1 | /* |
2 | * Bitmaps for the QCOW version 2 format |
3 | * |
4 | * Copyright (c) 2014-2017 Vladimir Sementsov-Ogievskiy |
5 | * |
6 | * This file is derived from qcow2-snapshot.c, original copyright: |
7 | * Copyright (c) 2004-2006 Fabrice Bellard |
8 | * |
9 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
10 | * of this software and associated documentation files (the "Software"), to deal |
11 | * in the Software without restriction, including without limitation the rights |
12 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
13 | * copies of the Software, and to permit persons to whom the Software is |
14 | * furnished to do so, subject to the following conditions: |
15 | * |
16 | * The above copyright notice and this permission notice shall be included in |
17 | * all copies or substantial portions of the Software. |
18 | * |
19 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
20 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
21 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
22 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
23 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
24 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
25 | * THE SOFTWARE. |
26 | */ |
27 | |
28 | #include "qemu/osdep.h" |
29 | #include "qapi/error.h" |
30 | #include "qemu/cutils.h" |
31 | |
32 | #include "qcow2.h" |
33 | |
34 | /* NOTICE: BME here means Bitmaps Extension and used as a namespace for |
35 | * _internal_ constants. Please do not use this _internal_ abbreviation for |
36 | * other needs and/or outside of this file. */ |
37 | |
38 | /* Bitmap directory entry constraints */ |
39 | #define BME_MAX_TABLE_SIZE 0x8000000 |
40 | #define BME_MAX_PHYS_SIZE 0x20000000 /* restrict BdrvDirtyBitmap size in RAM */ |
41 | #define BME_MAX_GRANULARITY_BITS 31 |
42 | #define BME_MIN_GRANULARITY_BITS 9 |
43 | #define BME_MAX_NAME_SIZE 1023 |
44 | |
45 | #if BME_MAX_TABLE_SIZE * 8ULL > INT_MAX |
46 | #error In the code bitmap table physical size assumed to fit into int |
47 | #endif |
48 | |
49 | /* Bitmap directory entry flags */ |
50 | #define BME_RESERVED_FLAGS 0xfffffffcU |
51 | #define BME_FLAG_IN_USE (1U << 0) |
52 | #define BME_FLAG_AUTO (1U << 1) |
53 | |
54 | /* bits [1, 8] U [56, 63] are reserved */ |
55 | #define BME_TABLE_ENTRY_RESERVED_MASK 0xff000000000001feULL |
56 | #define BME_TABLE_ENTRY_OFFSET_MASK 0x00fffffffffffe00ULL |
57 | #define BME_TABLE_ENTRY_FLAG_ALL_ONES (1ULL << 0) |
58 | |
59 | typedef struct QEMU_PACKED Qcow2BitmapDirEntry { |
60 | /* header is 8 byte aligned */ |
61 | uint64_t bitmap_table_offset; |
62 | |
63 | uint32_t bitmap_table_size; |
64 | uint32_t flags; |
65 | |
66 | uint8_t type; |
67 | uint8_t granularity_bits; |
68 | uint16_t name_size; |
69 | uint32_t ; |
70 | /* extra data follows */ |
71 | /* name follows */ |
72 | } Qcow2BitmapDirEntry; |
73 | |
74 | typedef struct Qcow2BitmapTable { |
75 | uint64_t offset; |
76 | uint32_t size; /* number of 64bit entries */ |
77 | QSIMPLEQ_ENTRY(Qcow2BitmapTable) entry; |
78 | } Qcow2BitmapTable; |
79 | |
80 | typedef struct Qcow2Bitmap { |
81 | Qcow2BitmapTable table; |
82 | uint32_t flags; |
83 | uint8_t granularity_bits; |
84 | char *name; |
85 | |
86 | BdrvDirtyBitmap *dirty_bitmap; |
87 | |
88 | QSIMPLEQ_ENTRY(Qcow2Bitmap) entry; |
89 | } Qcow2Bitmap; |
90 | typedef QSIMPLEQ_HEAD(Qcow2BitmapList, Qcow2Bitmap) Qcow2BitmapList; |
91 | |
92 | typedef enum BitmapType { |
93 | BT_DIRTY_TRACKING_BITMAP = 1 |
94 | } BitmapType; |
95 | |
96 | static inline bool can_write(BlockDriverState *bs) |
97 | { |
98 | return !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE); |
99 | } |
100 | |
101 | static int (BlockDriverState *bs) |
102 | { |
103 | int ret; |
104 | |
105 | ret = qcow2_update_header(bs); |
106 | if (ret < 0) { |
107 | return ret; |
108 | } |
109 | |
110 | return bdrv_flush(bs->file->bs); |
111 | } |
112 | |
113 | static inline void bitmap_table_to_be(uint64_t *bitmap_table, size_t size) |
114 | { |
115 | size_t i; |
116 | |
117 | for (i = 0; i < size; ++i) { |
118 | bitmap_table[i] = cpu_to_be64(bitmap_table[i]); |
119 | } |
120 | } |
121 | |
122 | static int check_table_entry(uint64_t entry, int cluster_size) |
123 | { |
124 | uint64_t offset; |
125 | |
126 | if (entry & BME_TABLE_ENTRY_RESERVED_MASK) { |
127 | return -EINVAL; |
128 | } |
129 | |
130 | offset = entry & BME_TABLE_ENTRY_OFFSET_MASK; |
131 | if (offset != 0) { |
132 | /* if offset specified, bit 0 is reserved */ |
133 | if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) { |
134 | return -EINVAL; |
135 | } |
136 | |
137 | if (offset % cluster_size != 0) { |
138 | return -EINVAL; |
139 | } |
140 | } |
141 | |
142 | return 0; |
143 | } |
144 | |
145 | static int check_constraints_on_bitmap(BlockDriverState *bs, |
146 | const char *name, |
147 | uint32_t granularity, |
148 | Error **errp) |
149 | { |
150 | BDRVQcow2State *s = bs->opaque; |
151 | int granularity_bits = ctz32(granularity); |
152 | int64_t len = bdrv_getlength(bs); |
153 | |
154 | assert(granularity > 0); |
155 | assert((granularity & (granularity - 1)) == 0); |
156 | |
157 | if (len < 0) { |
158 | error_setg_errno(errp, -len, "Failed to get size of '%s'" , |
159 | bdrv_get_device_or_node_name(bs)); |
160 | return len; |
161 | } |
162 | |
163 | if (granularity_bits > BME_MAX_GRANULARITY_BITS) { |
164 | error_setg(errp, "Granularity exceeds maximum (%llu bytes)" , |
165 | 1ULL << BME_MAX_GRANULARITY_BITS); |
166 | return -EINVAL; |
167 | } |
168 | if (granularity_bits < BME_MIN_GRANULARITY_BITS) { |
169 | error_setg(errp, "Granularity is under minimum (%llu bytes)" , |
170 | 1ULL << BME_MIN_GRANULARITY_BITS); |
171 | return -EINVAL; |
172 | } |
173 | |
174 | if ((len > (uint64_t)BME_MAX_PHYS_SIZE << granularity_bits) || |
175 | (len > (uint64_t)BME_MAX_TABLE_SIZE * s->cluster_size << |
176 | granularity_bits)) |
177 | { |
178 | error_setg(errp, "Too much space will be occupied by the bitmap. " |
179 | "Use larger granularity" ); |
180 | return -EINVAL; |
181 | } |
182 | |
183 | if (strlen(name) > BME_MAX_NAME_SIZE) { |
184 | error_setg(errp, "Name length exceeds maximum (%u characters)" , |
185 | BME_MAX_NAME_SIZE); |
186 | return -EINVAL; |
187 | } |
188 | |
189 | return 0; |
190 | } |
191 | |
192 | static void clear_bitmap_table(BlockDriverState *bs, uint64_t *bitmap_table, |
193 | uint32_t bitmap_table_size) |
194 | { |
195 | BDRVQcow2State *s = bs->opaque; |
196 | int i; |
197 | |
198 | for (i = 0; i < bitmap_table_size; ++i) { |
