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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" | |
737e150e | 26 | #include "block/block_int.h" |
f7d0fe02 KW |
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 | 34 | |
f7d0fe02 KW |
35 | /*********************************************************/ |
36 | /* refcount handling */ | |
37 | ||
ed6ccf0f | 38 | int qcow2_refcount_init(BlockDriverState *bs) |
f7d0fe02 KW |
39 | { |
40 | BDRVQcowState *s = bs->opaque; | |
41 | int ret, refcount_table_size2, i; | |
42 | ||
f7d0fe02 | 43 | refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); |
7267c094 | 44 | s->refcount_table = g_malloc(refcount_table_size2); |
f7d0fe02 | 45 | if (s->refcount_table_size > 0) { |
66f82cee KW |
46 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_LOAD); |
47 | ret = bdrv_pread(bs->file, s->refcount_table_offset, | |
f7d0fe02 KW |
48 | s->refcount_table, refcount_table_size2); |
49 | if (ret != refcount_table_size2) | |
50 | goto fail; | |
51 | for(i = 0; i < s->refcount_table_size; i++) | |
52 | be64_to_cpus(&s->refcount_table[i]); | |
53 | } | |
54 | return 0; | |
55 | fail: | |
56 | return -ENOMEM; | |
57 | } | |
58 | ||
ed6ccf0f | 59 | void qcow2_refcount_close(BlockDriverState *bs) |
f7d0fe02 KW |
60 | { |
61 | BDRVQcowState *s = bs->opaque; | |
7267c094 | 62 | g_free(s->refcount_table); |
f7d0fe02 KW |
63 | } |
64 | ||
65 | ||
66 | static int load_refcount_block(BlockDriverState *bs, | |
29c1a730 KW |
67 | int64_t refcount_block_offset, |
68 | void **refcount_block) | |
f7d0fe02 KW |
69 | { |
70 | BDRVQcowState *s = bs->opaque; | |
71 | int ret; | |
3b88e52b | 72 | |
66f82cee | 73 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_LOAD); |
29c1a730 KW |
74 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, |
75 | refcount_block); | |
e14e8ba5 | 76 | |
29c1a730 | 77 | return ret; |
f7d0fe02 KW |
78 | } |
79 | ||
018faafd KW |
80 | /* |
81 | * Returns the refcount of the cluster given by its index. Any non-negative | |
82 | * return value is the refcount of the cluster, negative values are -errno | |
83 | * and indicate an error. | |
84 | */ | |
f7d0fe02 KW |
85 | static int get_refcount(BlockDriverState *bs, int64_t cluster_index) |
86 | { | |
87 | BDRVQcowState *s = bs->opaque; | |
88 | int refcount_table_index, block_index; | |
89 | int64_t refcount_block_offset; | |
018faafd | 90 | int ret; |
29c1a730 KW |
91 | uint16_t *refcount_block; |
92 | uint16_t refcount; | |
f7d0fe02 KW |
93 | |
94 | refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); | |
95 | if (refcount_table_index >= s->refcount_table_size) | |
96 | return 0; | |
97 | refcount_block_offset = s->refcount_table[refcount_table_index]; | |
98 | if (!refcount_block_offset) | |
99 | return 0; | |
29c1a730 KW |
100 | |
101 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, | |
102 | (void**) &refcount_block); | |
103 | if (ret < 0) { | |
104 | return ret; | |
f7d0fe02 | 105 | } |
29c1a730 | 106 | |
f7d0fe02 KW |
107 | block_index = cluster_index & |
108 | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); | |
29c1a730 KW |
109 | refcount = be16_to_cpu(refcount_block[block_index]); |
110 | ||
111 | ret = qcow2_cache_put(bs, s->refcount_block_cache, | |
112 | (void**) &refcount_block); | |
113 | if (ret < 0) { | |
114 | return ret; | |
115 | } | |
116 | ||
117 | return refcount; | |
f7d0fe02 KW |
118 | } |
119 | ||
05121aed KW |
120 | /* |
121 | * Rounds the refcount table size up to avoid growing the table for each single | |
122 | * refcount block that is allocated. | |
123 | */ | |
124 | static unsigned int next_refcount_table_size(BDRVQcowState *s, | |
125 | unsigned int min_size) | |
126 | { | |
127 | unsigned int min_clusters = (min_size >> (s->cluster_bits - 3)) + 1; | |
128 | unsigned int refcount_table_clusters = | |
129 | MAX(1, s->refcount_table_size >> (s->cluster_bits - 3)); | |
130 | ||
131 | while (min_clusters > refcount_table_clusters) { | |
132 | refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; | |
133 | } | |
134 | ||
135 | return refcount_table_clusters << (s->cluster_bits - 3); | |
136 | } | |
137 | ||
92dcb59f KW |
138 | |
139 | /* Checks if two offsets are described by the same refcount block */ | |
140 | static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a, | |
141 | uint64_t offset_b) | |
142 | { | |
143 | uint64_t block_a = offset_a >> (2 * s->cluster_bits - REFCOUNT_SHIFT); | |
144 | uint64_t block_b = offset_b >> (2 * s->cluster_bits - REFCOUNT_SHIFT); | |
145 | ||
146 | return (block_a == block_b); | |
147 | } | |
148 | ||
149 | /* | |
150 | * Loads a refcount block. If it doesn't exist yet, it is allocated first | |
151 | * (including growing the refcount table if needed). | |
152 | * | |
29c1a730 | 153 | * Returns 0 on success or -errno in error case |
92dcb59f | 154 | */ |
29c1a730 KW |
155 | static int alloc_refcount_block(BlockDriverState *bs, |
156 | int64_t cluster_index, uint16_t **refcount_block) | |
f7d0fe02 KW |
157 | { |
158 | BDRVQcowState *s = bs->opaque; | |
92dcb59f KW |
159 | unsigned int refcount_table_index; |
160 | int ret; | |
161 | ||
66f82cee | 162 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); |
8252278a | 163 | |
92dcb59f KW |
164 | /* Find the refcount block for the given cluster */ |
165 | refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); | |
166 | ||
167 | if (refcount_table_index < s->refcount_table_size) { | |
168 | ||
169 | uint64_t refcount_block_offset = | |
76dc9e0c | 170 | s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; |
92dcb59f KW |
171 | |
172 | /* If it's already there, we're done */ | |
173 | if (refcount_block_offset) { | |
29c1a730 KW |
174 | return load_refcount_block(bs, refcount_block_offset, |
175 | (void**) refcount_block); | |
92dcb59f KW |
176 | } |
177 | } | |
178 | ||
179 | /* | |
180 | * If we came here, we need to allocate something. Something is at least | |
181 | * a cluster for the new refcount block. It may also include a new refcount | |
182 | * table if the old refcount table is too small. | |
183 | * | |
184 | * Note that allocating clusters here needs some special care: | |
