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1 | /* | |
2 | * Block driver for the QCOW 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 | #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 "qemu/bswap.h" | |
32 | #include <zlib.h> | |
33 | #include "qapi/qmp/qerror.h" | |
34 | #include "crypto/cipher.h" | |
35 | #include "migration/migration.h" | |
36 | ||
37 | /**************************************************************/ | |
38 | /* QEMU COW block driver with compression and encryption support */ | |
39 | ||
40 | #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) | |
41 | #define QCOW_VERSION 1 | |
42 | ||
43 | #define QCOW_CRYPT_NONE 0 | |
44 | #define QCOW_CRYPT_AES 1 | |
45 | ||
46 | #define QCOW_OFLAG_COMPRESSED (1LL << 63) | |
47 | ||
48 | typedef struct QCowHeader { | |
49 | uint32_t magic; | |
50 | uint32_t version; | |
51 | uint64_t backing_file_offset; | |
52 | uint32_t backing_file_size; | |
53 | uint32_t mtime; | |
54 | uint64_t size; /* in bytes */ | |
55 | uint8_t cluster_bits; | |
56 | uint8_t l2_bits; | |
57 | uint16_t padding; | |
58 | uint32_t crypt_method; | |
59 | uint64_t l1_table_offset; | |
60 | } QEMU_PACKED QCowHeader; | |
61 | ||
62 | #define L2_CACHE_SIZE 16 | |
63 | ||
64 | typedef struct BDRVQcowState { | |
65 | int cluster_bits; | |
66 | int cluster_size; | |
67 | int cluster_sectors; | |
68 | int l2_bits; | |
69 | int l2_size; | |
70 | unsigned int l1_size; | |
71 | uint64_t cluster_offset_mask; | |
72 | uint64_t l1_table_offset; | |
73 | uint64_t *l1_table; | |
74 | uint64_t *l2_cache; | |
75 | uint64_t l2_cache_offsets[L2_CACHE_SIZE]; | |
76 | uint32_t l2_cache_counts[L2_CACHE_SIZE]; | |
77 | uint8_t *cluster_cache; | |
78 | uint8_t *cluster_data; | |
79 | uint64_t cluster_cache_offset; | |
80 | QCryptoCipher *cipher; /* NULL if no key yet */ | |
81 | uint32_t crypt_method_header; | |
82 | CoMutex lock; | |
83 | Error *migration_blocker; | |
84 | } BDRVQcowState; | |
85 | ||
86 | static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset); | |
87 | ||
88 | static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) | |
89 | { | |
90 | const QCowHeader *cow_header = (const void *)buf; | |
91 | ||
92 | if (buf_size >= sizeof(QCowHeader) && | |
93 | be32_to_cpu(cow_header->magic) == QCOW_MAGIC && | |
94 | be32_to_cpu(cow_header->version) == QCOW_VERSION) | |
95 | return 100; | |
96 | else | |
97 | return 0; | |
98 | } | |
99 | ||
100 | static int qcow_open(BlockDriverState *bs, QDict *options, int flags, | |
101 | Error **errp) | |
102 | { | |
103 | BDRVQcowState *s = bs->opaque; | |
104 | unsigned int len, i, shift; | |
105 | int ret; | |
106 | QCowHeader header; | |
107 | Error *local_err = NULL; | |
108 | ||
109 | bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, | |
110 | false, errp); | |
111 | if (!bs->file) { | |
112 | return -EINVAL; | |
113 | } | |
114 | ||
115 | ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); | |
116 | if (ret < 0) { | |
117 | goto fail; | |
118 | } | |
119 | be32_to_cpus(&header.magic); | |
120 | be32_to_cpus(&header.version); | |
121 | be64_to_cpus(&header.backing_file_offset); | |
122 | be32_to_cpus(&header.backing_file_size); | |
123 | be32_to_cpus(&header.mtime); | |
124 | be64_to_cpus(&header.size); | |
125 | be32_to_cpus(&header.crypt_method); | |
126 | be64_to_cpus(&header.l1_table_offset); | |
127 | ||
128 | if (header.magic != QCOW_MAGIC) { | |
129 | error_setg(errp, "Image not in qcow format"); | |
130 | ret = -EINVAL; | |
131 | goto fail; | |
132 | } | |
133 | if (header.version != QCOW_VERSION) { | |
134 | error_setg(errp, "Unsupported qcow version %" PRIu32, header.version); | |
135 | ret = -ENOTSUP; | |
136 | goto fail; | |
137 | } | |
138 | ||
139 | if (header.size <= 1) { | |
140 | error_setg(errp, "Image size is too small (must be at least 2 bytes)"); | |
141 | ret = -EINVAL; | |
142 | goto fail; | |
143 | } | |
144 | if (header.cluster_bits < 9 || header.cluster_bits > 16) { | |
145 | error_setg(errp, "Cluster size must be between 512 and 64k"); | |
146 | ret = -EINVAL; | |
147 | goto fail; | |
148 | } | |
149 | ||
150 | /* l2_bits specifies number of entries; storing a uint64_t in each entry, | |
151 | * so bytes = num_entries << 3. */ | |
152 | if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) { | |
153 | error_setg(errp, "L2 table size must be between 512 and 64k"); | |
154 | ret = -EINVAL; | |
