]>
Commit | Line | Data |
---|---|---|
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 | #include "qemu-common.h" | |
25 | #include "block_int.h" | |
26 | #include "module.h" | |
27 | #include <zlib.h> | |
28 | #include "aes.h" | |
29 | #include "block/qcow2.h" | |
30 | ||
31 | /* | |
32 | Differences with QCOW: | |
33 | ||
34 | - Support for multiple incremental snapshots. | |
35 | - Memory management by reference counts. | |
36 | - Clusters which have a reference count of one have the bit | |
37 | QCOW_OFLAG_COPIED to optimize write performance. | |
38 | - Size of compressed clusters is stored in sectors to reduce bit usage | |
39 | in the cluster offsets. | |
40 | - Support for storing additional data (such as the VM state) in the | |
41 | snapshots. | |
42 | - If a backing store is used, the cluster size is not constrained | |
43 | (could be backported to QCOW). | |
44 | - L2 tables have always a size of one cluster. | |
45 | */ | |
46 | ||
47 | ||
48 | typedef struct { | |
49 | uint32_t magic; | |
50 | uint32_t len; | |
51 | } QCowExtension; | |
52 | #define QCOW_EXT_MAGIC_END 0 | |
53 | #define QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA | |
54 | ||
55 | ||
56 | ||
57 | static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) | |
58 | { | |
59 | const QCowHeader *cow_header = (const void *)buf; | |
60 | ||
61 | if (buf_size >= sizeof(QCowHeader) && | |
62 | be32_to_cpu(cow_header->magic) == QCOW_MAGIC && | |
63 | be32_to_cpu(cow_header->version) == QCOW_VERSION) | |
64 | return 100; | |
65 | else | |
66 | return 0; | |
67 | } | |
68 | ||
69 | ||
70 | /* | |
71 | * read qcow2 extension and fill bs | |
72 | * start reading from start_offset | |
73 | * finish reading upon magic of value 0 or when end_offset reached | |
74 | * unknown magic is skipped (future extension this version knows nothing about) | |
75 | * return 0 upon success, non-0 otherwise | |
76 | */ | |
77 | static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset, | |
78 | uint64_t end_offset) | |
79 | { | |
80 | BDRVQcowState *s = bs->opaque; | |
81 | QCowExtension ext; | |
82 | uint64_t offset; | |
83 | ||
84 | #ifdef DEBUG_EXT | |
85 | printf("qcow_read_extensions: start=%ld end=%ld\n", start_offset, end_offset); | |
86 | #endif | |
87 | offset = start_offset; | |
88 | while (offset < end_offset) { | |
89 | ||
90 | #ifdef DEBUG_EXT | |
91 | /* Sanity check */ | |
92 | if (offset > s->cluster_size) | |
93 | printf("qcow_handle_extension: suspicious offset %lu\n", offset); | |
94 | ||
95 | printf("attemting to read extended header in offset %lu\n", offset); | |
96 | #endif | |
97 | ||
98 | if (bdrv_pread(s->hd, offset, &ext, sizeof(ext)) != sizeof(ext)) { | |
99 | fprintf(stderr, "qcow_handle_extension: ERROR: pread fail from offset %llu\n", | |
100 | (unsigned long long)offset); | |
101 | return 1; | |
102 | } | |
103 | be32_to_cpus(&ext.magic); | |
104 | be32_to_cpus(&ext.len); | |
105 | offset += sizeof(ext); | |
106 | #ifdef DEBUG_EXT | |
107 | printf("ext.magic = 0x%x\n", ext.magic); | |
108 | #endif | |
109 | switch (ext.magic) { | |
110 | case QCOW_EXT_MAGIC_END: | |
111 | return 0; | |
112 | ||
113 | case QCOW_EXT_MAGIC_BACKING_FORMAT: | |
114 | if (ext.len >= sizeof(bs->backing_format)) { | |
115 | fprintf(stderr, "ERROR: ext_backing_format: len=%u too large" | |
116 | " (>=%zu)\n", | |
117 | ext.len, sizeof(bs->backing_format)); | |
118 | return 2; | |
119 | } | |
120 | if (bdrv_pread(s->hd, offset , bs->backing_format, | |
121 | ext.len) != ext.len) | |
122 | return 3; | |
123 | bs->backing_format[ext.len] = '\0'; | |
124 | #ifdef DEBUG_EXT | |
125 | printf("Qcow2: Got format extension %s\n", bs->backing_format); | |
126 | #endif | |
127 | offset += ((ext.len + 7) & ~7); | |
128 | break; | |
129 | ||
130 | default: | |
131 | /* unknown magic -- just skip it */ | |
132 | offset += ((ext.len + 7) & ~7); | |
133 | break; | |
134 | } | |
135 | } | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
140 | ||
141 | static int qcow_open(BlockDriverState *bs, const char *filename, int flags) | |
142 | { | |
143 | BDRVQcowState *s = bs->opaque; | |
144 | int len, i, shift, ret; | |
145 | QCowHeader header; | |
146 | uint64_t ext_end; | |
147 | ||
148 | ret = bdrv_file_open(&s->hd, filename, flags); | |
149 | if (ret < 0) | |
150 | return ret; | |
151 | if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) | |
152 | goto fail; | |
153 | be32_to_cpus(&header.magic); | |
154 | be32_to_cpus(&header.version); | |
155 | be64_to_cpus(&header.backing_file_offset); | |
156 | be32_to_cpus(&header.backing_file_size); | |
157 | be64_to_cpus(&header.size); | |
158 | be32_to_cpus(&header.cluster_bits); | |
159 | be32_to_cpus(&header.crypt_method); | |
160 | be64_to_cpus(&header.l1_table_offset); | |
