags))) {
+    if (unlikely(!(NVME_CQ_FLAGS_PC(qflags)))) {
+        trace_nvme_err_invalid_create_cq_qflags(NVME_CQ_FLAGS_PC(qflags));
         return NVME_INVALID_FIELD | NVME_DNR;
     }
 
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_identify_ctrl(NvmeCtrl *n, NvmeIdentify *c)
     uint64_t prp1 = le64_to_cpu(c->prp1);
     uint64_t prp2 = le64_to_cpu(c->prp2);
 
+    trace_nvme_identify_ctrl();
+
     return nvme_dma_read_prp(n, (uint8_t *)&n->id_ctrl, sizeof(n->id_ctrl),
         prp1, prp2);
 }
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_identify_ns(NvmeCtrl *n, NvmeIdentify *c)
     uint64_t prp1 = le64_to_cpu(c->prp1);
     uint64_t prp2 = le64_to_cpu(c->prp2);
 
-    if (nsid == 0 || nsid > n->num_namespaces) {
+    trace_nvme_identify_ns(nsid);
+
+    if (unlikely(nsid == 0 || nsid > n->num_namespaces)) {
+        trace_nvme_err_invalid_ns(nsid, n->num_namespaces);
         return NVME_INVALID_NSID | NVME_DNR;
     }
 
     ns = &n->namespaces[nsid - 1];
+
     return nvme_dma_read_prp(n, (uint8_t *)&ns->id_ns, sizeof(ns->id_ns),
         prp1, prp2);
 }
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_identify_nslist(NvmeCtrl *n, NvmeIdentify *c)
     uint16_t ret;
     int i, j = 0;
 
+    trace_nvme_identify_nslist(min_nsid);
+
     list = g_malloc0(data_len);
     for (i = 0; i < n->num_namespaces; i++) {
         if (i < min_nsid) {
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_identify(NvmeCtrl *n, NvmeCmd *cmd)
     case 0x02:
         return nvme_identify_nslist(n, c);
     default:
+        trace_nvme_err_invalid_identify_cns(le32_to_cpu(c->cns));
         return NVME_INVALID_FIELD | NVME_DNR;
     }
 }
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_get_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
     switch (dw10) {
     case NVME_VOLATILE_WRITE_CACHE:
         result = blk_enable_write_cache(n->conf.blk);
+        trace_nvme_getfeat_vwcache(result ? "enabled" : "disabled");
         break;
     case NVME_NUMBER_OF_QUEUES:
         result = cpu_to_le32((n->num_queues - 2) | ((n->num_queues - 2) << 16));
+        trace_nvme_getfeat_numq(result);
         break;
     default:
+        trace_nvme_err_invalid_getfeat(dw10);
         return NVME_INVALID_FIELD | NVME_DNR;
     }
 
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
         blk_set_enable_write_cache(n->conf.blk, dw11 & 1);
         break;
     case NVME_NUMBER_OF_QUEUES:
+        trace_nvme_setfeat_numq((dw11 & 0xFFFF) + 1,
+                                ((dw11 >> 16) & 0xFFFF) + 1,
+                                n->num_queues - 1, n->num_queues - 1);
         req->cqe.result =
             cpu_to_le32((n->num_queues - 2) | ((n->num_queues - 2) << 16));
         break;
     default:
+        trace_nvme_err_invalid_setfeat(dw10);
         return NVME_INVALID_FIELD | NVME_DNR;
     }
     return NVME_SUCCESS;
@@ -XXX,XX +XXX,XX @@ static uint16_t nvme_admin_cmd(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
     case NVME_ADM_CMD_GET_FEATURES:
         return nvme_get_feature(n, cmd, req);
     default:
+        trace_nvme_err_invalid_admin_opc(cmd->opcode);
         return NVME_INVALID_OPCODE | NVME_DNR;
     }
 }
@@ -XXX,XX +XXX,XX @@ static int nvme_start_ctrl(NvmeCtrl *n)
     uint32_t page_bits = NVME_CC_MPS(n->bar.cc) + 12;
     uint32_t page_size = 1 << page_bits;
 
-    if (n->cq[0] || n->sq[0] || !n->bar.asq || !n->bar.acq ||
-            n->bar.asq & (page_size - 1) || n->bar.acq & (page_size - 1) ||
-            NVME_CC_MPS(n->bar.cc) < NVME_CAP_MPSMIN(n->bar.cap) ||
-            NVME_CC_MPS(n->bar.cc) > NVME_CAP_MPSMAX(n->bar.cap) ||
-            NVME_CC_IOCQES(n->bar.cc) < NVME_CTRL_CQES_MIN(n->id_ctrl.cqes) ||
-            NVME_CC_IOCQES(n->bar.cc) > NVME_CTRL_CQES_MAX(n->id_ctrl.cqes) ||
-            NVME_CC_IOSQES(n->bar.cc) < NVME_CTRL_SQES_MIN(n->id_ctrl.sqes) ||
-            NVME_CC_IOSQES(n->bar.cc) > NVME_CTRL_SQES_MAX(n->id_ctrl.sqes) ||
-            !NVME_AQA_ASQS(n->bar.aqa) || !NVME_AQA_ACQS(n->bar.aqa)) {
+    if (unlikely(n->cq[0])) {
+        trace_nvme_err_startfail_cq();
+        return -1;
+    }
+    if (unlikely(n->sq[0])) {
+        trace_nvme_err_startfail_sq();
+        return -1;
+    }
+    if (unlikely(!n->bar.asq)) {
+        trace_nvme_err_startfail_nbarasq();
+        return -1;
+    }
+    if (unlikely(!n->bar.acq)) {
+        trace_nvme_err_startfail_nbaracq();
+        return -1;
+    }
+    if (unlikely(n->bar.asq & (page_size - 1))) {
+        trace_nvme_err_startfail_asq_misaligned(n->bar.asq);
+        return -1;
+    }
+    if (unlikely(n->bar.acq & (page_size - 1))) {
+        trace_nvme_err_startfail_acq_misaligned(n->bar.acq);
+        return -1;
+    }
+    if (unlikely(NVME_CC_MPS(n->bar.cc) <
+                 NVME_CAP_MPSMIN(n->bar.cap))) {
+        trace_nvme_err_startfail_page_too_small(
+                    NVME_CC_MPS(n->bar.cc),
+                    NVME_CAP_MPSMIN(n->bar.cap));
+        return -1;
+    }
+    if (unlikely(NVME_CC_MPS(n->bar.cc) >
+                 NVME_CAP_MPSMAX(n->bar.cap))) {
+        trace_nvme_err_startfail_page_too_large(
+                    NVME_CC_MPS(n->bar.cc),
+                    NVME_CAP_MPSMAX(n->bar.cap));
+        return -1;
+    }
+    if (unlikely(NVME_CC_IOCQES(n->bar.cc) <
+                 NVME_CTRL_CQES_MIN(n->id_ctrl.cqes))) {
+        trace_nvme_err_startfail_cqent_too_small(
+                    NVME_CC_IOCQES(n->bar.cc),
+                    NVME_CTRL_CQES_MIN(n->bar.cap));
+        return -1;
+    }
+    if (unlikely(NVME_CC_IOCQES(n->bar.cc) >
+                 NVME_CTRL_CQES_MAX(n->id_ctrl.cqes))) {
+        trace_nvme_err_startfail_cqent_too_large(
+                    NVME_CC_IOCQES(n->bar.cc),
+                    NVME_CTRL_CQES_MAX(n->bar.cap));
+        return -1;
+    }
+    if (unlikely(NVME_CC_IOSQES(n->bar.cc) <
+                 NVME_CTRL_SQES_MIN(n->id_ctrl.sqes))) {
+        trace_nvme_err_startfail_sqent_too_small(
+                    NVME_CC_IOSQES(n->bar.cc),
+                    NVME_CTRL_SQES_MIN(n->bar.cap));
+        return -1;
+    }
+    if (unlikely(NVME_CC_IOSQES(n->bar.cc) >
+                 NVME_CTRL_SQES_MAX(n->id_ctrl.sqes))) {
+        trace_nvme_err_startfail_sqent_too_large(
+                    NVME_CC_IOSQES(n->bar.cc),
+                    NVME_CTRL_SQES_MAX(n->bar.cap));
+        return -1;
+    }
+    if (unlikely(!NVME_AQA_ASQS(n->bar.aqa))) {
+        trace_nvme_err_startfail_asqent_sz_zero();
+        return -1;
+    }
+    if (unlikely(!NVME_AQA_ACQS(n->bar.aqa))) {
+        trace_nvme_err_startfail_acqent_sz_zero();
         return -1;
     }
 
@@ -XXX,XX +XXX,XX @@ static int nvme_start_ctrl(NvmeCtrl *n)
 static void nvme_write_bar(NvmeCtrl *n, hwaddr offset, uint64_t data,
     unsigned size)
 {
+    if (unlikely(offset & (sizeof(uint32_t) - 1))) {
+        NVME_GUEST_ERR(nvme_ub_mmiowr_misaligned32,
+                       "MMIO write not 32-bit aligned,"
+                       " offset=0x%"PRIx64"", offset);
+        /* should be ignored, fall through for now */
+    }
+
+    if (unlikely(size < sizeof(uint32_t))) {
+        NVME_GUEST_ERR(nvme_ub_mmiowr_toosmall,
+                       "MMIO write smaller than 32-bits,"
+                       " offset=0x%"PRIx64", size=%u",
+                       offset, size);
+        /* should be ignored, fall through for now */
+    }
+
     switch (offset) {
-    case 0xc:
+    case 0xc:   /* INTMS */
+        if (unlikely(msix_enabled(&(n->parent_obj)))) {
+            NVME_GUEST_ERR(nvme_ub_mmiowr_intmask_with_msix,
+                           "undefined access to interrupt mask set"
+                           " when MSI-X is enabled");
+            /* should be ignored, fall through for now */
+        }
         n->bar.intms |= data & 0xffffffff;
         n->bar.intmc = n->bar.intms;
+        trace_nvme_mmio_intm_set(data & 0xffffffff,
+                                 n->bar.intmc);
         break;
-    case 0x10:
+    case 0x10:  /* INTMC */
+        if (unlikely(msix_enabled(&(n->parent_obj)))) {
+            NVME_GUEST_ERR(nvme_ub_mmiowr_intmask_with_msix,
+                           "undefined access to interrupt mask clr"
+                           " when MSI-X is enabled");
+            /* should be ignored, fall through for now */
+        }
         n->bar.intms &= ~(data & 0xffffffff);
         n->bar.intmc = n->bar.intms;
+        trace_nvme_mmio_intm_clr(data & 0xffffffff,
+                                 n->bar.intmc);
         break;
-    case 0x14:
+    case 0x14:  /* CC */
+        trace_nvme_mmio_cfg(data & 0xffffffff);
         /* Windows first sends data, then sends enable bit */
         if (!NVME_CC_EN(data) && !NVME_CC_EN(n->bar.cc) &&
             !NVME_CC_SHN(data) && !NVME_CC_SHN(n->bar.cc))
@@ -XXX,XX +XXX,XX @@ static void nvme_write_bar(NvmeCtrl *n, hwaddr offset, uint64_t data,
 
