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Commit | Line | Data |
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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 | 84 | { |
ff99129a | 85 | BDRVQcow2State *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 | 118 | { |
ff99129a | 119 | BDRVQcow2State *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 | 216 | { |
ff99129a | 217 | BDRVQcow2State *s = bs->opaque; |
f7d0fe02 | 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 | 233 | { |
ff99129a | 234 | BDRVQcow2State *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 | |
a3f1afb4 | 268 | qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); |
29c1a730 | 269 | |
7324c10f | 270 | return 0; |
f7d0fe02 KW |
271 | } |
272 | ||
05121aed KW |
273 | /* |
274 | * Rounds the refcount table size up to avoid growing the table for each single | |
275 | * refcount block that is allocated. | |
276 | */ | |
ff99129a | 277 | static unsigned int next_refcount_table_size(BDRVQcow2State *s, |
05121aed KW |
278 | unsigned int min_size) |
279 | { | |
280 | unsigned int min_clusters = (min_size >> (s->cluster_bits - 3)) + 1; | |
281 | unsigned int refcount_table_clusters = | |
282 | MAX(1, s->refcount_table_size >> (s->cluster_bits - 3)); | |
283 | ||
284 | while (min_clusters > refcount_table_clusters) { | |
285 | refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; | |
286 | } | |
287 | ||
288 | return refcount_table_clusters << (s->cluster_bits - 3); | |
289 | } | |
290 | ||
92dcb59f KW |
291 | |
292 | /* Checks if two offsets are described by the same refcount block */ | |
ff99129a | 293 | static int in_same_refcount_block(BDRVQcow2State *s, uint64_t offset_a, |
92dcb59f KW |
294 | uint64_t offset_b) |
295 | { | |
17bd5f47 HR |
296 | uint64_t block_a = offset_a >> (s->cluster_bits + s->refcount_block_bits); |
297 | uint64_t block_b = offset_b >> (s->cluster_bits + s->refcount_block_bits); | |
92dcb59f KW |
298 | |
299 | return (block_a == block_b); | |
300 | } | |
301 | ||
302 | /* | |
303 | * Loads a refcount block. If it doesn't exist yet, it is allocated first | |
304 | * (including growing the refcount table if needed). | |
305 | * | |
29c1a730 | 306 | * Returns 0 on success or -errno in error case |
92dcb59f | 307 | */ |
29c1a730 | 308 | static int alloc_refcount_block(BlockDriverState *bs, |
7453c96b | 309 | int64_t cluster_index, void **refcount_block) |
f7d0fe02 | 310 | { |
ff99129a | 311 | BDRVQcow2State *s = bs->opaque; |
92dcb59f KW |
312 | unsigned int refcount_table_index; |
313 | int ret; | |
314 | ||
66f82cee | 315 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); |
8252278a | 316 | |
92dcb59f | 317 | /* Find the refcount block for the given cluster */ |
17bd5f47 | 318 | refcount_table_index = cluster_index >> s->refcount_block_bits; |
92dcb59f KW |
319 | |
320 | if (refcount_table_index < s->refcount_table_size) { | |
321 | ||
322 | uint64_t refcount_block_offset = | |
76dc9e0c | 323 | s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; |
92dcb59f KW |
324 | |
325 | /* If it's already there, we're done */ | |
326 | if (refcount_block_offset) { | |
a97c67ee HR |
327 | if (offset_into_cluster(s, refcount_block_offset)) { |
328 | qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#" | |
329 | PRIx64 " unaligned (reftable index: " | |
330 | "%#x)", refcount_block_offset, | |
331 | refcount_table_index); | |
332 | return -EIO; | |
333 | } | |
334 | ||
29c1a730 | 335 | return load_refcount_block(bs, refcount_block_offset, |
7453c96b | 336 | refcount_block); |
92dcb59f KW |
337 | } |
338 | } | |
339 | ||
340 | /* | |
341 | * If we came here, we need to allocate something. Something is at least | |
342 | * a cluster for the new refcount block. It may also include a new refcount | |
343 | * table if the old refcount table is too small. | |
344 | * | |
345 | * Note that allocating clusters here needs some special care: | |
346 | * | |
347 | * - We can't use the normal qcow2_alloc_clusters(), it would try to | |
348 | * increase the refcount and very likely we would end up with an endless | |
349 | * recursion. Instead we must place the refcount blocks in a way that | |
350 | * they can describe them themselves. | |
351 | * | |
352 | * - We need to consider that at this point we are inside update_refcounts | |
b106ad91 KW |
353 | * and potentially doing an initial refcount increase. This means that |
354 | * some clusters have already been allocated by the caller, but their | |
355 | * refcount isn't accurate yet. If we allocate clusters for metadata, we | |
356 | * need to return -EAGAIN to signal the caller that it needs to restart | |
357 | * the search for free clusters. | |
92dcb59f KW |
358 | * |
359 | * - alloc_clusters_noref and qcow2_free_clusters may load a different | |
360 | * refcount block into the cache | |
361 | */ | |
362 | ||
29c1a730 KW |
363 | *refcount_block = NULL; |
364 | ||
365 | /* We write to the refcount table, so we might depend on L2 tables */ | |
9991923b SH |
366 | ret = qcow2_cache_flush(bs, s->l2_table_cache); |
367 | if (ret < 0) { | |
368 | return ret; | |
369 | } | |
92dcb59f KW |
370 | |
371 | /* Allocate the refcount block itself and mark it as used */ | |
2eaa8f63 KW |
372 | int64_t new_block = alloc_clusters_noref(bs, s->cluster_size); |
373 | if (new_block < 0) { | |
374 | return new_block; | |
375 | } | |
f7d0fe02 | 376 | |
f7d0fe02 | 377 | #ifdef DEBUG_ALLOC2 |
92dcb59f KW |
378 | fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64 |
379 | " at %" PRIx64 "\n", | |
380 | refcount_table_index, cluster_index << s->cluster_bits, new_block); | |
f7d0fe02 | 381 | #endif |
92dcb59f KW |
382 | |
383 | if (in_same_refcount_block(s, new_block, cluster_index << s->cluster_bits)) { | |
25408c09 | 384 | /* Zero the new refcount block before updating it */ |
29c1a730 | 385 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
7453c96b | 386 | refcount_block); |
29c1a730 KW |
387 | if (ret < 0) { |
388 | goto fail_block; | |
389 | } | |
390 | ||
391 | memset(*refcount_block, 0, s->cluster_size); | |
25408c09 | 392 | |
92dcb59f KW |
393 | /* The block describes itself, need to update the cache */ |
394 | int block_index = (new_block >> s->cluster_bits) & | |
17bd5f47 | 395 | (s->refcount_block_size - 1); |
7453c96b | 396 | s->set_refcount(*refcount_block, block_index, 1); |
92dcb59f KW |
397 | } else { |
398 | /* Described somewhere else. This can recurse at most twice before we | |
399 | * arrive at a block that describes itself. */ | |
2aabe7c7 | 400 | ret = update_refcount(bs, new_block, s->cluster_size, 1, false, |
6cfcb9b8 | 401 | QCOW2_DISCARD_NEVER); |
92dcb59f KW |
402 | if (ret < 0) { |
403 | goto fail_block; | |
404 | } | |
25408c09 | 405 | |
9991923b SH |
406 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
407 | if (ret < 0) { | |
408 | goto fail_block; | |
409 | } | |
1c4c2814 | 410 | |
25408c09 KW |
411 | /* Initialize the new refcount block only after updating its refcount, |
412 | * update_refcount uses the refcount cache itself */ | |
29c1a730 | 413 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
7453c96b | 414 | refcount_block); |
29c1a730 KW |
415 | if (ret < 0) { |
416 | goto fail_block; | |
417 | } | |
418 | ||
419 | memset(*refcount_block, 0, s->cluster_size); | |
92dcb59f KW |
420 | } |
421 | ||
422 | /* Now the new refcount block needs to be written to disk */ | |
66f82cee | 423 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE); |
72e80b89 | 424 | qcow2_cache_entry_mark_dirty(bs, s->refcount_block_cache, *refcount_block); |
29c1a730 | 425 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
92dcb59f KW |
426 | if (ret < 0) { |
427 | goto fail_block; | |
428 | } | |
429 | ||
430 | /* If the refcount table is big enough, just hook the block up there */ | |
431 | if (refcount_table_index < s->refcount_table_size) { | |
432 | uint64_t data64 = cpu_to_be64(new_block); | |
66f82cee | 433 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_HOOKUP); |
8b3b7206 | 434 | ret = bdrv_pwrite_sync(bs->file, |
92dcb59f KW |
