From nobody Wed Oct 29 20:33:39 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 152588140211723.783257510594353; Wed, 9 May 2018 08:56:42 -0700 (PDT) Received: from localhost ([::1]:57244 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fGRSL-0000kK-BT for importer@patchew.org; Wed, 09 May 2018 11:56:41 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42139) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fGRLp-0002pZ-On for qemu-devel@nongnu.org; Wed, 09 May 2018 11:49:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fGRLo-0000Gl-LK for qemu-devel@nongnu.org; Wed, 09 May 2018 11:49:57 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:40272 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 1fGRLl-0000Bq-K8; Wed, 09 May 2018 11:49:53 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ED099EFDE1; Wed, 9 May 2018 15:49:52 +0000 (UTC) Received: from localhost (unknown [10.40.205.23]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 934352166BAD; Wed, 9 May 2018 15:49:52 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Wed, 9 May 2018 17:49:48 +0200 Message-Id: <20180509154949.8206-2-mreitz@redhat.com> In-Reply-To: <20180509154949.8206-1-mreitz@redhat.com> References: <20180509154949.8206-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Wed, 09 May 2018 15:49:52 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Wed, 09 May 2018 15:49:52 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.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 1/2] qemu-img: Resolve relative backing paths in rebase 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 , qemu-stable@nongnu.org, qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Currently, rebase interprets a relative path for the new backing image as follows: (1) Open the new backing image with the given relative path (thus relative = to qemu-img's working directory). (2) Write it directly into the overlay's backing path field (thus relative to the overlay). If the overlay is not in qemu-img's working directory, both will be different interpretations, which may either lead to an error somewhere (either rebase fails because it cannot open the new backing image, or your overlay becomes unusable because its backing path does not point to a file), or, even worse, it may result in your rebase being performed for a different backing file than what your overlay will point to after the rebase. Fix this by interpreting the target backing path as relative to the overlay, like qemu-img does everywhere else. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=3D1569835 Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz --- qemu-img.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/qemu-img.c b/qemu-img.c index ea62d2d61e..50540519e3 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3191,6 +3191,9 @@ static int img_rebase(int argc, char **argv) } =20 if (out_baseimg[0]) { + const char *overlay_filename; + char *out_real_path; + options =3D qdict_new(); if (out_basefmt) { qdict_put_str(options, "driver", out_basefmt); @@ -3199,8 +3202,25 @@ static int img_rebase(int argc, char **argv) qdict_put_bool(options, BDRV_OPT_FORCE_SHARE, true); } =20 - blk_new_backing =3D blk_new_open(out_baseimg, NULL, + overlay_filename =3D bs->exact_filename[0] ? bs->exact_filename + : bs->filename; + out_real_path =3D g_malloc(PATH_MAX); + + bdrv_get_full_backing_filename_from_filename(overlay_filename, + out_baseimg, + out_real_path, + PATH_MAX, + &local_err); + if (local_err) { + error_reportf_err(local_err, + "Could not resolve backing filename: "); + ret =3D -1; + goto out; + } + + blk_new_backing =3D blk_new_open(out_real_path, NULL, options, src_flags, &local_err); + g_free(out_real_path); if (!blk_new_backing) { error_reportf_err(local_err, "Could not open new backing file '%s': ", --=20 2.14.3 From nobody Wed Oct 29 20:33:39 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1525881578473845.1628564753136; Wed, 9 May 2018 08:59:38 -0700 (PDT) Received: from localhost ([::1]:57259 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fGRV3-0002yG-GB for importer@patchew.org; Wed, 09 May 2018 11:59:29 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42221) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fGRLt-0002wD-KG for qemu-devel@nongnu.org; Wed, 09 May 2018 11:50:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fGRLs-0000Nt-IG for qemu-devel@nongnu.org; Wed, 09 May 2018 11:50:01 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:40048 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 1fGRLn-0000Eg-Lb; Wed, 09 May 2018 11:49:55 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D1810818F6F2; Wed, 9 May 2018 15:49:54 +0000 (UTC) Received: from localhost (unknown [10.40.205.23]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7D88E2166BAD; Wed, 9 May 2018 15:49:54 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Wed, 9 May 2018 17:49:49 +0200 Message-Id: <20180509154949.8206-3-mreitz@redhat.com> In-Reply-To: <20180509154949.8206-1-mreitz@redhat.com> References: <20180509154949.8206-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 09 May 2018 15:49:54 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 09 May 2018 15:49:54 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.