185 | * | |
186 | * - We can't use the normal qcow2_alloc_clusters(), it would try to | |
187 | * increase the refcount and very likely we would end up with an endless | |
188 | * recursion. Instead we must place the refcount blocks in a way that | |
189 | * they can describe them themselves. | |
190 | * | |
191 | * - We need to consider that at this point we are inside update_refcounts | |
192 | * and doing the initial refcount increase. This means that some clusters | |
193 | * have already been allocated by the caller, but their refcount isn't | |
194 | * accurate yet. free_cluster_index tells us where this allocation ends | |
195 | * as long as we don't overwrite it by freeing clusters. | |
196 | * | |
197 | * - alloc_clusters_noref and qcow2_free_clusters may load a different | |
198 | * refcount block into the cache | |
199 | */ | |
200 | ||
29c1a730 KW |
201 | *refcount_block = NULL; |
202 | ||
203 | /* We write to the refcount table, so we might depend on L2 tables */ | |
9991923b SH |
204 | ret = qcow2_cache_flush(bs, s->l2_table_cache); |
205 | if (ret < 0) { | |
206 | return ret; | |
207 | } | |
92dcb59f KW |
208 | |
209 | /* Allocate the refcount block itself and mark it as used */ | |
2eaa8f63 KW |
210 | int64_t new_block = alloc_clusters_noref(bs, s->cluster_size); |
211 | if (new_block < 0) { | |
212 | return new_block; | |
213 | } | |
f7d0fe02 | 214 | |
f7d0fe02 | 215 | #ifdef DEBUG_ALLOC2 |
92dcb59f KW |
216 | fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64 |
217 | " at %" PRIx64 "\n", | |
218 | refcount_table_index, cluster_index << s->cluster_bits, new_block); | |
f7d0fe02 | 219 | #endif |
92dcb59f KW |
220 | |
221 | if (in_same_refcount_block(s, new_block, cluster_index << s->cluster_bits)) { | |
25408c09 | 222 | /* Zero the new refcount block before updating it */ |
29c1a730 KW |
223 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
224 | (void**) refcount_block); | |
225 | if (ret < 0) { | |
226 | goto fail_block; | |
227 | } | |
228 | ||
229 | memset(*refcount_block, 0, s->cluster_size); | |
25408c09 | 230 | |
92dcb59f KW |
231 | /* The block describes itself, need to update the cache */ |
232 | int block_index = (new_block >> s->cluster_bits) & | |
233 | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); | |
29c1a730 | 234 | (*refcount_block)[block_index] = cpu_to_be16(1); |
92dcb59f KW |
235 | } else { |
236 | /* Described somewhere else. This can recurse at most twice before we | |
237 | * arrive at a block that describes itself. */ | |
238 | ret = update_refcount(bs, new_block, s->cluster_size, 1); | |
239 | if (ret < 0) { | |
240 | goto fail_block; | |
241 | } | |
25408c09 | 242 | |
9991923b SH |
243 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
244 | if (ret < 0) { | |
245 | goto fail_block; | |
246 | } | |
1c4c2814 | 247 | |
25408c09 KW |
248 | /* Initialize the new refcount block only after updating its refcount, |
249 | * update_refcount uses the refcount cache itself */ | |
29c1a730 KW |
250 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
251 | (void**) refcount_block); | |
252 | if (ret < 0) { | |
253 | goto fail_block; | |
254 | } | |
255 | ||
256 | memset(*refcount_block, 0, s->cluster_size); | |
92dcb59f KW |
257 | } |
258 | ||
259 | /* Now the new refcount block needs to be written to disk */ | |
66f82cee | 260 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE); |
29c1a730 KW |
261 | qcow2_cache_entry_mark_dirty(s->refcount_block_cache, *refcount_block); |
262 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); | |
92dcb59f KW |
263 | if (ret < 0) { |
264 | goto fail_block; | |
265 | } | |
266 | ||
267 | /* If the refcount table is big enough, just hook the block up there */ | |
268 | if (refcount_table_index < s->refcount_table_size) { | |
269 | uint64_t data64 = cpu_to_be64(new_block); | |
66f82cee | 270 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_HOOKUP); |
8b3b7206 | 271 | ret = bdrv_pwrite_sync(bs->file, |
92dcb59f KW |
272 | s->refcount_table_offset + refcount_table_index * sizeof(uint64_t), |
273 | &data64, sizeof(data64)); | |
274 | if (ret < 0) { | |
275 | goto fail_block; | |
276 | } | |
277 | ||
278 | s->refcount_table[refcount_table_index] = new_block; | |
29c1a730 KW |
279 | return 0; |
280 | } | |
281 | ||
282 | ret = qcow2_cache_put(bs, s->refcount_block_cache, (void**) refcount_block); | |
283 | if (ret < 0) { | |
284 | goto fail_block; | |
92dcb59f KW |
285 | } |
286 | ||
287 | /* | |
288 | * If we come here, we need to grow the refcount table. Again, a new | |
289 | * refcount table needs some space and we can't simply allocate to avoid | |
290 | * endless recursion. | |
291 | * | |
292 | * Therefore let's grab new refcount blocks at the end of the image, which | |
293 | * will describe themselves and the new refcount table. This way we can | |
294 | * reference them only in the new table and do the switch to the new | |
295 | * refcount table at once without producing an inconsistent state in | |
296 | * between. | |
297 | */ | |
66f82cee | 298 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW); |
8252278a | 299 | |
92dcb59f KW |
300 | /* Calculate the number of refcount blocks needed so far */ |
301 | uint64_t refcount_block_clusters = 1 << (s->cluster_bits - REFCOUNT_SHIFT); | |
302 | uint64_t blocks_used = (s->free_cluster_index + | |
303 | refcount_block_clusters - 1) / refcount_block_clusters; | |
304 | ||
305 | /* And now we need at least one block more for the new metadata */ | |
306 | uint64_t table_size = next_refcount_table_size(s, blocks_used + 1); | |
307 | uint64_t last_table_size; | |
308 | uint64_t blocks_clusters; | |
309 | do { | |
a3548077 KW |
310 | uint64_t table_clusters = |
311 | size_to_clusters(s, table_size * sizeof(uint64_t)); | |
92dcb59f KW |
312 | blocks_clusters = 1 + |
313 | ((table_clusters + refcount_block_clusters - 1) | |
314 | / refcount_block_clusters); | |
315 | uint64_t meta_clusters = table_clusters + blocks_clusters; | |
316 | ||
317 | last_table_size = table_size; | |
318 | table_size = next_refcount_table_size(s, blocks_used + | |