155 | goto fail; | |
156 | } | |
157 | ||
158 | if (header.crypt_method > QCOW_CRYPT_AES) { | |
159 | error_setg(errp, "invalid encryption method in qcow header"); | |
160 | ret = -EINVAL; | |
161 | goto fail; | |
162 | } | |
163 | if (!qcrypto_cipher_supports(QCRYPTO_CIPHER_ALG_AES_128, | |
164 | QCRYPTO_CIPHER_MODE_CBC)) { | |
165 | error_setg(errp, "AES cipher not available"); | |
166 | ret = -EINVAL; | |
167 | goto fail; | |
168 | } | |
169 | s->crypt_method_header = header.crypt_method; | |
170 | if (s->crypt_method_header) { | |
171 | if (bdrv_uses_whitelist() && | |
172 | s->crypt_method_header == QCOW_CRYPT_AES) { | |
173 | error_setg(errp, | |
174 | "Use of AES-CBC encrypted qcow images is no longer " | |
175 | "supported in system emulators"); | |
176 | error_append_hint(errp, | |
177 | "You can use 'qemu-img convert' to convert your " | |
178 | "image to an alternative supported format, such " | |
179 | "as unencrypted qcow, or raw with the LUKS " | |
180 | "format instead.\n"); | |
181 | ret = -ENOSYS; | |
182 | goto fail; | |
183 | } | |
184 | ||
185 | bs->encrypted = true; | |
186 | } | |
187 | s->cluster_bits = header.cluster_bits; | |
188 | s->cluster_size = 1 << s->cluster_bits; | |
189 | s->cluster_sectors = 1 << (s->cluster_bits - 9); | |
190 | s->l2_bits = header.l2_bits; | |
191 | s->l2_size = 1 << s->l2_bits; | |
192 | bs->total_sectors = header.size / 512; | |
193 | s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1; | |
194 | ||
195 | /* read the level 1 table */ | |
196 | shift = s->cluster_bits + s->l2_bits; | |
197 | if (header.size > UINT64_MAX - (1LL << shift)) { | |
198 | error_setg(errp, "Image too large"); | |
199 | ret = -EINVAL; | |
200 | goto fail; | |
201 | } else { | |
202 | uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift; | |
203 | if (l1_size > INT_MAX / sizeof(uint64_t)) { | |
204 | error_setg(errp, "Image too large"); | |
205 | ret = -EINVAL; | |
206 | goto fail; | |
207 | } | |
208 | s->l1_size = l1_size; | |
209 | } | |
210 | ||
211 | s->l1_table_offset = header.l1_table_offset; | |
212 | s->l1_table = g_try_new(uint64_t, s->l1_size); | |
213 | if (s->l1_table == NULL) { | |
214 | error_setg(errp, "Could not allocate memory for L1 table"); | |
215 | ret = -ENOMEM; | |
216 | goto fail; | |
217 | } | |
218 | ||
219 | ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, | |
220 | s->l1_size * sizeof(uint64_t)); | |
221 | if (ret < 0) { | |
222 | goto fail; | |
223 | } | |
224 | ||
225 | for(i = 0;i < s->l1_size; i++) { | |
226 | be64_to_cpus(&s->l1_table[i]); | |
227 | } | |
228 | ||
229 | /* alloc L2 cache (max. 64k * 16 * 8 = 8 MB) */ | |
230 | s->l2_cache = | |
231 | qemu_try_blockalign(bs->file->bs, | |
232 | s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); | |
233 | if (s->l2_cache == NULL) { | |
234 | error_setg(errp, "Could not allocate L2 table cache"); | |
235 | ret = -ENOMEM; | |
236 | goto fail; | |
237 | } | |
238 | s->cluster_cache = g_malloc(s->cluster_size); | |
239 | s->cluster_data = g_malloc(s->cluster_size); | |
240 | s->cluster_cache_offset = -1; | |
241 | ||
242 | /* read the backing file name */ | |
243 | if (header.backing_file_offset != 0) { | |
244 | len = header.backing_file_size; | |
245 | if (len > 1023 || len >= sizeof(bs->backing_file)) { | |
246 | error_setg(errp, "Backing file name too long"); | |
247 | ret = -EINVAL; | |
248 | goto fail; | |
249 | } | |
250 | ret = bdrv_pread(bs->file, header.backing_file_offset, | |
251 | bs->backing_file, len); | |
252 | if (ret < 0) { | |
253 | goto fail; | |
254 | } | |
255 | bs->backing_file[len] = '\0'; | |
256 | } | |
257 | ||
258 | /* Disable migration when qcow images are used */ | |
259 | error_setg(&s->migration_blocker, "The qcow format used by node '%s' " | |
260 | "does not support live migration", | |
261 | bdrv_get_device_or_node_name(bs)); | |
262 | ret = migrate_add_blocker(s->migration_blocker, &local_err); | |
263 | if (local_err) { | |
264 | error_propagate(errp, local_err); | |
265 | error_free(s->migration_blocker); | |
266 | goto fail; | |
267 | } | |
268 | ||
269 | qemu_co_mutex_init(&s->lock); | |
270 | return 0; | |
271 | ||
272 | fail: | |
273 | g_free(s->l1_table); | |
274 | qemu_vfree(s->l2_cache); | |
275 | g_free(s->cluster_cache); | |
276 | g_free(s->cluster_data); | |
277 | return ret; | |
278 | } | |
279 | ||
280 | ||
