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25#include "qemu/osdep.h"
26#include <zlib.h>
27
28#include "qapi/error.h"
29#include "qemu-common.h"
30#include "block/block_int.h"
31#include "block/qcow2.h"
32#include "qemu/bswap.h"
33#include "trace.h"
34
35int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
36 bool exact_size)
37{
38 BDRVQcow2State *s = bs->opaque;
39 int new_l1_size2, ret, i;
40 uint64_t *new_l1_table;
41 int64_t old_l1_table_offset, old_l1_size;
42 int64_t new_l1_table_offset, new_l1_size;
43 uint8_t data[12];
44
45 if (min_size <= s->l1_size)
46 return 0;
47
48
49
50
51 if (min_size > INT_MAX / sizeof(uint64_t)) {
52 return -EFBIG;
53 }
54
55 if (exact_size) {
56 new_l1_size = min_size;
57 } else {
58
59 new_l1_size = s->l1_size;
60 if (new_l1_size == 0) {
61 new_l1_size = 1;
62 }
63 while (min_size > new_l1_size) {
64 new_l1_size = (new_l1_size * 3 + 1) / 2;
65 }
66 }
67
68 if (new_l1_size > INT_MAX / sizeof(uint64_t)) {
69 return -EFBIG;
70 }
71
72#ifdef DEBUG_ALLOC2
73 fprintf(stderr, "grow l1_table from %d to %" PRId64 "\n",
74 s->l1_size, new_l1_size);
75#endif
76
77 new_l1_size2 = sizeof(uint64_t) * new_l1_size;
78 new_l1_table = qemu_try_blockalign(bs->file->bs,
79 align_offset(new_l1_size2, 512));
80 if (new_l1_table == NULL) {
81 return -ENOMEM;
82 }
83 memset(new_l1_table, 0, align_offset(new_l1_size2, 512));
84
85 memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
86
87
88 BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ALLOC_TABLE);
89 new_l1_table_offset = qcow2_alloc_clusters(bs, new_l1_size2);
90 if (new_l1_table_offset < 0) {
91 qemu_vfree(new_l1_table);
92 return new_l1_table_offset;
93 }
94
95 ret = qcow2_cache_flush(bs, s->refcount_block_cache);
96 if (ret < 0) {
97 goto fail;
98 }
99
100
101
102 ret = qcow2_pre_write_overlap_check(bs, 0, new_l1_table_offset,
103 new_l1_size2);
104 if (ret < 0) {
105 goto fail;
106 }
107
108 BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_WRITE_TABLE);
109 for(i = 0; i < s->l1_size; i++)
110 new_l1_table[i] = cpu_to_be64(new_l1_table[i]);
111 ret = bdrv_pwrite_sync(bs->file->bs, new_l1_table_offset,
112 new_l1_table, new_l1_size2);
113 if (ret < 0)
114 goto fail;
115 for(i = 0; i < s->l1_size; i++)
116 new_l1_table[i] = be64_to_cpu(new_l1_table[i]);
117
118
119 BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ACTIVATE_TABLE);
120 cpu_to_be32w((uint32_t*)data, new_l1_size);
121 stq_be_p(data + 4, new_l1_table_offset);
122 ret = bdrv_pwrite_sync(bs->file->bs, offsetof(QCowHeader, l1_size),
123 data, sizeof(data));
124 if (ret < 0) {
125 goto fail;
126 }
127 qemu_vfree(s->l1_table);
128 old_l1_table_offset = s->l1_table_offset;
129 s->l1_table_offset = new_l1_table_offset;
130 s->l1_table = new_l1_table;
131 old_l1_size = s->l1_size;
132 s->l1_size = new_l1_size;
133 qcow2_free_clusters(bs, old_l1_table_offset, old_l1_size * sizeof(uint64_t),
134 QCOW2_DISCARD_OTHER);
135 return 0;
136 fail:
137 qemu_vfree(new_l1_table);
138 qcow2_free_clusters(bs, new_l1_table_offset, new_l1_size2,
139 QCOW2_DISCARD_OTHER);
140 return ret;
141}
142
143
144
145
146
147
148
149
150
151
152
153static int l2_load(BlockDriverState *bs, uint64_t l2_offset,
154 uint64_t **l2_table)
155{
156 BDRVQcow2State *s = bs->opaque;
157 int ret;
158
159 ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, (void**) l2_table);
160
161 return ret;
162}
163
164
165
166
167
168#define L1_ENTRIES_PER_SECTOR (512 / 8)
169int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index)
170{
171 BDRVQcow2State *s = bs->opaque;
172 uint64_t buf[L1_ENTRIES_PER_SECTOR] = { 0 };
173 int l1_start_index;
174 int i, ret;
175
176 l1_start_index = l1_index & ~(L1_ENTRIES_PER_SECTOR - 1);
177 for (i = 0; i < L1_ENTRIES_PER_SECTOR && l1_start_index + i < s->l1_size;
178 i++)
179 {
180 buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]);
181 }
182
183 ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L1,
184 s->l1_table_offset + 8 * l1_start_index, sizeof(buf));
185 if (ret < 0) {
186 return ret;
187 }
188
189 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
190 ret = bdrv_pwrite_sync(bs->file->bs,
191 s->l1_table_offset + 8 * l1_start_index,
192 buf, sizeof(buf));
193 if (ret < 0) {
194 return ret;
195 }
196
197 return 0;
198}
199
200
201
202
203
204
205
206
207
208
209
210static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
211{
212 BDRVQcow2State *s = bs->opaque;
213 uint64_t old_l2_offset;
214 uint64_t *l2_table = NULL;
215 int64_t l2_offset;
216 int ret;
217
218 old_l2_offset = s->l1_table[l1_index];
219
220 trace_qcow2_l2_allocate(bs, l1_index);
221
222
223
224 l2_offset = qcow2_alloc_clusters(bs, s->l2_size * sizeof(uint64_t));
225 if (l2_offset < 0) {
226 ret = l2_offset;
227 goto fail;
228 }
229
230 ret = qcow2_cache_flush(bs, s->refcount_block_cache);
231 if (ret < 0) {
232 goto fail;
233 }
234
235
236