         if (NVME_CC_EN(data) && !NVME_CC_EN(n->bar.cc)) {
             n->bar.cc = data;
-            if (nvme_start_ctrl(n)) {
+            if (unlikely(nvme_start_ctrl(n))) {
+                trace_nvme_err_startfail();
                 n->bar.csts = NVME_CSTS_FAILED;
             } else {
+                trace_nvme_mmio_start_success();
                 n->bar.csts = NVME_CSTS_READY;
             }
         } else if (!NVME_CC_EN(data) && NVME_CC_EN(n->bar.cc)) {
+            trace_nvme_mmio_stopped();
             nvme_clear_ctrl(n);
             n->bar.csts &= ~NVME_CSTS_READY;
         }
         if (NVME_CC_SHN(data) && !(NVME_CC_SHN(n->bar.cc))) {
-                nvme_clear_ctrl(n);
-                n->bar.cc = data;
-                n->bar.csts |= NVME_CSTS_SHST_COMPLETE;
+            trace_nvme_mmio_shutdown_set();
+            nvme_clear_ctrl(n);
+            n->bar.cc = data;
+            n->bar.csts |= NVME_CSTS_SHST_COMPLETE;
         } else if (!NVME_CC_SHN(data) && NVME_CC_SHN(n->bar.cc)) {
-                n->bar.csts &= ~NVME_CSTS_SHST_COMPLETE;
-                n->bar.cc = data;
+            trace_nvme_mmio_shutdown_cleared();
+            n->bar.csts &= ~NVME_CSTS_SHST_COMPLETE;
+            n->bar.cc = data;
+        }
+        break;
+    case 0x1C:  /* CSTS */
+        if (data & (1 << 4)) {
+            NVME_GUEST_ERR(nvme_ub_mmiowr_ssreset_w1c_unsupported,
+                           "attempted to W1C CSTS.NSSRO"
+                           " but CAP.NSSRS is zero (not supported)");
+        } else if (data != 0) {
+            NVME_GUEST_ERR(nvme_ub_mmiowr_ro_csts,
+                           "attempted to set a read only bit"
+                           " of controller status");
+        }
+        break;
+    case 0x20:  /* NSSR */
+        if (data == 0x4E564D65) {
+            trace_nvme_ub_mmiowr_ssreset_unsupported();
+        } else {
+            /* The spec says that writes of other values have no effect */
+            return;
         }
         break;
-    case 0x24:
+    case 0x24:  /* AQA */
         n->bar.aqa = data & 0xffffffff;
+        trace_nvme_mmio_aqattr(data & 0xffffffff);
         break;
-    case 0x28:
+    case 0x28:  /* ASQ */
         n->bar.asq = data;
+        trace_nvme_mmio_asqaddr(data);
         break;
-    case 0x2c:
+    case 0x2c:  /* ASQ hi */
         n->bar.asq |= data << 32;
+        trace_nvme_mmio_asqaddr_hi(data, n->bar.asq);
         break;
-    case 0x30:
+    case 0x30:  /* ACQ */
+        trace_nvme_mmio_acqaddr(data);
         n->bar.acq = data;
         break;
-    case 0x34:
+    case 0x34:  /* ACQ hi */
         n->bar.acq |= data << 32;
+        trace_nvme_mmio_acqaddr_hi(data, n->bar.acq);
         break;
+    case 0x38:  /* CMBLOC */
+        NVME_GUEST_ERR(nvme_ub_mmiowr_cmbloc_reserved,
+                       "invalid write to reserved CMBLOC"
+                       " when CMBSZ is zero, ignored");
+        return;
+    case 0x3C:  /* CMBSZ */
+        NVME_GUEST_ERR(nvme_ub_mmiowr_cmbsz_readonly,
+                       "invalid write to read only CMBSZ, ignored");
+        return;
     default:
+        NVME_GUEST_ERR(nvme_ub_mmiowr_invalid,
+                       "invalid MMIO write,"
+                       " offset=0x%"PRIx64", data=%"PRIx64"",
+                       offset, data);
         break;
     }
 }
@@ -XXX,XX +XXX,XX @@ static uint64_t nvme_mmio_read(void *opaque, hwaddr addr, unsigned size)
     uint8_t *ptr = (uint8_t *)&n->bar;
     uint64_t val = 0;
 
+    if (unlikely(addr & (sizeof(uint32_t) - 1))) {
+        NVME_GUEST_ERR(nvme_ub_mmiord_misaligned32,
+                       "MMIO read not 32-bit aligned,"
+                       " offset=0x%"PRIx64"", addr);
+        /* should RAZ, fall through for now */
+    } else if (unlikely(size < sizeof(uint32_t))) {
+        NVME_GUEST_ERR(nvme_ub_mmiord_toosmall,
+                       "MMIO read smaller than 32-bits,"
+                       " offset=0x%"PRIx64"", addr);
+        /* should RAZ, fall through for now */
+    }
+
     if (addr < sizeof(n->bar)) {
         memcpy(&val, ptr + addr, size);
+    } else {
+        NVME_GUEST_ERR(nvme_ub_mmiord_invalid_ofs,
+                       "MMIO read beyond last register,"
+                       " offset=0x%"PRIx64", returning 0", addr);
     }
+
     return val;
 }
 
@@ -XXX,XX +XXX,XX @@ static void nvme_process_db(NvmeCtrl *n, hwaddr addr, int val)
 {
     uint32_t qid;
 
-    if (addr & ((1 << 2) - 1)) {
+    if (unlikely(addr & ((1 << 2) - 1))) {
+        NVME_GUEST_ERR(nvme_ub_db_wr_misaligned,
+                       "doorbell write not 32-bit aligned,"
+                       " offset=0x%"PRIx64", ignoring", addr);
         return;
     }
 
     if (((addr - 0x1000) >> 2) & 1) {
+        /* Completion queue doorbell write */
+
         uint16_t new_head = val & 0xffff;
         int start_sqs;
         NvmeCQueue *cq;
 
         qid = (addr - (0x1000 + (1 << 2))) >> 3;
-        if (nvme_check_cqid(n, qid)) {
+        if (unlikely(nvme_check_cqid(n, qid))) {
+            NVME_GUEST_ERR(nvme_ub_db_wr_invalid_cq,
+                           "completion queue doorbell write"
+                           " for nonexistent queue,"
+                           " sqid=%"PRIu32", ignoring", qid);
             return;
         }
 
         cq = n->cq[qid];
-        if (new_head >= cq->size) {
+        if (unlikely(new_head >= cq->size)) {
+            NVME_GUEST_ERR(nvme_ub_db_wr_invalid_cqhead,
+                           "completion queue doorbell write value"
+                           " beyond queue size, sqid=%"PRIu32","
+                           " new_head=%"PRIu16", ignoring",
+                           qid, new_head);
             return;
         }
 
@@ -XXX,XX +XXX,XX @@ static void nvme_process_db(NvmeCtrl *n, hwaddr addr, int val)
             nvme_isr_notify(n, cq);
         }
     } else {
+        /* Submission queue doorbell write */
+
         uint16_t new_tail = val & 0xffff;
         NvmeSQueue *sq;
 
         qid = (addr - 0x1000) >> 3;
-        if (nvme_check_sqid(n, qid)) {
+        if (unlikely(nvme_check_sqid(n, qid))) {
+            NVME_GUEST_ERR(nvme_ub_db_wr_invalid_sq,
+                           "submission queue doorbell write"
+                           " for nonexistent queue,"
+                           " sqid=%"PRIu32", ignoring", qid);
             return;
         }
 
         sq = n->sq[qid];
-        if (new_tail >= sq->size) {
+        if (unlikely(new_tail >= sq->size)) {
+            NVME_GUEST_ERR(nvme_ub_db_wr_invalid_sqtail,
+                           "submission queue doorbell write value"
+                           " beyond queue size, sqid=%"PRIu32","
+                           " new_tail=%"PRIu16", ignoring",
+                           qid, new_tail);
             return;
         }
 
diff --git a/hw/block/trace-events b/hw/block/trace-events
index XXXXXXX..XXXXXXX 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -XXX,XX +XXX,XX @@ virtio_blk_submit_multireq(void *vdev, void *mrb, int start, int num_reqs, uint6
 hd_geometry_lchs_guess(void *blk, int cyls, int heads, int secs) "blk %p LCHS %d %d %d"
 hd_geometry_guess(void *blk, uint32_t cyls, uint32_t heads, uint32_t secs, int trans) "blk %p CHS %u %u %u trans %d"
 
+# hw/block/nvme.c
+# nvme traces for successful events
+nvme_irq_msix(uint32_t vector) "raising MSI-X IRQ vector %u"
+nvme_irq_pin(void) "pulsing IRQ pin"
+nvme_irq_masked(void) "IRQ is masked"
+nvme_dma_read(uint64_t prp1, uint64_t prp2) "DMA read, prp1=0x%"PRIx64" prp2=0x%"PRIx64""
+nvme_rw(char const *verb, uint32_t blk_count, uint64_t byte_count, uint64_t lba) "%s %"PRIu32" blocks (%"PRIu64" bytes) from LBA %"PRIu64""
+nvme_create_sq(uint64_t addr, uint16_t sqid, uint16_t cqid, uint16_t qsize, uint16_t qflags) "create submission queue, addr=0x%"PRIx64", sqid=%"PRIu16", cqid=%"PRIu16", qsize=%"PRIu16", qflags=%"PRIu16""
+nvme_create_cq(uint64_t addr, uint16_t cqid, uint16_t vector, uint16_t size, uint16_t qflags, int ien) "create completion queue, addr=0x%"PRIx64", cqid=%"PRIu16", vector=%"PRIu16", qsize=%"PRIu16", qflags=%"PRIu16", ien=%d"
+nvme_del_sq(uint16_t qid) "deleting submission queue sqid=%"PRIu16""
+nvme_del_cq(uint16_t cqid) "deleted completion queue, sqid=%"PRIu16""
+nvme_identify_ctrl(void) "identify controller"
+nvme_identify_ns(uint16_t ns) "identify namespace, nsid=%"PRIu16""
+nvme_identify_nslist(uint16_t ns) "identify namespace list, nsid=%"PRIu16""
+nvme_getfeat_vwcache(char const* result) "get feature volatile write cache, result=%s"
+nvme_getfeat_numq(int result) "get feature number of queues, result=%d"
+nvme_setfeat_numq(int reqcq, int reqsq, int gotcq, int gotsq) "requested cq_count=%d sq_count=%d, responding with cq_count=%d sq_count=%d"
+nvme_mmio_intm_set(uint64_t data, uint64_t new_mask) "wrote MMIO, interrupt mask set, data=0x%"PRIx64", new_mask=0x%"PRIx64""
+nvme_mmio_intm_clr(uint64_t data, uint64_t new_mask) "wrote MMIO, interrupt mask clr, data=0x%"PRIx64", new_mask=0x%"PRIx64""
+nvme_mmio_cfg(uint64_t data) "wrote MMIO, config controller config=0x%"PRIx64""
+nvme_mmio_aqattr(uint64_t data) "wrote MMIO, admin queue attributes=0x%"PRIx64""
+nvme_mmio_asqaddr(uint64_t data) "wrote MMIO, admin submission queue address=0x%"PRIx64""
+nvme_mmio_acqaddr(uint64_t data) "wrote MMIO, admin completion queue address=0x%"PRIx64""
+nvme_mmio_asqaddr_hi(uint64_t data, uint64_t new_addr) "wrote MMIO, admin submission queue high half=0x%"PRIx64", new_address=0x%"PRIx64""
+nvme_mmio_acqaddr_hi(uint64_t data, uint64_t new_addr) "wrote MMIO, admin completion queue high half=0x%"PRIx64", new_address=0x%"PRIx64""
+nvme_mmio_start_success(void) "setting controller enable bit succeeded"
+nvme_mmio_stopped(void) "cleared controller enable bit"
+nvme_mmio_shutdown_set(void) "shutdown bit set"
+nvme_mmio_shutdown_cleared(void) "shutdown bit cleared"
+
+# nvme traces for error conditions
+nvme_err_invalid_dma(void) "PRP/SGL is too small for transfer size"
+nvme_err_invalid_prplist_ent(uint64_t prplist) "PRP list entry is null or not page aligned: 0x%"PRIx64""
+nvme_err_invalid_prp2_align(uint64_t prp2) "PRP2 is not page aligned: 0x%"PRIx64""
+nvme_err_invalid_prp2_missing(void) "PRP2 is null and more data to be transferred"
+nvme_err_invalid_field(void) "invalid field"
+nvme_err_invalid_prp(void) "invalid PRP"
+nvme_err_invalid_sgl(void) "invalid SGL"
+nvme_err_invalid_ns(uint32_t ns, uint32_t limit) "invalid namespace %u not within 1-%u"
+nvme_err_invalid_opc(uint8_t opc) "invalid opcode 0x%"PRIx8""
+nvme_err_invalid_admin_opc(uint8_t opc) "invalid admin opcode 0x%"PRIx8""
+nvme_err_invalid_lba_range(uint64_t start, uint64_t len, uint64_t limit) "Invalid LBA start=%"PRIu64" len=%"PRIu64" limit=%"PRIu64""
+nvme_err_invalid_del_sq(uint16_t qid) "invalid submission queue deletion, sid=%"PRIu16""
+nvme_err_invalid_create_sq_cqid(uint16_t cqid) "failed creating submission queue, invalid cqid=%"PRIu16""
+nvme_err_invalid_create_sq_sqid(uint16_t sqid) "failed creating submission queue, invalid sqid=%"PRIu16""
+nvme_err_invalid_create_sq_size(uint16_t qsize) "failed creating submission queue, invalid qsize=%"PRIu16""
+nvme_err_invalid_create_sq_addr(uint64_t addr) "failed creating submission queue, addr=0x%"PRIx64""
+nvme_err_invalid_create_sq_qflags(uint16_t qflags) "failed creating submission queue, qflags=%"PRIu16""
+nvme_err_invalid_del_cq_cqid(uint16_t cqid) "failed deleting completion queue, cqid=%"PRIu16""
+nvme_err_invalid_del_cq_notempty(uint16_t cqid) "failed deleting completion queue, it is not empty, cqid=%"PRIu16""
+nvme_err_invalid_create_cq_cqid(uint16_t cqid) "failed creating completion queue, cqid=%"PRIu16""
+nvme_err_invalid_create_cq_size(uint16_t size) "failed creating completion queue, size=%"PRIu16""
+nvme_err_invalid_create_cq_addr(uint64_t addr) "failed creating completion queue, addr=0x%"PRIx64""
+nvme_err_invalid_create_cq_vector(uint16_t vector) "failed creating completion queue, vector=%"PRIu16""
+nvme_err_invalid_create_cq_qflags(uint16_t qflags) "failed creating completion queue, qflags=%"PRIu16""
+nvme_err_invalid_identify_cns(uint16_t cns) "identify, invalid cns=0x%"PRIx16""
+nvme_err_invalid_getfeat(int dw10) "invalid get features, dw10=0x%"PRIx32""
+nvme_err_invalid_setfeat(uint32_t dw10) "invalid set features, dw10=0x%"PRIx32""
+nvme_err_startfail_cq(void) "nvme_start_ctrl failed because there are non-admin completion queues"
+nvme_err_startfail_sq(void) "nvme_start_ctrl failed because there are non-admin submission queues"
+nvme_err_startfail_nbarasq(void) "nvme_start_ctrl failed because the admin submission queue address is null"
+nvme_err_startfail_nbaracq(void) "nvme_start_ctrl failed because the admin completion queue address is null"
+nvme_err_startfail_asq_misaligned(uint64_t addr) "nvme_start_ctrl failed because the admin submission queue address is misaligned: 0x%"PRIx64""
+nvme_err_startfail_acq_misaligned(uint64_t addr) "nvme_start_ctrl failed because the admin completion queue address is misaligned: 0x%"PRIx64""
+nvme_err_startfail_page_too_small(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the page size is too small: log2size=%u, min=%u"
+nvme_err_startfail_page_too_large(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the page size is too large: log2size=%u, max=%u"
+nvme_err_startfail_cqent_too_small(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the completion queue entry size is too small: log2size=%u, min=%u"
+nvme_err_startfail_cqent_too_large(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the completion queue entry size is too large: log2size=%u, max=%u"
+nvme_err_startfail_sqent_too_small(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the submission queue entry size is too small: log2size=%u, min=%u"
+nvme_err_startfail_sqent_too_large(uint8_t log2ps, uint8_t maxlog2ps) "nvme_start_ctrl failed because the submission queue entry size is too large: log2size=%u, max=%u"
+nvme_err_startfail_asqent_sz_zero(void) "nvme_start_ctrl failed because the admin submission queue size is zero"
+nvme_err_startfail_acqent_sz_zero(void) "nvme_start_ctrl failed because the admin completion queue size is zero"
+nvme_err_startfail(void) "setting controller enable bit failed"
+
+# Traces for undefined behavior
+nvme_ub_mmiowr_misaligned32(uint64_t offset) "MMIO write not 32-bit aligned, offset=0x%"PRIx64""
+nvme_ub_mmiowr_toosmall(uint64_t offset, unsigned size) "MMIO write smaller than 32 bits, offset=0x%"PRIx64", size=%u"
+nvme_ub_mmiowr_intmask_with_msix(void) "undefined access to interrupt mask set when MSI-X is enabled"
+nvme_ub_mmiowr_ro_csts(void) "attempted to set a read only bit of controller status"
+nvme_ub_mmiowr_ssreset_w1c_unsupported(void) "attempted to W1C CSTS.NSSRO but CAP.NSSRS is zero (not supported)"
+nvme_ub_mmiowr_ssreset_unsupported(void) "attempted NVM subsystem reset but CAP.NSSRS is zero (not supported)"
+nvme_ub_mmiowr_cmbloc_reserved(void) "invalid write to reserved CMBLOC when CMBSZ is zero, ignored"
+nvme_ub_mmiowr_cmbsz_readonly(void) "invalid write to read only CMBSZ, ignored"
+nvme_ub_mmiowr_invalid(uint64_t offset, uint64_t data) "invalid MMIO write, offset=0x%"PRIx64", data=0x%"PRIx64""
+nvme_ub_mmiord_misaligned32(uint64_t offset) "MMIO read not 32-bit aligned, offset=0x%"PRIx64""
+nvme_ub_mmiord_toosmall(uint64_t offset) "MMIO read smaller than 32-bits, offset=0x%"PRIx64""
+nvme_ub_mmiord_invalid_ofs(uint64_t offset) "MMIO read beyond last register, offset=0x%"PRIx64", returning 0"
+nvme_ub_db_wr_misaligned(uint64_t offset) "doorbell write not 32-bit aligned, offset=0x%"PRIx64", ignoring"
+nvme_ub_db_wr_invalid_cq(uint32_t qid) "completion queue doorbell write for nonexistent queue, cqid=%"PRIu32", ignoring"
+nvme_ub_db_wr_invalid_cqhead(uint32_t qid, uint16_t new_head) "completion queue doorbell write value beyond queue size, cqid=%"PRIu32", new_head=%"PRIu16", ignoring"
+nvme_ub_db_wr_invalid_sq(uint32_t qid) "submission queue doorbell write for nonexistent queue, sqid=%"PRIu32", ignoring"
+nvme_ub_db_wr_invalid_sqtail(uint32_t qid, uint16_t new_tail) "submission queue doorbell write value beyond queue size, sqid=%"PRIu32", new_head=%"PRIu16", ignoring"
+
 # hw/block/xen_disk.c
 xen_disk_alloc(char *name) "%s"
 xen_disk_init(char *name) "%s"
-- 
2.13.6