319 | ((meta_clusters + refcount_block_clusters - 1) | |
320 | / refcount_block_clusters)); | |
321 | ||
322 | } while (last_table_size != table_size); | |
323 | ||
324 | #ifdef DEBUG_ALLOC2 | |
325 | fprintf(stderr, "qcow2: Grow refcount table %" PRId32 " => %" PRId64 "\n", | |
326 | s->refcount_table_size, table_size); | |
327 | #endif | |
328 | ||
329 | /* Create the new refcount table and blocks */ | |
330 | uint64_t meta_offset = (blocks_used * refcount_block_clusters) * | |
331 | s->cluster_size; | |
332 | uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size; | |
7267c094 AL |
333 | uint16_t *new_blocks = g_malloc0(blocks_clusters * s->cluster_size); |
334 | uint64_t *new_table = g_malloc0(table_size * sizeof(uint64_t)); | |
92dcb59f KW |
335 | |
336 | assert(meta_offset >= (s->free_cluster_index * s->cluster_size)); | |
337 | ||
338 | /* Fill the new refcount table */ | |
f7d0fe02 | 339 | memcpy(new_table, s->refcount_table, |
92dcb59f KW |
340 | s->refcount_table_size * sizeof(uint64_t)); |
341 | new_table[refcount_table_index] = new_block; | |
342 | ||
343 | int i; | |
344 | for (i = 0; i < blocks_clusters; i++) { | |
345 | new_table[blocks_used + i] = meta_offset + (i * s->cluster_size); | |
346 | } | |
347 | ||
348 | /* Fill the refcount blocks */ | |
349 | uint64_t table_clusters = size_to_clusters(s, table_size * sizeof(uint64_t)); | |
350 | int block = 0; | |
351 | for (i = 0; i < table_clusters + blocks_clusters; i++) { | |
352 | new_blocks[block++] = cpu_to_be16(1); | |
353 | } | |
354 | ||
355 | /* Write refcount blocks to disk */ | |
66f82cee | 356 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS); |
8b3b7206 | 357 | ret = bdrv_pwrite_sync(bs->file, meta_offset, new_blocks, |
92dcb59f | 358 | blocks_clusters * s->cluster_size); |
7267c094 | 359 | g_free(new_blocks); |
92dcb59f KW |
360 | if (ret < 0) { |
361 | goto fail_table; | |
362 | } | |
363 | ||
364 | /* Write refcount table to disk */ | |
365 | for(i = 0; i < table_size; i++) { | |
366 | cpu_to_be64s(&new_table[i]); | |
367 | } | |
368 | ||
66f82cee | 369 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE); |
8b3b7206 | 370 | ret = bdrv_pwrite_sync(bs->file, table_offset, new_table, |
92dcb59f KW |
371 | table_size * sizeof(uint64_t)); |
372 | if (ret < 0) { | |
373 | goto fail_table; | |
374 | } | |
375 | ||
376 | for(i = 0; i < table_size; i++) { | |
87267753 | 377 | be64_to_cpus(&new_table[i]); |
92dcb59f | 378 | } |
f7d0fe02 | 379 | |
92dcb59f KW |
380 | /* Hook up the new refcount table in the qcow2 header */ |
381 | uint8_t data[12]; | |
f7d0fe02 | 382 | cpu_to_be64w((uint64_t*)data, table_offset); |
92dcb59f | 383 | cpu_to_be32w((uint32_t*)(data + 8), table_clusters); |
66f82cee | 384 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE); |
8b3b7206 | 385 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, refcount_table_offset), |
92dcb59f KW |
386 | data, sizeof(data)); |
387 | if (ret < 0) { | |
388 | goto fail_table; | |
f2b7c8b3 KW |
389 | } |
390 | ||
92dcb59f KW |
391 | /* And switch it in memory */ |
392 | uint64_t old_table_offset = s->refcount_table_offset; | |
393 | uint64_t old_table_size = s->refcount_table_size; | |
394 | ||
7267c094 | 395 | g_free(s->refcount_table); |
f7d0fe02 | 396 | s->refcount_table = new_table; |
92dcb59f | 397 | s->refcount_table_size = table_size; |
f7d0fe02 KW |
398 | s->refcount_table_offset = table_offset; |
399 | ||
92dcb59f KW |
400 | /* Free old table. Remember, we must not change free_cluster_index */ |
401 | uint64_t old_free_cluster_index = s->free_cluster_index; | |
ed6ccf0f | 402 | qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t)); |
92dcb59f | 403 | s->free_cluster_index = old_free_cluster_index; |
f7d0fe02 | 404 | |
29c1a730 | 405 | ret = load_refcount_block(bs, new_block, (void**) refcount_block); |
92dcb59f | 406 | if (ret < 0) { |
29c1a730 | 407 | return ret; |
f7d0fe02 KW |
408 | } |
409 | ||
2795ecf6 | 410 | return 0; |
f7d0fe02 | 411 | |
92dcb59f | 412 | fail_table: |
7267c094 | 413 | g_free(new_table); |
92dcb59f | 414 | fail_block: |
29c1a730 KW |
415 | if (*refcount_block != NULL) { |
416 | qcow2_cache_put(bs, s->refcount_block_cache, (void**) refcount_block); | |
3b88e52b | 417 | } |
29c1a730 | 418 | return ret; |
9923e05e KW |
419 | } |
420 | ||
f7d0fe02 | 421 | /* XXX: cache several refcount block clusters ? */ |
db3a964f KW |
422 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
423 | int64_t offset, int64_t length, int addend) | |
f7d0fe02 KW |
424 | { |
425 | BDRVQcowState *s = bs->opaque; | |
426 | int64_t start, last, cluster_offset; | |
29c1a730 KW |
427 | uint16_t *refcount_block = NULL; |
428 | int64_t old_table_index = -1; | |
09508d13 | 429 | int ret; |
f7d0fe02 KW |
430 | |
431 | #ifdef DEBUG_ALLOC2 | |
35ee5e39 | 432 | fprintf(stderr, "update_refcount: offset=%" PRId64 " size=%" PRId64 " addend=%d\n", |
f7d0fe02 KW |
433 | offset, length, addend); |
434 | #endif | |
7322afe7 | 435 | if (length < 0) { |
f7d0fe02 | 436 | return -EINVAL; |
7322afe7 KW |
437 | } else if (length == 0) { |
438 | return 0; | |
439 | } | |
440 | ||
29c1a730 KW |
441 | if (addend < 0) { |
442 | qcow2_cache_set_dependency(bs, s->refcount_block_cache, | |
443 | s->l2_table_cache); | |
444 | } | |
445 | ||
f7d0fe02 KW |
446 | start = offset & ~(s->cluster_size - 1); |
447 | last = (offset + length - 1) & ~(s->cluster_size - 1); | |
448 | for(cluster_offset = start; cluster_offset <= last; | |
449 | cluster_offset += s->cluster_size) | |
450 | { | |
451 | int block_index, refcount; | |
452 | int64_t cluster_index = cluster_offset >> s->cluster_bits; | |
29c1a730 KW |
453 | int64_t table_index = |
454 | cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); | |
f7d0fe02 | 455 | |
29c1a730 KW |
456 | /* Load the refcount block and allocate it if needed */ |
457 | if (table_index != old_table_index) { | |
458 | if (refcount_block) { | |
459 | ret = qcow2_cache_put(bs, s->refcount_block_cache, | |
460 | (void**) &refcount_block); | |
461 | if (ret < 0) { | |
462 | goto fail; | |
463 | } | |
464 | } | |
9923e05e | 465 | |
