summaryrefslogtreecommitdiffstats
path: root/tests/qemu-iotests/271
blob: c7c2cadda03115093c0bbb828696edcea48cb651 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
#!/usr/bin/env bash
# group: rw auto
#
# Test qcow2 images with extended L2 entries
#
# Copyright (C) 2019-2020 Igalia, S.L.
# Author: Alberto Garcia <berto@igalia.com>
#
# 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=berto@igalia.com

seq="$(basename $0)"
echo "QA output created by $seq"

here="$PWD"
status=1	# failure is the default!

_cleanup()
{
        _cleanup_test_img
        rm -f "$TEST_IMG.raw"
}
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 nfs
_supported_os Linux
_unsupported_imgopts extended_l2 compat=0.10 cluster_size data_file refcount_bits=1[^0-9]

l2_offset=$((0x40000))

_verify_img()
{
    $QEMU_IMG compare "$TEST_IMG" "$TEST_IMG.raw" | grep -v 'Images are identical'
    $QEMU_IMG check "$TEST_IMG" | _filter_qemu_img_check | \
        grep -v 'No errors were found on the image'
}

# Compare the bitmap of an extended L2 entry against an expected value
_verify_l2_bitmap()
{
    entry_no="$1"            # L2 entry number, starting from 0
    expected_alloc="$alloc"  # Space-separated list of allocated subcluster indexes
    expected_zero="$zero"    # Space-separated list of zero subcluster indexes

    offset=$(($l2_offset + $entry_no * 16))
    entry=$(peek_file_be "$TEST_IMG" $offset 8)
    offset=$(($offset + 8))
    bitmap=$(peek_file_be "$TEST_IMG" $offset 8)

    expected_bitmap=0
    for bit in $expected_alloc; do
        expected_bitmap=$(($expected_bitmap | (1 << $bit)))
    done
    for bit in $expected_zero; do
        expected_bitmap=$(($expected_bitmap | (1 << (32 + $bit))))
    done
    printf -v expected_bitmap "%u" $expected_bitmap # Convert to unsigned

    printf "L2 entry #%d: 0x%016x %016x\n" "$entry_no" "$entry" "$bitmap"
    if [ "$bitmap" != "$expected_bitmap" ]; then
        printf "ERROR: expecting bitmap       0x%016x\n" "$expected_bitmap"
    fi
}

# This should be called as _run_test c=XXX sc=XXX off=XXX len=XXX cmd=XXX
# c:   cluster number (0 if unset)
# sc:  subcluster number inside cluster @c (0 if unset)
# off: offset inside subcluster @sc, in kilobytes (0 if unset)
# len: request length, passed directly to qemu-io (e.g: 256, 4k, 1M, ...)
# cmd: the command to pass to qemu-io, must be one of
#      write    -> write
#      zero     -> write -z
#      unmap    -> write -z -u
#      compress -> write -c
#      discard  -> discard
_run_test()
{
    unset c sc off len cmd
    for var in "$@"; do eval "$var"; done
    case "${cmd:-write}" in
        zero)
            cmd="write -q -z";;
        unmap)
            cmd="write -q -z -u";;
        compress)
            pat=$((${pat:-0} + 1))
            cmd="write -q -c -P ${pat}";;
        write)
            pat=$((${pat:-0} + 1))
            cmd="write -q -P ${pat}";;
        discard)
            cmd="discard -q";;
        *)
            echo "Unknown option $cmd"
            exit 1;;
    esac
    c="${c:-0}"
    sc="${sc:-0}"
    off="${off:-0}"
    offset="$(($c * 64 + $sc * 2 + $off))"
    [ "$offset" != 0 ] && offset="${offset}k"
    cmd="$cmd ${offset} ${len}"
    raw_cmd=$(echo $cmd | sed s/-c//) # Raw images don't support -c
    echo $cmd | sed 's/-P [0-9][0-9]\?/-P PATTERN/'
    $QEMU_IO -c "$cmd" "$TEST_IMG" | _filter_qemu_io
    $QEMU_IO -c "$raw_cmd" -f raw "$TEST_IMG.raw" | _filter_qemu_io
    _verify_img
    _verify_l2_bitmap "$c"
}

_reset_img()
{
    size="$1"
    $QEMU_IMG create -f raw "$TEST_IMG.raw" "$size" | _filter_img_create
    if [ "$use_backing_file" = "yes" ]; then
        $QEMU_IMG create -f raw "$TEST_IMG.base" "$size" | _filter_img_create
        $QEMU_IO -c "write -q -P 0xFF 0 $size" -f raw "$TEST_IMG.base" | _filter_qemu_io
        $QEMU_IO -c "write -q -P 0xFF 0 $size" -f raw "$TEST_IMG.raw" | _filter_qemu_io
        _make_test_img -o extended_l2=on -F raw -b "$TEST_IMG.base" "$size"
    else
        _make_test_img -o extended_l2=on "$size"
    fi
}