435 | s->refcount_table_offset + refcount_table_index * sizeof(uint64_t), |
436 | &data64, sizeof(data64)); | |
437 | if (ret < 0) { | |
438 | goto fail_block; | |
439 | } | |
440 | ||
441 | s->refcount_table[refcount_table_index] = new_block; | |
b106ad91 KW |
442 | |
443 | /* The new refcount block may be where the caller intended to put its | |
444 | * data, so let it restart the search. */ | |
445 | return -EAGAIN; | |
29c1a730 KW |
446 | } |
447 | ||
a3f1afb4 | 448 | qcow2_cache_put(bs, s->refcount_block_cache, refcount_block); |
92dcb59f KW |
449 | |
450 | /* | |
451 | * If we come here, we need to grow the refcount table. Again, a new | |
452 | * refcount table needs some space and we can't simply allocate to avoid | |
453 | * endless recursion. | |
454 | * | |
455 | * Therefore let's grab new refcount blocks at the end of the image, which | |
456 | * will describe themselves and the new refcount table. This way we can | |
457 | * reference them only in the new table and do the switch to the new | |
458 | * refcount table at once without producing an inconsistent state in | |
459 | * between. | |
460 | */ | |
66f82cee | 461 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW); |
8252278a | 462 | |
14a58a4e HR |
463 | /* Calculate the number of refcount blocks needed so far; this will be the |
464 | * basis for calculating the index of the first cluster used for the | |
465 | * self-describing refcount structures which we are about to create. | |
466 | * | |
467 | * Because we reached this point, there cannot be any refcount entries for | |
468 | * cluster_index or higher indices yet. However, because new_block has been | |
469 | * allocated to describe that cluster (and it will assume this role later | |
470 | * on), we cannot use that index; also, new_block may actually have a higher | |
471 | * cluster index than cluster_index, so it needs to be taken into account | |
472 | * here (and 1 needs to be added to its value because that cluster is used). | |
473 | */ | |
474 | uint64_t blocks_used = DIV_ROUND_UP(MAX(cluster_index + 1, | |
475 | (new_block >> s->cluster_bits) + 1), | |
476 | s->refcount_block_size); | |
92dcb59f | 477 | |
2b5d5953 KW |
478 | if (blocks_used > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) { |
479 | return -EFBIG; | |
480 | } | |
481 | ||
92dcb59f KW |
482 | /* And now we need at least one block more for the new metadata */ |
483 | uint64_t table_size = next_refcount_table_size(s, blocks_used + 1); | |
484 | uint64_t last_table_size; | |
485 | uint64_t blocks_clusters; | |
486 | do { | |
a3548077 KW |
487 | uint64_t table_clusters = |
488 | size_to_clusters(s, table_size * sizeof(uint64_t)); | |
92dcb59f | 489 | blocks_clusters = 1 + |
17bd5f47 HR |
490 | ((table_clusters + s->refcount_block_size - 1) |
491 | / s->refcount_block_size); | |
92dcb59f KW |
492 | uint64_t meta_clusters = table_clusters + blocks_clusters; |
493 | ||
494 | last_table_size = table_size; | |
495 | table_size = next_refcount_table_size(s, blocks_used + | |
17bd5f47 HR |
496 | ((meta_clusters + s->refcount_block_size - 1) |
497 | / s->refcount_block_size)); | |
92dcb59f KW |
498 | |
499 | } while (last_table_size != table_size); | |
500 | ||
501 | #ifdef DEBUG_ALLOC2 | |
502 | fprintf(stderr, "qcow2: Grow refcount table %" PRId32 " => %" PRId64 "\n", | |
503 | s->refcount_table_size, table_size); | |
504 | #endif | |
505 | ||
506 | /* Create the new refcount table and blocks */ | |
17bd5f47 | 507 | uint64_t meta_offset = (blocks_used * s->refcount_block_size) * |
92dcb59f KW |
508 | s->cluster_size; |
509 | uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size; | |
5839e53b | 510 | uint64_t *new_table = g_try_new0(uint64_t, table_size); |
7453c96b | 511 | void *new_blocks = g_try_malloc0(blocks_clusters * s->cluster_size); |
de82815d KW |
512 | |
513 | assert(table_size > 0 && blocks_clusters > 0); | |
514 | if (new_table == NULL || new_blocks == NULL) { | |
515 | ret = -ENOMEM; | |
516 | goto fail_table; | |
517 | } | |
92dcb59f | 518 | |
92dcb59f | 519 | /* Fill the new refcount table */ |
f7d0fe02 | 520 | memcpy(new_table, s->refcount_table, |
92dcb59f KW |
521 | s->refcount_table_size * sizeof(uint64_t)); |
522 | new_table[refcount_table_index] = new_block; | |
523 | ||
524 | int i; | |
525 | for (i = 0; i < blocks_clusters; i++) { | |
526 | new_table[blocks_used + i] = meta_offset + (i * s->cluster_size); | |
527 | } | |
528 | ||
529 | /* Fill the refcount blocks */ | |
530 | uint64_t table_clusters = size_to_clusters(s, table_size * sizeof(uint64_t)); | |
531 | int block = 0; | |
532 | for (i = 0; i < table_clusters + blocks_clusters; i++) { | |
7453c96b | 533 | s->set_refcount(new_blocks, block++, 1); |
92dcb59f KW |
534 | } |
535 | ||
536 | /* Write refcount blocks to disk */ | |
66f82cee | 537 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS); |
8b3b7206 | 538 | ret = bdrv_pwrite_sync(bs->file, meta_offset, new_blocks, |
92dcb59f | 539 | blocks_clusters * s->cluster_size); |
7267c094 | 540 | g_free(new_blocks); |
39ba3bf6 | 541 | new_blocks = NULL; |
92dcb59f KW |
542 | if (ret < 0) { |
543 | goto fail_table; | |
544 | } | |
545 | ||
546 | /* Write refcount table to disk */ | |
547 | for(i = 0; i < table_size; i++) { | |
548 | cpu_to_be64s(&new_table[i]); | |
549 | } | |
550 | ||
66f82cee | 551 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE); |
8b3b7206 | 552 | ret = bdrv_pwrite_sync(bs->file, table_offset, new_table, |
92dcb59f KW |
553 | table_size * sizeof(uint64_t)); |
554 | if (ret < 0) { | |
555 | goto fail_table; | |
556 | } | |
557 | ||
558 | for(i = 0; i < table_size; i++) { | |
87267753 | 559 | be64_to_cpus(&new_table[i]); |
92dcb59f | 560 | } |
f7d0fe02 | 561 | |
92dcb59f KW |
562 | /* Hook up the new refcount table in the qcow2 header */ |
563 | uint8_t data[12]; | |
f7d0fe02 | 564 | cpu_to_be64w((uint64_t*)data, table_offset); |
92dcb59f | 565 | cpu_to_be32w((uint32_t*)(data + 8), table_clusters); |
66f82cee | 566 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE); |
8b3b7206 | 567 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, refcount_table_offset), |
92dcb59f KW |
568 | data, sizeof(data)); |
569 | if (ret < 0) { | |
570 | goto fail_table; | |
f2b7c8b3 KW |
571 | } |
572 | ||
92dcb59f KW |
573 | /* And switch it in memory */ |
574 | uint64_t old_table_offset = s->refcount_table_offset; | |
575 | uint64_t old_table_size = s->refcount_table_size; | |
576 | ||
7267c094 | 577 | g_free(s->refcount_table); |
f7d0fe02 | 578 | s->refcount_table = new_table; |
92dcb59f | 579 | s->refcount_table_size = table_size; |
f7d0fe02 KW |
580 | s->refcount_table_offset = table_offset; |
581 | ||
b106ad91 | 582 | /* Free old table. */ |
6cfcb9b8 KW |
583 | qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t), |
584 | QCOW2_DISCARD_OTHER); | |
f7d0fe02 | 585 | |
7453c96b | 586 | ret = load_refcount_block(bs, new_block, refcount_block); |
92dcb59f | 587 | if (ret < 0) { |
29c1a730 | 588 | return ret; |
f7d0fe02 KW |
589 | } |
590 | ||
b106ad91 KW |
591 | /* If we were trying to do the initial refcount update for some cluster |
592 | * allocation, we might have used the same clusters to store newly | |
593 | * allocated metadata. Make the caller search some new space. */ | |
594 | return -EAGAIN; | |
f7d0fe02 | 595 | |
92dcb59f | 596 | fail_table: |
de82815d | 597 | g_free(new_blocks); |
7267c094 | 598 | g_free(new_table); |
92dcb59f | 599 | fail_block: |
29c1a730 | 600 | if (*refcount_block != NULL) { |
7453c96b | 601 | qcow2_cache_put(bs, s->refcount_block_cache, refcount_block); |
3b88e52b | 602 | } |
29c1a730 | 603 | return ret; |
9923e05e KW |
604 | } |
605 | ||
0b919fae KW |
606 | void qcow2_process_discards(BlockDriverState *bs, int ret) |
607 | { | |
ff99129a | 608 | BDRVQcow2State *s = bs->opaque; |
0b919fae KW |
609 | Qcow2DiscardRegion *d, *next; |
610 | ||
611 | QTAILQ_FOREACH_SAFE(d, &s->discards, next, next) { | |
612 | QTAILQ_REMOVE(&s->discards, d, next); | |
613 | ||
614 | /* Discard is optional, ignore the return value */ | |
615 | if (ret >= 0) { | |
616 | bdrv_discard(bs->file, | |
