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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 | 27 | #include "block/qcow2.h" |
a40f1c2a HR |
28 | #include "qemu/range.h" |
29 | #include "qapi/qmp/types.h" | |
f7d0fe02 KW |
30 | |
31 | static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size); | |
92dcb59f | 32 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
f7d0fe02 | 33 | int64_t offset, int64_t length, |
6cfcb9b8 | 34 | int addend, enum qcow2_discard_type type); |
f7d0fe02 | 35 | |
3b88e52b | 36 | |
f7d0fe02 KW |
37 | /*********************************************************/ |
38 | /* refcount handling */ | |
39 | ||
ed6ccf0f | 40 | int qcow2_refcount_init(BlockDriverState *bs) |
f7d0fe02 KW |
41 | { |
42 | BDRVQcowState *s = bs->opaque; | |
43 | int ret, refcount_table_size2, i; | |
44 | ||
f7d0fe02 | 45 | refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); |
7267c094 | 46 | s->refcount_table = g_malloc(refcount_table_size2); |
f7d0fe02 | 47 | if (s->refcount_table_size > 0) { |
66f82cee KW |
48 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_LOAD); |
49 | ret = bdrv_pread(bs->file, s->refcount_table_offset, | |
f7d0fe02 KW |
50 | s->refcount_table, refcount_table_size2); |
51 | if (ret != refcount_table_size2) | |
52 | goto fail; | |
53 | for(i = 0; i < s->refcount_table_size; i++) | |
54 | be64_to_cpus(&s->refcount_table[i]); | |
55 | } | |
56 | return 0; | |
57 | fail: | |
58 | return -ENOMEM; | |
59 | } | |
60 | ||
ed6ccf0f | 61 | void qcow2_refcount_close(BlockDriverState *bs) |
f7d0fe02 KW |
62 | { |
63 | BDRVQcowState *s = bs->opaque; | |
7267c094 | 64 | g_free(s->refcount_table); |
f7d0fe02 KW |
65 | } |
66 | ||
67 | ||
68 | static int load_refcount_block(BlockDriverState *bs, | |
29c1a730 KW |
69 | int64_t refcount_block_offset, |
70 | void **refcount_block) | |
f7d0fe02 KW |
71 | { |
72 | BDRVQcowState *s = bs->opaque; | |
73 | int ret; | |
3b88e52b | 74 | |
66f82cee | 75 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_LOAD); |
29c1a730 KW |
76 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, |
77 | refcount_block); | |
e14e8ba5 | 78 | |
29c1a730 | 79 | return ret; |
f7d0fe02 KW |
80 | } |
81 | ||
018faafd KW |
82 | /* |
83 | * Returns the refcount of the cluster given by its index. Any non-negative | |
84 | * return value is the refcount of the cluster, negative values are -errno | |
85 | * and indicate an error. | |
86 | */ | |
f7d0fe02 KW |
87 | static int get_refcount(BlockDriverState *bs, int64_t cluster_index) |
88 | { | |
89 | BDRVQcowState *s = bs->opaque; | |
90 | int refcount_table_index, block_index; | |
91 | int64_t refcount_block_offset; | |
018faafd | 92 | int ret; |
29c1a730 KW |
93 | uint16_t *refcount_block; |
94 | uint16_t refcount; | |
f7d0fe02 KW |
95 | |
96 | refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); | |
97 | if (refcount_table_index >= s->refcount_table_size) | |
98 | return 0; | |
26d49c46 HR |
99 | refcount_block_offset = |
100 | s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; | |
f7d0fe02 KW |
101 | if (!refcount_block_offset) |
102 | return 0; | |
29c1a730 KW |
103 | |
104 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, | |
105 | (void**) &refcount_block); | |
106 | if (ret < 0) { | |
107 | return ret; | |
f7d0fe02 | 108 | } |
29c1a730 | 109 | |
f7d0fe02 KW |
110 | block_index = cluster_index & |
111 | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); | |
29c1a730 KW |
112 | refcount = be16_to_cpu(refcount_block[block_index]); |
113 | ||
114 | ret = qcow2_cache_put(bs, s->refcount_block_cache, | |
115 | (void**) &refcount_block); | |
116 | if (ret < 0) { | |
117 | return ret; | |
118 | } | |
119 | ||
120 | return refcount; | |
f7d0fe02 KW |
121 | } |
122 | ||
05121aed KW |
123 | /* |
124 | * Rounds the refcount table size up to avoid growing the table for each single | |
125 | * refcount block that is allocated. | |
126 | */ | |
127 | static unsigned int next_refcount_table_size(BDRVQcowState *s, | |
128 | unsigned int min_size) | |
129 | { | |
130 | unsigned int min_clusters = (min_size >> (s->cluster_bits - 3)) + 1; | |
131 | unsigned int refcount_table_clusters = | |
132 | MAX(1, s->refcount_table_size >> (s->cluster_bits - 3)); | |
133 | ||
134 | while (min_clusters > refcount_table_clusters) { | |
135 | refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; | |
136 | } | |
137 | ||
138 | return refcount_table_clusters << (s->cluster_bits - 3); | |
139 | } | |
140 | ||
92dcb59f KW |
141 | |
142 | /* Checks if two offsets are described by the same refcount block */ | |
143 | static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a, | |
144 | uint64_t offset_b) | |
145 | { | |
146 | uint64_t block_a = offset_a >> (2 * s->cluster_bits - REFCOUNT_SHIFT); | |
147 | uint64_t block_b = offset_b >> (2 * s->cluster_bits - REFCOUNT_SHIFT); | |
148 | ||
149 | return (block_a == block_b); | |
150 | } | |
151 | ||
152 | /* | |
153 | * Loads a refcount block. If it doesn't exist yet, it is allocated first | |
154 | * (including growing the refcount table if needed). | |
155 | * | |
29c1a730 | 156 | * Returns 0 on success or -errno in error case |
92dcb59f | 157 | */ |
29c1a730 KW |
158 | static int alloc_refcount_block(BlockDriverState *bs, |
159 | int64_t cluster_index, uint16_t **refcount_block) | |
f7d0fe02 KW |
160 | { |
161 | BDRVQcowState *s = bs->opaque; | |
92dcb59f KW |
162 | unsigned int refcount_table_index; |
163 | int ret; | |
164 | ||
66f82cee | 165 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); |
8252278a | 166 | |
92dcb59f KW |
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 = | |
76dc9e0c | 173 | s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; |
92dcb59f KW |
174 | |
175 | /* If it's already there, we're done */ | |
176 | if (refcount_block_offset) { | |
29c1a730 KW |
177 | return load_refcount_block(bs, refcount_block_offset, |
178 | (void**) refcount_block); | |
92dcb59f KW |
179 | } |
180 | } | |
181 | ||
182 | /* | |
183 | * If we came here, we need to allocate something. Something is at least | |
184 | * a cluster for the new refcount block. It may also include a new refcount | |
185 | * table if the old refcount table is too small. | |
186 | * | |
187 | * Note that allocating clusters here needs some special care: | |
188 | * | |
189 | * - We can't use the normal qcow2_alloc_clusters(), it would try to | |
190 | * increase the refcount and very likely we would end up with an endless | |
191 | * recursion. Instead we must place the refcount blocks in a way that | |
192 | * they can describe them themselves. | |
193 | * | |
194 | * - We need to consider that at this point we are inside update_refcounts | |
195 | * and doing the initial refcount increase. This means that some clusters | |
196 | * have already been allocated by the caller, but their refcount isn't | |
197 | * accurate yet. free_cluster_index tells us where this allocation ends | |
198 | * as long as we don't overwrite it by freeing clusters. | |
199 | * | |
200 | * - alloc_clusters_noref and qcow2_free_clusters may load a different | |
201 | * refcount block into the cache | |
202 | */ | |
203 | ||
29c1a730 KW |
204 | *refcount_block = NULL; |
205 | ||
206 | /* We write to the refcount table, so we might depend on L2 tables */ | |
9991923b SH |
207 | ret = qcow2_cache_flush(bs, s->l2_table_cache); |
208 | if (ret < 0) { | |
209 | return ret; | |
210 | } | |
92dcb59f KW |
211 | |
212 | /* Allocate the refcount block itself and mark it as used */ | |
2eaa8f63 KW |
213 | int64_t new_block = alloc_clusters_noref(bs, s->cluster_size); |
214 | if (new_block < 0) { | |
215 | return new_block; | |
216 | } | |
f7d0fe02 | 217 | |
f7d0fe02 | 218 | #ifdef DEBUG_ALLOC2 |
92dcb59f KW |
219 | fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64 |
220 | " at %" PRIx64 "\n", | |
221 | refcount_table_index, cluster_index << s->cluster_bits, new_block); | |
f7d0fe02 | 222 | #endif |
92dcb59f KW |
223 | |
224 | if (in_same_refcount_block(s, new_block, cluster_index << s->cluster_bits)) { | |
25408c09 | 225 | /* Zero the new refcount block before updating it */ |
29c1a730 KW |
226 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
227 | (void**) refcount_block); | |
228 | if (ret < 0) { | |
229 | goto fail_block; | |
230 | } | |
231 | ||
232 | memset(*refcount_block, 0, s->cluster_size); | |
25408c09 | 233 | |
92dcb59f KW |
234 | /* The block describes itself, need to update the cache */ |
235 | int block_index = (new_block >> s->cluster_bits) & | |
236 | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); | |
29c1a730 | 237 | (*refcount_block)[block_index] = cpu_to_be16(1); |
92dcb59f KW |
238 | } else { |
