From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44966) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1btxce-0005Kv-P3 for qemu-devel@nongnu.org; Tue, 11 Oct 2016 10:01:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1btxcY-00059Z-Ro for qemu-devel@nongnu.org; Tue, 11 Oct 2016 10:01:35 -0400 Date: Tue, 11 Oct 2016 16:01:15 +0200 From: Kevin Wolf Message-ID: <20161011140115.GE6334@noname.redhat.com> References: <20161010160341.GK6775@noname.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH v10 03/16] block: Use block_job_add_bdrv() in mirror_start_job() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alberto Garcia Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org, Max Reitz , Markus Armbruster , Stefan Hajnoczi Am 11.10.2016 um 15:46 hat Alberto Garcia geschrieben: > On Mon 10 Oct 2016 06:03:41 PM CEST, Kevin Wolf wrote: > > >> Use block_job_add_bdrv() instead of blocking all operations in > >> mirror_start_job() and unblocking them in mirror_exit(). > >> > >> Signed-off-by: Alberto Garcia > > > > Compared to the old code, this unblocks BLOCK_OP_TYPE_DATAPLANE, i.e. > > you can now run a dataplane device on a BDS used as the mirror target. > > > > This means that the target could require a different AioContext than > > the source, which we can't support. So it seems unlikely to me that we > > can lift this restriction. > > Thanks, I'll fix it. > > What happens if you run a dataplane on the source, though? That's > currently allowed as far as I'm aware. Wouldn't that have a similar > effect? The block job takes care to put the target into the same dataplane AioContext then. The job doesn't really care whether it works in the main thread or a separate I/O thread, it just requires that it's a single context, which is currently defined by the source. Kevin