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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 | 28 | #include "qemu/range.h" |
f7d0fe02 | 29 | |
bb572aef | 30 | static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size); |
92dcb59f | 31 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
0e06528e | 32 | int64_t offset, int64_t length, uint64_t addend, |
2aabe7c7 | 33 | bool decrease, enum qcow2_discard_type type); |
f7d0fe02 | 34 | |
59c0cb78 HR |
35 | static uint64_t get_refcount_ro0(const void *refcount_array, uint64_t index); |
36 | static uint64_t get_refcount_ro1(const void *refcount_array, uint64_t index); | |
37 | static uint64_t get_refcount_ro2(const void *refcount_array, uint64_t index); | |
38 | static uint64_t get_refcount_ro3(const void *refcount_array, uint64_t index); | |
7453c96b | 39 | static uint64_t get_refcount_ro4(const void *refcount_array, uint64_t index); |
59c0cb78 HR |
40 | static uint64_t get_refcount_ro5(const void *refcount_array, uint64_t index); |
41 | static uint64_t get_refcount_ro6(const void *refcount_array, uint64_t index); | |
7453c96b | 42 | |
59c0cb78 HR |
43 | static void set_refcount_ro0(void *refcount_array, uint64_t index, |
44 | uint64_t value); | |
45 | static void set_refcount_ro1(void *refcount_array, uint64_t index, | |
46 | uint64_t value); | |
47 | static void set_refcount_ro2(void *refcount_array, uint64_t index, | |
48 | uint64_t value); | |
49 | static void set_refcount_ro3(void *refcount_array, uint64_t index, | |
50 | uint64_t value); | |
7453c96b HR |
51 | static void set_refcount_ro4(void *refcount_array, uint64_t index, |
52 | uint64_t value); | |
59c0cb78 HR |
53 | static void set_refcount_ro5(void *refcount_array, uint64_t index, |
54 | uint64_t value); | |
55 | static void set_refcount_ro6(void *refcount_array, uint64_t index, | |
56 | uint64_t value); | |
57 | ||
58 | ||
59 | static Qcow2GetRefcountFunc *const get_refcount_funcs[] = { | |
60 | &get_refcount_ro0, | |
61 | &get_refcount_ro1, | |
62 | &get_refcount_ro2, | |
63 | &get_refcount_ro3, | |
64 | &get_refcount_ro4, | |
65 | &get_refcount_ro5, | |
66 | &get_refcount_ro6 | |
67 | }; | |
68 | ||
69 | static Qcow2SetRefcountFunc *const set_refcount_funcs[] = { | |
70 | &set_refcount_ro0, | |
71 | &set_refcount_ro1, | |
72 | &set_refcount_ro2, | |
73 | &set_refcount_ro3, | |
74 | &set_refcount_ro4, | |
75 | &set_refcount_ro5, | |
76 | &set_refcount_ro6 | |
77 | }; | |
7453c96b | 78 | |
3b88e52b | 79 | |
f7d0fe02 KW |
80 | /*********************************************************/ |
81 | /* refcount handling */ | |
82 | ||
ed6ccf0f | 83 | int qcow2_refcount_init(BlockDriverState *bs) |
f7d0fe02 KW |
84 | { |
85 | BDRVQcowState *s = bs->opaque; | |
5dab2fad KW |
86 | unsigned int refcount_table_size2, i; |
87 | int ret; | |
f7d0fe02 | 88 | |
59c0cb78 HR |
89 | assert(s->refcount_order >= 0 && s->refcount_order <= 6); |
90 | ||
91 | s->get_refcount = get_refcount_funcs[s->refcount_order]; | |
92 | s->set_refcount = set_refcount_funcs[s->refcount_order]; | |
7453c96b | 93 | |
5dab2fad | 94 | assert(s->refcount_table_size <= INT_MAX / sizeof(uint64_t)); |
f7d0fe02 | 95 | refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); |
de82815d KW |
96 | s->refcount_table = g_try_malloc(refcount_table_size2); |
97 | ||
f7d0fe02 | 98 | if (s->refcount_table_size > 0) { |
de82815d | 99 | if (s->refcount_table == NULL) { |
8fcffa98 | 100 | ret = -ENOMEM; |
de82815d KW |
101 | goto fail; |
102 | } | |
66f82cee KW |
103 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_LOAD); |
104 | ret = bdrv_pread(bs->file, s->refcount_table_offset, | |
f7d0fe02 | 105 | s->refcount_table, refcount_table_size2); |
8fcffa98 | 106 | if (ret < 0) { |
f7d0fe02 | 107 | goto fail; |
8fcffa98 | 108 | } |
f7d0fe02 KW |
109 | for(i = 0; i < s->refcount_table_size; i++) |
110 | be64_to_cpus(&s->refcount_table[i]); | |
111 | } | |
112 | return 0; | |
113 | fail: | |
8fcffa98 | 114 | return ret; |
f7d0fe02 KW |
115 | } |
116 | ||
ed6ccf0f | 117 | void qcow2_refcount_close(BlockDriverState *bs) |
f7d0fe02 KW |
118 | { |
119 | BDRVQcowState *s = bs->opaque; | |
7267c094 | 120 | g_free(s->refcount_table); |
f7d0fe02 KW |
121 | } |
122 | ||
123 | ||
59c0cb78 HR |
124 | static uint64_t get_refcount_ro0(const void *refcount_array, uint64_t index) |
125 | { | |
126 | return (((const uint8_t *)refcount_array)[index / 8] >> (index % 8)) & 0x1; | |
127 | } | |
128 | ||
129 | static void set_refcount_ro0(void *refcount_array, uint64_t index, | |
130 | uint64_t value) | |
131 | { | |
132 | assert(!(value >> 1)); | |
133 | ((uint8_t *)refcount_array)[index / 8] &= ~(0x1 << (index % 8)); | |
134 | ((uint8_t *)refcount_array)[index / 8] |= value << (index % 8); | |
135 | } | |
136 | ||
137 | static uint64_t get_refcount_ro1(const void *refcount_array, uint64_t index) | |
138 | { | |
139 | return (((const uint8_t *)refcount_array)[index / 4] >> (2 * (index % 4))) | |
140 | & 0x3; | |
141 | } | |
142 | ||
143 | static void set_refcount_ro1(void *refcount_array, uint64_t index, | |
144 | uint64_t value) | |
145 | { | |
146 | assert(!(value >> 2)); | |
147 | ((uint8_t *)refcount_array)[index / 4] &= ~(0x3 << (2 * (index % 4))); | |
148 | ((uint8_t *)refcount_array)[index / 4] |= value << (2 * (index % 4)); | |
149 | } | |
150 | ||
151 | static uint64_t get_refcount_ro2(const void *refcount_array, uint64_t index) | |
152 | { | |
153 | return (((const uint8_t *)refcount_array)[index / 2] >> (4 * (index % 2))) | |
154 | & 0xf; | |
155 | } | |
156 | ||
157 | static void set_refcount_ro2(void *refcount_array, uint64_t index, | |
158 | uint64_t value) | |
159 | { | |
160 | assert(!(value >> 4)); | |
161 | ((uint8_t *)refcount_array)[index / 2] &= ~(0xf << (4 * (index % 2))); | |
162 | ((uint8_t *)refcount_array)[index / 2] |= value << (4 * (index % 2)); | |
163 | } | |
164 | ||
165 | static uint64_t get_refcount_ro3(const void *refcount_array, uint64_t index) | |
166 | { | |
167 | return ((const uint8_t *)refcount_array)[index]; | |
168 | } | |
169 | ||
170 | static void set_refcount_ro3(void *refcount_array, uint64_t index, | |
171 | uint64_t value) | |
172 | { | |
173 | assert(!(value >> 8)); | |
174 | ((uint8_t *)refcount_array)[index] = value; | |
175 | } | |
176 | ||
7453c96b HR |
177 | static uint64_t get_refcount_ro4(const void *refcount_array, uint64_t index) |
178 | { | |
179 | return be16_to_cpu(((const uint16_t *)refcount_array)[index]); | |
180 | } | |
181 | ||
182 | static void set_refcount_ro4(void *refcount_array, uint64_t index, | |
183 | uint64_t value) | |
184 | { | |
185 | assert(!(value >> 16)); | |
186 | ((uint16_t *)refcount_array)[index] = cpu_to_be16(value); | |
187 | } | |
188 | ||
59c0cb78 HR |
189 | static uint64_t get_refcount_ro5(const void *refcount_array, uint64_t index) |
190 | { | |
191 | return be32_to_cpu(((const uint32_t *)refcount_array)[index]); | |
192 | } | |
193 | ||
194 | static void set_refcount_ro5(void *refcount_array, uint64_t index, | |
195 | uint64_t value) | |
196 | { | |
197 | assert(!(value >> 32)); | |
198 | ((uint32_t *)refcount_array)[index] = cpu_to_be32(value); | |
199 | } | |
200 | ||
201 | static uint64_t get_refcount_ro6(const void *refcount_array, uint64_t index) | |
202 | { | |
203 | return be64_to_cpu(((const uint64_t *)refcount_array)[index]); | |
204 | } | |
205 | ||
206 | static void set_refcount_ro6(void *refcount_array, uint64_t index, | |
207 | uint64_t value) | |
208 | { | |
209 | ((uint64_t *)refcount_array)[index] = cpu_to_be64(value); | |
210 | } | |
211 | ||
7453c96b | 212 | |
f7d0fe02 | 213 | static int load_refcount_block(BlockDriverState *bs, |
29c1a730 KW |
214 | int64_t refcount_block_offset, |
215 | void **refcount_block) | |
f7d0fe02 KW |
216 | { |
217 | BDRVQcowState *s = bs->opaque; | |
218 | int ret; | |
3b88e52b | 219 | |
66f82cee | 220 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_LOAD); |
29c1a730 KW |
221 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, |
222 | refcount_block); | |
e14e8ba5 | 223 | |
29c1a730 | 224 | return ret; |
f7d0fe02 KW |
225 | } |
226 | ||
018faafd | 227 | /* |
7324c10f HR |
228 | * Retrieves the refcount of the cluster given by its index and stores it in |
229 | * *refcount. Returns 0 on success and -errno on failure. | |
018faafd | 230 | */ |
7324c10f | 231 | int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index, |
0e06528e | 232 | uint64_t *refcount) |
f7d0fe02 KW |
233 | { |
234 | BDRVQcowState *s = bs->opaque; | |
db8a31d1 | 235 | uint64_t refcount_table_index, block_index; |
f7d0fe02 | 236 | int64_t refcount_block_offset; |
018faafd | 237 | int ret; |
7453c96b | 238 | void *refcount_block; |
f7d0fe02 | 239 | |
17bd5f47 | 240 | refcount_table_index = cluster_index >> s->refcount_block_bits; |
7324c10f HR |
241 | if (refcount_table_index >= s->refcount_table_size) { |
242 | *refcount = 0; | |
f7d0fe02 | 243 | return 0; |
7324c10f | 244 | } |
26d49c46 HR |
245 | refcount_block_offset = |
246 | s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; | |
7324c10f HR |
247 | if (!refcount_block_offset) { |
248 | *refcount = 0; | |
f7d0fe02 | 249 | return 0; |
7324c10f | 250 | } |
29c1a730 | 251 | |
a97c67ee HR |
252 | if (offset_into_cluster(s, refcount_block_offset)) { |
253 | qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#" PRIx64 | |
254 | " unaligned (reftable index: %#" PRIx64 ")", | |
255 | refcount_block_offset, refcount_table_index); | |
256 | return -EIO; | |
257 | } | |
258 | ||
29c1a730 | 259 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, |
7453c96b | 260 | &refcount_block); |
29c1a730 KW |
261 | if (ret < 0) { |
262 | return ret; | |
f7d0fe02 | 263 | } |
29c1a730 | 264 | |
17bd5f47 | 265 | block_index = cluster_index & (s->refcount_block_size - 1); |
7453c96b | 266 | *refcount = s->get_refcount(refcount_block, block_index); |
29c1a730 | 267 | |
7453c96b | 268 | ret = qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); |
29c1a730 KW |
269 | if (ret < 0) { |
270 | return ret; | |
271 | } | |
272 | ||
7324c10f | 273 | return 0; |
f7d0fe02 KW |
274 | } |
275 | ||
05121aed KW |
276 | /* |
277 | * Rounds the refcount table size up to avoid growing the table for each single | |
278 | * refcount block that is allocated. | |
279 | */ | |
280 | static unsigned int next_refcount_table_size(BDRVQcowState *s, | |
281 | unsigned int min_size) | |
282 | { | |
283 | unsigned int min_clusters = (min_size >> (s->cluster_bits - 3)) + 1; | |
284 | unsigned int refcount_table_clusters = | |
285 | MAX(1, s->refcount_table_size >> (s->cluster_bits - 3)); | |
286 | ||
287 | while (min_clusters > refcount_table_clusters) { | |
288 | refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; | |
289 | } | |
290 | ||
291 | return refcount_table_clusters << (s->cluster_bits - 3); | |
292 | } | |
293 | ||
92dcb59f KW |
294 | |
295 | /* Checks if two offsets are described by the same refcount block */ | |
296 | static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a, | |
297 | uint64_t offset_b) | |
298 | { | |
17bd5f47 HR |
299 | uint64_t block_a = offset_a >> (s->cluster_bits + s->refcount_block_bits); |
300 | uint64_t block_b = offset_b >> (s->cluster_bits + s->refcount_block_bits); | |
92dcb59f KW |
301 | |
302 | return (block_a == block_b); | |
303 | } | |
304 | ||
305 | /* | |
306 | * Loads a refcount block. If it doesn't exist yet, it is allocated first | |
307 | * (including growing the refcount table if needed). | |
308 | * | |
29c1a730 | 309 | * Returns 0 on success or -errno in error case |
92dcb59f | 310 | */ |
29c1a730 | 311 | static int alloc_refcount_block(BlockDriverState *bs, |
7453c96b | 312 | int64_t cluster_index, void **refcount_block) |
f7d0fe02 KW |
313 | { |
314 | BDRVQcowState *s = bs->opaque; | |
92dcb59f KW |
315 | unsigned int refcount_table_index; |
316 | int ret; | |
317 | ||
66f82cee | 318 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); |
