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24#include "qemu/osdep.h"
25#include "qapi/error.h"
26#include "qemu-common.h"
27#include "qemu/error-report.h"
28#include "block/block_int.h"
29#include "sysemu/block-backend.h"
30#include "qemu/module.h"
31#include <zlib.h>
32#include "qapi/qmp/qerror.h"
33#include "crypto/cipher.h"
34#include "migration/migration.h"
35
36
37
38
39#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
40#define QCOW_VERSION 1
41
42#define QCOW_CRYPT_NONE 0
43#define QCOW_CRYPT_AES 1
44
45#define QCOW_OFLAG_COMPRESSED (1LL << 63)
46
47typedef struct QCowHeader {
48 uint32_t magic;
49 uint32_t version;
50 uint64_t backing_file_offset;
51 uint32_t backing_file_size;
52 uint32_t mtime;
53 uint64_t size;
54 uint8_t cluster_bits;
55 uint8_t l2_bits;
56 uint16_t padding;
57 uint32_t crypt_method;
58 uint64_t l1_table_offset;
59} QEMU_PACKED QCowHeader;
60
61#define L2_CACHE_SIZE 16
62
63typedef struct BDRVQcowState {
64 int cluster_bits;
65 int cluster_size;
66 int cluster_sectors;
67 int l2_bits;
68 int l2_size;
69 unsigned int l1_size;
70 uint64_t cluster_offset_mask;
71 uint64_t l1_table_offset;
72 uint64_t *l1_table;
73 uint64_t *l2_cache;
74 uint64_t l2_cache_offsets[L2_CACHE_SIZE];
75 uint32_t l2_cache_counts[L2_CACHE_SIZE];
76 uint8_t *cluster_cache;
77 uint8_t *cluster_data;
78 uint64_t cluster_cache_offset;
79 QCryptoCipher *cipher;
80 uint32_t crypt_method_header;
81 CoMutex lock;
82 Error *migration_blocker;
83} BDRVQcowState;
84
85static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
86
87static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
88{
89 const QCowHeader *cow_header = (const void *)buf;
90
91 if (buf_size >= sizeof(QCowHeader) &&
92 be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
93 be32_to_cpu(cow_header->version) == QCOW_VERSION)
94 return 100;
95 else
96 return 0;
97}
98
99static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
100 Error **errp)
101{
102 BDRVQcowState *s = bs->opaque;
103 unsigned int len, i, shift;
104 int ret;
105 QCowHeader header;
106
107 ret = bdrv_pread(bs->file->bs, 0, &header, sizeof(header));
108 if (ret < 0) {
109 goto fail;
110 }
111 be32_to_cpus(&header.magic);
112 be32_to_cpus(&header.version);
113 be64_to_cpus(&header.backing_file_offset);
114 be32_to_cpus(&header.backing_file_size);
115 be32_to_cpus(&header.mtime);
116 be64_to_cpus(&header.size);
117 be32_to_cpus(&header.crypt_method);
118 be64_to_cpus(&header.l1_table_offset);
119
120 if (header.magic != QCOW_MAGIC) {
121 error_setg(errp, "Image not in qcow format");
122 ret = -EINVAL;
123 goto fail;
124 }
125 if (header.version != QCOW_VERSION) {
126 error_setg(errp, "Unsupported qcow version %" PRIu32, header.version);
127 ret = -ENOTSUP;
128 goto fail;
129 }
130
131 if (header.size <= 1) {
132 error_setg(errp, "Image size is too small (must be at least 2 bytes)");
133 ret = -EINVAL;
134 goto fail;
135 }
136 if (header.cluster_bits < 9 || header.cluster_bits > 16) {
137 error_setg(errp, "Cluster size must be between 512 and 64k");
138 ret = -EINVAL;
139 goto fail;
140 }
141
142
143
144 if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) {
145 error_setg(errp, "L2 table size must be between 512 and 64k");
146 ret = -EINVAL;
