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| author | Zhang Haoyu <zhanghy@sangfor.com> | 2014-10-21 16:38:01 +0800 |
|---|---|---|
| committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2015-01-06 18:40:28 -0600 |
| commit | b57b7ec340c128df59337822043b878b6f08cc4a (patch) | |
| tree | 0389a98d0e7a6b34008b942f5708645b18796328 | |
| parent | f8c61ebdd2e59e14b6f07ee2fe3e8be011a067f1 (diff) | |
| download | qemu-b57b7ec340c128df59337822043b878b6f08cc4a.tar.gz | |
snapshot: add bdrv_drain_all() to bdrv_snapshot_delete() to avoid concurrency problem
If there are still pending i/o while deleting snapshot,
because deleting snapshot is done in non-coroutine context, and
the pending i/o read/write (bdrv_co_do_rw) is done in coroutine context,
so it's possible to cause concurrency problem between above two operations.
Add bdrv_drain_all() to bdrv_snapshot_delete() to avoid this problem.
Signed-off-by: Zhang Haoyu <zhanghy@sangfor.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 201410211637596311287@sangfor.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 3432a1929ee18e08787ce35476abd74f2c93a17c)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
| -rw-r--r-- | block/snapshot.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/block/snapshot.c b/block/snapshot.c index 85c52ff455..698e1a1d58 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -236,6 +236,10 @@ int bdrv_snapshot_delete(BlockDriverState *bs, error_setg(errp, "snapshot_id and name are both NULL"); return -EINVAL; } + + /* drain all pending i/o before deleting snapshot */ + bdrv_drain_all(); + if (drv->bdrv_snapshot_delete) { return drv->bdrv_snapshot_delete(bs, snapshot_id, name, errp); } |