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 "sysemu/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 "qapi/qmp/qdict.h"
36 #include "qapi/qmp/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 if (!(flags & BDRV_O_NO_IO)) {
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_co_unref_child(bs, s->data_file);
1899 bdrv_graph_co_rdlock();
1900 s->data_file = NULL;
1901 }
1902 g_free(s->unknown_header_fields);
1903 cleanup_unknown_header_ext(bs);
1904 qcow2_free_snapshots(bs);
1905 qcow2_refcount_close(bs);
1906 qemu_vfree(s->l1_table);
1907 /* else pre-write overlap checks in cache_destroy may crash */
1908 s->l1_table = NULL;
1909 cache_clean_timer_del(bs);
1910 if (s->l2_table_cache) {
1911 qcow2_cache_destroy(s->l2_table_cache);
1912 }
1913 if (s->refcount_block_cache) {
1914 qcow2_cache_destroy(s->refcount_block_cache);
1915 }
1916 qcrypto_block_free(s->crypto);
1917 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts);
1918 return ret;
1919 }
1920
1921 typedef struct QCow2OpenCo {
1922 BlockDriverState *bs;
1923 QDict *options;
1924 int flags;
1925 Error **errp;
1926 int ret;
1927 } QCow2OpenCo;
1928
qcow2_open_entry(void * opaque)1929 static void coroutine_fn qcow2_open_entry(void *opaque)
1930 {
1931 QCow2OpenCo *qoc = opaque;
1932 BDRVQcow2State *s = qoc->bs->opaque;
1933
1934 GRAPH_RDLOCK_GUARD();
1935
1936 qemu_co_mutex_lock(&s->lock);
1937 qoc->ret = qcow2_do_open(qoc->bs, qoc->options, qoc->flags, true,
1938 qoc->errp);
1939 qemu_co_mutex_unlock(&s->lock);
1940
1941 aio_wait_kick();
1942 }
1943
qcow2_open(BlockDriverState * bs,QDict * options,int flags,Error ** errp)1944 static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
1945 Error **errp)
1946 {
1947 BDRVQcow2State *s = bs->opaque;
1948 QCow2OpenCo qoc = {
1949 .bs = bs,
1950 .options = options,
1951 .flags = flags,
1952 .errp = errp,
1953 .ret = -EINPROGRESS
1954 };
1955 int ret;
1956
1957 ret = bdrv_open_file_child(NULL, options, "file", bs, errp);
1958 if (ret < 0) {
1959 return ret;
1960 }
1961
1962 /* Initialise locks */
1963 qemu_co_mutex_init(&s->lock);
1964
1965 assert(!qemu_in_coroutine());
1966 assert(qemu_get_current_aio_context() == qemu_get_aio_context());
1967
1968 aio_co_enter(bdrv_get_aio_context(bs),
1969 qemu_coroutine_create(qcow2_open_entry, &qoc));
1970 AIO_WAIT_WHILE_UNLOCKED(NULL, qoc.ret == -EINPROGRESS);
1971
1972 return qoc.ret;
1973 }
1974
qcow2_refresh_limits(BlockDriverState * bs,Error ** errp)1975 static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp)
1976 {
1977 BDRVQcow2State *s = bs->opaque;
1978
1979 if (bs->encrypted) {
1980 /* Encryption works on a sector granularity */
1981 bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto);
1982 }
1983 bs->bl.pwrite_zeroes_alignment = s->subcluster_size;
1984 bs->bl.pdiscard_alignment = s->cluster_size;
1985 }
1986
1987 static int GRAPH_UNLOCKED
qcow2_reopen_prepare(BDRVReopenState * state,BlockReopenQueue * queue,Error ** errp)1988 qcow2_reopen_prepare(BDRVReopenState *state,BlockReopenQueue *queue,
1989 Error **errp)
1990 {
1991 BDRVQcow2State *s = state->bs->opaque;
1992 Qcow2ReopenState *r;
1993 int ret;
1994
1995 GLOBAL_STATE_CODE();
1996 GRAPH_RDLOCK_GUARD_MAINLOOP();
1997
1998 r = g_new0(Qcow2ReopenState, 1);
1999 state->opaque = r;
2000
2001 ret = qcow2_update_options_prepare(state->bs, r, state->options,
2002 state->flags, errp);
2003 if (ret < 0) {
2004 goto fail;
2005 }
2006
2007 /* We need to write out any unwritten data if we reopen read-only. */
2008 if ((state->flags & BDRV_O_RDWR) == 0) {
2009 ret = qcow2_reopen_bitmaps_ro(state->bs, errp);
2010 if (ret < 0) {
2011 goto fail;
2012 }
2013
2014 ret = bdrv_flush(state->bs);
2015 if (ret < 0) {
2016 goto fail;
2017 }
2018
2019 ret = qcow2_mark_clean(state->bs);
2020 if (ret < 0) {
2021 goto fail;
2022 }
2023 }
2024
2025 /*
2026 * Without an external data file, s->data_file points to the same BdrvChild
2027 * as bs->file. It needs to be resynced after reopen because bs->file may
2028 * be changed. We can't use it in the meantime.
2029 */
2030 if (!has_data_file(state->bs)) {
2031 assert(s->data_file == state->bs->file);
2032 s->data_file = NULL;
2033 }
2034
2035 return 0;
2036
2037 fail:
2038 qcow2_update_options_abort(state->bs, r);
2039 g_free(r);
2040 return ret;
2041 }
2042
qcow2_reopen_commit(BDRVReopenState * state)2043 static void qcow2_reopen_commit(BDRVReopenState *state)
2044 {
2045 BDRVQcow2State *s = state->bs->opaque;
2046
2047 GRAPH_RDLOCK_GUARD_MAINLOOP();
2048
2049 qcow2_update_options_commit(state->bs, state->opaque);
2050 if (!s->data_file) {
2051 /*
2052 * If we don't have an external data file, s->data_file was cleared by
2053 * qcow2_reopen_prepare() and needs to be updated.
2054 */
2055 s->data_file = state->bs->file;
2056 }
2057 g_free(state->opaque);
2058 }
2059
qcow2_reopen_commit_post(BDRVReopenState * state)2060 static void qcow2_reopen_commit_post(BDRVReopenState *state)
2061 {
2062 GRAPH_RDLOCK_GUARD_MAINLOOP();
2063
2064 if (state->flags & BDRV_O_RDWR) {
2065 Error *local_err = NULL;
2066
2067 if (qcow2_reopen_bitmaps_rw(state->bs, &local_err) < 0) {
2068 /*
2069 * This is not fatal, bitmaps just left read-only, so all following
2070 * writes will fail. User can remove read-only bitmaps to unblock
2071 * writes or retry reopen.
2072 */
2073 error_reportf_err(local_err,
2074 "%s: Failed to make dirty bitmaps writable: ",
2075 bdrv_get_node_name(state->bs));
2076 }
2077 }
2078 }
2079
qcow2_reopen_abort(BDRVReopenState * state)2080 static void qcow2_reopen_abort(BDRVReopenState *state)
2081 {
2082 BDRVQcow2State *s = state->bs->opaque;
2083
2084 GRAPH_RDLOCK_GUARD_MAINLOOP();
2085
2086 if (!s->data_file) {
2087 /*
2088 * If we don't have an external data file, s->data_file was cleared by
2089 * qcow2_reopen_prepare() and needs to be restored.
2090 */
2091 s->data_file = state->bs->file;
2092 }
2093 qcow2_update_options_abort(state->bs, state->opaque);
2094 g_free(state->opaque);
2095 }
2096
qcow2_join_options(QDict * options,QDict * old_options)2097 static void qcow2_join_options(QDict *options, QDict *old_options)
2098 {
2099 bool has_new_overlap_template =
2100 qdict_haskey(options, QCOW2_OPT_OVERLAP) ||
2101 qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE);
2102 bool has_new_total_cache_size =
2103 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE);
2104 bool has_all_cache_options;
2105
2106 /* New overlap template overrides all old overlap options */
2107 if (has_new_overlap_template) {
2108 qdict_del(old_options, QCOW2_OPT_OVERLAP);
2109 qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE);
2110 qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER);
2111 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1);
2112 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2);
2113 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE);
2114 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK);
2115 qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE);
2116 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1);
2117 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2);
2118 }
2119
2120 /* New total cache size overrides all old options */
2121 if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) {
2122 qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE);
2123 qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
2124 }
2125
2126 qdict_join(options, old_options, false);
2127
2128 /*
2129 * If after merging all cache size options are set, an old total size is
2130 * overwritten. Do keep all options, however, if all three are new. The
2131 * resulting error message is what we want to happen.
2132 */
2133 has_all_cache_options =
2134 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) ||
2135 qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) ||
2136 qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
2137
2138 if (has_all_cache_options && !has_new_total_cache_size) {
2139 qdict_del(options, QCOW2_OPT_CACHE_SIZE);
2140 }
2141 }
2142
2143 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_block_status(BlockDriverState * bs,bool want_zero,int64_t offset,int64_t count,int64_t * pnum,int64_t * map,BlockDriverState ** file)2144 qcow2_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset,
2145 int64_t count, int64_t *pnum, int64_t *map,
2146 BlockDriverState **file)
2147 {
2148 BDRVQcow2State *s = bs->opaque;
2149 uint64_t host_offset;
2150 unsigned int bytes;
2151 QCow2SubclusterType type;
2152 int ret, status = 0;
2153
2154 qemu_co_mutex_lock(&s->lock);
2155
2156 if (!s->metadata_preallocation_checked) {
2157 ret = qcow2_detect_metadata_preallocation(bs);
2158 s->metadata_preallocation = (ret == 1);
2159 s->metadata_preallocation_checked = true;
2160 }
2161
2162 bytes = MIN(INT_MAX, count);
2163 ret = qcow2_get_host_offset(bs, offset, &bytes, &host_offset, &type);
2164 qemu_co_mutex_unlock(&s->lock);
2165 if (ret < 0) {
2166 return ret;
2167 }
2168
2169 *pnum = bytes;
2170
2171 if ((type == QCOW2_SUBCLUSTER_NORMAL ||
2172 type == QCOW2_SUBCLUSTER_ZERO_ALLOC ||
2173 type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) && !s->crypto) {
2174 *map = host_offset;
2175 *file = s->data_file->bs;
2176 status |= BDRV_BLOCK_OFFSET_VALID;
2177 }
2178 if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN ||
2179 type == QCOW2_SUBCLUSTER_ZERO_ALLOC) {
2180 status |= BDRV_BLOCK_ZERO;
2181 } else if (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN &&
2182 type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) {
2183 status |= BDRV_BLOCK_DATA;
2184 }
2185 if (s->metadata_preallocation && (status & BDRV_BLOCK_DATA) &&
2186 (status & BDRV_BLOCK_OFFSET_VALID))
2187 {
2188 status |= BDRV_BLOCK_RECURSE;
2189 }
2190 if (type == QCOW2_SUBCLUSTER_COMPRESSED) {
2191 status |= BDRV_BLOCK_COMPRESSED;
2192 }
2193 return status;
2194 }
2195
2196 static int coroutine_fn GRAPH_RDLOCK
qcow2_handle_l2meta(BlockDriverState * bs,QCowL2Meta ** pl2meta,bool link_l2)2197 qcow2_handle_l2meta(BlockDriverState *bs, QCowL2Meta **pl2meta, bool link_l2)
2198 {
2199 int ret = 0;
2200 QCowL2Meta *l2meta = *pl2meta;
2201
2202 while (l2meta != NULL) {
2203 QCowL2Meta *next;
2204
2205 if (link_l2) {
2206 ret = qcow2_alloc_cluster_link_l2(bs, l2meta);
2207 if (ret) {
2208 goto out;
2209 }
2210 } else {
2211 qcow2_alloc_cluster_abort(bs, l2meta);
2212 }
2213
2214 /* Take the request off the list of running requests */
2215 QLIST_REMOVE(l2meta, next_in_flight);
2216
2217 qemu_co_queue_restart_all(&l2meta->dependent_requests);
2218
2219 next = l2meta->next;
2220 g_free(l2meta);
2221 l2meta = next;
2222 }
2223 out:
2224 *pl2meta = l2meta;
2225 return ret;
2226 }
2227
2228 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)2229 qcow2_co_preadv_encrypted(BlockDriverState *bs,
2230 uint64_t host_offset,
2231 uint64_t offset,
2232 uint64_t bytes,
2233 QEMUIOVector *qiov,
2234 uint64_t qiov_offset)
2235 {
2236 int ret;
2237 BDRVQcow2State *s = bs->opaque;
2238 uint8_t *buf;
2239
2240 assert(bs->encrypted && s->crypto);
2241 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
2242
2243 /*
2244 * For encrypted images, read everything into a temporary
2245 * contiguous buffer on which the AES functions can work.
2246 * Also, decryption in a separate buffer is better as it
2247 * prevents the guest from learning information about the
2248 * encrypted nature of the virtual disk.
2249 */
2250
2251 buf = qemu_try_blockalign(s->data_file->bs, bytes);
2252 if (buf == NULL) {
2253 return -ENOMEM;
2254 }
2255
2256 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO);
2257 ret = bdrv_co_pread(s->data_file, host_offset, bytes, buf, 0);
2258 if (ret < 0) {
2259 goto fail;
2260 }
2261
2262 if (qcow2_co_decrypt(bs, host_offset, offset, buf, bytes) < 0)
2263 {
2264 ret = -EIO;
2265 goto fail;
2266 }
2267 qemu_iovec_from_buf(qiov, qiov_offset, buf, bytes);
2268
2269 fail:
2270 qemu_vfree(buf);
2271
2272 return ret;
2273 }
2274
2275 typedef struct Qcow2AioTask {
2276 AioTask task;
2277
2278 BlockDriverState *bs;
2279 QCow2SubclusterType subcluster_type; /* only for read */
2280 uint64_t host_offset; /* or l2_entry for compressed read */
2281 uint64_t offset;
2282 uint64_t bytes;
2283 QEMUIOVector *qiov;
2284 uint64_t qiov_offset;
2285 QCowL2Meta *l2meta; /* only for write */
2286 } Qcow2AioTask;
2287
2288 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)2289 static coroutine_fn int qcow2_add_task(BlockDriverState *bs,
2290 AioTaskPool *pool,
2291 AioTaskFunc func,
2292 QCow2SubclusterType subcluster_type,
2293 uint64_t host_offset,
2294 uint64_t offset,
2295 uint64_t bytes,
2296 QEMUIOVector *qiov,
2297 size_t qiov_offset,
2298 QCowL2Meta *l2meta)
2299 {
2300 Qcow2AioTask local_task;
2301 Qcow2AioTask *task = pool ? g_new(Qcow2AioTask, 1) : &local_task;
2302
2303 *task = (Qcow2AioTask) {
2304 .task.func = func,
2305 .bs = bs,
2306 .subcluster_type = subcluster_type,
2307 .qiov = qiov,
2308 .host_offset = host_offset,
2309 .offset = offset,
2310 .bytes = bytes,
2311 .qiov_offset = qiov_offset,
2312 .l2meta = l2meta,
2313 };
2314
2315 trace_qcow2_add_task(qemu_coroutine_self(), bs, pool,
2316 func == qcow2_co_preadv_task_entry ? "read" : "write",
2317 subcluster_type, host_offset, offset, bytes,
2318 qiov, qiov_offset);
2319
2320 if (!pool) {
2321 return func(&task->task);
2322 }
2323
2324 aio_task_pool_start_task(pool, &task->task);
2325
2326 return 0;
2327 }
2328
2329 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)2330 qcow2_co_preadv_task(BlockDriverState *bs, QCow2SubclusterType subc_type,
2331 uint64_t host_offset, uint64_t offset, uint64_t bytes,
2332 QEMUIOVector *qiov, size_t qiov_offset)
2333 {
2334 BDRVQcow2State *s = bs->opaque;
2335
2336 switch (subc_type) {
2337 case QCOW2_SUBCLUSTER_ZERO_PLAIN:
2338 case QCOW2_SUBCLUSTER_ZERO_ALLOC:
2339 /* Both zero types are handled in qcow2_co_preadv_part */
2340 g_assert_not_reached();
2341
2342 case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN:
2343 case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC:
2344 assert(bs->backing); /* otherwise handled in qcow2_co_preadv_part */
2345
2346 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
2347 return bdrv_co_preadv_part(bs->backing, offset, bytes,
2348 qiov, qiov_offset, 0);
2349
2350 case QCOW2_SUBCLUSTER_COMPRESSED:
2351 return qcow2_co_preadv_compressed(bs, host_offset,
2352 offset, bytes, qiov, qiov_offset);
2353
2354 case QCOW2_SUBCLUSTER_NORMAL:
2355 if (bs->encrypted) {
2356 return qcow2_co_preadv_encrypted(bs, host_offset,
2357 offset, bytes, qiov, qiov_offset);
2358 }
2359
2360 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO);
2361 return bdrv_co_preadv_part(s->data_file, host_offset,
2362 bytes, qiov, qiov_offset, 0);
2363
2364 default:
2365 g_assert_not_reached();
2366 }
2367
2368 g_assert_not_reached();
2369 }
2370
2371 /*
2372 * This function can count as GRAPH_RDLOCK because qcow2_co_preadv_part() holds
2373 * the graph lock and keeps it until this coroutine has terminated.
2374 */
qcow2_co_preadv_task_entry(AioTask * task)2375 static int coroutine_fn GRAPH_RDLOCK qcow2_co_preadv_task_entry(AioTask *task)
2376 {
2377 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task);
2378
2379 assert(!t->l2meta);
2380
2381 return qcow2_co_preadv_task(t->bs, t->subcluster_type,
2382 t->host_offset, t->offset, t->bytes,
2383 t->qiov, t->qiov_offset);
2384 }
2385
2386 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)2387 qcow2_co_preadv_part(BlockDriverState *bs, int64_t offset, int64_t bytes,
2388 QEMUIOVector *qiov, size_t qiov_offset,
2389 BdrvRequestFlags flags)
2390 {
2391 BDRVQcow2State *s = bs->opaque;
2392 int ret = 0;
2393 unsigned int cur_bytes; /* number of bytes in current iteration */
2394 uint64_t host_offset = 0;
2395 QCow2SubclusterType type;
2396 AioTaskPool *aio = NULL;
2397
2398 while (bytes != 0 && aio_task_pool_status(aio) == 0) {
2399 /* prepare next request */
2400 cur_bytes = MIN(bytes, INT_MAX);
2401 if (s->crypto) {
2402 cur_bytes = MIN(cur_bytes,
2403 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
2404 }
2405
2406 qemu_co_mutex_lock(&s->lock);
2407 ret = qcow2_get_host_offset(bs, offset, &cur_bytes,
2408 &host_offset, &type);
2409 qemu_co_mutex_unlock(&s->lock);
2410 if (ret < 0) {
2411 goto out;
2412 }
2413
2414 if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN ||
2415 type == QCOW2_SUBCLUSTER_ZERO_ALLOC ||
2416 (type == QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && !bs->backing) ||
2417 (type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC && !bs->backing))
2418 {
2419 qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes);
2420 } else {
2421 if (!aio && cur_bytes != bytes) {
2422 aio = aio_task_pool_new(QCOW2_MAX_WORKERS);
2423 }
2424 ret = qcow2_add_task(bs, aio, qcow2_co_preadv_task_entry, type,
2425 host_offset, offset, cur_bytes,
2426 qiov, qiov_offset, NULL);
2427 if (ret < 0) {
2428 goto out;
2429 }
2430 }
2431
2432 bytes -= cur_bytes;
2433 offset += cur_bytes;
2434 qiov_offset += cur_bytes;
2435 }
2436
2437 out:
2438 if (aio) {
2439 aio_task_pool_wait_all(aio);
2440 if (ret == 0) {
2441 ret = aio_task_pool_status(aio);
2442 }
2443 g_free(aio);
2444 }
2445
2446 return ret;
2447 }
2448
2449 /* Check if it's possible to merge a write request with the writing of
2450 * the data from the COW regions */
merge_cow(uint64_t offset,unsigned bytes,QEMUIOVector * qiov,size_t qiov_offset,QCowL2Meta * l2meta)2451 static bool merge_cow(uint64_t offset, unsigned bytes,
2452 QEMUIOVector *qiov, size_t qiov_offset,
2453 QCowL2Meta *l2meta)
2454 {
2455 QCowL2Meta *m;
2456
2457 for (m = l2meta; m != NULL; m = m->next) {
2458 /* If both COW regions are empty then there's nothing to merge */
2459 if (m->cow_start.nb_bytes == 0 && m->cow_end.nb_bytes == 0) {
2460 continue;
2461 }
2462
2463 /* If COW regions are handled already, skip this too */
2464 if (m->skip_cow) {
2465 continue;
2466 }
2467
2468 /*
2469 * The write request should start immediately after the first
2470 * COW region. This does not always happen because the area
2471 * touched by the request can be larger than the one defined
2472 * by @m (a single request can span an area consisting of a
2473 * mix of previously unallocated and allocated clusters, that
2474 * is why @l2meta is a list).