From: Fam Zheng <famz@redhat.com>

Management tools create overlays of running guests with qemu-img:

$ qemu-img create -b /image/in/use.qcow2 -f qcow2 /overlay/image.qcow2

but this doesn't work anymore due to image locking:

qemu-img: /overlay/image.qcow2: Failed to get shared "write" lock
    Is another process using the image?
    Could not open backing image to determine size.
Use the force share option to allow this use case again.

Cc: qemu-stable@nongnu.org
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block.c b/block.c
index XXXXXXX..XXXXXXX 100644
--- a/block.c
+++ b/block.c
@@ -XXX,XX +XXX,XX @@ void bdrv_img_create(const char *filename, const char *fmt,
         back_flags = flags;
         back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
 
+        backing_options = qdict_new();
         if (backing_fmt) {
-            backing_options = qdict_new();
             qdict_put_str(backing_options, "driver", backing_fmt);
         }
+        qdict_put_bool(backing_options, BDRV_OPT_FORCE_SHARE, true);
 
         bs = bdrv_open(full_backing, NULL, backing_options, back_flags,
                        &local_err);
-- 
2.13.6

From: Thomas Huth <thuth@redhat.com>

It's not working anymore since QEMU v1.3.0 - time to remove it now.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 blockdev.c    | 11 -----------
 qemu-doc.texi |  6 ------
 2 files changed, 17 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index XXXXXXX..XXXXXXX 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -XXX,XX +XXX,XX @@ QemuOptsList qemu_legacy_drive_opts = {
             .type = QEMU_OPT_STRING,
             .help = "chs translation (auto, lba, none)",
         },{
-            .name = "boot",
-            .type = QEMU_OPT_BOOL,
-            .help = "(deprecated, ignored)",
-        },{
             .name = "addr",
             .type = QEMU_OPT_STRING,
             .help = "pci address (virtio only)",
@@ -XXX,XX +XXX,XX @@ DriveInfo *drive_new(QemuOpts *all_opts, BlockInterfaceType block_default_type)
         goto fail;
     }
 
-    /* Deprecated option boot=[on|off] */
-    if (qemu_opt_get(legacy_opts, "boot") != NULL) {
-        fprintf(stderr, "qemu-kvm: boot=on|off is deprecated and will be "
-                "ignored. Future versions will reject this parameter. Please "
-                "update your scripts.\n");
-    }
-
     /* Other deprecated options */
     if (!qtest_enabled()) {
         for (i = 0; i < ARRAY_SIZE(deprecated); i++) {
diff --git a/qemu-doc.texi b/qemu-doc.texi
index XXXXXXX..XXXXXXX 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -XXX,XX +XXX,XX @@ deprecated.
 
 @section System emulator command line arguments
 
-@subsection -drive boot=on|off (since 1.3.0)
-
-The ``boot=on|off'' option to the ``-drive'' argument is
-ignored. Applications should use the ``bootindex=N'' parameter
-to set an absolute ordering between devices instead.
-
 @subsection -tdf (since 1.3.0)
 
 The ``-tdf'' argument is ignored. The behaviour implemented
-- 
2.13.6

From: Thomas Huth <thuth@redhat.com>

It's been marked as deprecated since QEMU v2.10.0, and so far nobody
complained that we should keep it, so let's remove this legacy option
now to simplify the code quite a bit.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 vl.c            | 86 ++-------------------------------------------------------
 qemu-doc.texi   |  8 ------
 qemu-options.hx | 19 ++-----------
 3 files changed, 4 insertions(+), 109 deletions(-)

diff --git a/vl.c b/vl.c
index XXXXXXX..XXXXXXX 100644
--- a/vl.c
+++ b/vl.c
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
     const char *boot_order = NULL;
     const char *boot_once = NULL;
     DisplayState *ds;
-    int cyls, heads, secs, translation;
     QemuOpts *opts, *machine_opts;
-    QemuOpts *hda_opts = NULL, *icount_opts = NULL, *accel_opts = NULL;
+    QemuOpts *icount_opts = NULL, *accel_opts = NULL;
     QemuOptsList *olist;
     int optind;
     const char *optarg;
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
 
     cpu_model = NULL;
     snapshot = 0;
-    cyls = heads = secs = 0;
-    translation = BIOS_ATA_TRANSLATION_AUTO;
 
     nb_nics = 0;
 
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
         if (optind >= argc)
             break;
         if (argv[optind][0] != '-') {
-            hda_opts = drive_add(IF_DEFAULT, 0, argv[optind++], HD_OPTS);
+            drive_add(IF_DEFAULT, 0, argv[optind++], HD_OPTS);
         } else {
             const QEMUOption *popt;
 
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
                 cpu_model = optarg;
                 break;
             case QEMU_OPTION_hda:
-                {
-                    char buf[256];
-                    if (cyls == 0)
-                        snprintf(buf, sizeof(buf), "%s", HD_OPTS);
-                    else
-                        snprintf(buf, sizeof(buf),
-                                 "%s,cyls=%d,heads=%d,secs=%d%s",
-                                 HD_OPTS , cyls, heads, secs,
-                                 translation == BIOS_ATA_TRANSLATION_LBA ?
-                                 ",trans=lba" :
-                                 translation == BIOS_ATA_TRANSLATION_NONE ?
-                                 ",trans=none" : "");
-                    drive_add(IF_DEFAULT, 0, optarg, buf);
-                    break;
-                }
             case QEMU_OPTION_hdb:
             case QEMU_OPTION_hdc:
             case QEMU_OPTION_hdd:
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_snapshot:
                 snapshot = 1;
                 break;
-            case QEMU_OPTION_hdachs:
-                {
-                    const char *p;
-                    p = optarg;
-                    cyls = strtol(p, (char **)&p, 0);
-                    if (cyls < 1 || cyls > 16383)
-                        goto chs_fail;
-                    if (*p != ',')
-                        goto chs_fail;
-                    p++;
-                    heads = strtol(p, (char **)&p, 0);
-                    if (heads < 1 || heads > 16)
-                        goto chs_fail;
-                    if (*p != ',')
-                        goto chs_fail;
-                    p++;
-                    secs = strtol(p, (char **)&p, 0);
-                    if (secs < 1 || secs > 63)
-                        goto chs_fail;
-                    if (*p == ',') {
-                        p++;
-                        if (!strcmp(p, "large")) {
-                            translation = BIOS_ATA_TRANSLATION_LARGE;
-                        } else if (!strcmp(p, "rechs")) {
-                            translation = BIOS_ATA_TRANSLATION_RECHS;
-                        } else if (!strcmp(p, "none")) {
-                            translation = BIOS_ATA_TRANSLATION_NONE;
-                        } else if (!strcmp(p, "lba")) {
-                            translation = BIOS_ATA_TRANSLATION_LBA;
-                        } else if (!strcmp(p, "auto")) {
-                            translation = BIOS_ATA_TRANSLATION_AUTO;
-                        } else {
-                            goto chs_fail;
-                        }
-                    } else if (*p != '\0') {
-                    chs_fail:
-                        error_report("invalid physical CHS format");
-                        exit(1);
-                    }
-                    if (hda_opts != NULL) {
-                        qemu_opt_set_number(hda_opts, "cyls", cyls,
-                                            &error_abort);
-                        qemu_opt_set_number(hda_opts, "heads", heads,
-                                            &error_abort);
-                        qemu_opt_set_number(hda_opts, "secs", secs,
-                                            &error_abort);
-                        if (translation == BIOS_ATA_TRANSLATION_LARGE) {
-                            qemu_opt_set(hda_opts, "trans", "large",
-                                         &error_abort);
-                        } else if (translation == BIOS_ATA_TRANSLATION_RECHS) {
-                            qemu_opt_set(hda_opts, "trans", "rechs",
-                                         &error_abort);
-                        } else if (translation == BIOS_ATA_TRANSLATION_LBA) {
-                            qemu_opt_set(hda_opts, "trans", "lba",
-                                         &error_abort);
-                        } else if (translation == BIOS_ATA_TRANSLATION_NONE) {
-                            qemu_opt_set(hda_opts, "trans", "none",
-                                         &error_abort);
-                        }
-                    }
-                }
-                error_report("'-hdachs' is deprecated, please use '-device"
-                             " ide-hd,cyls=c,heads=h,secs=s,...' instead");
-                break;
             case QEMU_OPTION_numa:
                 opts = qemu_opts_parse_noisily(qemu_find_opts("numa"),
                                                optarg, true);
diff --git a/qemu-doc.texi b/qemu-doc.texi
index XXXXXXX..XXXXXXX 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -XXX,XX +XXX,XX @@ The ``--net dump'' argument is now replaced with the
 ``-object filter-dump'' argument which works in combination
 with the modern ``-netdev`` backends instead.
 