237 trace_qcow2_l2_allocate_get_empty(bs, l1_index);
238 ret = qcow2_cache_get_empty(bs, s->l2_table_cache, l2_offset, (void**) table);
239 if (ret < 0) {
240 goto fail;
241 }
242
243 l2_table = *table;
244
245 if ((old_l2_offset & L1E_OFFSET_MASK) == 0) {
246
247 memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
248 } else {
249 uint64_t* old_table;
250
251
252 BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_COW_READ);
253 ret = qcow2_cache_get(bs, s->l2_table_cache,
254 old_l2_offset & L1E_OFFSET_MASK,
255 (void**) &old_table);
256 if (ret < 0) {
257 goto fail;
258 }
259
260 memcpy(l2_table, old_table, s->cluster_size);
261
262 qcow2_cache_put(bs, s->l2_table_cache, (void **) &old_table);
263 }
264
265
266 BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_WRITE);
267
268 trace_qcow2_l2_allocate_write_l2(bs, l1_index);
269 qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
270 ret = qcow2_cache_flush(bs, s->l2_table_cache);
271 if (ret < 0) {
272 goto fail;
273 }
274
275
276 trace_qcow2_l2_allocate_write_l1(bs, l1_index);
277 s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED;
278 ret = qcow2_write_l1_entry(bs, l1_index);
279 if (ret < 0) {
280 goto fail;
281 }
282
283 *table = l2_table;
284 trace_qcow2_l2_allocate_done(bs, l1_index, 0);
285 return 0;
286
287fail:
288 trace_qcow2_l2_allocate_done(bs, l1_index, ret);
289 if (l2_table != NULL) {
290 qcow2_cache_put(bs, s->l2_table_cache, (void**) table);
291 }
292 s->l1_table[l1_index] = old_l2_offset;
293 if (l2_offset > 0) {
294 qcow2_free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t),
295 QCOW2_DISCARD_ALWAYS);
296 }
297 return ret;
298}
299
300
301
302
303
304
305
306
307static int count_contiguous_clusters(int nb_clusters, int cluster_size,
308 uint64_t *l2_table, uint64_t stop_flags)
309{
310 int i;
311 uint64_t mask = stop_flags | L2E_OFFSET_MASK | QCOW_OFLAG_COMPRESSED;
312 uint64_t first_entry = be64_to_cpu(l2_table[0]);
313 uint64_t offset = first_entry & mask;
314
315 if (!offset)
316 return 0;
317
318 assert(qcow2_get_cluster_type(first_entry) == QCOW2_CLUSTER_NORMAL);
319
320 for (i = 0; i < nb_clusters; i++) {
321 uint64_t l2_entry = be64_to_cpu(l2_table[i]) & mask;
322 if (offset + (uint64_t) i * cluster_size != l2_entry) {
323 break;
324 }
325 }
326
327 return i;
328}
329
330static int count_contiguous_clusters_by_type(int nb_clusters,
331 uint64_t *l2_table,
332 int wanted_type)
333{
334 int i;
335
336 for (i = 0; i < nb_clusters; i++) {
337 int type = qcow2_get_cluster_type(be64_to_cpu(l2_table[i]));
338
339 if (type != wanted_type) {
340 break;
341 }
342 }
343
344 return i;
345}
346
347
348
349
350int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
351 uint8_t *out_buf, const uint8_t *in_buf,
352 int nb_sectors, bool enc,
353 Error **errp)
354{
355 union {
356 uint64_t ll[2];
357 uint8_t b[16];
358 } ivec;
359 int i;
360 int ret;
361
362 for(i = 0; i < nb_sectors; i++) {
363 ivec.ll[0] = cpu_to_le64(sector_num);
364 ivec.ll[1] = 0;
365 if (qcrypto_cipher_setiv(s->cipher,
366 ivec.b, G_N_ELEMENTS(ivec.b),
367 errp) < 0) {
368 return -1;
369 }
370 if (enc) {
371 ret = qcrypto_cipher_encrypt(s->cipher,
372 in_buf,
373 out_buf,
374 512,
375 errp);
376 } else {
377 ret = qcrypto_cipher_decrypt(s->cipher,
378 in_buf,
379 out_buf,
380 512,
381 errp);
382 }
383 if (ret < 0) {
384 return -1;
385 }
386 sector_num++;
387 in_buf += 512;
388 out_buf += 512;
389 }
390 return 0;
391}
392
393static int coroutine_fn copy_sectors(BlockDriverState *bs,
394 uint64_t start_sect,
395 uint64_t cluster_offset,
396 int n_start, int n_end)
397{
398 BDRVQcow2State *s = bs->opaque;
399 QEMUIOVector qiov;
400 struct iovec iov;
401 int n, ret;
402
403 n = n_end - n_start;
404 if (n <= 0) {
405 return 0;
406 }
407
408 iov.iov_len = n * BDRV_SECTOR_SIZE;
409 iov.iov_base = qemu_try_blockalign(bs, iov.iov_len);
410 if (iov.iov_base == NULL) {
411 return -ENOMEM;
412 }
413
414 qemu_iovec_init_external(&qiov, &iov, 1);
415
416 BLKDBG_EVENT(bs->file, BLKDBG_COW_READ);
417
418 if (!bs->drv) {
419 ret = -ENOMEDIUM;
420 goto out;
421 }
422
423
424
425
426
427 ret = bs->drv->bdrv_co_readv(bs, start_sect + n_start, n, &qiov);
428 if (ret < 0) {
429 goto out;
430 }
431
432 if (bs->encrypted) {
433 Error *err = NULL;
434 assert(s->cipher);
435 if (qcow2_encrypt_sectors(s, start_sect + n_start,
436 iov.iov_base, iov.iov_base, n,
437 true, &err) < 0) {
438 ret = -EIO;
439 error_free(err);
440 goto out;
441 }
442 }
443
444 ret = qcow2_pre_write_overlap_check(bs, 0,
445 cluster_offset + n_start * BDRV_SECTOR_SIZE, n * BDRV_SECTOR_SIZE);
446 if (ret < 0) {
447 goto out;
448 }
449
450 BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE);
451 ret = bdrv_co_writev(bs->file->bs, (cluster_offset >> 9) + n_start, n,
452 &qiov);
453 if (ret < 0) {
454 goto out;
455 }
456
457 ret = 0;
458out:
459 qemu_vfree(iov.iov_base);
460 return ret;
