From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58449) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e7i2o-000073-GV for qemu-devel@nongnu.org; Thu, 26 Oct 2017 09:18:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e7i2n-0001cG-A5 for qemu-devel@nongnu.org; Thu, 26 Oct 2017 09:17:58 -0400 From: Kevin Wolf Date: Thu, 26 Oct 2017 15:17:07 +0200 Message-Id: <20171026131741.5059-2-kwolf@redhat.com> In-Reply-To: <20171026131741.5059-1-kwolf@redhat.com> References: <20171026131741.5059-1-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 01/35] block: don't add 'driver' to options when referring to backing via node name List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: Peter Krempa When referring to a backing file of an image via node name bdrv_open_backing_file would add the 'driver' option to the option list filling it with the backing format driver. This breaks construction of the backing chain via -blockdev, as bdrv_open_inherit reports an error if both 'reference' and 'options' are provided. $ qemu-img create -f raw /tmp/backing.raw 64M $ qemu-img create -f qcow2 -F raw -b /tmp/backing.raw /tmp/test.qcow2 $ qemu-system-x86_64 \ -blockdev driver=file,filename=/tmp/backing.raw,node-name=backing \ -blockdev driver=qcow2,file.driver=file,file.filename=/tmp/test.qcow2,node-name=root,backing=backing qemu-system-x86_64: -blockdev driver=qcow2,file.driver=file,file.filename=/tmp/test.qcow2,node-name=root,backing=backing: Could not open backing file: Cannot reference an existing block device with additional options or a new filename Signed-off-by: Peter Krempa Signed-off-by: Kevin Wolf --- block.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block.c b/block.c index 46eb1728da..684cb018da 100644 --- a/block.c +++ b/block.c @@ -2245,7 +2245,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, goto free_exit; } - if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { + if (!reference && + bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { qdict_put_str(options, "driver", bs->backing_format); } -- 2.13.6