199 | uint64_t addr = bitmap_table[i] & BME_TABLE_ENTRY_OFFSET_MASK; |
200 | if (!addr) { |
201 | continue; |
202 | } |
203 | |
204 | qcow2_free_clusters(bs, addr, s->cluster_size, QCOW2_DISCARD_ALWAYS); |
205 | bitmap_table[i] = 0; |
206 | } |
207 | } |
208 | |
209 | static int bitmap_table_load(BlockDriverState *bs, Qcow2BitmapTable *tb, |
210 | uint64_t **bitmap_table) |
211 | { |
212 | int ret; |
213 | BDRVQcow2State *s = bs->opaque; |
214 | uint32_t i; |
215 | uint64_t *table; |
216 | |
217 | assert(tb->size != 0); |
218 | table = g_try_new(uint64_t, tb->size); |
219 | if (table == NULL) { |
220 | return -ENOMEM; |
221 | } |
222 | |
223 | assert(tb->size <= BME_MAX_TABLE_SIZE); |
224 | ret = bdrv_pread(bs->file, tb->offset, |
225 | table, tb->size * sizeof(uint64_t)); |
226 | if (ret < 0) { |
227 | goto fail; |
228 | } |
229 | |
230 | for (i = 0; i < tb->size; ++i) { |
231 | table[i] = be64_to_cpu(table[i]); |
232 | ret = check_table_entry(table[i], s->cluster_size); |
233 | if (ret < 0) { |
234 | goto fail; |
235 | } |
236 | } |
237 | |
238 | *bitmap_table = table; |
239 | return 0; |
240 | |
241 | fail: |
242 | g_free(table); |
243 | |
244 | return ret; |
245 | } |
246 | |
247 | static int free_bitmap_clusters(BlockDriverState *bs, Qcow2BitmapTable *tb) |
248 | { |
249 | int ret; |
250 | uint64_t *bitmap_table; |
251 | |
252 | ret = bitmap_table_load(bs, tb, &bitmap_table); |
253 | if (ret < 0) { |
254 | return ret; |
255 | } |
256 | |
257 | clear_bitmap_table(bs, bitmap_table, tb->size); |
258 | qcow2_free_clusters(bs, tb->offset, tb->size * sizeof(uint64_t), |
259 | QCOW2_DISCARD_OTHER); |
260 | g_free(bitmap_table); |
261 | |
262 | tb->offset = 0; |
263 | tb->size = 0; |
264 | |
265 | return 0; |
266 | } |
267 | |
268 | /* Return the disk size covered by a single qcow2 cluster of bitmap data. */ |
269 | static uint64_t bytes_covered_by_bitmap_cluster(const BDRVQcow2State *s, |
270 | const BdrvDirtyBitmap *bitmap) |
271 | { |
272 | uint64_t granularity = bdrv_dirty_bitmap_granularity(bitmap); |
273 | uint64_t limit = granularity * (s->cluster_size << 3); |
274 | |
275 | assert(QEMU_IS_ALIGNED(limit, |
276 | bdrv_dirty_bitmap_serialization_align(bitmap))); |
277 | return limit; |
278 | } |
279 | |
280 | /* load_bitmap_data |
281 | * @bitmap_table entries must satisfy specification constraints. |
282 | * @bitmap must be cleared */ |
283 | static int load_bitmap_data(BlockDriverState *bs, |
284 | const uint64_t *bitmap_table, |
285 | uint32_t bitmap_table_size, |
286 | BdrvDirtyBitmap *bitmap) |
287 | { |
288 | int ret = 0; |
289 | BDRVQcow2State *s = bs->opaque; |
290 | uint64_t offset, limit; |
291 | uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap); |
292 | uint8_t *buf = NULL; |
293 | uint64_t i, tab_size = |
294 | size_to_clusters(s, |
295 | bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size)); |
296 | |
297 | if (tab_size != bitmap_table_size || tab_size > BME_MAX_TABLE_SIZE) { |
298 | return -EINVAL; |
299 | } |
300 | |
301 | buf = g_malloc(s->cluster_size); |
302 | limit = bytes_covered_by_bitmap_cluster(s, bitmap); |
303 | for (i = 0, offset = 0; i < tab_size; ++i, offset += limit) { |
304 | uint64_t count = MIN(bm_size - offset, limit); |
305 | uint64_t entry = bitmap_table[i]; |
306 | uint64_t data_offset = entry & BME_TABLE_ENTRY_OFFSET_MASK; |
307 | |
308 | assert(check_table_entry(entry, s->cluster_size) == 0); |
309 | |
310 | if (data_offset == 0) { |
311 | if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) { |
312 | bdrv_dirty_bitmap_deserialize_ones(bitmap, offset, count, |
313 | false); |
314 | } else { |
315 | /* No need to deserialize zeros because the dirty bitmap is |
316 | * already cleared */ |
317 | } |
318 | } else { |
319 | ret = bdrv_pread(bs->file, data_offset, buf, s->cluster_size); |
320 | if (ret < 0) { |
321 | goto finish; |
322 | } |
323 | bdrv_dirty_bitmap_deserialize_part(bitmap, buf, offset, count, |
324 | false); |
325 | } |
326 | } |
327 | ret = 0; |
328 | |
329 | bdrv_dirty_bitmap_deserialize_finish(bitmap); |
330 | |
331 | finish: |
332 | g_free(buf); |
333 | |
334 | return ret; |
335 | } |
336 | |
337 | static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs, |
338 | Qcow2Bitmap *bm, Error **errp) |
339 | { |
340 | int ret; |
341 | uint64_t *bitmap_table = NULL; |
342 | uint32_t granularity; |
343 | BdrvDirtyBitmap *bitmap = NULL; |
344 | |
345 | granularity = 1U << bm->granularity_bits; |
346 | bitmap = bdrv_create_dirty_bitmap(bs, granularity, bm->name, errp); |
347 | if (bitmap == NULL) { |
348 | goto fail; |
349 | } |
350 | |
351 | if (bm->flags & BME_FLAG_IN_USE) { |
352 | /* Data is unusable, skip loading it */ |
353 | return bitmap; |
354 | } |
355 | |
356 | ret = bitmap_table_load(bs, &bm->table, &bitmap_table); |
357 | if (ret < 0) { |
358 | error_setg_errno(errp, -ret, |
359 | "Could not read bitmap_table table from image for " |
360 | "bitmap '%s'" , bm->name); |
361 | goto fail; |
362 | } |
363 | |
364 | ret = load_bitmap_data(bs, bitmap_table, bm->table.size, bitmap); |
365 | if (ret < 0) { |
366 | error_setg_errno(errp, -ret, "Could not read bitmap '%s' from image" , |
367 | bm->name); |
368 | goto fail; |
369 | } |
370 | |
371 | g_free(bitmap_table); |
372 | return bitmap; |
373 | |
374 | fail: |
375 | g_free(bitmap_table); |
376 | if (bitmap != NULL) { |
377 | bdrv_release_dirty_bitmap(bs, bitmap); |
378 | } |
379 | |
380 | return NULL; |
381 | } |
382 | |
383 | /* |
384 | * Bitmap List |
385 | */ |
386 | |
387 | /* |
388 | * Bitmap List private functions |
389 | * Only Bitmap List knows about bitmap directory structure in Qcow2. |
390 | */ |
391 | |
392 | static inline void bitmap_dir_entry_to_cpu(Qcow2BitmapDirEntry *entry) |
393 | { |
394 | entry->bitmap_table_offset = be64_to_cpu(entry->bitmap_table_offset); |
395 | entry->bitmap_table_size = be32_to_cpu(entry->bitmap_table_size); |
396 | entry->flags = be32_to_cpu(entry->flags); |
397 | entry->name_size = be16_to_cpu(entry->name_size); |
398 | entry->extra_data_size = be32_to_cpu(entry->extra_data_size); |
399 | } |
400 | |
401 | static inline void bitmap_dir_entry_to_be(Qcow2BitmapDirEntry *entry) |
402 | { |
403 | entry->bitmap_table_offset = cpu_to_be64(entry->bitmap_table_offset); |
404 | entry->bitmap_table_size = cpu_to_be32(entry->bitmap_table_size); |
405 | entry->flags = cpu_to_be32(entry->flags); |
406 | entry->name_size = cpu_to_be16(entry->name_size); |