-@subsection -hdachs (since 2.10.0)
-
-The ``-hdachs'' argument is now a synonym for setting
-the ``cyls'', ``heads'', ``secs'', and ``trans'' properties
-on the ``ide-hd'' device using the ``-device'' argument.
-The new syntax allows different settings to be provided
-per disk.
-
 @subsection -usbdevice (since 2.10.0)
 
 The ``-usbdevice DEV'' argument is now a synonym for setting
diff --git a/qemu-options.hx b/qemu-options.hx
index XXXXXXX..XXXXXXX 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -XXX,XX +XXX,XX @@ of available connectors of a given interface type.
 @item media=@var{media}
 This option defines the type of the media: disk or cdrom.
 @item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
-These options have the same definition as they have in @option{-hdachs}.
-These parameters are deprecated, use the corresponding parameters
+Force disk physical geometry and the optional BIOS translation (trans=none or
+lba). These parameters are deprecated, use the corresponding parameters
 of @code{-device} instead.
 @item snapshot=@var{snapshot}
 @var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
@@ -XXX,XX +XXX,XX @@ the raw disk image you use is not written back. You can however force
 the write back by pressing @key{C-a s} (@pxref{disk_images}).
 ETEXI
 
-DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \
-    "-hdachs c,h,s[,t]\n" \
-    "                force hard disk 0 physical geometry and the optional BIOS\n" \
-    "                translation (t=none or lba) (usually QEMU can guess them)\n",
-    QEMU_ARCH_ALL)
-STEXI
-@item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
-@findex -hdachs
-Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
-@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
-translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
-all those parameters. This option is deprecated, please use
-@code{-device ide-hd,cyls=c,heads=h,secs=s,...} instead.
-ETEXI
-
 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
     "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
     " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
-- 
2.13.6

From: Thomas Huth <thuth@redhat.com>

Looks like we forgot to announce the deprecation of these options in
the corresponding chapter of the qemu-doc text, so let's do that now.

diff --git a/qemu-doc.texi b/qemu-doc.texi
index XXXXXXX..XXXXXXX 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -XXX,XX +XXX,XX @@ longer be directly supported in QEMU.
 The ``-drive if=scsi'' argument is replaced by the the
 ``-device BUS-TYPE'' argument combined with ``-drive if=none''.
 
+@subsection -drive cyls=...,heads=...,secs=...,trans=... (since 2.10.0)
+
+The drive geometry arguments are replaced by the the geometry arguments
+that can be specified with the ``-device'' parameter.
+
+@subsection -drive serial=... (since 2.10.0)
+
+The drive serial argument is replaced by the the serial argument
+that can be specified with the ``-device'' parameter.
+
+@subsection -drive addr=... (since 2.10.0)
+
+The drive addr argument is replaced by the the addr argument
+that can be specified with the ``-device'' parameter.
+
 @subsection -net dump (since 2.10.0)
 
 The ``--net dump'' argument is now replaced with the
-- 
2.13.6

From: Fam Zheng <famz@redhat.com>

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/block_int.h |  1 -
 block/io.c                | 18 ------------------
 2 files changed, 19 deletions(-)

diff --git a/include/block/block_int.h b/include/block/block_int.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -XXX,XX +XXX,XX @@ bool blk_dev_is_tray_open(BlockBackend *blk);
 bool blk_dev_is_medium_locked(BlockBackend *blk);
 
 void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes);
-bool bdrv_requests_pending(BlockDriverState *bs);
 
 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
 void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in);
diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ void bdrv_disable_copy_on_read(BlockDriverState *bs)
     assert(old >= 1);
 }
 
-/* Check if any requests are in-flight (including throttled requests) */
-bool bdrv_requests_pending(BlockDriverState *bs)
-{
-    BdrvChild *child;
-
-    if (atomic_read(&bs->in_flight)) {
-        return true;
-    }
-
-    QLIST_FOREACH(child, &bs->children, next) {
-        if (bdrv_requests_pending(child->bs)) {
-            return true;
-        }
-    }
-
-    return false;
-}
-
 typedef struct {
     Coroutine *co;
     BlockDriverState *bs;
-- 
2.13.6

bdrv_drained_begin() doesn't increase bs->quiesce_counter recursively
and also doesn't notify other parent nodes of children, which both means
that the child nodes are not actually drained, and bdrv_drained_begin()
is providing useful functionality only on a single node.

To keep things consistent, we also shouldn't call the block driver
callbacks recursively.

A proper recursive drain version that provides an actually working
drained section for child nodes will be introduced later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
---
 block/io.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
 }
 
 /* Recursively call BlockDriver.bdrv_co_drain_begin/end callbacks */
-static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
+static void bdrv_drain_invoke(BlockDriverState *bs, bool begin, bool recursive)
 {
     BdrvChild *child, *tmp;
     BdrvCoDrainData data = { .bs = bs, .done = false, .begin = begin};
@@ -XXX,XX +XXX,XX @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
     bdrv_coroutine_enter(bs, data.co);
     BDRV_POLL_WHILE(bs, !data.done);
 
-    QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {
-        bdrv_drain_invoke(child->bs, begin);
+    if (recursive) {
+        QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {
+            bdrv_drain_invoke(child->bs, begin, true);
+        }
     }
 }
 
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs)
         bdrv_parent_drained_begin(bs);
     }
 
-    bdrv_drain_invoke(bs, true);
+    bdrv_drain_invoke(bs, true, false);
     bdrv_drain_recurse(bs);
 }
 
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
     }
 
     /* Re-enable things in child-to-parent order */
-    bdrv_drain_invoke(bs, false);
+    bdrv_drain_invoke(bs, false, false);
     bdrv_parent_drained_end(bs);
     aio_enable_external(bdrv_get_aio_context(bs));
 }
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
         aio_context_acquire(aio_context);
         aio_disable_external(aio_context);
         bdrv_parent_drained_begin(bs);
-        bdrv_drain_invoke(bs, true);
+        bdrv_drain_invoke(bs, true, true);
         aio_context_release(aio_context);
 
         if (!g_slist_find(aio_ctxs, aio_context)) {
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
 
         /* Re-enable things in child-to-parent order */
         aio_context_acquire(aio_context);
-        bdrv_drain_invoke(bs, false);
+        bdrv_drain_invoke(bs, false, true);
         bdrv_parent_drained_end(bs);
         aio_enable_external(aio_context);
         aio_context_release(aio_context);
-- 
2.13.6

The existing test is for bdrv_drain_all_begin/end() only. Generalise the
test case so that it can be run for the other variants as well. At the
moment this is only bdrv_drain_begin/end(), but in a while, we'll add
another one.

Also, add a backing file to the test node to test whether the operations
work recursively.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/test-bdrv-drain.c | 69 ++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 62 insertions(+), 7 deletions(-)

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -XXX,XX +XXX,XX @@ static BlockDriver bdrv_test = {
 
     .bdrv_co_drain_begin    = bdrv_test_co_drain_begin,
     .bdrv_co_drain_end      = bdrv_test_co_drain_end,
+
+    .bdrv_child_perm        = bdrv_format_default_perms,
 };
 
 static void aio_ret_cb(void *opaque, int ret)
@@ -XXX,XX +XXX,XX @@ static void aio_ret_cb(void *opaque, int ret)
     *aio_ret = ret;
 }
 
-static void test_drv_cb_drain_all(void)
+enum drain_type {
+    BDRV_DRAIN_ALL,
+    BDRV_DRAIN,
+};
+
+static void do_drain_begin(enum drain_type drain_type, BlockDriverState *bs)
+{
+    switch (drain_type) {
+    case BDRV_DRAIN_ALL:        bdrv_drain_all_begin(); break;
+    case BDRV_DRAIN:            bdrv_drained_begin(bs); break;
+    default:                    g_assert_not_reached();
+    }
+}
+
+static void do_drain_end(enum drain_type drain_type, BlockDriverState *bs)
+{
+    switch (drain_type) {
+    case BDRV_DRAIN_ALL:        bdrv_drain_all_end(); break;
+    case BDRV_DRAIN:            bdrv_drained_end(bs); break;
+    default:                    g_assert_not_reached();
+    }
+}
+
+static void test_drv_cb_common(enum drain_type drain_type, bool recursive)
 {
     BlockBackend *blk;
-    BlockDriverState *bs;
-    BDRVTestState *s;
+    BlockDriverState *bs, *backing;
+    BDRVTestState *s, *backing_s;
     BlockAIOCB *acb;
     int aio_ret;
 
@@ -XXX,XX +XXX,XX @@ static void test_drv_cb_drain_all(void)
     s = bs->opaque;
     blk_insert_bs(blk, bs, &error_abort);
 
+    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort);
+    backing_s = backing->opaque;
+    bdrv_set_backing_hd(bs, backing, &error_abort);
+
     /* Simple bdrv_drain_all_begin/end pair, check that CBs are called */
     g_assert_cmpint(s->drain_count, ==, 0);
-    bdrv_drain_all_begin();
+    g_assert_cmpint(backing_s->drain_count, ==, 0);
+
+    do_drain_begin(drain_type, bs);
+
     g_assert_cmpint(s->drain_count, ==, 1);
-    bdrv_drain_all_end();
+    g_assert_cmpint(backing_s->drain_count, ==, !!recursive);
+
+    do_drain_end(drain_type, bs);
+
     g_assert_cmpint(s->drain_count, ==, 0);
+    g_assert_cmpint(backing_s->drain_count, ==, 0);
 
     /* Now do the same while a request is pending */
     aio_ret = -EINPROGRESS;
@@ -XXX,XX +XXX,XX @@ static void test_drv_cb_drain_all(void)
     g_assert_cmpint(aio_ret, ==, -EINPROGRESS);
 
     g_assert_cmpint(s->drain_count, ==, 0);
-    bdrv_drain_all_begin();
+    g_assert_cmpint(backing_s->drain_count, ==, 0);
+
+    do_drain_begin(drain_type, bs);
+
     g_assert_cmpint(aio_ret, ==, 0);
     g_assert_cmpint(s->drain_count, ==, 1);
-    bdrv_drain_all_end();
+    g_assert_cmpint(backing_s->drain_count, ==, !!recursive);
+
+    do_drain_end(drain_type, bs);
+
     g_assert_cmpint(s->drain_count, ==, 0);
+    g_assert_cmpint(backing_s->drain_count, ==, 0);
 
+    bdrv_unref(backing);
     bdrv_unref(bs);
     blk_unref(blk);
 }
 
+static void test_drv_cb_drain_all(void)
+{
+    test_drv_cb_common(BDRV_DRAIN_ALL, true);
+}
+
+static void test_drv_cb_drain(void)
+{
+    test_drv_cb_common(BDRV_DRAIN, false);
+}
+
 int main(int argc, char **argv)
 {
     bdrv_init();
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
     g_test_init(&argc, &argv, NULL);
 
     g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all);
+    g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain);
 
     return g_test_run();
 }
-- 
2.13.6

This is currently only working correctly for bdrv_drain(), not for
bdrv_drain_all(). Leave a comment for the drain_all case, we'll address
it later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/test-bdrv-drain.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -XXX,XX +XXX,XX @@ static void test_drv_cb_drain(void)
     test_drv_cb_common(BDRV_DRAIN, false);
 }
 
+static void test_quiesce_common(enum drain_type drain_type, bool recursive)
+{
+    BlockBackend *blk;
+    BlockDriverState *bs, *backing;
+
+    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
+                              &error_abort);
+    blk_insert_bs(blk, bs, &error_abort);
+
+    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort);
+    bdrv_set_backing_hd(bs, backing, &error_abort);
+
+    g_assert_cmpint(bs->quiesce_counter, ==, 0);
+    g_assert_cmpint(backing->quiesce_counter, ==, 0);
+
+    do_drain_begin(drain_type, bs);
+
+    g_assert_cmpint(bs->quiesce_counter, ==, 1);
+    g_assert_cmpint(backing->quiesce_counter, ==, !!recursive);
+
+    do_drain_end(drain_type, bs);
+
+    g_assert_cmpint(bs->quiesce_counter, ==, 0);
+    g_assert_cmpint(backing->quiesce_counter, ==, 0);
+
+    bdrv_unref(backing);
+    bdrv_unref(bs);
+    blk_unref(blk);
+}
+
+static void test_quiesce_drain_all(void)
+{
+    // XXX drain_all doesn't quiesce
+    //test_quiesce_common(BDRV_DRAIN_ALL, true);
+}
+
+static void test_quiesce_drain(void)
+{
+    test_quiesce_common(BDRV_DRAIN, false);
+}
+
 int main(int argc, char **argv)
 {
     bdrv_init();
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
     g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all);
     g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain);
 
+    g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all);
+    g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain);
+
     return g_test_run();
 }
-- 
2.13.6

Block jobs already paused themselves when their main BlockBackend
entered a drained section. This is not good enough: We also want to
pause a block job and may not submit new requests if, for example, the
mirror target node should be drained.

