diff mbox

[RFC,03/12] blockdev: Lock BDS during internal snapshot transaction

Message ID 1432896805-23867-4-git-send-email-famz@redhat.com
State New
Headers show

Commit Message

Fam Zheng May 29, 2015, 10:53 a.m. UTC 
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 blockdev.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Paolo Bonzini May 29, 2015, 11:39 a.m. UTC | #1 
On 29/05/2015 12:53, Fam Zheng wrote:
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  blockdev.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/blockdev.c b/blockdev.c
> index 5eaf77e..46f8d60 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1262,6 +1262,7 @@ typedef struct InternalSnapshotState {
>      BlockDriverState *bs;
>      AioContext *aio_context;
>      QEMUSnapshotInfo sn;
> +    bool needs_unlock;

No need for needs_unlock...

>  } InternalSnapshotState;
>  
>  static void internal_snapshot_prepare(BlkTransactionState *common,
> @@ -1356,6 +1357,8 @@ static void internal_snapshot_prepare(BlkTransactionState *common,
>      }
>  
>      /* 4. succeed, mark a snapshot is created */
> +    bdrv_lock(bs);
> +    state->needs_unlock = true;
>      state->bs = bs;
>  }
>  
> @@ -1387,6 +1390,9 @@ static void internal_snapshot_clean(BlkTransactionState *common)
>      InternalSnapshotState *state = DO_UPCAST(InternalSnapshotState,
>                                               common, common);
>  
> +    if (state->needs_unlock) {
> +        bdrv_unlock(state->bs);
> +    }

... you can use state->bs != NULL here.

Paolo

>      if (state->aio_context) {
>          aio_context_release(state->aio_context);
>      }
>
diff mbox

Patch

diff --git a/blockdev.c b/blockdev.c
index 5eaf77e..46f8d60 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1262,6 +1262,7 @@  typedef struct InternalSnapshotState {
     BlockDriverState *bs;
     AioContext *aio_context;
     QEMUSnapshotInfo sn;
+    bool needs_unlock;
 } InternalSnapshotState;
 
 static void internal_snapshot_prepare(BlkTransactionState *common,
@@ -1356,6 +1357,8 @@  static void internal_snapshot_prepare(BlkTransactionState *common,
     }
 
     /* 4. succeed, mark a snapshot is created */
+    bdrv_lock(bs);
+    state->needs_unlock = true;
     state->bs = bs;
 }
 
@@ -1387,6 +1390,9 @@  static void internal_snapshot_clean(BlkTransactionState *common)
     InternalSnapshotState *state = DO_UPCAST(InternalSnapshotState,
                                              common, common);
 
+    if (state->needs_unlock) {
+        bdrv_unlock(state->bs);
+    }
     if (state->aio_context) {
         aio_context_release(state->aio_context);
     }