8252278a | 319 | |
92dcb59f | 320 | /* Find the refcount block for the given cluster */ |
17bd5f47 | 321 | refcount_table_index = cluster_index >> s->refcount_block_bits; |
92dcb59f KW |
322 | |
323 | if (refcount_table_index < s->refcount_table_size) { | |
324 | ||
325 | uint64_t refcount_block_offset = | |
76dc9e0c | 326 | s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; |
92dcb59f KW |
327 | |
328 | /* If it's already there, we're done */ | |
329 | if (refcount_block_offset) { | |
a97c67ee HR |
330 | if (offset_into_cluster(s, refcount_block_offset)) { |
331 | qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#" | |
332 | PRIx64 " unaligned (reftable index: " | |
333 | "%#x)", refcount_block_offset, | |
334 | refcount_table_index); | |
335 | return -EIO; | |
336 | } | |
337 | ||
29c1a730 | 338 | return load_refcount_block(bs, refcount_block_offset, |
7453c96b | 339 | refcount_block); |
92dcb59f KW |
340 | } |
341 | } | |
342 | ||
343 | /* | |
344 | * If we came here, we need to allocate something. Something is at least | |
345 | * a cluster for the new refcount block. It may also include a new refcount | |
346 | * table if the old refcount table is too small. | |
347 | * | |
348 | * Note that allocating clusters here needs some special care: | |
349 | * | |
350 | * - We can't use the normal qcow2_alloc_clusters(), it would try to | |
351 | * increase the refcount and very likely we would end up with an endless | |
352 | * recursion. Instead we must place the refcount blocks in a way that | |
353 | * they can describe them themselves. | |
354 | * | |
355 | * - We need to consider that at this point we are inside update_refcounts | |
b106ad91 KW |
356 | * and potentially doing an initial refcount increase. This means that |
357 | * some clusters have already been allocated by the caller, but their | |
358 | * refcount isn't accurate yet. If we allocate clusters for metadata, we | |
359 | * need to return -EAGAIN to signal the caller that it needs to restart | |
360 | * the search for free clusters. | |
92dcb59f KW |
361 | * |
362 | * - alloc_clusters_noref and qcow2_free_clusters may load a different | |
363 | * refcount block into the cache | |
364 | */ | |
365 | ||
29c1a730 KW |
366 | *refcount_block = NULL; |
367 | ||
368 | /* We write to the refcount table, so we might depend on L2 tables */ | |
9991923b SH |
369 | ret = qcow2_cache_flush(bs, s->l2_table_cache); |
370 | if (ret < 0) { | |
371 | return ret; | |
372 | } | |
92dcb59f KW |
373 | |
374 | /* Allocate the refcount block itself and mark it as used */ | |
2eaa8f63 KW |
375 | int64_t new_block = alloc_clusters_noref(bs, s->cluster_size); |
376 | if (new_block < 0) { | |
377 | return new_block; | |
378 | } | |
f7d0fe02 | 379 | |
f7d0fe02 | 380 | #ifdef DEBUG_ALLOC2 |
92dcb59f KW |
381 | fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64 |
382 | " at %" PRIx64 "\n", | |
383 | refcount_table_index, cluster_index << s->cluster_bits, new_block); | |
f7d0fe02 | 384 | #endif |
92dcb59f KW |
385 | |
386 | if (in_same_refcount_block(s, new_block, cluster_index << s->cluster_bits)) { | |
25408c09 | 387 | /* Zero the new refcount block before updating it */ |
29c1a730 | 388 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
7453c96b | 389 | refcount_block); |
29c1a730 KW |
390 | if (ret < 0) { |
391 | goto fail_block; | |
392 | } | |
393 | ||
394 | memset(*refcount_block, 0, s->cluster_size); | |
25408c09 | 395 | |
92dcb59f KW |
396 | /* The block describes itself, need to update the cache */ |
397 | int block_index = (new_block >> s->cluster_bits) & | |
17bd5f47 | 398 | (s->refcount_block_size - 1); |
7453c96b | 399 | s->set_refcount(*refcount_block, block_index, 1); |
92dcb59f KW |
400 | } else { |
401 | /* Described somewhere else. This can recurse at most twice before we | |
402 | * arrive at a block that describes itself. */ | |
2aabe7c7 | 403 | ret = update_refcount(bs, new_block, s->cluster_size, 1, false, |
6cfcb9b8 | 404 | QCOW2_DISCARD_NEVER); |
92dcb59f KW |
405 | if (ret < 0) { |
406 | goto fail_block; | |
407 | } | |
25408c09 | 408 | |
9991923b SH |
409 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
410 | if (ret < 0) { | |
411 | goto fail_block; | |
412 | } | |
1c4c2814 | 413 | |
25408c09 KW |
414 | /* Initialize the new refcount block only after updating its refcount, |
415 | * update_refcount uses the refcount cache itself */ | |
29c1a730 | 416 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
7453c96b | 417 | refcount_block); |
29c1a730 KW |
418 | if (ret < 0) { |
419 | goto fail_block; | |
420 | } | |
421 | ||
422 | memset(*refcount_block, 0, s->cluster_size); | |
92dcb59f KW |
423 | } |
424 | ||
425 | /* Now the new refcount block needs to be written to disk */ | |
66f82cee | 426 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE); |
29c1a730 KW |
427 | qcow2_cache_entry_mark_dirty(s->refcount_block_cache, *refcount_block); |
428 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); | |
92dcb59f KW |
429 | if (ret < 0) { |
430 | goto fail_block; | |
431 | } | |
432 | ||
433 | /* If the refcount table is big enough, just hook the block up there */ | |
434 | if (refcount_table_index < s->refcount_table_size) { | |
435 | uint64_t data64 = cpu_to_be64(new_block); | |
66f82cee | 436 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_HOOKUP); |
8b3b7206 | 437 | ret = bdrv_pwrite_sync(bs->file, |
92dcb59f KW |
438 | s->refcount_table_offset + refcount_table_index * sizeof(uint64_t), |
439 | &data64, sizeof(data64)); | |
440 | if (ret < 0) { | |
441 | goto fail_block; | |
442 | } | |
443 | ||
444 | s->refcount_table[refcount_table_index] = new_block; | |
b106ad91 KW |
445 | |
446 | /* The new refcount block may be where the caller intended to put its | |
447 | * data, so let it restart the search. */ | |
448 | return -EAGAIN; | |
29c1a730 KW |
449 | } |
450 | ||
7453c96b | 451 | ret = qcow2_cache_put(bs, s->refcount_block_cache, refcount_block); |
29c1a730 KW |
452 | if (ret < 0) { |
453 | goto fail_block; | |
92dcb59f KW |
454 | } |
455 | ||
456 | /* | |
457 | * If we come here, we need to grow the refcount table. Again, a new | |
458 | * refcount table needs some space and we can't simply allocate to avoid | |
459 | * endless recursion. | |
460 | * | |
461 | * Therefore let's grab new refcount blocks at the end of the image, which | |
462 | * will describe themselves and the new refcount table. This way we can | |
463 | * reference them only in the new table and do the switch to the new | |
464 | * refcount table at once without producing an inconsistent state in | |
465 | * between. | |
466 | */ | |
66f82cee | 467 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW); |
8252278a | 468 | |
92dcb59f | 469 | /* Calculate the number of refcount blocks needed so far */ |
17bd5f47 | 470 | uint64_t blocks_used = DIV_ROUND_UP(cluster_index, s->refcount_block_size); |
92dcb59f | 471 | |
2b5d5953 KW |
472 | if (blocks_used > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) { |
473 | return -EFBIG; | |
474 | } | |
475 | ||
92dcb59f KW |
476 | /* And now we need at least one block more for the new metadata */ |
477 | uint64_t table_size = next_refcount_table_size(s, blocks_used + 1); | |
478 | uint64_t last_table_size; | |
479 | uint64_t blocks_clusters; | |
480 | do { | |
a3548077 KW |
481 | uint64_t table_clusters = |
482 | size_to_clusters(s, table_size * sizeof(uint64_t)); | |
92dcb59f | 483 | blocks_clusters = 1 + |
17bd5f47 HR |
484 | ((table_clusters + s->refcount_block_size - 1) |
485 | / s->refcount_block_size); | |
92dcb59f KW |
486 | uint64_t meta_clusters = table_clusters + blocks_clusters; |
487 | ||
488 | last_table_size = table_size; | |
489 | table_size = next_refcount_table_size(s, blocks_used + | |
17bd5f47 HR |
490 | ((meta_clusters + s->refcount_block_size - 1) |
491 | / s->refcount_block_size)); | |
92dcb59f KW |
492 | |
493 | } while (last_table_size != table_size); | |
494 | ||
495 | #ifdef DEBUG_ALLOC2 | |
496 | fprintf(stderr, "qcow2: Grow refcount table %" PRId32 " => %" PRId64 "\n", | |
497 | s->refcount_table_size, table_size); | |
498 | #endif | |
499 | ||
500 | /* Create the new refcount table and blocks */ | |
17bd5f47 | 501 | uint64_t meta_offset = (blocks_used * s->refcount_block_size) * |
92dcb59f KW |
502 | s->cluster_size; |
503 | uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size; | |
5839e53b | 504 | uint64_t *new_table = g_try_new0(uint64_t, table_size); |
7453c96b | 505 | void *new_blocks = g_try_malloc0(blocks_clusters * s->cluster_size); |
de82815d KW |
506 | |
507 | assert(table_size > 0 && blocks_clusters > 0); | |
508 | if (new_table == NULL || new_blocks == NULL) { | |
509 | ret = -ENOMEM; | |
510 | goto fail_table; | |
511 | } | |
92dcb59f | 512 | |
92dcb59f | 513 | /* Fill the new refcount table */ |
f7d0fe02 | 514 | memcpy(new_table, s->refcount_table, |
92dcb59f KW |
515 | s->refcount_table_size * sizeof(uint64_t)); |
516 | new_table[refcount_table_index] = new_block; | |
517 | ||
518 | int i; | |
519 | for (i = 0; i < blocks_clusters; i++) { | |
520 | new_table[blocks_used + i] = meta_offset + (i * s->cluster_size); | |
521 | } | |
522 | ||
523 | /* Fill the refcount blocks */ | |
524 | uint64_t table_clusters = size_to_clusters(s, table_size * sizeof(uint64_t)); | |
525 | int block = 0; | |
526 | for (i = 0; i < table_clusters + blocks_clusters; i++) { | |
7453c96b | 527 | s->set_refcount(new_blocks, block++, 1); |
92dcb59f KW |
528 | } |
529 | ||
530 | /* Write refcount blocks to disk */ | |
66f82cee | 531 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS); |
8b3b7206 | 532 | ret = bdrv_pwrite_sync(bs->file, meta_offset, new_blocks, |
92dcb59f | 533 | blocks_clusters * s->cluster_size); |
7267c094 | 534 | g_free(new_blocks); |
39ba3bf6 | 535 | new_blocks = NULL; |
92dcb59f KW |
536 | if (ret < 0) { |
537 | goto fail_table; | |
538 | } | |
539 | ||
540 | /* Write refcount table to disk */ | |
541 | for(i = 0; i < table_size; i++) { | |
542 | cpu_to_be64s(&new_table[i]); | |
543 | } | |
544 | ||
66f82cee | 545 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE); |
8b3b7206 | 546 | ret = bdrv_pwrite_sync(bs->file, table_offset, new_table, |
92dcb59f KW |
547 | table_size * sizeof(uint64_t)); |
548 | if (ret < 0) { | |
549 | goto fail_table; | |
550 | } | |
551 | ||
552 | for(i = 0; i < table_size; i++) { | |
87267753 | 553 | be64_to_cpus(&new_table[i]); |
92dcb59f | 554 | } |
f7d0fe02 | 555 | |
92dcb59f KW |
556 | /* Hook up the new refcount table in the qcow2 header */ |
557 | uint8_t data[12]; | |
f7d0fe02 | 558 | cpu_to_be64w((uint64_t*)data, table_offset); |
92dcb59f | 559 | cpu_to_be32w((uint32_t*)(data + 8), table_clusters); |
66f82cee | 560 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE); |
8b3b7206 | 561 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, refcount_table_offset), |
92dcb59f KW |
562 | data, sizeof(data)); |
563 | if (ret < 0) { | |
564 | goto fail_table; | |
f2b7c8b3 KW |
565 | } |
566 | ||
92dcb59f KW |
567 | /* And switch it in memory */ |
568 | uint64_t old_table_offset = s->refcount_table_offset; | |
569 | uint64_t old_table_size = s->refcount_table_size; | |
570 | ||
7267c094 | 571 | g_free(s->refcount_table); |
f7d0fe02 | 572 | s->refcount_table = new_table; |
92dcb59f | 573 | s->refcount_table_size = table_size; |
f7d0fe02 KW |
574 | s->refcount_table_offset = table_offset; |
575 | ||
b106ad91 | 576 | /* Free old table. */ |
6cfcb9b8 KW |
577 | qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t), |
578 | QCOW2_DISCARD_OTHER); | |
f7d0fe02 | 579 | |
7453c96b | 580 | ret = load_refcount_block(bs, new_block, refcount_block); |
92dcb59f | 581 | if (ret < 0) { |
29c1a730 | 582 | return ret; |
f7d0fe02 KW |
583 | } |
584 | ||
b106ad91 KW |
585 | /* If we were trying to do the initial refcount update for some cluster |
586 | * allocation, we might have used the same clusters to store newly | |
