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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/block_int.h" | |
26 | #include "qemu/module.h" | |
27 | #include <zlib.h> | |
28 | #include "block/qcow2.h" | |
29 | #include "qemu/error-report.h" | |
30 | #include "qapi/qmp/qerror.h" | |
31 | #include "qapi/qmp/qbool.h" | |
32 | #include "qapi/util.h" | |
33 | #include "qapi/qmp/types.h" | |
34 | #include "qapi-event.h" | |
35 | #include "trace.h" | |
36 | #include "qemu/option_int.h" | |
37 | ||
38 | /* | |
39 | Differences with QCOW: | |
40 | ||
41 | - Support for multiple incremental snapshots. | |
42 | - Memory management by reference counts. | |
43 | - Clusters which have a reference count of one have the bit | |
44 | QCOW_OFLAG_COPIED to optimize write performance. | |
45 | - Size of compressed clusters is stored in sectors to reduce bit usage | |
46 | in the cluster offsets. | |
47 | - Support for storing additional data (such as the VM state) in the | |
48 | snapshots. | |
49 | - If a backing store is used, the cluster size is not constrained | |
50 | (could be backported to QCOW). | |
51 | - L2 tables have always a size of one cluster. | |
52 | */ | |
53 | ||
54 | ||
55 | typedef struct { | |
56 | uint32_t magic; | |
57 | uint32_t len; | |
58 | } QEMU_PACKED QCowExtension; | |
59 | ||
60 | #define QCOW2_EXT_MAGIC_END 0 | |
61 | #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA | |
62 | #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 | |
63 | ||
64 | static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) | |
65 | { | |
66 | const QCowHeader *cow_header = (const void *)buf; | |
67 | ||
68 | if (buf_size >= sizeof(QCowHeader) && | |
69 | be32_to_cpu(cow_header->magic) == QCOW_MAGIC && | |
70 | be32_to_cpu(cow_header->version) >= 2) | |
71 | return 100; | |
72 | else | |
73 | return 0; | |
74 | } | |
75 | ||
76 | ||
77 | /* | |
78 | * read qcow2 extension and fill bs | |
79 | * start reading from start_offset | |
80 | * finish reading upon magic of value 0 or when end_offset reached | |
81 | * unknown magic is skipped (future extension this version knows nothing about) | |
82 | * return 0 upon success, non-0 otherwise | |
83 | */ | |
84 | static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, | |
85 | uint64_t end_offset, void **p_feature_table, | |
86 | Error **errp) | |
87 | { | |
88 | BDRVQcow2State *s = bs->opaque; | |
89 | QCowExtension ext; | |
90 | uint64_t offset; | |
91 | int ret; | |
92 | ||
93 | #ifdef DEBUG_EXT | |
94 | printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset); | |
95 | #endif | |
96 | offset = start_offset; | |
97 | while (offset < end_offset) { | |
98 | ||
99 | #ifdef DEBUG_EXT | |
100 | /* Sanity check */ | |
101 | if (offset > s->cluster_size) | |
102 | printf("qcow2_read_extension: suspicious offset %lu\n", offset); | |
103 | ||
104 | printf("attempting to read extended header in offset %lu\n", offset); | |
105 | #endif | |
106 | ||
107 | ret = bdrv_pread(bs->file, offset, &ext, sizeof(ext)); | |
108 | if (ret < 0) { | |
109 | error_setg_errno(errp, -ret, "qcow2_read_extension: ERROR: " | |
110 | "pread fail from offset %" PRIu64, offset); | |
111 | return 1; | |
112 | } | |
113 | be32_to_cpus(&ext.magic); | |
114 | be32_to_cpus(&ext.len); | |
115 | offset += sizeof(ext); | |
116 | #ifdef DEBUG_EXT | |
117 | printf("ext.magic = 0x%x\n", ext.magic); | |
118 | #endif | |
119 | if (offset > end_offset || ext.len > end_offset - offset) { | |
120 | error_setg(errp, "Header extension too large"); | |
121 | return -EINVAL; | |
122 | } | |
123 | ||
124 | switch (ext.magic) { | |
125 | case QCOW2_EXT_MAGIC_END: | |
126 | return 0; | |
127 | ||
128 | case QCOW2_EXT_MAGIC_BACKING_FORMAT: | |
129 | if (ext.len >= sizeof(bs->backing_format)) { | |
130 | error_setg(errp, "ERROR: ext_backing_format: len=%" PRIu32 | |
131 | " too large (>=%zu)", ext.len, | |
132 | sizeof(bs->backing_format)); | |
133 | return 2; | |
134 | } | |
135 | ret = bdrv_pread(bs->file, offset, bs->backing_format, ext.len); | |
136 | if (ret < 0) { | |
137 | error_setg_errno(errp, -ret, "ERROR: ext_backing_format: " | |
138 | "Could not read format name"); | |
139 | return 3; | |
140 | } | |
141 | bs->backing_format[ext.len] = '\0'; | |
142 | s->image_backing_format = g_strdup(bs->backing_format); | |
143 | #ifdef DEBUG_EXT | |
144 | printf("Qcow2: Got format extension %s\n", bs->backing_format); | |
145 | #endif | |
146 | break; | |
147 | ||
148 | case QCOW2_EXT_MAGIC_FEATURE_TABLE: | |
149 | if (p_feature_table != NULL) { | |
150 | void* feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); | |
151 | ret = bdrv_pread(bs->file, offset , feature_table, ext.len); | |
152 | if (ret < 0) { | |
153 | error_setg_errno(errp, -ret, "ERROR: ext_feature_table: " | |
154 | "Could not read table"); | |
155 | return ret; | |
156 | } | |
157 | ||
158 | *p_feature_table = feature_table; | |
159 | } | |
160 | break; | |
161 | ||
162 | default: | |
163 | /* unknown magic - save it in case we need to rewrite the header */ | |
164 | { | |
165 | Qcow2UnknownHeaderExtension *uext; | |
166 | ||
167 | uext = g_malloc0(sizeof(*uext) + ext.len); | |
168 | uext->magic = ext.magic; | |
169 | uext->len = ext.len; | |
170 | QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next); | |
171 | ||
172 | ret = bdrv_pread(bs->file, offset , uext->data, uext->len); | |
173 | if (ret < 0) { | |
174 | error_setg_errno(errp, -ret, "ERROR: unknown extension: " | |
175 | "Could not read data"); | |
176 | return ret; | |
177 | } | |
178 | } | |
179 | break; | |
180 | } | |
181 | ||
182 | offset += ((ext.len + 7) & ~7); | |
183 | } | |
184 | ||
185 | return 0; | |
186 | } | |
187 | ||
188 | static void cleanup_unknown_header_ext(BlockDriverState *bs) | |
189 | { | |
190 | BDRVQcow2State *s = bs->opaque; | |
191 | Qcow2UnknownHeaderExtension *uext, *next; | |
192 | ||
193 | QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { | |
194 | QLIST_REMOVE(uext, next); | |
195 | g_free(uext); | |
196 | } | |
197 | } | |
198 | ||
199 | static void GCC_FMT_ATTR(3, 4) report_unsupported(BlockDriverState *bs, | |
200 | Error **errp, const char *fmt, ...) | |
201 | { | |
202 | char msg[64]; | |
203 | va_list ap; | |
204 | ||
205 | va_start(ap, fmt); | |
206 | vsnprintf(msg, sizeof(msg), fmt, ap); | |
207 | va_end(ap); | |
208 | ||
209 | error_setg(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, | |
210 | bdrv_get_device_or_node_name(bs), "qcow2", msg); | |
211 | } | |
212 | ||
213 | static void report_unsupported_feature(BlockDriverState *bs, | |
214 | Error **errp, Qcow2Feature *table, uint64_t mask) | |
215 | { | |
216 | char *features = g_strdup(""); | |
217 | char *old; | |
218 | ||
219 | while (table && table->name[0] != '\0') { | |
220 | if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { | |
221 | if (mask & (1ULL << table->bit)) { | |
222 | old = features; | |
223 | features = g_strdup_printf("%s%s%.46s", old, *old ? ", " : "", | |
224 | table->name); | |
225 | g_free(old); | |
226 | mask &= ~(1ULL << table->bit); | |
227 | } | |
228 | } | |
229 | table++; | |
230 | } | |
231 | ||
232 | if (mask) { | |
233 | old = features; | |
234 | features = g_strdup_printf("%s%sUnknown incompatible feature: %" PRIx64, | |
235 | old, *old ? ", " : "", mask); | |
236 | g_free(old); | |
237 | } | |
238 | ||
239 | report_unsupported(bs, errp, "%s", features); | |
240 | g_free(features); | |
241 | } | |
242 | ||
243 | /* | |
244 | * Sets the dirty bit and flushes afterwards if necessary. | |
245 | * | |
246 | * The incompatible_features bit is only set if the image file header was | |
247 | * updated successfully. Therefore it is not required to check the return | |
248 | * value of this function. | |
249 | */ | |
250 | int qcow2_mark_dirty(BlockDriverState *bs) | |
251 | { | |
252 | BDRVQcow2State *s = bs->opaque; | |
253 | uint64_t val; | |
254 | int ret; | |
255 | ||
256 | assert(s->qcow_version >= 3); | |
257 | ||
258 | if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { | |
259 | return 0; /* already dirty */ | |
260 | } | |
261 | ||
262 | val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); | |
263 | ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features), | |
264 | &val, sizeof(val)); | |
265 | if (ret < 0) { | |
266 | return ret; | |
267 | } | |
268 | ret = bdrv_flush(bs->file); | |
269 | if (ret < 0) { | |
270 | return ret; | |
271 | } | |
272 | ||
273 | /* Only treat image as dirty if the header was updated successfully */ | |
274 | s->incompatible_features |= QCOW2_INCOMPAT_DIRTY; | |
275 | return 0; | |
276 | } | |
277 | ||
278 | /* | |
279 | * Clears the dirty bit and flushes before if necessary. Only call this | |
280 | * function when there are no pending requests, it does not guard against | |
281 | * concurrent requests dirtying the image. | |
282 | */ | |
283 | static int qcow2_mark_clean(BlockDriverState *bs) | |
284 | { | |
285 | BDRVQcow2State *s = bs->opaque; | |
286 | ||
287 | if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { | |
288 | int ret; | |
289 | ||
290 | s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; | |
291 | ||
292 | ret = bdrv_flush(bs); | |
293 | if (ret < 0) { | |
294 | return ret; | |
295 | } | |
296 | ||
297 | return qcow2_update_header(bs); | |
298 | } | |
299 | return 0; | |
300 | } | |
301 | ||
302 | /* | |
303 | * Marks the image as corrupt. | |
304 | */ | |
305 | int qcow2_mark_corrupt(BlockDriverState *bs) | |
306 | { | |
307 | BDRVQcow2State *s = bs->opaque; | |
308 | ||
309 | s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT; | |
310 | return qcow2_update_header(bs); | |
311 | } | |
312 | ||
313 | /* | |
314 | * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes | |
315 | * before if necessary. | |
316 | */ | |
317 | int qcow2_mark_consistent(BlockDriverState *bs) | |
318 | { | |
319 | BDRVQcow2State *s = bs->opaque; | |
320 | ||
321 | if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { | |
322 | int ret = bdrv_flush(bs); | |
323 | if (ret < 0) { | |
324 | return ret; | |
325 | } | |
326 | ||
327 | s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT; | |
328 | return qcow2_update_header(bs); | |
329 | } | |
330 | return 0; | |
331 | } | |
332 | ||
333 | static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result, | |
334 | BdrvCheckMode fix) | |
335 | { | |
336 | int ret = qcow2_check_refcounts(bs, result, fix); | |
337 | if (ret < 0) { | |
338 | return ret; | |
339 | } | |
340 | ||
341 | if (fix && result->check_errors == 0 && result->corruptions == 0) { | |
342 | ret = qcow2_mark_clean(bs); | |
343 | if (ret < 0) { | |
344 | return ret; | |
345 | } | |
346 | return qcow2_mark_consistent(bs); | |
347 | } | |
348 | return ret; | |
349 | } | |
350 | ||
351 | static int validate_table_offset(BlockDriverState *bs, uint64_t offset, | |
352 | uint64_t entries, size_t entry_len) | |
353 | { | |
354 | BDRVQcow2State *s = bs->opaque; | |
355 | uint64_t size; | |
356 | ||
357 | /* Use signed INT64_MAX as the maximum even for uint64_t header fields, | |
358 | * because values will be passed to qemu functions taking int64_t. */ | |
359 | if (entries > INT64_MAX / entry_len) { | |
360 | return -EINVAL; | |
361 | } | |
362 | ||
363 | size = entries * entry_len; | |
364 | ||
365 | if (INT64_MAX - size < offset) { | |
366 | return -EINVAL; | |
367 | } | |
368 | ||
369 | /* Tables must be cluster aligned */ | |
370 | if (offset & (s->cluster_size - 1)) { | |
371 | return -EINVAL; | |
372 | } | |
373 | ||
374 | return 0; | |
375 | } | |
376 | ||
377 | static QemuOptsList qcow2_runtime_opts = { | |
378 | .name = "qcow2", | |
379 | .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head), | |
380 | .desc = { | |
381 | { | |
382 | .name = QCOW2_OPT_LAZY_REFCOUNTS, | |
383 | .type = QEMU_OPT_BOOL, | |
384 | .help = "Postpone refcount updates", | |
385 | }, | |
386 | { | |
387 | .name = QCOW2_OPT_DISCARD_REQUEST, | |
388 | .type = QEMU_OPT_BOOL, | |
389 | .help = "Pass guest discard requests to the layer below", | |
390 | }, | |
391 | { | |
392 | .name = QCOW2_OPT_DISCARD_SNAPSHOT, | |
393 | .type = QEMU_OPT_BOOL, | |
394 | .help = "Generate discard requests when snapshot related space " | |
395 | "is freed", | |
396 | }, | |
397 | { | |
398 | .name = QCOW2_OPT_DISCARD_OTHER, | |
399 | .type = QEMU_OPT_BOOL, | |
400 | .help = "Generate discard requests when other clusters are freed", | |
401 | }, | |
402 | { | |
403 | .name = QCOW2_OPT_OVERLAP, | |
404 | .type = QEMU_OPT_STRING, | |
405 | .help = "Selects which overlap checks to perform from a range of " | |
406 | "templates (none, constant, cached, all)", | |
407 | }, | |
408 | { | |
409 | .name = QCOW2_OPT_OVERLAP_TEMPLATE, | |
410 | .type = QEMU_OPT_STRING, | |
411 | .help = "Selects which overlap checks to perform from a range of " | |
412 | "templates (none, constant, cached, all)", | |
413 | }, | |
414 | { | |
415 | .name = QCOW2_OPT_OVERLAP_MAIN_HEADER, | |
416 | .type = QEMU_OPT_BOOL, | |
417 | .help = "Check for unintended writes into the main qcow2 header", | |
418 | }, | |
419 | { | |
420 | .name = QCOW2_OPT_OVERLAP_ACTIVE_L1, | |
421 | .type = QEMU_OPT_BOOL, | |
422 | .help = "Check for unintended writes into the active L1 table", | |
423 | }, | |
424 | { | |
425 | .name = QCOW2_OPT_OVERLAP_ACTIVE_L2, | |
426 | .type = QEMU_OPT_BOOL, | |
427 | .help = "Check for unintended writes into an active L2 table", | |
428 | }, | |
429 | { | |
430 | .name = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, | |
431 | .type = QEMU_OPT_BOOL, | |
432 | .help = "Check for unintended writes into the refcount table", | |
433 | }, | |
434 | { | |
435 | .name = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, | |