29c1a730 | 466 | ret = alloc_refcount_block(bs, cluster_index, &refcount_block); |
ed0df867 | 467 | if (ret < 0) { |
29c1a730 | 468 | goto fail; |
f7d0fe02 | 469 | } |
f7d0fe02 | 470 | } |
29c1a730 | 471 | old_table_index = table_index; |
f7d0fe02 | 472 | |
29c1a730 | 473 | qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refcount_block); |
f7d0fe02 KW |
474 | |
475 | /* we can update the count and save it */ | |
476 | block_index = cluster_index & | |
477 | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); | |
f7d0fe02 | 478 | |
29c1a730 | 479 | refcount = be16_to_cpu(refcount_block[block_index]); |
f7d0fe02 | 480 | refcount += addend; |
09508d13 KW |
481 | if (refcount < 0 || refcount > 0xffff) { |
482 | ret = -EINVAL; | |
483 | goto fail; | |
484 | } | |
f7d0fe02 KW |
485 | if (refcount == 0 && cluster_index < s->free_cluster_index) { |
486 | s->free_cluster_index = cluster_index; | |
487 | } | |
29c1a730 | 488 | refcount_block[block_index] = cpu_to_be16(refcount); |
f7d0fe02 KW |
489 | } |
490 | ||
09508d13 KW |
491 | ret = 0; |
492 | fail: | |
f7d0fe02 | 493 | /* Write last changed block to disk */ |
29c1a730 | 494 | if (refcount_block) { |
ed0df867 | 495 | int wret; |
29c1a730 KW |
496 | wret = qcow2_cache_put(bs, s->refcount_block_cache, |
497 | (void**) &refcount_block); | |
ed0df867 KW |
498 | if (wret < 0) { |
499 | return ret < 0 ? ret : wret; | |
f7d0fe02 KW |
500 | } |
501 | } | |
502 | ||
09508d13 KW |
503 | /* |
504 | * Try do undo any updates if an error is returned (This may succeed in | |
505 | * some cases like ENOSPC for allocating a new refcount block) | |
506 | */ | |
507 | if (ret < 0) { | |
508 | int dummy; | |
509 | dummy = update_refcount(bs, offset, cluster_offset - offset, -addend); | |
83e3f76c | 510 | (void)dummy; |
09508d13 KW |
511 | } |
512 | ||
513 | return ret; | |
f7d0fe02 KW |
514 | } |
515 | ||
018faafd KW |
516 | /* |
517 | * Increases or decreases the refcount of a given cluster by one. | |
518 | * addend must be 1 or -1. | |
519 | * | |
520 | * If the return value is non-negative, it is the new refcount of the cluster. | |
521 | * If it is negative, it is -errno and indicates an error. | |
522 | */ | |
f7d0fe02 KW |
523 | static int update_cluster_refcount(BlockDriverState *bs, |
524 | int64_t cluster_index, | |
525 | int addend) | |
526 | { | |
527 | BDRVQcowState *s = bs->opaque; | |
528 | int ret; | |
529 | ||
530 | ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend); | |
531 | if (ret < 0) { | |
532 | return ret; | |
533 | } | |
534 | ||
1c4c2814 KW |
535 | bdrv_flush(bs->file); |
536 | ||
f7d0fe02 KW |
537 | return get_refcount(bs, cluster_index); |
538 | } | |
539 | ||
540 | ||
541 | ||
542 | /*********************************************************/ | |
543 | /* cluster allocation functions */ | |
544 | ||
545 | ||
546 | ||
547 | /* return < 0 if error */ | |
548 | static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size) | |
549 | { | |
550 | BDRVQcowState *s = bs->opaque; | |
2eaa8f63 | 551 | int i, nb_clusters, refcount; |
f7d0fe02 KW |
552 | |
553 | nb_clusters = size_to_clusters(s, size); | |
554 | retry: | |
555 | for(i = 0; i < nb_clusters; i++) { | |
508e0893 | 556 | int64_t next_cluster_index = s->free_cluster_index++; |
2eaa8f63 KW |
557 | refcount = get_refcount(bs, next_cluster_index); |
558 | ||
559 | if (refcount < 0) { | |
560 | return refcount; | |
561 | } else if (refcount != 0) { | |
f7d0fe02 | 562 | goto retry; |
2eaa8f63 | 563 | } |
f7d0fe02 KW |
564 | } |
565 | #ifdef DEBUG_ALLOC2 | |
35ee5e39 | 566 | fprintf(stderr, "alloc_clusters: size=%" PRId64 " -> %" PRId64 "\n", |
f7d0fe02 KW |
567 | size, |
568 | (s->free_cluster_index - nb_clusters) << s->cluster_bits); | |
569 | #endif | |
570 | return (s->free_cluster_index - nb_clusters) << s->cluster_bits; | |
571 | } | |
572 | ||
ed6ccf0f | 573 | int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size) |
f7d0fe02 KW |
574 | { |
575 | int64_t offset; | |
db3a964f | 576 | int ret; |
f7d0fe02 | 577 | |
66f82cee | 578 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC); |
f7d0fe02 | 579 | offset = alloc_clusters_noref(bs, size); |
2eaa8f63 KW |
580 | if (offset < 0) { |
581 | return offset; | |
582 | } | |
583 | ||
db3a964f KW |
584 | ret = update_refcount(bs, offset, size, 1); |
585 | if (ret < 0) { | |
586 | return ret; | |
587 | } | |
1c4c2814 | 588 | |
f7d0fe02 KW |
589 | return offset; |
590 | } | |
591 | ||
256900b1 KW |
592 | int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, |
593 | int nb_clusters) | |
594 | { | |
595 | BDRVQcowState *s = bs->opaque; | |
596 | uint64_t cluster_index; | |
f24423bd | 597 | uint64_t old_free_cluster_index; |
256900b1 KW |
598 | int i, refcount, ret; |
599 | ||
600 | /* Check how many clusters there are free */ | |
601 | cluster_index = offset >> s->cluster_bits; | |
602 | for(i = 0; i < nb_clusters; i++) { | |
603 | refcount = get_refcount(bs, cluster_index++); | |
604 | ||
605 | if (refcount < 0) { | |
606 | return refcount; | |
607 | } else if (refcount != 0) { | |
608 | break; | |
609 | } | |
610 | } | |
611 | ||
612 | /* And then allocate them */ | |
f24423bd KW |
613 | old_free_cluster_index = s->free_cluster_index; |
614 | s->free_cluster_index = cluster_index + i; | |
615 | ||
256900b1 KW |
616 | ret = update_refcount(bs, offset, i << s->cluster_bits, 1); |
617 | if (ret < 0) { | |
618 | return ret; | |
619 | } | |
620 | ||
f24423bd KW |
621 | s->free_cluster_index = old_free_cluster_index; |
622 | ||
256900b1 KW |
623 | return i; |
624 | } | |
625 | ||
f7d0fe02 KW |
626 | /* only used to allocate compressed sectors. We try to allocate |
627 | contiguous sectors. size must be <= cluster_size */ | |
ed6ccf0f | 628 | int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size) |
f7d0fe02 KW |
629 | { |
630 | BDRVQcowState *s = bs->opaque; | |
631 | int64_t offset, cluster_offset; | |
632 | int free_in_cluster; | |
633 | ||
66f82cee | 634 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_BYTES); |
f7d0fe02 KW |
635 | assert(size > 0 && size <= s->cluster_size); |
636 | if (s->free_byte_offset == 0) { | |
206e6d85 SH |
