From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35892) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W4CIh-0006as-GC for qemu-devel@nongnu.org; Fri, 17 Jan 2014 11:29:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W4CIb-0008Rk-8X for qemu-devel@nongnu.org; Fri, 17 Jan 2014 11:29:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59519) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W4CIa-0008RO-VB for qemu-devel@nongnu.org; Fri, 17 Jan 2014 11:29:37 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s0HGTYrJ011890 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 17 Jan 2014 11:29:35 -0500 Date: Fri, 17 Jan 2014 11:29:31 -0500 From: Jeff Cody Message-ID: <20140117162931.GC1485@localhost.localdomain> References: <20140115055829.GA25475@T430.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140115055829.GA25475@T430.nay.redhat.com> Subject: Re: [Qemu-devel] [PATCH 2/2] block: resize backing image during active layer commit, if needed List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: kwolf@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com On Wed, Jan 15, 2014 at 01:58:29PM +0800, Fam Zheng wrote: > On Mon, 01/13 15:18, Jeff Cody wrote: > > If the top image to commit is the active layer, and also larger than > > the base image, then an I/O error will likely be returned during > > block-commit. > > > > For instance, if we have a base image with a virtual size 10G, and a > > active layer image of size 20G, then committing the snapshot via > > 'block-commit' will likely fail. > > > > This will automatically attempt to resize the base image, if the > > active layer image to be committed is larger. > > > > Signed-off-by: Jeff Cody > > --- > > block/mirror.c | 13 +++++++++++++ > > 1 file changed, 13 insertions(+) > > > > diff --git a/block/mirror.c b/block/mirror.c > > index 2932bab..c4e42fa 100644 > > --- a/block/mirror.c > > +++ b/block/mirror.c > > @@ -630,9 +630,22 @@ void commit_active_start(BlockDriverState *bs, BlockDriverState *base, > > BlockDriverCompletionFunc *cb, > > void *opaque, Error **errp) > > { > > + int64_t length; > > if (bdrv_reopen(base, bs->open_flags, errp)) { > > return; > > } > > "base" is already reopened here. > > > + > > + length = bdrv_getlength(bs); > > + > > + if (length > bdrv_getlength(base)) { > > + if (bdrv_truncate(base, length) < 0) { > > + error_setg(errp, "Top image %s is larger than base image %s, and " > > + "resize of base image failed.", > > + bs->filename, base->filename); > > + return; > > Should we restore open flags for base? > Good catch. Yes, I think we should; and I think we should also do it after the call to mirror_start_job, if errp is set. I'll add that in for v2. > > + } > > + } > > + > > bdrv_ref(base); > > mirror_start_job(bs, base, speed, 0, 0, > > on_error, on_error, cb, opaque, errp, > > -- > > 1.8.3.1 > >