1 /*
2 * Block driver for the QCOW version 2 format
3 *
4 * Copyright (c) 2004-2006 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #include "qemu/osdep.h"
26
27 #include "block/qdict.h"
28 #include "system/block-backend.h"
29 #include "qemu/main-loop.h"
30 #include "qemu/module.h"
31 #include "qcow2.h"
32 #include "qemu/error-report.h"
33 #include "qapi/error.h"
34 #include "qapi/qapi-events-block-core.h"
35 #include "qobject/qdict.h"
36 #include "qobject/qstring.h"
37 #include "trace.h"
38 #include "qemu/option_int.h"
39 #include "qemu/cutils.h"
40 #include "qemu/bswap.h"
41 #include "qemu/memalign.h"
42 #include "qapi/qobject-input-visitor.h"
43 #include "qapi/qapi-visit-block-core.h"
44 #include "crypto.h"
45 #include "block/aio_task.h"
46 #include "block/dirty-bitmap.h"
47
48 /*
49 Differences with QCOW:
50
51 - Support for multiple incremental snapshots.
52 - Memory management by reference counts.
53 - Clusters which have a reference count of one have the bit
54 QCOW_OFLAG_COPIED to optimize write performance.
55 - Size of compressed clusters is stored in sectors to reduce bit usage
56 in the cluster offsets.
57 - Support for storing additional data (such as the VM state) in the
58 snapshots.
59 - If a backing store is used, the cluster size is not constrained
60 (could be backported to QCOW).
61 - L2 tables have always a size of one cluster.
62 */
63
64
65 typedef struct {
66 uint32_t magic;
67 uint32_t len;
68 } QEMU_PACKED QCowExtension;
69
70 #define QCOW2_EXT_MAGIC_END 0
71 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xe2792aca
72 #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
73 #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77
74 #define QCOW2_EXT_MAGIC_BITMAPS 0x23852875
75 #define QCOW2_EXT_MAGIC_DATA_FILE 0x44415441
76
77 static int coroutine_fn
78 qcow2_co_preadv_compressed(BlockDriverState *bs,
79 uint64_t l2_entry,
80 uint64_t offset,
81 uint64_t bytes,
82 QEMUIOVector *qiov,
83 size_t qiov_offset);
84
qcow2_probe(const uint8_t * buf,int buf_size,const char * filename)85 static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
86 {
87 const QCowHeader *cow_header = (const void *)buf;
88
89 if (buf_size >= sizeof(QCowHeader) &&
90 be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
91 be32_to_cpu(cow_header->version) >= 2)
92 return 100;
93 else
94 return 0;
95 }
96
97
98 static int GRAPH_RDLOCK
qcow2_crypto_hdr_read_func(QCryptoBlock * block,size_t offset,uint8_t * buf,size_t buflen,void * opaque,Error ** errp)99 qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset,
100 uint8_t *buf, size_t buflen,
101 void *opaque, Error **errp)
102 {
103 BlockDriverState *bs = opaque;
104 BDRVQcow2State *s = bs->opaque;
105 ssize_t ret;
106
107 if ((offset + buflen) > s->crypto_header.length) {
108 error_setg(errp, "Request for data outside of extension header");
109 return -1;
110 }
111
112 ret = bdrv_pread(bs->file, s->crypto_header.offset + offset, buflen, buf,
113 0);
114 if (ret < 0) {
115 error_setg_errno(errp, -ret, "Could not read encryption header");
116 return -1;
117 }
118 return 0;
119 }
120
121
122 static int coroutine_fn GRAPH_RDLOCK
qcow2_crypto_hdr_init_func(QCryptoBlock * block,size_t headerlen,void * opaque,Error ** errp)123 qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen, void *opaque,
124 Error **errp)
125 {
126 BlockDriverState *bs = opaque;
127 BDRVQcow2State *s = bs->opaque;
128 int64_t ret;
129 int64_t clusterlen;
130
131 ret = qcow2_alloc_clusters(bs, headerlen);
132 if (ret < 0) {
133 error_setg_errno(errp, -ret,
134 "Cannot allocate cluster for LUKS header size %zu",
135 headerlen);
136 return -1;
137 }
138
139 s->crypto_header.length = headerlen;
140 s->crypto_header.offset = ret;
141
142 /*
143 * Zero fill all space in cluster so it has predictable
144 * content, as we may not initialize some regions of the
145 * header (eg only 1 out of 8 key slots will be initialized)
146 */
147 clusterlen = size_to_clusters(s, headerlen) * s->cluster_size;
148 assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen, false) == 0);
149 ret = bdrv_co_pwrite_zeroes(bs->file, ret, clusterlen, 0);
150 if (ret < 0) {
151 error_setg_errno(errp, -ret, "Could not zero fill encryption header");
152 return -1;
153 }
154
155 return 0;
156 }
157
158
159 /* The graph lock must be held when called in coroutine context */
160 static int coroutine_mixed_fn GRAPH_RDLOCK
qcow2_crypto_hdr_write_func(QCryptoBlock * block,size_t offset,const uint8_t * buf,size_t buflen,void * opaque,Error ** errp)161 qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset,
162 const uint8_t *buf, size_t buflen,
163 void *opaque, Error **errp)
164 {
165 BlockDriverState *bs = opaque;
166 BDRVQcow2State *s = bs->opaque;
167 ssize_t ret;
168
169 if ((offset + buflen) > s->crypto_header.length) {
170 error_setg(errp, "Request for data outside of extension header");
171 return -1;
172 }
173
174 ret = bdrv_pwrite(bs->file, s->crypto_header.offset + offset, buflen, buf,
175 0);
176 if (ret < 0) {
177 error_setg_errno(errp, -ret, "Could not read encryption header");
178 return -1;
179 }
180 return 0;
181 }
182
183 static QDict*
qcow2_extract_crypto_opts(QemuOpts * opts,const char * fmt,Error ** errp)184 qcow2_extract_crypto_opts(QemuOpts *opts, const char *fmt, Error **errp)
185 {
186 QDict *cryptoopts_qdict;
187 QDict *opts_qdict;
188
189 /* Extract "encrypt." options into a qdict */
190 opts_qdict = qemu_opts_to_qdict(opts, NULL);
191 qdict_extract_subqdict(opts_qdict, &cryptoopts_qdict, "encrypt.");
192 qobject_unref(opts_qdict);
193 qdict_put_str(cryptoopts_qdict, "format", fmt);
194 return cryptoopts_qdict;
195 }
196
197 /*
198 * read qcow2 extension and fill bs
199 * start reading from start_offset
200 * finish reading upon magic of value 0 or when end_offset reached
201 * unknown magic is skipped (future extension this version knows nothing about)
202 * return 0 upon success, non-0 otherwise
203 */
204 static int coroutine_fn GRAPH_RDLOCK
qcow2_read_extensions(BlockDriverState * bs,uint64_t start_offset,uint64_t end_offset,void ** p_feature_table,int flags,bool * need_update_header,Error ** errp)205 qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset,
206 uint64_t end_offset, void **p_feature_table,
207 int flags, bool *need_update_header, Error **errp)
208 {
209 BDRVQcow2State *s = bs->opaque;
210 QCowExtension ext;
211 uint64_t offset;
212 int ret;
213 Qcow2BitmapHeaderExt bitmaps_ext;
214
215 if (need_update_header != NULL) {
216 *need_update_header = false;
217 }
218
219 #ifdef DEBUG_EXT
220 printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
221 #endif
222 offset = start_offset;
223 while (offset < end_offset) {
224
225 #ifdef DEBUG_EXT
226 /* Sanity check */
227 if (offset > s->cluster_size)
228 printf("qcow2_read_extension: suspicious offset %lu\n", offset);
229
230 printf("attempting to read extended header in offset %lu\n", offset);
231 #endif
232
233 ret = bdrv_co_pread(bs->file, offset, sizeof(ext), &ext, 0);
234 if (ret < 0) {
235 error_setg_errno(errp, -ret, "qcow2_read_extension: ERROR: "
236 "pread fail from offset %" PRIu64, offset);
237 return 1;
238 }
239 ext.magic = be32_to_cpu(ext.magic);
240 ext.len = be32_to_cpu(ext.len);
241 offset += sizeof(ext);
242 #ifdef DEBUG_EXT
243 printf("ext.magic = 0x%x\n", ext.magic);
244 #endif
245 if (offset > end_offset || ext.len > end_offset - offset) {
246 error_setg(errp, "Header extension too large");
247 return -EINVAL;
248 }
249
250 switch (ext.magic) {
251 case QCOW2_EXT_MAGIC_END:
252 return 0;
253
254 case QCOW2_EXT_MAGIC_BACKING_FORMAT:
255 if (ext.len >= sizeof(bs->backing_format)) {
256 error_setg(errp, "ERROR: ext_backing_format: len=%" PRIu32
257 " too large (>=%zu)", ext.len,
258 sizeof(bs->backing_format));
259 return 2;
260 }
261 ret = bdrv_co_pread(bs->file, offset, ext.len, bs->backing_format, 0);
262 if (ret < 0) {
263 error_setg_errno(errp, -ret, "ERROR: ext_backing_format: "
264 "Could not read format name");
265 return 3;
266 }
267 bs->backing_format[ext.len] = '\0';
268 s->image_backing_format = g_strdup(bs->backing_format);
269 #ifdef DEBUG_EXT
270 printf("Qcow2: Got format extension %s\n", bs->backing_format);
271 #endif
272 break;
273
274 case QCOW2_EXT_MAGIC_FEATURE_TABLE:
275 if (p_feature_table != NULL) {
276 void *feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature));
277 ret = bdrv_co_pread(bs->file, offset, ext.len, feature_table, 0);
278 if (ret < 0) {
279 error_setg_errno(errp, -ret, "ERROR: ext_feature_table: "
280 "Could not read table");
281 g_free(feature_table);
282 return ret;
283 }
284
285 *p_feature_table = feature_table;
286 }
287 break;
288
289 case QCOW2_EXT_MAGIC_CRYPTO_HEADER: {
290 unsigned int cflags = 0;
291 if (s->crypt_method_header != QCOW_CRYPT_LUKS) {
292 error_setg(errp, "CRYPTO header extension only "
293 "expected with LUKS encryption method");
294 return -EINVAL;
295 }
296 if (ext.len != sizeof(Qcow2CryptoHeaderExtension)) {
297 error_setg(errp, "CRYPTO header extension size %u, "
298 "but expected size %zu", ext.len,
299 sizeof(Qcow2CryptoHeaderExtension));
300 return -EINVAL;
301 }
302
303 ret = bdrv_co_pread(bs->file, offset, ext.len, &s->crypto_header, 0);
304 if (ret < 0) {
305 error_setg_errno(errp, -ret,
306 "Unable to read CRYPTO header extension");
307 return ret;
308 }
309 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset);
310 s->crypto_header.length = be64_to_cpu(s->crypto_header.length);
311
312 if ((s->crypto_header.offset % s->cluster_size) != 0) {
313 error_setg(errp, "Encryption header offset '%" PRIu64 "' is "
314 "not a multiple of cluster size '%u'",
315 s->crypto_header.offset, s->cluster_size);
316 return -EINVAL;
317 }
318
319 if (flags & BDRV_O_NO_IO) {
320 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
321 }
322 s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.",
323 qcow2_crypto_hdr_read_func,
324 bs, cflags, errp);
325 if (!s->crypto) {
326 return -EINVAL;
327 }
328 } break;
329
330 case QCOW2_EXT_MAGIC_BITMAPS:
331 if (ext.len != sizeof(bitmaps_ext)) {
332 error_setg_errno(errp, -ret, "bitmaps_ext: "
333 "Invalid extension length");
334 return -EINVAL;
335 }
336
337 if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) {
338 if (s->qcow_version < 3) {
339 /* Let's be a bit more specific */
340 warn_report("This qcow2 v2 image contains bitmaps, but "
341 "they may have been modified by a program "
342 "without persistent bitmap support; so now "
343 "they must all be considered inconsistent");
344 } else {
345 warn_report("a program lacking bitmap support "
346 "modified this file, so all bitmaps are now "
347 "considered inconsistent");
348 }
349 error_printf("Some clusters may be leaked, "
350 "run 'qemu-img check -r' on the image "
351 "file to fix.");
352 if (need_update_header != NULL) {
353 /* Updating is needed to drop invalid bitmap extension. */
354 *need_update_header = true;
355 }
356 break;
357 }
358
359 ret = bdrv_co_pread(bs->file, offset, ext.len, &bitmaps_ext, 0);
360 if (ret < 0) {
361 error_setg_errno(errp, -ret, "bitmaps_ext: "
362 "Could not read ext header");
363 return ret;
364 }
365
366 if (bitmaps_ext.reserved32 != 0) {
367 error_setg_errno(errp, -ret, "bitmaps_ext: "
368 "Reserved field is not zero");
369 return -EINVAL;
370 }
371
372 bitmaps_ext.nb_bitmaps = be32_to_cpu(bitmaps_ext.nb_bitmaps);
373 bitmaps_ext.bitmap_directory_size =
374 be64_to_cpu(bitmaps_ext.bitmap_directory_size);
375 bitmaps_ext.bitmap_directory_offset =
376 be64_to_cpu(bitmaps_ext.bitmap_directory_offset);
377
378 if (bitmaps_ext.nb_bitmaps > QCOW2_MAX_BITMAPS) {
379 error_setg(errp,
380 "bitmaps_ext: Image has %" PRIu32 " bitmaps, "
381 "exceeding the QEMU supported maximum of %d",
382 bitmaps_ext.nb_bitmaps, QCOW2_MAX_BITMAPS);
383 return -EINVAL;
384 }
385
386 if (bitmaps_ext.nb_bitmaps == 0) {
387 error_setg(errp, "found bitmaps extension with zero bitmaps");
388 return -EINVAL;
389 }
390
391 if (offset_into_cluster(s, bitmaps_ext.bitmap_directory_offset)) {
392 error_setg(errp, "bitmaps_ext: "
393 "invalid bitmap directory offset");
394 return -EINVAL;
395 }
396
397 if (bitmaps_ext.bitmap_directory_size >
398 QCOW2_MAX_BITMAP_DIRECTORY_SIZE) {
399 error_setg(errp, "bitmaps_ext: "
400 "bitmap directory size (%" PRIu64 ") exceeds "
401 "the maximum supported size (%d)",
402 bitmaps_ext.bitmap_directory_size,
403 QCOW2_MAX_BITMAP_DIRECTORY_SIZE);
404 return -EINVAL;
405 }
406
407 s->nb_bitmaps = bitmaps_ext.nb_bitmaps;
408 s->bitmap_directory_offset =
409 bitmaps_ext.bitmap_directory_offset;
410 s->bitmap_directory_size =
411 bitmaps_ext.bitmap_directory_size;
412
413 #ifdef DEBUG_EXT
414 printf("Qcow2: Got bitmaps extension: "
415 "offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n",
416 s->bitmap_directory_offset, s->nb_bitmaps);
417 #endif
418 break;
419
420 case QCOW2_EXT_MAGIC_DATA_FILE:
421 {
422 s->image_data_file = g_malloc0(ext.len + 1);
423 ret = bdrv_co_pread(bs->file, offset, ext.len, s->image_data_file, 0);
424 if (ret < 0) {
425 error_setg_errno(errp, -ret,
426 "ERROR: Could not read data file name");
427 return ret;
428 }
429 #ifdef DEBUG_EXT
430 printf("Qcow2: Got external data file %s\n", s->image_data_file);
431 #endif
432 break;
433 }
434
435 default:
436 /* unknown magic - save it in case we need to rewrite the header */
437 /* If you add a new feature, make sure to also update the fast
438 * path of qcow2_make_empty() to deal with it. */
439 {
440 Qcow2UnknownHeaderExtension *uext;
441
442 uext = g_malloc0(sizeof(*uext) + ext.len);
443 uext->magic = ext.magic;
444 uext->len = ext.len;
445 QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next);
446
447 ret = bdrv_co_pread(bs->file, offset, uext->len, uext->data, 0);
448 if (ret < 0) {
449 error_setg_errno(errp, -ret, "ERROR: unknown extension: "
450 "Could not read data");
451 return ret;
452 }
453 }
454 break;
455 }
456
457 offset += ((ext.len + 7) & ~7);
458 }
459
460 return 0;
461 }
462
cleanup_unknown_header_ext(BlockDriverState * bs)463 static void cleanup_unknown_header_ext(BlockDriverState *bs)
464 {
465 BDRVQcow2State *s = bs->opaque;
466 Qcow2UnknownHeaderExtension *uext, *next;
467
468 QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) {
469 QLIST_REMOVE(uext, next);
470 g_free(uext);
471 }
472 }
473
report_unsupported_feature(Error ** errp,Qcow2Feature * table,uint64_t mask)474 static void report_unsupported_feature(Error **errp, Qcow2Feature *table,
475 uint64_t mask)
476 {
477 g_autoptr(GString) features = g_string_sized_new(60);
478
479 while (table && table->name[0] != '\0') {
480 if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) {
481 if (mask & (1ULL << table->bit)) {
482 if (features->len > 0) {
483 g_string_append(features, ", ");
484 }
485 g_string_append_printf(features, "%.46s", table->name);
486 mask &= ~(1ULL << table->bit);
487 }
488 }
489 table++;
490 }
491
492 if (mask) {
493 if (features->len > 0) {
494 g_string_append(features, ", ");
495 }
496 g_string_append_printf(features,
497 "Unknown incompatible feature: %" PRIx64, mask);
498 }
499
500 error_setg(errp, "Unsupported qcow2 feature(s): %s", features->str);
501 }
502
503 /*
504 * Sets the dirty bit and flushes afterwards if necessary.
505 *
506 * The incompatible_features bit is only set if the image file header was
507 * updated successfully. Therefore it is not required to check the return
508 * value of this function.
509 */
qcow2_mark_dirty(BlockDriverState * bs)510 int qcow2_mark_dirty(BlockDriverState *bs)
511 {
512 BDRVQcow2State *s = bs->opaque;
513 uint64_t val;
514 int ret;
515
516 assert(s->qcow_version >= 3);
517
518 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
519 return 0; /* already dirty */
520 }
521
522 val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY);
523 ret = bdrv_pwrite_sync(bs->file,
524 offsetof(QCowHeader, incompatible_features),
525 sizeof(val), &val, 0);
526 if (ret < 0) {
527 return ret;
528 }
529
530 /* Only treat image as dirty if the header was updated successfully */
531 s->incompatible_features |= QCOW2_INCOMPAT_DIRTY;
532 return 0;
533 }
534
535 /*
536 * Clears the dirty bit and flushes before if necessary. Only call this
537 * function when there are no pending requests, it does not guard against
538 * concurrent requests dirtying the image.
539 */
qcow2_mark_clean(BlockDriverState * bs)540 static int GRAPH_RDLOCK qcow2_mark_clean(BlockDriverState *bs)
541 {
542 BDRVQcow2State *s = bs->opaque;
543
544 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
545 int ret;
546
547 s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY;
548
549 ret = qcow2_flush_caches(bs);
550 if (ret < 0) {
551 return ret;
552 }
553
554 return qcow2_update_header(bs);
555 }
556 return 0;
557 }
558
559 /*
560 * Marks the image as corrupt.
561 */
qcow2_mark_corrupt(BlockDriverState * bs)562 int qcow2_mark_corrupt(BlockDriverState *bs)
563 {
564 BDRVQcow2State *s = bs->opaque;
565
566 s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT;
567 return qcow2_update_header(bs);
568 }
569
570 /*
571 * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes
572 * before if necessary.
573 */
574 static int coroutine_fn GRAPH_RDLOCK
qcow2_mark_consistent(BlockDriverState * bs)575 qcow2_mark_consistent(BlockDriverState *bs)
576 {
577 BDRVQcow2State *s = bs->opaque;
578
579 if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) {
580 int ret = qcow2_flush_caches(bs);
581 if (ret < 0) {
582 return ret;
583 }
584
585 s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT;
586 return qcow2_update_header(bs);
587 }
588 return 0;
589 }
590
qcow2_add_check_result(BdrvCheckResult * out,const BdrvCheckResult * src,bool set_allocation_info)591 static void qcow2_add_check_result(BdrvCheckResult *out,
592 const BdrvCheckResult *src,
593 bool set_allocation_info)
594 {
595 out->corruptions += src->corruptions;
596 out->leaks += src->leaks;
597 out->check_errors += src->check_errors;
598 out->corruptions_fixed += src->corruptions_fixed;
599 out->leaks_fixed += src->leaks_fixed;
600
601 if (set_allocation_info) {
602 out->image_end_offset = src->image_end_offset;
603 out->bfi = src->bfi;
604 }
605 }
606
607 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_check_locked(BlockDriverState * bs,BdrvCheckResult * result,BdrvCheckMode fix)608 qcow2_co_check_locked(BlockDriverState *bs, BdrvCheckResult *result,
609 BdrvCheckMode fix)
610 {
611 BdrvCheckResult snapshot_res = {};
612 BdrvCheckResult refcount_res = {};
613 int ret;
614
615 memset(result, 0, sizeof(*result));
616
617 ret = qcow2_check_read_snapshot_table(bs, &snapshot_res, fix);
618 if (ret < 0) {
619 qcow2_add_check_result(result, &snapshot_res, false);
620 return ret;
621 }
622
623 ret = qcow2_check_refcounts(bs, &refcount_res, fix);
624 qcow2_add_check_result(result, &refcount_res, true);
625 if (ret < 0) {
626 qcow2_add_check_result(result, &snapshot_res, false);
627 return ret;
628 }
629
630 ret = qcow2_check_fix_snapshot_table(bs, &snapshot_res, fix);
631 qcow2_add_check_result(result, &snapshot_res, false);
632 if (ret < 0) {
633 return ret;
634 }
635
636 if (fix && result->check_errors == 0 && result->corruptions == 0) {
637 ret = qcow2_mark_clean(bs);
638 if (ret < 0) {
639 return ret;
640 }
641 return qcow2_mark_consistent(bs);
642 }
643 return ret;
644 }
645
646 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_check(BlockDriverState * bs,BdrvCheckResult * result,BdrvCheckMode fix)647 qcow2_co_check(BlockDriverState *bs, BdrvCheckResult *result,
648 BdrvCheckMode fix)
649 {
650 BDRVQcow2State *s = bs->opaque;
651 int ret;
652
653 qemu_co_mutex_lock(&s->lock);
654 ret = qcow2_co_check_locked(bs, result, fix);
655 qemu_co_mutex_unlock(&s->lock);
656 return ret;
657 }
658
qcow2_validate_table(BlockDriverState * bs,uint64_t offset,uint64_t entries,size_t entry_len,int64_t max_size_bytes,const char * table_name,Error ** errp)659 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
660 uint64_t entries, size_t entry_len,
661 int64_t max_size_bytes, const char *table_name,
662 Error **errp)
663 {
664 BDRVQcow2State *s = bs->opaque;
665
666 if (entries > max_size_bytes / entry_len) {
667 error_setg(errp, "%s too large", table_name);
668 return -EFBIG;
669 }
670
671 /* Use signed INT64_MAX as the maximum even for uint64_t header fields,
672 * because values will be passed to qemu functions taking int64_t. */
673 if ((INT64_MAX - entries * entry_len < offset) ||
674 (offset_into_cluster(s, offset) != 0)) {
675 error_setg(errp, "%s offset invalid", table_name);
676 return -EINVAL;
677 }
678
679 return 0;
680 }
681
682 static const char *const mutable_opts[] = {
683 QCOW2_OPT_LAZY_REFCOUNTS,
684 QCOW2_OPT_DISCARD_REQUEST,
685 QCOW2_OPT_DISCARD_SNAPSHOT,
686 QCOW2_OPT_DISCARD_OTHER,
687 QCOW2_OPT_DISCARD_NO_UNREF,
688 QCOW2_OPT_OVERLAP,
689 QCOW2_OPT_OVERLAP_TEMPLATE,
690 QCOW2_OPT_OVERLAP_MAIN_HEADER,
691 QCOW2_OPT_OVERLAP_ACTIVE_L1,
692 QCOW2_OPT_OVERLAP_ACTIVE_L2,
693 QCOW2_OPT_OVERLAP_REFCOUNT_TABLE,
694 QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK,
695 QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE,
696 QCOW2_OPT_OVERLAP_INACTIVE_L1,
697 QCOW2_OPT_OVERLAP_INACTIVE_L2,
698 QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY,
699 QCOW2_OPT_CACHE_SIZE,
700 QCOW2_OPT_L2_CACHE_SIZE,
701 QCOW2_OPT_L2_CACHE_ENTRY_SIZE,
702 QCOW2_OPT_REFCOUNT_CACHE_SIZE,
703 QCOW2_OPT_CACHE_CLEAN_INTERVAL,
704 NULL
705 };
706
707 static QemuOptsList qcow2_runtime_opts = {
708 .name = "qcow2",
709 .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head),
710 .desc = {
711 {
712 .name = QCOW2_OPT_LAZY_REFCOUNTS,
713 .type = QEMU_OPT_BOOL,
714 .help = "Postpone refcount updates",
715 },
716 {
717 .name = QCOW2_OPT_DISCARD_REQUEST,
718 .type = QEMU_OPT_BOOL,
719 .help = "Pass guest discard requests to the layer below",
720 },
721 {
722 .name = QCOW2_OPT_DISCARD_SNAPSHOT,
723 .type = QEMU_OPT_BOOL,
724 .help = "Generate discard requests when snapshot related space "
725 "is freed",
726 },
727 {
728 .name = QCOW2_OPT_DISCARD_OTHER,
729 .type = QEMU_OPT_BOOL,
730 .help = "Generate discard requests when other clusters are freed",
731 },
732 {
733 .name = QCOW2_OPT_DISCARD_NO_UNREF,
734 .type = QEMU_OPT_BOOL,
735 .help = "Do not unreference discarded clusters",
736 },
737 {
738 .name = QCOW2_OPT_OVERLAP,
739 .type = QEMU_OPT_STRING,
740 .help = "Selects which overlap checks to perform from a range of "
741 "templates (none, constant, cached, all)",
742 },
743 {
744 .name = QCOW2_OPT_OVERLAP_TEMPLATE,
745 .type = QEMU_OPT_STRING,
746 .help = "Selects which overlap checks to perform from a range of "
747 "templates (none, constant, cached, all)",
748 },
749 {
750 .name = QCOW2_OPT_OVERLAP_MAIN_HEADER,
751 .type = QEMU_OPT_BOOL,
752 .help = "Check for unintended writes into the main qcow2 header",
753 },
754 {
755 .name = QCOW2_OPT_OVERLAP_ACTIVE_L1,
756 .type = QEMU_OPT_BOOL,
757 .help = "Check for unintended writes into the active L1 table",
758 },
759 {
760 .name = QCOW2_OPT_OVERLAP_ACTIVE_L2,
761 .type = QEMU_OPT_BOOL,
762 .help = "Check for unintended writes into an active L2 table",
763 },
764 {
765 .name = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE,
766 .type = QEMU_OPT_BOOL,
767 .help = "Check for unintended writes into the refcount table",
768 },
769 {
770 .name = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK,
771 .type = QEMU_OPT_BOOL,
772 .help = "Check for unintended writes into a refcount block",
773 },
774 {
775 .name = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE,
776 .type = QEMU_OPT_BOOL,
777 .help = "Check for unintended writes into the snapshot table",
778 },
779 {
780 .name = QCOW2_OPT_OVERLAP_INACTIVE_L1,
781 .type = QEMU_OPT_BOOL,
782 .help = "Check for unintended writes into an inactive L1 table",
783 },
784 {
785 .name = QCOW2_OPT_OVERLAP_INACTIVE_L2,
786 .type = QEMU_OPT_BOOL,
787 .help = "Check for unintended writes into an inactive L2 table",
788 },
789 {
790 .name = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY,
791 .type = QEMU_OPT_BOOL,
792 .help = "Check for unintended writes into the bitmap directory",
793 },
794 {
795 .name = QCOW2_OPT_CACHE_SIZE,
796 .type = QEMU_OPT_SIZE,
797 .help = "Maximum combined metadata (L2 tables and refcount blocks) "
798 "cache size",
799 },
800 {
801 .name = QCOW2_OPT_L2_CACHE_SIZE,
802 .type = QEMU_OPT_SIZE,
803 .help = "Maximum L2 table cache size",
804 },
805 {
806 .name = QCOW2_OPT_L2_CACHE_ENTRY_SIZE,
807 .type = QEMU_OPT_SIZE,
808 .help = "Size of each entry in the L2 cache",
809 },
810 {
811 .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE,
812 .type = QEMU_OPT_SIZE,
813 .help = "Maximum refcount block cache size",
814 },
815 {
816 .name = QCOW2_OPT_CACHE_CLEAN_INTERVAL,
817 .type = QEMU_OPT_NUMBER,
818 .help = "Clean unused cache entries after this time (in seconds)",
819 },
820 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
821 "ID of secret providing qcow2 AES key or LUKS passphrase"),
822 { /* end of list */ }
823 },
824 };
825
826 static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = {
827 [QCOW2_OL_MAIN_HEADER_BITNR] = QCOW2_OPT_OVERLAP_MAIN_HEADER,
828 [QCOW2_OL_ACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L1,
829 [QCOW2_OL_ACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L2,
830 [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE,
831 [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK,
832 [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE,
833 [QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1,
834 [QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2,
835 [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY,
836 };
837
cache_clean_timer_cb(void * opaque)838 static void cache_clean_timer_cb(void *opaque)
839 {
840 BlockDriverState *bs = opaque;
841 BDRVQcow2State *s = bs->opaque;
842 qcow2_cache_clean_unused(s->l2_table_cache);
843 qcow2_cache_clean_unused(s->refcount_block_cache);
844 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
845 (int64_t) s->cache_clean_interval * 1000);
846 }
847
cache_clean_timer_init(BlockDriverState * bs,AioContext * context)848 static void cache_clean_timer_init(BlockDriverState *bs, AioContext *context)
849 {
850 BDRVQcow2State *s = bs->opaque;
851 if (s->cache_clean_interval > 0) {
852 s->cache_clean_timer =
853 aio_timer_new_with_attrs(context, QEMU_CLOCK_VIRTUAL,
854 SCALE_MS, QEMU_TIMER_ATTR_EXTERNAL,
855 cache_clean_timer_cb, bs);
856 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
857 (int64_t) s->cache_clean_interval * 1000);
858 }
859 }
860
cache_clean_timer_del(BlockDriverState * bs)861 static void cache_clean_timer_del(BlockDriverState *bs)
862 {
863 BDRVQcow2State *s = bs->opaque;
864 if (s->cache_clean_timer) {
865 timer_free(s->cache_clean_timer);
866 s->cache_clean_timer = NULL;
867 }
868 }
869
qcow2_detach_aio_context(BlockDriverState * bs)870 static void qcow2_detach_aio_context(BlockDriverState *bs)
871 {
872 cache_clean_timer_del(bs);
873 }
874
qcow2_attach_aio_context(BlockDriverState * bs,AioContext * new_context)875 static void qcow2_attach_aio_context(BlockDriverState *bs,
876 AioContext *new_context)
877 {
878 cache_clean_timer_init(bs, new_context);
879 }
880
read_cache_sizes(BlockDriverState * bs,QemuOpts * opts,uint64_t * l2_cache_size,uint64_t * l2_cache_entry_size,uint64_t * refcount_cache_size,Error ** errp)881 static bool read_cache_sizes(BlockDriverState *bs, QemuOpts *opts,
882 uint64_t *l2_cache_size,
883 uint64_t *l2_cache_entry_size,
884 uint64_t *refcount_cache_size, Error **errp)
885 {
886 BDRVQcow2State *s = bs->opaque;
887 uint64_t combined_cache_size, l2_cache_max_setting;
888 bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set;
889 bool l2_cache_entry_size_set;
890 int min_refcount_cache = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size;
891 uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE;
892 uint64_t max_l2_entries = DIV_ROUND_UP(virtual_disk_size, s->cluster_size);
893 /* An L2 table is always one cluster in size so the max cache size
894 * should be a multiple of the cluster size. */
895 uint64_t max_l2_cache = ROUND_UP(max_l2_entries * l2_entry_size(s),
896 s->cluster_size);
897
898 combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE);
899 l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE);
900 refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
901 l2_cache_entry_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE);
902
903 combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0);
904 l2_cache_max_setting = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE,
905 DEFAULT_L2_CACHE_MAX_SIZE);
906 *refcount_cache_size = qemu_opt_get_size(opts,
907 QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0);
908
909 *l2_cache_entry_size = qemu_opt_get_size(
910 opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE, s->cluster_size);
911
912 *l2_cache_size = MIN(max_l2_cache, l2_cache_max_setting);
913
914 if (combined_cache_size_set) {
915 if (l2_cache_size_set && refcount_cache_size_set) {
916 error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE
917 " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set "
918 "at the same time");
919 return false;
920 } else if (l2_cache_size_set &&
921 (l2_cache_max_setting > combined_cache_size)) {
922 error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed "
923 QCOW2_OPT_CACHE_SIZE);
924 return false;
925 } else if (*refcount_cache_size > combined_cache_size) {
926 error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed "
927 QCOW2_OPT_CACHE_SIZE);
928 return false;
929 }
930
931 if (l2_cache_size_set) {
932 *refcount_cache_size = combined_cache_size - *l2_cache_size;
933 } else if (refcount_cache_size_set) {
934 *l2_cache_size = combined_cache_size - *refcount_cache_size;
935 } else {
936 /* Assign as much memory as possible to the L2 cache, and
937 * use the remainder for the refcount cache */
938 if (combined_cache_size >= max_l2_cache + min_refcount_cache) {
939 *l2_cache_size = max_l2_cache;
940 *refcount_cache_size = combined_cache_size - *l2_cache_size;
941 } else {
942 *refcount_cache_size =
943 MIN(combined_cache_size, min_refcount_cache);
944 *l2_cache_size = combined_cache_size - *refcount_cache_size;
945 }
946 }
947 }
948
949 /*
950 * If the L2 cache is not enough to cover the whole disk then
951 * default to 4KB entries. Smaller entries reduce the cost of
952 * loads and evictions and increase I/O performance.