637 | offset = qcow2_alloc_clusters(bs, s->cluster_size); |
638 | if (offset < 0) { | |
639 | return offset; | |
5d757b56 | 640 | } |
206e6d85 | 641 | s->free_byte_offset = offset; |
f7d0fe02 KW |
642 | } |
643 | redo: | |
644 | free_in_cluster = s->cluster_size - | |
645 | (s->free_byte_offset & (s->cluster_size - 1)); | |
646 | if (size <= free_in_cluster) { | |
647 | /* enough space in current cluster */ | |
648 | offset = s->free_byte_offset; | |
649 | s->free_byte_offset += size; | |
650 | free_in_cluster -= size; | |
651 | if (free_in_cluster == 0) | |
652 | s->free_byte_offset = 0; | |
653 | if ((offset & (s->cluster_size - 1)) != 0) | |
654 | update_cluster_refcount(bs, offset >> s->cluster_bits, 1); | |
655 | } else { | |
ed6ccf0f | 656 | offset = qcow2_alloc_clusters(bs, s->cluster_size); |
5d757b56 KW |
657 | if (offset < 0) { |
658 | return offset; | |
659 | } | |
f7d0fe02 KW |
660 | cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1); |
661 | if ((cluster_offset + s->cluster_size) == offset) { | |
662 | /* we are lucky: contiguous data */ | |
663 | offset = s->free_byte_offset; | |
664 | update_cluster_refcount(bs, offset >> s->cluster_bits, 1); | |
665 | s->free_byte_offset += size; | |
666 | } else { | |
667 | s->free_byte_offset = offset; | |
668 | goto redo; | |
669 | } | |
670 | } | |
29216ed1 KW |
671 | |
672 | bdrv_flush(bs->file); | |
f7d0fe02 KW |
673 | return offset; |
674 | } | |
675 | ||
ed6ccf0f | 676 | void qcow2_free_clusters(BlockDriverState *bs, |
f7d0fe02 KW |
677 | int64_t offset, int64_t size) |
678 | { | |
db3a964f KW |
679 | int ret; |
680 | ||
66f82cee | 681 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_FREE); |
db3a964f KW |
682 | ret = update_refcount(bs, offset, size, -1); |
683 | if (ret < 0) { | |
684 | fprintf(stderr, "qcow2_free_clusters failed: %s\n", strerror(-ret)); | |
003fad6e | 685 | /* TODO Remember the clusters to free them later and avoid leaking */ |
db3a964f | 686 | } |
f7d0fe02 KW |
687 | } |
688 | ||
45aba42f | 689 | /* |
c7a4c37a KW |
690 | * Free a cluster using its L2 entry (handles clusters of all types, e.g. |
691 | * normal cluster, compressed cluster, etc.) | |
45aba42f | 692 | */ |
ed6ccf0f | 693 | void qcow2_free_any_clusters(BlockDriverState *bs, |
c7a4c37a | 694 | uint64_t l2_entry, int nb_clusters) |
45aba42f KW |
695 | { |
696 | BDRVQcowState *s = bs->opaque; | |
697 | ||
c7a4c37a KW |
698 | switch (qcow2_get_cluster_type(l2_entry)) { |
699 | case QCOW2_CLUSTER_COMPRESSED: | |
700 | { | |
701 | int nb_csectors; | |
702 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
703 | s->csize_mask) + 1; | |
704 | qcow2_free_clusters(bs, | |
705 | (l2_entry & s->cluster_offset_mask) & ~511, | |
706 | nb_csectors * 512); | |
707 | } | |
708 | break; | |
709 | case QCOW2_CLUSTER_NORMAL: | |
710 | qcow2_free_clusters(bs, l2_entry & L2E_OFFSET_MASK, | |
711 | nb_clusters << s->cluster_bits); | |
712 | break; | |
713 | case QCOW2_CLUSTER_UNALLOCATED: | |
6377af48 | 714 | case QCOW2_CLUSTER_ZERO: |
c7a4c37a KW |
715 | break; |
716 | default: | |
717 | abort(); | |
45aba42f | 718 | } |
45aba42f KW |
719 | } |
720 | ||
f7d0fe02 KW |
721 | |
722 | ||
723 | /*********************************************************/ | |
724 | /* snapshots and image creation */ | |
725 | ||
726 | ||
727 | ||
f7d0fe02 | 728 | /* update the refcounts of snapshots and the copied flag */ |
ed6ccf0f KW |
729 | int qcow2_update_snapshot_refcount(BlockDriverState *bs, |
730 | int64_t l1_table_offset, int l1_size, int addend) | |
f7d0fe02 KW |
731 | { |
732 | BDRVQcowState *s = bs->opaque; | |
733 | uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; | |
734 | int64_t old_offset, old_l2_offset; | |
93913dfd | 735 | int i, j, l1_modified = 0, nb_csectors, refcount; |
29c1a730 | 736 | int ret; |
f7d0fe02 KW |
737 | |
738 | l2_table = NULL; | |
739 | l1_table = NULL; | |
740 | l1_size2 = l1_size * sizeof(uint64_t); | |
43a0cac4 KW |
741 | |
742 | /* WARNING: qcow2_snapshot_goto relies on this function not using the | |
743 | * l1_table_offset when it is the current s->l1_table_offset! Be careful | |
744 | * when changing this! */ | |
f7d0fe02 | 745 | if (l1_table_offset != s->l1_table_offset) { |
6528499f | 746 | l1_table = g_malloc0(align_offset(l1_size2, 512)); |
f7d0fe02 | 747 | l1_allocated = 1; |
66f82cee | 748 | if (bdrv_pread(bs->file, l1_table_offset, |
f7d0fe02 | 749 | l1_table, l1_size2) != l1_size2) |
93913dfd KW |
750 | { |
751 | ret = -EIO; | |
f7d0fe02 | 752 | goto fail; |
93913dfd KW |
753 | } |
754 | ||
f7d0fe02 KW |
755 | for(i = 0;i < l1_size; i++) |
756 | be64_to_cpus(&l1_table[i]); | |
757 | } else { | |
758 | assert(l1_size == s->l1_size); | |
759 | l1_table = s->l1_table; | |
760 | l1_allocated = 0; | |
761 | } | |
762 | ||
f7d0fe02 KW |
763 | for(i = 0; i < l1_size; i++) { |
764 | l2_offset = l1_table[i]; | |
765 | if (l2_offset) { | |
766 | old_l2_offset = l2_offset; | |
8e37f681 | 767 | l2_offset &= L1E_OFFSET_MASK; |
29c1a730 KW |
768 | |
769 | ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, | |
770 | (void**) &l2_table); | |
771 | if (ret < 0) { | |
f7d0fe02 | 772 | goto fail; |
29c1a730 KW |
773 | } |
774 | ||
f7d0fe02 KW |
775 | for(j = 0; j < s->l2_size; j++) { |
776 | offset = be64_to_cpu(l2_table[j]); | |
777 | if (offset != 0) { | |
778 | old_offset = offset; | |
779 | offset &= ~QCOW_OFLAG_COPIED; | |
780 | if (offset & QCOW_OFLAG_COMPRESSED) { | |
781 | nb_csectors = ((offset >> s->csize_shift) & | |
782 | s->csize_mask) + 1; | |
db3a964f KW |
783 | if (addend != 0) { |
784 | int ret; | |
785 | ret = update_refcount(bs, | |
786 | (offset & s->cluster_offset_mask) & ~511, | |
787 | nb_csectors * 512, addend); | |
788 | if (ret < 0) { | |
789 | goto fail; | |
790 | } | |
1c4c2814 KW |
791 | |
792 | /* TODO Flushing once for the whole function should | |
793 | * be enough */ | |
794 | bdrv_flush(bs->file); | |
db3a964f | 795 | } |
f7d0fe02 KW |
796 | /* compressed clusters are never modified */ |
797 | refcount = 2; | |
798 | } else { | |
8e37f681 | 799 | uint64_t cluster_index = (offset & L2E_OFFSET_MASK) >> s->cluster_bits; |
f7d0fe02 | 800 | if (addend != 0) { |
