From patchwork Thu Jan 26 01:08:20 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Cody X-Patchwork-Id: 719923 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)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3v83jj52zTz9t0p for ; Thu, 26 Jan 2017 12:09:42 +1100 (AEDT) Received: from localhost ([::1]:35474 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cWYZH-00079k-F8 for incoming@patchwork.ozlabs.org; Wed, 25 Jan 2017 20:09:39 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42724) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cWYYC-0006Uj-5C for qemu-devel@nongnu.org; Wed, 25 Jan 2017 20:08:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cWYYB-0007B5-4a for qemu-devel@nongnu.org; Wed, 25 Jan 2017 20:08:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39508) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cWYY5-00075w-Ot; Wed, 25 Jan 2017 20:08:25 -0500 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 01251804FE; Thu, 26 Jan 2017 01:08:26 +0000 (UTC) Received: from localhost (ovpn-116-248.phx2.redhat.com [10.3.116.248]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v0Q18Oip026849 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 25 Jan 2017 20:08:25 -0500 From: Jeff Cody To: qemu-devel@nongnu.org Date: Wed, 25 Jan 2017 20:08:20 -0500 Message-Id: In-Reply-To: References: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Thu, 26 Jan 2017 01:08:26 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 1/3] block: check full backing filename when searching protocol filenames X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-block@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" In bdrv_find_backing_image(), if we are searching an image for a backing file that contains a protocol, we currently only compare unmodified paths. However, some management software will change the backing filename to be a relative filename in a path. QEMU is able to handle this fine, because internally it will use path_combine to put together the full protocol URI. However, this can lead to an inability to match an image during a QAPI command that needs to use bdrv_find_backing_image() to find the image, when it is searched by the full URI. When searching for a protocol filename, if the straight comparison fails, this patch will also compare against the full backing filename to see if that is a match. Signed-off-by: Jeff Cody --- block.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/block.c b/block.c index 39ddea3..d97c009 100644 --- a/block.c +++ b/block.c @@ -3145,6 +3145,7 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, int is_protocol = 0; BlockDriverState *curr_bs = NULL; BlockDriverState *retval = NULL; + Error *local_error = NULL; if (!bs || !bs->drv || !backing_file) { return NULL; @@ -3165,6 +3166,18 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, retval = curr_bs->backing->bs; break; } + /* Also check against the full backing filename for the image */ + bdrv_get_full_backing_filename(curr_bs, backing_file_full, PATH_MAX, + &local_error); + if (local_error == NULL) { + if (strcmp(backing_file, backing_file_full) == 0) { + retval = curr_bs->backing->bs; + break; + } + } else { + error_free(local_error); + local_error = NULL; + } } else { /* If not an absolute filename path, make it relative to the current * image's filename path */