1#!/usr/bin/env bash 2# 3# Test preallocated growth of qcow2 images 4# 5# Copyright (C) 2017 Red Hat, Inc. 6# 7# This program is free software; you can redistribute it and/or modify 8# it under the terms of the GNU General Public License as published by 9# the Free Software Foundation; either version 2 of the License, or 10# (at your option) any later version. 11# 12# This program is distributed in the hope that it will be useful, 13# but WITHOUT ANY WARRANTY; without even the implied warranty of 14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15# GNU General Public License for more details. 16# 17# You should have received a copy of the GNU General Public License 18# along with this program. If not, see <http://www.gnu.org/licenses/>. 19# 20 21# creator 22owner=mreitz@redhat.com 23 24seq=$(basename $0) 25echo "QA output created by $seq" 26 27status=1 # failure is the default! 28 29_cleanup() 30{ 31 _cleanup_test_img 32} 33trap "_cleanup; exit \$status" 0 1 2 3 15 34 35get_image_size_on_host() 36{ 37 echo $(($(stat -c '%b * %B' "$TEST_IMG_FILE"))) 38} 39 40# get standard environment and filters 41. ./common.rc 42. ./common.filter 43 44_supported_fmt qcow2 45_supported_proto file 46 47if [ -z "$TEST_IMG_FILE" ]; then 48 TEST_IMG_FILE=$TEST_IMG 49fi 50 51# Test whether we are running on a broken XFS version. There is this 52# bug: 53 54# $ rm -f foo 55# $ touch foo 56# $ block_size=4096 # Your FS's block size 57# $ fallocate -o $((block_size / 2)) -l $block_size foo 58# $ LANG=C xfs_bmap foo | grep hole 59# 1: [8..15]: hole 60# 61# The problem is that the XFS driver rounds down the offset and 62# rounds up the length to the block size, but independently. As 63# such, it only allocates the first block in the example above, 64# even though it should allocate the first two blocks (because our 65# request is to fallocate something that touches both the first 66# two blocks). 67# 68# This means that when you then write to the beginning of the 69# second block, the disk usage of the first two blocks grows. 70# 71# That is precisely what fallocate() promises, though: That when you 72# write to an area that you have fallocated, no new blocks will have 73# to be allocated. 74 75touch "$TEST_IMG_FILE" 76# Assuming there is no FS with a block size greater than 64k 77fallocate -o 65535 -l 2 "$TEST_IMG_FILE" 78len0=$(get_image_size_on_host) 79 80# Write to something that in theory we have just fallocated 81# (Thus, the on-disk size should not increase) 82poke_file "$TEST_IMG_FILE" 65536 42 83len1=$(get_image_size_on_host) 84 85if [ $len1 -gt $len0 ]; then 86 _notrun "the test filesystem's fallocate() is broken" 87fi 88 89rm -f "$TEST_IMG_FILE" 90 91# Generally, we create some image with or without existing preallocation and 92# then resize it. Then we write some data into the image and verify that its 93# size does not change if we have used preallocation. 94 95# With a cluster size of 512 B, one L2 table covers 64 * 512 B = 32 kB. 96# One cluster of the L1 table covers 64 * 32 kB = 2 MB. 97# There are multiple cases we want to test: 98# (1) Grow an image without having to allocate a new L2 table. 99# (2) Grow an image, having to allocate a new L2 table. 100# (3) Grow an image, having to grow the L1 table. 101# Therefore, we create an image that is 48 kB below 2 MB. Then: 102# (1) We resize it to 2 MB - 32 kB. (+ 16 kB) 103# (2) We resize it to 2 MB. (+ 48 kB) 104# (3) We resize it to 2 MB + 32 kB. (+ 80 kB) 105 106# in B 107CREATION_SIZE=$((2 * 1024 * 1024 - 48 * 1024)) 108 109# 512 is the actual test -- but it's good to test 64k as well, just to be sure. 110for cluster_size in 512 64k; do 111# in kB 112for GROWTH_SIZE in 16 48 80; do 113 for create_mode in off metadata falloc full; do 114 for growth_mode in off metadata falloc full; do 115 echo "--- cluster_size=$cluster_size growth_size=$GROWTH_SIZE create_mode=$create_mode growth_mode=$growth_mode ---" 116 117 _make_test_img -o "preallocation=$create_mode,cluster_size=$cluster_size" ${CREATION_SIZE} 118 $QEMU_IMG resize -f "$IMGFMT" --preallocation=$growth_mode "$TEST_IMG" +${GROWTH_SIZE}K 119 120 host_size_0=$(get_image_size_on_host) 121 file_length_0=$(stat -c '%s' "$TEST_IMG_FILE") 122 123 $QEMU_IO -c "write 0 $CREATION_SIZE" "$TEST_IMG" | _filter_qemu_io 124 125 host_size_1=$(get_image_size_on_host) 126 file_length_1=$(stat -c '%s' "$TEST_IMG_FILE") 127 128 $QEMU_IO -c "write $CREATION_SIZE ${GROWTH_SIZE}K" "$TEST_IMG" | _filter_qemu_io 129 130 host_size_2=$(get_image_size_on_host) 131 file_length_2=$(stat -c '%s' "$TEST_IMG_FILE") 132 133 # Test creation preallocation: Compare #0 against #1 134 if [ $create_mode != off ]; then 135 # The image length should not have grown 136 if [ $file_length_1 -gt $file_length_0 ]; then 137 echo "ERROR (create): Image length has grown from $file_length_0 to $file_length_1" 138 fi 139 if [ $create_mode != metadata ]; then 140 # The host size should not have grown either 141 if [ $host_size_1 -gt $host_size_0 ]; then 142 echo "ERROR (create): Host size has grown from $host_size_0 to $host_size_1" 143 fi 144 fi 145 fi 146 147 # Test resize preallocation: Compare #2 against #1 148 if [ $growth_mode != off ]; then 149 # The image length should not have grown 150 if [ $file_length_2 -gt $file_length_1 ]; then 151 echo "ERROR (grow): Image length has grown from $file_length_1 to $file_length_2" 152 fi 153 if [ $growth_mode != metadata ]; then 154 # The host size should not have grown either 155 if [ $host_size_2 -gt $host_size_1 ]; then 156 echo "ERROR (grow): Host size has grown from $host_size_1 to $host_size_2" 157 fi 158 fi 159 fi 160 161 echo 162 done 163 done 164done 165done 166 167# success, all done 168echo '*** done' 169rm -f $seq.full 170status=0 171