############################################################
############################################################
############################################################

# Test that writing to an image with subclusters produces the expected
# results, in images with and without backing files
for use_backing_file in yes no; do
    echo
    echo "### Standard write tests (backing file: $use_backing_file) ###"
    echo
    _reset_img 1M
    ### Write subcluster #0 (beginning of subcluster) ###
    alloc="0"; zero=""
    _run_test sc=0 len=1k

    ### Write subcluster #1 (middle of subcluster) ###
    alloc="0 1"; zero=""
    _run_test sc=1 off=1 len=512

    ### Write subcluster #2 (end of subcluster) ###
    alloc="0 1 2"; zero=""
    _run_test sc=2 off=1 len=1k

    ### Write subcluster #3 (full subcluster) ###
    alloc="0 1 2 3"; zero=""
    _run_test sc=3 len=2k

    ### Write subclusters #4-6 (full subclusters) ###
    alloc="$(seq 0 6)"; zero=""
    _run_test sc=4 len=6k

    ### Write subclusters #7-9 (partial subclusters) ###
    alloc="$(seq 0 9)"; zero=""
    _run_test sc=7 off=1 len=4k

    ### Write subcluster #16 (partial subcluster) ###
    alloc="$(seq 0 9) 16"; zero=""
    _run_test sc=16 len=1k

    ### Write subcluster #31-#33 (cluster overlap) ###
    alloc="$(seq 0 9) 16 31"; zero=""
    _run_test sc=31 off=1 len=4k
    alloc="0 1" ; zero=""
    _verify_l2_bitmap 1

    ### Zero subcluster #1
    alloc="0 $(seq 2 9) 16 31"; zero="1"
    _run_test sc=1 len=2k cmd=zero

    ### Zero cluster #0
    alloc=""; zero="$(seq 0 31)"
    _run_test sc=0 len=64k cmd=zero

    ### Fill cluster #0 with data
    alloc="$(seq 0 31)"; zero=""
    _run_test sc=0 len=64k

    ### Zero and unmap half of cluster #0 (this won't unmap it)
    alloc="$(seq 16 31)"; zero="$(seq 0 15)"
    _run_test sc=0 len=32k cmd=unmap

    ### Zero and unmap cluster #0
    alloc=""; zero="$(seq 0 31)"
    _run_test sc=0 len=64k cmd=unmap

    ### Write subcluster #1 (middle of subcluster)
    alloc="1"; zero="0 $(seq 2 31)"
    _run_test sc=1 off=1 len=512

    ### Fill cluster #0 with data
    alloc="$(seq 0 31)"; zero=""
    _run_test sc=0 len=64k

    ### Discard cluster #0
    alloc=""; zero="$(seq 0 31)"
    _run_test sc=0 len=64k cmd=discard

    ### Write compressed data to cluster #0
    alloc=""; zero=""
    _run_test sc=0 len=64k cmd=compress

    ### Write subcluster #1 (middle of subcluster)
    alloc="$(seq 0 31)"; zero=""
    _run_test sc=1 off=1 len=512
done

############################################################
############################################################
############################################################

# calculate_l2_meta() checks if none of the clusters affected by a
# write operation need COW or changes to their L2 metadata and simply
# returns when they don't. This is a test for that optimization.
# Here clusters #0-#3 are overwritten but only #1 and #2 need changes.
echo
echo '### Overwriting several clusters without COW ###'
echo
use_backing_file="no" _reset_img 1M
# Write cluster #0, subclusters #12-#31
alloc="$(seq 12 31)"; zero=""
_run_test sc=12 len=40k

# Write cluster #1, subcluster #13
alloc="13"; zero=""
_run_test c=1 sc=13 len=2k

# Zeroize cluster #2, subcluster #14
alloc="14"; zero=""
_run_test c=2 sc=14 len=2k
alloc=""; zero="14"
_run_test c=2 sc=14 len=2k cmd=zero

# Write cluster #3, subclusters #0-#16
alloc="$(seq 0 16)"; zero=""
_run_test c=3 sc=0 len=34k

# Write from cluster #0, subcluster #12 to cluster #3, subcluster #11
alloc="$(seq 12 31)"; zero=""
_run_test sc=12 len=192k
alloc="$(seq 0 31)"; zero=""
_verify_l2_bitmap 1
_verify_l2_bitmap 2

alloc="$(seq 0 16)"; zero=""
_verify_l2_bitmap 3

############################################################
############################################################
############################################################

# Test different patterns of writing zeroes
for use_backing_file in yes no; do
    echo
    echo "### Writing zeroes 1: unallocated clusters (backing file: $use_backing_file) ###"
    echo
    # Note that the image size is not a multiple of the cluster size
    _reset_img 2083k

