1#!/usr/bin/env bash 2# group: rw 3# 4# Test case for qcow2's handling of extra data in snapshot table entries 5# (and more generally, how certain cases of broken snapshot tables are 6# handled) 7# 8# Copyright (C) 2019 Red Hat, Inc. 9# 10# This program is free software; you can redistribute it and/or modify 11# it under the terms of the GNU General Public License as published by 12# the Free Software Foundation; either version 2 of the License, or 13# (at your option) any later version. 14# 15# This program is distributed in the hope that it will be useful, 16# but WITHOUT ANY WARRANTY; without even the implied warranty of 17# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18# GNU General Public License for more details. 19# 20# You should have received a copy of the GNU General Public License 21# along with this program. If not, see <http://www.gnu.org/licenses/>. 22# 23 24# creator 25owner=hreitz@redhat.com 26 27seq=$(basename $0) 28echo "QA output created by $seq" 29 30status=1 # failure is the default! 31 32_cleanup() 33{ 34 _cleanup_test_img 35 rm -f "$TEST_IMG".v{2,3}.orig 36 rm -f "$TEST_DIR"/sn{0,1,2}{,-pre,-extra,-post} 37} 38trap "_cleanup; exit \$status" 0 1 2 3 15 39 40# get standard environment, filters and checks 41. ./common.rc 42. ./common.filter 43 44# This tests qcow2-specific low-level functionality 45_supported_fmt qcow2 46_supported_proto file 47_supported_os Linux 48# (1) We create a v2 image that supports nothing but refcount_bits=16 49# (2) We do some refcount management on our own which expects 50# refcount_bits=16 51# As for data files, they do not support snapshots at all. 52_unsupported_imgopts 'refcount_bits=\([^1]\|.\([^6]\|$\)\)' data_file 53 54# Parameters: 55# $1: image filename 56# $2: snapshot table entry offset in the image 57snapshot_table_entry_size() 58{ 59 id_len=$(peek_file_be "$1" $(($2 + 12)) 2) 60 name_len=$(peek_file_be "$1" $(($2 + 14)) 2) 61 extra_len=$(peek_file_be "$1" $(($2 + 36)) 4) 62 63 full_len=$((40 + extra_len + id_len + name_len)) 64 echo $(((full_len + 7) / 8 * 8)) 65} 66 67# Parameter: 68# $1: image filename 69print_snapshot_table() 70{ 71 nb_entries=$(peek_file_be "$1" 60 4) 72 offset=$(peek_file_be "$1" 64 8) 73 74 echo "Snapshots in $1:" | _filter_testdir | _filter_imgfmt 75 76 for ((i = 0; i < nb_entries; i++)); do 77 id_len=$(peek_file_be "$1" $((offset + 12)) 2) 78 name_len=$(peek_file_be "$1" $((offset + 14)) 2) 79 extra_len=$(peek_file_be "$1" $((offset + 36)) 4) 80 81 extra_ofs=$((offset + 40)) 82 id_ofs=$((extra_ofs + extra_len)) 83 name_ofs=$((id_ofs + id_len)) 84 85 echo " [$i]" 86 echo " ID: $(peek_file_raw "$1" $id_ofs $id_len)" 87 echo " Name: $(peek_file_raw "$1" $name_ofs $name_len)" 88 echo " Extra data size: $extra_len" 89 if [ $extra_len -ge 8 ]; then 90 echo " VM state size: $(peek_file_be "$1" $extra_ofs 8)" 91 fi 92 if [ $extra_len -ge 16 ]; then 93 echo " Disk size: $(peek_file_be "$1" $((extra_ofs + 8)) 