iotests: test big qcow2 shrink

#!/usr/bin/env bash

#

# Test big discard in qcow2 shrink

#

# Copyright (c) 2019 Virtuozzo International GmbH. All rights reserved.

#

# 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=vsementsov@virtuozzo.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

_supported_os Linux

# This test checks that qcow2_process_discards does not truncate a discard

# request > 2G.

# To reproduce bug we need to overflow int by one sequential discard, so we

# need size > 2G, bigger cluster size (as with default 64k we may have maximum

# of 512M sequential data, corresponding to one L1 entry), and we need some

# data of the beginning of the disk mapped to the end of file to prevent

# bdrv_co_truncate(bs->file) call in qcow2_co_truncate(), which might succeed

# anyway.

disk_usage()

{

    du --block-size=1 $1 | awk '{print $1}'

}

size=2100M

IMGOPTS="cluster_size=1M,preallocation=metadata"

_make_test_img $size

$QEMU_IO -c 'discard 0 10M' -c 'discard 2090M 10M' \

         -c 'write 2090M 10M' -c 'write 0 10M' "$TEST_IMG" | _filter_qemu_io

# Check that our trick with swapping first and last 10M chunks succeeded.

# Otherwise test may pass even if bdrv_pdiscard() fails in

# qcow2_process_discards()

$QEMU_IMG map "$TEST_IMG" | _filter_testdir

before=$(disk_usage "$TEST_IMG")

$QEMU_IMG resize --shrink "$TEST_IMG" 5M

after=$(disk_usage "$TEST_IMG")

echo "Disk usage delta: $((before - after))"

# success, all done

echo "*** done"

rm -f $seq.full

status=0

QA output created by 250

Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=2202009600 preallocation=metadata

discard 10485760/10485760 bytes at offset 0

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

discard 10485760/10485760 bytes at offset 2191523840

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

wrote 10485760/10485760 bytes at offset 2191523840

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

wrote 10485760/10485760 bytes at offset 0

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

Offset          Length          Mapped to       File

0               0xa00000        0x82f00000      TEST_DIR/t.qcow2

0x82a00000      0xa00000        0x500000        TEST_DIR/t.qcow2

Image resized.

Disk usage delta: 15728640

*** done

247 rw quick

248 rw quick

249 rw auto quick

250 rw auto quick

252 rw auto backing quick

253 rw auto quick

254 rw auto backing quick