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f7d0fe02 KW |
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 | ||
25 | #include "qemu-common.h" | |
26 | #include "block_int.h" | |
27 | #include "block/qcow2.h" | |
28 | ||
29 | static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size); | |
92dcb59f | 30 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
f7d0fe02 KW |
31 | int64_t offset, int64_t length, |
32 | int addend); | |
33 | ||
3b88e52b KW |
34 | |
35 | static int cache_refcount_updates = 0; | |
36 | ||
37 | static int write_refcount_block(BDRVQcowState *s) | |
38 | { | |
39 | size_t size = s->cluster_size; | |
40 | ||
41 | if (s->refcount_block_cache_offset == 0) { | |
42 | return 0; | |
43 | } | |
44 | ||
45 | if (bdrv_pwrite(s->hd, s->refcount_block_cache_offset, | |
46 | s->refcount_block_cache, size) != size) | |
47 | { | |
48 | return -EIO; | |
49 | } | |
50 | ||
51 | return 0; | |
52 | } | |
53 | ||
f7d0fe02 KW |
54 | /*********************************************************/ |
55 | /* refcount handling */ | |
56 | ||
ed6ccf0f | 57 | int qcow2_refcount_init(BlockDriverState *bs) |
f7d0fe02 KW |
58 | { |
59 | BDRVQcowState *s = bs->opaque; | |
60 | int ret, refcount_table_size2, i; | |
61 | ||
62 | s->refcount_block_cache = qemu_malloc(s->cluster_size); | |
63 | refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); | |
64 | s->refcount_table = qemu_malloc(refcount_table_size2); | |
65 | if (s->refcount_table_size > 0) { | |
66 | ret = bdrv_pread(s->hd, s->refcount_table_offset, | |
67 | s->refcount_table, refcount_table_size2); | |
68 | if (ret != refcount_table_size2) | |
69 | goto fail; | |
70 | for(i = 0; i < s->refcount_table_size; i++) | |
71 | be64_to_cpus(&s->refcount_table[i]); | |
72 | } | |
73 | return 0; | |
74 | fail: | |
75 | return -ENOMEM; | |
76 | } | |
77 | ||
ed6ccf0f | 78 | void qcow2_refcount_close(BlockDriverState *bs) |
f7d0fe02 KW |
79 | { |
80 | BDRVQcowState *s = bs->opaque; | |
81 | qemu_free(s->refcount_block_cache); | |
82 | qemu_free(s->refcount_table); | |
83 | } | |
84 | ||
85 | ||
86 | static int load_refcount_block(BlockDriverState *bs, | |
87 | int64_t refcount_block_offset) | |
88 | { | |
89 | BDRVQcowState *s = bs->opaque; | |
90 | int ret; | |
3b88e52b KW |
91 | |
92 | if (cache_refcount_updates) { | |
93 | write_refcount_block(s); | |
94 | } | |
95 | ||
f7d0fe02 KW |
96 | ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache, |
97 | s->cluster_size); | |
98 | if (ret != s->cluster_size) | |
99 | return -EIO; | |
100 | s->refcount_block_cache_offset = refcount_block_offset; | |
101 | return 0; | |
102 | } | |
103 | ||
104 | static int get_refcount(BlockDriverState *bs, int64_t cluster_index) | |
105 | { | |
106 | BDRVQcowState *s = bs->opaque; | |
107 | int refcount_table_index, block_index; | |
108 | int64_t refcount_block_offset; | |
109 | ||
110 | refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); | |
111 | if (refcount_table_index >= s->refcount_table_size) | |
112 | return 0; | |
113 | refcount_block_offset = s->refcount_table[refcount_table_index]; | |
114 | if (!refcount_block_offset) | |
115 | return 0; | |
116 | if (refcount_block_offset != s->refcount_block_cache_offset) { | |
117 | /* better than nothing: return allocated if read error */ | |
118 | if (load_refcount_block(bs, refcount_block_offset) < 0) | |
119 | return 1; | |
120 | } | |
121 | block_index = cluster_index & | |
122 | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); | |
123 | return be16_to_cpu(s->refcount_block_cache[block_index]); | |
124 | } | |
125 | ||
05121aed KW |
126 | /* |
127 | * Rounds the refcount table size up to avoid growing the table for each single | |
128 | * refcount block that is allocated. | |
129 | */ | |
130 | static unsigned int next_refcount_table_size(BDRVQcowState *s, | |
131 | unsigned int min_size) | |
132 | { | |
133 | unsigned int min_clusters = (min_size >> (s->cluster_bits - 3)) + 1; | |
134 | unsigned int refcount_table_clusters = | |
135 | MAX(1, s->refcount_table_size >> (s->cluster_bits - 3)); | |
136 | ||
137 | while (min_clusters > refcount_table_clusters) { | |
138 | refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; | |
139 | } | |
140 | ||
141 | return refcount_table_clusters << (s->cluster_bits - 3); | |
142 | } | |
143 | ||
92dcb59f KW |
144 | |
145 | /* Checks if two offsets are described by the same refcount block */ | |
146 | static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a, | |
147 | uint64_t offset_b) | |
148 | { | |
149 | uint64_t block_a = offset_a >> (2 * s->cluster_bits - REFCOUNT_SHIFT); | |
150 | uint64_t block_b = offset_b >> (2 * s->cluster_bits - REFCOUNT_SHIFT); | |
151 | ||
152 | return (block_a == block_b); | |
153 | } | |
154 | ||
155 | /* | |
156 | * Loads a refcount block. If it doesn't exist yet, it is allocated first | |
157 | * (including growing the refcount table if needed). | |
158 | * | |