    # Cluster-aligned request from clusters #0 to #2
    alloc=""; zero="$(seq 0 31)"
    _run_test c=0 sc=0 len=192k cmd=zero
    _verify_l2_bitmap 1
    _verify_l2_bitmap 2

    # Subcluster-aligned request from clusters #3 to #5
    alloc=""; zero="$(seq 16 31)"
    _run_test c=3 sc=16 len=128k cmd=zero
    alloc=""; zero="$(seq 0 31)"
    _verify_l2_bitmap 4
    alloc=""; zero="$(seq 0 15)"
    _verify_l2_bitmap 5

    # Unaligned request from clusters #6 to #8
    if [ "$use_backing_file" = "yes" ]; then
        alloc="15"; zero="$(seq 16 31)" # copy-on-write happening here
    else
        alloc=""; zero="$(seq 15 31)"
    fi
    _run_test c=6 sc=15 off=1 len=128k cmd=zero
    alloc=""; zero="$(seq 0 31)"
    _verify_l2_bitmap 7
    if [ "$use_backing_file" = "yes" ]; then
        alloc="15"; zero="$(seq 0 14)" # copy-on-write happening here
    else
        alloc=""; zero="$(seq 0 15)"
    fi
    _verify_l2_bitmap 8

    echo
    echo "### Writing zeroes 2: allocated clusters (backing file: $use_backing_file) ###"
    echo
    alloc="$(seq 0 31)"; zero=""
    _run_test c=9 sc=0 len=576k
    _verify_l2_bitmap 10
    _verify_l2_bitmap 11
    _verify_l2_bitmap 12
    _verify_l2_bitmap 13
    _verify_l2_bitmap 14
    _verify_l2_bitmap 15
    _verify_l2_bitmap 16
    _verify_l2_bitmap 17

    # Cluster-aligned request from clusters #9 to #11
    alloc=""; zero="$(seq 0 31)"
    _run_test c=9 sc=0 len=192k cmd=zero
    _verify_l2_bitmap 10
    _verify_l2_bitmap 11

    # Subcluster-aligned request from clusters #12 to #14
    alloc="$(seq 0 15)"; zero="$(seq 16 31)"
    _run_test c=12 sc=16 len=128k cmd=zero
    alloc=""; zero="$(seq 0 31)"
    _verify_l2_bitmap 13
    alloc="$(seq 16 31)"; zero="$(seq 0 15)"
    _verify_l2_bitmap 14

    # Unaligned request from clusters #15 to #17
    alloc="$(seq 0 15)"; zero="$(seq 16 31)"
    _run_test c=15 sc=15 off=1 len=128k cmd=zero
    alloc=""; zero="$(seq 0 31)"
    _verify_l2_bitmap 16
    alloc="$(seq 15 31)"; zero="$(seq 0 14)"
    _verify_l2_bitmap 17

    echo
    echo "### Writing zeroes 3: compressed clusters (backing file: $use_backing_file) ###"
    echo
    alloc=""; zero=""
    for c in $(seq 18 28); do
        _run_test c=$c sc=0 len=64k cmd=compress
    done

    # Cluster-aligned request from clusters #18 to #20
    alloc=""; zero="$(seq 0 31)"
    _run_test c=18 sc=0 len=192k cmd=zero
    _verify_l2_bitmap 19
    _verify_l2_bitmap 20

    # Subcluster-aligned request from clusters #21 to #23.
    # We cannot partially zero a compressed cluster so the code
    # returns -ENOTSUP, which means copy-on-write of the compressed
    # data and fill the rest with actual zeroes on disk.
    # TODO: cluster #22 should use the 'all zeroes' bits.
    alloc="$(seq 0 31)"; zero=""
    _run_test c=21 sc=16 len=128k cmd=zero
    _verify_l2_bitmap 22
    _verify_l2_bitmap 23

    # Unaligned request from clusters #24 to #26
    # In this case QEMU internally sends a 1k request followed by a
    # subcluster-aligned 128k request. The first request decompresses
    # cluster #24, but that's not enough to perform the second request
    # efficiently because it partially writes to cluster #26 (which is
    # compressed) so we hit the same problem as before.
    alloc="$(seq 0 31)"; zero=""
    _run_test c=24 sc=15 off=1 len=129k cmd=zero
    _verify_l2_bitmap 25
    _verify_l2_bitmap 26