461}
462
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473
474
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476
477
478int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
479 int *num, uint64_t *cluster_offset)
480{
481 BDRVQcow2State *s = bs->opaque;
482 unsigned int l2_index;
483 uint64_t l1_index, l2_offset, *l2_table;
484 int l1_bits, c;
485 unsigned int index_in_cluster, nb_clusters;
486 uint64_t nb_available, nb_needed;
487 int ret;
488
489 index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1);
490 nb_needed = *num + index_in_cluster;
491
492 l1_bits = s->l2_bits + s->cluster_bits;
493
494
495
496
497
498 nb_available = (1ULL << l1_bits) - (offset & ((1ULL << l1_bits) - 1));
499
500
501
502 nb_available = (nb_available >> 9) + index_in_cluster;
503
504 if (nb_needed > nb_available) {
505 nb_needed = nb_available;
506 }
507 assert(nb_needed <= INT_MAX);
508
509 *cluster_offset = 0;
510
511
512
513 l1_index = offset >> l1_bits;
514 if (l1_index >= s->l1_size) {
515 ret = QCOW2_CLUSTER_UNALLOCATED;
516 goto out;
517 }
518
519 l2_offset = s->l1_table[l1_index] & L1E_OFFSET_MASK;
520 if (!l2_offset) {
521 ret = QCOW2_CLUSTER_UNALLOCATED;
522 goto out;
523 }
524
525 if (offset_into_cluster(s, l2_offset)) {
526 qcow2_signal_corruption(bs, true, -1, -1, "L2 table offset %#" PRIx64
527 " unaligned (L1 index: %#" PRIx64 ")",
528 l2_offset, l1_index);
529 return -EIO;
530 }
531
532
533
534 ret = l2_load(bs, l2_offset, &l2_table);
535 if (ret < 0) {
536 return ret;
537 }
538
539
540
541 l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
542 *cluster_offset = be64_to_cpu(l2_table[l2_index]);
543
544
545 nb_clusters = size_to_clusters(s, nb_needed << 9);
546
547 ret = qcow2_get_cluster_type(*cluster_offset);
548 switch (ret) {
549 case QCOW2_CLUSTER_COMPRESSED:
550
551 c = 1;
552 *cluster_offset &= L2E_COMPRESSED_OFFSET_SIZE_MASK;
553 break;
554 case QCOW2_CLUSTER_ZERO:
555 if (s->qcow_version < 3) {
556 qcow2_signal_corruption(bs, true, -1, -1, "Zero cluster entry found"
557 " in pre-v3 image (L2 offset: %#" PRIx64
558 ", L2 index: %#x)", l2_offset, l2_index);
559 ret = -EIO;
560 goto fail;
561 }
562 c = count_contiguous_clusters_by_type(nb_clusters, &l2_table[l2_index],
563 QCOW2_CLUSTER_ZERO);
564 *cluster_offset = 0;
565 break;
566 case QCOW2_CLUSTER_UNALLOCATED:
567
568 c = count_contiguous_clusters_by_type(nb_clusters, &l2_table[l2_index],
569 QCOW2_CLUSTER_UNALLOCATED);
570 *cluster_offset = 0;
571 break;
572 case QCOW2_CLUSTER_NORMAL:
573
574 c = count_contiguous_clusters(nb_clusters, s->cluster_size,
575 &l2_table[l2_index], QCOW_OFLAG_ZERO);
576 *cluster_offset &= L2E_OFFSET_MASK;
577 if (offset_into_cluster(s, *cluster_offset)) {
578 qcow2_signal_corruption(bs, true, -1, -1, "Data cluster offset %#"
579 PRIx64 " unaligned (L2 offset: %#" PRIx64
580 ", L2 index: %#x)", *cluster_offset,
581 l2_offset, l2_index);
582 ret = -EIO;
583 goto fail;
584 }
585 break;
586 default:
587 abort();
588 }
589
590 qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
591
592 nb_available = (c * s->cluster_sectors);
593
594out:
595 if (nb_available > nb_needed)
596 nb_available = nb_needed;
597
598 *num = nb_available - index_in_cluster;
599
600 return ret;
601
602fail:
603 qcow2_cache_put(bs, s->l2_table_cache, (void **)&l2_table);
604 return ret;
605}
606
607
608
609
610
611
612
613
614
615
616
617
618static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
619 uint64_t **new_l2_table,
620 int *new_l2_index)
621{
622 BDRVQcow2State *s = bs->opaque;
623 unsigned int l2_index;
624 uint64_t l1_index, l2_offset;
625 uint64_t *l2_table = NULL;
626 int ret;
627
628
629
630 l1_index = offset >> (s->l2_bits + s->cluster_bits);
631 if (l1_index >= s->l1_size) {
632 ret = qcow2_grow_l1_table(bs, l1_index + 1, false);
633 if (ret < 0) {
634 return ret;
635 }
636 }
637
638 assert(l1_index < s->l1_size);
639 l2_offset = s->l1_table[l1_index] & L1E_OFFSET_MASK;
640 if (offset_into_cluster(s, l2_offset)) {
641 qcow2_signal_corruption(bs, true, -1, -1, "L2 table offset %#" PRIx64
642 " unaligned (L1 index: %#" PRIx64 ")",
643 l2_offset, l1_index);
644 return -EIO;
645 }
646
647
648
649 if (s->l1_table[l1_index] & QCOW_OFLAG_COPIED) {
650
651 ret = l2_load(bs, l2_offset, &l2_table);
652 if (ret < 0) {
653 return ret;
654 }
655 } else {
656
657 ret = l2_allocate(bs, l1_index, &l2_table);
658 if (ret < 0) {
659 return ret;
660 }
661
662
663 if (l2_offset) {
664 qcow2_free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t),
665 QCOW2_DISCARD_OTHER);
666 }
667 }
668
669
670
671 l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
672
673 *new_l2_table = l2_table;
674 *new_l2_index = l2_index;
675
676 return 0;
677}
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
693 uint64_t offset,
694 int compressed_size)
695{
696 BDRVQcow2State *s = bs->opaque;
697 int l2_index, ret;