161 | be32_to_cpus(&header.l1_size); | |
162 | be64_to_cpus(&header.refcount_table_offset); | |
163 | be32_to_cpus(&header.refcount_table_clusters); | |
164 | be64_to_cpus(&header.snapshots_offset); | |
165 | be32_to_cpus(&header.nb_snapshots); | |
166 | ||
167 | if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION) | |
168 | goto fail; | |
169 | if (header.size <= 1 || | |
170 | header.cluster_bits < MIN_CLUSTER_BITS || | |
171 | header.cluster_bits > MAX_CLUSTER_BITS) | |
172 | goto fail; | |
173 | if (header.crypt_method > QCOW_CRYPT_AES) | |
174 | goto fail; | |
175 | s->crypt_method_header = header.crypt_method; | |
176 | if (s->crypt_method_header) | |
177 | bs->encrypted = 1; | |
178 | s->cluster_bits = header.cluster_bits; | |
179 | s->cluster_size = 1 << s->cluster_bits; | |
180 | s->cluster_sectors = 1 << (s->cluster_bits - 9); | |
181 | s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ | |
182 | s->l2_size = 1 << s->l2_bits; | |
183 | bs->total_sectors = header.size / 512; | |
184 | s->csize_shift = (62 - (s->cluster_bits - 8)); | |
185 | s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; | |
186 | s->cluster_offset_mask = (1LL << s->csize_shift) - 1; | |
187 | s->refcount_table_offset = header.refcount_table_offset; | |
188 | s->refcount_table_size = | |
189 | header.refcount_table_clusters << (s->cluster_bits - 3); | |
190 | ||
191 | s->snapshots_offset = header.snapshots_offset; | |
192 | s->nb_snapshots = header.nb_snapshots; | |
193 | ||
194 | /* read the level 1 table */ | |
195 | s->l1_size = header.l1_size; | |
196 | shift = s->cluster_bits + s->l2_bits; | |
197 | s->l1_vm_state_index = (header.size + (1LL << shift) - 1) >> shift; | |
198 | /* the L1 table must contain at least enough entries to put | |
199 | header.size bytes */ | |
200 | if (s->l1_size < s->l1_vm_state_index) | |
201 | goto fail; | |
202 | s->l1_table_offset = header.l1_table_offset; | |
203 | s->l1_table = qemu_mallocz( | |
204 | align_offset(s->l1_size * sizeof(uint64_t), 512)); | |
205 | if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != | |
206 | s->l1_size * sizeof(uint64_t)) | |
207 | goto fail; | |
208 | for(i = 0;i < s->l1_size; i++) { | |
209 | be64_to_cpus(&s->l1_table[i]); | |
210 | } | |
211 | /* alloc L2 cache */ | |
212 | s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); | |
213 | s->cluster_cache = qemu_malloc(s->cluster_size); | |
214 | /* one more sector for decompressed data alignment */ | |
215 | s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size | |
216 | + 512); | |
217 | s->cluster_cache_offset = -1; | |
218 | ||
219 | if (qcow2_refcount_init(bs) < 0) | |
220 | goto fail; | |
221 | ||
222 | QLIST_INIT(&s->cluster_allocs); | |
223 | ||
224 | /* read qcow2 extensions */ | |
225 | if (header.backing_file_offset) | |
226 | ext_end = header.backing_file_offset; | |
227 | else | |
228 | ext_end = s->cluster_size; | |
229 | if (qcow_read_extensions(bs, sizeof(header), ext_end)) | |
230 | goto fail; | |
231 | ||
232 | /* read the backing file name */ | |
233 | if (header.backing_file_offset != 0) { | |
234 | len = header.backing_file_size; | |
235 | if (len > 1023) | |
236 | len = 1023; | |
237 | if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len) | |
238 | goto fail; | |
239 | bs->backing_file[len] = '\0'; | |
240 | } | |
241 | if (qcow2_read_snapshots(bs) < 0) | |
242 | goto fail; | |
243 | ||
244 | #ifdef DEBUG_ALLOC | |
245 | qcow2_check_refcounts(bs); | |
246 | #endif | |
247 | return 0; | |
248 | ||
249 | fail: | |
250 | qcow2_free_snapshots(bs); | |
251 | qcow2_refcount_close(bs); | |
252 | qemu_free(s->l1_table); | |
253 | qemu_free(s->l2_cache); | |
254 | qemu_free(s->cluster_cache); | |
255 | qemu_free(s->cluster_data); | |
256 | bdrv_delete(s->hd); | |
257 | return -1; | |
258 | } | |
259 | ||
260 | static int qcow_set_key(BlockDriverState *bs, const char *key) | |
261 | { | |
262 | BDRVQcowState *s = bs->opaque; | |
263 | uint8_t keybuf[16]; | |
264 | int len, i; | |
265 | ||
266 | memset(keybuf, 0, 16); | |
267 | len = strlen(key); | |
268 | if (len > 16) | |
269 | len = 16; | |
270 | /* XXX: we could compress the chars to 7 bits to increase | |
271 | entropy */ | |
272 | for(i = 0;i < len;i++) { | |
273 | keybuf[i] = key[i]; | |
274 | } | |
275 | s->crypt_method = s->crypt_method_header; | |
276 | ||
277 | if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) | |
278 | return -1; | |
279 | if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) | |
280 | return -1; | |
281 | #if 0 | |
282 | /* test */ | |
283 | { | |
284 | uint8_t in[16]; | |
285 | uint8_t out[16]; | |
286 | uint8_t tmp[16]; | |
287 | for(i=0;i<16;i++) | |
288 | in[i] = i; | |
289 | AES_encrypt(in, tmp, &s->aes_encrypt_key); | |
290 | AES_decrypt(tmp, out, &s->aes_decrypt_key); | |