    # Unaligned request from clusters #27 to #29
    # Similar to the previous case, but this time the tail of the
    # request does not correspond to a compressed cluster, so it can
    # be zeroed efficiently.
    # Note that the very last subcluster is partially written, so if
    # there's a backing file we need to perform cow.
    alloc="$(seq 0 15)"; zero="$(seq 16 31)"
    _run_test c=27 sc=15 off=1 len=128k cmd=zero
    alloc=""; zero="$(seq 0 31)"
    _verify_l2_bitmap 28
    if [ "$use_backing_file" = "yes" ]; then
        alloc="15"; zero="$(seq 0 14)" # copy-on-write happening here
    else
        alloc=""; zero="$(seq 0 15)"
    fi
    _verify_l2_bitmap 29

    echo
    echo "### Writing zeroes 4: other tests (backing file: $use_backing_file) ###"
    echo
    # Unaligned request in the middle of cluster #30.
    # If there's a backing file we need to allocate and do
    # copy-on-write on the partially zeroed subclusters.
    # If not we can set the 'all zeroes' bit on them.
    if [ "$use_backing_file" = "yes" ]; then
        alloc="15 19"; zero="$(seq 16 18)" # copy-on-write happening here
    else
        alloc=""; zero="$(seq 15 19)"
    fi
    _run_test c=30 sc=15 off=1 len=8k cmd=zero

    # Fill the last cluster with zeroes, up to the end of the image
    # (the image size is not a multiple of the cluster or subcluster size).
    alloc=""; zero="$(seq 0 17)"
    _run_test c=32 sc=0 len=35k cmd=zero
done

############################################################
############################################################
############################################################

# Zero + unmap
for use_backing_file in yes no; do
    echo
    echo "### Zero + unmap 1: allocated clusters (backing file: $use_backing_file) ###"
    echo
    # Note that the image size is not a multiple of the cluster size
    _reset_img 2083k
    alloc="$(seq 0 31)"; zero=""
    _run_test c=9 sc=0 len=576k
    _verify_l2_bitmap 10
    _verify_l2_bitmap 11
    _verify_l2_bitmap 12
    _verify_l2_bitmap 13
    _verify_l2_bitmap 14
    _verify_l2_bitmap 15
    _verify_l2_bitmap 16
    _verify_l2_bitmap 17

    # Cluster-aligned request from clusters #9 to #11
    alloc=""; zero="$(seq 0 31)"
    _run_test c=9 sc=0 len=192k cmd=unmap
    _verify_l2_bitmap 10
    _verify_l2_bitmap 11

    # Subcluster-aligned request from clusters #12 to #14
    alloc="$(seq 0 15)"; zero="$(seq 16 31)"
    _run_test c=12 sc=16 len=128k cmd=unmap
    alloc=""; zero="$(seq 0 31)"
    _verify_l2_bitmap 13
    alloc="$(seq 16 31)"; zero="$(seq 0 15)"
    _verify_l2_bitmap 14

    # Unaligned request from clusters #15 to #17
    alloc="$(seq 0 15)"; zero="$(seq 16 31)"
    _run_test c=15 sc=15 off=1 len=128k cmd=unmap
    alloc=""; zero="$(seq 0 31)"
    _verify_l2_bitmap 16
    alloc="$(seq 15 31)"; zero="$(seq 0 14)"
    _verify_l2_bitmap 17

    echo
    echo "### Zero + unmap 2: compressed clusters (backing file: $use_backing_file) ###"
    echo
    alloc=""; zero=""
    for c in $(seq 18 28); do
        _run_test c=$c sc=0 len=64k cmd=compress
    done

    # Cluster-aligned request from clusters #18 to #20
    alloc=""; zero="$(seq 0 31)"
    _run_test c=18 sc=0 len=192k cmd=unmap
    _verify_l2_bitmap 19
    _verify_l2_bitmap 20

    # Subcluster-aligned request from clusters #21 to #23.
    # We cannot partially zero a compressed cluster so the code
    # returns -ENOTSUP, which means copy-on-write of the compressed
    # data and fill the rest with actual zeroes on disk.
    # TODO: cluster #22 should use the 'all zeroes' bits.
    alloc="$(seq 0 31)"; zero=""
    _run_test c=21 sc=16 len=128k cmd=unmap
    _verify_l2_bitmap 22
    _verify_l2_bitmap 23

    # Unaligned request from clusters #24 to #26
    # In this case QEMU internally sends a 1k request followed by a
    # subcluster-aligned 128k request. The first request decompresses
    # cluster #24, but that's not enough to perform the second request
    # efficiently because it partially writes to cluster #26 (which is
    # compressed) so we hit the same problem as before.
    alloc="$(seq 0 31)"; zero=""
    _run_test c=24 sc=15 off=1 len=129k cmd=unmap
    _verify_l2_bitmap 25
    _verify_l2_bitmap 26