147 goto fail;
148 }
149
150 if (header.crypt_method > QCOW_CRYPT_AES) {
151 error_setg(errp, "invalid encryption method in qcow header");
152 ret = -EINVAL;
153 goto fail;
154 }
155 if (!qcrypto_cipher_supports(QCRYPTO_CIPHER_ALG_AES_128)) {
156 error_setg(errp, "AES cipher not available");
157 ret = -EINVAL;
158 goto fail;
159 }
160 s->crypt_method_header = header.crypt_method;
161 if (s->crypt_method_header) {
162 if (bdrv_uses_whitelist() &&
163 s->crypt_method_header == QCOW_CRYPT_AES) {
164 error_report("qcow built-in AES encryption is deprecated");
165 error_printf("Support for it will be removed in a future release.\n"
166 "You can use 'qemu-img convert' to switch to an\n"
167 "unencrypted qcow image, or a LUKS raw image.\n");
168 }
169
170 bs->encrypted = 1;
171 }
172 s->cluster_bits = header.cluster_bits;
173 s->cluster_size = 1 << s->cluster_bits;
174 s->cluster_sectors = 1 << (s->cluster_bits - 9);
175 s->l2_bits = header.l2_bits;
176 s->l2_size = 1 << s->l2_bits;
177 bs->total_sectors = header.size / 512;
178 s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1;
179
180
181 shift = s->cluster_bits + s->l2_bits;
182 if (header.size > UINT64_MAX - (1LL << shift)) {
183 error_setg(errp, "Image too large");
184 ret = -EINVAL;
185 goto fail;
186 } else {
187 uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift;
188 if (l1_size > INT_MAX / sizeof(uint64_t)) {
189 error_setg(errp, "Image too large");
190 ret = -EINVAL;
191 goto fail;
192 }
193 s->l1_size = l1_size;
194 }
195
196 s->l1_table_offset = header.l1_table_offset;
197 s->l1_table = g_try_new(uint64_t, s->l1_size);
198 if (s->l1_table == NULL) {
199 error_setg(errp, "Could not allocate memory for L1 table");
200 ret = -ENOMEM;
201 goto fail;
202 }
203
204 ret = bdrv_pread(bs->file->bs, s->l1_table_offset, s->l1_table,
205 s->l1_size * sizeof(uint64_t));
206 if (ret < 0) {
207 goto fail;
208 }
209
210 for(i = 0;i < s->l1_size; i++) {
211 be64_to_cpus(&s->l1_table[i]);
212 }
213
214
215 s->l2_cache =
216 qemu_try_blockalign(bs->file->bs,
217 s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
218 if (s->l2_cache == NULL) {
219 error_setg(errp, "Could not allocate L2 table cache");
220 ret = -ENOMEM;
221 goto fail;
222 }
223 s->cluster_cache = g_malloc(s->cluster_size);
224 s->cluster_data = g_malloc(s->cluster_size);
225 s->cluster_cache_offset = -1;
226
227
228 if (header.backing_file_offset != 0) {
229 len = header.backing_file_size;
230 if (len > 1023 || len >= sizeof(bs->backing_file)) {
231 error_setg(errp, "Backing file name too long");
232 ret = -EINVAL;
233 goto fail;
234 }
235 ret = bdrv_pread(bs->file->bs, header.backing_file_offset,
236 bs->backing_file, len);
237 if (ret < 0) {
238 goto fail;
239 }
240 bs->backing_file[len] = '\0';
241 }
242
243
244 error_setg(&s->migration_blocker, "The qcow format used by node '%s' "
245 "does not support live migration",
246 bdrv_get_device_or_node_name(bs));
247 migrate_add_blocker(s->migration_blocker);
248
249 qemu_co_mutex_init(&s->lock);
250 return 0;
251
252 fail:
253 g_free(s->l1_table);
254 qemu_vfree(s->l2_cache);
255 g_free(s->cluster_cache);
256 g_free(s->cluster_data);
257 return ret;
258}
259
260
261
262
263static int qcow_reopen_prepare(BDRVReopenState *state,