953 */
954 if (*l2_cache_size < max_l2_cache && !l2_cache_entry_size_set) {
955 *l2_cache_entry_size = MIN(s->cluster_size, 4096);
956 }
957
958 /* l2_cache_size and refcount_cache_size are ensured to have at least
959 * their minimum values in qcow2_update_options_prepare() */
960
961 if (*l2_cache_entry_size < (1 << MIN_CLUSTER_BITS) ||
962 *l2_cache_entry_size > s->cluster_size ||
963 !is_power_of_2(*l2_cache_entry_size)) {
964 error_setg(errp, "L2 cache entry size must be a power of two "
965 "between %d and the cluster size (%d)",
966 1 << MIN_CLUSTER_BITS, s->cluster_size);
967 return false;
968 }
969
970 return true;
971 }
972
973 typedef struct Qcow2ReopenState {
974 Qcow2Cache *l2_table_cache;
975 Qcow2Cache *refcount_block_cache;
976 int l2_slice_size; /* Number of entries in a slice of the L2 table */
977 bool use_lazy_refcounts;
978 int overlap_check;
979 bool discard_passthrough[QCOW2_DISCARD_MAX];
980 bool discard_no_unref;
981 uint64_t cache_clean_interval;
982 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
983 } Qcow2ReopenState;
984
985 static int GRAPH_RDLOCK
qcow2_update_options_prepare(BlockDriverState * bs,Qcow2ReopenState * r,QDict * options,int flags,Error ** errp)986 qcow2_update_options_prepare(BlockDriverState *bs, Qcow2ReopenState *r,
987 QDict *options, int flags, Error **errp)
988 {
989 BDRVQcow2State *s = bs->opaque;
990 QemuOpts *opts = NULL;
991 const char *opt_overlap_check, *opt_overlap_check_template;
992 int overlap_check_template = 0;
993 uint64_t l2_cache_size, l2_cache_entry_size, refcount_cache_size;
994 int i;
995 const char *encryptfmt;
996 QDict *encryptopts = NULL;
997 int ret;
998
999 qdict_extract_subqdict(options, &encryptopts, "encrypt.");
1000 encryptfmt = qdict_get_try_str(encryptopts, "format");
1001
1002 opts = qemu_opts_create(&qcow2_runtime_opts, NULL, 0, &error_abort);
1003 if (!qemu_opts_absorb_qdict(opts, options, errp)) {
1004 ret = -EINVAL;
1005 goto fail;
1006 }
1007
1008 /* get L2 table/refcount block cache size from command line options */
1009 if (!read_cache_sizes(bs, opts, &l2_cache_size, &l2_cache_entry_size,
1010 &refcount_cache_size, errp)) {
1011 ret = -EINVAL;
1012 goto fail;
1013 }
1014
1015 l2_cache_size /= l2_cache_entry_size;
1016 if (l2_cache_size < MIN_L2_CACHE_SIZE) {
1017 l2_cache_size = MIN_L2_CACHE_SIZE;
1018 }
1019 if (l2_cache_size > INT_MAX) {
1020 error_setg(errp, "L2 cache size too big");
1021 ret = -EINVAL;
1022 goto fail;
1023 }
1024
1025 refcount_cache_size /= s->cluster_size;
1026 if (refcount_cache_size < MIN_REFCOUNT_CACHE_SIZE) {
1027 refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE;
1028 }
1029 if (refcount_cache_size > INT_MAX) {
1030 error_setg(errp, "Refcount cache size too big");
1031 ret = -EINVAL;
1032 goto fail;
1033 }
1034
1035 /* alloc new L2 table/refcount block cache, flush old one */
1036 if (s->l2_table_cache) {
1037 ret = qcow2_cache_flush(bs, s->l2_table_cache);
1038 if (ret) {
1039 error_setg_errno(errp, -ret, "Failed to flush the L2 table cache");
1040 goto fail;
1041 }
1042 }
1043
1044 if (s->refcount_block_cache) {
1045 ret = qcow2_cache_flush(bs, s->refcount_block_cache);
1046 if (ret) {
1047 error_setg_errno(errp, -ret,
1048 "Failed to flush the refcount block cache");
1049 goto fail;
1050 }
1051 }
1052
1053 r->l2_slice_size = l2_cache_entry_size / l2_entry_size(s);
1054 r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size,
1055 l2_cache_entry_size);
1056 r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size,
1057 s->cluster_size);
1058 if (r->l2_table_cache == NULL || r->refcount_block_cache == NULL) {
1059 error_setg(errp, "Could not allocate metadata caches");
1060 ret = -ENOMEM;
1061 goto fail;
1062 }
1063
1064 /* New interval for cache cleanup timer */
1065 r->cache_clean_interval =
1066 qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL,
1067 DEFAULT_CACHE_CLEAN_INTERVAL);
1068 #ifndef CONFIG_LINUX
1069 if (r->cache_clean_interval != 0) {
1070 error_setg(errp, QCOW2_OPT_CACHE_CLEAN_INTERVAL
1071 " not supported on this host");
1072 ret = -EINVAL;
1073 goto fail;
1074 }
1075 #endif
1076 if (r->cache_clean_interval > UINT_MAX) {
1077 error_setg(errp, "Cache clean interval too big");
1078 ret = -EINVAL;
1079 goto fail;
1080 }
1081
1082 /* lazy-refcounts; flush if going from enabled to disabled */
1083 r->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS,
1084 (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS));
1085 if (r->use_lazy_refcounts && s->qcow_version < 3) {
1086 error_setg(errp, "Lazy refcounts require a qcow2 image with at least "
1087 "qemu 1.1 compatibility level");
1088 ret = -EINVAL;
1089 goto fail;
1090 }
1091
1092 if (s->use_lazy_refcounts && !r->use_lazy_refcounts) {
1093 ret = qcow2_mark_clean(bs);
1094 if (ret < 0) {
1095 error_setg_errno(errp, -ret, "Failed to disable lazy refcounts");
1096 goto fail;
1097 }
1098 }
1099
1100 /* Overlap check options */
1101 opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP);
1102 opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE);
1103 if (opt_overlap_check_template && opt_overlap_check &&
1104 strcmp(opt_overlap_check_template, opt_overlap_check))
1105 {
1106 error_setg(errp, "Conflicting values for qcow2 options '"
1107 QCOW2_OPT_OVERLAP "' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE
1108 "' ('%s')", opt_overlap_check, opt_overlap_check_template);
1109 ret = -EINVAL;
1110 goto fail;
1111 }
1112 if (!opt_overlap_check) {
1113 opt_overlap_check = opt_overlap_check_template ?: "cached";
1114 }
1115
1116 if (!strcmp(opt_overlap_check, "none")) {
1117 overlap_check_template = 0;
1118 } else if (!strcmp(opt_overlap_check, "constant")) {
1119 overlap_check_template = QCOW2_OL_CONSTANT;
1120 } else if (!strcmp(opt_overlap_check, "cached")) {
1121 overlap_check_template = QCOW2_OL_CACHED;
1122 } else if (!strcmp(opt_overlap_check, "all")) {
1123 overlap_check_template = QCOW2_OL_ALL;
1124 } else {
1125 error_setg(errp, "Unsupported value '%s' for qcow2 option "
1126 "'overlap-check'. Allowed are any of the following: "
1127 "none, constant, cached, all", opt_overlap_check);
1128 ret = -EINVAL;
1129 goto fail;
1130 }
1131
1132 r->overlap_check = 0;
1133 for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) {
1134 /* overlap-check defines a template bitmask, but every flag may be
1135 * overwritten through the associated boolean option */
1136 r->overlap_check |=
1137 qemu_opt_get_bool(opts, overlap_bool_option_names[i],
1138 overlap_check_template & (1 << i)) << i;
1139 }
1140
1141 r->discard_passthrough[QCOW2_DISCARD_NEVER] = false;
1142 r->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true;
1143 r->discard_passthrough[QCOW2_DISCARD_REQUEST] =
1144 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST,
1145 flags & BDRV_O_UNMAP);
1146 r->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] =
1147 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true);
1148 r->discard_passthrough[QCOW2_DISCARD_OTHER] =
1149 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false);
1150
1151 r->discard_no_unref = qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_NO_UNREF,
1152 false);
1153 if (r->discard_no_unref && s->qcow_version < 3) {
1154 error_setg(errp,
1155 "discard-no-unref is only supported since qcow2 version 3");
1156 ret = -EINVAL;
1157 goto fail;
1158 }
1159
1160 switch (s->crypt_method_header) {
1161 case QCOW_CRYPT_NONE:
1162 if (encryptfmt) {
1163 error_setg(errp, "No encryption in image header, but options "
1164 "specified format '%s'", encryptfmt);
1165 ret = -EINVAL;
1166 goto fail;
1167 }
1168 break;
1169
1170 case QCOW_CRYPT_AES:
1171 if (encryptfmt && !g_str_equal(encryptfmt, "aes")) {
1172 error_setg(errp,
1173 "Header reported 'aes' encryption format but "
1174 "options specify '%s'", encryptfmt);
1175 ret = -EINVAL;
1176 goto fail;
1177 }
1178 qdict_put_str(encryptopts, "format", "qcow");
1179 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp);
1180 if (!r->crypto_opts) {
1181 ret = -EINVAL;
1182 goto fail;
1183 }
1184 break;
1185
1186 case QCOW_CRYPT_LUKS:
1187 if (encryptfmt && !g_str_equal(encryptfmt, "luks")) {
1188 error_setg(errp,
1189 "Header reported 'luks' encryption format but "
1190 "options specify '%s'", encryptfmt);
1191 ret = -EINVAL;
1192 goto fail;
1193 }
1194 qdict_put_str(encryptopts, "format", "luks");
1195 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp);
1196 if (!r->crypto_opts) {
1197 ret = -EINVAL;
1198 goto fail;
1199 }
1200 break;
1201
1202 default:
1203 error_setg(errp, "Unsupported encryption method %d",
1204 s->crypt_method_header);
1205 ret = -EINVAL;
1206 goto fail;
1207 }
1208
1209 ret = 0;
1210 fail:
1211 qobject_unref(encryptopts);
1212 qemu_opts_del(opts);
1213 opts = NULL;
1214 return ret;
1215 }
1216
qcow2_update_options_commit(BlockDriverState * bs,Qcow2ReopenState * r)1217 static void qcow2_update_options_commit(BlockDriverState *bs,
1218 Qcow2ReopenState *r)
1219 {
1220 BDRVQcow2State *s = bs->opaque;
1221 int i;
1222
1223 if (s->l2_table_cache) {
1224 qcow2_cache_destroy(s->l2_table_cache);
1225 }
1226 if (s->refcount_block_cache) {
1227 qcow2_cache_destroy(s->refcount_block_cache);
1228 }
1229 s->l2_table_cache = r->l2_table_cache;
1230 s->refcount_block_cache = r->refcount_block_cache;
1231 s->l2_slice_size = r->l2_slice_size;
1232
1233 s->overlap_check = r->overlap_check;
1234 s->use_lazy_refcounts = r->use_lazy_refcounts;
1235
1236 for (i = 0; i < QCOW2_DISCARD_MAX; i++) {
1237 s->discard_passthrough[i] = r->discard_passthrough[i];
1238 }
1239
1240 s->discard_no_unref = r->discard_no_unref;
1241
1242 if (s->cache_clean_interval != r->cache_clean_interval) {
1243 cache_clean_timer_del(bs);
1244 s->cache_clean_interval = r->cache_clean_interval;
1245 cache_clean_timer_init(bs, bdrv_get_aio_context(bs));
1246 }
1247
1248 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts);
1249 s->crypto_opts = r->crypto_opts;
1250 }
1251
qcow2_update_options_abort(BlockDriverState * bs,Qcow2ReopenState * r)1252 static void qcow2_update_options_abort(BlockDriverState *bs,
1253 Qcow2ReopenState *r)
1254 {
1255 if (r->l2_table_cache) {
1256 qcow2_cache_destroy(r->l2_table_cache);
1257 }
1258 if (r->refcount_block_cache) {
1259 qcow2_cache_destroy(r->refcount_block_cache);
1260 }
1261 qapi_free_QCryptoBlockOpenOptions(r->crypto_opts);
1262 }
1263
1264 static int coroutine_fn GRAPH_RDLOCK
qcow2_update_options(BlockDriverState * bs,QDict * options,int flags,Error ** errp)1265 qcow2_update_options(BlockDriverState *bs, QDict *options, int flags,
1266 Error **errp)
1267 {
1268 Qcow2ReopenState r = {};
1269 int ret;
1270
1271 ret = qcow2_update_options_prepare(bs, &r, options, flags, errp);
1272 if (ret >= 0) {
1273 qcow2_update_options_commit(bs, &r);
1274 } else {
1275 qcow2_update_options_abort(bs, &r);
1276 }
1277
1278 return ret;
1279 }
1280
validate_compression_type(BDRVQcow2State * s,Error ** errp)1281 static int validate_compression_type(BDRVQcow2State *s, Error **errp)
1282 {
1283 switch (s->compression_type) {
1284 case QCOW2_COMPRESSION_TYPE_ZLIB:
1285 #ifdef CONFIG_ZSTD
1286 case QCOW2_COMPRESSION_TYPE_ZSTD:
1287 #endif
1288 break;
1289
1290 default:
1291 error_setg(errp, "qcow2: unknown compression type: %u",
1292 s->compression_type);
1293 return -ENOTSUP;
1294 }
1295
1296 /*
1297 * if the compression type differs from QCOW2_COMPRESSION_TYPE_ZLIB
1298 * the incompatible feature flag must be set
1299 */
1300 if (s->compression_type == QCOW2_COMPRESSION_TYPE_ZLIB) {
1301 if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) {
1302 error_setg(errp, "qcow2: Compression type incompatible feature "
1303 "bit must not be set");
1304 return -EINVAL;
1305 }
1306 } else {
1307 if (!(s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION)) {
1308 error_setg(errp, "qcow2: Compression type incompatible feature "
1309 "bit must be set");
1310 return -EINVAL;
1311 }
1312 }
1313
1314 return 0;
1315 }
1316
1317 /* Called with s->lock held. */
1318 static int coroutine_fn GRAPH_RDLOCK
qcow2_do_open(BlockDriverState * bs,QDict * options,int flags,bool open_data_file,Error ** errp)1319 qcow2_do_open(BlockDriverState *bs, QDict *options, int flags,
1320 bool open_data_file, Error **errp)
1321 {
1322 ERRP_GUARD();
1323 BDRVQcow2State *s = bs->opaque;
1324 unsigned int len, i;
1325 int ret = 0;
1326 QCowHeader header;
1327 uint64_t ext_end;
1328 uint64_t l1_vm_state_index;
1329 bool update_header = false;
1330
1331 ret = bdrv_co_pread(bs->file, 0, sizeof(header), &header, 0);
1332 if (ret < 0) {
1333 error_setg_errno(errp, -ret, "Could not read qcow2 header");
1334 goto fail;
1335 }
1336 header.magic = be32_to_cpu(header.magic);
1337 header.version = be32_to_cpu(header.version);
1338 header.backing_file_offset = be64_to_cpu(header.backing_file_offset);
1339 header.backing_file_size = be32_to_cpu(header.backing_file_size);
1340 header.size = be64_to_cpu(header.size);
1341 header.cluster_bits = be32_to_cpu(header.cluster_bits);
1342 header.crypt_method = be32_to_cpu(header.crypt_method);
1343 header.l1_table_offset = be64_to_cpu(header.l1_table_offset);
1344 header.l1_size = be32_to_cpu(header.l1_size);
1345 header.refcount_table_offset = be64_to_cpu(header.refcount_table_offset);
1346 header.refcount_table_clusters =
1347 be32_to_cpu(header.refcount_table_clusters);
1348 header.snapshots_offset = be64_to_cpu(header.snapshots_offset);
1349 header.nb_snapshots = be32_to_cpu(header.nb_snapshots);
1350
1351 if (header.magic != QCOW_MAGIC) {
1352 error_setg(errp, "Image is not in qcow2 format");
1353 ret = -EINVAL;
1354 goto fail;
1355 }
1356 if (header.version < 2 || header.version > 3) {
1357 error_setg(errp, "Unsupported qcow2 version %" PRIu32, header.version);
1358 ret = -ENOTSUP;
1359 goto fail;
1360 }
1361
1362 s->qcow_version = header.version;
1363
1364 /* Initialise cluster size */
1365 if (header.cluster_bits < MIN_CLUSTER_BITS ||
1366 header.cluster_bits > MAX_CLUSTER_BITS) {
1367 error_setg(errp, "Unsupported cluster size: 2^%" PRIu32,
1368 header.cluster_bits);
1369 ret = -EINVAL;
1370 goto fail;
1371 }
1372
1373 s->cluster_bits = header.cluster_bits;
1374 s->cluster_size = 1 << s->cluster_bits;
1375
1376 /* Initialise version 3 header fields */
1377 if (header.version == 2) {
1378 header.incompatible_features = 0;
1379 header.compatible_features = 0;
1380 header.autoclear_features = 0;
1381 header.refcount_order = 4;
1382 header.header_length = 72;
1383 } else {
1384 header.incompatible_features =
1385 be64_to_cpu(header.incompatible_features);
1386 header.compatible_features = be64_to_cpu(header.compatible_features);
1387 header.autoclear_features = be64_to_cpu(header.autoclear_features);
1388 header.refcount_order = be32_to_cpu(header.refcount_order);
1389 header.header_length = be32_to_cpu(header.header_length);
1390
1391 if (header.header_length < 104) {
1392 error_setg(errp, "qcow2 header too short");
1393 ret = -EINVAL;
1394 goto fail;
1395 }
1396 }
1397
1398 if (header.header_length > s->cluster_size) {
1399 error_setg(errp, "qcow2 header exceeds cluster size");
1400 ret = -EINVAL;
1401 goto fail;
1402 }
1403
1404 if (header.header_length > sizeof(header)) {
1405 s->unknown_header_fields_size = header.header_length - sizeof(header);
1406 s->unknown_header_fields = g_malloc(s->unknown_header_fields_size);
1407 ret = bdrv_co_pread(bs->file, sizeof(header),
1408 s->unknown_header_fields_size,
1409 s->unknown_header_fields, 0);
1410 if (ret < 0) {
1411 error_setg_errno(errp, -ret, "Could not read unknown qcow2 header "
1412 "fields");
1413 goto fail;
1414 }
1415 }
1416
1417 if (header.backing_file_offset > s->cluster_size) {
1418 error_setg(errp, "Invalid backing file offset");
1419 ret = -EINVAL;
1420 goto fail;
1421 }
1422
1423 if (header.backing_file_offset) {
1424 ext_end = header.backing_file_offset;
1425 } else {
1426 ext_end = 1 << header.cluster_bits;
1427 }
1428
1429 /* Handle feature bits */
1430 s->incompatible_features = header.incompatible_features;
1431 s->compatible_features = header.compatible_features;
1432 s->autoclear_features = header.autoclear_features;
1433
1434 /*
1435 * Handle compression type
1436 * Older qcow2 images don't contain the compression type header.
1437 * Distinguish them by the header length and use
1438 * the only valid (default) compression type in that case
1439 */
1440 if (header.header_length > offsetof(QCowHeader, compression_type)) {
1441 s->compression_type = header.compression_type;
1442 } else {
1443 s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB;
1444 }
1445
1446 ret = validate_compression_type(s, errp);
1447 if (ret) {
1448 goto fail;
1449 }
1450
1451 if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) {
1452 void *feature_table = NULL;
1453 qcow2_read_extensions(bs, header.header_length, ext_end,
1454 &feature_table, flags, NULL, NULL);
1455 report_unsupported_feature(errp, feature_table,
1456 s->incompatible_features &
1457 ~QCOW2_INCOMPAT_MASK);
1458 ret = -ENOTSUP;
1459 g_free(feature_table);
1460 goto fail;
1461 }
1462
1463 if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) {
1464 /* Corrupt images may not be written to unless they are being repaired
1465 */
1466 if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
1467 error_setg(errp, "qcow2: Image is corrupt; cannot be opened "
1468 "read/write");
1469 ret = -EACCES;
1470 goto fail;
1471 }
1472 }
1473
1474 s->subclusters_per_cluster =
1475 has_subclusters(s) ? QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER : 1;
1476 s->subcluster_size = s->cluster_size / s->subclusters_per_cluster;
1477 s->subcluster_bits = ctz32(s->subcluster_size);
1478
1479 if (s->subcluster_size < (1 << MIN_CLUSTER_BITS)) {
1480 error_setg(errp, "Unsupported subcluster size: %d", s->subcluster_size);
1481 ret = -EINVAL;
1482 goto fail;
1483 }
1484
1485 /* Check support for various header values */
1486 if (header.refcount_order > 6) {
1487 error_setg(errp, "Reference count entry width too large; may not "
1488 "exceed 64 bits");
1489 ret = -EINVAL;
1490 goto fail;
1491 }
1492 s->refcount_order = header.refcount_order;
1493 s->refcount_bits = 1 << s->refcount_order;
1494 s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1);
1495 s->refcount_max += s->refcount_max - 1;
1496
1497 s->crypt_method_header = header.crypt_method;
1498 if (s->crypt_method_header) {
1499 if (bdrv_uses_whitelist() &&
1500 s->crypt_method_header == QCOW_CRYPT_AES) {
1501 error_setg(errp,
1502 "Use of AES-CBC encrypted qcow2 images is no longer "
1503 "supported in system emulators");
1504 error_append_hint(errp,
1505 "You can use 'qemu-img convert' to convert your "
1506 "image to an alternative supported format, such "
1507 "as unencrypted qcow2, or raw with the LUKS "
1508 "format instead.\n");
1509 ret = -ENOSYS;
1510 goto fail;
1511 }
1512
1513 if (s->crypt_method_header == QCOW_CRYPT_AES) {
1514 s->crypt_physical_offset = false;
1515 } else {
1516 /* Assuming LUKS and any future crypt methods we
1517 * add will all use physical offsets, due to the
1518 * fact that the alternative is insecure... */
1519 s->crypt_physical_offset = true;
1520 }
1521
1522 bs->encrypted = true;
1523 }
1524
1525 s->l2_bits = s->cluster_bits - ctz32(l2_entry_size(s));
1526 s->l2_size = 1 << s->l2_bits;
1527 /* 2^(s->refcount_order - 3) is the refcount width in bytes */
1528 s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3);
1529 s->refcount_block_size = 1 << s->refcount_block_bits;
1530 bs->total_sectors = header.size / BDRV_SECTOR_SIZE;
1531 s->csize_shift = (62 - (s->cluster_bits - 8));
1532 s->csize_mask = (1 << (s->cluster_bits - 8)) - 1;
1533 s->cluster_offset_mask = (1LL << s->csize_shift) - 1;
1534
1535 s->refcount_table_offset = header.refcount_table_offset;
1536 s->refcount_table_size =
1537 header.refcount_table_clusters << (s->cluster_bits - 3);
1538
1539 if (header.refcount_table_clusters == 0 && !(flags & BDRV_O_CHECK)) {
1540 error_setg(errp, "Image does not contain a reference count table");
1541 ret = -EINVAL;
1542 goto fail;
1543 }
1544
1545 ret = qcow2_validate_table(bs, s->refcount_table_offset,
1546 header.refcount_table_clusters,
1547 s->cluster_size, QCOW_MAX_REFTABLE_SIZE,
1548 "Reference count table", errp);
1549 if (ret < 0) {
1550 goto fail;
1551 }
1552
1553 if (!(flags & BDRV_O_CHECK)) {
1554 /*
1555 * The total size in bytes of the snapshot table is checked in
1556 * qcow2_read_snapshots() because the size of each snapshot is
1557 * variable and we don't know it yet.
