Series comparison

-[Qemu-devel] [PULL 0/2] Block patches
+[PULL for-6.1 0/3] Block patches
-The following changes since commit bb9bf94b3e8926553290bc9a7cb84315af422086:
+The following changes since commit 3521ade3510eb5cefb2e27a101667f25dad89935:
-  Merge remote-tracking branch 'remotes/ehabkost/tags/machine-next-pull-request' into staging (2018-12-11 19:18:58 +0000)
+  Merge remote-tracking branch 'remotes/thuth-gitlab/tags/pull-request-2021-07-29' into staging (2021-07-29 13:17:20 +0100)
 are available in the Git repository at:
-  git://github.com/stefanha/qemu.git tags/block-pull-request
+  https://gitlab.com/stefanha/qemu.git tags/block-pull-request
-for you to fetch changes up to e61809ed8ac3a2f68eb1cc231244f84eb06adacf:
+for you to fetch changes up to cc8eecd7f105a1dff5876adeb238a14696061a4a:
-  virtio-blk: fix comment for virtio_blk_rw_complete as nalloc is initially -1 (2018-12-12 09:16:55 +0000)
+  MAINTAINERS: Added myself as a reviewer for the NVMe Block Driver (2021-07-29 17:17:34 +0100)
 ----------------------------------------------------------------
 Pull request
-Minor virtio-blk fixes.
+The main fix here is for io_uring. Spurious -EAGAIN errors can happen and the
 request needs to be resubmitted.
 The MAINTAINERS changes carry no risk and we might as well include them in QEMU
 .1.
 ----------------------------------------------------------------
-Dongli Zhang (2):
+Fabian Ebner (1):
-  virtio-blk: rename iov to out_iov in virtio_blk_handle_request()
+  block/io_uring: resubmit when result is -EAGAIN
   virtio-blk: fix comment for virtio_blk_rw_complete as nalloc is
     initially -1
- hw/block/virtio-blk.c | 10 +++++-----
+Philippe Mathieu-Daudé (1):
-file changed, 5 insertions(+), 5 deletions(-)
+  MAINTAINERS: Added myself as a reviewer for the NVMe Block Driver
 Stefano Garzarella (1):
   MAINTAINERS: add Stefano Garzarella as io_uring reviewer
  MAINTAINERS      |  2 ++
  block/io_uring.c | 16 +++++++++++++++-
 files changed, 17 insertions(+), 1 deletion(-)
 --
-.19.2
+.31.1

-New patch
+[PULL for-6.1 1/3] MAINTAINERS: add Stefano Garzarella as io_uring reviewer
+From: Stefano Garzarella <sgarzare@redhat.com>
+I've been working with io_uring for a while so I'd like to help
+with reviews.
+Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
+Message-Id: <20210728131515.131045-1-sgarzare@redhat.com>
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ MAINTAINERS | 1 +
+file changed, 1 insertion(+)
+diff --git a/MAINTAINERS b/MAINTAINERS
+index XXXXXXX..XXXXXXX 100644
+--- a/MAINTAINERS
++++ b/MAINTAINERS
+@@ -XXX,XX +XXX,XX @@ Linux io_uring
+ M: Aarushi Mehta <mehta.aaru20@gmail.com>
+ M: Julia Suvorova <jusual@redhat.com>
+ M: Stefan Hajnoczi <stefanha@redhat.com>
++R: Stefano Garzarella <sgarzare@redhat.com>
+ L: qemu-block@nongnu.org
+ S: Maintained
+ F: block/io_uring.c
+--
+.31.1