291 | for(i = 0; i < 16; i++) | |
292 | printf(" %02x", tmp[i]); | |
293 | printf("\n"); | |
294 | for(i = 0; i < 16; i++) | |
295 | printf(" %02x", out[i]); | |
296 | printf("\n"); | |
297 | } | |
298 | #endif | |
299 | return 0; | |
300 | } | |
301 | ||
302 | static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, | |
303 | int nb_sectors, int *pnum) | |
304 | { | |
305 | uint64_t cluster_offset; | |
306 | ||
307 | *pnum = nb_sectors; | |
308 | cluster_offset = qcow2_get_cluster_offset(bs, sector_num << 9, pnum); | |
309 | ||
310 | return (cluster_offset != 0); | |
311 | } | |
312 | ||
313 | /* handle reading after the end of the backing file */ | |
314 | int qcow2_backing_read1(BlockDriverState *bs, | |
315 | int64_t sector_num, uint8_t *buf, int nb_sectors) | |
316 | { | |
317 | int n1; | |
318 | if ((sector_num + nb_sectors) <= bs->total_sectors) | |
319 | return nb_sectors; | |
320 | if (sector_num >= bs->total_sectors) | |
321 | n1 = 0; | |
322 | else | |
323 | n1 = bs->total_sectors - sector_num; | |
324 | memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1)); | |
325 | return n1; | |
326 | } | |
327 | ||
328 | typedef struct QCowAIOCB { | |
329 | BlockDriverAIOCB common; | |
330 | int64_t sector_num; | |
331 | QEMUIOVector *qiov; | |
332 | uint8_t *buf; | |
333 | void *orig_buf; | |
334 | int nb_sectors; | |
335 | int n; | |
336 | uint64_t cluster_offset; | |
337 | uint8_t *cluster_data; | |
338 | BlockDriverAIOCB *hd_aiocb; | |
339 | struct iovec hd_iov; | |
340 | QEMUIOVector hd_qiov; | |
341 | QEMUBH *bh; | |
342 | QCowL2Meta l2meta; | |
343 | QLIST_ENTRY(QCowAIOCB) next_depend; | |
344 | } QCowAIOCB; | |
345 | ||
346 | static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) | |
347 | { | |
348 | QCowAIOCB *acb = (QCowAIOCB *)blockacb; | |
349 | if (acb->hd_aiocb) | |
350 | bdrv_aio_cancel(acb->hd_aiocb); | |
351 | qemu_aio_release(acb); | |
352 | } | |
353 | ||
354 | static AIOPool qcow_aio_pool = { | |
355 | .aiocb_size = sizeof(QCowAIOCB), | |
356 | .cancel = qcow_aio_cancel, | |
357 | }; | |
358 | ||
359 | static void qcow_aio_read_cb(void *opaque, int ret); | |
360 | static void qcow_aio_read_bh(void *opaque) | |
361 | { | |
362 | QCowAIOCB *acb = opaque; | |
363 | qemu_bh_delete(acb->bh); | |
364 | acb->bh = NULL; | |
365 | qcow_aio_read_cb(opaque, 0); | |
366 | } | |
367 | ||
368 | static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb) | |
369 | { | |
370 | if (acb->bh) | |
371 | return -EIO; | |
372 | ||
373 | acb->bh = qemu_bh_new(cb, acb); | |
374 | if (!acb->bh) | |
375 | return -EIO; | |
376 | ||
377 | qemu_bh_schedule(acb->bh); | |
378 | ||
379 | return 0; | |
380 | } | |
381 | ||
382 | static void qcow_aio_read_cb(void *opaque, int ret) | |
383 | { | |
384 | QCowAIOCB *acb = opaque; | |
385 | BlockDriverState *bs = acb->common.bs; | |
386 | BDRVQcowState *s = bs->opaque; | |
387 | int index_in_cluster, n1; | |
388 | ||
389 | acb->hd_aiocb = NULL; | |
390 | if (ret < 0) | |
391 | goto done; | |
392 | ||
393 | /* post process the read buffer */ | |
394 | if (!acb->cluster_offset) { | |
395 | /* nothing to do */ | |
396 | } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { | |
397 | /* nothing to do */ | |
398 | } else { | |
399 | if (s->crypt_method) { | |
400 | qcow2_encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, | |
401 | acb->n, 0, | |
402 | &s->aes_decrypt_key); | |
403 | } | |
404 | } | |
405 | ||
406 | acb->nb_sectors -= acb->n; | |
407 | acb->sector_num += acb->n; | |
408 | acb->buf += acb->n * 512; | |
409 | ||
410 | if (acb->nb_sectors == 0) { | |
411 | /* request completed */ | |
412 | ret = 0; | |
413 | goto done; | |
414 | } | |
415 | ||
416 | /* prepare next AIO request */ | |
417 | acb->n = acb->nb_sectors; | |
418 | acb->cluster_offset = | |
419 | qcow2_get_cluster_offset(bs, acb->sector_num << 9, &acb->n); | |
420 | index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); | |
421 | ||
422 | if (!acb->cluster_offset) { | |
423 | if (bs->backing_hd) { | |
424 | /* read from the base image */ | |
425 | n1 = qcow2_backing_read1(bs->backing_hd, acb->sector_num, | |
426 | acb->buf, acb->n); | |
427 | if (n1 > 0) { | |
428 | acb->hd_iov.iov_base = (void *)acb->buf; | |
429 | acb->hd_iov.iov_len = acb->n * 512; | |
430 | qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); | |
431 | acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num, | |
432 | &acb->hd_qiov, acb->n, | |
433 | qcow_aio_read_cb, acb); | |
434 | if (acb->hd_aiocb == NULL) | |
435 | goto done; | |
436 | } else { | |
437 | ret = qcow_schedule_bh(qcow_aio_read_bh, acb); | |
438 | if (ret < 0) | |
439 | goto done; | |
440 | } | |
441 | } else { | |
442 | /* Note: in this case, no need to wait */ | |
443 | memset(acb->buf, 0, 512 * acb->n); | |