617 | d->offset >> BDRV_SECTOR_BITS, | |
618 | d->bytes >> BDRV_SECTOR_BITS); | |
619 | } | |
620 | ||
621 | g_free(d); | |
622 | } | |
623 | } | |
624 | ||
625 | static void update_refcount_discard(BlockDriverState *bs, | |
626 | uint64_t offset, uint64_t length) | |
627 | { | |
ff99129a | 628 | BDRVQcow2State *s = bs->opaque; |
0b919fae KW |
629 | Qcow2DiscardRegion *d, *p, *next; |
630 | ||
631 | QTAILQ_FOREACH(d, &s->discards, next) { | |
632 | uint64_t new_start = MIN(offset, d->offset); | |
633 | uint64_t new_end = MAX(offset + length, d->offset + d->bytes); | |
634 | ||
635 | if (new_end - new_start <= length + d->bytes) { | |
636 | /* There can't be any overlap, areas ending up here have no | |
637 | * references any more and therefore shouldn't get freed another | |
638 | * time. */ | |
639 | assert(d->bytes + length == new_end - new_start); | |
640 | d->offset = new_start; | |
641 | d->bytes = new_end - new_start; | |
642 | goto found; | |
643 | } | |
644 | } | |
645 | ||
646 | d = g_malloc(sizeof(*d)); | |
647 | *d = (Qcow2DiscardRegion) { | |
648 | .bs = bs, | |
649 | .offset = offset, | |
650 | .bytes = length, | |
651 | }; | |
652 | QTAILQ_INSERT_TAIL(&s->discards, d, next); | |
653 | ||
654 | found: | |
655 | /* Merge discard requests if they are adjacent now */ | |
656 | QTAILQ_FOREACH_SAFE(p, &s->discards, next, next) { | |
657 | if (p == d | |
658 | || p->offset > d->offset + d->bytes | |
659 | || d->offset > p->offset + p->bytes) | |
660 | { | |
661 | continue; | |
662 | } | |
663 | ||
664 | /* Still no overlap possible */ | |
665 | assert(p->offset == d->offset + d->bytes | |
666 | || d->offset == p->offset + p->bytes); | |
667 | ||
668 | QTAILQ_REMOVE(&s->discards, p, next); | |
669 | d->offset = MIN(d->offset, p->offset); | |
670 | d->bytes += p->bytes; | |
d8bb71b6 | 671 | g_free(p); |
0b919fae KW |
672 | } |
673 | } | |
674 | ||
f7d0fe02 | 675 | /* XXX: cache several refcount block clusters ? */ |
2aabe7c7 HR |
676 | /* @addend is the absolute value of the addend; if @decrease is set, @addend |
677 | * will be subtracted from the current refcount, otherwise it will be added */ | |
db3a964f | 678 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
2aabe7c7 HR |
679 | int64_t offset, |
680 | int64_t length, | |
0e06528e | 681 | uint64_t addend, |
2aabe7c7 HR |
682 | bool decrease, |
683 | enum qcow2_discard_type type) | |
f7d0fe02 | 684 | { |
ff99129a | 685 | BDRVQcow2State *s = bs->opaque; |
f7d0fe02 | 686 | int64_t start, last, cluster_offset; |
7453c96b | 687 | void *refcount_block = NULL; |
29c1a730 | 688 | int64_t old_table_index = -1; |
09508d13 | 689 | int ret; |
f7d0fe02 KW |
690 | |
691 | #ifdef DEBUG_ALLOC2 | |
2aabe7c7 | 692 | fprintf(stderr, "update_refcount: offset=%" PRId64 " size=%" PRId64 |
0e06528e | 693 | " addend=%s%" PRIu64 "\n", offset, length, decrease ? "-" : "", |
2aabe7c7 | 694 | addend); |
f7d0fe02 | 695 | #endif |
7322afe7 | 696 | if (length < 0) { |
f7d0fe02 | 697 | return -EINVAL; |
7322afe7 KW |
698 | } else if (length == 0) { |
699 | return 0; | |
700 | } | |
701 | ||
2aabe7c7 | 702 | if (decrease) { |
29c1a730 KW |
703 | qcow2_cache_set_dependency(bs, s->refcount_block_cache, |
704 | s->l2_table_cache); | |
705 | } | |
706 | ||
ac95acdb HT |
707 | start = start_of_cluster(s, offset); |
708 | last = start_of_cluster(s, offset + length - 1); | |
f7d0fe02 KW |
709 | for(cluster_offset = start; cluster_offset <= last; |
710 | cluster_offset += s->cluster_size) | |
711 | { | |
2aabe7c7 | 712 | int block_index; |
0e06528e | 713 | uint64_t refcount; |
f7d0fe02 | 714 | int64_t cluster_index = cluster_offset >> s->cluster_bits; |
17bd5f47 | 715 | int64_t table_index = cluster_index >> s->refcount_block_bits; |
f7d0fe02 | 716 | |
29c1a730 KW |
717 | /* Load the refcount block and allocate it if needed */ |
718 | if (table_index != old_table_index) { | |
719 | if (refcount_block) { | |
a3f1afb4 | 720 | qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); |
29c1a730 | 721 | } |
29c1a730 | 722 | ret = alloc_refcount_block(bs, cluster_index, &refcount_block); |
ed0df867 | 723 | if (ret < 0) { |
29c1a730 | 724 | goto fail; |
f7d0fe02 | 725 | } |
f7d0fe02 | 726 | } |
29c1a730 | 727 | old_table_index = table_index; |
f7d0fe02 | 728 | |
72e80b89 AG |
729 | qcow2_cache_entry_mark_dirty(bs, s->refcount_block_cache, |
730 | refcount_block); | |
f7d0fe02 KW |
731 | |
732 | /* we can update the count and save it */ | |
17bd5f47 | 733 | block_index = cluster_index & (s->refcount_block_size - 1); |
f7d0fe02 | 734 | |
7453c96b | 735 | refcount = s->get_refcount(refcount_block, block_index); |
0e06528e HR |
736 | if (decrease ? (refcount - addend > refcount) |
737 | : (refcount + addend < refcount || | |
738 | refcount + addend > s->refcount_max)) | |
2aabe7c7 | 739 | { |
09508d13 KW |
740 | ret = -EINVAL; |
741 | goto fail; | |
742 | } | |
2aabe7c7 HR |
743 | if (decrease) { |
744 | refcount -= addend; | |
745 | } else { | |
746 | refcount += addend; | |
747 | } | |
f7d0fe02 KW |
748 | if (refcount == 0 && cluster_index < s->free_cluster_index) { |
749 | s->free_cluster_index = cluster_index; | |
750 | } | |
7453c96b | 751 | s->set_refcount(refcount_block, block_index, refcount); |
0b919fae | 752 | |
67af674e | 753 | if (refcount == 0 && s->discard_passthrough[type]) { |
0b919fae | 754 | update_refcount_discard(bs, cluster_offset, s->cluster_size); |
67af674e | 755 | } |
f7d0fe02 KW |
756 | } |
757 | ||
09508d13 KW |
758 | ret = 0; |
759 | fail: | |
0b919fae KW |
760 | if (!s->cache_discards) { |
761 | qcow2_process_discards(bs, ret); | |
762 | } | |
763 | ||
f7d0fe02 | 764 | /* Write last changed block to disk */ |
29c1a730 | 765 | if (refcount_block) { |
a3f1afb4 | 766 | qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); |
f7d0fe02 KW |
767 | } |
768 | ||
09508d13 KW |
769 | /* |
770 | * Try do undo any updates if an error is returned (This may succeed in | |
771 | * some cases like ENOSPC for allocating a new refcount block) | |
772 | */ | |
773 | if (ret < 0) { | |
774 | int dummy; | |
2aabe7c7 HR |
775 | dummy = update_refcount(bs, offset, cluster_offset - offset, addend, |
776 | !decrease, QCOW2_DISCARD_NEVER); | |
83e3f76c | 777 | (void)dummy; |
09508d13 KW |
778 | } |
779 | ||
780 | return ret; | |
f7d0fe02 KW |
781 | } |
782 | ||
018faafd | 783 | /* |
44751917 | 784 | * Increases or decreases the refcount of a given cluster. |
018faafd | 785 | * |
2aabe7c7 HR |
786 | * @addend is the absolute value of the addend; if @decrease is set, @addend |
787 | * will be subtracted from the current refcount, otherwise it will be added. | |
788 | * | |
c6e9d8ae | 789 | * On success 0 is returned; on failure -errno is returned. |
018faafd | 790 | */ |
32b6444d HR |
791 | int qcow2_update_cluster_refcount(BlockDriverState *bs, |
792 | int64_t cluster_index, | |
0e06528e | 793 | uint64_t addend, bool decrease, |
32b6444d | 794 | enum qcow2_discard_type type) |
f7d0fe02 | 795 | { |
ff99129a | 796 | BDRVQcow2State *s = bs->opaque; |
f7d0fe02 KW |
797 | int ret; |
798 | ||
6cfcb9b8 | 799 | ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend, |
2aabe7c7 | 800 | decrease, type); |
f7d0fe02 KW |
801 | if (ret < 0) { |
802 | return ret; | |
803 | } | |
804 | ||
c6e9d8ae | 805 | return 0; |
f7d0fe02 KW |
806 | } |
807 | ||
808 | ||
809 | ||
810 | /*********************************************************/ | |
811 | /* cluster allocation functions */ | |
812 | ||
813 | ||
814 | ||
815 | /* return < 0 if error */ | |
bb572aef | 816 | static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size) |
f7d0fe02 | 817 | { |
ff99129a | 818 | BDRVQcow2State *s = bs->opaque; |
0e06528e | 819 | uint64_t i, nb_clusters, refcount; |
7324c10f | 820 | int ret; |
f7d0fe02 | 821 | |
ecbda7a2 KW |
822 | /* We can't allocate clusters if they may still be queued for discard. */ |
823 | if (s->cache_discards) { | |
824 | qcow2_process_discards(bs, 0); | |
825 | } | |
826 | ||
f7d0fe02 KW |
827 | nb_clusters = size_to_clusters(s, size); |
828 | retry: | |
829 | for(i = 0; i < nb_clusters; i++) { | |