8)" 94 fi 95 if [ $extra_len -ge 24 ]; then 96 echo " Icount: $(peek_file_be "$1" $((extra_ofs + 16)) 8)" 97 fi 98 if [ $extra_len -gt 24 ]; then 99 echo ' Unknown extra data:' \ 100 "$(peek_file_raw "$1" $((extra_ofs + 16)) $((extra_len - 16)) \ 101 | tr -d '\0')" 102 fi 103 104 offset=$((offset + $(snapshot_table_entry_size "$1" $offset))) 105 done 106} 107 108# Mark clusters as allocated; works only in refblock 0 (i.e. before 109# cluster #32768). 110# Parameters: 111# $1: Start offset of what to allocate 112# $2: End offset (exclusive) 113refblock0_allocate() 114{ 115 reftable_ofs=$(peek_file_be "$TEST_IMG" 48 8) 116 refblock_ofs=$(peek_file_be "$TEST_IMG" $reftable_ofs 8) 117 118 cluster=$(($1 / 65536)) 119 ecluster=$((($2 + 65535) / 65536)) 120 121 while [ $cluster -lt $ecluster ]; do 122 if [ $cluster -ge 32768 ]; then 123 echo "*** Abort: Cluster $cluster exceeds refblock 0 ***" 124 exit 1 125 fi 126 poke_file "$TEST_IMG" $((refblock_ofs + cluster * 2)) '\x00\x01' 127 cluster=$((cluster + 1)) 128 done 129} 130 131 132echo 133echo '=== Create v2 template ===' 134echo 135 136# Create v2 image with a snapshot table with three entries: 137# [0]: No extra data (valid with v2, not valid with v3) 138# [1]: Has extra data unknown to qemu 139# [2]: Has the 64-bit VM state size, but not the disk size (again, 140# valid with v2, not valid with v3) 141 142TEST_IMG="$TEST_IMG.v2.orig" IMGOPTS='compat=0.10' _make_test_img 64M 143$QEMU_IMG snapshot -c sn0 "$TEST_IMG.v2.orig" 144$QEMU_IMG snapshot -c sn1 "$TEST_IMG.v2.orig" 145$QEMU_IMG snapshot -c sn2 "$TEST_IMG.v2.orig" 146 147# Copy out all existing snapshot table entries 148sn_table_ofs=$(peek_file_be "$TEST_IMG.v2.orig" 64 8) 149 150# ofs: Snapshot table entry offset 151# eds: Extra data size 152# ids: Name + ID size 153# len: Total entry length 154sn0_ofs=$sn_table_ofs 155sn0_eds=$(peek_file_be "$TEST_IMG.v2.orig" $((sn0_ofs + 36)) 4) 156sn0_ids=$(($(peek_file_be "$TEST_IMG.v2.orig" $((sn0_ofs + 12)) 2) + 157 $(peek_file_be "$TEST_IMG.v2.orig" $((sn0_ofs + 14)) 2))) 158sn0_len=$(snapshot_table_entry_size "$TEST_IMG.v2.orig" $sn0_ofs) 159sn1_ofs=$((sn0_ofs + sn0_len)) 160sn1_eds=$(peek_file_be "$TEST_IMG.v2.orig" $((sn1_ofs + 36)) 4) 161sn1_ids=$(($(peek_file_be "$TEST_IMG.v2.orig" $((sn1_ofs + 12)) 2) + 162 $(peek_file_be "$TEST_IMG.v2.orig" $((sn1_ofs + 14)) 2))) 163sn1_len=$(snapshot_table_entry_size "$TEST_IMG.v2.orig" $sn1_ofs) 164sn2_ofs=$((sn1_ofs + sn1_len)) 165sn2_eds=$(peek_file_be "$TEST_IMG.v2.orig" $((sn2_ofs + 36)) 4) 166sn2_ids=$(($(peek_file_be "$TEST_IMG.v2.orig" $((sn2_ofs + 12)) 2) + 167 $(peek_file_be "$TEST_IMG.v2.orig" $((sn2_ofs + 14)) 2))) 168sn2_len=$(snapshot_table_entry_size "$TEST_IMG.v2.orig" $sn2_ofs) 169 170# Data before extra data 171dd if="$TEST_IMG.v2.orig" of="$TEST_DIR/sn0-pre" bs=1 skip=$sn0_ofs count=40 \ 172 &> /dev/null 173dd if="$TEST_IMG.v2.orig" of="$TEST_DIR/sn1-pre" bs=1 skip=$sn1_ofs count=40 \ 