From patchwork Mon Jul 15 09:42:33 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xu Wang X-Patchwork-Id: 258975 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 2D7922C00BE for ; Mon, 15 Jul 2013 19:46:22 +1000 (EST) Received: from localhost ([::1]:41326 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UyfMK-00045P-2h for incoming@patchwork.ozlabs.org; Mon, 15 Jul 2013 05:46:20 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44915) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UyfJY-0008VF-Ko for qemu-devel@nongnu.org; Mon, 15 Jul 2013 05:43:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UyfJU-0002rh-Rh for qemu-devel@nongnu.org; Mon, 15 Jul 2013 05:43:28 -0400 Received: from mail-pa0-x22c.google.com ([2607:f8b0:400e:c03::22c]:50395) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UyfJU-0002rF-Kg for qemu-devel@nongnu.org; Mon, 15 Jul 2013 05:43:24 -0400 Received: by mail-pa0-f44.google.com with SMTP id lj1so10998646pab.3 for ; Mon, 15 Jul 2013 02:43:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=koiIFbxptjTjG81UmOmWkJQHmLNfO+hwERmFTm2eOyI=; b=dP21iqi3as9L/gb5A25128BqvURplLiJ42Xy5UVCeuQ4uLkWs3HXxF9bvejj8w0Kvt 6j/RgKPDNKZITFPyszGEeEkHVJ1ZjSNXJ7aa+AUkk2+sDVJip85QYVR08KWX73Lvxrfm 3y1Etf80lAJW5o+gmPiE8qKT4J4ZlxfVvA7SMq9JQaCPxPm8LpZyY6QSPwt8+5WG2xZB 5CVGbcdZ0FuscfPAKYOAF1Lu8TMr+MbyPTIbiA1MnFcpcBtBRnbWGm0yMYST0VVDr1Xa z4RxZc7qLLDapBpynYdLQDfEXKVkMTcPJbor8BiUyCTsvZLA9Qq1tKSVDG0F5mBKShF3 Fjwg== X-Received: by 10.68.162.97 with SMTP id xz1mr53332678pbb.166.1373881403877; Mon, 15 Jul 2013 02:43:23 -0700 (PDT) Received: from localhost.localdomain ([202.108.130.194]) by mx.google.com with ESMTPSA id py4sm16734218pbc.14.2013.07.15.02.43.21 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Mon, 15 Jul 2013 02:43:23 -0700 (PDT) From: Xu Wang To: qemu-devel@nongnu.org Date: Mon, 15 Jul 2013 05:42:33 -0400 Message-Id: <1373881356-3294-5-git-send-email-cngesaint@gmail.com> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1373881356-3294-1-git-send-email-cngesaint@gmail.com> References: <1373881356-3294-1-git-send-email-cngesaint@gmail.com> X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2607:f8b0:400e:c03::22c Cc: kwolf@redhat.com, famz@redhat.com, stefanha@gmail.com, wdongxu@linux.vnet.ibm.com, Xu Wang , xiawenc@linux.vnet.ibm.com Subject: [Qemu-devel] [PATCH V3 4/7] block: Add backing file loop check in change_backing_file() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org 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 e9b9112..bd8240c 100644 --- a/block.c +++ b/block.c @@ -1967,6 +1967,13 @@ 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 {