444 | ret = qcow_schedule_bh(qcow_aio_read_bh, acb); | |
445 | if (ret < 0) | |
446 | goto done; | |
447 | } | |
448 | } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { | |
449 | /* add AIO support for compressed blocks ? */ | |
450 | if (qcow2_decompress_cluster(s, acb->cluster_offset) < 0) | |
451 | goto done; | |
452 | memcpy(acb->buf, | |
453 | s->cluster_cache + index_in_cluster * 512, 512 * acb->n); | |
454 | ret = qcow_schedule_bh(qcow_aio_read_bh, acb); | |
455 | if (ret < 0) | |
456 | goto done; | |
457 | } else { | |
458 | if ((acb->cluster_offset & 511) != 0) { | |
459 | ret = -EIO; | |
460 | goto done; | |
461 | } | |
462 | ||
463 | acb->hd_iov.iov_base = (void *)acb->buf; | |
464 | acb->hd_iov.iov_len = acb->n * 512; | |
465 | qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); | |
466 | acb->hd_aiocb = bdrv_aio_readv(s->hd, | |
467 | (acb->cluster_offset >> 9) + index_in_cluster, | |
468 | &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb); | |
469 | if (acb->hd_aiocb == NULL) | |
470 | goto done; | |
471 | } | |
472 | ||
473 | return; | |
474 | done: | |
475 | if (acb->qiov->niov > 1) { | |
476 | qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size); | |
477 | qemu_vfree(acb->orig_buf); | |
478 | } | |
479 | acb->common.cb(acb->common.opaque, ret); | |
480 | qemu_aio_release(acb); | |
481 | } | |
482 | ||
483 | static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs, | |
484 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
485 | BlockDriverCompletionFunc *cb, void *opaque, int is_write) | |
486 | { | |
487 | QCowAIOCB *acb; | |
488 | ||
489 | acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque); | |
490 | if (!acb) | |
491 | return NULL; | |
492 | acb->hd_aiocb = NULL; | |
493 | acb->sector_num = sector_num; | |
494 | acb->qiov = qiov; | |
495 | if (qiov->niov > 1) { | |
496 | acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size); | |
497 | if (is_write) | |
498 | qemu_iovec_to_buffer(qiov, acb->buf); | |
499 | } else { | |
500 | acb->buf = (uint8_t *)qiov->iov->iov_base; | |
501 | } | |
502 | acb->nb_sectors = nb_sectors; | |
503 | acb->n = 0; | |
504 | acb->cluster_offset = 0; | |
505 | acb->l2meta.nb_clusters = 0; | |
506 | QLIST_INIT(&acb->l2meta.dependent_requests); | |
507 | return acb; | |
508 | } | |
509 | ||
510 | static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs, | |
511 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
512 | BlockDriverCompletionFunc *cb, void *opaque) | |
513 | { | |
514 | QCowAIOCB *acb; | |
515 | ||
516 | acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); | |
517 | if (!acb) | |
518 | return NULL; | |
519 | ||
520 | qcow_aio_read_cb(acb, 0); | |
521 | return &acb->common; | |
522 | } | |
523 | ||
524 | static void qcow_aio_write_cb(void *opaque, int ret); | |
525 | ||
526 | static void run_dependent_requests(QCowL2Meta *m) | |
527 | { | |
528 | QCowAIOCB *req; | |
529 | QCowAIOCB *next; | |
530 | ||
531 | /* Take the request off the list of running requests */ | |
532 | if (m->nb_clusters != 0) { | |
533 | QLIST_REMOVE(m, next_in_flight); | |
534 | } | |
535 | ||
536 | /* | |
537 | * Restart all dependent requests. | |
538 | * Can't use QLIST_FOREACH here - the next link might not be the same | |
539 | * any more after the callback (request could depend on a different | |
540 | * request now) | |
541 | */ | |
542 | for (req = m->dependent_requests.lh_first; req != NULL; req = next) { | |
543 | next = req->next_depend.le_next; | |
544 | qcow_aio_write_cb(req, 0); | |
545 | } | |
546 | ||
547 | /* Empty the list for the next part of the request */ | |
548 | QLIST_INIT(&m->dependent_requests); | |
549 | } | |
550 | ||
551 | static void qcow_aio_write_cb(void *opaque, int ret) | |
552 | { | |
553 | QCowAIOCB *acb = opaque; | |
554 | BlockDriverState *bs = acb->common.bs; | |
555 | BDRVQcowState *s = bs->opaque; | |
556 | int index_in_cluster; | |
557 | const uint8_t *src_buf; | |
558 | int n_end; | |
559 | ||
560 | acb->hd_aiocb = NULL; | |
561 | ||
562 | if (ret >= 0) { | |
563 | ret = qcow2_alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta); | |
564 | } | |
565 | ||
566 | run_dependent_requests(&acb->l2meta); | |
567 | ||
568 | if (ret < 0) | |
569 | goto done; | |
570 | ||
571 | acb->nb_sectors -= acb->n; | |
572 | acb->sector_num += acb->n; | |
573 | acb->buf += acb->n * 512; | |
574 | ||
575 | if (acb->nb_sectors == 0) { | |
576 | /* request completed */ | |
577 | ret = 0; | |
578 | goto done; | |
579 | } | |
580 | ||
581 | index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); | |
582 | n_end = index_in_cluster + acb->nb_sectors; | |
583 | if (s->crypt_method && | |
584 | n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) | |
585 | n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; | |