698 uint64_t *l2_table;
699 int64_t cluster_offset;
700 int nb_csectors;
701
702 ret = get_cluster_table(bs, offset, &l2_table, &l2_index);
703 if (ret < 0) {
704 return 0;
705 }
706
707
708
709 cluster_offset = be64_to_cpu(l2_table[l2_index]);
710 if (cluster_offset & L2E_OFFSET_MASK) {
711 qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
712 return 0;
713 }
714
715 cluster_offset = qcow2_alloc_bytes(bs, compressed_size);
716 if (cluster_offset < 0) {
717 qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
718 return 0;
719 }
720
721 nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) -
722 (cluster_offset >> 9);
723
724 cluster_offset |= QCOW_OFLAG_COMPRESSED |
725 ((uint64_t)nb_csectors << s->csize_shift);
726
727
728
729
730
731 BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED);
732 qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
733 l2_table[l2_index] = cpu_to_be64(cluster_offset);
734 qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
735
736 return cluster_offset;
737}
738
739static int perform_cow(BlockDriverState *bs, QCowL2Meta *m, Qcow2COWRegion *r)
740{
741 BDRVQcow2State *s = bs->opaque;
742 int ret;
743
744 if (r->nb_sectors == 0) {
745 return 0;
746 }
747
748 qemu_co_mutex_unlock(&s->lock);
749 ret = copy_sectors(bs, m->offset / BDRV_SECTOR_SIZE, m->alloc_offset,
750 r->offset / BDRV_SECTOR_SIZE,
751 r->offset / BDRV_SECTOR_SIZE + r->nb_sectors);
752 qemu_co_mutex_lock(&s->lock);
753
754 if (ret < 0) {
755 return ret;
756 }
757
758
759
760
761
762
763 qcow2_cache_depends_on_flush(s->l2_table_cache);
764
765 return 0;
766}
767
768int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
769{
770 BDRVQcow2State *s = bs->opaque;
771 int i, j = 0, l2_index, ret;
772 uint64_t *old_cluster, *l2_table;
773 uint64_t cluster_offset = m->alloc_offset;
774
775 trace_qcow2_cluster_link_l2(qemu_coroutine_self(), m->nb_clusters);
776 assert(m->nb_clusters > 0);
777
778 old_cluster = g_try_new(uint64_t, m->nb_clusters);
779 if (old_cluster == NULL) {
780 ret = -ENOMEM;
781 goto err;
782 }
783
784
785 ret = perform_cow(bs, m, &m->cow_start);
786 if (ret < 0) {
787 goto err;
788 }
789
790 ret = perform_cow(bs, m, &m->cow_end);
791 if (ret < 0) {
792 goto err;
793 }
794
795
796 if (s->use_lazy_refcounts) {
797 qcow2_mark_dirty(bs);
798 }
799 if (qcow2_need_accurate_refcounts(s)) {
800 qcow2_cache_set_dependency(bs, s->l2_table_cache,
801 s->refcount_block_cache);
802 }
803
804 ret = get_cluster_table(bs, m->offset, &l2_table, &l2_index);
805 if (ret < 0) {
806 goto err;
807 }
808 qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
809
810 assert(l2_index + m->nb_clusters <= s->l2_size);
811 for (i = 0; i < m->nb_clusters; i++) {
812
813
814
815
816
817
818 if(l2_table[l2_index + i] != 0)
819 old_cluster[j++] = l2_table[l2_index + i];
820
821 l2_table[l2_index + i] = cpu_to_be64((cluster_offset +
822 (i << s->cluster_bits)) | QCOW_OFLAG_COPIED);
823 }
824
825
826 qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
827
828
829
830
831
832
833
834 if (j != 0) {
835 for (i = 0; i < j; i++) {
836 qcow2_free_any_clusters(bs, be64_to_cpu(old_cluster[i]), 1,
837 QCOW2_DISCARD_NEVER);
838 }
839 }
840
841 ret = 0;
842err:
843 g_free(old_cluster);
844 return ret;
845 }
846
847
848
849
850
851
852static int count_cow_clusters(BDRVQcow2State *s, int nb_clusters,
853 uint64_t *l2_table, int l2_index)
854{
855 int i;
856
857 for (i = 0; i < nb_clusters; i++) {
858 uint64_t l2_entry = be64_to_cpu(l2_table[l2_index + i]);
859 int cluster_type = qcow2_get_cluster_type(l2_entry);
860
861 switch(cluster_type) {
862 case QCOW2_CLUSTER_NORMAL:
863 if (l2_entry & QCOW_OFLAG_COPIED) {
864 goto out;
865 }
866 break;
867 case QCOW2_CLUSTER_UNALLOCATED:
868 case QCOW2_CLUSTER_COMPRESSED:
869 case QCOW2_CLUSTER_ZERO:
870 break;
871 default:
872 abort();
873 }
874 }
875
876out:
877 assert(i <= nb_clusters);
878 return i;
879}
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset,
896 uint64_t *cur_bytes, QCowL2Meta **m)
897{
898 BDRVQcow2State *s = bs->opaque;
899 QCowL2Meta *old_alloc;
900 uint64_t bytes = *cur_bytes;
901
902 QLIST_FOREACH(old_alloc, &s->cluster_allocs, next_in_flight) {
903
904 uint64_t start = guest_offset;
905 uint64_t end = start + bytes;
906 uint64_t old_start = l2meta_cow_start(old_alloc);
907 uint64_t old_end = l2meta_cow_end(old_alloc);
908
909 if (end <= old_start || start >= old_end) {
910
911 } else {
912 if (start < old_start) {
913
914 bytes = old_start - start;
915 } else {
916 bytes = 0;
917 }
918
919
920
921
922
923 if (bytes == 0 && *m) {
924 *cur_bytes = 0;
925 return 0;
926 }
927
928 if (bytes == 0) {
929
930
931 qemu_co_mutex_unlock(&s->lock);
932 qemu_co_queue_wait(&old_alloc->dependent_requests);
933 qemu_co_mutex_lock(&s->lock);
934 return -EAGAIN;
935 }
936 }
937 }
938
939
940
941 *cur_bytes = bytes;
942
943 return 0;
944}