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 2/2] iotests: Add test for rebasing with relative paths 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 , qemu-stable@nongnu.org, qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Signed-off-by: Max Reitz Reviewed-by: Eric Blake --- tests/qemu-iotests/024 | 82 ++++++++++++++++++++++++++++++++++++++++++= ++-- tests/qemu-iotests/024.out | 30 +++++++++++++++++ 2 files changed, 109 insertions(+), 3 deletions(-) diff --git a/tests/qemu-iotests/024 b/tests/qemu-iotests/024 index e0d77ce2f5..4071ed6093 100755 --- a/tests/qemu-iotests/024 +++ b/tests/qemu-iotests/024 @@ -29,9 +29,14 @@ status=3D1 # failure is the default! =20 _cleanup() { - _cleanup_test_img - rm -f "$TEST_DIR/t.$IMGFMT.base_old" - rm -f "$TEST_DIR/t.$IMGFMT.base_new" + _cleanup_test_img + rm -f "$TEST_DIR/t.$IMGFMT.base_old" + rm -f "$TEST_DIR/t.$IMGFMT.base_new" + + rm -f "$TEST_DIR/subdir/t.$IMGFMT" + rm -f "$TEST_DIR/subdir/t.$IMGFMT.base_old" + rm -f "$TEST_DIR/subdir/t.$IMGFMT.base_new" + rmdir "$TEST_DIR/subdir" 2> /dev/null } trap "_cleanup; exit \$status" 0 1 2 3 15 =20 @@ -123,6 +128,77 @@ io_pattern readv $((13 * CLUSTER_SIZE)) $CLUSTER_SIZE = 0 1 0x00 io_pattern readv $((14 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x11 io_pattern readv $((15 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x00 =20 +echo +echo "=3D=3D=3D Test rebase in a subdirectory of the working directory =3D= =3D=3D" +echo + +# Clean up the old images beforehand so they do not interfere with +# this test +_cleanup + +mkdir "$TEST_DIR/subdir" + +# Relative to the overlay +BASE_OLD_OREL=3D"t.$IMGFMT.base_old" +BASE_NEW_OREL=3D"t.$IMGFMT.base_new" + +# Relative to $TEST_DIR (which is going to be our working directory) +OVERLAY_WREL=3D"subdir/t.$IMGFMT" + +BASE_OLD=3D"$TEST_DIR/subdir/$BASE_OLD_OREL" +BASE_NEW=3D"$TEST_DIR/subdir/$BASE_NEW_OREL" +OVERLAY=3D"$TEST_DIR/$OVERLAY_WREL" + +# Test done here: +# +# Backing (old): 11 11 -- 11 +# Backing (new): -- 22 22 11 +# Overlay: -- -- -- -- +# +# Rebasing works, we have verified that above. Here, we just want to +# see that rebasing is done for the correct target backing file. + +TEST_IMG=3D$BASE_OLD _make_test_img 1M +TEST_IMG=3D$BASE_NEW _make_test_img 1M +TEST_IMG=3D$OVERLAY _make_test_img -b "$BASE_OLD_OREL" 1M + +echo + +$QEMU_IO "$BASE_OLD" \ + -c "write -P 0x11 $((0 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \ + -c "write -P 0x11 $((3 * CLUSTER_SIZE)) $((1 * CLUSTER_SIZE))" \ + | _filter_qemu_io + +$QEMU_IO "$BASE_NEW" \ + -c "write -P 0x22 $((1 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \ + -c "write -P 0x11 $((3 * CLUSTER_SIZE)) $((1 * CLUSTER_SIZE))" \ + | _filter_qemu_io + +echo + +pushd "$TEST_DIR" >/dev/null +$QEMU_IMG rebase -f "$IMGFMT" -b "$BASE_NEW_OREL" "$OVERLAY_WREL" +popd >/dev/null + +# Verify the backing path is correct +TEST_IMG=3D$OVERLAY _img_info | grep '^backing file' + +echo + +# Verify the data is correct +$QEMU_IO "$OVERLAY" \ + -c "read -P 0x11 $((0 * CLUSTER_SIZE)) $CLUSTER_SIZE" \ + -c "read -P 0x11 $((1 * CLUSTER_SIZE)) $CLUSTER_SIZE" \ + -c "read -P 0x00 $((2 * CLUSTER_SIZE)) $CLUSTER_SIZE" \ + -c "read -P 0x11 $((3 * CLUSTER_SIZE)) $CLUSTER_SIZE" \ + | _filter_qemu_io + +echo + +# Verify that cluster #3 is not allocated (because it is the same in +# $BASE_OLD and $BASE_NEW) +$QEMU_IMG map "$OVERLAY" | _filter_qemu_img_map + =20 # success, all done echo "*** done" diff --git a/tests/qemu-iotests/024.out b/tests/qemu-iotests/024.out index 33cfaf5cfc..024dc786b3 100644 --- a/tests/qemu-iotests/024.out +++ b/tests/qemu-iotests/024.out @@ -141,4 +141,34 @@ read 65536/65536 bytes at offset 917504 =3D=3D=3D IO: pattern 0x00 read 65536/65536 bytes at offset 983040 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) + +=3D=3D=3D Test rebase in a subdirectory of the working directory =3D=3D=3D + +Formatting 'TEST_DIR/subdir/t.IMGFMT.base_old', fmt=3DIMGFMT size=3D1048576 +Formatting 'TEST_DIR/subdir/t.IMGFMT.base_new', fmt=3DIMGFMT size=3D1048576 +Formatting 'TEST_DIR/subdir/t.IMGFMT', fmt=3DIMGFMT size=3D1048576 backing= _file=3Dt.IMGFMT.base_old + +wrote 131072/131072 bytes at offset 0 +128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +wrote 65536/65536 bytes at offset 196608 +64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +wrote 131072/131072 bytes at offset 65536 +128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +wrote 65536/65536 bytes at offset 196608 +64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) + +backing file: t.IMGFMT.base_new (actual path: TEST_DIR/subdir/t.IMGFMT.bas= e_new) + +read 65536/65536 bytes at offset 0 +64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +read 65536/65536 bytes at offset 65536 +64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +read 65536/65536 bytes at offset 131072 +64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +read 65536/65536 bytes at offset 196608 +64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) + +Offset Length File +0 0x30000 TEST_DIR/subdir/t.IMGFMT +0x30000 0x10000 TEST_DIR/subdir/t.IMGFMT.base_new *** done --=20 2.14.3