586 | ||
587 | acb->cluster_offset = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9, | |
588 | index_in_cluster, | |
589 | n_end, &acb->n, &acb->l2meta); | |
590 | ||
591 | /* Need to wait for another request? If so, we are done for now. */ | |
592 | if (!acb->cluster_offset && acb->l2meta.depends_on != NULL) { | |
593 | QLIST_INSERT_HEAD(&acb->l2meta.depends_on->dependent_requests, | |
594 | acb, next_depend); | |
595 | return; | |
596 | } | |
597 | ||
598 | if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) { | |
599 | ret = -EIO; | |
600 | goto done; | |
601 | } | |
602 | if (s->crypt_method) { | |
603 | if (!acb->cluster_data) { | |
604 | acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * | |
605 | s->cluster_size); | |
606 | } | |
607 | qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, | |
608 | acb->n, 1, &s->aes_encrypt_key); | |
609 | src_buf = acb->cluster_data; | |
610 | } else { | |
611 | src_buf = acb->buf; | |
612 | } | |
613 | acb->hd_iov.iov_base = (void *)src_buf; | |
614 | acb->hd_iov.iov_len = acb->n * 512; | |
615 | qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); | |
616 | acb->hd_aiocb = bdrv_aio_writev(s->hd, | |
617 | (acb->cluster_offset >> 9) + index_in_cluster, | |
618 | &acb->hd_qiov, acb->n, | |
619 | qcow_aio_write_cb, acb); | |
620 | if (acb->hd_aiocb == NULL) | |
621 | goto done; | |
622 | ||
623 | return; | |
624 | ||
625 | done: | |
626 | if (acb->qiov->niov > 1) | |
627 | qemu_vfree(acb->orig_buf); | |
628 | acb->common.cb(acb->common.opaque, ret); | |
629 | qemu_aio_release(acb); | |
630 | } | |
631 | ||
632 | static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs, | |
633 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
634 | BlockDriverCompletionFunc *cb, void *opaque) | |
635 | { | |
636 | BDRVQcowState *s = bs->opaque; | |
637 | QCowAIOCB *acb; | |
638 | ||
639 | s->cluster_cache_offset = -1; /* disable compressed cache */ | |
640 | ||
641 | acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); | |
642 | if (!acb) | |
643 | return NULL; | |
644 | ||
645 | qcow_aio_write_cb(acb, 0); | |
646 | return &acb->common; | |
647 | } | |
648 | ||
649 | static void qcow_close(BlockDriverState *bs) | |
650 | { | |
651 | BDRVQcowState *s = bs->opaque; | |
652 | qemu_free(s->l1_table); | |
653 | qemu_free(s->l2_cache); | |
654 | qemu_free(s->cluster_cache); | |
655 | qemu_free(s->cluster_data); | |
656 | qcow2_refcount_close(bs); | |
657 | bdrv_delete(s->hd); | |
658 | } | |
659 | ||
660 | static int get_bits_from_size(size_t size) | |
661 | { | |
662 | int res = 0; | |
663 | ||
664 | if (size == 0) { | |
665 | return -1; | |
666 | } | |
667 | ||
668 | while (size != 1) { | |
669 | /* Not a power of two */ | |
670 | if (size & 1) { | |
671 | return -1; | |
672 | } | |
673 | ||
674 | size >>= 1; | |
675 | res++; | |
676 | } | |
677 | ||
678 | return res; | |
679 | } | |
680 | ||
681 | ||
682 | static int preallocate(BlockDriverState *bs) | |
683 | { | |
684 | BDRVQcowState *s = bs->opaque; | |
685 | uint64_t cluster_offset = 0; | |
686 | uint64_t nb_sectors; | |
687 | uint64_t offset; | |
688 | int num; | |
689 | QCowL2Meta meta; | |
690 | ||
691 | nb_sectors = bdrv_getlength(bs) >> 9; | |
692 | offset = 0; | |
693 | QLIST_INIT(&meta.dependent_requests); | |
694 | ||
695 | while (nb_sectors) { | |
696 | num = MIN(nb_sectors, INT_MAX >> 9); | |
697 | cluster_offset = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, | |
698 | &meta); | |
699 | ||
700 | if (cluster_offset == 0) { | |
701 | return -1; | |
702 | } | |
703 | ||
704 | if (qcow2_alloc_cluster_link_l2(bs, cluster_offset, &meta) < 0) { | |
705 | qcow2_free_any_clusters(bs, cluster_offset, meta.nb_clusters); | |
706 | return -1; | |
707 | } | |
708 | ||
709 | /* There are no dependent requests, but we need to remove our request | |
710 | * from the list of in-flight requests */ | |
711 | run_dependent_requests(&meta); | |
712 | ||
713 | /* TODO Preallocate data if requested */ | |
714 | ||
715 | nb_sectors -= num; | |
716 | offset += num << 9; | |
717 | } | |
718 | ||
719 | /* | |
720 | * It is expected that the image file is large enough to actually contain | |
721 | * all of the allocated clusters (otherwise we get failing reads after | |
722 | * EOF). Extend the image to the last allocated sector. | |
723 | */ | |
724 | if (cluster_offset != 0) { | |
725 | uint8_t buf[512]; | |
726 | memset(buf, 0, 512); | |
727 | bdrv_write(s->hd, (cluster_offset >> 9) + num - 1, buf, 1); | |
728 | } | |
729 | ||
730 | return 0; | |
731 | } | |
732 | ||
733 | static int qcow_create2(const char *filename, int64_t total_size, | |
734 | const char *backing_file, const char *backing_format, | |
735 | int flags, size_t cluster_size, int prealloc) | |
736 | { | |