159 | * Returns the offset of the refcount block on success or -errno in error case | |
160 | */ | |
161 | static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index) | |
f7d0fe02 KW |
162 | { |
163 | BDRVQcowState *s = bs->opaque; | |
92dcb59f KW |
164 | unsigned int refcount_table_index; |
165 | int ret; | |
166 | ||
167 | /* Find the refcount block for the given cluster */ | |
168 | refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); | |
169 | ||
170 | if (refcount_table_index < s->refcount_table_size) { | |
171 | ||
172 | uint64_t refcount_block_offset = | |
173 | s->refcount_table[refcount_table_index]; | |
174 | ||
175 | /* If it's already there, we're done */ | |
176 | if (refcount_block_offset) { | |
177 | if (refcount_block_offset != s->refcount_block_cache_offset) { | |
178 | ret = load_refcount_block(bs, refcount_block_offset); | |
179 | if (ret < 0) { | |
180 | return ret; | |
181 | } | |
182 | } | |
183 | return refcount_block_offset; | |
184 | } | |
185 | } | |
186 | ||
187 | /* | |
188 | * If we came here, we need to allocate something. Something is at least | |
189 | * a cluster for the new refcount block. It may also include a new refcount | |
190 | * table if the old refcount table is too small. | |
191 | * | |
192 | * Note that allocating clusters here needs some special care: | |
193 | * | |
194 | * - We can't use the normal qcow2_alloc_clusters(), it would try to | |
195 | * increase the refcount and very likely we would end up with an endless | |
196 | * recursion. Instead we must place the refcount blocks in a way that | |
197 | * they can describe them themselves. | |
198 | * | |
199 | * - We need to consider that at this point we are inside update_refcounts | |
200 | * and doing the initial refcount increase. This means that some clusters | |
201 | * have already been allocated by the caller, but their refcount isn't | |
202 | * accurate yet. free_cluster_index tells us where this allocation ends | |
203 | * as long as we don't overwrite it by freeing clusters. | |
204 | * | |
205 | * - alloc_clusters_noref and qcow2_free_clusters may load a different | |
206 | * refcount block into the cache | |
207 | */ | |
208 | ||
209 | if (cache_refcount_updates) { | |
210 | ret = write_refcount_block(s); | |
211 | if (ret < 0) { | |
212 | return ret; | |
213 | } | |
214 | } | |
215 | ||
216 | /* Allocate the refcount block itself and mark it as used */ | |
217 | uint64_t new_block = alloc_clusters_noref(bs, s->cluster_size); | |
218 | memset(s->refcount_block_cache, 0, s->cluster_size); | |
219 | s->refcount_block_cache_offset = new_block; | |
f7d0fe02 | 220 | |
f7d0fe02 | 221 | #ifdef DEBUG_ALLOC2 |
92dcb59f KW |
222 | fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64 |
223 | " at %" PRIx64 "\n", | |
224 | refcount_table_index, cluster_index << s->cluster_bits, new_block); | |
f7d0fe02 | 225 | #endif |
92dcb59f KW |
226 | |
227 | if (in_same_refcount_block(s, new_block, cluster_index << s->cluster_bits)) { | |
228 | /* The block describes itself, need to update the cache */ | |
229 | int block_index = (new_block >> s->cluster_bits) & | |
230 | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); | |
231 | s->refcount_block_cache[block_index] = cpu_to_be16(1); | |
232 | } else { | |
233 | /* Described somewhere else. This can recurse at most twice before we | |
234 | * arrive at a block that describes itself. */ | |
235 | ret = update_refcount(bs, new_block, s->cluster_size, 1); | |
236 | if (ret < 0) { | |
237 | goto fail_block; | |
238 | } | |
239 | } | |
240 | ||
241 | /* Now the new refcount block needs to be written to disk */ | |
242 | ret = bdrv_pwrite(s->hd, new_block, s->refcount_block_cache, | |
243 | s->cluster_size); | |
244 | if (ret < 0) { | |
245 | goto fail_block; | |
246 | } | |
247 | ||
248 | /* If the refcount table is big enough, just hook the block up there */ | |
249 | if (refcount_table_index < s->refcount_table_size) { | |
250 | uint64_t data64 = cpu_to_be64(new_block); | |
251 | ret = bdrv_pwrite(s->hd, | |
252 | s->refcount_table_offset + refcount_table_index * sizeof(uint64_t), | |
253 | &data64, sizeof(data64)); | |
254 | if (ret < 0) { | |
255 | goto fail_block; | |
256 | } | |
257 | ||
258 | s->refcount_table[refcount_table_index] = new_block; | |
259 | return new_block; | |
260 | } | |
261 | ||
262 | /* | |
263 | * If we come here, we need to grow the refcount table. Again, a new | |
264 | * refcount table needs some space and we can't simply allocate to avoid | |
265 | * endless recursion. | |
266 | * | |
267 | * Therefore let's grab new refcount blocks at the end of the image, which | |
268 | * will describe themselves and the new refcount table. This way we can | |
269 | * reference them only in the new table and do the switch to the new | |
270 | * refcount table at once without producing an inconsistent state in | |
271 | * between. | |
272 | */ | |
273 | /* Calculate the number of refcount blocks needed so far */ | |