This implements .drained_begin/end callbacks in child_job in order to
consider all block nodes related to the job, and removes the
BlockBackend callbacks which are unnecessary now because the root of the
job main BlockBackend is always referenced with a child_job, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 blockjob.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ static char *child_job_get_parent_desc(BdrvChild *c)
                            job->id);
 }
 
-static const BdrvChildRole child_job = {
-    .get_parent_desc    = child_job_get_parent_desc,
-    .stay_at_node       = true,
-};
-
-static void block_job_drained_begin(void *opaque)
+static void child_job_drained_begin(BdrvChild *c)
 {
-    BlockJob *job = opaque;
+    BlockJob *job = c->opaque;
     block_job_pause(job);
 }
 
-static void block_job_drained_end(void *opaque)
+static void child_job_drained_end(BdrvChild *c)
 {
-    BlockJob *job = opaque;
+    BlockJob *job = c->opaque;
     block_job_resume(job);
 }
 
-static const BlockDevOps block_job_dev_ops = {
-    .drained_begin = block_job_drained_begin,
-    .drained_end = block_job_drained_end,
+static const BdrvChildRole child_job = {
+    .get_parent_desc    = child_job_get_parent_desc,
+    .drained_begin      = child_job_drained_begin,
+    .drained_end        = child_job_drained_end,
+    .stay_at_node       = true,
 };
 
 void block_job_remove_all_bdrv(BlockJob *job)
@@ -XXX,XX +XXX,XX @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,
     block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort);
     bs->job = job;
 
-    blk_set_dev_ops(blk, &block_job_dev_ops, job);
     bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
 
     QLIST_INSERT_HEAD(&block_jobs, job, job_list);
-- 
2.13.6

Block jobs must be paused if any of the involved nodes are drained.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/test-bdrv-drain.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -XXX,XX +XXX,XX @@
 
 #include "qemu/osdep.h"
 #include "block/block.h"
+#include "block/blockjob_int.h"
 #include "sysemu/block-backend.h"
 #include "qapi/error.h"
 
@@ -XXX,XX +XXX,XX @@ static void test_quiesce_drain(void)
     test_quiesce_common(BDRV_DRAIN, false);
 }
 
+
+typedef struct TestBlockJob {
+    BlockJob common;
+    bool should_complete;
+} TestBlockJob;
+
+static void test_job_completed(BlockJob *job, void *opaque)
+{
+    block_job_completed(job, 0);
+}
+
+static void coroutine_fn test_job_start(void *opaque)
+{
+    TestBlockJob *s = opaque;
+
+    while (!s->should_complete) {
+        block_job_sleep_ns(&s->common, 100000);
+    }
+
+    block_job_defer_to_main_loop(&s->common, test_job_completed, NULL);
+}
+
+static void test_job_complete(BlockJob *job, Error **errp)
+{
+    TestBlockJob *s = container_of(job, TestBlockJob, common);
+    s->should_complete = true;
+}
+
+BlockJobDriver test_job_driver = {
+    .instance_size  = sizeof(TestBlockJob),
+    .start          = test_job_start,
+    .complete       = test_job_complete,
+};
+
+static void test_blockjob_common(enum drain_type drain_type)
+{
+    BlockBackend *blk_src, *blk_target;
+    BlockDriverState *src, *target;
+    BlockJob *job;
+    int ret;
+
+    src = bdrv_new_open_driver(&bdrv_test, "source", BDRV_O_RDWR,
+                               &error_abort);
+    blk_src = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk_insert_bs(blk_src, src, &error_abort);
+
+    target = bdrv_new_open_driver(&bdrv_test, "target", BDRV_O_RDWR,
+                                  &error_abort);
+    blk_target = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk_insert_bs(blk_target, target, &error_abort);
+
+    job = block_job_create("job0", &test_job_driver, src, 0, BLK_PERM_ALL, 0,
+                           0, NULL, NULL, &error_abort);
+    block_job_add_bdrv(job, "target", target, 0, BLK_PERM_ALL, &error_abort);
+    block_job_start(job);
+
+    g_assert_cmpint(job->pause_count, ==, 0);
+    g_assert_false(job->paused);
+    g_assert_false(job->busy); /* We're in block_job_sleep_ns() */
+
+    do_drain_begin(drain_type, src);
+
+    if (drain_type == BDRV_DRAIN_ALL) {
+        /* bdrv_drain_all() drains both src and target, and involves an
+         * additional block_job_pause_all() */
+        g_assert_cmpint(job->pause_count, ==, 3);
+    } else {
+        g_assert_cmpint(job->pause_count, ==, 1);
+    }
+    /* XXX We don't wait until the job is actually paused. Is this okay? */
+    /* g_assert_true(job->paused); */
+    g_assert_false(job->busy); /* The job is paused */
+
+    do_drain_end(drain_type, src);
+
+    g_assert_cmpint(job->pause_count, ==, 0);
+    g_assert_false(job->paused);
+    g_assert_false(job->busy); /* We're in block_job_sleep_ns() */
+
+    do_drain_begin(drain_type, target);
+
+    if (drain_type == BDRV_DRAIN_ALL) {
+        /* bdrv_drain_all() drains both src and target, and involves an
+         * additional block_job_pause_all() */
+        g_assert_cmpint(job->pause_count, ==, 3);
+    } else {
+        g_assert_cmpint(job->pause_count, ==, 1);
+    }
+    /* XXX We don't wait until the job is actually paused. Is this okay? */
+    /* g_assert_true(job->paused); */
+    g_assert_false(job->busy); /* The job is paused */
+
+    do_drain_end(drain_type, target);
+
+    g_assert_cmpint(job->pause_count, ==, 0);
+    g_assert_false(job->paused);
+    g_assert_false(job->busy); /* We're in block_job_sleep_ns() */
+
+    ret = block_job_complete_sync(job, &error_abort);
+    g_assert_cmpint(ret, ==, 0);
+
+    blk_unref(blk_src);
+    blk_unref(blk_target);
+    bdrv_unref(src);
+    bdrv_unref(target);
+}
+
+static void test_blockjob_drain_all(void)
+{
+    test_blockjob_common(BDRV_DRAIN_ALL);
+}
+
+static void test_blockjob_drain(void)
+{
+    test_blockjob_common(BDRV_DRAIN);
+}
+
 int main(int argc, char **argv)
 {
     bdrv_init();
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
     g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all);
     g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain);
 
+    g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
+    g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain);
+
     return g_test_run();
 }
-- 
2.13.6

Block jobs are already paused using the BdrvChildRole drain callbacks,
so we don't need an additional block_job_pause_all() call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/io.c              |  4 ----
 tests/test-bdrv-drain.c | 10 ++++------
 2 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
      * context. */
     assert(qemu_get_current_aio_context() == qemu_get_aio_context());
 
-    block_job_pause_all();
-
     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
         AioContext *aio_context = bdrv_get_aio_context(bs);
 
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
         aio_enable_external(aio_context);
         aio_context_release(aio_context);
     }
-
-    block_job_resume_all();
 }
 
 void bdrv_drain_all(void)
diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -XXX,XX +XXX,XX @@ static void test_blockjob_common(enum drain_type drain_type)
     do_drain_begin(drain_type, src);
 
     if (drain_type == BDRV_DRAIN_ALL) {
-        /* bdrv_drain_all() drains both src and target, and involves an
-         * additional block_job_pause_all() */
-        g_assert_cmpint(job->pause_count, ==, 3);
+        /* bdrv_drain_all() drains both src and target */
+        g_assert_cmpint(job->pause_count, ==, 2);
     } else {
         g_assert_cmpint(job->pause_count, ==, 1);
     }
@@ -XXX,XX +XXX,XX @@ static void test_blockjob_common(enum drain_type drain_type)
     do_drain_begin(drain_type, target);
 
     if (drain_type == BDRV_DRAIN_ALL) {
-        /* bdrv_drain_all() drains both src and target, and involves an
-         * additional block_job_pause_all() */
-        g_assert_cmpint(job->pause_count, ==, 3);
+        /* bdrv_drain_all() drains both src and target */
+        g_assert_cmpint(job->pause_count, ==, 2);
     } else {
         g_assert_cmpint(job->pause_count, ==, 1);
     }
-- 
2.13.6

bdrv_do_drained_begin() restricts the call of parent callbacks and
aio_disable_external() to the outermost drain section, but the block
driver callbacks are always called. bdrv_do_drained_end() must match
this behaviour, otherwise nodes stay drained even if begin/end calls
were balanced.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/io.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs)
 
 void bdrv_drained_end(BlockDriverState *bs)
 {
+    int old_quiesce_counter;
+
     if (qemu_in_coroutine()) {
         bdrv_co_yield_to_drain(bs, false);
         return;
     }
     assert(bs->quiesce_counter > 0);
-    if (atomic_fetch_dec(&bs->quiesce_counter) > 1) {
-        return;
-    }
+    old_quiesce_counter = atomic_fetch_dec(&bs->quiesce_counter);
 
     /* Re-enable things in child-to-parent order */
     bdrv_drain_invoke(bs, false, false);
-    bdrv_parent_drained_end(bs);
-    aio_enable_external(bdrv_get_aio_context(bs));
+    if (old_quiesce_counter == 1) {
+        bdrv_parent_drained_end(bs);
+        aio_enable_external(bdrv_get_aio_context(bs));
+    }
 }
 
 /*
-- 
2.13.6

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/test-bdrv-drain.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -XXX,XX +XXX,XX @@ static void aio_ret_cb(void *opaque, int ret)
 enum drain_type {
     BDRV_DRAIN_ALL,
     BDRV_DRAIN,
+    DRAIN_TYPE_MAX,
 };
 
 static void do_drain_begin(enum drain_type drain_type, BlockDriverState *bs)
@@ -XXX,XX +XXX,XX @@ static void test_quiesce_drain(void)
     test_quiesce_common(BDRV_DRAIN, false);
 }
 
+static void test_nested(void)
+{
+    BlockBackend *blk;
+    BlockDriverState *bs, *backing;
+    BDRVTestState *s, *backing_s;
+    enum drain_type outer, inner;
+
+    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
+                              &error_abort);
+    s = bs->opaque;
+    blk_insert_bs(blk, bs, &error_abort);
+
+    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort);
+    backing_s = backing->opaque;
+    bdrv_set_backing_hd(bs, backing, &error_abort);
+
+    for (outer = 0; outer < DRAIN_TYPE_MAX; outer++) {
+        for (inner = 0; inner < DRAIN_TYPE_MAX; inner++) {
+            /* XXX bdrv_drain_all() doesn't increase the quiesce_counter */
+            int bs_quiesce      = (outer != BDRV_DRAIN_ALL) +
+                                  (inner != BDRV_DRAIN_ALL);
+            int backing_quiesce = 0;
+            int backing_cb_cnt  = (outer != BDRV_DRAIN) +
+                                  (inner != BDRV_DRAIN);
+
+            g_assert_cmpint(bs->quiesce_counter, ==, 0);
+            g_assert_cmpint(backing->quiesce_counter, ==, 0);
+            g_assert_cmpint(s->drain_count, ==, 0);
+            g_assert_cmpint(backing_s->drain_count, ==, 0);
+
+            do_drain_begin(outer, bs);
+            do_drain_begin(inner, bs);
+
+            g_assert_cmpint(bs->quiesce_counter, ==, bs_quiesce);
+            g_assert_cmpint(backing->quiesce_counter, ==, backing_quiesce);
+            g_assert_cmpint(s->drain_count, ==, 2);
+            g_assert_cmpint(backing_s->drain_count, ==, backing_cb_cnt);
+
+            do_drain_end(inner, bs);
+            do_drain_end(outer, bs);
+
+            g_assert_cmpint(bs->quiesce_counter, ==, 0);
+            g_assert_cmpint(backing->quiesce_counter, ==, 0);
+            g_assert_cmpint(s->drain_count, ==, 0);
+            g_assert_cmpint(backing_s->drain_count, ==, 0);
+        }
+    }
+
+    bdrv_unref(backing);
+    bdrv_unref(bs);
+    blk_unref(blk);
+}
+
 
 typedef struct TestBlockJob {
     BlockJob common;
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
     g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all);
     g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain);
 
+    g_test_add_func("/bdrv-drain/nested", test_nested);
+
     g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
     g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain);
 
-- 
2.13.6

This is in preparation for subtree drains, i.e. drained sections that
affect not only a single node, but recursively all child nodes, too.

Calling the parent callbacks for drain is pointless when we just came
from that parent node recursively and leads to multiple increases of
bs->quiesce_counter in a single drain call. Don't do it.