174 &> /dev/null 175dd if="$TEST_IMG.v2.orig" of="$TEST_DIR/sn2-pre" bs=1 skip=$sn2_ofs count=40 \ 176 &> /dev/null 177 178# Extra data 179dd if="$TEST_IMG.v2.orig" of="$TEST_DIR/sn0-extra" bs=1 \ 180 skip=$((sn0_ofs + 40)) count=$sn0_eds &> /dev/null 181dd if="$TEST_IMG.v2.orig" of="$TEST_DIR/sn1-extra" bs=1 \ 182 skip=$((sn1_ofs + 40)) count=$sn1_eds &> /dev/null 183dd if="$TEST_IMG.v2.orig" of="$TEST_DIR/sn2-extra" bs=1 \ 184 skip=$((sn2_ofs + 40)) count=$sn2_eds &> /dev/null 185 186# Data after extra data 187dd if="$TEST_IMG.v2.orig" of="$TEST_DIR/sn0-post" bs=1 \ 188 skip=$((sn0_ofs + 40 + sn0_eds)) count=$sn0_ids \ 189 &> /dev/null 190dd if="$TEST_IMG.v2.orig" of="$TEST_DIR/sn1-post" bs=1 \ 191 skip=$((sn1_ofs + 40 + sn1_eds)) count=$sn1_ids \ 192 &> /dev/null 193dd if="$TEST_IMG.v2.orig" of="$TEST_DIR/sn2-post" bs=1 \ 194 skip=$((sn2_ofs + 40 + sn2_eds)) count=$sn2_ids \ 195 &> /dev/null 196 197# Amend them, one by one 198# Set sn0's extra data size to 0 199poke_file "$TEST_DIR/sn0-pre" 36 '\x00\x00\x00\x00' 200truncate -s 0 "$TEST_DIR/sn0-extra" 201# Grow sn0-post to pad 202truncate -s $(($(snapshot_table_entry_size "$TEST_DIR/sn0-pre") - 40)) \ 203 "$TEST_DIR/sn0-post" 204 205# Set sn1's extra data size to 50 206poke_file "$TEST_DIR/sn1-pre" 36 '\x00\x00\x00\x32' 207truncate -s 50 "$TEST_DIR/sn1-extra" 208poke_file "$TEST_DIR/sn1-extra" 24 'very important data' 209# Grow sn1-post to pad 210truncate -s $(($(snapshot_table_entry_size "$TEST_DIR/sn1-pre") - 90)) \ 211 "$TEST_DIR/sn1-post" 212 213# Set sn2's extra data size to 8 214poke_file "$TEST_DIR/sn2-pre" 36 '\x00\x00\x00\x08' 215truncate -s 8 "$TEST_DIR/sn2-extra" 216# Grow sn2-post to pad 217truncate -s $(($(snapshot_table_entry_size "$TEST_DIR/sn2-pre") - 48)) \ 218 "$TEST_DIR/sn2-post" 219 220# Construct snapshot table 221cat "$TEST_DIR"/sn0-{pre,extra,post} \ 222 "$TEST_DIR"/sn1-{pre,extra,post} \ 223 "$TEST_DIR"/sn2-{pre,extra,post} \ 224 | dd of="$TEST_IMG.v2.orig" bs=1 seek=$sn_table_ofs conv=notrunc \ 225 &> /dev/null 226 227# Done! 228TEST_IMG="$TEST_IMG.v2.orig" _check_test_img 229print_snapshot_table "$TEST_IMG.v2.orig" 230 231echo 232echo '=== Upgrade to v3 ===' 233echo 234 235cp "$TEST_IMG.v2.orig" "$TEST_IMG.v3.orig" 236$QEMU_IMG amend -o compat=1.1 "$TEST_IMG.v3.orig" 237TEST_IMG="$TEST_IMG.v3.orig" _check_test_img 238print_snapshot_table "$TEST_IMG.v3.orig" 239 240echo 241echo '=== Repair botched v3 ===' 242echo 243 244# Force the v2 file to be v3. v3 requires each snapshot table entry 245# to have at least 16 bytes of extra data, so it will not comply to 246# the qcow2 v3 specification; but we can fix that. 247cp "$TEST_IMG.v2.orig" "$TEST_IMG" 248 249# Set version 250poke_file "$TEST_IMG" 4 '\x00\x00\x00\x03' 251# Increase header length (necessary for v3) 252poke_file "$TEST_IMG" 100 '\x00\x00\x00\x68' 253# Set refcount order (necessary for v3) 254poke_file "$TEST_IMG" 96 '\x00\x00\x00\x04' 255 256_check_test_img -r all 257print_snapshot_table "$TEST_IMG" 258 259 260# From now on, just test the qcow2 version we are supposed to test. 261# (v3 by default, v2 by choice through $IMGOPTS.) 