239 | /* Described somewhere else. This can recurse at most twice before we | |
240 | * arrive at a block that describes itself. */ | |
6cfcb9b8 KW |
241 | ret = update_refcount(bs, new_block, s->cluster_size, 1, |
242 | QCOW2_DISCARD_NEVER); | |
92dcb59f KW |
243 | if (ret < 0) { |
244 | goto fail_block; | |
245 | } | |
25408c09 | 246 | |
9991923b SH |
247 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
248 | if (ret < 0) { | |
249 | goto fail_block; | |
250 | } | |
1c4c2814 | 251 | |
25408c09 KW |
252 | /* Initialize the new refcount block only after updating its refcount, |
253 | * update_refcount uses the refcount cache itself */ | |
29c1a730 KW |
254 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
255 | (void**) refcount_block); | |
256 | if (ret < 0) { | |
257 | goto fail_block; | |
258 | } | |
259 | ||
260 | memset(*refcount_block, 0, s->cluster_size); | |
92dcb59f KW |
261 | } |
262 | ||
263 | /* Now the new refcount block needs to be written to disk */ | |
66f82cee | 264 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE); |
29c1a730 KW |
265 | qcow2_cache_entry_mark_dirty(s->refcount_block_cache, *refcount_block); |
266 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); | |
92dcb59f KW |
267 | if (ret < 0) { |
268 | goto fail_block; | |
269 | } | |
270 | ||
271 | /* If the refcount table is big enough, just hook the block up there */ | |
272 | if (refcount_table_index < s->refcount_table_size) { | |
273 | uint64_t data64 = cpu_to_be64(new_block); | |
66f82cee | 274 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_HOOKUP); |
8b3b7206 | 275 | ret = bdrv_pwrite_sync(bs->file, |
92dcb59f KW |
276 | s->refcount_table_offset + refcount_table_index * sizeof(uint64_t), |
277 | &data64, sizeof(data64)); | |
278 | if (ret < 0) { | |
279 | goto fail_block; | |
280 | } | |
281 | ||
282 | s->refcount_table[refcount_table_index] = new_block; | |
29c1a730 KW |
283 | return 0; |
284 | } | |
285 | ||
286 | ret = qcow2_cache_put(bs, s->refcount_block_cache, (void**) refcount_block); | |
287 | if (ret < 0) { | |
288 | goto fail_block; | |
92dcb59f KW |
289 | } |
290 | ||
291 | /* | |
292 | * If we come here, we need to grow the refcount table. Again, a new | |
293 | * refcount table needs some space and we can't simply allocate to avoid | |
294 | * endless recursion. | |
295 | * | |
296 | * Therefore let's grab new refcount blocks at the end of the image, which | |
297 | * will describe themselves and the new refcount table. This way we can | |
298 | * reference them only in the new table and do the switch to the new | |
299 | * refcount table at once without producing an inconsistent state in | |
300 | * between. | |
301 | */ | |
66f82cee | 302 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW); |
8252278a | 303 | |
92dcb59f KW |
304 | /* Calculate the number of refcount blocks needed so far */ |
305 | uint64_t refcount_block_clusters = 1 << (s->cluster_bits - REFCOUNT_SHIFT); | |
306 | uint64_t blocks_used = (s->free_cluster_index + | |
307 | refcount_block_clusters - 1) / refcount_block_clusters; | |
308 | ||
309 | /* And now we need at least one block more for the new metadata */ | |
310 | uint64_t table_size = next_refcount_table_size(s, blocks_used + 1); | |
311 | uint64_t last_table_size; | |
312 | uint64_t blocks_clusters; | |
313 | do { | |
a3548077 KW |
314 | uint64_t table_clusters = |
315 | size_to_clusters(s, table_size * sizeof(uint64_t)); | |
92dcb59f KW |
316 | blocks_clusters = 1 + |
317 | ((table_clusters + refcount_block_clusters - 1) | |
318 | / refcount_block_clusters); | |
319 | uint64_t meta_clusters = table_clusters + blocks_clusters; | |
320 | ||
321 | last_table_size = table_size; | |
322 | table_size = next_refcount_table_size(s, blocks_used + | |
323 | ((meta_clusters + refcount_block_clusters - 1) | |
324 | / refcount_block_clusters)); | |
325 | ||
326 | } while (last_table_size != table_size); | |
327 | ||
328 | #ifdef DEBUG_ALLOC2 | |
329 | fprintf(stderr, "qcow2: Grow refcount table %" PRId32 " => %" PRId64 "\n", | |
330 | s->refcount_table_size, table_size); | |
331 | #endif | |
332 | ||
333 | /* Create the new refcount table and blocks */ | |
334 | uint64_t meta_offset = (blocks_used * refcount_block_clusters) * | |
335 | s->cluster_size; | |
336 | uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size; | |
7267c094 AL |
337 | uint16_t *new_blocks = g_malloc0(blocks_clusters * s->cluster_size); |
338 | uint64_t *new_table = g_malloc0(table_size * sizeof(uint64_t)); | |
92dcb59f KW |
339 | |
340 | assert(meta_offset >= (s->free_cluster_index * s->cluster_size)); | |
341 | ||
342 | /* Fill the new refcount table */ | |
f7d0fe02 | 343 | memcpy(new_table, s->refcount_table, |
92dcb59f KW |
344 | s->refcount_table_size * sizeof(uint64_t)); |
345 | new_table[refcount_table_index] = new_block; | |
346 | ||
347 | int i; | |
348 | for (i = 0; i < blocks_clusters; i++) { | |
349 | new_table[blocks_used + i] = meta_offset + (i * s->cluster_size); | |
350 | } | |
351 | ||
352 | /* Fill the refcount blocks */ | |
353 | uint64_t table_clusters = size_to_clusters(s, table_size * sizeof(uint64_t)); | |
354 | int block = 0; | |
355 | for (i = 0; i < table_clusters + blocks_clusters; i++) { | |
356 | new_blocks[block++] = cpu_to_be16(1); | |
357 | } | |
358 | ||
359 | /* Write refcount blocks to disk */ | |
66f82cee | 360 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS); |
8b3b7206 | 361 | ret = bdrv_pwrite_sync(bs->file, meta_offset, new_blocks, |
92dcb59f | 362 | blocks_clusters * s->cluster_size); |
7267c094 | 363 | g_free(new_blocks); |
92dcb59f KW |
364 | if (ret < 0) { |
365 | goto fail_table; | |
366 | } | |
367 | ||
368 | /* Write refcount table to disk */ | |
369 | for(i = 0; i < table_size; i++) { | |
370 | cpu_to_be64s(&new_table[i]); | |
371 | } | |
372 | ||
66f82cee | 373 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE); |
8b3b7206 | 374 | ret = bdrv_pwrite_sync(bs->file, table_offset, new_table, |
92dcb59f KW |
375 | table_size * sizeof(uint64_t)); |
376 | if (ret < 0) { | |
377 | goto fail_table; | |
378 | } | |
379 | ||
380 | for(i = 0; i < table_size; i++) { | |
87267753 | 381 | be64_to_cpus(&new_table[i]); |
92dcb59f | 382 | } |
f7d0fe02 | 383 | |
92dcb59f KW |
384 | /* Hook up the new refcount table in the qcow2 header */ |
385 | uint8_t data[12]; | |
f7d0fe02 | 386 | cpu_to_be64w((uint64_t*)data, table_offset); |
92dcb59f | 387 | cpu_to_be32w((uint32_t*)(data + 8), table_clusters); |
66f82cee | 388 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE); |
8b3b7206 | 389 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, refcount_table_offset), |
92dcb59f KW |
390 | data, sizeof(data)); |
391 | if (ret < 0) { | |
392 | goto fail_table; | |
f2b7c8b3 KW |
393 | } |
394 | ||
92dcb59f KW |
395 | /* And switch it in memory */ |
396 | uint64_t old_table_offset = s->refcount_table_offset; | |
397 | uint64_t old_table_size = s->refcount_table_size; | |
398 | ||
7267c094 | 399 | g_free(s->refcount_table); |
f7d0fe02 | 400 | s->refcount_table = new_table; |
92dcb59f | 401 | s->refcount_table_size = table_size; |
f7d0fe02 KW |
402 | s->refcount_table_offset = table_offset; |
403 | ||
92dcb59f KW |
404 | /* Free old table. Remember, we must not change free_cluster_index */ |
405 | uint64_t old_free_cluster_index = s->free_cluster_index; | |
6cfcb9b8 KW |
406 | qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t), |
407 | QCOW2_DISCARD_OTHER); | |
92dcb59f | 408 | s->free_cluster_index = old_free_cluster_index; |
f7d0fe02 | 409 | |
29c1a730 | 410 | ret = load_refcount_block(bs, new_block, (void**) refcount_block); |
92dcb59f | 411 | if (ret < 0) { |
29c1a730 | 412 | return ret; |
f7d0fe02 KW |
413 | } |
414 | ||
2795ecf6 | 415 | return 0; |
f7d0fe02 | 416 | |
92dcb59f | 417 | fail_table: |
7267c094 | 418 | g_free(new_table); |
92dcb59f | 419 | fail_block: |
29c1a730 KW |
420 | if (*refcount_block != NULL) { |
421 | qcow2_cache_put(bs, s->refcount_block_cache, (void**) refcount_block); | |
3b88e52b | 422 | } |
29c1a730 | 423 | return ret; |
9923e05e KW |
424 | } |
425 | ||
0b919fae KW |
426 | void qcow2_process_discards(BlockDriverState *bs, int ret) |
427 | { | |
428 | BDRVQcowState *s = bs->opaque; | |
429 | Qcow2DiscardRegion *d, *next; | |
430 | ||
431 | QTAILQ_FOREACH_SAFE(d, &s->discards, next, next) { | |
432 | QTAILQ_REMOVE(&s->discards, d, next); | |
433 | ||
434 | /* Discard is optional, ignore the return value */ | |
435 | if (ret >= 0) { | |
436 | bdrv_discard(bs->file, | |
437 | d->offset >> BDRV_SECTOR_BITS, | |
438 | d->bytes >> BDRV_SECTOR_BITS); | |
439 | } | |
440 | ||
441 | g_free(d); | |
442 | } | |
443 | } | |
444 | ||
445 | static void update_refcount_discard(BlockDriverState *bs, | |