In order for this to work correctly, the parent callback must be called
for every bdrv_drain_begin/end() call, not only for the outermost one:

If we have a node N with two parents A and B, recursive draining of A
should cause the quiesce_counter of B to increase because its child N is
drained independently of B. If now B is recursively drained, too, A must
increase its quiesce_counter because N is drained independently of A
only now, even if N is going from quiesce_counter 1 to 2.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/block.h |  4 ++--
 block.c               | 13 +++++++++----
 block/io.c            | 47 ++++++++++++++++++++++++++++++++++-------------
 3 files changed, 45 insertions(+), 19 deletions(-)

diff --git a/include/block/block.h b/include/block/block.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -XXX,XX +XXX,XX @@ void bdrv_io_unplug(BlockDriverState *bs);
  * Begin a quiesced section of all users of @bs. This is part of
  * bdrv_drained_begin.
  */
-void bdrv_parent_drained_begin(BlockDriverState *bs);
+void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore);
 
 /**
  * bdrv_parent_drained_end:
@@ -XXX,XX +XXX,XX @@ void bdrv_parent_drained_begin(BlockDriverState *bs);
  * End a quiesced section of all users of @bs. This is part of
  * bdrv_drained_end.
  */
-void bdrv_parent_drained_end(BlockDriverState *bs);
+void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore);
 
 /**
  * bdrv_drained_begin:
diff --git a/block.c b/block.c
index XXXXXXX..XXXXXXX 100644
--- a/block.c
+++ b/block.c
@@ -XXX,XX +XXX,XX @@ static void bdrv_replace_child_noperm(BdrvChild *child,
                                       BlockDriverState *new_bs)
 {
     BlockDriverState *old_bs = child->bs;
+    int i;
 
     if (old_bs && new_bs) {
         assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
     }
     if (old_bs) {
         if (old_bs->quiesce_counter && child->role->drained_end) {
-            child->role->drained_end(child);
+            for (i = 0; i < old_bs->quiesce_counter; i++) {
+                child->role->drained_end(child);
+            }
         }
         if (child->role->detach) {
             child->role->detach(child);
@@ -XXX,XX +XXX,XX @@ static void bdrv_replace_child_noperm(BdrvChild *child,
     if (new_bs) {
         QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
         if (new_bs->quiesce_counter && child->role->drained_begin) {
-            child->role->drained_begin(child);
+            for (i = 0; i < new_bs->quiesce_counter; i++) {
+                child->role->drained_begin(child);
+            }
         }
 
         if (child->role->attach) {
@@ -XXX,XX +XXX,XX @@ void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
     AioContext *ctx = bdrv_get_aio_context(bs);
 
     aio_disable_external(ctx);
-    bdrv_parent_drained_begin(bs);
+    bdrv_parent_drained_begin(bs, NULL);
     bdrv_drain(bs); /* ensure there are no in-flight requests */
 
     while (aio_poll(ctx, false)) {
@@ -XXX,XX +XXX,XX @@ void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
      */
     aio_context_acquire(new_context);
     bdrv_attach_aio_context(bs, new_context);
-    bdrv_parent_drained_end(bs);
+    bdrv_parent_drained_end(bs, NULL);
     aio_enable_external(ctx);
     aio_context_release(new_context);
 }
diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@
 static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
     int64_t offset, int bytes, BdrvRequestFlags flags);
 
-void bdrv_parent_drained_begin(BlockDriverState *bs)
+void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore)
 {
     BdrvChild *c, *next;
 
     QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) {
+        if (c == ignore) {
+            continue;
+        }
         if (c->role->drained_begin) {
             c->role->drained_begin(c);
         }
     }
 }
 
-void bdrv_parent_drained_end(BlockDriverState *bs)
+void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore)
 {
     BdrvChild *c, *next;
 
     QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) {
+        if (c == ignore) {
+            continue;
+        }
         if (c->role->drained_end) {
             c->role->drained_end(c);
         }
@@ -XXX,XX +XXX,XX @@ typedef struct {
     BlockDriverState *bs;
     bool done;
     bool begin;
+    BdrvChild *parent;
 } BdrvCoDrainData;
 
 static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
@@ -XXX,XX +XXX,XX @@ static bool bdrv_drain_recurse(BlockDriverState *bs)
     return waited;
 }
 
+static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent);
+static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent);
+
 static void bdrv_co_drain_bh_cb(void *opaque)
 {
     BdrvCoDrainData *data = opaque;
@@ -XXX,XX +XXX,XX @@ static void bdrv_co_drain_bh_cb(void *opaque)
 
     bdrv_dec_in_flight(bs);
     if (data->begin) {
-        bdrv_drained_begin(bs);
+        bdrv_do_drained_begin(bs, data->parent);
     } else {
-        bdrv_drained_end(bs);
+        bdrv_do_drained_end(bs, data->parent);
     }
 
     data->done = true;
@@ -XXX,XX +XXX,XX @@ static void bdrv_co_drain_bh_cb(void *opaque)
 }
 
 static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
-                                                bool begin)
+                                                bool begin, BdrvChild *parent)
 {
     BdrvCoDrainData data;
 
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
         .bs = bs,
         .done = false,
         .begin = begin,
+        .parent = parent,
     };
     bdrv_inc_in_flight(bs);
     aio_bh_schedule_oneshot(bdrv_get_aio_context(bs),
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
     assert(data.done);
 }
 
-void bdrv_drained_begin(BlockDriverState *bs)
+static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent)
 {
     if (qemu_in_coroutine()) {
-        bdrv_co_yield_to_drain(bs, true);
+        bdrv_co_yield_to_drain(bs, true, parent);
         return;
     }
 
     /* Stop things in parent-to-child order */
     if (atomic_fetch_inc(&bs->quiesce_counter) == 0) {
         aio_disable_external(bdrv_get_aio_context(bs));
-        bdrv_parent_drained_begin(bs);
     }
 
+    bdrv_parent_drained_begin(bs, parent);
     bdrv_drain_invoke(bs, true, false);
     bdrv_drain_recurse(bs);
 }
 
-void bdrv_drained_end(BlockDriverState *bs)
+void bdrv_drained_begin(BlockDriverState *bs)
+{
+    bdrv_do_drained_begin(bs, NULL);
+}
+
+static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent)
 {
     int old_quiesce_counter;
 
     if (qemu_in_coroutine()) {
-        bdrv_co_yield_to_drain(bs, false);
+        bdrv_co_yield_to_drain(bs, false, parent);
         return;
     }
     assert(bs->quiesce_counter > 0);
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_end(BlockDriverState *bs)
 
     /* Re-enable things in child-to-parent order */
     bdrv_drain_invoke(bs, false, false);
+    bdrv_parent_drained_end(bs, parent);
     if (old_quiesce_counter == 1) {
-        bdrv_parent_drained_end(bs);
         aio_enable_external(bdrv_get_aio_context(bs));
     }
 }
 
+void bdrv_drained_end(BlockDriverState *bs)
+{
+    bdrv_do_drained_end(bs, NULL);
+}
+
 /*
  * Wait for pending requests to complete on a single BlockDriverState subtree,
  * and suspend block driver's internal I/O until next request arrives.
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
         /* Stop things in parent-to-child order */
         aio_context_acquire(aio_context);
         aio_disable_external(aio_context);
-        bdrv_parent_drained_begin(bs);
+        bdrv_parent_drained_begin(bs, NULL);
         bdrv_drain_invoke(bs, true, true);
         aio_context_release(aio_context);
 
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
         /* Re-enable things in child-to-parent order */
         aio_context_acquire(aio_context);
         bdrv_drain_invoke(bs, false, true);
-        bdrv_parent_drained_end(bs);
+        bdrv_parent_drained_end(bs, NULL);
         aio_enable_external(aio_context);
         aio_context_release(aio_context);
     }
-- 
2.13.6

bdrv_drained_begin() waits for the completion of requests in the whole
subtree, but it only actually keeps its immediate bs parameter quiesced
until bdrv_drained_end().

Add a version that keeps the whole subtree drained. As of this commit,
graph changes cannot be allowed during a subtree drained section, but
this will be fixed soon.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/block.h | 13 +++++++++++++
 block/io.c            | 54 ++++++++++++++++++++++++++++++++++++++++-----------
 2 files changed, 56 insertions(+), 11 deletions(-)

diff --git a/include/block/block.h b/include/block/block.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -XXX,XX +XXX,XX @@ void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore);
 void bdrv_drained_begin(BlockDriverState *bs);
 
 /**
+ * Like bdrv_drained_begin, but recursively begins a quiesced section for
+ * exclusive access to all child nodes as well.
+ *
+ * Graph changes are not allowed during a subtree drain section.
+ */
+void bdrv_subtree_drained_begin(BlockDriverState *bs);
+
+/**
  * bdrv_drained_end:
  *
  * End a quiescent section started by bdrv_drained_begin().
  */
 void bdrv_drained_end(BlockDriverState *bs);
 
+/**
+ * End a quiescent section started by bdrv_subtree_drained_begin().
+ */
+void bdrv_subtree_drained_end(BlockDriverState *bs);
+
 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
                     Error **errp);
 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ typedef struct {
     BlockDriverState *bs;
     bool done;
     bool begin;
+    bool recursive;
     BdrvChild *parent;
 } BdrvCoDrainData;
 
@@ -XXX,XX +XXX,XX @@ static bool bdrv_drain_recurse(BlockDriverState *bs)
     return waited;
 }
 
-static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent);
-static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent);
+static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
+                                  BdrvChild *parent);
+static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
+                                BdrvChild *parent);
 
 static void bdrv_co_drain_bh_cb(void *opaque)
 {
@@ -XXX,XX +XXX,XX @@ static void bdrv_co_drain_bh_cb(void *opaque)
 
     bdrv_dec_in_flight(bs);
     if (data->begin) {
-        bdrv_do_drained_begin(bs, data->parent);
+        bdrv_do_drained_begin(bs, data->recursive, data->parent);
     } else {
-        bdrv_do_drained_end(bs, data->parent);
+        bdrv_do_drained_end(bs, data->recursive, data->parent);
     }
 
     data->done = true;
@@ -XXX,XX +XXX,XX @@ static void bdrv_co_drain_bh_cb(void *opaque)
 }
 
 static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
-                                                bool begin, BdrvChild *parent)
+                                                bool begin, bool recursive,
+                                                BdrvChild *parent)
 {
     BdrvCoDrainData data;
 
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
         .bs = bs,
         .done = false,
         .begin = begin,
+        .recursive = recursive,
         .parent = parent,
     };
     bdrv_inc_in_flight(bs);
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
     assert(data.done);
 }
 
-static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent)
+static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
+                                  BdrvChild *parent)
 {
+    BdrvChild *child, *next;
+
     if (qemu_in_coroutine()) {
-        bdrv_co_yield_to_drain(bs, true, parent);
+        bdrv_co_yield_to_drain(bs, true, recursive, parent);
         return;
     }
 
@@ -XXX,XX +XXX,XX @@ static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent)
     bdrv_parent_drained_begin(bs, parent);
     bdrv_drain_invoke(bs, true, false);
     bdrv_drain_recurse(bs);
+
+    if (recursive) {
+        QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
+            bdrv_do_drained_begin(child->bs, true, child);
+        }
+    }
 }
 
 void bdrv_drained_begin(BlockDriverState *bs)
 {
-    bdrv_do_drained_begin(bs, NULL);
+    bdrv_do_drained_begin(bs, false, NULL);
+}
+
+void bdrv_subtree_drained_begin(BlockDriverState *bs)
+{
+    bdrv_do_drained_begin(bs, true, NULL);
 }
 
-static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent)
+static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
+                                BdrvChild *parent)
 {
+    BdrvChild *child, *next;
     int old_quiesce_counter;
 
     if (qemu_in_coroutine()) {
-        bdrv_co_yield_to_drain(bs, false, parent);
+        bdrv_co_yield_to_drain(bs, false, recursive, parent);
         return;
     }
     assert(bs->quiesce_counter > 0);
@@ -XXX,XX +XXX,XX @@ static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent)
     if (old_quiesce_counter == 1) {
         aio_enable_external(bdrv_get_aio_context(bs));
     }
+
+    if (recursive) {
+        QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
+            bdrv_do_drained_end(child->bs, true, child);
+        }
+    }
 }
 
 void bdrv_drained_end(BlockDriverState *bs)
 {
-    bdrv_do_drained_end(bs, NULL);
+    bdrv_do_drained_end(bs, false, NULL);
+}
+
+void bdrv_subtree_drained_end(BlockDriverState *bs)
+{
+    bdrv_do_drained_end(bs, true, NULL);
 }
 
 /*
-- 
2.13.6

Add a subtree drain version to the existing test cases.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/test-bdrv-drain.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -XXX,XX +XXX,XX @@ static void aio_ret_cb(void *opaque, int ret)
 enum drain_type {
     BDRV_DRAIN_ALL,
     BDRV_DRAIN,
+    BDRV_SUBTREE_DRAIN,
     DRAIN_TYPE_MAX,
 };
 
@@ -XXX,XX +XXX,XX @@ static void do_drain_begin(enum drain_type drain_type, BlockDriverState *bs)
     switch (drain_type) {
     case BDRV_DRAIN_ALL:        bdrv_drain_all_begin(); break;
     case BDRV_DRAIN:            bdrv_drained_begin(bs); break;
+    case BDRV_SUBTREE_DRAIN:    bdrv_subtree_drained_begin(bs); break;
     default:                    g_assert_not_reached();
     }
 }
@@ -XXX,XX +XXX,XX @@ static void do_drain_end(enum drain_type drain_type, BlockDriverState *bs)
     switch (drain_type) {
     case BDRV_DRAIN_ALL:        bdrv_drain_all_end(); break;
     case BDRV_DRAIN:            bdrv_drained_end(bs); break;
+    case BDRV_SUBTREE_DRAIN:    bdrv_subtree_drained_end(bs); break;
     default:                    g_assert_not_reached();
     }
 }
@@ -XXX,XX +XXX,XX @@ static void test_drv_cb_drain(void)
     test_drv_cb_common(BDRV_DRAIN, false);
 }
 