-[Qemu-devel] [PULL 2/2] virtio-blk: fix comment for virtio_blk_rw_complete as nalloc is initially -1
+[PULL for-6.1 2/3] block/io_uring: resubmit when result is -EAGAIN
-From: Dongli Zhang <dongli.zhang@oracle.com>
+From: Fabian Ebner <f.ebner@proxmox.com>
-The initial value of nalloc is -1, but not 1.
+Linux SCSI can throw spurious -EAGAIN in some corner cases in its
 completion path, which will end up being the result in the completed
 io_uring request.
-Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
+Resubmitting such requests should allow block jobs to complete, even
-Reviewed-by: Laurent Vivier <laurent@vivier.eu>
+if such spurious errors are encountered.
-Message-id: 1541479952-32355-1-git-send-email-dongli.zhang@oracle.com
 Co-authored-by: Stefan Hajnoczi <stefanha@gmail.com>
 Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
 Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
 Message-id: 20210729091029.65369-1-f.ebner@proxmox.com
 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 ---
- hw/block/virtio-blk.c | 2 +-
+ block/io_uring.c | 16 +++++++++++++++-
-file changed, 1 insertion(+), 1 deletion(-)
+file changed, 15 insertions(+), 1 deletion(-)
-diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
+diff --git a/block/io_uring.c b/block/io_uring.c
 index XXXXXXX..XXXXXXX 100644
---- a/hw/block/virtio-blk.c
+--- a/block/io_uring.c
-+++ b/hw/block/virtio-blk.c
++++ b/block/io_uring.c
-@@ -XXX,XX +XXX,XX @@ static void virtio_blk_rw_complete(void *opaque, int ret)
+@@ -XXX,XX +XXX,XX @@ static void luring_process_completions(LuringState *s)
-         trace_virtio_blk_rw_complete(vdev, req, ret);
+         total_bytes = ret + luringcb->total_read;
-         if (req->qiov.nalloc != -1) {
+         if (ret < 0) {
--            /* If nalloc is != 1 req->qiov is a local copy of the original
+-            if (ret == -EINTR) {
-+            /* If nalloc is != -1 req->qiov is a local copy of the original
++            /*
-              * external iovec. It was allocated in submit_requests to be
++             * Only writev/readv/fsync requests on regular files or host block
-              * able to merge requests. */
++             * devices are submitted. Therefore -EAGAIN is not expected but it's
-             qemu_iovec_destroy(&req->qiov);
++             * known to happen sometimes with Linux SCSI. Submit again and hope
 +             * the request completes successfully.
 +             *
 +             * For more information, see:
 +             * https://lore.kernel.org/io-uring/20210727165811.284510-3-axboe@kernel.dk/T/#u
 +             *
 +             * If the code is changed to submit other types of requests in the
 +             * future, then this workaround may need to be extended to deal with
 +             * genuine -EAGAIN results that should not be resubmitted
 +             * immediately.
 +             */
 +            if (ret == -EINTR || ret == -EAGAIN) {
                  luring_resubmit(s, luringcb);
                  continue;
              }
 --
-.19.2
+.31.1

-[Qemu-devel] [PULL 1/2] virtio-blk: rename iov to out_iov in virtio_blk_handle_request()
+[PULL for-6.1 3/3] MAINTAINERS: Added myself as a reviewer for the NVMe Block Driver
-From: Dongli Zhang <dongli.zhang@oracle.com>
+From: Philippe Mathieu-Daudé <philmd@redhat.com>
-In virtio_blk_handle_request(), in_iov is used for input header while iov
+I'm interested in following the activity around the NVMe bdrv.
 is used for output header. Rename iov to out_iov to pair output header's
 name with in_iov to avoid confusing people when reading source code.
-Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
+Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
-Message-id: 1541520556-8334-1-git-send-email-dongli.zhang@oracle.com
+Message-id: 20210728183340.2018313-1-philmd@redhat.com
 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 ---
- hw/block/virtio-blk.c | 8 ++++----
+ MAINTAINERS | 1 +
-file changed, 4 insertions(+), 4 deletions(-)
+file changed, 1 insertion(+)
-diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
+diff --git a/MAINTAINERS b/MAINTAINERS
 index XXXXXXX..XXXXXXX 100644
---- a/hw/block/virtio-blk.c
+--- a/MAINTAINERS
-+++ b/hw/block/virtio-blk.c
++++ b/MAINTAINERS
-@@ -XXX,XX +XXX,XX @@ static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
+@@ -XXX,XX +XXX,XX @@ F: block/null.c
- {
+ NVMe Block Driver
-     uint32_t type;
+ M: Stefan Hajnoczi <stefanha@redhat.com>
-     struct iovec *in_iov = req->elem.in_sg;
+ R: Fam Zheng <fam@euphon.net>
--    struct iovec *iov = req->elem.out_sg;
++R: Philippe Mathieu-Daudé <philmd@redhat.com>
-+    struct iovec *out_iov = req->elem.out_sg;
+ L: qemu-block@nongnu.org
-     unsigned in_num = req->elem.in_num;
+ S: Supported
-     unsigned out_num = req->elem.out_num;
+ F: block/nvme*
      VirtIOBlock *s = req->dev;
@@ -XXX,XX +XXX,XX @@ static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
          return -1;
      }
 -    if (unlikely(iov_to_buf(iov, out_num, 0, &req->out,
 +    if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out,
                              sizeof(req->out)) != sizeof(req->out))) {
          virtio_error(vdev, "virtio-blk request outhdr too short");
          return -1;
      }
 -    iov_discard_front(&iov, &out_num, sizeof(req->out));
 +    iov_discard_front(&out_iov, &out_num, sizeof(req->out));
      if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
          virtio_error(vdev, "virtio-blk request inhdr too short");
@@ -XXX,XX +XXX,XX @@ static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
                                         &req->out.sector);
          if (is_write) {
 -            qemu_iovec_init_external(&req->qiov, iov, out_num);
 +            qemu_iovec_init_external(&req->qiov, out_iov, out_num);
              trace_virtio_blk_handle_write(vdev, req, req->sector_num,
                                            req->qiov.size / BDRV_SECTOR_SIZE);
          } else {
 --
-.19.2
+.31.1