407 | entry->extra_data_size = cpu_to_be32(entry->extra_data_size); |
408 | } |
409 | |
410 | static inline int calc_dir_entry_size(size_t name_size, size_t ) |
411 | { |
412 | int size = sizeof(Qcow2BitmapDirEntry) + name_size + extra_data_size; |
413 | return ROUND_UP(size, 8); |
414 | } |
415 | |
416 | static inline int dir_entry_size(Qcow2BitmapDirEntry *entry) |
417 | { |
418 | return calc_dir_entry_size(entry->name_size, entry->extra_data_size); |
419 | } |
420 | |
421 | static inline const char *dir_entry_name_field(Qcow2BitmapDirEntry *entry) |
422 | { |
423 | return (const char *)(entry + 1) + entry->extra_data_size; |
424 | } |
425 | |
426 | static inline char *dir_entry_copy_name(Qcow2BitmapDirEntry *entry) |
427 | { |
428 | const char *name_field = dir_entry_name_field(entry); |
429 | return g_strndup(name_field, entry->name_size); |
430 | } |
431 | |
432 | static inline Qcow2BitmapDirEntry *next_dir_entry(Qcow2BitmapDirEntry *entry) |
433 | { |
434 | return (Qcow2BitmapDirEntry *)((uint8_t *)entry + dir_entry_size(entry)); |
435 | } |
436 | |
437 | static int check_dir_entry(BlockDriverState *bs, Qcow2BitmapDirEntry *entry) |
438 | { |
439 | BDRVQcow2State *s = bs->opaque; |
440 | uint64_t phys_bitmap_bytes; |
441 | int64_t len; |
442 | |
443 | bool fail = (entry->bitmap_table_size == 0) || |
444 | (entry->bitmap_table_offset == 0) || |
445 | (entry->bitmap_table_offset % s->cluster_size) || |
446 | (entry->bitmap_table_size > BME_MAX_TABLE_SIZE) || |
447 | (entry->granularity_bits > BME_MAX_GRANULARITY_BITS) || |
448 | (entry->granularity_bits < BME_MIN_GRANULARITY_BITS) || |
449 | (entry->flags & BME_RESERVED_FLAGS) || |
450 | (entry->name_size > BME_MAX_NAME_SIZE) || |
451 | (entry->type != BT_DIRTY_TRACKING_BITMAP); |
452 | |
453 | if (fail) { |
454 | return -EINVAL; |
455 | } |
456 | |
457 | phys_bitmap_bytes = (uint64_t)entry->bitmap_table_size * s->cluster_size; |
458 | len = bdrv_getlength(bs); |
459 | |
460 | if (len < 0) { |
461 | return len; |
462 | } |
463 | |
464 | if (phys_bitmap_bytes > BME_MAX_PHYS_SIZE) { |
465 | return -EINVAL; |
466 | } |
467 | |
468 | if (!(entry->flags & BME_FLAG_IN_USE) && |
469 | (len > ((phys_bitmap_bytes * 8) << entry->granularity_bits))) |
470 | { |
471 | /* |
472 | * We've loaded a valid bitmap (IN_USE not set) or we are going to |
473 | * store a valid bitmap, but the allocated bitmap table size is not |
474 | * enough to store this bitmap. |
475 | * |
476 | * Note, that it's OK to have an invalid bitmap with invalid size due |
477 | * to a bitmap that was not correctly saved after image resize. |
478 | */ |
479 | return -EINVAL; |
480 | } |
481 | |
482 | return 0; |
483 | } |
484 | |
485 | static inline void bitmap_directory_to_be(uint8_t *dir, size_t size) |
486 | { |
487 | uint8_t *end = dir + size; |
488 | while (dir < end) { |
489 | Qcow2BitmapDirEntry *e = (Qcow2BitmapDirEntry *)dir; |
490 | dir += dir_entry_size(e); |
491 | |
492 | bitmap_dir_entry_to_be(e); |
493 | } |
494 | } |
495 | |
496 | /* |
497 | * Bitmap List public functions |
498 | */ |
499 | |
500 | static void bitmap_free(Qcow2Bitmap *bm) |
501 | { |
502 | if (bm == NULL) { |
503 | return; |
504 | } |
505 | |
506 | g_free(bm->name); |
507 | g_free(bm); |
508 | } |
509 | |
510 | static void bitmap_list_free(Qcow2BitmapList *bm_list) |
511 | { |
512 | Qcow2Bitmap *bm; |
513 | |
514 | if (bm_list == NULL) { |
515 | return; |
516 | } |
517 | |
518 | while ((bm = QSIMPLEQ_FIRST(bm_list)) != NULL) { |
519 | QSIMPLEQ_REMOVE_HEAD(bm_list, entry); |
520 | bitmap_free(bm); |
521 | } |
522 | |
523 | g_free(bm_list); |
524 | } |
525 | |
526 | static Qcow2BitmapList *bitmap_list_new(void) |
527 | { |
528 | Qcow2BitmapList *bm_list = g_new(Qcow2BitmapList, 1); |
529 | QSIMPLEQ_INIT(bm_list); |
530 | |
531 | return bm_list; |
532 | } |
533 | |
534 | static uint32_t bitmap_list_count(Qcow2BitmapList *bm_list) |
535 | { |
536 | Qcow2Bitmap *bm; |
537 | uint32_t nb_bitmaps = 0; |
538 | |
539 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
540 | nb_bitmaps++; |
541 | } |
542 | |
543 | return nb_bitmaps; |
544 | } |
545 | |
546 | /* bitmap_list_load |
547 | * Get bitmap list from qcow2 image. Actually reads bitmap directory, |
548 | * checks it and convert to bitmap list. |
549 | */ |
550 | static Qcow2BitmapList *bitmap_list_load(BlockDriverState *bs, uint64_t offset, |
551 | uint64_t size, Error **errp) |
552 | { |
553 | int ret; |
554 | BDRVQcow2State *s = bs->opaque; |
555 | uint8_t *dir, *dir_end; |
556 | Qcow2BitmapDirEntry *e; |
557 | uint32_t nb_dir_entries = 0; |
558 | Qcow2BitmapList *bm_list = NULL; |
559 | |
560 | if (size == 0) { |
561 | error_setg(errp, "Requested bitmap directory size is zero" ); |
562 | return NULL; |
563 | } |
564 | |
565 | if (size > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { |
566 | error_setg(errp, "Requested bitmap directory size is too big" ); |
567 | return NULL; |
568 | } |
569 | |
570 | dir = g_try_malloc(size); |
571 | if (dir == NULL) { |
572 | error_setg(errp, "Failed to allocate space for bitmap directory" ); |
573 | return NULL; |
574 | } |
575 | dir_end = dir + size; |
576 | |
577 | ret = bdrv_pread(bs->file, offset, dir, size); |
578 | if (ret < 0) { |
579 | error_setg_errno(errp, -ret, "Failed to read bitmap directory" ); |
580 | goto fail; |
581 | } |
582 | |
583 | bm_list = bitmap_list_new(); |
584 | for (e = (Qcow2BitmapDirEntry *)dir; |
585 | e < (Qcow2BitmapDirEntry *)dir_end; |
586 | e = next_dir_entry(e)) |
587 | { |
588 | Qcow2Bitmap *bm; |
589 | |
590 | if ((uint8_t *)(e + 1) > dir_end) { |
591 | goto broken_dir; |
592 | } |
593 | |
594 | if (++nb_dir_entries > s->nb_bitmaps) { |
595 | error_setg(errp, "More bitmaps found than specified in header" |
596 | " extension" ); |
597 | goto fail; |
598 | } |
599 | bitmap_dir_entry_to_cpu(e); |
600 | |
601 | if ((uint8_t *)next_dir_entry(e) > dir_end) { |
602 | goto broken_dir; |
603 | } |
604 | |
605 | if (e->extra_data_size != 0) { |
606 | error_setg(errp, "Bitmap extra data is not supported" ); |
607 | goto fail; |
608 | } |
609 | |
610 | ret = check_dir_entry(bs, e); |
611 | if (ret < 0) { |
612 | error_setg(errp, "Bitmap '%.*s' doesn't satisfy the constraints" , |
613 | e->name_size, dir_entry_name_field(e)); |
614 | goto fail; |
615 | } |
616 | |
617 | bm = g_new0(Qcow2Bitmap, 1); |
618 | bm->table.offset = e->bitmap_table_offset; |
619 | bm->table.size = e->bitmap_table_size; |
620 | bm->flags = e->flags; |
621 | bm->granularity_bits = e->granularity_bits; |