bb572aef | 830 | uint64_t next_cluster_index = s->free_cluster_index++; |
7324c10f | 831 | ret = qcow2_get_refcount(bs, next_cluster_index, &refcount); |
2eaa8f63 | 832 | |
7324c10f HR |
833 | if (ret < 0) { |
834 | return ret; | |
2eaa8f63 | 835 | } else if (refcount != 0) { |
f7d0fe02 | 836 | goto retry; |
2eaa8f63 | 837 | } |
f7d0fe02 | 838 | } |
91f827dc HR |
839 | |
840 | /* Make sure that all offsets in the "allocated" range are representable | |
841 | * in an int64_t */ | |
65f33bc0 HR |
842 | if (s->free_cluster_index > 0 && |
843 | s->free_cluster_index - 1 > (INT64_MAX >> s->cluster_bits)) | |
844 | { | |
91f827dc HR |
845 | return -EFBIG; |
846 | } | |
847 | ||
f7d0fe02 | 848 | #ifdef DEBUG_ALLOC2 |
35ee5e39 | 849 | fprintf(stderr, "alloc_clusters: size=%" PRId64 " -> %" PRId64 "\n", |
f7d0fe02 KW |
850 | size, |
851 | (s->free_cluster_index - nb_clusters) << s->cluster_bits); | |
852 | #endif | |
853 | return (s->free_cluster_index - nb_clusters) << s->cluster_bits; | |
854 | } | |
855 | ||
bb572aef | 856 | int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size) |
f7d0fe02 KW |
857 | { |
858 | int64_t offset; | |
db3a964f | 859 | int ret; |
f7d0fe02 | 860 | |
66f82cee | 861 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC); |
b106ad91 KW |
862 | do { |
863 | offset = alloc_clusters_noref(bs, size); | |
864 | if (offset < 0) { | |
865 | return offset; | |
866 | } | |
867 | ||
2aabe7c7 | 868 | ret = update_refcount(bs, offset, size, 1, false, QCOW2_DISCARD_NEVER); |
b106ad91 | 869 | } while (ret == -EAGAIN); |
2eaa8f63 | 870 | |
db3a964f KW |
871 | if (ret < 0) { |
872 | return ret; | |
873 | } | |
1c4c2814 | 874 | |
f7d0fe02 KW |
875 | return offset; |
876 | } | |
877 | ||
256900b1 KW |
878 | int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, |
879 | int nb_clusters) | |
880 | { | |
ff99129a | 881 | BDRVQcow2State *s = bs->opaque; |
0e06528e | 882 | uint64_t cluster_index, refcount; |
33304ec9 | 883 | uint64_t i; |
7324c10f | 884 | int ret; |
33304ec9 HT |
885 | |
886 | assert(nb_clusters >= 0); | |
887 | if (nb_clusters == 0) { | |
888 | return 0; | |
889 | } | |
256900b1 | 890 | |
b106ad91 KW |
891 | do { |
892 | /* Check how many clusters there are free */ | |
893 | cluster_index = offset >> s->cluster_bits; | |
894 | for(i = 0; i < nb_clusters; i++) { | |
7324c10f HR |
895 | ret = qcow2_get_refcount(bs, cluster_index++, &refcount); |
896 | if (ret < 0) { | |
897 | return ret; | |
b106ad91 KW |
898 | } else if (refcount != 0) { |
899 | break; | |
900 | } | |
256900b1 | 901 | } |
256900b1 | 902 | |
b106ad91 | 903 | /* And then allocate them */ |
2aabe7c7 | 904 | ret = update_refcount(bs, offset, i << s->cluster_bits, 1, false, |
b106ad91 KW |
905 | QCOW2_DISCARD_NEVER); |
906 | } while (ret == -EAGAIN); | |
f24423bd | 907 | |
256900b1 KW |
908 | if (ret < 0) { |
909 | return ret; | |
910 | } | |
911 | ||
912 | return i; | |
913 | } | |
914 | ||
f7d0fe02 KW |
915 | /* only used to allocate compressed sectors. We try to allocate |
916 | contiguous sectors. size must be <= cluster_size */ | |
ed6ccf0f | 917 | int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size) |
f7d0fe02 | 918 | { |
ff99129a | 919 | BDRVQcow2State *s = bs->opaque; |
8c44dfbc HR |
920 | int64_t offset; |
921 | size_t free_in_cluster; | |
922 | int ret; | |
f7d0fe02 | 923 | |
66f82cee | 924 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_BYTES); |
f7d0fe02 | 925 | assert(size > 0 && size <= s->cluster_size); |
8c44dfbc HR |
926 | assert(!s->free_byte_offset || offset_into_cluster(s, s->free_byte_offset)); |
927 | ||
928 | offset = s->free_byte_offset; | |
929 | ||
930 | if (offset) { | |
0e06528e | 931 | uint64_t refcount; |
7324c10f HR |
932 | ret = qcow2_get_refcount(bs, offset >> s->cluster_bits, &refcount); |
933 | if (ret < 0) { | |
934 | return ret; | |
5d757b56 | 935 | } |
8c44dfbc | 936 | |
346a53df | 937 | if (refcount == s->refcount_max) { |
8c44dfbc | 938 | offset = 0; |
5d757b56 | 939 | } |
8c44dfbc HR |
940 | } |
941 | ||
942 | free_in_cluster = s->cluster_size - offset_into_cluster(s, offset); | |
3e5feb62 JM |
943 | do { |
944 | if (!offset || free_in_cluster < size) { | |
945 | int64_t new_cluster = alloc_clusters_noref(bs, s->cluster_size); | |
946 | if (new_cluster < 0) { | |
947 | return new_cluster; | |
948 | } | |
8c44dfbc | 949 | |
3e5feb62 JM |
950 | if (!offset || ROUND_UP(offset, s->cluster_size) != new_cluster) { |
951 | offset = new_cluster; | |
952 | } | |
f7d0fe02 | 953 | } |
29216ed1 | 954 | |
3e5feb62 JM |
955 | assert(offset); |
956 | ret = update_refcount(bs, offset, size, 1, false, QCOW2_DISCARD_NEVER); | |
957 | } while (ret == -EAGAIN); | |
8c44dfbc HR |
958 | if (ret < 0) { |
959 | return ret; | |
960 | } | |
961 | ||
962 | /* The cluster refcount was incremented; refcount blocks must be flushed | |
963 | * before the caller's L2 table updates. */ | |
c1f5bafd | 964 | qcow2_cache_set_dependency(bs, s->l2_table_cache, s->refcount_block_cache); |
8c44dfbc HR |
965 | |
966 | s->free_byte_offset = offset + size; | |
967 | if (!offset_into_cluster(s, s->free_byte_offset)) { | |
968 | s->free_byte_offset = 0; | |
969 | } | |
970 | ||
f7d0fe02 KW |
971 | return offset; |
972 | } | |
973 | ||
ed6ccf0f | 974 | void qcow2_free_clusters(BlockDriverState *bs, |
6cfcb9b8 KW |
975 | int64_t offset, int64_t size, |
976 | enum qcow2_discard_type type) | |
f7d0fe02 | 977 | { |
db3a964f KW |
978 | int ret; |
979 | ||
66f82cee | 980 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_FREE); |
2aabe7c7 | 981 | ret = update_refcount(bs, offset, size, 1, true, type); |
db3a964f KW |
982 | if (ret < 0) { |
983 | fprintf(stderr, "qcow2_free_clusters failed: %s\n", strerror(-ret)); | |
003fad6e | 984 | /* TODO Remember the clusters to free them later and avoid leaking */ |
db3a964f | 985 | } |
f7d0fe02 KW |
986 | } |
987 | ||
45aba42f | 988 | /* |
c7a4c37a KW |
989 | * Free a cluster using its L2 entry (handles clusters of all types, e.g. |
990 | * normal cluster, compressed cluster, etc.) | |
45aba42f | 991 | */ |
6cfcb9b8 KW |
992 | void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry, |
993 | int nb_clusters, enum qcow2_discard_type type) | |
45aba42f | 994 | { |
ff99129a | 995 | BDRVQcow2State *s = bs->opaque; |
45aba42f | 996 | |
c7a4c37a KW |
997 | switch (qcow2_get_cluster_type(l2_entry)) { |
998 | case QCOW2_CLUSTER_COMPRESSED: | |
999 | { | |
1000 | int nb_csectors; | |
1001 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
1002 | s->csize_mask) + 1; | |
1003 | qcow2_free_clusters(bs, | |
1004 | (l2_entry & s->cluster_offset_mask) & ~511, | |
6cfcb9b8 | 1005 | nb_csectors * 512, type); |
c7a4c37a KW |
1006 | } |
1007 | break; | |
1008 | case QCOW2_CLUSTER_NORMAL: | |
8f730dd2 HR |
1009 | case QCOW2_CLUSTER_ZERO: |
1010 | if (l2_entry & L2E_OFFSET_MASK) { | |
a97c67ee HR |
1011 | if (offset_into_cluster(s, l2_entry & L2E_OFFSET_MASK)) { |
1012 | qcow2_signal_corruption(bs, false, -1, -1, | |
1013 | "Cannot free unaligned cluster %#llx", | |
1014 | l2_entry & L2E_OFFSET_MASK); | |
1015 | } else { | |
1016 | qcow2_free_clusters(bs, l2_entry & L2E_OFFSET_MASK, | |
1017 | nb_clusters << s->cluster_bits, type); | |
1018 | } | |
8f730dd2 | 1019 | } |
c7a4c37a KW |
1020 | break; |
1021 | case QCOW2_CLUSTER_UNALLOCATED: | |
1022 | break; | |
1023 | default: | |
1024 | abort(); | |
45aba42f | 1025 | } |
45aba42f KW |
1026 | } |
1027 | ||
f7d0fe02 KW |
1028 | |
1029 | ||
1030 | /*********************************************************/ | |
1031 | /* snapshots and image creation */ | |
1032 | ||
1033 | ||
1034 | ||
f7d0fe02 | 1035 | /* update the refcounts of snapshots and the copied flag */ |
ed6ccf0f KW |
1036 | int qcow2_update_snapshot_refcount(BlockDriverState *bs, |
1037 | int64_t l1_table_offset, int l1_size, int addend) | |
f7d0fe02 | 1038 | { |
ff99129a | 1039 | BDRVQcow2State *s = bs->opaque; |
0e06528e | 1040 | uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, refcount; |
de82815d | 1041 | bool l1_allocated = false; |
f7d0fe02 | 1042 | int64_t old_offset, old_l2_offset; |