1558 * Here we only check the offset and number of snapshots.
1559 */
1560 ret = qcow2_validate_table(bs, header.snapshots_offset,
1561 header.nb_snapshots,
1562 sizeof(QCowSnapshotHeader),
1563 sizeof(QCowSnapshotHeader) *
1564 QCOW_MAX_SNAPSHOTS,
1565 "Snapshot table", errp);
1566 if (ret < 0) {
1567 goto fail;
1568 }
1569 }
1570
1571 /* read the level 1 table */
1572 ret = qcow2_validate_table(bs, header.l1_table_offset,
1573 header.l1_size, L1E_SIZE,
1574 QCOW_MAX_L1_SIZE, "Active L1 table", errp);
1575 if (ret < 0) {
1576 goto fail;
1577 }
1578 s->l1_size = header.l1_size;
1579 s->l1_table_offset = header.l1_table_offset;
1580
1581 l1_vm_state_index = size_to_l1(s, header.size);
1582 if (l1_vm_state_index > INT_MAX) {
1583 error_setg(errp, "Image is too big");
1584 ret = -EFBIG;
1585 goto fail;
1586 }
1587 s->l1_vm_state_index = l1_vm_state_index;
1588
1589 /* the L1 table must contain at least enough entries to put
1590 header.size bytes */
1591 if (s->l1_size < s->l1_vm_state_index) {
1592 error_setg(errp, "L1 table is too small");
1593 ret = -EINVAL;
1594 goto fail;
1595 }
1596
1597 if (s->l1_size > 0) {
1598 s->l1_table = qemu_try_blockalign(bs->file->bs, s->l1_size * L1E_SIZE);
1599 if (s->l1_table == NULL) {
1600 error_setg(errp, "Could not allocate L1 table");
1601 ret = -ENOMEM;
1602 goto fail;
1603 }
1604 ret = bdrv_co_pread(bs->file, s->l1_table_offset, s->l1_size * L1E_SIZE,
1605 s->l1_table, 0);
1606 if (ret < 0) {
1607 error_setg_errno(errp, -ret, "Could not read L1 table");
1608 goto fail;
1609 }
1610 for(i = 0;i < s->l1_size; i++) {
1611 s->l1_table[i] = be64_to_cpu(s->l1_table[i]);
1612 }
1613 }
1614
1615 /* Parse driver-specific options */
1616 ret = qcow2_update_options(bs, options, flags, errp);
1617 if (ret < 0) {
1618 goto fail;
1619 }
1620
1621 s->flags = flags;
1622
1623 ret = qcow2_refcount_init(bs);
1624 if (ret != 0) {
1625 error_setg_errno(errp, -ret, "Could not initialize refcount handling");
1626 goto fail;
1627 }
1628
1629 QLIST_INIT(&s->cluster_allocs);
1630 QTAILQ_INIT(&s->discards);
1631
1632 /* read qcow2 extensions */
1633 if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL,
1634 flags, &update_header, errp)) {
1635 ret = -EINVAL;
1636 goto fail;
1637 }
1638
1639 if (open_data_file && (flags & BDRV_O_NO_IO)) {
1640 /*
1641 * Don't open the data file for 'qemu-img info' so that it can be used
1642 * to verify that an untrusted qcow2 image doesn't refer to external
1643 * files.
1644 *
1645 * Note: This still makes has_data_file() return true.
1646 */
1647 if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) {
1648 s->data_file = NULL;
1649 } else {
1650 s->data_file = bs->file;
1651 }
1652 qdict_extract_subqdict(options, NULL, "data-file.");
1653 qdict_del(options, "data-file");
1654 } else if (open_data_file) {
1655 /* Open external data file */
1656 bdrv_graph_co_rdunlock();
1657 s->data_file = bdrv_co_open_child(NULL, options, "data-file", bs,
1658 &child_of_bds, BDRV_CHILD_DATA,
1659 true, errp);
1660 bdrv_graph_co_rdlock();
1661 if (*errp) {
1662 ret = -EINVAL;
1663 goto fail;
1664 }
1665
1666 if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) {
1667 if (!s->data_file && s->image_data_file) {
1668 bdrv_graph_co_rdunlock();
1669 s->data_file = bdrv_co_open_child(s->image_data_file, options,
1670 "data-file", bs,
1671 &child_of_bds,
1672 BDRV_CHILD_DATA, false, errp);
1673 bdrv_graph_co_rdlock();
1674 if (!s->data_file) {
1675 ret = -EINVAL;
1676 goto fail;
1677 }
1678 }
1679 if (!s->data_file) {
1680 error_setg(errp, "'data-file' is required for this image");
1681 ret = -EINVAL;
1682 goto fail;
1683 }
1684
1685 /* No data here */
1686 bs->file->role &= ~BDRV_CHILD_DATA;
1687
1688 /* Must succeed because we have given up permissions if anything */
1689 bdrv_child_refresh_perms(bs, bs->file, &error_abort);
1690 } else {
1691 if (s->data_file) {
1692 error_setg(errp, "'data-file' can only be set for images with "
1693 "an external data file");
1694 ret = -EINVAL;
1695 goto fail;
1696 }
1697
1698 s->data_file = bs->file;
1699
1700 if (data_file_is_raw(bs)) {
1701 error_setg(errp, "data-file-raw requires a data file");
1702 ret = -EINVAL;
1703 goto fail;
1704 }
1705 }
1706 }
1707
1708 /* qcow2_read_extension may have set up the crypto context
1709 * if the crypt method needs a header region, some methods
1710 * don't need header extensions, so must check here
1711 */
1712 if (s->crypt_method_header && !s->crypto) {
1713 if (s->crypt_method_header == QCOW_CRYPT_AES) {
1714 unsigned int cflags = 0;
1715 if (flags & BDRV_O_NO_IO) {
1716 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
1717 }
1718 s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.",
1719 NULL, NULL, cflags, errp);
1720 if (!s->crypto) {
1721 ret = -EINVAL;
1722 goto fail;
1723 }
1724 } else {
1725 error_setg(errp, "Missing CRYPTO header for crypt method %d",
1726 s->crypt_method_header);
1727 ret = -EINVAL;
1728 goto fail;
1729 }
1730 }
1731
1732 /* read the backing file name */
1733 if (header.backing_file_offset != 0) {
1734 len = header.backing_file_size;
1735 if (len > MIN(1023, s->cluster_size - header.backing_file_offset) ||
1736 len >= sizeof(bs->backing_file)) {
1737 error_setg(errp, "Backing file name too long");
1738 ret = -EINVAL;
1739 goto fail;
1740 }
1741
1742 s->image_backing_file = g_malloc(len + 1);
1743 ret = bdrv_co_pread(bs->file, header.backing_file_offset, len,
1744 s->image_backing_file, 0);
1745 if (ret < 0) {
1746 error_setg_errno(errp, -ret, "Could not read backing file name");
1747 goto fail;
1748 }
1749 s->image_backing_file[len] = '\0';
1750
1751 /*
1752 * Update only when something has changed. This function is called by
1753 * qcow2_co_invalidate_cache(), and we do not want to reset
1754 * auto_backing_file unless necessary.
1755 */
1756 if (!g_str_equal(s->image_backing_file, bs->backing_file)) {
1757 pstrcpy(bs->backing_file, sizeof(bs->backing_file),
1758 s->image_backing_file);
1759 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file),
1760 s->image_backing_file);
1761 }
1762 }
1763
1764 /*
1765 * Internal snapshots; skip reading them in check mode, because
1766 * we do not need them then, and we do not want to abort because
1767 * of a broken table.
1768 */
1769 if (!(flags & BDRV_O_CHECK)) {
1770 s->snapshots_offset = header.snapshots_offset;
1771 s->nb_snapshots = header.nb_snapshots;
1772
1773 ret = qcow2_read_snapshots(bs, errp);
1774 if (ret < 0) {
1775 goto fail;
1776 }
1777 }
1778
1779 /* Clear unknown autoclear feature bits */
1780 update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK;
1781 update_header = update_header && bdrv_is_writable(bs);
1782 if (update_header) {
1783 s->autoclear_features &= QCOW2_AUTOCLEAR_MASK;
1784 }
1785
1786 /* == Handle persistent dirty bitmaps ==
1787 *
1788 * We want load dirty bitmaps in three cases:
1789 *
1790 * 1. Normal open of the disk in active mode, not related to invalidation
1791 * after migration.
1792 *
1793 * 2. Invalidation of the target vm after pre-copy phase of migration, if
1794 * bitmaps are _not_ migrating through migration channel, i.e.
1795 * 'dirty-bitmaps' capability is disabled.
1796 *
1797 * 3. Invalidation of source vm after failed or canceled migration.
1798 * This is a very interesting case. There are two possible types of
1799 * bitmaps:
1800 *
1801 * A. Stored on inactivation and removed. They should be loaded from the
1802 * image.
1803 *
1804 * B. Not stored: not-persistent bitmaps and bitmaps, migrated through
1805 * the migration channel (with dirty-bitmaps capability).
1806 *
1807 * On the other hand, there are two possible sub-cases:
1808 *
1809 * 3.1 disk was changed by somebody else while were inactive. In this
1810 * case all in-RAM dirty bitmaps (both persistent and not) are
1811 * definitely invalid. And we don't have any method to determine
1812 * this.
1813 *
1814 * Simple and safe thing is to just drop all the bitmaps of type B on
1815 * inactivation. But in this case we lose bitmaps in valid 4.2 case.
1816 *
1817 * On the other hand, resuming source vm, if disk was already changed
1818 * is a bad thing anyway: not only bitmaps, the whole vm state is
1819 * out of sync with disk.
1820 *
1821 * This means, that user or management tool, who for some reason
1822 * decided to resume source vm, after disk was already changed by
1823 * target vm, should at least drop all dirty bitmaps by hand.
1824 *
1825 * So, we can ignore this case for now, but TODO: "generation"
1826 * extension for qcow2, to determine, that image was changed after
1827 * last inactivation. And if it is changed, we will drop (or at least
1828 * mark as 'invalid' all the bitmaps of type B, both persistent
1829 * and not).
1830 *
1831 * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved
1832 * to disk ('dirty-bitmaps' capability disabled), or not saved
1833 * ('dirty-bitmaps' capability enabled), but we don't need to care
1834 * of: let's load bitmaps as always: stored bitmaps will be loaded,
1835 * and not stored has flag IN_USE=1 in the image and will be skipped
1836 * on loading.
1837 *
1838 * One remaining possible case when we don't want load bitmaps:
1839 *
1840 * 4. Open disk in inactive mode in target vm (bitmaps are migrating or
1841 * will be loaded on invalidation, no needs try loading them before)
1842 */
1843
1844 if (!(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) {
1845 /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */
1846 bool header_updated;
1847 if (!qcow2_load_dirty_bitmaps(bs, &header_updated, errp)) {
1848 ret = -EINVAL;
1849 goto fail;
1850 }
1851
1852 update_header = update_header && !header_updated;
1853 }
1854
1855 if (update_header) {
1856 ret = qcow2_update_header(bs);
1857 if (ret < 0) {
1858 error_setg_errno(errp, -ret, "Could not update qcow2 header");
1859 goto fail;
1860 }
1861 }
1862
1863 bs->supported_zero_flags = header.version >= 3 ?
1864 BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK : 0;
1865 bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
1866
1867 /* Repair image if dirty */
1868 if (!(flags & BDRV_O_CHECK) && bdrv_is_writable(bs) &&
1869 (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) {
1870 BdrvCheckResult result = {0};
1871
1872 ret = qcow2_co_check_locked(bs, &result,
1873 BDRV_FIX_ERRORS | BDRV_FIX_LEAKS);
1874 if (ret < 0 || result.check_errors) {
1875 if (ret >= 0) {
1876 ret = -EIO;
1877 }
1878 error_setg_errno(errp, -ret, "Could not repair dirty image");
1879 goto fail;
1880 }
1881 }
1882
1883 #ifdef DEBUG_ALLOC
1884 {
1885 BdrvCheckResult result = {0};
1886 qcow2_check_refcounts(bs, &result, 0);
1887 }
1888 #endif
1889
1890 qemu_co_queue_init(&s->thread_task_queue);
1891
1892 return ret;
1893
1894 fail:
1895 g_free(s->image_data_file);
1896 if (open_data_file && has_data_file(bs)) {
1897 bdrv_graph_co_rdunlock();
1898 bdrv_drain_all_begin();
1899 bdrv_co_unref_child(bs, s->data_file);
1900 bdrv_drain_all_end();
1901 bdrv_graph_co_rdlock();
1902 s->data_file = NULL;
1903 }
1904 g_free(s->unknown_header_fields);
1905 cleanup_unknown_header_ext(bs);
1906 qcow2_free_snapshots(bs);
1907 qcow2_refcount_close(bs);
1908 qemu_vfree(s->l1_table);
1909 /* else pre-write overlap checks in cache_destroy may crash */
1910 s->l1_table = NULL;
1911 cache_clean_timer_del(bs);
1912 if (s->l2_table_cache) {
1913 qcow2_cache_destroy(s->l2_table_cache);
1914 }
1915 if (s->refcount_block_cache) {
1916 qcow2_cache_destroy(s->refcount_block_cache);
1917 }
1918 qcrypto_block_free(s->crypto);
1919 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts);
1920 return ret;
1921 }
1922
1923 typedef struct QCow2OpenCo {
1924 BlockDriverState *bs;
1925 QDict *options;
1926 int flags;
1927 Error **errp;
1928 int ret;
1929 } QCow2OpenCo;
1930
qcow2_open_entry(void * opaque)1931 static void coroutine_fn qcow2_open_entry(void *opaque)
1932 {
1933 QCow2OpenCo *qoc = opaque;
1934 BDRVQcow2State *s = qoc->bs->opaque;
1935
1936 GRAPH_RDLOCK_GUARD();
1937
1938 qemu_co_mutex_lock(&s->lock);
1939 qoc->ret = qcow2_do_open(qoc->bs, qoc->options, qoc->flags, true,
1940 qoc->errp);
1941 qemu_co_mutex_unlock(&s->lock);
1942
1943 aio_wait_kick();
1944 }
1945
qcow2_open(BlockDriverState * bs,QDict * options,int flags,Error ** errp)1946 static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
1947 Error **errp)
1948 {
1949 BDRVQcow2State *s = bs->opaque;
1950 QCow2OpenCo qoc = {
1951 .bs = bs,
1952 .options = options,
1953 .flags = flags,
1954 .errp = errp,
1955 .ret = -EINPROGRESS
1956 };
1957 int ret;
1958
1959 ret = bdrv_open_file_child(NULL, options, "file", bs, errp);
1960 if (ret < 0) {
1961 return ret;
1962 }
1963
1964 /* Initialise locks */
1965 qemu_co_mutex_init(&s->lock);
1966
1967 assert(!qemu_in_coroutine());
1968 assert(qemu_get_current_aio_context() == qemu_get_aio_context());
1969
1970 aio_co_enter(bdrv_get_aio_context(bs),
1971 qemu_coroutine_create(qcow2_open_entry, &qoc));
1972 AIO_WAIT_WHILE_UNLOCKED(NULL, qoc.ret == -EINPROGRESS);
1973
1974 return qoc.ret;
1975 }
1976
qcow2_refresh_limits(BlockDriverState * bs,Error ** errp)1977 static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp)
1978 {
1979 BDRVQcow2State *s = bs->opaque;
1980
1981 if (s->crypto) {
1982 /* Encryption works on a sector granularity */
1983 bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto);
1984 }
1985 bs->bl.pwrite_zeroes_alignment = s->subcluster_size;
1986 bs->bl.pdiscard_alignment = s->cluster_size;
1987 }
1988
1989 static int GRAPH_UNLOCKED
qcow2_reopen_prepare(BDRVReopenState * state,BlockReopenQueue * queue,Error ** errp)1990 qcow2_reopen_prepare(BDRVReopenState *state,BlockReopenQueue *queue,
1991 Error **errp)
1992 {
1993 BDRVQcow2State *s = state->bs->opaque;
1994 Qcow2ReopenState *r;
1995 int ret;
1996
1997 GLOBAL_STATE_CODE();
1998 GRAPH_RDLOCK_GUARD_MAINLOOP();
1999
2000 r = g_new0(Qcow2ReopenState, 1);
2001 state->opaque = r;
2002
2003 ret = qcow2_update_options_prepare(state->bs, r, state->options,
2004 state->flags, errp);
2005 if (ret < 0) {
2006 goto fail;
2007 }
2008
2009 /* We need to write out any unwritten data if we reopen read-only. */
2010 if ((state->flags & BDRV_O_RDWR) == 0) {
2011 ret = qcow2_reopen_bitmaps_ro(state->bs, errp);
2012 if (ret < 0) {
2013 goto fail;
2014 }
2015
2016 ret = bdrv_flush(state->bs);
2017 if (ret < 0) {
2018 goto fail;
2019 }
2020
2021 ret = qcow2_mark_clean(state->bs);
2022 if (ret < 0) {
2023 goto fail;
2024 }
2025 }
2026
2027 /*
2028 * Without an external data file, s->data_file points to the same BdrvChild
2029 * as bs->file. It needs to be resynced after reopen because bs->file may
2030 * be changed. We can't use it in the meantime.
2031 */
2032 if (!has_data_file(state->bs)) {
2033 assert(s->data_file == state->bs->file);
2034 s->data_file = NULL;
2035 }
2036
2037 return 0;
2038
2039 fail:
2040 qcow2_update_options_abort(state->bs, r);
2041 g_free(r);
2042 return ret;
2043 }
2044
qcow2_reopen_commit(BDRVReopenState * state)2045 static void qcow2_reopen_commit(BDRVReopenState *state)
2046 {
2047 BDRVQcow2State *s = state->bs->opaque;
2048
2049 GRAPH_RDLOCK_GUARD_MAINLOOP();
2050
2051 qcow2_update_options_commit(state->bs, state->opaque);
2052 if (!s->data_file) {
2053 /*
2054 * If we don't have an external data file, s->data_file was cleared by
2055 * qcow2_reopen_prepare() and needs to be updated.
2056 */
2057 s->data_file = state->bs->file;
2058 }
2059 g_free(state->opaque);
2060 }
2061
qcow2_reopen_commit_post(BDRVReopenState * state)2062 static void qcow2_reopen_commit_post(BDRVReopenState *state)
2063 {
2064 GRAPH_RDLOCK_GUARD_MAINLOOP();
2065
2066 if (state->flags & BDRV_O_RDWR) {
2067 Error *local_err = NULL;
2068
2069 if (qcow2_reopen_bitmaps_rw(state->bs, &local_err) < 0) {
2070 /*
2071 * This is not fatal, bitmaps just left read-only, so all following
2072 * writes will fail. User can remove read-only bitmaps to unblock
2073 * writes or retry reopen.
2074 */
2075 error_reportf_err(local_err,
2076 "%s: Failed to make dirty bitmaps writable: ",
2077 bdrv_get_node_name(state->bs));
2078 }
2079 }
2080 }
2081
qcow2_reopen_abort(BDRVReopenState * state)2082 static void qcow2_reopen_abort(BDRVReopenState *state)
2083 {
2084 BDRVQcow2State *s = state->bs->opaque;
2085
2086 GRAPH_RDLOCK_GUARD_MAINLOOP();
2087
2088 if (!s->data_file) {
2089 /*
2090 * If we don't have an external data file, s->data_file was cleared by
2091 * qcow2_reopen_prepare() and needs to be restored.
2092 */
2093 s->data_file = state->bs->file;
2094 }
2095 qcow2_update_options_abort(state->bs, state->opaque);
2096 g_free(state->opaque);
2097 }
2098
qcow2_join_options(QDict * options,QDict * old_options)2099 static void qcow2_join_options(QDict *options, QDict *old_options)
2100 {
2101 bool has_new_overlap_template =
2102 qdict_haskey(options, QCOW2_OPT_OVERLAP) ||
2103 qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE);
2104 bool has_new_total_cache_size =
2105 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE);
2106 bool has_all_cache_options;
2107
2108 /* New overlap template overrides all old overlap options */
2109 if (has_new_overlap_template) {
2110 qdict_del(old_options, QCOW2_OPT_OVERLAP);
2111 qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE);
2112 qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER);
2113 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1);
2114 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2);
2115 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE);
2116 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK);
2117 qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE);
2118 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1);
2119 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2);
2120 }
2121
2122 /* New total cache size overrides all old options */
2123 if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) {
2124 qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE);
2125 qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
2126 }
2127
2128 qdict_join(options, old_options, false);
2129
2130 /*
2131 * If after merging all cache size options are set, an old total size is
2132 * overwritten. Do keep all options, however, if all three are new. The
2133 * resulting error message is what we want to happen.
2134 */
2135 has_all_cache_options =
2136 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) ||
2137 qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) ||
2138 qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
2139
2140 if (has_all_cache_options && !has_new_total_cache_size) {
2141 qdict_del(options, QCOW2_OPT_CACHE_SIZE);
2142 }
2143 }
2144
2145 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_block_status(BlockDriverState * bs,unsigned int mode,int64_t offset,int64_t count,int64_t * pnum,int64_t * map,BlockDriverState ** file)2146 qcow2_co_block_status(BlockDriverState *bs, unsigned int mode,
2147 int64_t offset, int64_t count, int64_t *pnum,
2148 int64_t *map, BlockDriverState **file)
2149 {
2150 BDRVQcow2State *s = bs->opaque;
2151 uint64_t host_offset;
2152 unsigned int bytes;
2153 QCow2SubclusterType type;
2154 int ret, status = 0;
2155
2156 qemu_co_mutex_lock(&s->lock);
2157
2158 if (!s->metadata_preallocation_checked) {
2159 ret = qcow2_detect_metadata_preallocation(bs);
2160 s->metadata_preallocation = (ret == 1);
2161 s->metadata_preallocation_checked = true;
2162 }
2163
2164 bytes = MIN(INT_MAX, count);
2165 ret = qcow2_get_host_offset(bs, offset, &bytes, &host_offset, &type);
2166 qemu_co_mutex_unlock(&s->lock);
2167 if (ret < 0) {
2168 return ret;
2169 }
2170
2171 *pnum = bytes;
2172
2173 if ((type == QCOW2_SUBCLUSTER_NORMAL ||
2174 type == QCOW2_SUBCLUSTER_ZERO_ALLOC ||
2175 type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) && !s->crypto) {
2176 *map = host_offset;
2177 *file = s->data_file->bs;
2178 status |= BDRV_BLOCK_OFFSET_VALID;
2179 }
2180 if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN ||
2181 type == QCOW2_SUBCLUSTER_ZERO_ALLOC) {
2182 status |= BDRV_BLOCK_ZERO;
2183 } else if (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN &&
2184 type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) {
2185 status |= BDRV_BLOCK_DATA;
2186 }
2187 if (s->metadata_preallocation && (status & BDRV_BLOCK_DATA) &&
2188 (status & BDRV_BLOCK_OFFSET_VALID))
2189 {
2190 status |= BDRV_BLOCK_RECURSE;
2191 }
2192 if (type == QCOW2_SUBCLUSTER_COMPRESSED) {
2193 status |= BDRV_BLOCK_COMPRESSED;
2194 }
2195 return status;
2196 }
2197
2198 static int coroutine_fn GRAPH_RDLOCK
qcow2_handle_l2meta(BlockDriverState * bs,QCowL2Meta ** pl2meta,bool link_l2)2199 qcow2_handle_l2meta(BlockDriverState *bs, QCowL2Meta **pl2meta, bool link_l2)
2200 {
2201 int ret = 0;
2202 QCowL2Meta *l2meta = *pl2meta;
2203
2204 while (l2meta != NULL) {
2205 QCowL2Meta *next;
2206
2207 if (link_l2) {
2208 ret = qcow2_alloc_cluster_link_l2(bs, l2meta);
2209 if (ret) {
2210 goto out;
2211 }
2212 } else {
2213 qcow2_alloc_cluster_abort(bs, l2meta);
2214 }
2215
2216 /* Take the request off the list of running requests */
2217 QLIST_REMOVE(l2meta, next_in_flight);
2218
2219 qemu_co_queue_restart_all(&l2meta->dependent_requests);
2220
2221 next = l2meta->next;
2222 g_free(l2meta);
2223 l2meta = next;
2224 }
2225 out:
2226 *pl2meta = l2meta;
2227 return ret;
2228 }
2229
2230 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_preadv_encrypted(BlockDriverState * bs,uint64_t host_offset,uint64_t offset,uint64_t bytes,QEMUIOVector * qiov,uint64_t qiov_offset)2231 qcow2_co_preadv_encrypted(BlockDriverState *bs,
2232 uint64_t host_offset,
2233 uint64_t offset,
2234 uint64_t bytes,
2235 QEMUIOVector *qiov,
2236 uint64_t qiov_offset)
2237 {
2238 int ret;
2239 BDRVQcow2State *s = bs->opaque;
2240 uint8_t *buf;
2241
2242 assert(bs->encrypted && s->crypto);
2243 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
2244
2245 /*
2246 * For encrypted images, read everything into a temporary
2247 * contiguous buffer on which the AES functions can work.
2248 * Also, decryption in a separate buffer is better as it
2249 * prevents the guest from learning information about the
2250 * encrypted nature of the virtual disk.
2251 */
2252
2253 buf = qemu_try_blockalign(s->data_file->bs, bytes);
2254 if (buf == NULL) {
2255 return -ENOMEM;
2256 }
2257
2258 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO);
2259 ret = bdrv_co_pread(s->data_file, host_offset, bytes, buf, 0);
2260 if (ret < 0) {
2261 goto fail;
2262 }
2263
2264 if (qcow2_co_decrypt(bs, host_offset, offset, buf, bytes) < 0)
2265 {
2266 ret = -EIO;
2267 goto fail;
2268 }
2269 qemu_iovec_from_buf(qiov, qiov_offset, buf, bytes);
2270
2271 fail:
2272 qemu_vfree(buf);
2273
2274 return ret;
2275 }
2276
2277 typedef struct Qcow2AioTask {
2278 AioTask task;
2279
2280 BlockDriverState *bs;
2281 QCow2SubclusterType subcluster_type; /* only for read */
2282 uint64_t host_offset; /* or l2_entry for compressed read */
2283 uint64_t offset;
2284 uint64_t bytes;
2285 QEMUIOVector *qiov;
2286 uint64_t qiov_offset;
2287 QCowL2Meta *l2meta; /* only for write */
2288 } Qcow2AioTask;
2289
2290 static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task);
qcow2_add_task(BlockDriverState * bs,AioTaskPool * pool,AioTaskFunc func,QCow2SubclusterType subcluster_type,uint64_t host_offset,uint64_t offset,uint64_t bytes,QEMUIOVector * qiov,size_t qiov_offset,QCowL2Meta * l2meta)2291 static coroutine_fn int qcow2_add_task(BlockDriverState *bs,
2292 AioTaskPool *pool,
2293 AioTaskFunc func,
2294 QCow2SubclusterType subcluster_type,
2295 uint64_t host_offset,
2296 uint64_t offset,
2297 uint64_t bytes,
2298 QEMUIOVector *qiov,
2299 size_t qiov_offset,
2300 QCowL2Meta *l2meta)
2301 {
2302 Qcow2AioTask local_task;
2303 Qcow2AioTask *task = pool ? g_new(Qcow2AioTask, 1) : &local_task;
2304
2305 *task = (Qcow2AioTask) {
2306 .task.func = func,
2307 .bs = bs,
2308 .subcluster_type = subcluster_type,
2309 .qiov = qiov,
2310 .host_offset = host_offset,
2311 .offset = offset,
2312 .bytes = bytes,
2313 .qiov_offset = qiov_offset,
2314 .l2meta = l2meta,
2315 };
2316
2317 trace_qcow2_add_task(qemu_coroutine_self(), bs, pool,
2318 func == qcow2_co_preadv_task_entry ? "read" : "write",
2319 subcluster_type, host_offset, offset, bytes,
2320 qiov, qiov_offset);
2321
2322 if (!pool) {
2323 return func(&task->task);
2324 }
2325
2326 aio_task_pool_start_task(pool, &task->task);
2327
2328 return 0;
2329 }
2330
2331 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_preadv_task(BlockDriverState * bs,QCow2SubclusterType subc_type,uint64_t host_offset,uint64_t offset,uint64_t bytes,QEMUIOVector * qiov,size_t qiov_offset)2332 qcow2_co_preadv_task(BlockDriverState *bs, QCow2SubclusterType subc_type,
2333 uint64_t host_offset, uint64_t offset, uint64_t bytes,
2334 QEMUIOVector *qiov, size_t qiov_offset)
2335 {
2336 BDRVQcow2State *s = bs->opaque;
2337
2338 switch (subc_type) {
2339 case QCOW2_SUBCLUSTER_ZERO_PLAIN:
2340 case QCOW2_SUBCLUSTER_ZERO_ALLOC:
2341 /* Both zero types are handled in qcow2_co_preadv_part */
2342 g_assert_not_reached();
2343
2344 case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN:
2345 case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC:
2346 assert(bs->backing); /* otherwise handled in qcow2_co_preadv_part */
2347
2348 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
2349 return bdrv_co_preadv_part(bs->backing, offset, bytes,
2350 qiov, qiov_offset, 0);
2351
2352 case QCOW2_SUBCLUSTER_COMPRESSED:
2353 return qcow2_co_preadv_compressed(bs, host_offset,
2354 offset, bytes, qiov, qiov_offset);
2355
2356 case QCOW2_SUBCLUSTER_NORMAL:
2357 if (bs->encrypted) {
2358 return qcow2_co_preadv_encrypted(bs, host_offset,
2359 offset, bytes, qiov, qiov_offset);
2360 }
2361
2362 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO);
2363 return bdrv_co_preadv_part(s->data_file, host_offset,
2364 bytes, qiov, qiov_offset, 0);
2365
2366 default:
2367 g_assert_not_reached();
2368 }
2369
2370 g_assert_not_reached();
2371 }
2372
2373 /*
2374 * This function can count as GRAPH_RDLOCK because qcow2_co_preadv_part() holds
2375 * the graph lock and keeps it until this coroutine has terminated.