587 | * allocated metadata. Make the caller search some new space. */ | |
588 | return -EAGAIN; | |
f7d0fe02 | 589 | |
92dcb59f | 590 | fail_table: |
de82815d | 591 | g_free(new_blocks); |
7267c094 | 592 | g_free(new_table); |
92dcb59f | 593 | fail_block: |
29c1a730 | 594 | if (*refcount_block != NULL) { |
7453c96b | 595 | qcow2_cache_put(bs, s->refcount_block_cache, refcount_block); |
3b88e52b | 596 | } |
29c1a730 | 597 | return ret; |
9923e05e KW |
598 | } |
599 | ||
0b919fae KW |
600 | void qcow2_process_discards(BlockDriverState *bs, int ret) |
601 | { | |
602 | BDRVQcowState *s = bs->opaque; | |
603 | Qcow2DiscardRegion *d, *next; | |
604 | ||
605 | QTAILQ_FOREACH_SAFE(d, &s->discards, next, next) { | |
606 | QTAILQ_REMOVE(&s->discards, d, next); | |
607 | ||
608 | /* Discard is optional, ignore the return value */ | |
609 | if (ret >= 0) { | |
610 | bdrv_discard(bs->file, | |
611 | d->offset >> BDRV_SECTOR_BITS, | |
612 | d->bytes >> BDRV_SECTOR_BITS); | |
613 | } | |
614 | ||
615 | g_free(d); | |
616 | } | |
617 | } | |
618 | ||
619 | static void update_refcount_discard(BlockDriverState *bs, | |
620 | uint64_t offset, uint64_t length) | |
621 | { | |
622 | BDRVQcowState *s = bs->opaque; | |
623 | Qcow2DiscardRegion *d, *p, *next; | |
624 | ||
625 | QTAILQ_FOREACH(d, &s->discards, next) { | |
626 | uint64_t new_start = MIN(offset, d->offset); | |
627 | uint64_t new_end = MAX(offset + length, d->offset + d->bytes); | |
628 | ||
629 | if (new_end - new_start <= length + d->bytes) { | |
630 | /* There can't be any overlap, areas ending up here have no | |
631 | * references any more and therefore shouldn't get freed another | |
632 | * time. */ | |
633 | assert(d->bytes + length == new_end - new_start); | |
634 | d->offset = new_start; | |
635 | d->bytes = new_end - new_start; | |
636 | goto found; | |
637 | } | |
638 | } | |
639 | ||
640 | d = g_malloc(sizeof(*d)); | |
641 | *d = (Qcow2DiscardRegion) { | |
642 | .bs = bs, | |
643 | .offset = offset, | |
644 | .bytes = length, | |
645 | }; | |
646 | QTAILQ_INSERT_TAIL(&s->discards, d, next); | |
647 | ||
648 | found: | |
649 | /* Merge discard requests if they are adjacent now */ | |
650 | QTAILQ_FOREACH_SAFE(p, &s->discards, next, next) { | |
651 | if (p == d | |
652 | || p->offset > d->offset + d->bytes | |
653 | || d->offset > p->offset + p->bytes) | |
654 | { | |
655 | continue; | |
656 | } | |
657 | ||
658 | /* Still no overlap possible */ | |
659 | assert(p->offset == d->offset + d->bytes | |
660 | || d->offset == p->offset + p->bytes); | |
661 | ||
662 | QTAILQ_REMOVE(&s->discards, p, next); | |
663 | d->offset = MIN(d->offset, p->offset); | |
664 | d->bytes += p->bytes; | |
d8bb71b6 | 665 | g_free(p); |
0b919fae KW |
666 | } |
667 | } | |
668 | ||
f7d0fe02 | 669 | /* XXX: cache several refcount block clusters ? */ |
2aabe7c7 HR |
670 | /* @addend is the absolute value of the addend; if @decrease is set, @addend |
671 | * will be subtracted from the current refcount, otherwise it will be added */ | |
db3a964f | 672 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
2aabe7c7 HR |
673 | int64_t offset, |
674 | int64_t length, | |
0e06528e | 675 | uint64_t addend, |
2aabe7c7 HR |
676 | bool decrease, |
677 | enum qcow2_discard_type type) | |
f7d0fe02 KW |
678 | { |
679 | BDRVQcowState *s = bs->opaque; | |
680 | int64_t start, last, cluster_offset; | |
7453c96b | 681 | void *refcount_block = NULL; |
29c1a730 | 682 | int64_t old_table_index = -1; |
09508d13 | 683 | int ret; |
f7d0fe02 KW |
684 | |
685 | #ifdef DEBUG_ALLOC2 | |
2aabe7c7 | 686 | fprintf(stderr, "update_refcount: offset=%" PRId64 " size=%" PRId64 |
0e06528e | 687 | " addend=%s%" PRIu64 "\n", offset, length, decrease ? "-" : "", |
2aabe7c7 | 688 | addend); |
f7d0fe02 | 689 | #endif |
7322afe7 | 690 | if (length < 0) { |
f7d0fe02 | 691 | return -EINVAL; |
7322afe7 KW |
692 | } else if (length == 0) { |
693 | return 0; | |
694 | } | |
695 | ||
2aabe7c7 | 696 | if (decrease) { |
29c1a730 KW |
697 | qcow2_cache_set_dependency(bs, s->refcount_block_cache, |
698 | s->l2_table_cache); | |
699 | } | |
700 | ||
ac95acdb HT |
701 | start = start_of_cluster(s, offset); |
702 | last = start_of_cluster(s, offset + length - 1); | |
f7d0fe02 KW |
703 | for(cluster_offset = start; cluster_offset <= last; |
704 | cluster_offset += s->cluster_size) | |
705 | { | |
2aabe7c7 | 706 | int block_index; |
0e06528e | 707 | uint64_t refcount; |
f7d0fe02 | 708 | int64_t cluster_index = cluster_offset >> s->cluster_bits; |
17bd5f47 | 709 | int64_t table_index = cluster_index >> s->refcount_block_bits; |
f7d0fe02 | 710 | |
29c1a730 KW |
711 | /* Load the refcount block and allocate it if needed */ |
712 | if (table_index != old_table_index) { | |
713 | if (refcount_block) { | |
714 | ret = qcow2_cache_put(bs, s->refcount_block_cache, | |
7453c96b | 715 | &refcount_block); |
29c1a730 KW |
716 | if (ret < 0) { |
717 | goto fail; | |
718 | } | |
719 | } | |
9923e05e | 720 | |
29c1a730 | 721 | ret = alloc_refcount_block(bs, cluster_index, &refcount_block); |
ed0df867 | 722 | if (ret < 0) { |
29c1a730 | 723 | goto fail; |
f7d0fe02 | 724 | } |
f7d0fe02 | 725 | } |
29c1a730 | 726 | old_table_index = table_index; |
f7d0fe02 | 727 | |
29c1a730 | 728 | qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refcount_block); |
f7d0fe02 KW |
729 | |
730 | /* we can update the count and save it */ | |
17bd5f47 | 731 | block_index = cluster_index & (s->refcount_block_size - 1); |
f7d0fe02 | 732 | |
7453c96b | 733 | refcount = s->get_refcount(refcount_block, block_index); |
0e06528e HR |
734 | if (decrease ? (refcount - addend > refcount) |
735 | : (refcount + addend < refcount || | |
736 | refcount + addend > s->refcount_max)) | |
2aabe7c7 | 737 | { |
09508d13 KW |
738 | ret = -EINVAL; |
739 | goto fail; | |
740 | } | |
2aabe7c7 HR |
741 | if (decrease) { |
742 | refcount -= addend; | |
743 | } else { | |
744 | refcount += addend; | |
745 | } | |
f7d0fe02 KW |
746 | if (refcount == 0 && cluster_index < s->free_cluster_index) { |
747 | s->free_cluster_index = cluster_index; | |
748 | } | |
7453c96b | 749 | s->set_refcount(refcount_block, block_index, refcount); |
0b919fae | 750 | |
67af674e | 751 | if (refcount == 0 && s->discard_passthrough[type]) { |
0b919fae | 752 | update_refcount_discard(bs, cluster_offset, s->cluster_size); |
67af674e | 753 | } |
f7d0fe02 KW |
754 | } |
755 | ||
09508d13 KW |
756 | ret = 0; |
757 | fail: | |
0b919fae KW |
758 | if (!s->cache_discards) { |
759 | qcow2_process_discards(bs, ret); | |
760 | } | |
761 | ||
f7d0fe02 | 762 | /* Write last changed block to disk */ |
29c1a730 | 763 | if (refcount_block) { |
ed0df867 | 764 | int wret; |
7453c96b | 765 | wret = qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); |
ed0df867 KW |
766 | if (wret < 0) { |
767 | return ret < 0 ? ret : wret; | |
f7d0fe02 KW |
768 | } |
769 | } | |
770 | ||
09508d13 KW |
771 | /* |
772 | * Try do undo any updates if an error is returned (This may succeed in | |
773 | * some cases like ENOSPC for allocating a new refcount block) | |
774 | */ | |
775 | if (ret < 0) { | |
776 | int dummy; | |
2aabe7c7 HR |
777 | dummy = update_refcount(bs, offset, cluster_offset - offset, addend, |
778 | !decrease, QCOW2_DISCARD_NEVER); | |
83e3f76c | 779 | (void)dummy; |
09508d13 KW |
780 | } |
781 | ||
782 | return ret; | |
f7d0fe02 KW |
783 | } |
784 | ||
018faafd | 785 | /* |
44751917 | 786 | * Increases or decreases the refcount of a given cluster. |
018faafd | 787 | * |
2aabe7c7 HR |
788 | * @addend is the absolute value of the addend; if @decrease is set, @addend |
789 | * will be subtracted from the current refcount, otherwise it will be added. | |
790 | * | |
c6e9d8ae | 791 | * On success 0 is returned; on failure -errno is returned. |
018faafd | 792 | */ |
32b6444d HR |
793 | int qcow2_update_cluster_refcount(BlockDriverState *bs, |
794 | int64_t cluster_index, | |
0e06528e | 795 | uint64_t addend, bool decrease, |
32b6444d | 796 | enum qcow2_discard_type type) |
f7d0fe02 KW |
797 | { |
798 | BDRVQcowState *s = bs->opaque; | |
799 | int ret; | |
800 | ||
6cfcb9b8 | 801 | ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend, |
2aabe7c7 | 802 | decrease, type); |
f7d0fe02 KW |
803 | if (ret < 0) { |
804 | return ret; | |
805 | } | |
806 | ||
c6e9d8ae | 807 | return 0; |
f7d0fe02 KW |
808 | } |
809 | ||
810 | ||
811 | ||
812 | /*********************************************************/ | |
813 | /* cluster allocation functions */ | |
814 | ||
815 | ||
816 | ||
817 | /* return < 0 if error */ | |
bb572aef | 818 | static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size) |
f7d0fe02 KW |
819 | { |
820 | BDRVQcowState *s = bs->opaque; | |
0e06528e | 821 | uint64_t i, nb_clusters, refcount; |
7324c10f | 822 | int ret; |
f7d0fe02 KW |
823 | |
824 | nb_clusters = size_to_clusters(s, size); | |
825 | retry: | |
826 | for(i = 0; i < nb_clusters; i++) { | |
bb572aef | 827 | uint64_t next_cluster_index = s->free_cluster_index++; |
7324c10f | 828 | ret = qcow2_get_refcount(bs, next_cluster_index, &refcount); |
2eaa8f63 | 829 | |
7324c10f HR |
830 | if (ret < 0) { |
831 | return ret; | |
2eaa8f63 | 832 | } else if (refcount != 0) { |
f7d0fe02 | 833 | goto retry; |
2eaa8f63 | 834 | } |
f7d0fe02 | 835 | } |
91f827dc HR |
836 | |
837 | /* Make sure that all offsets in the "allocated" range are representable | |
838 | * in an int64_t */ | |
65f33bc0 HR |
839 | if (s->free_cluster_index > 0 && |
840 | s->free_cluster_index - 1 > (INT64_MAX >> s->cluster_bits)) | |
841 | { | |
91f827dc HR |
842 | return -EFBIG; |
843 | } | |
844 | ||
f7d0fe02 | 845 | #ifdef DEBUG_ALLOC2 |
35ee5e39 | 846 | fprintf(stderr, "alloc_clusters: size=%" PRId64 " -> %" PRId64 "\n", |
f7d0fe02 KW |
847 | size, |
848 | (s->free_cluster_index - nb_clusters) << s->cluster_bits); | |
849 | #endif | |
850 | return (s->free_cluster_index - nb_clusters) << s->cluster_bits; | |
851 | } | |
852 | ||
bb572aef | 853 | int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size) |
f7d0fe02 KW |
854 | { |
855 | int64_t offset; | |
db3a964f | 856 | int ret; |
f7d0fe02 | 857 | |
66f82cee | 858 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC); |
b106ad91 KW |
859 | do { |
860 | offset = alloc_clusters_noref(bs, size); | |
861 | if (offset < 0) { | |
862 | return offset; | |
863 | } | |
864 | ||
2aabe7c7 | 865 | ret = update_refcount(bs, offset, size, 1, false, QCOW2_DISCARD_NEVER); |
b106ad91 | 866 | } while (ret == -EAGAIN); |
2eaa8f63 | 867 | |
db3a964f KW |
868 | if (ret < 0) { |
869 | return ret; | |
870 | } | |
1c4c2814 | 871 | |
f7d0fe02 KW |
872 | return offset; |
873 | } | |
874 | ||
256900b1 KW |
875 | int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, |
876 | int nb_clusters) | |
877 | { | |
878 | BDRVQcowState *s = bs->opaque; | |
0e06528e | 879 | uint64_t cluster_index, refcount; |
33304ec9 | 880 | uint64_t i; |
7324c10f | 881 | int ret; |
33304ec9 HT |
882 | |
883 | assert(nb_clusters >= 0); | |
884 | if (nb_clusters == 0) { | |
885 | return 0; | |
886 | } | |
256900b1 | 887 | |
b106ad91 KW |
888 | do { |
889 | /* Check how many clusters there are free */ | |
890 | cluster_index = offset >> s->cluster_bits; | |
891 | for(i = 0; i < nb_clusters; i++) { | |
7324c10f HR |
892 | ret = qcow2_get_refcount(bs, cluster_index++, &refcount); |
893 | if (ret < 0) { | |
894 | return ret; | |
b106ad91 KW |
895 | } else if (refcount != 0) { |
896 | break; | |
897 | } | |
256900b1 | 898 | } |
256900b1 | 899 | |
b106ad91 | 900 | /* And then allocate them */ |
2aabe7c7 | 901 | ret = update_refcount(bs, offset, i << s->cluster_bits, 1, false, |
b106ad91 KW |
902 | QCOW2_DISCARD_NEVER); |
903 | } while (ret == -EAGAIN); | |
f24423bd | 904 | |
256900b1 KW |
905 | if (ret < 0) { |
906 | return ret; | |
907 | } | |
908 | ||
909 | return i; | |
910 | } | |
911 | ||
f7d0fe02 KW |