281 | /* We have nothing to do for QCOW reopen, stubs just return | |
282 | * success */ | |
283 | static int qcow_reopen_prepare(BDRVReopenState *state, | |
284 | BlockReopenQueue *queue, Error **errp) | |
285 | { | |
286 | return 0; | |
287 | } | |
288 | ||
289 | static int qcow_set_key(BlockDriverState *bs, const char *key) | |
290 | { | |
291 | BDRVQcowState *s = bs->opaque; | |
292 | uint8_t keybuf[16]; | |
293 | int len, i; | |
294 | Error *err; | |
295 | ||
296 | memset(keybuf, 0, 16); | |
297 | len = strlen(key); | |
298 | if (len > 16) | |
299 | len = 16; | |
300 | /* XXX: we could compress the chars to 7 bits to increase | |
301 | entropy */ | |
302 | for(i = 0;i < len;i++) { | |
303 | keybuf[i] = key[i]; | |
304 | } | |
305 | assert(bs->encrypted); | |
306 | ||
307 | qcrypto_cipher_free(s->cipher); | |
308 | s->cipher = qcrypto_cipher_new( | |
309 | QCRYPTO_CIPHER_ALG_AES_128, | |
310 | QCRYPTO_CIPHER_MODE_CBC, | |
311 | keybuf, G_N_ELEMENTS(keybuf), | |
312 | &err); | |
313 | ||
314 | if (!s->cipher) { | |
315 | /* XXX would be nice if errors in this method could | |
316 | * be properly propagate to the caller. Would need | |
317 | * the bdrv_set_key() API signature to be fixed. */ | |
318 | error_free(err); | |
319 | return -1; | |
320 | } | |
321 | return 0; | |
322 | } | |
323 | ||
324 | /* The crypt function is compatible with the linux cryptoloop | |
325 | algorithm for < 4 GB images. NOTE: out_buf == in_buf is | |
326 | supported */ | |
327 | static int encrypt_sectors(BDRVQcowState *s, int64_t sector_num, | |
328 | uint8_t *out_buf, const uint8_t *in_buf, | |
329 | int nb_sectors, bool enc, Error **errp) | |
330 | { | |
331 | union { | |
332 | uint64_t ll[2]; | |
333 | uint8_t b[16]; | |
334 | } ivec; | |
335 | int i; | |
336 | int ret; | |
337 | ||
338 | for(i = 0; i < nb_sectors; i++) { | |
339 | ivec.ll[0] = cpu_to_le64(sector_num); | |
340 | ivec.ll[1] = 0; | |
341 | if (qcrypto_cipher_setiv(s->cipher, | |
342 | ivec.b, G_N_ELEMENTS(ivec.b), | |
343 | errp) < 0) { | |
344 | return -1; | |
345 | } | |
346 | if (enc) { | |
347 | ret = qcrypto_cipher_encrypt(s->cipher, | |
348 | in_buf, | |
349 | out_buf, | |
350 | 512, | |
351 | errp); | |
352 | } else { | |
353 | ret = qcrypto_cipher_decrypt(s->cipher, | |
354 | in_buf, | |
355 | out_buf, | |
356 | 512, | |
357 | errp); | |
358 | } | |
359 | if (ret < 0) { | |
360 | return -1; | |
361 | } | |
362 | sector_num++; | |
363 | in_buf += 512; | |
364 | out_buf += 512; | |
365 | } | |
366 | return 0; | |
367 | } | |
368 | ||
369 | /* 'allocate' is: | |
370 | * | |
371 | * 0 to not allocate. | |
372 | * | |
373 | * 1 to allocate a normal cluster (for sector indexes 'n_start' to | |
374 | * 'n_end') | |
375 | * | |
376 | * 2 to allocate a compressed cluster of size | |
377 | * 'compressed_size'. 'compressed_size' must be > 0 and < | |
378 | * cluster_size | |
379 | * | |
380 | * return 0 if not allocated. | |
381 | */ | |
382 | static uint64_t get_cluster_offset(BlockDriverState *bs, | |
383 | uint64_t offset, int allocate, | |
384 | int compressed_size, | |
385 | int n_start, int n_end) | |
386 | { | |
387 | BDRVQcowState *s = bs->opaque; | |
388 | int min_index, i, j, l1_index, l2_index; | |
389 | uint64_t l2_offset, *l2_table, cluster_offset, tmp; | |
390 | uint32_t min_count; | |
391 | int new_l2_table; | |
392 | ||
393 | l1_index = offset >> (s->l2_bits + s->cluster_bits); | |
394 | l2_offset = s->l1_table[l1_index]; | |
395 | new_l2_table = 0; | |
396 | if (!l2_offset) { | |
397 | if (!allocate) | |
398 | return 0; | |
399 | /* allocate a new l2 entry */ | |
400 | l2_offset = bdrv_getlength(bs->file->bs); | |
401 | /* round to cluster size */ | |
402 | l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); | |
403 | /* update the L1 entry */ | |
404 | s->l1_table[l1_index] = l2_offset; | |
405 | tmp = cpu_to_be64(l2_offset); | |
406 | if (bdrv_pwrite_sync(bs->file, | |
407 | s->l1_table_offset + l1_index * sizeof(tmp), | |
408 | &tmp, sizeof(tmp)) < 0) | |
409 | return 0; | |
410 | new_l2_table = 1; | |
411 | } | |
412 | for(i = 0; i < L2_CACHE_SIZE; i++) { | |
413 | if (l2_offset == s->l2_cache_offsets[i]) { | |
414 | /* increment the hit count */ | |
415 | if (++s->l2_cache_counts[i] == 0xffffffff) { | |
416 | for(j = 0; j < L2_CACHE_SIZE; j++) { | |
417 | s->l2_cache_counts[j] >>= 1; | |
418 | } | |
419 | } | |
420 | l2_table = s->l2_cache + (i << s->l2_bits); | |