2475 */
2476 if (l2meta_cow_start(m) + m->cow_start.nb_bytes != offset) {
2477 /* In this case the request starts before this region */
2478 assert(offset < l2meta_cow_start(m));
2479 assert(m->cow_start.nb_bytes == 0);
2480 continue;
2481 }
2482
2483 /* The write request should end immediately before the second
2484 * COW region (see above for why it does not always happen) */
2485 if (m->offset + m->cow_end.offset != offset + bytes) {
2486 assert(offset + bytes > m->offset + m->cow_end.offset);
2487 assert(m->cow_end.nb_bytes == 0);
2488 continue;
2489 }
2490
2491 /* Make sure that adding both COW regions to the QEMUIOVector
2492 * does not exceed IOV_MAX */
2493 if (qemu_iovec_subvec_niov(qiov, qiov_offset, bytes) > IOV_MAX - 2) {
2494 continue;
2495 }
2496
2497 m->data_qiov = qiov;
2498 m->data_qiov_offset = qiov_offset;
2499 return true;
2500 }
2501
2502 return false;
2503 }
2504
2505 /*
2506 * Return 1 if the COW regions read as zeroes, 0 if not, < 0 on error.
2507 * Note that returning 0 does not guarantee non-zero data.
2508 */
2509 static int coroutine_fn GRAPH_RDLOCK
is_zero_cow(BlockDriverState * bs,QCowL2Meta * m)2510 is_zero_cow(BlockDriverState *bs, QCowL2Meta *m)
2511 {
2512 /*
2513 * This check is designed for optimization shortcut so it must be
2514 * efficient.
2515 * Instead of is_zero(), use bdrv_co_is_zero_fast() as it is
2516 * faster (but not as accurate and can result in false negatives).
2517 */
2518 int ret = bdrv_co_is_zero_fast(bs, m->offset + m->cow_start.offset,
2519 m->cow_start.nb_bytes);
2520 if (ret <= 0) {
2521 return ret;
2522 }
2523
2524 return bdrv_co_is_zero_fast(bs, m->offset + m->cow_end.offset,
2525 m->cow_end.nb_bytes);
2526 }
2527
2528 static int coroutine_fn GRAPH_RDLOCK
handle_alloc_space(BlockDriverState * bs,QCowL2Meta * l2meta)2529 handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta)
2530 {
2531 BDRVQcow2State *s = bs->opaque;
2532 QCowL2Meta *m;
2533
2534 if (!(s->data_file->bs->supported_zero_flags & BDRV_REQ_NO_FALLBACK)) {
2535 return 0;
2536 }
2537
2538 if (bs->encrypted) {
2539 return 0;
2540 }
2541
2542 for (m = l2meta; m != NULL; m = m->next) {
2543 int ret;
2544 uint64_t start_offset = m->alloc_offset + m->cow_start.offset;
2545 unsigned nb_bytes = m->cow_end.offset + m->cow_end.nb_bytes -
2546 m->cow_start.offset;
2547
2548 if (!m->cow_start.nb_bytes && !m->cow_end.nb_bytes) {
2549 continue;
2550 }
2551
2552 ret = is_zero_cow(bs, m);
2553 if (ret < 0) {
2554 return ret;
2555 } else if (ret == 0) {
2556 continue;
2557 }
2558
2559 /*
2560 * instead of writing zero COW buffers,
2561 * efficiently zero out the whole clusters
2562 */
2563
2564 ret = qcow2_pre_write_overlap_check(bs, 0, start_offset, nb_bytes,
2565 true);
2566 if (ret < 0) {
2567 return ret;
2568 }
2569
2570 BLKDBG_CO_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_SPACE);
2571 ret = bdrv_co_pwrite_zeroes(s->data_file, start_offset, nb_bytes,
2572 BDRV_REQ_NO_FALLBACK);
2573 if (ret < 0) {
2574 if (ret != -ENOTSUP && ret != -EAGAIN) {
2575 return ret;
2576 }
2577 continue;
2578 }
2579
2580 trace_qcow2_skip_cow(qemu_coroutine_self(), m->offset, m->nb_clusters);
2581 m->skip_cow = true;
2582 }
2583 return 0;
2584 }
2585
2586 /*
2587 * qcow2_co_pwritev_task
2588 * Called with s->lock unlocked
2589 * l2meta - if not NULL, qcow2_co_pwritev_task() will consume it. Caller must
2590 * not use it somehow after qcow2_co_pwritev_task() call
2591 */
2592 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)2593 int qcow2_co_pwritev_task(BlockDriverState *bs, uint64_t host_offset,
2594 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov,
2595 uint64_t qiov_offset, QCowL2Meta *l2meta)
2596 {
2597 int ret;
2598 BDRVQcow2State *s = bs->opaque;
2599 void *crypt_buf = NULL;
2600 QEMUIOVector encrypted_qiov;
2601
2602 if (bs->encrypted) {
2603 assert(s->crypto);
2604 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
2605 crypt_buf = qemu_try_blockalign(bs->file->bs, bytes);
2606 if (crypt_buf == NULL) {
2607 ret = -ENOMEM;
2608 goto out_unlocked;
2609 }
2610 qemu_iovec_to_buf(qiov, qiov_offset, crypt_buf, bytes);
2611
2612 if (qcow2_co_encrypt(bs, host_offset, offset, crypt_buf, bytes) < 0) {
2613 ret = -EIO;
2614 goto out_unlocked;
2615 }
2616
2617 qemu_iovec_init_buf(&encrypted_qiov, crypt_buf, bytes);
2618 qiov = &encrypted_qiov;
2619 qiov_offset = 0;
2620 }
2621
2622 /* Try to efficiently initialize the physical space with zeroes */
2623 ret = handle_alloc_space(bs, l2meta);
2624 if (ret < 0) {
2625 goto out_unlocked;
2626 }
2627
2628 /*
2629 * If we need to do COW, check if it's possible to merge the
2630 * writing of the guest data together with that of the COW regions.
2631 * If it's not possible (or not necessary) then write the
2632 * guest data now.
2633 */
2634 if (!merge_cow(offset, bytes, qiov, qiov_offset, l2meta)) {
2635 BLKDBG_CO_EVENT(bs->file, BLKDBG_WRITE_AIO);
2636 trace_qcow2_writev_data(qemu_coroutine_self(), host_offset);
2637 ret = bdrv_co_pwritev_part(s->data_file, host_offset,
2638 bytes, qiov, qiov_offset, 0);
2639 if (ret < 0) {
2640 goto out_unlocked;
2641 }
2642 }
2643
2644 qemu_co_mutex_lock(&s->lock);
2645
2646 ret = qcow2_handle_l2meta(bs, &l2meta, true);
2647 goto out_locked;
2648
2649 out_unlocked:
2650 qemu_co_mutex_lock(&s->lock);
2651
2652 out_locked:
2653 qcow2_handle_l2meta(bs, &l2meta, false);
2654 qemu_co_mutex_unlock(&s->lock);
2655
2656 qemu_vfree(crypt_buf);
2657
2658 return ret;
2659 }
2660
2661 /*
2662 * This function can count as GRAPH_RDLOCK because qcow2_co_pwritev_part() holds
2663 * the graph lock and keeps it until this coroutine has terminated.
2664 */
qcow2_co_pwritev_task_entry(AioTask * task)2665 static coroutine_fn GRAPH_RDLOCK int qcow2_co_pwritev_task_entry(AioTask *task)
2666 {
2667 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task);
2668
2669 assert(!t->subcluster_type);
2670
2671 return qcow2_co_pwritev_task(t->bs, t->host_offset,
2672 t->offset, t->bytes, t->qiov, t->qiov_offset,
2673 t->l2meta);
2674 }
2675
2676 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)2677 qcow2_co_pwritev_part(BlockDriverState *bs, int64_t offset, int64_t bytes,
2678 QEMUIOVector *qiov, size_t qiov_offset,
2679 BdrvRequestFlags flags)
2680 {
2681 BDRVQcow2State *s = bs->opaque;
2682 int offset_in_cluster;
2683 int ret;
2684 unsigned int cur_bytes; /* number of sectors in current iteration */
2685 uint64_t host_offset;
2686 QCowL2Meta *l2meta = NULL;
2687 AioTaskPool *aio = NULL;
2688
2689 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes);
2690
2691 while (bytes != 0 && aio_task_pool_status(aio) == 0) {
2692
2693 l2meta = NULL;
2694
2695 trace_qcow2_writev_start_part(qemu_coroutine_self());
2696 offset_in_cluster = offset_into_cluster(s, offset);
2697 cur_bytes = MIN(bytes, INT_MAX);
2698 if (bs->encrypted) {
2699 cur_bytes = MIN(cur_bytes,
2700 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size
2701 - offset_in_cluster);
2702 }
2703
2704 qemu_co_mutex_lock(&s->lock);
2705
2706 ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes,
2707 &host_offset, &l2meta);
2708 if (ret < 0) {
2709 goto out_locked;
2710 }
2711
2712 ret = qcow2_pre_write_overlap_check(bs, 0, host_offset,
2713 cur_bytes, true);
2714 if (ret < 0) {
2715 goto out_locked;
2716 }
2717
2718 qemu_co_mutex_unlock(&s->lock);
2719
2720 if (!aio && cur_bytes != bytes) {
2721 aio = aio_task_pool_new(QCOW2_MAX_WORKERS);
2722 }
2723 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_task_entry, 0,
2724 host_offset, offset,
2725 cur_bytes, qiov, qiov_offset, l2meta);
2726 l2meta = NULL; /* l2meta is consumed by qcow2_co_pwritev_task() */
2727 if (ret < 0) {
2728 goto fail_nometa;
2729 }
2730
2731 bytes -= cur_bytes;
2732 offset += cur_bytes;
2733 qiov_offset += cur_bytes;
2734 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes);
2735 }
2736 ret = 0;
2737
2738 qemu_co_mutex_lock(&s->lock);
2739
2740 out_locked:
2741 qcow2_handle_l2meta(bs, &l2meta, false);
2742
2743 qemu_co_mutex_unlock(&s->lock);
2744
2745 fail_nometa:
2746 if (aio) {
2747 aio_task_pool_wait_all(aio);
2748 if (ret == 0) {
2749 ret = aio_task_pool_status(aio);
2750 }
2751 g_free(aio);
2752 }
2753
2754 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
2755
2756 return ret;
2757 }
2758
qcow2_inactivate(BlockDriverState * bs)2759 static int GRAPH_RDLOCK qcow2_inactivate(BlockDriverState *bs)
2760 {
2761 BDRVQcow2State *s = bs->opaque;
2762 int ret, result = 0;
2763 Error *local_err = NULL;
2764
2765 qcow2_store_persistent_dirty_bitmaps(bs, true, &local_err);
2766 if (local_err != NULL) {
2767 result = -EINVAL;
2768 error_reportf_err(local_err, "Lost persistent bitmaps during "
2769 "inactivation of node '%s': ",
2770 bdrv_get_device_or_node_name(bs));
2771 }
2772
2773 ret = qcow2_cache_flush(bs, s->l2_table_cache);
2774 if (ret) {
2775 result = ret;
2776 error_report("Failed to flush the L2 table cache: %s",
2777 strerror(-ret));
2778 }
2779
2780 ret = qcow2_cache_flush(bs, s->refcount_block_cache);
2781 if (ret) {
2782 result = ret;
2783 error_report("Failed to flush the refcount block cache: %s",
2784 strerror(-ret));
2785 }
2786
2787 if (result == 0) {
2788 qcow2_mark_clean(bs);
2789 }
2790
2791 return result;
2792 }
2793
2794 static void coroutine_mixed_fn GRAPH_RDLOCK
qcow2_do_close(BlockDriverState * bs,bool close_data_file)2795 qcow2_do_close(BlockDriverState *bs, bool close_data_file)
2796 {
2797 BDRVQcow2State *s = bs->opaque;
2798 qemu_vfree(s->l1_table);
2799 /* else pre-write overlap checks in cache_destroy may crash */
2800 s->l1_table = NULL;
2801
2802 if (!(s->flags & BDRV_O_INACTIVE)) {
2803 qcow2_inactivate(bs);
2804 }
2805
2806 cache_clean_timer_del(bs);
2807 qcow2_cache_destroy(s->l2_table_cache);
2808 qcow2_cache_destroy(s->refcount_block_cache);
2809
2810 qcrypto_block_free(s->crypto);
2811 s->crypto = NULL;
2812 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts);
2813
2814 g_free(s->unknown_header_fields);
2815 cleanup_unknown_header_ext(bs);
2816
2817 g_free(s->image_data_file);
2818 g_free(s->image_backing_file);
2819 g_free(s->image_backing_format);
2820
2821 if (close_data_file && has_data_file(bs)) {
2822 GLOBAL_STATE_CODE();
2823 bdrv_graph_rdunlock_main_loop();
2824 bdrv_graph_wrlock();
2825 bdrv_unref_child(bs, s->data_file);
2826 bdrv_graph_wrunlock();
2827 s->data_file = NULL;
2828 bdrv_graph_rdlock_main_loop();
2829 }
2830
2831 qcow2_refcount_close(bs);
2832 qcow2_free_snapshots(bs);
2833 }
2834
qcow2_close(BlockDriverState * bs)2835 static void GRAPH_UNLOCKED qcow2_close(BlockDriverState *bs)
2836 {
2837 GLOBAL_STATE_CODE();
2838 GRAPH_RDLOCK_GUARD_MAINLOOP();
2839
2840 qcow2_do_close(bs, true);
2841 }
2842
2843 static void coroutine_fn GRAPH_RDLOCK
qcow2_co_invalidate_cache(BlockDriverState * bs,Error ** errp)2844 qcow2_co_invalidate_cache(BlockDriverState *bs, Error **errp)
2845 {
2846 ERRP_GUARD();
2847 BDRVQcow2State *s = bs->opaque;
2848 BdrvChild *data_file;
2849 int flags = s->flags;
2850 QCryptoBlock *crypto = NULL;
2851 QDict *options;
2852 int ret;
2853
2854 /*
2855 * Backing files are read-only which makes all of their metadata immutable,
2856 * that means we don't have to worry about reopening them here.
2857 */
2858
2859 crypto = s->crypto;
2860 s->crypto = NULL;
2861
2862 /*
2863 * Do not reopen s->data_file (i.e., have qcow2_do_close() not close it,
2864 * and then prevent qcow2_do_open() from opening it), because this function
2865 * runs in the I/O path and as such we must not invoke global-state
2866 * functions like bdrv_unref_child() and bdrv_open_child().
2867 */
2868
2869 qcow2_do_close(bs, false);
2870
2871 data_file = s->data_file;
2872 memset(s, 0, sizeof(BDRVQcow2State));
2873 s->data_file = data_file;
2874
2875 options = qdict_clone_shallow(bs->options);
2876
2877 flags &= ~BDRV_O_INACTIVE;
2878 qemu_co_mutex_lock(&s->lock);
2879 ret = qcow2_do_open(bs, options, flags, false, errp);
2880 qemu_co_mutex_unlock(&s->lock);
2881 qobject_unref(options);
2882 if (ret < 0) {
2883 error_prepend(errp, "Could not reopen qcow2 layer: ");
2884 bs->drv = NULL;
2885 return;
2886 }
2887
2888 s->crypto = crypto;
2889 }
2890
header_ext_add(char * buf,uint32_t magic,const void * s,size_t len,size_t buflen)2891 static size_t header_ext_add(char *buf, uint32_t magic, const void *s,
2892 size_t len, size_t buflen)
2893 {
2894 QCowExtension *ext_backing_fmt = (QCowExtension*) buf;
2895 size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7);
2896
2897 if (buflen < ext_len) {
2898 return -ENOSPC;
2899 }
2900
2901 *ext_backing_fmt = (QCowExtension) {
2902 .magic = cpu_to_be32(magic),
2903 .len = cpu_to_be32(len),
2904 };
2905
2906 if (len) {
2907 memcpy(buf + sizeof(QCowExtension), s, len);
2908 }
2909
2910 return ext_len;
2911 }
2912
2913 /*
2914 * Updates the qcow2 header, including the variable length parts of it, i.e.
2915 * the backing file name and all extensions. qcow2 was not designed to allow
2916 * such changes, so if we run out of space (we can only use the first cluster)
2917 * this function may fail.
2918 *
2919 * Returns 0 on success, -errno in error cases.
2920 */
qcow2_update_header(BlockDriverState * bs)2921 int qcow2_update_header(BlockDriverState *bs)
2922 {
2923 BDRVQcow2State *s = bs->opaque;
2924 QCowHeader *header;
2925 char *buf;
2926 size_t buflen = s->cluster_size;
2927 int ret;
2928 uint64_t total_size;
2929 uint32_t refcount_table_clusters;
2930 size_t header_length;
2931 Qcow2UnknownHeaderExtension *uext;
2932
2933 buf = qemu_blockalign(bs, buflen);
2934
2935 /* Header structure */
2936 header = (QCowHeader*) buf;
2937
2938 if (buflen < sizeof(*header)) {
2939 ret = -ENOSPC;
2940 goto fail;
2941 }
2942
2943 header_length = sizeof(*header) + s->unknown_header_fields_size;
2944 total_size = bs->total_sectors * BDRV_SECTOR_SIZE;
2945 refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
2946
2947 ret = validate_compression_type(s, NULL);
2948 if (ret) {
2949 goto fail;
2950 }
2951
2952 *header = (QCowHeader) {
2953 /* Version 2 fields */
2954 .magic = cpu_to_be32(QCOW_MAGIC),
2955 .version = cpu_to_be32(s->qcow_version),
2956 .backing_file_offset = 0,
2957 .backing_file_size = 0,
2958 .cluster_bits = cpu_to_be32(s->cluster_bits),
2959 .size = cpu_to_be64(total_size),
2960 .crypt_method = cpu_to_be32(s->crypt_method_header),
2961 .l1_size = cpu_to_be32(s->l1_size),
2962 .l1_table_offset = cpu_to_be64(s->l1_table_offset),
2963 .refcount_table_offset = cpu_to_be64(s->refcount_table_offset),
2964 .refcount_table_clusters = cpu_to_be32(refcount_table_clusters),
2965 .nb_snapshots = cpu_to_be32(s->nb_snapshots),
2966 .snapshots_offset = cpu_to_be64(s->snapshots_offset),
2967
2968 /* Version 3 fields */
2969 .incompatible_features = cpu_to_be64(s->incompatible_features),
2970 .compatible_features = cpu_to_be64(s->compatible_features),
2971 .autoclear_features = cpu_to_be64(s->autoclear_features),
2972 .refcount_order = cpu_to_be32(s->refcount_order),
2973 .header_length = cpu_to_be32(header_length),
2974 .compression_type = s->compression_type,
2975 };
2976
2977 /* For older versions, write a shorter header */
2978 switch (s->qcow_version) {
2979 case 2:
2980 ret = offsetof(QCowHeader, incompatible_features);
2981 break;
2982 case 3:
2983 ret = sizeof(*header);
2984 break;
2985 default:
2986 ret = -EINVAL;
2987 goto fail;
2988 }
2989
2990 buf += ret;
2991 buflen -= ret;
2992 memset(buf, 0, buflen);
2993
2994 /* Preserve any unknown field in the header */
2995 if (s->unknown_header_fields_size) {
2996 if (buflen < s->unknown_header_fields_size) {
2997 ret = -ENOSPC;
2998 goto fail;
2999 }
3000
3001 memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size);
3002 buf += s->unknown_header_fields_size;
3003 buflen -= s->unknown_header_fields_size;
3004 }
3005
3006 /* Backing file format header extension */
3007 if (s->image_backing_format) {
3008 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT,
3009 s->image_backing_format,
3010 strlen(s->image_backing_format),
3011 buflen);
3012 if (ret < 0) {
3013 goto fail;
3014 }
3015
3016 buf += ret;
3017 buflen -= ret;
3018 }
3019
3020 /* External data file header extension */
3021 if (has_data_file(bs) && s->image_data_file) {
3022 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE,
3023 s->image_data_file, strlen(s->image_data_file),
3024 buflen);
3025 if (ret < 0) {
3026 goto fail;
3027 }
3028
3029 buf += ret;
3030 buflen -= ret;
3031 }
3032
3033 /* Full disk encryption header pointer extension */
3034 if (s->crypto_header.offset != 0) {
3035 s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset);
3036 s->crypto_header.length = cpu_to_be64(s->crypto_header.length);
3037 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER,
3038 &s->crypto_header, sizeof(s->crypto_header),
3039 buflen);
3040 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset);
3041 s->crypto_header.length = be64_to_cpu(s->crypto_header.length);
3042 if (ret < 0) {
3043 goto fail;
3044 }
3045 buf += ret;
3046 buflen -= ret;
3047 }
3048
3049 /*
3050 * Feature table. A mere 8 feature names occupies 392 bytes, and
3051 * when coupled with the v3 minimum header of 104 bytes plus the
3052 * 8-byte end-of-extension marker, that would leave only 8 bytes
3053 * for a backing file name in an image with 512-byte clusters.