274 | uint64_t refcount_block_clusters = 1 << (s->cluster_bits - REFCOUNT_SHIFT); | |
275 | uint64_t blocks_used = (s->free_cluster_index + | |
276 | refcount_block_clusters - 1) / refcount_block_clusters; | |
277 | ||
278 | /* And now we need at least one block more for the new metadata */ | |
279 | uint64_t table_size = next_refcount_table_size(s, blocks_used + 1); | |
280 | uint64_t last_table_size; | |
281 | uint64_t blocks_clusters; | |
282 | do { | |
283 | uint64_t table_clusters = size_to_clusters(s, table_size); | |
284 | blocks_clusters = 1 + | |
285 | ((table_clusters + refcount_block_clusters - 1) | |
286 | / refcount_block_clusters); | |
287 | uint64_t meta_clusters = table_clusters + blocks_clusters; | |
288 | ||
289 | last_table_size = table_size; | |
290 | table_size = next_refcount_table_size(s, blocks_used + | |
291 | ((meta_clusters + refcount_block_clusters - 1) | |
292 | / refcount_block_clusters)); | |
293 | ||
294 | } while (last_table_size != table_size); | |
295 | ||
296 | #ifdef DEBUG_ALLOC2 | |
297 | fprintf(stderr, "qcow2: Grow refcount table %" PRId32 " => %" PRId64 "\n", | |
298 | s->refcount_table_size, table_size); | |
299 | #endif | |
300 | ||
301 | /* Create the new refcount table and blocks */ | |
302 | uint64_t meta_offset = (blocks_used * refcount_block_clusters) * | |
303 | s->cluster_size; | |
304 | uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size; | |
305 | uint16_t *new_blocks = qemu_mallocz(blocks_clusters * s->cluster_size); | |
306 | uint64_t *new_table = qemu_mallocz(table_size * sizeof(uint64_t)); | |
307 | ||
308 | assert(meta_offset >= (s->free_cluster_index * s->cluster_size)); | |
309 | ||
310 | /* Fill the new refcount table */ | |
f7d0fe02 | 311 | memcpy(new_table, s->refcount_table, |
92dcb59f KW |
312 | s->refcount_table_size * sizeof(uint64_t)); |
313 | new_table[refcount_table_index] = new_block; | |
314 | ||
315 | int i; | |
316 | for (i = 0; i < blocks_clusters; i++) { | |
317 | new_table[blocks_used + i] = meta_offset + (i * s->cluster_size); | |
318 | } | |
319 | ||
320 | /* Fill the refcount blocks */ | |
321 | uint64_t table_clusters = size_to_clusters(s, table_size * sizeof(uint64_t)); | |
322 | int block = 0; | |
323 | for (i = 0; i < table_clusters + blocks_clusters; i++) { | |
324 | new_blocks[block++] = cpu_to_be16(1); | |
325 | } | |
326 | ||
327 | /* Write refcount blocks to disk */ | |
328 | ret = bdrv_pwrite(s->hd, meta_offset, new_blocks, | |
329 | blocks_clusters * s->cluster_size); | |
330 | qemu_free(new_blocks); | |
331 | if (ret < 0) { | |
332 | goto fail_table; | |
333 | } | |
334 | ||
335 | /* Write refcount table to disk */ | |
336 | for(i = 0; i < table_size; i++) { | |
337 | cpu_to_be64s(&new_table[i]); | |
338 | } | |
339 | ||
340 | ret = bdrv_pwrite(s->hd, table_offset, new_table, | |
341 | table_size * sizeof(uint64_t)); | |
342 | if (ret < 0) { | |
343 | goto fail_table; | |
344 | } | |
345 | ||
346 | for(i = 0; i < table_size; i++) { | |
f7d0fe02 | 347 | cpu_to_be64s(&new_table[i]); |
92dcb59f | 348 | } |
f7d0fe02 | 349 | |
92dcb59f KW |
350 | /* Hook up the new refcount table in the qcow2 header */ |
351 | uint8_t data[12]; | |
f7d0fe02 | 352 | cpu_to_be64w((uint64_t*)data, table_offset); |
92dcb59f | 353 | cpu_to_be32w((uint32_t*)(data + 8), table_clusters); |
f2b7c8b3 | 354 | ret = bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset), |
92dcb59f KW |
355 | data, sizeof(data)); |
356 | if (ret < 0) { | |
357 | goto fail_table; | |
f2b7c8b3 KW |
358 | } |
359 | ||
92dcb59f KW |
360 | /* And switch it in memory */ |
361 | uint64_t old_table_offset = s->refcount_table_offset; | |
362 | uint64_t old_table_size = s->refcount_table_size; | |
363 | ||
f7d0fe02 | 364 | qemu_free(s->refcount_table); |
f7d0fe02 | 365 | s->refcount_table = new_table; |
92dcb59f | 366 | s->refcount_table_size = table_size; |
f7d0fe02 KW |
367 | s->refcount_table_offset = table_offset; |
368 | ||
92dcb59f KW |
369 | /* Free old table. Remember, we must not change free_cluster_index */ |
370 | uint64_t old_free_cluster_index = s->free_cluster_index; | |
ed6ccf0f | 371 | qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t)); |
92dcb59f | 372 | s->free_cluster_index = old_free_cluster_index; |
f7d0fe02 | 373 | |
92dcb59f KW |
374 | ret = load_refcount_block(bs, new_block); |
375 | if (ret < 0) { | |
376 | goto fail_block; | |
f7d0fe02 KW |
377 | } |
378 | ||
92dcb59f | 379 | return new_block; |
f7d0fe02 | 380 | |
92dcb59f KW |
381 | fail_table: |
382 | qemu_free(new_table); | |
383 | fail_block: | |
384 | s->refcount_block_cache_offset = 0; | |
385 | return ret; | |
f7d0fe02 KW |
386 | } |
387 | ||
9923e05e KW |
388 | #define REFCOUNTS_PER_SECTOR (512 >> REFCOUNT_SHIFT) |
389 | static int write_refcount_block_entries(BDRVQcowState *s, | |
390 | int64_t refcount_block_offset, int first_index, int last_index) | |
391 | { | |
392 | size_t size; | |
393 | ||
3b88e52b KW |
394 | if (cache_refcount_updates) { |