From: Dongli Zhang <dongli.zhang@oracle.com>

In virtio_blk_handle_request(), in_iov is used for input header while iov
is used for output header. Rename iov to out_iov to pair output header's
name with in_iov to avoid confusing people when reading source code.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Message-id: 1541520556-8334-1-git-send-email-dongli.zhang@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/block/virtio-blk.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -XXX,XX +XXX,XX @@ static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
 {
     uint32_t type;
     struct iovec *in_iov = req->elem.in_sg;
-    struct iovec *iov = req->elem.out_sg;
+    struct iovec *out_iov = req->elem.out_sg;
     unsigned in_num = req->elem.in_num;
     unsigned out_num = req->elem.out_num;
     VirtIOBlock *s = req->dev;
@@ -XXX,XX +XXX,XX @@ static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
         return -1;
     }
 
-    if (unlikely(iov_to_buf(iov, out_num, 0, &req->out,
+    if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out,
                             sizeof(req->out)) != sizeof(req->out))) {
         virtio_error(vdev, "virtio-blk request outhdr too short");
         return -1;
     }
 
-    iov_discard_front(&iov, &out_num, sizeof(req->out));
+    iov_discard_front(&out_iov, &out_num, sizeof(req->out));
 
     if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
         virtio_error(vdev, "virtio-blk request inhdr too short");
@@ -XXX,XX +XXX,XX @@ static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
                                        &req->out.sector);
 
         if (is_write) {
-            qemu_iovec_init_external(&req->qiov, iov, out_num);
+            qemu_iovec_init_external(&req->qiov, out_iov, out_num);
             trace_virtio_blk_handle_write(vdev, req, req->sector_num,
                                           req->qiov.size / BDRV_SECTOR_SIZE);
         } else {
-- 
2.19.2

From: Dongli Zhang <dongli.zhang@oracle.com>

The initial value of nalloc is -1, but not 1.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-id: 1541479952-32355-1-git-send-email-dongli.zhang@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/block/virtio-blk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -XXX,XX +XXX,XX @@ static void virtio_blk_rw_complete(void *opaque, int ret)
         trace_virtio_blk_rw_complete(vdev, req, ret);
 
         if (req->qiov.nalloc != -1) {
-            /* If nalloc is != 1 req->qiov is a local copy of the original
+            /* If nalloc is != -1 req->qiov is a local copy of the original
              * external iovec. It was allocated in submit_requests to be
              * able to merge requests. */
             qemu_iovec_destroy(&req->qiov);
-- 
2.19.2

The following changes since commit 3521ade3510eb5cefb2e27a101667f25dad89935:

Merge remote-tracking branch 'remotes/thuth-gitlab/tags/pull-request-2021-07-29' into staging (2021-07-29 13:17:20 +0100)

are available in the Git repository at:

https://gitlab.com/stefanha/qemu.git tags/block-pull-request

for you to fetch changes up to cc8eecd7f105a1dff5876adeb238a14696061a4a:

MAINTAINERS: Added myself as a reviewer for the NVMe Block Driver (2021-07-29 17:17:34 +0100)

----------------------------------------------------------------
Pull request

The main fix here is for io_uring. Spurious -EAGAIN errors can happen and the
request needs to be resubmitted.

The MAINTAINERS changes carry no risk and we might as well include them in QEMU
6.1.

----------------------------------------------------------------

Fabian Ebner (1):
  block/io_uring: resubmit when result is -EAGAIN

Philippe Mathieu-Daudé (1):
  MAINTAINERS: Added myself as a reviewer for the NVMe Block Driver

Stefano Garzarella (1):
  MAINTAINERS: add Stefano Garzarella as io_uring reviewer

MAINTAINERS      |  2 ++
 block/io_uring.c | 16 +++++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

-- 
2.31.1

From: Fabian Ebner <f.ebner@proxmox.com>

Linux SCSI can throw spurious -EAGAIN in some corner cases in its
completion path, which will end up being the result in the completed
io_uring request.

Resubmitting such requests should allow block jobs to complete, even
if such spurious errors are encountered.

Co-authored-by: Stefan Hajnoczi <stefanha@gmail.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
Message-id: 20210729091029.65369-1-f.ebner@proxmox.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io_uring.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/block/io_uring.c b/block/io_uring.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io_uring.c
+++ b/block/io_uring.c
@@ -XXX,XX +XXX,XX @@ static void luring_process_completions(LuringState *s)
         total_bytes = ret + luringcb->total_read;
 
         if (ret < 0) {
-            if (ret == -EINTR) {
+            /*
+             * Only writev/readv/fsync requests on regular files or host block
+             * devices are submitted. Therefore -EAGAIN is not expected but it's
+             * known to happen sometimes with Linux SCSI. Submit again and hope
+             * the request completes successfully.
+             *
+             * For more information, see:
+             * https://lore.kernel.org/io-uring/20210727165811.284510-3-axboe@kernel.dk/T/#u
+             *
+             * If the code is changed to submit other types of requests in the
+             * future, then this workaround may need to be extended to deal with
+             * genuine -EAGAIN results that should not be resubmitted
+             * immediately.
+             */
+            if (ret == -EINTR || ret == -EAGAIN) {
                 luring_resubmit(s, luringcb);
                 continue;
             }
-- 
2.31.1