    # Unaligned request from clusters #27 to #29
    # Similar to the previous case, but this time the tail of the
    # request does not correspond to a compressed cluster, so it can
    # be zeroed efficiently.
    # Note that the very last subcluster is partially written, so if
    # there's a backing file we need to perform cow.
    alloc="$(seq 0 15)"; zero="$(seq 16 31)"
    _run_test c=27 sc=15 off=1 len=128k cmd=unmap
    alloc=""; zero="$(seq 0 31)"
    _verify_l2_bitmap 28
    if [ "$use_backing_file" = "yes" ]; then
        alloc="15"; zero="$(seq 0 14)" # copy-on-write happening here
    else
        alloc=""; zero="$(seq 0 15)"
    fi
    _verify_l2_bitmap 29
done

############################################################
############################################################
############################################################

# Test qcow2_cluster_discard() with full and normal discards
for use_backing_file in yes no; do
    echo
    echo "### Discarding clusters with non-zero bitmaps (backing file: $use_backing_file) ###"
    echo
    if [ "$use_backing_file" = "yes" ]; then
        _make_test_img -o extended_l2=on -F raw -b "$TEST_IMG.base" 1M
    else
        _make_test_img -o extended_l2=on 1M
    fi
    # Write clusters #0-#2 and then discard them
    $QEMU_IO -c 'write -q 0 128k' "$TEST_IMG"
    $QEMU_IO -c 'discard -q 0 128k' "$TEST_IMG"
    # 'qemu-io discard' doesn't do a full discard, it zeroizes the
    # cluster, so both clusters have all zero bits set now
    alloc=""; zero="$(seq 0 31)"
    _verify_l2_bitmap 0
    _verify_l2_bitmap 1
    # Now mark the 2nd half of the subclusters from cluster #0 as unallocated
    poke_file "$TEST_IMG" $(($l2_offset+8)) "\x00\x00"
    # Discard cluster #0 again to see how the zero bits have changed
    $QEMU_IO -c 'discard -q 0 64k' "$TEST_IMG"
    # And do a full discard of cluster #1 by shrinking and growing the image
    $QEMU_IMG resize --shrink "$TEST_IMG" 64k
    $QEMU_IMG resize "$TEST_IMG" 1M
    # A normal discard sets all 'zero' bits only if the image has a
    # backing file, otherwise it won't touch them.
    if [ "$use_backing_file" = "yes" ]; then
        alloc=""; zero="$(seq 0 31)"
    else
        alloc=""; zero="$(seq 0 15)"
    fi
    _verify_l2_bitmap 0
    # A full discard should clear the L2 entry completely. However
    # when growing an image with a backing file the new clusters are
    # zeroized to hide the stale data from the backing file
    if [ "$use_backing_file" = "yes" ]; then
        alloc=""; zero="$(seq 0 31)"
    else
        alloc=""; zero=""
    fi
    _verify_l2_bitmap 1
done

############################################################
############################################################
############################################################

# Test that corrupted L2 entries are detected in both read and write
# operations
for corruption_test_cmd in read write; do
    echo
    echo "### Corrupted L2 entries - $corruption_test_cmd test (allocated) ###"
    echo
    echo "# 'cluster is zero' bit set on the standard cluster descriptor"
    echo
    # We actually don't consider this a corrupted image.
    # The 'cluster is zero' bit is unused in extended L2 entries so
    # QEMU ignores it.
    # TODO: maybe treat the image as corrupted and make qemu-img check fix it?
    _make_test_img -o extended_l2=on 1M
    $QEMU_IO -c 'write -q -P 0x11 0 2k' "$TEST_IMG"
    poke_file "$TEST_IMG" $(($l2_offset+7)) "\x01"
    alloc="0"; zero=""
    _verify_l2_bitmap 0
    $QEMU_IO -c "$corruption_test_cmd -q -P 0x11 0 1k" "$TEST_IMG"
    if [ "$corruption_test_cmd" = "write" ]; then
        alloc="0"; zero=""
    fi
    _verify_l2_bitmap 0

    echo
    echo "# Both 'subcluster is zero' and 'subcluster is allocated' bits set"
    echo
    _make_test_img -o extended_l2=on 1M
    # Write from the middle of cluster #0 to the middle of cluster #2
    $QEMU_IO -c 'write -q 32k 128k' "$TEST_IMG"
    # Corrupt the L2 entry from cluster #1
    poke_file_be "$TEST_IMG" $(($l2_offset+24)) 4 1
    alloc="$(seq 0 31)"; zero="0"
    _verify_l2_bitmap 1
    $QEMU_IO -c "$corruption_test_cmd 0 192k" "$TEST_IMG"

