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From: Stefan Hajnoczi <stefanha@gmail.com>
To: Zhang Haoyu <zhanghy@sangfor.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Max Reitz <mreitz@redhat.com>,
	qemu-devel <qemu-devel@nongnu.org>,
	Stefan Hajnoczi <stefanha@redhat.com>,
	qemu-stable <qemu-stable@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH bugfix] snapshot: add bdrv_drain_all() to bdrv_snapshot_delete() to avoid concurrency problem
Date: Tue, 28 Oct 2014 15:18:52 +0000	[thread overview]
Message-ID: <20141028151852.GK22805@stefanha-thinkpad.redhat.com> (raw)
In-Reply-To: <201410211637596311287@sangfor.com>

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On Tue, Oct 21, 2014 at 04:38:01PM +0800, Zhang Haoyu wrote:
> If there are still pending i/o while deleting snapshot,
> because deleting snapshot is done in non-coroutine context, and
> the pending i/o read/write (bdrv_co_do_rw) is done in coroutine context,
> so it's possible to cause concurrency problem between above two operations.
> Add bdrv_drain_all() to bdrv_snapshot_delete() to avoid this problem.
> 
> Signed-off-by: Zhang Haoyu <zhanghy@sangfor.com>
> ---
>  block/snapshot.c | 4 ++++
>  1 file changed, 4 insertions(+)

Thanks, applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan

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      parent reply	other threads:[~2014-10-28 15:19 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-21  8:38 [Qemu-devel] [PATCH bugfix] snapshot: add bdrv_drain_all() to bdrv_snapshot_delete() to avoid concurrency problem Zhang Haoyu
2014-10-21 11:12 ` Paolo Bonzini
2014-10-28 15:18 ` Stefan Hajnoczi [this message]

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