446 | uint64_t offset, uint64_t length) | |
447 | { | |
448 | BDRVQcowState *s = bs->opaque; | |
449 | Qcow2DiscardRegion *d, *p, *next; | |
450 | ||
451 | QTAILQ_FOREACH(d, &s->discards, next) { | |
452 | uint64_t new_start = MIN(offset, d->offset); | |
453 | uint64_t new_end = MAX(offset + length, d->offset + d->bytes); | |
454 | ||
455 | if (new_end - new_start <= length + d->bytes) { | |
456 | /* There can't be any overlap, areas ending up here have no | |
457 | * references any more and therefore shouldn't get freed another | |
458 | * time. */ | |
459 | assert(d->bytes + length == new_end - new_start); | |
460 | d->offset = new_start; | |
461 | d->bytes = new_end - new_start; | |
462 | goto found; | |
463 | } | |
464 | } | |
465 | ||
466 | d = g_malloc(sizeof(*d)); | |
467 | *d = (Qcow2DiscardRegion) { | |
468 | .bs = bs, | |
469 | .offset = offset, | |
470 | .bytes = length, | |
471 | }; | |
472 | QTAILQ_INSERT_TAIL(&s->discards, d, next); | |
473 | ||
474 | found: | |
475 | /* Merge discard requests if they are adjacent now */ | |
476 | QTAILQ_FOREACH_SAFE(p, &s->discards, next, next) { | |
477 | if (p == d | |
478 | || p->offset > d->offset + d->bytes | |
479 | || d->offset > p->offset + p->bytes) | |
480 | { | |
481 | continue; | |
482 | } | |
483 | ||
484 | /* Still no overlap possible */ | |
485 | assert(p->offset == d->offset + d->bytes | |
486 | || d->offset == p->offset + p->bytes); | |
487 | ||
488 | QTAILQ_REMOVE(&s->discards, p, next); | |
489 | d->offset = MIN(d->offset, p->offset); | |
490 | d->bytes += p->bytes; | |
491 | } | |
492 | } | |
493 | ||
f7d0fe02 | 494 | /* XXX: cache several refcount block clusters ? */ |
db3a964f | 495 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
6cfcb9b8 | 496 | int64_t offset, int64_t length, int addend, enum qcow2_discard_type type) |
f7d0fe02 KW |
497 | { |
498 | BDRVQcowState *s = bs->opaque; | |
499 | int64_t start, last, cluster_offset; | |
29c1a730 KW |
500 | uint16_t *refcount_block = NULL; |
501 | int64_t old_table_index = -1; | |
09508d13 | 502 | int ret; |
f7d0fe02 KW |
503 | |
504 | #ifdef DEBUG_ALLOC2 | |
35ee5e39 | 505 | fprintf(stderr, "update_refcount: offset=%" PRId64 " size=%" PRId64 " addend=%d\n", |
f7d0fe02 KW |
506 | offset, length, addend); |
507 | #endif | |
7322afe7 | 508 | if (length < 0) { |
f7d0fe02 | 509 | return -EINVAL; |
7322afe7 KW |
510 | } else if (length == 0) { |
511 | return 0; | |
512 | } | |
513 | ||
29c1a730 KW |
514 | if (addend < 0) { |
515 | qcow2_cache_set_dependency(bs, s->refcount_block_cache, | |
516 | s->l2_table_cache); | |
517 | } | |
518 | ||
ac95acdb HT |
519 | start = start_of_cluster(s, offset); |
520 | last = start_of_cluster(s, offset + length - 1); | |
f7d0fe02 KW |
521 | for(cluster_offset = start; cluster_offset <= last; |
522 | cluster_offset += s->cluster_size) | |
523 | { | |
524 | int block_index, refcount; | |
525 | int64_t cluster_index = cluster_offset >> s->cluster_bits; | |
29c1a730 KW |
526 | int64_t table_index = |
527 | cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); | |
f7d0fe02 | 528 | |
29c1a730 KW |
529 | /* Load the refcount block and allocate it if needed */ |
530 | if (table_index != old_table_index) { | |
531 | if (refcount_block) { | |
532 | ret = qcow2_cache_put(bs, s->refcount_block_cache, | |
533 | (void**) &refcount_block); | |
534 | if (ret < 0) { | |
535 | goto fail; | |
536 | } | |
537 | } | |
9923e05e | 538 | |
29c1a730 | 539 | ret = alloc_refcount_block(bs, cluster_index, &refcount_block); |
ed0df867 | 540 | if (ret < 0) { |
29c1a730 | 541 | goto fail; |
f7d0fe02 | 542 | } |
f7d0fe02 | 543 | } |
29c1a730 | 544 | old_table_index = table_index; |
f7d0fe02 | 545 | |
29c1a730 | 546 | qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refcount_block); |
f7d0fe02 KW |
547 | |
548 | /* we can update the count and save it */ | |
549 | block_index = cluster_index & | |
550 | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); | |
f7d0fe02 | 551 | |
29c1a730 | 552 | refcount = be16_to_cpu(refcount_block[block_index]); |
f7d0fe02 | 553 | refcount += addend; |
09508d13 KW |
554 | if (refcount < 0 || refcount > 0xffff) { |
555 | ret = -EINVAL; | |
556 | goto fail; | |
557 | } | |
f7d0fe02 KW |
558 | if (refcount == 0 && cluster_index < s->free_cluster_index) { |
559 | s->free_cluster_index = cluster_index; | |
560 | } | |
29c1a730 | 561 | refcount_block[block_index] = cpu_to_be16(refcount); |
0b919fae | 562 | |
67af674e | 563 | if (refcount == 0 && s->discard_passthrough[type]) { |
0b919fae | 564 | update_refcount_discard(bs, cluster_offset, s->cluster_size); |
67af674e | 565 | } |
f7d0fe02 KW |
566 | } |
567 | ||
09508d13 KW |
568 | ret = 0; |
569 | fail: | |
0b919fae KW |
570 | if (!s->cache_discards) { |
571 | qcow2_process_discards(bs, ret); | |
572 | } | |
573 | ||
f7d0fe02 | 574 | /* Write last changed block to disk */ |
29c1a730 | 575 | if (refcount_block) { |
ed0df867 | 576 | int wret; |
29c1a730 KW |
577 | wret = qcow2_cache_put(bs, s->refcount_block_cache, |
578 | (void**) &refcount_block); | |
ed0df867 KW |
579 | if (wret < 0) { |
580 | return ret < 0 ? ret : wret; | |
f7d0fe02 KW |
581 | } |
582 | } | |
583 | ||
09508d13 KW |
584 | /* |
585 | * Try do undo any updates if an error is returned (This may succeed in | |
586 | * some cases like ENOSPC for allocating a new refcount block) | |
587 | */ | |
588 | if (ret < 0) { | |
589 | int dummy; | |
6cfcb9b8 KW |
590 | dummy = update_refcount(bs, offset, cluster_offset - offset, -addend, |
591 | QCOW2_DISCARD_NEVER); | |
83e3f76c | 592 | (void)dummy; |
09508d13 KW |
593 | } |
594 | ||
595 | return ret; | |
f7d0fe02 KW |
596 | } |
597 | ||
018faafd KW |
598 | /* |
599 | * Increases or decreases the refcount of a given cluster by one. | |
600 | * addend must be 1 or -1. | |
601 | * | |
602 | * If the return value is non-negative, it is the new refcount of the cluster. | |
603 | * If it is negative, it is -errno and indicates an error. | |
604 | */ | |
32b6444d HR |
605 | int qcow2_update_cluster_refcount(BlockDriverState *bs, |
606 | int64_t cluster_index, | |
607 | int addend, | |
608 | enum qcow2_discard_type type) | |
f7d0fe02 KW |
609 | { |
610 | BDRVQcowState *s = bs->opaque; | |
611 | int ret; | |
612 | ||
6cfcb9b8 KW |
613 | ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend, |
614 | type); | |
f7d0fe02 KW |
615 | if (ret < 0) { |
616 | return ret; | |
617 | } | |
618 | ||
619 | return get_refcount(bs, cluster_index); | |
620 | } | |
621 | ||
622 | ||
623 | ||
624 | /*********************************************************/ | |
625 | /* cluster allocation functions */ | |
626 | ||
627 | ||
628 | ||
629 | /* return < 0 if error */ | |
630 | static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size) | |
631 | { | |
632 | BDRVQcowState *s = bs->opaque; | |
2eaa8f63 | 633 | int i, nb_clusters, refcount; |
f7d0fe02 KW |
634 | |
635 | nb_clusters = size_to_clusters(s, size); | |
636 | retry: | |
637 | for(i = 0; i < nb_clusters; i++) { | |
508e0893 | 638 | int64_t next_cluster_index = s->free_cluster_index++; |
2eaa8f63 KW |
639 | refcount = get_refcount(bs, next_cluster_index); |
640 | ||
641 | if (refcount < 0) { | |
642 | return refcount; | |
643 | } else if (refcount != 0) { | |
f7d0fe02 | 644 | goto retry; |
2eaa8f63 | 645 | } |
f7d0fe02 KW |
646 | } |
647 | #ifdef DEBUG_ALLOC2 | |
35ee5e39 | 648 | fprintf(stderr, "alloc_clusters: size=%" PRId64 " -> %" PRId64 "\n", |
f7d0fe02 KW |
649 | size, |
650 | (s->free_cluster_index - nb_clusters) << s->cluster_bits); | |
651 | #endif | |
652 | return (s->free_cluster_index - nb_clusters) << s->cluster_bits; | |
653 | } | |
654 | ||
ed6ccf0f | 655 | int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size) |
f7d0fe02 KW |
656 | { |
657 | int64_t offset; | |
db3a964f | 658 | int ret; |
f7d0fe02 | 659 | |
66f82cee | 660 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC); |
f7d0fe02 | 661 | offset = alloc_clusters_noref(bs, size); |
2eaa8f63 KW |
662 | if (offset < 0) { |
663 | return offset; | |
664 | } | |
665 | ||
6cfcb9b8 | 666 | ret = update_refcount(bs, offset, size, 1, QCOW2_DISCARD_NEVER); |
db3a964f KW |
667 | if (ret < 0) { |
668 | return ret; | |
669 | } | |
1c4c2814 | 670 | |
f7d0fe02 KW |
671 | return offset; |
672 | } | |
673 | ||
256900b1 KW |
674 | int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, |
675 | int nb_clusters) | |
676 | { | |
677 | BDRVQcowState *s = bs->opaque; | |
678 | uint64_t cluster_index; | |
f24423bd | 679 | uint64_t old_free_cluster_index; |
33304ec9 HT |
680 | uint64_t i; |
681 | int refcount, ret; | |
682 | ||
683 | assert(nb_clusters >= 0); | |
684 | if (nb_clusters == 0) { | |
685 | return 0; | |