2376 */
qcow2_co_preadv_task_entry(AioTask * task)2377 static int coroutine_fn GRAPH_RDLOCK qcow2_co_preadv_task_entry(AioTask *task)
2378 {
2379 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task);
2380
2381 assert(!t->l2meta);
2382
2383 return qcow2_co_preadv_task(t->bs, t->subcluster_type,
2384 t->host_offset, t->offset, t->bytes,
2385 t->qiov, t->qiov_offset);
2386 }
2387
2388 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_preadv_part(BlockDriverState * bs,int64_t offset,int64_t bytes,QEMUIOVector * qiov,size_t qiov_offset,BdrvRequestFlags flags)2389 qcow2_co_preadv_part(BlockDriverState *bs, int64_t offset, int64_t bytes,
2390 QEMUIOVector *qiov, size_t qiov_offset,
2391 BdrvRequestFlags flags)
2392 {
2393 BDRVQcow2State *s = bs->opaque;
2394 int ret = 0;
2395 unsigned int cur_bytes; /* number of bytes in current iteration */
2396 uint64_t host_offset = 0;
2397 QCow2SubclusterType type;
2398 AioTaskPool *aio = NULL;
2399
2400 while (bytes != 0 && aio_task_pool_status(aio) == 0) {
2401 /* prepare next request */
2402 cur_bytes = MIN(bytes, INT_MAX);
2403 if (s->crypto) {
2404 cur_bytes = MIN(cur_bytes,
2405 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
2406 }
2407
2408 qemu_co_mutex_lock(&s->lock);
2409 ret = qcow2_get_host_offset(bs, offset, &cur_bytes,
2410 &host_offset, &type);
2411 qemu_co_mutex_unlock(&s->lock);
2412 if (ret < 0) {
2413 goto out;
2414 }
2415
2416 if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN ||
2417 type == QCOW2_SUBCLUSTER_ZERO_ALLOC ||
2418 (type == QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && !bs->backing) ||
2419 (type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC && !bs->backing))
2420 {
2421 qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes);
2422 } else {
2423 if (!aio && cur_bytes != bytes) {
2424 aio = aio_task_pool_new(QCOW2_MAX_WORKERS);
2425 }
2426 ret = qcow2_add_task(bs, aio, qcow2_co_preadv_task_entry, type,
2427 host_offset, offset, cur_bytes,
2428 qiov, qiov_offset, NULL);
2429 if (ret < 0) {
2430 goto out;
2431 }
2432 }
2433
2434 bytes -= cur_bytes;
2435 offset += cur_bytes;
2436 qiov_offset += cur_bytes;
2437 }
2438
2439 out:
2440 if (aio) {
2441 aio_task_pool_wait_all(aio);
2442 if (ret == 0) {
2443 ret = aio_task_pool_status(aio);
2444 }
2445 g_free(aio);
2446 }
2447
2448 return ret;
2449 }
2450
2451 /* Check if it's possible to merge a write request with the writing of
2452 * the data from the COW regions */
merge_cow(uint64_t offset,unsigned bytes,QEMUIOVector * qiov,size_t qiov_offset,QCowL2Meta * l2meta)2453 static bool merge_cow(uint64_t offset, unsigned bytes,
2454 QEMUIOVector *qiov, size_t qiov_offset,
2455 QCowL2Meta *l2meta)
2456 {
2457 QCowL2Meta *m;
2458
2459 for (m = l2meta; m != NULL; m = m->next) {
2460 /* If both COW regions are empty then there's nothing to merge */
2461 if (m->cow_start.nb_bytes == 0 && m->cow_end.nb_bytes == 0) {
2462 continue;
2463 }
2464
2465 /* If COW regions are handled already, skip this too */
2466 if (m->skip_cow) {
2467 continue;
2468 }
2469
2470 /*
2471 * The write request should start immediately after the first
2472 * COW region. This does not always happen because the area
2473 * touched by the request can be larger than the one defined
2474 * by @m (a single request can span an area consisting of a
2475 * mix of previously unallocated and allocated clusters, that
2476 * is why @l2meta is a list).
2477 */
2478 if (l2meta_cow_start(m) + m->cow_start.nb_bytes != offset) {
2479 /* In this case the request starts before this region */
2480 assert(offset < l2meta_cow_start(m));
2481 assert(m->cow_start.nb_bytes == 0);
2482 continue;
2483 }
2484
2485 /* The write request should end immediately before the second
2486 * COW region (see above for why it does not always happen) */
2487 if (m->offset + m->cow_end.offset != offset + bytes) {
2488 assert(offset + bytes > m->offset + m->cow_end.offset);
2489 assert(m->cow_end.nb_bytes == 0);
2490 continue;
2491 }
2492
2493 /* Make sure that adding both COW regions to the QEMUIOVector
2494 * does not exceed IOV_MAX */
2495 if (qemu_iovec_subvec_niov(qiov, qiov_offset, bytes) > IOV_MAX - 2) {
2496 continue;
2497 }
2498
2499 m->data_qiov = qiov;
2500 m->data_qiov_offset = qiov_offset;
2501 return true;
2502 }
2503
2504 return false;
2505 }
2506
2507 /*
2508 * Return 1 if the COW regions read as zeroes, 0 if not, < 0 on error.
2509 * Note that returning 0 does not guarantee non-zero data.
2510 */
2511 static int coroutine_fn GRAPH_RDLOCK
is_zero_cow(BlockDriverState * bs,QCowL2Meta * m)2512 is_zero_cow(BlockDriverState *bs, QCowL2Meta *m)
2513 {
2514 /*
2515 * This check is designed for optimization shortcut so it must be
2516 * efficient.
2517 * Instead of is_zero(), use bdrv_co_is_zero_fast() as it is
2518 * faster (but not as accurate and can result in false negatives).
2519 */
2520 int ret = bdrv_co_is_zero_fast(bs, m->offset + m->cow_start.offset,
2521 m->cow_start.nb_bytes);
2522 if (ret <= 0) {
2523 return ret;
2524 }
2525
2526 return bdrv_co_is_zero_fast(bs, m->offset + m->cow_end.offset,
2527 m->cow_end.nb_bytes);
2528 }
2529
2530 static int coroutine_fn GRAPH_RDLOCK
handle_alloc_space(BlockDriverState * bs,QCowL2Meta * l2meta)2531 handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta)
2532 {
2533 BDRVQcow2State *s = bs->opaque;
2534 QCowL2Meta *m;
2535
2536 if (!(s->data_file->bs->supported_zero_flags & BDRV_REQ_NO_FALLBACK)) {
2537 return 0;
2538 }
2539
2540 if (bs->encrypted) {
2541 return 0;
2542 }
2543
2544 for (m = l2meta; m != NULL; m = m->next) {
2545 int ret;
2546 uint64_t start_offset = m->alloc_offset + m->cow_start.offset;
2547 unsigned nb_bytes = m->cow_end.offset + m->cow_end.nb_bytes -
2548 m->cow_start.offset;
2549
2550 if (!m->cow_start.nb_bytes && !m->cow_end.nb_bytes) {
2551 continue;
2552 }
2553
2554 ret = is_zero_cow(bs, m);
2555 if (ret < 0) {
2556 return ret;
2557 } else if (ret == 0) {
2558 continue;
2559 }
2560
2561 /*
2562 * instead of writing zero COW buffers,
2563 * efficiently zero out the whole clusters
2564 */
2565
2566 ret = qcow2_pre_write_overlap_check(bs, 0, start_offset, nb_bytes,
2567 true);
2568 if (ret < 0) {
2569 return ret;
2570 }
2571
2572 BLKDBG_CO_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_SPACE);
2573 ret = bdrv_co_pwrite_zeroes(s->data_file, start_offset, nb_bytes,
2574 BDRV_REQ_NO_FALLBACK);
2575 if (ret < 0) {
2576 if (ret != -ENOTSUP && ret != -EAGAIN) {
2577 return ret;
2578 }
2579 continue;
2580 }
2581
2582 trace_qcow2_skip_cow(qemu_coroutine_self(), m->offset, m->nb_clusters);
2583 m->skip_cow = true;
2584 }
2585 return 0;
2586 }
2587
2588 /*
2589 * qcow2_co_pwritev_task
2590 * Called with s->lock unlocked
2591 * l2meta - if not NULL, qcow2_co_pwritev_task() will consume it. Caller must
2592 * not use it somehow after qcow2_co_pwritev_task() call
2593 */
2594 static coroutine_fn GRAPH_RDLOCK
qcow2_co_pwritev_task(BlockDriverState * bs,uint64_t host_offset,uint64_t offset,uint64_t bytes,QEMUIOVector * qiov,uint64_t qiov_offset,QCowL2Meta * l2meta)2595 int qcow2_co_pwritev_task(BlockDriverState *bs, uint64_t host_offset,
2596 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov,
2597 uint64_t qiov_offset, QCowL2Meta *l2meta)
2598 {
2599 int ret;
2600 BDRVQcow2State *s = bs->opaque;
2601 void *crypt_buf = NULL;
2602 QEMUIOVector encrypted_qiov;
2603
2604 if (bs->encrypted) {
2605 assert(s->crypto);
2606 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
2607 crypt_buf = qemu_try_blockalign(bs->file->bs, bytes);
2608 if (crypt_buf == NULL) {
2609 ret = -ENOMEM;
2610 goto out_unlocked;
2611 }
2612 qemu_iovec_to_buf(qiov, qiov_offset, crypt_buf, bytes);
2613
2614 if (qcow2_co_encrypt(bs, host_offset, offset, crypt_buf, bytes) < 0) {
2615 ret = -EIO;
2616 goto out_unlocked;
2617 }
2618
2619 qemu_iovec_init_buf(&encrypted_qiov, crypt_buf, bytes);
2620 qiov = &encrypted_qiov;
2621 qiov_offset = 0;
2622 }
2623
2624 /* Try to efficiently initialize the physical space with zeroes */
2625 ret = handle_alloc_space(bs, l2meta);
2626 if (ret < 0) {
2627 goto out_unlocked;
2628 }
2629
2630 /*
2631 * If we need to do COW, check if it's possible to merge the
2632 * writing of the guest data together with that of the COW regions.
2633 * If it's not possible (or not necessary) then write the
2634 * guest data now.
2635 */
2636 if (!merge_cow(offset, bytes, qiov, qiov_offset, l2meta)) {
2637 BLKDBG_CO_EVENT(bs->file, BLKDBG_WRITE_AIO);
2638 trace_qcow2_writev_data(qemu_coroutine_self(), host_offset);
2639 ret = bdrv_co_pwritev_part(s->data_file, host_offset,
2640 bytes, qiov, qiov_offset, 0);
2641 if (ret < 0) {
2642 goto out_unlocked;
2643 }
2644 }
2645
2646 qemu_co_mutex_lock(&s->lock);
2647
2648 ret = qcow2_handle_l2meta(bs, &l2meta, true);
2649 goto out_locked;
2650
2651 out_unlocked:
2652 qemu_co_mutex_lock(&s->lock);
2653
2654 out_locked:
2655 qcow2_handle_l2meta(bs, &l2meta, false);
2656 qemu_co_mutex_unlock(&s->lock);
2657
2658 qemu_vfree(crypt_buf);
2659
2660 return ret;
2661 }
2662
2663 /*
2664 * This function can count as GRAPH_RDLOCK because qcow2_co_pwritev_part() holds
2665 * the graph lock and keeps it until this coroutine has terminated.
2666 */
qcow2_co_pwritev_task_entry(AioTask * task)2667 static coroutine_fn GRAPH_RDLOCK int qcow2_co_pwritev_task_entry(AioTask *task)
2668 {
2669 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task);
2670
2671 assert(!t->subcluster_type);
2672
2673 return qcow2_co_pwritev_task(t->bs, t->host_offset,
2674 t->offset, t->bytes, t->qiov, t->qiov_offset,
2675 t->l2meta);
2676 }
2677
2678 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_pwritev_part(BlockDriverState * bs,int64_t offset,int64_t bytes,QEMUIOVector * qiov,size_t qiov_offset,BdrvRequestFlags flags)2679 qcow2_co_pwritev_part(BlockDriverState *bs, int64_t offset, int64_t bytes,
2680 QEMUIOVector *qiov, size_t qiov_offset,
2681 BdrvRequestFlags flags)
2682 {
2683 BDRVQcow2State *s = bs->opaque;
2684 int offset_in_cluster;
2685 int ret;
2686 unsigned int cur_bytes; /* number of sectors in current iteration */
2687 uint64_t host_offset;
2688 QCowL2Meta *l2meta = NULL;
2689 AioTaskPool *aio = NULL;
2690
2691 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes);
2692
2693 while (bytes != 0 && aio_task_pool_status(aio) == 0) {
2694
2695 l2meta = NULL;
2696
2697 trace_qcow2_writev_start_part(qemu_coroutine_self());
2698 offset_in_cluster = offset_into_cluster(s, offset);
2699 cur_bytes = MIN(bytes, INT_MAX);
2700 if (bs->encrypted) {
2701 cur_bytes = MIN(cur_bytes,
2702 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size
2703 - offset_in_cluster);
2704 }
2705
2706 qemu_co_mutex_lock(&s->lock);
2707
2708 ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes,
2709 &host_offset, &l2meta);
2710 if (ret < 0) {
2711 goto out_locked;
2712 }
2713
2714 ret = qcow2_pre_write_overlap_check(bs, 0, host_offset,
2715 cur_bytes, true);
2716 if (ret < 0) {
2717 goto out_locked;
2718 }
2719
2720 qemu_co_mutex_unlock(&s->lock);
2721
2722 if (!aio && cur_bytes != bytes) {
2723 aio = aio_task_pool_new(QCOW2_MAX_WORKERS);
2724 }
2725 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_task_entry, 0,
2726 host_offset, offset,
2727 cur_bytes, qiov, qiov_offset, l2meta);
2728 l2meta = NULL; /* l2meta is consumed by qcow2_co_pwritev_task() */
2729 if (ret < 0) {
2730 goto fail_nometa;
2731 }
2732
2733 bytes -= cur_bytes;
2734 offset += cur_bytes;
2735 qiov_offset += cur_bytes;
2736 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes);
2737 }
2738 ret = 0;
2739
2740 qemu_co_mutex_lock(&s->lock);
2741
2742 out_locked:
2743 qcow2_handle_l2meta(bs, &l2meta, false);
2744
2745 qemu_co_mutex_unlock(&s->lock);
2746
2747 fail_nometa:
2748 if (aio) {
2749 aio_task_pool_wait_all(aio);
2750 if (ret == 0) {
2751 ret = aio_task_pool_status(aio);
2752 }
2753 g_free(aio);
2754 }
2755
2756 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
2757
2758 return ret;
2759 }
2760
qcow2_inactivate(BlockDriverState * bs)2761 static int GRAPH_RDLOCK qcow2_inactivate(BlockDriverState *bs)
2762 {
2763 BDRVQcow2State *s = bs->opaque;
2764 int ret, result = 0;
2765 Error *local_err = NULL;
2766
2767 qcow2_store_persistent_dirty_bitmaps(bs, true, &local_err);
2768 if (local_err != NULL) {
2769 result = -EINVAL;
2770 error_reportf_err(local_err, "Lost persistent bitmaps during "
2771 "inactivation of node '%s': ",
2772 bdrv_get_device_or_node_name(bs));
2773 }
2774
2775 ret = qcow2_cache_flush(bs, s->l2_table_cache);
2776 if (ret) {
2777 result = ret;
2778 error_report("Failed to flush the L2 table cache: %s",
2779 strerror(-ret));
2780 }
2781
2782 ret = qcow2_cache_flush(bs, s->refcount_block_cache);
2783 if (ret) {
2784 result = ret;
2785 error_report("Failed to flush the refcount block cache: %s",
2786 strerror(-ret));
2787 }
2788
2789 if (result == 0) {
2790 qcow2_mark_clean(bs);
2791 }
2792
2793 return result;
2794 }
2795
2796 static void coroutine_mixed_fn GRAPH_RDLOCK
qcow2_do_close(BlockDriverState * bs,bool close_data_file)2797 qcow2_do_close(BlockDriverState *bs, bool close_data_file)
2798 {
2799 BDRVQcow2State *s = bs->opaque;
2800 qemu_vfree(s->l1_table);
2801 /* else pre-write overlap checks in cache_destroy may crash */
2802 s->l1_table = NULL;
2803
2804 if (!(s->flags & BDRV_O_INACTIVE)) {
2805 qcow2_inactivate(bs);
2806 }
2807
2808 cache_clean_timer_del(bs);
2809 qcow2_cache_destroy(s->l2_table_cache);
2810 qcow2_cache_destroy(s->refcount_block_cache);
2811
2812 qcrypto_block_free(s->crypto);
2813 s->crypto = NULL;
2814 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts);
2815
2816 g_free(s->unknown_header_fields);
2817 cleanup_unknown_header_ext(bs);
2818
2819 g_free(s->image_data_file);
2820 g_free(s->image_backing_file);
2821 g_free(s->image_backing_format);
2822
2823 if (close_data_file && has_data_file(bs)) {
2824 GLOBAL_STATE_CODE();
2825 bdrv_graph_rdunlock_main_loop();
2826 bdrv_drain_all_begin();
2827 bdrv_graph_wrlock();
2828 bdrv_unref_child(bs, s->data_file);
2829 bdrv_graph_wrunlock();
2830 bdrv_drain_all_end();
2831 s->data_file = NULL;
2832 bdrv_graph_rdlock_main_loop();
2833 }
2834
2835 qcow2_refcount_close(bs);
2836 qcow2_free_snapshots(bs);
2837 }
2838
qcow2_close(BlockDriverState * bs)2839 static void GRAPH_UNLOCKED qcow2_close(BlockDriverState *bs)
2840 {
2841 GLOBAL_STATE_CODE();
2842 GRAPH_RDLOCK_GUARD_MAINLOOP();
2843
2844 qcow2_do_close(bs, true);
2845 }
2846
2847 static void coroutine_fn GRAPH_RDLOCK
qcow2_co_invalidate_cache(BlockDriverState * bs,Error ** errp)2848 qcow2_co_invalidate_cache(BlockDriverState *bs, Error **errp)
2849 {
2850 ERRP_GUARD();
2851 BDRVQcow2State *s = bs->opaque;
2852 BdrvChild *data_file;
2853 int flags = s->flags;
2854 QCryptoBlock *crypto = NULL;
2855 QDict *options;
2856 int ret;
2857
2858 /*
2859 * Backing files are read-only which makes all of their metadata immutable,
2860 * that means we don't have to worry about reopening them here.
2861 */
2862
2863 crypto = s->crypto;
2864 s->crypto = NULL;
2865
2866 /*
2867 * Do not reopen s->data_file (i.e., have qcow2_do_close() not close it,
2868 * and then prevent qcow2_do_open() from opening it), because this function
2869 * runs in the I/O path and as such we must not invoke global-state
2870 * functions like bdrv_unref_child() and bdrv_open_child().
2871 */
2872
2873 qcow2_do_close(bs, false);
2874
2875 data_file = s->data_file;
2876 memset(s, 0, sizeof(BDRVQcow2State));
2877 s->data_file = data_file;
2878
2879 options = qdict_clone_shallow(bs->options);
2880
2881 flags &= ~BDRV_O_INACTIVE;
2882 qemu_co_mutex_lock(&s->lock);
2883 ret = qcow2_do_open(bs, options, flags, false, errp);
2884 qemu_co_mutex_unlock(&s->lock);
2885 qobject_unref(options);
2886 if (ret < 0) {
2887 error_prepend(errp, "Could not reopen qcow2 layer: ");
2888 bs->drv = NULL;
2889 return;
2890 }
2891
2892 s->crypto = crypto;
2893 }
2894
header_ext_add(char * buf,uint32_t magic,const void * s,size_t len,size_t buflen)2895 static size_t header_ext_add(char *buf, uint32_t magic, const void *s,
2896 size_t len, size_t buflen)
2897 {
2898 QCowExtension *ext_backing_fmt = (QCowExtension*) buf;
2899 size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7);
2900
2901 if (buflen < ext_len) {
2902 return -ENOSPC;
2903 }
2904
2905 *ext_backing_fmt = (QCowExtension) {
2906 .magic = cpu_to_be32(magic),
2907 .len = cpu_to_be32(len),
2908 };
2909
2910 if (len) {
2911 memcpy(buf + sizeof(QCowExtension), s, len);
2912 }
2913
2914 return ext_len;
2915 }
2916
2917 /*
2918 * Updates the qcow2 header, including the variable length parts of it, i.e.
2919 * the backing file name and all extensions. qcow2 was not designed to allow
2920 * such changes, so if we run out of space (we can only use the first cluster)
2921 * this function may fail.
2922 *
2923 * Returns 0 on success, -errno in error cases.
2924 */
qcow2_update_header(BlockDriverState * bs)2925 int qcow2_update_header(BlockDriverState *bs)
2926 {
2927 BDRVQcow2State *s = bs->opaque;
2928 QCowHeader *header;
2929 char *buf;
2930 size_t buflen = s->cluster_size;
2931 int ret;
2932 uint64_t total_size;
2933 uint32_t refcount_table_clusters;
2934 size_t header_length;
2935 Qcow2UnknownHeaderExtension *uext;
2936
2937 buf = qemu_blockalign(bs, buflen);
2938
2939 /* Header structure */
2940 header = (QCowHeader*) buf;
2941
2942 if (buflen < sizeof(*header)) {
2943 ret = -ENOSPC;
2944 goto fail;
2945 }
2946
2947 header_length = sizeof(*header) + s->unknown_header_fields_size;
2948 total_size = bs->total_sectors * BDRV_SECTOR_SIZE;
2949 refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
2950
2951 ret = validate_compression_type(s, NULL);
2952 if (ret) {
2953 goto fail;
2954 }
2955
2956 *header = (QCowHeader) {
2957 /* Version 2 fields */
2958 .magic = cpu_to_be32(QCOW_MAGIC),
2959 .version = cpu_to_be32(s->qcow_version),
2960 .backing_file_offset = 0,
2961 .backing_file_size = 0,
2962 .cluster_bits = cpu_to_be32(s->cluster_bits),
2963 .size = cpu_to_be64(total_size),
2964 .crypt_method = cpu_to_be32(s->crypt_method_header),
2965 .l1_size = cpu_to_be32(s->l1_size),
2966 .l1_table_offset = cpu_to_be64(s->l1_table_offset),
2967 .refcount_table_offset = cpu_to_be64(s->refcount_table_offset),
2968 .refcount_table_clusters = cpu_to_be32(refcount_table_clusters),
2969 .nb_snapshots = cpu_to_be32(s->nb_snapshots),
2970 .snapshots_offset = cpu_to_be64(s->snapshots_offset),
2971
2972 /* Version 3 fields */
2973 .incompatible_features = cpu_to_be64(s->incompatible_features),
2974 .compatible_features = cpu_to_be64(s->compatible_features),
2975 .autoclear_features = cpu_to_be64(s->autoclear_features),
2976 .refcount_order = cpu_to_be32(s->refcount_order),
2977 .header_length = cpu_to_be32(header_length),
2978 .compression_type = s->compression_type,
2979 };
2980
2981 /* For older versions, write a shorter header */
2982 switch (s->qcow_version) {
2983 case 2:
2984 ret = offsetof(QCowHeader, incompatible_features);
2985 break;
2986 case 3:
2987 ret = sizeof(*header);
2988 break;
2989 default:
2990 ret = -EINVAL;
2991 goto fail;
2992 }
2993
2994 buf += ret;
2995 buflen -= ret;
2996 memset(buf, 0, buflen);
2997
2998 /* Preserve any unknown field in the header */
2999 if (s->unknown_header_fields_size) {
3000 if (buflen < s->unknown_header_fields_size) {
3001 ret = -ENOSPC;
3002 goto fail;
3003 }
3004
3005 memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size);
3006 buf += s->unknown_header_fields_size;
3007 buflen -= s->unknown_header_fields_size;
3008 }
3009
3010 /* Backing file format header extension */
3011 if (s->image_backing_format) {
3012 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT,
3013 s->image_backing_format,
3014 strlen(s->image_backing_format),
3015 buflen);
3016 if (ret < 0) {
3017 goto fail;
3018 }
3019
3020 buf += ret;
3021 buflen -= ret;
3022 }
3023
3024 /* External data file header extension */
3025 if (has_data_file(bs) && s->image_data_file) {
3026 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE,
3027 s->image_data_file, strlen(s->image_data_file),
3028 buflen);
3029 if (ret < 0) {
3030 goto fail;
3031 }
3032
3033 buf += ret;
3034 buflen -= ret;
3035 }
3036
3037 /* Full disk encryption header pointer extension */
3038 if (s->crypto_header.offset != 0) {
3039 s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset);
3040 s->crypto_header.length = cpu_to_be64(s->crypto_header.length);
3041 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER,
3042 &s->crypto_header, sizeof(s->crypto_header),
3043 buflen);
3044 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset);
3045 s->crypto_header.length = be64_to_cpu(s->crypto_header.length);
3046 if (ret < 0) {
3047 goto fail;
3048 }
3049 buf += ret;
3050 buflen -= ret;
3051 }
3052
3053 /*
3054 * Feature table. A mere 8 feature names occupies 392 bytes, and
3055 * when coupled with the v3 minimum header of 104 bytes plus the
3056 * 8-byte end-of-extension marker, that would leave only 8 bytes
3057 * for a backing file name in an image with 512-byte clusters.
3058 * Thus, we choose to omit this header for cluster sizes 4k and
3059 * smaller.