264 BlockReopenQueue *queue, Error **errp)
265{
266 return 0;
267}
268
269static int qcow_set_key(BlockDriverState *bs, const char *key)
270{
271 BDRVQcowState *s = bs->opaque;
272 uint8_t keybuf[16];
273 int len, i;
274 Error *err;
275
276 memset(keybuf, 0, 16);
277 len = strlen(key);
278 if (len > 16)
279 len = 16;
280
281
282 for(i = 0;i < len;i++) {
283 keybuf[i] = key[i];
284 }
285 assert(bs->encrypted);
286
287 qcrypto_cipher_free(s->cipher);
288 s->cipher = qcrypto_cipher_new(
289 QCRYPTO_CIPHER_ALG_AES_128,
290 QCRYPTO_CIPHER_MODE_CBC,
291 keybuf, G_N_ELEMENTS(keybuf),
292 &err);
293
294 if (!s->cipher) {
295
296
297
298 error_free(err);
299 return -1;
300 }
301 return 0;
302}
303
304
305
306
307static int encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
308 uint8_t *out_buf, const uint8_t *in_buf,
309 int nb_sectors, bool enc, Error **errp)
310{
311 union {
312 uint64_t ll[2];
313 uint8_t b[16];
314 } ivec;
315 int i;
316 int ret;
317
318 for(i = 0; i < nb_sectors; i++) {
319 ivec.ll[0] = cpu_to_le64(sector_num);
320 ivec.ll[1] = 0;
321 if (qcrypto_cipher_setiv(s->cipher,
322 ivec.b, G_N_ELEMENTS(ivec.b),
323 errp) < 0) {
324 return -1;
325 }
326 if (enc) {
327 ret = qcrypto_cipher_encrypt(s->cipher,
328 in_buf,
329 out_buf,
330 512,
331 errp);
332 } else {
333 ret = qcrypto_cipher_decrypt(s->cipher,
334 in_buf,
335 out_buf,
336 512,
337 errp);
338 }
339 if (ret < 0) {
340 return -1;
341 }
342 sector_num++;
343 in_buf += 512;
344 out_buf += 512;
345 }
346 return 0;
347}
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362static uint64_t get_cluster_offset(BlockDriverState *bs,
363 uint64_t offset, int allocate,
364 int compressed_size,
365 int n_start, int n_end)
366{
367 BDRVQcowState *s = bs->opaque;
368 int min_index, i, j, l1_index, l2_index;
369 uint64_t l2_offset, *l2_table, cluster_offset, tmp;
370 uint32_t min_count;
371 int new_l2_table;
372
373 l1_index = offset >> (s->l2_bits + s->cluster_bits);
374 l2_offset = s->l1_table[l1_index];
375 new_l2_table = 0;
376 if (!l2_offset) {
377 if (!allocate)
378 return 0;
379
380 l2_offset = bdrv_getlength(bs->file->bs);
381
382 l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1);
383
384 s->l1_table[l1_index] = l2_offset;
385 tmp = cpu_to_be64(l2_offset);
386 if (bdrv_pwrite_sync(bs->file->bs,
387 s->l1_table_offset + l1_index * sizeof(tmp),
388 &tmp, sizeof(tmp)) < 0)
389 return 0;
390 new_l2_table = 1;
391 }
392 for(i = 0; i < L2_CACHE_SIZE; i++) {
393 if (l2_offset == s->l2_cache_offsets[i]) {
394
395 if (++s->l2_cache_counts[i] == 0xffffffff) {
396 for(j = 0; j < L2_CACHE_SIZE; j++) {
397 s->l2_cache_counts[j] >>= 1;
398 }
399 }
400 l2_table = s->l2_cache + (i << s->l2_bits);
401 goto found;
402 }
403 }
404
405 min_index = 0;
406 min_count = 0xffffffff;
407 for(i = 0; i < L2_CACHE_SIZE; i++) {
408 if (s->l2_cache_counts[i] < min_count) {
409 min_count = s->l2_cache_counts[i];
410 min_index = i;
411 }
412 }
413 l2_table = s->l2_cache + (min_index << s->l2_bits);
414 if (new_l2_table) {
415 memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
416 if (bdrv_pwrite_sync(bs->file->bs, l2_offset, l2_table,
417 s->l2_size * sizeof(uint64_t)) < 0)
418 return 0;
419 } else {