262# That works because we always write all known extra data when 263# updating the snapshot table, independent of the version. 264 265if echo "$IMGOPTS" | grep -q 'compat=\(0\.10\|v2\)' 2> /dev/null; then 266 subver=v2 267else 268 subver=v3 269fi 270 271echo 272echo '=== Add new snapshot ===' 273echo 274 275cp "$TEST_IMG.$subver.orig" "$TEST_IMG" 276$QEMU_IMG snapshot -c sn3 "$TEST_IMG" 277_check_test_img 278print_snapshot_table "$TEST_IMG" 279 280echo 281echo '=== Remove different snapshots ===' 282 283for sn in sn0 sn1 sn2; do 284 echo 285 echo "--- $sn ---" 286 287 cp "$TEST_IMG.$subver.orig" "$TEST_IMG" 288 $QEMU_IMG snapshot -d $sn "$TEST_IMG" 289 _check_test_img 290 print_snapshot_table "$TEST_IMG" 291done 292 293echo 294echo '=== Reject too much unknown extra data ===' 295echo 296 297cp "$TEST_IMG.$subver.orig" "$TEST_IMG" 298$QEMU_IMG snapshot -c sn3 "$TEST_IMG" 299 300sn_table_ofs=$(peek_file_be "$TEST_IMG" 64 8) 301sn0_ofs=$sn_table_ofs 302sn1_ofs=$((sn0_ofs + $(snapshot_table_entry_size "$TEST_IMG" $sn0_ofs))) 303sn2_ofs=$((sn1_ofs + $(snapshot_table_entry_size "$TEST_IMG" $sn1_ofs))) 304sn3_ofs=$((sn2_ofs + $(snapshot_table_entry_size "$TEST_IMG" $sn2_ofs))) 305 306# 64 kB of extra data should be rejected 307# (Note that this also induces a refcount error, because it spills 308# over to the next cluster. That's a good way to test that we can 309# handle simultaneous snapshot table and refcount errors.) 310poke_file "$TEST_IMG" $((sn3_ofs + 36)) '\x00\x01\x00\x00' 311 312# Print error 313_img_info 314echo 315_check_test_img 316echo 317 318# Should be repairable 319_check_test_img -r all 320 321echo 322echo '=== Snapshot table too big ===' 323echo 324 325sn_table_ofs=$(peek_file_be "$TEST_IMG.v3.orig" 64 8) 326 327# Fill a snapshot with 1 kB of extra data, a 65535-char ID, and a 328# 65535-char name, and repeat it as many times as necessary to fill 329# 64 MB (the maximum supported by qemu) 330 331touch "$TEST_DIR/sn0" 332 333# Full size (fixed + extra + ID + name + padding) 334sn_size=$((40 + 1024 + 65535 + 65535 + 2)) 335 336# We only need the fixed part, though. 337truncate -s 40 "$TEST_DIR/sn0" 338 339# 65535-char ID string 340poke_file "$TEST_DIR/sn0" 12 '\xff\xff' 341# 65535-char name 342poke_file "$TEST_DIR/sn0" 14 '\xff\xff' 343# 1 kB of extra data 344poke_file "$TEST_DIR/sn0" 36 '\x00\x00\x04\x00' 345 346# Create test image 347_make_test_img 64M 348 349# Hook up snapshot table somewhere safe (at 1 MB) 350poke_file "$TEST_IMG" 64 '\x00\x00\x00\x00\x00\x10\x00\x00' 351 352offset=1048576 353size_written=0 354sn_count=0 355while [ $size_written -le $((64 * 1048576)) ]; do 356 dd if="$TEST_DIR/sn0" of="$TEST_IMG" bs=1 seek=$offset conv=notrunc \ 357 &> /dev/null 358 offset=$((offset + sn_size)) 359 