3060 */
3061 if (s->qcow_version >= 3 && s->cluster_size > 4096) {
3062 static const Qcow2Feature features[] = {
3063 {
3064 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
3065 .bit = QCOW2_INCOMPAT_DIRTY_BITNR,
3066 .name = "dirty bit",
3067 },
3068 {
3069 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
3070 .bit = QCOW2_INCOMPAT_CORRUPT_BITNR,
3071 .name = "corrupt bit",
3072 },
3073 {
3074 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
3075 .bit = QCOW2_INCOMPAT_DATA_FILE_BITNR,
3076 .name = "external data file",
3077 },
3078 {
3079 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
3080 .bit = QCOW2_INCOMPAT_COMPRESSION_BITNR,
3081 .name = "compression type",
3082 },
3083 {
3084 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
3085 .bit = QCOW2_INCOMPAT_EXTL2_BITNR,
3086 .name = "extended L2 entries",
3087 },
3088 {
3089 .type = QCOW2_FEAT_TYPE_COMPATIBLE,
3090 .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
3091 .name = "lazy refcounts",
3092 },
3093 {
3094 .type = QCOW2_FEAT_TYPE_AUTOCLEAR,
3095 .bit = QCOW2_AUTOCLEAR_BITMAPS_BITNR,
3096 .name = "bitmaps",
3097 },
3098 {
3099 .type = QCOW2_FEAT_TYPE_AUTOCLEAR,
3100 .bit = QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
3101 .name = "raw external data",
3102 },
3103 };
3104
3105 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE,
3106 features, sizeof(features), buflen);
3107 if (ret < 0) {
3108 goto fail;
3109 }
3110 buf += ret;
3111 buflen -= ret;
3112 }
3113
3114 /* Bitmap extension */
3115 if (s->nb_bitmaps > 0) {
3116 Qcow2BitmapHeaderExt bitmaps_header = {
3117 .nb_bitmaps = cpu_to_be32(s->nb_bitmaps),
3118 .bitmap_directory_size =
3119 cpu_to_be64(s->bitmap_directory_size),
3120 .bitmap_directory_offset =
3121 cpu_to_be64(s->bitmap_directory_offset)
3122 };
3123 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS,
3124 &bitmaps_header, sizeof(bitmaps_header),
3125 buflen);
3126 if (ret < 0) {
3127 goto fail;
3128 }
3129 buf += ret;
3130 buflen -= ret;
3131 }
3132
3133 /* Keep unknown header extensions */
3134 QLIST_FOREACH(uext, &s->unknown_header_ext, next) {
3135 ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen);
3136 if (ret < 0) {
3137 goto fail;
3138 }
3139
3140 buf += ret;
3141 buflen -= ret;
3142 }
3143
3144 /* End of header extensions */
3145 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen);
3146 if (ret < 0) {
3147 goto fail;
3148 }
3149
3150 buf += ret;
3151 buflen -= ret;
3152
3153 /* Backing file name */
3154 if (s->image_backing_file) {
3155 size_t backing_file_len = strlen(s->image_backing_file);
3156
3157 if (buflen < backing_file_len) {
3158 ret = -ENOSPC;
3159 goto fail;
3160 }
3161
3162 /* Using strncpy is ok here, since buf is not NUL-terminated. */
3163 strncpy(buf, s->image_backing_file, buflen);
3164
3165 header->backing_file_offset = cpu_to_be64(buf - ((char*) header));
3166 header->backing_file_size = cpu_to_be32(backing_file_len);
3167 }
3168
3169 /* Write the new header */
3170 ret = bdrv_pwrite(bs->file, 0, s->cluster_size, header, 0);
3171 if (ret < 0) {
3172 goto fail;
3173 }
3174
3175 ret = 0;
3176 fail:
3177 qemu_vfree(header);
3178 return ret;
3179 }
3180
3181 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_change_backing_file(BlockDriverState * bs,const char * backing_file,const char * backing_fmt)3182 qcow2_co_change_backing_file(BlockDriverState *bs, const char *backing_file,
3183 const char *backing_fmt)
3184 {
3185 BDRVQcow2State *s = bs->opaque;
3186
3187 /* Adding a backing file means that the external data file alone won't be
3188 * enough to make sense of the content */
3189 if (backing_file && data_file_is_raw(bs)) {
3190 return -EINVAL;
3191 }
3192
3193 if (backing_file && strlen(backing_file) > 1023) {
3194 return -EINVAL;
3195 }
3196
3197 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file),
3198 backing_file ?: "");
3199 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
3200 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
3201
3202 g_free(s->image_backing_file);
3203 g_free(s->image_backing_format);
3204
3205 s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL;
3206 s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL;
3207
3208 return qcow2_update_header(bs);
3209 }
3210
3211 static int coroutine_fn GRAPH_RDLOCK
qcow2_set_up_encryption(BlockDriverState * bs,QCryptoBlockCreateOptions * cryptoopts,Error ** errp)3212 qcow2_set_up_encryption(BlockDriverState *bs,
3213 QCryptoBlockCreateOptions *cryptoopts,
3214 Error **errp)
3215 {
3216 BDRVQcow2State *s = bs->opaque;
3217 QCryptoBlock *crypto = NULL;
3218 int fmt, ret;
3219
3220 switch (cryptoopts->format) {
3221 case QCRYPTO_BLOCK_FORMAT_LUKS:
3222 fmt = QCOW_CRYPT_LUKS;
3223 break;
3224 case QCRYPTO_BLOCK_FORMAT_QCOW:
3225 fmt = QCOW_CRYPT_AES;
3226 break;
3227 default:
3228 error_setg(errp, "Crypto format not supported in qcow2");
3229 return -EINVAL;
3230 }
3231
3232 s->crypt_method_header = fmt;
3233
3234 crypto = qcrypto_block_create(cryptoopts, "encrypt.",
3235 qcow2_crypto_hdr_init_func,
3236 qcow2_crypto_hdr_write_func,
3237 bs, 0, errp);
3238 if (!crypto) {
3239 return -EINVAL;
3240 }
3241
3242 ret = qcow2_update_header(bs);
3243 if (ret < 0) {
3244 error_setg_errno(errp, -ret, "Could not write encryption header");
3245 goto out;
3246 }
3247
3248 ret = 0;
3249 out:
3250 qcrypto_block_free(crypto);
3251 return ret;
3252 }
3253
3254 /**
3255 * Preallocates metadata structures for data clusters between @offset (in the
3256 * guest disk) and @new_length (which is thus generally the new guest disk
3257 * size).
3258 *
3259 * Returns: 0 on success, -errno on failure.
3260 */
3261 static int coroutine_fn GRAPH_RDLOCK
preallocate_co(BlockDriverState * bs,uint64_t offset,uint64_t new_length,PreallocMode mode,Error ** errp)3262 preallocate_co(BlockDriverState *bs, uint64_t offset, uint64_t new_length,
3263 PreallocMode mode, Error **errp)
3264 {
3265 BDRVQcow2State *s = bs->opaque;
3266 uint64_t bytes;
3267 uint64_t host_offset = 0;
3268 int64_t file_length;
3269 unsigned int cur_bytes;
3270 int ret;
3271 QCowL2Meta *meta = NULL, *m;
3272
3273 assert(offset <= new_length);
3274 bytes = new_length - offset;
3275
3276 while (bytes) {
3277 cur_bytes = MIN(bytes, QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size));
3278 ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes,
3279 &host_offset, &meta);
3280 if (ret < 0) {
3281 error_setg_errno(errp, -ret, "Allocating clusters failed");
3282 goto out;
3283 }
3284
3285 for (m = meta; m != NULL; m = m->next) {
3286 m->prealloc = true;
3287 }
3288
3289 ret = qcow2_handle_l2meta(bs, &meta, true);
3290 if (ret < 0) {
3291 error_setg_errno(errp, -ret, "Mapping clusters failed");
3292 goto out;
3293 }
3294
3295 /* TODO Preallocate data if requested */
3296
3297 bytes -= cur_bytes;
3298 offset += cur_bytes;
3299 }
3300
3301 /*
3302 * It is expected that the image file is large enough to actually contain
3303 * all of the allocated clusters (otherwise we get failing reads after
3304 * EOF). Extend the image to the last allocated sector.
3305 */
3306 file_length = bdrv_co_getlength(s->data_file->bs);
3307 if (file_length < 0) {
3308 error_setg_errno(errp, -file_length, "Could not get file size");
3309 ret = file_length;
3310 goto out;
3311 }
3312
3313 if (host_offset + cur_bytes > file_length) {
3314 if (mode == PREALLOC_MODE_METADATA) {
3315 mode = PREALLOC_MODE_OFF;
3316 }
3317 ret = bdrv_co_truncate(s->data_file, host_offset + cur_bytes, false,
3318 mode, 0, errp);
3319 if (ret < 0) {
3320 goto out;
3321 }
3322 }
3323
3324 ret = 0;
3325
3326 out:
3327 qcow2_handle_l2meta(bs, &meta, false);
3328 return ret;
3329 }
3330
3331 /* qcow2_refcount_metadata_size:
3332 * @clusters: number of clusters to refcount (including data and L1/L2 tables)
3333 * @cluster_size: size of a cluster, in bytes
3334 * @refcount_order: refcount bits power-of-2 exponent
3335 * @generous_increase: allow for the refcount table to be 1.5x as large as it
3336 * needs to be
3337 *
3338 * Returns: Number of bytes required for refcount blocks and table metadata.
3339 */
qcow2_refcount_metadata_size(int64_t clusters,size_t cluster_size,int refcount_order,bool generous_increase,uint64_t * refblock_count)3340 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
3341 int refcount_order, bool generous_increase,
3342 uint64_t *refblock_count)
3343 {
3344 /*
3345 * Every host cluster is reference-counted, including metadata (even
3346 * refcount metadata is recursively included).
3347 *
3348 * An accurate formula for the size of refcount metadata size is difficult
3349 * to derive. An easier method of calculation is finding the fixed point
3350 * where no further refcount blocks or table clusters are required to
3351 * reference count every cluster.
3352 */
3353 int64_t blocks_per_table_cluster = cluster_size / REFTABLE_ENTRY_SIZE;
3354 int64_t refcounts_per_block = cluster_size * 8 / (1 << refcount_order);
3355 int64_t table = 0; /* number of refcount table clusters */
3356 int64_t blocks = 0; /* number of refcount block clusters */
3357 int64_t last;
3358 int64_t n = 0;
3359
3360 do {
3361 last = n;
3362 blocks = DIV_ROUND_UP(clusters + table + blocks, refcounts_per_block);
3363 table = DIV_ROUND_UP(blocks, blocks_per_table_cluster);
3364 n = clusters + blocks + table;
3365
3366 if (n == last && generous_increase) {
3367 clusters += DIV_ROUND_UP(table, 2);
3368 n = 0; /* force another loop */
3369 generous_increase = false;
3370 }
3371 } while (n != last);
3372
3373 if (refblock_count) {
3374 *refblock_count = blocks;
3375 }
3376
3377 return (blocks + table) * cluster_size;
3378 }
3379
3380 /**
3381 * qcow2_calc_prealloc_size:
3382 * @total_size: virtual disk size in bytes
3383 * @cluster_size: cluster size in bytes
3384 * @refcount_order: refcount bits power-of-2 exponent
3385 * @extended_l2: true if the image has extended L2 entries
3386 *
3387 * Returns: Total number of bytes required for the fully allocated image
3388 * (including metadata).
3389 */
qcow2_calc_prealloc_size(int64_t total_size,size_t cluster_size,int refcount_order,bool extended_l2)3390 static int64_t qcow2_calc_prealloc_size(int64_t total_size,
3391 size_t cluster_size,
3392 int refcount_order,
3393 bool extended_l2)
3394 {
3395 int64_t meta_size = 0;
3396 uint64_t nl1e, nl2e;
3397 int64_t aligned_total_size = ROUND_UP(total_size, cluster_size);
3398 size_t l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
3399
3400 /* header: 1 cluster */
3401 meta_size += cluster_size;
3402
3403 /* total size of L2 tables */
3404 nl2e = aligned_total_size / cluster_size;
3405 nl2e = ROUND_UP(nl2e, cluster_size / l2e_size);
3406 meta_size += nl2e * l2e_size;
3407
3408 /* total size of L1 tables */
3409 nl1e = nl2e * l2e_size / cluster_size;
3410 nl1e = ROUND_UP(nl1e, cluster_size / L1E_SIZE);
3411 meta_size += nl1e * L1E_SIZE;
3412
3413 /* total size of refcount table and blocks */
3414 meta_size += qcow2_refcount_metadata_size(
3415 (meta_size + aligned_total_size) / cluster_size,
3416 cluster_size, refcount_order, false, NULL);
3417
3418 return meta_size + aligned_total_size;
3419 }
3420
validate_cluster_size(size_t cluster_size,bool extended_l2,Error ** errp)3421 static bool validate_cluster_size(size_t cluster_size, bool extended_l2,
3422 Error **errp)
3423 {
3424 int cluster_bits = ctz32(cluster_size);
3425 if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS ||
3426 (1 << cluster_bits) != cluster_size)
3427 {
3428 error_setg(errp, "Cluster size must be a power of two between %d and "
3429 "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10));
3430 return false;
3431 }
3432
3433 if (extended_l2) {
3434 unsigned min_cluster_size =
3435 (1 << MIN_CLUSTER_BITS) * QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER;
3436 if (cluster_size < min_cluster_size) {
3437 error_setg(errp, "Extended L2 entries are only supported with "
3438 "cluster sizes of at least %u bytes", min_cluster_size);
3439 return false;
3440 }
3441 }
3442
3443 return true;
3444 }
3445
qcow2_opt_get_cluster_size_del(QemuOpts * opts,bool extended_l2,Error ** errp)3446 static size_t qcow2_opt_get_cluster_size_del(QemuOpts *opts, bool extended_l2,
3447 Error **errp)
3448 {
3449 size_t cluster_size;
3450
3451 cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE,
3452 DEFAULT_CLUSTER_SIZE);
3453 if (!validate_cluster_size(cluster_size, extended_l2, errp)) {
3454 return 0;
3455 }
3456 return cluster_size;
3457 }
3458
qcow2_opt_get_version_del(QemuOpts * opts,Error ** errp)3459 static int qcow2_opt_get_version_del(QemuOpts *opts, Error **errp)
3460 {
3461 char *buf;
3462 int ret;
3463
3464 buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL);
3465 if (!buf) {
3466 ret = 3; /* default */
3467 } else if (!strcmp(buf, "0.10")) {
3468 ret = 2;
3469 } else if (!strcmp(buf, "1.1")) {
3470 ret = 3;
3471 } else {
3472 error_setg(errp, "Invalid compatibility level: '%s'", buf);
3473 ret = -EINVAL;
3474 }
3475 g_free(buf);
3476 return ret;
3477 }
3478
qcow2_opt_get_refcount_bits_del(QemuOpts * opts,int version,Error ** errp)3479 static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts *opts, int version,
3480 Error **errp)
3481 {
3482 uint64_t refcount_bits;
3483
3484 refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, 16);
3485 if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) {
3486 error_setg(errp, "Refcount width must be a power of two and may not "
3487 "exceed 64 bits");
3488 return 0;
3489 }
3490
3491 if (version < 3 && refcount_bits != 16) {
3492 error_setg(errp, "Different refcount widths than 16 bits require "
3493 "compatibility level 1.1 or above (use compat=1.1 or "
3494 "greater)");
3495 return 0;
3496 }
3497
3498 return refcount_bits;
3499 }
3500
3501 static int coroutine_fn GRAPH_UNLOCKED
qcow2_co_create(BlockdevCreateOptions * create_options,Error ** errp)3502 qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
3503 {
3504 ERRP_GUARD();
3505 BlockdevCreateOptionsQcow2 *qcow2_opts;
3506 QDict *options;
3507
3508 /*
3509 * Open the image file and write a minimal qcow2 header.
3510 *
3511 * We keep things simple and start with a zero-sized image. We also
3512 * do without refcount blocks or a L1 table for now. We'll fix the
3513 * inconsistency later.
3514 *
3515 * We do need a refcount table because growing the refcount table means
3516 * allocating two new refcount blocks - the second of which would be at
3517 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
3518 * size for any qcow2 image.
3519 */
3520 BlockBackend *blk = NULL;
3521 BlockDriverState *bs = NULL;
3522 BlockDriverState *data_bs = NULL;
3523 QCowHeader *header;
3524 size_t cluster_size;
3525 int version;
3526 int refcount_order;
3527 uint64_t *refcount_table;
3528 int ret;
3529 uint8_t compression_type = QCOW2_COMPRESSION_TYPE_ZLIB;
3530
3531 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2);
3532 qcow2_opts = &create_options->u.qcow2;
3533
3534 bs = bdrv_co_open_blockdev_ref(qcow2_opts->file, errp);
3535 if (bs == NULL) {
3536 return -EIO;
3537 }
3538
3539 /* Validate options and set default values */
3540 if (!QEMU_IS_ALIGNED(qcow2_opts->size, BDRV_SECTOR_SIZE)) {
3541 error_setg(errp, "Image size must be a multiple of %u bytes",
3542 (unsigned) BDRV_SECTOR_SIZE);
3543 ret = -EINVAL;
3544 goto out;
3545 }
3546
3547 if (qcow2_opts->has_version) {
3548 switch (qcow2_opts->version) {
3549 case BLOCKDEV_QCOW2_VERSION_V2:
3550 version = 2;
3551 break;
3552 case BLOCKDEV_QCOW2_VERSION_V3:
3553 version = 3;
3554 break;
3555 default:
3556 g_assert_not_reached();
3557 }
3558 } else {
3559 version = 3;
3560 }
3561
3562 if (qcow2_opts->has_cluster_size) {
3563 cluster_size = qcow2_opts->cluster_size;
3564 } else {
3565 cluster_size = DEFAULT_CLUSTER_SIZE;
3566 }
3567
3568 if (!qcow2_opts->has_extended_l2) {
3569 qcow2_opts->extended_l2 = false;
3570 }
3571 if (qcow2_opts->extended_l2) {
3572 if (version < 3) {
3573 error_setg(errp, "Extended L2 entries are only supported with "
3574 "compatibility level 1.1 and above (use version=v3 or "
3575 "greater)");
3576 ret = -EINVAL;
3577 goto out;
3578 }
3579 }
3580
3581 if (!validate_cluster_size(cluster_size, qcow2_opts->extended_l2, errp)) {
3582 ret = -EINVAL;
3583 goto out;
3584 }
3585
3586 if (!qcow2_opts->has_preallocation) {
3587 qcow2_opts->preallocation = PREALLOC_MODE_OFF;
3588 }
3589 if (qcow2_opts->backing_file &&
3590 qcow2_opts->preallocation != PREALLOC_MODE_OFF &&
3591 !qcow2_opts->extended_l2)
3592 {
3593 error_setg(errp, "Backing file and preallocation can only be used at "
3594 "the same time if extended_l2 is on");
3595 ret = -EINVAL;
3596 goto out;
3597 }
3598 if (qcow2_opts->has_backing_fmt && !qcow2_opts->backing_file) {
3599 error_setg(errp, "Backing format cannot be used without backing file");
3600 ret = -EINVAL;
3601 goto out;
3602 }
3603
3604 if (!qcow2_opts->has_lazy_refcounts) {
3605 qcow2_opts->lazy_refcounts = false;
3606 }
3607 if (version < 3 && qcow2_opts->lazy_refcounts) {
3608 error_setg(errp, "Lazy refcounts only supported with compatibility "
3609 "level 1.1 and above (use version=v3 or greater)");
3610 ret = -EINVAL;
3611 goto out;
3612 }
3613
3614 if (!qcow2_opts->has_refcount_bits) {
3615 qcow2_opts->refcount_bits = 16;
3616 }
3617 if (qcow2_opts->refcount_bits > 64 ||
3618 !is_power_of_2(qcow2_opts->refcount_bits))
3619 {
3620 error_setg(errp, "Refcount width must be a power of two and may not "
3621 "exceed 64 bits");
3622 ret = -EINVAL;
3623 goto out;
3624 }
3625 if (version < 3 && qcow2_opts->refcount_bits != 16) {
3626 error_setg(errp, "Different refcount widths than 16 bits require "
3627 "compatibility level 1.1 or above (use version=v3 or "
3628 "greater)");
3629 ret = -EINVAL;
3630 goto out;
3631 }
3632 refcount_order = ctz32(qcow2_opts->refcount_bits);
3633
3634 if (qcow2_opts->data_file_raw && !qcow2_opts->data_file) {
3635 error_setg(errp, "data-file-raw requires data-file");
3636 ret = -EINVAL;
3637 goto out;
3638 }
3639 if (qcow2_opts->data_file_raw && qcow2_opts->backing_file) {
3640 error_setg(errp, "Backing file and data-file-raw cannot be used at "
3641 "the same time");
3642 ret = -EINVAL;
3643 goto out;
3644 }
3645 if (qcow2_opts->data_file_raw &&
3646 qcow2_opts->preallocation == PREALLOC_MODE_OFF)
3647 {
3648 /*
3649 * data-file-raw means that "the external data file can be
3650 * read as a consistent standalone raw image without looking
3651 * at the qcow2 metadata." It does not say that the metadata
3652 * must be ignored, though (and the qcow2 driver in fact does
3653 * not ignore it), so the L1/L2 tables must be present and
3654 * give a 1:1 mapping, so you get the same result regardless
3655 * of whether you look at the metadata or whether you ignore
3656 * it.
3657 */
3658 qcow2_opts->preallocation = PREALLOC_MODE_METADATA;
3659
3660 /*
3661 * Cannot use preallocation with backing files, but giving a
3662 * backing file when specifying data_file_raw is an error
3663 * anyway.
3664 */
3665 assert(!qcow2_opts->backing_file);
3666 }
3667
3668 if (qcow2_opts->data_file) {
3669 if (version < 3) {
3670 error_setg(errp, "External data files are only supported with "
3671 "compatibility level 1.1 and above (use version=v3 or "
3672 "greater)");
3673 ret = -EINVAL;
3674 goto out;
3675 }
3676 data_bs = bdrv_co_open_blockdev_ref(qcow2_opts->data_file, errp);
3677 if (data_bs == NULL) {
3678 ret = -EIO;
3679 goto out;
3680 }
3681 }
3682
3683 if (qcow2_opts->has_compression_type &&
3684 qcow2_opts->compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) {
3685
3686 ret = -EINVAL;
3687
3688 if (version < 3) {
3689 error_setg(errp, "Non-zlib compression type is only supported with "
3690 "compatibility level 1.1 and above (use version=v3 or "
3691 "greater)");
3692 goto out;
3693 }
3694
3695 switch (qcow2_opts->compression_type) {
3696 #ifdef CONFIG_ZSTD
3697 case QCOW2_COMPRESSION_TYPE_ZSTD:
3698 break;
3699 #endif
3700 default:
3701 error_setg(errp, "Unknown compression type");
3702 goto out;
3703 }
3704
3705 compression_type = qcow2_opts->compression_type;
3706 }
3707
3708 /* Create BlockBackend to write to the image */
3709 blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL,
3710 errp);
3711 if (!blk) {
3712 ret = -EPERM;
3713 goto out;
3714 }
3715 blk_set_allow_write_beyond_eof(blk, true);
3716
3717 /* Write the header */
3718 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header));
3719 header = g_malloc0(cluster_size);
3720 *header = (QCowHeader) {
3721 .magic = cpu_to_be32(QCOW_MAGIC),
3722 .version = cpu_to_be32(version),
3723 .cluster_bits = cpu_to_be32(ctz32(cluster_size)),
3724 .size = cpu_to_be64(0),
3725 .l1_table_offset = cpu_to_be64(0),
3726 .l1_size = cpu_to_be32(0),
3727 .refcount_table_offset = cpu_to_be64(cluster_size),
3728 .refcount_table_clusters = cpu_to_be32(1),
3729 .refcount_order = cpu_to_be32(refcount_order),
3730 /* don't deal with endianness since compression_type is 1 byte long */
3731 .compression_type = compression_type,
3732 .header_length = cpu_to_be32(sizeof(*header)),
3733 };
3734
3735 /* We'll update this to correct value later */
3736 header->crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
3737
3738 if (qcow2_opts->lazy_refcounts) {
3739 header->compatible_features |=
3740 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS);
3741 }
3742 if (data_bs) {
3743 header->incompatible_features |=
3744 cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE);
3745 }
3746 if (qcow2_opts->data_file_raw) {
3747 header->autoclear_features |=
3748 cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW);
3749 }
3750 if (compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) {
3751 header->incompatible_features |=
3752 cpu_to_be64(QCOW2_INCOMPAT_COMPRESSION);
3753 }
3754
3755 if (qcow2_opts->extended_l2) {
3756 header->incompatible_features |=
3757 cpu_to_be64(QCOW2_INCOMPAT_EXTL2);
3758 }
3759
3760 ret = blk_co_pwrite(blk, 0, cluster_size, header, 0);
3761 g_free(header);
3762 if (ret < 0) {
3763 error_setg_errno(errp, -ret, "Could not write qcow2 header");
3764 goto out;
3765 }
3766
3767 /* Write a refcount table with one refcount block */
3768 refcount_table = g_malloc0(2 * cluster_size);
3769 refcount_table[0] = cpu_to_be64(2 * cluster_size);
3770 ret = blk_co_pwrite(blk, cluster_size, 2 * cluster_size, refcount_table, 0);
3771 g_free(refcount_table);
3772
3773 if (ret < 0) {
3774 error_setg_errno(errp, -ret, "Could not write refcount table");
3775 goto out;
3776 }
3777
3778 blk_co_unref(blk);
3779 blk = NULL;
3780
3781 /*
3782 * And now open the image and make it consistent first (i.e. increase the
3783 * refcount of the cluster that is occupied by the header and the refcount
3784 * table)
3785 */
3786 options = qdict_new();
3787 qdict_put_str(options, "driver", "qcow2");
3788 qdict_put_str(options, "file", bs->node_name);
3789 if (data_bs) {
3790 qdict_put_str(options, "data-file", data_bs->node_name);
3791 }
3792 blk = blk_co_new_open(NULL, NULL, options,
3793 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH,
3794 errp);
3795 if (blk == NULL) {
3796 ret = -EIO;
3797 goto out;
3798 }
3799
3800 bdrv_graph_co_rdlock();
3801 ret = qcow2_alloc_clusters(blk_bs(blk), 3 * cluster_size);
3802 if (ret < 0) {
3803 bdrv_graph_co_rdunlock();
3804 error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 "
3805 "header and refcount table");
3806 goto out;
3807
3808 } else if (ret != 0) {
3809 error_report("Huh, first cluster in empty image is already in use?");
3810 abort();
3811 }
3812
3813 /* Set the external data file if necessary */
3814 if (data_bs) {
3815 BDRVQcow2State *s = blk_bs(blk)->opaque;
3816 s->image_data_file = g_strdup(data_bs->filename);
3817 }
3818
3819 /* Create a full header (including things like feature table) */
3820 ret = qcow2_update_header(blk_bs(blk));
3821 bdrv_graph_co_rdunlock();
3822
3823 if (ret < 0) {
3824 error_setg_errno(errp, -ret, "Could not update qcow2 header");
3825 goto out;
3826 }
3827
3828 /* Okay, now that we have a valid image, let's give it the right size */
3829 ret = blk_co_truncate(blk, qcow2_opts->size, false,
3830 qcow2_opts->preallocation, 0, errp);
3831 if (ret < 0) {
3832 error_prepend(errp, "Could not resize image: ");
3833 goto out;
3834 }
3835
3836 /* Want a backing file? There you go. */
3837 if (qcow2_opts->backing_file) {
3838 const char *backing_format = NULL;
3839
3840 if (qcow2_opts->has_backing_fmt) {
3841 backing_format = BlockdevDriver_str(qcow2_opts->backing_fmt);
3842 }
3843
3844 bdrv_graph_co_rdlock();
3845 ret = bdrv_co_change_backing_file(blk_bs(blk), qcow2_opts->backing_file,
3846 backing_format, false);
3847 bdrv_graph_co_rdunlock();
3848
3849 if (ret < 0) {
3850 error_setg_errno(errp, -ret, "Could not assign backing file '%s' "
3851 "with format '%s'", qcow2_opts->backing_file,
3852 backing_format);
3853 goto out;
3854 }
3855 }
3856
3857 /* Want encryption? There you go. */
3858 if (qcow2_opts->encrypt) {
3859 bdrv_graph_co_rdlock();
3860 ret = qcow2_set_up_encryption(blk_bs(blk), qcow2_opts->encrypt, errp);
3861 bdrv_graph_co_rdunlock();
3862
3863 if (ret < 0) {
3864 goto out;
3865 }
3866 }
3867
3868 blk_co_unref(blk);
3869 blk = NULL;
3870
3871 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning.
3872 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to
3873 * have to setup decryption context. We're not doing any I/O on the top
3874 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does
3875 * not have effect.