686 | } | |
256900b1 KW |
687 | |
688 | /* Check how many clusters there are free */ | |
689 | cluster_index = offset >> s->cluster_bits; | |
690 | for(i = 0; i < nb_clusters; i++) { | |
691 | refcount = get_refcount(bs, cluster_index++); | |
692 | ||
693 | if (refcount < 0) { | |
694 | return refcount; | |
695 | } else if (refcount != 0) { | |
696 | break; | |
697 | } | |
698 | } | |
699 | ||
700 | /* And then allocate them */ | |
f24423bd KW |
701 | old_free_cluster_index = s->free_cluster_index; |
702 | s->free_cluster_index = cluster_index + i; | |
703 | ||
6cfcb9b8 KW |
704 | ret = update_refcount(bs, offset, i << s->cluster_bits, 1, |
705 | QCOW2_DISCARD_NEVER); | |
256900b1 KW |
706 | if (ret < 0) { |
707 | return ret; | |
708 | } | |
709 | ||
f24423bd KW |
710 | s->free_cluster_index = old_free_cluster_index; |
711 | ||
256900b1 KW |
712 | return i; |
713 | } | |
714 | ||
f7d0fe02 KW |
715 | /* only used to allocate compressed sectors. We try to allocate |
716 | contiguous sectors. size must be <= cluster_size */ | |
ed6ccf0f | 717 | int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size) |
f7d0fe02 KW |
718 | { |
719 | BDRVQcowState *s = bs->opaque; | |
720 | int64_t offset, cluster_offset; | |
721 | int free_in_cluster; | |
722 | ||
66f82cee | 723 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_BYTES); |
f7d0fe02 KW |
724 | assert(size > 0 && size <= s->cluster_size); |
725 | if (s->free_byte_offset == 0) { | |
206e6d85 SH |
726 | offset = qcow2_alloc_clusters(bs, s->cluster_size); |
727 | if (offset < 0) { | |
728 | return offset; | |
5d757b56 | 729 | } |
206e6d85 | 730 | s->free_byte_offset = offset; |
f7d0fe02 KW |
731 | } |
732 | redo: | |
733 | free_in_cluster = s->cluster_size - | |
ac95acdb | 734 | offset_into_cluster(s, s->free_byte_offset); |
f7d0fe02 KW |
735 | if (size <= free_in_cluster) { |
736 | /* enough space in current cluster */ | |
737 | offset = s->free_byte_offset; | |
738 | s->free_byte_offset += size; | |
739 | free_in_cluster -= size; | |
740 | if (free_in_cluster == 0) | |
741 | s->free_byte_offset = 0; | |
ac95acdb | 742 | if (offset_into_cluster(s, offset) != 0) |
32b6444d HR |
743 | qcow2_update_cluster_refcount(bs, offset >> s->cluster_bits, 1, |
744 | QCOW2_DISCARD_NEVER); | |
f7d0fe02 | 745 | } else { |
ed6ccf0f | 746 | offset = qcow2_alloc_clusters(bs, s->cluster_size); |
5d757b56 KW |
747 | if (offset < 0) { |
748 | return offset; | |
749 | } | |
ac95acdb | 750 | cluster_offset = start_of_cluster(s, s->free_byte_offset); |
f7d0fe02 KW |
751 | if ((cluster_offset + s->cluster_size) == offset) { |
752 | /* we are lucky: contiguous data */ | |
753 | offset = s->free_byte_offset; | |
32b6444d HR |
754 | qcow2_update_cluster_refcount(bs, offset >> s->cluster_bits, 1, |
755 | QCOW2_DISCARD_NEVER); | |
f7d0fe02 KW |
756 | s->free_byte_offset += size; |
757 | } else { | |
758 | s->free_byte_offset = offset; | |
759 | goto redo; | |
760 | } | |
761 | } | |
29216ed1 | 762 | |
c1f5bafd | 763 | /* The cluster refcount was incremented, either by qcow2_alloc_clusters() |
32b6444d HR |
764 | * or explicitly by qcow2_update_cluster_refcount(). Refcount blocks must |
765 | * be flushed before the caller's L2 table updates. | |
c1f5bafd SH |
766 | */ |
767 | qcow2_cache_set_dependency(bs, s->l2_table_cache, s->refcount_block_cache); | |
f7d0fe02 KW |
768 | return offset; |
769 | } | |
770 | ||
ed6ccf0f | 771 | void qcow2_free_clusters(BlockDriverState *bs, |
6cfcb9b8 KW |
772 | int64_t offset, int64_t size, |
773 | enum qcow2_discard_type type) | |
f7d0fe02 | 774 | { |
db3a964f KW |
775 | int ret; |
776 | ||
66f82cee | 777 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_FREE); |
6cfcb9b8 | 778 | ret = update_refcount(bs, offset, size, -1, type); |
db3a964f KW |
779 | if (ret < 0) { |
780 | fprintf(stderr, "qcow2_free_clusters failed: %s\n", strerror(-ret)); | |
003fad6e | 781 | /* TODO Remember the clusters to free them later and avoid leaking */ |
db3a964f | 782 | } |
f7d0fe02 KW |
783 | } |
784 | ||
45aba42f | 785 | /* |
c7a4c37a KW |
786 | * Free a cluster using its L2 entry (handles clusters of all types, e.g. |
787 | * normal cluster, compressed cluster, etc.) | |
45aba42f | 788 | */ |
6cfcb9b8 KW |
789 | void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry, |
790 | int nb_clusters, enum qcow2_discard_type type) | |
45aba42f KW |
791 | { |
792 | BDRVQcowState *s = bs->opaque; | |
793 | ||
c7a4c37a KW |
794 | switch (qcow2_get_cluster_type(l2_entry)) { |
795 | case QCOW2_CLUSTER_COMPRESSED: | |
796 | { | |
797 | int nb_csectors; | |
798 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
799 | s->csize_mask) + 1; | |
800 | qcow2_free_clusters(bs, | |
801 | (l2_entry & s->cluster_offset_mask) & ~511, | |
6cfcb9b8 | 802 | nb_csectors * 512, type); |
c7a4c37a KW |
803 | } |
804 | break; | |
805 | case QCOW2_CLUSTER_NORMAL: | |
8f730dd2 HR |
806 | case QCOW2_CLUSTER_ZERO: |
807 | if (l2_entry & L2E_OFFSET_MASK) { | |
808 | qcow2_free_clusters(bs, l2_entry & L2E_OFFSET_MASK, | |
809 | nb_clusters << s->cluster_bits, type); | |
810 | } | |
c7a4c37a KW |
811 | break; |
812 | case QCOW2_CLUSTER_UNALLOCATED: | |
813 | break; | |
814 | default: | |
815 | abort(); | |
45aba42f | 816 | } |
45aba42f KW |
817 | } |
818 | ||
f7d0fe02 KW |
819 | |
820 | ||
821 | /*********************************************************/ | |
822 | /* snapshots and image creation */ | |
823 | ||
824 | ||
825 | ||
f7d0fe02 | 826 | /* update the refcounts of snapshots and the copied flag */ |
ed6ccf0f KW |
827 | int qcow2_update_snapshot_refcount(BlockDriverState *bs, |
828 | int64_t l1_table_offset, int l1_size, int addend) | |
f7d0fe02 KW |
829 | { |
830 | BDRVQcowState *s = bs->opaque; | |
831 | uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; | |
832 | int64_t old_offset, old_l2_offset; | |
93913dfd | 833 | int i, j, l1_modified = 0, nb_csectors, refcount; |
29c1a730 | 834 | int ret; |
f7d0fe02 KW |
835 | |
836 | l2_table = NULL; | |
837 | l1_table = NULL; | |
838 | l1_size2 = l1_size * sizeof(uint64_t); | |
43a0cac4 | 839 | |
0b919fae KW |
840 | s->cache_discards = true; |
841 | ||
43a0cac4 KW |
842 | /* WARNING: qcow2_snapshot_goto relies on this function not using the |
843 | * l1_table_offset when it is the current s->l1_table_offset! Be careful | |
844 | * when changing this! */ | |
f7d0fe02 | 845 | if (l1_table_offset != s->l1_table_offset) { |
6528499f | 846 | l1_table = g_malloc0(align_offset(l1_size2, 512)); |
f7d0fe02 | 847 | l1_allocated = 1; |
c2bc78b6 KW |
848 | |
849 | ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2); | |
850 | if (ret < 0) { | |
f7d0fe02 | 851 | goto fail; |
93913dfd KW |
852 | } |
853 | ||
f7d0fe02 KW |
854 | for(i = 0;i < l1_size; i++) |
855 | be64_to_cpus(&l1_table[i]); | |
856 | } else { | |
857 | assert(l1_size == s->l1_size); | |
858 | l1_table = s->l1_table; | |
859 | l1_allocated = 0; | |
860 | } | |
861 | ||
f7d0fe02 KW |
862 | for(i = 0; i < l1_size; i++) { |
863 | l2_offset = l1_table[i]; | |
864 | if (l2_offset) { | |
865 | old_l2_offset = l2_offset; | |
8e37f681 | 866 | l2_offset &= L1E_OFFSET_MASK; |
29c1a730 KW |
867 | |
868 | ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, | |
869 | (void**) &l2_table); | |
870 | if (ret < 0) { | |
f7d0fe02 | 871 | goto fail; |
29c1a730 KW |
872 | } |
873 | ||
f7d0fe02 | 874 | for(j = 0; j < s->l2_size; j++) { |
8b81a7b6 HR |
875 | uint64_t cluster_index; |
876 | ||
f7d0fe02 | 877 | offset = be64_to_cpu(l2_table[j]); |
8b81a7b6 HR |
878 | old_offset = offset; |
879 | offset &= ~QCOW_OFLAG_COPIED; | |
880 | ||
881 | switch (qcow2_get_cluster_type(offset)) { | |
882 | case QCOW2_CLUSTER_COMPRESSED: | |
f7d0fe02 KW |
883 | nb_csectors = ((offset >> s->csize_shift) & |
884 | s->csize_mask) + 1; | |
db3a964f | 885 | if (addend != 0) { |
db3a964f KW |
886 | ret = update_refcount(bs, |
887 | (offset & s->cluster_offset_mask) & ~511, | |
6cfcb9b8 KW |
888 | nb_csectors * 512, addend, |
889 | QCOW2_DISCARD_SNAPSHOT); | |
db3a964f KW |
890 | if (ret < 0) { |
891 | goto fail; | |
892 | } | |
893 | } | |
f7d0fe02 KW |
894 | /* compressed clusters are never modified */ |
895 | refcount = 2; | |
8b81a7b6 HR |
896 | break; |
897 | ||
898 | case QCOW2_CLUSTER_NORMAL: | |
899 | case QCOW2_CLUSTER_ZERO: | |
900 | cluster_index = (offset & L2E_OFFSET_MASK) >> s->cluster_bits; | |
901 | if (!cluster_index) { | |
902 | /* unallocated */ | |
903 | refcount = 0; | |
904 | break; | |
905 | } | |
f7d0fe02 | 906 | if (addend != 0) { |
32b6444d HR |
907 | refcount = qcow2_update_cluster_refcount(bs, |
908 | cluster_index, addend, | |
909 | QCOW2_DISCARD_SNAPSHOT); | |
f7d0fe02 | 910 | } else { |
8e37f681 | 911 | refcount = get_refcount(bs, cluster_index); |