3054 * Thus, we choose to omit this header for cluster sizes 4k and
3055 * smaller.
3056 */
3057 if (s->qcow_version >= 3 && s->cluster_size > 4096) {
3058 static const Qcow2Feature features[] = {
3059 {
3060 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
3061 .bit = QCOW2_INCOMPAT_DIRTY_BITNR,
3062 .name = "dirty bit",
3063 },
3064 {
3065 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
3066 .bit = QCOW2_INCOMPAT_CORRUPT_BITNR,
3067 .name = "corrupt bit",
3068 },
3069 {
3070 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
3071 .bit = QCOW2_INCOMPAT_DATA_FILE_BITNR,
3072 .name = "external data file",
3073 },
3074 {
3075 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
3076 .bit = QCOW2_INCOMPAT_COMPRESSION_BITNR,
3077 .name = "compression type",
3078 },
3079 {
3080 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
3081 .bit = QCOW2_INCOMPAT_EXTL2_BITNR,
3082 .name = "extended L2 entries",
3083 },
3084 {
3085 .type = QCOW2_FEAT_TYPE_COMPATIBLE,
3086 .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
3087 .name = "lazy refcounts",
3088 },
3089 {
3090 .type = QCOW2_FEAT_TYPE_AUTOCLEAR,
3091 .bit = QCOW2_AUTOCLEAR_BITMAPS_BITNR,
3092 .name = "bitmaps",
3093 },
3094 {
3095 .type = QCOW2_FEAT_TYPE_AUTOCLEAR,
3096 .bit = QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
3097 .name = "raw external data",
3098 },
3099 };
3100
3101 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE,
3102 features, sizeof(features), buflen);
3103 if (ret < 0) {
3104 goto fail;
3105 }
3106 buf += ret;
3107 buflen -= ret;
3108 }
3109
3110 /* Bitmap extension */
3111 if (s->nb_bitmaps > 0) {
3112 Qcow2BitmapHeaderExt bitmaps_header = {
3113 .nb_bitmaps = cpu_to_be32(s->nb_bitmaps),
3114 .bitmap_directory_size =
3115 cpu_to_be64(s->bitmap_directory_size),
3116 .bitmap_directory_offset =
3117 cpu_to_be64(s->bitmap_directory_offset)
3118 };
3119 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS,
3120 &bitmaps_header, sizeof(bitmaps_header),
3121 buflen);
3122 if (ret < 0) {
3123 goto fail;
3124 }
3125 buf += ret;
3126 buflen -= ret;
3127 }
3128
3129 /* Keep unknown header extensions */
3130 QLIST_FOREACH(uext, &s->unknown_header_ext, next) {
3131 ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen);
3132 if (ret < 0) {
3133 goto fail;
3134 }
3135
3136 buf += ret;
3137 buflen -= ret;
3138 }
3139
3140 /* End of header extensions */
3141 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen);
3142 if (ret < 0) {
3143 goto fail;
3144 }
3145
3146 buf += ret;
3147 buflen -= ret;
3148
3149 /* Backing file name */
3150 if (s->image_backing_file) {
3151 size_t backing_file_len = strlen(s->image_backing_file);
3152
3153 if (buflen < backing_file_len) {
3154 ret = -ENOSPC;
3155 goto fail;
3156 }
3157
3158 /* Using strncpy is ok here, since buf is not NUL-terminated. */
3159 strncpy(buf, s->image_backing_file, buflen);
3160
3161 header->backing_file_offset = cpu_to_be64(buf - ((char*) header));
3162 header->backing_file_size = cpu_to_be32(backing_file_len);
3163 }
3164
3165 /* Write the new header */
3166 ret = bdrv_pwrite(bs->file, 0, s->cluster_size, header, 0);
3167 if (ret < 0) {
3168 goto fail;
3169 }
3170
3171 ret = 0;
3172 fail:
3173 qemu_vfree(header);
3174 return ret;
3175 }
3176
3177 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_change_backing_file(BlockDriverState * bs,const char * backing_file,const char * backing_fmt)3178 qcow2_co_change_backing_file(BlockDriverState *bs, const char *backing_file,
3179 const char *backing_fmt)
3180 {
3181 BDRVQcow2State *s = bs->opaque;
3182
3183 /* Adding a backing file means that the external data file alone won't be
3184 * enough to make sense of the content */
3185 if (backing_file && data_file_is_raw(bs)) {
3186 return -EINVAL;
3187 }
3188
3189 if (backing_file && strlen(backing_file) > 1023) {
3190 return -EINVAL;
3191 }
3192
3193 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file),
3194 backing_file ?: "");
3195 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
3196 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
3197
3198 g_free(s->image_backing_file);
3199 g_free(s->image_backing_format);
3200
3201 s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL;
3202 s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL;
3203
3204 return qcow2_update_header(bs);
3205 }
3206
3207 static int coroutine_fn GRAPH_RDLOCK
qcow2_set_up_encryption(BlockDriverState * bs,QCryptoBlockCreateOptions * cryptoopts,Error ** errp)3208 qcow2_set_up_encryption(BlockDriverState *bs,
3209 QCryptoBlockCreateOptions *cryptoopts,
3210 Error **errp)
3211 {
3212 BDRVQcow2State *s = bs->opaque;
3213 QCryptoBlock *crypto = NULL;
3214 int fmt, ret;
3215
3216 switch (cryptoopts->format) {
3217 case Q_CRYPTO_BLOCK_FORMAT_LUKS:
3218 fmt = QCOW_CRYPT_LUKS;
3219 break;
3220 case Q_CRYPTO_BLOCK_FORMAT_QCOW:
3221 fmt = QCOW_CRYPT_AES;
3222 break;
3223 default:
3224 error_setg(errp, "Crypto format not supported in qcow2");
3225 return -EINVAL;
3226 }
3227
3228 s->crypt_method_header = fmt;
3229
3230 crypto = qcrypto_block_create(cryptoopts, "encrypt.",
3231 qcow2_crypto_hdr_init_func,
3232 qcow2_crypto_hdr_write_func,
3233 bs, 0, errp);
3234 if (!crypto) {
3235 return -EINVAL;
3236 }
3237
3238 ret = qcow2_update_header(bs);
3239 if (ret < 0) {
3240 error_setg_errno(errp, -ret, "Could not write encryption header");
3241 goto out;
3242 }
3243
3244 ret = 0;
3245 out:
3246 qcrypto_block_free(crypto);
3247 return ret;
3248 }
3249
3250 /**
3251 * Preallocates metadata structures for data clusters between @offset (in the
3252 * guest disk) and @new_length (which is thus generally the new guest disk
3253 * size).
3254 *
3255 * Returns: 0 on success, -errno on failure.
3256 */
3257 static int coroutine_fn GRAPH_RDLOCK
preallocate_co(BlockDriverState * bs,uint64_t offset,uint64_t new_length,PreallocMode mode,Error ** errp)3258 preallocate_co(BlockDriverState *bs, uint64_t offset, uint64_t new_length,
3259 PreallocMode mode, Error **errp)
3260 {
3261 BDRVQcow2State *s = bs->opaque;
3262 uint64_t bytes;
3263 uint64_t host_offset = 0;
3264 int64_t file_length;
3265 unsigned int cur_bytes;
3266 int ret;
3267 QCowL2Meta *meta = NULL, *m;
3268
3269 assert(offset <= new_length);
3270 bytes = new_length - offset;
3271
3272 while (bytes) {
3273 cur_bytes = MIN(bytes, QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size));
3274 ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes,
3275 &host_offset, &meta);
3276 if (ret < 0) {
3277 error_setg_errno(errp, -ret, "Allocating clusters failed");
3278 goto out;
3279 }
3280
3281 for (m = meta; m != NULL; m = m->next) {
3282 m->prealloc = true;
3283 }
3284
3285 ret = qcow2_handle_l2meta(bs, &meta, true);
3286 if (ret < 0) {
3287 error_setg_errno(errp, -ret, "Mapping clusters failed");
3288 goto out;
3289 }
3290
3291 /* TODO Preallocate data if requested */
3292
3293 bytes -= cur_bytes;
3294 offset += cur_bytes;
3295 }
3296
3297 /*
3298 * It is expected that the image file is large enough to actually contain
3299 * all of the allocated clusters (otherwise we get failing reads after
3300 * EOF). Extend the image to the last allocated sector.
3301 */
3302 file_length = bdrv_co_getlength(s->data_file->bs);
3303 if (file_length < 0) {
3304 error_setg_errno(errp, -file_length, "Could not get file size");
3305 ret = file_length;
3306 goto out;
3307 }
3308
3309 if (host_offset + cur_bytes > file_length) {
3310 if (mode == PREALLOC_MODE_METADATA) {
3311 mode = PREALLOC_MODE_OFF;
3312 }
3313 ret = bdrv_co_truncate(s->data_file, host_offset + cur_bytes, false,
3314 mode, 0, errp);
3315 if (ret < 0) {
3316 goto out;
3317 }
3318 }
3319
3320 ret = 0;
3321
3322 out:
3323 qcow2_handle_l2meta(bs, &meta, false);
3324 return ret;
3325 }
3326
3327 /* qcow2_refcount_metadata_size:
3328 * @clusters: number of clusters to refcount (including data and L1/L2 tables)
3329 * @cluster_size: size of a cluster, in bytes
3330 * @refcount_order: refcount bits power-of-2 exponent
3331 * @generous_increase: allow for the refcount table to be 1.5x as large as it
3332 * needs to be
3333 *
3334 * Returns: Number of bytes required for refcount blocks and table metadata.
3335 */
qcow2_refcount_metadata_size(int64_t clusters,size_t cluster_size,int refcount_order,bool generous_increase,uint64_t * refblock_count)3336 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
3337 int refcount_order, bool generous_increase,
3338 uint64_t *refblock_count)
3339 {
3340 /*
3341 * Every host cluster is reference-counted, including metadata (even
3342 * refcount metadata is recursively included).
3343 *
3344 * An accurate formula for the size of refcount metadata size is difficult
3345 * to derive. An easier method of calculation is finding the fixed point
3346 * where no further refcount blocks or table clusters are required to
3347 * reference count every cluster.
3348 */
3349 int64_t blocks_per_table_cluster = cluster_size / REFTABLE_ENTRY_SIZE;
3350 int64_t refcounts_per_block = cluster_size * 8 / (1 << refcount_order);
3351 int64_t table = 0; /* number of refcount table clusters */
3352 int64_t blocks = 0; /* number of refcount block clusters */
3353 int64_t last;
3354 int64_t n = 0;
3355
3356 do {
3357 last = n;
3358 blocks = DIV_ROUND_UP(clusters + table + blocks, refcounts_per_block);
3359 table = DIV_ROUND_UP(blocks, blocks_per_table_cluster);
3360 n = clusters + blocks + table;
3361
3362 if (n == last && generous_increase) {
3363 clusters += DIV_ROUND_UP(table, 2);
3364 n = 0; /* force another loop */
3365 generous_increase = false;
3366 }
3367 } while (n != last);
3368
3369 if (refblock_count) {
3370 *refblock_count = blocks;
3371 }
3372
3373 return (blocks + table) * cluster_size;
3374 }
3375
3376 /**
3377 * qcow2_calc_prealloc_size:
3378 * @total_size: virtual disk size in bytes
3379 * @cluster_size: cluster size in bytes
3380 * @refcount_order: refcount bits power-of-2 exponent
3381 * @extended_l2: true if the image has extended L2 entries
3382 *
3383 * Returns: Total number of bytes required for the fully allocated image
3384 * (including metadata).
3385 */
qcow2_calc_prealloc_size(int64_t total_size,size_t cluster_size,int refcount_order,bool extended_l2)3386 static int64_t qcow2_calc_prealloc_size(int64_t total_size,
3387 size_t cluster_size,
3388 int refcount_order,
3389 bool extended_l2)
3390 {
3391 int64_t meta_size = 0;
3392 uint64_t nl1e, nl2e;
3393 int64_t aligned_total_size = ROUND_UP(total_size, cluster_size);
3394 size_t l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
3395
3396 /* header: 1 cluster */
3397 meta_size += cluster_size;
3398
3399 /* total size of L2 tables */
3400 nl2e = aligned_total_size / cluster_size;
3401 nl2e = ROUND_UP(nl2e, cluster_size / l2e_size);
3402 meta_size += nl2e * l2e_size;
3403
3404 /* total size of L1 tables */
3405 nl1e = nl2e * l2e_size / cluster_size;
3406 nl1e = ROUND_UP(nl1e, cluster_size / L1E_SIZE);
3407 meta_size += nl1e * L1E_SIZE;
3408
3409 /* total size of refcount table and blocks */
3410 meta_size += qcow2_refcount_metadata_size(
3411 (meta_size + aligned_total_size) / cluster_size,
3412 cluster_size, refcount_order, false, NULL);
3413
3414 return meta_size + aligned_total_size;
3415 }
3416
validate_cluster_size(size_t cluster_size,bool extended_l2,Error ** errp)3417 static bool validate_cluster_size(size_t cluster_size, bool extended_l2,
3418 Error **errp)
3419 {
3420 int cluster_bits = ctz32(cluster_size);
3421 if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS ||
3422 (1 << cluster_bits) != cluster_size)
3423 {
3424 error_setg(errp, "Cluster size must be a power of two between %d and "
3425 "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10));
3426 return false;
3427 }
3428
3429 if (extended_l2) {
3430 unsigned min_cluster_size =
3431 (1 << MIN_CLUSTER_BITS) * QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER;
3432 if (cluster_size < min_cluster_size) {
3433 error_setg(errp, "Extended L2 entries are only supported with "
3434 "cluster sizes of at least %u bytes", min_cluster_size);
3435 return false;
3436 }
3437 }
3438
3439 return true;
3440 }
3441
qcow2_opt_get_cluster_size_del(QemuOpts * opts,bool extended_l2,Error ** errp)3442 static size_t qcow2_opt_get_cluster_size_del(QemuOpts *opts, bool extended_l2,
3443 Error **errp)
3444 {
3445 size_t cluster_size;
3446
3447 cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE,
3448 DEFAULT_CLUSTER_SIZE);
3449 if (!validate_cluster_size(cluster_size, extended_l2, errp)) {
3450 return 0;
3451 }
3452 return cluster_size;
3453 }
3454
qcow2_opt_get_version_del(QemuOpts * opts,Error ** errp)3455 static int qcow2_opt_get_version_del(QemuOpts *opts, Error **errp)
3456 {
3457 char *buf;
3458 int ret;
3459
3460 buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL);
3461 if (!buf) {
3462 ret = 3; /* default */
3463 } else if (!strcmp(buf, "0.10")) {
3464 ret = 2;
3465 } else if (!strcmp(buf, "1.1")) {
3466 ret = 3;
3467 } else {
3468 error_setg(errp, "Invalid compatibility level: '%s'", buf);
3469 ret = -EINVAL;
3470 }
3471 g_free(buf);
3472 return ret;
3473 }
3474
qcow2_opt_get_refcount_bits_del(QemuOpts * opts,int version,Error ** errp)3475 static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts *opts, int version,
3476 Error **errp)
3477 {
3478 uint64_t refcount_bits;
3479
3480 refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, 16);
3481 if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) {
3482 error_setg(errp, "Refcount width must be a power of two and may not "
3483 "exceed 64 bits");
3484 return 0;
3485 }
3486
3487 if (version < 3 && refcount_bits != 16) {
3488 error_setg(errp, "Different refcount widths than 16 bits require "
3489 "compatibility level 1.1 or above (use compat=1.1 or "
3490 "greater)");
3491 return 0;
3492 }
3493
3494 return refcount_bits;
3495 }
3496
3497 static int coroutine_fn GRAPH_UNLOCKED
qcow2_co_create(BlockdevCreateOptions * create_options,Error ** errp)3498 qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
3499 {
3500 ERRP_GUARD();
3501 BlockdevCreateOptionsQcow2 *qcow2_opts;
3502 QDict *options;
3503
3504 /*
3505 * Open the image file and write a minimal qcow2 header.
3506 *
3507 * We keep things simple and start with a zero-sized image. We also
3508 * do without refcount blocks or a L1 table for now. We'll fix the
3509 * inconsistency later.
3510 *
3511 * We do need a refcount table because growing the refcount table means
3512 * allocating two new refcount blocks - the second of which would be at
3513 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
3514 * size for any qcow2 image.
