diff mbox

[v4,06/12] block: Add "drained begin/end" for transactional external snapshot

Message ID 1445318223-30055-7-git-send-email-famz@redhat.com
State New
Headers show

Commit Message

Fam Zheng Oct. 20, 2015, 5:16 a.m. UTC
This ensures the atomicity of the transaction by avoiding processing of
external requests such as those from ioeventfd.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 blockdev.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)
diff mbox

Patch

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),