f7d0fe02 | 912 | } |
018faafd KW |
913 | |
914 | if (refcount < 0) { | |
c2bc78b6 | 915 | ret = refcount; |
018faafd KW |
916 | goto fail; |
917 | } | |
8b81a7b6 | 918 | break; |
f7d0fe02 | 919 | |
8b81a7b6 HR |
920 | case QCOW2_CLUSTER_UNALLOCATED: |
921 | refcount = 0; | |
922 | break; | |
923 | ||
924 | default: | |
925 | abort(); | |
926 | } | |
927 | ||
928 | if (refcount == 1) { | |
929 | offset |= QCOW_OFLAG_COPIED; | |
930 | } | |
931 | if (offset != old_offset) { | |
932 | if (addend > 0) { | |
933 | qcow2_cache_set_dependency(bs, s->l2_table_cache, | |
934 | s->refcount_block_cache); | |
f7d0fe02 | 935 | } |
8b81a7b6 HR |
936 | l2_table[j] = cpu_to_be64(offset); |
937 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); | |
f7d0fe02 KW |
938 | } |
939 | } | |
29c1a730 KW |
940 | |
941 | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); | |
942 | if (ret < 0) { | |
943 | goto fail; | |
f7d0fe02 KW |
944 | } |
945 | ||
29c1a730 | 946 | |
f7d0fe02 | 947 | if (addend != 0) { |
32b6444d HR |
948 | refcount = qcow2_update_cluster_refcount(bs, l2_offset >> |
949 | s->cluster_bits, addend, QCOW2_DISCARD_SNAPSHOT); | |
f7d0fe02 KW |
950 | } else { |
951 | refcount = get_refcount(bs, l2_offset >> s->cluster_bits); | |
952 | } | |
018faafd | 953 | if (refcount < 0) { |
c2bc78b6 | 954 | ret = refcount; |
018faafd KW |
955 | goto fail; |
956 | } else if (refcount == 1) { | |
f7d0fe02 KW |
957 | l2_offset |= QCOW_OFLAG_COPIED; |
958 | } | |
959 | if (l2_offset != old_l2_offset) { | |
960 | l1_table[i] = l2_offset; | |
961 | l1_modified = 1; | |
962 | } | |
963 | } | |
964 | } | |
93913dfd | 965 | |
2154f24e | 966 | ret = bdrv_flush(bs); |
93913dfd KW |
967 | fail: |
968 | if (l2_table) { | |
969 | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); | |
970 | } | |
971 | ||
0b919fae KW |
972 | s->cache_discards = false; |
973 | qcow2_process_discards(bs, ret); | |
974 | ||
43a0cac4 | 975 | /* Update L1 only if it isn't deleted anyway (addend = -1) */ |
c2b6ff51 KW |
976 | if (ret == 0 && addend >= 0 && l1_modified) { |
977 | for (i = 0; i < l1_size; i++) { | |
f7d0fe02 | 978 | cpu_to_be64s(&l1_table[i]); |
c2b6ff51 KW |
979 | } |
980 | ||
981 | ret = bdrv_pwrite_sync(bs->file, l1_table_offset, l1_table, l1_size2); | |
982 | ||
983 | for (i = 0; i < l1_size; i++) { | |
f7d0fe02 | 984 | be64_to_cpus(&l1_table[i]); |
c2b6ff51 | 985 | } |
f7d0fe02 KW |
986 | } |
987 | if (l1_allocated) | |
7267c094 | 988 | g_free(l1_table); |
93913dfd | 989 | return ret; |
f7d0fe02 KW |
990 | } |
991 | ||
992 | ||
993 | ||
994 | ||
995 | /*********************************************************/ | |
996 | /* refcount checking functions */ | |
997 | ||
998 | ||
999 | ||
1000 | /* | |
1001 | * Increases the refcount for a range of clusters in a given refcount table. | |
1002 | * This is used to construct a temporary refcount table out of L1 and L2 tables | |
1003 | * which can be compared the the refcount table saved in the image. | |
1004 | * | |
9ac228e0 | 1005 | * Modifies the number of errors in res. |
f7d0fe02 | 1006 | */ |
9ac228e0 KW |
1007 | static void inc_refcounts(BlockDriverState *bs, |
1008 | BdrvCheckResult *res, | |
f7d0fe02 KW |
1009 | uint16_t *refcount_table, |
1010 | int refcount_table_size, | |
1011 | int64_t offset, int64_t size) | |
1012 | { | |
1013 | BDRVQcowState *s = bs->opaque; | |
1014 | int64_t start, last, cluster_offset; | |
1015 | int k; | |
f7d0fe02 KW |
1016 | |
1017 | if (size <= 0) | |
9ac228e0 | 1018 | return; |
f7d0fe02 | 1019 | |
ac95acdb HT |
1020 | start = start_of_cluster(s, offset); |
1021 | last = start_of_cluster(s, offset + size - 1); | |
f7d0fe02 KW |
1022 | for(cluster_offset = start; cluster_offset <= last; |
1023 | cluster_offset += s->cluster_size) { | |
1024 | k = cluster_offset >> s->cluster_bits; | |
9ac228e0 | 1025 | if (k < 0) { |
f7d0fe02 KW |
1026 | fprintf(stderr, "ERROR: invalid cluster offset=0x%" PRIx64 "\n", |
1027 | cluster_offset); | |
9ac228e0 KW |
1028 | res->corruptions++; |
1029 | } else if (k >= refcount_table_size) { | |
1030 | fprintf(stderr, "Warning: cluster offset=0x%" PRIx64 " is after " | |
1031 | "the end of the image file, can't properly check refcounts.\n", | |
1032 | cluster_offset); | |
1033 | res->check_errors++; | |
f7d0fe02 KW |
1034 | } else { |
1035 | if (++refcount_table[k] == 0) { | |
1036 | fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64 | |
1037 | "\n", cluster_offset); | |
9ac228e0 | 1038 | res->corruptions++; |
f7d0fe02 KW |
1039 | } |
1040 | } | |
1041 | } | |
f7d0fe02 KW |
1042 | } |
1043 | ||
801f7044 SH |
1044 | /* Flags for check_refcounts_l1() and check_refcounts_l2() */ |
1045 | enum { | |
fba31bae | 1046 | CHECK_FRAG_INFO = 0x2, /* update BlockFragInfo counters */ |
801f7044 SH |
1047 | }; |
1048 | ||
f7d0fe02 KW |
1049 | /* |
1050 | * Increases the refcount in the given refcount table for the all clusters | |
1051 | * referenced in the L2 table. While doing so, performs some checks on L2 | |
1052 | * entries. | |
1053 | * | |
1054 | * Returns the number of errors found by the checks or -errno if an internal | |
1055 | * error occurred. | |
1056 | */ | |
9ac228e0 | 1057 | static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, |
f7d0fe02 | 1058 | uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset, |
801f7044 | 1059 | int flags) |
f7d0fe02 KW |
1060 | { |
1061 | BDRVQcowState *s = bs->opaque; | |
afdf0abe | 1062 | uint64_t *l2_table, l2_entry; |
fba31bae | 1063 | uint64_t next_contiguous_offset = 0; |
4f6ed88c | 1064 | int i, l2_size, nb_csectors; |
f7d0fe02 KW |
1065 | |
1066 | /* Read L2 table from disk */ | |
1067 | l2_size = s->l2_size * sizeof(uint64_t); | |
7267c094 | 1068 | l2_table = g_malloc(l2_size); |
f7d0fe02 | 1069 | |
66f82cee | 1070 | if (bdrv_pread(bs->file, l2_offset, l2_table, l2_size) != l2_size) |
f7d0fe02 KW |
1071 | goto fail; |
1072 | ||
1073 | /* Do the actual checks */ | |
1074 | for(i = 0; i < s->l2_size; i++) { | |
afdf0abe KW |
1075 | l2_entry = be64_to_cpu(l2_table[i]); |
1076 | ||
1077 | switch (qcow2_get_cluster_type(l2_entry)) { | |
1078 | case QCOW2_CLUSTER_COMPRESSED: | |
1079 | /* Compressed clusters don't have QCOW_OFLAG_COPIED */ | |
1080 | if (l2_entry & QCOW_OFLAG_COPIED) { | |
1081 | fprintf(stderr, "ERROR: cluster %" PRId64 ": " | |
1082 | "copied flag must never be set for compressed " | |
1083 | "clusters\n", l2_entry >> s->cluster_bits); | |
1084 | l2_entry &= ~QCOW_OFLAG_COPIED; | |
1085 | res->corruptions++; | |
1086 | } | |
f7d0fe02 | 1087 | |
afdf0abe KW |
1088 | /* Mark cluster as used */ |
1089 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
1090 | s->csize_mask) + 1; | |
1091 | l2_entry &= s->cluster_offset_mask; | |
1092 | inc_refcounts(bs, res, refcount_table, refcount_table_size, | |
1093 | l2_entry & ~511, nb_csectors * 512); | |
fba31bae SH |
1094 | |
1095 | if (flags & CHECK_FRAG_INFO) { | |
1096 | res->bfi.allocated_clusters++; | |
4db35162 | 1097 | res->bfi.compressed_clusters++; |
fba31bae SH |
1098 | |
1099 | /* Compressed clusters are fragmented by nature. Since they | |
1100 | * take up sub-sector space but we only have sector granularity | |
1101 | * I/O we need to re-read the same sectors even for adjacent | |
1102 | * compressed clusters. | |
1103 | */ | |
1104 | res->bfi.fragmented_clusters++; | |
1105 | } | |
afdf0abe | 1106 | break; |
f7d0fe02 | 1107 | |
6377af48 KW |
1108 | case QCOW2_CLUSTER_ZERO: |
1109 | if ((l2_entry & L2E_OFFSET_MASK) == 0) { | |
1110 | break; | |
1111 | } | |
1112 | /* fall through */ | |
1113 | ||
afdf0abe KW |
1114 | case QCOW2_CLUSTER_NORMAL: |
1115 | { | |
afdf0abe | 1116 | uint64_t offset = l2_entry & L2E_OFFSET_MASK; |
f7d0fe02 | 1117 | |
fba31bae SH |
1118 | if (flags & CHECK_FRAG_INFO) { |
1119 | res->bfi.allocated_clusters++; | |
1120 | if (next_contiguous_offset && | |
1121 | offset != next_contiguous_offset) { | |
1122 | res->bfi.fragmented_clusters++; | |
1123 | } | |
1124 | next_contiguous_offset = offset + s->cluster_size; | |
1125 | } | |
1126 | ||
afdf0abe KW |
1127 | /* Mark cluster as used */ |
1128 | inc_refcounts(bs, res, refcount_table,refcount_table_size, | |
1129 | offset, s->cluster_size); | |
1130 | ||
1131 | /* Correct offsets are cluster aligned */ | |
ac95acdb | 1132 | if (offset_into_cluster(s, offset)) { |
afdf0abe KW |
1133 | fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " |
1134 | "properly aligned; L2 entry corrupted.\n", offset); | |
1135 | res->corruptions++; | |
1136 | } | |
1137 | break; | |
1138 | } | |
1139 | ||
1140 | case QCOW2_CLUSTER_UNALLOCATED: | |
1141 | break; | |
1142 | ||
1143 | default: | |
1144 | abort(); | |
f7d0fe02 KW |
1145 | } |
1146 | } | |
1147 | ||