395 | return 0; | |
396 | } | |
397 | ||
9923e05e KW |
398 | first_index &= ~(REFCOUNTS_PER_SECTOR - 1); |
399 | last_index = (last_index + REFCOUNTS_PER_SECTOR) | |
400 | & ~(REFCOUNTS_PER_SECTOR - 1); | |
401 | ||
402 | size = (last_index - first_index) << REFCOUNT_SHIFT; | |
403 | if (bdrv_pwrite(s->hd, | |
404 | refcount_block_offset + (first_index << REFCOUNT_SHIFT), | |
405 | &s->refcount_block_cache[first_index], size) != size) | |
406 | { | |
407 | return -EIO; | |
408 | } | |
409 | ||
410 | return 0; | |
411 | } | |
412 | ||
f7d0fe02 | 413 | /* XXX: cache several refcount block clusters ? */ |
db3a964f KW |
414 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
415 | int64_t offset, int64_t length, int addend) | |
f7d0fe02 KW |
416 | { |
417 | BDRVQcowState *s = bs->opaque; | |
418 | int64_t start, last, cluster_offset; | |
419 | int64_t refcount_block_offset = 0; | |
420 | int64_t table_index = -1, old_table_index; | |
421 | int first_index = -1, last_index = -1; | |
09508d13 | 422 | int ret; |
f7d0fe02 KW |
423 | |
424 | #ifdef DEBUG_ALLOC2 | |
0bf9e31a | 425 | printf("update_refcount: offset=%" PRId64 " size=%" PRId64 " addend=%d\n", |
f7d0fe02 KW |
426 | offset, length, addend); |
427 | #endif | |
7322afe7 | 428 | if (length < 0) { |
f7d0fe02 | 429 | return -EINVAL; |
7322afe7 KW |
430 | } else if (length == 0) { |
431 | return 0; | |
432 | } | |
433 | ||
f7d0fe02 KW |
434 | start = offset & ~(s->cluster_size - 1); |
435 | last = (offset + length - 1) & ~(s->cluster_size - 1); | |
436 | for(cluster_offset = start; cluster_offset <= last; | |
437 | cluster_offset += s->cluster_size) | |
438 | { | |
439 | int block_index, refcount; | |
440 | int64_t cluster_index = cluster_offset >> s->cluster_bits; | |
09508d13 | 441 | int64_t new_block; |
f7d0fe02 KW |
442 | |
443 | /* Only write refcount block to disk when we are done with it */ | |
444 | old_table_index = table_index; | |
445 | table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); | |
446 | if ((old_table_index >= 0) && (table_index != old_table_index)) { | |
9923e05e KW |
447 | |
448 | if (write_refcount_block_entries(s, refcount_block_offset, | |
449 | first_index, last_index) < 0) | |
f7d0fe02 KW |
450 | { |
451 | return -EIO; | |
452 | } | |
453 | ||
454 | first_index = -1; | |
455 | last_index = -1; | |
456 | } | |
457 | ||
458 | /* Load the refcount block and allocate it if needed */ | |
09508d13 KW |
459 | new_block = alloc_refcount_block(bs, cluster_index); |
460 | if (new_block < 0) { | |
461 | ret = new_block; | |
462 | goto fail; | |
f7d0fe02 | 463 | } |
09508d13 | 464 | refcount_block_offset = new_block; |
f7d0fe02 KW |
465 | |
466 | /* we can update the count and save it */ | |
467 | block_index = cluster_index & | |
468 | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); | |
469 | if (first_index == -1 || block_index < first_index) { | |
470 | first_index = block_index; | |
471 | } | |
472 | if (block_index > last_index) { | |
473 | last_index = block_index; | |
474 | } | |
475 | ||
476 | refcount = be16_to_cpu(s->refcount_block_cache[block_index]); | |
477 | refcount += addend; | |
09508d13 KW |
478 | if (refcount < 0 || refcount > 0xffff) { |
479 | ret = -EINVAL; | |
480 | goto fail; | |
481 | } | |
f7d0fe02 KW |
482 | if (refcount == 0 && cluster_index < s->free_cluster_index) { |
483 | s->free_cluster_index = cluster_index; | |
484 | } | |
485 | s->refcount_block_cache[block_index] = cpu_to_be16(refcount); | |
486 | } | |
487 | ||
09508d13 KW |
488 | ret = 0; |
489 | fail: | |
490 | ||
f7d0fe02 KW |
491 | /* Write last changed block to disk */ |
492 | if (refcount_block_offset != 0) { | |
9923e05e KW |
493 | if (write_refcount_block_entries(s, refcount_block_offset, |
494 | first_index, last_index) < 0) | |
f7d0fe02 | 495 | { |
09508d13 | 496 | return ret < 0 ? ret : -EIO; |
f7d0fe02 KW |
497 | } |
498 | } | |
499 | ||
09508d13 KW |
500 | /* |
501 | * Try do undo any updates if an error is returned (This may succeed in | |
502 | * some cases like ENOSPC for allocating a new refcount block) | |
503 | */ | |
504 | if (ret < 0) { | |
505 | int dummy; | |
506 | dummy = update_refcount(bs, offset, cluster_offset - offset, -addend); | |
507 | } | |
508 | ||
509 | return ret; | |
f7d0fe02 KW |
510 | } |
511 | ||
512 | /* addend must be 1 or -1 */ | |
513 | static int update_cluster_refcount(BlockDriverState *bs, | |
514 | int64_t cluster_index, | |
515 | int addend) | |
516 | { | |
517 | BDRVQcowState *s = bs->opaque; | |
518 | int ret; | |
519 | ||
520 | ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend); | |
521 | if (ret < 0) { | |
522 | return ret; | |
523 | } | |
524 | ||
525 | return get_refcount(bs, cluster_index); | |
526 | } | |
527 | ||
528 | ||
529 | ||
530 | /*********************************************************/ | |
531 | /* cluster allocation functions */ | |
532 | ||
533 | ||
534 | ||
535 | /* return < 0 if error */ | |