622 | bm->name = dir_entry_copy_name(e); |
623 | QSIMPLEQ_INSERT_TAIL(bm_list, bm, entry); |
624 | } |
625 | |
626 | if (nb_dir_entries != s->nb_bitmaps) { |
627 | error_setg(errp, "Less bitmaps found than specified in header" |
628 | " extension" ); |
629 | goto fail; |
630 | } |
631 | |
632 | if ((uint8_t *)e != dir_end) { |
633 | goto broken_dir; |
634 | } |
635 | |
636 | g_free(dir); |
637 | return bm_list; |
638 | |
639 | broken_dir: |
640 | ret = -EINVAL; |
641 | error_setg(errp, "Broken bitmap directory" ); |
642 | |
643 | fail: |
644 | g_free(dir); |
645 | bitmap_list_free(bm_list); |
646 | |
647 | return NULL; |
648 | } |
649 | |
650 | int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res, |
651 | void **refcount_table, |
652 | int64_t *refcount_table_size) |
653 | { |
654 | int ret; |
655 | BDRVQcow2State *s = bs->opaque; |
656 | Qcow2BitmapList *bm_list; |
657 | Qcow2Bitmap *bm; |
658 | |
659 | if (s->nb_bitmaps == 0) { |
660 | return 0; |
661 | } |
662 | |
663 | ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, refcount_table_size, |
664 | s->bitmap_directory_offset, |
665 | s->bitmap_directory_size); |
666 | if (ret < 0) { |
667 | return ret; |
668 | } |
669 | |
670 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
671 | s->bitmap_directory_size, NULL); |
672 | if (bm_list == NULL) { |
673 | res->corruptions++; |
674 | return -EINVAL; |
675 | } |
676 | |
677 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
678 | uint64_t *bitmap_table = NULL; |
679 | int i; |
680 | |
681 | ret = qcow2_inc_refcounts_imrt(bs, res, |
682 | refcount_table, refcount_table_size, |
683 | bm->table.offset, |
684 | bm->table.size * sizeof(uint64_t)); |
685 | if (ret < 0) { |
686 | goto out; |
687 | } |
688 | |
689 | ret = bitmap_table_load(bs, &bm->table, &bitmap_table); |
690 | if (ret < 0) { |
691 | res->corruptions++; |
692 | goto out; |
693 | } |
694 | |
695 | for (i = 0; i < bm->table.size; ++i) { |
696 | uint64_t entry = bitmap_table[i]; |
697 | uint64_t offset = entry & BME_TABLE_ENTRY_OFFSET_MASK; |
698 | |
699 | if (check_table_entry(entry, s->cluster_size) < 0) { |
700 | res->corruptions++; |
701 | continue; |
702 | } |
703 | |
704 | if (offset == 0) { |
705 | continue; |
706 | } |
707 | |
708 | ret = qcow2_inc_refcounts_imrt(bs, res, |
709 | refcount_table, refcount_table_size, |
710 | offset, s->cluster_size); |
711 | if (ret < 0) { |
712 | g_free(bitmap_table); |
713 | goto out; |
714 | } |
715 | } |
716 | |
717 | g_free(bitmap_table); |
718 | } |
719 | |
720 | out: |
721 | bitmap_list_free(bm_list); |
722 | |
723 | return ret; |
724 | } |
725 | |
726 | /* bitmap_list_store |
727 | * Store bitmap list to qcow2 image as a bitmap directory. |
728 | * Everything is checked. |
729 | */ |
730 | static int bitmap_list_store(BlockDriverState *bs, Qcow2BitmapList *bm_list, |
731 | uint64_t *offset, uint64_t *size, bool in_place) |
732 | { |
733 | int ret; |
734 | uint8_t *dir; |
735 | int64_t dir_offset = 0; |
736 | uint64_t dir_size = 0; |
737 | Qcow2Bitmap *bm; |
738 | Qcow2BitmapDirEntry *e; |
739 | |
740 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
741 | dir_size += calc_dir_entry_size(strlen(bm->name), 0); |
742 | } |
743 | |
744 | if (dir_size == 0 || dir_size > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { |
745 | return -EINVAL; |
746 | } |
747 | |
748 | if (in_place) { |
749 | if (*size != dir_size || *offset == 0) { |
750 | return -EINVAL; |
751 | } |
752 | |
753 | dir_offset = *offset; |
754 | } |
755 | |
756 | dir = g_try_malloc0(dir_size); |
757 | if (dir == NULL) { |
758 | return -ENOMEM; |
759 | } |
760 | |
761 | e = (Qcow2BitmapDirEntry *)dir; |
762 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
763 | e->bitmap_table_offset = bm->table.offset; |
764 | e->bitmap_table_size = bm->table.size; |
765 | e->flags = bm->flags; |
766 | e->type = BT_DIRTY_TRACKING_BITMAP; |
767 | e->granularity_bits = bm->granularity_bits; |
768 | e->name_size = strlen(bm->name); |
769 | e->extra_data_size = 0; |
770 | memcpy(e + 1, bm->name, e->name_size); |
771 | |
772 | if (check_dir_entry(bs, e) < 0) { |
773 | ret = -EINVAL; |
774 | goto fail; |
775 | } |
776 | |
777 | e = next_dir_entry(e); |
778 | } |
779 | |
780 | bitmap_directory_to_be(dir, dir_size); |
781 | |
782 | if (!in_place) { |
783 | dir_offset = qcow2_alloc_clusters(bs, dir_size); |
784 | if (dir_offset < 0) { |
785 | ret = dir_offset; |
786 | goto fail; |
787 | } |
788 | } |
789 | |
790 | /* Actually, even in in-place case ignoring QCOW2_OL_BITMAP_DIRECTORY is not |
791 | * necessary, because we drop QCOW2_AUTOCLEAR_BITMAPS when updating bitmap |
792 | * directory in-place (actually, turn-off the extension), which is checked |
793 | * in qcow2_check_metadata_overlap() */ |
794 | ret = qcow2_pre_write_overlap_check( |
795 | bs, in_place ? QCOW2_OL_BITMAP_DIRECTORY : 0, dir_offset, dir_size, |
796 | false); |
797 | if (ret < 0) { |
798 | goto fail; |
799 | } |
800 | |
801 | ret = bdrv_pwrite(bs->file, dir_offset, dir, dir_size); |
802 | if (ret < 0) { |
803 | goto fail; |
804 | } |
805 | |
806 | g_free(dir); |
807 | |
808 | if (!in_place) { |
809 | *size = dir_size; |
810 | *offset = dir_offset; |
811 | } |
812 | |
813 | return 0; |
814 | |
815 | fail: |
816 | g_free(dir); |
817 | |
818 | if (!in_place && dir_offset > 0) { |
819 | qcow2_free_clusters(bs, dir_offset, dir_size, QCOW2_DISCARD_OTHER); |
820 | } |
821 | |
822 | return ret; |
823 | } |
824 | |
825 | /* |
826 | * Bitmap List end |
827 | */ |
828 | |
829 | static int update_ext_header_and_dir_in_place(BlockDriverState *bs, |
830 | Qcow2BitmapList *bm_list) |
831 | { |
832 | BDRVQcow2State *s = bs->opaque; |
833 | int ret; |
834 | |
835 | if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS) || |
836 | bm_list == NULL || QSIMPLEQ_EMPTY(bm_list) || |
837 | bitmap_list_count(bm_list) != s->nb_bitmaps) |
838 | { |
839 | return -EINVAL; |
840 | } |
841 | |
842 | s->autoclear_features &= ~(uint64_t)QCOW2_AUTOCLEAR_BITMAPS; |
843 | ret = update_header_sync(bs); |
844 | if (ret < 0) { |
845 | /* Two variants are possible here: |
846 | * 1. Autoclear flag is dropped, all bitmaps will be lost. |
847 | * 2. Autoclear flag is not dropped, old state is left. |
848 | */ |
849 | return ret; |
850 | } |
851 | |
852 | /* autoclear bit is not set, so we can safely update bitmap directory */ |
853 | |
854 | ret = bitmap_list_store(bs, bm_list, &s->bitmap_directory_offset, |
855 | &s->bitmap_directory_size, true); |