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
969 uint64_t *host_offset, uint64_t *bytes, QCowL2Meta **m)
970{
971 BDRVQcow2State *s = bs->opaque;
972 int l2_index;
973 uint64_t cluster_offset;
974 uint64_t *l2_table;
975 uint64_t nb_clusters;
976 unsigned int keep_clusters;
977 int ret;
978
979 trace_qcow2_handle_copied(qemu_coroutine_self(), guest_offset, *host_offset,
980 *bytes);
981
982 assert(*host_offset == 0 || offset_into_cluster(s, guest_offset)
983 == offset_into_cluster(s, *host_offset));
984
985
986
987
988
989 nb_clusters =
990 size_to_clusters(s, offset_into_cluster(s, guest_offset) + *bytes);
991
992 l2_index = offset_to_l2_index(s, guest_offset);
993 nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
994 assert(nb_clusters <= INT_MAX);
995
996
997 ret = get_cluster_table(bs, guest_offset, &l2_table, &l2_index);
998 if (ret < 0) {
999 return ret;
1000 }
1001
1002 cluster_offset = be64_to_cpu(l2_table[l2_index]);
1003
1004
1005 if (qcow2_get_cluster_type(cluster_offset) == QCOW2_CLUSTER_NORMAL
1006 && (cluster_offset & QCOW_OFLAG_COPIED))
1007 {
1008
1009 bool offset_matches =
1010 (cluster_offset & L2E_OFFSET_MASK) == *host_offset;
1011
1012 if (offset_into_cluster(s, cluster_offset & L2E_OFFSET_MASK)) {
1013 qcow2_signal_corruption(bs, true, -1, -1, "Data cluster offset "
1014 "%#llx unaligned (guest offset: %#" PRIx64
1015 ")", cluster_offset & L2E_OFFSET_MASK,
1016 guest_offset);
1017 ret = -EIO;
1018 goto out;
1019 }
1020
1021 if (*host_offset != 0 && !offset_matches) {
1022 *bytes = 0;
1023 ret = 0;
1024 goto out;
1025 }
1026
1027
1028 keep_clusters =
1029 count_contiguous_clusters(nb_clusters, s->cluster_size,
1030 &l2_table[l2_index],
1031 QCOW_OFLAG_COPIED | QCOW_OFLAG_ZERO);
1032 assert(keep_clusters <= nb_clusters);
1033
1034 *bytes = MIN(*bytes,
1035 keep_clusters * s->cluster_size
1036 - offset_into_cluster(s, guest_offset));
1037
1038 ret = 1;
1039 } else {
1040 ret = 0;
1041 }
1042
1043
1044out:
1045 qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
1046
1047
1048
1049 if (ret > 0) {
1050 *host_offset = (cluster_offset & L2E_OFFSET_MASK)
1051 + offset_into_cluster(s, guest_offset);
1052 }
1053
1054 return ret;
1055}
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset,
1077 uint64_t *host_offset, uint64_t *nb_clusters)
1078{
1079 BDRVQcow2State *s = bs->opaque;
1080
1081 trace_qcow2_do_alloc_clusters_offset(qemu_coroutine_self(), guest_offset,
1082 *host_offset, *nb_clusters);
1083
1084
1085 trace_qcow2_cluster_alloc_phys(qemu_coroutine_self());
1086 if (*host_offset == 0) {
1087 int64_t cluster_offset =
1088 qcow2_alloc_clusters(bs, *nb_clusters * s->cluster_size);
1089 if (cluster_offset < 0) {
1090 return cluster_offset;
1091 }
1092 *host_offset = cluster_offset;
1093 return 0;
1094 } else {
1095 int64_t ret = qcow2_alloc_clusters_at(bs, *host_offset, *nb_clusters);
1096 if (ret < 0) {
1097 return ret;
1098 }
1099 *nb_clusters = ret;
1100 return 0;
1101 }
1102}
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
1125 uint64_t *host_offset, uint64_t *bytes, QCowL2Meta **m)
1126{
1127 BDRVQcow2State *s = bs->opaque;
1128 int l2_index;
1129 uint64_t *l2_table;
1130 uint64_t entry;
1131 uint64_t nb_clusters;
1132 int ret;
1133
1134 uint64_t alloc_cluster_offset;
1135
1136 trace_qcow2_handle_alloc(qemu_coroutine_self(), guest_offset, *host_offset,
1137 *bytes);
1138 assert(*bytes > 0);
1139
1140
1141
1142
1143
1144 nb_clusters =
1145 size_to_clusters(s, offset_into_cluster(s, guest_offset) + *bytes);
1146
1147 l2_index = offset_to_l2_index(s, guest_offset);
1148 nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
1149 assert(nb_clusters <= INT_MAX);
1150
1151
1152 ret = get_cluster_table(bs, guest_offset, &l2_table, &l2_index);
1153 if (ret < 0) {
1154 return ret;
1155 }
1156
1157 entry = be64_to_cpu(l2_table[l2_index]);
1158
1159
1160 if (entry & QCOW_OFLAG_COMPRESSED) {
1161 nb_clusters = 1;
1162 } else {
1163 nb_clusters = count_cow_clusters(s, nb_clusters, l2_table, l2_index);
1164 }
1165
1166
1167
1168
1169 assert(nb_clusters > 0);
1170
1171 qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
1172
1173
1174 alloc_cluster_offset = start_of_cluster(s, *host_offset);
1175 ret = do_alloc_cluster_offset(bs, guest_offset, &alloc_cluster_offset,
1176 &nb_clusters);
1177 if (ret < 0) {
1178 goto fail;
1179 }
1180
1181
1182 if (nb_clusters == 0) {
1183 *bytes = 0;
1184 return 0;
1185 }
1186
1187
1188
1189
1190
1191 if (!alloc_cluster_offset) {
1192 ret = qcow2_pre_write_overlap_check(bs, 0, alloc_cluster_offset,
1193 nb_clusters * s->cluster_size);
1194 assert(ret < 0);
1195 goto fail;
1196 }
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212 int requested_sectors =
1213 (*bytes + offset_into_cluster(s, guest_offset))
1214 >> BDRV_SECTOR_BITS;
1215 int avail_sectors = nb_clusters
1216 << (s->cluster_bits - BDRV_SECTOR_BITS);