536 | static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size) | |
537 | { | |
538 | BDRVQcowState *s = bs->opaque; | |
539 | int i, nb_clusters; | |
540 | ||
541 | nb_clusters = size_to_clusters(s, size); | |
542 | retry: | |
543 | for(i = 0; i < nb_clusters; i++) { | |
544 | int64_t i = s->free_cluster_index++; | |
545 | if (get_refcount(bs, i) != 0) | |
546 | goto retry; | |
547 | } | |
548 | #ifdef DEBUG_ALLOC2 | |
0bf9e31a | 549 | printf("alloc_clusters: size=%" PRId64 " -> %" PRId64 "\n", |
f7d0fe02 KW |
550 | size, |
551 | (s->free_cluster_index - nb_clusters) << s->cluster_bits); | |
552 | #endif | |
553 | return (s->free_cluster_index - nb_clusters) << s->cluster_bits; | |
554 | } | |
555 | ||
ed6ccf0f | 556 | int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size) |
f7d0fe02 KW |
557 | { |
558 | int64_t offset; | |
db3a964f | 559 | int ret; |
f7d0fe02 KW |
560 | |
561 | offset = alloc_clusters_noref(bs, size); | |
db3a964f KW |
562 | ret = update_refcount(bs, offset, size, 1); |
563 | if (ret < 0) { | |
564 | return ret; | |
565 | } | |
f7d0fe02 KW |
566 | return offset; |
567 | } | |
568 | ||
569 | /* only used to allocate compressed sectors. We try to allocate | |
570 | contiguous sectors. size must be <= cluster_size */ | |
ed6ccf0f | 571 | int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size) |
f7d0fe02 KW |
572 | { |
573 | BDRVQcowState *s = bs->opaque; | |
574 | int64_t offset, cluster_offset; | |
575 | int free_in_cluster; | |
576 | ||
577 | assert(size > 0 && size <= s->cluster_size); | |
578 | if (s->free_byte_offset == 0) { | |
ed6ccf0f | 579 | s->free_byte_offset = qcow2_alloc_clusters(bs, s->cluster_size); |
5d757b56 KW |
580 | if (s->free_byte_offset < 0) { |
581 | return s->free_byte_offset; | |
582 | } | |
f7d0fe02 KW |
583 | } |
584 | redo: | |
585 | free_in_cluster = s->cluster_size - | |
586 | (s->free_byte_offset & (s->cluster_size - 1)); | |
587 | if (size <= free_in_cluster) { | |
588 | /* enough space in current cluster */ | |
589 | offset = s->free_byte_offset; | |
590 | s->free_byte_offset += size; | |
591 | free_in_cluster -= size; | |
592 | if (free_in_cluster == 0) | |
593 | s->free_byte_offset = 0; | |
594 | if ((offset & (s->cluster_size - 1)) != 0) | |
595 | update_cluster_refcount(bs, offset >> s->cluster_bits, 1); | |
596 | } else { | |
ed6ccf0f | 597 | offset = qcow2_alloc_clusters(bs, s->cluster_size); |
5d757b56 KW |
598 | if (offset < 0) { |
599 | return offset; | |
600 | } | |
f7d0fe02 KW |
601 | cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1); |
602 | if ((cluster_offset + s->cluster_size) == offset) { | |
603 | /* we are lucky: contiguous data */ | |
604 | offset = s->free_byte_offset; | |
605 | update_cluster_refcount(bs, offset >> s->cluster_bits, 1); | |
606 | s->free_byte_offset += size; | |
607 | } else { | |
608 | s->free_byte_offset = offset; | |
609 | goto redo; | |
610 | } | |
611 | } | |
612 | return offset; | |
613 | } | |
614 | ||
ed6ccf0f | 615 | void qcow2_free_clusters(BlockDriverState *bs, |
f7d0fe02 KW |
616 | int64_t offset, int64_t size) |
617 | { | |
db3a964f KW |
618 | int ret; |
619 | ||
620 | ret = update_refcount(bs, offset, size, -1); | |
621 | if (ret < 0) { | |
622 | fprintf(stderr, "qcow2_free_clusters failed: %s\n", strerror(-ret)); | |
623 | abort(); | |
624 | } | |
f7d0fe02 KW |
625 | } |
626 | ||
45aba42f KW |
627 | /* |
628 | * free_any_clusters | |
629 | * | |
630 | * free clusters according to its type: compressed or not | |
631 | * | |
632 | */ | |
633 | ||
ed6ccf0f | 634 | void qcow2_free_any_clusters(BlockDriverState *bs, |
45aba42f KW |
635 | uint64_t cluster_offset, int nb_clusters) |
636 | { | |
637 | BDRVQcowState *s = bs->opaque; | |
638 | ||
639 | /* free the cluster */ | |
640 | ||
641 | if (cluster_offset & QCOW_OFLAG_COMPRESSED) { | |
642 | int nb_csectors; | |
643 | nb_csectors = ((cluster_offset >> s->csize_shift) & | |
644 | s->csize_mask) + 1; | |
ed6ccf0f KW |
645 | qcow2_free_clusters(bs, |
646 | (cluster_offset & s->cluster_offset_mask) & ~511, | |
647 | nb_csectors * 512); | |
45aba42f KW |
648 | return; |
649 | } | |
650 | ||
ed6ccf0f | 651 | qcow2_free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits); |
45aba42f KW |
652 | |
653 | return; | |
654 | } | |
655 | ||
f7d0fe02 KW |
656 | |
657 | ||
658 | /*********************************************************/ | |
659 | /* snapshots and image creation */ | |
660 | ||
661 | ||
662 | ||
ed6ccf0f KW |
663 | void qcow2_create_refcount_update(QCowCreateState *s, int64_t offset, |
664 | int64_t size) | |
f7d0fe02 KW |
665 | { |
666 | int refcount; | |
667 | int64_t start, last, cluster_offset; | |
668 | uint16_t *p; | |
669 | ||
670 | start = offset & ~(s->cluster_size - 1); | |
671 | last = (offset + size - 1) & ~(s->cluster_size - 1); | |
672 | for(cluster_offset = start; cluster_offset <= last; | |
673 | cluster_offset += s->cluster_size) { | |
674 | p = &s->refcount_block[cluster_offset >> s->cluster_bits]; | |