3515 */
3516 BlockBackend *blk = NULL;
3517 BlockDriverState *bs = NULL;
3518 BlockDriverState *data_bs = NULL;
3519 QCowHeader *header;
3520 size_t cluster_size;
3521 int version;
3522 int refcount_order;
3523 uint64_t *refcount_table;
3524 int ret;
3525 uint8_t compression_type = QCOW2_COMPRESSION_TYPE_ZLIB;
3526
3527 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2);
3528 qcow2_opts = &create_options->u.qcow2;
3529
3530 bs = bdrv_co_open_blockdev_ref(qcow2_opts->file, errp);
3531 if (bs == NULL) {
3532 return -EIO;
3533 }
3534
3535 /* Validate options and set default values */
3536 if (!QEMU_IS_ALIGNED(qcow2_opts->size, BDRV_SECTOR_SIZE)) {
3537 error_setg(errp, "Image size must be a multiple of %u bytes",
3538 (unsigned) BDRV_SECTOR_SIZE);
3539 ret = -EINVAL;
3540 goto out;
3541 }
3542
3543 if (qcow2_opts->has_version) {
3544 switch (qcow2_opts->version) {
3545 case BLOCKDEV_QCOW2_VERSION_V2:
3546 version = 2;
3547 break;
3548 case BLOCKDEV_QCOW2_VERSION_V3:
3549 version = 3;
3550 break;
3551 default:
3552 g_assert_not_reached();
3553 }
3554 } else {
3555 version = 3;
3556 }
3557
3558 if (qcow2_opts->has_cluster_size) {
3559 cluster_size = qcow2_opts->cluster_size;
3560 } else {
3561 cluster_size = DEFAULT_CLUSTER_SIZE;
3562 }
3563
3564 if (!qcow2_opts->has_extended_l2) {
3565 qcow2_opts->extended_l2 = false;
3566 }
3567 if (qcow2_opts->extended_l2) {
3568 if (version < 3) {
3569 error_setg(errp, "Extended L2 entries are only supported with "
3570 "compatibility level 1.1 and above (use version=v3 or "
3571 "greater)");
3572 ret = -EINVAL;
3573 goto out;
3574 }
3575 }
3576
3577 if (!validate_cluster_size(cluster_size, qcow2_opts->extended_l2, errp)) {
3578 ret = -EINVAL;
3579 goto out;
3580 }
3581
3582 if (!qcow2_opts->has_preallocation) {
3583 qcow2_opts->preallocation = PREALLOC_MODE_OFF;
3584 }
3585 if (qcow2_opts->backing_file &&
3586 qcow2_opts->preallocation != PREALLOC_MODE_OFF &&
3587 !qcow2_opts->extended_l2)
3588 {
3589 error_setg(errp, "Backing file and preallocation can only be used at "
3590 "the same time if extended_l2 is on");
3591 ret = -EINVAL;
3592 goto out;
3593 }
3594 if (qcow2_opts->has_backing_fmt && !qcow2_opts->backing_file) {
3595 error_setg(errp, "Backing format cannot be used without backing file");
3596 ret = -EINVAL;
3597 goto out;
3598 }
3599
3600 if (!qcow2_opts->has_lazy_refcounts) {
3601 qcow2_opts->lazy_refcounts = false;
3602 }
3603 if (version < 3 && qcow2_opts->lazy_refcounts) {
3604 error_setg(errp, "Lazy refcounts only supported with compatibility "
3605 "level 1.1 and above (use version=v3 or greater)");
3606 ret = -EINVAL;
3607 goto out;
3608 }
3609
3610 if (!qcow2_opts->has_refcount_bits) {
3611 qcow2_opts->refcount_bits = 16;
3612 }
3613 if (qcow2_opts->refcount_bits > 64 ||
3614 !is_power_of_2(qcow2_opts->refcount_bits))
3615 {
3616 error_setg(errp, "Refcount width must be a power of two and may not "
3617 "exceed 64 bits");
3618 ret = -EINVAL;
3619 goto out;
3620 }
3621 if (version < 3 && qcow2_opts->refcount_bits != 16) {
3622 error_setg(errp, "Different refcount widths than 16 bits require "
3623 "compatibility level 1.1 or above (use version=v3 or "
3624 "greater)");
3625 ret = -EINVAL;
3626 goto out;
3627 }
3628 refcount_order = ctz32(qcow2_opts->refcount_bits);
3629
3630 if (qcow2_opts->data_file_raw && !qcow2_opts->data_file) {
3631 error_setg(errp, "data-file-raw requires data-file");
3632 ret = -EINVAL;
3633 goto out;
3634 }
3635 if (qcow2_opts->data_file_raw && qcow2_opts->backing_file) {
3636 error_setg(errp, "Backing file and data-file-raw cannot be used at "
3637 "the same time");
3638 ret = -EINVAL;
3639 goto out;
3640 }
3641 if (qcow2_opts->data_file_raw &&
3642 qcow2_opts->preallocation == PREALLOC_MODE_OFF)
3643 {
3644 /*
3645 * data-file-raw means that "the external data file can be
3646 * read as a consistent standalone raw image without looking
3647 * at the qcow2 metadata." It does not say that the metadata
3648 * must be ignored, though (and the qcow2 driver in fact does
3649 * not ignore it), so the L1/L2 tables must be present and
3650 * give a 1:1 mapping, so you get the same result regardless
3651 * of whether you look at the metadata or whether you ignore
3652 * it.
3653 */
3654 qcow2_opts->preallocation = PREALLOC_MODE_METADATA;
3655
3656 /*
3657 * Cannot use preallocation with backing files, but giving a
3658 * backing file when specifying data_file_raw is an error
3659 * anyway.
3660 */
3661 assert(!qcow2_opts->backing_file);
3662 }
3663
3664 if (qcow2_opts->data_file) {
3665 if (version < 3) {
3666 error_setg(errp, "External data files are only supported with "
3667 "compatibility level 1.1 and above (use version=v3 or "
3668 "greater)");
3669 ret = -EINVAL;
3670 goto out;
3671 }
3672 data_bs = bdrv_co_open_blockdev_ref(qcow2_opts->data_file, errp);
3673 if (data_bs == NULL) {
3674 ret = -EIO;
3675 goto out;
3676 }
3677 }
3678
3679 if (qcow2_opts->has_compression_type &&
3680 qcow2_opts->compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) {
3681
3682 ret = -EINVAL;
3683
3684 if (version < 3) {
3685 error_setg(errp, "Non-zlib compression type is only supported with "
3686 "compatibility level 1.1 and above (use version=v3 or "
3687 "greater)");
3688 goto out;
3689 }
3690
3691 switch (qcow2_opts->compression_type) {
3692 #ifdef CONFIG_ZSTD
3693 case QCOW2_COMPRESSION_TYPE_ZSTD:
3694 break;
3695 #endif
3696 default:
3697 error_setg(errp, "Unknown compression type");
3698 goto out;
3699 }
3700
3701 compression_type = qcow2_opts->compression_type;
3702 }
3703
3704 /* Create BlockBackend to write to the image */
3705 blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL,
3706 errp);
3707 if (!blk) {
3708 ret = -EPERM;
3709 goto out;
3710 }
3711 blk_set_allow_write_beyond_eof(blk, true);
3712
3713 /* Write the header */
3714 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header));
3715 header = g_malloc0(cluster_size);
3716 *header = (QCowHeader) {
3717 .magic = cpu_to_be32(QCOW_MAGIC),
3718 .version = cpu_to_be32(version),
3719 .cluster_bits = cpu_to_be32(ctz32(cluster_size)),
3720 .size = cpu_to_be64(0),
3721 .l1_table_offset = cpu_to_be64(0),
3722 .l1_size = cpu_to_be32(0),
3723 .refcount_table_offset = cpu_to_be64(cluster_size),
3724 .refcount_table_clusters = cpu_to_be32(1),
3725 .refcount_order = cpu_to_be32(refcount_order),
3726 /* don't deal with endianness since compression_type is 1 byte long */
3727 .compression_type = compression_type,
3728 .header_length = cpu_to_be32(sizeof(*header)),
3729 };
3730
3731 /* We'll update this to correct value later */
3732 header->crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
3733
3734 if (qcow2_opts->lazy_refcounts) {
3735 header->compatible_features |=
3736 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS);
3737 }
3738 if (data_bs) {
3739 header->incompatible_features |=
3740 cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE);
3741 }
3742 if (qcow2_opts->data_file_raw) {
3743 header->autoclear_features |=
3744 cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW);
3745 }
3746 if (compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) {
3747 header->incompatible_features |=
3748 cpu_to_be64(QCOW2_INCOMPAT_COMPRESSION);
3749 }
3750
3751 if (qcow2_opts->extended_l2) {
3752 header->incompatible_features |=
3753 cpu_to_be64(QCOW2_INCOMPAT_EXTL2);
3754 }
3755
3756 ret = blk_co_pwrite(blk, 0, cluster_size, header, 0);
3757 g_free(header);
3758 if (ret < 0) {
3759 error_setg_errno(errp, -ret, "Could not write qcow2 header");
3760 goto out;
3761 }
3762
3763 /* Write a refcount table with one refcount block */
3764 refcount_table = g_malloc0(2 * cluster_size);
3765 refcount_table[0] = cpu_to_be64(2 * cluster_size);
3766 ret = blk_co_pwrite(blk, cluster_size, 2 * cluster_size, refcount_table, 0);
3767 g_free(refcount_table);
3768
3769 if (ret < 0) {
3770 error_setg_errno(errp, -ret, "Could not write refcount table");
3771 goto out;
3772 }
3773
3774 blk_co_unref(blk);
3775 blk = NULL;
3776
3777 /*
3778 * And now open the image and make it consistent first (i.e. increase the
3779 * refcount of the cluster that is occupied by the header and the refcount
3780 * table)
3781 */
3782 options = qdict_new();
3783 qdict_put_str(options, "driver", "qcow2");
3784 qdict_put_str(options, "file", bs->node_name);
3785 if (data_bs) {
3786 qdict_put_str(options, "data-file", data_bs->node_name);
3787 }
3788 blk = blk_co_new_open(NULL, NULL, options,
3789 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH,
3790 errp);
3791 if (blk == NULL) {
3792 ret = -EIO;
3793 goto out;
3794 }
3795
3796 bdrv_graph_co_rdlock();
3797 ret = qcow2_alloc_clusters(blk_bs(blk), 3 * cluster_size);
3798 if (ret < 0) {
3799 bdrv_graph_co_rdunlock();
3800 error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 "
3801 "header and refcount table");
3802 goto out;
3803
3804 } else if (ret != 0) {
3805 error_report("Huh, first cluster in empty image is already in use?");
3806 abort();
3807 }
3808
3809 /* Set the external data file if necessary */
3810 if (data_bs) {
3811 BDRVQcow2State *s = blk_bs(blk)->opaque;
3812 s->image_data_file = g_strdup(data_bs->filename);
3813 }
3814
3815 /* Create a full header (including things like feature table) */
3816 ret = qcow2_update_header(blk_bs(blk));
3817 bdrv_graph_co_rdunlock();
3818
3819 if (ret < 0) {
3820 error_setg_errno(errp, -ret, "Could not update qcow2 header");
3821 goto out;
3822 }
3823
3824 /* Okay, now that we have a valid image, let's give it the right size */
3825 ret = blk_co_truncate(blk, qcow2_opts->size, false,
3826 qcow2_opts->preallocation, 0, errp);
3827 if (ret < 0) {
3828 error_prepend(errp, "Could not resize image: ");
3829 goto out;
3830 }
3831
3832 /* Want a backing file? There you go. */
3833 if (qcow2_opts->backing_file) {
3834 const char *backing_format = NULL;
3835
3836 if (qcow2_opts->has_backing_fmt) {
3837 backing_format = BlockdevDriver_str(qcow2_opts->backing_fmt);
3838 }
3839
3840 bdrv_graph_co_rdlock();
3841 ret = bdrv_co_change_backing_file(blk_bs(blk), qcow2_opts->backing_file,
3842 backing_format, false);
3843 bdrv_graph_co_rdunlock();
3844
3845 if (ret < 0) {
3846 error_setg_errno(errp, -ret, "Could not assign backing file '%s' "
3847 "with format '%s'", qcow2_opts->backing_file,
3848 backing_format);
3849 goto out;
3850 }
3851 }
3852
3853 /* Want encryption? There you go. */
3854 if (qcow2_opts->encrypt) {
3855 bdrv_graph_co_rdlock();
3856 ret = qcow2_set_up_encryption(blk_bs(blk), qcow2_opts->encrypt, errp);
3857 bdrv_graph_co_rdunlock();
3858
3859 if (ret < 0) {
3860 goto out;
3861 }
3862 }
3863
3864 blk_co_unref(blk);
3865 blk = NULL;
3866
3867 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning.
3868 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to
3869 * have to setup decryption context. We're not doing any I/O on the top
3870 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does
3871 * not have effect.
3872 */
3873 options = qdict_new();
3874 qdict_put_str(options, "driver", "qcow2");
3875 qdict_put_str(options, "file", bs->node_name);
3876 if (data_bs) {
3877 qdict_put_str(options, "data-file", data_bs->node_name);
3878 }
3879 blk = blk_co_new_open(NULL, NULL, options,
3880 BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO,
3881 errp);
3882 if (blk == NULL) {
3883 ret = -EIO;
3884 goto out;
3885 }
3886
3887 ret = 0;
3888 out:
3889 blk_co_unref(blk);
3890 bdrv_co_unref(bs);
3891 bdrv_co_unref(data_bs);
3892 return ret;
3893 }
3894
3895 static int coroutine_fn GRAPH_UNLOCKED
qcow2_co_create_opts(BlockDriver * drv,const char * filename,QemuOpts * opts,Error ** errp)3896 qcow2_co_create_opts(BlockDriver *drv, const char *filename, QemuOpts *opts,
3897 Error **errp)
3898 {
3899 BlockdevCreateOptions *create_options = NULL;
3900 QDict *qdict;
3901 Visitor *v;
3902 BlockDriverState *bs = NULL;
3903 BlockDriverState *data_bs = NULL;
3904 const char *val;
3905 int ret;
3906
3907 /* Only the keyval visitor supports the dotted syntax needed for
3908 * encryption, so go through a QDict before getting a QAPI type. Ignore
3909 * options meant for the protocol layer so that the visitor doesn't
3910 * complain. */
3911 qdict = qemu_opts_to_qdict_filtered(opts, NULL, bdrv_qcow2.create_opts,
3912 true);
3913
3914 /* Handle encryption options */
3915 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT);
3916 if (val && !strcmp(val, "on")) {
3917 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow");
3918 } else if (val && !strcmp(val, "off")) {
3919 qdict_del(qdict, BLOCK_OPT_ENCRYPT);
3920 }
3921
3922 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT);
3923 if (val && !strcmp(val, "aes")) {
3924 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow");
3925 }
3926
3927 /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into
3928 * version=v2/v3 below. */
3929 val = qdict_get_try_str(qdict, BLOCK_OPT_COMPAT_LEVEL);
3930 if (val && !strcmp(val, "0.10")) {
3931 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v2");
3932 } else if (val && !strcmp(val, "1.1")) {
3933 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v3");
3934 }
3935
3936 /* Change legacy command line options into QMP ones */
3937 static const QDictRenames opt_renames[] = {
3938 { BLOCK_OPT_BACKING_FILE, "backing-file" },
3939 { BLOCK_OPT_BACKING_FMT, "backing-fmt" },
3940 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" },
3941 { BLOCK_OPT_LAZY_REFCOUNTS, "lazy-refcounts" },
3942 { BLOCK_OPT_EXTL2, "extended-l2" },
3943 { BLOCK_OPT_REFCOUNT_BITS, "refcount-bits" },
3944 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT },
3945 { BLOCK_OPT_COMPAT_LEVEL, "version" },
3946 { BLOCK_OPT_DATA_FILE_RAW, "data-file-raw" },
3947 { BLOCK_OPT_COMPRESSION_TYPE, "compression-type" },
3948 { NULL, NULL },
3949 };
3950
3951 if (!qdict_rename_keys(qdict, opt_renames, errp)) {
3952 ret = -EINVAL;
3953 goto finish;
3954 }
3955
3956 /* Create and open the file (protocol layer) */
3957 ret = bdrv_co_create_file(filename, opts, errp);
3958 if (ret < 0) {
3959 goto finish;
3960 }
3961
3962 bs = bdrv_co_open(filename, NULL, NULL,
3963 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
3964 if (bs == NULL) {
3965 ret = -EIO;
3966 goto finish;
3967 }
3968
3969 /* Create and open an external data file (protocol layer) */
3970 val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE);
3971 if (val) {
3972 ret = bdrv_co_create_file(val, opts, errp);
3973 if (ret < 0) {
3974 goto finish;
3975 }
3976
3977 data_bs = bdrv_co_open(val, NULL, NULL,
3978 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
3979 errp);
3980 if (data_bs == NULL) {
3981 ret = -EIO;
3982 goto finish;
3983 }
3984
3985 qdict_del(qdict, BLOCK_OPT_DATA_FILE);
3986 qdict_put_str(qdict, "data-file", data_bs->node_name);
3987 }
3988
3989 /* Set 'driver' and 'node' options */
3990 qdict_put_str(qdict, "driver", "qcow2");
3991 qdict_put_str(qdict, "file", bs->node_name);
3992
3993 /* Now get the QAPI type BlockdevCreateOptions */
3994 v = qobject_input_visitor_new_flat_confused(qdict, errp);
3995 if (!v) {
3996 ret = -EINVAL;
3997 goto finish;
3998 }
3999
4000 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp);
4001 visit_free(v);
4002 if (!create_options) {
4003 ret = -EINVAL;
4004 goto finish;
4005 }
4006
4007 /* Silently round up size */
4008 create_options->u.qcow2.size = ROUND_UP(create_options->u.qcow2.size,
4009 BDRV_SECTOR_SIZE);
4010
4011 /* Create the qcow2 image (format layer) */
4012 ret = qcow2_co_create(create_options, errp);
4013 finish:
4014 if (ret < 0) {
4015 bdrv_graph_co_rdlock();
4016 bdrv_co_delete_file_noerr(bs);
4017 bdrv_co_delete_file_noerr(data_bs);
4018 bdrv_graph_co_rdunlock();
4019 } else {
4020 ret = 0;
4021 }
4022
4023 qobject_unref(qdict);
4024 bdrv_co_unref(bs);
4025 bdrv_co_unref(data_bs);
4026 qapi_free_BlockdevCreateOptions(create_options);
4027 return ret;
4028 }
4029
4030
4031 static bool coroutine_fn GRAPH_RDLOCK
is_zero(BlockDriverState * bs,int64_t offset,int64_t bytes)4032 is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes)
4033 {
4034 int64_t nr;
4035 int res;
4036
4037 /* Clamp to image length, before checking status of underlying sectors */
4038 if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) {
4039 bytes = bs->total_sectors * BDRV_SECTOR_SIZE - offset;
4040 }
4041
4042 if (!bytes) {
4043 return true;
4044 }
4045
4046 /*
4047 * bdrv_block_status_above doesn't merge different types of zeros, for
4048 * example, zeros which come from the region which is unallocated in
4049 * the whole backing chain, and zeros which come because of a short
4050 * backing file. So, we need a loop.