7267c094 | 1148 | g_free(l2_table); |
9ac228e0 | 1149 | return 0; |
f7d0fe02 KW |
1150 | |
1151 | fail: | |
9ac228e0 | 1152 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l2\n"); |
7267c094 | 1153 | g_free(l2_table); |
f7d0fe02 KW |
1154 | return -EIO; |
1155 | } | |
1156 | ||
1157 | /* | |
1158 | * Increases the refcount for the L1 table, its L2 tables and all referenced | |
1159 | * clusters in the given refcount table. While doing so, performs some checks | |
1160 | * on L1 and L2 entries. | |
1161 | * | |
1162 | * Returns the number of errors found by the checks or -errno if an internal | |
1163 | * error occurred. | |
1164 | */ | |
1165 | static int check_refcounts_l1(BlockDriverState *bs, | |
9ac228e0 | 1166 | BdrvCheckResult *res, |
f7d0fe02 KW |
1167 | uint16_t *refcount_table, |
1168 | int refcount_table_size, | |
1169 | int64_t l1_table_offset, int l1_size, | |
801f7044 | 1170 | int flags) |
f7d0fe02 KW |
1171 | { |
1172 | BDRVQcowState *s = bs->opaque; | |
1173 | uint64_t *l1_table, l2_offset, l1_size2; | |
4f6ed88c | 1174 | int i, ret; |
f7d0fe02 KW |
1175 | |
1176 | l1_size2 = l1_size * sizeof(uint64_t); | |
1177 | ||
1178 | /* Mark L1 table as used */ | |
9ac228e0 KW |
1179 | inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1180 | l1_table_offset, l1_size2); | |
f7d0fe02 KW |
1181 | |
1182 | /* Read L1 table entries from disk */ | |
702ef63f KW |
1183 | if (l1_size2 == 0) { |
1184 | l1_table = NULL; | |
1185 | } else { | |
7267c094 | 1186 | l1_table = g_malloc(l1_size2); |
66f82cee | 1187 | if (bdrv_pread(bs->file, l1_table_offset, |
702ef63f KW |
1188 | l1_table, l1_size2) != l1_size2) |
1189 | goto fail; | |
1190 | for(i = 0;i < l1_size; i++) | |
1191 | be64_to_cpus(&l1_table[i]); | |
1192 | } | |
f7d0fe02 KW |
1193 | |
1194 | /* Do the actual checks */ | |
1195 | for(i = 0; i < l1_size; i++) { | |
1196 | l2_offset = l1_table[i]; | |
1197 | if (l2_offset) { | |
f7d0fe02 | 1198 | /* Mark L2 table as used */ |
afdf0abe | 1199 | l2_offset &= L1E_OFFSET_MASK; |
9ac228e0 KW |
1200 | inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1201 | l2_offset, s->cluster_size); | |
f7d0fe02 KW |
1202 | |
1203 | /* L2 tables are cluster aligned */ | |
ac95acdb | 1204 | if (offset_into_cluster(s, l2_offset)) { |
f7d0fe02 KW |
1205 | fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " |
1206 | "cluster aligned; L1 entry corrupted\n", l2_offset); | |
9ac228e0 | 1207 | res->corruptions++; |
f7d0fe02 KW |
1208 | } |
1209 | ||
1210 | /* Process and check L2 entries */ | |
9ac228e0 | 1211 | ret = check_refcounts_l2(bs, res, refcount_table, |
801f7044 | 1212 | refcount_table_size, l2_offset, flags); |
f7d0fe02 KW |
1213 | if (ret < 0) { |
1214 | goto fail; | |
1215 | } | |
f7d0fe02 KW |
1216 | } |
1217 | } | |
7267c094 | 1218 | g_free(l1_table); |
9ac228e0 | 1219 | return 0; |
f7d0fe02 KW |
1220 | |
1221 | fail: | |
1222 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); | |
9ac228e0 | 1223 | res->check_errors++; |
7267c094 | 1224 | g_free(l1_table); |
f7d0fe02 KW |
1225 | return -EIO; |
1226 | } | |
1227 | ||
4f6ed88c HR |
1228 | /* |
1229 | * Checks the OFLAG_COPIED flag for all L1 and L2 entries. | |
1230 | * | |
1231 | * This function does not print an error message nor does it increment | |
1232 | * check_errors if get_refcount fails (this is because such an error will have | |
1233 | * been already detected and sufficiently signaled by the calling function | |
1234 | * (qcow2_check_refcounts) by the time this function is called). | |
1235 | */ | |
e23e400e HR |
1236 | static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res, |
1237 | BdrvCheckMode fix) | |
4f6ed88c HR |
1238 | { |
1239 | BDRVQcowState *s = bs->opaque; | |
1240 | uint64_t *l2_table = qemu_blockalign(bs, s->cluster_size); | |
1241 | int ret; | |
1242 | int refcount; | |
1243 | int i, j; | |
1244 | ||
1245 | for (i = 0; i < s->l1_size; i++) { | |
1246 | uint64_t l1_entry = s->l1_table[i]; | |
1247 | uint64_t l2_offset = l1_entry & L1E_OFFSET_MASK; | |
e23e400e | 1248 | bool l2_dirty = false; |
4f6ed88c HR |
1249 | |
1250 | if (!l2_offset) { | |
1251 | continue; | |
1252 | } | |
1253 | ||
1254 | refcount = get_refcount(bs, l2_offset >> s->cluster_bits); | |
1255 | if (refcount < 0) { | |
1256 | /* don't print message nor increment check_errors */ | |
1257 | continue; | |
1258 | } | |
1259 | if ((refcount == 1) != ((l1_entry & QCOW_OFLAG_COPIED) != 0)) { | |
e23e400e | 1260 | fprintf(stderr, "%s OFLAG_COPIED L2 cluster: l1_index=%d " |
4f6ed88c | 1261 | "l1_entry=%" PRIx64 " refcount=%d\n", |
e23e400e HR |
1262 | fix & BDRV_FIX_ERRORS ? "Repairing" : |
1263 | "ERROR", | |
4f6ed88c | 1264 | i, l1_entry, refcount); |
e23e400e HR |
1265 | if (fix & BDRV_FIX_ERRORS) { |
1266 | s->l1_table[i] = refcount == 1 | |
1267 | ? l1_entry | QCOW_OFLAG_COPIED | |
1268 | : l1_entry & ~QCOW_OFLAG_COPIED; | |
1269 | ret = qcow2_write_l1_entry(bs, i); | |
1270 | if (ret < 0) { | |
1271 | res->check_errors++; | |
1272 | goto fail; | |
1273 | } | |
1274 | res->corruptions_fixed++; | |
1275 | } else { | |
1276 | res->corruptions++; | |
1277 | } | |
4f6ed88c HR |
1278 | } |
1279 | ||
1280 | ret = bdrv_pread(bs->file, l2_offset, l2_table, | |
1281 | s->l2_size * sizeof(uint64_t)); | |
1282 | if (ret < 0) { | |
1283 | fprintf(stderr, "ERROR: Could not read L2 table: %s\n", | |
1284 | strerror(-ret)); | |
1285 | res->check_errors++; | |
1286 | goto fail; | |
1287 | } | |
1288 | ||
1289 | for (j = 0; j < s->l2_size; j++) { | |
1290 | uint64_t l2_entry = be64_to_cpu(l2_table[j]); | |
1291 | uint64_t data_offset = l2_entry & L2E_OFFSET_MASK; | |
1292 | int cluster_type = qcow2_get_cluster_type(l2_entry); | |
1293 | ||
1294 | if ((cluster_type == QCOW2_CLUSTER_NORMAL) || | |
1295 | ((cluster_type == QCOW2_CLUSTER_ZERO) && (data_offset != 0))) { | |
1296 | refcount = get_refcount(bs, data_offset >> s->cluster_bits); | |
1297 | if (refcount < 0) { | |
1298 | /* don't print message nor increment check_errors */ | |
1299 | continue; | |
1300 | } | |
1301 | if ((refcount == 1) != ((l2_entry & QCOW_OFLAG_COPIED) != 0)) { | |
e23e400e | 1302 | fprintf(stderr, "%s OFLAG_COPIED data cluster: " |
4f6ed88c | 1303 | "l2_entry=%" PRIx64 " refcount=%d\n", |
e23e400e HR |
1304 | fix & BDRV_FIX_ERRORS ? "Repairing" : |
1305 | "ERROR", | |
4f6ed88c | 1306 | l2_entry, refcount); |
e23e400e HR |
1307 | if (fix & BDRV_FIX_ERRORS) { |
1308 | l2_table[j] = cpu_to_be64(refcount == 1 | |
1309 | ? l2_entry | QCOW_OFLAG_COPIED | |
1310 | : l2_entry & ~QCOW_OFLAG_COPIED); | |
1311 | l2_dirty = true; | |
1312 | res->corruptions_fixed++; | |
1313 | } else { | |
1314 | res->corruptions++; | |
1315 | } | |
4f6ed88c HR |
1316 | } |
1317 | } | |
1318 | } | |
e23e400e HR |
1319 | |
1320 | if (l2_dirty) { | |
231bb267 HR |
1321 | ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L2, |
1322 | l2_offset, s->cluster_size); | |
e23e400e HR |
1323 | if (ret < 0) { |
1324 | fprintf(stderr, "ERROR: Could not write L2 table; metadata " | |
1325 | "overlap check failed: %s\n", strerror(-ret)); | |
1326 | res->check_errors++; | |
1327 | goto fail; | |
1328 | } | |
1329 | ||
1330 | ret = bdrv_pwrite(bs->file, l2_offset, l2_table, s->cluster_size); | |
1331 | if (ret < 0) { | |
1332 | fprintf(stderr, "ERROR: Could not write L2 table: %s\n", | |
1333 | strerror(-ret)); | |
1334 | res->check_errors++; | |
1335 | goto fail; | |
1336 | } | |
1337 | } | |
4f6ed88c HR |
1338 | } |
1339 | ||
1340 | ret = 0; | |
1341 | ||
1342 | fail: | |
1343 | qemu_vfree(l2_table); | |
1344 | return ret; | |
1345 | } | |
1346 | ||
afa50193 HR |
1347 | /* |
1348 | * Writes one sector of the refcount table to the disk | |
1349 | */ | |
1350 | #define RT_ENTRIES_PER_SECTOR (512 / sizeof(uint64_t)) | |
1351 | static int write_reftable_entry(BlockDriverState *bs, int rt_index) | |
1352 | { | |
1353 | BDRVQcowState *s = bs->opaque; | |
1354 | uint64_t buf[RT_ENTRIES_PER_SECTOR]; | |
1355 | int rt_start_index; | |
1356 | int i, ret; | |
1357 | ||
1358 | rt_start_index = rt_index & ~(RT_ENTRIES_PER_SECTOR - 1); | |
1359 | for (i = 0; i < RT_ENTRIES_PER_SECTOR; i++) { | |
1360 | buf[i] = cpu_to_be64(s->refcount_table[rt_start_index + i]); | |
1361 | } | |
1362 | ||
231bb267 | 1363 | ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_REFCOUNT_TABLE, |
afa50193 HR |
1364 | s->refcount_table_offset + rt_start_index * sizeof(uint64_t), |
1365 | sizeof(buf)); | |
1366 | if (ret < 0) { | |
1367 | return ret; | |
1368 | } | |
1369 | ||
1370 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE); | |
1371 | ret = bdrv_pwrite_sync(bs->file, s->refcount_table_offset + | |
1372 | rt_start_index * sizeof(uint64_t), buf, sizeof(buf)); | |
1373 | if (ret < 0) { | |