436 | .type = QEMU_OPT_BOOL, | |
437 | .help = "Check for unintended writes into a refcount block", | |
438 | }, | |
439 | { | |
440 | .name = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, | |
441 | .type = QEMU_OPT_BOOL, | |
442 | .help = "Check for unintended writes into the snapshot table", | |
443 | }, | |
444 | { | |
445 | .name = QCOW2_OPT_OVERLAP_INACTIVE_L1, | |
446 | .type = QEMU_OPT_BOOL, | |
447 | .help = "Check for unintended writes into an inactive L1 table", | |
448 | }, | |
449 | { | |
450 | .name = QCOW2_OPT_OVERLAP_INACTIVE_L2, | |
451 | .type = QEMU_OPT_BOOL, | |
452 | .help = "Check for unintended writes into an inactive L2 table", | |
453 | }, | |
454 | { | |
455 | .name = QCOW2_OPT_CACHE_SIZE, | |
456 | .type = QEMU_OPT_SIZE, | |
457 | .help = "Maximum combined metadata (L2 tables and refcount blocks) " | |
458 | "cache size", | |
459 | }, | |
460 | { | |
461 | .name = QCOW2_OPT_L2_CACHE_SIZE, | |
462 | .type = QEMU_OPT_SIZE, | |
463 | .help = "Maximum L2 table cache size", | |
464 | }, | |
465 | { | |
466 | .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE, | |
467 | .type = QEMU_OPT_SIZE, | |
468 | .help = "Maximum refcount block cache size", | |
469 | }, | |
470 | { | |
471 | .name = QCOW2_OPT_CACHE_CLEAN_INTERVAL, | |
472 | .type = QEMU_OPT_NUMBER, | |
473 | .help = "Clean unused cache entries after this time (in seconds)", | |
474 | }, | |
475 | { /* end of list */ } | |
476 | }, | |
477 | }; | |
478 | ||
479 | static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = { | |
480 | [QCOW2_OL_MAIN_HEADER_BITNR] = QCOW2_OPT_OVERLAP_MAIN_HEADER, | |
481 | [QCOW2_OL_ACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L1, | |
482 | [QCOW2_OL_ACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L2, | |
483 | [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, | |
484 | [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, | |
485 | [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, | |
486 | [QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1, | |
487 | [QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2, | |
488 | }; | |
489 | ||
490 | static void cache_clean_timer_cb(void *opaque) | |
491 | { | |
492 | BlockDriverState *bs = opaque; | |
493 | BDRVQcow2State *s = bs->opaque; | |
494 | qcow2_cache_clean_unused(bs, s->l2_table_cache); | |
495 | qcow2_cache_clean_unused(bs, s->refcount_block_cache); | |
496 | timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + | |
497 | (int64_t) s->cache_clean_interval * 1000); | |
498 | } | |
499 | ||
500 | static void cache_clean_timer_init(BlockDriverState *bs, AioContext *context) | |
501 | { | |
502 | BDRVQcow2State *s = bs->opaque; | |
503 | if (s->cache_clean_interval > 0) { | |
504 | s->cache_clean_timer = aio_timer_new(context, QEMU_CLOCK_VIRTUAL, | |
505 | SCALE_MS, cache_clean_timer_cb, | |
506 | bs); | |
507 | timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + | |
508 | (int64_t) s->cache_clean_interval * 1000); | |
509 | } | |
510 | } | |
511 | ||
512 | static void cache_clean_timer_del(BlockDriverState *bs) | |
513 | { | |
514 | BDRVQcow2State *s = bs->opaque; | |
515 | if (s->cache_clean_timer) { | |
516 | timer_del(s->cache_clean_timer); | |
517 | timer_free(s->cache_clean_timer); | |
518 | s->cache_clean_timer = NULL; | |
519 | } | |
520 | } | |
521 | ||
522 | static void qcow2_detach_aio_context(BlockDriverState *bs) | |
523 | { | |
524 | cache_clean_timer_del(bs); | |
525 | } | |
526 | ||
527 | static void qcow2_attach_aio_context(BlockDriverState *bs, | |
528 | AioContext *new_context) | |
529 | { | |
530 | cache_clean_timer_init(bs, new_context); | |
531 | } | |
532 | ||
533 | static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, | |
534 | uint64_t *l2_cache_size, | |
535 | uint64_t *refcount_cache_size, Error **errp) | |
536 | { | |
537 | BDRVQcow2State *s = bs->opaque; | |
538 | uint64_t combined_cache_size; | |
539 | bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set; | |
540 | ||
541 | combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE); | |
542 | l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE); | |
543 | refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE); | |
544 | ||
545 | combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0); | |
546 | *l2_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE, 0); | |
547 | *refcount_cache_size = qemu_opt_get_size(opts, | |
548 | QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0); | |
549 | ||
550 | if (combined_cache_size_set) { | |
551 | if (l2_cache_size_set && refcount_cache_size_set) { | |
552 | error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE | |
553 | " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set " | |
554 | "the same time"); | |
555 | return; | |
556 | } else if (*l2_cache_size > combined_cache_size) { | |
557 | error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed " | |
558 | QCOW2_OPT_CACHE_SIZE); | |
559 | return; | |
560 | } else if (*refcount_cache_size > combined_cache_size) { | |
561 | error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed " | |
562 | QCOW2_OPT_CACHE_SIZE); | |
563 | return; | |
564 | } | |
565 | ||
566 | if (l2_cache_size_set) { | |
567 | *refcount_cache_size = combined_cache_size - *l2_cache_size; | |
568 | } else if (refcount_cache_size_set) { | |
569 | *l2_cache_size = combined_cache_size - *refcount_cache_size; | |
570 | } else { | |
571 | *refcount_cache_size = combined_cache_size | |
572 | / (DEFAULT_L2_REFCOUNT_SIZE_RATIO + 1); | |
573 | *l2_cache_size = combined_cache_size - *refcount_cache_size; | |
574 | } | |
575 | } else { | |
576 | if (!l2_cache_size_set && !refcount_cache_size_set) { | |
577 | *l2_cache_size = MAX(DEFAULT_L2_CACHE_BYTE_SIZE, | |
578 | (uint64_t)DEFAULT_L2_CACHE_CLUSTERS | |
579 | * s->cluster_size); | |
580 | *refcount_cache_size = *l2_cache_size | |
581 | / DEFAULT_L2_REFCOUNT_SIZE_RATIO; | |
582 | } else if (!l2_cache_size_set) { | |
583 | *l2_cache_size = *refcount_cache_size | |
584 | * DEFAULT_L2_REFCOUNT_SIZE_RATIO; | |
585 | } else if (!refcount_cache_size_set) { | |
586 | *refcount_cache_size = *l2_cache_size | |
587 | / DEFAULT_L2_REFCOUNT_SIZE_RATIO; | |
588 | } | |
589 | } | |
590 | } | |
591 | ||
592 | static int qcow2_update_options(BlockDriverState *bs, QemuOpts *opts, | |
593 | int flags, Error **errp) | |
594 | { | |
595 | BDRVQcow2State *s = bs->opaque; | |
596 | const char *opt_overlap_check, *opt_overlap_check_template; | |
597 | int overlap_check_template = 0; | |
598 | int i; | |
599 | int ret; | |
600 | ||
601 | s->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS, | |
602 | (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)); | |
603 | ||
604 | s->discard_passthrough[QCOW2_DISCARD_NEVER] = false; | |
605 | s->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true; | |
606 | s->discard_passthrough[QCOW2_DISCARD_REQUEST] = | |
607 | qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST, | |
608 | flags & BDRV_O_UNMAP); | |
609 | s->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] = | |
610 | qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true); | |
611 | s->discard_passthrough[QCOW2_DISCARD_OTHER] = | |
612 | qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false); | |
613 | ||
614 | opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP); | |
615 | opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE); | |
616 | if (opt_overlap_check_template && opt_overlap_check && | |
617 | strcmp(opt_overlap_check_template, opt_overlap_check)) | |
618 | { | |
619 | error_setg(errp, "Conflicting values for qcow2 options '" | |
620 | QCOW2_OPT_OVERLAP "' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE | |
621 | "' ('%s')", opt_overlap_check, opt_overlap_check_template); | |
622 | ret = -EINVAL; | |
623 | goto fail; | |
624 | } | |
625 | if (!opt_overlap_check) { | |
626 | opt_overlap_check = opt_overlap_check_template ?: "cached"; | |
627 | } | |
628 | ||
629 | if (!strcmp(opt_overlap_check, "none")) { | |
630 | overlap_check_template = 0; | |
631 | } else if (!strcmp(opt_overlap_check, "constant")) { | |
632 | overlap_check_template = QCOW2_OL_CONSTANT; | |
633 | } else if (!strcmp(opt_overlap_check, "cached")) { | |
634 | overlap_check_template = QCOW2_OL_CACHED; | |
635 | } else if (!strcmp(opt_overlap_check, "all")) { | |
636 | overlap_check_template = QCOW2_OL_ALL; | |
637 | } else { | |
638 | error_setg(errp, "Unsupported value '%s' for qcow2 option " | |
639 | "'overlap-check'. Allowed are any of the following: " | |
640 | "none, constant, cached, all", opt_overlap_check); | |
641 | ret = -EINVAL; | |
642 | goto fail; | |
643 | } | |
644 | ||
645 | s->overlap_check = 0; | |
646 | for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) { | |
647 | /* overlap-check defines a template bitmask, but every flag may be | |
648 | * overwritten through the associated boolean option */ | |
649 | s->overlap_check |= | |
650 | qemu_opt_get_bool(opts, overlap_bool_option_names[i], | |
651 | overlap_check_template & (1 << i)) << i; | |
652 | } | |
653 | ||
654 | if (s->use_lazy_refcounts && s->qcow_version < 3) { | |
655 | error_setg(errp, "Lazy refcounts require a qcow2 image with at least " | |
656 | "qemu 1.1 compatibility level"); | |
657 | ret = -EINVAL; | |
658 | goto fail; | |
659 | } | |
660 | ||
661 | ret = 0; | |
662 | fail: | |
663 | return ret; | |
664 | } | |
665 | ||
666 | static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, | |
667 | Error **errp) | |
668 | { | |
669 | BDRVQcow2State *s = bs->opaque; | |
670 | unsigned int len, i; | |
671 | int ret = 0; | |
672 | QCowHeader header; | |
673 | QemuOpts *opts = NULL; | |
674 | Error *local_err = NULL; | |
675 | uint64_t ext_end; | |
676 | uint64_t l1_vm_state_index; | |
677 | uint64_t l2_cache_size, refcount_cache_size; | |
678 | uint64_t cache_clean_interval; | |
679 | ||
680 | ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); | |
681 | if (ret < 0) { | |
682 | error_setg_errno(errp, -ret, "Could not read qcow2 header"); | |
683 | goto fail; | |
684 | } | |
685 | be32_to_cpus(&header.magic); | |
686 | be32_to_cpus(&header.version); | |
687 | be64_to_cpus(&header.backing_file_offset); | |
688 | be32_to_cpus(&header.backing_file_size); | |
689 | be64_to_cpus(&header.size); | |
690 | be32_to_cpus(&header.cluster_bits); | |
691 | be32_to_cpus(&header.crypt_method); | |
692 | be64_to_cpus(&header.l1_table_offset); | |
693 | be32_to_cpus(&header.l1_size); | |
694 | be64_to_cpus(&header.refcount_table_offset); | |
695 | be32_to_cpus(&header.refcount_table_clusters); | |
696 | be64_to_cpus(&header.snapshots_offset); | |
697 | be32_to_cpus(&header.nb_snapshots); | |
698 | ||
699 | if (header.magic != QCOW_MAGIC) { | |
700 | error_setg(errp, "Image is not in qcow2 format"); | |
701 | ret = -EINVAL; | |
702 | goto fail; | |
703 | } | |
704 | if (header.version < 2 || header.version > 3) { | |
705 | report_unsupported(bs, errp, "QCOW version %" PRIu32, header.version); | |
706 | ret = -ENOTSUP; | |
707 | goto fail; | |
708 | } | |
709 | ||
710 | s->qcow_version = header.version; | |
711 | ||
712 | /* Initialise cluster size */ | |
713 | if (header.cluster_bits < MIN_CLUSTER_BITS || | |
714 | header.cluster_bits > MAX_CLUSTER_BITS) { | |
715 | error_setg(errp, "Unsupported cluster size: 2^%" PRIu32, | |
716 | header.cluster_bits); | |
717 | ret = -EINVAL; | |
718 | goto fail; | |
719 | } | |
720 | ||
721 | s->cluster_bits = header.cluster_bits; | |
722 | s->cluster_size = 1 << s->cluster_bits; | |
723 | s->cluster_sectors = 1 << (s->cluster_bits - 9); | |
724 | ||
725 | /* Initialise version 3 header fields */ | |
726 | if (header.version == 2) { | |
727 | header.incompatible_features = 0; | |
728 | header.compatible_features = 0; | |
729 | header.autoclear_features = 0; | |
730 | header.refcount_order = 4; | |
731 | header.header_length = 72; | |
732 | } else { | |
733 | be64_to_cpus(&header.incompatible_features); | |
734 | be64_to_cpus(&header.compatible_features); | |
735 | be64_to_cpus(&header.autoclear_features); | |
736 | be32_to_cpus(&header.refcount_order); | |
737 | be32_to_cpus(&header.header_length); | |
738 | ||
739 | if (header.header_length < 104) { | |
740 | error_setg(errp, "qcow2 header too short"); | |
741 | ret = -EINVAL; | |
742 | goto fail; | |
743 | } | |
744 | } | |
745 | ||
746 | if (header.header_length > s->cluster_size) { | |
747 | error_setg(errp, "qcow2 header exceeds cluster size"); | |
748 | ret = -EINVAL; | |
749 | goto fail; | |
750 | } | |
751 | ||
752 | if (header.header_length > sizeof(header)) { | |
753 | s->unknown_header_fields_size = header.header_length - sizeof(header); | |
754 | s->unknown_header_fields = g_malloc(s->unknown_header_fields_size); | |
755 | ret = bdrv_pread(bs->file, sizeof(header), s->unknown_header_fields, | |
756 | s->unknown_header_fields_size); | |
757 | if (ret < 0) { | |
758 | error_setg_errno(errp, -ret, "Could not read unknown qcow2 header " | |
759 | "fields"); | |
760 | goto fail; | |
761 | } | |
762 | } | |
763 | ||
764 | if (header.backing_file_offset > s->cluster_size) { | |
765 | error_setg(errp, "Invalid backing file offset"); | |
766 | ret = -EINVAL; | |
767 | goto fail; | |
768 | } | |
769 | ||
770 | if (header.backing_file_offset) { | |
771 | ext_end = header.backing_file_offset; | |
772 | } else { | |
773 | ext_end = 1 << header.cluster_bits; | |
774 | } | |
775 | ||
776 | /* Handle feature bits */ | |
777 | s->incompatible_features = header.incompatible_features; | |
778 | s->compatible_features = header.compatible_features; | |
779 | s->autoclear_features = header.autoclear_features; | |