675 | refcount = be16_to_cpu(*p); | |
676 | refcount++; | |
677 | *p = cpu_to_be16(refcount); | |
678 | } | |
679 | } | |
680 | ||
681 | /* update the refcounts of snapshots and the copied flag */ | |
ed6ccf0f KW |
682 | int qcow2_update_snapshot_refcount(BlockDriverState *bs, |
683 | int64_t l1_table_offset, int l1_size, int addend) | |
f7d0fe02 KW |
684 | { |
685 | BDRVQcowState *s = bs->opaque; | |
686 | uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; | |
687 | int64_t old_offset, old_l2_offset; | |
688 | int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount; | |
689 | ||
ed6ccf0f | 690 | qcow2_l2_cache_reset(bs); |
3b88e52b | 691 | cache_refcount_updates = 1; |
f7d0fe02 KW |
692 | |
693 | l2_table = NULL; | |
694 | l1_table = NULL; | |
695 | l1_size2 = l1_size * sizeof(uint64_t); | |
f7d0fe02 | 696 | if (l1_table_offset != s->l1_table_offset) { |
702ef63f KW |
697 | if (l1_size2 != 0) { |
698 | l1_table = qemu_mallocz(align_offset(l1_size2, 512)); | |
699 | } else { | |
700 | l1_table = NULL; | |
701 | } | |
f7d0fe02 KW |
702 | l1_allocated = 1; |
703 | if (bdrv_pread(s->hd, l1_table_offset, | |
704 | l1_table, l1_size2) != l1_size2) | |
705 | goto fail; | |
706 | for(i = 0;i < l1_size; i++) | |
707 | be64_to_cpus(&l1_table[i]); | |
708 | } else { | |
709 | assert(l1_size == s->l1_size); | |
710 | l1_table = s->l1_table; | |
711 | l1_allocated = 0; | |
712 | } | |
713 | ||
714 | l2_size = s->l2_size * sizeof(uint64_t); | |
715 | l2_table = qemu_malloc(l2_size); | |
716 | l1_modified = 0; | |
717 | for(i = 0; i < l1_size; i++) { | |
718 | l2_offset = l1_table[i]; | |
719 | if (l2_offset) { | |
720 | old_l2_offset = l2_offset; | |
721 | l2_offset &= ~QCOW_OFLAG_COPIED; | |
722 | l2_modified = 0; | |
723 | if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size) | |
724 | goto fail; | |
725 | for(j = 0; j < s->l2_size; j++) { | |
726 | offset = be64_to_cpu(l2_table[j]); | |
727 | if (offset != 0) { | |
728 | old_offset = offset; | |
729 | offset &= ~QCOW_OFLAG_COPIED; | |
730 | if (offset & QCOW_OFLAG_COMPRESSED) { | |
731 | nb_csectors = ((offset >> s->csize_shift) & | |
732 | s->csize_mask) + 1; | |
db3a964f KW |
733 | if (addend != 0) { |
734 | int ret; | |
735 | ret = update_refcount(bs, | |
736 | (offset & s->cluster_offset_mask) & ~511, | |
737 | nb_csectors * 512, addend); | |
738 | if (ret < 0) { | |
739 | goto fail; | |
740 | } | |
741 | } | |
f7d0fe02 KW |
742 | /* compressed clusters are never modified */ |
743 | refcount = 2; | |
744 | } else { | |
745 | if (addend != 0) { | |
746 | refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend); | |
747 | } else { | |
748 | refcount = get_refcount(bs, offset >> s->cluster_bits); | |
749 | } | |
750 | } | |
751 | ||
752 | if (refcount == 1) { | |
753 | offset |= QCOW_OFLAG_COPIED; | |
754 | } | |
755 | if (offset != old_offset) { | |
756 | l2_table[j] = cpu_to_be64(offset); | |
757 | l2_modified = 1; | |
758 | } | |
759 | } | |
760 | } | |
761 | if (l2_modified) { | |
762 | if (bdrv_pwrite(s->hd, | |
763 | l2_offset, l2_table, l2_size) != l2_size) | |
764 | goto fail; | |
765 | } | |
766 | ||
767 | if (addend != 0) { | |
768 | refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); | |
769 | } else { | |
770 | refcount = get_refcount(bs, l2_offset >> s->cluster_bits); | |
771 | } | |
772 | if (refcount == 1) { | |
773 | l2_offset |= QCOW_OFLAG_COPIED; | |
774 | } | |
775 | if (l2_offset != old_l2_offset) { | |
776 | l1_table[i] = l2_offset; | |
777 | l1_modified = 1; | |
778 | } | |
779 | } | |
780 | } | |
781 | if (l1_modified) { | |
782 | for(i = 0; i < l1_size; i++) | |
783 | cpu_to_be64s(&l1_table[i]); | |
784 | if (bdrv_pwrite(s->hd, l1_table_offset, l1_table, | |
785 | l1_size2) != l1_size2) | |
786 | goto fail; | |
787 | for(i = 0; i < l1_size; i++) | |
788 | be64_to_cpus(&l1_table[i]); | |
789 | } | |
790 | if (l1_allocated) | |
791 | qemu_free(l1_table); | |
792 | qemu_free(l2_table); | |
3b88e52b KW |
793 | cache_refcount_updates = 0; |
794 | write_refcount_block(s); | |
f7d0fe02 KW |
795 | return 0; |
796 | fail: | |
797 | if (l1_allocated) | |
798 | qemu_free(l1_table); | |
799 | qemu_free(l2_table); | |
3b88e52b KW |
800 | cache_refcount_updates = 0; |
801 | write_refcount_block(s); | |
f7d0fe02 KW |
802 | return -EIO; |
803 | } | |
804 | ||
805 | ||
806 | ||
807 | ||
808 | /*********************************************************/ | |
809 | /* refcount checking functions */ | |
810 | ||
811 | ||
812 | ||
813 | /* | |
814 | * Increases the refcount for a range of clusters in a given refcount table. | |
815 | * This is used to construct a temporary refcount table out of L1 and L2 tables | |
816 | * which can be compared the the refcount table saved in the image. | |
817 | * | |
818 | * Returns the number of errors in the image that were found | |
819 | */ | |
820 | static int inc_refcounts(BlockDriverState *bs, | |
821 | uint16_t *refcount_table, | |