421 | goto found; | |
422 | } | |
423 | } | |
424 | /* not found: load a new entry in the least used one */ | |
425 | min_index = 0; | |
426 | min_count = 0xffffffff; | |
427 | for(i = 0; i < L2_CACHE_SIZE; i++) { | |
428 | if (s->l2_cache_counts[i] < min_count) { | |
429 | min_count = s->l2_cache_counts[i]; | |
430 | min_index = i; | |
431 | } | |
432 | } | |
433 | l2_table = s->l2_cache + (min_index << s->l2_bits); | |
434 | if (new_l2_table) { | |
435 | memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); | |
436 | if (bdrv_pwrite_sync(bs->file, l2_offset, l2_table, | |
437 | s->l2_size * sizeof(uint64_t)) < 0) | |
438 | return 0; | |
439 | } else { | |
440 | if (bdrv_pread(bs->file, l2_offset, l2_table, | |
441 | s->l2_size * sizeof(uint64_t)) != | |
442 | s->l2_size * sizeof(uint64_t)) | |
443 | return 0; | |
444 | } | |
445 | s->l2_cache_offsets[min_index] = l2_offset; | |
446 | s->l2_cache_counts[min_index] = 1; | |
447 | found: | |
448 | l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1); | |
449 | cluster_offset = be64_to_cpu(l2_table[l2_index]); | |
450 | if (!cluster_offset || | |
451 | ((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) { | |
452 | if (!allocate) | |
453 | return 0; | |
454 | /* allocate a new cluster */ | |
455 | if ((cluster_offset & QCOW_OFLAG_COMPRESSED) && | |
456 | (n_end - n_start) < s->cluster_sectors) { | |
457 | /* if the cluster is already compressed, we must | |
458 | decompress it in the case it is not completely | |
459 | overwritten */ | |
460 | if (decompress_cluster(bs, cluster_offset) < 0) | |
461 | return 0; | |
462 | cluster_offset = bdrv_getlength(bs->file->bs); | |
463 | cluster_offset = (cluster_offset + s->cluster_size - 1) & | |
464 | ~(s->cluster_size - 1); | |
465 | /* write the cluster content */ | |
466 | if (bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache, | |
467 | s->cluster_size) != | |
468 | s->cluster_size) | |
469 | return -1; | |
470 | } else { | |
471 | cluster_offset = bdrv_getlength(bs->file->bs); | |
472 | if (allocate == 1) { | |
473 | /* round to cluster size */ | |
474 | cluster_offset = (cluster_offset + s->cluster_size - 1) & | |
475 | ~(s->cluster_size - 1); | |
476 | bdrv_truncate(bs->file, cluster_offset + s->cluster_size); | |
477 | /* if encrypted, we must initialize the cluster | |
478 | content which won't be written */ | |
479 | if (bs->encrypted && | |
480 | (n_end - n_start) < s->cluster_sectors) { | |
481 | uint64_t start_sect; | |
482 | assert(s->cipher); | |
483 | start_sect = (offset & ~(s->cluster_size - 1)) >> 9; | |
484 | memset(s->cluster_data + 512, 0x00, 512); | |
485 | for(i = 0; i < s->cluster_sectors; i++) { | |
486 | if (i < n_start || i >= n_end) { | |
487 | Error *err = NULL; | |
488 | if (encrypt_sectors(s, start_sect + i, | |
489 | s->cluster_data, | |
490 | s->cluster_data + 512, 1, | |
491 | true, &err) < 0) { | |
492 | error_free(err); | |
493 | errno = EIO; | |
494 | return -1; | |
495 | } | |
496 | if (bdrv_pwrite(bs->file, | |
497 | cluster_offset + i * 512, | |
498 | s->cluster_data, 512) != 512) | |
499 | return -1; | |
500 | } | |
501 | } | |
502 | } | |
503 | } else if (allocate == 2) { | |
504 | cluster_offset |= QCOW_OFLAG_COMPRESSED | | |
505 | (uint64_t)compressed_size << (63 - s->cluster_bits); | |
506 | } | |
507 | } | |
508 | /* update L2 table */ | |
509 | tmp = cpu_to_be64(cluster_offset); | |
510 | l2_table[l2_index] = tmp; | |
511 | if (bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp), | |
512 | &tmp, sizeof(tmp)) < 0) | |
513 | return 0; | |
514 | } | |
515 | return cluster_offset; | |
516 | } | |
517 | ||
518 | static int64_t coroutine_fn qcow_co_get_block_status(BlockDriverState *bs, | |
519 | int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file) | |
520 | { | |
521 | BDRVQcowState *s = bs->opaque; | |
522 | int index_in_cluster, n; | |
523 | uint64_t cluster_offset; | |
524 | ||
525 | qemu_co_mutex_lock(&s->lock); | |
526 | cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0); | |
527 | qemu_co_mutex_unlock(&s->lock); | |
528 | index_in_cluster = sector_num & (s->cluster_sectors - 1); | |
529 | n = s->cluster_sectors - index_in_cluster; | |
530 | if (n > nb_sectors) | |
531 | n = nb_sectors; | |
532 | *pnum = n; | |
533 | if (!cluster_offset) { | |
534 | return 0; | |
535 | } | |
536 | if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->cipher) { | |