780 | ||
781 | if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) { | |
782 | void *feature_table = NULL; | |
783 | qcow2_read_extensions(bs, header.header_length, ext_end, | |
784 | &feature_table, NULL); | |
785 | report_unsupported_feature(bs, errp, feature_table, | |
786 | s->incompatible_features & | |
787 | ~QCOW2_INCOMPAT_MASK); | |
788 | ret = -ENOTSUP; | |
789 | g_free(feature_table); | |
790 | goto fail; | |
791 | } | |
792 | ||
793 | if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { | |
794 | /* Corrupt images may not be written to unless they are being repaired | |
795 | */ | |
796 | if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) { | |
797 | error_setg(errp, "qcow2: Image is corrupt; cannot be opened " | |
798 | "read/write"); | |
799 | ret = -EACCES; | |
800 | goto fail; | |
801 | } | |
802 | } | |
803 | ||
804 | /* Check support for various header values */ | |
805 | if (header.refcount_order > 6) { | |
806 | error_setg(errp, "Reference count entry width too large; may not " | |
807 | "exceed 64 bits"); | |
808 | ret = -EINVAL; | |
809 | goto fail; | |
810 | } | |
811 | s->refcount_order = header.refcount_order; | |
812 | s->refcount_bits = 1 << s->refcount_order; | |
813 | s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1); | |
814 | s->refcount_max += s->refcount_max - 1; | |
815 | ||
816 | if (header.crypt_method > QCOW_CRYPT_AES) { | |
817 | error_setg(errp, "Unsupported encryption method: %" PRIu32, | |
818 | header.crypt_method); | |
819 | ret = -EINVAL; | |
820 | goto fail; | |
821 | } | |
822 | if (!qcrypto_cipher_supports(QCRYPTO_CIPHER_ALG_AES_128)) { | |
823 | error_setg(errp, "AES cipher not available"); | |
824 | ret = -EINVAL; | |
825 | goto fail; | |
826 | } | |
827 | s->crypt_method_header = header.crypt_method; | |
828 | if (s->crypt_method_header) { | |
829 | bs->encrypted = 1; | |
830 | } | |
831 | ||
832 | s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ | |
833 | s->l2_size = 1 << s->l2_bits; | |
834 | /* 2^(s->refcount_order - 3) is the refcount width in bytes */ | |
835 | s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3); | |
836 | s->refcount_block_size = 1 << s->refcount_block_bits; | |
837 | bs->total_sectors = header.size / 512; | |
838 | s->csize_shift = (62 - (s->cluster_bits - 8)); | |
839 | s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; | |
840 | s->cluster_offset_mask = (1LL << s->csize_shift) - 1; | |
841 | ||
842 | s->refcount_table_offset = header.refcount_table_offset; | |
843 | s->refcount_table_size = | |
844 | header.refcount_table_clusters << (s->cluster_bits - 3); | |
845 | ||
846 | if (header.refcount_table_clusters > qcow2_max_refcount_clusters(s)) { | |
847 | error_setg(errp, "Reference count table too large"); | |
848 | ret = -EINVAL; | |
849 | goto fail; | |
850 | } | |
851 | ||
852 | ret = validate_table_offset(bs, s->refcount_table_offset, | |
853 | s->refcount_table_size, sizeof(uint64_t)); | |
854 | if (ret < 0) { | |
855 | error_setg(errp, "Invalid reference count table offset"); | |
856 | goto fail; | |
857 | } | |
858 | ||
859 | /* Snapshot table offset/length */ | |
860 | if (header.nb_snapshots > QCOW_MAX_SNAPSHOTS) { | |
861 | error_setg(errp, "Too many snapshots"); | |
862 | ret = -EINVAL; | |
863 | goto fail; | |
864 | } | |
865 | ||
866 | ret = validate_table_offset(bs, header.snapshots_offset, | |
867 | header.nb_snapshots, | |
868 | sizeof(QCowSnapshotHeader)); | |
869 | if (ret < 0) { | |
870 | error_setg(errp, "Invalid snapshot table offset"); | |
871 | goto fail; | |
872 | } | |
873 | ||
874 | /* read the level 1 table */ | |
875 | if (header.l1_size > QCOW_MAX_L1_SIZE / sizeof(uint64_t)) { | |
876 | error_setg(errp, "Active L1 table too large"); | |
877 | ret = -EFBIG; | |
878 | goto fail; | |
879 | } | |
880 | s->l1_size = header.l1_size; | |
881 | ||
882 | l1_vm_state_index = size_to_l1(s, header.size); | |
883 | if (l1_vm_state_index > INT_MAX) { | |
884 | error_setg(errp, "Image is too big"); | |
885 | ret = -EFBIG; | |
886 | goto fail; | |
887 | } | |
888 | s->l1_vm_state_index = l1_vm_state_index; | |
889 | ||
890 | /* the L1 table must contain at least enough entries to put | |
891 | header.size bytes */ | |
892 | if (s->l1_size < s->l1_vm_state_index) { | |
893 | error_setg(errp, "L1 table is too small"); | |
894 | ret = -EINVAL; | |
895 | goto fail; | |
896 | } | |
897 | ||
898 | ret = validate_table_offset(bs, header.l1_table_offset, | |
899 | header.l1_size, sizeof(uint64_t)); | |
900 | if (ret < 0) { | |
901 | error_setg(errp, "Invalid L1 table offset"); | |
902 | goto fail; | |
903 | } | |
904 | s->l1_table_offset = header.l1_table_offset; | |
905 | ||
906 | ||
907 | if (s->l1_size > 0) { | |
908 | s->l1_table = qemu_try_blockalign(bs->file, | |
909 | align_offset(s->l1_size * sizeof(uint64_t), 512)); | |
910 | if (s->l1_table == NULL) { | |
911 | error_setg(errp, "Could not allocate L1 table"); | |
912 | ret = -ENOMEM; | |
913 | goto fail; | |
914 | } | |
915 | ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, | |
916 | s->l1_size * sizeof(uint64_t)); | |
917 | if (ret < 0) { | |
918 | error_setg_errno(errp, -ret, "Could not read L1 table"); | |
919 | goto fail; | |
920 | } | |
921 | for(i = 0;i < s->l1_size; i++) { | |
922 | be64_to_cpus(&s->l1_table[i]); | |
923 | } | |
924 | } | |
925 | ||
926 | /* get L2 table/refcount block cache size from command line options */ | |
927 | opts = qemu_opts_create(&qcow2_runtime_opts, NULL, 0, &error_abort); | |
928 | qemu_opts_absorb_qdict(opts, options, &local_err); | |
929 | if (local_err) { | |
930 | error_propagate(errp, local_err); | |
931 | ret = -EINVAL; | |
932 | goto fail; | |
933 | } | |
934 | ||
935 | read_cache_sizes(bs, opts, &l2_cache_size, &refcount_cache_size, | |
936 | &local_err); | |
937 | if (local_err) { | |
938 | error_propagate(errp, local_err); | |
939 | ret = -EINVAL; | |
940 | goto fail; | |
941 | } | |
942 | ||
943 | l2_cache_size /= s->cluster_size; | |
944 | if (l2_cache_size < MIN_L2_CACHE_SIZE) { | |
945 | l2_cache_size = MIN_L2_CACHE_SIZE; | |
946 | } | |
947 | if (l2_cache_size > INT_MAX) { | |
948 | error_setg(errp, "L2 cache size too big"); | |
949 | ret = -EINVAL; | |
950 | goto fail; | |
951 | } | |
952 | ||
953 | refcount_cache_size /= s->cluster_size; | |
954 | if (refcount_cache_size < MIN_REFCOUNT_CACHE_SIZE) { | |
955 | refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE; | |
956 | } | |
957 | if (refcount_cache_size > INT_MAX) { | |
958 | error_setg(errp, "Refcount cache size too big"); | |
959 | ret = -EINVAL; | |
960 | goto fail; | |
961 | } | |
962 | ||
963 | /* alloc L2 table/refcount block cache */ | |
964 | s->l2_table_cache = qcow2_cache_create(bs, l2_cache_size); | |
965 | s->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size); | |
966 | if (s->l2_table_cache == NULL || s->refcount_block_cache == NULL) { | |
967 | error_setg(errp, "Could not allocate metadata caches"); | |
968 | ret = -ENOMEM; | |
969 | goto fail; | |
970 | } | |
971 | ||
972 | cache_clean_interval = | |
973 | qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL, 0); | |
974 | if (cache_clean_interval > UINT_MAX) { | |
975 | error_setg(errp, "Cache clean interval too big"); | |
976 | ret = -EINVAL; | |
977 | goto fail; | |
978 | } | |
979 | s->cache_clean_interval = cache_clean_interval; | |
980 | cache_clean_timer_init(bs, bdrv_get_aio_context(bs)); | |
981 | ||
982 | /* Enable lazy_refcounts according to image and command line options */ | |
983 | ret = qcow2_update_options(bs, opts, flags, errp); | |
984 | if (ret < 0) { | |
985 | goto fail; | |
986 | } | |
987 | ||
988 | qemu_opts_del(opts); | |
989 | opts = NULL; | |
990 | ||
991 | s->cluster_cache = g_malloc(s->cluster_size); | |
992 | /* one more sector for decompressed data alignment */ | |
993 | s->cluster_data = qemu_try_blockalign(bs->file, QCOW_MAX_CRYPT_CLUSTERS | |
994 | * s->cluster_size + 512); | |
995 | if (s->cluster_data == NULL) { | |
996 | error_setg(errp, "Could not allocate temporary cluster buffer"); | |
997 | ret = -ENOMEM; | |
998 | goto fail; | |
999 | } | |
1000 | ||
1001 | s->cluster_cache_offset = -1; | |
1002 | s->flags = flags; | |
1003 | ||
1004 | ret = qcow2_refcount_init(bs); | |
1005 | if (ret != 0) { | |
1006 | error_setg_errno(errp, -ret, "Could not initialize refcount handling"); | |
1007 | goto fail; | |
1008 | } | |
1009 | ||
1010 | QLIST_INIT(&s->cluster_allocs); | |
1011 | QTAILQ_INIT(&s->discards); | |
1012 | ||
1013 | /* read qcow2 extensions */ | |
1014 | if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL, | |
1015 | &local_err)) { | |
1016 | error_propagate(errp, local_err); | |
1017 | ret = -EINVAL; | |
1018 | goto fail; | |
1019 | } | |
1020 | ||
1021 | /* read the backing file name */ | |
1022 | if (header.backing_file_offset != 0) { | |
1023 | len = header.backing_file_size; | |
1024 | if (len > MIN(1023, s->cluster_size - header.backing_file_offset) || | |
1025 | len >= sizeof(bs->backing_file)) { | |
1026 | error_setg(errp, "Backing file name too long"); | |
1027 | ret = -EINVAL; | |
1028 | goto fail; | |
1029 | } | |
1030 | ret = bdrv_pread(bs->file, header.backing_file_offset, | |
1031 | bs->backing_file, len); | |
1032 | if (ret < 0) { | |
1033 | error_setg_errno(errp, -ret, "Could not read backing file name"); | |
1034 | goto fail; | |
1035 | } | |
1036 | bs->backing_file[len] = '\0'; | |
1037 | s->image_backing_file = g_strdup(bs->backing_file); | |
1038 | } | |
1039 | ||
1040 | /* Internal snapshots */ | |
1041 | s->snapshots_offset = header.snapshots_offset; | |
1042 | s->nb_snapshots = header.nb_snapshots; | |
1043 | ||
1044 | ret = qcow2_read_snapshots(bs); | |
1045 | if (ret < 0) { | |
1046 | error_setg_errno(errp, -ret, "Could not read snapshots"); | |
1047 | goto fail; | |
1048 | } | |
1049 | ||
1050 | /* Clear unknown autoclear feature bits */ | |
1051 | if (!bs->read_only && !(flags & BDRV_O_INCOMING) && s->autoclear_features) { | |
1052 | s->autoclear_features = 0; | |
1053 | ret = qcow2_update_header(bs); | |
1054 | if (ret < 0) { | |
1055 | error_setg_errno(errp, -ret, "Could not update qcow2 header"); | |
1056 | goto fail; | |
1057 | } | |
1058 | } | |
1059 | ||
1060 | /* Initialise locks */ | |
1061 | qemu_co_mutex_init(&s->lock); | |
1062 | ||
1063 | /* Repair image if dirty */ | |
1064 | if (!(flags & (BDRV_O_CHECK | BDRV_O_INCOMING)) && !bs->read_only && | |
1065 | (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { | |
1066 | BdrvCheckResult result = {0}; | |
1067 | ||
1068 | ret = qcow2_check(bs, &result, BDRV_FIX_ERRORS | BDRV_FIX_LEAKS); | |
1069 | if (ret < 0) { | |
1070 | error_setg_errno(errp, -ret, "Could not repair dirty image"); | |
1071 | goto fail; | |
1072 | } | |
1073 | } | |
1074 | ||
1075 | #ifdef DEBUG_ALLOC | |
1076 | { | |
1077 | BdrvCheckResult result = {0}; | |
1078 | qcow2_check_refcounts(bs, &result, 0); | |
1079 | } | |
1080 | #endif | |
1081 | return ret; | |
1082 | ||
1083 | fail: | |
1084 | qemu_opts_del(opts); | |
1085 | g_free(s->unknown_header_fields); | |
1086 | cleanup_unknown_header_ext(bs); | |
1087 | qcow2_free_snapshots(bs); | |
1088 | qcow2_refcount_close(bs); | |
1089 | qemu_vfree(s->l1_table); | |
1090 | /* else pre-write overlap checks in cache_destroy may crash */ | |
1091 | s->l1_table = NULL; | |
1092 | cache_clean_timer_del(bs); | |
1093 | if (s->l2_table_cache) { | |
1094 | qcow2_cache_destroy(bs, s->l2_table_cache); | |
1095 | } | |
1096 | if (s->refcount_block_cache) { | |
1097 | qcow2_cache_destroy(bs, s->refcount_block_cache); | |
1098 | } | |
1099 | g_free(s->cluster_cache); | |
1100 | qemu_vfree(s->cluster_data); | |
1101 | return ret; | |
1102 | } | |
1103 | ||
1104 | static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) | |
1105 | { | |
1106 | BDRVQcow2State *s = bs->opaque; | |
1107 | ||
1108 | bs->bl.write_zeroes_alignment = s->cluster_sectors; | |
1109 | } | |
1110 | ||
1111 | static int qcow2_set_key(BlockDriverState *bs, const char *key) | |
1112 | { | |
1113 | BDRVQcow2State *s = bs->opaque; | |
1114 | uint8_t keybuf[16]; | |
1115 | int len, i; | |
1116 | Error *err = NULL; | |
1117 | ||
1118 | memset(keybuf, 0, 16); | |
1119 | len = strlen(key); | |
1120 | if (len > 16) | |
1121 | len = 16; | |
1122 | /* XXX: we could compress the chars to 7 bits to increase | |
1123 | entropy */ | |
1124 | for(i = 0;i < len;i++) { | |
1125 | keybuf[i] = key[i]; | |
1126 | } | |
1127 | assert(bs->encrypted); | |
1128 | ||
1129 | qcrypto_cipher_free(s->cipher); | |
1130 | s->cipher = qcrypto_cipher_new( | |
1131 | QCRYPTO_CIPHER_ALG_AES_128, | |
1132 | QCRYPTO_CIPHER_MODE_CBC, | |
1133 | keybuf, G_N_ELEMENTS(keybuf), | |
1134 | &err); | |
1135 | ||
1136 | if (!s->cipher) { | |
1137 | /* XXX would be nice if errors in this method could | |
1138 | * be properly propagate to the caller. Would need | |
1139 | * the bdrv_set_key() API signature to be fixed. */ | |
1140 | error_free(err); | |
1141 | return -1; | |
1142 | } | |
1143 | return 0; | |
1144 | } | |
1145 | ||
1146 | /* We have no actual commit/abort logic for qcow2, but we need to write out any | |
1147 | * unwritten data if we reopen read-only. */ | |
1148 | static int qcow2_reopen_prepare(BDRVReopenState *state, | |
1149 | BlockReopenQueue *queue, Error **errp) | |
1150 | { | |
1151 | int ret; | |
1152 | ||
1153 | if ((state->flags & BDRV_O_RDWR) == 0) { | |
1154 | ret = bdrv_flush(state->bs); | |
1155 | if (ret < 0) { | |
1156 | return ret; | |
1157 | } | |
1158 | ||
1159 | ret = qcow2_mark_clean(state->bs); | |
1160 | if (ret < 0) { | |
1161 | return ret; | |
1162 | } | |
1163 | } | |
1164 | ||
1165 | return 0; | |
1166 | } | |
1167 | ||