4051 */
4052 do {
4053 res = bdrv_co_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL);
4054 offset += nr;
4055 bytes -= nr;
4056 } while (res >= 0 && (res & BDRV_BLOCK_ZERO) && nr && bytes);
4057
4058 return res >= 0 && (res & BDRV_BLOCK_ZERO) && bytes == 0;
4059 }
4060
4061 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_pwrite_zeroes(BlockDriverState * bs,int64_t offset,int64_t bytes,BdrvRequestFlags flags)4062 qcow2_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
4063 BdrvRequestFlags flags)
4064 {
4065 int ret;
4066 BDRVQcow2State *s = bs->opaque;
4067
4068 uint32_t head = offset_into_subcluster(s, offset);
4069 uint32_t tail = ROUND_UP(offset + bytes, s->subcluster_size) -
4070 (offset + bytes);
4071
4072 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, bytes);
4073 if (offset + bytes == bs->total_sectors * BDRV_SECTOR_SIZE) {
4074 tail = 0;
4075 }
4076
4077 if (head || tail) {
4078 uint64_t off;
4079 unsigned int nr;
4080 QCow2SubclusterType type;
4081
4082 assert(head + bytes + tail <= s->subcluster_size);
4083
4084 /* check whether remainder of cluster already reads as zero */
4085 if (!(is_zero(bs, offset - head, head) &&
4086 is_zero(bs, offset + bytes, tail))) {
4087 return -ENOTSUP;
4088 }
4089
4090 qemu_co_mutex_lock(&s->lock);
4091 /* We can have new write after previous check */
4092 offset -= head;
4093 bytes = s->subcluster_size;
4094 nr = s->subcluster_size;
4095 ret = qcow2_get_host_offset(bs, offset, &nr, &off, &type);
4096 if (ret < 0 ||
4097 (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN &&
4098 type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC &&
4099 type != QCOW2_SUBCLUSTER_ZERO_PLAIN &&
4100 type != QCOW2_SUBCLUSTER_ZERO_ALLOC)) {
4101 qemu_co_mutex_unlock(&s->lock);
4102 return ret < 0 ? ret : -ENOTSUP;
4103 }
4104 } else {
4105 qemu_co_mutex_lock(&s->lock);
4106 }
4107
4108 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes);
4109
4110 /* Whatever is left can use real zero subclusters */
4111 ret = qcow2_subcluster_zeroize(bs, offset, bytes, flags);
4112 qemu_co_mutex_unlock(&s->lock);
4113
4114 return ret;
4115 }
4116
4117 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_pdiscard(BlockDriverState * bs,int64_t offset,int64_t bytes)4118 qcow2_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
4119 {
4120 int ret;
4121 BDRVQcow2State *s = bs->opaque;
4122
4123 /* If the image does not support QCOW_OFLAG_ZERO then discarding
4124 * clusters could expose stale data from the backing file. */
4125 if (s->qcow_version < 3 && bs->backing) {
4126 return -ENOTSUP;
4127 }
4128
4129 if (!QEMU_IS_ALIGNED(offset | bytes, s->cluster_size)) {
4130 assert(bytes < s->cluster_size);
4131 /* Ignore partial clusters, except for the special case of the
4132 * complete partial cluster at the end of an unaligned file */
4133 if (!QEMU_IS_ALIGNED(offset, s->cluster_size) ||
4134 offset + bytes != bs->total_sectors * BDRV_SECTOR_SIZE) {
4135 return -ENOTSUP;
4136 }
4137 }
4138
4139 qemu_co_mutex_lock(&s->lock);
4140 ret = qcow2_cluster_discard(bs, offset, bytes, QCOW2_DISCARD_REQUEST,
4141 false);
4142 qemu_co_mutex_unlock(&s->lock);
4143 return ret;
4144 }
4145
4146 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)4147 qcow2_co_copy_range_from(BlockDriverState *bs,
4148 BdrvChild *src, int64_t src_offset,
4149 BdrvChild *dst, int64_t dst_offset,
4150 int64_t bytes, BdrvRequestFlags read_flags,
4151 BdrvRequestFlags write_flags)
4152 {
4153 BDRVQcow2State *s = bs->opaque;
4154 int ret;
4155 unsigned int cur_bytes; /* number of bytes in current iteration */
4156 BdrvChild *child = NULL;
4157 BdrvRequestFlags cur_write_flags;
4158
4159 assert(!bs->encrypted);
4160 qemu_co_mutex_lock(&s->lock);
4161
4162 while (bytes != 0) {
4163 uint64_t copy_offset = 0;
4164 QCow2SubclusterType type;
4165 /* prepare next request */
4166 cur_bytes = MIN(bytes, INT_MAX);
4167 cur_write_flags = write_flags;
4168
4169 ret = qcow2_get_host_offset(bs, src_offset, &cur_bytes,
4170 ©_offset, &type);
4171 if (ret < 0) {
4172 goto out;
4173 }
4174
4175 switch (type) {
4176 case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN:
4177 case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC:
4178 if (bs->backing && bs->backing->bs) {
4179 int64_t backing_length = bdrv_co_getlength(bs->backing->bs);
4180 if (src_offset >= backing_length) {
4181 cur_write_flags |= BDRV_REQ_ZERO_WRITE;
4182 } else {
4183 child = bs->backing;
4184 cur_bytes = MIN(cur_bytes, backing_length - src_offset);
4185 copy_offset = src_offset;
4186 }
4187 } else {
4188 cur_write_flags |= BDRV_REQ_ZERO_WRITE;
4189 }
4190 break;
4191
4192 case QCOW2_SUBCLUSTER_ZERO_PLAIN:
4193 case QCOW2_SUBCLUSTER_ZERO_ALLOC:
4194 cur_write_flags |= BDRV_REQ_ZERO_WRITE;
4195 break;
4196
4197 case QCOW2_SUBCLUSTER_COMPRESSED:
4198 ret = -ENOTSUP;
4199 goto out;
4200
4201 case QCOW2_SUBCLUSTER_NORMAL:
4202 child = s->data_file;
4203 break;
4204
4205 default:
4206 abort();
4207 }
4208 qemu_co_mutex_unlock(&s->lock);
4209 ret = bdrv_co_copy_range_from(child,
4210 copy_offset,
4211 dst, dst_offset,
4212 cur_bytes, read_flags, cur_write_flags);
4213 qemu_co_mutex_lock(&s->lock);
4214 if (ret < 0) {
4215 goto out;
4216 }
4217
4218 bytes -= cur_bytes;
4219 src_offset += cur_bytes;
4220 dst_offset += cur_bytes;
4221 }
4222 ret = 0;
4223
4224 out:
4225 qemu_co_mutex_unlock(&s->lock);
4226 return ret;
4227 }
4228
4229 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)4230 qcow2_co_copy_range_to(BlockDriverState *bs,
4231 BdrvChild *src, int64_t src_offset,
4232 BdrvChild *dst, int64_t dst_offset,
4233 int64_t bytes, BdrvRequestFlags read_flags,
4234 BdrvRequestFlags write_flags)
4235 {
4236 BDRVQcow2State *s = bs->opaque;
4237 int ret;
4238 unsigned int cur_bytes; /* number of sectors in current iteration */
4239 uint64_t host_offset;
4240 QCowL2Meta *l2meta = NULL;
4241
4242 assert(!bs->encrypted);
4243
4244 qemu_co_mutex_lock(&s->lock);
4245
4246 while (bytes != 0) {
4247
4248 l2meta = NULL;
4249
4250 cur_bytes = MIN(bytes, INT_MAX);
4251
4252 /* TODO:
4253 * If src->bs == dst->bs, we could simply copy by incrementing
4254 * the refcnt, without copying user data.
4255 * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */
4256 ret = qcow2_alloc_host_offset(bs, dst_offset, &cur_bytes,
4257 &host_offset, &l2meta);
4258 if (ret < 0) {
4259 goto fail;
4260 }
4261
4262 ret = qcow2_pre_write_overlap_check(bs, 0, host_offset, cur_bytes,
4263 true);
4264 if (ret < 0) {
4265 goto fail;
4266 }
4267
4268 qemu_co_mutex_unlock(&s->lock);
4269 ret = bdrv_co_copy_range_to(src, src_offset, s->data_file, host_offset,
4270 cur_bytes, read_flags, write_flags);
4271 qemu_co_mutex_lock(&s->lock);
4272 if (ret < 0) {
4273 goto fail;
4274 }
4275
4276 ret = qcow2_handle_l2meta(bs, &l2meta, true);
4277 if (ret) {
4278 goto fail;
4279 }
4280
4281 bytes -= cur_bytes;
4282 src_offset += cur_bytes;
4283 dst_offset += cur_bytes;
4284 }
4285 ret = 0;
4286
4287 fail:
4288 qcow2_handle_l2meta(bs, &l2meta, false);
4289
4290 qemu_co_mutex_unlock(&s->lock);
4291
4292 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
4293
4294 return ret;
4295 }
4296
4297 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_truncate(BlockDriverState * bs,int64_t offset,bool exact,PreallocMode prealloc,BdrvRequestFlags flags,Error ** errp)4298 qcow2_co_truncate(BlockDriverState *bs, int64_t offset, bool exact,
4299 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp)
4300 {
4301 ERRP_GUARD();
4302 BDRVQcow2State *s = bs->opaque;
4303 uint64_t old_length;
4304 int64_t new_l1_size;
4305 int ret;
4306 QDict *options;
4307
4308 if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA &&
4309 prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL)
4310 {
4311 error_setg(errp, "Unsupported preallocation mode '%s'",
4312 PreallocMode_str(prealloc));
4313 return -ENOTSUP;
4314 }
4315
4316 if (!QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)) {
4317 error_setg(errp, "The new size must be a multiple of %u",
4318 (unsigned) BDRV_SECTOR_SIZE);
4319 return -EINVAL;
4320 }
4321
4322 qemu_co_mutex_lock(&s->lock);
4323
4324 /*
4325 * Even though we store snapshot size for all images, it was not
4326 * required until v3, so it is not safe to proceed for v2.
4327 */
4328 if (s->nb_snapshots && s->qcow_version < 3) {
4329 error_setg(errp, "Can't resize a v2 image which has snapshots");
4330 ret = -ENOTSUP;
4331 goto fail;
4332 }
4333
4334 /* See qcow2-bitmap.c for which bitmap scenarios prevent a resize. */
4335 if (qcow2_truncate_bitmaps_check(bs, errp)) {
4336 ret = -ENOTSUP;
4337 goto fail;
4338 }
4339
4340 old_length = bs->total_sectors * BDRV_SECTOR_SIZE;
4341 new_l1_size = size_to_l1(s, offset);
4342
4343 if (offset < old_length) {
4344 int64_t last_cluster, old_file_size;
4345 if (prealloc != PREALLOC_MODE_OFF) {
4346 error_setg(errp,
4347 "Preallocation can't be used for shrinking an image");
4348 ret = -EINVAL;
4349 goto fail;
4350 }
4351
4352 ret = qcow2_cluster_discard(bs, ROUND_UP(offset, s->cluster_size),
4353 old_length - ROUND_UP(offset,
4354 s->cluster_size),
4355 QCOW2_DISCARD_ALWAYS, true);
4356 if (ret < 0) {
4357 error_setg_errno(errp, -ret, "Failed to discard cropped clusters");
4358 goto fail;
4359 }
4360
4361 ret = qcow2_shrink_l1_table(bs, new_l1_size);
4362 if (ret < 0) {
4363 error_setg_errno(errp, -ret,
4364 "Failed to reduce the number of L2 tables");
4365 goto fail;
4366 }
4367
4368 ret = qcow2_shrink_reftable(bs);
4369 if (ret < 0) {
4370 error_setg_errno(errp, -ret,
4371 "Failed to discard unused refblocks");
4372 goto fail;
4373 }
4374
4375 old_file_size = bdrv_co_getlength(bs->file->bs);
4376 if (old_file_size < 0) {
4377 error_setg_errno(errp, -old_file_size,
4378 "Failed to inquire current file length");
4379 ret = old_file_size;
4380 goto fail;
4381 }
4382 last_cluster = qcow2_get_last_cluster(bs, old_file_size);
4383 if (last_cluster < 0) {
4384 error_setg_errno(errp, -last_cluster,
4385 "Failed to find the last cluster");
4386 ret = last_cluster;
4387 goto fail;
4388 }
4389 if ((last_cluster + 1) * s->cluster_size < old_file_size) {
4390 Error *local_err = NULL;
4391
4392 /*
4393 * Do not pass @exact here: It will not help the user if
4394 * we get an error here just because they wanted to shrink
4395 * their qcow2 image (on a block device) with qemu-img.
4396 * (And on the qcow2 layer, the @exact requirement is
4397 * always fulfilled, so there is no need to pass it on.)
4398 */
4399 bdrv_co_truncate(bs->file, (last_cluster + 1) * s->cluster_size,
4400 false, PREALLOC_MODE_OFF, 0, &local_err);
4401 if (local_err) {
4402 warn_reportf_err(local_err,
4403 "Failed to truncate the tail of the image: ");
4404 }
4405 }
4406 } else {
4407 ret = qcow2_grow_l1_table(bs, new_l1_size, true);
4408 if (ret < 0) {
4409 error_setg_errno(errp, -ret, "Failed to grow the L1 table");
4410 goto fail;
4411 }
4412
4413 if (data_file_is_raw(bs) && prealloc == PREALLOC_MODE_OFF) {
4414 /*
4415 * When creating a qcow2 image with data-file-raw, we enforce
4416 * at least prealloc=metadata, so that the L1/L2 tables are
4417 * fully allocated and reading from the data file will return
4418 * the same data as reading from the qcow2 image. When the
4419 * image is grown, we must consequently preallocate the
4420 * metadata structures to cover the added area.
4421 */
4422 prealloc = PREALLOC_MODE_METADATA;
4423 }
4424 }
4425
4426 switch (prealloc) {
4427 case PREALLOC_MODE_OFF:
4428 if (has_data_file(bs)) {
4429 /*
4430 * If the caller wants an exact resize, the external data
4431 * file should be resized to the exact target size, too,
4432 * so we pass @exact here.
4433 */
4434 ret = bdrv_co_truncate(s->data_file, offset, exact, prealloc, 0,
4435 errp);
4436 if (ret < 0) {
4437 goto fail;
4438 }
4439 }
4440 break;
4441
4442 case PREALLOC_MODE_METADATA:
4443 ret = preallocate_co(bs, old_length, offset, prealloc, errp);
4444 if (ret < 0) {
4445 goto fail;
4446 }
4447 break;
4448
4449 case PREALLOC_MODE_FALLOC:
4450 case PREALLOC_MODE_FULL:
4451 {
4452 int64_t allocation_start, host_offset, guest_offset;
4453 int64_t clusters_allocated;
4454 int64_t old_file_size, last_cluster, new_file_size;
4455 uint64_t nb_new_data_clusters, nb_new_l2_tables;
4456 bool subclusters_need_allocation = false;
4457
4458 /* With a data file, preallocation means just allocating the metadata
4459 * and forwarding the truncate request to the data file */
4460 if (has_data_file(bs)) {
4461 ret = preallocate_co(bs, old_length, offset, prealloc, errp);
4462 if (ret < 0) {
4463 goto fail;
4464 }
4465 break;
4466 }
4467
4468 old_file_size = bdrv_co_getlength(bs->file->bs);
4469 if (old_file_size < 0) {
4470 error_setg_errno(errp, -old_file_size,
4471 "Failed to inquire current file length");
4472 ret = old_file_size;
4473 goto fail;
4474 }
4475
4476 last_cluster = qcow2_get_last_cluster(bs, old_file_size);
4477 if (last_cluster >= 0) {
4478 old_file_size = (last_cluster + 1) * s->cluster_size;
4479 } else {
4480 old_file_size = ROUND_UP(old_file_size, s->cluster_size);
4481 }
4482
4483 nb_new_data_clusters = (ROUND_UP(offset, s->cluster_size) -
4484 start_of_cluster(s, old_length)) >> s->cluster_bits;
4485
4486 /* This is an overestimation; we will not actually allocate space for
4487 * these in the file but just make sure the new refcount structures are
4488 * able to cover them so we will not have to allocate new refblocks
4489 * while entering the data blocks in the potentially new L2 tables.
4490 * (We do not actually care where the L2 tables are placed. Maybe they
4491 * are already allocated or they can be placed somewhere before
4492 * @old_file_size. It does not matter because they will be fully
4493 * allocated automatically, so they do not need to be covered by the
4494 * preallocation. All that matters is that we will not have to allocate
4495 * new refcount structures for them.) */
4496 nb_new_l2_tables = DIV_ROUND_UP(nb_new_data_clusters,
4497 s->cluster_size / l2_entry_size(s));
4498 /* The cluster range may not be aligned to L2 boundaries, so add one L2
4499 * table for a potential head/tail */
4500 nb_new_l2_tables++;
4501
4502 allocation_start = qcow2_refcount_area(bs, old_file_size,
4503 nb_new_data_clusters +
4504 nb_new_l2_tables,
4505 true, 0, 0);
4506 if (allocation_start < 0) {
4507 error_setg_errno(errp, -allocation_start,
4508 "Failed to resize refcount structures");
4509 ret = allocation_start;
4510 goto fail;
4511 }
4512
4513 clusters_allocated = qcow2_alloc_clusters_at(bs, allocation_start,
4514 nb_new_data_clusters);
4515 if (clusters_allocated < 0) {
4516 error_setg_errno(errp, -clusters_allocated,
4517 "Failed to allocate data clusters");
4518 ret = clusters_allocated;
4519 goto fail;
4520 }
4521
4522 assert(clusters_allocated == nb_new_data_clusters);
4523
4524 /* Allocate the data area */
4525 new_file_size = allocation_start +
4526 nb_new_data_clusters * s->cluster_size;
4527 /*
4528 * Image file grows, so @exact does not matter.
4529 *
4530 * If we need to zero out the new area, try first whether the protocol
4531 * driver can already take care of this.
4532 */
4533 if (flags & BDRV_REQ_ZERO_WRITE) {
4534 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc,
4535 BDRV_REQ_ZERO_WRITE, NULL);
4536 if (ret >= 0) {
4537 flags &= ~BDRV_REQ_ZERO_WRITE;
4538 /* Ensure that we read zeroes and not backing file data */
4539 subclusters_need_allocation = true;
4540 }
4541 } else {
4542 ret = -1;
4543 }
4544 if (ret < 0) {
4545 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 0,
4546 errp);
4547 }
4548 if (ret < 0) {
4549 error_prepend(errp, "Failed to resize underlying file: ");
4550 qcow2_free_clusters(bs, allocation_start,
4551 nb_new_data_clusters * s->cluster_size,
4552 QCOW2_DISCARD_OTHER);
4553 goto fail;
4554 }
4555
4556 /* Create the necessary L2 entries */
4557 host_offset = allocation_start;
4558 guest_offset = old_length;
4559 while (nb_new_data_clusters) {
4560 int64_t nb_clusters = MIN(
4561 nb_new_data_clusters,
4562 s->l2_slice_size - offset_to_l2_slice_index(s, guest_offset));
4563 unsigned cow_start_length = offset_into_cluster(s, guest_offset);
4564 QCowL2Meta allocation;
4565 guest_offset = start_of_cluster(s, guest_offset);
4566 allocation = (QCowL2Meta) {
4567 .offset = guest_offset,
4568 .alloc_offset = host_offset,
4569 .nb_clusters = nb_clusters,
4570 .cow_start = {
4571 .offset = 0,
4572 .nb_bytes = cow_start_length,
4573 },
4574 .cow_end = {
4575 .offset = nb_clusters << s->cluster_bits,
4576 .nb_bytes = 0,
4577 },
4578 .prealloc = !subclusters_need_allocation,
4579 };
4580 qemu_co_queue_init(&allocation.dependent_requests);
4581
4582 ret = qcow2_alloc_cluster_link_l2(bs, &allocation);
4583 if (ret < 0) {
4584 error_setg_errno(errp, -ret, "Failed to update L2 tables");
4585 qcow2_free_clusters(bs, host_offset,
4586 nb_new_data_clusters * s->cluster_size,
4587 QCOW2_DISCARD_OTHER);
4588 goto fail;
4589 }
4590
4591 guest_offset += nb_clusters * s->cluster_size;
4592 host_offset += nb_clusters * s->cluster_size;
4593 nb_new_data_clusters -= nb_clusters;
4594 }
4595 break;
4596 }
4597
4598 default:
4599 g_assert_not_reached();
4600 }
4601
4602 if ((flags & BDRV_REQ_ZERO_WRITE) && offset > old_length) {
4603 uint64_t zero_start = QEMU_ALIGN_UP(old_length, s->subcluster_size);
4604
4605 /*
4606 * Use zero clusters as much as we can. qcow2_subcluster_zeroize()
4607 * requires a subcluster-aligned start. The end may be unaligned if
4608 * it is at the end of the image (which it is here).