    echo
    echo "### Corrupted L2 entries - $corruption_test_cmd test (unallocated) ###"
    echo
    echo "# 'cluster is zero' bit set on the standard cluster descriptor"
    echo
    # We actually don't consider this a corrupted image.
    # The 'cluster is zero' bit is unused in extended L2 entries so
    # QEMU ignores it.
    # TODO: maybe treat the image as corrupted and make qemu-img check fix it?
    _make_test_img -o extended_l2=on 1M
    # We want to modify the (empty) L2 entry from cluster #0,
    # but we write to #4 in order to initialize the L2 table first
    $QEMU_IO -c 'write -q 256k 1k' "$TEST_IMG"
    poke_file "$TEST_IMG" $(($l2_offset+7)) "\x01"
    alloc=""; zero=""
    _verify_l2_bitmap 0
    $QEMU_IO -c "$corruption_test_cmd -q 0 1k" "$TEST_IMG"
    if [ "$corruption_test_cmd" = "write" ]; then
        alloc="0"; zero=""
    fi
    _verify_l2_bitmap 0

    echo
    echo "# 'subcluster is allocated' bit set"
    echo
    _make_test_img -o extended_l2=on 1M
    # We want to corrupt the (empty) L2 entry from cluster #0,
    # but we write to #4 in order to initialize the L2 table first
    $QEMU_IO -c 'write -q 256k 1k' "$TEST_IMG"
    poke_file "$TEST_IMG" $(($l2_offset+15)) "\x01"
    alloc="0"; zero=""
    _verify_l2_bitmap 0
    $QEMU_IO -c "$corruption_test_cmd 0 1k" "$TEST_IMG"

    echo
    echo "# Both 'subcluster is zero' and 'subcluster is allocated' bits set"
    echo
    _make_test_img -o extended_l2=on 1M
    # We want to corrupt the (empty) L2 entry from cluster #1,
    # but we write to #4 in order to initialize the L2 table first
    $QEMU_IO -c 'write -q 256k 1k' "$TEST_IMG"
    # Corrupt the L2 entry from cluster #1
    poke_file_be "$TEST_IMG" $(($l2_offset+24)) 8 $(((1 << 32) | 1))
    alloc="0"; zero="0"
    _verify_l2_bitmap 1
    $QEMU_IO -c "$corruption_test_cmd 0 192k" "$TEST_IMG"

    echo
    echo "### Compressed cluster with subcluster bitmap != 0 - $corruption_test_cmd test ###"
    echo
    # We actually don't consider this a corrupted image.
    # The bitmap in compressed clusters is unused so QEMU should just ignore it.
    _make_test_img -o extended_l2=on 1M
    $QEMU_IO -c 'write -q -P 11 -c 0 64k' "$TEST_IMG"
    # Change the L2 bitmap to allocate subcluster #31 and zeroize subcluster #0
    poke_file "$TEST_IMG" $(($l2_offset+11)) "\x01\x80"
    alloc="31"; zero="0"
    _verify_l2_bitmap 0
    $QEMU_IO -c "$corruption_test_cmd -P 11 0 64k" "$TEST_IMG" | _filter_qemu_io
    # Writing allocates a new uncompressed cluster so we get a new bitmap
    if [ "$corruption_test_cmd" = "write" ]; then
        alloc="$(seq 0 31)"; zero=""
    fi
    _verify_l2_bitmap 0
done

############################################################
############################################################
############################################################

echo
echo "### Detect and repair unaligned clusters ###"
echo
# Create a backing file and fill it with data
$QEMU_IMG create -f raw "$TEST_IMG.base" 128k | _filter_img_create
$QEMU_IO -c "write -q -P 0xff 0 128k" -f raw "$TEST_IMG.base" | _filter_qemu_io

echo "# Corrupted L2 entry, allocated subcluster #"
# Create a new image, allocate a cluster and write some data to it
_make_test_img -o extended_l2=on -F raw -b "$TEST_IMG.base"
$QEMU_IO -c 'write -q -P 1 4k 2k' "$TEST_IMG"
# Corrupt the L2 entry by making the offset unaligned
poke_file "$TEST_IMG" "$(($l2_offset+6))" "\x02"
# This cannot be repaired, qemu-img check will fail to fix it
_check_test_img -r all
# Attempting to read the image will still show that it's corrupted
$QEMU_IO -c 'read -q 0 2k' "$TEST_IMG"

echo "# Corrupted L2 entry, no allocated subclusters #"
# Create a new image, allocate a cluster and zeroize subcluster #2
_make_test_img -o extended_l2=on -F raw -b "$TEST_IMG.base"
$QEMU_IO -c 'write -q -P 1 4k 2k' "$TEST_IMG"
$QEMU_IO -c 'write -q -z   4k 2k' "$TEST_IMG"
# Corrupt the L2 entry by making the offset unaligned
poke_file "$TEST_IMG" "$(($l2_offset+6))" "\x02"
# This time none of the subclusters are allocated so we can repair the image
_check_test_img -r all
# And the data can be read normally
$QEMU_IO -c 'read -q -P 0xff  0   4k' "$TEST_IMG"
$QEMU_IO -c 'read -q -P 0x00 4k   2k' "$TEST_IMG"
$QEMU_IO -c 'read -q -P 0xff 6k 122k' "$TEST_IMG"