1168 | static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs, | |
1169 | int64_t sector_num, int nb_sectors, int *pnum) | |
1170 | { | |
1171 | BDRVQcow2State *s = bs->opaque; | |
1172 | uint64_t cluster_offset; | |
1173 | int index_in_cluster, ret; | |
1174 | int64_t status = 0; | |
1175 | ||
1176 | *pnum = nb_sectors; | |
1177 | qemu_co_mutex_lock(&s->lock); | |
1178 | ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset); | |
1179 | qemu_co_mutex_unlock(&s->lock); | |
1180 | if (ret < 0) { | |
1181 | return ret; | |
1182 | } | |
1183 | ||
1184 | if (cluster_offset != 0 && ret != QCOW2_CLUSTER_COMPRESSED && | |
1185 | !s->cipher) { | |
1186 | index_in_cluster = sector_num & (s->cluster_sectors - 1); | |
1187 | cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS); | |
1188 | status |= BDRV_BLOCK_OFFSET_VALID | cluster_offset; | |
1189 | } | |
1190 | if (ret == QCOW2_CLUSTER_ZERO) { | |
1191 | status |= BDRV_BLOCK_ZERO; | |
1192 | } else if (ret != QCOW2_CLUSTER_UNALLOCATED) { | |
1193 | status |= BDRV_BLOCK_DATA; | |
1194 | } | |
1195 | return status; | |
1196 | } | |
1197 | ||
1198 | /* handle reading after the end of the backing file */ | |
1199 | int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov, | |
1200 | int64_t sector_num, int nb_sectors) | |
1201 | { | |
1202 | int n1; | |
1203 | if ((sector_num + nb_sectors) <= bs->total_sectors) | |
1204 | return nb_sectors; | |
1205 | if (sector_num >= bs->total_sectors) | |
1206 | n1 = 0; | |
1207 | else | |
1208 | n1 = bs->total_sectors - sector_num; | |
1209 | ||
1210 | qemu_iovec_memset(qiov, 512 * n1, 0, 512 * (nb_sectors - n1)); | |
1211 | ||
1212 | return n1; | |
1213 | } | |
1214 | ||
1215 | static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, | |
1216 | int remaining_sectors, QEMUIOVector *qiov) | |
1217 | { | |
1218 | BDRVQcow2State *s = bs->opaque; | |
1219 | int index_in_cluster, n1; | |
1220 | int ret; | |
1221 | int cur_nr_sectors; /* number of sectors in current iteration */ | |
1222 | uint64_t cluster_offset = 0; | |
1223 | uint64_t bytes_done = 0; | |
1224 | QEMUIOVector hd_qiov; | |
1225 | uint8_t *cluster_data = NULL; | |
1226 | ||
1227 | qemu_iovec_init(&hd_qiov, qiov->niov); | |
1228 | ||
1229 | qemu_co_mutex_lock(&s->lock); | |
1230 | ||
1231 | while (remaining_sectors != 0) { | |
1232 | ||
1233 | /* prepare next request */ | |
1234 | cur_nr_sectors = remaining_sectors; | |
1235 | if (s->cipher) { | |
1236 | cur_nr_sectors = MIN(cur_nr_sectors, | |
1237 | QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); | |
1238 | } | |
1239 | ||
1240 | ret = qcow2_get_cluster_offset(bs, sector_num << 9, | |
1241 | &cur_nr_sectors, &cluster_offset); | |
1242 | if (ret < 0) { | |
1243 | goto fail; | |
1244 | } | |
1245 | ||
1246 | index_in_cluster = sector_num & (s->cluster_sectors - 1); | |
1247 | ||
1248 | qemu_iovec_reset(&hd_qiov); | |
1249 | qemu_iovec_concat(&hd_qiov, qiov, bytes_done, | |
1250 | cur_nr_sectors * 512); | |
1251 | ||
1252 | switch (ret) { | |
1253 | case QCOW2_CLUSTER_UNALLOCATED: | |
1254 | ||
1255 | if (bs->backing_hd) { | |
1256 | /* read from the base image */ | |
1257 | n1 = qcow2_backing_read1(bs->backing_hd, &hd_qiov, | |
1258 | sector_num, cur_nr_sectors); | |
1259 | if (n1 > 0) { | |
1260 | QEMUIOVector local_qiov; | |
1261 | ||
1262 | qemu_iovec_init(&local_qiov, hd_qiov.niov); | |
1263 | qemu_iovec_concat(&local_qiov, &hd_qiov, 0, | |
1264 | n1 * BDRV_SECTOR_SIZE); | |
1265 | ||
1266 | BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); | |
1267 | qemu_co_mutex_unlock(&s->lock); | |
1268 | ret = bdrv_co_readv(bs->backing_hd, sector_num, | |
1269 | n1, &local_qiov); | |
1270 | qemu_co_mutex_lock(&s->lock); | |
1271 | ||
1272 | qemu_iovec_destroy(&local_qiov); | |
1273 | ||
1274 | if (ret < 0) { | |
1275 | goto fail; | |
1276 | } | |
1277 | } | |
1278 | } else { | |
1279 | /* Note: in this case, no need to wait */ | |
1280 | qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors); | |
1281 | } | |
1282 | break; | |
1283 | ||
1284 | case QCOW2_CLUSTER_ZERO: | |
1285 | qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors); | |
1286 | break; | |
1287 | ||
1288 | case QCOW2_CLUSTER_COMPRESSED: | |
1289 | /* add AIO support for compressed blocks ? */ | |
1290 | ret = qcow2_decompress_cluster(bs, cluster_offset); | |
1291 | if (ret < 0) { | |
1292 | goto fail; | |
1293 | } | |
1294 | ||
1295 | qemu_iovec_from_buf(&hd_qiov, 0, | |
1296 | s->cluster_cache + index_in_cluster * 512, | |
1297 | 512 * cur_nr_sectors); | |
1298 | break; | |
1299 | ||
1300 | case QCOW2_CLUSTER_NORMAL: | |
1301 | if ((cluster_offset & 511) != 0) { | |
1302 | ret = -EIO; | |
1303 | goto fail; | |
1304 | } | |
1305 | ||
1306 | if (bs->encrypted) { | |
1307 | assert(s->cipher); | |
1308 | ||
1309 | /* | |
1310 | * For encrypted images, read everything into a temporary | |
1311 | * contiguous buffer on which the AES functions can work. | |
1312 | */ | |
1313 | if (!cluster_data) { | |
1314 | cluster_data = | |
1315 | qemu_try_blockalign(bs->file, QCOW_MAX_CRYPT_CLUSTERS | |
1316 | * s->cluster_size); | |
1317 | if (cluster_data == NULL) { | |
1318 | ret = -ENOMEM; | |
1319 | goto fail; | |
1320 | } | |
1321 | } | |
1322 | ||
1323 | assert(cur_nr_sectors <= | |
1324 | QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); | |
1325 | qemu_iovec_reset(&hd_qiov); | |
1326 | qemu_iovec_add(&hd_qiov, cluster_data, | |
1327 | 512 * cur_nr_sectors); | |
1328 | } | |
1329 | ||
1330 | BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); | |
1331 | qemu_co_mutex_unlock(&s->lock); | |
1332 | ret = bdrv_co_readv(bs->file, | |
1333 | (cluster_offset >> 9) + index_in_cluster, | |
1334 | cur_nr_sectors, &hd_qiov); | |
1335 | qemu_co_mutex_lock(&s->lock); | |
1336 | if (ret < 0) { | |
1337 | goto fail; | |
1338 | } | |
1339 | if (bs->encrypted) { | |
1340 | assert(s->cipher); | |
1341 | Error *err = NULL; | |
1342 | if (qcow2_encrypt_sectors(s, sector_num, cluster_data, | |
1343 | cluster_data, cur_nr_sectors, false, | |
1344 | &err) < 0) { | |
1345 | error_free(err); | |
1346 | ret = -EIO; | |
1347 | goto fail; | |
1348 | } | |
1349 | qemu_iovec_from_buf(qiov, bytes_done, | |
1350 | cluster_data, 512 * cur_nr_sectors); | |
1351 | } | |
1352 | break; | |
1353 | ||
1354 | default: | |
1355 | g_assert_not_reached(); | |
1356 | ret = -EIO; | |
1357 | goto fail; | |
1358 | } | |
1359 | ||
1360 | remaining_sectors -= cur_nr_sectors; | |
1361 | sector_num += cur_nr_sectors; | |
1362 | bytes_done += cur_nr_sectors * 512; | |
1363 | } | |
1364 | ret = 0; | |
1365 | ||
1366 | fail: | |
1367 | qemu_co_mutex_unlock(&s->lock); | |
1368 | ||
1369 | qemu_iovec_destroy(&hd_qiov); | |
1370 | qemu_vfree(cluster_data); | |
1371 | ||
1372 | return ret; | |
1373 | } | |
1374 | ||
1375 | static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, | |
1376 | int64_t sector_num, | |
1377 | int remaining_sectors, | |
1378 | QEMUIOVector *qiov) | |
1379 | { | |
1380 | BDRVQcow2State *s = bs->opaque; | |
1381 | int index_in_cluster; | |
1382 | int ret; | |
1383 | int cur_nr_sectors; /* number of sectors in current iteration */ | |
1384 | uint64_t cluster_offset; | |
1385 | QEMUIOVector hd_qiov; | |
1386 | uint64_t bytes_done = 0; | |
1387 | uint8_t *cluster_data = NULL; | |
1388 | QCowL2Meta *l2meta = NULL; | |
1389 | ||
1390 | trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num, | |
1391 | remaining_sectors); | |
1392 | ||
1393 | qemu_iovec_init(&hd_qiov, qiov->niov); | |
1394 | ||
1395 | s->cluster_cache_offset = -1; /* disable compressed cache */ | |
1396 | ||
1397 | qemu_co_mutex_lock(&s->lock); | |
1398 | ||
1399 | while (remaining_sectors != 0) { | |
1400 | ||
1401 | l2meta = NULL; | |
1402 | ||
1403 | trace_qcow2_writev_start_part(qemu_coroutine_self()); | |
1404 | index_in_cluster = sector_num & (s->cluster_sectors - 1); | |
1405 | cur_nr_sectors = remaining_sectors; | |
1406 | if (bs->encrypted && | |
1407 | cur_nr_sectors > | |
1408 | QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster) { | |
1409 | cur_nr_sectors = | |
1410 | QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster; | |
1411 | } | |
1412 | ||
1413 | ret = qcow2_alloc_cluster_offset(bs, sector_num << 9, | |
1414 | &cur_nr_sectors, &cluster_offset, &l2meta); | |
1415 | if (ret < 0) { | |
1416 | goto fail; | |
1417 | } | |
1418 | ||
1419 | assert((cluster_offset & 511) == 0); | |
1420 | ||
1421 | qemu_iovec_reset(&hd_qiov); | |
1422 | qemu_iovec_concat(&hd_qiov, qiov, bytes_done, | |
1423 | cur_nr_sectors * 512); | |
1424 | ||
1425 | if (bs->encrypted) { | |
1426 | Error *err = NULL; | |
1427 | assert(s->cipher); | |
1428 | if (!cluster_data) { | |
1429 | cluster_data = qemu_try_blockalign(bs->file, | |
1430 | QCOW_MAX_CRYPT_CLUSTERS | |
1431 | * s->cluster_size); | |
1432 | if (cluster_data == NULL) { | |
1433 | ret = -ENOMEM; | |
1434 | goto fail; | |
1435 | } | |
1436 | } | |
1437 | ||
1438 | assert(hd_qiov.size <= | |
1439 | QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); | |
1440 | qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size); | |
1441 | ||
1442 | if (qcow2_encrypt_sectors(s, sector_num, cluster_data, | |
1443 | cluster_data, cur_nr_sectors, | |
1444 | true, &err) < 0) { | |
1445 | error_free(err); | |
1446 | ret = -EIO; | |
1447 | goto fail; | |
1448 | } | |
1449 | ||
1450 | qemu_iovec_reset(&hd_qiov); | |
1451 | qemu_iovec_add(&hd_qiov, cluster_data, | |
1452 | cur_nr_sectors * 512); | |
1453 | } | |
1454 | ||
1455 | ret = qcow2_pre_write_overlap_check(bs, 0, | |
1456 | cluster_offset + index_in_cluster * BDRV_SECTOR_SIZE, | |
1457 | cur_nr_sectors * BDRV_SECTOR_SIZE); | |
1458 | if (ret < 0) { | |
1459 | goto fail; | |
1460 | } | |
1461 | ||
1462 | qemu_co_mutex_unlock(&s->lock); | |
1463 | BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); | |
1464 | trace_qcow2_writev_data(qemu_coroutine_self(), | |
1465 | (cluster_offset >> 9) + index_in_cluster); | |
1466 | ret = bdrv_co_writev(bs->file, | |
1467 | (cluster_offset >> 9) + index_in_cluster, | |
1468 | cur_nr_sectors, &hd_qiov); | |
1469 | qemu_co_mutex_lock(&s->lock); | |
1470 | if (ret < 0) { | |
1471 | goto fail; | |
1472 | } | |
1473 | ||
1474 | while (l2meta != NULL) { | |
1475 | QCowL2Meta *next; | |
1476 | ||
1477 | ret = qcow2_alloc_cluster_link_l2(bs, l2meta); | |
1478 | if (ret < 0) { | |
1479 | goto fail; | |
1480 | } | |
1481 | ||
1482 | /* Take the request off the list of running requests */ | |
1483 | if (l2meta->nb_clusters != 0) { | |
1484 | QLIST_REMOVE(l2meta, next_in_flight); | |
1485 | } | |
1486 | ||
1487 | qemu_co_queue_restart_all(&l2meta->dependent_requests); | |
1488 | ||
1489 | next = l2meta->next; | |
1490 | g_free(l2meta); | |
1491 | l2meta = next; | |
1492 | } | |
1493 | ||
1494 | remaining_sectors -= cur_nr_sectors; | |
1495 | sector_num += cur_nr_sectors; | |
1496 | bytes_done += cur_nr_sectors * 512; | |
1497 | trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_nr_sectors); | |
1498 | } | |
1499 | ret = 0; | |
1500 | ||
1501 | fail: | |
1502 | qemu_co_mutex_unlock(&s->lock); | |
1503 | ||
1504 | while (l2meta != NULL) { | |
1505 | QCowL2Meta *next; | |
1506 | ||
1507 | if (l2meta->nb_clusters != 0) { | |
1508 | QLIST_REMOVE(l2meta, next_in_flight); | |
1509 | } | |
1510 | qemu_co_queue_restart_all(&l2meta->dependent_requests); | |
1511 | ||
1512 | next = l2meta->next; | |
1513 | g_free(l2meta); | |
1514 | l2meta = next; | |
1515 | } | |
1516 | ||
1517 | qemu_iovec_destroy(&hd_qiov); | |
1518 | qemu_vfree(cluster_data); | |
1519 | trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); | |
1520 | ||
1521 | return ret; | |
1522 | } | |
1523 | ||
1524 | static void qcow2_close(BlockDriverState *bs) | |
1525 | { | |
1526 | BDRVQcow2State *s = bs->opaque; | |
1527 | qemu_vfree(s->l1_table); | |
1528 | /* else pre-write overlap checks in cache_destroy may crash */ | |
1529 | s->l1_table = NULL; | |
1530 | ||
1531 | if (!(bs->open_flags & BDRV_O_INCOMING)) { | |
1532 | int ret1, ret2; | |
1533 | ||
1534 | ret1 = qcow2_cache_flush(bs, s->l2_table_cache); | |
1535 | ret2 = qcow2_cache_flush(bs, s->refcount_block_cache); | |
1536 | ||
1537 | if (ret1) { | |
1538 | error_report("Failed to flush the L2 table cache: %s", | |
1539 | strerror(-ret1)); | |
1540 | } | |
1541 | if (ret2) { | |
1542 | error_report("Failed to flush the refcount block cache: %s", | |
1543 | strerror(-ret2)); | |
1544 | } | |
1545 | ||
1546 | if (!ret1 && !ret2) { | |
1547 | qcow2_mark_clean(bs); | |
1548 | } | |
1549 | } | |
1550 | ||
1551 | cache_clean_timer_del(bs); | |
1552 | qcow2_cache_destroy(bs, s->l2_table_cache); | |
1553 | qcow2_cache_destroy(bs, s->refcount_block_cache); | |
1554 | ||
1555 | qcrypto_cipher_free(s->cipher); | |
1556 | s->cipher = NULL; | |
1557 | ||
1558 | g_free(s->unknown_header_fields); | |
1559 | cleanup_unknown_header_ext(bs); | |
1560 | ||
1561 | g_free(s->image_backing_file); | |
1562 | g_free(s->image_backing_format); | |
1563 | ||
1564 | g_free(s->cluster_cache); | |
1565 | qemu_vfree(s->cluster_data); | |
1566 | qcow2_refcount_close(bs); | |
1567 | qcow2_free_snapshots(bs); | |
1568 | } | |
1569 | ||
1570 | static void qcow2_invalidate_cache(BlockDriverState *bs, Error **errp) | |
1571 | { | |
1572 | BDRVQcow2State *s = bs->opaque; | |
1573 | int flags = s->flags; | |
1574 | QCryptoCipher *cipher = NULL; | |
1575 | QDict *options; | |
1576 | Error *local_err = NULL; | |
1577 | int ret; | |
1578 | ||
1579 | /* | |
1580 | * Backing files are read-only which makes all of their metadata immutable, | |
1581 | * that means we don't have to worry about reopening them here. | |
1582 | */ | |
1583 | ||
1584 | cipher = s->cipher; | |
1585 | s->cipher = NULL; | |
1586 | ||