4609 */
4610 if (offset > zero_start) {
4611 ret = qcow2_subcluster_zeroize(bs, zero_start, offset - zero_start,
4612 0);
4613 if (ret < 0) {
4614 error_setg_errno(errp, -ret, "Failed to zero out new clusters");
4615 goto fail;
4616 }
4617 }
4618
4619 /* Write explicit zeros for the unaligned head */
4620 if (zero_start > old_length) {
4621 uint64_t len = MIN(zero_start, offset) - old_length;
4622 uint8_t *buf = qemu_blockalign0(bs, len);
4623 QEMUIOVector qiov;
4624 qemu_iovec_init_buf(&qiov, buf, len);
4625
4626 qemu_co_mutex_unlock(&s->lock);
4627 ret = qcow2_co_pwritev_part(bs, old_length, len, &qiov, 0, 0);
4628 qemu_co_mutex_lock(&s->lock);
4629
4630 qemu_vfree(buf);
4631 if (ret < 0) {
4632 error_setg_errno(errp, -ret, "Failed to zero out the new area");
4633 goto fail;
4634 }
4635 }
4636 }
4637
4638 if (prealloc != PREALLOC_MODE_OFF) {
4639 /* Flush metadata before actually changing the image size */
4640 ret = qcow2_write_caches(bs);
4641 if (ret < 0) {
4642 error_setg_errno(errp, -ret,
4643 "Failed to flush the preallocated area to disk");
4644 goto fail;
4645 }
4646 }
4647
4648 bs->total_sectors = offset / BDRV_SECTOR_SIZE;
4649
4650 /* write updated header.size */
4651 offset = cpu_to_be64(offset);
4652 ret = bdrv_co_pwrite_sync(bs->file, offsetof(QCowHeader, size),
4653 sizeof(offset), &offset, 0);
4654 if (ret < 0) {
4655 error_setg_errno(errp, -ret, "Failed to update the image size");
4656 goto fail;
4657 }
4658
4659 s->l1_vm_state_index = new_l1_size;
4660
4661 /* Update cache sizes */
4662 options = qdict_clone_shallow(bs->options);
4663 ret = qcow2_update_options(bs, options, s->flags, errp);
4664 qobject_unref(options);
4665 if (ret < 0) {
4666 goto fail;
4667 }
4668 ret = 0;
4669 fail:
4670 qemu_co_mutex_unlock(&s->lock);
4671 return ret;
4672 }
4673
4674 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)4675 qcow2_co_pwritev_compressed_task(BlockDriverState *bs,
4676 uint64_t offset, uint64_t bytes,
4677 QEMUIOVector *qiov, size_t qiov_offset)
4678 {
4679 BDRVQcow2State *s = bs->opaque;
4680 int ret;
4681 ssize_t out_len;
4682 uint8_t *buf, *out_buf;
4683 uint64_t cluster_offset;
4684
4685 assert(bytes == s->cluster_size || (bytes < s->cluster_size &&
4686 (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS)));
4687
4688 buf = qemu_blockalign(bs, s->cluster_size);
4689 if (bytes < s->cluster_size) {
4690 /* Zero-pad last write if image size is not cluster aligned */
4691 memset(buf + bytes, 0, s->cluster_size - bytes);
4692 }
4693 qemu_iovec_to_buf(qiov, qiov_offset, buf, bytes);
4694
4695 out_buf = g_malloc(s->cluster_size);
4696
4697 out_len = qcow2_co_compress(bs, out_buf, s->cluster_size - 1,
4698 buf, s->cluster_size);
4699 if (out_len == -ENOMEM) {
4700 /* could not compress: write normal cluster */
4701 ret = qcow2_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, 0);
4702 if (ret < 0) {
4703 goto fail;
4704 }
4705 goto success;
4706 } else if (out_len < 0) {
4707 ret = -EINVAL;
4708 goto fail;
4709 }
4710
4711 qemu_co_mutex_lock(&s->lock);
4712 ret = qcow2_alloc_compressed_cluster_offset(bs, offset, out_len,
4713 &cluster_offset);
4714 if (ret < 0) {
4715 qemu_co_mutex_unlock(&s->lock);
4716 goto fail;
4717 }
4718
4719 ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len, true);
4720 qemu_co_mutex_unlock(&s->lock);
4721 if (ret < 0) {
4722 goto fail;
4723 }
4724
4725 BLKDBG_CO_EVENT(s->data_file, BLKDBG_WRITE_COMPRESSED);
4726 ret = bdrv_co_pwrite(s->data_file, cluster_offset, out_len, out_buf, 0);
4727 if (ret < 0) {
4728 goto fail;
4729 }
4730 success:
4731 ret = 0;
4732 fail:
4733 qemu_vfree(buf);
4734 g_free(out_buf);
4735 return ret;
4736 }
4737
4738 /*
4739 * This function can count as GRAPH_RDLOCK because
4740 * qcow2_co_pwritev_compressed_part() holds the graph lock and keeps it until
4741 * this coroutine has terminated.
4742 */
4743 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_pwritev_compressed_task_entry(AioTask * task)4744 qcow2_co_pwritev_compressed_task_entry(AioTask *task)
4745 {
4746 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task);
4747
4748 assert(!t->subcluster_type && !t->l2meta);
4749
4750 return qcow2_co_pwritev_compressed_task(t->bs, t->offset, t->bytes, t->qiov,
4751 t->qiov_offset);
4752 }
4753
4754 /*
4755 * XXX: put compressed sectors first, then all the cluster aligned
4756 * tables to avoid losing bytes in alignment
4757 */
4758 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)4759 qcow2_co_pwritev_compressed_part(BlockDriverState *bs,
4760 int64_t offset, int64_t bytes,
4761 QEMUIOVector *qiov, size_t qiov_offset)
4762 {
4763 BDRVQcow2State *s = bs->opaque;
4764 AioTaskPool *aio = NULL;
4765 int ret = 0;
4766
4767 if (has_data_file(bs)) {
4768 return -ENOTSUP;
4769 }
4770
4771 if (bytes == 0) {
4772 /*
4773 * align end of file to a sector boundary to ease reading with
4774 * sector based I/Os
4775 */
4776 int64_t len = bdrv_co_getlength(bs->file->bs);
4777 if (len < 0) {
4778 return len;
4779 }
4780 return bdrv_co_truncate(bs->file, len, false, PREALLOC_MODE_OFF, 0,
4781 NULL);
4782 }
4783
4784 if (offset_into_cluster(s, offset)) {
4785 return -EINVAL;
4786 }
4787
4788 if (offset_into_cluster(s, bytes) &&
4789 (offset + bytes) != (bs->total_sectors << BDRV_SECTOR_BITS)) {
4790 return -EINVAL;
4791 }
4792
4793 while (bytes && aio_task_pool_status(aio) == 0) {
4794 uint64_t chunk_size = MIN(bytes, s->cluster_size);
4795
4796 if (!aio && chunk_size != bytes) {
4797 aio = aio_task_pool_new(QCOW2_MAX_WORKERS);
4798 }
4799
4800 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_compressed_task_entry,
4801 0, 0, offset, chunk_size, qiov, qiov_offset, NULL);
4802 if (ret < 0) {
4803 break;
4804 }
4805 qiov_offset += chunk_size;
4806 offset += chunk_size;
4807 bytes -= chunk_size;
4808 }
4809
4810 if (aio) {
4811 aio_task_pool_wait_all(aio);
4812 if (ret == 0) {
4813 ret = aio_task_pool_status(aio);
4814 }
4815 g_free(aio);
4816 }
4817
4818 return ret;
4819 }
4820
4821 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)4822 qcow2_co_preadv_compressed(BlockDriverState *bs,
4823 uint64_t l2_entry,
4824 uint64_t offset,
4825 uint64_t bytes,
4826 QEMUIOVector *qiov,
4827 size_t qiov_offset)
4828 {
4829 BDRVQcow2State *s = bs->opaque;
4830 int ret = 0, csize;
4831 uint64_t coffset;
4832 uint8_t *buf, *out_buf;
4833 int offset_in_cluster = offset_into_cluster(s, offset);
4834
4835 qcow2_parse_compressed_l2_entry(bs, l2_entry, &coffset, &csize);
4836
4837 buf = g_try_malloc(csize);
4838 if (!buf) {
4839 return -ENOMEM;
4840 }
4841
4842 out_buf = qemu_blockalign(bs, s->cluster_size);
4843
4844 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
4845 ret = bdrv_co_pread(bs->file, coffset, csize, buf, 0);
4846 if (ret < 0) {
4847 goto fail;
4848 }
4849
4850 if (qcow2_co_decompress(bs, out_buf, s->cluster_size, buf, csize) < 0) {
4851 ret = -EIO;
4852 goto fail;
4853 }
4854
4855 qemu_iovec_from_buf(qiov, qiov_offset, out_buf + offset_in_cluster, bytes);
4856
4857 fail:
4858 qemu_vfree(out_buf);
4859 g_free(buf);
4860
4861 return ret;
4862 }
4863
make_completely_empty(BlockDriverState * bs)4864 static int GRAPH_RDLOCK make_completely_empty(BlockDriverState *bs)
4865 {
4866 BDRVQcow2State *s = bs->opaque;
4867 Error *local_err = NULL;
4868 int ret, l1_clusters;
4869 int64_t offset;
4870 uint64_t *new_reftable = NULL;
4871 uint64_t rt_entry, l1_size2;
4872 struct {
4873 uint64_t l1_offset;
4874 uint64_t reftable_offset;
4875 uint32_t reftable_clusters;
4876 } QEMU_PACKED l1_ofs_rt_ofs_cls;
4877
4878 ret = qcow2_cache_empty(bs, s->l2_table_cache);
4879 if (ret < 0) {
4880 goto fail;
4881 }
4882
4883 ret = qcow2_cache_empty(bs, s->refcount_block_cache);
4884 if (ret < 0) {
4885 goto fail;
4886 }
4887
4888 /* Refcounts will be broken utterly */
4889 ret = qcow2_mark_dirty(bs);
4890 if (ret < 0) {
4891 goto fail;
4892 }
4893
4894 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
4895
4896 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE);
4897 l1_size2 = (uint64_t)s->l1_size * L1E_SIZE;
4898
4899 /* After this call, neither the in-memory nor the on-disk refcount
4900 * information accurately describe the actual references */
4901
4902 ret = bdrv_pwrite_zeroes(bs->file, s->l1_table_offset,
4903 l1_clusters * s->cluster_size, 0);
4904 if (ret < 0) {
4905 goto fail_broken_refcounts;
4906 }
4907 memset(s->l1_table, 0, l1_size2);
4908
4909 BLKDBG_EVENT(bs->file, BLKDBG_EMPTY_IMAGE_PREPARE);
4910
4911 /* Overwrite enough clusters at the beginning of the sectors to place
4912 * the refcount table, a refcount block and the L1 table in; this may
4913 * overwrite parts of the existing refcount and L1 table, which is not
4914 * an issue because the dirty flag is set, complete data loss is in fact
4915 * desired and partial data loss is consequently fine as well */
4916 ret = bdrv_pwrite_zeroes(bs->file, s->cluster_size,
4917 (2 + l1_clusters) * s->cluster_size, 0);
4918 /* This call (even if it failed overall) may have overwritten on-disk
4919 * refcount structures; in that case, the in-memory refcount information
4920 * will probably differ from the on-disk information which makes the BDS
4921 * unusable */
4922 if (ret < 0) {
4923 goto fail_broken_refcounts;
4924 }
4925
4926 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
4927 BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE);
4928
4929 /* "Create" an empty reftable (one cluster) directly after the image
4930 * header and an empty L1 table three clusters after the image header;
4931 * the cluster between those two will be used as the first refblock */
4932 l1_ofs_rt_ofs_cls.l1_offset = cpu_to_be64(3 * s->cluster_size);
4933 l1_ofs_rt_ofs_cls.reftable_offset = cpu_to_be64(s->cluster_size);
4934 l1_ofs_rt_ofs_cls.reftable_clusters = cpu_to_be32(1);
4935 ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_table_offset),
4936 sizeof(l1_ofs_rt_ofs_cls), &l1_ofs_rt_ofs_cls, 0);
4937 if (ret < 0) {
4938 goto fail_broken_refcounts;
4939 }
4940
4941 s->l1_table_offset = 3 * s->cluster_size;
4942
4943 new_reftable = g_try_new0(uint64_t, s->cluster_size / REFTABLE_ENTRY_SIZE);
4944 if (!new_reftable) {
4945 ret = -ENOMEM;
4946 goto fail_broken_refcounts;
4947 }
4948
4949 s->refcount_table_offset = s->cluster_size;
4950 s->refcount_table_size = s->cluster_size / REFTABLE_ENTRY_SIZE;
4951 s->max_refcount_table_index = 0;
4952
4953 g_free(s->refcount_table);
4954 s->refcount_table = new_reftable;
4955 new_reftable = NULL;
4956
4957 /* Now the in-memory refcount information again corresponds to the on-disk
4958 * information (reftable is empty and no refblocks (the refblock cache is
4959 * empty)); however, this means some clusters (e.g. the image header) are
4960 * referenced, but not refcounted, but the normal qcow2 code assumes that
4961 * the in-memory information is always correct */
4962
4963 BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC);
4964
4965 /* Enter the first refblock into the reftable */
4966 rt_entry = cpu_to_be64(2 * s->cluster_size);
4967 ret = bdrv_pwrite_sync(bs->file, s->cluster_size, sizeof(rt_entry),
4968 &rt_entry, 0);
4969 if (ret < 0) {
4970 goto fail_broken_refcounts;
4971 }
4972 s->refcount_table[0] = 2 * s->cluster_size;
4973
4974 s->free_cluster_index = 0;
4975 assert(3 + l1_clusters <= s->refcount_block_size);
4976 offset = qcow2_alloc_clusters(bs, 3 * s->cluster_size + l1_size2);
4977 if (offset < 0) {
4978 ret = offset;
4979 goto fail_broken_refcounts;
4980 } else if (offset > 0) {
4981 error_report("First cluster in emptied image is in use");
4982 abort();
4983 }
4984
4985 /* Now finally the in-memory information corresponds to the on-disk
4986 * structures and is correct */
4987 ret = qcow2_mark_clean(bs);
4988 if (ret < 0) {
4989 goto fail;
4990 }
4991
4992 ret = bdrv_truncate(bs->file, (3 + l1_clusters) * s->cluster_size, false,
4993 PREALLOC_MODE_OFF, 0, &local_err);
4994 if (ret < 0) {
4995 error_report_err(local_err);
4996 goto fail;
4997 }
4998
4999 return 0;
5000
5001 fail_broken_refcounts:
5002 /* The BDS is unusable at this point. If we wanted to make it usable, we
5003 * would have to call qcow2_refcount_close(), qcow2_refcount_init(),
5004 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init()
5005 * again. However, because the functions which could have caused this error
5006 * path to be taken are used by those functions as well, it's very likely
5007 * that that sequence will fail as well. Therefore, just eject the BDS. */
5008 bs->drv = NULL;
5009
5010 fail:
5011 g_free(new_reftable);
5012 return ret;
5013 }
5014
qcow2_make_empty(BlockDriverState * bs)5015 static int GRAPH_RDLOCK qcow2_make_empty(BlockDriverState *bs)
5016 {
5017 BDRVQcow2State *s = bs->opaque;
5018 uint64_t offset, end_offset;
5019 int step = QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size);
5020 int l1_clusters, ret = 0;
5021
5022 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE);
5023
5024 if (s->qcow_version >= 3 && !s->snapshots && !s->nb_bitmaps &&
5025 3 + l1_clusters <= s->refcount_block_size &&
5026 s->crypt_method_header != QCOW_CRYPT_LUKS &&
5027 !has_data_file(bs)) {
5028 /* The following function only works for qcow2 v3 images (it
5029 * requires the dirty flag) and only as long as there are no
5030 * features that reserve extra clusters (such as snapshots,
5031 * LUKS header, or persistent bitmaps), because it completely
5032 * empties the image. Furthermore, the L1 table and three
5033 * additional clusters (image header, refcount table, one
5034 * refcount block) have to fit inside one refcount block. It
5035 * only resets the image file, i.e. does not work with an
5036 * external data file. */
5037 return make_completely_empty(bs);
5038 }
5039
5040 /* This fallback code simply discards every active cluster; this is slow,
5041 * but works in all cases */
5042 end_offset = bs->total_sectors * BDRV_SECTOR_SIZE;
5043 for (offset = 0; offset < end_offset; offset += step) {
5044 /* As this function is generally used after committing an external
5045 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the
5046 * default action for this kind of discard is to pass the discard,
5047 * which will ideally result in an actually smaller image file, as
5048 * is probably desired. */
5049 ret = qcow2_cluster_discard(bs, offset, MIN(step, end_offset - offset),
5050 QCOW2_DISCARD_SNAPSHOT, true);
5051 if (ret < 0) {
5052 break;
5053 }
5054 }
5055
5056 return ret;
5057 }
5058
qcow2_co_flush_to_os(BlockDriverState * bs)5059 static coroutine_fn GRAPH_RDLOCK int qcow2_co_flush_to_os(BlockDriverState *bs)
5060 {
5061 BDRVQcow2State *s = bs->opaque;
5062 int ret;
5063
5064 qemu_co_mutex_lock(&s->lock);
5065 ret = qcow2_write_caches(bs);
5066 qemu_co_mutex_unlock(&s->lock);
5067
5068 return ret;
5069 }
5070
qcow2_measure(QemuOpts * opts,BlockDriverState * in_bs,Error ** errp)5071 static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
5072 Error **errp)
5073 {
5074 Error *local_err = NULL;
5075 BlockMeasureInfo *info;
5076 uint64_t required = 0; /* bytes that contribute to required size */
5077 uint64_t virtual_size; /* disk size as seen by guest */
5078 uint64_t refcount_bits;
5079 uint64_t l2_tables;
5080 uint64_t luks_payload_size = 0;
5081 size_t cluster_size;
5082 int version;
5083 char *optstr;
5084 PreallocMode prealloc;
5085 bool has_backing_file;
5086 bool has_luks;
5087 bool extended_l2;
5088 size_t l2e_size;
5089
5090 /* Parse image creation options */
5091 extended_l2 = qemu_opt_get_bool_del(opts, BLOCK_OPT_EXTL2, false);
5092
5093 cluster_size = qcow2_opt_get_cluster_size_del(opts, extended_l2,
5094 &local_err);
5095 if (local_err) {
5096 goto err;
5097 }
5098
5099 version = qcow2_opt_get_version_del(opts, &local_err);
5100 if (local_err) {
5101 goto err;
5102 }
5103
5104 refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err);
5105 if (local_err) {
5106 goto err;
5107 }
5108
5109 optstr = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
5110 prealloc = qapi_enum_parse(&PreallocMode_lookup, optstr,
5111 PREALLOC_MODE_OFF, &local_err);
5112 g_free(optstr);
5113 if (local_err) {
5114 goto err;
5115 }
5116
5117 optstr = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
5118 has_backing_file = !!optstr;
5119 g_free(optstr);
5120
5121 optstr = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT);
5122 has_luks = optstr && strcmp(optstr, "luks") == 0;
5123 g_free(optstr);
5124
5125 if (has_luks) {
5126 g_autoptr(QCryptoBlockCreateOptions) create_opts = NULL;
5127 QDict *cryptoopts = qcow2_extract_crypto_opts(opts, "luks", errp);
5128 size_t headerlen;
5129
5130 create_opts = block_crypto_create_opts_init(cryptoopts, errp);
5131 qobject_unref(cryptoopts);
5132 if (!create_opts) {
5133 goto err;
5134 }
5135
5136 if (!qcrypto_block_calculate_payload_offset(create_opts,
5137 "encrypt.",
5138 &headerlen,
5139 &local_err)) {
5140 goto err;
5141 }
5142
5143 luks_payload_size = ROUND_UP(headerlen, cluster_size);
5144 }
5145
5146 virtual_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
5147 virtual_size = ROUND_UP(virtual_size, cluster_size);
5148
5149 /* Check that virtual disk size is valid */
5150 l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
5151 l2_tables = DIV_ROUND_UP(virtual_size / cluster_size,
5152 cluster_size / l2e_size);
5153 if (l2_tables * L1E_SIZE > QCOW_MAX_L1_SIZE) {
5154 error_setg(&local_err, "The image size is too large "
5155 "(try using a larger cluster size)");
5156 goto err;
5157 }
5158
5159 /* Account for input image */
5160 if (in_bs) {
5161 int64_t ssize = bdrv_getlength(in_bs);
5162 if (ssize < 0) {
5163 error_setg_errno(&local_err, -ssize,
5164 "Unable to get image virtual_size");
5165 goto err;
5166 }
5167
5168 virtual_size = ROUND_UP(ssize, cluster_size);
5169
5170 if (has_backing_file) {
5171 /* We don't how much of the backing chain is shared by the input
5172 * image and the new image file. In the worst case the new image's
5173 * backing file has nothing in common with the input image. Be
5174 * conservative and assume all clusters need to be written.