737 | ||
738 | int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits; | |
739 | int ref_clusters, backing_format_len = 0; | |
740 | QCowHeader header; | |
741 | uint64_t tmp, offset; | |
742 | QCowCreateState s1, *s = &s1; | |
743 | QCowExtension ext_bf = {0, 0}; | |
744 | ||
745 | ||
746 | memset(s, 0, sizeof(*s)); | |
747 | ||
748 | fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); | |
749 | if (fd < 0) | |
750 | return -1; | |
751 | memset(&header, 0, sizeof(header)); | |
752 | header.magic = cpu_to_be32(QCOW_MAGIC); | |
753 | header.version = cpu_to_be32(QCOW_VERSION); | |
754 | header.size = cpu_to_be64(total_size * 512); | |
755 | header_size = sizeof(header); | |
756 | backing_filename_len = 0; | |
757 | if (backing_file) { | |
758 | if (backing_format) { | |
759 | ext_bf.magic = QCOW_EXT_MAGIC_BACKING_FORMAT; | |
760 | backing_format_len = strlen(backing_format); | |
761 | ext_bf.len = (backing_format_len + 7) & ~7; | |
762 | header_size += ((sizeof(ext_bf) + ext_bf.len + 7) & ~7); | |
763 | } | |
764 | header.backing_file_offset = cpu_to_be64(header_size); | |
765 | backing_filename_len = strlen(backing_file); | |
766 | header.backing_file_size = cpu_to_be32(backing_filename_len); | |
767 | header_size += backing_filename_len; | |
768 | } | |
769 | ||
770 | /* Cluster size */ | |
771 | s->cluster_bits = get_bits_from_size(cluster_size); | |
772 | if (s->cluster_bits < MIN_CLUSTER_BITS || | |
773 | s->cluster_bits > MAX_CLUSTER_BITS) | |
774 | { | |
775 | fprintf(stderr, "Cluster size must be a power of two between " | |
776 | "%d and %dk\n", | |
777 | 1 << MIN_CLUSTER_BITS, | |
778 | 1 << (MAX_CLUSTER_BITS - 10)); | |
779 | return -EINVAL; | |
780 | } | |
781 | s->cluster_size = 1 << s->cluster_bits; | |
782 | ||
783 | header.cluster_bits = cpu_to_be32(s->cluster_bits); | |
784 | header_size = (header_size + 7) & ~7; | |
785 | if (flags & BLOCK_FLAG_ENCRYPT) { | |
786 | header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); | |
787 | } else { | |
788 | header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); | |
789 | } | |
790 | l2_bits = s->cluster_bits - 3; | |
791 | shift = s->cluster_bits + l2_bits; | |
792 | l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift); | |
793 | offset = align_offset(header_size, s->cluster_size); | |
794 | s->l1_table_offset = offset; | |
795 | header.l1_table_offset = cpu_to_be64(s->l1_table_offset); | |
796 | header.l1_size = cpu_to_be32(l1_size); | |
797 | offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size); | |
798 | ||
799 | s->refcount_table = qemu_mallocz(s->cluster_size); | |
800 | ||
801 | s->refcount_table_offset = offset; | |
802 | header.refcount_table_offset = cpu_to_be64(offset); | |
803 | header.refcount_table_clusters = cpu_to_be32(1); | |
804 | offset += s->cluster_size; | |
805 | s->refcount_block_offset = offset; | |
806 | ||
807 | /* count how many refcount blocks needed */ | |
808 | tmp = offset >> s->cluster_bits; | |
809 | ref_clusters = (tmp >> (s->cluster_bits - REFCOUNT_SHIFT)) + 1; | |
810 | for (i=0; i < ref_clusters; i++) { | |
811 | s->refcount_table[i] = cpu_to_be64(offset); | |
812 | offset += s->cluster_size; | |
813 | } | |
814 | ||
815 | s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size); | |
816 | ||
817 | /* update refcounts */ | |
818 | qcow2_create_refcount_update(s, 0, header_size); | |
819 | qcow2_create_refcount_update(s, s->l1_table_offset, | |
820 | l1_size * sizeof(uint64_t)); | |
821 | qcow2_create_refcount_update(s, s->refcount_table_offset, s->cluster_size); | |
822 | qcow2_create_refcount_update(s, s->refcount_block_offset, | |
823 | ref_clusters * s->cluster_size); | |
824 | ||
825 | /* write all the data */ | |
826 | write(fd, &header, sizeof(header)); | |
827 | if (backing_file) { | |
828 | if (backing_format_len) { | |
829 | char zero[16]; | |
830 | int d = ext_bf.len - backing_format_len; | |
831 | ||
832 | memset(zero, 0, sizeof(zero)); | |
833 | cpu_to_be32s(&ext_bf.magic); | |
834 | cpu_to_be32s(&ext_bf.len); | |
835 | write(fd, &ext_bf, sizeof(ext_bf)); | |
836 | write(fd, backing_format, backing_format_len); | |
837 | if (d>0) { | |
838 | write(fd, zero, d); | |
839 | } | |
840 | } | |
841 | write(fd, backing_file, backing_filename_len); | |
842 | } | |
843 | lseek(fd, s->l1_table_offset, SEEK_SET); | |
844 | tmp = 0; | |
845 | for(i = 0;i < l1_size; i++) { | |
846 | write(fd, &tmp, sizeof(tmp)); | |
847 | } | |
848 | lseek(fd, s->refcount_table_offset, SEEK_SET); | |
849 | write(fd, s->refcount_table, s->cluster_size); | |
850 | ||
851 | lseek(fd, s->refcount_block_offset, SEEK_SET); | |
852 | write(fd, s->refcount_block, ref_clusters * s->cluster_size); | |
853 | ||
854 | qemu_free(s->refcount_table); | |
855 | qemu_free(s->refcount_block); | |