1217 int alloc_n_start = offset_into_cluster(s, guest_offset)
1218 >> BDRV_SECTOR_BITS;
1219 int nb_sectors = MIN(requested_sectors, avail_sectors);
1220 QCowL2Meta *old_m = *m;
1221
1222 *m = g_malloc0(sizeof(**m));
1223
1224 **m = (QCowL2Meta) {
1225 .next = old_m,
1226
1227 .alloc_offset = alloc_cluster_offset,
1228 .offset = start_of_cluster(s, guest_offset),
1229 .nb_clusters = nb_clusters,
1230 .nb_available = nb_sectors,
1231
1232 .cow_start = {
1233 .offset = 0,
1234 .nb_sectors = alloc_n_start,
1235 },
1236 .cow_end = {
1237 .offset = nb_sectors * BDRV_SECTOR_SIZE,
1238 .nb_sectors = avail_sectors - nb_sectors,
1239 },
1240 };
1241 qemu_co_queue_init(&(*m)->dependent_requests);
1242 QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight);
1243
1244 *host_offset = alloc_cluster_offset + offset_into_cluster(s, guest_offset);
1245 *bytes = MIN(*bytes, (nb_sectors * BDRV_SECTOR_SIZE)
1246 - offset_into_cluster(s, guest_offset));
1247 assert(*bytes != 0);
1248
1249 return 1;
1250
1251fail:
1252 if (*m && (*m)->nb_clusters > 0) {
1253 QLIST_REMOVE(*m, next_in_flight);
1254 }
1255 return ret;
1256}
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
1278 int *num, uint64_t *host_offset, QCowL2Meta **m)
1279{
1280 BDRVQcow2State *s = bs->opaque;
1281 uint64_t start, remaining;
1282 uint64_t cluster_offset;
1283 uint64_t cur_bytes;
1284 int ret;
1285
1286 trace_qcow2_alloc_clusters_offset(qemu_coroutine_self(), offset, *num);
1287
1288 assert((offset & ~BDRV_SECTOR_MASK) == 0);
1289
1290again:
1291 start = offset;
1292 remaining = (uint64_t)*num << BDRV_SECTOR_BITS;
1293 cluster_offset = 0;
1294 *host_offset = 0;
1295 cur_bytes = 0;
1296 *m = NULL;
1297
1298 while (true) {
1299
1300 if (!*host_offset) {
1301 *host_offset = start_of_cluster(s, cluster_offset);
1302 }
1303
1304 assert(remaining >= cur_bytes);
1305
1306 start += cur_bytes;
1307 remaining -= cur_bytes;
1308 cluster_offset += cur_bytes;
1309
1310 if (remaining == 0) {
1311 break;
1312 }
1313
1314 cur_bytes = remaining;
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334 ret = handle_dependencies(bs, start, &cur_bytes, m);
1335 if (ret == -EAGAIN) {
1336
1337
1338
1339 assert(*m == NULL);
1340 goto again;
1341 } else if (ret < 0) {
1342 return ret;
1343 } else if (cur_bytes == 0) {
1344 break;
1345 } else {
1346
1347
1348
1349 }
1350
1351
1352
1353
1354 ret = handle_copied(bs, start, &cluster_offset, &cur_bytes, m);
1355 if (ret < 0) {
1356 return ret;
1357 } else if (ret) {
1358 continue;
1359 } else if (cur_bytes == 0) {
1360 break;
1361 }
1362
1363
1364
1365
1366
1367 ret = handle_alloc(bs, start, &cluster_offset, &cur_bytes, m);
1368 if (ret < 0) {
1369 return ret;
1370 } else if (ret) {
1371 continue;
1372 } else {
1373 assert(cur_bytes == 0);
1374 break;
1375 }
1376 }
1377
1378 *num -= remaining >> BDRV_SECTOR_BITS;
1379 assert(*num > 0);
1380 assert(*host_offset != 0);
1381
1382 return 0;
1383}
1384
1385static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
1386 const uint8_t *buf, int buf_size)
1387{
1388 z_stream strm1, *strm = &strm1;
1389 int ret, out_len;
1390
1391 memset(strm, 0, sizeof(*strm));
1392
1393 strm->next_in = (uint8_t *)buf;
1394 strm->avail_in = buf_size;
1395 strm->next_out = out_buf;
1396 strm->avail_out = out_buf_size;
1397
1398 ret = inflateInit2(strm, -12);
1399 if (ret != Z_OK)
1400 return -1;
1401 ret = inflate(strm, Z_FINISH);
1402 out_len = strm->next_out - out_buf;
1403 if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
1404 out_len != out_buf_size) {
1405 inflateEnd(strm);
1406 return -1;
1407 }
1408 inflateEnd(strm);
1409 return 0;
1410}
1411
1412int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
1413{
1414 BDRVQcow2State *s = bs->opaque;
1415 int ret, csize, nb_csectors, sector_offset;
1416 uint64_t coffset;
1417
1418 coffset = cluster_offset & s->cluster_offset_mask;
1419 if (s->cluster_cache_offset != coffset) {
1420 nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
1421 sector_offset = coffset & 511;
1422 csize = nb_csectors * 512 - sector_offset;
1423 BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
1424 ret = bdrv_read(bs->file->bs, coffset >> 9, s->cluster_data,
1425 nb_csectors);
1426 if (ret < 0) {
1427 return ret;
1428 }
1429 if (decompress_buffer(s->cluster_cache, s->cluster_size,
1430 s->cluster_data + sector_offset, csize) < 0) {
1431 return -EIO;
1432 }
1433 s->cluster_cache_offset = coffset;
1434 }
1435 return 0;
1436}
1437
1438
1439
1440
1441
1442
1443static int discard_single_l2(BlockDriverState *bs, uint64_t offset,
1444 uint64_t nb_clusters, enum qcow2_discard_type type,
1445 bool full_discard)
1446{
1447 BDRVQcow2State *s = bs->opaque;
1448 uint64_t *l2_table;
1449 int l2_index;
1450 int ret;
1451 int i;
1452
1453 ret = get_cluster_table(bs, offset, &l2_table, &l2_index);
1454 if (ret < 0) {
1455 return ret;
1456 }
1457
1458