5175 */
5176 required = virtual_size;
5177 } else {
5178 int64_t offset;
5179 int64_t pnum = 0;
5180
5181 for (offset = 0; offset < ssize; offset += pnum) {
5182 int ret;
5183
5184 ret = bdrv_block_status_above(in_bs, NULL, offset,
5185 ssize - offset, &pnum, NULL,
5186 NULL);
5187 if (ret < 0) {
5188 error_setg_errno(&local_err, -ret,
5189 "Unable to get block status");
5190 goto err;
5191 }
5192
5193 if (ret & BDRV_BLOCK_ZERO) {
5194 /* Skip zero regions (safe with no backing file) */
5195 } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) ==
5196 (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) {
5197 /* Extend pnum to end of cluster for next iteration */
5198 pnum = ROUND_UP(offset + pnum, cluster_size) - offset;
5199
5200 /* Count clusters we've seen */
5201 required += offset % cluster_size + pnum;
5202 }
5203 }
5204 }
5205 }
5206
5207 /* Take into account preallocation. Nothing special is needed for
5208 * PREALLOC_MODE_METADATA since metadata is always counted.
5209 */
5210 if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) {
5211 required = virtual_size;
5212 }
5213
5214 info = g_new0(BlockMeasureInfo, 1);
5215 info->fully_allocated = luks_payload_size +
5216 qcow2_calc_prealloc_size(virtual_size, cluster_size,
5217 ctz32(refcount_bits), extended_l2);
5218
5219 /*
5220 * Remove data clusters that are not required. This overestimates the
5221 * required size because metadata needed for the fully allocated file is
5222 * still counted. Show bitmaps only if both source and destination
5223 * would support them.
5224 */
5225 info->required = info->fully_allocated - virtual_size + required;
5226 info->has_bitmaps = version >= 3 && in_bs &&
5227 bdrv_supports_persistent_dirty_bitmap(in_bs);
5228 if (info->has_bitmaps) {
5229 info->bitmaps = qcow2_get_persistent_dirty_bitmap_size(in_bs,
5230 cluster_size);
5231 }
5232 return info;
5233
5234 err:
5235 error_propagate(errp, local_err);
5236 return NULL;
5237 }
5238
5239 static int coroutine_fn
qcow2_co_get_info(BlockDriverState * bs,BlockDriverInfo * bdi)5240 qcow2_co_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
5241 {
5242 BDRVQcow2State *s = bs->opaque;
5243 bdi->cluster_size = s->cluster_size;
5244 bdi->subcluster_size = s->subcluster_size;
5245 bdi->vm_state_offset = qcow2_vm_state_offset(s);
5246 bdi->is_dirty = s->incompatible_features & QCOW2_INCOMPAT_DIRTY;
5247 return 0;
5248 }
5249
5250 static ImageInfoSpecific * GRAPH_RDLOCK
qcow2_get_specific_info(BlockDriverState * bs,Error ** errp)5251 qcow2_get_specific_info(BlockDriverState *bs, Error **errp)
5252 {
5253 BDRVQcow2State *s = bs->opaque;
5254 ImageInfoSpecific *spec_info;
5255 QCryptoBlockInfo *encrypt_info = NULL;
5256
5257 if (s->crypto != NULL) {
5258 encrypt_info = qcrypto_block_get_info(s->crypto, errp);
5259 if (!encrypt_info) {
5260 return NULL;
5261 }
5262 }
5263
5264 spec_info = g_new(ImageInfoSpecific, 1);
5265 *spec_info = (ImageInfoSpecific){
5266 .type = IMAGE_INFO_SPECIFIC_KIND_QCOW2,
5267 .u.qcow2.data = g_new0(ImageInfoSpecificQCow2, 1),
5268 };
5269 if (s->qcow_version == 2) {
5270 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){
5271 .compat = g_strdup("0.10"),
5272 .refcount_bits = s->refcount_bits,
5273 };
5274 } else if (s->qcow_version == 3) {
5275 Qcow2BitmapInfoList *bitmaps;
5276 if (!qcow2_get_bitmap_info_list(bs, &bitmaps, errp)) {
5277 qapi_free_ImageInfoSpecific(spec_info);
5278 qapi_free_QCryptoBlockInfo(encrypt_info);
5279 return NULL;
5280 }
5281 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){
5282 .compat = g_strdup("1.1"),
5283 .lazy_refcounts = s->compatible_features &
5284 QCOW2_COMPAT_LAZY_REFCOUNTS,
5285 .has_lazy_refcounts = true,
5286 .corrupt = s->incompatible_features &
5287 QCOW2_INCOMPAT_CORRUPT,
5288 .has_corrupt = true,
5289 .has_extended_l2 = true,
5290 .extended_l2 = has_subclusters(s),
5291 .refcount_bits = s->refcount_bits,
5292 .has_bitmaps = !!bitmaps,
5293 .bitmaps = bitmaps,
5294 .data_file = g_strdup(s->image_data_file),
5295 .has_data_file_raw = has_data_file(bs),
5296 .data_file_raw = data_file_is_raw(bs),
5297 .compression_type = s->compression_type,
5298 };
5299 } else {
5300 /* if this assertion fails, this probably means a new version was
5301 * added without having it covered here */
5302 assert(false);
5303 }
5304
5305 if (encrypt_info) {
5306 ImageInfoSpecificQCow2Encryption *qencrypt =
5307 g_new(ImageInfoSpecificQCow2Encryption, 1);
5308 switch (encrypt_info->format) {
5309 case Q_CRYPTO_BLOCK_FORMAT_QCOW:
5310 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES;
5311 break;
5312 case Q_CRYPTO_BLOCK_FORMAT_LUKS:
5313 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS;
5314 qencrypt->u.luks = encrypt_info->u.luks;
5315 break;
5316 default:
5317 abort();
5318 }
5319 /* Since we did shallow copy above, erase any pointers
5320 * in the original info */
5321 memset(&encrypt_info->u, 0, sizeof(encrypt_info->u));
5322 qapi_free_QCryptoBlockInfo(encrypt_info);
5323
5324 spec_info->u.qcow2.data->encrypt = qencrypt;
5325 }
5326
5327 return spec_info;
5328 }
5329
5330 static int coroutine_mixed_fn GRAPH_RDLOCK
qcow2_has_zero_init(BlockDriverState * bs)5331 qcow2_has_zero_init(BlockDriverState *bs)
5332 {
5333 BDRVQcow2State *s = bs->opaque;
5334 bool preallocated;
5335
5336 if (qemu_in_coroutine()) {
5337 qemu_co_mutex_lock(&s->lock);
5338 }
5339 /*
5340 * Check preallocation status: Preallocated images have all L2
5341 * tables allocated, nonpreallocated images have none. It is
5342 * therefore enough to check the first one.
5343 */
5344 preallocated = s->l1_size > 0 && s->l1_table[0] != 0;
5345 if (qemu_in_coroutine()) {
5346 qemu_co_mutex_unlock(&s->lock);
5347 }
5348
5349 if (!preallocated) {
5350 return 1;
5351 } else if (bs->encrypted) {
5352 return 0;
5353 } else {
5354 return bdrv_has_zero_init(s->data_file->bs);
5355 }
5356 }
5357
5358 /*
5359 * Check the request to vmstate. On success return
5360 * qcow2_vm_state_offset(bs) + @pos
5361 */
qcow2_check_vmstate_request(BlockDriverState * bs,QEMUIOVector * qiov,int64_t pos)5362 static int64_t qcow2_check_vmstate_request(BlockDriverState *bs,
5363 QEMUIOVector *qiov, int64_t pos)
5364 {
5365 BDRVQcow2State *s = bs->opaque;
5366 int64_t vmstate_offset = qcow2_vm_state_offset(s);
5367 int ret;
5368
5369 /* Incoming requests must be OK */
5370 bdrv_check_qiov_request(pos, qiov->size, qiov, 0, &error_abort);
5371
5372 if (INT64_MAX - pos < vmstate_offset) {
5373 return -EIO;
5374 }
5375
5376 pos += vmstate_offset;
5377 ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL);
5378 if (ret < 0) {
5379 return ret;
5380 }
5381
5382 return pos;
5383 }
5384
5385 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_save_vmstate(BlockDriverState * bs,QEMUIOVector * qiov,int64_t pos)5386 qcow2_co_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
5387 {
5388 int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos);
5389 if (offset < 0) {
5390 return offset;
5391 }
5392
5393 BLKDBG_CO_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
5394 return bs->drv->bdrv_co_pwritev_part(bs, offset, qiov->size, qiov, 0, 0);
5395 }
5396
5397 static int coroutine_fn GRAPH_RDLOCK
qcow2_co_load_vmstate(BlockDriverState * bs,QEMUIOVector * qiov,int64_t pos)5398 qcow2_co_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
5399 {
5400 int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos);
5401 if (offset < 0) {
5402 return offset;
5403 }
5404
5405 BLKDBG_CO_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
5406 return bs->drv->bdrv_co_preadv_part(bs, offset, qiov->size, qiov, 0, 0);
5407 }
5408
qcow2_has_compressed_clusters(BlockDriverState * bs)5409 static int GRAPH_RDLOCK qcow2_has_compressed_clusters(BlockDriverState *bs)
5410 {
5411 int64_t offset = 0;
5412 int64_t bytes = bdrv_getlength(bs);
5413
5414 if (bytes < 0) {
5415 return bytes;
5416 }
5417
5418 while (bytes != 0) {
5419 int ret;
5420 QCow2SubclusterType type;
5421 unsigned int cur_bytes = MIN(INT_MAX, bytes);
5422 uint64_t host_offset;
5423
5424 ret = qcow2_get_host_offset(bs, offset, &cur_bytes, &host_offset,
5425 &type);
5426 if (ret < 0) {
5427 return ret;
5428 }
5429
5430 if (type == QCOW2_SUBCLUSTER_COMPRESSED) {
5431 return 1;
5432 }
5433
5434 offset += cur_bytes;
5435 bytes -= cur_bytes;
5436 }
5437
5438 return 0;
5439 }
5440
5441 /*
5442 * Downgrades an image's version. To achieve this, any incompatible features
5443 * have to be removed.
5444 */
5445 static int GRAPH_RDLOCK
qcow2_downgrade(BlockDriverState * bs,int target_version,BlockDriverAmendStatusCB * status_cb,void * cb_opaque,Error ** errp)5446 qcow2_downgrade(BlockDriverState *bs, int target_version,
5447 BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
5448 Error **errp)
5449 {
5450 BDRVQcow2State *s = bs->opaque;
5451 int current_version = s->qcow_version;
5452 int ret;
5453 int i;
5454
5455 /* This is qcow2_downgrade(), not qcow2_upgrade() */
5456 assert(target_version < current_version);
5457
5458 /* There are no other versions (now) that you can downgrade to */
5459 assert(target_version == 2);
5460
5461 if (s->refcount_order != 4) {
5462 error_setg(errp, "compat=0.10 requires refcount_bits=16");
5463 return -ENOTSUP;
5464 }
5465
5466 if (has_data_file(bs)) {
5467 error_setg(errp, "Cannot downgrade an image with a data file");
5468 return -ENOTSUP;
5469 }
5470
5471 /*
5472 * If any internal snapshot has a different size than the current
5473 * image size, or VM state size that exceeds 32 bits, downgrading
5474 * is unsafe. Even though we would still use v3-compliant output
5475 * to preserve that data, other v2 programs might not realize
5476 * those optional fields are important.
5477 */
5478 for (i = 0; i < s->nb_snapshots; i++) {
5479 if (s->snapshots[i].vm_state_size > UINT32_MAX ||
5480 s->snapshots[i].disk_size != bs->total_sectors * BDRV_SECTOR_SIZE) {
5481 error_setg(errp, "Internal snapshots prevent downgrade of image");
5482 return -ENOTSUP;
5483 }
5484 }
5485
5486 /* clear incompatible features */
5487 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
5488 ret = qcow2_mark_clean(bs);
5489 if (ret < 0) {
5490 error_setg_errno(errp, -ret, "Failed to make the image clean");
5491 return ret;
5492 }
5493 }
5494
5495 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in
5496 * the first place; if that happens nonetheless, returning -ENOTSUP is the
5497 * best thing to do anyway */
5498
5499 if (s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION) {
5500 error_setg(errp, "Cannot downgrade an image with incompatible features "
5501 "0x%" PRIx64 " set",
5502 s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION);
5503 return -ENOTSUP;
5504 }
5505
5506 /* since we can ignore compatible features, we can set them to 0 as well */
5507 s->compatible_features = 0;
5508 /* if lazy refcounts have been used, they have already been fixed through
5509 * clearing the dirty flag */
5510
5511 /* clearing autoclear features is trivial */
5512 s->autoclear_features = 0;
5513
5514 ret = qcow2_expand_zero_clusters(bs, status_cb, cb_opaque);
5515 if (ret < 0) {
5516 error_setg_errno(errp, -ret, "Failed to turn zero into data clusters");
5517 return ret;
5518 }
5519
5520 if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) {
5521 ret = qcow2_has_compressed_clusters(bs);
5522 if (ret < 0) {
5523 error_setg(errp, "Failed to check block status");
5524 return -EINVAL;
5525 }
5526 if (ret) {
5527 error_setg(errp, "Cannot downgrade an image with zstd compression "
5528 "type and existing compressed clusters");
5529 return -ENOTSUP;
5530 }
5531 /*
5532 * No compressed clusters for now, so just chose default zlib
5533 * compression.
5534 */
5535 s->incompatible_features &= ~QCOW2_INCOMPAT_COMPRESSION;
5536 s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB;
5537 }
5538
5539 assert(s->incompatible_features == 0);
5540
5541 s->qcow_version = target_version;
5542 ret = qcow2_update_header(bs);
5543 if (ret < 0) {
5544 s->qcow_version = current_version;
5545 error_setg_errno(errp, -ret, "Failed to update the image header");
5546 return ret;
5547 }
5548 return 0;
5549 }
5550
5551 /*
5552 * Upgrades an image's version. While newer versions encompass all
5553 * features of older versions, some things may have to be presented
5554 * differently.
5555 */
5556 static int GRAPH_RDLOCK
qcow2_upgrade(BlockDriverState * bs,int target_version,BlockDriverAmendStatusCB * status_cb,void * cb_opaque,Error ** errp)5557 qcow2_upgrade(BlockDriverState *bs, int target_version,
5558 BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
5559 Error **errp)
5560 {
5561 BDRVQcow2State *s = bs->opaque;
5562 bool need_snapshot_update;
5563 int current_version = s->qcow_version;
5564 int i;
5565 int ret;
5566
5567 /* This is qcow2_upgrade(), not qcow2_downgrade() */
5568 assert(target_version > current_version);
5569
5570 /* There are no other versions (yet) that you can upgrade to */
5571 assert(target_version == 3);
5572
5573 status_cb(bs, 0, 2, cb_opaque);
5574
5575 /*
5576 * In v2, snapshots do not need to have extra data. v3 requires
5577 * the 64-bit VM state size and the virtual disk size to be
5578 * present.
5579 * qcow2_write_snapshots() will always write the list in the
5580 * v3-compliant format.