420 if (bdrv_pread(bs->file->bs, l2_offset, l2_table,
421 s->l2_size * sizeof(uint64_t)) !=
422 s->l2_size * sizeof(uint64_t))
423 return 0;
424 }
425 s->l2_cache_offsets[min_index] = l2_offset;
426 s->l2_cache_counts[min_index] = 1;
427 found:
428 l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
429 cluster_offset = be64_to_cpu(l2_table[l2_index]);
430 if (!cluster_offset ||
431 ((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
432 if (!allocate)
433 return 0;
434
435 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
436 (n_end - n_start) < s->cluster_sectors) {
437
438
439
440 if (decompress_cluster(bs, cluster_offset) < 0)
441 return 0;
442 cluster_offset = bdrv_getlength(bs->file->bs);
443 cluster_offset = (cluster_offset + s->cluster_size - 1) &
444 ~(s->cluster_size - 1);
445
446 if (bdrv_pwrite(bs->file->bs, cluster_offset, s->cluster_cache,
447 s->cluster_size) !=
448 s->cluster_size)
449 return -1;
450 } else {
451 cluster_offset = bdrv_getlength(bs->file->bs);
452 if (allocate == 1) {
453
454 cluster_offset = (cluster_offset + s->cluster_size - 1) &
455 ~(s->cluster_size - 1);
456 bdrv_truncate(bs->file->bs, cluster_offset + s->cluster_size);
457
458
459 if (bs->encrypted &&
460 (n_end - n_start) < s->cluster_sectors) {
461 uint64_t start_sect;
462 assert(s->cipher);
463 start_sect = (offset & ~(s->cluster_size - 1)) >> 9;
464 memset(s->cluster_data + 512, 0x00, 512);
465 for(i = 0; i < s->cluster_sectors; i++) {
466 if (i < n_start || i >= n_end) {
467 Error *err = NULL;
468 if (encrypt_sectors(s, start_sect + i,
469 s->cluster_data,
470 s->cluster_data + 512, 1,
471 true, &err) < 0) {
472 error_free(err);
473 errno = EIO;
474 return -1;
475 }
476 if (bdrv_pwrite(bs->file->bs,
477 cluster_offset + i * 512,
478 s->cluster_data, 512) != 512)
479 return -1;
480 }
481 }
482 }
483 } else if (allocate == 2) {
484 cluster_offset |= QCOW_OFLAG_COMPRESSED |
485 (uint64_t)compressed_size << (63 - s->cluster_bits);
486 }
487 }
488
489 tmp = cpu_to_be64(cluster_offset);
490 l2_table[l2_index] = tmp;
491 if (bdrv_pwrite_sync(bs->file->bs, l2_offset + l2_index * sizeof(tmp),
492 &tmp, sizeof(tmp)) < 0)
493 return 0;
494 }
495 return cluster_offset;
496}
497
498static int64_t coroutine_fn qcow_co_get_block_status(BlockDriverState *bs,
499 int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
500{
501 BDRVQcowState *s = bs->opaque;
502 int index_in_cluster, n;
503 uint64_t cluster_offset;
504
505 qemu_co_mutex_lock(&s->lock);
506 cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
507 qemu_co_mutex_unlock(&s->lock);
508 index_in_cluster = sector_num & (s->cluster_sectors - 1);
509 n = s->cluster_sectors - index_in_cluster;
510 if (n > nb_sectors)
511 n = nb_sectors;
512 *pnum = n;
513 if (!cluster_offset) {
514 return 0;
515 }
516 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->cipher) {
517 return BDRV_BLOCK_DATA;
518 }
519 cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS);
520 *file = bs->file->bs;
521 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | cluster_offset;
522}
523
524static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
525 const uint8_t *buf, int buf_size)
526{
527 z_stream strm1, *strm = &strm1;
528 int ret, out_len;
529
530 memset(strm, 0, sizeof(*strm));