7324c10f | 1043 | int i, j, l1_modified = 0, nb_csectors; |
29c1a730 | 1044 | int ret; |
f7d0fe02 | 1045 | |
2aabe7c7 HR |
1046 | assert(addend >= -1 && addend <= 1); |
1047 | ||
f7d0fe02 KW |
1048 | l2_table = NULL; |
1049 | l1_table = NULL; | |
1050 | l1_size2 = l1_size * sizeof(uint64_t); | |
43a0cac4 | 1051 | |
0b919fae KW |
1052 | s->cache_discards = true; |
1053 | ||
43a0cac4 KW |
1054 | /* WARNING: qcow2_snapshot_goto relies on this function not using the |
1055 | * l1_table_offset when it is the current s->l1_table_offset! Be careful | |
1056 | * when changing this! */ | |
f7d0fe02 | 1057 | if (l1_table_offset != s->l1_table_offset) { |
de82815d KW |
1058 | l1_table = g_try_malloc0(align_offset(l1_size2, 512)); |
1059 | if (l1_size2 && l1_table == NULL) { | |
1060 | ret = -ENOMEM; | |
1061 | goto fail; | |
1062 | } | |
1063 | l1_allocated = true; | |
c2bc78b6 KW |
1064 | |
1065 | ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2); | |
1066 | if (ret < 0) { | |
f7d0fe02 | 1067 | goto fail; |
93913dfd KW |
1068 | } |
1069 | ||
f7d0fe02 KW |
1070 | for(i = 0;i < l1_size; i++) |
1071 | be64_to_cpus(&l1_table[i]); | |
1072 | } else { | |
1073 | assert(l1_size == s->l1_size); | |
1074 | l1_table = s->l1_table; | |
de82815d | 1075 | l1_allocated = false; |
f7d0fe02 KW |
1076 | } |
1077 | ||
f7d0fe02 KW |
1078 | for(i = 0; i < l1_size; i++) { |
1079 | l2_offset = l1_table[i]; | |
1080 | if (l2_offset) { | |
1081 | old_l2_offset = l2_offset; | |
8e37f681 | 1082 | l2_offset &= L1E_OFFSET_MASK; |
29c1a730 | 1083 | |
a97c67ee HR |
1084 | if (offset_into_cluster(s, l2_offset)) { |
1085 | qcow2_signal_corruption(bs, true, -1, -1, "L2 table offset %#" | |
1086 | PRIx64 " unaligned (L1 index: %#x)", | |
1087 | l2_offset, i); | |
1088 | ret = -EIO; | |
1089 | goto fail; | |
1090 | } | |
1091 | ||
29c1a730 KW |
1092 | ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, |
1093 | (void**) &l2_table); | |
1094 | if (ret < 0) { | |
f7d0fe02 | 1095 | goto fail; |
29c1a730 KW |
1096 | } |
1097 | ||
f7d0fe02 | 1098 | for(j = 0; j < s->l2_size; j++) { |
8b81a7b6 HR |
1099 | uint64_t cluster_index; |
1100 | ||
f7d0fe02 | 1101 | offset = be64_to_cpu(l2_table[j]); |
8b81a7b6 HR |
1102 | old_offset = offset; |
1103 | offset &= ~QCOW_OFLAG_COPIED; | |
1104 | ||
1105 | switch (qcow2_get_cluster_type(offset)) { | |
1106 | case QCOW2_CLUSTER_COMPRESSED: | |
f7d0fe02 KW |
1107 | nb_csectors = ((offset >> s->csize_shift) & |
1108 | s->csize_mask) + 1; | |
db3a964f | 1109 | if (addend != 0) { |
db3a964f KW |
1110 | ret = update_refcount(bs, |
1111 | (offset & s->cluster_offset_mask) & ~511, | |
2aabe7c7 | 1112 | nb_csectors * 512, abs(addend), addend < 0, |
6cfcb9b8 | 1113 | QCOW2_DISCARD_SNAPSHOT); |
db3a964f KW |
1114 | if (ret < 0) { |
1115 | goto fail; | |
1116 | } | |
1117 | } | |
f7d0fe02 KW |
1118 | /* compressed clusters are never modified */ |
1119 | refcount = 2; | |
8b81a7b6 HR |
1120 | break; |
1121 | ||
1122 | case QCOW2_CLUSTER_NORMAL: | |
1123 | case QCOW2_CLUSTER_ZERO: | |
a97c67ee HR |
1124 | if (offset_into_cluster(s, offset & L2E_OFFSET_MASK)) { |
1125 | qcow2_signal_corruption(bs, true, -1, -1, "Data " | |
1126 | "cluster offset %#llx " | |
1127 | "unaligned (L2 offset: %#" | |
1128 | PRIx64 ", L2 index: %#x)", | |
1129 | offset & L2E_OFFSET_MASK, | |
1130 | l2_offset, j); | |
1131 | ret = -EIO; | |
1132 | goto fail; | |
1133 | } | |
1134 | ||
8b81a7b6 HR |
1135 | cluster_index = (offset & L2E_OFFSET_MASK) >> s->cluster_bits; |
1136 | if (!cluster_index) { | |
1137 | /* unallocated */ | |
1138 | refcount = 0; | |
1139 | break; | |
1140 | } | |
f7d0fe02 | 1141 | if (addend != 0) { |
c6e9d8ae | 1142 | ret = qcow2_update_cluster_refcount(bs, |
2aabe7c7 | 1143 | cluster_index, abs(addend), addend < 0, |
32b6444d | 1144 | QCOW2_DISCARD_SNAPSHOT); |
c6e9d8ae HR |
1145 | if (ret < 0) { |
1146 | goto fail; | |
1147 | } | |
f7d0fe02 | 1148 | } |
018faafd | 1149 | |
7324c10f HR |
1150 | ret = qcow2_get_refcount(bs, cluster_index, &refcount); |
1151 | if (ret < 0) { | |
018faafd KW |
1152 | goto fail; |
1153 | } | |
8b81a7b6 | 1154 | break; |
f7d0fe02 | 1155 | |
8b81a7b6 HR |
1156 | case QCOW2_CLUSTER_UNALLOCATED: |
1157 | refcount = 0; | |
1158 | break; | |
1159 | ||
1160 | default: | |
1161 | abort(); | |
1162 | } | |
1163 | ||
1164 | if (refcount == 1) { | |
1165 | offset |= QCOW_OFLAG_COPIED; | |
1166 | } | |
1167 | if (offset != old_offset) { | |
1168 | if (addend > 0) { | |
1169 | qcow2_cache_set_dependency(bs, s->l2_table_cache, | |
1170 | s->refcount_block_cache); | |
f7d0fe02 | 1171 | } |
8b81a7b6 | 1172 | l2_table[j] = cpu_to_be64(offset); |
72e80b89 AG |
1173 | qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, |
1174 | l2_table); | |
f7d0fe02 KW |
1175 | } |
1176 | } | |
29c1a730 | 1177 | |
a3f1afb4 | 1178 | qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table); |
29c1a730 | 1179 | |
f7d0fe02 | 1180 | if (addend != 0) { |
c6e9d8ae HR |
1181 | ret = qcow2_update_cluster_refcount(bs, l2_offset >> |
1182 | s->cluster_bits, | |
2aabe7c7 | 1183 | abs(addend), addend < 0, |
c6e9d8ae HR |
1184 | QCOW2_DISCARD_SNAPSHOT); |
1185 | if (ret < 0) { | |
1186 | goto fail; | |
1187 | } | |
f7d0fe02 | 1188 | } |
7324c10f HR |
1189 | ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, |
1190 | &refcount); | |
1191 | if (ret < 0) { | |
018faafd KW |
1192 | goto fail; |
1193 | } else if (refcount == 1) { | |
f7d0fe02 KW |
1194 | l2_offset |= QCOW_OFLAG_COPIED; |
1195 | } | |
1196 | if (l2_offset != old_l2_offset) { | |
1197 | l1_table[i] = l2_offset; | |
1198 | l1_modified = 1; | |
1199 | } | |
1200 | } | |
1201 | } | |
93913dfd | 1202 | |
2154f24e | 1203 | ret = bdrv_flush(bs); |
93913dfd KW |
1204 | fail: |
1205 | if (l2_table) { | |
1206 | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); | |
1207 | } | |
1208 | ||
0b919fae KW |
1209 | s->cache_discards = false; |
1210 | qcow2_process_discards(bs, ret); | |
1211 | ||
43a0cac4 | 1212 | /* Update L1 only if it isn't deleted anyway (addend = -1) */ |
c2b6ff51 KW |
1213 | if (ret == 0 && addend >= 0 && l1_modified) { |
1214 | for (i = 0; i < l1_size; i++) { | |
f7d0fe02 | 1215 | cpu_to_be64s(&l1_table[i]); |
c2b6ff51 KW |
1216 | } |
1217 | ||
1218 | ret = bdrv_pwrite_sync(bs->file, l1_table_offset, l1_table, l1_size2); | |
1219 | ||
1220 | for (i = 0; i < l1_size; i++) { | |
f7d0fe02 | 1221 | be64_to_cpus(&l1_table[i]); |
c2b6ff51 | 1222 | } |
f7d0fe02 KW |
1223 | } |
1224 | if (l1_allocated) | |
7267c094 | 1225 | g_free(l1_table); |
93913dfd | 1226 | return ret; |
f7d0fe02 KW |
1227 | } |
1228 | ||
1229 | ||
1230 | ||
1231 | ||
1232 | /*********************************************************/ | |
1233 | /* refcount checking functions */ | |
1234 | ||
1235 | ||
ff99129a | 1236 | static size_t refcount_array_byte_size(BDRVQcow2State *s, uint64_t entries) |
5fee192e HR |
1237 | { |
1238 | /* This assertion holds because there is no way we can address more than | |
1239 | * 2^(64 - 9) clusters at once (with cluster size 512 = 2^9, and because | |
1240 | * offsets have to be representable in bytes); due to every cluster | |
1241 | * corresponding to one refcount entry, we are well below that limit */ | |
1242 | assert(entries < (UINT64_C(1) << (64 - 9))); | |
1243 | ||
1244 | /* Thanks to the assertion this will not overflow, because | |
1245 | * s->refcount_order < 7. | |
1246 | * (note: x << s->refcount_order == x * s->refcount_bits) */ | |
1247 | return DIV_ROUND_UP(entries << s->refcount_order, 8); | |
1248 | } | |
1249 | ||
1250 | /** | |
1251 | * Reallocates *array so that it can hold new_size entries. *size must contain | |
1252 | * the current number of entries in *array. If the reallocation fails, *array | |
1253 | * and *size will not be modified and -errno will be returned. If the | |
1254 | * reallocation is successful, *array will be set to the new buffer, *size | |
1255 | * will be set to new_size and 0 will be returned. The size of the reallocated | |
1256 | * refcount array buffer will be aligned to a cluster boundary, and the newly | |
1257 | * allocated area will be zeroed. | |
1258 | */ | |
