Re: [Qemu-block] [PATCH v5 08/12] block: Add "drained begin/end" for transactional blockdev-backup

[Jeff Cody]

On Wed, Oct 21, 2015 at 10:06:45AM +0800, Fam Zheng wrote:
> Similar to the previous patch, make sure that external events are not
> dispatched during transaction operations.
> 
> Signed-off-by: Fam Zheng 
> ---
>  blockdev.c | 9 -
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/blockdev.c b/blockdev.c
> index 0a7848b..52f44b2 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1756,6 +1756,11 @@ static void 
> blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
>  return;
>  }
>  
> +if (!blk_is_available(blk)) {
> +error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, backup->device);
> +return;
> +}
> +
>  target = blk_by_name(backup->target);
>  if (!target) {
>  error_setg(errp, "Device '%s' not found", backup->target);
> @@ -1770,6 +1775,8 @@ static void blockdev_backup_prepare(BlkTransactionState 
> *common, Error **errp)
>  return;
>  }
>  aio_context_acquire(state->aio_context);
> +state->bs = blk_bs(blk);
> +bdrv_drained_begin(state->bs);
>  
>  qmp_blockdev_backup(backup->device, backup->target,
>  backup->sync,
> @@ -1782,7 +1789,6 @@ static void blockdev_backup_prepare(BlkTransactionState 
> *common, Error **errp)
>  return;
>  }
>  
> -state->bs = blk_bs(blk);
>  state->job = state->bs->job;
>  }
>  
> @@ -1802,6 +1808,7 @@ static void blockdev_backup_clean(BlkTransactionState 
> *common)
>  BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, 
> common);
>  
>  if (state->aio_context) {
> +bdrv_drained_end(state->bs);
>  aio_context_release(state->aio_context);
>  }
>  }
> -- 
> 2.4.3
> 
> 

Reviewed-by: Jeff Cody 

[Qemu-block] [PATCH v5 08/12] block: Add "drained begin/end" for transactional blockdev-backup

[Fam Zheng]

Similar to the previous patch, make sure that external events are not
dispatched during transaction operations.

Signed-off-by: Fam Zheng 
---
 blockdev.c | 9 -
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/blockdev.c b/blockdev.c
index 0a7848b..52f44b2 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1756,6 +1756,11 @@ static void blockdev_backup_prepare(BlkTransactionState 
*common, Error **errp)
 return;
 }
 
+if (!blk_is_available(blk)) {
+error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, backup->device);
+return;
+}
+
 target = blk_by_name(backup->target);
 if (!target) {
 error_setg(errp, "Device '%s' not found", backup->target);
@@ -1770,6 +1775,8 @@ static void blockdev_backup_prepare(BlkTransactionState 
*common, Error **errp)
 return;
 }
 aio_context_acquire(state->aio_context);
+state->bs = blk_bs(blk);
+bdrv_drained_begin(state->bs);
 
 qmp_blockdev_backup(backup->device, backup->target,
 backup->sync,
@@ -1782,7 +1789,6 @@ static void blockdev_backup_prepare(BlkTransactionState 
*common, Error **errp)
 return;
 }
 
-state->bs = blk_bs(blk);
 state->job = state->bs->job;
 }
 
@@ -1802,6 +1808,7 @@ static void blockdev_backup_clean(BlkTransactionState 
*common)
 BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, 
common);
 
 if (state->aio_context) {
+bdrv_drained_end(state->bs);
 aio_context_release(state->aio_context);
 }
 }
-- 
2.4.3