From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41953) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VdtVc-0006Ty-F8 for qemu-devel@nongnu.org; Tue, 05 Nov 2013 22:10:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VdtVU-0003OE-2h for qemu-devel@nongnu.org; Tue, 05 Nov 2013 22:10:20 -0500 Received: from mail-ob0-x22f.google.com ([2607:f8b0:4003:c01::22f]:41501) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VdtVT-0003OA-VQ for qemu-devel@nongnu.org; Tue, 05 Nov 2013 22:10:12 -0500 Received: by mail-ob0-f175.google.com with SMTP id va2so1686001obc.6 for ; Tue, 05 Nov 2013 19:10:11 -0800 (PST) From: Xu Wang Date: Tue, 5 Nov 2013 22:09:20 -0500 Message-Id: <1383707361-19580-5-git-send-email-gesaint@linux.vnet.ibm.com> In-Reply-To: <1383707361-19580-1-git-send-email-gesaint@linux.vnet.ibm.com> References: <1383707361-19580-1-git-send-email-gesaint@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH V6 4/5] block: Add backing file loop check in change_backing_file() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, stefanha@gmail.com, Xu Wang , wdongxu@linux.vnet.ibm.com, xiawenc@linux.vnet.ibm.com Backing file loop should be checked before calling change_backing_ file(). If loop appeared, this calling should be stopped and an error printed. Signed-off-by: Xu Wang --- block.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/block.c b/block.c index 8423e80..cb50bfd 100644 --- a/block.c +++ b/block.c @@ -2083,6 +2083,11 @@ int bdrv_change_backing_file(BlockDriverState *bs, return -EINVAL; } + /* Check if loop exists in backing files chain after change */ + if (!bdrv_new_chain_okay(bs->filename, backing_file, backing_fmt)) { + return -EIO; + } + if (drv->bdrv_change_backing_file != NULL) { ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); } else { -- 1.8.1.4