537 | return BDRV_BLOCK_DATA; | |
538 | } | |
539 | cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS); | |
540 | *file = bs->file->bs; | |
541 | return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | cluster_offset; | |
542 | } | |
543 | ||
544 | static int decompress_buffer(uint8_t *out_buf, int out_buf_size, | |
545 | const uint8_t *buf, int buf_size) | |
546 | { | |
547 | z_stream strm1, *strm = &strm1; | |
548 | int ret, out_len; | |
549 | ||
550 | memset(strm, 0, sizeof(*strm)); | |
551 | ||
552 | strm->next_in = (uint8_t *)buf; | |
553 | strm->avail_in = buf_size; | |
554 | strm->next_out = out_buf; | |
555 | strm->avail_out = out_buf_size; | |
556 | ||
557 | ret = inflateInit2(strm, -12); | |
558 | if (ret != Z_OK) | |
559 | return -1; | |
560 | ret = inflate(strm, Z_FINISH); | |
561 | out_len = strm->next_out - out_buf; | |
562 | if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || | |
563 | out_len != out_buf_size) { | |
564 | inflateEnd(strm); | |
565 | return -1; | |
566 | } | |
567 | inflateEnd(strm); | |
568 | return 0; | |
569 | } | |
570 | ||
571 | static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) | |
572 | { | |
573 | BDRVQcowState *s = bs->opaque; | |
574 | int ret, csize; | |
575 | uint64_t coffset; | |
576 | ||
577 | coffset = cluster_offset & s->cluster_offset_mask; | |
578 | if (s->cluster_cache_offset != coffset) { | |
579 | csize = cluster_offset >> (63 - s->cluster_bits); | |
580 | csize &= (s->cluster_size - 1); | |
581 | ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize); | |
582 | if (ret != csize) | |
583 | return -1; | |
584 | if (decompress_buffer(s->cluster_cache, s->cluster_size, | |
585 | s->cluster_data, csize) < 0) { | |
586 | return -1; | |
587 | } | |
588 | s->cluster_cache_offset = coffset; | |
589 | } | |
590 | return 0; | |
591 | } | |
592 | ||
593 | static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, | |
594 | int nb_sectors, QEMUIOVector *qiov) | |
595 | { | |
596 | BDRVQcowState *s = bs->opaque; | |
597 | int index_in_cluster; | |
598 | int ret = 0, n; | |
599 | uint64_t cluster_offset; | |
600 | struct iovec hd_iov; | |
601 | QEMUIOVector hd_qiov; | |
602 | uint8_t *buf; | |
603 | void *orig_buf; | |
604 | Error *err = NULL; | |
605 | ||
606 | if (qiov->niov > 1) { | |
607 | buf = orig_buf = qemu_try_blockalign(bs, qiov->size); | |
608 | if (buf == NULL) { | |
609 | return -ENOMEM; | |
610 | } | |
611 | } else { | |
612 | orig_buf = NULL; | |
613 | buf = (uint8_t *)qiov->iov->iov_base; | |
614 | } | |
615 | ||
616 | qemu_co_mutex_lock(&s->lock); | |
617 | ||
618 | while (nb_sectors != 0) { | |
619 | /* prepare next request */ | |
620 | cluster_offset = get_cluster_offset(bs, sector_num << 9, | |
621 | 0, 0, 0, 0); | |
622 | index_in_cluster = sector_num & (s->cluster_sectors - 1); | |
623 | n = s->cluster_sectors - index_in_cluster; | |
624 | if (n > nb_sectors) { | |
625 | n = nb_sectors; | |
626 | } | |
627 | ||
628 | if (!cluster_offset) { | |
629 | if (bs->backing) { | |
630 | /* read from the base image */ | |
631 | hd_iov.iov_base = (void *)buf; | |
632 | hd_iov.iov_len = n * 512; | |
633 | qemu_iovec_init_external(&hd_qiov, &hd_iov, 1); | |
634 | qemu_co_mutex_unlock(&s->lock); | |
635 | ret = bdrv_co_readv(bs->backing, sector_num, n, &hd_qiov); | |
636 | qemu_co_mutex_lock(&s->lock); | |
637 | if (ret < 0) { | |
638 | goto fail; | |
639 | } | |
640 | } else { | |
641 | /* Note: in this case, no need to wait */ | |
642 | memset(buf, 0, 512 * n); | |
643 | } | |
644 | } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { | |
645 | /* add AIO support for compressed blocks ? */ | |
646 | if (decompress_cluster(bs, cluster_offset) < 0) { | |
647 | goto fail; | |
648 | } | |
649 | memcpy(buf, | |
650 | s->cluster_cache + index_in_cluster * 512, 512 * n); | |
651 | } else { | |
652 | if ((cluster_offset & 511) != 0) { | |
653 | goto fail; | |
654 | } | |
655 | hd_iov.iov_base = (void *)buf; | |
656 | hd_iov.iov_len = n * 512; | |
657 | qemu_iovec_init_external(&hd_qiov, &hd_iov, 1); | |
658 | qemu_co_mutex_unlock(&s->lock); | |
659 | ret = bdrv_co_readv(bs->file, | |
660 | (cluster_offset >> 9) + index_in_cluster, | |
661 | n, &hd_qiov); | |
662 | qemu_co_mutex_lock(&s->lock); | |
663 | if (ret < 0) { | |
664 | break; | |
665 | } | |
666 | if (bs->encrypted) { | |
667 | assert(s->cipher); | |