822 | int refcount_table_size, | |
823 | int64_t offset, int64_t size) | |
824 | { | |
825 | BDRVQcowState *s = bs->opaque; | |
826 | int64_t start, last, cluster_offset; | |
827 | int k; | |
828 | int errors = 0; | |
829 | ||
830 | if (size <= 0) | |
831 | return 0; | |
832 | ||
833 | start = offset & ~(s->cluster_size - 1); | |
834 | last = (offset + size - 1) & ~(s->cluster_size - 1); | |
835 | for(cluster_offset = start; cluster_offset <= last; | |
836 | cluster_offset += s->cluster_size) { | |
837 | k = cluster_offset >> s->cluster_bits; | |
838 | if (k < 0 || k >= refcount_table_size) { | |
839 | fprintf(stderr, "ERROR: invalid cluster offset=0x%" PRIx64 "\n", | |
840 | cluster_offset); | |
841 | errors++; | |
842 | } else { | |
843 | if (++refcount_table[k] == 0) { | |
844 | fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64 | |
845 | "\n", cluster_offset); | |
846 | errors++; | |
847 | } | |
848 | } | |
849 | } | |
850 | ||
851 | return errors; | |
852 | } | |
853 | ||
854 | /* | |
855 | * Increases the refcount in the given refcount table for the all clusters | |
856 | * referenced in the L2 table. While doing so, performs some checks on L2 | |
857 | * entries. | |
858 | * | |
859 | * Returns the number of errors found by the checks or -errno if an internal | |
860 | * error occurred. | |
861 | */ | |
862 | static int check_refcounts_l2(BlockDriverState *bs, | |
863 | uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset, | |
864 | int check_copied) | |
865 | { | |
866 | BDRVQcowState *s = bs->opaque; | |
867 | uint64_t *l2_table, offset; | |
868 | int i, l2_size, nb_csectors, refcount; | |
869 | int errors = 0; | |
870 | ||
871 | /* Read L2 table from disk */ | |
872 | l2_size = s->l2_size * sizeof(uint64_t); | |
873 | l2_table = qemu_malloc(l2_size); | |
874 | ||
875 | if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size) | |
876 | goto fail; | |
877 | ||
878 | /* Do the actual checks */ | |
879 | for(i = 0; i < s->l2_size; i++) { | |
880 | offset = be64_to_cpu(l2_table[i]); | |
881 | if (offset != 0) { | |
882 | if (offset & QCOW_OFLAG_COMPRESSED) { | |
883 | /* Compressed clusters don't have QCOW_OFLAG_COPIED */ | |
884 | if (offset & QCOW_OFLAG_COPIED) { | |
885 | fprintf(stderr, "ERROR: cluster %" PRId64 ": " | |
886 | "copied flag must never be set for compressed " | |
887 | "clusters\n", offset >> s->cluster_bits); | |
888 | offset &= ~QCOW_OFLAG_COPIED; | |
889 | errors++; | |
890 | } | |
891 | ||
892 | /* Mark cluster as used */ | |
893 | nb_csectors = ((offset >> s->csize_shift) & | |
894 | s->csize_mask) + 1; | |
895 | offset &= s->cluster_offset_mask; | |
896 | errors += inc_refcounts(bs, refcount_table, | |
897 | refcount_table_size, | |
898 | offset & ~511, nb_csectors * 512); | |
899 | } else { | |
900 | /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */ | |
901 | if (check_copied) { | |
902 | uint64_t entry = offset; | |
903 | offset &= ~QCOW_OFLAG_COPIED; | |
904 | refcount = get_refcount(bs, offset >> s->cluster_bits); | |
905 | if ((refcount == 1) != ((entry & QCOW_OFLAG_COPIED) != 0)) { | |
906 | fprintf(stderr, "ERROR OFLAG_COPIED: offset=%" | |
907 | PRIx64 " refcount=%d\n", entry, refcount); | |
908 | errors++; | |
909 | } | |
910 | } | |
911 | ||
912 | /* Mark cluster as used */ | |
913 | offset &= ~QCOW_OFLAG_COPIED; | |
914 | errors += inc_refcounts(bs, refcount_table, | |
915 | refcount_table_size, | |
916 | offset, s->cluster_size); | |
917 | ||
918 | /* Correct offsets are cluster aligned */ | |
919 | if (offset & (s->cluster_size - 1)) { | |
920 | fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " | |
921 | "properly aligned; L2 entry corrupted.\n", offset); | |
922 | errors++; | |
923 | } | |
924 | } | |
925 | } | |
926 | } | |
927 | ||
928 | qemu_free(l2_table); | |
929 | return errors; | |
930 | ||
931 | fail: | |
932 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); | |
933 | qemu_free(l2_table); | |
934 | return -EIO; | |
935 | } | |
936 | ||
937 | /* | |
938 | * Increases the refcount for the L1 table, its L2 tables and all referenced | |
939 | * clusters in the given refcount table. While doing so, performs some checks | |
940 | * on L1 and L2 entries. | |
941 | * | |
942 | * Returns the number of errors found by the checks or -errno if an internal | |
943 | * error occurred. | |
944 | */ | |
945 | static int check_refcounts_l1(BlockDriverState *bs, | |
946 | uint16_t *refcount_table, | |
947 | int refcount_table_size, | |
948 | int64_t l1_table_offset, int l1_size, | |
949 | int check_copied) | |
950 | { | |
951 | BDRVQcowState *s = bs->opaque; | |
952 | uint64_t *l1_table, l2_offset, l1_size2; | |
953 | int i, refcount, ret; | |
954 | int errors = 0; | |
955 | ||
956 | l1_size2 = l1_size * sizeof(uint64_t); | |
957 | ||
958 | /* Mark L1 table as used */ | |
959 | errors += inc_refcounts(bs, refcount_table, refcount_table_size, | |
960 | l1_table_offset, l1_size2); | |
961 | ||