856 | if (ret < 0) { |
857 | /* autoclear bit is cleared, so all leaked clusters would be removed on |
858 | * qemu-img check */ |
859 | return ret; |
860 | } |
861 | |
862 | ret = update_header_sync(bs); |
863 | if (ret < 0) { |
864 | /* autoclear bit is cleared, so all leaked clusters would be removed on |
865 | * qemu-img check */ |
866 | return ret; |
867 | } |
868 | |
869 | s->autoclear_features |= QCOW2_AUTOCLEAR_BITMAPS; |
870 | return update_header_sync(bs); |
871 | /* If final update_header_sync() fails, two variants are possible: |
872 | * 1. Autoclear flag is not set, all bitmaps will be lost. |
873 | * 2. Autoclear flag is set, header and directory are successfully updated. |
874 | */ |
875 | } |
876 | |
877 | static int update_ext_header_and_dir(BlockDriverState *bs, |
878 | Qcow2BitmapList *bm_list) |
879 | { |
880 | BDRVQcow2State *s = bs->opaque; |
881 | int ret; |
882 | uint64_t new_offset = 0; |
883 | uint64_t new_size = 0; |
884 | uint32_t new_nb_bitmaps = 0; |
885 | uint64_t old_offset = s->bitmap_directory_offset; |
886 | uint64_t old_size = s->bitmap_directory_size; |
887 | uint32_t old_nb_bitmaps = s->nb_bitmaps; |
888 | uint64_t old_autocl = s->autoclear_features; |
889 | |
890 | if (bm_list != NULL && !QSIMPLEQ_EMPTY(bm_list)) { |
891 | new_nb_bitmaps = bitmap_list_count(bm_list); |
892 | |
893 | if (new_nb_bitmaps > QCOW2_MAX_BITMAPS) { |
894 | return -EINVAL; |
895 | } |
896 | |
897 | ret = bitmap_list_store(bs, bm_list, &new_offset, &new_size, false); |
898 | if (ret < 0) { |
899 | return ret; |
900 | } |
901 | |
902 | ret = qcow2_flush_caches(bs); |
903 | if (ret < 0) { |
904 | goto fail; |
905 | } |
906 | |
907 | s->autoclear_features |= QCOW2_AUTOCLEAR_BITMAPS; |
908 | } else { |
909 | s->autoclear_features &= ~(uint64_t)QCOW2_AUTOCLEAR_BITMAPS; |
910 | } |
911 | |
912 | s->bitmap_directory_offset = new_offset; |
913 | s->bitmap_directory_size = new_size; |
914 | s->nb_bitmaps = new_nb_bitmaps; |
915 | |
916 | ret = update_header_sync(bs); |
917 | if (ret < 0) { |
918 | goto fail; |
919 | } |
920 | |
921 | if (old_size > 0) { |
922 | qcow2_free_clusters(bs, old_offset, old_size, QCOW2_DISCARD_OTHER); |
923 | } |
924 | |
925 | return 0; |
926 | |
927 | fail: |
928 | if (new_offset > 0) { |
929 | qcow2_free_clusters(bs, new_offset, new_size, QCOW2_DISCARD_OTHER); |
930 | } |
931 | |
932 | s->bitmap_directory_offset = old_offset; |
933 | s->bitmap_directory_size = old_size; |
934 | s->nb_bitmaps = old_nb_bitmaps; |
935 | s->autoclear_features = old_autocl; |
936 | |
937 | return ret; |
938 | } |
939 | |
940 | /* for g_slist_foreach for GSList of BdrvDirtyBitmap* elements */ |
941 | static void release_dirty_bitmap_helper(gpointer bitmap, |
942 | gpointer bs) |
943 | { |
944 | bdrv_release_dirty_bitmap(bs, bitmap); |
945 | } |
946 | |
947 | /* for g_slist_foreach for GSList of BdrvDirtyBitmap* elements */ |
948 | static void set_readonly_helper(gpointer bitmap, gpointer value) |
949 | { |
950 | bdrv_dirty_bitmap_set_readonly(bitmap, (bool)value); |
951 | } |
952 | |
953 | /* qcow2_load_dirty_bitmaps() |
954 | * Return value is a hint for caller: true means that the Qcow2 header was |
955 | * updated. (false doesn't mean that the header should be updated by the |
956 | * caller, it just means that updating was not needed or the image cannot be |
957 | * written to). |
958 | * On failure the function returns false. |
959 | */ |
960 | bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp) |
961 | { |
962 | BDRVQcow2State *s = bs->opaque; |
963 | Qcow2BitmapList *bm_list; |
964 | Qcow2Bitmap *bm; |
965 | GSList *created_dirty_bitmaps = NULL; |
966 | bool = false; |
967 | bool needs_update = false; |
968 | |
969 | if (s->nb_bitmaps == 0) { |
970 | /* No bitmaps - nothing to do */ |
971 | return false; |
972 | } |
973 | |
974 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
975 | s->bitmap_directory_size, errp); |
976 | if (bm_list == NULL) { |
977 | return false; |
978 | } |
979 | |
980 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
981 | BdrvDirtyBitmap *bitmap = load_bitmap(bs, bm, errp); |
982 | if (bitmap == NULL) { |
983 | goto fail; |
984 | } |
985 | |
986 | bdrv_dirty_bitmap_set_persistence(bitmap, true); |
987 | if (bm->flags & BME_FLAG_IN_USE) { |
988 | bdrv_dirty_bitmap_set_inconsistent(bitmap); |
989 | } else { |
990 | /* NB: updated flags only get written if can_write(bs) is true. */ |
991 | bm->flags |= BME_FLAG_IN_USE; |
992 | needs_update = true; |
993 | } |
994 | if (!(bm->flags & BME_FLAG_AUTO)) { |
995 | bdrv_disable_dirty_bitmap(bitmap); |
996 | } |
997 | created_dirty_bitmaps = |
998 | g_slist_append(created_dirty_bitmaps, bitmap); |
999 | } |
1000 | |
1001 | if (needs_update && can_write(bs)) { |
1002 | /* in_use flags must be updated */ |
1003 | int ret = update_ext_header_and_dir_in_place(bs, bm_list); |
1004 | if (ret < 0) { |
1005 | error_setg_errno(errp, -ret, "Can't update bitmap directory" ); |
1006 | goto fail; |
1007 | } |
1008 | header_updated = true; |
1009 | } |
1010 | |
1011 | if (!can_write(bs)) { |
1012 | g_slist_foreach(created_dirty_bitmaps, set_readonly_helper, |
1013 | (gpointer)true); |
1014 | } |
1015 | |
1016 | g_slist_free(created_dirty_bitmaps); |
1017 | bitmap_list_free(bm_list); |
1018 | |
1019 | return header_updated; |
1020 | |
1021 | fail: |
1022 | g_slist_foreach(created_dirty_bitmaps, release_dirty_bitmap_helper, bs); |
1023 | g_slist_free(created_dirty_bitmaps); |
1024 | bitmap_list_free(bm_list); |
1025 | |
1026 | return false; |
1027 | } |
1028 | |
1029 | |
1030 | static Qcow2BitmapInfoFlagsList *get_bitmap_info_flags(uint32_t flags) |
1031 | { |
1032 | Qcow2BitmapInfoFlagsList *list = NULL; |
1033 | Qcow2BitmapInfoFlagsList **plist = &list; |
1034 | int i; |
1035 | |
1036 | static const struct { |
1037 | int bme; /* Bitmap directory entry flags */ |
1038 | int info; /* The flags to report to the user */ |
1039 | } map[] = { |
1040 | { BME_FLAG_IN_USE, QCOW2_BITMAP_INFO_FLAGS_IN_USE }, |
1041 | { BME_FLAG_AUTO, QCOW2_BITMAP_INFO_FLAGS_AUTO }, |
1042 | }; |
1043 | |
1044 | int map_size = ARRAY_SIZE(map); |
1045 | |
1046 | for (i = 0; i < map_size; ++i) { |
1047 | if (flags & map[i].bme) { |
1048 | Qcow2BitmapInfoFlagsList *entry = |
1049 | g_new0(Qcow2BitmapInfoFlagsList, 1); |
1050 | entry->value = map[i].info; |
1051 | *plist = entry; |
1052 | plist = &entry->next; |
1053 | flags &= ~map[i].bme; |
1054 | } |
1055 | } |
1056 | /* Check if the BME_* mapping above is complete */ |