668 | if (encrypt_sectors(s, sector_num, buf, buf, | |
669 | n, false, &err) < 0) { | |
670 | goto fail; | |
671 | } | |
672 | } | |
673 | } | |
674 | ret = 0; | |
675 | ||
676 | nb_sectors -= n; | |
677 | sector_num += n; | |
678 | buf += n * 512; | |
679 | } | |
680 | ||
681 | done: | |
682 | qemu_co_mutex_unlock(&s->lock); | |
683 | ||
684 | if (qiov->niov > 1) { | |
685 | qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size); | |
686 | qemu_vfree(orig_buf); | |
687 | } | |
688 | ||
689 | return ret; | |
690 | ||
691 | fail: | |
692 | error_free(err); | |
693 | ret = -EIO; | |
694 | goto done; | |
695 | } | |
696 | ||
697 | static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num, | |
698 | int nb_sectors, QEMUIOVector *qiov) | |
699 | { | |
700 | BDRVQcowState *s = bs->opaque; | |
701 | int index_in_cluster; | |
702 | uint64_t cluster_offset; | |
703 | const uint8_t *src_buf; | |
704 | int ret = 0, n; | |
705 | uint8_t *cluster_data = NULL; | |
706 | struct iovec hd_iov; | |
707 | QEMUIOVector hd_qiov; | |
708 | uint8_t *buf; | |
709 | void *orig_buf; | |
710 | ||
711 | s->cluster_cache_offset = -1; /* disable compressed cache */ | |
712 | ||
713 | if (qiov->niov > 1) { | |
714 | buf = orig_buf = qemu_try_blockalign(bs, qiov->size); | |
715 | if (buf == NULL) { | |
716 | return -ENOMEM; | |
717 | } | |
718 | qemu_iovec_to_buf(qiov, 0, buf, qiov->size); | |
719 | } else { | |
720 | orig_buf = NULL; | |
721 | buf = (uint8_t *)qiov->iov->iov_base; | |
722 | } | |
723 | ||
724 | qemu_co_mutex_lock(&s->lock); | |
725 | ||
726 | while (nb_sectors != 0) { | |
727 | ||
728 | index_in_cluster = sector_num & (s->cluster_sectors - 1); | |
729 | n = s->cluster_sectors - index_in_cluster; | |
730 | if (n > nb_sectors) { | |
731 | n = nb_sectors; | |
732 | } | |
733 | cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0, | |
734 | index_in_cluster, | |
735 | index_in_cluster + n); | |
736 | if (!cluster_offset || (cluster_offset & 511) != 0) { | |
737 | ret = -EIO; | |
738 | break; | |
739 | } | |
740 | if (bs->encrypted) { | |
741 | Error *err = NULL; | |
742 | assert(s->cipher); | |
743 | if (!cluster_data) { | |
744 | cluster_data = g_malloc0(s->cluster_size); | |
745 | } | |
746 | if (encrypt_sectors(s, sector_num, cluster_data, buf, | |
747 | n, true, &err) < 0) { | |
748 | error_free(err); | |
749 | ret = -EIO; | |
750 | break; | |
751 | } | |
752 | src_buf = cluster_data; | |
753 | } else { | |
754 | src_buf = buf; | |
755 | } | |
756 | ||
757 | hd_iov.iov_base = (void *)src_buf; | |
758 | hd_iov.iov_len = n * 512; | |
759 | qemu_iovec_init_external(&hd_qiov, &hd_iov, 1); | |
760 | qemu_co_mutex_unlock(&s->lock); | |
761 | ret = bdrv_co_writev(bs->file, | |
762 | (cluster_offset >> 9) + index_in_cluster, | |
763 | n, &hd_qiov); | |
764 | qemu_co_mutex_lock(&s->lock); | |
765 | if (ret < 0) { | |
766 | break; | |
767 | } | |
768 | ret = 0; | |
769 | ||
770 | nb_sectors -= n; | |
771 | sector_num += n; | |
772 | buf += n * 512; | |
773 | } | |
774 | qemu_co_mutex_unlock(&s->lock); | |
775 | ||
776 | if (qiov->niov > 1) { | |
777 | qemu_vfree(orig_buf); | |
778 | } | |
779 | g_free(cluster_data); | |
780 | ||
781 | return ret; | |
782 | } | |
783 | ||
784 | static void qcow_close(BlockDriverState *bs) | |
785 | { | |
786 | BDRVQcowState *s = bs->opaque; | |
787 | ||
788 | qcrypto_cipher_free(s->cipher); | |
789 | s->cipher = NULL; | |
790 | g_free(s->l1_table); | |
791 | qemu_vfree(s->l2_cache); | |
792 | g_free(s->cluster_cache); | |
793 | g_free(s->cluster_data); | |
794 | ||
795 | migrate_del_blocker(s->migration_blocker); | |
796 | error_free(s->migration_blocker); | |
797 | } | |
798 | ||
799 | static int qcow_create(const char *filename, QemuOpts *opts, Error **errp) | |
800 | { | |
801 | int header_size, backing_filename_len, l1_size, shift, i; | |
802 | QCowHeader header; | |
803 | uint8_t *tmp; | |
804 | int64_t total_size = 0; | |
805 | char *backing_file = NULL; | |
806 | int flags = 0; | |
807 | Error *local_err = NULL; | |
808 | int ret; | |
809 | BlockBackend *qcow_blk; | |
810 | ||
811 | /* Read out options */ | |
812 | total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), | |
813 | BDRV_SECTOR_SIZE); | |
814 | backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); | |
815 | if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) { | |
816 | flags |= BLOCK_FLAG_ENCRYPT; | |
817 | } | |
818 | ||