1587 | qcow2_close(bs); | |
1588 | ||
1589 | bdrv_invalidate_cache(bs->file, &local_err); | |
1590 | if (local_err) { | |
1591 | error_propagate(errp, local_err); | |
1592 | return; | |
1593 | } | |
1594 | ||
1595 | memset(s, 0, sizeof(BDRVQcow2State)); | |
1596 | options = qdict_clone_shallow(bs->options); | |
1597 | ||
1598 | ret = qcow2_open(bs, options, flags, &local_err); | |
1599 | QDECREF(options); | |
1600 | if (local_err) { | |
1601 | error_setg(errp, "Could not reopen qcow2 layer: %s", | |
1602 | error_get_pretty(local_err)); | |
1603 | error_free(local_err); | |
1604 | return; | |
1605 | } else if (ret < 0) { | |
1606 | error_setg_errno(errp, -ret, "Could not reopen qcow2 layer"); | |
1607 | return; | |
1608 | } | |
1609 | ||
1610 | s->cipher = cipher; | |
1611 | } | |
1612 | ||
1613 | static size_t header_ext_add(char *buf, uint32_t magic, const void *s, | |
1614 | size_t len, size_t buflen) | |
1615 | { | |
1616 | QCowExtension *ext_backing_fmt = (QCowExtension*) buf; | |
1617 | size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7); | |
1618 | ||
1619 | if (buflen < ext_len) { | |
1620 | return -ENOSPC; | |
1621 | } | |
1622 | ||
1623 | *ext_backing_fmt = (QCowExtension) { | |
1624 | .magic = cpu_to_be32(magic), | |
1625 | .len = cpu_to_be32(len), | |
1626 | }; | |
1627 | memcpy(buf + sizeof(QCowExtension), s, len); | |
1628 | ||
1629 | return ext_len; | |
1630 | } | |
1631 | ||
1632 | /* | |
1633 | * Updates the qcow2 header, including the variable length parts of it, i.e. | |
1634 | * the backing file name and all extensions. qcow2 was not designed to allow | |
1635 | * such changes, so if we run out of space (we can only use the first cluster) | |
1636 | * this function may fail. | |
1637 | * | |
1638 | * Returns 0 on success, -errno in error cases. | |
1639 | */ | |
1640 | int qcow2_update_header(BlockDriverState *bs) | |
1641 | { | |
1642 | BDRVQcow2State *s = bs->opaque; | |
1643 | QCowHeader *header; | |
1644 | char *buf; | |
1645 | size_t buflen = s->cluster_size; | |
1646 | int ret; | |
1647 | uint64_t total_size; | |
1648 | uint32_t refcount_table_clusters; | |
1649 | size_t header_length; | |
1650 | Qcow2UnknownHeaderExtension *uext; | |
1651 | ||
1652 | buf = qemu_blockalign(bs, buflen); | |
1653 | ||
1654 | /* Header structure */ | |
1655 | header = (QCowHeader*) buf; | |
1656 | ||
1657 | if (buflen < sizeof(*header)) { | |
1658 | ret = -ENOSPC; | |
1659 | goto fail; | |
1660 | } | |
1661 | ||
1662 | header_length = sizeof(*header) + s->unknown_header_fields_size; | |
1663 | total_size = bs->total_sectors * BDRV_SECTOR_SIZE; | |
1664 | refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); | |
1665 | ||
1666 | *header = (QCowHeader) { | |
1667 | /* Version 2 fields */ | |
1668 | .magic = cpu_to_be32(QCOW_MAGIC), | |
1669 | .version = cpu_to_be32(s->qcow_version), | |
1670 | .backing_file_offset = 0, | |
1671 | .backing_file_size = 0, | |
1672 | .cluster_bits = cpu_to_be32(s->cluster_bits), | |
1673 | .size = cpu_to_be64(total_size), | |
1674 | .crypt_method = cpu_to_be32(s->crypt_method_header), | |
1675 | .l1_size = cpu_to_be32(s->l1_size), | |
1676 | .l1_table_offset = cpu_to_be64(s->l1_table_offset), | |
1677 | .refcount_table_offset = cpu_to_be64(s->refcount_table_offset), | |
1678 | .refcount_table_clusters = cpu_to_be32(refcount_table_clusters), | |
1679 | .nb_snapshots = cpu_to_be32(s->nb_snapshots), | |
1680 | .snapshots_offset = cpu_to_be64(s->snapshots_offset), | |
1681 | ||
1682 | /* Version 3 fields */ | |
1683 | .incompatible_features = cpu_to_be64(s->incompatible_features), | |
1684 | .compatible_features = cpu_to_be64(s->compatible_features), | |
1685 | .autoclear_features = cpu_to_be64(s->autoclear_features), | |
1686 | .refcount_order = cpu_to_be32(s->refcount_order), | |
1687 | .header_length = cpu_to_be32(header_length), | |
1688 | }; | |
1689 | ||
1690 | /* For older versions, write a shorter header */ | |
1691 | switch (s->qcow_version) { | |
1692 | case 2: | |
1693 | ret = offsetof(QCowHeader, incompatible_features); | |
1694 | break; | |
1695 | case 3: | |
1696 | ret = sizeof(*header); | |
1697 | break; | |
1698 | default: | |
1699 | ret = -EINVAL; | |
1700 | goto fail; | |
1701 | } | |
1702 | ||
1703 | buf += ret; | |
1704 | buflen -= ret; | |
1705 | memset(buf, 0, buflen); | |
1706 | ||
1707 | /* Preserve any unknown field in the header */ | |
1708 | if (s->unknown_header_fields_size) { | |
1709 | if (buflen < s->unknown_header_fields_size) { | |
1710 | ret = -ENOSPC; | |
1711 | goto fail; | |
1712 | } | |
1713 | ||
1714 | memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); | |
1715 | buf += s->unknown_header_fields_size; | |
1716 | buflen -= s->unknown_header_fields_size; | |
1717 | } | |
1718 | ||
1719 | /* Backing file format header extension */ | |
1720 | if (s->image_backing_format) { | |
1721 | ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, | |
1722 | s->image_backing_format, | |
1723 | strlen(s->image_backing_format), | |
1724 | buflen); | |
1725 | if (ret < 0) { | |
1726 | goto fail; | |
1727 | } | |
1728 | ||
1729 | buf += ret; | |
1730 | buflen -= ret; | |
1731 | } | |
1732 | ||
1733 | /* Feature table */ | |
1734 | Qcow2Feature features[] = { | |
1735 | { | |
1736 | .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, | |
1737 | .bit = QCOW2_INCOMPAT_DIRTY_BITNR, | |
1738 | .name = "dirty bit", | |
1739 | }, | |
1740 | { | |
1741 | .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, | |
1742 | .bit = QCOW2_INCOMPAT_CORRUPT_BITNR, | |
1743 | .name = "corrupt bit", | |
1744 | }, | |
1745 | { | |
1746 | .type = QCOW2_FEAT_TYPE_COMPATIBLE, | |
1747 | .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, | |
1748 | .name = "lazy refcounts", | |
1749 | }, | |
1750 | }; | |
1751 | ||
1752 | ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, | |
1753 | features, sizeof(features), buflen); | |
1754 | if (ret < 0) { | |
1755 | goto fail; | |
1756 | } | |
1757 | buf += ret; | |
1758 | buflen -= ret; | |
1759 | ||
1760 | /* Keep unknown header extensions */ | |
1761 | QLIST_FOREACH(uext, &s->unknown_header_ext, next) { | |
1762 | ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); | |
1763 | if (ret < 0) { | |
1764 | goto fail; | |
1765 | } | |
1766 | ||
1767 | buf += ret; | |
1768 | buflen -= ret; | |
1769 | } | |
1770 | ||
1771 | /* End of header extensions */ | |
1772 | ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); | |
1773 | if (ret < 0) { | |
1774 | goto fail; | |
1775 | } | |
1776 | ||
1777 | buf += ret; | |
1778 | buflen -= ret; | |
1779 | ||
1780 | /* Backing file name */ | |
1781 | if (s->image_backing_file) { | |
1782 | size_t backing_file_len = strlen(s->image_backing_file); | |
1783 | ||
1784 | if (buflen < backing_file_len) { | |
1785 | ret = -ENOSPC; | |
1786 | goto fail; | |
1787 | } | |
1788 | ||
1789 | /* Using strncpy is ok here, since buf is not NUL-terminated. */ | |
1790 | strncpy(buf, s->image_backing_file, buflen); | |
1791 | ||
1792 | header->backing_file_offset = cpu_to_be64(buf - ((char*) header)); | |
1793 | header->backing_file_size = cpu_to_be32(backing_file_len); | |
1794 | } | |
1795 | ||
1796 | /* Write the new header */ | |
1797 | ret = bdrv_pwrite(bs->file, 0, header, s->cluster_size); | |
1798 | if (ret < 0) { | |
1799 | goto fail; | |
1800 | } | |
1801 | ||
1802 | ret = 0; | |
1803 | fail: | |
1804 | qemu_vfree(header); | |
1805 | return ret; | |
1806 | } | |
1807 | ||
1808 | static int qcow2_change_backing_file(BlockDriverState *bs, | |
1809 | const char *backing_file, const char *backing_fmt) | |
1810 | { | |
1811 | BDRVQcow2State *s = bs->opaque; | |
1812 | ||
1813 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); | |
1814 | pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); | |
1815 | ||
1816 | g_free(s->image_backing_file); | |
1817 | g_free(s->image_backing_format); | |
1818 | ||
1819 | s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL; | |
1820 | s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL; | |
1821 | ||
1822 | return qcow2_update_header(bs); | |
1823 | } | |
1824 | ||
1825 | static int preallocate(BlockDriverState *bs) | |
1826 | { | |
1827 | uint64_t nb_sectors; | |
1828 | uint64_t offset; | |
1829 | uint64_t host_offset = 0; | |
1830 | int num; | |
1831 | int ret; | |
1832 | QCowL2Meta *meta; | |
1833 | ||
1834 | nb_sectors = bdrv_nb_sectors(bs); | |
1835 | offset = 0; | |
1836 | ||
1837 | while (nb_sectors) { | |
1838 | num = MIN(nb_sectors, INT_MAX >> BDRV_SECTOR_BITS); | |
1839 | ret = qcow2_alloc_cluster_offset(bs, offset, &num, | |
1840 | &host_offset, &meta); | |
1841 | if (ret < 0) { | |
1842 | return ret; | |
1843 | } | |
1844 | ||
1845 | while (meta) { | |
1846 | QCowL2Meta *next = meta->next; | |
1847 | ||
1848 | ret = qcow2_alloc_cluster_link_l2(bs, meta); | |
1849 | if (ret < 0) { | |
1850 | qcow2_free_any_clusters(bs, meta->alloc_offset, | |
1851 | meta->nb_clusters, QCOW2_DISCARD_NEVER); | |
1852 | return ret; | |
1853 | } | |
1854 | ||
1855 | /* There are no dependent requests, but we need to remove our | |
1856 | * request from the list of in-flight requests */ | |
1857 | QLIST_REMOVE(meta, next_in_flight); | |
1858 | ||
1859 | g_free(meta); | |
1860 | meta = next; | |
1861 | } | |
1862 | ||
1863 | /* TODO Preallocate data if requested */ | |
1864 | ||
1865 | nb_sectors -= num; | |
1866 | offset += num << BDRV_SECTOR_BITS; | |
1867 | } | |
1868 | ||
1869 | /* | |
1870 | * It is expected that the image file is large enough to actually contain | |
1871 | * all of the allocated clusters (otherwise we get failing reads after | |
1872 | * EOF). Extend the image to the last allocated sector. | |
1873 | */ | |
1874 | if (host_offset != 0) { | |
1875 | uint8_t buf[BDRV_SECTOR_SIZE]; | |
1876 | memset(buf, 0, BDRV_SECTOR_SIZE); | |
1877 | ret = bdrv_write(bs->file, (host_offset >> BDRV_SECTOR_BITS) + num - 1, | |
1878 | buf, 1); | |
1879 | if (ret < 0) { | |
1880 | return ret; | |
1881 | } | |
1882 | } | |
1883 | ||
1884 | return 0; | |
1885 | } | |
1886 | ||
1887 | static int qcow2_create2(const char *filename, int64_t total_size, | |
1888 | const char *backing_file, const char *backing_format, | |
1889 | int flags, size_t cluster_size, PreallocMode prealloc, | |
1890 | QemuOpts *opts, int version, int refcount_order, | |
1891 | Error **errp) | |
1892 | { | |
1893 | int cluster_bits; | |
1894 | QDict *options; | |
1895 | ||
1896 | /* Calculate cluster_bits */ | |
1897 | cluster_bits = ctz32(cluster_size); | |
1898 | if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS || | |
1899 | (1 << cluster_bits) != cluster_size) | |
1900 | { | |
1901 | error_setg(errp, "Cluster size must be a power of two between %d and " | |
1902 | "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); | |
1903 | return -EINVAL; | |
1904 | } | |
1905 | ||
1906 | /* | |
1907 | * Open the image file and write a minimal qcow2 header. | |
1908 | * | |
1909 | * We keep things simple and start with a zero-sized image. We also | |
1910 | * do without refcount blocks or a L1 table for now. We'll fix the | |
1911 | * inconsistency later. | |
1912 | * | |
1913 | * We do need a refcount table because growing the refcount table means | |
1914 | * allocating two new refcount blocks - the seconds of which would be at | |
1915 | * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file | |
1916 | * size for any qcow2 image. | |
1917 | */ | |
1918 | BlockDriverState* bs; | |
1919 | QCowHeader *header; | |
1920 | uint64_t* refcount_table; | |
1921 | Error *local_err = NULL; | |
1922 | int ret; | |
1923 | ||
1924 | if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) { | |
1925 | /* Note: The following calculation does not need to be exact; if it is a | |
1926 | * bit off, either some bytes will be "leaked" (which is fine) or we | |
1927 | * will need to increase the file size by some bytes (which is fine, | |
1928 | * too, as long as the bulk is allocated here). Therefore, using | |
1929 | * floating point arithmetic is fine. */ | |
1930 | int64_t meta_size = 0; | |
1931 | uint64_t nreftablee, nrefblocke, nl1e, nl2e; | |
1932 | int64_t aligned_total_size = align_offset(total_size, cluster_size); | |
1933 | int refblock_bits, refblock_size; | |
1934 | /* refcount entry size in bytes */ | |
1935 | double rces = (1 << refcount_order) / 8.; | |
1936 | ||
1937 | /* see qcow2_open() */ | |
1938 | refblock_bits = cluster_bits - (refcount_order - 3); | |
1939 | refblock_size = 1 << refblock_bits; | |
1940 | ||
1941 | /* header: 1 cluster */ | |
1942 | meta_size += cluster_size; | |
1943 | ||
1944 | /* total size of L2 tables */ | |
1945 | nl2e = aligned_total_size / cluster_size; | |
1946 | nl2e = align_offset(nl2e, cluster_size / sizeof(uint64_t)); | |
1947 | meta_size += nl2e * sizeof(uint64_t); | |
1948 | ||
1949 | /* total size of L1 tables */ | |
1950 | nl1e = nl2e * sizeof(uint64_t) / cluster_size; | |
1951 | nl1e = align_offset(nl1e, cluster_size / sizeof(uint64_t)); | |
1952 | meta_size += nl1e * sizeof(uint64_t); | |
1953 | ||
1954 | /* total size of refcount blocks | |
1955 | * | |
1956 | * note: every host cluster is reference-counted, including metadata | |
1957 | * (even refcount blocks are recursively included). | |
1958 | * Let: | |
1959 | * a = total_size (this is the guest disk size) | |
1960 | * m = meta size not including refcount blocks and refcount tables | |
1961 | * c = cluster size | |
1962 | * y1 = number of refcount blocks entries | |
1963 | * y2 = meta size including everything | |
1964 | * rces = refcount entry size in bytes | |
1965 | * then, | |
1966 | * y1 = (y2 + a)/c | |
1967 | * y2 = y1 * rces + y1 * rces * sizeof(u64) / c + m | |
1968 | * we can get y1: | |