5581 */
5582 need_snapshot_update = false;
5583 for (i = 0; i < s->nb_snapshots; i++) {
5584 if (s->snapshots[i].extra_data_size <
5585 sizeof_field(QCowSnapshotExtraData, vm_state_size_large) +
5586 sizeof_field(QCowSnapshotExtraData, disk_size))
5587 {
5588 need_snapshot_update = true;
5589 break;
5590 }
5591 }
5592 if (need_snapshot_update) {
5593 ret = qcow2_write_snapshots(bs);
5594 if (ret < 0) {
5595 error_setg_errno(errp, -ret, "Failed to update the snapshot table");
5596 return ret;
5597 }
5598 }
5599 status_cb(bs, 1, 2, cb_opaque);
5600
5601 s->qcow_version = target_version;
5602 ret = qcow2_update_header(bs);
5603 if (ret < 0) {
5604 s->qcow_version = current_version;
5605 error_setg_errno(errp, -ret, "Failed to update the image header");
5606 return ret;
5607 }
5608 status_cb(bs, 2, 2, cb_opaque);
5609
5610 return 0;
5611 }
5612
5613 typedef enum Qcow2AmendOperation {
5614 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be
5615 * statically initialized to so that the helper CB can discern the first
5616 * invocation from an operation change */
5617 QCOW2_NO_OPERATION = 0,
5618
5619 QCOW2_UPGRADING,
5620 QCOW2_UPDATING_ENCRYPTION,
5621 QCOW2_CHANGING_REFCOUNT_ORDER,
5622 QCOW2_DOWNGRADING,
5623 } Qcow2AmendOperation;
5624
5625 typedef struct Qcow2AmendHelperCBInfo {
5626 /* The code coordinating the amend operations should only modify
5627 * these four fields; the rest will be managed by the CB */
5628 BlockDriverAmendStatusCB *original_status_cb;
5629 void *original_cb_opaque;
5630
5631 Qcow2AmendOperation current_operation;
5632
5633 /* Total number of operations to perform (only set once) */
5634 int total_operations;
5635
5636 /* The following fields are managed by the CB */
5637
5638 /* Number of operations completed */
5639 int operations_completed;
5640
5641 /* Cumulative offset of all completed operations */
5642 int64_t offset_completed;
5643
5644 Qcow2AmendOperation last_operation;
5645 int64_t last_work_size;
5646 } Qcow2AmendHelperCBInfo;
5647
qcow2_amend_helper_cb(BlockDriverState * bs,int64_t operation_offset,int64_t operation_work_size,void * opaque)5648 static void qcow2_amend_helper_cb(BlockDriverState *bs,
5649 int64_t operation_offset,
5650 int64_t operation_work_size, void *opaque)
5651 {
5652 Qcow2AmendHelperCBInfo *info = opaque;
5653 int64_t current_work_size;
5654 int64_t projected_work_size;
5655
5656 if (info->current_operation != info->last_operation) {
5657 if (info->last_operation != QCOW2_NO_OPERATION) {
5658 info->offset_completed += info->last_work_size;
5659 info->operations_completed++;
5660 }
5661
5662 info->last_operation = info->current_operation;
5663 }
5664
5665 assert(info->total_operations > 0);
5666 assert(info->operations_completed < info->total_operations);
5667
5668 info->last_work_size = operation_work_size;
5669
5670 current_work_size = info->offset_completed + operation_work_size;
5671
5672 /* current_work_size is the total work size for (operations_completed + 1)
5673 * operations (which includes this one), so multiply it by the number of
5674 * operations not covered and divide it by the number of operations
5675 * covered to get a projection for the operations not covered */
5676 projected_work_size = current_work_size * (info->total_operations -
5677 info->operations_completed - 1)
5678 / (info->operations_completed + 1);
5679
5680 info->original_status_cb(bs, info->offset_completed + operation_offset,
5681 current_work_size + projected_work_size,
5682 info->original_cb_opaque);
5683 }
5684
5685 static int GRAPH_RDLOCK
qcow2_amend_options(BlockDriverState * bs,QemuOpts * opts,BlockDriverAmendStatusCB * status_cb,void * cb_opaque,bool force,Error ** errp)5686 qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
5687 BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
5688 bool force, Error **errp)
5689 {
5690 BDRVQcow2State *s = bs->opaque;
5691 int old_version = s->qcow_version, new_version = old_version;
5692 uint64_t new_size = 0;
5693 const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL;
5694 bool lazy_refcounts = s->use_lazy_refcounts;
5695 bool data_file_raw = data_file_is_raw(bs);
5696 const char *compat = NULL;
5697 int refcount_bits = s->refcount_bits;
5698 int ret;
5699 QemuOptDesc *desc = opts->list->desc;
5700 Qcow2AmendHelperCBInfo helper_cb_info;
5701 bool encryption_update = false;
5702
5703 while (desc && desc->name) {
5704 if (!qemu_opt_find(opts, desc->name)) {
5705 /* only change explicitly defined options */
5706 desc++;
5707 continue;
5708 }
5709
5710 if (!strcmp(desc->name, BLOCK_OPT_COMPAT_LEVEL)) {
5711 compat = qemu_opt_get(opts, BLOCK_OPT_COMPAT_LEVEL);
5712 if (!compat) {
5713 /* preserve default */
5714 } else if (!strcmp(compat, "0.10") || !strcmp(compat, "v2")) {
5715 new_version = 2;
5716 } else if (!strcmp(compat, "1.1") || !strcmp(compat, "v3")) {
5717 new_version = 3;
5718 } else {
5719 error_setg(errp, "Unknown compatibility level %s", compat);
5720 return -EINVAL;
5721 }
5722 } else if (!strcmp(desc->name, BLOCK_OPT_SIZE)) {
5723 new_size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0);
5724 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FILE)) {
5725 backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
5726 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FMT)) {
5727 backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT);
5728 } else if (g_str_has_prefix(desc->name, "encrypt.")) {
5729 if (!s->crypto) {
5730 error_setg(errp,
5731 "Can't amend encryption options - encryption not present");
5732 return -EINVAL;
5733 }
5734 if (s->crypt_method_header != QCOW_CRYPT_LUKS) {
5735 error_setg(errp,
5736 "Only LUKS encryption options can be amended");
5737 return -ENOTSUP;
5738 }
5739 encryption_update = true;
5740 } else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) {
5741 lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS,
5742 lazy_refcounts);
5743 } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) {
5744 refcount_bits = qemu_opt_get_number(opts, BLOCK_OPT_REFCOUNT_BITS,
5745 refcount_bits);
5746
5747 if (refcount_bits <= 0 || refcount_bits > 64 ||
5748 !is_power_of_2(refcount_bits))
5749 {
5750 error_setg(errp, "Refcount width must be a power of two and "
5751 "may not exceed 64 bits");
5752 return -EINVAL;
5753 }
5754 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE)) {
5755 data_file = qemu_opt_get(opts, BLOCK_OPT_DATA_FILE);
5756 if (data_file && !has_data_file(bs)) {
5757 error_setg(errp, "data-file can only be set for images that "
5758 "use an external data file");
5759 return -EINVAL;
5760 }
5761 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE_RAW)) {
5762 data_file_raw = qemu_opt_get_bool(opts, BLOCK_OPT_DATA_FILE_RAW,
5763 data_file_raw);
5764 if (data_file_raw && !data_file_is_raw(bs)) {
5765 error_setg(errp, "data-file-raw cannot be set on existing "
5766 "images");
5767 return -EINVAL;
5768 }
5769 } else {
5770 /* if this point is reached, this probably means a new option was
5771 * added without having it covered here */
5772 abort();
5773 }
5774
5775 desc++;
5776 }
5777
5778 helper_cb_info = (Qcow2AmendHelperCBInfo){
5779 .original_status_cb = status_cb,
5780 .original_cb_opaque = cb_opaque,
5781 .total_operations = (new_version != old_version)
5782 + (s->refcount_bits != refcount_bits) +
5783 (encryption_update == true)
5784 };
5785
5786 /* Upgrade first (some features may require compat=1.1) */
5787 if (new_version > old_version) {
5788 helper_cb_info.current_operation = QCOW2_UPGRADING;
5789 ret = qcow2_upgrade(bs, new_version, &qcow2_amend_helper_cb,
5790 &helper_cb_info, errp);
5791 if (ret < 0) {
5792 return ret;
5793 }
5794 }
5795
5796 if (encryption_update) {
5797 QDict *amend_opts_dict;
5798 QCryptoBlockAmendOptions *amend_opts;
5799
5800 helper_cb_info.current_operation = QCOW2_UPDATING_ENCRYPTION;
5801 amend_opts_dict = qcow2_extract_crypto_opts(opts, "luks", errp);
5802 if (!amend_opts_dict) {
5803 return -EINVAL;
5804 }
5805 amend_opts = block_crypto_amend_opts_init(amend_opts_dict, errp);
5806 qobject_unref(amend_opts_dict);
5807 if (!amend_opts) {
5808 return -EINVAL;
5809 }
5810 ret = qcrypto_block_amend_options(s->crypto,
5811 qcow2_crypto_hdr_read_func,
5812 qcow2_crypto_hdr_write_func,
5813 bs,
5814 amend_opts,
5815 force,
5816 errp);
5817 qapi_free_QCryptoBlockAmendOptions(amend_opts);
5818 if (ret < 0) {
5819 return ret;
5820 }
5821 }
5822
5823 if (s->refcount_bits != refcount_bits) {
5824 int refcount_order = ctz32(refcount_bits);
5825
5826 if (new_version < 3 && refcount_bits != 16) {
5827 error_setg(errp, "Refcount widths other than 16 bits require "
5828 "compatibility level 1.1 or above (use compat=1.1 or "
5829 "greater)");
5830 return -EINVAL;
5831 }
5832
5833 helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER;
5834 ret = qcow2_change_refcount_order(bs, refcount_order,
5835 &qcow2_amend_helper_cb,
5836 &helper_cb_info, errp);
5837 if (ret < 0) {
5838 return ret;
5839 }
5840 }
5841
5842 /* data-file-raw blocks backing files, so clear it first if requested */
5843 if (data_file_raw) {
5844 s->autoclear_features |= QCOW2_AUTOCLEAR_DATA_FILE_RAW;
5845 } else {
5846 s->autoclear_features &= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW;
5847 }
5848
5849 if (data_file) {
5850 g_free(s->image_data_file);
5851 s->image_data_file = *data_file ? g_strdup(data_file) : NULL;
5852 }
5853
5854 ret = qcow2_update_header(bs);
5855 if (ret < 0) {
5856 error_setg_errno(errp, -ret, "Failed to update the image header");
5857 return ret;
5858 }
5859
5860 if (backing_file || backing_format) {
5861 if (g_strcmp0(backing_file, s->image_backing_file) ||
5862 g_strcmp0(backing_format, s->image_backing_format)) {
5863 error_setg(errp, "Cannot amend the backing file");
5864 error_append_hint(errp,
5865 "You can use 'qemu-img rebase' instead.\n");
5866 return -EINVAL;
5867 }
5868 }
5869
5870 if (s->use_lazy_refcounts != lazy_refcounts) {
5871 if (lazy_refcounts) {
5872 if (new_version < 3) {
5873 error_setg(errp, "Lazy refcounts only supported with "
5874 "compatibility level 1.1 and above (use compat=1.1 "
5875 "or greater)");
5876 return -EINVAL;
5877 }
5878 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS;
5879 ret = qcow2_update_header(bs);
5880 if (ret < 0) {
5881 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS;
5882 error_setg_errno(errp, -ret, "Failed to update the image header");
5883 return ret;
5884 }
5885 s->use_lazy_refcounts = true;
5886 } else {
5887 /* make image clean first */
5888 ret = qcow2_mark_clean(bs);
5889 if (ret < 0) {
5890 error_setg_errno(errp, -ret, "Failed to make the image clean");
5891 return ret;
5892 }
5893 /* now disallow lazy refcounts */
5894 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS;
5895 ret = qcow2_update_header(bs);
5896 if (ret < 0) {
5897 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS;
5898 error_setg_errno(errp, -ret, "Failed to update the image header");
5899 return ret;
5900 }
5901 s->use_lazy_refcounts = false;
5902 }
5903 }
5904
5905 if (new_size) {
5906 BlockBackend *blk = blk_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL,
5907 errp);
5908 if (!blk) {
5909 return -EPERM;
5910 }
5911
5912 /*
5913 * Amending image options should ensure that the image has
5914 * exactly the given new values, so pass exact=true here.
5915 */
5916 ret = blk_truncate(blk, new_size, true, PREALLOC_MODE_OFF, 0, errp);
5917 blk_unref(blk);
5918 if (ret < 0) {
5919 return ret;
5920 }
5921 }
5922
5923 /* Downgrade last (so unsupported features can be removed before) */
5924 if (new_version < old_version) {
5925 helper_cb_info.current_operation = QCOW2_DOWNGRADING;
5926 ret = qcow2_downgrade(bs, new_version, &qcow2_amend_helper_cb,
5927 &helper_cb_info, errp);
5928 if (ret < 0) {
5929 return ret;
5930 }
5931 }
5932
5933 return 0;
5934 }
5935
qcow2_co_amend(BlockDriverState * bs,BlockdevAmendOptions * opts,bool force,Error ** errp)5936 static int coroutine_fn qcow2_co_amend(BlockDriverState *bs,
5937 BlockdevAmendOptions *opts,
5938 bool force,
5939 Error **errp)
5940 {
5941 BlockdevAmendOptionsQcow2 *qopts = &opts->u.qcow2;
5942 BDRVQcow2State *s = bs->opaque;
5943 int ret = 0;
5944
5945 if (qopts->encrypt) {
5946 if (!s->crypto) {
5947 error_setg(errp, "image is not encrypted, can't amend");
5948 return -EOPNOTSUPP;
5949 }
5950
5951 if (qopts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_LUKS) {
5952 error_setg(errp,
5953 "Amend can't be used to change the qcow2 encryption format");
5954 return -EOPNOTSUPP;
5955 }
5956
5957 if (s->crypt_method_header != QCOW_CRYPT_LUKS) {
5958 error_setg(errp,
5959 "Only LUKS encryption options can be amended for qcow2 with blockdev-amend");
5960 return -EOPNOTSUPP;
5961 }
5962
5963 ret = qcrypto_block_amend_options(s->crypto,
5964 qcow2_crypto_hdr_read_func,
5965 qcow2_crypto_hdr_write_func,
5966 bs,
5967 qopts->encrypt,
5968 force,
5969 errp);
5970 }
5971 return ret;
5972 }
5973
5974 /*
5975 * If offset or size are negative, respectively, they will not be included in
5976 * the BLOCK_IMAGE_CORRUPTED event emitted.
5977 * fatal will be ignored for read-only BDS; corruptions found there will always
5978 * be considered non-fatal.
5979 */
qcow2_signal_corruption(BlockDriverState * bs,bool fatal,int64_t offset,int64_t size,const char * message_format,...)5980 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
5981 int64_t size, const char *message_format, ...)
5982 {
5983 BDRVQcow2State *s = bs->opaque;
5984 const char *node_name;
5985 char *message;
5986 va_list ap;
5987
5988 fatal = fatal && bdrv_is_writable(bs);
5989
5990 if (s->signaled_corruption &&
5991 (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT)))
5992 {
5993 return;
5994 }
5995
5996 va_start(ap, message_format);
5997 message = g_strdup_vprintf(message_format, ap);
5998 va_end(ap);
5999
6000 if (fatal) {
6001 fprintf(stderr, "qcow2: Marking image as corrupt: %s; further "
6002 "corruption events will be suppressed\n", message);
6003 } else {
6004 fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal "
6005 "corruption events will be suppressed\n", message);
6006 }
6007
6008 node_name = bdrv_get_node_name(bs);
6009 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs),
6010 *node_name ? node_name : NULL,
6011 message, offset >= 0, offset,
6012 size >= 0, size,
6013 fatal);
6014 g_free(message);
6015
6016 if (fatal) {
6017 qcow2_mark_corrupt(bs);
6018 bs->drv = NULL; /* make BDS unusable */
6019 }
6020
6021 s->signaled_corruption = true;
6022 }
6023
6024 #define QCOW_COMMON_OPTIONS \
6025 { \
6026 .name = BLOCK_OPT_SIZE, \
6027 .type = QEMU_OPT_SIZE, \
6028 .help = "Virtual disk size" \
6029 }, \
6030 { \
6031 .name = BLOCK_OPT_COMPAT_LEVEL, \
6032 .type = QEMU_OPT_STRING, \
6033 .help = "Compatibility level (v2 [0.10] or v3 [1.1])" \
6034 }, \
6035 { \
6036 .name = BLOCK_OPT_BACKING_FILE, \
6037 .type = QEMU_OPT_STRING, \
6038 .help = "File name of a base image" \
6039 }, \
6040 { \
6041 .name = BLOCK_OPT_BACKING_FMT, \
6042 .type = QEMU_OPT_STRING, \
6043 .help = "Image format of the base image" \
6044 }, \
6045 { \
6046 .name = BLOCK_OPT_DATA_FILE, \
6047 .type = QEMU_OPT_STRING, \
6048 .help = "File name of an external data file" \
6049 }, \
6050 { \
6051 .name = BLOCK_OPT_DATA_FILE_RAW, \
6052 .type = QEMU_OPT_BOOL, \
6053 .help = "The external data file must stay valid " \
6054 "as a raw image" \
6055 }, \
6056 { \
6057 .name = BLOCK_OPT_LAZY_REFCOUNTS, \
6058 .type = QEMU_OPT_BOOL, \
6059 .help = "Postpone refcount updates", \
6060 .def_value_str = "off" \
6061 }, \
6062 { \
6063 .name = BLOCK_OPT_REFCOUNT_BITS, \
6064 .type = QEMU_OPT_NUMBER, \
6065 .help = "Width of a reference count entry in bits", \
6066 .def_value_str = "16" \
6067 }
6068
6069 static QemuOptsList qcow2_create_opts = {
6070 .name = "qcow2-create-opts",
6071 .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head),
6072 .desc = {
6073 { \
6074 .name = BLOCK_OPT_ENCRYPT, \
6075 .type = QEMU_OPT_BOOL, \
6076 .help = "Encrypt the image with format 'aes'. (Deprecated " \
6077 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)", \
6078 }, \
6079 { \
6080 .name = BLOCK_OPT_ENCRYPT_FORMAT, \
6081 .type = QEMU_OPT_STRING, \
6082 .help = "Encrypt the image, format choices: 'aes', 'luks'", \
6083 }, \
6084 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", \
6085 "ID of secret providing qcow AES key or LUKS passphrase"), \
6086 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."), \
6087 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."), \
6088 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."), \
6089 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."), \
6090 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."), \
6091 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), \
6092 { \
6093 .name = BLOCK_OPT_CLUSTER_SIZE, \
6094 .type = QEMU_OPT_SIZE, \
6095 .help = "qcow2 cluster size", \
6096 .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) \
6097 }, \
6098 { \
6099 .name = BLOCK_OPT_EXTL2, \
6100 .type = QEMU_OPT_BOOL, \
6101 .help = "Extended L2 tables", \
6102 .def_value_str = "off" \
6103 }, \
6104 { \
6105 .name = BLOCK_OPT_PREALLOC, \
6106 .type = QEMU_OPT_STRING, \
6107 .help = "Preallocation mode (allowed values: off, " \
6108 "metadata, falloc, full)" \
6109 }, \
6110 { \
6111 .name = BLOCK_OPT_COMPRESSION_TYPE, \
6112 .type = QEMU_OPT_STRING, \
6113 .help = "Compression method used for image cluster " \
6114 "compression", \
6115 .def_value_str = "zlib" \
6116 },
6117 QCOW_COMMON_OPTIONS,
6118 { /* end of list */ }
6119 }
6120 };
6121
6122 static QemuOptsList qcow2_amend_opts = {
6123 .name = "qcow2-amend-opts",
6124 .head = QTAILQ_HEAD_INITIALIZER(qcow2_amend_opts.head),
6125 .desc = {
6126 BLOCK_CRYPTO_OPT_DEF_LUKS_STATE("encrypt."),
6127 BLOCK_CRYPTO_OPT_DEF_LUKS_KEYSLOT("encrypt."),
6128 BLOCK_CRYPTO_OPT_DEF_LUKS_OLD_SECRET("encrypt."),
6129 BLOCK_CRYPTO_OPT_DEF_LUKS_NEW_SECRET("encrypt."),
6130 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."),
6131 QCOW_COMMON_OPTIONS,
6132 { /* end of list */ }
6133 }
6134 };
6135
6136 static const char *const qcow2_strong_runtime_opts[] = {
6137 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET,
6138
6139 NULL
6140 };
6141
6142 BlockDriver bdrv_qcow2 = {
6143 .format_name = "qcow2",
6144 .instance_size = sizeof(BDRVQcow2State),
6145 .bdrv_probe = qcow2_probe,
6146 .bdrv_open = qcow2_open,
6147 .bdrv_close = qcow2_close,
6148 .bdrv_reopen_prepare = qcow2_reopen_prepare,
6149 .bdrv_reopen_commit = qcow2_reopen_commit,
6150 .bdrv_reopen_commit_post = qcow2_reopen_commit_post,
6151 .bdrv_reopen_abort = qcow2_reopen_abort,
6152 .bdrv_join_options = qcow2_join_options,
6153 .bdrv_child_perm = bdrv_default_perms,
6154 .bdrv_co_create_opts = qcow2_co_create_opts,
6155 .bdrv_co_create = qcow2_co_create,
6156 .bdrv_has_zero_init = qcow2_has_zero_init,
6157 .bdrv_co_block_status = qcow2_co_block_status,
6158
6159 .bdrv_co_preadv_part = qcow2_co_preadv_part,
6160 .bdrv_co_pwritev_part = qcow2_co_pwritev_part,
6161 .bdrv_co_flush_to_os = qcow2_co_flush_to_os,
6162
6163 .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes,
6164 .bdrv_co_pdiscard = qcow2_co_pdiscard,
6165 .bdrv_co_copy_range_from = qcow2_co_copy_range_from,
6166 .bdrv_co_copy_range_to = qcow2_co_copy_range_to,
6167 .bdrv_co_truncate = qcow2_co_truncate,
6168 .bdrv_co_pwritev_compressed_part = qcow2_co_pwritev_compressed_part,
6169 .bdrv_make_empty = qcow2_make_empty,
6170
6171 .bdrv_snapshot_create = qcow2_snapshot_create,
6172 .bdrv_snapshot_goto = qcow2_snapshot_goto,
6173 .bdrv_snapshot_delete = qcow2_snapshot_delete,
6174 .bdrv_snapshot_list = qcow2_snapshot_list,
6175 .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp,
6176 .bdrv_measure = qcow2_measure,
6177 .bdrv_co_get_info = qcow2_co_get_info,
6178 .bdrv_get_specific_info = qcow2_get_specific_info,
6179
6180 .bdrv_co_save_vmstate = qcow2_co_save_vmstate,
6181 .bdrv_co_load_vmstate = qcow2_co_load_vmstate,
6182
6183 .is_format = true,
6184 .supports_backing = true,
6185 .bdrv_co_change_backing_file = qcow2_co_change_backing_file,
6186
6187 .bdrv_refresh_limits = qcow2_refresh_limits,
6188 .bdrv_co_invalidate_cache = qcow2_co_invalidate_cache,
6189 .bdrv_inactivate = qcow2_inactivate,
6190
6191 .create_opts = &qcow2_create_opts,
6192 .amend_opts = &qcow2_amend_opts,
6193 .strong_runtime_opts = qcow2_strong_runtime_opts,
6194 .mutable_opts = mutable_opts,
6195 .bdrv_co_check = qcow2_co_check,
6196 .bdrv_amend_options = qcow2_amend_options,
6197 .bdrv_co_amend = qcow2_co_amend,
6198
6199 .bdrv_detach_aio_context = qcow2_detach_aio_context,
6200 .bdrv_attach_aio_context = qcow2_attach_aio_context,
6201
6202 .bdrv_supports_persistent_dirty_bitmap =
6203 qcow2_supports_persistent_dirty_bitmap,
6204 .bdrv_co_can_store_new_dirty_bitmap = qcow2_co_can_store_new_dirty_bitmap,
6205 .bdrv_co_remove_persistent_dirty_bitmap =
6206 qcow2_co_remove_persistent_dirty_bitmap,
6207 };
6208
bdrv_qcow2_init(void)6209 static void bdrv_qcow2_init(void)
6210 {
6211 bdrv_register(&bdrv_qcow2);
6212 }
6213
6214 block_init(bdrv_qcow2_init);
6215