1374 | return ret; | |
1375 | } | |
1376 | ||
1377 | return 0; | |
1378 | } | |
1379 | ||
1380 | /* | |
1381 | * Allocates a new cluster for the given refcount block (represented by its | |
1382 | * offset in the image file) and copies the current content there. This function | |
1383 | * does _not_ decrement the reference count for the currently occupied cluster. | |
1384 | * | |
1385 | * This function prints an informative message to stderr on error (and returns | |
8a15b813 | 1386 | * -errno); on success, the offset of the newly allocated cluster is returned. |
afa50193 HR |
1387 | */ |
1388 | static int64_t realloc_refcount_block(BlockDriverState *bs, int reftable_index, | |
1389 | uint64_t offset) | |
1390 | { | |
1391 | BDRVQcowState *s = bs->opaque; | |
1392 | int64_t new_offset = 0; | |
1393 | void *refcount_block = NULL; | |
1394 | int ret; | |
1395 | ||
1396 | /* allocate new refcount block */ | |
1397 | new_offset = qcow2_alloc_clusters(bs, s->cluster_size); | |
1398 | if (new_offset < 0) { | |
1399 | fprintf(stderr, "Could not allocate new cluster: %s\n", | |
1400 | strerror(-new_offset)); | |
1401 | ret = new_offset; | |
a134d90f | 1402 | goto done; |
afa50193 HR |
1403 | } |
1404 | ||
1405 | /* fetch current refcount block content */ | |
1406 | ret = qcow2_cache_get(bs, s->refcount_block_cache, offset, &refcount_block); | |
1407 | if (ret < 0) { | |
1408 | fprintf(stderr, "Could not fetch refcount block: %s\n", strerror(-ret)); | |
a134d90f | 1409 | goto fail_free_cluster; |
afa50193 HR |
1410 | } |
1411 | ||
1412 | /* new block has not yet been entered into refcount table, therefore it is | |
1413 | * no refcount block yet (regarding this check) */ | |
231bb267 | 1414 | ret = qcow2_pre_write_overlap_check(bs, 0, new_offset, s->cluster_size); |
afa50193 HR |
1415 | if (ret < 0) { |
1416 | fprintf(stderr, "Could not write refcount block; metadata overlap " | |
1417 | "check failed: %s\n", strerror(-ret)); | |
1418 | /* the image will be marked corrupt, so don't even attempt on freeing | |
1419 | * the cluster */ | |
a134d90f | 1420 | goto done; |
afa50193 HR |
1421 | } |
1422 | ||
1423 | /* write to new block */ | |
1424 | ret = bdrv_write(bs->file, new_offset / BDRV_SECTOR_SIZE, refcount_block, | |
1425 | s->cluster_sectors); | |
1426 | if (ret < 0) { | |
1427 | fprintf(stderr, "Could not write refcount block: %s\n", strerror(-ret)); | |
a134d90f | 1428 | goto fail_free_cluster; |
afa50193 HR |
1429 | } |
1430 | ||
1431 | /* update refcount table */ | |
ac95acdb | 1432 | assert(!offset_into_cluster(s, new_offset)); |
afa50193 HR |
1433 | s->refcount_table[reftable_index] = new_offset; |
1434 | ret = write_reftable_entry(bs, reftable_index); | |
1435 | if (ret < 0) { | |
1436 | fprintf(stderr, "Could not update refcount table: %s\n", | |
1437 | strerror(-ret)); | |
a134d90f | 1438 | goto fail_free_cluster; |
afa50193 HR |
1439 | } |
1440 | ||
a134d90f HR |
1441 | goto done; |
1442 | ||
1443 | fail_free_cluster: | |
1444 | qcow2_free_clusters(bs, new_offset, s->cluster_size, QCOW2_DISCARD_OTHER); | |
1445 | ||
1446 | done: | |
afa50193 | 1447 | if (refcount_block) { |
a134d90f HR |
1448 | /* This should never fail, as it would only do so if the given refcount |
1449 | * block cannot be found in the cache. As this is impossible as long as | |
1450 | * there are no bugs, assert the success. */ | |
1451 | int tmp = qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); | |
1452 | assert(tmp == 0); | |
afa50193 | 1453 | } |
a134d90f | 1454 | |
afa50193 HR |
1455 | if (ret < 0) { |
1456 | return ret; | |
1457 | } | |
a134d90f | 1458 | |
afa50193 HR |
1459 | return new_offset; |
1460 | } | |
1461 | ||
f7d0fe02 KW |
1462 | /* |
1463 | * Checks an image for refcount consistency. | |
1464 | * | |
1465 | * Returns 0 if no errors are found, the number of errors in case the image is | |
a1c7273b | 1466 | * detected as corrupted, and -errno when an internal error occurred. |
f7d0fe02 | 1467 | */ |
166acf54 KW |
1468 | int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, |
1469 | BdrvCheckMode fix) | |
f7d0fe02 KW |
1470 | { |
1471 | BDRVQcowState *s = bs->opaque; | |
c6bb9ad1 | 1472 | int64_t size, i, highest_cluster; |
166acf54 | 1473 | int nb_clusters, refcount1, refcount2; |
f7d0fe02 KW |
1474 | QCowSnapshot *sn; |
1475 | uint16_t *refcount_table; | |
9ac228e0 | 1476 | int ret; |
f7d0fe02 | 1477 | |
66f82cee | 1478 | size = bdrv_getlength(bs->file); |
f7d0fe02 | 1479 | nb_clusters = size_to_clusters(s, size); |
7267c094 | 1480 | refcount_table = g_malloc0(nb_clusters * sizeof(uint16_t)); |
f7d0fe02 | 1481 | |
c349ca4b KW |
1482 | res->bfi.total_clusters = |
1483 | size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE); | |
1484 | ||
f7d0fe02 | 1485 | /* header */ |
9ac228e0 KW |
1486 | inc_refcounts(bs, res, refcount_table, nb_clusters, |
1487 | 0, s->cluster_size); | |
f7d0fe02 KW |
1488 | |
1489 | /* current L1 table */ | |
9ac228e0 | 1490 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
db074901 | 1491 | s->l1_table_offset, s->l1_size, CHECK_FRAG_INFO); |
f7d0fe02 | 1492 | if (ret < 0) { |
80fa3341 | 1493 | goto fail; |
f7d0fe02 | 1494 | } |
f7d0fe02 KW |
1495 | |
1496 | /* snapshots */ | |
1497 | for(i = 0; i < s->nb_snapshots; i++) { | |
1498 | sn = s->snapshots + i; | |
9ac228e0 KW |
1499 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
1500 | sn->l1_table_offset, sn->l1_size, 0); | |
1501 | if (ret < 0) { | |
80fa3341 | 1502 | goto fail; |
9ac228e0 | 1503 | } |
f7d0fe02 | 1504 | } |
9ac228e0 KW |
1505 | inc_refcounts(bs, res, refcount_table, nb_clusters, |
1506 | s->snapshots_offset, s->snapshots_size); | |
f7d0fe02 KW |
1507 | |
1508 | /* refcount data */ | |
9ac228e0 KW |
1509 | inc_refcounts(bs, res, refcount_table, nb_clusters, |
1510 | s->refcount_table_offset, | |
1511 | s->refcount_table_size * sizeof(uint64_t)); | |
1512 | ||
f7d0fe02 | 1513 | for(i = 0; i < s->refcount_table_size; i++) { |
6882c8fa | 1514 | uint64_t offset, cluster; |
f7d0fe02 | 1515 | offset = s->refcount_table[i]; |
6882c8fa | 1516 | cluster = offset >> s->cluster_bits; |
746c3cb5 KW |
1517 | |
1518 | /* Refcount blocks are cluster aligned */ | |
ac95acdb | 1519 | if (offset_into_cluster(s, offset)) { |
166acf54 | 1520 | fprintf(stderr, "ERROR refcount block %" PRId64 " is not " |
746c3cb5 | 1521 | "cluster aligned; refcount table entry corrupted\n", i); |
9ac228e0 | 1522 | res->corruptions++; |
6882c8fa KW |
1523 | continue; |
1524 | } | |
1525 | ||
1526 | if (cluster >= nb_clusters) { | |
166acf54 KW |
1527 | fprintf(stderr, "ERROR refcount block %" PRId64 |
1528 | " is outside image\n", i); | |
9ac228e0 | 1529 | res->corruptions++; |
6882c8fa | 1530 | continue; |
746c3cb5 KW |
1531 | } |
1532 | ||
f7d0fe02 | 1533 | if (offset != 0) { |
9ac228e0 KW |
1534 | inc_refcounts(bs, res, refcount_table, nb_clusters, |
1535 | offset, s->cluster_size); | |
6882c8fa | 1536 | if (refcount_table[cluster] != 1) { |
afa50193 | 1537 | fprintf(stderr, "%s refcount block %" PRId64 |
166acf54 | 1538 | " refcount=%d\n", |
afa50193 HR |
1539 | fix & BDRV_FIX_ERRORS ? "Repairing" : |
1540 | "ERROR", | |
6882c8fa | 1541 | i, refcount_table[cluster]); |
afa50193 HR |
1542 | |
1543 | if (fix & BDRV_FIX_ERRORS) { | |
1544 | int64_t new_offset; | |
1545 | ||
1546 | new_offset = realloc_refcount_block(bs, i, offset); | |
1547 | if (new_offset < 0) { | |
1548 | res->corruptions++; | |
1549 | continue; | |
1550 | } | |
1551 | ||
1552 | /* update refcounts */ | |
1553 | if ((new_offset >> s->cluster_bits) >= nb_clusters) { | |
1554 | /* increase refcount_table size if necessary */ | |
1555 | int old_nb_clusters = nb_clusters; | |
1556 | nb_clusters = (new_offset >> s->cluster_bits) + 1; | |
1557 | refcount_table = g_realloc(refcount_table, | |
1558 | nb_clusters * sizeof(uint16_t)); | |
1559 | memset(&refcount_table[old_nb_clusters], 0, (nb_clusters | |
1560 | - old_nb_clusters) * sizeof(uint16_t)); | |
1561 | } | |
1562 | refcount_table[cluster]--; | |
1563 | inc_refcounts(bs, res, refcount_table, nb_clusters, | |
1564 | new_offset, s->cluster_size); | |
1565 | ||
1566 | res->corruptions_fixed++; | |
1567 | } else { | |
1568 | res->corruptions++; | |
1569 | } | |
746c3cb5 | 1570 | } |
f7d0fe02 KW |
1571 | } |
1572 | } | |
1573 | ||
1574 | /* compare ref counts */ | |
c6bb9ad1 | 1575 | for (i = 0, highest_cluster = 0; i < nb_clusters; i++) { |
f7d0fe02 | 1576 | refcount1 = get_refcount(bs, i); |
018faafd | 1577 | if (refcount1 < 0) { |
166acf54 | 1578 | fprintf(stderr, "Can't get refcount for cluster %" PRId64 ": %s\n", |
018faafd | 1579 | i, strerror(-refcount1)); |
9ac228e0 | 1580 | res->check_errors++; |
f74550fd | 1581 | continue; |
018faafd KW |