ff99129a | 1259 | static int realloc_refcount_array(BDRVQcow2State *s, void **array, |
5fee192e HR |
1260 | int64_t *size, int64_t new_size) |
1261 | { | |
1262 | size_t old_byte_size, new_byte_size; | |
7453c96b | 1263 | void *new_ptr; |
5fee192e HR |
1264 | |
1265 | /* Round to clusters so the array can be directly written to disk */ | |
1266 | old_byte_size = size_to_clusters(s, refcount_array_byte_size(s, *size)) | |
1267 | * s->cluster_size; | |
1268 | new_byte_size = size_to_clusters(s, refcount_array_byte_size(s, new_size)) | |
1269 | * s->cluster_size; | |
1270 | ||
1271 | if (new_byte_size == old_byte_size) { | |
1272 | *size = new_size; | |
1273 | return 0; | |
1274 | } | |
1275 | ||
1276 | assert(new_byte_size > 0); | |
1277 | ||
1278 | new_ptr = g_try_realloc(*array, new_byte_size); | |
1279 | if (!new_ptr) { | |
1280 | return -ENOMEM; | |
1281 | } | |
1282 | ||
1283 | if (new_byte_size > old_byte_size) { | |
1284 | memset((void *)((uintptr_t)new_ptr + old_byte_size), 0, | |
1285 | new_byte_size - old_byte_size); | |
1286 | } | |
1287 | ||
1288 | *array = new_ptr; | |
1289 | *size = new_size; | |
1290 | ||
1291 | return 0; | |
1292 | } | |
f7d0fe02 KW |
1293 | |
1294 | /* | |
1295 | * Increases the refcount for a range of clusters in a given refcount table. | |
1296 | * This is used to construct a temporary refcount table out of L1 and L2 tables | |
b6af0975 | 1297 | * which can be compared to the refcount table saved in the image. |
f7d0fe02 | 1298 | * |
9ac228e0 | 1299 | * Modifies the number of errors in res. |
f7d0fe02 | 1300 | */ |
fef4d3d5 HR |
1301 | static int inc_refcounts(BlockDriverState *bs, |
1302 | BdrvCheckResult *res, | |
7453c96b | 1303 | void **refcount_table, |
641bb63c | 1304 | int64_t *refcount_table_size, |
fef4d3d5 | 1305 | int64_t offset, int64_t size) |
f7d0fe02 | 1306 | { |
ff99129a | 1307 | BDRVQcow2State *s = bs->opaque; |
7453c96b | 1308 | uint64_t start, last, cluster_offset, k, refcount; |
5fee192e | 1309 | int ret; |
f7d0fe02 | 1310 | |
fef4d3d5 HR |
1311 | if (size <= 0) { |
1312 | return 0; | |
1313 | } | |
f7d0fe02 | 1314 | |
ac95acdb HT |
1315 | start = start_of_cluster(s, offset); |
1316 | last = start_of_cluster(s, offset + size - 1); | |
f7d0fe02 KW |
1317 | for(cluster_offset = start; cluster_offset <= last; |
1318 | cluster_offset += s->cluster_size) { | |
1319 | k = cluster_offset >> s->cluster_bits; | |
641bb63c | 1320 | if (k >= *refcount_table_size) { |
5fee192e HR |
1321 | ret = realloc_refcount_array(s, refcount_table, |
1322 | refcount_table_size, k + 1); | |
1323 | if (ret < 0) { | |
641bb63c | 1324 | res->check_errors++; |
5fee192e | 1325 | return ret; |
f7d0fe02 | 1326 | } |
641bb63c HR |
1327 | } |
1328 | ||
7453c96b HR |
1329 | refcount = s->get_refcount(*refcount_table, k); |
1330 | if (refcount == s->refcount_max) { | |
641bb63c HR |
1331 | fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64 |
1332 | "\n", cluster_offset); | |
1333 | res->corruptions++; | |
7453c96b | 1334 | continue; |
f7d0fe02 | 1335 | } |
7453c96b | 1336 | s->set_refcount(*refcount_table, k, refcount + 1); |
f7d0fe02 | 1337 | } |
fef4d3d5 HR |
1338 | |
1339 | return 0; | |
f7d0fe02 KW |
1340 | } |
1341 | ||
801f7044 SH |
1342 | /* Flags for check_refcounts_l1() and check_refcounts_l2() */ |
1343 | enum { | |
fba31bae | 1344 | CHECK_FRAG_INFO = 0x2, /* update BlockFragInfo counters */ |
801f7044 SH |
1345 | }; |
1346 | ||
f7d0fe02 KW |
1347 | /* |
1348 | * Increases the refcount in the given refcount table for the all clusters | |
1349 | * referenced in the L2 table. While doing so, performs some checks on L2 | |
1350 | * entries. | |
1351 | * | |
1352 | * Returns the number of errors found by the checks or -errno if an internal | |
1353 | * error occurred. | |
1354 | */ | |
9ac228e0 | 1355 | static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, |
7453c96b HR |
1356 | void **refcount_table, |
1357 | int64_t *refcount_table_size, int64_t l2_offset, | |
1358 | int flags) | |
f7d0fe02 | 1359 | { |
ff99129a | 1360 | BDRVQcow2State *s = bs->opaque; |
afdf0abe | 1361 | uint64_t *l2_table, l2_entry; |
fba31bae | 1362 | uint64_t next_contiguous_offset = 0; |
ad27390c | 1363 | int i, l2_size, nb_csectors, ret; |
f7d0fe02 KW |
1364 | |
1365 | /* Read L2 table from disk */ | |
1366 | l2_size = s->l2_size * sizeof(uint64_t); | |
7267c094 | 1367 | l2_table = g_malloc(l2_size); |
f7d0fe02 | 1368 | |
ad27390c HR |
1369 | ret = bdrv_pread(bs->file, l2_offset, l2_table, l2_size); |
1370 | if (ret < 0) { | |
1371 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l2\n"); | |
1372 | res->check_errors++; | |
f7d0fe02 | 1373 | goto fail; |
ad27390c | 1374 | } |
f7d0fe02 KW |
1375 | |
1376 | /* Do the actual checks */ | |
1377 | for(i = 0; i < s->l2_size; i++) { | |
afdf0abe KW |
1378 | l2_entry = be64_to_cpu(l2_table[i]); |
1379 | ||
1380 | switch (qcow2_get_cluster_type(l2_entry)) { | |
1381 | case QCOW2_CLUSTER_COMPRESSED: | |
1382 | /* Compressed clusters don't have QCOW_OFLAG_COPIED */ | |
1383 | if (l2_entry & QCOW_OFLAG_COPIED) { | |
1384 | fprintf(stderr, "ERROR: cluster %" PRId64 ": " | |
1385 | "copied flag must never be set for compressed " | |
1386 | "clusters\n", l2_entry >> s->cluster_bits); | |
1387 | l2_entry &= ~QCOW_OFLAG_COPIED; | |
1388 | res->corruptions++; | |
1389 | } | |
f7d0fe02 | 1390 | |
afdf0abe KW |
1391 | /* Mark cluster as used */ |
1392 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
1393 | s->csize_mask) + 1; | |
1394 | l2_entry &= s->cluster_offset_mask; | |
fef4d3d5 HR |
1395 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1396 | l2_entry & ~511, nb_csectors * 512); | |
1397 | if (ret < 0) { | |
1398 | goto fail; | |
1399 | } | |
fba31bae SH |
1400 | |
1401 | if (flags & CHECK_FRAG_INFO) { | |
1402 | res->bfi.allocated_clusters++; | |
4db35162 | 1403 | res->bfi.compressed_clusters++; |
fba31bae SH |
1404 | |
1405 | /* Compressed clusters are fragmented by nature. Since they | |
1406 | * take up sub-sector space but we only have sector granularity | |
1407 | * I/O we need to re-read the same sectors even for adjacent | |
1408 | * compressed clusters. | |
1409 | */ | |
1410 | res->bfi.fragmented_clusters++; | |
1411 | } | |
afdf0abe | 1412 | break; |
f7d0fe02 | 1413 | |
6377af48 KW |
1414 | case QCOW2_CLUSTER_ZERO: |
1415 | if ((l2_entry & L2E_OFFSET_MASK) == 0) { | |
1416 | break; | |
1417 | } | |
1418 | /* fall through */ | |
1419 | ||
afdf0abe KW |
1420 | case QCOW2_CLUSTER_NORMAL: |
1421 | { | |
afdf0abe | 1422 | uint64_t offset = l2_entry & L2E_OFFSET_MASK; |
f7d0fe02 | 1423 | |
fba31bae SH |
1424 | if (flags & CHECK_FRAG_INFO) { |
1425 | res->bfi.allocated_clusters++; | |
1426 | if (next_contiguous_offset && | |
1427 | offset != next_contiguous_offset) { | |
1428 | res->bfi.fragmented_clusters++; | |
1429 | } | |
1430 | next_contiguous_offset = offset + s->cluster_size; | |
1431 | } | |
1432 | ||
afdf0abe | 1433 | /* Mark cluster as used */ |
fef4d3d5 HR |
1434 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1435 | offset, s->cluster_size); | |
1436 | if (ret < 0) { | |
1437 | goto fail; | |
1438 | } | |
afdf0abe KW |
1439 | |
1440 | /* Correct offsets are cluster aligned */ | |
ac95acdb | 1441 | if (offset_into_cluster(s, offset)) { |
afdf0abe KW |
1442 | fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " |
1443 | "properly aligned; L2 entry corrupted.\n", offset); | |
1444 | res->corruptions++; | |
1445 | } | |
1446 | break; | |
1447 | } | |
1448 | ||
1449 | case QCOW2_CLUSTER_UNALLOCATED: | |
1450 | break; | |
1451 | ||
1452 | default: | |
1453 | abort(); | |
f7d0fe02 KW |
1454 | } |
1455 | } | |
1456 | ||
7267c094 | 1457 | g_free(l2_table); |
9ac228e0 | 1458 | return 0; |
f7d0fe02 KW |
1459 | |
1460 | fail: | |
7267c094 | 1461 | g_free(l2_table); |
ad27390c | 1462 | return ret; |
f7d0fe02 KW |
1463 | } |
1464 | ||
1465 | /* | |
1466 | * Increases the refcount for the L1 table, its L2 tables and all referenced | |
1467 | * clusters in the given refcount table. While doing so, performs some checks | |
1468 | * on L1 and L2 entries. | |
