From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43118) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WGLtl-0007Wt-Lw for qemu-devel@nongnu.org; Thu, 20 Feb 2014 00:10:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WGLtf-0005QP-M7 for qemu-devel@nongnu.org; Thu, 20 Feb 2014 00:10:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:22565) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WGLtf-0005QC-F3 for qemu-devel@nongnu.org; Thu, 20 Feb 2014 00:10:07 -0500 Date: Thu, 20 Feb 2014 00:08:00 -0500 From: Jeff Cody Message-ID: <20140220050800.GC4059@localhost.localdomain> References: <1392817351-22148-1-git-send-email-famz@redhat.com> <1392817351-22148-7-git-send-email-famz@redhat.com> <20140219211732.GB4059@localhost.localdomain> <20140220050138.GC6744@T430.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140220050138.GC6744@T430.redhat.com> Subject: Re: [Qemu-devel] [PATCH v14 06/14] block: Add backing_blocker in BlockDriverState List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: kwolf@redhat.com, benoit.canet@irqsave.net, rjones@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com, imain@redhat.com, stefanha@redhat.com, pbonzini@redhat.com On Thu, Feb 20, 2014 at 01:01:38PM +0800, Fam Zheng wrote: > On Wed, 02/19 16:17, Jeff Cody wrote: > > On Wed, Feb 19, 2014 at 09:42:23PM +0800, Fam Zheng wrote: > > > This makes use of op_blocker and blocks all the operations except for > > > commit target, on each BlockDriverState->backing_hd. > > > > > > The asserts for op_blocker in bdrv_swap are removed because with this > > > change, the target of block commit has at least the backing blocker of > > > its child, so the assertion is not true. Callers should do their check. > > > > > > Signed-off-by: Fam Zheng > > > --- > > > block.c | 19 +++++++++++++++---- > > > include/block/block_int.h | 3 +++ > > > 2 files changed, 18 insertions(+), 4 deletions(-) > > > > > > diff --git a/block.c b/block.c > > > index dec44d4..95d8c1f 100644 > > > --- a/block.c > > > +++ b/block.c > > > @@ -1044,19 +1044,33 @@ fail: > > > void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) > > > { > > > if (bs->backing_hd) { > > > + assert(error_is_set(&bs->backing_blocker)); > > > > When I run block-commit, on either the active or non-active layer, I > > get an assertion here. The qemu-iotests do not catch it, and I > > presume it is because happens a couple of seconds or so after the > > success message is returned over QMP. > > > > I can't reproduce this, could you give some specific steps? Thanks. > Sure - I am guessing the key is performing some live block snapshots first. Here is what I did (this is from memory, but I think the steps are right): Nothing special really about the cmdline: qemu-system-x86_64 -drive file=/home/jtc/test.qcow2,if=virtio -qmp stdio ... The QMP commands: For the non-active layer case: { "execute": "qmp_capabilities" } { "execute": "blockdev-snapshot-sync", "arguments": { "device": "virtio0","snapshot-file":"/tmp/snap1.qcow2","format": "qcow2" } } { "execute": "blockdev-snapshot-sync", "arguments": { "device": "virtio0","snapshot-file":"/tmp/snap2.qcow2","format": "qcow2" } } { "execute": "block-commit", "arguments": { "device": "virtio0", "top": "/tmp/snap1.qcow2" } } For the active layer case (I think I still had 2 snapshots here, not entirely positive): { "execute": "qmp_capabilities" } { "execute": "blockdev-snapshot-sync", "arguments": { "device": "virtio0","snapshot-file":"/tmp/snap1.qcow2","format": "qcow2" } } { "execute": "blockdev-snapshot-sync", "arguments": { "device": "virtio0","snapshot-file":"/tmp/snap2.qcow2","format": "qcow2" } } { "execute": "block-commit", "arguments": { "device": "virtio0", "top": "/tmp/snap2.qcow2" } } { "execute": "block-job-complete", "arguments": { "device": "virtio0" }}