962 | /* Read L1 table entries from disk */ | |
702ef63f KW |
963 | if (l1_size2 == 0) { |
964 | l1_table = NULL; | |
965 | } else { | |
966 | l1_table = qemu_malloc(l1_size2); | |
967 | if (bdrv_pread(s->hd, l1_table_offset, | |
968 | l1_table, l1_size2) != l1_size2) | |
969 | goto fail; | |
970 | for(i = 0;i < l1_size; i++) | |
971 | be64_to_cpus(&l1_table[i]); | |
972 | } | |
f7d0fe02 KW |
973 | |
974 | /* Do the actual checks */ | |
975 | for(i = 0; i < l1_size; i++) { | |
976 | l2_offset = l1_table[i]; | |
977 | if (l2_offset) { | |
978 | /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */ | |
979 | if (check_copied) { | |
980 | refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) | |
981 | >> s->cluster_bits); | |
982 | if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { | |
983 | fprintf(stderr, "ERROR OFLAG_COPIED: l2_offset=%" PRIx64 | |
984 | " refcount=%d\n", l2_offset, refcount); | |
985 | errors++; | |
986 | } | |
987 | } | |
988 | ||
989 | /* Mark L2 table as used */ | |
990 | l2_offset &= ~QCOW_OFLAG_COPIED; | |
991 | errors += inc_refcounts(bs, refcount_table, | |
992 | refcount_table_size, | |
993 | l2_offset, | |
994 | s->cluster_size); | |
995 | ||
996 | /* L2 tables are cluster aligned */ | |
997 | if (l2_offset & (s->cluster_size - 1)) { | |
998 | fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " | |
999 | "cluster aligned; L1 entry corrupted\n", l2_offset); | |
1000 | errors++; | |
1001 | } | |
1002 | ||
1003 | /* Process and check L2 entries */ | |
1004 | ret = check_refcounts_l2(bs, refcount_table, refcount_table_size, | |
1005 | l2_offset, check_copied); | |
1006 | if (ret < 0) { | |
1007 | goto fail; | |
1008 | } | |
1009 | errors += ret; | |
1010 | } | |
1011 | } | |
1012 | qemu_free(l1_table); | |
1013 | return errors; | |
1014 | ||
1015 | fail: | |
1016 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); | |
1017 | qemu_free(l1_table); | |
1018 | return -EIO; | |
1019 | } | |
1020 | ||
1021 | /* | |
1022 | * Checks an image for refcount consistency. | |
1023 | * | |
1024 | * Returns 0 if no errors are found, the number of errors in case the image is | |
1025 | * detected as corrupted, and -errno when an internal error occured. | |
1026 | */ | |
ed6ccf0f | 1027 | int qcow2_check_refcounts(BlockDriverState *bs) |
f7d0fe02 KW |
1028 | { |
1029 | BDRVQcowState *s = bs->opaque; | |
1030 | int64_t size; | |
1031 | int nb_clusters, refcount1, refcount2, i; | |
1032 | QCowSnapshot *sn; | |
1033 | uint16_t *refcount_table; | |
1034 | int ret, errors = 0; | |
1035 | ||
1036 | size = bdrv_getlength(s->hd); | |
1037 | nb_clusters = size_to_clusters(s, size); | |
1038 | refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t)); | |
1039 | ||
1040 | /* header */ | |
1041 | errors += inc_refcounts(bs, refcount_table, nb_clusters, | |
1042 | 0, s->cluster_size); | |
1043 | ||
1044 | /* current L1 table */ | |
1045 | ret = check_refcounts_l1(bs, refcount_table, nb_clusters, | |
1046 | s->l1_table_offset, s->l1_size, 1); | |
1047 | if (ret < 0) { | |
1048 | return ret; | |
1049 | } | |
1050 | errors += ret; | |
1051 | ||
1052 | /* snapshots */ | |
1053 | for(i = 0; i < s->nb_snapshots; i++) { | |
1054 | sn = s->snapshots + i; | |
1055 | check_refcounts_l1(bs, refcount_table, nb_clusters, | |
1056 | sn->l1_table_offset, sn->l1_size, 0); | |
1057 | } | |
1058 | errors += inc_refcounts(bs, refcount_table, nb_clusters, | |
1059 | s->snapshots_offset, s->snapshots_size); | |
1060 | ||
1061 | /* refcount data */ | |
1062 | errors += inc_refcounts(bs, refcount_table, nb_clusters, | |
1063 | s->refcount_table_offset, | |
1064 | s->refcount_table_size * sizeof(uint64_t)); | |
1065 | for(i = 0; i < s->refcount_table_size; i++) { | |
1066 | int64_t offset; | |
1067 | offset = s->refcount_table[i]; | |
746c3cb5 KW |
1068 | |
1069 | /* Refcount blocks are cluster aligned */ | |
1070 | if (offset & (s->cluster_size - 1)) { | |
1071 | fprintf(stderr, "ERROR refcount block %d is not " | |
1072 | "cluster aligned; refcount table entry corrupted\n", i); | |
1073 | errors++; | |
1074 | } | |
1075 | ||
f7d0fe02 KW |
1076 | if (offset != 0) { |
1077 | errors += inc_refcounts(bs, refcount_table, nb_clusters, | |
1078 | offset, s->cluster_size); | |
746c3cb5 KW |
1079 | if (refcount_table[offset / s->cluster_size] != 1) { |
1080 | fprintf(stderr, "ERROR refcount block %d refcount=%d\n", | |
1081 | i, refcount_table[offset / s->cluster_size]); | |
1082 | } | |
f7d0fe02 KW |
1083 | } |
1084 | } | |
1085 | ||
1086 | /* compare ref counts */ | |
1087 | for(i = 0; i < nb_clusters; i++) { | |
1088 | refcount1 = get_refcount(bs, i); | |
1089 | refcount2 = refcount_table[i]; | |
1090 | if (refcount1 != refcount2) { | |
1091 | fprintf(stderr, "ERROR cluster %d refcount=%d reference=%d\n", | |
1092 | i, refcount1, refcount2); | |
1093 | errors++; | |
1094 | } | |
1095 | } | |
1096 | ||
1097 | qemu_free(refcount_table); | |
1098 | ||
1099 | return errors; | |
1100 | } | |
1101 |