1469 | * | |
1470 | * Returns the number of errors found by the checks or -errno if an internal | |
1471 | * error occurred. | |
1472 | */ | |
1473 | static int check_refcounts_l1(BlockDriverState *bs, | |
9ac228e0 | 1474 | BdrvCheckResult *res, |
7453c96b | 1475 | void **refcount_table, |
641bb63c | 1476 | int64_t *refcount_table_size, |
f7d0fe02 | 1477 | int64_t l1_table_offset, int l1_size, |
801f7044 | 1478 | int flags) |
f7d0fe02 | 1479 | { |
ff99129a | 1480 | BDRVQcow2State *s = bs->opaque; |
fef4d3d5 | 1481 | uint64_t *l1_table = NULL, l2_offset, l1_size2; |
4f6ed88c | 1482 | int i, ret; |
f7d0fe02 KW |
1483 | |
1484 | l1_size2 = l1_size * sizeof(uint64_t); | |
1485 | ||
1486 | /* Mark L1 table as used */ | |
fef4d3d5 HR |
1487 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1488 | l1_table_offset, l1_size2); | |
1489 | if (ret < 0) { | |
1490 | goto fail; | |
1491 | } | |
f7d0fe02 KW |
1492 | |
1493 | /* Read L1 table entries from disk */ | |
fef4d3d5 | 1494 | if (l1_size2 > 0) { |
de82815d KW |
1495 | l1_table = g_try_malloc(l1_size2); |
1496 | if (l1_table == NULL) { | |
1497 | ret = -ENOMEM; | |
ad27390c | 1498 | res->check_errors++; |
de82815d KW |
1499 | goto fail; |
1500 | } | |
ad27390c HR |
1501 | ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2); |
1502 | if (ret < 0) { | |
1503 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); | |
1504 | res->check_errors++; | |
702ef63f | 1505 | goto fail; |
ad27390c | 1506 | } |
702ef63f KW |
1507 | for(i = 0;i < l1_size; i++) |
1508 | be64_to_cpus(&l1_table[i]); | |
1509 | } | |
f7d0fe02 KW |
1510 | |
1511 | /* Do the actual checks */ | |
1512 | for(i = 0; i < l1_size; i++) { | |
1513 | l2_offset = l1_table[i]; | |
1514 | if (l2_offset) { | |
f7d0fe02 | 1515 | /* Mark L2 table as used */ |
afdf0abe | 1516 | l2_offset &= L1E_OFFSET_MASK; |
fef4d3d5 HR |
1517 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1518 | l2_offset, s->cluster_size); | |
1519 | if (ret < 0) { | |
1520 | goto fail; | |
1521 | } | |
f7d0fe02 KW |
1522 | |
1523 | /* L2 tables are cluster aligned */ | |
ac95acdb | 1524 | if (offset_into_cluster(s, l2_offset)) { |
f7d0fe02 KW |
1525 | fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " |
1526 | "cluster aligned; L1 entry corrupted\n", l2_offset); | |
9ac228e0 | 1527 | res->corruptions++; |
f7d0fe02 KW |
1528 | } |
1529 | ||
1530 | /* Process and check L2 entries */ | |
9ac228e0 | 1531 | ret = check_refcounts_l2(bs, res, refcount_table, |
801f7044 | 1532 | refcount_table_size, l2_offset, flags); |
f7d0fe02 KW |
1533 | if (ret < 0) { |
1534 | goto fail; | |
1535 | } | |
f7d0fe02 KW |
1536 | } |
1537 | } | |
7267c094 | 1538 | g_free(l1_table); |
9ac228e0 | 1539 | return 0; |
f7d0fe02 KW |
1540 | |
1541 | fail: | |
7267c094 | 1542 | g_free(l1_table); |
ad27390c | 1543 | return ret; |
f7d0fe02 KW |
1544 | } |
1545 | ||
4f6ed88c HR |
1546 | /* |
1547 | * Checks the OFLAG_COPIED flag for all L1 and L2 entries. | |
1548 | * | |
1549 | * This function does not print an error message nor does it increment | |
44751917 HR |
1550 | * check_errors if qcow2_get_refcount fails (this is because such an error will |
1551 | * have been already detected and sufficiently signaled by the calling function | |
4f6ed88c HR |
1552 | * (qcow2_check_refcounts) by the time this function is called). |
1553 | */ | |
e23e400e HR |
1554 | static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res, |
1555 | BdrvCheckMode fix) | |
4f6ed88c | 1556 | { |
ff99129a | 1557 | BDRVQcow2State *s = bs->opaque; |
4f6ed88c HR |
1558 | uint64_t *l2_table = qemu_blockalign(bs, s->cluster_size); |
1559 | int ret; | |
0e06528e | 1560 | uint64_t refcount; |
4f6ed88c HR |
1561 | int i, j; |
1562 | ||
1563 | for (i = 0; i < s->l1_size; i++) { | |
1564 | uint64_t l1_entry = s->l1_table[i]; | |
1565 | uint64_t l2_offset = l1_entry & L1E_OFFSET_MASK; | |
e23e400e | 1566 | bool l2_dirty = false; |
4f6ed88c HR |
1567 | |
1568 | if (!l2_offset) { | |
1569 | continue; | |
1570 | } | |
1571 | ||
7324c10f HR |
1572 | ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, |
1573 | &refcount); | |
1574 | if (ret < 0) { | |
4f6ed88c HR |
1575 | /* don't print message nor increment check_errors */ |
1576 | continue; | |
1577 | } | |
1578 | if ((refcount == 1) != ((l1_entry & QCOW_OFLAG_COPIED) != 0)) { | |
e23e400e | 1579 | fprintf(stderr, "%s OFLAG_COPIED L2 cluster: l1_index=%d " |
0e06528e | 1580 | "l1_entry=%" PRIx64 " refcount=%" PRIu64 "\n", |
e23e400e HR |
1581 | fix & BDRV_FIX_ERRORS ? "Repairing" : |
1582 | "ERROR", | |
4f6ed88c | 1583 | i, l1_entry, refcount); |
e23e400e HR |
1584 | if (fix & BDRV_FIX_ERRORS) { |
1585 | s->l1_table[i] = refcount == 1 | |
1586 | ? l1_entry | QCOW_OFLAG_COPIED | |
1587 | : l1_entry & ~QCOW_OFLAG_COPIED; | |
1588 | ret = qcow2_write_l1_entry(bs, i); | |
1589 | if (ret < 0) { | |
1590 | res->check_errors++; | |
1591 | goto fail; | |
1592 | } | |
1593 | res->corruptions_fixed++; | |
1594 | } else { | |
1595 | res->corruptions++; | |
1596 | } | |
4f6ed88c HR |
1597 | } |
1598 | ||
1599 | ret = bdrv_pread(bs->file, l2_offset, l2_table, | |
1600 | s->l2_size * sizeof(uint64_t)); | |
1601 | if (ret < 0) { | |
1602 | fprintf(stderr, "ERROR: Could not read L2 table: %s\n", | |
1603 | strerror(-ret)); | |
1604 | res->check_errors++; | |
1605 | goto fail; | |
1606 | } | |
1607 | ||
1608 | for (j = 0; j < s->l2_size; j++) { | |
1609 | uint64_t l2_entry = be64_to_cpu(l2_table[j]); | |
1610 | uint64_t data_offset = l2_entry & L2E_OFFSET_MASK; | |
1611 | int cluster_type = qcow2_get_cluster_type(l2_entry); | |
1612 | ||
1613 | if ((cluster_type == QCOW2_CLUSTER_NORMAL) || | |
1614 | ((cluster_type == QCOW2_CLUSTER_ZERO) && (data_offset != 0))) { | |
7324c10f HR |
1615 | ret = qcow2_get_refcount(bs, |
1616 | data_offset >> s->cluster_bits, | |
1617 | &refcount); | |
1618 | if (ret < 0) { | |
4f6ed88c HR |
1619 | /* don't print message nor increment check_errors */ |
1620 | continue; | |
1621 | } | |
1622 | if ((refcount == 1) != ((l2_entry & QCOW_OFLAG_COPIED) != 0)) { | |
e23e400e | 1623 | fprintf(stderr, "%s OFLAG_COPIED data cluster: " |
0e06528e | 1624 | "l2_entry=%" PRIx64 " refcount=%" PRIu64 "\n", |
e23e400e HR |
1625 | fix & BDRV_FIX_ERRORS ? "Repairing" : |
1626 | "ERROR", | |
4f6ed88c | 1627 | l2_entry, refcount); |
e23e400e HR |
1628 | if (fix & BDRV_FIX_ERRORS) { |
1629 | l2_table[j] = cpu_to_be64(refcount == 1 | |
1630 | ? l2_entry | QCOW_OFLAG_COPIED | |
1631 | : l2_entry & ~QCOW_OFLAG_COPIED); | |
1632 | l2_dirty = true; | |
1633 | res->corruptions_fixed++; | |
1634 | } else { | |
1635 | res->corruptions++; | |
1636 | } | |
4f6ed88c HR |
1637 | } |
1638 | } | |
1639 | } | |
e23e400e HR |
1640 | |
1641 | if (l2_dirty) { | |
231bb267 HR |
1642 | ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L2, |
1643 | l2_offset, s->cluster_size); | |
e23e400e HR |
1644 | if (ret < 0) { |
1645 | fprintf(stderr, "ERROR: Could not write L2 table; metadata " | |
1646 | "overlap check failed: %s\n", strerror(-ret)); | |
1647 | res->check_errors++; | |
1648 | goto fail; | |
1649 | } | |
1650 | ||
1651 | ret = bdrv_pwrite(bs->file, l2_offset, l2_table, s->cluster_size); | |
1652 | if (ret < 0) { | |
1653 | fprintf(stderr, "ERROR: Could not write L2 table: %s\n", | |
1654 | strerror(-ret)); | |
1655 | res->check_errors++; | |
1656 | goto fail; | |
1657 | } | |
1658 | } | |
4f6ed88c HR |
1659 | } |
1660 | ||
1661 | ret = 0; | |
1662 | ||
1663 | fail: | |
1664 | qemu_vfree(l2_table); | |
1665 | return ret; | |
1666 | } | |
1667 | ||
6ca56bf5 HR |
1668 | /* |
1669 | * Checks consistency of refblocks and accounts for each refblock in | |
1670 | * *refcount_table. | |
1671 | */ | |
1672 | static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 | 1673 | BdrvCheckMode fix, bool *rebuild, |
7453c96b | 1674 | void **refcount_table, int64_t *nb_clusters) |
6ca56bf5 | 1675 | { |
ff99129a | 1676 | BDRVQcow2State *s = bs->opaque; |
001c158d | 1677 | int64_t i, size; |
fef4d3d5 | 1678 | int ret; |
6ca56bf5 | 1679 | |
f7d0fe02 | 1680 | for(i = 0; i < s->refcount_table_size; i++) { |