856 | close(fd); | |
857 | ||
858 | /* Preallocate metadata */ | |
859 | if (prealloc) { | |
860 | BlockDriverState *bs; | |
861 | bs = bdrv_new(""); | |
862 | bdrv_open(bs, filename, BDRV_O_CACHE_WB); | |
863 | preallocate(bs); | |
864 | bdrv_close(bs); | |
865 | } | |
866 | ||
867 | return 0; | |
868 | } | |
869 | ||
870 | static int qcow_create(const char *filename, QEMUOptionParameter *options) | |
871 | { | |
872 | const char *backing_file = NULL; | |
873 | const char *backing_fmt = NULL; | |
874 | uint64_t sectors = 0; | |
875 | int flags = 0; | |
876 | size_t cluster_size = 65536; | |
877 | int prealloc = 0; | |
878 | ||
879 | /* Read out options */ | |
880 | while (options && options->name) { | |
881 | if (!strcmp(options->name, BLOCK_OPT_SIZE)) { | |
882 | sectors = options->value.n / 512; | |
883 | } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { | |
884 | backing_file = options->value.s; | |
885 | } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { | |
886 | backing_fmt = options->value.s; | |
887 | } else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { | |
888 | flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0; | |
889 | } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { | |
890 | if (options->value.n) { | |
891 | cluster_size = options->value.n; | |
892 | } | |
893 | } else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) { | |
894 | if (!options->value.s || !strcmp(options->value.s, "off")) { | |
895 | prealloc = 0; | |
896 | } else if (!strcmp(options->value.s, "metadata")) { | |
897 | prealloc = 1; | |
898 | } else { | |
899 | fprintf(stderr, "Invalid preallocation mode: '%s'\n", | |
900 | options->value.s); | |
901 | return -EINVAL; | |
902 | } | |
903 | } | |
904 | options++; | |
905 | } | |
906 | ||
907 | if (backing_file && prealloc) { | |
908 | fprintf(stderr, "Backing file and preallocation cannot be used at " | |
909 | "the same time\n"); | |
910 | return -EINVAL; | |
911 | } | |
912 | ||
913 | return qcow_create2(filename, sectors, backing_file, backing_fmt, flags, | |
914 | cluster_size, prealloc); | |
915 | } | |
916 | ||
917 | static int qcow_make_empty(BlockDriverState *bs) | |
918 | { | |
919 | #if 0 | |
920 | /* XXX: not correct */ | |
921 | BDRVQcowState *s = bs->opaque; | |
922 | uint32_t l1_length = s->l1_size * sizeof(uint64_t); | |
923 | int ret; | |
924 | ||
925 | memset(s->l1_table, 0, l1_length); | |
926 | if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0) | |
927 | return -1; | |
928 | ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length); | |
929 | if (ret < 0) | |
930 | return ret; | |
931 | ||
932 | l2_cache_reset(bs); | |
933 | #endif | |
934 | return 0; | |
935 | } | |
936 | ||
937 | /* XXX: put compressed sectors first, then all the cluster aligned | |
938 | tables to avoid losing bytes in alignment */ | |
939 | static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, | |
940 | const uint8_t *buf, int nb_sectors) | |
941 | { | |
942 | BDRVQcowState *s = bs->opaque; | |
943 | z_stream strm; | |
944 | int ret, out_len; | |
945 | uint8_t *out_buf; | |
946 | uint64_t cluster_offset; | |
947 | ||
948 | if (nb_sectors == 0) { | |
949 | /* align end of file to a sector boundary to ease reading with | |
950 | sector based I/Os */ | |
951 | cluster_offset = bdrv_getlength(s->hd); | |
952 | cluster_offset = (cluster_offset + 511) & ~511; | |
953 | bdrv_truncate(s->hd, cluster_offset); | |
954 | return 0; | |
955 | } | |
956 | ||
957 | if (nb_sectors != s->cluster_sectors) | |
958 | return -EINVAL; | |
959 | ||
960 | out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); | |
961 | ||
962 | /* best compression, small window, no zlib header */ | |
963 | memset(&strm, 0, sizeof(strm)); | |
964 | ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, | |
965 | Z_DEFLATED, -12, | |
966 | 9, Z_DEFAULT_STRATEGY); | |
967 | if (ret != 0) { | |
968 | qemu_free(out_buf); | |
969 | return -1; | |
970 | } | |
971 | ||
972 | strm.avail_in = s->cluster_size; | |
973 | strm.next_in = (uint8_t *)buf; | |
974 | strm.avail_out = s->cluster_size; | |
975 | strm.next_out = out_buf; | |
976 | ||
977 | ret = deflate(&strm, Z_FINISH); | |
978 | if (ret != Z_STREAM_END && ret != Z_OK) { | |
979 | qemu_free(out_buf); | |
980 | deflateEnd(&strm); | |
981 | return -1; | |
982 | } | |
983 | out_len = strm.next_out - out_buf; | |
984 | ||
985 | deflateEnd(&strm); | |
986 | ||
987 | if (ret != Z_STREAM_END || out_len >= s->cluster_size) { | |
988 | /* could not compress: write normal cluster */ | |
989 | bdrv_write(bs, sector_num, buf, s->cluster_sectors); | |
990 | } else { | |
991 | cluster_offset = qcow2_alloc_compressed_cluster_offset(bs, | |
992 | sector_num << 9, out_len); | |
993 | if (!cluster_offset) | |
994 | return -1; | |
