From patchwork Wed Nov 30 01:18:41 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 9453397 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 18CD96071C for ; Wed, 30 Nov 2016 01:28:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F2800281B7 for ; Wed, 30 Nov 2016 01:28:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E43F9283E0; Wed, 30 Nov 2016 01:28:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 53073281B7 for ; Wed, 30 Nov 2016 01:28:40 +0000 (UTC) Received: from localhost ([::1]:40181 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cBthO-00070S-Gw for patchwork-qemu-devel@patchwork.kernel.org; Tue, 29 Nov 2016 20:28:38 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54563) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cBtYg-000835-41 for qemu-devel@nongnu.org; Tue, 29 Nov 2016 20:19:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cBtYf-0006OT-8n for qemu-devel@nongnu.org; Tue, 29 Nov 2016 20:19:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58814) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cBtYY-0006Kq-QQ; Tue, 29 Nov 2016 20:19:30 -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 01E14C04B920; Wed, 30 Nov 2016 01:19:30 +0000 (UTC) Received: from localhost (ovpn-116-36.phx2.redhat.com [10.3.116.36]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id uAU1JSdd020743 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 29 Nov 2016 20:19:29 -0500 From: Max Reitz To: qemu-block@nongnu.org Date: Wed, 30 Nov 2016 02:18:41 +0100 Message-Id: <20161130011851.24696-16-mreitz@redhat.com> In-Reply-To: <20161130011851.24696-1-mreitz@redhat.com> References: <20161130011851.24696-1-mreitz@redhat.com> 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 [10.5.110.31]); Wed, 30 Nov 2016 01:19:30 +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 v3 15/25] block: Use bdrv_dirname() for relative 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: Kevin Wolf , Alberto Garcia , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP bdrv_get_full_backing_filename_from_filename() breaks down when it comes to JSON filenames. Using bdrv_dirname() as the basis is better because since we have BDS, we can descend through the BDS tree to the protocol layer, which gives us a greater probability of finding a non-JSON name; also, bdrv_dirname() is more correct as it allows block drivers to override the generation of that directory name in a protocol-specific way. We still need to keep bdrv_get_full_backing_filename_from_filename(), though, because it has valid callers which need it during image creation when no BDS is available yet. This makes a test case in qemu-iotest 110, which was supposed to fail, work. That is actually good, but we need to change the reference output (and the comment in 110) accordingly. Signed-off-by: Max Reitz --- block.c | 20 +++++++++++++++----- tests/qemu-iotests/110 | 3 ++- tests/qemu-iotests/110.out | 2 +- 3 files changed, 18 insertions(+), 7 deletions(-) diff --git a/block.c b/block.c index c48121b..16eda37 100644 --- a/block.c +++ b/block.c @@ -214,12 +214,22 @@ char *bdrv_get_full_backing_filename_from_filename(const char *backed, static char *bdrv_make_absolute_filename(BlockDriverState *relative_to, const char *filename, Error **errp) { - char *bs_filename = relative_to->exact_filename[0] - ? relative_to->exact_filename - : relative_to->filename; + char *dir, *full_name; - return bdrv_get_full_backing_filename_from_filename(bs_filename, filename, - errp); + if (filename[0] == '\0' || path_has_protocol(filename) || + path_is_absolute(filename)) + { + return g_strdup(filename); + } + + dir = bdrv_dirname(relative_to, errp); + if (!dir) { + return NULL; + } + + full_name = g_strconcat(dir, filename, NULL); + g_free(dir); + return full_name; } char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp) diff --git a/tests/qemu-iotests/110 b/tests/qemu-iotests/110 index 9de7369..ba1b3c6 100755 --- a/tests/qemu-iotests/110 +++ b/tests/qemu-iotests/110 @@ -61,7 +61,8 @@ echo '=== Non-reconstructable filename ===' echo # Across blkdebug without a config file, you cannot reconstruct filenames, so -# qemu is incapable of knowing the directory of the top image +# qemu is incapable of knowing the directory of the top image from the filename +# alone. However, using bdrv_dirname(), it should still work. TEST_IMG="json:{ 'driver': '$IMGFMT', 'file': { diff --git a/tests/qemu-iotests/110.out b/tests/qemu-iotests/110.out index b3584ff..5370bc1 100644 --- a/tests/qemu-iotests/110.out +++ b/tests/qemu-iotests/110.out @@ -14,7 +14,7 @@ backing file: t.IMGFMT.base (actual path: TEST_DIR/t.IMGFMT.base) image: json:{"driver": "IMGFMT", "file": {"set-state.0.event": "read_aio", "image": {"driver": "file", "filename": "TEST_DIR/t.IMGFMT"}, "driver": "blkdebug", "set-state.0.new_state": 42}} file format: IMGFMT virtual size: 64M (67108864 bytes) -backing file: t.IMGFMT.base (cannot determine actual path) +backing file: t.IMGFMT.base (actual path: TEST_DIR/t.IMGFMT.base) === Backing name is always relative to the backed image ===