Re: [PATCH v5 0/4] blockdev: avoid acquiring AioContext lock twice at do_drive_backup and do_blockdev_backup

[Kevin Wolf <kwolf@redhat.com>]

Am 28.11.2019 um 11:41 hat Sergio Lopez geschrieben:
> do_drive_backup() acquires the AioContext lock of the corresponding
> BlockDriverState. This is not a problem when it's called from
> qmp_drive_backup(), but drive_backup_prepare() also acquires the lock
> before calling it. The same things happens with do_blockdev_backup()
> and blockdev_backup_prepare().
> 
> This patch series merges do_drive_backup() with drive_backup_prepare()
> and do_blockdev_backup() with blockdev_backup_prepare(), and ensures
> they're only getting called from a transaction context. This way,
> there's a single code path for both transaction requests and qmp
> commands, as suggested by Kevin Wolf.
> 
> We also take this opportunity to ensure we're honoring the context
> acquisition semantics required by bdrv_try_set_aio_context, as
> suggested by Max Reitz.

I think there is a small problem with the error paths in patch 4, but
for patches 1 to 3 you can add:

Reviewed-by: Kevin Wolf <kwolf@redhat.com>