From 65d01862c82d46a2f440dab3818e8e08e6879551 Mon Sep 17 00:00:00 2001

From: Max Reitz <mreitz@redhat.com>

Date: Sat, 13 Jun 2015 16:22:34 +0200

Subject: [PATCH 40/42] iotests: Add tests for refcount table growth

Message-id: <1434212556-3927-41-git-send-email-mreitz@redhat.com>

Patchwork-id: 66059

O-Subject: [RHEL-7.2 qemu-kvm PATCH 40/42] iotests: Add tests for refcount table growth

Bugzilla: 1129893

RH-Acked-by: Jeffrey Cody <jcody@redhat.com>

RH-Acked-by: Fam Zheng <famz@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

BZ: 1129893

Signed-off-by: Max Reitz <mreitz@redhat.com>

Message-id: 1423598552-24301-3-git-send-email-mreitz@redhat.com

Reviewed-by: Eric Blake <eblake@redhat.com>

Reviewed-by: Kevin Wolf <kwolf@redhat.com>

Signed-off-by: Max Reitz <mreitz@redhat.com>

(cherry picked from commit 0e8a371468ce24513b15a9ae362f12822e1973a3)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

Conflicts:

	tests/qemu-iotests/group

Signed-off-by: Max Reitz <mreitz@redhat.com>

---

 tests/qemu-iotests/121     | 102 +++++++++++++++++++++++++++++++++++++++++++++

 tests/qemu-iotests/121.out |  23 ++++++++++

 tests/qemu-iotests/group   |   1 +

 3 files changed, 126 insertions(+)

 create mode 100755 tests/qemu-iotests/121

 create mode 100644 tests/qemu-iotests/121.out

diff --git a/tests/qemu-iotests/121 b/tests/qemu-iotests/121

new file mode 100755

index 0000000..0912c3f

--- /dev/null

+++ b/tests/qemu-iotests/121

@@ -0,0 +1,102 @@

+#!/bin/bash

+#

+# Test cases for qcow2 refcount table growth

+#

+# Copyright (C) 2015 Red Hat, Inc.

+#

+# This program is free software; you can redistribute it and/or modify

+# it under the terms of the GNU General Public License as published by

+# the Free Software Foundation; either version 2 of the License, or

+# (at your option) any later version.

+#

+# This program is distributed in the hope that it will be useful,

+# but WITHOUT ANY WARRANTY; without even the implied warranty of

+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+# GNU General Public License for more details.

+#

+# You should have received a copy of the GNU General Public License

+# along with this program.  If not, see <http://www.gnu.org/licenses/>.

+#

+

+# creator

+owner=mreitz@redhat.com

+

+seq="$(basename $0)"

+echo "QA output created by $seq"

+

+here="$PWD"

+tmp=/tmp/$$

+status=1	# failure is the default!

+

+_cleanup()

+{

+	_cleanup_test_img

+}

+trap "_cleanup; exit \$status" 0 1 2 3 15

+

+# get standard environment, filters and checks

+. ./common.rc

+. ./common.filter

+

+_supported_fmt qcow2

+_supported_proto file

+_supported_os Linux

+

+echo

+echo '=== New refcount structures may not conflict with existing structures ==='

+

+echo

+echo '--- Test 1 ---'

+echo

+

+# Preallocation speeds up the write operation, but preallocating everything will

+# destroy the purpose of the write; so preallocate one KB less than what would

+# cause a reftable growth...

+IMGOPTS='preallocation=metadata,cluster_size=1k' _make_test_img 64512K

+# ...and make the image the desired size afterwards.

+$QEMU_IMG resize "$TEST_IMG" 65M

+

+# The first write results in a growth of the refcount table during an allocation

+# which has precisely the required size so that the new refcount block allocated

+# in alloc_refcount_block() is right after cluster_index; this did lead to a

+# different refcount block being written to disk (a zeroed cluster) than what is

+# cached (a refblock with one entry having a refcount of 1), and the second

+# write would then result in that cached cluster being marked dirty and then

+# in it being written to disk.

+# This should not happen, the new refcount structures may not conflict with

+# new_block.

+# (Note that for some reason, 'write 63M 1K' does not trigger the problem)

+$QEMU_IO -c 'write 62M 1025K' -c 'write 64M 1M' "$TEST_IMG" | _filter_qemu_io

+

+_check_test_img

+

+

+echo

+echo '--- Test 2 ---'

+echo

+

+IMGOPTS='preallocation=metadata,cluster_size=1k' _make_test_img 64513K

+# This results in an L1 table growth which in turn results in some clusters at

+# the start of the image becoming free

+$QEMU_IMG resize "$TEST_IMG" 65M

+

+# This write results in a refcount table growth; but the refblock allocated

+# immediately before that (new_block) takes cluster index 4 (which is now free)

+# and is thus not self-describing (in contrast to test 1, where new_block was

+# self-describing). The refcount table growth algorithm then used to place the

+# new refcount structures at cluster index 65536 (which is the same as the

+# cluster_index parameter in this case), allocating a new refcount block for

+# that cluster while new_block already existed, leaking new_block.

+# Therefore, the new refcount structures may not be put at cluster_index

+# (because new_block already describes that cluster, and the new structures try

+# to be self-describing).

+$QEMU_IO -c 'write 63M 130K' "$TEST_IMG" | _filter_qemu_io

+

+_check_test_img

+

+

+# success, all done

+echo

+echo '*** done'

+rm -f $seq.full

+status=0

diff --git a/tests/qemu-iotests/121.out b/tests/qemu-iotests/121.out

new file mode 100644

index 0000000..ff18e2c

--- /dev/null

+++ b/tests/qemu-iotests/121.out

@@ -0,0 +1,23 @@

+QA output created by 121

+

+=== New refcount structures may not conflict with existing structures ===

+

+--- Test 1 ---

+

+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=66060288 preallocation='metadata'

+Image resized.

+wrote 1049600/1049600 bytes at offset 65011712

+1.001 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)

+wrote 1048576/1048576 bytes at offset 67108864

+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)

+No errors were found on the image.

+

+--- Test 2 ---

+

+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=66061312 preallocation='metadata'

+Image resized.

+wrote 133120/133120 bytes at offset 66060288

+130 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)

+No errors were found on the image.

+

+*** done

diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group

index 5867cf7..dbb2a36 100644

--- a/tests/qemu-iotests/group

+++ b/tests/qemu-iotests/group

@@ -89,3 +89,4 @@

 107 rw auto quick

 108 rw auto quick

 114 rw auto quick

+121 rw auto

-- 

1.8.3.1