531
532 strm->next_in = (uint8_t *)buf;
533 strm->avail_in = buf_size;
534 strm->next_out = out_buf;
535 strm->avail_out = out_buf_size;
536
537 ret = inflateInit2(strm, -12);
538 if (ret != Z_OK)
539 return -1;
540 ret = inflate(strm, Z_FINISH);
541 out_len = strm->next_out - out_buf;
542 if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
543 out_len != out_buf_size) {
544 inflateEnd(strm);
545 return -1;
546 }
547 inflateEnd(strm);
548 return 0;
549}
550
551static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
552{
553 BDRVQcowState *s = bs->opaque;
554 int ret, csize;
555 uint64_t coffset;
556
557 coffset = cluster_offset & s->cluster_offset_mask;
558 if (s->cluster_cache_offset != coffset) {
559 csize = cluster_offset >> (63 - s->cluster_bits);
560 csize &= (s->cluster_size - 1);
561 ret = bdrv_pread(bs->file->bs, coffset, s->cluster_data, csize);
562 if (ret != csize)
563 return -1;
564 if (decompress_buffer(s->cluster_cache, s->cluster_size,
565 s->cluster_data, csize) < 0) {
566 return -1;
567 }
568 s->cluster_cache_offset = coffset;
569 }
570 return 0;
571}
572
573static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num,
574 int nb_sectors, QEMUIOVector *qiov)
575{
576 BDRVQcowState *s = bs->opaque;
577 int index_in_cluster;
578 int ret = 0, n;
579 uint64_t cluster_offset;
580 struct iovec hd_iov;
581 QEMUIOVector hd_qiov;
582 uint8_t *buf;
583 void *orig_buf;
584 Error *err = NULL;
585
586 if (qiov->niov > 1) {
587 buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
588 if (buf == NULL) {
589 return -ENOMEM;
590 }
591 } else {
592 orig_buf = NULL;
593 buf = (uint8_t *)qiov->iov->iov_base;
594 }
595
596 qemu_co_mutex_lock(&s->lock);
597
598 while (nb_sectors != 0) {
599
600 cluster_offset = get_cluster_offset(bs, sector_num << 9,
601 0, 0, 0, 0);
602 index_in_cluster = sector_num & (s->cluster_sectors - 1);
603 n = s->cluster_sectors - index_in_cluster;
604 if (n > nb_sectors) {
605 n = nb_sectors;
606 }
607
608 if (!cluster_offset) {
609 if (bs->backing) {
610
611 hd_iov.iov_base = (void *)buf;
612 hd_iov.iov_len = n * 512;
613 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
614 qemu_co_mutex_unlock(&s->lock);
615 ret = bdrv_co_readv(bs->backing->bs, sector_num,
616 n, &hd_qiov);
617 qemu_co_mutex_lock(&s->lock);
618 if (ret < 0) {
619 goto fail;
620 }
621 } else {
622
623 memset(buf, 0, 512 * n);
624 }
625 } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
626
627 if (decompress_cluster(bs, cluster_offset) < 0) {
628 goto fail;
629 }
630 memcpy(buf,
631 s->cluster_cache + index_in_cluster * 512, 512 * n);
632 } else {
633 if ((cluster_offset & 511) != 0) {
634 goto fail;
635 }
636 hd_iov.iov_base = (void *)buf;
637 hd_iov.iov_len = n * 512;
638 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
639 qemu_co_mutex_unlock(&s->lock);
640 ret = bdrv_co_readv(bs->file->bs,
641 (cluster_offset >> 9) + index_in_cluster,
642 n, &hd_qiov);
643 qemu_co_mutex_lock(&s->lock);
644 if (ret < 0) {
645 break;
646 }
647 if (bs->encrypted) {
648 assert(s->cipher);
649 if (encrypt_sectors(s, sector_num, buf, buf,
650 n, false, &err) < 0) {
651 goto fail;
652 }
653 }
654 }
655 ret = 0;
656
657 nb_sectors -= n;
658 sector_num += n;
659 buf += n * 512;
660 }
