diff options
| author | Zhang Haoyu <zhanghy@sangfor.com> | 2014-10-21 16:38:01 +0800 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-11-03 09:48:42 +0000 |
| commit | 3432a1929ee18e08787ce35476abd74f2c93a17c (patch) | |
| tree | 13a81c0a46707d91622f1593ccf7b926935371fd | |
| parent | 573742a5431a99ceaba6968ae269cee247727cce (diff) | |
| download | qemu-3432a1929ee18e08787ce35476abd74f2c93a17c.zip | |
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>
| -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); } |