8e37f681 | 801 | refcount = update_cluster_refcount(bs, cluster_index, addend); |
f7d0fe02 | 802 | } else { |
8e37f681 | 803 | refcount = get_refcount(bs, cluster_index); |
f7d0fe02 | 804 | } |
018faafd KW |
805 | |
806 | if (refcount < 0) { | |
93913dfd | 807 | ret = -EIO; |
018faafd KW |
808 | goto fail; |
809 | } | |
f7d0fe02 KW |
810 | } |
811 | ||
812 | if (refcount == 1) { | |
813 | offset |= QCOW_OFLAG_COPIED; | |
814 | } | |
815 | if (offset != old_offset) { | |
29c1a730 KW |
816 | if (addend > 0) { |
817 | qcow2_cache_set_dependency(bs, s->l2_table_cache, | |
818 | s->refcount_block_cache); | |
819 | } | |
f7d0fe02 | 820 | l2_table[j] = cpu_to_be64(offset); |
29c1a730 | 821 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); |
f7d0fe02 KW |
822 | } |
823 | } | |
824 | } | |
29c1a730 KW |
825 | |
826 | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); | |
827 | if (ret < 0) { | |
828 | goto fail; | |
f7d0fe02 KW |
829 | } |
830 | ||
29c1a730 | 831 | |
f7d0fe02 KW |
832 | if (addend != 0) { |
833 | refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); | |
834 | } else { | |
835 | refcount = get_refcount(bs, l2_offset >> s->cluster_bits); | |
836 | } | |
018faafd | 837 | if (refcount < 0) { |
93913dfd | 838 | ret = -EIO; |
018faafd KW |
839 | goto fail; |
840 | } else if (refcount == 1) { | |
f7d0fe02 KW |
841 | l2_offset |= QCOW_OFLAG_COPIED; |
842 | } | |
843 | if (l2_offset != old_l2_offset) { | |
844 | l1_table[i] = l2_offset; | |
845 | l1_modified = 1; | |
846 | } | |
847 | } | |
848 | } | |
93913dfd KW |
849 | |
850 | ret = 0; | |
851 | fail: | |
852 | if (l2_table) { | |
853 | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); | |
854 | } | |
855 | ||
43a0cac4 KW |
856 | /* Update L1 only if it isn't deleted anyway (addend = -1) */ |
857 | if (addend >= 0 && l1_modified) { | |
f7d0fe02 KW |
858 | for(i = 0; i < l1_size; i++) |
859 | cpu_to_be64s(&l1_table[i]); | |
8b3b7206 KW |
860 | if (bdrv_pwrite_sync(bs->file, l1_table_offset, l1_table, |
861 | l1_size2) < 0) | |
f7d0fe02 KW |
862 | goto fail; |
863 | for(i = 0; i < l1_size; i++) | |
864 | be64_to_cpus(&l1_table[i]); | |
865 | } | |
866 | if (l1_allocated) | |
7267c094 | 867 | g_free(l1_table); |
93913dfd | 868 | return ret; |
f7d0fe02 KW |
869 | } |
870 | ||
871 | ||
872 | ||
873 | ||
874 | /*********************************************************/ | |
875 | /* refcount checking functions */ | |
876 | ||
877 | ||
878 | ||
879 | /* | |
880 | * Increases the refcount for a range of clusters in a given refcount table. | |
881 | * This is used to construct a temporary refcount table out of L1 and L2 tables | |
882 | * which can be compared the the refcount table saved in the image. | |
883 | * | |
9ac228e0 | 884 | * Modifies the number of errors in res. |
f7d0fe02 | 885 | */ |
9ac228e0 KW |
886 | static void inc_refcounts(BlockDriverState *bs, |
887 | BdrvCheckResult *res, | |
f7d0fe02 KW |
888 | uint16_t *refcount_table, |
889 | int refcount_table_size, | |
890 | int64_t offset, int64_t size) | |
891 | { | |
892 | BDRVQcowState *s = bs->opaque; | |
893 | int64_t start, last, cluster_offset; | |
894 | int k; | |
f7d0fe02 KW |
895 | |
896 | if (size <= 0) | |
9ac228e0 | 897 | return; |
f7d0fe02 KW |
898 | |
899 | start = offset & ~(s->cluster_size - 1); | |
900 | last = (offset + size - 1) & ~(s->cluster_size - 1); | |
901 | for(cluster_offset = start; cluster_offset <= last; | |
902 | cluster_offset += s->cluster_size) { | |
903 | k = cluster_offset >> s->cluster_bits; | |
9ac228e0 | 904 | if (k < 0) { |
f7d0fe02 KW |
905 | fprintf(stderr, "ERROR: invalid cluster offset=0x%" PRIx64 "\n", |
906 | cluster_offset); | |
9ac228e0 KW |
907 | res->corruptions++; |
908 | } else if (k >= refcount_table_size) { | |
909 | fprintf(stderr, "Warning: cluster offset=0x%" PRIx64 " is after " | |
910 | "the end of the image file, can't properly check refcounts.\n", | |
911 | cluster_offset); | |
912 | res->check_errors++; | |
f7d0fe02 KW |
913 | } else { |
914 | if (++refcount_table[k] == 0) { | |
915 | fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64 | |
916 | "\n", cluster_offset); | |
9ac228e0 | 917 | res->corruptions++; |
f7d0fe02 KW |
918 | } |
919 | } | |
920 | } | |
f7d0fe02 KW |
921 | } |
922 | ||
801f7044 SH |
923 | /* Flags for check_refcounts_l1() and check_refcounts_l2() */ |
924 | enum { | |
925 | CHECK_OFLAG_COPIED = 0x1, /* check QCOW_OFLAG_COPIED matches refcount */ | |
fba31bae | 926 | CHECK_FRAG_INFO = 0x2, /* update BlockFragInfo counters */ |
801f7044 SH |
927 | }; |
928 | ||
f7d0fe02 KW |
929 | /* |
930 | * Increases the refcount in the given refcount table for the all clusters | |
931 | * referenced in the L2 table. While doing so, performs some checks on L2 | |
932 | * entries. | |
933 | * | |
934 | * Returns the number of errors found by the checks or -errno if an internal | |
935 | * error occurred. | |
936 | */ | |
9ac228e0 | 937 | static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, |
f7d0fe02 | 938 | uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset, |
801f7044 | 939 | int flags) |
f7d0fe02 KW |
940 | { |
941 | BDRVQcowState *s = bs->opaque; | |
afdf0abe | 942 | uint64_t *l2_table, l2_entry; |
fba31bae | 943 | uint64_t next_contiguous_offset = 0; |
f7d0fe02 | 944 | int i, l2_size, nb_csectors, refcount; |
f7d0fe02 KW |
945 | |
946 | /* Read L2 table from disk */ | |
947 | l2_size = s->l2_size * sizeof(uint64_t); | |
7267c094 | 948 | l2_table = g_malloc(l2_size); |
f7d0fe02 | 949 | |
66f82cee | 950 | if (bdrv_pread(bs->file, l2_offset, l2_table, l2_size) != l2_size) |
f7d0fe02 KW |
951 | goto fail; |
952 | ||
953 | /* Do the actual checks */ | |
954 | for(i = 0; i < s->l2_size; i++) { | |
afdf0abe KW |
955 | l2_entry = be64_to_cpu(l2_table[i]); |
956 | ||
957 | switch (qcow2_get_cluster_type(l2_entry)) { | |
958 | case QCOW2_CLUSTER_COMPRESSED: | |
959 | /* Compressed clusters don't have QCOW_OFLAG_COPIED */ | |
960 | if (l2_entry & QCOW_OFLAG_COPIED) { | |
961 | fprintf(stderr, "ERROR: cluster %" PRId64 ": " | |
962 | "copied flag must never be set for compressed " | |