1969 | * y1 = (a + m) / (c - rces - rces * sizeof(u64) / c) | |
1970 | */ | |
1971 | nrefblocke = (aligned_total_size + meta_size + cluster_size) | |
1972 | / (cluster_size - rces - rces * sizeof(uint64_t) | |
1973 | / cluster_size); | |
1974 | meta_size += DIV_ROUND_UP(nrefblocke, refblock_size) * cluster_size; | |
1975 | ||
1976 | /* total size of refcount tables */ | |
1977 | nreftablee = nrefblocke / refblock_size; | |
1978 | nreftablee = align_offset(nreftablee, cluster_size / sizeof(uint64_t)); | |
1979 | meta_size += nreftablee * sizeof(uint64_t); | |
1980 | ||
1981 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, | |
1982 | aligned_total_size + meta_size, &error_abort); | |
1983 | qemu_opt_set(opts, BLOCK_OPT_PREALLOC, PreallocMode_lookup[prealloc], | |
1984 | &error_abort); | |
1985 | } | |
1986 | ||
1987 | ret = bdrv_create_file(filename, opts, &local_err); | |
1988 | if (ret < 0) { | |
1989 | error_propagate(errp, local_err); | |
1990 | return ret; | |
1991 | } | |
1992 | ||
1993 | bs = NULL; | |
1994 | ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, | |
1995 | &local_err); | |
1996 | if (ret < 0) { | |
1997 | error_propagate(errp, local_err); | |
1998 | return ret; | |
1999 | } | |
2000 | ||
2001 | /* Write the header */ | |
2002 | QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header)); | |
2003 | header = g_malloc0(cluster_size); | |
2004 | *header = (QCowHeader) { | |
2005 | .magic = cpu_to_be32(QCOW_MAGIC), | |
2006 | .version = cpu_to_be32(version), | |
2007 | .cluster_bits = cpu_to_be32(cluster_bits), | |
2008 | .size = cpu_to_be64(0), | |
2009 | .l1_table_offset = cpu_to_be64(0), | |
2010 | .l1_size = cpu_to_be32(0), | |
2011 | .refcount_table_offset = cpu_to_be64(cluster_size), | |
2012 | .refcount_table_clusters = cpu_to_be32(1), | |
2013 | .refcount_order = cpu_to_be32(refcount_order), | |
2014 | .header_length = cpu_to_be32(sizeof(*header)), | |
2015 | }; | |
2016 | ||
2017 | if (flags & BLOCK_FLAG_ENCRYPT) { | |
2018 | header->crypt_method = cpu_to_be32(QCOW_CRYPT_AES); | |
2019 | } else { | |
2020 | header->crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); | |
2021 | } | |
2022 | ||
2023 | if (flags & BLOCK_FLAG_LAZY_REFCOUNTS) { | |
2024 | header->compatible_features |= | |
2025 | cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS); | |
2026 | } | |
2027 | ||
2028 | ret = bdrv_pwrite(bs, 0, header, cluster_size); | |
2029 | g_free(header); | |
2030 | if (ret < 0) { | |
2031 | error_setg_errno(errp, -ret, "Could not write qcow2 header"); | |
2032 | goto out; | |
2033 | } | |
2034 | ||
2035 | /* Write a refcount table with one refcount block */ | |
2036 | refcount_table = g_malloc0(2 * cluster_size); | |
2037 | refcount_table[0] = cpu_to_be64(2 * cluster_size); | |
2038 | ret = bdrv_pwrite(bs, cluster_size, refcount_table, 2 * cluster_size); | |
2039 | g_free(refcount_table); | |
2040 | ||
2041 | if (ret < 0) { | |
2042 | error_setg_errno(errp, -ret, "Could not write refcount table"); | |
2043 | goto out; | |
2044 | } | |
2045 | ||
2046 | bdrv_unref(bs); | |
2047 | bs = NULL; | |
2048 | ||
2049 | /* | |
2050 | * And now open the image and make it consistent first (i.e. increase the | |
2051 | * refcount of the cluster that is occupied by the header and the refcount | |
2052 | * table) | |
2053 | */ | |
2054 | options = qdict_new(); | |
2055 | qdict_put(options, "driver", qstring_from_str("qcow2")); | |
2056 | ret = bdrv_open(&bs, filename, NULL, options, | |
2057 | BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, | |
2058 | &local_err); | |
2059 | if (ret < 0) { | |
2060 | error_propagate(errp, local_err); | |
2061 | goto out; | |
2062 | } | |
2063 | ||
2064 | ret = qcow2_alloc_clusters(bs, 3 * cluster_size); | |
2065 | if (ret < 0) { | |
2066 | error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 " | |
2067 | "header and refcount table"); | |
2068 | goto out; | |
2069 | ||
2070 | } else if (ret != 0) { | |
2071 | error_report("Huh, first cluster in empty image is already in use?"); | |
2072 | abort(); | |
2073 | } | |
2074 | ||
2075 | /* Okay, now that we have a valid image, let's give it the right size */ | |
2076 | ret = bdrv_truncate(bs, total_size); | |
2077 | if (ret < 0) { | |
2078 | error_setg_errno(errp, -ret, "Could not resize image"); | |
2079 | goto out; | |
2080 | } | |
2081 | ||
2082 | /* Want a backing file? There you go.*/ | |
2083 | if (backing_file) { | |
2084 | ret = bdrv_change_backing_file(bs, backing_file, backing_format); | |
2085 | if (ret < 0) { | |
2086 | error_setg_errno(errp, -ret, "Could not assign backing file '%s' " | |
2087 | "with format '%s'", backing_file, backing_format); | |
2088 | goto out; | |
2089 | } | |
2090 | } | |
2091 | ||
2092 | /* And if we're supposed to preallocate metadata, do that now */ | |
2093 | if (prealloc != PREALLOC_MODE_OFF) { | |
2094 | BDRVQcow2State *s = bs->opaque; | |
2095 | qemu_co_mutex_lock(&s->lock); | |
2096 | ret = preallocate(bs); | |
2097 | qemu_co_mutex_unlock(&s->lock); | |
2098 | if (ret < 0) { | |
2099 | error_setg_errno(errp, -ret, "Could not preallocate metadata"); | |
2100 | goto out; | |
2101 | } | |
2102 | } | |
2103 | ||
2104 | bdrv_unref(bs); | |
2105 | bs = NULL; | |
2106 | ||
2107 | /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning */ | |
2108 | options = qdict_new(); | |
2109 | qdict_put(options, "driver", qstring_from_str("qcow2")); | |
2110 | ret = bdrv_open(&bs, filename, NULL, options, | |
2111 | BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_BACKING, | |
2112 | &local_err); | |
2113 | if (local_err) { | |
2114 | error_propagate(errp, local_err); | |
2115 | goto out; | |
2116 | } | |
2117 | ||
2118 | ret = 0; | |
2119 | out: | |
2120 | if (bs) { | |
2121 | bdrv_unref(bs); | |
2122 | } | |
2123 | return ret; | |
2124 | } | |
2125 | ||
2126 | static int qcow2_create(const char *filename, QemuOpts *opts, Error **errp) | |
2127 | { | |
2128 | char *backing_file = NULL; | |
2129 | char *backing_fmt = NULL; | |
2130 | char *buf = NULL; | |
2131 | uint64_t size = 0; | |
2132 | int flags = 0; | |
2133 | size_t cluster_size = DEFAULT_CLUSTER_SIZE; | |
2134 | PreallocMode prealloc; | |
2135 | int version = 3; | |
2136 | uint64_t refcount_bits = 16; | |
2137 | int refcount_order; | |
2138 | Error *local_err = NULL; | |
2139 | int ret; | |
2140 | ||
2141 | /* Read out options */ | |
2142 | size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), | |
2143 | BDRV_SECTOR_SIZE); | |
2144 | backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); | |
2145 | backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT); | |
2146 | if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) { | |
2147 | flags |= BLOCK_FLAG_ENCRYPT; | |
2148 | } | |
2149 | cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, | |
2150 | DEFAULT_CLUSTER_SIZE); | |
2151 | buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); | |
2152 | prealloc = qapi_enum_parse(PreallocMode_lookup, buf, | |
2153 | PREALLOC_MODE_MAX, PREALLOC_MODE_OFF, | |
2154 | &local_err); | |
2155 | if (local_err) { | |
2156 | error_propagate(errp, local_err); | |
2157 | ret = -EINVAL; | |
2158 | goto finish; | |
2159 | } | |
2160 | g_free(buf); | |
2161 | buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL); | |
2162 | if (!buf) { | |
2163 | /* keep the default */ | |
2164 | } else if (!strcmp(buf, "0.10")) { | |
2165 | version = 2; | |
2166 | } else if (!strcmp(buf, "1.1")) { | |
2167 | version = 3; | |
2168 | } else { | |
2169 | error_setg(errp, "Invalid compatibility level: '%s'", buf); | |
2170 | ret = -EINVAL; | |
2171 | goto finish; | |
2172 | } | |
2173 | ||
2174 | if (qemu_opt_get_bool_del(opts, BLOCK_OPT_LAZY_REFCOUNTS, false)) { | |
2175 | flags |= BLOCK_FLAG_LAZY_REFCOUNTS; | |
2176 | } | |
2177 | ||
2178 | if (backing_file && prealloc != PREALLOC_MODE_OFF) { | |
2179 | error_setg(errp, "Backing file and preallocation cannot be used at " | |
2180 | "the same time"); | |
2181 | ret = -EINVAL; | |
2182 | goto finish; | |
2183 | } | |
2184 | ||
2185 | if (version < 3 && (flags & BLOCK_FLAG_LAZY_REFCOUNTS)) { | |
2186 | error_setg(errp, "Lazy refcounts only supported with compatibility " | |
2187 | "level 1.1 and above (use compat=1.1 or greater)"); | |
2188 | ret = -EINVAL; | |
2189 | goto finish; | |
2190 | } | |
2191 | ||
2192 | refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, | |
2193 | refcount_bits); | |
2194 | if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) { | |
2195 | error_setg(errp, "Refcount width must be a power of two and may not " | |
2196 | "exceed 64 bits"); | |
2197 | ret = -EINVAL; | |
2198 | goto finish; | |
2199 | } | |
2200 | ||
2201 | if (version < 3 && refcount_bits != 16) { | |
2202 | error_setg(errp, "Different refcount widths than 16 bits require " | |
2203 | "compatibility level 1.1 or above (use compat=1.1 or " | |
2204 | "greater)"); | |
2205 | ret = -EINVAL; | |
2206 | goto finish; | |
2207 | } | |
2208 | ||
2209 | refcount_order = ctz32(refcount_bits); | |
2210 | ||
2211 | ret = qcow2_create2(filename, size, backing_file, backing_fmt, flags, | |
2212 | cluster_size, prealloc, opts, version, refcount_order, | |
2213 | &local_err); | |
2214 | if (local_err) { | |
2215 | error_propagate(errp, local_err); | |
2216 | } | |
2217 | ||
2218 | finish: | |
2219 | g_free(backing_file); | |
2220 | g_free(backing_fmt); | |
2221 | g_free(buf); | |
2222 | return ret; | |
2223 | } | |
2224 | ||
2225 | static coroutine_fn int qcow2_co_write_zeroes(BlockDriverState *bs, | |
2226 | int64_t sector_num, int nb_sectors, BdrvRequestFlags flags) | |
2227 | { | |
2228 | int ret; | |
2229 | BDRVQcow2State *s = bs->opaque; | |
2230 | ||
2231 | /* Emulate misaligned zero writes */ | |
2232 | if (sector_num % s->cluster_sectors || nb_sectors % s->cluster_sectors) { | |
2233 | return -ENOTSUP; | |
2234 | } | |
2235 | ||
2236 | /* Whatever is left can use real zero clusters */ | |
2237 | qemu_co_mutex_lock(&s->lock); | |
2238 | ret = qcow2_zero_clusters(bs, sector_num << BDRV_SECTOR_BITS, | |
2239 | nb_sectors); | |
2240 | qemu_co_mutex_unlock(&s->lock); | |
2241 | ||
2242 | return ret; | |
2243 | } | |
2244 | ||
2245 | static coroutine_fn int qcow2_co_discard(BlockDriverState *bs, | |
2246 | int64_t sector_num, int nb_sectors) | |
2247 | { | |
2248 | int ret; | |
2249 | BDRVQcow2State *s = bs->opaque; | |
2250 | ||
2251 | qemu_co_mutex_lock(&s->lock); | |
2252 | ret = qcow2_discard_clusters(bs, sector_num << BDRV_SECTOR_BITS, | |
2253 | nb_sectors, QCOW2_DISCARD_REQUEST, false); | |
2254 | qemu_co_mutex_unlock(&s->lock); | |
2255 | return ret; | |
2256 | } | |
2257 | ||
2258 | static int qcow2_truncate(BlockDriverState *bs, int64_t offset) | |
2259 | { | |
2260 | BDRVQcow2State *s = bs->opaque; | |
2261 | int64_t new_l1_size; | |
2262 | int ret; | |
2263 | ||
2264 | if (offset & 511) { | |
2265 | error_report("The new size must be a multiple of 512"); | |
2266 | return -EINVAL; | |
2267 | } | |
2268 | ||
2269 | /* cannot proceed if image has snapshots */ | |
2270 | if (s->nb_snapshots) { | |
2271 | error_report("Can't resize an image which has snapshots"); | |
2272 | return -ENOTSUP; | |
2273 | } | |
2274 | ||
2275 | /* shrinking is currently not supported */ | |
2276 | if (offset < bs->total_sectors * 512) { | |
2277 | error_report("qcow2 doesn't support shrinking images yet"); | |
2278 | return -ENOTSUP; | |
2279 | } | |
2280 | ||
2281 | new_l1_size = size_to_l1(s, offset); | |
2282 | ret = qcow2_grow_l1_table(bs, new_l1_size, true); | |
2283 | if (ret < 0) { | |
2284 | return ret; | |
2285 | } | |
2286 | ||
2287 | /* write updated header.size */ | |
2288 | offset = cpu_to_be64(offset); | |
2289 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size), | |
2290 | &offset, sizeof(uint64_t)); | |
2291 | if (ret < 0) { | |
2292 | return ret; | |
2293 | } | |
2294 | ||
2295 | s->l1_vm_state_index = new_l1_size; | |
2296 | return 0; | |
2297 | } | |
2298 | ||
2299 | /* XXX: put compressed sectors first, then all the cluster aligned | |
2300 | tables to avoid losing bytes in alignment */ | |
2301 | static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, | |
2302 | const uint8_t *buf, int nb_sectors) | |
2303 | { | |
2304 | BDRVQcow2State *s = bs->opaque; | |
2305 | z_stream strm; | |
2306 | int ret, out_len; | |
2307 | uint8_t *out_buf; | |
2308 | uint64_t cluster_offset; | |
2309 | ||
2310 | if (nb_sectors == 0) { | |
2311 | /* align end of file to a sector boundary to ease reading with | |
2312 | sector based I/Os */ | |
2313 | cluster_offset = bdrv_getlength(bs->file); | |
2314 | return bdrv_truncate(bs->file, cluster_offset); | |
2315 | } | |
2316 | ||
2317 | if (nb_sectors != s->cluster_sectors) { | |
2318 | ret = -EINVAL; | |
2319 | ||
2320 | /* Zero-pad last write if image size is not cluster aligned */ | |
2321 | if (sector_num + nb_sectors == bs->total_sectors && | |
2322 | nb_sectors < s->cluster_sectors) { | |
2323 | uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size); | |
2324 | memset(pad_buf, 0, s->cluster_size); | |
2325 | memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE); | |
2326 | ret = qcow2_write_compressed(bs, sector_num, | |
2327 | pad_buf, s->cluster_sectors); | |
2328 | qemu_vfree(pad_buf); | |
2329 | } | |
2330 | return ret; | |
2331 | } | |
2332 | ||
2333 | out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); | |
2334 | ||
2335 | /* best compression, small window, no zlib header */ | |
2336 | memset(&strm, 0, sizeof(strm)); | |
2337 | ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, | |
2338 | Z_DEFLATED, -12, | |
2339 | 9, Z_DEFAULT_STRATEGY); | |
2340 | if (ret != 0) { | |
2341 | ret = -EINVAL; | |
