mirror of https://gitlab.com/qemu-project/qemu
You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
125 lines
4.2 KiB
Bash
125 lines
4.2 KiB
Bash
#!/usr/bin/env bash
|
|
# group: rw
|
|
#
|
|
# 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=hreitz@redhat.com
|
|
|
|
seq="$(basename $0)"
|
|
echo "QA output created by $seq"
|
|
|
|
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 fuse
|
|
_supported_os Linux
|
|
# Refcount structures are used much differently with external data
|
|
# files
|
|
_unsupported_imgopts data_file
|
|
|
|
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...
|
|
_make_test_img -o 'preallocation=metadata,cluster_size=1k' 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
|
|
|
|
_make_test_img -o 'preallocation=metadata,cluster_size=1k' 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
|
|
|
|
echo
|
|
echo '=== Allocating a new refcount block must not leave holes in the image ==='
|
|
echo
|
|
|
|
_make_test_img -o 'cluster_size=512,refcount_bits=16' 1M
|
|
|
|
# This results in an image with 256 used clusters: the qcow2 header,
|
|
# the refcount table, one refcount block, the L1 table, four L2 tables
|
|
# and 248 data clusters
|
|
$QEMU_IO -c 'write 0 124k' "$TEST_IMG" | _filter_qemu_io
|
|
|
|
# 256 clusters of 512 bytes each give us a 128K image
|
|
stat -c "size=%s (expected 131072)" $TEST_IMG
|
|
|
|
# All 256 entries of the refcount block are used, so writing a new
|
|
# data cluster also allocates a new refcount block
|
|
$QEMU_IO -c 'write 124k 512' "$TEST_IMG" | _filter_qemu_io
|
|
|
|
# Two more clusters, the image size should be 129K now
|
|
stat -c "size=%s (expected 132096)" $TEST_IMG
|
|
|
|
# success, all done
|
|
echo
|
|
echo '*** done'
|
|
rm -f $seq.full
|
|
status=0
|