661
662done:
663 qemu_co_mutex_unlock(&s->lock);
664
665 if (qiov->niov > 1) {
666 qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size);
667 qemu_vfree(orig_buf);
668 }
669
670 return ret;
671
672fail:
673 error_free(err);
674 ret = -EIO;
675 goto done;
676}
677
678static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num,
679 int nb_sectors, QEMUIOVector *qiov)
680{
681 BDRVQcowState *s = bs->opaque;
682 int index_in_cluster;
683 uint64_t cluster_offset;
684 const uint8_t *src_buf;
685 int ret = 0, n;
686 uint8_t *cluster_data = NULL;
687 struct iovec hd_iov;
688 QEMUIOVector hd_qiov;
689 uint8_t *buf;
690 void *orig_buf;
691
692 s->cluster_cache_offset = -1;
693
694 if (qiov->niov > 1) {
695 buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
696 if (buf == NULL) {
697 return -ENOMEM;
698 }
699 qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
700 } else {
701 orig_buf = NULL;
702 buf = (uint8_t *)qiov->iov->iov_base;
703 }
704
705 qemu_co_mutex_lock(&s->lock);
706
707 while (nb_sectors != 0) {
708
709 index_in_cluster = sector_num & (s->cluster_sectors - 1);
710 n = s->cluster_sectors - index_in_cluster;
711 if (n > nb_sectors) {
712 n = nb_sectors;
713 }
714 cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0,
715 index_in_cluster,
716 index_in_cluster + n);
717 if (!cluster_offset || (cluster_offset & 511) != 0) {
718 ret = -EIO;
719 break;
720 }
721 if (bs->encrypted) {
722 Error *err = NULL;
723 assert(s->cipher);
724 if (!cluster_data) {
725 cluster_data = g_malloc0(s->cluster_size);
726 }
727 if (encrypt_sectors(s, sector_num, cluster_data, buf,
728 n, true, &err) < 0) {
729 error_free(err);
730 ret = -EIO;
731 break;
732 }
733 src_buf = cluster_data;
734 } else {
735 src_buf = buf;
736 }
737
738 hd_iov.iov_base = (void *)src_buf;
739 hd_iov.iov_len = n * 512;
740 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
741 qemu_co_mutex_unlock(&s->lock);
742 ret = bdrv_co_writev(bs->file->bs,
743 (cluster_offset >> 9) + index_in_cluster,
744 n, &hd_qiov);
745 qemu_co_mutex_lock(&s->lock);
746 if (ret < 0) {
747 break;
748 }
749 ret = 0;
750
751 nb_sectors -= n;
752 sector_num += n;
753 buf += n * 512;
754 }
755 qemu_co_mutex_unlock(&s->lock);
756
757 if (qiov->niov > 1) {
758 qemu_vfree(orig_buf);
759 }
760 g_free(cluster_data);
761
762 return ret;
763}
764
765static void qcow_close(BlockDriverState *bs)
766{
767 BDRVQcowState *s = bs->opaque;
768
769 qcrypto_cipher_free(s->cipher);
770 s->cipher = NULL;
771 g_free(s->l1_table);
772 qemu_vfree(s->l2_cache);
773 g_free(s->cluster_cache);
774 g_free(s->cluster_data);
775
776 migrate_del_blocker(s->migration_blocker);
777 error_free(s->migration_blocker);
778}
779
780static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
781{
782 int header_size, backing_filename_len, l1_size, shift, i;
783 QCowHeader header;
784 uint8_t *tmp;
785 int64_t total_size = 0;
786 char *backing_file = NULL;
787 int flags = 0;
788 Error *local_err = NULL;
789 int ret;
790 BlockBackend *qcow_blk;
791
792
793 total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
794 BDRV_SECTOR_SIZE);
795 backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
796 if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) {