size_written=$((size_written + sn_size)) 360 sn_count=$((sn_count + 1)) 361done 362truncate -s "$offset" "$TEST_IMG" 363 364# Give the last snapshot (the one to be removed) an L1 table so we can 365# see how that is handled when repairing the image 366# (Put it two clusters before 1 MB, and one L2 table one cluster 367# before 1 MB) 368poke_file "$TEST_IMG" $((offset - sn_size + 0)) \ 369 '\x00\x00\x00\x00\x00\x0e\x00\x00' 370poke_file "$TEST_IMG" $((offset - sn_size + 8)) \ 371 '\x00\x00\x00\x01' 372 373# Hook up the L2 table 374poke_file "$TEST_IMG" $((1048576 - 2 * 65536)) \ 375 '\x80\x00\x00\x00\x00\x0f\x00\x00' 376 377# Make sure all of the clusters we just hooked up are allocated: 378# - The snapshot table 379# - The last snapshot's L1 and L2 table 380refblock0_allocate $((1048576 - 2 * 65536)) $offset 381 382poke_file "$TEST_IMG" 60 \ 383 "$(printf '%08x' $sn_count | sed -e 's/\(..\)/\\x\1/g')" 384 385# Print error 386_img_info 387echo 388_check_test_img 389echo 390 391# Should be repairable 392_check_test_img -r all 393 394echo 395echo "$((sn_count - 1)) snapshots should remain:" 396echo " qemu-img info reports $(_img_info | grep -c '^ \{32\}') snapshots" 397echo " Image header reports $(peek_file_be "$TEST_IMG" 60 4) snapshots" 398 399echo 400echo '=== Snapshot table too big with one entry with too much extra data ===' 401echo 402 403# For this test, we reuse the image from the previous case, which has 404# a snapshot table that is right at the limit. 405# Our layout looks like this: 406# - (a number of snapshot table entries) 407# - One snapshot with $extra_data_size extra data 408# - One normal snapshot that breaks the 64 MB boundary 409# - One normal snapshot beyond the 64 MB boundary 410# 411# $extra_data_size is calculated so that simply by virtue of it 412# decreasing to 1 kB, the penultimate snapshot will fit into 64 MB 413# limit again. The final snapshot will always be beyond the limit, so 414# that we can see that the repair algorithm does still determine the 415# limit to be somewhere, even when truncating one snapshot's extra 416# data. 417 418# The last case has removed the last snapshot, so calculate 419# $old_offset to get the current image's real length 420old_offset=$((offset - sn_size)) 421 422# The layout from the previous test had one snapshot beyond the 64 MB 423# limit; we want the same (after the oversized extra data has been 424# truncated to 1 kB), so we drop the last three snapshots and 425# construct them from scratch. 426offset=$((offset - 3 * sn_size)) 427sn_count=$((sn_count - 3)) 428 429# Assuming we had already written one of the three snapshots 430# (necessary so we can calculate $extra_data_size next). 431size_written=$((size_written - 2 * sn_size)) 432 433# Increase the extra data size so we go past the limit 434# (The -1024 comes from the 1 kB of extra data we already have) 435extra_data_size=$((64 * 1048576 + 8 - sn_size - (size_written - 1024))) 436 437poke_file "$TEST_IMG" $((offset + 36)) \ 438 "$(printf '%08x' $extra_data_size | sed -e 's/\(..