This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_has_zero_init() need to hold a reader lock for the graph because
it calls bdrv_filter_bs(), which accesses bs->file/backing.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-3-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
include/block/block-global-state.h | 2 +-
include/block/block_int-common.h | 2 +-
block.c | 2 +-
block/qcow2.c | 3 ++-
block/raw-format.c | 2 +-
block/vdi.c | 2 +-
block/vhdx.c | 13 +++++++++----
block/vmdk.c | 2 +-
block/vpc.c | 2 +-
blockdev.c | 2 ++
qemu-img.c | 2 ++
11 files changed, 22 insertions(+), 12 deletions(-)
diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h
index fca0a40dbd..3ae468ea15 100644
--- a/include/block/block-global-state.h
+++ b/include/block/block-global-state.h
@@ -189,7 +189,7 @@ void bdrv_drain_all(void);
void bdrv_aio_cancel(BlockAIOCB *acb);
int bdrv_has_zero_init_1(BlockDriverState *bs);
-int bdrv_has_zero_init(BlockDriverState *bs);
+int coroutine_mixed_fn GRAPH_RDLOCK bdrv_has_zero_init(BlockDriverState *bs);
BlockDriverState *bdrv_find_node(const char *node_name);
BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp);
XDbgBlockGraph * GRAPH_RDLOCK bdrv_get_xdbg_block_graph(Error **errp);
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index 8abdd2724b..c0db862de7 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -349,7 +349,7 @@ struct BlockDriver {
* Returns 1 if newly created images are guaranteed to contain only
* zeros, 0 otherwise.
*/
- int (*bdrv_has_zero_init)(BlockDriverState *bs);
+ int GRAPH_RDLOCK_PTR (*bdrv_has_zero_init)(BlockDriverState *bs);
/*
* Remove fd handlers, timers, and other event loop callbacks so the event
diff --git a/block.c b/block.c
index a527aa1a4c..1171f47570 100644
--- a/block.c
+++ b/block.c
@@ -6587,7 +6587,7 @@ int bdrv_has_zero_init_1(BlockDriverState *bs)
return 1;
}
-int bdrv_has_zero_init(BlockDriverState *bs)
+int coroutine_mixed_fn bdrv_has_zero_init(BlockDriverState *bs)
{
BlockDriverState *filtered;
GLOBAL_STATE_CODE();
diff --git a/block/qcow2.c b/block/qcow2.c
index aa01d9e7b5..a1443a31aa 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -5302,7 +5302,8 @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs,
return spec_info;
}
-static int coroutine_mixed_fn qcow2_has_zero_init(BlockDriverState *bs)
+static int coroutine_mixed_fn GRAPH_RDLOCK
+qcow2_has_zero_init(BlockDriverState *bs)
{
BDRVQcow2State *s = bs->opaque;
bool preallocated;
diff --git a/block/raw-format.c b/block/raw-format.c
index 3fb77b0097..8ca74c1cf3 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -452,7 +452,7 @@ raw_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
return bdrv_co_ioctl(bs->file->bs, req, buf);
}
-static int raw_has_zero_init(BlockDriverState *bs)
+static int GRAPH_RDLOCK raw_has_zero_init(BlockDriverState *bs)
{
return bdrv_has_zero_init(bs->file->bs);
}
diff --git a/block/vdi.c b/block/vdi.c
index 7cfd12b50d..8e144ce523 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -990,7 +990,7 @@ static void vdi_close(BlockDriverState *bs)
migrate_del_blocker(&s->migration_blocker);
}
-static int vdi_has_zero_init(BlockDriverState *bs)
+static int GRAPH_RDLOCK vdi_has_zero_init(BlockDriverState *bs)
{
BDRVVdiState *s = bs->opaque;
diff --git a/block/vhdx.c b/block/vhdx.c
index a9d08742f9..e136ba1ae1 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -1695,7 +1695,7 @@ exit:
* Fixed images: default state of the BAT is fully populated, with
* file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT.
*/
-static int coroutine_fn
+static int coroutine_fn GRAPH_UNLOCKED
vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s,
uint64_t image_size, VHDXImageType type,
bool use_zero_blocks, uint64_t file_offset,
@@ -1708,6 +1708,7 @@ vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s,
uint64_t unused;
int block_state;
VHDXSectorInfo sinfo;
+ bool has_zero_init;
assert(s->bat == NULL);
@@ -1737,9 +1738,13 @@ vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s,
goto exit;
}
+ bdrv_graph_co_rdlock();
+ has_zero_init = bdrv_has_zero_init(blk_bs(blk));
+ bdrv_graph_co_rdunlock();
+
if (type == VHDX_TYPE_FIXED ||
use_zero_blocks ||
- bdrv_has_zero_init(blk_bs(blk)) == 0) {
+ has_zero_init == 0) {
/* for a fixed file, the default BAT entry is not zero */
s->bat = g_try_malloc0(length);
if (length && s->bat == NULL) {
@@ -1782,7 +1787,7 @@ exit:
* to create the BAT itself, we will also cause the BAT to be
* created.
*/
-static int coroutine_fn
+static int coroutine_fn GRAPH_UNLOCKED
vhdx_create_new_region_table(BlockBackend *blk, uint64_t image_size,
uint32_t block_size, uint32_t sector_size,
uint32_t log_size, bool use_zero_blocks,
@@ -2173,7 +2178,7 @@ static int coroutine_fn vhdx_co_check(BlockDriverState *bs,
return 0;
}
-static int vhdx_has_zero_init(BlockDriverState *bs)
+static int GRAPH_RDLOCK vhdx_has_zero_init(BlockDriverState *bs)
{
BDRVVHDXState *s = bs->opaque;
int state;
diff --git a/block/vmdk.c b/block/vmdk.c
index 85864b8045..91ed7a8d93 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2894,7 +2894,7 @@ vmdk_co_get_allocated_file_size(BlockDriverState *bs)
return ret;
}
-static int vmdk_has_zero_init(BlockDriverState *bs)
+static int GRAPH_RDLOCK vmdk_has_zero_init(BlockDriverState *bs)
{
int i;
BDRVVmdkState *s = bs->opaque;
diff --git a/block/vpc.c b/block/vpc.c
index aa1a48ae0e..483775103c 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -1170,7 +1170,7 @@ fail:
}
-static int vpc_has_zero_init(BlockDriverState *bs)
+static int GRAPH_RDLOCK vpc_has_zero_init(BlockDriverState *bs)
{
BDRVVPCState *s = bs->opaque;
diff --git a/blockdev.c b/blockdev.c
index e9b7e38dc4..148df99e00 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3156,9 +3156,11 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp)
return;
}
+ bdrv_graph_rdlock_main_loop();
zero_target = (arg->sync == MIRROR_SYNC_MODE_FULL &&
(arg->mode == NEW_IMAGE_MODE_EXISTING ||
!bdrv_has_zero_init(target_bs)));
+ bdrv_graph_rdunlock_main_loop();
/* Honor bdrv_try_change_aio_context() context acquisition requirements. */
diff --git a/qemu-img.c b/qemu-img.c
index 369c2e8ddf..c061fd0634 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2099,7 +2099,9 @@ static int convert_do_copy(ImgConvertState *s)
/* Check whether we have zero initialisation or can get it efficiently */
if (!s->has_zero_init && s->target_is_new && s->min_sparse &&
!s->target_has_backing) {
+ bdrv_graph_rdlock_main_loop();
s->has_zero_init = bdrv_has_zero_init(blk_bs(s->target));
+ bdrv_graph_rdunlock_main_loop();
}
/* Allocate buffer for copied data. For compressed images, only one cluster
--
2.41.0