912 | /* only used to allocate compressed sectors. We try to allocate |
913 | contiguous sectors. size must be <= cluster_size */ | |
ed6ccf0f | 914 | int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size) |
f7d0fe02 KW |
915 | { |
916 | BDRVQcowState *s = bs->opaque; | |
8c44dfbc HR |
917 | int64_t offset; |
918 | size_t free_in_cluster; | |
919 | int ret; | |
f7d0fe02 | 920 | |
66f82cee | 921 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_BYTES); |
f7d0fe02 | 922 | assert(size > 0 && size <= s->cluster_size); |
8c44dfbc HR |
923 | assert(!s->free_byte_offset || offset_into_cluster(s, s->free_byte_offset)); |
924 | ||
925 | offset = s->free_byte_offset; | |
926 | ||
927 | if (offset) { | |
0e06528e | 928 | uint64_t refcount; |
7324c10f HR |
929 | ret = qcow2_get_refcount(bs, offset >> s->cluster_bits, &refcount); |
930 | if (ret < 0) { | |
931 | return ret; | |
5d757b56 | 932 | } |
8c44dfbc | 933 | |
346a53df | 934 | if (refcount == s->refcount_max) { |
8c44dfbc | 935 | offset = 0; |
5d757b56 | 936 | } |
8c44dfbc HR |
937 | } |
938 | ||
939 | free_in_cluster = s->cluster_size - offset_into_cluster(s, offset); | |
940 | if (!offset || free_in_cluster < size) { | |
941 | int64_t new_cluster = alloc_clusters_noref(bs, s->cluster_size); | |
942 | if (new_cluster < 0) { | |
943 | return new_cluster; | |
944 | } | |
945 | ||
946 | if (!offset || ROUND_UP(offset, s->cluster_size) != new_cluster) { | |
947 | offset = new_cluster; | |
f7d0fe02 KW |
948 | } |
949 | } | |
29216ed1 | 950 | |
8c44dfbc | 951 | assert(offset); |
2aabe7c7 | 952 | ret = update_refcount(bs, offset, size, 1, false, QCOW2_DISCARD_NEVER); |
8c44dfbc HR |
953 | if (ret < 0) { |
954 | return ret; | |
955 | } | |
956 | ||
957 | /* The cluster refcount was incremented; refcount blocks must be flushed | |
958 | * before the caller's L2 table updates. */ | |
c1f5bafd | 959 | qcow2_cache_set_dependency(bs, s->l2_table_cache, s->refcount_block_cache); |
8c44dfbc HR |
960 | |
961 | s->free_byte_offset = offset + size; | |
962 | if (!offset_into_cluster(s, s->free_byte_offset)) { | |
963 | s->free_byte_offset = 0; | |
964 | } | |
965 | ||
f7d0fe02 KW |
966 | return offset; |
967 | } | |
968 | ||
ed6ccf0f | 969 | void qcow2_free_clusters(BlockDriverState *bs, |
6cfcb9b8 KW |
970 | int64_t offset, int64_t size, |
971 | enum qcow2_discard_type type) | |
f7d0fe02 | 972 | { |
db3a964f KW |
973 | int ret; |
974 | ||
66f82cee | 975 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_FREE); |
2aabe7c7 | 976 | ret = update_refcount(bs, offset, size, 1, true, type); |
db3a964f KW |
977 | if (ret < 0) { |
978 | fprintf(stderr, "qcow2_free_clusters failed: %s\n", strerror(-ret)); | |
003fad6e | 979 | /* TODO Remember the clusters to free them later and avoid leaking */ |
db3a964f | 980 | } |
f7d0fe02 KW |
981 | } |
982 | ||
45aba42f | 983 | /* |
c7a4c37a KW |
984 | * Free a cluster using its L2 entry (handles clusters of all types, e.g. |
985 | * normal cluster, compressed cluster, etc.) | |
45aba42f | 986 | */ |
6cfcb9b8 KW |
987 | void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry, |
988 | int nb_clusters, enum qcow2_discard_type type) | |
45aba42f KW |
989 | { |
990 | BDRVQcowState *s = bs->opaque; | |
991 | ||
c7a4c37a KW |
992 | switch (qcow2_get_cluster_type(l2_entry)) { |
993 | case QCOW2_CLUSTER_COMPRESSED: | |
994 | { | |
995 | int nb_csectors; | |
996 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
997 | s->csize_mask) + 1; | |
998 | qcow2_free_clusters(bs, | |
999 | (l2_entry & s->cluster_offset_mask) & ~511, | |
6cfcb9b8 | 1000 | nb_csectors * 512, type); |
c7a4c37a KW |
1001 | } |
1002 | break; | |
1003 | case QCOW2_CLUSTER_NORMAL: | |
8f730dd2 HR |
1004 | case QCOW2_CLUSTER_ZERO: |
1005 | if (l2_entry & L2E_OFFSET_MASK) { | |
a97c67ee HR |
1006 | if (offset_into_cluster(s, l2_entry & L2E_OFFSET_MASK)) { |
1007 | qcow2_signal_corruption(bs, false, -1, -1, | |
1008 | "Cannot free unaligned cluster %#llx", | |
1009 | l2_entry & L2E_OFFSET_MASK); | |
1010 | } else { | |
1011 | qcow2_free_clusters(bs, l2_entry & L2E_OFFSET_MASK, | |
1012 | nb_clusters << s->cluster_bits, type); | |
1013 | } | |
8f730dd2 | 1014 | } |
c7a4c37a KW |
1015 | break; |
1016 | case QCOW2_CLUSTER_UNALLOCATED: | |
1017 | break; | |
1018 | default: | |
1019 | abort(); | |
45aba42f | 1020 | } |
45aba42f KW |
1021 | } |
1022 | ||
f7d0fe02 KW |
1023 | |
1024 | ||
1025 | /*********************************************************/ | |
1026 | /* snapshots and image creation */ | |
1027 | ||
1028 | ||
1029 | ||
f7d0fe02 | 1030 | /* update the refcounts of snapshots and the copied flag */ |
ed6ccf0f KW |
1031 | int qcow2_update_snapshot_refcount(BlockDriverState *bs, |
1032 | int64_t l1_table_offset, int l1_size, int addend) | |
f7d0fe02 KW |
1033 | { |
1034 | BDRVQcowState *s = bs->opaque; | |
0e06528e | 1035 | uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, refcount; |
de82815d | 1036 | bool l1_allocated = false; |
f7d0fe02 | 1037 | int64_t old_offset, old_l2_offset; |
7324c10f | 1038 | int i, j, l1_modified = 0, nb_csectors; |
29c1a730 | 1039 | int ret; |
f7d0fe02 | 1040 | |
2aabe7c7 HR |
1041 | assert(addend >= -1 && addend <= 1); |
1042 | ||
f7d0fe02 KW |
1043 | l2_table = NULL; |
1044 | l1_table = NULL; | |
1045 | l1_size2 = l1_size * sizeof(uint64_t); | |
43a0cac4 | 1046 | |
0b919fae KW |
1047 | s->cache_discards = true; |
1048 | ||
43a0cac4 KW |
1049 | /* WARNING: qcow2_snapshot_goto relies on this function not using the |
1050 | * l1_table_offset when it is the current s->l1_table_offset! Be careful | |
1051 | * when changing this! */ | |
f7d0fe02 | 1052 | if (l1_table_offset != s->l1_table_offset) { |
de82815d KW |
1053 | l1_table = g_try_malloc0(align_offset(l1_size2, 512)); |
1054 | if (l1_size2 && l1_table == NULL) { | |
1055 | ret = -ENOMEM; | |
1056 | goto fail; | |
1057 | } | |
1058 | l1_allocated = true; | |
c2bc78b6 KW |
1059 | |
1060 | ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2); | |
1061 | if (ret < 0) { | |
f7d0fe02 | 1062 | goto fail; |
93913dfd KW |
1063 | } |
1064 | ||
f7d0fe02 KW |
1065 | for(i = 0;i < l1_size; i++) |
1066 | be64_to_cpus(&l1_table[i]); | |
1067 | } else { | |
1068 | assert(l1_size == s->l1_size); | |
1069 | l1_table = s->l1_table; | |
de82815d | 1070 | l1_allocated = false; |
f7d0fe02 KW |
1071 | } |
1072 | ||
f7d0fe02 KW |
1073 | for(i = 0; i < l1_size; i++) { |
1074 | l2_offset = l1_table[i]; | |
1075 | if (l2_offset) { | |
1076 | old_l2_offset = l2_offset; | |
8e37f681 | 1077 | l2_offset &= L1E_OFFSET_MASK; |
29c1a730 | 1078 | |
a97c67ee HR |
1079 | if (offset_into_cluster(s, l2_offset)) { |
1080 | qcow2_signal_corruption(bs, true, -1, -1, "L2 table offset %#" | |
1081 | PRIx64 " unaligned (L1 index: %#x)", | |
1082 | l2_offset, i); | |
1083 | ret = -EIO; | |
1084 | goto fail; | |
1085 | } | |
1086 | ||
29c1a730 KW |
1087 | ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, |
1088 | (void**) &l2_table); | |
1089 | if (ret < 0) { | |
f7d0fe02 | 1090 | goto fail; |
29c1a730 KW |
1091 | } |
1092 | ||
f7d0fe02 | 1093 | for(j = 0; j < s->l2_size; j++) { |
8b81a7b6 HR |
1094 | uint64_t cluster_index; |
1095 | ||
f7d0fe02 | 1096 | offset = be64_to_cpu(l2_table[j]); |
8b81a7b6 HR |
1097 | old_offset = offset; |
1098 | offset &= ~QCOW_OFLAG_COPIED; | |
1099 | ||
1100 | switch (qcow2_get_cluster_type(offset)) { | |
1101 | case QCOW2_CLUSTER_COMPRESSED: | |
f7d0fe02 KW |
1102 | nb_csectors = ((offset >> s->csize_shift) & |
1103 | s->csize_mask) + 1; | |
db3a964f | 1104 | if (addend != 0) { |
db3a964f KW |
1105 | ret = update_refcount(bs, |
1106 | (offset & s->cluster_offset_mask) & ~511, | |
2aabe7c7 | 1107 | nb_csectors * 512, abs(addend), addend < 0, |
6cfcb9b8 | 1108 | QCOW2_DISCARD_SNAPSHOT); |
db3a964f KW |
1109 | if (ret < 0) { |
1110 | goto fail; | |
1111 | } | |
1112 | } | |
f7d0fe02 KW |
1113 | /* compressed clusters are never modified */ |
1114 | refcount = 2; | |
8b81a7b6 HR |
1115 | break; |
1116 | ||
1117 | case QCOW2_CLUSTER_NORMAL: | |
1118 | case QCOW2_CLUSTER_ZERO: | |
a97c67ee HR |
1119 | if (offset_into_cluster(s, offset & L2E_OFFSET_MASK)) { |
1120 | qcow2_signal_corruption(bs, true, -1, -1, "Data " | |
1121 | "cluster offset %#llx " | |
1122 | "unaligned (L2 offset: %#" | |
1123 | PRIx64 ", L2 index: %#x)", | |
1124 | offset & L2E_OFFSET_MASK, | |
1125 | l2_offset, j); | |
1126 | ret = -EIO; | |
1127 | goto fail; | |
1128 | } | |
1129 | ||
8b81a7b6 HR |
1130 | cluster_index = (offset & L2E_OFFSET_MASK) >> s->cluster_bits; |
1131 | if (!cluster_index) { | |
1132 | /* unallocated */ | |
1133 | refcount = 0; | |
1134 | break; | |
1135 | } | |
f7d0fe02 | 1136 | if (addend != 0) { |
c6e9d8ae | 1137 | ret = qcow2_update_cluster_refcount(bs, |
2aabe7c7 | 1138 | cluster_index, abs(addend), addend < 0, |
32b6444d | 1139 | QCOW2_DISCARD_SNAPSHOT); |
c6e9d8ae HR |
1140 | if (ret < 0) { |
1141 | goto fail; | |
1142 | } | |
f7d0fe02 | 1143 | } |
018faafd | 1144 | |
7324c10f HR |
1145 | ret = qcow2_get_refcount(bs, cluster_index, &refcount); |
1146 | if (ret < 0) { | |
018faafd KW |
1147 | goto fail; |
1148 | } | |
8b81a7b6 | 1149 | break; |
f7d0fe02 | 1150 | |
8b81a7b6 HR |
1151 | case QCOW2_CLUSTER_UNALLOCATED: |
1152 | refcount = 0; | |
1153 | break; | |
1154 | ||
1155 | default: | |
1156 | abort(); | |
1157 | } | |
1158 | ||
1159 | if (refcount == 1) { | |
1160 | offset |= QCOW_OFLAG_COPIED; | |
1161 | } | |
1162 | if (offset != old_offset) { | |
1163 | if (addend > 0) { | |
1164 | qcow2_cache_set_dependency(bs, s->l2_table_cache, | |
1165 | s->refcount_block_cache); | |
f7d0fe02 | 1166 | } |
8b81a7b6 HR |
1167 | l2_table[j] = cpu_to_be64(offset); |
1168 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); | |
f7d0fe02 KW |
1169 | } |
1170 | } | |
29c1a730 KW |
1171 | |
1172 | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); | |
1173 | if (ret < 0) { | |
1174 | goto fail; | |
f7d0fe02 KW |
1175 | } |
1176 | ||
29c1a730 | 1177 | |
f7d0fe02 | 1178 | if (addend != 0) { |
c6e9d8ae HR |
1179 | ret = qcow2_update_cluster_refcount(bs, l2_offset >> |
1180 | s->cluster_bits, | |
2aabe7c7 | 1181 | abs(addend), addend < 0, |
c6e9d8ae HR |
1182 | QCOW2_DISCARD_SNAPSHOT); |
1183 | if (ret < 0) { | |
1184 | goto fail; | |
1185 | } | |
f7d0fe02 | 1186 | } |
7324c10f HR |
1187 | ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, |
1188 | &refcount); | |
1189 | if (ret < 0) { | |
018faafd KW |
1190 | goto fail; |
1191 | } else if (refcount == 1) { | |
f7d0fe02 KW |
1192 | l2_offset |= QCOW_OFLAG_COPIED; |
1193 | } | |
1194 | if (l2_offset != old_l2_offset) { | |
1195 | l1_table[i] = l2_offset; | |
1196 | l1_modified = 1; | |
1197 | } | |
1198 | } | |
1199 | } | |
93913dfd | 1200 | |
2154f24e | 1201 | ret = bdrv_flush(bs); |
93913dfd KW |
1202 | fail: |
1203 | if (l2_table) { | |
1204 | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); | |
1205 | } | |
1206 | ||
0b919fae KW |
1207 | s->cache_discards = false; |
1208 | qcow2_process_discards(bs, ret); | |
1209 | ||
43a0cac4 | 1210 | /* Update L1 only if it isn't deleted anyway (addend = -1) */ |
c2b6ff51 KW |
1211 | if (ret == 0 && addend >= 0 && l1_modified) { |
1212 | for (i = 0; i < l1_size; i++) { | |
f7d0fe02 | 1213 | cpu_to_be64s(&l1_table[i]); |
c2b6ff51 KW |
1214 | } |
1215 | ||
1216 | ret = bdrv_pwrite_sync(bs->file, l1_table_offset, l1_table, l1_size2); | |
1217 | ||
1218 | for (i = 0; i < l1_size; i++) { | |
f7d0fe02 | 1219 | be64_to_cpus(&l1_table[i]); |
c2b6ff51 | 1220 | } |
f7d0fe02 KW |
1221 | } |
1222 | if (l1_allocated) | |
7267c094 | 1223 | g_free(l1_table); |
93913dfd | 1224 | return ret; |
f7d0fe02 KW |
1225 | } |
1226 | ||
1227 | ||
1228 | ||
1229 | ||
1230 | /*********************************************************/ | |
1231 | /* refcount checking functions */ | |
1232 | ||
1233 | ||
5fee192e HR |
1234 | static size_t refcount_array_byte_size(BDRVQcowState *s, uint64_t entries) |
1235 | { | |
