From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57980) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V5BPy-0005W1-55 for qemu-devel@nongnu.org; Fri, 02 Aug 2013 05:13:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V5BPo-0000RF-KL for qemu-devel@nongnu.org; Fri, 02 Aug 2013 05:13:01 -0400 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:53467) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V5BPn-0000Qe-Pi for qemu-devel@nongnu.org; Fri, 02 Aug 2013 05:12:52 -0400 Received: from /spool/local by e28smtp09.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 2 Aug 2013 14:27:09 +0530 Received: from d28relay01.in.ibm.com (d28relay01.in.ibm.com [9.184.220.58]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id C037D1258051 for ; Fri, 2 Aug 2013 14:32:04 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay01.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r7293YRU6881306 for ; Fri, 2 Aug 2013 14:33:34 +0530 Received: from d28av02.in.ibm.com (loopback [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r7292SW4015394 for ; Fri, 2 Aug 2013 19:02:28 +1000 From: Xu Wang Date: Fri, 2 Aug 2013 05:02:16 -0400 Message-Id: <1375434137-4452-6-git-send-email-gesaint@linux.vnet.ibm.com> In-Reply-To: <1375434137-4452-1-git-send-email-gesaint@linux.vnet.ibm.com> References: <1375434137-4452-1-git-send-email-gesaint@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH V5 5/6] 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, wdongxu@linux.vnet.ibm.com, Xu Wang , xiawenc@linux.vnet.ibm.com From: Xu Wang Backing file loop should be checked before calling change_backing_ file(). If loop appeared, this calling should be stopped and an error was printed. Signed-off-by: Xu Wang --- block.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/block.c b/block.c index 8bb63c2..a14488f 100644 --- a/block.c +++ b/block.c @@ -1963,6 +1963,13 @@ int bdrv_change_backing_file(BlockDriverState *bs, return -EINVAL; } + /* Check if loop exists in backing files chain after changed */ + if (bdrv_backing_file_loop_check(bs->filename, + bs->drv ? bs->drv->format_name : NULL, + 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