1057 | assert(!flags); |
1058 | |
1059 | return list; |
1060 | } |
1061 | |
1062 | /* |
1063 | * qcow2_get_bitmap_info_list() |
1064 | * Returns a list of QCOW2 bitmap details. |
1065 | * In case of no bitmaps, the function returns NULL and |
1066 | * the @errp parameter is not set. |
1067 | * When bitmap information can not be obtained, the function returns |
1068 | * NULL and the @errp parameter is set. |
1069 | */ |
1070 | Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs, |
1071 | Error **errp) |
1072 | { |
1073 | BDRVQcow2State *s = bs->opaque; |
1074 | Qcow2BitmapList *bm_list; |
1075 | Qcow2Bitmap *bm; |
1076 | Qcow2BitmapInfoList *list = NULL; |
1077 | Qcow2BitmapInfoList **plist = &list; |
1078 | |
1079 | if (s->nb_bitmaps == 0) { |
1080 | return NULL; |
1081 | } |
1082 | |
1083 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
1084 | s->bitmap_directory_size, errp); |
1085 | if (bm_list == NULL) { |
1086 | return NULL; |
1087 | } |
1088 | |
1089 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
1090 | Qcow2BitmapInfo *info = g_new0(Qcow2BitmapInfo, 1); |
1091 | Qcow2BitmapInfoList *obj = g_new0(Qcow2BitmapInfoList, 1); |
1092 | info->granularity = 1U << bm->granularity_bits; |
1093 | info->name = g_strdup(bm->name); |
1094 | info->flags = get_bitmap_info_flags(bm->flags & ~BME_RESERVED_FLAGS); |
1095 | obj->value = info; |
1096 | *plist = obj; |
1097 | plist = &obj->next; |
1098 | } |
1099 | |
1100 | bitmap_list_free(bm_list); |
1101 | |
1102 | return list; |
1103 | } |
1104 | |
1105 | int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *, |
1106 | Error **errp) |
1107 | { |
1108 | BDRVQcow2State *s = bs->opaque; |
1109 | Qcow2BitmapList *bm_list; |
1110 | Qcow2Bitmap *bm; |
1111 | GSList *ro_dirty_bitmaps = NULL; |
1112 | int ret = 0; |
1113 | |
1114 | if (header_updated != NULL) { |
1115 | *header_updated = false; |
1116 | } |
1117 | |
1118 | if (s->nb_bitmaps == 0) { |
1119 | /* No bitmaps - nothing to do */ |
1120 | return 0; |
1121 | } |
1122 | |
1123 | if (!can_write(bs)) { |
1124 | error_setg(errp, "Can't write to the image on reopening bitmaps rw" ); |
1125 | return -EINVAL; |
1126 | } |
1127 | |
1128 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
1129 | s->bitmap_directory_size, errp); |
1130 | if (bm_list == NULL) { |
1131 | return -EINVAL; |
1132 | } |
1133 | |
1134 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
1135 | BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(bs, bm->name); |
1136 | if (bitmap == NULL) { |
1137 | continue; |
1138 | } |
1139 | |
1140 | if (!bdrv_dirty_bitmap_readonly(bitmap)) { |
1141 | error_setg(errp, "Bitmap %s was loaded prior to rw-reopen, but was " |
1142 | "not marked as readonly. This is a bug, something went " |
1143 | "wrong. All of the bitmaps may be corrupted" , bm->name); |
1144 | ret = -EINVAL; |
1145 | goto out; |
1146 | } |
1147 | |
1148 | bm->flags |= BME_FLAG_IN_USE; |
1149 | ro_dirty_bitmaps = g_slist_append(ro_dirty_bitmaps, bitmap); |
1150 | } |
1151 | |
1152 | if (ro_dirty_bitmaps != NULL) { |
1153 | /* in_use flags must be updated */ |
1154 | ret = update_ext_header_and_dir_in_place(bs, bm_list); |
1155 | if (ret < 0) { |
1156 | error_setg_errno(errp, -ret, "Can't update bitmap directory" ); |
1157 | goto out; |
1158 | } |
1159 | if (header_updated != NULL) { |
1160 | *header_updated = true; |
1161 | } |
1162 | g_slist_foreach(ro_dirty_bitmaps, set_readonly_helper, false); |
1163 | } |
1164 | |
1165 | out: |
1166 | g_slist_free(ro_dirty_bitmaps); |
1167 | bitmap_list_free(bm_list); |
1168 | |
1169 | return ret; |
1170 | } |
1171 | |
1172 | int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp) |
1173 | { |
1174 | return qcow2_reopen_bitmaps_rw_hint(bs, NULL, errp); |
1175 | } |
1176 | |
1177 | /* Checks to see if it's safe to resize bitmaps */ |
1178 | int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp) |
1179 | { |
1180 | BDRVQcow2State *s = bs->opaque; |
1181 | Qcow2BitmapList *bm_list; |
1182 | Qcow2Bitmap *bm; |
1183 | int ret = 0; |
1184 | |
1185 | if (s->nb_bitmaps == 0) { |
1186 | return 0; |
1187 | } |
1188 | |
1189 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
1190 | s->bitmap_directory_size, errp); |
1191 | if (bm_list == NULL) { |
1192 | return -EINVAL; |
1193 | } |
1194 | |
1195 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
1196 | BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(bs, bm->name); |
1197 | if (bitmap == NULL) { |
1198 | /* |
1199 | * We rely on all bitmaps being in-memory to be able to resize them, |
1200 | * Otherwise, we'd need to resize them on disk explicitly |
1201 | */ |
1202 | error_setg(errp, "Cannot resize qcow2 with persistent bitmaps that " |
1203 | "were not loaded into memory" ); |
1204 | ret = -ENOTSUP; |
1205 | goto out; |
1206 | } |
1207 | |
1208 | /* |
1209 | * The checks against readonly and busy are redundant, but certainly |
1210 | * do no harm. checks against inconsistent are crucial: |
1211 | */ |
1212 | if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, errp)) { |
1213 | ret = -ENOTSUP; |
1214 | goto out; |
1215 | } |
1216 | } |
1217 | |
1218 | out: |
1219 | bitmap_list_free(bm_list); |
1220 | return ret; |
1221 | } |
1222 | |
1223 | /* store_bitmap_data() |
1224 | * Store bitmap to image, filling bitmap table accordingly. |
1225 | */ |
1226 | static uint64_t *store_bitmap_data(BlockDriverState *bs, |
1227 | BdrvDirtyBitmap *bitmap, |
1228 | uint32_t *bitmap_table_size, Error **errp) |
1229 | { |
1230 | int ret; |
1231 | BDRVQcow2State *s = bs->opaque; |
1232 | int64_t offset; |
1233 | uint64_t limit; |
1234 | uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap); |
1235 | const char *bm_name = bdrv_dirty_bitmap_name(bitmap); |
1236 | uint8_t *buf = NULL; |
1237 | BdrvDirtyBitmapIter *dbi; |
1238 | uint64_t *tb; |
1239 | uint64_t tb_size = |
1240 | size_to_clusters(s, |
1241 | bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size)); |
1242 | |
1243 | if (tb_size > BME_MAX_TABLE_SIZE || |
1244 | tb_size * s->cluster_size > BME_MAX_PHYS_SIZE) |
1245 | { |
1246 | error_setg(errp, "Bitmap '%s' is too big" , bm_name); |
1247 | return NULL; |
1248 | } |
1249 | |
1250 | tb = g_try_new0(uint64_t, tb_size); |
1251 | if (tb == NULL) { |
1252 | error_setg(errp, "No memory" ); |
1253 | return NULL; |
1254 | } |
1255 | |
1256 | dbi = bdrv_dirty_iter_new(bitmap); |
1257 | buf = g_malloc(s->cluster_size); |
1258 | limit = bytes_covered_by_bitmap_cluster(s, bitmap); |