1236 | /* This assertion holds because there is no way we can address more than | |
1237 | * 2^(64 - 9) clusters at once (with cluster size 512 = 2^9, and because | |
1238 | * offsets have to be representable in bytes); due to every cluster | |
1239 | * corresponding to one refcount entry, we are well below that limit */ | |
1240 | assert(entries < (UINT64_C(1) << (64 - 9))); | |
1241 | ||
1242 | /* Thanks to the assertion this will not overflow, because | |
1243 | * s->refcount_order < 7. | |
1244 | * (note: x << s->refcount_order == x * s->refcount_bits) */ | |
1245 | return DIV_ROUND_UP(entries << s->refcount_order, 8); | |
1246 | } | |
1247 | ||
1248 | /** | |
1249 | * Reallocates *array so that it can hold new_size entries. *size must contain | |
1250 | * the current number of entries in *array. If the reallocation fails, *array | |
1251 | * and *size will not be modified and -errno will be returned. If the | |
1252 | * reallocation is successful, *array will be set to the new buffer, *size | |
1253 | * will be set to new_size and 0 will be returned. The size of the reallocated | |
1254 | * refcount array buffer will be aligned to a cluster boundary, and the newly | |
1255 | * allocated area will be zeroed. | |
1256 | */ | |
7453c96b | 1257 | static int realloc_refcount_array(BDRVQcowState *s, void **array, |
5fee192e HR |
1258 | int64_t *size, int64_t new_size) |
1259 | { | |
1260 | size_t old_byte_size, new_byte_size; | |
7453c96b | 1261 | void *new_ptr; |
5fee192e HR |
1262 | |
1263 | /* Round to clusters so the array can be directly written to disk */ | |
1264 | old_byte_size = size_to_clusters(s, refcount_array_byte_size(s, *size)) | |
1265 | * s->cluster_size; | |
1266 | new_byte_size = size_to_clusters(s, refcount_array_byte_size(s, new_size)) | |
1267 | * s->cluster_size; | |
1268 | ||
1269 | if (new_byte_size == old_byte_size) { | |
1270 | *size = new_size; | |
1271 | return 0; | |
1272 | } | |
1273 | ||
1274 | assert(new_byte_size > 0); | |
1275 | ||
1276 | new_ptr = g_try_realloc(*array, new_byte_size); | |
1277 | if (!new_ptr) { | |
1278 | return -ENOMEM; | |
1279 | } | |
1280 | ||
1281 | if (new_byte_size > old_byte_size) { | |
1282 | memset((void *)((uintptr_t)new_ptr + old_byte_size), 0, | |
1283 | new_byte_size - old_byte_size); | |
1284 | } | |
1285 | ||
1286 | *array = new_ptr; | |
1287 | *size = new_size; | |
1288 | ||
1289 | return 0; | |
1290 | } | |
f7d0fe02 KW |
1291 | |
1292 | /* | |
1293 | * Increases the refcount for a range of clusters in a given refcount table. | |
1294 | * This is used to construct a temporary refcount table out of L1 and L2 tables | |
1295 | * which can be compared the the refcount table saved in the image. | |
1296 | * | |
9ac228e0 | 1297 | * Modifies the number of errors in res. |
f7d0fe02 | 1298 | */ |
fef4d3d5 HR |
1299 | static int inc_refcounts(BlockDriverState *bs, |
1300 | BdrvCheckResult *res, | |
7453c96b | 1301 | void **refcount_table, |
641bb63c | 1302 | int64_t *refcount_table_size, |
fef4d3d5 | 1303 | int64_t offset, int64_t size) |
f7d0fe02 KW |
1304 | { |
1305 | BDRVQcowState *s = bs->opaque; | |
7453c96b | 1306 | uint64_t start, last, cluster_offset, k, refcount; |
5fee192e | 1307 | int ret; |
f7d0fe02 | 1308 | |
fef4d3d5 HR |
1309 | if (size <= 0) { |
1310 | return 0; | |
1311 | } | |
f7d0fe02 | 1312 | |
ac95acdb HT |
1313 | start = start_of_cluster(s, offset); |
1314 | last = start_of_cluster(s, offset + size - 1); | |
f7d0fe02 KW |
1315 | for(cluster_offset = start; cluster_offset <= last; |
1316 | cluster_offset += s->cluster_size) { | |
1317 | k = cluster_offset >> s->cluster_bits; | |
641bb63c | 1318 | if (k >= *refcount_table_size) { |
5fee192e HR |
1319 | ret = realloc_refcount_array(s, refcount_table, |
1320 | refcount_table_size, k + 1); | |
1321 | if (ret < 0) { | |
641bb63c | 1322 | res->check_errors++; |
5fee192e | 1323 | return ret; |
f7d0fe02 | 1324 | } |
641bb63c HR |
1325 | } |
1326 | ||
7453c96b HR |
1327 | refcount = s->get_refcount(*refcount_table, k); |
1328 | if (refcount == s->refcount_max) { | |
641bb63c HR |
1329 | fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64 |
1330 | "\n", cluster_offset); | |
1331 | res->corruptions++; | |
7453c96b | 1332 | continue; |
f7d0fe02 | 1333 | } |
7453c96b | 1334 | s->set_refcount(*refcount_table, k, refcount + 1); |
f7d0fe02 | 1335 | } |
fef4d3d5 HR |
1336 | |
1337 | return 0; | |
f7d0fe02 KW |
1338 | } |
1339 | ||
801f7044 SH |
1340 | /* Flags for check_refcounts_l1() and check_refcounts_l2() */ |
1341 | enum { | |
fba31bae | 1342 | CHECK_FRAG_INFO = 0x2, /* update BlockFragInfo counters */ |
801f7044 SH |
1343 | }; |
1344 | ||
f7d0fe02 KW |
1345 | /* |
1346 | * Increases the refcount in the given refcount table for the all clusters | |
1347 | * referenced in the L2 table. While doing so, performs some checks on L2 | |
1348 | * entries. | |
1349 | * | |
1350 | * Returns the number of errors found by the checks or -errno if an internal | |
1351 | * error occurred. | |
1352 | */ | |
9ac228e0 | 1353 | static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, |
7453c96b HR |
1354 | void **refcount_table, |
1355 | int64_t *refcount_table_size, int64_t l2_offset, | |
1356 | int flags) | |
f7d0fe02 KW |
1357 | { |
1358 | BDRVQcowState *s = bs->opaque; | |
afdf0abe | 1359 | uint64_t *l2_table, l2_entry; |
fba31bae | 1360 | uint64_t next_contiguous_offset = 0; |
ad27390c | 1361 | int i, l2_size, nb_csectors, ret; |
f7d0fe02 KW |
1362 | |
1363 | /* Read L2 table from disk */ | |
1364 | l2_size = s->l2_size * sizeof(uint64_t); | |
7267c094 | 1365 | l2_table = g_malloc(l2_size); |
f7d0fe02 | 1366 | |
ad27390c HR |
1367 | ret = bdrv_pread(bs->file, l2_offset, l2_table, l2_size); |
1368 | if (ret < 0) { | |
1369 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l2\n"); | |
1370 | res->check_errors++; | |
f7d0fe02 | 1371 | goto fail; |
ad27390c | 1372 | } |
f7d0fe02 KW |
1373 | |
1374 | /* Do the actual checks */ | |
1375 | for(i = 0; i < s->l2_size; i++) { | |
afdf0abe KW |
1376 | l2_entry = be64_to_cpu(l2_table[i]); |
1377 | ||
1378 | switch (qcow2_get_cluster_type(l2_entry)) { | |
1379 | case QCOW2_CLUSTER_COMPRESSED: | |
1380 | /* Compressed clusters don't have QCOW_OFLAG_COPIED */ | |
1381 | if (l2_entry & QCOW_OFLAG_COPIED) { | |
1382 | fprintf(stderr, "ERROR: cluster %" PRId64 ": " | |
1383 | "copied flag must never be set for compressed " | |
1384 | "clusters\n", l2_entry >> s->cluster_bits); | |
1385 | l2_entry &= ~QCOW_OFLAG_COPIED; | |
1386 | res->corruptions++; | |
1387 | } | |
f7d0fe02 | 1388 | |
afdf0abe KW |
1389 | /* Mark cluster as used */ |
1390 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
1391 | s->csize_mask) + 1; | |
1392 | l2_entry &= s->cluster_offset_mask; | |
fef4d3d5 HR |
1393 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1394 | l2_entry & ~511, nb_csectors * 512); | |
1395 | if (ret < 0) { | |
1396 | goto fail; | |
1397 | } | |
fba31bae SH |
1398 | |
1399 | if (flags & CHECK_FRAG_INFO) { | |
1400 | res->bfi.allocated_clusters++; | |
4db35162 | 1401 | res->bfi.compressed_clusters++; |
fba31bae SH |
1402 | |
1403 | /* Compressed clusters are fragmented by nature. Since they | |
1404 | * take up sub-sector space but we only have sector granularity | |
1405 | * I/O we need to re-read the same sectors even for adjacent | |
1406 | * compressed clusters. | |
1407 | */ | |
1408 | res->bfi.fragmented_clusters++; | |
1409 | } | |
afdf0abe | 1410 | break; |
f7d0fe02 | 1411 | |
6377af48 KW |
1412 | case QCOW2_CLUSTER_ZERO: |
1413 | if ((l2_entry & L2E_OFFSET_MASK) == 0) { | |
1414 | break; | |
1415 | } | |
1416 | /* fall through */ | |
1417 | ||
afdf0abe KW |
1418 | case QCOW2_CLUSTER_NORMAL: |
1419 | { | |
afdf0abe | 1420 | uint64_t offset = l2_entry & L2E_OFFSET_MASK; |
f7d0fe02 | 1421 | |
fba31bae SH |
1422 | if (flags & CHECK_FRAG_INFO) { |
1423 | res->bfi.allocated_clusters++; | |
1424 | if (next_contiguous_offset && | |
1425 | offset != next_contiguous_offset) { | |
1426 | res->bfi.fragmented_clusters++; | |
1427 | } | |
1428 | next_contiguous_offset = offset + s->cluster_size; | |
1429 | } | |
1430 | ||
afdf0abe | 1431 | /* Mark cluster as used */ |
fef4d3d5 HR |
1432 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1433 | offset, s->cluster_size); | |
1434 | if (ret < 0) { | |
1435 | goto fail; | |
1436 | } | |
afdf0abe KW |
1437 | |
1438 | /* Correct offsets are cluster aligned */ | |
ac95acdb | 1439 | if (offset_into_cluster(s, offset)) { |
afdf0abe KW |
1440 | fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " |
1441 | "properly aligned; L2 entry corrupted.\n", offset); | |
1442 | res->corruptions++; | |
1443 | } | |
1444 | break; | |
1445 | } | |
1446 | ||
1447 | case QCOW2_CLUSTER_UNALLOCATED: | |
1448 | break; | |
1449 | ||
1450 | default: | |
1451 | abort(); | |
f7d0fe02 KW |
1452 | } |
1453 | } | |
1454 | ||
7267c094 | 1455 | g_free(l2_table); |
9ac228e0 | 1456 | return 0; |
f7d0fe02 KW |
1457 | |
1458 | fail: | |
7267c094 | 1459 | g_free(l2_table); |
ad27390c | 1460 | return ret; |
f7d0fe02 KW |
1461 | } |
1462 | ||
1463 | /* | |
1464 | * Increases the refcount for the L1 table, its L2 tables and all referenced | |
1465 | * clusters in the given refcount table. While doing so, performs some checks | |
1466 | * on L1 and L2 entries. | |
1467 | * | |
1468 | * Returns the number of errors found by the checks or -errno if an internal | |
1469 | * error occurred. | |
1470 | */ | |
1471 | static int check_refcounts_l1(BlockDriverState *bs, | |
9ac228e0 | 1472 | BdrvCheckResult *res, |
7453c96b | 1473 | void **refcount_table, |
641bb63c | 1474 | int64_t *refcount_table_size, |
f7d0fe02 | 1475 | int64_t l1_table_offset, int l1_size, |
801f7044 | 1476 | int flags) |
f7d0fe02 KW |
1477 | { |
1478 | BDRVQcowState *s = bs->opaque; | |
fef4d3d5 | 1479 | uint64_t *l1_table = NULL, l2_offset, l1_size2; |
4f6ed88c | 1480 | int i, ret; |
f7d0fe02 KW |
1481 | |
1482 | l1_size2 = l1_size * sizeof(uint64_t); | |
1483 | ||
1484 | /* Mark L1 table as used */ | |
fef4d3d5 HR |
1485 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1486 | l1_table_offset, l1_size2); | |
1487 | if (ret < 0) { | |
1488 | goto fail; | |
1489 | } | |
f7d0fe02 KW |
1490 | |
1491 | /* Read L1 table entries from disk */ | |
fef4d3d5 | 1492 | if (l1_size2 > 0) { |
de82815d KW |
1493 | l1_table = g_try_malloc(l1_size2); |
1494 | if (l1_table == NULL) { | |
1495 | ret = -ENOMEM; | |
ad27390c | 1496 | res->check_errors++; |
de82815d KW |
1497 | goto fail; |
1498 | } | |
ad27390c HR |
1499 | ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2); |
1500 | if (ret < 0) { | |
1501 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); | |
1502 | res->check_errors++; | |
702ef63f | 1503 | goto fail; |
ad27390c | 1504 | } |
702ef63f KW |
1505 | for(i = 0;i < l1_size; i++) |
1506 | be64_to_cpus(&l1_table[i]); | |
1507 | } | |
f7d0fe02 KW |
1508 | |
1509 | /* Do the actual checks */ | |
1510 | for(i = 0; i < l1_size; i++) { | |
1511 | l2_offset = l1_table[i]; | |
1512 | if (l2_offset) { | |
f7d0fe02 | 1513 | /* Mark L2 table as used */ |
afdf0abe | 1514 | l2_offset &= L1E_OFFSET_MASK; |
fef4d3d5 HR |
1515 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1516 | l2_offset, s->cluster_size); | |
1517 | if (ret < 0) { | |
1518 | goto fail; | |
1519 | } | |
f7d0fe02 KW |
1520 | |
1521 | /* L2 tables are cluster aligned */ | |
ac95acdb | 1522 | if (offset_into_cluster(s, l2_offset)) { |
f7d0fe02 KW |
1523 | fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " |
1524 | "cluster aligned; L1 entry corrupted\n", l2_offset); | |
9ac228e0 | 1525 | res->corruptions++; |
f7d0fe02 KW |
1526 | } |
1527 | ||
1528 | /* Process and check L2 entries */ | |
9ac228e0 | 1529 | ret = check_refcounts_l2(bs, res, refcount_table, |
801f7044 | 1530 | refcount_table_size, l2_offset, flags); |
f7d0fe02 KW |
1531 | if (ret < 0) { |
1532 | goto fail; | |
1533 | } | |
f7d0fe02 KW |
1534 | } |