3876 */
3877 options = qdict_new();
3878 qdict_put_str(options, "driver", "qcow2");
3879 qdict_put_str(options, "file", bs->node_name);
3880 if (data_bs) {
3881 qdict_put_str(options, "data-file", data_bs->node_name);
3882 }
3883 blk = blk_co_new_open(NULL, NULL, options,
3884 BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO,
3885 errp);
3886 if (blk == NULL) {
3887 ret = -EIO;
3888 goto out;
3889 }
3890
3891 ret = 0;
3892 out:
3893 blk_co_unref(blk);
3894 bdrv_co_unref(bs);
3895 bdrv_co_unref(data_bs);
3896 return ret;
3897 }
3898
3899 static int coroutine_fn GRAPH_UNLOCKED
qcow2_co_create_opts(BlockDriver * drv,const char * filename,QemuOpts * opts,Error ** errp)3900 qcow2_co_create_opts(BlockDriver *drv, const char *filename, QemuOpts *opts,
3901 Error **errp)
3902 {
3903 BlockdevCreateOptions *create_options = NULL;
3904 QDict *qdict;
3905 Visitor *v;
3906 BlockDriverState *bs = NULL;
3907 BlockDriverState *data_bs = NULL;
3908 const char *val;
3909 int ret;
3910
3911 /* Only the keyval visitor supports the dotted syntax needed for
3912 * encryption, so go through a QDict before getting a QAPI type. Ignore
3913 * options meant for the protocol layer so that the visitor doesn't
3914 * complain. */
3915 qdict = qemu_opts_to_qdict_filtered(opts, NULL, bdrv_qcow2.create_opts,
3916 true);
3917
3918 /* Handle encryption options */
3919 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT);
3920 if (val && !strcmp(val, "on")) {
3921 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow");
3922 } else if (val && !strcmp(val, "off")) {
3923 qdict_del(qdict, BLOCK_OPT_ENCRYPT);
3924 }
3925
3926 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT);
3927 if (val && !strcmp(val, "aes")) {
3928 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow");
3929 }
3930
3931 /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into
3932 * version=v2/v3 below. */
3933 val = qdict_get_try_str(qdict, BLOCK_OPT_COMPAT_LEVEL);
3934 if (val && !strcmp(val, "0.10")) {
3935 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v2");
3936 } else if (val && !strcmp(val, "1.1")) {
3937 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v3");
3938 }
3939
3940 /* Change legacy command line options into QMP ones */
3941 static const QDictRenames opt_renames[] = {
3942 { BLOCK_OPT_BACKING_FILE, "backing-file" },
3943 { BLOCK_OPT_BACKING_FMT, "backing-fmt" },
3944 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" },
3945 { BLOCK_OPT_LAZY_REFCOUNTS, "lazy-refcounts" },
3946 { BLOCK_OPT_EXTL2, "extended-l2" },
3947 { BLOCK_OPT_REFCOUNT_BITS, "refcount-bits" },
3948 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT },
3949 { BLOCK_OPT_COMPAT_LEVEL, "version" },
3950 { BLOCK_OPT_DATA_FILE_RAW, "data-file-raw" },
3951 { BLOCK_OPT_COMPRESSION_TYPE, "compression-type" },
3952 { NULL, NULL },
3953 };
3954
3955 if (!qdict_rename_keys(qdict, opt_renames, errp)) {
3956 ret = -EINVAL;
3957 goto finish;
3958 }
3959
3960 /* Create and open the file (protocol layer) */
3961 ret = bdrv_co_create_file(filename, opts, errp);
3962 if (ret < 0) {
3963 goto finish;
3964 }
3965
3966 bs = bdrv_co_open(filename, NULL, NULL,
3967 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
3968 if (bs == NULL) {
3969 ret = -EIO;
3970 goto finish;
3971 }
3972
3973 /* Create and open an external data file (protocol layer) */
3974 val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE);
3975 if (val) {
3976 ret = bdrv_co_create_file(val, opts, errp);
3977 if (ret < 0) {
3978 goto finish;
3979 }
3980
3981 data_bs = bdrv_co_open(val, NULL, NULL,
3982 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
3983 errp);
3984 if (data_bs == NULL) {
3985 ret = -EIO;
3986 goto finish;
3987 }
3988
3989 qdict_del(qdict, BLOCK_OPT_DATA_FILE);
3990 qdict_put_str(qdict, "data-file", data_bs->node_name);
3991 }
3992
3993 /* Set 'driver' and 'node' options */
3994 qdict_put_str(qdict, "driver", "qcow2");
3995 qdict_put_str(qdict, "file", bs->node_name);
3996
3997 /* Now get the QAPI type BlockdevCreateOptions */
3998 v = qobject_input_visitor_new_flat_confused(qdict, errp);
3999 if (!v) {
4000 ret = -EINVAL;
4001 goto finish;
4002 }
4003
4004 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp);
4005 visit_free(v);
4006 if (!create_options) {
4007 ret = -EINVAL;
4008 goto finish;
4009 }
4010
4011 /* Silently round up size */
4012 create_options->u.qcow2.size = ROUND_UP(create_options->u.qcow2.size,
4013 BDRV_SECTOR_SIZE);
4014
4015 /* Create the qcow2 image (format layer) */
4016 ret = qcow2_co_create(create_options, errp);
4017 finish:
4018 if (ret < 0) {
4019 bdrv_graph_co_rdlock();
4020 bdrv_co_delete_file_noerr(bs);
4021 bdrv_co_delete_file_noerr(data_bs);
4022 bdrv_graph_co_rdunlock();
4023 } else {
4024 ret = 0;
4025 }
4026
4027 qobject_unref(qdict);
4028 bdrv_co_unref(bs);
4029 bdrv_co_unref(data_bs);
4030 qapi_free_BlockdevCreateOptions(create_options);
4031 return ret;
4032 }
4033
4034
4035 static bool coroutine_fn GRAPH_RDLOCK
is_zero(BlockDriverState * bs,int64_t offset,int64_t bytes)4036 is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes)
4037 {
4038 int64_t nr;
4039 int res;
4040
4041 /* Clamp to image length, before checking status of underlying sectors */
4042 if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) {
4043 bytes = bs->total_sectors * BDRV_SECTOR_SIZE - offset;
4044 }
4045
4046 if (!bytes) {
4047 return true;
4048 }
4049
4050 /*
4051 * bdrv_block_status_above doesn't merge different types of zeros, for
4052 * example, zeros which come from the region which is unallocated in
4053 * the whole backing chain, and zeros which come because of a short
4054 * backing file. So, we need a loop.
4055 */
4056 do {
4057 res = bdrv_co_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL);
4058 offset += nr;
4059 bytes -= nr;
4060 } while (res >= 0 && (res & BDRV_BLOCK_ZERO) && nr && bytes);
4061
4062 return res >= 0 && (res & BDRV_BLOCK_ZERO) && bytes == 0;
4063 }
4064
4065 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_pwrite_zeroes(BlockDriverState * bs,int64_t offset,int64_t bytes,BdrvRequestFlags flags)4066 qcow2_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
4067 BdrvRequestFlags flags)
4068 {
4069 int ret;
4070 BDRVQcow2State *s = bs->opaque;
4071
4072 uint32_t head = offset_into_subcluster(s, offset);
4073 uint32_t tail = ROUND_UP(offset + bytes, s->subcluster_size) -
4074 (offset + bytes);
4075
4076 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, bytes);
4077 if (offset + bytes == bs->total_sectors * BDRV_SECTOR_SIZE) {
4078 tail = 0;
4079 }
4080
4081 if (head || tail) {
4082 uint64_t off;
4083 unsigned int nr;
4084 QCow2SubclusterType type;
4085
4086 assert(head + bytes + tail <= s->subcluster_size);
4087
4088 /* check whether remainder of cluster already reads as zero */
4089 if (!(is_zero(bs, offset - head, head) &&
4090 is_zero(bs, offset + bytes, tail))) {
4091 return -ENOTSUP;
4092 }
4093
4094 qemu_co_mutex_lock(&s->lock);
4095 /* We can have new write after previous check */
4096 offset -= head;
4097 bytes = s->subcluster_size;
4098 nr = s->subcluster_size;
4099 ret = qcow2_get_host_offset(bs, offset, &nr, &off, &type);
4100 if (ret < 0 ||
4101 (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN &&
4102 type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC &&
4103 type != QCOW2_SUBCLUSTER_ZERO_PLAIN &&
4104 type != QCOW2_SUBCLUSTER_ZERO_ALLOC)) {
4105 qemu_co_mutex_unlock(&s->lock);
4106 return ret < 0 ? ret : -ENOTSUP;
4107 }
4108 } else {
4109 qemu_co_mutex_lock(&s->lock);
4110 }
4111
4112 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes);
4113
4114 /* Whatever is left can use real zero subclusters */
4115 ret = qcow2_subcluster_zeroize(bs, offset, bytes, flags);
4116 qemu_co_mutex_unlock(&s->lock);
4117
4118 return ret;
4119 }
4120
4121 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_pdiscard(BlockDriverState * bs,int64_t offset,int64_t bytes)4122 qcow2_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
4123 {
4124 int ret;
4125 BDRVQcow2State *s = bs->opaque;
4126
4127 /* If the image does not support QCOW_OFLAG_ZERO then discarding
4128 * clusters could expose stale data from the backing file. */
4129 if (s->qcow_version < 3 && bs->backing) {
4130 return -ENOTSUP;
4131 }
4132
4133 if (!QEMU_IS_ALIGNED(offset | bytes, s->cluster_size)) {
4134 assert(bytes < s->cluster_size);
4135 /* Ignore partial clusters, except for the special case of the
4136 * complete partial cluster at the end of an unaligned file */
4137 if (!QEMU_IS_ALIGNED(offset, s->cluster_size) ||
4138 offset + bytes != bs->total_sectors * BDRV_SECTOR_SIZE) {
4139 return -ENOTSUP;
4140 }
4141 }
4142
4143 qemu_co_mutex_lock(&s->lock);
4144 ret = qcow2_cluster_discard(bs, offset, bytes, QCOW2_DISCARD_REQUEST,
4145 false);
4146 qemu_co_mutex_unlock(&s->lock);
4147 return ret;
4148 }
4149
4150 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_copy_range_from(BlockDriverState * bs,BdrvChild * src,int64_t src_offset,BdrvChild * dst,int64_t dst_offset,int64_t bytes,BdrvRequestFlags read_flags,BdrvRequestFlags write_flags)4151 qcow2_co_copy_range_from(BlockDriverState *bs,
4152 BdrvChild *src, int64_t src_offset,
4153 BdrvChild *dst, int64_t dst_offset,
4154 int64_t bytes, BdrvRequestFlags read_flags,
4155 BdrvRequestFlags write_flags)
4156 {
4157 BDRVQcow2State *s = bs->opaque;
4158 int ret;
4159 unsigned int cur_bytes; /* number of bytes in current iteration */
4160 BdrvChild *child = NULL;
4161 BdrvRequestFlags cur_write_flags;
4162
4163 assert(!bs->encrypted);
4164 qemu_co_mutex_lock(&s->lock);
4165
4166 while (bytes != 0) {
4167 uint64_t copy_offset = 0;
4168 QCow2SubclusterType type;
4169 /* prepare next request */
4170 cur_bytes = MIN(bytes, INT_MAX);
4171 cur_write_flags = write_flags;
4172
4173 ret = qcow2_get_host_offset(bs, src_offset, &cur_bytes,
4174 ©_offset, &type);
4175 if (ret < 0) {
4176 goto out;
4177 }
4178
4179 switch (type) {
4180 case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN:
4181 case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC:
4182 if (bs->backing && bs->backing->bs) {
4183 int64_t backing_length = bdrv_co_getlength(bs->backing->bs);
4184 if (src_offset >= backing_length) {
4185 cur_write_flags |= BDRV_REQ_ZERO_WRITE;
4186 } else {
4187 child = bs->backing;
4188 cur_bytes = MIN(cur_bytes, backing_length - src_offset);
4189 copy_offset = src_offset;
4190 }
4191 } else {
4192 cur_write_flags |= BDRV_REQ_ZERO_WRITE;
4193 }
4194 break;
4195
4196 case QCOW2_SUBCLUSTER_ZERO_PLAIN:
4197 case QCOW2_SUBCLUSTER_ZERO_ALLOC:
4198 cur_write_flags |= BDRV_REQ_ZERO_WRITE;
4199 break;
4200
4201 case QCOW2_SUBCLUSTER_COMPRESSED:
4202 ret = -ENOTSUP;
4203 goto out;
4204
4205 case QCOW2_SUBCLUSTER_NORMAL:
4206 child = s->data_file;
4207 break;
4208
4209 default:
4210 abort();
4211 }
4212 qemu_co_mutex_unlock(&s->lock);
4213 ret = bdrv_co_copy_range_from(child,
4214 copy_offset,
4215 dst, dst_offset,
4216 cur_bytes, read_flags, cur_write_flags);
4217 qemu_co_mutex_lock(&s->lock);
4218 if (ret < 0) {
4219 goto out;
4220 }
4221
4222 bytes -= cur_bytes;
4223 src_offset += cur_bytes;
4224 dst_offset += cur_bytes;
4225 }
4226 ret = 0;
4227
4228 out:
4229 qemu_co_mutex_unlock(&s->lock);
4230 return ret;
4231 }
4232
4233 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_copy_range_to(BlockDriverState * bs,BdrvChild * src,int64_t src_offset,BdrvChild * dst,int64_t dst_offset,int64_t bytes,BdrvRequestFlags read_flags,BdrvRequestFlags write_flags)4234 qcow2_co_copy_range_to(BlockDriverState *bs,
4235 BdrvChild *src, int64_t src_offset,
4236 BdrvChild *dst, int64_t dst_offset,
4237 int64_t bytes, BdrvRequestFlags read_flags,
4238 BdrvRequestFlags write_flags)
4239 {
4240 BDRVQcow2State *s = bs->opaque;
4241 int ret;
4242 unsigned int cur_bytes; /* number of sectors in current iteration */
4243 uint64_t host_offset;
4244 QCowL2Meta *l2meta = NULL;
4245
4246 assert(!bs->encrypted);
4247
4248 qemu_co_mutex_lock(&s->lock);
4249
4250 while (bytes != 0) {
4251
4252 l2meta = NULL;
4253
4254 cur_bytes = MIN(bytes, INT_MAX);
4255
4256 /* TODO:
4257 * If src->bs == dst->bs, we could simply copy by incrementing
4258 * the refcnt, without copying user data.
4259 * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */
4260 ret = qcow2_alloc_host_offset(bs, dst_offset, &cur_bytes,
4261 &host_offset, &l2meta);
4262 if (ret < 0) {
4263 goto fail;
4264 }
4265
4266 ret = qcow2_pre_write_overlap_check(bs, 0, host_offset, cur_bytes,
4267 true);
4268 if (ret < 0) {
4269 goto fail;
4270 }
4271
4272 qemu_co_mutex_unlock(&s->lock);
4273 ret = bdrv_co_copy_range_to(src, src_offset, s->data_file, host_offset,
4274 cur_bytes, read_flags, write_flags);
4275 qemu_co_mutex_lock(&s->lock);
4276 if (ret < 0) {
4277 goto fail;
4278 }
4279
4280 ret = qcow2_handle_l2meta(bs, &l2meta, true);
4281 if (ret) {
4282 goto fail;
4283 }
4284
4285 bytes -= cur_bytes;
4286 src_offset += cur_bytes;
4287 dst_offset += cur_bytes;
4288 }
4289 ret = 0;
4290
4291 fail:
4292 qcow2_handle_l2meta(bs, &l2meta, false);
4293
4294 qemu_co_mutex_unlock(&s->lock);
4295
4296 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
4297
4298 return ret;
4299 }
4300
4301 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_truncate(BlockDriverState * bs,int64_t offset,bool exact,PreallocMode prealloc,BdrvRequestFlags flags,Error ** errp)4302 qcow2_co_truncate(BlockDriverState *bs, int64_t offset, bool exact,
4303 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp)
4304 {
4305 ERRP_GUARD();
4306 BDRVQcow2State *s = bs->opaque;
4307 uint64_t old_length;
4308 int64_t new_l1_size;
4309 int ret;
4310 QDict *options;
4311
4312 if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA &&
4313 prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL)
4314 {
4315 error_setg(errp, "Unsupported preallocation mode '%s'",
4316 PreallocMode_str(prealloc));
4317 return -ENOTSUP;
4318 }
4319
4320 if (!QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)) {
4321 error_setg(errp, "The new size must be a multiple of %u",
4322 (unsigned) BDRV_SECTOR_SIZE);
4323 return -EINVAL;
4324 }
4325
4326 qemu_co_mutex_lock(&s->lock);
4327
4328 /*
4329 * Even though we store snapshot size for all images, it was not
4330 * required until v3, so it is not safe to proceed for v2.
4331 */
4332 if (s->nb_snapshots && s->qcow_version < 3) {
4333 error_setg(errp, "Can't resize a v2 image which has snapshots");
4334 ret = -ENOTSUP;
4335 goto fail;
4336 }
4337
4338 /* See qcow2-bitmap.c for which bitmap scenarios prevent a resize. */
4339 if (qcow2_truncate_bitmaps_check(bs, errp)) {
4340 ret = -ENOTSUP;
4341 goto fail;
4342 }
4343
4344 old_length = bs->total_sectors * BDRV_SECTOR_SIZE;
4345 new_l1_size = size_to_l1(s, offset);
4346
4347 if (offset < old_length) {
4348 int64_t last_cluster, old_file_size;
4349 if (prealloc != PREALLOC_MODE_OFF) {
4350 error_setg(errp,
4351 "Preallocation can't be used for shrinking an image");
4352 ret = -EINVAL;
4353 goto fail;
4354 }
4355
4356 ret = qcow2_cluster_discard(bs, ROUND_UP(offset, s->cluster_size),
4357 old_length - ROUND_UP(offset,
4358 s->cluster_size),
4359 QCOW2_DISCARD_ALWAYS, true);
4360 if (ret < 0) {
4361 error_setg_errno(errp, -ret, "Failed to discard cropped clusters");
4362 goto fail;
4363 }
4364
4365 ret = qcow2_shrink_l1_table(bs, new_l1_size);
4366 if (ret < 0) {
4367 error_setg_errno(errp, -ret,
4368 "Failed to reduce the number of L2 tables");
4369 goto fail;
4370 }
4371
4372 ret = qcow2_shrink_reftable(bs);
4373 if (ret < 0) {
4374 error_setg_errno(errp, -ret,
4375 "Failed to discard unused refblocks");
4376 goto fail;
4377 }
4378
4379 old_file_size = bdrv_co_getlength(bs->file->bs);
4380 if (old_file_size < 0) {
4381 error_setg_errno(errp, -old_file_size,
4382 "Failed to inquire current file length");
4383 ret = old_file_size;
4384 goto fail;
4385 }
4386 last_cluster = qcow2_get_last_cluster(bs, old_file_size);
4387 if (last_cluster < 0) {
4388 error_setg_errno(errp, -last_cluster,
4389 "Failed to find the last cluster");
4390 ret = last_cluster;
4391 goto fail;
4392 }
4393 if ((last_cluster + 1) * s->cluster_size < old_file_size) {
4394 Error *local_err = NULL;
4395
4396 /*
4397 * Do not pass @exact here: It will not help the user if
4398 * we get an error here just because they wanted to shrink
4399 * their qcow2 image (on a block device) with qemu-img.
4400 * (And on the qcow2 layer, the @exact requirement is
4401 * always fulfilled, so there is no need to pass it on.)
4402 */
4403 bdrv_co_truncate(bs->file, (last_cluster + 1) * s->cluster_size,
4404 false, PREALLOC_MODE_OFF, 0, &local_err);
4405 if (local_err) {
4406 warn_reportf_err(local_err,
4407 "Failed to truncate the tail of the image: ");
4408 }
4409 }
4410 } else {
4411 ret = qcow2_grow_l1_table(bs, new_l1_size, true);
4412 if (ret < 0) {
4413 error_setg_errno(errp, -ret, "Failed to grow the L1 table");
4414 goto fail;
4415 }
4416
4417 if (data_file_is_raw(bs) && prealloc == PREALLOC_MODE_OFF) {
4418 /*
4419 * When creating a qcow2 image with data-file-raw, we enforce
4420 * at least prealloc=metadata, so that the L1/L2 tables are
4421 * fully allocated and reading from the data file will return
4422 * the same data as reading from the qcow2 image. When the
4423 * image is grown, we must consequently preallocate the
4424 * metadata structures to cover the added area.
4425 */
4426 prealloc = PREALLOC_MODE_METADATA;
4427 }
4428 }
4429
4430 switch (prealloc) {
4431 case PREALLOC_MODE_OFF:
4432 if (has_data_file(bs)) {
4433 /*
4434 * If the caller wants an exact resize, the external data
4435 * file should be resized to the exact target size, too,
4436 * so we pass @exact here.
4437 */
4438 ret = bdrv_co_truncate(s->data_file, offset, exact, prealloc, 0,
4439 errp);
4440 if (ret < 0) {
4441 goto fail;
4442 }
4443 }
4444 break;
4445
4446 case PREALLOC_MODE_METADATA:
4447 ret = preallocate_co(bs, old_length, offset, prealloc, errp);
4448 if (ret < 0) {
4449 goto fail;
4450 }
4451 break;
4452
4453 case PREALLOC_MODE_FALLOC:
4454 case PREALLOC_MODE_FULL:
4455 {
4456 int64_t allocation_start, host_offset, guest_offset;
4457 int64_t clusters_allocated;
4458 int64_t old_file_size, last_cluster, new_file_size;
4459 uint64_t nb_new_data_clusters, nb_new_l2_tables;
4460 bool subclusters_need_allocation = false;
4461
4462 /* With a data file, preallocation means just allocating the metadata
4463 * and forwarding the truncate request to the data file */
4464 if (has_data_file(bs)) {
4465 ret = preallocate_co(bs, old_length, offset, prealloc, errp);
4466 if (ret < 0) {
4467 goto fail;
4468 }
4469 break;
4470 }
4471
4472 old_file_size = bdrv_co_getlength(bs->file->bs);
4473 if (old_file_size < 0) {
4474 error_setg_errno(errp, -old_file_size,
4475 "Failed to inquire current file length");
4476 ret = old_file_size;
4477 goto fail;
4478 }
4479
4480 last_cluster = qcow2_get_last_cluster(bs, old_file_size);
4481 if (last_cluster >= 0) {
4482 old_file_size = (last_cluster + 1) * s->cluster_size;
4483 } else {
4484 old_file_size = ROUND_UP(old_file_size, s->cluster_size);
4485 }
4486
4487 nb_new_data_clusters = (ROUND_UP(offset, s->cluster_size) -
4488 start_of_cluster(s, old_length)) >> s->cluster_bits;
4489
4490 /* This is an overestimation; we will not actually allocate space for
4491 * these in the file but just make sure the new refcount structures are
4492 * able to cover them so we will not have to allocate new refblocks
4493 * while entering the data blocks in the potentially new L2 tables.
4494 * (We do not actually care where the L2 tables are placed. Maybe they
4495 * are already allocated or they can be placed somewhere before
4496 * @old_file_size. It does not matter because they will be fully
4497 * allocated automatically, so they do not need to be covered by the
4498 * preallocation. All that matters is that we will not have to allocate
4499 * new refcount structures for them.) */
4500 nb_new_l2_tables = DIV_ROUND_UP(nb_new_data_clusters,
4501 s->cluster_size / l2_entry_size(s));
4502 /* The cluster range may not be aligned to L2 boundaries, so add one L2
4503 * table for a potential head/tail */
4504 nb_new_l2_tables++;
4505
4506 allocation_start = qcow2_refcount_area(bs, old_file_size,
4507 nb_new_data_clusters +
4508 nb_new_l2_tables,
4509 true, 0, 0);
4510 if (allocation_start < 0) {
4511 error_setg_errno(errp, -allocation_start,
4512 "Failed to resize refcount structures");
4513 ret = allocation_start;
4514 goto fail;
4515 }
4516
4517 clusters_allocated = qcow2_alloc_clusters_at(bs, allocation_start,
4518 nb_new_data_clusters);
4519 if (clusters_allocated < 0) {
4520 error_setg_errno(errp, -clusters_allocated,
4521 "Failed to allocate data clusters");
4522 ret = clusters_allocated;
4523 goto fail;
4524 }
4525
4526 assert(clusters_allocated == nb_new_data_clusters);
4527
4528 /* Allocate the data area */
4529 new_file_size = allocation_start +
4530 nb_new_data_clusters * s->cluster_size;
4531 /*
4532 * Image file grows, so @exact does not matter.
4533 *
4534 * If we need to zero out the new area, try first whether the protocol
4535 * driver can already take care of this.
4536 */
4537 if (flags & BDRV_REQ_ZERO_WRITE) {
4538 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc,
4539 BDRV_REQ_ZERO_WRITE, NULL);
4540 if (ret >= 0) {
4541 flags &= ~BDRV_REQ_ZERO_WRITE;
4542 /* Ensure that we read zeroes and not backing file data */
4543 subclusters_need_allocation = true;
4544 }
4545 } else {
4546 ret = -1;
4547 }
4548 if (ret < 0) {
4549 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 0,
4550 errp);
4551 }
4552 if (ret < 0) {
4553 error_prepend(errp, "Failed to resize underlying file: ");
4554 qcow2_free_clusters(bs, allocation_start,
4555 nb_new_data_clusters * s->cluster_size,
4556 QCOW2_DISCARD_OTHER);
4557 goto fail;
4558 }
4559
4560 /* Create the necessary L2 entries */
4561 host_offset = allocation_start;
4562 guest_offset = old_length;
4563 while (nb_new_data_clusters) {
4564 int64_t nb_clusters = MIN(
4565 nb_new_data_clusters,
4566 s->l2_slice_size - offset_to_l2_slice_index(s, guest_offset));
4567 unsigned cow_start_length = offset_into_cluster(s, guest_offset);
4568 QCowL2Meta allocation;
4569 guest_offset = start_of_cluster(s, guest_offset);
4570 allocation = (QCowL2Meta) {
4571 .offset = guest_offset,
4572 .alloc_offset = host_offset,
4573 .nb_clusters = nb_clusters,
4574 .cow_start = {
4575 .offset = 0,
4576 .nb_bytes = cow_start_length,
4577 },
4578 .cow_end = {
4579 .offset = nb_clusters << s->cluster_bits,
4580 .nb_bytes = 0,
4581 },
4582 .prealloc = !subclusters_need_allocation,
4583 };
4584 qemu_co_queue_init(&allocation.dependent_requests);
4585
4586 ret = qcow2_alloc_cluster_link_l2(bs, &allocation);
4587 if (ret < 0) {
4588 error_setg_errno(errp, -ret, "Failed to update L2 tables");
4589 qcow2_free_clusters(bs, host_offset,
4590 nb_new_data_clusters * s->cluster_size,
4591 QCOW2_DISCARD_OTHER);
4592 goto fail;
4593 }
4594
4595 guest_offset += nb_clusters * s->cluster_size;
4596 host_offset += nb_clusters * s->cluster_size;
4597 nb_new_data_clusters -= nb_clusters;
4598 }
4599 break;
4600 }
4601
4602 default:
4603 g_assert_not_reached();
4604 }
4605
4606 if ((flags & BDRV_REQ_ZERO_WRITE) && offset > old_length) {
4607 uint64_t zero_start = QEMU_ALIGN_UP(old_length, s->subcluster_size);
4608
4609 /*
4610 * Use zero clusters as much as we can. qcow2_subcluster_zeroize()
4611 * requires a subcluster-aligned start. The end may be unaligned if
4612 * it is at the end of the image (which it is here).
4613 */
4614 if (offset > zero_start) {
4615 ret = qcow2_subcluster_zeroize(bs, zero_start, offset - zero_start,
4616 0);
4617 if (ret < 0) {
4618 error_setg_errno(errp, -ret, "Failed to zero out new clusters");
4619 goto fail;
4620 }
4621 }
4622
4623 /* Write explicit zeros for the unaligned head */
4624 if (zero_start > old_length) {
4625 uint64_t len = MIN(zero_start, offset) - old_length;
4626 uint8_t *buf = qemu_blockalign0(bs, len);
4627 QEMUIOVector qiov;
4628 qemu_iovec_init_buf(&qiov, buf, len);
4629
4630 qemu_co_mutex_unlock(&s->lock);
4631 ret = qcow2_co_pwritev_part(bs, old_length, len, &qiov, 0, 0);
4632 qemu_co_mutex_lock(&s->lock);
4633
4634 qemu_vfree(buf);
4635 if (ret < 0) {
4636 error_setg_errno(errp, -ret, "Failed to zero out the new area");
4637 goto fail;
4638 }
4639 }
4640 }
4641
4642 if (prealloc != PREALLOC_MODE_OFF) {
4643 /* Flush metadata before actually changing the image size */
4644 ret = qcow2_write_caches(bs);
4645 if (ret < 0) {
4646 error_setg_errno(errp, -ret,
4647 "Failed to flush the preallocated area to disk");
4648 goto fail;
4649 }
4650 }
4651
4652 bs->total_sectors = offset / BDRV_SECTOR_SIZE;
4653
4654 /* write updated header.size */
4655 offset = cpu_to_be64(offset);
4656 ret = bdrv_co_pwrite_sync(bs->file, offsetof(QCowHeader, size),
4657 sizeof(offset), &offset, 0);
4658 if (ret < 0) {
4659 error_setg_errno(errp, -ret, "Failed to update the image size");
4660 goto fail;
4661 }
4662
4663 s->l1_vm_state_index = new_l1_size;
4664
4665 /* Update cache sizes */
4666 options = qdict_clone_shallow(bs->options);
4667 ret = qcow2_update_options(bs, options, s->flags, errp);
4668 qobject_unref(options);
4669 if (ret < 0) {
4670 goto fail;
4671 }
4672 ret = 0;
4673 fail:
4674 qemu_co_mutex_unlock(&s->lock);
4675 return ret;
4676 }
4677
4678 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_pwritev_compressed_task(BlockDriverState * bs,uint64_t offset,uint64_t bytes,QEMUIOVector * qiov,size_t qiov_offset)4679 qcow2_co_pwritev_compressed_task(BlockDriverState *bs,
4680 uint64_t offset, uint64_t bytes,
4681 QEMUIOVector *qiov, size_t qiov_offset)
4682 {
4683 BDRVQcow2State *s = bs->opaque;
4684 int ret;
4685 ssize_t out_len;
4686 uint8_t *buf, *out_buf;
4687 uint64_t cluster_offset;
4688
4689 assert(bytes == s->cluster_size || (bytes < s->cluster_size &&
4690 (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS)));
4691
4692 buf = qemu_blockalign(bs, s->cluster_size);
4693 if (bytes < s->cluster_size) {
4694 /* Zero-pad last write if image size is not cluster aligned */
4695 memset(buf + bytes, 0, s->cluster_size - bytes);
4696 }
4697 qemu_iovec_to_buf(qiov, qiov_offset, buf, bytes);
4698
4699 out_buf = g_malloc(s->cluster_size);
4700
4701 out_len = qcow2_co_compress(bs, out_buf, s->cluster_size - 1,
4702 buf, s->cluster_size);
4703 if (out_len == -ENOMEM) {
4704 /* could not compress: write normal cluster */
4705 ret = qcow2_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, 0);
4706 if (ret < 0) {
4707 goto fail;
4708 }
4709 goto success;
4710 } else if (out_len < 0) {
4711 ret = -EINVAL;
4712 goto fail;
4713 }
4714
4715 qemu_co_mutex_lock(&s->lock);
4716 ret = qcow2_alloc_compressed_cluster_offset(bs, offset, out_len,
4717 &cluster_offset);
4718 if (ret < 0) {
4719 qemu_co_mutex_unlock(&s->lock);
4720 goto fail;
4721 }
4722
4723 ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len, true);
4724 qemu_co_mutex_unlock(&s->lock);
4725 if (ret < 0) {
4726 goto fail;
4727 }
4728
4729 BLKDBG_CO_EVENT(s->data_file, BLKDBG_WRITE_COMPRESSED);
4730 ret = bdrv_co_pwrite(s->data_file, cluster_offset, out_len, out_buf, 0);
4731 if (ret < 0) {
4732 goto fail;
4733 }
4734 success:
4735 ret = 0;
4736 fail:
4737 qemu_vfree(buf);
4738 g_free(out_buf);
4739 return ret;
4740 }
4741
4742 /*
4743 * This function can count as GRAPH_RDLOCK because
4744 * qcow2_co_pwritev_compressed_part() holds the graph lock and keeps it until
4745 * this coroutine has terminated.