############################################################
############################################################
############################################################

echo
echo "### Image creation options ###"
echo
echo "# cluster_size < 16k"
_make_test_img -o extended_l2=on,cluster_size=8k 1M

echo "# backing file and preallocation=metadata"
# For preallocation with backing files, create a backing file first
$QEMU_IMG create -f raw "$TEST_IMG.base" 1M | _filter_img_create
$QEMU_IO -c "write -q -P 0xff 0 1M" -f raw "$TEST_IMG.base" | _filter_qemu_io

_make_test_img -o extended_l2=on,preallocation=metadata -F raw -b "$TEST_IMG.base" 512k
$QEMU_IMG resize "$TEST_IMG" 1M
$QEMU_IO -c 'read -P 0xff    0 512k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c 'read -P 0x00 512k 512k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map "$TEST_IMG" | _filter_testdir

echo "# backing file and preallocation=falloc"
_make_test_img -o extended_l2=on,preallocation=falloc -F raw -b "$TEST_IMG.base" 512k
$QEMU_IMG resize "$TEST_IMG" 1M
$QEMU_IO -c 'read -P 0xff    0 512k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c 'read -P 0x00 512k 512k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map "$TEST_IMG" | _filter_testdir

echo "# backing file and preallocation=full"
_make_test_img -o extended_l2=on,preallocation=full -F raw -b "$TEST_IMG.base" 512k
$QEMU_IMG resize "$TEST_IMG" 1M
$QEMU_IO -c 'read -P 0xff    0 512k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c 'read -P 0x00 512k 512k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map "$TEST_IMG" | _filter_testdir

echo
echo "### Image resizing with preallocation and backing files ###"
echo
# In this case the new subclusters must have the 'all zeroes' bit set
echo "# resize --preallocation=metadata"
_make_test_img -o extended_l2=on -F raw -b "$TEST_IMG.base" 503k
$QEMU_IMG resize --preallocation=metadata "$TEST_IMG" 1013k
$QEMU_IO -c 'read -P 0xff    0 503k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c 'read -P 0x00 503k 510k' "$TEST_IMG" | _filter_qemu_io

# In this case and the next one the new subclusters must be allocated
echo "# resize --preallocation=falloc"
_make_test_img -o extended_l2=on -F raw -b "$TEST_IMG.base" 503k
$QEMU_IMG resize --preallocation=falloc "$TEST_IMG" 1013k
$QEMU_IO -c 'read -P 0xff    0 503k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c 'read -P 0x00 503k 510k' "$TEST_IMG" | _filter_qemu_io

echo "# resize --preallocation=full"
_make_test_img -o extended_l2=on -F raw -b "$TEST_IMG.base" 503k
$QEMU_IMG resize --preallocation=full "$TEST_IMG" 1013k
$QEMU_IO -c 'read -P 0xff    0 503k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c 'read -P 0x00 503k 510k' "$TEST_IMG" | _filter_qemu_io

echo
echo "### Image resizing with preallocation without backing files ###"
echo
# In this case the new subclusters must have the 'all zeroes' bit set
echo "# resize --preallocation=metadata"
_make_test_img -o extended_l2=on 503k
$QEMU_IO -c 'write -P 0xff    0 503k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG resize --preallocation=metadata "$TEST_IMG" 1013k
$QEMU_IO -c 'read -P 0xff    0 503k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c 'read -P 0x00 503k 510k' "$TEST_IMG" | _filter_qemu_io

# In this case and the next one the new subclusters must be allocated
echo "# resize --preallocation=falloc"
_make_test_img -o extended_l2=on 503k
$QEMU_IO -c 'write -P 0xff    0 503k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG resize --preallocation=falloc "$TEST_IMG" 1013k
$QEMU_IO -c 'read -P 0xff    0 503k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c 'read -P 0x00 503k 510k' "$TEST_IMG" | _filter_qemu_io

echo "# resize --preallocation=full"
_make_test_img -o extended_l2=on 503k
$QEMU_IO -c 'write -P 0xff    0 503k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG resize --preallocation=full "$TEST_IMG" 1013k
$QEMU_IO -c 'read -P 0xff    0 503k' "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c 'read -P 0x00 503k 510k' "$TEST_IMG" | _filter_qemu_io

echo
echo "### qemu-img measure ###"
echo
echo "# 512MB, extended_l2=off" # This needs one L2 table
$QEMU_IMG measure --size 512M -O qcow2 -o extended_l2=off
echo "# 512MB, extended_l2=on"  # This needs two L2 tables
$QEMU_IMG measure --size 512M -O qcow2 -o extended_l2=on