797 flags |= BLOCK_FLAG_ENCRYPT;
798 }
799
800 ret = bdrv_create_file(filename, opts, &local_err);
801 if (ret < 0) {
802 error_propagate(errp, local_err);
803 goto cleanup;
804 }
805
806 qcow_blk = blk_new_open(filename, NULL, NULL,
807 BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
808 if (qcow_blk == NULL) {
809 error_propagate(errp, local_err);
810 ret = -EIO;
811 goto cleanup;
812 }
813
814 blk_set_allow_write_beyond_eof(qcow_blk, true);
815
816 ret = blk_truncate(qcow_blk, 0);
817 if (ret < 0) {
818 goto exit;
819 }
820
821 memset(&header, 0, sizeof(header));
822 header.magic = cpu_to_be32(QCOW_MAGIC);
823 header.version = cpu_to_be32(QCOW_VERSION);
824 header.size = cpu_to_be64(total_size);
825 header_size = sizeof(header);
826 backing_filename_len = 0;
827 if (backing_file) {
828 if (strcmp(backing_file, "fat:")) {
829 header.backing_file_offset = cpu_to_be64(header_size);
830 backing_filename_len = strlen(backing_file);
831 header.backing_file_size = cpu_to_be32(backing_filename_len);
832 header_size += backing_filename_len;
833 } else {
834
835 backing_file = NULL;
836 }
837 header.cluster_bits = 9;
838
839 header.l2_bits = 12;
840 } else {
841 header.cluster_bits = 12;
842 header.l2_bits = 9;
843 }
844 header_size = (header_size + 7) & ~7;
845 shift = header.cluster_bits + header.l2_bits;
846 l1_size = (total_size + (1LL << shift) - 1) >> shift;
847
848 header.l1_table_offset = cpu_to_be64(header_size);
849 if (flags & BLOCK_FLAG_ENCRYPT) {
850 header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
851 } else {
852 header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
853 }
854
855
856 ret = blk_pwrite(qcow_blk, 0, &header, sizeof(header));
857 if (ret != sizeof(header)) {
858 goto exit;
859 }
860
861 if (backing_file) {
862 ret = blk_pwrite(qcow_blk, sizeof(header),
863 backing_file, backing_filename_len);
864 if (ret != backing_filename_len) {
865 goto exit;
866 }
867 }
868
869 tmp = g_malloc0(BDRV_SECTOR_SIZE);
870 for (i = 0; i < ((sizeof(uint64_t)*l1_size + BDRV_SECTOR_SIZE - 1)/
871 BDRV_SECTOR_SIZE); i++) {
872 ret = blk_pwrite(qcow_blk, header_size +
873 BDRV_SECTOR_SIZE*i, tmp, BDRV_SECTOR_SIZE);
874 if (ret != BDRV_SECTOR_SIZE) {
875 g_free(tmp);
876 goto exit;
877 }
878 }
879
880 g_free(tmp);
881 ret = 0;
882exit:
883 blk_unref(qcow_blk);
884cleanup:
885 g_free(backing_file);
886 return ret;
887}
888
889static int qcow_make_empty(BlockDriverState *bs)
890{
891 BDRVQcowState *s = bs->opaque;
892 uint32_t l1_length = s->l1_size * sizeof(uint64_t);
893 int ret;
894
895 memset(s->l1_table, 0, l1_length);
896 if (bdrv_pwrite_sync(bs->file->bs, s->l1_table_offset, s->l1_table,
897 l1_length) < 0)
898 return -1;
899 ret = bdrv_truncate(bs->file->bs, s->l1_table_offset + l1_length);
900 if (ret < 0)
901 return ret;
902
903 memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
904 memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
905 memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
906
907 return 0;
908}
909
910
911
912static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
913 const uint8_t *buf, int nb_sectors)
914{
915 BDRVQcowState *s = bs->opaque;
916 z_stream strm;
917 int ret, out_len;
918 uint8_t *out_buf;
919 uint64_t cluster_offset;
920