4746 */
4747 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_pwritev_compressed_task_entry(AioTask * task)4748 qcow2_co_pwritev_compressed_task_entry(AioTask *task)
4749 {
4750 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task);
4751
4752 assert(!t->subcluster_type && !t->l2meta);
4753
4754 return qcow2_co_pwritev_compressed_task(t->bs, t->offset, t->bytes, t->qiov,
4755 t->qiov_offset);
4756 }
4757
4758 /*
4759 * XXX: put compressed sectors first, then all the cluster aligned
4760 * tables to avoid losing bytes in alignment
4761 */
4762 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_pwritev_compressed_part(BlockDriverState * bs,int64_t offset,int64_t bytes,QEMUIOVector * qiov,size_t qiov_offset)4763 qcow2_co_pwritev_compressed_part(BlockDriverState *bs,
4764 int64_t offset, int64_t bytes,
4765 QEMUIOVector *qiov, size_t qiov_offset)
4766 {
4767 BDRVQcow2State *s = bs->opaque;
4768 AioTaskPool *aio = NULL;
4769 int ret = 0;
4770
4771 if (has_data_file(bs)) {
4772 return -ENOTSUP;
4773 }
4774
4775 if (bytes == 0) {
4776 /*
4777 * align end of file to a sector boundary to ease reading with
4778 * sector based I/Os
4779 */
4780 int64_t len = bdrv_co_getlength(bs->file->bs);
4781 if (len < 0) {
4782 return len;
4783 }
4784 return bdrv_co_truncate(bs->file, len, false, PREALLOC_MODE_OFF, 0,
4785 NULL);
4786 }
4787
4788 if (offset_into_cluster(s, offset)) {
4789 return -EINVAL;
4790 }
4791
4792 if (offset_into_cluster(s, bytes) &&
4793 (offset + bytes) != (bs->total_sectors << BDRV_SECTOR_BITS)) {
4794 return -EINVAL;
4795 }
4796
4797 while (bytes && aio_task_pool_status(aio) == 0) {
4798 uint64_t chunk_size = MIN(bytes, s->cluster_size);
4799
4800 if (!aio && chunk_size != bytes) {
4801 aio = aio_task_pool_new(QCOW2_MAX_WORKERS);
4802 }
4803
4804 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_compressed_task_entry,
4805 0, 0, offset, chunk_size, qiov, qiov_offset, NULL);
4806 if (ret < 0) {
4807 break;
4808 }
4809 qiov_offset += chunk_size;
4810 offset += chunk_size;
4811 bytes -= chunk_size;
4812 }
4813
4814 if (aio) {
4815 aio_task_pool_wait_all(aio);
4816 if (ret == 0) {
4817 ret = aio_task_pool_status(aio);
4818 }
4819 g_free(aio);
4820 }
4821
4822 return ret;
4823 }
4824
4825 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_preadv_compressed(BlockDriverState * bs,uint64_t l2_entry,uint64_t offset,uint64_t bytes,QEMUIOVector * qiov,size_t qiov_offset)4826 qcow2_co_preadv_compressed(BlockDriverState *bs,
4827 uint64_t l2_entry,
4828 uint64_t offset,
4829 uint64_t bytes,
4830 QEMUIOVector *qiov,
4831 size_t qiov_offset)
4832 {
4833 BDRVQcow2State *s = bs->opaque;
4834 int ret = 0, csize;
4835 uint64_t coffset;
4836 uint8_t *buf, *out_buf;
4837 int offset_in_cluster = offset_into_cluster(s, offset);
4838
4839 qcow2_parse_compressed_l2_entry(bs, l2_entry, &coffset, &csize);
4840
4841 buf = g_try_malloc(csize);
4842 if (!buf) {
4843 return -ENOMEM;
4844 }
4845
4846 out_buf = qemu_blockalign(bs, s->cluster_size);
4847
4848 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
4849 ret = bdrv_co_pread(bs->file, coffset, csize, buf, 0);
4850 if (ret < 0) {
4851 goto fail;
4852 }
4853
4854 if (qcow2_co_decompress(bs, out_buf, s->cluster_size, buf, csize) < 0) {
4855 ret = -EIO;
4856 goto fail;
4857 }
4858
4859 qemu_iovec_from_buf(qiov, qiov_offset, out_buf + offset_in_cluster, bytes);
4860
4861 fail:
4862 qemu_vfree(out_buf);
4863 g_free(buf);
4864
4865 return ret;
4866 }
4867
make_completely_empty(BlockDriverState * bs)4868 static int GRAPH_RDLOCK make_completely_empty(BlockDriverState *bs)
4869 {
4870 BDRVQcow2State *s = bs->opaque;
4871 Error *local_err = NULL;
4872 int ret, l1_clusters;
4873 int64_t offset;
4874 uint64_t *new_reftable = NULL;
4875 uint64_t rt_entry, l1_size2;
4876 struct {
4877 uint64_t l1_offset;
4878 uint64_t reftable_offset;
4879 uint32_t reftable_clusters;
4880 } QEMU_PACKED l1_ofs_rt_ofs_cls;
4881
4882 ret = qcow2_cache_empty(bs, s->l2_table_cache);
4883 if (ret < 0) {
4884 goto fail;
4885 }
4886
4887 ret = qcow2_cache_empty(bs, s->refcount_block_cache);
4888 if (ret < 0) {
4889 goto fail;
4890 }
4891
4892 /* Refcounts will be broken utterly */
4893 ret = qcow2_mark_dirty(bs);
4894 if (ret < 0) {
4895 goto fail;
4896 }
4897
4898 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
4899
4900 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE);
4901 l1_size2 = (uint64_t)s->l1_size * L1E_SIZE;
4902
4903 /* After this call, neither the in-memory nor the on-disk refcount
4904 * information accurately describe the actual references */
4905
4906 ret = bdrv_pwrite_zeroes(bs->file, s->l1_table_offset,
4907 l1_clusters * s->cluster_size, 0);
4908 if (ret < 0) {
4909 goto fail_broken_refcounts;
4910 }
4911 memset(s->l1_table, 0, l1_size2);
4912
4913 BLKDBG_EVENT(bs->file, BLKDBG_EMPTY_IMAGE_PREPARE);
4914
4915 /* Overwrite enough clusters at the beginning of the sectors to place
4916 * the refcount table, a refcount block and the L1 table in; this may
4917 * overwrite parts of the existing refcount and L1 table, which is not
4918 * an issue because the dirty flag is set, complete data loss is in fact
4919 * desired and partial data loss is consequently fine as well */
4920 ret = bdrv_pwrite_zeroes(bs->file, s->cluster_size,
4921 (2 + l1_clusters) * s->cluster_size, 0);
4922 /* This call (even if it failed overall) may have overwritten on-disk
4923 * refcount structures; in that case, the in-memory refcount information
4924 * will probably differ from the on-disk information which makes the BDS
4925 * unusable */
4926 if (ret < 0) {
4927 goto fail_broken_refcounts;
4928 }
4929
4930 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
4931 BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE);
4932
4933 /* "Create" an empty reftable (one cluster) directly after the image
4934 * header and an empty L1 table three clusters after the image header;
4935 * the cluster between those two will be used as the first refblock */
4936 l1_ofs_rt_ofs_cls.l1_offset = cpu_to_be64(3 * s->cluster_size);
4937 l1_ofs_rt_ofs_cls.reftable_offset = cpu_to_be64(s->cluster_size);
4938 l1_ofs_rt_ofs_cls.reftable_clusters = cpu_to_be32(1);
4939 ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_table_offset),
4940 sizeof(l1_ofs_rt_ofs_cls), &l1_ofs_rt_ofs_cls, 0);
4941 if (ret < 0) {
4942 goto fail_broken_refcounts;
4943 }
4944
4945 s->l1_table_offset = 3 * s->cluster_size;
4946
4947 new_reftable = g_try_new0(uint64_t, s->cluster_size / REFTABLE_ENTRY_SIZE);
4948 if (!new_reftable) {
4949 ret = -ENOMEM;
4950 goto fail_broken_refcounts;
4951 }
4952
4953 s->refcount_table_offset = s->cluster_size;
4954 s->refcount_table_size = s->cluster_size / REFTABLE_ENTRY_SIZE;
4955 s->max_refcount_table_index = 0;
4956
4957 g_free(s->refcount_table);
4958 s->refcount_table = new_reftable;
4959 new_reftable = NULL;
4960
4961 /* Now the in-memory refcount information again corresponds to the on-disk
4962 * information (reftable is empty and no refblocks (the refblock cache is
4963 * empty)); however, this means some clusters (e.g. the image header) are
4964 * referenced, but not refcounted, but the normal qcow2 code assumes that
4965 * the in-memory information is always correct */
4966
4967 BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC);
4968
4969 /* Enter the first refblock into the reftable */
4970 rt_entry = cpu_to_be64(2 * s->cluster_size);
4971 ret = bdrv_pwrite_sync(bs->file, s->cluster_size, sizeof(rt_entry),
4972 &rt_entry, 0);
4973 if (ret < 0) {
4974 goto fail_broken_refcounts;
4975 }
4976 s->refcount_table[0] = 2 * s->cluster_size;
4977
4978 s->free_cluster_index = 0;
4979 assert(3 + l1_clusters <= s->refcount_block_size);
4980 offset = qcow2_alloc_clusters(bs, 3 * s->cluster_size + l1_size2);
4981 if (offset < 0) {
4982 ret = offset;
4983 goto fail_broken_refcounts;
4984 } else if (offset > 0) {
4985 error_report("First cluster in emptied image is in use");
4986 abort();
4987 }
4988
4989 /* Now finally the in-memory information corresponds to the on-disk
4990 * structures and is correct */
4991 ret = qcow2_mark_clean(bs);
4992 if (ret < 0) {
4993 goto fail;
4994 }
4995
4996 ret = bdrv_truncate(bs->file, (3 + l1_clusters) * s->cluster_size, false,
4997 PREALLOC_MODE_OFF, 0, &local_err);
4998 if (ret < 0) {
4999 error_report_err(local_err);
5000 goto fail;
5001 }
5002
5003 return 0;
5004
5005 fail_broken_refcounts:
5006 /* The BDS is unusable at this point. If we wanted to make it usable, we
5007 * would have to call qcow2_refcount_close(), qcow2_refcount_init(),
5008 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init()
5009 * again. However, because the functions which could have caused this error
5010 * path to be taken are used by those functions as well, it's very likely
5011 * that that sequence will fail as well. Therefore, just eject the BDS. */
5012 bs->drv = NULL;
5013
5014 fail:
5015 g_free(new_reftable);
5016 return ret;
5017 }
5018
qcow2_make_empty(BlockDriverState * bs)5019 static int GRAPH_RDLOCK qcow2_make_empty(BlockDriverState *bs)
5020 {
5021 BDRVQcow2State *s = bs->opaque;
5022 uint64_t offset, end_offset;
5023 int step = QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size);
5024 int l1_clusters, ret = 0;
5025
5026 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE);
5027
5028 if (s->qcow_version >= 3 && !s->snapshots && !s->nb_bitmaps &&
5029 3 + l1_clusters <= s->refcount_block_size &&
5030 s->crypt_method_header != QCOW_CRYPT_LUKS &&
5031 !has_data_file(bs)) {
5032 /* The following function only works for qcow2 v3 images (it
5033 * requires the dirty flag) and only as long as there are no
5034 * features that reserve extra clusters (such as snapshots,
5035 * LUKS header, or persistent bitmaps), because it completely
5036 * empties the image. Furthermore, the L1 table and three
5037 * additional clusters (image header, refcount table, one
5038 * refcount block) have to fit inside one refcount block. It
5039 * only resets the image file, i.e. does not work with an
5040 * external data file. */
5041 return make_completely_empty(bs);
5042 }
5043
5044 /* This fallback code simply discards every active cluster; this is slow,
5045 * but works in all cases */
5046 end_offset = bs->total_sectors * BDRV_SECTOR_SIZE;
5047 for (offset = 0; offset < end_offset; offset += step) {
5048 /* As this function is generally used after committing an external
5049 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the
5050 * default action for this kind of discard is to pass the discard,
5051 * which will ideally result in an actually smaller image file, as
5052 * is probably desired. */
5053 ret = qcow2_cluster_discard(bs, offset, MIN(step, end_offset - offset),
5054 QCOW2_DISCARD_SNAPSHOT, true);
5055 if (ret < 0) {
5056 break;
5057 }
5058 }
5059
5060 return ret;
5061 }
5062
qcow2_co_flush_to_os(BlockDriverState * bs)5063 static coroutine_fn GRAPH_RDLOCK int qcow2_co_flush_to_os(BlockDriverState *bs)
5064 {
5065 BDRVQcow2State *s = bs->opaque;
5066 int ret;
5067
5068 qemu_co_mutex_lock(&s->lock);
5069 ret = qcow2_write_caches(bs);
5070 qemu_co_mutex_unlock(&s->lock);
5071
5072 return ret;
5073 }
5074
qcow2_measure(QemuOpts * opts,BlockDriverState * in_bs,Error ** errp)5075 static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
5076 Error **errp)
5077 {
5078 Error *local_err = NULL;
5079 BlockMeasureInfo *info;
5080 uint64_t required = 0; /* bytes that contribute to required size */
5081 uint64_t virtual_size; /* disk size as seen by guest */
5082 uint64_t refcount_bits;
5083 uint64_t l2_tables;
5084 uint64_t luks_payload_size = 0;
5085 size_t cluster_size;
5086 int version;
5087 char *optstr;
5088 PreallocMode prealloc;
5089 bool has_backing_file;
5090 bool has_luks;
5091 bool extended_l2;
5092 size_t l2e_size;
5093
5094 /* Parse image creation options */
5095 extended_l2 = qemu_opt_get_bool_del(opts, BLOCK_OPT_EXTL2, false);
5096
5097 cluster_size = qcow2_opt_get_cluster_size_del(opts, extended_l2,
5098 &local_err);
5099 if (local_err) {
5100 goto err;
5101 }
5102
5103 version = qcow2_opt_get_version_del(opts, &local_err);
5104 if (local_err) {
5105 goto err;
5106 }
5107
5108 refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err);
5109 if (local_err) {
5110 goto err;
5111 }
5112
5113 optstr = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
5114 prealloc = qapi_enum_parse(&PreallocMode_lookup, optstr,
5115 PREALLOC_MODE_OFF, &local_err);
5116 g_free(optstr);
5117 if (local_err) {
5118 goto err;
5119 }
5120
5121 optstr = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
5122 has_backing_file = !!optstr;
5123 g_free(optstr);
5124
5125 optstr = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT);
5126 has_luks = optstr && strcmp(optstr, "luks") == 0;
5127 g_free(optstr);
5128
5129 if (has_luks) {
5130 g_autoptr(QCryptoBlockCreateOptions) create_opts = NULL;
5131 QDict *cryptoopts = qcow2_extract_crypto_opts(opts, "luks", errp);
5132 size_t headerlen;
5133
5134 create_opts = block_crypto_create_opts_init(cryptoopts, errp);
5135 qobject_unref(cryptoopts);
5136 if (!create_opts) {
5137 goto err;
5138 }
5139
5140 if (!qcrypto_block_calculate_payload_offset(create_opts,
5141 "encrypt.",
5142 &headerlen,
5143 &local_err)) {
5144 goto err;
5145 }
5146
5147 luks_payload_size = ROUND_UP(headerlen, cluster_size);
5148 }
5149
5150 virtual_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
5151 virtual_size = ROUND_UP(virtual_size, cluster_size);
5152
5153 /* Check that virtual disk size is valid */
5154 l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
5155 l2_tables = DIV_ROUND_UP(virtual_size / cluster_size,
5156 cluster_size / l2e_size);
5157 if (l2_tables * L1E_SIZE > QCOW_MAX_L1_SIZE) {
5158 error_setg(&local_err, "The image size is too large "
5159 "(try using a larger cluster size)");
5160 goto err;
5161 }
5162
5163 /* Account for input image */
5164 if (in_bs) {
5165 int64_t ssize = bdrv_getlength(in_bs);
5166 if (ssize < 0) {
5167 error_setg_errno(&local_err, -ssize,
5168 "Unable to get image virtual_size");
5169 goto err;
5170 }
5171
5172 virtual_size = ROUND_UP(ssize, cluster_size);
5173
5174 if (has_backing_file) {
5175 /* We don't how much of the backing chain is shared by the input
5176 * image and the new image file. In the worst case the new image's
5177 * backing file has nothing in common with the input image. Be
5178 * conservative and assume all clusters need to be written.
5179 */
5180 required = virtual_size;
5181 } else {
5182 int64_t offset;
5183 int64_t pnum = 0;
5184
5185 for (offset = 0; offset < ssize; offset += pnum) {
5186 int ret;
5187
5188 ret = bdrv_block_status_above(in_bs, NULL, offset,
5189 ssize - offset, &pnum, NULL,
5190 NULL);
5191 if (ret < 0) {
5192 error_setg_errno(&local_err, -ret,
5193 "Unable to get block status");
5194 goto err;
5195 }
5196
5197 if (ret & BDRV_BLOCK_ZERO) {
5198 /* Skip zero regions (safe with no backing file) */
5199 } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) ==
5200 (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) {
5201 /* Extend pnum to end of cluster for next iteration */
5202 pnum = ROUND_UP(offset + pnum, cluster_size) - offset;
5203
5204 /* Count clusters we've seen */
5205 required += offset % cluster_size + pnum;
5206 }
5207 }
5208 }
5209 }
5210
5211 /* Take into account preallocation. Nothing special is needed for
5212 * PREALLOC_MODE_METADATA since metadata is always counted.
5213 */
5214 if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) {
5215 required = virtual_size;
5216 }
5217
5218 info = g_new0(BlockMeasureInfo, 1);
5219 info->fully_allocated = luks_payload_size +
5220 qcow2_calc_prealloc_size(virtual_size, cluster_size,
5221 ctz32(refcount_bits), extended_l2);
5222
5223 /*
5224 * Remove data clusters that are not required. This overestimates the
5225 * required size because metadata needed for the fully allocated file is
5226 * still counted. Show bitmaps only if both source and destination
5227 * would support them.
5228 */
5229 info->required = info->fully_allocated - virtual_size + required;
5230 info->has_bitmaps = version >= 3 && in_bs &&
5231 bdrv_supports_persistent_dirty_bitmap(in_bs);
5232 if (info->has_bitmaps) {
5233 info->bitmaps = qcow2_get_persistent_dirty_bitmap_size(in_bs,
5234 cluster_size);
5235 }
5236 return info;
5237
5238 err:
5239 error_propagate(errp, local_err);
5240 return NULL;
5241 }
5242
5243 static int coroutine_fn
qcow2_co_get_info(BlockDriverState * bs,BlockDriverInfo * bdi)5244 qcow2_co_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
5245 {
5246 BDRVQcow2State *s = bs->opaque;
5247 bdi->cluster_size = s->cluster_size;
5248 bdi->subcluster_size = s->subcluster_size;
5249 bdi->vm_state_offset = qcow2_vm_state_offset(s);
5250 bdi->is_dirty = s->incompatible_features & QCOW2_INCOMPAT_DIRTY;
5251 return 0;
5252 }
5253
5254 static ImageInfoSpecific * GRAPH_RDLOCK
qcow2_get_specific_info(BlockDriverState * bs,Error ** errp)5255 qcow2_get_specific_info(BlockDriverState *bs, Error **errp)
5256 {
5257 BDRVQcow2State *s = bs->opaque;
5258 ImageInfoSpecific *spec_info;
5259 QCryptoBlockInfo *encrypt_info = NULL;
5260
5261 if (s->crypto != NULL) {
5262 encrypt_info = qcrypto_block_get_info(s->crypto, errp);
5263 if (!encrypt_info) {
5264 return NULL;
5265 }
5266 }
5267
5268 spec_info = g_new(ImageInfoSpecific, 1);
5269 *spec_info = (ImageInfoSpecific){
5270 .type = IMAGE_INFO_SPECIFIC_KIND_QCOW2,
5271 .u.qcow2.data = g_new0(ImageInfoSpecificQCow2, 1),
5272 };
5273 if (s->qcow_version == 2) {
5274 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){
5275 .compat = g_strdup("0.10"),
5276 .refcount_bits = s->refcount_bits,
5277 };
5278 } else if (s->qcow_version == 3) {
5279 Qcow2BitmapInfoList *bitmaps;
5280 if (!qcow2_get_bitmap_info_list(bs, &bitmaps, errp)) {
5281 qapi_free_ImageInfoSpecific(spec_info);
5282 qapi_free_QCryptoBlockInfo(encrypt_info);
5283 return NULL;
5284 }
5285 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){
5286 .compat = g_strdup("1.1"),
5287 .lazy_refcounts = s->compatible_features &
5288 QCOW2_COMPAT_LAZY_REFCOUNTS,
5289 .has_lazy_refcounts = true,
5290 .corrupt = s->incompatible_features &
5291 QCOW2_INCOMPAT_CORRUPT,
5292 .has_corrupt = true,
5293 .has_extended_l2 = true,
5294 .extended_l2 = has_subclusters(s),
5295 .refcount_bits = s->refcount_bits,
5296 .has_bitmaps = !!bitmaps,
5297 .bitmaps = bitmaps,
5298 .data_file = g_strdup(s->image_data_file),
5299 .has_data_file_raw = has_data_file(bs),
5300 .data_file_raw = data_file_is_raw(bs),
5301 .compression_type = s->compression_type,
5302 };
5303 } else {
5304 /* if this assertion fails, this probably means a new version was
5305 * added without having it covered here */
5306 g_assert_not_reached();
5307 }
5308
5309 if (encrypt_info) {
5310 ImageInfoSpecificQCow2Encryption *qencrypt =
5311 g_new(ImageInfoSpecificQCow2Encryption, 1);
5312 switch (encrypt_info->format) {
5313 case QCRYPTO_BLOCK_FORMAT_QCOW:
5314 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES;
5315 break;
5316 case QCRYPTO_BLOCK_FORMAT_LUKS:
5317 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS;
5318 qencrypt->u.luks = encrypt_info->u.luks;
5319 break;
5320 default:
5321 abort();
5322 }
5323 /* Since we did shallow copy above, erase any pointers
5324 * in the original info */
5325 memset(&encrypt_info->u, 0, sizeof(encrypt_info->u));
5326 qapi_free_QCryptoBlockInfo(encrypt_info);
5327
5328 spec_info->u.qcow2.data->encrypt = qencrypt;
5329 }
5330
5331 return spec_info;
5332 }
5333
5334 static int coroutine_mixed_fn GRAPH_RDLOCK
qcow2_has_zero_init(BlockDriverState * bs)5335 qcow2_has_zero_init(BlockDriverState *bs)
5336 {
5337 BDRVQcow2State *s = bs->opaque;
5338 bool preallocated;
5339
5340 if (qemu_in_coroutine()) {
5341 qemu_co_mutex_lock(&s->lock);
5342 }
5343 /*
5344 * Check preallocation status: Preallocated images have all L2
5345 * tables allocated, nonpreallocated images have none. It is
5346 * therefore enough to check the first one.
5347 */
5348 preallocated = s->l1_size > 0 && s->l1_table[0] != 0;
5349 if (qemu_in_coroutine()) {
5350 qemu_co_mutex_unlock(&s->lock);
5351 }
5352
5353 if (!preallocated) {
5354 return 1;
5355 } else if (bs->encrypted) {
5356 return 0;
5357 } else {
5358 return bdrv_has_zero_init(s->data_file->bs);
5359 }
5360 }
5361
5362 /*
5363 * Check the request to vmstate. On success return
5364 * qcow2_vm_state_offset(bs) + @pos
5365 */
qcow2_check_vmstate_request(BlockDriverState * bs,QEMUIOVector * qiov,int64_t pos)5366 static int64_t qcow2_check_vmstate_request(BlockDriverState *bs,
5367 QEMUIOVector *qiov, int64_t pos)
5368 {
5369 BDRVQcow2State *s = bs->opaque;
5370 int64_t vmstate_offset = qcow2_vm_state_offset(s);
5371 int ret;
5372
5373 /* Incoming requests must be OK */
5374 bdrv_check_qiov_request(pos, qiov->size, qiov, 0, &error_abort);
5375
5376 if (INT64_MAX - pos < vmstate_offset) {
5377 return -EIO;
5378 }
5379
5380 pos += vmstate_offset;
5381 ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL);
5382 if (ret < 0) {
5383 return ret;
5384 }
5385
5386 return pos;
5387 }
5388
5389 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_save_vmstate(BlockDriverState * bs,QEMUIOVector * qiov,int64_t pos)5390 qcow2_co_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
5391 {
5392 int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos);
5393 if (offset < 0) {
5394 return offset;
5395 }
5396
5397 BLKDBG_CO_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
5398 return bs->drv->bdrv_co_pwritev_part(bs, offset, qiov->size, qiov, 0, 0);
5399 }
5400
5401 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_load_vmstate(BlockDriverState * bs,QEMUIOVector * qiov,int64_t pos)5402 qcow2_co_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
5403 {
5404 int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos);
5405 if (offset < 0) {
5406 return offset;
5407 }
5408
5409 BLKDBG_CO_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
5410 return bs->drv->bdrv_co_preadv_part(bs, offset, qiov->size, qiov, 0, 0);
5411 }
5412
qcow2_has_compressed_clusters(BlockDriverState * bs)5413 static int GRAPH_RDLOCK qcow2_has_compressed_clusters(BlockDriverState *bs)
5414 {
5415 int64_t offset = 0;
5416 int64_t bytes = bdrv_getlength(bs);
5417
5418 if (bytes < 0) {
5419 return bytes;
5420 }
5421
5422 while (bytes != 0) {
5423 int ret;
5424 QCow2SubclusterType type;
5425 unsigned int cur_bytes = MIN(INT_MAX, bytes);
5426 uint64_t host_offset;
5427
5428 ret = qcow2_get_host_offset(bs, offset, &cur_bytes, &host_offset,
5429 &type);
5430 if (ret < 0) {
5431 return ret;
5432 }
5433
5434 if (type == QCOW2_SUBCLUSTER_COMPRESSED) {
5435 return 1;
5436 }
5437
5438 offset += cur_bytes;
5439 bytes -= cur_bytes;
5440 }
5441
5442 return 0;
5443 }
5444
5445 /*
5446 * Downgrades an image's version. To achieve this, any incompatible features
5447 * have to be removed.
5448 */
5449 static int GRAPH_RDLOCK
qcow2_downgrade(BlockDriverState * bs,int target_version,BlockDriverAmendStatusCB * status_cb,void * cb_opaque,Error ** errp)5450 qcow2_downgrade(BlockDriverState *bs, int target_version,
5451 BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
5452 Error **errp)
5453 {
5454 BDRVQcow2State *s = bs->opaque;
5455 int current_version = s->qcow_version;
5456 int ret;
5457 int i;
5458
5459 /* This is qcow2_downgrade(), not qcow2_upgrade() */
5460 assert(target_version < current_version);
5461
5462 /* There are no other versions (now) that you can downgrade to */
5463 assert(target_version == 2);
5464
5465 if (s->refcount_order != 4) {
5466 error_setg(errp, "compat=0.10 requires refcount_bits=16");
5467 return -ENOTSUP;
5468 }
5469
5470 if (has_data_file(bs)) {
5471 error_setg(errp, "Cannot downgrade an image with a data file");
5472 return -ENOTSUP;
5473 }
5474
5475 /*
5476 * If any internal snapshot has a different size than the current
5477 * image size, or VM state size that exceeds 32 bits, downgrading
5478 * is unsafe. Even though we would still use v3-compliant output
5479 * to preserve that data, other v2 programs might not realize
5480 * those optional fields are important.
