Re: [Qemu-devel] [Qemu-block] [PATCH v2 06/16] backup: Request BLK_PERM_AIO_CONTEXT_CHANGE on target

[Fam Zheng]

On Thu, 05/11 15:41, Stefan Hajnoczi wrote:
> On Wed, Apr 19, 2017 at 05:43:46PM +0800, Fam Zheng wrote:
> > What's done in the source's context change notifier is moving the
> > target's context to follow the new one, so we request this permission
> > here.
> 
> It's true that the backup block job must be able to set target's
> AioContext, but does this change also allow other users to set target's
> AioContext while the backup job is running?  If yes, then we need to
> handle that.

If through job->target, yes, but I don't think there is any user of job->target.
Otherwise, it's not allowed, because the second parameter of blk_new doesn't
have BLK_PERM_AIO_CONTEXT_CHANGE.

So it's okay.

Fam