963 | "clusters\n", l2_entry >> s->cluster_bits); | |
964 | l2_entry &= ~QCOW_OFLAG_COPIED; | |
965 | res->corruptions++; | |
966 | } | |
f7d0fe02 | 967 | |
afdf0abe KW |
968 | /* Mark cluster as used */ |
969 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
970 | s->csize_mask) + 1; | |
971 | l2_entry &= s->cluster_offset_mask; | |
972 | inc_refcounts(bs, res, refcount_table, refcount_table_size, | |
973 | l2_entry & ~511, nb_csectors * 512); | |
fba31bae SH |
974 | |
975 | if (flags & CHECK_FRAG_INFO) { | |
976 | res->bfi.allocated_clusters++; | |
4db35162 | 977 | res->bfi.compressed_clusters++; |
fba31bae SH |
978 | |
979 | /* Compressed clusters are fragmented by nature. Since they | |
980 | * take up sub-sector space but we only have sector granularity | |
981 | * I/O we need to re-read the same sectors even for adjacent | |
982 | * compressed clusters. | |
983 | */ | |
984 | res->bfi.fragmented_clusters++; | |
985 | } | |
afdf0abe | 986 | break; |
f7d0fe02 | 987 | |
6377af48 KW |
988 | case QCOW2_CLUSTER_ZERO: |
989 | if ((l2_entry & L2E_OFFSET_MASK) == 0) { | |
990 | break; | |
991 | } | |
992 | /* fall through */ | |
993 | ||
afdf0abe KW |
994 | case QCOW2_CLUSTER_NORMAL: |
995 | { | |
996 | /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */ | |
997 | uint64_t offset = l2_entry & L2E_OFFSET_MASK; | |
f7d0fe02 | 998 | |
801f7044 | 999 | if (flags & CHECK_OFLAG_COPIED) { |
afdf0abe KW |
1000 | refcount = get_refcount(bs, offset >> s->cluster_bits); |
1001 | if (refcount < 0) { | |
1002 | fprintf(stderr, "Can't get refcount for offset %" | |
1003 | PRIx64 ": %s\n", l2_entry, strerror(-refcount)); | |
1004 | goto fail; | |
1005 | } | |
1006 | if ((refcount == 1) != ((l2_entry & QCOW_OFLAG_COPIED) != 0)) { | |
1007 | fprintf(stderr, "ERROR OFLAG_COPIED: offset=%" | |
1008 | PRIx64 " refcount=%d\n", l2_entry, refcount); | |
9ac228e0 | 1009 | res->corruptions++; |
f7d0fe02 KW |
1010 | } |
1011 | } | |
afdf0abe | 1012 | |
fba31bae SH |
1013 | if (flags & CHECK_FRAG_INFO) { |
1014 | res->bfi.allocated_clusters++; | |
1015 | if (next_contiguous_offset && | |
1016 | offset != next_contiguous_offset) { | |
1017 | res->bfi.fragmented_clusters++; | |
1018 | } | |
1019 | next_contiguous_offset = offset + s->cluster_size; | |
1020 | } | |
1021 | ||
afdf0abe KW |
1022 | /* Mark cluster as used */ |
1023 | inc_refcounts(bs, res, refcount_table,refcount_table_size, | |
1024 | offset, s->cluster_size); | |
1025 | ||
1026 | /* Correct offsets are cluster aligned */ | |
1027 | if (offset & (s->cluster_size - 1)) { | |
1028 | fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " | |
1029 | "properly aligned; L2 entry corrupted.\n", offset); | |
1030 | res->corruptions++; | |
1031 | } | |
1032 | break; | |
1033 | } | |
1034 | ||
1035 | case QCOW2_CLUSTER_UNALLOCATED: | |
1036 | break; | |
1037 | ||
1038 | default: | |
1039 | abort(); | |
f7d0fe02 KW |
1040 | } |
1041 | } | |
1042 | ||
7267c094 | 1043 | g_free(l2_table); |
9ac228e0 | 1044 | return 0; |
f7d0fe02 KW |
1045 | |
1046 | fail: | |
9ac228e0 | 1047 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l2\n"); |
7267c094 | 1048 | g_free(l2_table); |
f7d0fe02 KW |
1049 | return -EIO; |
1050 | } | |
1051 | ||
1052 | /* | |
1053 | * Increases the refcount for the L1 table, its L2 tables and all referenced | |
1054 | * clusters in the given refcount table. While doing so, performs some checks | |
1055 | * on L1 and L2 entries. | |
1056 | * | |
1057 | * Returns the number of errors found by the checks or -errno if an internal | |
1058 | * error occurred. | |
1059 | */ | |
1060 | static int check_refcounts_l1(BlockDriverState *bs, | |
9ac228e0 | 1061 | BdrvCheckResult *res, |
f7d0fe02 KW |
1062 | uint16_t *refcount_table, |
1063 | int refcount_table_size, | |
1064 | int64_t l1_table_offset, int l1_size, | |
801f7044 | 1065 | int flags) |
f7d0fe02 KW |
1066 | { |
1067 | BDRVQcowState *s = bs->opaque; | |
1068 | uint64_t *l1_table, l2_offset, l1_size2; | |
1069 | int i, refcount, ret; | |
f7d0fe02 KW |
1070 | |
1071 | l1_size2 = l1_size * sizeof(uint64_t); | |
1072 | ||
1073 | /* Mark L1 table as used */ | |
9ac228e0 KW |
1074 | inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1075 | l1_table_offset, l1_size2); | |
f7d0fe02 KW |
1076 | |
1077 | /* Read L1 table entries from disk */ | |
702ef63f KW |
1078 | if (l1_size2 == 0) { |
1079 | l1_table = NULL; | |
1080 | } else { | |
7267c094 | 1081 | l1_table = g_malloc(l1_size2); |
66f82cee | 1082 | if (bdrv_pread(bs->file, l1_table_offset, |
702ef63f KW |
1083 | l1_table, l1_size2) != l1_size2) |
1084 | goto fail; | |
1085 | for(i = 0;i < l1_size; i++) | |
1086 | be64_to_cpus(&l1_table[i]); | |
1087 | } | |
f7d0fe02 KW |
1088 | |
1089 | /* Do the actual checks */ | |
1090 | for(i = 0; i < l1_size; i++) { | |
1091 | l2_offset = l1_table[i]; | |
1092 | if (l2_offset) { | |
1093 | /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */ | |
801f7044 | 1094 | if (flags & CHECK_OFLAG_COPIED) { |
f7d0fe02 KW |
1095 | refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) |
1096 | >> s->cluster_bits); | |
018faafd KW |
1097 | if (refcount < 0) { |
1098 | fprintf(stderr, "Can't get refcount for l2_offset %" | |
1099 | PRIx64 ": %s\n", l2_offset, strerror(-refcount)); | |
9ac228e0 | 1100 | goto fail; |
018faafd | 1101 | } |
f7d0fe02 KW |
1102 | if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { |
1103 | fprintf(stderr, "ERROR OFLAG_COPIED: l2_offset=%" PRIx64 | |
1104 | " refcount=%d\n", l2_offset, refcount); | |
9ac228e0 | 1105 | res->corruptions++; |
f7d0fe02 KW |
1106 | } |
1107 | } | |
1108 | ||
1109 | /* Mark L2 table as used */ | |
afdf0abe | 1110 | l2_offset &= L1E_OFFSET_MASK; |
9ac228e0 KW |
1111 | inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1112 | l2_offset, s->cluster_size); | |
f7d0fe02 KW |
1113 | |
1114 | /* L2 tables are cluster aligned */ | |
1115 | if (l2_offset & (s->cluster_size - 1)) { | |
1116 | fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " | |
1117 | "cluster aligned; L1 entry corrupted\n", l2_offset); | |
9ac228e0 | 1118 | res->corruptions++; |
f7d0fe02 KW |
1119 | } |