1535 | } | |
7267c094 | 1536 | g_free(l1_table); |
9ac228e0 | 1537 | return 0; |
f7d0fe02 KW |
1538 | |
1539 | fail: | |
7267c094 | 1540 | g_free(l1_table); |
ad27390c | 1541 | return ret; |
f7d0fe02 KW |
1542 | } |
1543 | ||
4f6ed88c HR |
1544 | /* |
1545 | * Checks the OFLAG_COPIED flag for all L1 and L2 entries. | |
1546 | * | |
1547 | * This function does not print an error message nor does it increment | |
44751917 HR |
1548 | * check_errors if qcow2_get_refcount fails (this is because such an error will |
1549 | * have been already detected and sufficiently signaled by the calling function | |
4f6ed88c HR |
1550 | * (qcow2_check_refcounts) by the time this function is called). |
1551 | */ | |
e23e400e HR |
1552 | static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res, |
1553 | BdrvCheckMode fix) | |
4f6ed88c HR |
1554 | { |
1555 | BDRVQcowState *s = bs->opaque; | |
1556 | uint64_t *l2_table = qemu_blockalign(bs, s->cluster_size); | |
1557 | int ret; | |
0e06528e | 1558 | uint64_t refcount; |
4f6ed88c HR |
1559 | int i, j; |
1560 | ||
1561 | for (i = 0; i < s->l1_size; i++) { | |
1562 | uint64_t l1_entry = s->l1_table[i]; | |
1563 | uint64_t l2_offset = l1_entry & L1E_OFFSET_MASK; | |
e23e400e | 1564 | bool l2_dirty = false; |
4f6ed88c HR |
1565 | |
1566 | if (!l2_offset) { | |
1567 | continue; | |
1568 | } | |
1569 | ||
7324c10f HR |
1570 | ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, |
1571 | &refcount); | |
1572 | if (ret < 0) { | |
4f6ed88c HR |
1573 | /* don't print message nor increment check_errors */ |
1574 | continue; | |
1575 | } | |
1576 | if ((refcount == 1) != ((l1_entry & QCOW_OFLAG_COPIED) != 0)) { | |
e23e400e | 1577 | fprintf(stderr, "%s OFLAG_COPIED L2 cluster: l1_index=%d " |
0e06528e | 1578 | "l1_entry=%" PRIx64 " refcount=%" PRIu64 "\n", |
e23e400e HR |
1579 | fix & BDRV_FIX_ERRORS ? "Repairing" : |
1580 | "ERROR", | |
4f6ed88c | 1581 | i, l1_entry, refcount); |
e23e400e HR |
1582 | if (fix & BDRV_FIX_ERRORS) { |
1583 | s->l1_table[i] = refcount == 1 | |
1584 | ? l1_entry | QCOW_OFLAG_COPIED | |
1585 | : l1_entry & ~QCOW_OFLAG_COPIED; | |
1586 | ret = qcow2_write_l1_entry(bs, i); | |
1587 | if (ret < 0) { | |
1588 | res->check_errors++; | |
1589 | goto fail; | |
1590 | } | |
1591 | res->corruptions_fixed++; | |
1592 | } else { | |
1593 | res->corruptions++; | |
1594 | } | |
4f6ed88c HR |
1595 | } |
1596 | ||
1597 | ret = bdrv_pread(bs->file, l2_offset, l2_table, | |
1598 | s->l2_size * sizeof(uint64_t)); | |
1599 | if (ret < 0) { | |
1600 | fprintf(stderr, "ERROR: Could not read L2 table: %s\n", | |
1601 | strerror(-ret)); | |
1602 | res->check_errors++; | |
1603 | goto fail; | |
1604 | } | |
1605 | ||
1606 | for (j = 0; j < s->l2_size; j++) { | |
1607 | uint64_t l2_entry = be64_to_cpu(l2_table[j]); | |
1608 | uint64_t data_offset = l2_entry & L2E_OFFSET_MASK; | |
1609 | int cluster_type = qcow2_get_cluster_type(l2_entry); | |
1610 | ||
1611 | if ((cluster_type == QCOW2_CLUSTER_NORMAL) || | |
1612 | ((cluster_type == QCOW2_CLUSTER_ZERO) && (data_offset != 0))) { | |
7324c10f HR |
1613 | ret = qcow2_get_refcount(bs, |
1614 | data_offset >> s->cluster_bits, | |
1615 | &refcount); | |
1616 | if (ret < 0) { | |
4f6ed88c HR |
1617 | /* don't print message nor increment check_errors */ |
1618 | continue; | |
1619 | } | |
1620 | if ((refcount == 1) != ((l2_entry & QCOW_OFLAG_COPIED) != 0)) { | |
e23e400e | 1621 | fprintf(stderr, "%s OFLAG_COPIED data cluster: " |
0e06528e | 1622 | "l2_entry=%" PRIx64 " refcount=%" PRIu64 "\n", |
e23e400e HR |
1623 | fix & BDRV_FIX_ERRORS ? "Repairing" : |
1624 | "ERROR", | |
4f6ed88c | 1625 | l2_entry, refcount); |
e23e400e HR |
1626 | if (fix & BDRV_FIX_ERRORS) { |
1627 | l2_table[j] = cpu_to_be64(refcount == 1 | |
1628 | ? l2_entry | QCOW_OFLAG_COPIED | |
1629 | : l2_entry & ~QCOW_OFLAG_COPIED); | |
1630 | l2_dirty = true; | |
1631 | res->corruptions_fixed++; | |
1632 | } else { | |
1633 | res->corruptions++; | |
1634 | } | |
4f6ed88c HR |
1635 | } |
1636 | } | |
1637 | } | |
e23e400e HR |
1638 | |
1639 | if (l2_dirty) { | |
231bb267 HR |
1640 | ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L2, |
1641 | l2_offset, s->cluster_size); | |
e23e400e HR |
1642 | if (ret < 0) { |
1643 | fprintf(stderr, "ERROR: Could not write L2 table; metadata " | |
1644 | "overlap check failed: %s\n", strerror(-ret)); | |
1645 | res->check_errors++; | |
1646 | goto fail; | |
1647 | } | |
1648 | ||
1649 | ret = bdrv_pwrite(bs->file, l2_offset, l2_table, s->cluster_size); | |
1650 | if (ret < 0) { | |
1651 | fprintf(stderr, "ERROR: Could not write L2 table: %s\n", | |
1652 | strerror(-ret)); | |
1653 | res->check_errors++; | |
1654 | goto fail; | |
1655 | } | |
1656 | } | |
4f6ed88c HR |
1657 | } |
1658 | ||
1659 | ret = 0; | |
1660 | ||
1661 | fail: | |
1662 | qemu_vfree(l2_table); | |
1663 | return ret; | |
1664 | } | |
1665 | ||
6ca56bf5 HR |
1666 | /* |
1667 | * Checks consistency of refblocks and accounts for each refblock in | |
1668 | * *refcount_table. | |
1669 | */ | |
1670 | static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 | 1671 | BdrvCheckMode fix, bool *rebuild, |
7453c96b | 1672 | void **refcount_table, int64_t *nb_clusters) |
6ca56bf5 HR |
1673 | { |
1674 | BDRVQcowState *s = bs->opaque; | |
001c158d | 1675 | int64_t i, size; |
fef4d3d5 | 1676 | int ret; |
6ca56bf5 | 1677 | |
f7d0fe02 | 1678 | for(i = 0; i < s->refcount_table_size; i++) { |
6882c8fa | 1679 | uint64_t offset, cluster; |
f7d0fe02 | 1680 | offset = s->refcount_table[i]; |
6882c8fa | 1681 | cluster = offset >> s->cluster_bits; |
746c3cb5 KW |
1682 | |
1683 | /* Refcount blocks are cluster aligned */ | |
ac95acdb | 1684 | if (offset_into_cluster(s, offset)) { |
166acf54 | 1685 | fprintf(stderr, "ERROR refcount block %" PRId64 " is not " |
746c3cb5 | 1686 | "cluster aligned; refcount table entry corrupted\n", i); |
9ac228e0 | 1687 | res->corruptions++; |
f307b255 | 1688 | *rebuild = true; |
6882c8fa KW |
1689 | continue; |
1690 | } | |
1691 | ||
6ca56bf5 | 1692 | if (cluster >= *nb_clusters) { |
001c158d HR |
1693 | fprintf(stderr, "%s refcount block %" PRId64 " is outside image\n", |
1694 | fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i); | |
1695 | ||
1696 | if (fix & BDRV_FIX_ERRORS) { | |
5fee192e | 1697 | int64_t new_nb_clusters; |
001c158d HR |
1698 | |
1699 | if (offset > INT64_MAX - s->cluster_size) { | |
1700 | ret = -EINVAL; | |
1701 | goto resize_fail; | |
1702 | } | |
1703 | ||
1704 | ret = bdrv_truncate(bs->file, offset + s->cluster_size); | |
1705 | if (ret < 0) { | |
1706 | goto resize_fail; | |
1707 | } | |
1708 | size = bdrv_getlength(bs->file); | |
1709 | if (size < 0) { | |
1710 | ret = size; | |
1711 | goto resize_fail; | |
1712 | } | |
1713 | ||
5fee192e HR |
1714 | new_nb_clusters = size_to_clusters(s, size); |
1715 | assert(new_nb_clusters >= *nb_clusters); | |
001c158d | 1716 | |
5fee192e HR |
1717 | ret = realloc_refcount_array(s, refcount_table, |
1718 | nb_clusters, new_nb_clusters); | |
1719 | if (ret < 0) { | |
001c158d | 1720 | res->check_errors++; |
5fee192e | 1721 | return ret; |
001c158d | 1722 | } |
001c158d HR |
1723 | |
1724 | if (cluster >= *nb_clusters) { | |
1725 | ret = -EINVAL; | |
1726 | goto resize_fail; | |
1727 | } | |
1728 | ||
1729 | res->corruptions_fixed++; | |
1730 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, | |
1731 | offset, s->cluster_size); | |
1732 | if (ret < 0) { | |
1733 | return ret; | |
1734 | } | |
1735 | /* No need to check whether the refcount is now greater than 1: | |
1736 | * This area was just allocated and zeroed, so it can only be | |
1737 | * exactly 1 after inc_refcounts() */ | |
1738 | continue; | |
1739 | ||
1740 | resize_fail: | |
1741 | res->corruptions++; | |
f307b255 | 1742 | *rebuild = true; |
001c158d HR |
1743 | fprintf(stderr, "ERROR could not resize image: %s\n", |
1744 | strerror(-ret)); | |
1745 | } else { | |
1746 | res->corruptions++; | |
1747 | } | |
6882c8fa | 1748 | continue; |
746c3cb5 KW |
1749 | } |
1750 | ||
f7d0fe02 | 1751 | if (offset != 0) { |
641bb63c | 1752 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1753 | offset, s->cluster_size); |
1754 | if (ret < 0) { | |
1755 | return ret; | |
1756 | } | |
7453c96b | 1757 | if (s->get_refcount(*refcount_table, cluster) != 1) { |
f307b255 | 1758 | fprintf(stderr, "ERROR refcount block %" PRId64 |
7453c96b HR |
1759 | " refcount=%" PRIu64 "\n", i, |
1760 | s->get_refcount(*refcount_table, cluster)); | |
f307b255 HR |
1761 | res->corruptions++; |
1762 | *rebuild = true; | |
746c3cb5 | 1763 | } |
f7d0fe02 KW |
1764 | } |
1765 | } | |
1766 | ||
6ca56bf5 HR |
1767 | return 0; |
1768 | } | |
1769 | ||
057a3fe5 HR |
1770 | /* |
1771 | * Calculates an in-memory refcount table. | |
1772 | */ | |
1773 | static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 | 1774 | BdrvCheckMode fix, bool *rebuild, |
7453c96b | 1775 | void **refcount_table, int64_t *nb_clusters) |
057a3fe5 HR |
1776 | { |
1777 | BDRVQcowState *s = bs->opaque; | |
1778 | int64_t i; | |
1779 | QCowSnapshot *sn; | |
1780 | int ret; | |
1781 | ||
9696df21 | 1782 | if (!*refcount_table) { |
5fee192e HR |
1783 | int64_t old_size = 0; |
1784 | ret = realloc_refcount_array(s, refcount_table, | |
1785 | &old_size, *nb_clusters); | |
1786 | if (ret < 0) { | |
9696df21 | 1787 | res->check_errors++; |
5fee192e | 1788 | return ret; |
9696df21 | 1789 | } |
057a3fe5 HR |
1790 | } |
1791 | ||
1792 | /* header */ | |
641bb63c | 1793 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1794 | 0, s->cluster_size); |
1795 | if (ret < 0) { | |
1796 | return ret; | |
1797 | } | |
057a3fe5 HR |
1798 | |
1799 | /* current L1 table */ | |
641bb63c | 1800 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
057a3fe5 HR |
1801 | s->l1_table_offset, s->l1_size, CHECK_FRAG_INFO); |
1802 | if (ret < 0) { | |
1803 | return ret; | |
1804 | } | |
1805 | ||
1806 | /* snapshots */ | |
1807 | for (i = 0; i < s->nb_snapshots; i++) { | |
1808 | sn = s->snapshots + i; | |
641bb63c | 1809 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
fef4d3d5 | 1810 | sn->l1_table_offset, sn->l1_size, 0); |
057a3fe5 HR |
1811 | if (ret < 0) { |
1812 | return ret; | |
1813 | } | |
1814 | } | |
641bb63c | 1815 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1816 | s->snapshots_offset, s->snapshots_size); |
1817 | if (ret < 0) { | |
1818 | return ret; | |
1819 | } | |
057a3fe5 HR |
1820 | |
1821 | /* refcount data */ | |
641bb63c | 1822 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1823 | s->refcount_table_offset, |
1824 | s->refcount_table_size * sizeof(uint64_t)); | |
1825 | if (ret < 0) { | |
1826 | return ret; | |
1827 | } | |
057a3fe5 | 1828 | |
f307b255 | 1829 | return check_refblocks(bs, res, fix, rebuild, refcount_table, nb_clusters); |
057a3fe5 HR |
1830 | } |
1831 | ||
6ca56bf5 HR |
1832 | /* |
1833 | * Compares the actual reference count for each cluster in the image against the | |
1834 | * refcount as reported by the refcount structures on-disk. | |
1835 | */ | |
1836 | static void compare_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 HR |
1837 | BdrvCheckMode fix, bool *rebuild, |
1838 | int64_t *highest_cluster, | |
7453c96b | 1839 | void *refcount_table, int64_t nb_clusters) |
6ca56bf5 HR |
1840 | { |
1841 | BDRVQcowState *s = bs->opaque; | |
1842 | int64_t i; | |
0e06528e | 1843 | uint64_t refcount1, refcount2; |
7324c10f | 1844 | int ret; |
6ca56bf5 HR |
1845 | |
1846 | for (i = 0, *highest_cluster = 0; i < nb_clusters; i++) { | |
7324c10f HR |
1847 | ret = qcow2_get_refcount(bs, i, &refcount1); |
1848 | if (ret < 0) { | |
166acf54 | 1849 | fprintf(stderr, "Can't get refcount for cluster %" PRId64 ": %s\n", |
7324c10f | 1850 | i, strerror(-ret)); |
9ac228e0 | 1851 | res->check_errors++; |
f74550fd | 1852 | continue; |
018faafd KW |
1853 | } |
1854 | ||
7453c96b | 1855 | refcount2 = s->get_refcount(refcount_table, i); |