echo "# 16K clusters, 64GB, extended_l2=off" # This needs one full L1 table cluster
$QEMU_IMG measure --size 64G -O qcow2 -o cluster_size=16k,extended_l2=off
echo "# 16K clusters, 64GB, extended_l2=on"  # This needs two full L2 table clusters
$QEMU_IMG measure --size 64G -O qcow2 -o cluster_size=16k,extended_l2=on

echo "# 8k clusters" # This should fail
$QEMU_IMG measure --size 1M -O qcow2 -o cluster_size=8k,extended_l2=on

echo "# 1024 TB" # Maximum allowed size with extended_l2=on and 64K clusters
$QEMU_IMG measure --size 1024T -O qcow2 -o extended_l2=on
echo "# 1025 TB" # This should fail
$QEMU_IMG measure --size 1025T -O qcow2 -o extended_l2=on

echo
echo "### qemu-img amend ###"
echo
_make_test_img -o extended_l2=on 1M
$QEMU_IMG amend -o extended_l2=off "$TEST_IMG" && echo "Unexpected pass"

_make_test_img -o extended_l2=off 1M
$QEMU_IMG amend -o extended_l2=on "$TEST_IMG" && echo "Unexpected pass"

echo
echo "### Test copy-on-write on an image with snapshots ###"
echo
_make_test_img -o extended_l2=on 1M

# For each cluster from #0 to #9 this loop zeroes subcluster #7
# and allocates subclusters #13 and #18.
alloc="13 18"; zero="7"
for c in $(seq 0 9); do
    $QEMU_IO -c "write -q -z $((64*$c+14))k 2k" \
             -c "write -q -P $((0xd0+$c)) $((64*$c+26))k 2k" \
             -c "write -q -P $((0xe0+$c)) $((64*$c+36))k 2k" "$TEST_IMG"
    _verify_l2_bitmap "$c"
done

# Create a snapshot and set l2_offset to the new L2 table
$QEMU_IMG snapshot -c snap1 "$TEST_IMG"
l2_offset=$((0x110000))

# Write different patterns to each one of the clusters
# in order to see how copy-on-write behaves in each case.
$QEMU_IO -c "write -q -P 0xf0 $((64*0+30))k 1k" \
         -c "write -q -P 0xf1 $((64*1+20))k 1k" \
         -c "write -q -P 0xf2 $((64*2+40))k 1k" \
         -c "write -q -P 0xf3 $((64*3+26))k 1k" \
         -c "write -q -P 0xf4 $((64*4+14))k 1k" \
         -c "write -q -P 0xf5 $((64*5+1))k  1k" \
         -c "write -q -z      $((64*6+30))k 3k" \
         -c "write -q -z      $((64*7+26))k 2k" \
         -c "write -q -z      $((64*8+26))k 1k" \
         -c "write -q -z      $((64*9+12))k 1k" \
         "$TEST_IMG"
alloc="$(seq 13 18)"; zero="7" _verify_l2_bitmap 0
alloc="$(seq 10 18)"; zero="7" _verify_l2_bitmap 1
alloc="$(seq 13 20)"; zero="7" _verify_l2_bitmap 2
alloc="$(seq 13 18)"; zero="7" _verify_l2_bitmap 3
alloc="$(seq 7 18)";  zero=""  _verify_l2_bitmap 4
alloc="$(seq 0 18)";  zero=""  _verify_l2_bitmap 5
alloc="13 18";  zero="7 15 16" _verify_l2_bitmap 6
alloc="18";        zero="7 13" _verify_l2_bitmap 7
alloc="$(seq 13 18)"; zero="7" _verify_l2_bitmap 8
alloc="13 18";      zero="6 7" _verify_l2_bitmap 9

echo
echo "### Test concurrent requests ###"
echo

_concurrent_io()
{
# Allocate three subclusters in the same cluster.
# This works because handle_dependencies() checks whether the requests
# allocate the same cluster, even if the COW regions don't overlap (in
# this case they don't).
cat <<EOF
open -o driver=$IMGFMT blkdebug::$TEST_IMG
break write_aio A
aio_write -P 10 30k 2k
wait_break A
aio_write -P 11 20k 2k
aio_write -P 12 40k 2k
resume A
aio_flush
EOF
}

_concurrent_verify()
{
cat <<EOF
open -o driver=$IMGFMT $TEST_IMG
read -q -P 10 30k 2k
read -q -P 11 20k 2k
read -q -P 12 40k 2k
EOF
}

_make_test_img -o extended_l2=on 1M
# Second and third writes in _concurrent_io() are independent and may finish in
# different order. So, filter offset out to match both possible variants.
_concurrent_io     | $QEMU_IO | _filter_qemu_io | \
    sed -e 's/\(20480\|40960\)/OFFSET/'
_concurrent_verify | $QEMU_IO | _filter_qemu_io

# success, all done
echo "*** done"
rm -f $seq.full
status=0