+static void test_drv_cb_drain_subtree(void)
+{
+    test_drv_cb_common(BDRV_SUBTREE_DRAIN, true);
+}
+
 static void test_quiesce_common(enum drain_type drain_type, bool recursive)
 {
     BlockBackend *blk;
@@ -XXX,XX +XXX,XX @@ static void test_quiesce_drain(void)
     test_quiesce_common(BDRV_DRAIN, false);
 }
 
+static void test_quiesce_drain_subtree(void)
+{
+    test_quiesce_common(BDRV_SUBTREE_DRAIN, true);
+}
+
 static void test_nested(void)
 {
     BlockBackend *blk;
@@ -XXX,XX +XXX,XX @@ static void test_nested(void)
             /* XXX bdrv_drain_all() doesn't increase the quiesce_counter */
             int bs_quiesce      = (outer != BDRV_DRAIN_ALL) +
                                   (inner != BDRV_DRAIN_ALL);
-            int backing_quiesce = 0;
+            int backing_quiesce = (outer == BDRV_SUBTREE_DRAIN) +
+                                  (inner == BDRV_SUBTREE_DRAIN);
             int backing_cb_cnt  = (outer != BDRV_DRAIN) +
                                   (inner != BDRV_DRAIN);
 
@@ -XXX,XX +XXX,XX @@ static void test_blockjob_drain(void)
     test_blockjob_common(BDRV_DRAIN);
 }
 
+static void test_blockjob_drain_subtree(void)
+{
+    test_blockjob_common(BDRV_SUBTREE_DRAIN);
+}
+
 int main(int argc, char **argv)
 {
     bdrv_init();
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
 
     g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all);
     g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain);
+    g_test_add_func("/bdrv-drain/driver-cb/drain_subtree",
+                    test_drv_cb_drain_subtree);
 
     g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all);
     g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain);
+    g_test_add_func("/bdrv-drain/quiesce/drain_subtree",
+                    test_quiesce_drain_subtree);
 
     g_test_add_func("/bdrv-drain/nested", test_nested);
 
     g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
     g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain);
+    g_test_add_func("/bdrv-drain/blockjob/drain_subtree",
+                    test_blockjob_drain_subtree);
 
     return g_test_run();
 }
-- 
2.13.6

If bdrv_do_drained_begin/end() are called in coroutine context, they
first use a BH to get out of the coroutine context. Call some existing
tests again from a coroutine to cover this code path.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/test-bdrv-drain.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -XXX,XX +XXX,XX @@ static void aio_ret_cb(void *opaque, int ret)
     *aio_ret = ret;
 }
 
+typedef struct CallInCoroutineData {
+    void (*entry)(void);
+    bool done;
+} CallInCoroutineData;
+
+static coroutine_fn void call_in_coroutine_entry(void *opaque)
+{
+    CallInCoroutineData *data = opaque;
+
+    data->entry();
+    data->done = true;
+}
+
+static void call_in_coroutine(void (*entry)(void))
+{
+    Coroutine *co;
+    CallInCoroutineData data = {
+        .entry  = entry,
+        .done   = false,
+    };
+
+    co = qemu_coroutine_create(call_in_coroutine_entry, &data);
+    qemu_coroutine_enter(co);
+    while (!data.done) {
+        aio_poll(qemu_get_aio_context(), true);
+    }
+}
+
 enum drain_type {
     BDRV_DRAIN_ALL,
     BDRV_DRAIN,
@@ -XXX,XX +XXX,XX @@ static void test_drv_cb_drain_subtree(void)
     test_drv_cb_common(BDRV_SUBTREE_DRAIN, true);
 }
 
+static void test_drv_cb_co_drain(void)
+{
+    call_in_coroutine(test_drv_cb_drain);
+}
+
+static void test_drv_cb_co_drain_subtree(void)
+{
+    call_in_coroutine(test_drv_cb_drain_subtree);
+}
+
 static void test_quiesce_common(enum drain_type drain_type, bool recursive)
 {
     BlockBackend *blk;
@@ -XXX,XX +XXX,XX @@ static void test_quiesce_drain_subtree(void)
     test_quiesce_common(BDRV_SUBTREE_DRAIN, true);
 }
 
+static void test_quiesce_co_drain(void)
+{
+    call_in_coroutine(test_quiesce_drain);
+}
+
+static void test_quiesce_co_drain_subtree(void)
+{
+    call_in_coroutine(test_quiesce_drain_subtree);
+}
+
 static void test_nested(void)
 {
     BlockBackend *blk;
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
     g_test_add_func("/bdrv-drain/driver-cb/drain_subtree",
                     test_drv_cb_drain_subtree);
 
+    // XXX bdrv_drain_all() doesn't work in coroutine context
+    g_test_add_func("/bdrv-drain/driver-cb/co/drain", test_drv_cb_co_drain);
+    g_test_add_func("/bdrv-drain/driver-cb/co/drain_subtree",
+                    test_drv_cb_co_drain_subtree);
+
+
     g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all);
     g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain);
     g_test_add_func("/bdrv-drain/quiesce/drain_subtree",
                     test_quiesce_drain_subtree);
 
+    // XXX bdrv_drain_all() doesn't work in coroutine context
+    g_test_add_func("/bdrv-drain/quiesce/co/drain", test_quiesce_co_drain);
+    g_test_add_func("/bdrv-drain/quiesce/co/drain_subtree",
+                    test_quiesce_co_drain_subtree);
+
     g_test_add_func("/bdrv-drain/nested", test_nested);
 
     g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
-- 
2.13.6

Test that drain sections are correctly propagated through the graph.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/test-bdrv-drain.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -XXX,XX +XXX,XX @@ static void test_nested(void)
     blk_unref(blk);
 }
 
+static void test_multiparent(void)
+{
+    BlockBackend *blk_a, *blk_b;
+    BlockDriverState *bs_a, *bs_b, *backing;
+    BDRVTestState *a_s, *b_s, *backing_s;
+
+    blk_a = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR,
+                                &error_abort);
+    a_s = bs_a->opaque;
+    blk_insert_bs(blk_a, bs_a, &error_abort);
+
+    blk_b = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR,
+                                &error_abort);
+    b_s = bs_b->opaque;
+    blk_insert_bs(blk_b, bs_b, &error_abort);
+
+    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort);
+    backing_s = backing->opaque;
+    bdrv_set_backing_hd(bs_a, backing, &error_abort);
+    bdrv_set_backing_hd(bs_b, backing, &error_abort);
+
+    g_assert_cmpint(bs_a->quiesce_counter, ==, 0);
+    g_assert_cmpint(bs_b->quiesce_counter, ==, 0);
+    g_assert_cmpint(backing->quiesce_counter, ==, 0);
+    g_assert_cmpint(a_s->drain_count, ==, 0);
+    g_assert_cmpint(b_s->drain_count, ==, 0);
+    g_assert_cmpint(backing_s->drain_count, ==, 0);
+
+    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a);
+
+    g_assert_cmpint(bs_a->quiesce_counter, ==, 1);
+    g_assert_cmpint(bs_b->quiesce_counter, ==, 1);
+    g_assert_cmpint(backing->quiesce_counter, ==, 1);
+    g_assert_cmpint(a_s->drain_count, ==, 1);
+    g_assert_cmpint(b_s->drain_count, ==, 1);
+    g_assert_cmpint(backing_s->drain_count, ==, 1);
+
+    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b);
+
+    g_assert_cmpint(bs_a->quiesce_counter, ==, 2);
+    g_assert_cmpint(bs_b->quiesce_counter, ==, 2);
+    g_assert_cmpint(backing->quiesce_counter, ==, 2);
+    g_assert_cmpint(a_s->drain_count, ==, 2);
+    g_assert_cmpint(b_s->drain_count, ==, 2);
+    g_assert_cmpint(backing_s->drain_count, ==, 2);
+
+    do_drain_end(BDRV_SUBTREE_DRAIN, bs_b);
+
+    g_assert_cmpint(bs_a->quiesce_counter, ==, 1);
+    g_assert_cmpint(bs_b->quiesce_counter, ==, 1);
+    g_assert_cmpint(backing->quiesce_counter, ==, 1);
+    g_assert_cmpint(a_s->drain_count, ==, 1);
+    g_assert_cmpint(b_s->drain_count, ==, 1);
+    g_assert_cmpint(backing_s->drain_count, ==, 1);
+
+    do_drain_end(BDRV_SUBTREE_DRAIN, bs_a);
+
+    g_assert_cmpint(bs_a->quiesce_counter, ==, 0);
+    g_assert_cmpint(bs_b->quiesce_counter, ==, 0);
+    g_assert_cmpint(backing->quiesce_counter, ==, 0);
+    g_assert_cmpint(a_s->drain_count, ==, 0);
+    g_assert_cmpint(b_s->drain_count, ==, 0);
+    g_assert_cmpint(backing_s->drain_count, ==, 0);
+
+    bdrv_unref(backing);
+    bdrv_unref(bs_a);
+    bdrv_unref(bs_b);
+    blk_unref(blk_a);
+    blk_unref(blk_b);
+}
+
 
 typedef struct TestBlockJob {
     BlockJob common;
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
                     test_quiesce_co_drain_subtree);
 
     g_test_add_func("/bdrv-drain/nested", test_nested);
+    g_test_add_func("/bdrv-drain/multiparent", test_multiparent);
 
     g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
     g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain);
-- 
2.13.6

We need to remember how many of the drain sections in which a node is
were recursive (i.e. subtree drain rather than node drain), so that they
can be correctly applied when children are added or removed during the
drained section.

With this change, it is safe to modify the graph even inside a
bdrv_subtree_drained_begin/end() section.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/block.h     |  2 --
 include/block/block_int.h |  5 +++++
 block.c                   | 32 +++++++++++++++++++++++++++++---
 block/io.c                | 28 ++++++++++++++++++++++++----
 4 files changed, 58 insertions(+), 9 deletions(-)

diff --git a/include/block/block.h b/include/block/block.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -XXX,XX +XXX,XX @@ void bdrv_drained_begin(BlockDriverState *bs);
 /**
  * Like bdrv_drained_begin, but recursively begins a quiesced section for
  * exclusive access to all child nodes as well.
- *
- * Graph changes are not allowed during a subtree drain section.
  */
 void bdrv_subtree_drained_begin(BlockDriverState *bs);
 
diff --git a/include/block/block_int.h b/include/block/block_int.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -XXX,XX +XXX,XX @@ struct BlockDriverState {
 
     /* Accessed with atomic ops.  */
     int quiesce_counter;
+    int recursive_quiesce_counter;
+
     unsigned int write_gen;               /* Current data generation */
 
     /* Protected by reqs_lock.  */
@@ -XXX,XX +XXX,XX @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
     int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
     BdrvRequestFlags flags);
 
+void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent);
+void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent);
+
 int get_tmp_filename(char *filename, int size);
 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
                             const char *filename);
diff --git a/block.c b/block.c
index XXXXXXX..XXXXXXX 100644
--- a/block.c
+++ b/block.c
@@ -XXX,XX +XXX,XX @@ static void bdrv_child_cb_drained_end(BdrvChild *child)
     bdrv_drained_end(bs);
 }
 
+static void bdrv_child_cb_attach(BdrvChild *child)
+{
+    BlockDriverState *bs = child->opaque;
+    bdrv_apply_subtree_drain(child, bs);
+}
+
+static void bdrv_child_cb_detach(BdrvChild *child)
+{
+    BlockDriverState *bs = child->opaque;
+    bdrv_unapply_subtree_drain(child, bs);
+}
+
 static int bdrv_child_cb_inactivate(BdrvChild *child)
 {
     BlockDriverState *bs = child->opaque;
@@ -XXX,XX +XXX,XX @@ const BdrvChildRole child_file = {
     .inherit_options = bdrv_inherited_options,
     .drained_begin   = bdrv_child_cb_drained_begin,
     .drained_end     = bdrv_child_cb_drained_end,
+    .attach          = bdrv_child_cb_attach,
+    .detach          = bdrv_child_cb_detach,
     .inactivate      = bdrv_child_cb_inactivate,
 };
 
@@ -XXX,XX +XXX,XX @@ const BdrvChildRole child_format = {
     .inherit_options = bdrv_inherited_fmt_options,
     .drained_begin   = bdrv_child_cb_drained_begin,
     .drained_end     = bdrv_child_cb_drained_end,
+    .attach          = bdrv_child_cb_attach,
+    .detach          = bdrv_child_cb_detach,
     .inactivate      = bdrv_child_cb_inactivate,
 };
 
@@ -XXX,XX +XXX,XX @@ static void bdrv_backing_attach(BdrvChild *c)
                     parent->backing_blocker);
     bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET,
                     parent->backing_blocker);
+
+    bdrv_child_cb_attach(c);
 }
 
 static void bdrv_backing_detach(BdrvChild *c)
@@ -XXX,XX +XXX,XX @@ static void bdrv_backing_detach(BdrvChild *c)
     bdrv_op_unblock_all(c->bs, parent->backing_blocker);
     error_free(parent->backing_blocker);
     parent->backing_blocker = NULL;
+
+    bdrv_child_cb_detach(c);
 }
 