995 | cluster_offset &= s->cluster_offset_mask; | |
996 | if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) { | |
997 | qemu_free(out_buf); | |
998 | return -1; | |
999 | } | |
1000 | } | |
1001 | ||
1002 | qemu_free(out_buf); | |
1003 | return 0; | |
1004 | } | |
1005 | ||
1006 | static void qcow_flush(BlockDriverState *bs) | |
1007 | { | |
1008 | BDRVQcowState *s = bs->opaque; | |
1009 | bdrv_flush(s->hd); | |
1010 | } | |
1011 | ||
1012 | static int64_t qcow_vm_state_offset(BDRVQcowState *s) | |
1013 | { | |
1014 | return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits); | |
1015 | } | |
1016 | ||
1017 | static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) | |
1018 | { | |
1019 | BDRVQcowState *s = bs->opaque; | |
1020 | bdi->cluster_size = s->cluster_size; | |
1021 | bdi->vm_state_offset = qcow_vm_state_offset(s); | |
1022 | return 0; | |
1023 | } | |
1024 | ||
1025 | ||
1026 | static int qcow_check(BlockDriverState *bs) | |
1027 | { | |
1028 | return qcow2_check_refcounts(bs); | |
1029 | } | |
1030 | ||
1031 | #if 0 | |
1032 | static void dump_refcounts(BlockDriverState *bs) | |
1033 | { | |
1034 | BDRVQcowState *s = bs->opaque; | |
1035 | int64_t nb_clusters, k, k1, size; | |
1036 | int refcount; | |
1037 | ||
1038 | size = bdrv_getlength(s->hd); | |
1039 | nb_clusters = size_to_clusters(s, size); | |
1040 | for(k = 0; k < nb_clusters;) { | |
1041 | k1 = k; | |
1042 | refcount = get_refcount(bs, k); | |
1043 | k++; | |
1044 | while (k < nb_clusters && get_refcount(bs, k) == refcount) | |
1045 | k++; | |
1046 | printf("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1); | |
1047 | } | |
1048 | } | |
1049 | #endif | |
1050 | ||
1051 | static int qcow_save_vmstate(BlockDriverState *bs, const uint8_t *buf, | |
1052 | int64_t pos, int size) | |
1053 | { | |
1054 | BDRVQcowState *s = bs->opaque; | |
1055 | int growable = bs->growable; | |
1056 | ||
1057 | bs->growable = 1; | |
1058 | bdrv_pwrite(bs, qcow_vm_state_offset(s) + pos, buf, size); | |
1059 | bs->growable = growable; | |
1060 | ||
1061 | return size; | |
1062 | } | |
1063 | ||
1064 | static int qcow_load_vmstate(BlockDriverState *bs, uint8_t *buf, | |
1065 | int64_t pos, int size) | |
1066 | { | |
1067 | BDRVQcowState *s = bs->opaque; | |
1068 | int growable = bs->growable; | |
1069 | int ret; | |
1070 | ||
1071 | bs->growable = 1; | |
1072 | ret = bdrv_pread(bs, qcow_vm_state_offset(s) + pos, buf, size); | |
1073 | bs->growable = growable; | |
1074 | ||
1075 | return ret; | |
1076 | } | |
1077 | ||
1078 | static QEMUOptionParameter qcow_create_options[] = { | |
1079 | { | |
1080 | .name = BLOCK_OPT_SIZE, | |
1081 | .type = OPT_SIZE, | |
1082 | .help = "Virtual disk size" | |
1083 | }, | |
1084 | { | |
1085 | .name = BLOCK_OPT_BACKING_FILE, | |
1086 | .type = OPT_STRING, | |
1087 | .help = "File name of a base image" | |
1088 | }, | |
1089 | { | |
1090 | .name = BLOCK_OPT_BACKING_FMT, | |
1091 | .type = OPT_STRING, | |
1092 | .help = "Image format of the base image" | |
1093 | }, | |
1094 | { | |
1095 | .name = BLOCK_OPT_ENCRYPT, | |
1096 | .type = OPT_FLAG, | |
1097 | .help = "Encrypt the image" | |
1098 | }, | |
1099 | { | |
1100 | .name = BLOCK_OPT_CLUSTER_SIZE, | |
1101 | .type = OPT_SIZE, | |
1102 | .help = "qcow2 cluster size" | |
1103 | }, | |
1104 | { | |
1105 | .name = BLOCK_OPT_PREALLOC, | |
1106 | .type = OPT_STRING, | |
1107 | .help = "Preallocation mode (allowed values: off, metadata)" | |
1108 | }, | |
1109 | { NULL } | |
1110 | }; | |
1111 | ||
1112 | static BlockDriver bdrv_qcow2 = { | |
1113 | .format_name = "qcow2", | |
1114 | .instance_size = sizeof(BDRVQcowState), | |
1115 | .bdrv_probe = qcow_probe, | |
1116 | .bdrv_open = qcow_open, | |
1117 | .bdrv_close = qcow_close, | |
1118 | .bdrv_create = qcow_create, | |
1119 | .bdrv_flush = qcow_flush, | |
1120 | .bdrv_is_allocated = qcow_is_allocated, | |
1121 | .bdrv_set_key = qcow_set_key, | |
1122 | .bdrv_make_empty = qcow_make_empty, | |
1123 | ||
1124 | .bdrv_aio_readv = qcow_aio_readv, | |
1125 | .bdrv_aio_writev = qcow_aio_writev, | |
1126 | .bdrv_write_compressed = qcow_write_compressed, | |
1127 | ||
1128 | .bdrv_snapshot_create = qcow2_snapshot_create, | |
1129 | .bdrv_snapshot_goto = qcow2_snapshot_goto, | |
1130 | .bdrv_snapshot_delete = qcow2_snapshot_delete, | |
1131 | .bdrv_snapshot_list = qcow2_snapshot_list, | |
1132 | .bdrv_get_info = qcow_get_info, | |
1133 | ||
1134 | .bdrv_save_vmstate = qcow_save_vmstate, | |
1135 | .bdrv_load_vmstate = qcow_load_vmstate, | |
1136 | ||
1137 | .create_options = qcow_create_options, | |
1138 | .bdrv_check = qcow_check, | |
1139 | }; | |
1140 | ||
1141 | static void bdrv_qcow2_init(void) | |
1142 | { | |
1143 | bdrv_register(&bdrv_qcow2); | |
1144 | } | |
1145 | ||
1146 | block_init(bdrv_qcow2_init); |