c6bb9ad1 FS |
1856 | |
1857 | if (refcount1 > 0 || refcount2 > 0) { | |
6ca56bf5 | 1858 | *highest_cluster = i; |
c6bb9ad1 FS |
1859 | } |
1860 | ||
f7d0fe02 | 1861 | if (refcount1 != refcount2) { |
166acf54 KW |
1862 | /* Check if we're allowed to fix the mismatch */ |
1863 | int *num_fixed = NULL; | |
f307b255 HR |
1864 | if (refcount1 == 0) { |
1865 | *rebuild = true; | |
1866 | } else if (refcount1 > refcount2 && (fix & BDRV_FIX_LEAKS)) { | |
166acf54 KW |
1867 | num_fixed = &res->leaks_fixed; |
1868 | } else if (refcount1 < refcount2 && (fix & BDRV_FIX_ERRORS)) { | |
1869 | num_fixed = &res->corruptions_fixed; | |
1870 | } | |
1871 | ||
0e06528e HR |
1872 | fprintf(stderr, "%s cluster %" PRId64 " refcount=%" PRIu64 |
1873 | " reference=%" PRIu64 "\n", | |
166acf54 KW |
1874 | num_fixed != NULL ? "Repairing" : |
1875 | refcount1 < refcount2 ? "ERROR" : | |
1876 | "Leaked", | |
f7d0fe02 | 1877 | i, refcount1, refcount2); |
166acf54 KW |
1878 | |
1879 | if (num_fixed) { | |
1880 | ret = update_refcount(bs, i << s->cluster_bits, 1, | |
2aabe7c7 HR |
1881 | refcount_diff(refcount1, refcount2), |
1882 | refcount1 > refcount2, | |
6cfcb9b8 | 1883 | QCOW2_DISCARD_ALWAYS); |
166acf54 KW |
1884 | if (ret >= 0) { |
1885 | (*num_fixed)++; | |
1886 | continue; | |
1887 | } | |
1888 | } | |
1889 | ||
1890 | /* And if we couldn't, print an error */ | |
9ac228e0 KW |
1891 | if (refcount1 < refcount2) { |
1892 | res->corruptions++; | |
1893 | } else { | |
1894 | res->leaks++; | |
1895 | } | |
f7d0fe02 KW |
1896 | } |
1897 | } | |
6ca56bf5 HR |
1898 | } |
1899 | ||
c7c0681b HR |
1900 | /* |
1901 | * Allocates clusters using an in-memory refcount table (IMRT) in contrast to | |
1902 | * the on-disk refcount structures. | |
1903 | * | |
1904 | * On input, *first_free_cluster tells where to start looking, and need not | |
1905 | * actually be a free cluster; the returned offset will not be before that | |
1906 | * cluster. On output, *first_free_cluster points to the first gap found, even | |
1907 | * if that gap was too small to be used as the returned offset. | |
1908 | * | |
1909 | * Note that *first_free_cluster is a cluster index whereas the return value is | |
1910 | * an offset. | |
1911 | */ | |
1912 | static int64_t alloc_clusters_imrt(BlockDriverState *bs, | |
1913 | int cluster_count, | |
7453c96b | 1914 | void **refcount_table, |
c7c0681b HR |
1915 | int64_t *imrt_nb_clusters, |
1916 | int64_t *first_free_cluster) | |
1917 | { | |
1918 | BDRVQcowState *s = bs->opaque; | |
1919 | int64_t cluster = *first_free_cluster, i; | |
1920 | bool first_gap = true; | |
1921 | int contiguous_free_clusters; | |
5fee192e | 1922 | int ret; |
c7c0681b HR |
1923 | |
1924 | /* Starting at *first_free_cluster, find a range of at least cluster_count | |
1925 | * continuously free clusters */ | |
1926 | for (contiguous_free_clusters = 0; | |
1927 | cluster < *imrt_nb_clusters && | |
1928 | contiguous_free_clusters < cluster_count; | |
1929 | cluster++) | |
1930 | { | |
7453c96b | 1931 | if (!s->get_refcount(*refcount_table, cluster)) { |
c7c0681b HR |
1932 | contiguous_free_clusters++; |
1933 | if (first_gap) { | |
1934 | /* If this is the first free cluster found, update | |
1935 | * *first_free_cluster accordingly */ | |
1936 | *first_free_cluster = cluster; | |
1937 | first_gap = false; | |
1938 | } | |
1939 | } else if (contiguous_free_clusters) { | |
1940 | contiguous_free_clusters = 0; | |
1941 | } | |
1942 | } | |
1943 | ||
1944 | /* If contiguous_free_clusters is greater than zero, it contains the number | |
1945 | * of continuously free clusters until the current cluster; the first free | |
1946 | * cluster in the current "gap" is therefore | |
1947 | * cluster - contiguous_free_clusters */ | |
1948 | ||
1949 | /* If no such range could be found, grow the in-memory refcount table | |
1950 | * accordingly to append free clusters at the end of the image */ | |
1951 | if (contiguous_free_clusters < cluster_count) { | |
c7c0681b HR |
1952 | /* contiguous_free_clusters clusters are already empty at the image end; |
1953 | * we need cluster_count clusters; therefore, we have to allocate | |
1954 | * cluster_count - contiguous_free_clusters new clusters at the end of | |
1955 | * the image (which is the current value of cluster; note that cluster | |
1956 | * may exceed old_imrt_nb_clusters if *first_free_cluster pointed beyond | |
1957 | * the image end) */ | |
5fee192e HR |
1958 | ret = realloc_refcount_array(s, refcount_table, imrt_nb_clusters, |
1959 | cluster + cluster_count | |
1960 | - contiguous_free_clusters); | |
1961 | if (ret < 0) { | |
1962 | return ret; | |
c7c0681b | 1963 | } |
c7c0681b HR |
1964 | } |
1965 | ||
1966 | /* Go back to the first free cluster */ | |
1967 | cluster -= contiguous_free_clusters; | |
1968 | for (i = 0; i < cluster_count; i++) { | |
7453c96b | 1969 | s->set_refcount(*refcount_table, cluster + i, 1); |
c7c0681b HR |
1970 | } |
1971 | ||
1972 | return cluster << s->cluster_bits; | |
1973 | } | |
1974 | ||
1975 | /* | |
1976 | * Creates a new refcount structure based solely on the in-memory information | |
1977 | * given through *refcount_table. All necessary allocations will be reflected | |
1978 | * in that array. | |
1979 | * | |
1980 | * On success, the old refcount structure is leaked (it will be covered by the | |
1981 | * new refcount structure). | |
1982 | */ | |
1983 | static int rebuild_refcount_structure(BlockDriverState *bs, | |
1984 | BdrvCheckResult *res, | |
7453c96b | 1985 | void **refcount_table, |
c7c0681b HR |
1986 | int64_t *nb_clusters) |
1987 | { | |
1988 | BDRVQcowState *s = bs->opaque; | |
1989 | int64_t first_free_cluster = 0, reftable_offset = -1, cluster = 0; | |
1990 | int64_t refblock_offset, refblock_start, refblock_index; | |
1991 | uint32_t reftable_size = 0; | |
1992 | uint64_t *on_disk_reftable = NULL; | |
7453c96b HR |
1993 | void *on_disk_refblock; |
1994 | int ret = 0; | |
c7c0681b HR |
1995 | struct { |
1996 | uint64_t reftable_offset; | |
1997 | uint32_t reftable_clusters; | |
1998 | } QEMU_PACKED reftable_offset_and_clusters; | |
1999 | ||
2000 | qcow2_cache_empty(bs, s->refcount_block_cache); | |
2001 | ||
2002 | write_refblocks: | |
2003 | for (; cluster < *nb_clusters; cluster++) { | |
7453c96b | 2004 | if (!s->get_refcount(*refcount_table, cluster)) { |
c7c0681b HR |
2005 | continue; |
2006 | } | |
2007 | ||
2008 | refblock_index = cluster >> s->refcount_block_bits; | |
2009 | refblock_start = refblock_index << s->refcount_block_bits; | |
2010 | ||
2011 | /* Don't allocate a cluster in a refblock already written to disk */ | |
2012 | if (first_free_cluster < refblock_start) { | |
2013 | first_free_cluster = refblock_start; | |
2014 | } | |
2015 | refblock_offset = alloc_clusters_imrt(bs, 1, refcount_table, | |
2016 | nb_clusters, &first_free_cluster); | |
2017 | if (refblock_offset < 0) { | |
2018 | fprintf(stderr, "ERROR allocating refblock: %s\n", | |
2019 | strerror(-refblock_offset)); | |
2020 | res->check_errors++; | |
2021 | ret = refblock_offset; | |
2022 | goto fail; | |
2023 | } | |
2024 | ||
2025 | if (reftable_size <= refblock_index) { | |
2026 | uint32_t old_reftable_size = reftable_size; | |
2027 | uint64_t *new_on_disk_reftable; | |
2028 | ||
2029 | reftable_size = ROUND_UP((refblock_index + 1) * sizeof(uint64_t), | |
2030 | s->cluster_size) / sizeof(uint64_t); | |
2031 | new_on_disk_reftable = g_try_realloc(on_disk_reftable, | |
2032 | reftable_size * | |
2033 | sizeof(uint64_t)); | |
2034 | if (!new_on_disk_reftable) { | |
2035 | res->check_errors++; | |
2036 | ret = -ENOMEM; | |
2037 | goto fail; | |
2038 | } | |
2039 | on_disk_reftable = new_on_disk_reftable; | |
2040 | ||
2041 | memset(on_disk_reftable + old_reftable_size, 0, | |
2042 | (reftable_size - old_reftable_size) * sizeof(uint64_t)); | |
2043 | ||
2044 | /* The offset we have for the reftable is now no longer valid; | |
2045 | * this will leak that range, but we can easily fix that by running | |
2046 | * a leak-fixing check after this rebuild operation */ | |
2047 | reftable_offset = -1; | |
2048 | } | |
2049 | on_disk_reftable[refblock_index] = refblock_offset; | |
2050 | ||
2051 | /* If this is apparently the last refblock (for now), try to squeeze the | |
2052 | * reftable in */ | |
2053 | if (refblock_index == (*nb_clusters - 1) >> s->refcount_block_bits && | |
2054 | reftable_offset < 0) | |
2055 | { | |
2056 | uint64_t reftable_clusters = size_to_clusters(s, reftable_size * | |
2057 | sizeof(uint64_t)); | |
2058 | reftable_offset = alloc_clusters_imrt(bs, reftable_clusters, | |
2059 | refcount_table, nb_clusters, | |
2060 | &first_free_cluster); | |
2061 | if (reftable_offset < 0) { | |
2062 | fprintf(stderr, "ERROR allocating reftable: %s\n", | |
2063 | strerror(-reftable_offset)); | |
2064 | res->check_errors++; | |
2065 | ret = reftable_offset; | |
2066 | goto fail; | |
2067 | } | |
2068 | } | |
2069 | ||
2070 | ret = qcow2_pre_write_overlap_check(bs, 0, refblock_offset, | |
2071 | s->cluster_size); | |
2072 | if (ret < 0) { | |
2073 | fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret)); | |
2074 | goto fail; | |
2075 | } | |
2076 | ||
7453c96b HR |
2077 | /* The size of *refcount_table is always cluster-aligned, therefore the |
2078 | * write operation will not overflow */ | |
2079 | on_disk_refblock = (void *)((char *) *refcount_table + | |
2080 | refblock_index * s->cluster_size); | |
c7c0681b HR |
2081 | |
2082 | ret = bdrv_write(bs->file, refblock_offset / BDRV_SECTOR_SIZE, | |
7453c96b | 2083 | on_disk_refblock, s->cluster_sectors); |
c7c0681b HR |
2084 | if (ret < 0) { |
2085 | fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret)); | |
2086 | goto fail; | |
2087 | } | |
2088 | ||
2089 | /* Go to the end of this refblock */ | |
2090 | cluster = refblock_start + s->refcount_block_size - 1; | |
2091 | } | |
2092 | ||
2093 | if (reftable_offset < 0) { | |
2094 | uint64_t post_refblock_start, reftable_clusters; | |
2095 | ||
2096 | post_refblock_start = ROUND_UP(*nb_clusters, s->refcount_block_size); | |
2097 | reftable_clusters = size_to_clusters(s, | |
2098 | reftable_size * sizeof(uint64_t)); | |
2099 | /* Not pretty but simple */ | |
2100 | if (first_free_cluster < post_refblock_start) { | |
2101 | first_free_cluster = post_refblock_start; | |
2102 | } | |
2103 | reftable_offset = alloc_clusters_imrt(bs, reftable_clusters, | |
2104 | refcount_table, nb_clusters, | |
2105 | &first_free_cluster); | |
2106 | if (reftable_offset < 0) { | |
2107 | fprintf(stderr, "ERROR allocating reftable: %s\n", | |
2108 | strerror(-reftable_offset)); | |
2109 | res->check_errors++; | |
2110 | ret = reftable_offset; | |
2111 | goto fail; | |
2112 | } | |
2113 | ||
2114 | goto write_refblocks; | |
2115 | } | |
2116 | ||
2117 | assert(on_disk_reftable); | |
2118 | ||
2119 | for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) { | |
2120 | cpu_to_be64s(&on_disk_reftable[refblock_index]); | |
2121 | } | |
2122 | ||
2123 | ret = qcow2_pre_write_overlap_check(bs, 0, reftable_offset, | |
2124 | reftable_size * sizeof(uint64_t)); | |
2125 | if (ret < 0) { | |
2126 | fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret)); | |
2127 | goto fail; | |
2128 | } | |
2129 | ||
2130 | assert(reftable_size < INT_MAX / sizeof(uint64_t)); | |
2131 | ret = bdrv_pwrite(bs->file, reftable_offset, on_disk_reftable, | |
2132 | reftable_size * sizeof(uint64_t)); | |
2133 | if (ret < 0) { | |
2134 | fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret)); | |
2135 | goto fail; | |
2136 | } | |
2137 | ||
2138 | /* Enter new reftable into the image header */ | |
2139 | cpu_to_be64w(&reftable_offset_and_clusters.reftable_offset, | |
2140 | reftable_offset); | |
2141 | cpu_to_be32w(&reftable_offset_and_clusters.reftable_clusters, | |
2142 | size_to_clusters(s, reftable_size * sizeof(uint64_t))); | |
2143 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, | |