 /*
@@ -XXX,XX +XXX,XX @@ static void bdrv_replace_child_noperm(BdrvChild *child,
         assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
     }
     if (old_bs) {
+        /* Detach first so that the recursive drain sections coming from @child
+         * are already gone and we only end the drain sections that came from
+         * elsewhere. */
+        if (child->role->detach) {
+            child->role->detach(child);
+        }
         if (old_bs->quiesce_counter && child->role->drained_end) {
             for (i = 0; i < old_bs->quiesce_counter; i++) {
                 child->role->drained_end(child);
             }
         }
-        if (child->role->detach) {
-            child->role->detach(child);
-        }
         QLIST_REMOVE(child, next_parent);
     }
 
@@ -XXX,XX +XXX,XX @@ static void bdrv_replace_child_noperm(BdrvChild *child,
             }
         }
 
+        /* Attach only after starting new drained sections, so that recursive
+         * drain sections coming from @child don't get an extra .drained_begin
+         * callback. */
         if (child->role->attach) {
             child->role->attach(child);
         }
diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
     assert(data.done);
 }
 
-static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
-                                  BdrvChild *parent)
+void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
+                           BdrvChild *parent)
 {
     BdrvChild *child, *next;
 
@@ -XXX,XX +XXX,XX @@ static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
     bdrv_drain_recurse(bs);
 
     if (recursive) {
+        bs->recursive_quiesce_counter++;
         QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
             bdrv_do_drained_begin(child->bs, true, child);
         }
@@ -XXX,XX +XXX,XX @@ void bdrv_subtree_drained_begin(BlockDriverState *bs)
     bdrv_do_drained_begin(bs, true, NULL);
 }
 
-static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
-                                BdrvChild *parent)
+void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
+                         BdrvChild *parent)
 {
     BdrvChild *child, *next;
     int old_quiesce_counter;
@@ -XXX,XX +XXX,XX @@ static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
     }
 
     if (recursive) {
+        bs->recursive_quiesce_counter--;
         QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
             bdrv_do_drained_end(child->bs, true, child);
         }
@@ -XXX,XX +XXX,XX @@ void bdrv_subtree_drained_end(BlockDriverState *bs)
     bdrv_do_drained_end(bs, true, NULL);
 }
 
+void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent)
+{
+    int i;
+
+    for (i = 0; i < new_parent->recursive_quiesce_counter; i++) {
+        bdrv_do_drained_begin(child->bs, true, child);
+    }
+}
+
+void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent)
+{
+    int i;
+
+    for (i = 0; i < old_parent->recursive_quiesce_counter; i++) {
+        bdrv_do_drained_end(child->bs, true, child);
+    }
+}
+
 /*
  * Wait for pending requests to complete on a single BlockDriverState subtree,
  * and suspend block driver's internal I/O until next request arrives.
-- 
2.13.6

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/test-bdrv-drain.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -XXX,XX +XXX,XX @@ static void test_multiparent(void)
     blk_unref(blk_b);
 }
 
+static void test_graph_change(void)
+{
+    BlockBackend *blk_a, *blk_b;
+    BlockDriverState *bs_a, *bs_b, *backing;
+    BDRVTestState *a_s, *b_s, *backing_s;
+
+    blk_a = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR,
+                                &error_abort);
+    a_s = bs_a->opaque;
+    blk_insert_bs(blk_a, bs_a, &error_abort);
+
+    blk_b = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR,
+                                &error_abort);
+    b_s = bs_b->opaque;
+    blk_insert_bs(blk_b, bs_b, &error_abort);
+
+    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort);
+    backing_s = backing->opaque;
+    bdrv_set_backing_hd(bs_a, backing, &error_abort);
+
+    g_assert_cmpint(bs_a->quiesce_counter, ==, 0);
+    g_assert_cmpint(bs_b->quiesce_counter, ==, 0);
+    g_assert_cmpint(backing->quiesce_counter, ==, 0);
+    g_assert_cmpint(a_s->drain_count, ==, 0);
+    g_assert_cmpint(b_s->drain_count, ==, 0);
+    g_assert_cmpint(backing_s->drain_count, ==, 0);
+
+    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a);
+    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a);
+    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a);
+    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b);
+    do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b);
+
+    bdrv_set_backing_hd(bs_b, backing, &error_abort);
+    g_assert_cmpint(bs_a->quiesce_counter, ==, 5);
+    g_assert_cmpint(bs_b->quiesce_counter, ==, 5);
+    g_assert_cmpint(backing->quiesce_counter, ==, 5);
+    g_assert_cmpint(a_s->drain_count, ==, 5);
+    g_assert_cmpint(b_s->drain_count, ==, 5);
+    g_assert_cmpint(backing_s->drain_count, ==, 5);
+
+    bdrv_set_backing_hd(bs_b, NULL, &error_abort);
+    g_assert_cmpint(bs_a->quiesce_counter, ==, 3);
+    g_assert_cmpint(bs_b->quiesce_counter, ==, 2);
+    g_assert_cmpint(backing->quiesce_counter, ==, 3);
+    g_assert_cmpint(a_s->drain_count, ==, 3);
+    g_assert_cmpint(b_s->drain_count, ==, 2);
+    g_assert_cmpint(backing_s->drain_count, ==, 3);
+
+    bdrv_set_backing_hd(bs_b, backing, &error_abort);
+    g_assert_cmpint(bs_a->quiesce_counter, ==, 5);
+    g_assert_cmpint(bs_b->quiesce_counter, ==, 5);
+    g_assert_cmpint(backing->quiesce_counter, ==, 5);
+    g_assert_cmpint(a_s->drain_count, ==, 5);
+    g_assert_cmpint(b_s->drain_count, ==, 5);
+    g_assert_cmpint(backing_s->drain_count, ==, 5);
+
+    do_drain_end(BDRV_SUBTREE_DRAIN, bs_b);
+    do_drain_end(BDRV_SUBTREE_DRAIN, bs_b);
+    do_drain_end(BDRV_SUBTREE_DRAIN, bs_a);
+    do_drain_end(BDRV_SUBTREE_DRAIN, bs_a);
+    do_drain_end(BDRV_SUBTREE_DRAIN, bs_a);
+
+    g_assert_cmpint(bs_a->quiesce_counter, ==, 0);
+    g_assert_cmpint(bs_b->quiesce_counter, ==, 0);
+    g_assert_cmpint(backing->quiesce_counter, ==, 0);
+    g_assert_cmpint(a_s->drain_count, ==, 0);
+    g_assert_cmpint(b_s->drain_count, ==, 0);
+    g_assert_cmpint(backing_s->drain_count, ==, 0);
+
+    bdrv_unref(backing);
+    bdrv_unref(bs_a);
+    bdrv_unref(bs_b);
+    blk_unref(blk_a);
+    blk_unref(blk_b);
+}
+
 
 typedef struct TestBlockJob {
     BlockJob common;
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
 
     g_test_add_func("/bdrv-drain/nested", test_nested);
     g_test_add_func("/bdrv-drain/multiparent", test_multiparent);
+    g_test_add_func("/bdrv-drain/graph-change", test_graph_change);
 
     g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all);
     g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain);
-- 
2.13.6

Since commit bde70715, base is the only node that is reopened in
commit_start(). This means that the code, which still involves an
explicit BlockReopenQueue, can now be simplified by using bdrv_reopen().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
---
 block/commit.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/block/commit.c b/block/commit.c
index XXXXXXX..XXXXXXX 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -XXX,XX +XXX,XX @@ void commit_start(const char *job_id, BlockDriverState *bs,
                   const char *filter_node_name, Error **errp)
 {
     CommitBlockJob *s;
-    BlockReopenQueue *reopen_queue = NULL;
     int orig_base_flags;
     BlockDriverState *iter;
     BlockDriverState *commit_top_bs = NULL;
@@ -XXX,XX +XXX,XX @@ void commit_start(const char *job_id, BlockDriverState *bs,
     /* convert base to r/w, if necessary */
     orig_base_flags = bdrv_get_flags(base);
     if (!(orig_base_flags & BDRV_O_RDWR)) {
-        reopen_queue = bdrv_reopen_queue(reopen_queue, base, NULL,
-                                         orig_base_flags | BDRV_O_RDWR);
-    }
-
-    if (reopen_queue) {
-        bdrv_reopen_multiple(bdrv_get_aio_context(bs), reopen_queue, &local_err);
+        bdrv_reopen(base, orig_base_flags | BDRV_O_RDWR, &local_err);
         if (local_err != NULL) {
             error_propagate(errp, local_err);
             goto fail;
-- 
2.13.6

The bdrv_reopen*() implementation doesn't like it if the graph is
changed between queuing nodes for reopen and actually reopening them
(one of the reasons is that queuing can be recursive).

So instead of draining the device only in bdrv_reopen_multiple(),
require that callers already drained all affected nodes, and assert this
in bdrv_reopen_queue().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
---
 block.c             | 23 ++++++++++++++++-------
 block/replication.c |  6 ++++++
 qemu-io-cmds.c      |  3 +++
 3 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/block.c b/block.c
index XXXXXXX..XXXXXXX 100644
--- a/block.c
+++ b/block.c
@@ -XXX,XX +XXX,XX @@ BlockDriverState *bdrv_open(const char *filename, const char *reference,
  * returns a pointer to bs_queue, which is either the newly allocated
  * bs_queue, or the existing bs_queue being used.
  *
+ * bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
  */
 static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
                                                  BlockDriverState *bs,
@@ -XXX,XX +XXX,XX @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
     BdrvChild *child;
     QDict *old_options, *explicit_options;
 
+    /* Make sure that the caller remembered to use a drained section. This is
+     * important to avoid graph changes between the recursive queuing here and
+     * bdrv_reopen_multiple(). */
+    assert(bs->quiesce_counter > 0);
+
     if (bs_queue == NULL) {
         bs_queue = g_new0(BlockReopenQueue, 1);
         QSIMPLEQ_INIT(bs_queue);
@@ -XXX,XX +XXX,XX @@ BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
  * If all devices prepare successfully, then the changes are committed
  * to all devices.
  *
+ * All affected nodes must be drained between bdrv_reopen_queue() and
+ * bdrv_reopen_multiple().
  */
 int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp)
 {
@@ -XXX,XX +XXX,XX @@ int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **er
 
     assert(bs_queue != NULL);
 
-    aio_context_release(ctx);
-    bdrv_drain_all_begin();
-    aio_context_acquire(ctx);
-
     QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
+        assert(bs_entry->state.bs->quiesce_counter > 0);
         if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) {
             error_propagate(errp, local_err);
             goto cleanup;
@@ -XXX,XX +XXX,XX @@ cleanup:
     }
     g_free(bs_queue);
 
-    bdrv_drain_all_end();
-
     return ret;
 }
 
@@ -XXX,XX +XXX,XX @@ int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp)
 {
     int ret = -1;
     Error *local_err = NULL;
-    BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags);
+    BlockReopenQueue *queue;
 
+    bdrv_subtree_drained_begin(bs);
+
+    queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags);
     ret = bdrv_reopen_multiple(bdrv_get_aio_context(bs), queue, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
     }
+
+    bdrv_subtree_drained_end(bs);
+
     return ret;
 }
 
diff --git a/block/replication.c b/block/replication.c
index XXXXXXX..XXXXXXX 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -XXX,XX +XXX,XX @@ static void reopen_backing_file(BlockDriverState *bs, bool writable,
         new_secondary_flags = s->orig_secondary_flags;
     }
 
+    bdrv_subtree_drained_begin(s->hidden_disk->bs);
+    bdrv_subtree_drained_begin(s->secondary_disk->bs);
+
     if (orig_hidden_flags != new_hidden_flags) {
         reopen_queue = bdrv_reopen_queue(reopen_queue, s->hidden_disk->bs, NULL,
                                          new_hidden_flags);
@@ -XXX,XX +XXX,XX @@ static void reopen_backing_file(BlockDriverState *bs, bool writable,
                              reopen_queue, &local_err);
         error_propagate(errp, local_err);
     }
+
+    bdrv_subtree_drained_end(s->hidden_disk->bs);
+    bdrv_subtree_drained_end(s->secondary_disk->bs);
 }
 
 static void backup_job_cleanup(BlockDriverState *bs)
diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index XXXXXXX..XXXXXXX 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -XXX,XX +XXX,XX @@ static int reopen_f(BlockBackend *blk, int argc, char **argv)
     opts = qopts ? qemu_opts_to_qdict(qopts, NULL) : NULL;
     qemu_opts_reset(&reopen_opts);
 
+    bdrv_subtree_drained_begin(bs);
     brq = bdrv_reopen_queue(NULL, bs, opts, flags);
     bdrv_reopen_multiple(bdrv_get_aio_context(bs), brq, &local_err);
+    bdrv_subtree_drained_end(bs);
+
     if (local_err) {
         error_report_err(local_err);
     } else {
-- 
2.13.6