2342 | goto fail; | |
2343 | } | |
2344 | ||
2345 | strm.avail_in = s->cluster_size; | |
2346 | strm.next_in = (uint8_t *)buf; | |
2347 | strm.avail_out = s->cluster_size; | |
2348 | strm.next_out = out_buf; | |
2349 | ||
2350 | ret = deflate(&strm, Z_FINISH); | |
2351 | if (ret != Z_STREAM_END && ret != Z_OK) { | |
2352 | deflateEnd(&strm); | |
2353 | ret = -EINVAL; | |
2354 | goto fail; | |
2355 | } | |
2356 | out_len = strm.next_out - out_buf; | |
2357 | ||
2358 | deflateEnd(&strm); | |
2359 | ||
2360 | if (ret != Z_STREAM_END || out_len >= s->cluster_size) { | |
2361 | /* could not compress: write normal cluster */ | |
2362 | ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors); | |
2363 | if (ret < 0) { | |
2364 | goto fail; | |
2365 | } | |
2366 | } else { | |
2367 | cluster_offset = qcow2_alloc_compressed_cluster_offset(bs, | |
2368 | sector_num << 9, out_len); | |
2369 | if (!cluster_offset) { | |
2370 | ret = -EIO; | |
2371 | goto fail; | |
2372 | } | |
2373 | cluster_offset &= s->cluster_offset_mask; | |
2374 | ||
2375 | ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len); | |
2376 | if (ret < 0) { | |
2377 | goto fail; | |
2378 | } | |
2379 | ||
2380 | BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); | |
2381 | ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len); | |
2382 | if (ret < 0) { | |
2383 | goto fail; | |
2384 | } | |
2385 | } | |
2386 | ||
2387 | ret = 0; | |
2388 | fail: | |
2389 | g_free(out_buf); | |
2390 | return ret; | |
2391 | } | |
2392 | ||
2393 | static int make_completely_empty(BlockDriverState *bs) | |
2394 | { | |
2395 | BDRVQcow2State *s = bs->opaque; | |
2396 | int ret, l1_clusters; | |
2397 | int64_t offset; | |
2398 | uint64_t *new_reftable = NULL; | |
2399 | uint64_t rt_entry, l1_size2; | |
2400 | struct { | |
2401 | uint64_t l1_offset; | |
2402 | uint64_t reftable_offset; | |
2403 | uint32_t reftable_clusters; | |
2404 | } QEMU_PACKED l1_ofs_rt_ofs_cls; | |
2405 | ||
2406 | ret = qcow2_cache_empty(bs, s->l2_table_cache); | |
2407 | if (ret < 0) { | |
2408 | goto fail; | |
2409 | } | |
2410 | ||
2411 | ret = qcow2_cache_empty(bs, s->refcount_block_cache); | |
2412 | if (ret < 0) { | |
2413 | goto fail; | |
2414 | } | |
2415 | ||
2416 | /* Refcounts will be broken utterly */ | |
2417 | ret = qcow2_mark_dirty(bs); | |
2418 | if (ret < 0) { | |
2419 | goto fail; | |
2420 | } | |
2421 | ||
2422 | BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); | |
2423 | ||
2424 | l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / sizeof(uint64_t)); | |
2425 | l1_size2 = (uint64_t)s->l1_size * sizeof(uint64_t); | |
2426 | ||
2427 | /* After this call, neither the in-memory nor the on-disk refcount | |
2428 | * information accurately describe the actual references */ | |
2429 | ||
2430 | ret = bdrv_write_zeroes(bs->file, s->l1_table_offset / BDRV_SECTOR_SIZE, | |
2431 | l1_clusters * s->cluster_sectors, 0); | |
2432 | if (ret < 0) { | |
2433 | goto fail_broken_refcounts; | |
2434 | } | |
2435 | memset(s->l1_table, 0, l1_size2); | |
2436 | ||
2437 | BLKDBG_EVENT(bs->file, BLKDBG_EMPTY_IMAGE_PREPARE); | |
2438 | ||
2439 | /* Overwrite enough clusters at the beginning of the sectors to place | |
2440 | * the refcount table, a refcount block and the L1 table in; this may | |
2441 | * overwrite parts of the existing refcount and L1 table, which is not | |
2442 | * an issue because the dirty flag is set, complete data loss is in fact | |
2443 | * desired and partial data loss is consequently fine as well */ | |
2444 | ret = bdrv_write_zeroes(bs->file, s->cluster_size / BDRV_SECTOR_SIZE, | |
2445 | (2 + l1_clusters) * s->cluster_size / | |
2446 | BDRV_SECTOR_SIZE, 0); | |
2447 | /* This call (even if it failed overall) may have overwritten on-disk | |
2448 | * refcount structures; in that case, the in-memory refcount information | |
2449 | * will probably differ from the on-disk information which makes the BDS | |
2450 | * unusable */ | |
2451 | if (ret < 0) { | |
2452 | goto fail_broken_refcounts; | |
2453 | } | |
2454 | ||
2455 | BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); | |
2456 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE); | |
2457 | ||
2458 | /* "Create" an empty reftable (one cluster) directly after the image | |
2459 | * header and an empty L1 table three clusters after the image header; | |
2460 | * the cluster between those two will be used as the first refblock */ | |
2461 | cpu_to_be64w(&l1_ofs_rt_ofs_cls.l1_offset, 3 * s->cluster_size); | |
2462 | cpu_to_be64w(&l1_ofs_rt_ofs_cls.reftable_offset, s->cluster_size); | |
2463 | cpu_to_be32w(&l1_ofs_rt_ofs_cls.reftable_clusters, 1); | |
2464 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_table_offset), | |
2465 | &l1_ofs_rt_ofs_cls, sizeof(l1_ofs_rt_ofs_cls)); | |
2466 | if (ret < 0) { | |
2467 | goto fail_broken_refcounts; | |
2468 | } | |
2469 | ||
2470 | s->l1_table_offset = 3 * s->cluster_size; | |
2471 | ||
2472 | new_reftable = g_try_new0(uint64_t, s->cluster_size / sizeof(uint64_t)); | |
2473 | if (!new_reftable) { | |
2474 | ret = -ENOMEM; | |
2475 | goto fail_broken_refcounts; | |
2476 | } | |
2477 | ||
2478 | s->refcount_table_offset = s->cluster_size; | |
2479 | s->refcount_table_size = s->cluster_size / sizeof(uint64_t); | |
2480 | ||
2481 | g_free(s->refcount_table); | |
2482 | s->refcount_table = new_reftable; | |
2483 | new_reftable = NULL; | |
2484 | ||
2485 | /* Now the in-memory refcount information again corresponds to the on-disk | |
2486 | * information (reftable is empty and no refblocks (the refblock cache is | |
2487 | * empty)); however, this means some clusters (e.g. the image header) are | |
2488 | * referenced, but not refcounted, but the normal qcow2 code assumes that | |
2489 | * the in-memory information is always correct */ | |
2490 | ||
2491 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); | |
2492 | ||
2493 | /* Enter the first refblock into the reftable */ | |
2494 | rt_entry = cpu_to_be64(2 * s->cluster_size); | |
2495 | ret = bdrv_pwrite_sync(bs->file, s->cluster_size, | |
2496 | &rt_entry, sizeof(rt_entry)); | |
2497 | if (ret < 0) { | |
2498 | goto fail_broken_refcounts; | |
2499 | } | |
2500 | s->refcount_table[0] = 2 * s->cluster_size; | |
2501 | ||
2502 | s->free_cluster_index = 0; | |
2503 | assert(3 + l1_clusters <= s->refcount_block_size); | |
2504 | offset = qcow2_alloc_clusters(bs, 3 * s->cluster_size + l1_size2); | |
2505 | if (offset < 0) { | |
2506 | ret = offset; | |
2507 | goto fail_broken_refcounts; | |
2508 | } else if (offset > 0) { | |
2509 | error_report("First cluster in emptied image is in use"); | |
2510 | abort(); | |
2511 | } | |
2512 | ||
2513 | /* Now finally the in-memory information corresponds to the on-disk | |
2514 | * structures and is correct */ | |
2515 | ret = qcow2_mark_clean(bs); | |
2516 | if (ret < 0) { | |
2517 | goto fail; | |
2518 | } | |
2519 | ||
2520 | ret = bdrv_truncate(bs->file, (3 + l1_clusters) * s->cluster_size); | |
2521 | if (ret < 0) { | |
2522 | goto fail; | |
2523 | } | |
2524 | ||
2525 | return 0; | |
2526 | ||
2527 | fail_broken_refcounts: | |
2528 | /* The BDS is unusable at this point. If we wanted to make it usable, we | |
2529 | * would have to call qcow2_refcount_close(), qcow2_refcount_init(), | |
2530 | * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init() | |
2531 | * again. However, because the functions which could have caused this error | |
2532 | * path to be taken are used by those functions as well, it's very likely | |
2533 | * that that sequence will fail as well. Therefore, just eject the BDS. */ | |
2534 | bs->drv = NULL; | |
2535 | ||
2536 | fail: | |
2537 | g_free(new_reftable); | |
2538 | return ret; | |
2539 | } | |
2540 | ||
2541 | static int qcow2_make_empty(BlockDriverState *bs) | |
2542 | { | |
2543 | BDRVQcow2State *s = bs->opaque; | |
2544 | uint64_t start_sector; | |
2545 | int sector_step = INT_MAX / BDRV_SECTOR_SIZE; | |
2546 | int l1_clusters, ret = 0; | |
2547 | ||
2548 | l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / sizeof(uint64_t)); | |
2549 | ||
2550 | if (s->qcow_version >= 3 && !s->snapshots && | |
2551 | 3 + l1_clusters <= s->refcount_block_size) { | |
2552 | /* The following function only works for qcow2 v3 images (it requires | |
2553 | * the dirty flag) and only as long as there are no snapshots (because | |
2554 | * it completely empties the image). Furthermore, the L1 table and three | |
2555 | * additional clusters (image header, refcount table, one refcount | |
2556 | * block) have to fit inside one refcount block. */ | |
2557 | return make_completely_empty(bs); | |
2558 | } | |
2559 | ||
2560 | /* This fallback code simply discards every active cluster; this is slow, | |
2561 | * but works in all cases */ | |
2562 | for (start_sector = 0; start_sector < bs->total_sectors; | |
2563 | start_sector += sector_step) | |
2564 | { | |
2565 | /* As this function is generally used after committing an external | |
2566 | * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the | |
2567 | * default action for this kind of discard is to pass the discard, | |
2568 | * which will ideally result in an actually smaller image file, as | |
2569 | * is probably desired. */ | |
2570 | ret = qcow2_discard_clusters(bs, start_sector * BDRV_SECTOR_SIZE, | |
2571 | MIN(sector_step, | |
2572 | bs->total_sectors - start_sector), | |
2573 | QCOW2_DISCARD_SNAPSHOT, true); | |
2574 | if (ret < 0) { | |
2575 | break; | |
2576 | } | |
2577 | } | |
2578 | ||
2579 | return ret; | |
2580 | } | |
2581 | ||
2582 | static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs) | |
2583 | { | |
2584 | BDRVQcow2State *s = bs->opaque; | |
2585 | int ret; | |
2586 | ||
2587 | qemu_co_mutex_lock(&s->lock); | |
2588 | ret = qcow2_cache_flush(bs, s->l2_table_cache); | |
2589 | if (ret < 0) { | |
2590 | qemu_co_mutex_unlock(&s->lock); | |
2591 | return ret; | |
2592 | } | |
2593 | ||
2594 | if (qcow2_need_accurate_refcounts(s)) { | |
2595 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); | |
2596 | if (ret < 0) { | |
2597 | qemu_co_mutex_unlock(&s->lock); | |
2598 | return ret; | |
2599 | } | |
2600 | } | |
2601 | qemu_co_mutex_unlock(&s->lock); | |
2602 | ||
2603 | return 0; | |
2604 | } | |
2605 | ||
2606 | static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) | |
2607 | { | |
2608 | BDRVQcow2State *s = bs->opaque; | |
2609 | bdi->unallocated_blocks_are_zero = true; | |
2610 | bdi->can_write_zeroes_with_unmap = (s->qcow_version >= 3); | |
2611 | bdi->cluster_size = s->cluster_size; | |
2612 | bdi->vm_state_offset = qcow2_vm_state_offset(s); | |
2613 | return 0; | |
2614 | } | |
2615 | ||
2616 | static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs) | |
2617 | { | |
2618 | BDRVQcow2State *s = bs->opaque; | |
2619 | ImageInfoSpecific *spec_info = g_new(ImageInfoSpecific, 1); | |
2620 | ||
2621 | *spec_info = (ImageInfoSpecific){ | |
2622 | .kind = IMAGE_INFO_SPECIFIC_KIND_QCOW2, | |
2623 | { | |
2624 | .qcow2 = g_new(ImageInfoSpecificQCow2, 1), | |
2625 | }, | |
2626 | }; | |
2627 | if (s->qcow_version == 2) { | |
2628 | *spec_info->qcow2 = (ImageInfoSpecificQCow2){ | |
2629 | .compat = g_strdup("0.10"), | |
2630 | .refcount_bits = s->refcount_bits, | |
2631 | }; | |
2632 | } else if (s->qcow_version == 3) { | |
2633 | *spec_info->qcow2 = (ImageInfoSpecificQCow2){ | |
2634 | .compat = g_strdup("1.1"), | |
2635 | .lazy_refcounts = s->compatible_features & | |
2636 | QCOW2_COMPAT_LAZY_REFCOUNTS, | |
2637 | .has_lazy_refcounts = true, | |
2638 | .corrupt = s->incompatible_features & | |
2639 | QCOW2_INCOMPAT_CORRUPT, | |
2640 | .has_corrupt = true, | |
2641 | .refcount_bits = s->refcount_bits, | |
2642 | }; | |
2643 | } | |
2644 | ||
2645 | return spec_info; | |
2646 | } | |
2647 | ||
2648 | #if 0 | |
2649 | static void dump_refcounts(BlockDriverState *bs) | |
2650 | { | |
2651 | BDRVQcow2State *s = bs->opaque; | |
2652 | int64_t nb_clusters, k, k1, size; | |
2653 | int refcount; | |
2654 | ||
2655 | size = bdrv_getlength(bs->file); | |
2656 | nb_clusters = size_to_clusters(s, size); | |
2657 | for(k = 0; k < nb_clusters;) { | |
2658 | k1 = k; | |
2659 | refcount = get_refcount(bs, k); | |
2660 | k++; | |
2661 | while (k < nb_clusters && get_refcount(bs, k) == refcount) | |
2662 | k++; | |
2663 | printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount, | |
2664 | k - k1); | |
2665 | } | |
2666 | } | |
2667 | #endif | |
2668 | ||
2669 | static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, | |
2670 | int64_t pos) | |
2671 | { | |
2672 | BDRVQcow2State *s = bs->opaque; | |
2673 | int64_t total_sectors = bs->total_sectors; | |
2674 | bool zero_beyond_eof = bs->zero_beyond_eof; | |
2675 | int ret; | |
2676 | ||
2677 | BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); | |
2678 | bs->zero_beyond_eof = false; | |
2679 | ret = bdrv_pwritev(bs, qcow2_vm_state_offset(s) + pos, qiov); | |
2680 | bs->zero_beyond_eof = zero_beyond_eof; | |
2681 | ||
2682 | /* bdrv_co_do_writev will have increased the total_sectors value to include | |
2683 | * the VM state - the VM state is however not an actual part of the block | |
2684 | * device, therefore, we need to restore the old value. */ | |
2685 | bs->total_sectors = total_sectors; | |
2686 | ||
2687 | return ret; | |
2688 | } | |
2689 | ||
2690 | static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf, | |
2691 | int64_t pos, int size) | |
2692 | { | |
2693 | BDRVQcow2State *s = bs->opaque; | |
2694 | bool zero_beyond_eof = bs->zero_beyond_eof; | |
2695 | int ret; | |
2696 | ||
2697 | BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); | |
2698 | bs->zero_beyond_eof = false; | |