2144 | refcount_table_offset), | |
2145 | &reftable_offset_and_clusters, | |
2146 | sizeof(reftable_offset_and_clusters)); | |
2147 | if (ret < 0) { | |
2148 | fprintf(stderr, "ERROR setting reftable: %s\n", strerror(-ret)); | |
2149 | goto fail; | |
2150 | } | |
2151 | ||
2152 | for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) { | |
2153 | be64_to_cpus(&on_disk_reftable[refblock_index]); | |
2154 | } | |
2155 | s->refcount_table = on_disk_reftable; | |
2156 | s->refcount_table_offset = reftable_offset; | |
2157 | s->refcount_table_size = reftable_size; | |
2158 | ||
2159 | return 0; | |
2160 | ||
2161 | fail: | |
2162 | g_free(on_disk_reftable); | |
2163 | return ret; | |
2164 | } | |
2165 | ||
6ca56bf5 HR |
2166 | /* |
2167 | * Checks an image for refcount consistency. | |
2168 | * | |
2169 | * Returns 0 if no errors are found, the number of errors in case the image is | |
2170 | * detected as corrupted, and -errno when an internal error occurred. | |
2171 | */ | |
2172 | int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
2173 | BdrvCheckMode fix) | |
2174 | { | |
2175 | BDRVQcowState *s = bs->opaque; | |
c7c0681b | 2176 | BdrvCheckResult pre_compare_res; |
6ca56bf5 | 2177 | int64_t size, highest_cluster, nb_clusters; |
7453c96b | 2178 | void *refcount_table = NULL; |
f307b255 | 2179 | bool rebuild = false; |
6ca56bf5 HR |
2180 | int ret; |
2181 | ||
2182 | size = bdrv_getlength(bs->file); | |
2183 | if (size < 0) { | |
2184 | res->check_errors++; | |
2185 | return size; | |
2186 | } | |
2187 | ||
2188 | nb_clusters = size_to_clusters(s, size); | |
2189 | if (nb_clusters > INT_MAX) { | |
2190 | res->check_errors++; | |
2191 | return -EFBIG; | |
2192 | } | |
2193 | ||
2194 | res->bfi.total_clusters = | |
2195 | size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE); | |
2196 | ||
f307b255 HR |
2197 | ret = calculate_refcounts(bs, res, fix, &rebuild, &refcount_table, |
2198 | &nb_clusters); | |
6ca56bf5 HR |
2199 | if (ret < 0) { |
2200 | goto fail; | |
2201 | } | |
2202 | ||
c7c0681b HR |
2203 | /* In case we don't need to rebuild the refcount structure (but want to fix |
2204 | * something), this function is immediately called again, in which case the | |
2205 | * result should be ignored */ | |
2206 | pre_compare_res = *res; | |
2207 | compare_refcounts(bs, res, 0, &rebuild, &highest_cluster, refcount_table, | |
6ca56bf5 | 2208 | nb_clusters); |
f7d0fe02 | 2209 | |
c7c0681b | 2210 | if (rebuild && (fix & BDRV_FIX_ERRORS)) { |
791230d8 HR |
2211 | BdrvCheckResult old_res = *res; |
2212 | int fresh_leaks = 0; | |
2213 | ||
c7c0681b HR |
2214 | fprintf(stderr, "Rebuilding refcount structure\n"); |
2215 | ret = rebuild_refcount_structure(bs, res, &refcount_table, | |
2216 | &nb_clusters); | |
2217 | if (ret < 0) { | |
2218 | goto fail; | |
2219 | } | |
791230d8 HR |
2220 | |
2221 | res->corruptions = 0; | |
2222 | res->leaks = 0; | |
2223 | ||
2224 | /* Because the old reftable has been exchanged for a new one the | |
2225 | * references have to be recalculated */ | |
2226 | rebuild = false; | |
7453c96b | 2227 | memset(refcount_table, 0, refcount_array_byte_size(s, nb_clusters)); |
791230d8 HR |
2228 | ret = calculate_refcounts(bs, res, 0, &rebuild, &refcount_table, |
2229 | &nb_clusters); | |
2230 | if (ret < 0) { | |
2231 | goto fail; | |
2232 | } | |
2233 | ||
2234 | if (fix & BDRV_FIX_LEAKS) { | |
2235 | /* The old refcount structures are now leaked, fix it; the result | |
2236 | * can be ignored, aside from leaks which were introduced by | |
2237 | * rebuild_refcount_structure() that could not be fixed */ | |
2238 | BdrvCheckResult saved_res = *res; | |
2239 | *res = (BdrvCheckResult){ 0 }; | |
2240 | ||
2241 | compare_refcounts(bs, res, BDRV_FIX_LEAKS, &rebuild, | |
2242 | &highest_cluster, refcount_table, nb_clusters); | |
2243 | if (rebuild) { | |
2244 | fprintf(stderr, "ERROR rebuilt refcount structure is still " | |
2245 | "broken\n"); | |
2246 | } | |
2247 | ||
2248 | /* Any leaks accounted for here were introduced by | |
2249 | * rebuild_refcount_structure() because that function has created a | |
2250 | * new refcount structure from scratch */ | |
2251 | fresh_leaks = res->leaks; | |
2252 | *res = saved_res; | |
2253 | } | |
2254 | ||
2255 | if (res->corruptions < old_res.corruptions) { | |
2256 | res->corruptions_fixed += old_res.corruptions - res->corruptions; | |
2257 | } | |
2258 | if (res->leaks < old_res.leaks) { | |
2259 | res->leaks_fixed += old_res.leaks - res->leaks; | |
2260 | } | |
2261 | res->leaks += fresh_leaks; | |
c7c0681b HR |
2262 | } else if (fix) { |
2263 | if (rebuild) { | |
2264 | fprintf(stderr, "ERROR need to rebuild refcount structures\n"); | |
2265 | res->check_errors++; | |
2266 | ret = -EIO; | |
2267 | goto fail; | |
2268 | } | |
2269 | ||
2270 | if (res->leaks || res->corruptions) { | |
2271 | *res = pre_compare_res; | |
2272 | compare_refcounts(bs, res, fix, &rebuild, &highest_cluster, | |
2273 | refcount_table, nb_clusters); | |
2274 | } | |
f307b255 HR |
2275 | } |
2276 | ||
4f6ed88c | 2277 | /* check OFLAG_COPIED */ |
e23e400e | 2278 | ret = check_oflag_copied(bs, res, fix); |
4f6ed88c HR |
2279 | if (ret < 0) { |
2280 | goto fail; | |
2281 | } | |
2282 | ||
c6bb9ad1 | 2283 | res->image_end_offset = (highest_cluster + 1) * s->cluster_size; |
80fa3341 KW |
2284 | ret = 0; |
2285 | ||
2286 | fail: | |
7267c094 | 2287 | g_free(refcount_table); |
f7d0fe02 | 2288 | |
80fa3341 | 2289 | return ret; |
f7d0fe02 KW |
2290 | } |
2291 | ||
a40f1c2a HR |
2292 | #define overlaps_with(ofs, sz) \ |
2293 | ranges_overlap(offset, size, ofs, sz) | |
2294 | ||
2295 | /* | |
2296 | * Checks if the given offset into the image file is actually free to use by | |
2297 | * looking for overlaps with important metadata sections (L1/L2 tables etc.), | |
2298 | * i.e. a sanity check without relying on the refcount tables. | |
2299 | * | |
231bb267 HR |
2300 | * The ign parameter specifies what checks not to perform (being a bitmask of |
2301 | * QCow2MetadataOverlap values), i.e., what sections to ignore. | |
a40f1c2a HR |
2302 | * |
2303 | * Returns: | |
2304 | * - 0 if writing to this offset will not affect the mentioned metadata | |
2305 | * - a positive QCow2MetadataOverlap value indicating one overlapping section | |
2306 | * - a negative value (-errno) indicating an error while performing a check, | |
2307 | * e.g. when bdrv_read failed on QCOW2_OL_INACTIVE_L2 | |
2308 | */ | |
231bb267 | 2309 | int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset, |
a40f1c2a HR |
2310 | int64_t size) |
2311 | { | |
2312 | BDRVQcowState *s = bs->opaque; | |
3e355390 | 2313 | int chk = s->overlap_check & ~ign; |
a40f1c2a HR |
2314 | int i, j; |
2315 | ||
2316 | if (!size) { | |
2317 | return 0; | |
2318 | } | |
2319 | ||
2320 | if (chk & QCOW2_OL_MAIN_HEADER) { | |
2321 | if (offset < s->cluster_size) { | |
2322 | return QCOW2_OL_MAIN_HEADER; | |
2323 | } | |
2324 | } | |
2325 | ||
2326 | /* align range to test to cluster boundaries */ | |
2327 | size = align_offset(offset_into_cluster(s, offset) + size, s->cluster_size); | |
2328 | offset = start_of_cluster(s, offset); | |
2329 | ||
2330 | if ((chk & QCOW2_OL_ACTIVE_L1) && s->l1_size) { | |
2331 | if (overlaps_with(s->l1_table_offset, s->l1_size * sizeof(uint64_t))) { | |
2332 | return QCOW2_OL_ACTIVE_L1; | |
2333 | } | |
2334 | } | |
2335 | ||
2336 | if ((chk & QCOW2_OL_REFCOUNT_TABLE) && s->refcount_table_size) { | |
2337 | if (overlaps_with(s->refcount_table_offset, | |
2338 | s->refcount_table_size * sizeof(uint64_t))) { | |
2339 | return QCOW2_OL_REFCOUNT_TABLE; | |
2340 | } | |
2341 | } | |
2342 | ||
2343 | if ((chk & QCOW2_OL_SNAPSHOT_TABLE) && s->snapshots_size) { | |
2344 | if (overlaps_with(s->snapshots_offset, s->snapshots_size)) { | |
2345 | return QCOW2_OL_SNAPSHOT_TABLE; | |
2346 | } | |
2347 | } | |
2348 | ||
2349 | if ((chk & QCOW2_OL_INACTIVE_L1) && s->snapshots) { | |
2350 | for (i = 0; i < s->nb_snapshots; i++) { | |
2351 | if (s->snapshots[i].l1_size && | |
2352 | overlaps_with(s->snapshots[i].l1_table_offset, | |
2353 | s->snapshots[i].l1_size * sizeof(uint64_t))) { | |
2354 | return QCOW2_OL_INACTIVE_L1; | |
2355 | } | |
2356 | } | |
2357 | } | |
2358 | ||
2359 | if ((chk & QCOW2_OL_ACTIVE_L2) && s->l1_table) { | |
2360 | for (i = 0; i < s->l1_size; i++) { | |
2361 | if ((s->l1_table[i] & L1E_OFFSET_MASK) && | |
2362 | overlaps_with(s->l1_table[i] & L1E_OFFSET_MASK, | |
2363 | s->cluster_size)) { | |
2364 | return QCOW2_OL_ACTIVE_L2; | |
2365 | } | |
2366 | } | |
2367 | } | |
2368 | ||
2369 | if ((chk & QCOW2_OL_REFCOUNT_BLOCK) && s->refcount_table) { | |
2370 | for (i = 0; i < s->refcount_table_size; i++) { | |
2371 | if ((s->refcount_table[i] & REFT_OFFSET_MASK) && | |
2372 | overlaps_with(s->refcount_table[i] & REFT_OFFSET_MASK, | |
2373 | s->cluster_size)) { | |
2374 | return QCOW2_OL_REFCOUNT_BLOCK; | |
2375 | } | |
2376 | } | |
2377 | } | |
2378 | ||
2379 | if ((chk & QCOW2_OL_INACTIVE_L2) && s->snapshots) { | |
2380 | for (i = 0; i < s->nb_snapshots; i++) { | |
2381 | uint64_t l1_ofs = s->snapshots[i].l1_table_offset; | |
2382 | uint32_t l1_sz = s->snapshots[i].l1_size; | |
998b959c | 2383 | uint64_t l1_sz2 = l1_sz * sizeof(uint64_t); |
de82815d | 2384 | uint64_t *l1 = g_try_malloc(l1_sz2); |
a40f1c2a HR |
2385 | int ret; |
2386 | ||
de82815d KW |
2387 | if (l1_sz2 && l1 == NULL) { |
2388 | return -ENOMEM; | |
2389 | } | |
2390 | ||
998b959c | 2391 | ret = bdrv_pread(bs->file, l1_ofs, l1, l1_sz2); |
a40f1c2a HR |
2392 | if (ret < 0) { |
2393 | g_free(l1); | |
2394 | return ret; | |
2395 | } | |
2396 | ||
2397 | for (j = 0; j < l1_sz; j++) { | |
1e242b55 HR |
2398 | uint64_t l2_ofs = be64_to_cpu(l1[j]) & L1E_OFFSET_MASK; |
2399 | if (l2_ofs && overlaps_with(l2_ofs, s->cluster_size)) { | |
a40f1c2a HR |
2400 | g_free(l1); |
2401 | return QCOW2_OL_INACTIVE_L2; | |
2402 | } | |
2403 | } | |
2404 | ||
2405 | g_free(l1); | |
2406 | } | |
2407 | } | |
2408 | ||
2409 | return 0; | |
2410 | } | |
2411 | ||
2412 | static const char *metadata_ol_names[] = { | |
2413 | [QCOW2_OL_MAIN_HEADER_BITNR] = "qcow2_header", | |
2414 | [QCOW2_OL_ACTIVE_L1_BITNR] = "active L1 table", | |
2415 | [QCOW2_OL_ACTIVE_L2_BITNR] = "active L2 table", | |
2416 | [QCOW2_OL_REFCOUNT_TABLE_BITNR] = "refcount table", | |
2417 | [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = "refcount block", | |
2418 | [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = "snapshot table", | |
2419 | [QCOW2_OL_INACTIVE_L1_BITNR] = "inactive L1 table", | |
2420 | [QCOW2_OL_INACTIVE_L2_BITNR] = "inactive L2 table", | |
2421 | }; | |
2422 | ||
2423 | /* | |
2424 | * First performs a check for metadata overlaps (through | |
2425 | * qcow2_check_metadata_overlap); if that fails with a negative value (error | |
2426 | * while performing a check), that value is returned. If an impending overlap | |
2427 | * is detected, the BDS will be made unusable, the qcow2 file marked corrupt | |
2428 | * and -EIO returned. | |
2429 | * | |
2430 | * Returns 0 if there were neither overlaps nor errors while checking for | |
2431 | * overlaps; or a negative value (-errno) on error. | |
2432 | */ | |
231bb267 | 2433 | int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset, |
a40f1c2a HR |
2434 | int64_t size) |
2435 | { | |
231bb267 | 2436 | int ret = qcow2_check_metadata_overlap(bs, ign, offset, size); |
a40f1c2a HR |
2437 | |
2438 | if (ret < 0) { | |
2439 | return ret; | |
2440 | } else if (ret > 0) { | |
2441 | int metadata_ol_bitnr = ffs(ret) - 1; | |
a40f1c2a HR |
2442 | assert(metadata_ol_bitnr < QCOW2_OL_MAX_BITNR); |
2443 | ||
adb43552 HR |
2444 | qcow2_signal_corruption(bs, true, offset, size, "Preventing invalid " |
2445 | "write on metadata (overlaps with %s)", | |
2446 | metadata_ol_names[metadata_ol_bitnr]); | |
a40f1c2a HR |
2447 | return -EIO; |
2448 | } | |
2449 | ||
2450 | return 0; | |
2451 | } |