819 | ret = bdrv_create_file(filename, opts, &local_err); | |
820 | if (ret < 0) { | |
821 | error_propagate(errp, local_err); | |
822 | goto cleanup; | |
823 | } | |
824 | ||
825 | qcow_blk = blk_new_open(filename, NULL, NULL, | |
826 | BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, | |
827 | &local_err); | |
828 | if (qcow_blk == NULL) { | |
829 | error_propagate(errp, local_err); | |
830 | ret = -EIO; | |
831 | goto cleanup; | |
832 | } | |
833 | ||
834 | blk_set_allow_write_beyond_eof(qcow_blk, true); | |
835 | ||
836 | ret = blk_truncate(qcow_blk, 0); | |
837 | if (ret < 0) { | |
838 | goto exit; | |
839 | } | |
840 | ||
841 | memset(&header, 0, sizeof(header)); | |
842 | header.magic = cpu_to_be32(QCOW_MAGIC); | |
843 | header.version = cpu_to_be32(QCOW_VERSION); | |
844 | header.size = cpu_to_be64(total_size); | |
845 | header_size = sizeof(header); | |
846 | backing_filename_len = 0; | |
847 | if (backing_file) { | |
848 | if (strcmp(backing_file, "fat:")) { | |
849 | header.backing_file_offset = cpu_to_be64(header_size); | |
850 | backing_filename_len = strlen(backing_file); | |
851 | header.backing_file_size = cpu_to_be32(backing_filename_len); | |
852 | header_size += backing_filename_len; | |
853 | } else { | |
854 | /* special backing file for vvfat */ | |
855 | backing_file = NULL; | |
856 | } | |
857 | header.cluster_bits = 9; /* 512 byte cluster to avoid copying | |
858 | unmodified sectors */ | |
859 | header.l2_bits = 12; /* 32 KB L2 tables */ | |
860 | } else { | |
861 | header.cluster_bits = 12; /* 4 KB clusters */ | |
862 | header.l2_bits = 9; /* 4 KB L2 tables */ | |
863 | } | |
864 | header_size = (header_size + 7) & ~7; | |
865 | shift = header.cluster_bits + header.l2_bits; | |
866 | l1_size = (total_size + (1LL << shift) - 1) >> shift; | |
867 | ||
868 | header.l1_table_offset = cpu_to_be64(header_size); | |
869 | if (flags & BLOCK_FLAG_ENCRYPT) { | |
870 | header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); | |
871 | } else { | |
872 | header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); | |
873 | } | |
874 | ||
875 | /* write all the data */ | |
876 | ret = blk_pwrite(qcow_blk, 0, &header, sizeof(header), 0); | |
877 | if (ret != sizeof(header)) { | |
878 | goto exit; | |
879 | } | |
880 | ||
881 | if (backing_file) { | |
882 | ret = blk_pwrite(qcow_blk, sizeof(header), | |
883 | backing_file, backing_filename_len, 0); | |
884 | if (ret != backing_filename_len) { | |
885 | goto exit; | |
886 | } | |
887 | } | |
888 | ||
889 | tmp = g_malloc0(BDRV_SECTOR_SIZE); | |
890 | for (i = 0; i < DIV_ROUND_UP(sizeof(uint64_t) * l1_size, BDRV_SECTOR_SIZE); | |
891 | i++) { | |
892 | ret = blk_pwrite(qcow_blk, header_size + BDRV_SECTOR_SIZE * i, | |
893 | tmp, BDRV_SECTOR_SIZE, 0); | |
894 | if (ret != BDRV_SECTOR_SIZE) { | |
895 | g_free(tmp); | |
896 | goto exit; | |
897 | } | |
898 | } | |
899 | ||
900 | g_free(tmp); | |
901 | ret = 0; | |
902 | exit: | |
903 | blk_unref(qcow_blk); | |
904 | cleanup: | |
905 | g_free(backing_file); | |
906 | return ret; | |
907 | } | |
908 | ||
909 | static int qcow_make_empty(BlockDriverState *bs) | |
910 | { | |
911 | BDRVQcowState *s = bs->opaque; | |
912 | uint32_t l1_length = s->l1_size * sizeof(uint64_t); | |
913 | int ret; | |
914 | ||
915 | memset(s->l1_table, 0, l1_length); | |
916 | if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table, | |
917 | l1_length) < 0) | |
918 | return -1; | |
919 | ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length); | |
920 | if (ret < 0) | |
921 | return ret; | |
922 | ||
923 | memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); | |
924 | memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); | |
925 | memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); | |
926 | ||
927 | return 0; | |
928 | } | |
929 | ||
930 | /* XXX: put compressed sectors first, then all the cluster aligned | |
931 | tables to avoid losing bytes in alignment */ | |
932 | static coroutine_fn int | |
933 | qcow_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset, | |
934 | uint64_t bytes, QEMUIOVector *qiov) | |
935 | { | |
936 | BDRVQcowState *s = bs->opaque; | |
937 | QEMUIOVector hd_qiov; | |
938 | struct iovec iov; | |
939 | z_stream strm; | |
940 | int ret, out_len; | |
941 | uint8_t *buf, *out_buf; | |
942 | uint64_t cluster_offset; | |
943 | ||
944 | buf = qemu_blockalign(bs, s->cluster_size); | |