\)/\\x\1/g')" 439 440offset=$((offset + sn_size - 1024 + extra_data_size)) 441size_written=$((size_written - 1024 + extra_data_size)) 442sn_count=$((sn_count + 1)) 443 444# Write the two normal snapshots 445for ((i = 0; i < 2; i++)); do 446 dd if="$TEST_DIR/sn0" of="$TEST_IMG" bs=1 seek=$offset conv=notrunc \ 447 &> /dev/null 448 offset=$((offset + sn_size)) 449 size_written=$((size_written + sn_size)) 450 sn_count=$((sn_count + 1)) 451 452 if [ $i = 0 ]; then 453 # Check that the penultimate snapshot is beyond the 64 MB limit 454 echo "Snapshot table size should equal $((64 * 1048576 + 8)):" \ 455 $size_written 456 echo 457 fi 458done 459 460truncate -s $offset "$TEST_IMG" 461refblock0_allocate $old_offset $offset 462 463poke_file "$TEST_IMG" 60 \ 464 "$(printf '%08x' $sn_count | sed -e 's/\(..\)/\\x\1/g')" 465 466# Print error 467_img_info 468echo 469_check_test_img 470echo 471 472# Just truncating the extra data should be sufficient to shorten the 473# snapshot table so only one snapshot exceeds the extra size 474_check_test_img -r all 475 476echo 477echo '=== Too many snapshots ===' 478echo 479 480# Create a v2 image, for speeds' sake: All-zero snapshot table entries 481# are only valid in v2. 482IMGOPTS='compat=0.10' _make_test_img 64M 483 484# Hook up snapshot table somewhere safe (at 1 MB) 485poke_file "$TEST_IMG" 64 '\x00\x00\x00\x00\x00\x10\x00\x00' 486# "Create" more than 65536 snapshots (twice that many here) 487poke_file "$TEST_IMG" 60 '\x00\x02\x00\x00' 488 489# 40-byte all-zero snapshot table entries are valid snapshots, but 490# only in v2 (v3 needs 16 bytes of extra data, so we would have to 491# write 131072x '\x10'). 492truncate -s $((1048576 + 40 * 131072)) "$TEST_IMG" 493 494# But let us give one of the snapshots to be removed an L1 table so 495# we can see how that is handled when repairing the image. 496# (Put it two clusters before 1 MB, and one L2 table one cluster 497# before 1 MB) 498poke_file "$TEST_IMG" $((1048576 + 40 * 65536 + 0)) \ 499 '\x00\x00\x00\x00\x00\x0e\x00\x00' 500poke_file "$TEST_IMG" $((1048576 + 40 * 65536 + 8)) \ 501 '\x00\x00\x00\x01' 502 503# Hook up the L2 table 504poke_file "$TEST_IMG" $((1048576 - 2 * 65536)) \ 505 '\x80\x00\x00\x00\x00\x0f\x00\x00' 506 507# Make sure all of the clusters we just hooked up are allocated: 508# - The snapshot table 509# - The last snapshot's L1 and L2 table 510refblock0_allocate $((1048576 - 2 * 65536)) $((1048576 + 40 * 131072)) 511 512# Print error 513_img_info 514echo 515_check_test_img 516echo 517 518# Should be repairable 519_check_test_img -r all 520 521echo 522echo '65536 snapshots should remain:' 523echo " qemu-img info reports $(_img_info | grep -c '^ \{32\}') snapshots" 524echo " Image header reports $(peek_file_be "$TEST_IMG" 60 4) snapshots" 525 526# success, all done 527echo "*** done" 528status=0 529