From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56745) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dDLt1-0008VF-3z for qemu-devel@nongnu.org; Tue, 23 May 2017 22:18:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dDLt0-00057E-9U for qemu-devel@nongnu.org; Tue, 23 May 2017 22:18:55 -0400 Date: Wed, 24 May 2017 10:18:44 +0800 From: Fam Zheng Message-ID: <20170524021844.GG12279@lemon.lan> References: <20170419094356.19826-1-famz@redhat.com> <20170419094356.19826-7-famz@redhat.com> <20170511194100.GI24584@stefanha-x1.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170511194100.GI24584@stefanha-x1.localdomain> Subject: Re: [Qemu-devel] [Qemu-block] [PATCH v2 06/16] backup: Request BLK_PERM_AIO_CONTEXT_CHANGE on target List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: qemu-devel@nongnu.org, Kevin Wolf , qemu-block@nongnu.org, Stefan Hajnoczi , Max Reitz 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