945 | if (bytes != s->cluster_size) { | |
946 | if (bytes > s->cluster_size || | |
947 | offset + bytes != bs->total_sectors << BDRV_SECTOR_BITS) | |
948 | { | |
949 | qemu_vfree(buf); | |
950 | return -EINVAL; | |
951 | } | |
952 | /* Zero-pad last write if image size is not cluster aligned */ | |
953 | memset(buf + bytes, 0, s->cluster_size - bytes); | |
954 | } | |
955 | qemu_iovec_to_buf(qiov, 0, buf, qiov->size); | |
956 | ||
957 | out_buf = g_malloc(s->cluster_size); | |
958 | ||
959 | /* best compression, small window, no zlib header */ | |
960 | memset(&strm, 0, sizeof(strm)); | |
961 | ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, | |
962 | Z_DEFLATED, -12, | |
963 | 9, Z_DEFAULT_STRATEGY); | |
964 | if (ret != 0) { | |
965 | ret = -EINVAL; | |
966 | goto fail; | |
967 | } | |
968 | ||
969 | strm.avail_in = s->cluster_size; | |
970 | strm.next_in = (uint8_t *)buf; | |
971 | strm.avail_out = s->cluster_size; | |
972 | strm.next_out = out_buf; | |
973 | ||
974 | ret = deflate(&strm, Z_FINISH); | |
975 | if (ret != Z_STREAM_END && ret != Z_OK) { | |
976 | deflateEnd(&strm); | |
977 | ret = -EINVAL; | |
978 | goto fail; | |
979 | } | |
980 | out_len = strm.next_out - out_buf; | |
981 | ||
982 | deflateEnd(&strm); | |
983 | ||
984 | if (ret != Z_STREAM_END || out_len >= s->cluster_size) { | |
985 | /* could not compress: write normal cluster */ | |
986 | ret = qcow_co_writev(bs, offset >> BDRV_SECTOR_BITS, | |
987 | bytes >> BDRV_SECTOR_BITS, qiov); | |
988 | if (ret < 0) { | |
989 | goto fail; | |
990 | } | |
991 | goto success; | |
992 | } | |
993 | qemu_co_mutex_lock(&s->lock); | |
994 | cluster_offset = get_cluster_offset(bs, offset, 2, out_len, 0, 0); | |
995 | qemu_co_mutex_unlock(&s->lock); | |
996 | if (cluster_offset == 0) { | |
997 | ret = -EIO; | |
998 | goto fail; | |
999 | } | |
1000 | cluster_offset &= s->cluster_offset_mask; | |
1001 | ||
1002 | iov = (struct iovec) { | |
1003 | .iov_base = out_buf, | |
1004 | .iov_len = out_len, | |
1005 | }; | |
1006 | qemu_iovec_init_external(&hd_qiov, &iov, 1); | |
1007 | ret = bdrv_co_pwritev(bs->file, cluster_offset, out_len, &hd_qiov, 0); | |
1008 | if (ret < 0) { | |
1009 | goto fail; | |
1010 | } | |
1011 | success: | |
1012 | ret = 0; | |
1013 | fail: | |
1014 | qemu_vfree(buf); | |
1015 | g_free(out_buf); | |
1016 | return ret; | |
1017 | } | |
1018 | ||
1019 | static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) | |
1020 | { | |
1021 | BDRVQcowState *s = bs->opaque; | |
1022 | bdi->cluster_size = s->cluster_size; | |
1023 | return 0; | |
1024 | } | |
1025 | ||
1026 | static QemuOptsList qcow_create_opts = { | |
1027 | .name = "qcow-create-opts", | |
1028 | .head = QTAILQ_HEAD_INITIALIZER(qcow_create_opts.head), | |
1029 | .desc = { | |
1030 | { | |
1031 | .name = BLOCK_OPT_SIZE, | |
1032 | .type = QEMU_OPT_SIZE, | |
1033 | .help = "Virtual disk size" | |
1034 | }, | |
1035 | { | |
1036 | .name = BLOCK_OPT_BACKING_FILE, | |
1037 | .type = QEMU_OPT_STRING, | |
1038 | .help = "File name of a base image" | |
1039 | }, | |
1040 | { | |
1041 | .name = BLOCK_OPT_ENCRYPT, | |
1042 | .type = QEMU_OPT_BOOL, | |
1043 | .help = "Encrypt the image", | |
1044 | .def_value_str = "off" | |
1045 | }, | |
1046 | { /* end of list */ } | |
1047 | } | |
1048 | }; | |
1049 | ||
1050 | static BlockDriver bdrv_qcow = { | |
1051 | .format_name = "qcow", | |
1052 | .instance_size = sizeof(BDRVQcowState), | |
1053 | .bdrv_probe = qcow_probe, | |
1054 | .bdrv_open = qcow_open, | |
1055 | .bdrv_close = qcow_close, | |
1056 | .bdrv_child_perm = bdrv_format_default_perms, | |
1057 | .bdrv_reopen_prepare = qcow_reopen_prepare, | |
1058 | .bdrv_create = qcow_create, | |
1059 | .bdrv_has_zero_init = bdrv_has_zero_init_1, | |
1060 | .supports_backing = true, | |
1061 | ||
1062 | .bdrv_co_readv = qcow_co_readv, | |
1063 | .bdrv_co_writev = qcow_co_writev, | |
1064 | .bdrv_co_get_block_status = qcow_co_get_block_status, | |
1065 | ||
1066 | .bdrv_set_key = qcow_set_key, | |
1067 | .bdrv_make_empty = qcow_make_empty, | |
1068 | .bdrv_co_pwritev_compressed = qcow_co_pwritev_compressed, | |
1069 | .bdrv_get_info = qcow_get_info, | |
1070 | ||
1071 | .create_opts = &qcow_create_opts, | |
1072 | }; | |
1073 | ||
1074 | static void bdrv_qcow_init(void) | |
1075 | { | |
1076 | bdrv_register(&bdrv_qcow); | |
1077 | } | |
1078 | ||
1079 | block_init(bdrv_qcow_init); |