2699 | ret = bdrv_pread(bs, qcow2_vm_state_offset(s) + pos, buf, size); | |
2700 | bs->zero_beyond_eof = zero_beyond_eof; | |
2701 | ||
2702 | return ret; | |
2703 | } | |
2704 | ||
2705 | /* | |
2706 | * Downgrades an image's version. To achieve this, any incompatible features | |
2707 | * have to be removed. | |
2708 | */ | |
2709 | static int qcow2_downgrade(BlockDriverState *bs, int target_version, | |
2710 | BlockDriverAmendStatusCB *status_cb) | |
2711 | { | |
2712 | BDRVQcow2State *s = bs->opaque; | |
2713 | int current_version = s->qcow_version; | |
2714 | int ret; | |
2715 | ||
2716 | if (target_version == current_version) { | |
2717 | return 0; | |
2718 | } else if (target_version > current_version) { | |
2719 | return -EINVAL; | |
2720 | } else if (target_version != 2) { | |
2721 | return -EINVAL; | |
2722 | } | |
2723 | ||
2724 | if (s->refcount_order != 4) { | |
2725 | /* we would have to convert the image to a refcount_order == 4 image | |
2726 | * here; however, since qemu (at the time of writing this) does not | |
2727 | * support anything different than 4 anyway, there is no point in doing | |
2728 | * so right now; however, we should error out (if qemu supports this in | |
2729 | * the future and this code has not been adapted) */ | |
2730 | error_report("qcow2_downgrade: Image refcount orders other than 4 are " | |
2731 | "currently not supported."); | |
2732 | return -ENOTSUP; | |
2733 | } | |
2734 | ||
2735 | /* clear incompatible features */ | |
2736 | if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { | |
2737 | ret = qcow2_mark_clean(bs); | |
2738 | if (ret < 0) { | |
2739 | return ret; | |
2740 | } | |
2741 | } | |
2742 | ||
2743 | /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in | |
2744 | * the first place; if that happens nonetheless, returning -ENOTSUP is the | |
2745 | * best thing to do anyway */ | |
2746 | ||
2747 | if (s->incompatible_features) { | |
2748 | return -ENOTSUP; | |
2749 | } | |
2750 | ||
2751 | /* since we can ignore compatible features, we can set them to 0 as well */ | |
2752 | s->compatible_features = 0; | |
2753 | /* if lazy refcounts have been used, they have already been fixed through | |
2754 | * clearing the dirty flag */ | |
2755 | ||
2756 | /* clearing autoclear features is trivial */ | |
2757 | s->autoclear_features = 0; | |
2758 | ||
2759 | ret = qcow2_expand_zero_clusters(bs, status_cb); | |
2760 | if (ret < 0) { | |
2761 | return ret; | |
2762 | } | |
2763 | ||
2764 | s->qcow_version = target_version; | |
2765 | ret = qcow2_update_header(bs); | |
2766 | if (ret < 0) { | |
2767 | s->qcow_version = current_version; | |
2768 | return ret; | |
2769 | } | |
2770 | return 0; | |
2771 | } | |
2772 | ||
2773 | static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, | |
2774 | BlockDriverAmendStatusCB *status_cb) | |
2775 | { | |
2776 | BDRVQcow2State *s = bs->opaque; | |
2777 | int old_version = s->qcow_version, new_version = old_version; | |
2778 | uint64_t new_size = 0; | |
2779 | const char *backing_file = NULL, *backing_format = NULL; | |
2780 | bool lazy_refcounts = s->use_lazy_refcounts; | |
2781 | const char *compat = NULL; | |
2782 | uint64_t cluster_size = s->cluster_size; | |
2783 | bool encrypt; | |
2784 | int ret; | |
2785 | QemuOptDesc *desc = opts->list->desc; | |
2786 | ||
2787 | while (desc && desc->name) { | |
2788 | if (!qemu_opt_find(opts, desc->name)) { | |
2789 | /* only change explicitly defined options */ | |
2790 | desc++; | |
2791 | continue; | |
2792 | } | |
2793 | ||
2794 | if (!strcmp(desc->name, BLOCK_OPT_COMPAT_LEVEL)) { | |
2795 | compat = qemu_opt_get(opts, BLOCK_OPT_COMPAT_LEVEL); | |
2796 | if (!compat) { | |
2797 | /* preserve default */ | |
2798 | } else if (!strcmp(compat, "0.10")) { | |
2799 | new_version = 2; | |
2800 | } else if (!strcmp(compat, "1.1")) { | |
2801 | new_version = 3; | |
2802 | } else { | |
2803 | fprintf(stderr, "Unknown compatibility level %s.\n", compat); | |
2804 | return -EINVAL; | |
2805 | } | |
2806 | } else if (!strcmp(desc->name, BLOCK_OPT_PREALLOC)) { | |
2807 | fprintf(stderr, "Cannot change preallocation mode.\n"); | |
2808 | return -ENOTSUP; | |
2809 | } else if (!strcmp(desc->name, BLOCK_OPT_SIZE)) { | |
2810 | new_size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); | |
2811 | } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FILE)) { | |
2812 | backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); | |
2813 | } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FMT)) { | |
2814 | backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); | |
2815 | } else if (!strcmp(desc->name, BLOCK_OPT_ENCRYPT)) { | |
2816 | encrypt = qemu_opt_get_bool(opts, BLOCK_OPT_ENCRYPT, | |
2817 | !!s->cipher); | |
2818 | ||
2819 | if (encrypt != !!s->cipher) { | |
2820 | fprintf(stderr, "Changing the encryption flag is not " | |
2821 | "supported.\n"); | |
2822 | return -ENOTSUP; | |
2823 | } | |
2824 | } else if (!strcmp(desc->name, BLOCK_OPT_CLUSTER_SIZE)) { | |
2825 | cluster_size = qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, | |
2826 | cluster_size); | |
2827 | if (cluster_size != s->cluster_size) { | |
2828 | fprintf(stderr, "Changing the cluster size is not " | |
2829 | "supported.\n"); | |
2830 | return -ENOTSUP; | |
2831 | } | |
2832 | } else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) { | |
2833 | lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS, | |
2834 | lazy_refcounts); | |
2835 | } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) { | |
2836 | error_report("Cannot change refcount entry width"); | |
2837 | return -ENOTSUP; | |
2838 | } else { | |
2839 | /* if this assertion fails, this probably means a new option was | |
2840 | * added without having it covered here */ | |
2841 | assert(false); | |
2842 | } | |
2843 | ||
2844 | desc++; | |
2845 | } | |
2846 | ||
2847 | if (new_version != old_version) { | |
2848 | if (new_version > old_version) { | |
2849 | /* Upgrade */ | |
2850 | s->qcow_version = new_version; | |
2851 | ret = qcow2_update_header(bs); | |
2852 | if (ret < 0) { | |
2853 | s->qcow_version = old_version; | |
2854 | return ret; | |
2855 | } | |
2856 | } else { | |
2857 | ret = qcow2_downgrade(bs, new_version, status_cb); | |
2858 | if (ret < 0) { | |
2859 | return ret; | |
2860 | } | |
2861 | } | |
2862 | } | |
2863 | ||
2864 | if (backing_file || backing_format) { | |
2865 | ret = qcow2_change_backing_file(bs, | |
2866 | backing_file ?: s->image_backing_file, | |
2867 | backing_format ?: s->image_backing_format); | |
2868 | if (ret < 0) { | |
2869 | return ret; | |
2870 | } | |
2871 | } | |
2872 | ||
2873 | if (s->use_lazy_refcounts != lazy_refcounts) { | |
2874 | if (lazy_refcounts) { | |
2875 | if (s->qcow_version < 3) { | |
2876 | fprintf(stderr, "Lazy refcounts only supported with compatibility " | |
2877 | "level 1.1 and above (use compat=1.1 or greater)\n"); | |
2878 | return -EINVAL; | |
2879 | } | |
2880 | s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; | |
2881 | ret = qcow2_update_header(bs); | |
2882 | if (ret < 0) { | |
2883 | s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; | |
2884 | return ret; | |
2885 | } | |
2886 | s->use_lazy_refcounts = true; | |
2887 | } else { | |
2888 | /* make image clean first */ | |
2889 | ret = qcow2_mark_clean(bs); | |
2890 | if (ret < 0) { | |
2891 | return ret; | |
2892 | } | |
2893 | /* now disallow lazy refcounts */ | |
2894 | s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; | |
2895 | ret = qcow2_update_header(bs); | |
2896 | if (ret < 0) { | |
2897 | s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; | |
2898 | return ret; | |
2899 | } | |
2900 | s->use_lazy_refcounts = false; | |
2901 | } | |
2902 | } | |
2903 | ||
2904 | if (new_size) { | |
2905 | ret = bdrv_truncate(bs, new_size); | |
2906 | if (ret < 0) { | |
2907 | return ret; | |
2908 | } | |
2909 | } | |
2910 | ||
2911 | return 0; | |
2912 | } | |
2913 | ||
2914 | /* | |
2915 | * If offset or size are negative, respectively, they will not be included in | |
2916 | * the BLOCK_IMAGE_CORRUPTED event emitted. | |
2917 | * fatal will be ignored for read-only BDS; corruptions found there will always | |
2918 | * be considered non-fatal. | |
2919 | */ | |
2920 | void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, | |
2921 | int64_t size, const char *message_format, ...) | |
2922 | { | |
2923 | BDRVQcow2State *s = bs->opaque; | |
2924 | const char *node_name; | |
2925 | char *message; | |
2926 | va_list ap; | |
2927 | ||
2928 | fatal = fatal && !bs->read_only; | |
2929 | ||
2930 | if (s->signaled_corruption && | |
2931 | (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT))) | |
2932 | { | |
2933 | return; | |
2934 | } | |
2935 | ||
2936 | va_start(ap, message_format); | |
2937 | message = g_strdup_vprintf(message_format, ap); | |
2938 | va_end(ap); | |
2939 | ||
2940 | if (fatal) { | |
2941 | fprintf(stderr, "qcow2: Marking image as corrupt: %s; further " | |
2942 | "corruption events will be suppressed\n", message); | |
2943 | } else { | |
2944 | fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal " | |
2945 | "corruption events will be suppressed\n", message); | |
2946 | } | |
2947 | ||
2948 | node_name = bdrv_get_node_name(bs); | |
2949 | qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs), | |
2950 | *node_name != '\0', node_name, | |
2951 | message, offset >= 0, offset, | |
2952 | size >= 0, size, | |
2953 | fatal, &error_abort); | |
2954 | g_free(message); | |
2955 | ||
2956 | if (fatal) { | |
2957 | qcow2_mark_corrupt(bs); | |
2958 | bs->drv = NULL; /* make BDS unusable */ | |
2959 | } | |
2960 | ||
2961 | s->signaled_corruption = true; | |
2962 | } | |
2963 | ||
2964 | static QemuOptsList qcow2_create_opts = { | |
2965 | .name = "qcow2-create-opts", | |
2966 | .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head), | |
2967 | .desc = { | |
2968 | { | |
2969 | .name = BLOCK_OPT_SIZE, | |
2970 | .type = QEMU_OPT_SIZE, | |
2971 | .help = "Virtual disk size" | |
2972 | }, | |
2973 | { | |
2974 | .name = BLOCK_OPT_COMPAT_LEVEL, | |
2975 | .type = QEMU_OPT_STRING, | |
2976 | .help = "Compatibility level (0.10 or 1.1)" | |
2977 | }, | |
2978 | { | |
2979 | .name = BLOCK_OPT_BACKING_FILE, | |
2980 | .type = QEMU_OPT_STRING, | |
2981 | .help = "File name of a base image" | |
2982 | }, | |
2983 | { | |
2984 | .name = BLOCK_OPT_BACKING_FMT, | |
2985 | .type = QEMU_OPT_STRING, | |
2986 | .help = "Image format of the base image" | |
2987 | }, | |
2988 | { | |
2989 | .name = BLOCK_OPT_ENCRYPT, | |
2990 | .type = QEMU_OPT_BOOL, | |
2991 | .help = "Encrypt the image", | |
2992 | .def_value_str = "off" | |
2993 | }, | |
2994 | { | |
2995 | .name = BLOCK_OPT_CLUSTER_SIZE, | |
2996 | .type = QEMU_OPT_SIZE, | |
2997 | .help = "qcow2 cluster size", | |
2998 | .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) | |
2999 | }, | |
3000 | { | |
3001 | .name = BLOCK_OPT_PREALLOC, | |
3002 | .type = QEMU_OPT_STRING, | |
3003 | .help = "Preallocation mode (allowed values: off, metadata, " | |
3004 | "falloc, full)" | |
3005 | }, | |
3006 | { | |
3007 | .name = BLOCK_OPT_LAZY_REFCOUNTS, | |
3008 | .type = QEMU_OPT_BOOL, | |
3009 | .help = "Postpone refcount updates", | |
3010 | .def_value_str = "off" | |
3011 | }, | |
3012 | { | |
3013 | .name = BLOCK_OPT_REFCOUNT_BITS, | |
3014 | .type = QEMU_OPT_NUMBER, | |
3015 | .help = "Width of a reference count entry in bits", | |
3016 | .def_value_str = "16" | |
3017 | }, | |
3018 | { /* end of list */ } | |
3019 | } | |
3020 | }; | |
3021 | ||
3022 | BlockDriver bdrv_qcow2 = { | |
3023 | .format_name = "qcow2", | |
3024 | .instance_size = sizeof(BDRVQcow2State), | |
3025 | .bdrv_probe = qcow2_probe, | |
3026 | .bdrv_open = qcow2_open, | |
3027 | .bdrv_close = qcow2_close, | |
3028 | .bdrv_reopen_prepare = qcow2_reopen_prepare, | |
3029 | .bdrv_create = qcow2_create, | |
3030 | .bdrv_has_zero_init = bdrv_has_zero_init_1, | |
3031 | .bdrv_co_get_block_status = qcow2_co_get_block_status, | |
3032 | .bdrv_set_key = qcow2_set_key, | |
3033 | ||
3034 | .bdrv_co_readv = qcow2_co_readv, | |
3035 | .bdrv_co_writev = qcow2_co_writev, | |
3036 | .bdrv_co_flush_to_os = qcow2_co_flush_to_os, | |
3037 | ||
3038 | .bdrv_co_write_zeroes = qcow2_co_write_zeroes, | |
3039 | .bdrv_co_discard = qcow2_co_discard, | |
3040 | .bdrv_truncate = qcow2_truncate, | |
3041 | .bdrv_write_compressed = qcow2_write_compressed, | |
3042 | .bdrv_make_empty = qcow2_make_empty, | |
3043 | ||
3044 | .bdrv_snapshot_create = qcow2_snapshot_create, | |
3045 | .bdrv_snapshot_goto = qcow2_snapshot_goto, | |
3046 | .bdrv_snapshot_delete = qcow2_snapshot_delete, | |
3047 | .bdrv_snapshot_list = qcow2_snapshot_list, | |
3048 | .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, | |
3049 | .bdrv_get_info = qcow2_get_info, | |
3050 | .bdrv_get_specific_info = qcow2_get_specific_info, | |
3051 | ||
3052 | .bdrv_save_vmstate = qcow2_save_vmstate, | |
3053 | .bdrv_load_vmstate = qcow2_load_vmstate, | |
3054 | ||
3055 | .supports_backing = true, | |
3056 | .bdrv_change_backing_file = qcow2_change_backing_file, | |
3057 | ||
3058 | .bdrv_refresh_limits = qcow2_refresh_limits, | |
3059 | .bdrv_invalidate_cache = qcow2_invalidate_cache, | |
3060 | ||
3061 | .create_opts = &qcow2_create_opts, | |
3062 | .bdrv_check = qcow2_check, | |
3063 | .bdrv_amend_options = qcow2_amend_options, | |
3064 | ||
3065 | .bdrv_detach_aio_context = qcow2_detach_aio_context, | |
3066 | .bdrv_attach_aio_context = qcow2_attach_aio_context, | |
3067 | }; | |
3068 | ||
3069 | static void bdrv_qcow2_init(void) | |
3070 | { | |
3071 | bdrv_register(&bdrv_qcow2); | |
3072 | } | |
3073 | ||
3074 | block_init(bdrv_qcow2_init); |