1259 | assert(DIV_ROUND_UP(bm_size, limit) == tb_size); |
1260 | |
1261 | while ((offset = bdrv_dirty_iter_next(dbi)) >= 0) { |
1262 | uint64_t cluster = offset / limit; |
1263 | uint64_t end, write_size; |
1264 | int64_t off; |
1265 | |
1266 | /* |
1267 | * We found the first dirty offset, but want to write out the |
1268 | * entire cluster of the bitmap that includes that offset, |
1269 | * including any leading zero bits. |
1270 | */ |
1271 | offset = QEMU_ALIGN_DOWN(offset, limit); |
1272 | end = MIN(bm_size, offset + limit); |
1273 | write_size = bdrv_dirty_bitmap_serialization_size(bitmap, offset, |
1274 | end - offset); |
1275 | assert(write_size <= s->cluster_size); |
1276 | |
1277 | off = qcow2_alloc_clusters(bs, s->cluster_size); |
1278 | if (off < 0) { |
1279 | error_setg_errno(errp, -off, |
1280 | "Failed to allocate clusters for bitmap '%s'" , |
1281 | bm_name); |
1282 | goto fail; |
1283 | } |
1284 | tb[cluster] = off; |
1285 | |
1286 | bdrv_dirty_bitmap_serialize_part(bitmap, buf, offset, end - offset); |
1287 | if (write_size < s->cluster_size) { |
1288 | memset(buf + write_size, 0, s->cluster_size - write_size); |
1289 | } |
1290 | |
1291 | ret = qcow2_pre_write_overlap_check(bs, 0, off, s->cluster_size, false); |
1292 | if (ret < 0) { |
1293 | error_setg_errno(errp, -ret, "Qcow2 overlap check failed" ); |
1294 | goto fail; |
1295 | } |
1296 | |
1297 | ret = bdrv_pwrite(bs->file, off, buf, s->cluster_size); |
1298 | if (ret < 0) { |
1299 | error_setg_errno(errp, -ret, "Failed to write bitmap '%s' to file" , |
1300 | bm_name); |
1301 | goto fail; |
1302 | } |
1303 | |
1304 | if (end >= bm_size) { |
1305 | break; |
1306 | } |
1307 | |
1308 | bdrv_set_dirty_iter(dbi, end); |
1309 | } |
1310 | |
1311 | *bitmap_table_size = tb_size; |
1312 | g_free(buf); |
1313 | bdrv_dirty_iter_free(dbi); |
1314 | |
1315 | return tb; |
1316 | |
1317 | fail: |
1318 | clear_bitmap_table(bs, tb, tb_size); |
1319 | g_free(buf); |
1320 | bdrv_dirty_iter_free(dbi); |
1321 | g_free(tb); |
1322 | |
1323 | return NULL; |
1324 | } |
1325 | |
1326 | /* store_bitmap() |
1327 | * Store bm->dirty_bitmap to qcow2. |
1328 | * Set bm->table_offset and bm->table_size accordingly. |
1329 | */ |
1330 | static int store_bitmap(BlockDriverState *bs, Qcow2Bitmap *bm, Error **errp) |
1331 | { |
1332 | int ret; |
1333 | uint64_t *tb; |
1334 | int64_t tb_offset; |
1335 | uint32_t tb_size; |
1336 | BdrvDirtyBitmap *bitmap = bm->dirty_bitmap; |
1337 | const char *bm_name; |
1338 | |
1339 | assert(bitmap != NULL); |
1340 | |
1341 | bm_name = bdrv_dirty_bitmap_name(bitmap); |
1342 | |
1343 | tb = store_bitmap_data(bs, bitmap, &tb_size, errp); |
1344 | if (tb == NULL) { |
1345 | return -EINVAL; |
1346 | } |
1347 | |
1348 | assert(tb_size <= BME_MAX_TABLE_SIZE); |
1349 | tb_offset = qcow2_alloc_clusters(bs, tb_size * sizeof(tb[0])); |
1350 | if (tb_offset < 0) { |
1351 | error_setg_errno(errp, -tb_offset, |
1352 | "Failed to allocate clusters for bitmap '%s'" , |
1353 | bm_name); |
1354 | ret = tb_offset; |
1355 | goto fail; |
1356 | } |
1357 | |
1358 | ret = qcow2_pre_write_overlap_check(bs, 0, tb_offset, |
1359 | tb_size * sizeof(tb[0]), false); |
1360 | if (ret < 0) { |
1361 | error_setg_errno(errp, -ret, "Qcow2 overlap check failed" ); |
1362 | goto fail; |
1363 | } |
1364 | |
1365 | bitmap_table_to_be(tb, tb_size); |
1366 | ret = bdrv_pwrite(bs->file, tb_offset, tb, tb_size * sizeof(tb[0])); |
1367 | if (ret < 0) { |
1368 | error_setg_errno(errp, -ret, "Failed to write bitmap '%s' to file" , |
1369 | bm_name); |
1370 | goto fail; |
1371 | } |
1372 | |
1373 | g_free(tb); |
1374 | |
1375 | bm->table.offset = tb_offset; |
1376 | bm->table.size = tb_size; |
1377 | |
1378 | return 0; |
1379 | |
1380 | fail: |
1381 | clear_bitmap_table(bs, tb, tb_size); |
1382 | |
1383 | if (tb_offset > 0) { |
1384 | qcow2_free_clusters(bs, tb_offset, tb_size * sizeof(tb[0]), |
1385 | QCOW2_DISCARD_OTHER); |
1386 | } |
1387 | |
1388 | g_free(tb); |
1389 | |
1390 | return ret; |
1391 | } |
1392 | |
1393 | static Qcow2Bitmap *find_bitmap_by_name(Qcow2BitmapList *bm_list, |
1394 | const char *name) |
1395 | { |
1396 | Qcow2Bitmap *bm; |
1397 | |
1398 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
1399 | if (strcmp(name, bm->name) == 0) { |
1400 | return bm; |
1401 | } |
1402 | } |
1403 | |
1404 | return NULL; |
1405 | } |
1406 | |
1407 | void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs, |
1408 | const char *name, |
1409 | Error **errp) |
1410 | { |
1411 | int ret; |
1412 | BDRVQcow2State *s = bs->opaque; |
1413 | Qcow2Bitmap *bm; |
1414 | Qcow2BitmapList *bm_list; |
1415 | |
1416 | if (s->nb_bitmaps == 0) { |
1417 | /* Absence of the bitmap is not an error: see explanation above |
1418 | * bdrv_remove_persistent_dirty_bitmap() definition. */ |
1419 | return; |
1420 | } |
1421 | |
1422 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
1423 | s->bitmap_directory_size, errp); |
1424 | if (bm_list == NULL) { |
1425 | return; |
1426 | } |
1427 | |
1428 | bm = find_bitmap_by_name(bm_list, name); |
1429 | if (bm == NULL) { |
1430 | goto fail; |
1431 | } |
1432 | |
1433 | QSIMPLEQ_REMOVE(bm_list, bm, Qcow2Bitmap, entry); |
1434 | |
1435 | ret = update_ext_header_and_dir(bs, bm_list); |
1436 | if (ret < 0) { |
1437 | error_setg_errno(errp, -ret, "Failed to update bitmap extension" ); |
1438 | goto fail; |
1439 | } |
1440 | |
1441 | free_bitmap_clusters(bs, &bm->table); |
1442 | |
1443 | fail: |
1444 | bitmap_free(bm); |
1445 | bitmap_list_free(bm_list); |
1446 | } |
1447 | |
1448 | void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp) |
1449 | { |
1450 | BdrvDirtyBitmap *bitmap; |
1451 | BDRVQcow2State *s = bs->opaque; |
1452 | uint32_t new_nb_bitmaps = s->nb_bitmaps; |
1453 | uint64_t new_dir_size = s->bitmap_directory_size; |
1454 | int ret; |
1455 | Qcow2BitmapList *bm_list; |
1456 | Qcow2Bitmap *bm; |
1457 | QSIMPLEQ_HEAD(, Qcow2BitmapTable) drop_tables; |
1458 | Qcow2BitmapTable *tb, *tb_next; |
1459 | |
1460 | if (!bdrv_has_changed_persistent_bitmaps(bs)) { |
1461 | /* nothing to do */ |
1462 | return; |
1463 | } |
1464 | |
1465 | if (!can_write(bs)) { |
1466 | error_setg(errp, "No write access" ); |
1467 | return; |
1468 | } |
1469 | |
1470 | QSIMPLEQ_INIT(&drop_tables); |
1471 | |
1472 | if (s->nb_bitmaps == 0) { |
1473 | bm_list = bitmap_list_new(); |
1474 | } else { |
1475 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
1476 | s->bitmap_directory_size, errp); |
