From patchwork Thu Aug 9 21:35:16 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 955801 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 41mhZl4BB9z9s3Z for ; Fri, 10 Aug 2018 07:43:27 +1000 (AEST) Received: from localhost ([::1]:52918 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fnsiL-0001kz-4m for incoming@patchwork.ozlabs.org; Thu, 09 Aug 2018 17:43:25 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42961) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fnsbN-0002kN-9e for qemu-devel@nongnu.org; Thu, 09 Aug 2018 17:36:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fnsbM-0008Ip-A2 for qemu-devel@nongnu.org; Thu, 09 Aug 2018 17:36:13 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:52598 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fnsbJ-0008Ff-Sy; Thu, 09 Aug 2018 17:36:10 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 60CB2402333A; Thu, 9 Aug 2018 21:36:09 +0000 (UTC) Received: from localhost (ovpn-204-42.brq.redhat.com [10.40.204.42]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 04AF710FFE53; Thu, 9 Aug 2018 21:36:08 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Thu, 9 Aug 2018 23:35:16 +0200 Message-Id: <20180809213528.14738-20-mreitz@redhat.com> In-Reply-To: <20180809213528.14738-1-mreitz@redhat.com> References: <20180809213528.14738-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Thu, 09 Aug 2018 21:36:09 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Thu, 09 Aug 2018 21:36:09 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mreitz@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH for-3.1 v10 19/31] 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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 Reviewed-by: Alberto Garcia --- block.c | 20 +++++++++++++------- tests/qemu-iotests/110 | 3 ++- tests/qemu-iotests/110.out | 2 +- 3 files changed, 16 insertions(+), 9 deletions(-) diff --git a/block.c b/block.c index b68297e6f3..1fdbf627e0 100644 --- a/block.c +++ b/block.c @@ -318,16 +318,22 @@ 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; + char *dir, *full_name; - bdrv_refresh_filename(relative_to); + if (!filename || filename[0] == '\0') { + return NULL; + } else if (path_has_protocol(filename) || path_is_absolute(filename)) { + return g_strdup(filename); + } - bs_filename = relative_to->exact_filename[0] - ? relative_to->exact_filename - : relative_to->filename; + dir = bdrv_dirname(relative_to, errp); + if (!dir) { + return NULL; + } - return bdrv_get_full_backing_filename_from_filename(bs_filename, - filename ?: "", errp); + 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 9de7369f3a..ba1b3c6c7d 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 b3584ff87f..5370bc1d26 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 ===