From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40461) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WMubh-0006VQ-AI for qemu-devel@nongnu.org; Mon, 10 Mar 2014 03:26:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WMubb-00078Z-7X for qemu-devel@nongnu.org; Mon, 10 Mar 2014 03:26:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60122) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WMuba-00078N-RS for qemu-devel@nongnu.org; Mon, 10 Mar 2014 03:26:35 -0400 From: Fam Zheng Date: Mon, 10 Mar 2014 15:26:03 +0800 Message-Id: <1394436370-8908-8-git-send-email-famz@redhat.com> In-Reply-To: <1394436370-8908-1-git-send-email-famz@redhat.com> References: <1394436370-8908-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [PATCH v17 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 95247c8..05f7766 100644 --- a/block.c +++ b/block.c @@ -1401,12 +1401,35 @@ 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