1477 | if (bm_list == NULL) { |
1478 | return; |
1479 | } |
1480 | } |
1481 | |
1482 | /* check constraints and names */ |
1483 | for (bitmap = bdrv_dirty_bitmap_next(bs, NULL); bitmap != NULL; |
1484 | bitmap = bdrv_dirty_bitmap_next(bs, bitmap)) |
1485 | { |
1486 | const char *name = bdrv_dirty_bitmap_name(bitmap); |
1487 | uint32_t granularity = bdrv_dirty_bitmap_granularity(bitmap); |
1488 | Qcow2Bitmap *bm; |
1489 | |
1490 | if (!bdrv_dirty_bitmap_get_persistence(bitmap) || |
1491 | bdrv_dirty_bitmap_readonly(bitmap) || |
1492 | bdrv_dirty_bitmap_inconsistent(bitmap)) { |
1493 | continue; |
1494 | } |
1495 | |
1496 | if (check_constraints_on_bitmap(bs, name, granularity, errp) < 0) { |
1497 | error_prepend(errp, "Bitmap '%s' doesn't satisfy the constraints: " , |
1498 | name); |
1499 | goto fail; |
1500 | } |
1501 | |
1502 | bm = find_bitmap_by_name(bm_list, name); |
1503 | if (bm == NULL) { |
1504 | if (++new_nb_bitmaps > QCOW2_MAX_BITMAPS) { |
1505 | error_setg(errp, "Too many persistent bitmaps" ); |
1506 | goto fail; |
1507 | } |
1508 | |
1509 | new_dir_size += calc_dir_entry_size(strlen(name), 0); |
1510 | if (new_dir_size > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { |
1511 | error_setg(errp, "Bitmap directory is too large" ); |
1512 | goto fail; |
1513 | } |
1514 | |
1515 | bm = g_new0(Qcow2Bitmap, 1); |
1516 | bm->name = g_strdup(name); |
1517 | QSIMPLEQ_INSERT_TAIL(bm_list, bm, entry); |
1518 | } else { |
1519 | if (!(bm->flags & BME_FLAG_IN_USE)) { |
1520 | error_setg(errp, "Bitmap '%s' already exists in the image" , |
1521 | name); |
1522 | goto fail; |
1523 | } |
1524 | tb = g_memdup(&bm->table, sizeof(bm->table)); |
1525 | bm->table.offset = 0; |
1526 | bm->table.size = 0; |
1527 | QSIMPLEQ_INSERT_TAIL(&drop_tables, tb, entry); |
1528 | } |
1529 | bm->flags = bdrv_dirty_bitmap_enabled(bitmap) ? BME_FLAG_AUTO : 0; |
1530 | bm->granularity_bits = ctz32(bdrv_dirty_bitmap_granularity(bitmap)); |
1531 | bm->dirty_bitmap = bitmap; |
1532 | } |
1533 | |
1534 | /* allocate clusters and store bitmaps */ |
1535 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
1536 | if (bm->dirty_bitmap == NULL) { |
1537 | continue; |
1538 | } |
1539 | |
1540 | ret = store_bitmap(bs, bm, errp); |
1541 | if (ret < 0) { |
1542 | goto fail; |
1543 | } |
1544 | } |
1545 | |
1546 | ret = update_ext_header_and_dir(bs, bm_list); |
1547 | if (ret < 0) { |
1548 | error_setg_errno(errp, -ret, "Failed to update bitmap extension" ); |
1549 | goto fail; |
1550 | } |
1551 | |
1552 | /* Bitmap directory was successfully updated, so, old data can be dropped. |
1553 | * TODO it is better to reuse these clusters */ |
1554 | QSIMPLEQ_FOREACH_SAFE(tb, &drop_tables, entry, tb_next) { |
1555 | free_bitmap_clusters(bs, tb); |
1556 | g_free(tb); |
1557 | } |
1558 | |
1559 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
1560 | /* For safety, we remove bitmap after storing. |
1561 | * We may be here in two cases: |
1562 | * 1. bdrv_close. It's ok to drop bitmap. |
1563 | * 2. inactivation. It means migration without 'dirty-bitmaps' |
1564 | * capability, so bitmaps are not marked with |
1565 | * BdrvDirtyBitmap.migration flags. It's not bad to drop them too, |
1566 | * and reload on invalidation. |
1567 | */ |
1568 | if (bm->dirty_bitmap == NULL) { |
1569 | continue; |
1570 | } |
1571 | |
1572 | bdrv_release_dirty_bitmap(bs, bm->dirty_bitmap); |
1573 | } |
1574 | |
1575 | bitmap_list_free(bm_list); |
1576 | return; |
1577 | |
1578 | fail: |
1579 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
1580 | if (bm->dirty_bitmap == NULL || bm->table.offset == 0) { |
1581 | continue; |
1582 | } |
1583 | |
1584 | free_bitmap_clusters(bs, &bm->table); |
1585 | } |
1586 | |
1587 | QSIMPLEQ_FOREACH_SAFE(tb, &drop_tables, entry, tb_next) { |
1588 | g_free(tb); |
1589 | } |
1590 | |
1591 | bitmap_list_free(bm_list); |
1592 | } |
1593 | |
1594 | int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp) |
1595 | { |
1596 | BdrvDirtyBitmap *bitmap; |
1597 | Error *local_err = NULL; |
1598 | |
1599 | qcow2_store_persistent_dirty_bitmaps(bs, &local_err); |
1600 | if (local_err != NULL) { |
1601 | error_propagate(errp, local_err); |
1602 | return -EINVAL; |
1603 | } |
1604 | |
1605 | for (bitmap = bdrv_dirty_bitmap_next(bs, NULL); bitmap != NULL; |
1606 | bitmap = bdrv_dirty_bitmap_next(bs, bitmap)) |
1607 | { |
1608 | if (bdrv_dirty_bitmap_get_persistence(bitmap)) { |
1609 | bdrv_dirty_bitmap_set_readonly(bitmap, true); |
1610 | } |
1611 | } |
1612 | |
1613 | return 0; |
1614 | } |
1615 | |
1616 | bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs, |
1617 | const char *name, |
1618 | uint32_t granularity, |
1619 | Error **errp) |
1620 | { |
1621 | BDRVQcow2State *s = bs->opaque; |
1622 | bool found; |
1623 | Qcow2BitmapList *bm_list; |
1624 | |
1625 | if (s->qcow_version < 3) { |
1626 | /* Without autoclear_features, we would always have to assume |
1627 | * that a program without persistent dirty bitmap support has |
1628 | * accessed this qcow2 file when opening it, and would thus |
1629 | * have to drop all dirty bitmaps (defeating their purpose). |
1630 | */ |
1631 | error_setg(errp, "Cannot store dirty bitmaps in qcow2 v2 files" ); |
1632 | goto fail; |
1633 | } |
1634 | |
1635 | if (check_constraints_on_bitmap(bs, name, granularity, errp) != 0) { |
1636 | goto fail; |
1637 | } |
1638 | |
1639 | if (s->nb_bitmaps == 0) { |
1640 | return true; |
1641 | } |
1642 | |
1643 | if (s->nb_bitmaps >= QCOW2_MAX_BITMAPS) { |
1644 | error_setg(errp, |
1645 | "Maximum number of persistent bitmaps is already reached" ); |
1646 | goto fail; |
1647 | } |
1648 | |
1649 | if (s->bitmap_directory_size + calc_dir_entry_size(strlen(name), 0) > |
1650 | QCOW2_MAX_BITMAP_DIRECTORY_SIZE) |
1651 | { |
1652 | error_setg(errp, "Not enough space in the bitmap directory" ); |
1653 | goto fail; |
1654 | } |
1655 | |
1656 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
1657 | s->bitmap_directory_size, errp); |
1658 | if (bm_list == NULL) { |
1659 | goto fail; |
1660 | } |
1661 | |
1662 | found = find_bitmap_by_name(bm_list, name); |
1663 | bitmap_list_free(bm_list); |
1664 | if (found) { |
1665 | error_setg(errp, "Bitmap with the same name is already stored" ); |
1666 | goto fail; |
1667 | } |
1668 | |
1669 | return true; |
1670 | |
1671 | fail: |
1672 | error_prepend(errp, "Can't make bitmap '%s' persistent in '%s': " , |
1673 | name, bdrv_get_device_or_node_name(bs)); |
1674 | return false; |
1675 | } |
1676 | |