1459 nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
1460 assert(nb_clusters <= INT_MAX);
1461
1462 for (i = 0; i < nb_clusters; i++) {
1463 uint64_t old_l2_entry;
1464
1465 old_l2_entry = be64_to_cpu(l2_table[l2_index + i]);
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480 switch (qcow2_get_cluster_type(old_l2_entry)) {
1481 case QCOW2_CLUSTER_UNALLOCATED:
1482 if (full_discard || !bs->backing) {
1483 continue;
1484 }
1485 break;
1486
1487 case QCOW2_CLUSTER_ZERO:
1488 if (!full_discard) {
1489 continue;
1490 }
1491 break;
1492
1493 case QCOW2_CLUSTER_NORMAL:
1494 case QCOW2_CLUSTER_COMPRESSED:
1495 break;
1496
1497 default:
1498 abort();
1499 }
1500
1501
1502 qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
1503 if (!full_discard && s->qcow_version >= 3) {
1504 l2_table[l2_index + i] = cpu_to_be64(QCOW_OFLAG_ZERO);
1505 } else {
1506 l2_table[l2_index + i] = cpu_to_be64(0);
1507 }
1508
1509
1510 qcow2_free_any_clusters(bs, old_l2_entry, 1, type);
1511 }
1512
1513 qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
1514
1515 return nb_clusters;
1516}
1517
1518int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset,
1519 int nb_sectors, enum qcow2_discard_type type, bool full_discard)
1520{
1521 BDRVQcow2State *s = bs->opaque;
1522 uint64_t end_offset;
1523 uint64_t nb_clusters;
1524 int ret;
1525
1526 end_offset = offset + (nb_sectors << BDRV_SECTOR_BITS);
1527
1528
1529 offset = align_offset(offset, s->cluster_size);
1530 end_offset = start_of_cluster(s, end_offset);
1531
1532 if (offset > end_offset) {
1533 return 0;
1534 }
1535
1536 nb_clusters = size_to_clusters(s, end_offset - offset);
1537
1538 s->cache_discards = true;
1539
1540
1541 while (nb_clusters > 0) {
1542 ret = discard_single_l2(bs, offset, nb_clusters, type, full_discard);
1543 if (ret < 0) {
1544 goto fail;
1545 }
1546
1547 nb_clusters -= ret;
1548 offset += (ret * s->cluster_size);
1549 }
1550
1551 ret = 0;
1552fail:
1553 s->cache_discards = false;
1554 qcow2_process_discards(bs, ret);
1555
1556 return ret;
1557}
1558
1559
1560
1561
1562
1563
1564static int zero_single_l2(BlockDriverState *bs, uint64_t offset,
1565 uint64_t nb_clusters)
1566{
1567 BDRVQcow2State *s = bs->opaque;
1568 uint64_t *l2_table;
1569 int l2_index;
1570 int ret;
1571 int i;
1572
1573 ret = get_cluster_table(bs, offset, &l2_table, &l2_index);
1574 if (ret < 0) {
1575 return ret;
1576 }
1577
1578
1579 nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
1580 assert(nb_clusters <= INT_MAX);
1581
1582 for (i = 0; i < nb_clusters; i++) {
1583 uint64_t old_offset;
1584
1585 old_offset = be64_to_cpu(l2_table[l2_index + i]);
1586
1587
1588 qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
1589 if (old_offset & QCOW_OFLAG_COMPRESSED) {
1590 l2_table[l2_index + i] = cpu_to_be64(QCOW_OFLAG_ZERO);
1591 qcow2_free_any_clusters(bs, old_offset, 1, QCOW2_DISCARD_REQUEST);
1592 } else {
1593 l2_table[l2_index + i] |= cpu_to_be64(QCOW_OFLAG_ZERO);
1594 }
1595 }
1596
1597 qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
1598
1599 return nb_clusters;
1600}
1601
1602int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors)
1603{
1604 BDRVQcow2State *s = bs->opaque;
1605 uint64_t nb_clusters;
1606 int ret;
1607
1608
1609 if (s->qcow_version < 3) {
1610 return -ENOTSUP;
1611 }
1612
1613
1614 nb_clusters = size_to_clusters(s, nb_sectors << BDRV_SECTOR_BITS);
1615
1616 s->cache_discards = true;
1617
1618 while (nb_clusters > 0) {
1619 ret = zero_single_l2(bs, offset, nb_clusters);
1620 if (ret < 0) {
1621 goto fail;
1622 }
1623
1624 nb_clusters -= ret;
1625 offset += (ret * s->cluster_size);
1626 }
1627
1628 ret = 0;
1629fail:
1630 s->cache_discards = false;
1631 qcow2_process_discards(bs, ret);
1632
1633 return ret;
1634}
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
1645 int l1_size, int64_t *visited_l1_entries,
1646 int64_t l1_entries,
1647 BlockDriverAmendStatusCB *status_cb,
1648 void *cb_opaque)
1649{
1650 BDRVQcow2State *s = bs->opaque;
1651 bool is_active_l1 = (l1_table == s->l1_table);
1652 uint64_t *l2_table = NULL;
1653 int ret;
1654 int i, j;
1655
1656 if (!is_active_l1) {
1657
1658
1659 l2_table = qemu_try_blockalign(bs->file->bs, s->cluster_size);
1660 if (l2_table == NULL) {
1661 return -ENOMEM;
1662 }
1663 }
1664
1665 for (i = 0; i < l1_size; i++) {
1666 uint64_t l2_offset = l1_table[i] & L1E_OFFSET_MASK;
1667 bool l2_dirty = false;
1668 uint64_t l2_refcount;
1669
1670 if (!l2_offset) {
1671
1672 (*visited_l1_entries)++;
1673 if (status_cb) {
1674 status_cb(bs, *visited_l1_entries, l1_entries, cb_opaque);
1675 }
1676 continue;
1677 }
1678
1679 if (offset_into_cluster(s, l2_offset)) {
1680 qcow2_signal_corruption(bs, true, -1, -1, "L2 table offset %#"
1681 PRIx64 " unaligned (L1 index: %#x)",
1682 l2_offset, i);
1683 ret = -EIO;
1684 goto fail;
1685 }
1686
1687 if (is_active_l1) {
1688
1689 ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset,
