From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36626) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WLq2A-0007eh-5U for qemu-devel@nongnu.org; Fri, 07 Mar 2014 03:21:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WLq24-0006pL-5E for qemu-devel@nongnu.org; Fri, 07 Mar 2014 03:21:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33232) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WLq23-0006pE-Sm for qemu-devel@nongnu.org; Fri, 07 Mar 2014 03:21:28 -0500 From: Fam Zheng Date: Fri, 7 Mar 2014 16:20:49 +0800 Message-Id: <1394180456-18139-8-git-send-email-famz@redhat.com> In-Reply-To: <1394180456-18139-1-git-send-email-famz@redhat.com> References: <1394180456-18139-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [PATCH v16 07/14] block: Parse "backing" option to reference existing BDS List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, benoit.canet@irqsave.net, rjones@redhat.com, jcody@redhat.com, armbru@redhat.com, ptoscano@redhat.com, imain@redhat.com, stefanha@redhat.com, pbonzini@redhat.com Now it's safe to allow reference for backing_hd in the interface. Signed-off-by: Fam Zheng --- block.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/block.c b/block.c index 650931f..bcfeb50 100644 --- a/block.c +++ b/block.c @@ -1395,12 +1395,35 @@ int bdrv_open(BlockDriverState **pbs, const char *filename, /* If there is a backing file, use it */ if ((flags & BDRV_O_NO_BACKING) == 0) { QDict *backing_options; + const char *backing_name; + BlockDriverState *backing_hd; + backing_name = qdict_get_try_str(options, "backing"); qdict_extract_subqdict(options, &backing_options, "backing."); - ret = bdrv_open_backing_file(bs, backing_options, &local_err); - if (ret < 0) { + + if (backing_name && qdict_size(backing_options)) { + error_setg(&local_err, + "Option \"backing\" and \"backing.*\" cannot be " + "used together"); + ret = -EINVAL; goto close_and_fail; } + if (backing_name) { + backing_hd = bdrv_find(backing_name); + if (!backing_hd) { + error_set(&local_err, QERR_DEVICE_NOT_FOUND, backing_name); + ret = -ENOENT; + goto close_and_fail; + } + qdict_del(options, "backing"); + bdrv_set_backing_hd(bs, backing_hd); + bdrv_ref(backing_hd); + } else { + ret = bdrv_open_backing_file(bs, backing_options, &local_err); + if (ret < 0) { + goto close_and_fail; + } + } } done: -- 1.9.0