1582 | } |
1583 | ||
f7d0fe02 | 1584 | refcount2 = refcount_table[i]; |
c6bb9ad1 FS |
1585 | |
1586 | if (refcount1 > 0 || refcount2 > 0) { | |
1587 | highest_cluster = i; | |
1588 | } | |
1589 | ||
f7d0fe02 | 1590 | if (refcount1 != refcount2) { |
166acf54 KW |
1591 | |
1592 | /* Check if we're allowed to fix the mismatch */ | |
1593 | int *num_fixed = NULL; | |
1594 | if (refcount1 > refcount2 && (fix & BDRV_FIX_LEAKS)) { | |
1595 | num_fixed = &res->leaks_fixed; | |
1596 | } else if (refcount1 < refcount2 && (fix & BDRV_FIX_ERRORS)) { | |
1597 | num_fixed = &res->corruptions_fixed; | |
1598 | } | |
1599 | ||
1600 | fprintf(stderr, "%s cluster %" PRId64 " refcount=%d reference=%d\n", | |
1601 | num_fixed != NULL ? "Repairing" : | |
1602 | refcount1 < refcount2 ? "ERROR" : | |
1603 | "Leaked", | |
f7d0fe02 | 1604 | i, refcount1, refcount2); |
166acf54 KW |
1605 | |
1606 | if (num_fixed) { | |
1607 | ret = update_refcount(bs, i << s->cluster_bits, 1, | |
6cfcb9b8 KW |
1608 | refcount2 - refcount1, |
1609 | QCOW2_DISCARD_ALWAYS); | |
166acf54 KW |
1610 | if (ret >= 0) { |
1611 | (*num_fixed)++; | |
1612 | continue; | |
1613 | } | |
1614 | } | |
1615 | ||
1616 | /* And if we couldn't, print an error */ | |
9ac228e0 KW |
1617 | if (refcount1 < refcount2) { |
1618 | res->corruptions++; | |
1619 | } else { | |
1620 | res->leaks++; | |
1621 | } | |
f7d0fe02 KW |
1622 | } |
1623 | } | |
1624 | ||
4f6ed88c | 1625 | /* check OFLAG_COPIED */ |
e23e400e | 1626 | ret = check_oflag_copied(bs, res, fix); |
4f6ed88c HR |
1627 | if (ret < 0) { |
1628 | goto fail; | |
1629 | } | |
1630 | ||
c6bb9ad1 | 1631 | res->image_end_offset = (highest_cluster + 1) * s->cluster_size; |
80fa3341 KW |
1632 | ret = 0; |
1633 | ||
1634 | fail: | |
7267c094 | 1635 | g_free(refcount_table); |
f7d0fe02 | 1636 | |
80fa3341 | 1637 | return ret; |
f7d0fe02 KW |
1638 | } |
1639 | ||
a40f1c2a HR |
1640 | #define overlaps_with(ofs, sz) \ |
1641 | ranges_overlap(offset, size, ofs, sz) | |
1642 | ||
1643 | /* | |
1644 | * Checks if the given offset into the image file is actually free to use by | |
1645 | * looking for overlaps with important metadata sections (L1/L2 tables etc.), | |
1646 | * i.e. a sanity check without relying on the refcount tables. | |
1647 | * | |
231bb267 HR |
1648 | * The ign parameter specifies what checks not to perform (being a bitmask of |
1649 | * QCow2MetadataOverlap values), i.e., what sections to ignore. | |
a40f1c2a HR |
1650 | * |
1651 | * Returns: | |
1652 | * - 0 if writing to this offset will not affect the mentioned metadata | |
1653 | * - a positive QCow2MetadataOverlap value indicating one overlapping section | |
1654 | * - a negative value (-errno) indicating an error while performing a check, | |
1655 | * e.g. when bdrv_read failed on QCOW2_OL_INACTIVE_L2 | |
1656 | */ | |
231bb267 | 1657 | int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset, |
a40f1c2a HR |
1658 | int64_t size) |
1659 | { | |
1660 | BDRVQcowState *s = bs->opaque; | |
3e355390 | 1661 | int chk = s->overlap_check & ~ign; |
a40f1c2a HR |
1662 | int i, j; |
1663 | ||
1664 | if (!size) { | |
1665 | return 0; | |
1666 | } | |
1667 | ||
1668 | if (chk & QCOW2_OL_MAIN_HEADER) { | |
1669 | if (offset < s->cluster_size) { | |
1670 | return QCOW2_OL_MAIN_HEADER; | |
1671 | } | |
1672 | } | |
1673 | ||
1674 | /* align range to test to cluster boundaries */ | |
1675 | size = align_offset(offset_into_cluster(s, offset) + size, s->cluster_size); | |
1676 | offset = start_of_cluster(s, offset); | |
1677 | ||
1678 | if ((chk & QCOW2_OL_ACTIVE_L1) && s->l1_size) { | |
1679 | if (overlaps_with(s->l1_table_offset, s->l1_size * sizeof(uint64_t))) { | |
1680 | return QCOW2_OL_ACTIVE_L1; | |
1681 | } | |
1682 | } | |
1683 | ||
1684 | if ((chk & QCOW2_OL_REFCOUNT_TABLE) && s->refcount_table_size) { | |
1685 | if (overlaps_with(s->refcount_table_offset, | |
1686 | s->refcount_table_size * sizeof(uint64_t))) { | |
1687 | return QCOW2_OL_REFCOUNT_TABLE; | |
1688 | } | |
1689 | } | |
1690 | ||
1691 | if ((chk & QCOW2_OL_SNAPSHOT_TABLE) && s->snapshots_size) { | |
1692 | if (overlaps_with(s->snapshots_offset, s->snapshots_size)) { | |
1693 | return QCOW2_OL_SNAPSHOT_TABLE; | |
1694 | } | |
1695 | } | |
1696 | ||
1697 | if ((chk & QCOW2_OL_INACTIVE_L1) && s->snapshots) { | |
1698 | for (i = 0; i < s->nb_snapshots; i++) { | |
1699 | if (s->snapshots[i].l1_size && | |
1700 | overlaps_with(s->snapshots[i].l1_table_offset, | |
1701 | s->snapshots[i].l1_size * sizeof(uint64_t))) { | |
1702 | return QCOW2_OL_INACTIVE_L1; | |
1703 | } | |
1704 | } | |
1705 | } | |
1706 | ||
1707 | if ((chk & QCOW2_OL_ACTIVE_L2) && s->l1_table) { | |
1708 | for (i = 0; i < s->l1_size; i++) { | |
1709 | if ((s->l1_table[i] & L1E_OFFSET_MASK) && | |
1710 | overlaps_with(s->l1_table[i] & L1E_OFFSET_MASK, | |
1711 | s->cluster_size)) { | |
1712 | return QCOW2_OL_ACTIVE_L2; | |
1713 | } | |
1714 | } | |
1715 | } | |
1716 | ||
1717 | if ((chk & QCOW2_OL_REFCOUNT_BLOCK) && s->refcount_table) { | |
1718 | for (i = 0; i < s->refcount_table_size; i++) { | |
1719 | if ((s->refcount_table[i] & REFT_OFFSET_MASK) && | |
1720 | overlaps_with(s->refcount_table[i] & REFT_OFFSET_MASK, | |
1721 | s->cluster_size)) { | |
1722 | return QCOW2_OL_REFCOUNT_BLOCK; | |
1723 | } | |
1724 | } | |
1725 | } | |
1726 | ||
1727 | if ((chk & QCOW2_OL_INACTIVE_L2) && s->snapshots) { | |
1728 | for (i = 0; i < s->nb_snapshots; i++) { | |
1729 | uint64_t l1_ofs = s->snapshots[i].l1_table_offset; | |
1730 | uint32_t l1_sz = s->snapshots[i].l1_size; | |
998b959c HR |
1731 | uint64_t l1_sz2 = l1_sz * sizeof(uint64_t); |
1732 | uint64_t *l1 = g_malloc(l1_sz2); | |
a40f1c2a HR |
1733 | int ret; |
1734 | ||
998b959c | 1735 | ret = bdrv_pread(bs->file, l1_ofs, l1, l1_sz2); |
a40f1c2a HR |
1736 | if (ret < 0) { |
1737 | g_free(l1); | |
1738 | return ret; | |
1739 | } | |
1740 | ||
1741 | for (j = 0; j < l1_sz; j++) { | |
1e242b55 HR |
1742 | uint64_t l2_ofs = be64_to_cpu(l1[j]) & L1E_OFFSET_MASK; |
1743 | if (l2_ofs && overlaps_with(l2_ofs, s->cluster_size)) { | |
a40f1c2a HR |
1744 | g_free(l1); |
1745 | return QCOW2_OL_INACTIVE_L2; | |
1746 | } | |
1747 | } | |
1748 | ||
1749 | g_free(l1); | |
1750 | } | |
1751 | } | |
1752 | ||
1753 | return 0; | |
1754 | } | |
1755 | ||
1756 | static const char *metadata_ol_names[] = { | |
1757 | [QCOW2_OL_MAIN_HEADER_BITNR] = "qcow2_header", | |
1758 | [QCOW2_OL_ACTIVE_L1_BITNR] = "active L1 table", | |
1759 | [QCOW2_OL_ACTIVE_L2_BITNR] = "active L2 table", | |
1760 | [QCOW2_OL_REFCOUNT_TABLE_BITNR] = "refcount table", | |
1761 | [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = "refcount block", | |
1762 | [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = "snapshot table", | |
1763 | [QCOW2_OL_INACTIVE_L1_BITNR] = "inactive L1 table", | |
1764 | [QCOW2_OL_INACTIVE_L2_BITNR] = "inactive L2 table", | |
1765 | }; | |
1766 | ||
1767 | /* | |
1768 | * First performs a check for metadata overlaps (through | |
1769 | * qcow2_check_metadata_overlap); if that fails with a negative value (error | |
1770 | * while performing a check), that value is returned. If an impending overlap | |
1771 | * is detected, the BDS will be made unusable, the qcow2 file marked corrupt | |
1772 | * and -EIO returned. | |
1773 | * | |
1774 | * Returns 0 if there were neither overlaps nor errors while checking for | |
1775 | * overlaps; or a negative value (-errno) on error. | |
1776 | */ | |
231bb267 | 1777 | int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset, |
a40f1c2a HR |
1778 | int64_t size) |
1779 | { | |
231bb267 | 1780 | int ret = qcow2_check_metadata_overlap(bs, ign, offset, size); |
a40f1c2a HR |
1781 | |
1782 | if (ret < 0) { | |
1783 | return ret; | |
1784 | } else if (ret > 0) { | |
1785 | int metadata_ol_bitnr = ffs(ret) - 1; | |
1786 | char *message; | |
1787 | QObject *data; | |
1788 | ||
1789 | assert(metadata_ol_bitnr < QCOW2_OL_MAX_BITNR); | |
1790 | ||
1791 | fprintf(stderr, "qcow2: Preventing invalid write on metadata (overlaps " | |
1792 | "with %s); image marked as corrupt.\n", | |
1793 | metadata_ol_names[metadata_ol_bitnr]); | |
1794 | message = g_strdup_printf("Prevented %s overwrite", | |
1795 | metadata_ol_names[metadata_ol_bitnr]); | |
1796 | data = qobject_from_jsonf("{ 'device': %s, 'msg': %s, 'offset': %" | |
1797 | PRId64 ", 'size': %" PRId64 " }", bs->device_name, message, | |
1798 | offset, size); | |
1799 | monitor_protocol_event(QEVENT_BLOCK_IMAGE_CORRUPTED, data); | |
1800 | g_free(message); | |
1801 | qobject_decref(data); | |
1802 | ||
1803 | qcow2_mark_corrupt(bs); | |
1804 | bs->drv = NULL; /* make BDS unusable */ | |
1805 | return -EIO; | |
1806 | } | |
1807 | ||
1808 | return 0; | |
1809 | } |