1120 | ||
1121 | /* Process and check L2 entries */ | |
9ac228e0 | 1122 | ret = check_refcounts_l2(bs, res, refcount_table, |
801f7044 | 1123 | refcount_table_size, l2_offset, flags); |
f7d0fe02 KW |
1124 | if (ret < 0) { |
1125 | goto fail; | |
1126 | } | |
f7d0fe02 KW |
1127 | } |
1128 | } | |
7267c094 | 1129 | g_free(l1_table); |
9ac228e0 | 1130 | return 0; |
f7d0fe02 KW |
1131 | |
1132 | fail: | |
1133 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); | |
9ac228e0 | 1134 | res->check_errors++; |
7267c094 | 1135 | g_free(l1_table); |
f7d0fe02 KW |
1136 | return -EIO; |
1137 | } | |
1138 | ||
1139 | /* | |
1140 | * Checks an image for refcount consistency. | |
1141 | * | |
1142 | * Returns 0 if no errors are found, the number of errors in case the image is | |
a1c7273b | 1143 | * detected as corrupted, and -errno when an internal error occurred. |
f7d0fe02 | 1144 | */ |
166acf54 KW |
1145 | int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, |
1146 | BdrvCheckMode fix) | |
f7d0fe02 KW |
1147 | { |
1148 | BDRVQcowState *s = bs->opaque; | |
c6bb9ad1 | 1149 | int64_t size, i, highest_cluster; |
166acf54 | 1150 | int nb_clusters, refcount1, refcount2; |
f7d0fe02 KW |
1151 | QCowSnapshot *sn; |
1152 | uint16_t *refcount_table; | |
9ac228e0 | 1153 | int ret; |
f7d0fe02 | 1154 | |
66f82cee | 1155 | size = bdrv_getlength(bs->file); |
f7d0fe02 | 1156 | nb_clusters = size_to_clusters(s, size); |
fba31bae | 1157 | res->bfi.total_clusters = nb_clusters; |
7267c094 | 1158 | refcount_table = g_malloc0(nb_clusters * sizeof(uint16_t)); |
f7d0fe02 KW |
1159 | |
1160 | /* header */ | |
9ac228e0 KW |
1161 | inc_refcounts(bs, res, refcount_table, nb_clusters, |
1162 | 0, s->cluster_size); | |
f7d0fe02 KW |
1163 | |
1164 | /* current L1 table */ | |
9ac228e0 | 1165 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
801f7044 | 1166 | s->l1_table_offset, s->l1_size, |
fba31bae | 1167 | CHECK_OFLAG_COPIED | CHECK_FRAG_INFO); |
f7d0fe02 | 1168 | if (ret < 0) { |
80fa3341 | 1169 | goto fail; |
f7d0fe02 | 1170 | } |
f7d0fe02 KW |
1171 | |
1172 | /* snapshots */ | |
1173 | for(i = 0; i < s->nb_snapshots; i++) { | |
1174 | sn = s->snapshots + i; | |
9ac228e0 KW |
1175 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
1176 | sn->l1_table_offset, sn->l1_size, 0); | |
1177 | if (ret < 0) { | |
80fa3341 | 1178 | goto fail; |
9ac228e0 | 1179 | } |
f7d0fe02 | 1180 | } |
9ac228e0 KW |
1181 | inc_refcounts(bs, res, refcount_table, nb_clusters, |
1182 | s->snapshots_offset, s->snapshots_size); | |
f7d0fe02 KW |
1183 | |
1184 | /* refcount data */ | |
9ac228e0 KW |
1185 | inc_refcounts(bs, res, refcount_table, nb_clusters, |
1186 | s->refcount_table_offset, | |
1187 | s->refcount_table_size * sizeof(uint64_t)); | |
1188 | ||
f7d0fe02 | 1189 | for(i = 0; i < s->refcount_table_size; i++) { |
6882c8fa | 1190 | uint64_t offset, cluster; |
f7d0fe02 | 1191 | offset = s->refcount_table[i]; |
6882c8fa | 1192 | cluster = offset >> s->cluster_bits; |
746c3cb5 KW |
1193 | |
1194 | /* Refcount blocks are cluster aligned */ | |
1195 | if (offset & (s->cluster_size - 1)) { | |
166acf54 | 1196 | fprintf(stderr, "ERROR refcount block %" PRId64 " is not " |
746c3cb5 | 1197 | "cluster aligned; refcount table entry corrupted\n", i); |
9ac228e0 | 1198 | res->corruptions++; |
6882c8fa KW |
1199 | continue; |
1200 | } | |
1201 | ||
1202 | if (cluster >= nb_clusters) { | |
166acf54 KW |
1203 | fprintf(stderr, "ERROR refcount block %" PRId64 |
1204 | " is outside image\n", i); | |
9ac228e0 | 1205 | res->corruptions++; |
6882c8fa | 1206 | continue; |
746c3cb5 KW |
1207 | } |
1208 | ||
f7d0fe02 | 1209 | if (offset != 0) { |
9ac228e0 KW |
1210 | inc_refcounts(bs, res, refcount_table, nb_clusters, |
1211 | offset, s->cluster_size); | |
6882c8fa | 1212 | if (refcount_table[cluster] != 1) { |
166acf54 KW |
1213 | fprintf(stderr, "ERROR refcount block %" PRId64 |
1214 | " refcount=%d\n", | |
6882c8fa | 1215 | i, refcount_table[cluster]); |
9ac228e0 | 1216 | res->corruptions++; |
746c3cb5 | 1217 | } |
f7d0fe02 KW |
1218 | } |
1219 | } | |
1220 | ||
1221 | /* compare ref counts */ | |
c6bb9ad1 | 1222 | for (i = 0, highest_cluster = 0; i < nb_clusters; i++) { |
f7d0fe02 | 1223 | refcount1 = get_refcount(bs, i); |
018faafd | 1224 | if (refcount1 < 0) { |
166acf54 | 1225 | fprintf(stderr, "Can't get refcount for cluster %" PRId64 ": %s\n", |
018faafd | 1226 | i, strerror(-refcount1)); |
9ac228e0 | 1227 | res->check_errors++; |
f74550fd | 1228 | continue; |
018faafd KW |
1229 | } |
1230 | ||
f7d0fe02 | 1231 | refcount2 = refcount_table[i]; |
c6bb9ad1 FS |
1232 | |
1233 | if (refcount1 > 0 || refcount2 > 0) { | |
1234 | highest_cluster = i; | |
1235 | } | |
1236 | ||
f7d0fe02 | 1237 | if (refcount1 != refcount2) { |
166acf54 KW |
1238 | |
1239 | /* Check if we're allowed to fix the mismatch */ | |
1240 | int *num_fixed = NULL; | |
1241 | if (refcount1 > refcount2 && (fix & BDRV_FIX_LEAKS)) { | |
1242 | num_fixed = &res->leaks_fixed; | |
1243 | } else if (refcount1 < refcount2 && (fix & BDRV_FIX_ERRORS)) { | |
1244 | num_fixed = &res->corruptions_fixed; | |
1245 | } | |
1246 | ||
1247 | fprintf(stderr, "%s cluster %" PRId64 " refcount=%d reference=%d\n", | |
1248 | num_fixed != NULL ? "Repairing" : | |
1249 | refcount1 < refcount2 ? "ERROR" : | |
1250 | "Leaked", | |
f7d0fe02 | 1251 | i, refcount1, refcount2); |
166acf54 KW |
1252 | |
1253 | if (num_fixed) { | |
1254 | ret = update_refcount(bs, i << s->cluster_bits, 1, | |
1255 | refcount2 - refcount1); | |
1256 | if (ret >= 0) { | |
1257 | (*num_fixed)++; | |
1258 | continue; | |
1259 | } | |
1260 | } | |
1261 | ||
1262 | /* And if we couldn't, print an error */ | |
9ac228e0 KW |
1263 | if (refcount1 < refcount2) { |
1264 | res->corruptions++; | |
1265 | } else { | |
1266 | res->leaks++; | |
1267 | } | |
f7d0fe02 KW |
1268 | } |
1269 | } | |
1270 | ||
c6bb9ad1 | 1271 | res->image_end_offset = (highest_cluster + 1) * s->cluster_size; |
80fa3341 KW |
1272 | ret = 0; |
1273 | ||
1274 | fail: | |
7267c094 | 1275 | g_free(refcount_table); |
f7d0fe02 | 1276 | |
80fa3341 | 1277 | return ret; |
f7d0fe02 KW |
1278 | } |
1279 |