921 if (nb_sectors != s->cluster_sectors) {
922 ret = -EINVAL;
923
924
925 if (sector_num + nb_sectors == bs->total_sectors &&
926 nb_sectors < s->cluster_sectors) {
927 uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size);
928 memset(pad_buf, 0, s->cluster_size);
929 memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE);
930 ret = qcow_write_compressed(bs, sector_num,
931 pad_buf, s->cluster_sectors);
932 qemu_vfree(pad_buf);
933 }
934 return ret;
935 }
936
937 out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
938
939
940 memset(&strm, 0, sizeof(strm));
941 ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
942 Z_DEFLATED, -12,
943 9, Z_DEFAULT_STRATEGY);
944 if (ret != 0) {
945 ret = -EINVAL;
946 goto fail;
947 }
948
949 strm.avail_in = s->cluster_size;
950 strm.next_in = (uint8_t *)buf;
951 strm.avail_out = s->cluster_size;
952 strm.next_out = out_buf;
953
954 ret = deflate(&strm, Z_FINISH);
955 if (ret != Z_STREAM_END && ret != Z_OK) {
956 deflateEnd(&strm);
957 ret = -EINVAL;
958 goto fail;
959 }
960 out_len = strm.next_out - out_buf;
961
962 deflateEnd(&strm);
963
964 if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
965
966 ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors);
967 if (ret < 0) {
968 goto fail;
969 }
970 } else {
971 cluster_offset = get_cluster_offset(bs, sector_num << 9, 2,
972 out_len, 0, 0);
973 if (cluster_offset == 0) {
974 ret = -EIO;
975 goto fail;
976 }
977
978 cluster_offset &= s->cluster_offset_mask;
979 ret = bdrv_pwrite(bs->file->bs, cluster_offset, out_buf, out_len);
980 if (ret < 0) {
981 goto fail;
982 }
983 }
984
985 ret = 0;
986fail:
987 g_free(out_buf);
988 return ret;
989}
990
991static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
992{
993 BDRVQcowState *s = bs->opaque;
994 bdi->cluster_size = s->cluster_size;
995 return 0;
996}
997
998static QemuOptsList qcow_create_opts = {
999 .name = "qcow-create-opts",
1000 .head = QTAILQ_HEAD_INITIALIZER(qcow_create_opts.head),
1001 .desc = {
1002 {
1003 .name = BLOCK_OPT_SIZE,
1004 .type = QEMU_OPT_SIZE,
1005 .help = "Virtual disk size"
1006 },
1007 {
1008 .name = BLOCK_OPT_BACKING_FILE,
1009 .type = QEMU_OPT_STRING,
1010 .help = "File name of a base image"
1011 },
1012 {
1013 .name = BLOCK_OPT_ENCRYPT,
1014 .type = QEMU_OPT_BOOL,
1015 .help = "Encrypt the image",
1016 .def_value_str = "off"
1017 },
1018 { }
1019 }
1020};
1021
1022static BlockDriver bdrv_qcow = {
1023 .format_name = "qcow",
1024 .instance_size = sizeof(BDRVQcowState),
1025 .bdrv_probe = qcow_probe,
1026 .bdrv_open = qcow_open,
1027 .bdrv_close = qcow_close,
1028 .bdrv_reopen_prepare = qcow_reopen_prepare,
1029 .bdrv_create = qcow_create,
1030 .bdrv_has_zero_init = bdrv_has_zero_init_1,
1031 .supports_backing = true,
1032
1033 .bdrv_co_readv = qcow_co_readv,
1034 .bdrv_co_writev = qcow_co_writev,
1035 .bdrv_co_get_block_status = qcow_co_get_block_status,
1036
1037 .bdrv_set_key = qcow_set_key,
1038 .bdrv_make_empty = qcow_make_empty,
1039 .bdrv_write_compressed = qcow_write_compressed,
1040 .bdrv_get_info = qcow_get_info,
1041
1042 .create_opts = &qcow_create_opts,
1043};
1044
1045static void bdrv_qcow_init(void)
1046{
1047 bdrv_register(&bdrv_qcow);
1048}
1049
1050block_init(bdrv_qcow_init);
1051