5481 */
5482 for (i = 0; i < s->nb_snapshots; i++) {
5483 if (s->snapshots[i].vm_state_size > UINT32_MAX ||
5484 s->snapshots[i].disk_size != bs->total_sectors * BDRV_SECTOR_SIZE) {
5485 error_setg(errp, "Internal snapshots prevent downgrade of image");
5486 return -ENOTSUP;
5487 }
5488 }
5489
5490 /* clear incompatible features */
5491 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
5492 ret = qcow2_mark_clean(bs);
5493 if (ret < 0) {
5494 error_setg_errno(errp, -ret, "Failed to make the image clean");
5495 return ret;
5496 }
5497 }
5498
5499 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in
5500 * the first place; if that happens nonetheless, returning -ENOTSUP is the
5501 * best thing to do anyway */
5502
5503 if (s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION) {
5504 error_setg(errp, "Cannot downgrade an image with incompatible features "
5505 "0x%" PRIx64 " set",
5506 s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION);
5507 return -ENOTSUP;
5508 }
5509
5510 /* since we can ignore compatible features, we can set them to 0 as well */
5511 s->compatible_features = 0;
5512 /* if lazy refcounts have been used, they have already been fixed through
5513 * clearing the dirty flag */
5514
5515 /* clearing autoclear features is trivial */
5516 s->autoclear_features = 0;
5517
5518 ret = qcow2_expand_zero_clusters(bs, status_cb, cb_opaque);
5519 if (ret < 0) {
5520 error_setg_errno(errp, -ret, "Failed to turn zero into data clusters");
5521 return ret;
5522 }
5523
5524 if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) {
5525 ret = qcow2_has_compressed_clusters(bs);
5526 if (ret < 0) {
5527 error_setg(errp, "Failed to check block status");
5528 return -EINVAL;
5529 }
5530 if (ret) {
5531 error_setg(errp, "Cannot downgrade an image with zstd compression "
5532 "type and existing compressed clusters");
5533 return -ENOTSUP;
5534 }
5535 /*
5536 * No compressed clusters for now, so just chose default zlib
5537 * compression.
5538 */
5539 s->incompatible_features &= ~QCOW2_INCOMPAT_COMPRESSION;
5540 s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB;
5541 }
5542
5543 assert(s->incompatible_features == 0);
5544
5545 s->qcow_version = target_version;
5546 ret = qcow2_update_header(bs);
5547 if (ret < 0) {
5548 s->qcow_version = current_version;
5549 error_setg_errno(errp, -ret, "Failed to update the image header");
5550 return ret;
5551 }
5552 return 0;
5553 }
5554
5555 /*
5556 * Upgrades an image's version. While newer versions encompass all
5557 * features of older versions, some things may have to be presented
5558 * differently.
5559 */
5560 static int GRAPH_RDLOCK
qcow2_upgrade(BlockDriverState * bs,int target_version,BlockDriverAmendStatusCB * status_cb,void * cb_opaque,Error ** errp)5561 qcow2_upgrade(BlockDriverState *bs, int target_version,
5562 BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
5563 Error **errp)
5564 {
5565 BDRVQcow2State *s = bs->opaque;
5566 bool need_snapshot_update;
5567 int current_version = s->qcow_version;
5568 int i;
5569 int ret;
5570
5571 /* This is qcow2_upgrade(), not qcow2_downgrade() */
5572 assert(target_version > current_version);
5573
5574 /* There are no other versions (yet) that you can upgrade to */
5575 assert(target_version == 3);
5576
5577 status_cb(bs, 0, 2, cb_opaque);
5578
5579 /*
5580 * In v2, snapshots do not need to have extra data. v3 requires
5581 * the 64-bit VM state size and the virtual disk size to be
5582 * present.
5583 * qcow2_write_snapshots() will always write the list in the
5584 * v3-compliant format.
5585 */
5586 need_snapshot_update = false;
5587 for (i = 0; i < s->nb_snapshots; i++) {
5588 if (s->snapshots[i].extra_data_size <
5589 sizeof_field(QCowSnapshotExtraData, vm_state_size_large) +
5590 sizeof_field(QCowSnapshotExtraData, disk_size))
5591 {
5592 need_snapshot_update = true;
5593 break;
5594 }
5595 }
5596 if (need_snapshot_update) {
5597 ret = qcow2_write_snapshots(bs);
5598 if (ret < 0) {
5599 error_setg_errno(errp, -ret, "Failed to update the snapshot table");
5600 return ret;
5601 }
5602 }
5603 status_cb(bs, 1, 2, cb_opaque);
5604
5605 s->qcow_version = target_version;
5606 ret = qcow2_update_header(bs);
5607 if (ret < 0) {
5608 s->qcow_version = current_version;
5609 error_setg_errno(errp, -ret, "Failed to update the image header");
5610 return ret;
5611 }
5612 status_cb(bs, 2, 2, cb_opaque);
5613
5614 return 0;
5615 }
5616
5617 typedef enum Qcow2AmendOperation {
5618 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be
5619 * statically initialized to so that the helper CB can discern the first
5620 * invocation from an operation change */
5621 QCOW2_NO_OPERATION = 0,
5622
5623 QCOW2_UPGRADING,
5624 QCOW2_UPDATING_ENCRYPTION,
5625 QCOW2_CHANGING_REFCOUNT_ORDER,
5626 QCOW2_DOWNGRADING,
5627 } Qcow2AmendOperation;
5628
5629 typedef struct Qcow2AmendHelperCBInfo {
5630 /* The code coordinating the amend operations should only modify
5631 * these four fields; the rest will be managed by the CB */
5632 BlockDriverAmendStatusCB *original_status_cb;
5633 void *original_cb_opaque;
5634
5635 Qcow2AmendOperation current_operation;
5636
5637 /* Total number of operations to perform (only set once) */
5638 int total_operations;
5639
5640 /* The following fields are managed by the CB */
5641
5642 /* Number of operations completed */
5643 int operations_completed;
5644
5645 /* Cumulative offset of all completed operations */
5646 int64_t offset_completed;
5647
5648 Qcow2AmendOperation last_operation;
5649 int64_t last_work_size;
5650 } Qcow2AmendHelperCBInfo;
5651
qcow2_amend_helper_cb(BlockDriverState * bs,int64_t operation_offset,int64_t operation_work_size,void * opaque)5652 static void qcow2_amend_helper_cb(BlockDriverState *bs,
5653 int64_t operation_offset,
5654 int64_t operation_work_size, void *opaque)
5655 {
5656 Qcow2AmendHelperCBInfo *info = opaque;
5657 int64_t current_work_size;
5658 int64_t projected_work_size;
5659
5660 if (info->current_operation != info->last_operation) {
5661 if (info->last_operation != QCOW2_NO_OPERATION) {
5662 info->offset_completed += info->last_work_size;
5663 info->operations_completed++;
5664 }
5665
5666 info->last_operation = info->current_operation;
5667 }
5668
5669 assert(info->total_operations > 0);
5670 assert(info->operations_completed < info->total_operations);
5671
5672 info->last_work_size = operation_work_size;
5673
5674 current_work_size = info->offset_completed + operation_work_size;
5675
5676 /* current_work_size is the total work size for (operations_completed + 1)
5677 * operations (which includes this one), so multiply it by the number of
5678 * operations not covered and divide it by the number of operations
5679 * covered to get a projection for the operations not covered */
5680 projected_work_size = current_work_size * (info->total_operations -
5681 info->operations_completed - 1)
5682 / (info->operations_completed + 1);
5683
5684 info->original_status_cb(bs, info->offset_completed + operation_offset,
5685 current_work_size + projected_work_size,
5686 info->original_cb_opaque);
5687 }
5688
5689 static int GRAPH_RDLOCK
qcow2_amend_options(BlockDriverState * bs,QemuOpts * opts,BlockDriverAmendStatusCB * status_cb,void * cb_opaque,bool force,Error ** errp)5690 qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
5691 BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
5692 bool force, Error **errp)
5693 {
5694 BDRVQcow2State *s = bs->opaque;
5695 int old_version = s->qcow_version, new_version = old_version;
5696 uint64_t new_size = 0;
5697 const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL;
5698 bool lazy_refcounts = s->use_lazy_refcounts;
5699 bool data_file_raw = data_file_is_raw(bs);
5700 const char *compat = NULL;
5701 int refcount_bits = s->refcount_bits;
5702 int ret;
5703 QemuOptDesc *desc = opts->list->desc;
5704 Qcow2AmendHelperCBInfo helper_cb_info;
5705 bool encryption_update = false;
5706
5707 while (desc && desc->name) {
5708 if (!qemu_opt_find(opts, desc->name)) {
5709 /* only change explicitly defined options */
5710 desc++;
5711 continue;
5712 }
5713
5714 if (!strcmp(desc->name, BLOCK_OPT_COMPAT_LEVEL)) {
5715 compat = qemu_opt_get(opts, BLOCK_OPT_COMPAT_LEVEL);
5716 if (!compat) {
5717 /* preserve default */
5718 } else if (!strcmp(compat, "0.10") || !strcmp(compat, "v2")) {
5719 new_version = 2;
5720 } else if (!strcmp(compat, "1.1") || !strcmp(compat, "v3")) {
5721 new_version = 3;
5722 } else {
5723 error_setg(errp, "Unknown compatibility level %s", compat);
5724 return -EINVAL;
5725 }
5726 } else if (!strcmp(desc->name, BLOCK_OPT_SIZE)) {
5727 new_size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0);
5728 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FILE)) {
5729 backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
5730 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FMT)) {
5731 backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT);
5732 } else if (g_str_has_prefix(desc->name, "encrypt.")) {
5733 if (!s->crypto) {
5734 error_setg(errp,
5735 "Can't amend encryption options - encryption not present");
5736 return -EINVAL;
5737 }
5738 if (s->crypt_method_header != QCOW_CRYPT_LUKS) {
5739 error_setg(errp,
5740 "Only LUKS encryption options can be amended");
5741 return -ENOTSUP;
5742 }
5743 encryption_update = true;
5744 } else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) {
5745 lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS,
5746 lazy_refcounts);
5747 } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) {
5748 refcount_bits = qemu_opt_get_number(opts, BLOCK_OPT_REFCOUNT_BITS,
5749 refcount_bits);
5750
5751 if (refcount_bits <= 0 || refcount_bits > 64 ||
5752 !is_power_of_2(refcount_bits))
5753 {
5754 error_setg(errp, "Refcount width must be a power of two and "
5755 "may not exceed 64 bits");
5756 return -EINVAL;
5757 }
5758 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE)) {
5759 data_file = qemu_opt_get(opts, BLOCK_OPT_DATA_FILE);
5760 if (data_file && !has_data_file(bs)) {
5761 error_setg(errp, "data-file can only be set for images that "
5762 "use an external data file");
5763 return -EINVAL;
5764 }
5765 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE_RAW)) {
5766 data_file_raw = qemu_opt_get_bool(opts, BLOCK_OPT_DATA_FILE_RAW,
5767 data_file_raw);
5768 if (data_file_raw && !data_file_is_raw(bs)) {
5769 error_setg(errp, "data-file-raw cannot be set on existing "
5770 "images");
5771 return -EINVAL;
5772 }
5773 } else {
5774 /* if this point is reached, this probably means a new option was
5775 * added without having it covered here */
5776 abort();
5777 }
5778
5779 desc++;
5780 }
5781
5782 helper_cb_info = (Qcow2AmendHelperCBInfo){
5783 .original_status_cb = status_cb,
5784 .original_cb_opaque = cb_opaque,
5785 .total_operations = (new_version != old_version)
5786 + (s->refcount_bits != refcount_bits) +
5787 (encryption_update == true)
5788 };
5789
5790 /* Upgrade first (some features may require compat=1.1) */
5791 if (new_version > old_version) {
5792 helper_cb_info.current_operation = QCOW2_UPGRADING;
5793 ret = qcow2_upgrade(bs, new_version, &qcow2_amend_helper_cb,
5794 &helper_cb_info, errp);
5795 if (ret < 0) {
5796 return ret;
5797 }
5798 }
5799
5800 if (encryption_update) {
5801 QDict *amend_opts_dict;
5802 QCryptoBlockAmendOptions *amend_opts;
5803
5804 helper_cb_info.current_operation = QCOW2_UPDATING_ENCRYPTION;
5805 amend_opts_dict = qcow2_extract_crypto_opts(opts, "luks", errp);
5806 if (!amend_opts_dict) {
5807 return -EINVAL;
5808 }
5809 amend_opts = block_crypto_amend_opts_init(amend_opts_dict, errp);
5810 qobject_unref(amend_opts_dict);
5811 if (!amend_opts) {
5812 return -EINVAL;
5813 }
5814 ret = qcrypto_block_amend_options(s->crypto,
5815 qcow2_crypto_hdr_read_func,
5816 qcow2_crypto_hdr_write_func,
5817 bs,
5818 amend_opts,
5819 force,
5820 errp);
5821 qapi_free_QCryptoBlockAmendOptions(amend_opts);
5822 if (ret < 0) {
5823 return ret;
5824 }
5825 }
5826
5827 if (s->refcount_bits != refcount_bits) {
5828 int refcount_order = ctz32(refcount_bits);
5829
5830 if (new_version < 3 && refcount_bits != 16) {
5831 error_setg(errp, "Refcount widths other than 16 bits require "
5832 "compatibility level 1.1 or above (use compat=1.1 or "
5833 "greater)");
5834 return -EINVAL;
5835 }
5836
5837 helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER;
5838 ret = qcow2_change_refcount_order(bs, refcount_order,
5839 &qcow2_amend_helper_cb,
5840 &helper_cb_info, errp);
5841 if (ret < 0) {
5842 return ret;
5843 }
5844 }
5845
5846 /* data-file-raw blocks backing files, so clear it first if requested */
5847 if (data_file_raw) {
5848 s->autoclear_features |= QCOW2_AUTOCLEAR_DATA_FILE_RAW;
5849 } else {
5850 s->autoclear_features &= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW;
5851 }
5852
5853 if (data_file) {
5854 g_free(s->image_data_file);
5855 s->image_data_file = *data_file ? g_strdup(data_file) : NULL;
5856 }
5857
5858 ret = qcow2_update_header(bs);
5859 if (ret < 0) {
5860 error_setg_errno(errp, -ret, "Failed to update the image header");
5861 return ret;
5862 }
5863
5864 if (backing_file || backing_format) {
5865 if (g_strcmp0(backing_file, s->image_backing_file) ||
5866 g_strcmp0(backing_format, s->image_backing_format)) {
5867 error_setg(errp, "Cannot amend the backing file");
5868 error_append_hint(errp,
5869 "You can use 'qemu-img rebase' instead.\n");
5870 return -EINVAL;
5871 }
5872 }
5873
5874 if (s->use_lazy_refcounts != lazy_refcounts) {
5875 if (lazy_refcounts) {
5876 if (new_version < 3) {
5877 error_setg(errp, "Lazy refcounts only supported with "
5878 "compatibility level 1.1 and above (use compat=1.1 "
5879 "or greater)");
5880 return -EINVAL;
5881 }
5882 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS;
5883 ret = qcow2_update_header(bs);
5884 if (ret < 0) {
5885 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS;
5886 error_setg_errno(errp, -ret, "Failed to update the image header");
5887 return ret;
5888 }
5889 s->use_lazy_refcounts = true;
5890 } else {
5891 /* make image clean first */
5892 ret = qcow2_mark_clean(bs);
5893 if (ret < 0) {
5894 error_setg_errno(errp, -ret, "Failed to make the image clean");
5895 return ret;
5896 }
5897 /* now disallow lazy refcounts */
5898 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS;
5899 ret = qcow2_update_header(bs);
5900 if (ret < 0) {
5901 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS;
5902 error_setg_errno(errp, -ret, "Failed to update the image header");
5903 return ret;
5904 }
5905 s->use_lazy_refcounts = false;
5906 }
5907 }
5908
5909 if (new_size) {
5910 BlockBackend *blk = blk_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL,
5911 errp);
5912 if (!blk) {
5913 return -EPERM;
5914 }
5915
5916 /*
5917 * Amending image options should ensure that the image has
5918 * exactly the given new values, so pass exact=true here.
5919 */
5920 ret = blk_truncate(blk, new_size, true, PREALLOC_MODE_OFF, 0, errp);
5921 blk_unref(blk);
5922 if (ret < 0) {
5923 return ret;
5924 }
5925 }
5926
5927 /* Downgrade last (so unsupported features can be removed before) */
5928 if (new_version < old_version) {
5929 helper_cb_info.current_operation = QCOW2_DOWNGRADING;
5930 ret = qcow2_downgrade(bs, new_version, &qcow2_amend_helper_cb,
5931 &helper_cb_info, errp);
5932 if (ret < 0) {
5933 return ret;
5934 }
5935 }
5936
5937 return 0;
5938 }
5939
qcow2_co_amend(BlockDriverState * bs,BlockdevAmendOptions * opts,bool force,Error ** errp)5940 static int coroutine_fn qcow2_co_amend(BlockDriverState *bs,
5941 BlockdevAmendOptions *opts,
5942 bool force,
5943 Error **errp)
5944 {
5945 BlockdevAmendOptionsQcow2 *qopts = &opts->u.qcow2;
5946 BDRVQcow2State *s = bs->opaque;
5947 int ret = 0;
5948
5949 if (qopts->encrypt) {
5950 if (!s->crypto) {
5951 error_setg(errp, "image is not encrypted, can't amend");
5952 return -EOPNOTSUPP;
5953 }
5954
5955 if (qopts->encrypt->format != QCRYPTO_BLOCK_FORMAT_LUKS) {
5956 error_setg(errp,
5957 "Amend can't be used to change the qcow2 encryption format");
5958 return -EOPNOTSUPP;
5959 }
5960
5961 if (s->crypt_method_header != QCOW_CRYPT_LUKS) {
5962 error_setg(errp,
5963 "Only LUKS encryption options can be amended for qcow2 with blockdev-amend");
5964 return -EOPNOTSUPP;
5965 }
5966
5967 ret = qcrypto_block_amend_options(s->crypto,
5968 qcow2_crypto_hdr_read_func,
5969 qcow2_crypto_hdr_write_func,
5970 bs,
5971 qopts->encrypt,
5972 force,
5973 errp);
5974 }
5975 return ret;
5976 }
5977
5978 /*
5979 * If offset or size are negative, respectively, they will not be included in
5980 * the BLOCK_IMAGE_CORRUPTED event emitted.
5981 * fatal will be ignored for read-only BDS; corruptions found there will always
5982 * be considered non-fatal.
5983 */
qcow2_signal_corruption(BlockDriverState * bs,bool fatal,int64_t offset,int64_t size,const char * message_format,...)5984 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
5985 int64_t size, const char *message_format, ...)
5986 {
5987 BDRVQcow2State *s = bs->opaque;
5988 const char *node_name;
5989 char *message;
5990 va_list ap;
5991
5992 fatal = fatal && bdrv_is_writable(bs);
5993
5994 if (s->signaled_corruption &&
5995 (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT)))
5996 {
5997 return;
5998 }
5999
6000 va_start(ap, message_format);
6001 message = g_strdup_vprintf(message_format, ap);
6002 va_end(ap);
6003
6004 if (fatal) {
6005 fprintf(stderr, "qcow2: Marking image as corrupt: %s; further "
6006 "corruption events will be suppressed\n", message);
6007 } else {
6008 fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal "
6009 "corruption events will be suppressed\n", message);
6010 }
6011
6012 node_name = bdrv_get_node_name(bs);
6013 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs),
6014 *node_name ? node_name : NULL,
6015 message, offset >= 0, offset,
6016 size >= 0, size,
6017 fatal);
6018 g_free(message);
6019
6020 if (fatal) {
6021 qcow2_mark_corrupt(bs);
6022 bs->drv = NULL; /* make BDS unusable */
6023 }
6024
6025 s->signaled_corruption = true;
6026 }
6027
6028 #define QCOW_COMMON_OPTIONS \
6029 { \
6030 .name = BLOCK_OPT_SIZE, \
6031 .type = QEMU_OPT_SIZE, \
6032 .help = "Virtual disk size" \
6033 }, \
6034 { \
6035 .name = BLOCK_OPT_COMPAT_LEVEL, \
6036 .type = QEMU_OPT_STRING, \
6037 .help = "Compatibility level (v2 [0.10] or v3 [1.1])" \
6038 }, \
6039 { \
6040 .name = BLOCK_OPT_BACKING_FILE, \
6041 .type = QEMU_OPT_STRING, \
6042 .help = "File name of a base image" \
6043 }, \
6044 { \
6045 .name = BLOCK_OPT_BACKING_FMT, \
6046 .type = QEMU_OPT_STRING, \
6047 .help = "Image format of the base image" \
6048 }, \
6049 { \
6050 .name = BLOCK_OPT_DATA_FILE, \
6051 .type = QEMU_OPT_STRING, \
6052 .help = "File name of an external data file" \
6053 }, \
6054 { \
6055 .name = BLOCK_OPT_DATA_FILE_RAW, \
6056 .type = QEMU_OPT_BOOL, \
6057 .help = "The external data file must stay valid " \
6058 "as a raw image" \
6059 }, \
6060 { \
6061 .name = BLOCK_OPT_LAZY_REFCOUNTS, \
6062 .type = QEMU_OPT_BOOL, \
6063 .help = "Postpone refcount updates", \
6064 .def_value_str = "off" \
6065 }, \
6066 { \
6067 .name = BLOCK_OPT_REFCOUNT_BITS, \
6068 .type = QEMU_OPT_NUMBER, \
6069 .help = "Width of a reference count entry in bits", \
6070 .def_value_str = "16" \
6071 }
6072
6073 static QemuOptsList qcow2_create_opts = {
6074 .name = "qcow2-create-opts",
6075 .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head),
6076 .desc = {
6077 { \
6078 .name = BLOCK_OPT_ENCRYPT, \
6079 .type = QEMU_OPT_BOOL, \
6080 .help = "Encrypt the image with format 'aes'. (Deprecated " \
6081 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)", \
6082 }, \
6083 { \
6084 .name = BLOCK_OPT_ENCRYPT_FORMAT, \
6085 .type = QEMU_OPT_STRING, \
6086 .help = "Encrypt the image, format choices: 'aes', 'luks'", \
6087 }, \
6088 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", \
6089 "ID of secret providing qcow AES key or LUKS passphrase"), \
6090 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."), \
6091 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."), \
6092 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."), \
6093 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."), \
6094 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."), \
6095 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), \
6096 { \
6097 .name = BLOCK_OPT_CLUSTER_SIZE, \
6098 .type = QEMU_OPT_SIZE, \
6099 .help = "qcow2 cluster size", \
6100 .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) \
6101 }, \
6102 { \
6103 .name = BLOCK_OPT_EXTL2, \
6104 .type = QEMU_OPT_BOOL, \
6105 .help = "Extended L2 tables", \
6106 .def_value_str = "off" \
6107 }, \
6108 { \
6109 .name = BLOCK_OPT_PREALLOC, \
6110 .type = QEMU_OPT_STRING, \
6111 .help = "Preallocation mode (allowed values: off, " \
6112 "metadata, falloc, full)" \
6113 }, \
6114 { \
6115 .name = BLOCK_OPT_COMPRESSION_TYPE, \
6116 .type = QEMU_OPT_STRING, \
6117 .help = "Compression method used for image cluster " \
6118 "compression", \
6119 .def_value_str = "zlib" \
6120 },
6121 QCOW_COMMON_OPTIONS,
6122 { /* end of list */ }
6123 }
6124 };
6125
6126 static QemuOptsList qcow2_amend_opts = {
6127 .name = "qcow2-amend-opts",
6128 .head = QTAILQ_HEAD_INITIALIZER(qcow2_amend_opts.head),
6129 .desc = {
6130 BLOCK_CRYPTO_OPT_DEF_LUKS_STATE("encrypt."),
6131 BLOCK_CRYPTO_OPT_DEF_LUKS_KEYSLOT("encrypt."),
6132 BLOCK_CRYPTO_OPT_DEF_LUKS_OLD_SECRET("encrypt."),
6133 BLOCK_CRYPTO_OPT_DEF_LUKS_NEW_SECRET("encrypt."),
6134 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."),
6135 QCOW_COMMON_OPTIONS,
6136 { /* end of list */ }
6137 }
6138 };
6139
6140 static const char *const qcow2_strong_runtime_opts[] = {
6141 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET,
6142
6143 NULL
6144 };
6145
6146 BlockDriver bdrv_qcow2 = {
6147 .format_name = "qcow2",
6148 .instance_size = sizeof(BDRVQcow2State),
6149 .bdrv_probe = qcow2_probe,
6150 .bdrv_open = qcow2_open,
6151 .bdrv_close = qcow2_close,
6152 .bdrv_reopen_prepare = qcow2_reopen_prepare,
6153 .bdrv_reopen_commit = qcow2_reopen_commit,
6154 .bdrv_reopen_commit_post = qcow2_reopen_commit_post,
6155 .bdrv_reopen_abort = qcow2_reopen_abort,
6156 .bdrv_join_options = qcow2_join_options,
6157 .bdrv_child_perm = bdrv_default_perms,
6158 .bdrv_co_create_opts = qcow2_co_create_opts,
6159 .bdrv_co_create = qcow2_co_create,
6160 .bdrv_has_zero_init = qcow2_has_zero_init,
6161 .bdrv_co_block_status = qcow2_co_block_status,
6162
6163 .bdrv_co_preadv_part = qcow2_co_preadv_part,
6164 .bdrv_co_pwritev_part = qcow2_co_pwritev_part,
6165 .bdrv_co_flush_to_os = qcow2_co_flush_to_os,
6166
6167 .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes,
6168 .bdrv_co_pdiscard = qcow2_co_pdiscard,
6169 .bdrv_co_copy_range_from = qcow2_co_copy_range_from,
6170 .bdrv_co_copy_range_to = qcow2_co_copy_range_to,
6171 .bdrv_co_truncate = qcow2_co_truncate,
6172 .bdrv_co_pwritev_compressed_part = qcow2_co_pwritev_compressed_part,
6173 .bdrv_make_empty = qcow2_make_empty,
6174
6175 .bdrv_snapshot_create = qcow2_snapshot_create,
6176 .bdrv_snapshot_goto = qcow2_snapshot_goto,
6177 .bdrv_snapshot_delete = qcow2_snapshot_delete,
6178 .bdrv_snapshot_list = qcow2_snapshot_list,
6179 .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp,
6180 .bdrv_measure = qcow2_measure,
6181 .bdrv_co_get_info = qcow2_co_get_info,
6182 .bdrv_get_specific_info = qcow2_get_specific_info,
6183
6184 .bdrv_co_save_vmstate = qcow2_co_save_vmstate,
6185 .bdrv_co_load_vmstate = qcow2_co_load_vmstate,
6186
6187 .is_format = true,
6188 .supports_backing = true,
6189 .bdrv_co_change_backing_file = qcow2_co_change_backing_file,
6190
6191 .bdrv_refresh_limits = qcow2_refresh_limits,
6192 .bdrv_co_invalidate_cache = qcow2_co_invalidate_cache,
6193 .bdrv_inactivate = qcow2_inactivate,
6194
6195 .create_opts = &qcow2_create_opts,
6196 .amend_opts = &qcow2_amend_opts,
6197 .strong_runtime_opts = qcow2_strong_runtime_opts,
6198 .mutable_opts = mutable_opts,
6199 .bdrv_co_check = qcow2_co_check,
6200 .bdrv_amend_options = qcow2_amend_options,
6201 .bdrv_co_amend = qcow2_co_amend,
6202
6203 .bdrv_detach_aio_context = qcow2_detach_aio_context,
6204 .bdrv_attach_aio_context = qcow2_attach_aio_context,
6205
6206 .bdrv_supports_persistent_dirty_bitmap =
6207 qcow2_supports_persistent_dirty_bitmap,
6208 .bdrv_co_can_store_new_dirty_bitmap = qcow2_co_can_store_new_dirty_bitmap,
6209 .bdrv_co_remove_persistent_dirty_bitmap =
6210 qcow2_co_remove_persistent_dirty_bitmap,
6211 };
6212
bdrv_qcow2_init(void)6213 static void bdrv_qcow2_init(void)
6214 {
6215 bdrv_register(&bdrv_qcow2);
6216 }
6217
6218 block_init(bdrv_qcow2_init);
6219