1690 (void **)&l2_table);
1691 } else {
1692
1693 ret = bdrv_read(bs->file->bs, l2_offset / BDRV_SECTOR_SIZE,
1694 (void *)l2_table, s->cluster_sectors);
1695 }
1696 if (ret < 0) {
1697 goto fail;
1698 }
1699
1700 ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits,
1701 &l2_refcount);
1702 if (ret < 0) {
1703 goto fail;
1704 }
1705
1706 for (j = 0; j < s->l2_size; j++) {
1707 uint64_t l2_entry = be64_to_cpu(l2_table[j]);
1708 int64_t offset = l2_entry & L2E_OFFSET_MASK;
1709 int cluster_type = qcow2_get_cluster_type(l2_entry);
1710 bool preallocated = offset != 0;
1711
1712 if (cluster_type != QCOW2_CLUSTER_ZERO) {
1713 continue;
1714 }
1715
1716 if (!preallocated) {
1717 if (!bs->backing) {
1718
1719
1720 l2_table[j] = 0;
1721 l2_dirty = true;
1722 continue;
1723 }
1724
1725 offset = qcow2_alloc_clusters(bs, s->cluster_size);
1726 if (offset < 0) {
1727 ret = offset;
1728 goto fail;
1729 }
1730
1731 if (l2_refcount > 1) {
1732
1733
1734 ret = qcow2_update_cluster_refcount(bs,
1735 offset >> s->cluster_bits,
1736 refcount_diff(1, l2_refcount), false,
1737 QCOW2_DISCARD_OTHER);
1738 if (ret < 0) {
1739 qcow2_free_clusters(bs, offset, s->cluster_size,
1740 QCOW2_DISCARD_OTHER);
1741 goto fail;
1742 }
1743 }
1744 }
1745
1746 if (offset_into_cluster(s, offset)) {
1747 qcow2_signal_corruption(bs, true, -1, -1, "Data cluster offset "
1748 "%#" PRIx64 " unaligned (L2 offset: %#"
1749 PRIx64 ", L2 index: %#x)", offset,
1750 l2_offset, j);
1751 if (!preallocated) {
1752 qcow2_free_clusters(bs, offset, s->cluster_size,
1753 QCOW2_DISCARD_ALWAYS);
1754 }
1755 ret = -EIO;
1756 goto fail;
1757 }
1758
1759 ret = qcow2_pre_write_overlap_check(bs, 0, offset, s->cluster_size);
1760 if (ret < 0) {
1761 if (!preallocated) {
1762 qcow2_free_clusters(bs, offset, s->cluster_size,
1763 QCOW2_DISCARD_ALWAYS);
1764 }
1765 goto fail;
1766 }
1767
1768 ret = bdrv_write_zeroes(bs->file->bs, offset / BDRV_SECTOR_SIZE,
1769 s->cluster_sectors, 0);
1770 if (ret < 0) {
1771 if (!preallocated) {
1772 qcow2_free_clusters(bs, offset, s->cluster_size,
1773 QCOW2_DISCARD_ALWAYS);
1774 }
1775 goto fail;
1776 }
1777
1778 if (l2_refcount == 1) {
1779 l2_table[j] = cpu_to_be64(offset | QCOW_OFLAG_COPIED);
1780 } else {
1781 l2_table[j] = cpu_to_be64(offset);
1782 }
1783 l2_dirty = true;
1784 }
1785
1786 if (is_active_l1) {
1787 if (l2_dirty) {
1788 qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
1789 qcow2_cache_depends_on_flush(s->l2_table_cache);
1790 }
1791 qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
1792 } else {
1793 if (l2_dirty) {
1794 ret = qcow2_pre_write_overlap_check(bs,
1795 QCOW2_OL_INACTIVE_L2 | QCOW2_OL_ACTIVE_L2, l2_offset,
1796 s->cluster_size);
1797 if (ret < 0) {
1798 goto fail;
1799 }
1800
1801 ret = bdrv_write(bs->file->bs, l2_offset / BDRV_SECTOR_SIZE,
1802 (void *)l2_table, s->cluster_sectors);
1803 if (ret < 0) {
1804 goto fail;
1805 }
1806 }
1807 }
1808
1809 (*visited_l1_entries)++;
1810 if (status_cb) {
1811 status_cb(bs, *visited_l1_entries, l1_entries, cb_opaque);
1812 }
1813 }
1814
1815 ret = 0;
1816
1817fail:
1818 if (l2_table) {
1819 if (!is_active_l1) {
1820 qemu_vfree(l2_table);
1821 } else {
1822 qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table);
1823 }
1824 }
1825 return ret;
1826}
1827
1828
1829
1830
1831
1832
1833
1834int qcow2_expand_zero_clusters(BlockDriverState *bs,
1835 BlockDriverAmendStatusCB *status_cb,
1836 void *cb_opaque)
1837{
1838 BDRVQcow2State *s = bs->opaque;
1839 uint64_t *l1_table = NULL;
1840 int64_t l1_entries = 0, visited_l1_entries = 0;
1841 int ret;
1842 int i, j;
1843
1844 if (status_cb) {
1845 l1_entries = s->l1_size;
1846 for (i = 0; i < s->nb_snapshots; i++) {
1847 l1_entries += s->snapshots[i].l1_size;
1848 }
1849 }
1850
1851 ret = expand_zero_clusters_in_l1(bs, s->l1_table, s->l1_size,
1852 &visited_l1_entries, l1_entries,
1853 status_cb, cb_opaque);
1854 if (ret < 0) {
1855 goto fail;
1856 }
1857
1858
1859
1860
1861
1862
1863
1864
1865 ret = qcow2_cache_empty(bs, s->l2_table_cache);
1866 if (ret < 0) {
1867 goto fail;
1868 }
1869
1870 for (i = 0; i < s->nb_snapshots; i++) {
1871 int l1_sectors = (s->snapshots[i].l1_size * sizeof(uint64_t) +
1872 BDRV_SECTOR_SIZE - 1) / BDRV_SECTOR_SIZE;
1873
1874 l1_table = g_realloc(l1_table, l1_sectors * BDRV_SECTOR_SIZE);
1875
1876 ret = bdrv_read(bs->file->bs,
1877 s->snapshots[i].l1_table_offset / BDRV_SECTOR_SIZE,
1878 (void *)l1_table, l1_sectors);
1879 if (ret < 0) {
1880 goto fail;
1881 }
1882
1883 for (j = 0; j < s->snapshots[i].l1_size; j++) {
1884 be64_to_cpus(&l1_table[j]);
1885 }
1886
1887 ret = expand_zero_clusters_in_l1(bs, l1_table, s->snapshots[i].l1_size,
1888 &visited_l1_entries, l1_entries,
1889 status_cb, cb_opaque);
1890 if (ret < 0) {
1891 goto fail;
1892 }
1893 }
1894
1895 ret = 0;
1896
1897fail:
1898 g_free(l1_table);
1899 return ret;
1900}
1901