This ensures the atomicity of the transaction by avoiding processing of external requests such as those from ioeventfd.
Signed-off-by: Fam Zheng <f...@redhat.com> --- blockdev.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/blockdev.c b/blockdev.c index 8141b6b..fc63c3d 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1477,6 +1477,7 @@ static void external_snapshot_prepare(BlkTransactionState *common, /* Acquire AioContext now so any threads operating on old_bs stop */ state->aio_context = bdrv_get_aio_context(state->old_bs); aio_context_acquire(state->aio_context); + bdrv_drained_begin(state->old_bs); if (!bdrv_is_inserted(state->old_bs)) { error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device); @@ -1546,8 +1547,6 @@ static void external_snapshot_commit(BlkTransactionState *common) * don't want to abort all of them if one of them fails the reopen */ bdrv_reopen(state->old_bs, state->old_bs->open_flags & ~BDRV_O_RDWR, NULL); - - aio_context_release(state->aio_context); } static void external_snapshot_abort(BlkTransactionState *common) @@ -1557,7 +1556,14 @@ static void external_snapshot_abort(BlkTransactionState *common) if (state->new_bs) { bdrv_unref(state->new_bs); } +} + +static void external_snapshot_clean(BlkTransactionState *common) +{ + ExternalSnapshotState *state = + DO_UPCAST(ExternalSnapshotState, common, common); if (state->aio_context) { + bdrv_drained_end(state->old_bs); aio_context_release(state->aio_context); } } @@ -1722,6 +1728,7 @@ static const BdrvActionOps actions[] = { .prepare = external_snapshot_prepare, .commit = external_snapshot_commit, .abort = external_snapshot_abort, + .clean = external_snapshot_clean, }, [TRANSACTION_ACTION_KIND_DRIVE_BACKUP] = { .instance_size = sizeof(DriveBackupState), -- 2.4.3