6882c8fa | 1681 | uint64_t offset, cluster; |
f7d0fe02 | 1682 | offset = s->refcount_table[i]; |
6882c8fa | 1683 | cluster = offset >> s->cluster_bits; |
746c3cb5 KW |
1684 | |
1685 | /* Refcount blocks are cluster aligned */ | |
ac95acdb | 1686 | if (offset_into_cluster(s, offset)) { |
166acf54 | 1687 | fprintf(stderr, "ERROR refcount block %" PRId64 " is not " |
746c3cb5 | 1688 | "cluster aligned; refcount table entry corrupted\n", i); |
9ac228e0 | 1689 | res->corruptions++; |
f307b255 | 1690 | *rebuild = true; |
6882c8fa KW |
1691 | continue; |
1692 | } | |
1693 | ||
6ca56bf5 | 1694 | if (cluster >= *nb_clusters) { |
001c158d HR |
1695 | fprintf(stderr, "%s refcount block %" PRId64 " is outside image\n", |
1696 | fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i); | |
1697 | ||
1698 | if (fix & BDRV_FIX_ERRORS) { | |
5fee192e | 1699 | int64_t new_nb_clusters; |
001c158d HR |
1700 | |
1701 | if (offset > INT64_MAX - s->cluster_size) { | |
1702 | ret = -EINVAL; | |
1703 | goto resize_fail; | |
1704 | } | |
1705 | ||
1706 | ret = bdrv_truncate(bs->file, offset + s->cluster_size); | |
1707 | if (ret < 0) { | |
1708 | goto resize_fail; | |
1709 | } | |
1710 | size = bdrv_getlength(bs->file); | |
1711 | if (size < 0) { | |
1712 | ret = size; | |
1713 | goto resize_fail; | |
1714 | } | |
1715 | ||
5fee192e HR |
1716 | new_nb_clusters = size_to_clusters(s, size); |
1717 | assert(new_nb_clusters >= *nb_clusters); | |
001c158d | 1718 | |
5fee192e HR |
1719 | ret = realloc_refcount_array(s, refcount_table, |
1720 | nb_clusters, new_nb_clusters); | |
1721 | if (ret < 0) { | |
001c158d | 1722 | res->check_errors++; |
5fee192e | 1723 | return ret; |
001c158d | 1724 | } |
001c158d HR |
1725 | |
1726 | if (cluster >= *nb_clusters) { | |
1727 | ret = -EINVAL; | |
1728 | goto resize_fail; | |
1729 | } | |
1730 | ||
1731 | res->corruptions_fixed++; | |
1732 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, | |
1733 | offset, s->cluster_size); | |
1734 | if (ret < 0) { | |
1735 | return ret; | |
1736 | } | |
1737 | /* No need to check whether the refcount is now greater than 1: | |
1738 | * This area was just allocated and zeroed, so it can only be | |
1739 | * exactly 1 after inc_refcounts() */ | |
1740 | continue; | |
1741 | ||
1742 | resize_fail: | |
1743 | res->corruptions++; | |
f307b255 | 1744 | *rebuild = true; |
001c158d HR |
1745 | fprintf(stderr, "ERROR could not resize image: %s\n", |
1746 | strerror(-ret)); | |
1747 | } else { | |
1748 | res->corruptions++; | |
1749 | } | |
6882c8fa | 1750 | continue; |
746c3cb5 KW |
1751 | } |
1752 | ||
f7d0fe02 | 1753 | if (offset != 0) { |
641bb63c | 1754 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1755 | offset, s->cluster_size); |
1756 | if (ret < 0) { | |
1757 | return ret; | |
1758 | } | |
7453c96b | 1759 | if (s->get_refcount(*refcount_table, cluster) != 1) { |
f307b255 | 1760 | fprintf(stderr, "ERROR refcount block %" PRId64 |
7453c96b HR |
1761 | " refcount=%" PRIu64 "\n", i, |
1762 | s->get_refcount(*refcount_table, cluster)); | |
f307b255 HR |
1763 | res->corruptions++; |
1764 | *rebuild = true; | |
746c3cb5 | 1765 | } |
f7d0fe02 KW |
1766 | } |
1767 | } | |
1768 | ||
6ca56bf5 HR |
1769 | return 0; |
1770 | } | |
1771 | ||
057a3fe5 HR |
1772 | /* |
1773 | * Calculates an in-memory refcount table. | |
1774 | */ | |
1775 | static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 | 1776 | BdrvCheckMode fix, bool *rebuild, |
7453c96b | 1777 | void **refcount_table, int64_t *nb_clusters) |
057a3fe5 | 1778 | { |
ff99129a | 1779 | BDRVQcow2State *s = bs->opaque; |
057a3fe5 HR |
1780 | int64_t i; |
1781 | QCowSnapshot *sn; | |
1782 | int ret; | |
1783 | ||
9696df21 | 1784 | if (!*refcount_table) { |
5fee192e HR |
1785 | int64_t old_size = 0; |
1786 | ret = realloc_refcount_array(s, refcount_table, | |
1787 | &old_size, *nb_clusters); | |
1788 | if (ret < 0) { | |
9696df21 | 1789 | res->check_errors++; |
5fee192e | 1790 | return ret; |
9696df21 | 1791 | } |
057a3fe5 HR |
1792 | } |
1793 | ||
1794 | /* header */ | |
641bb63c | 1795 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1796 | 0, s->cluster_size); |
1797 | if (ret < 0) { | |
1798 | return ret; | |
1799 | } | |
057a3fe5 HR |
1800 | |
1801 | /* current L1 table */ | |
641bb63c | 1802 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
057a3fe5 HR |
1803 | s->l1_table_offset, s->l1_size, CHECK_FRAG_INFO); |
1804 | if (ret < 0) { | |
1805 | return ret; | |
1806 | } | |
1807 | ||
1808 | /* snapshots */ | |
1809 | for (i = 0; i < s->nb_snapshots; i++) { | |
1810 | sn = s->snapshots + i; | |
641bb63c | 1811 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
fef4d3d5 | 1812 | sn->l1_table_offset, sn->l1_size, 0); |
057a3fe5 HR |
1813 | if (ret < 0) { |
1814 | return ret; | |
1815 | } | |
1816 | } | |
641bb63c | 1817 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1818 | s->snapshots_offset, s->snapshots_size); |
1819 | if (ret < 0) { | |
1820 | return ret; | |
1821 | } | |
057a3fe5 HR |
1822 | |
1823 | /* refcount data */ | |
641bb63c | 1824 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1825 | s->refcount_table_offset, |
1826 | s->refcount_table_size * sizeof(uint64_t)); | |
1827 | if (ret < 0) { | |
1828 | return ret; | |
1829 | } | |
057a3fe5 | 1830 | |
f307b255 | 1831 | return check_refblocks(bs, res, fix, rebuild, refcount_table, nb_clusters); |
057a3fe5 HR |
1832 | } |
1833 | ||
6ca56bf5 HR |
1834 | /* |
1835 | * Compares the actual reference count for each cluster in the image against the | |
1836 | * refcount as reported by the refcount structures on-disk. | |
1837 | */ | |
1838 | static void compare_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 HR |
1839 | BdrvCheckMode fix, bool *rebuild, |
1840 | int64_t *highest_cluster, | |
7453c96b | 1841 | void *refcount_table, int64_t nb_clusters) |
6ca56bf5 | 1842 | { |
ff99129a | 1843 | BDRVQcow2State *s = bs->opaque; |
6ca56bf5 | 1844 | int64_t i; |
0e06528e | 1845 | uint64_t refcount1, refcount2; |
7324c10f | 1846 | int ret; |
6ca56bf5 HR |
1847 | |
1848 | for (i = 0, *highest_cluster = 0; i < nb_clusters; i++) { | |
7324c10f HR |
1849 | ret = qcow2_get_refcount(bs, i, &refcount1); |
1850 | if (ret < 0) { | |
166acf54 | 1851 | fprintf(stderr, "Can't get refcount for cluster %" PRId64 ": %s\n", |
7324c10f | 1852 | i, strerror(-ret)); |
9ac228e0 | 1853 | res->check_errors++; |
f74550fd | 1854 | continue; |
018faafd KW |
1855 | } |
1856 | ||
7453c96b | 1857 | refcount2 = s->get_refcount(refcount_table, i); |
c6bb9ad1 FS |
1858 | |
1859 | if (refcount1 > 0 || refcount2 > 0) { | |
6ca56bf5 | 1860 | *highest_cluster = i; |
c6bb9ad1 FS |
1861 | } |
1862 | ||
f7d0fe02 | 1863 | if (refcount1 != refcount2) { |
166acf54 KW |
1864 | /* Check if we're allowed to fix the mismatch */ |
1865 | int *num_fixed = NULL; | |
f307b255 HR |
1866 | if (refcount1 == 0) { |
1867 | *rebuild = true; | |
1868 | } else if (refcount1 > refcount2 && (fix & BDRV_FIX_LEAKS)) { | |
166acf54 KW |
1869 | num_fixed = &res->leaks_fixed; |
1870 | } else if (refcount1 < refcount2 && (fix & BDRV_FIX_ERRORS)) { | |
1871 | num_fixed = &res->corruptions_fixed; | |
1872 | } | |
1873 | ||
0e06528e HR |
1874 | fprintf(stderr, "%s cluster %" PRId64 " refcount=%" PRIu64 |
1875 | " reference=%" PRIu64 "\n", | |
166acf54 KW |
1876 | num_fixed != NULL ? "Repairing" : |
1877 | refcount1 < refcount2 ? "ERROR" : | |
1878 | "Leaked", | |
f7d0fe02 | 1879 | i, refcount1, refcount2); |
166acf54 KW |
1880 | |
1881 | if (num_fixed) { | |
1882 | ret = update_refcount(bs, i << s->cluster_bits, 1, | |
2aabe7c7 HR |
1883 | refcount_diff(refcount1, refcount2), |
1884 | refcount1 > refcount2, | |
6cfcb9b8 | 1885 | QCOW2_DISCARD_ALWAYS); |
166acf54 KW |
1886 | if (ret >= 0) { |
1887 | (*num_fixed)++; | |
1888 | continue; | |
1889 | } | |
1890 | } | |
1891 | ||
1892 | /* And if we couldn't, print an error */ | |
9ac228e0 KW |
1893 | if (refcount1 < refcount2) { |
1894 | res->corruptions++; | |
1895 | } else { | |
1896 | res->leaks++; | |
1897 | } | |
f7d0fe02 KW |
1898 | } |
1899 | } | |
6ca56bf5 HR |
1900 | } |
1901 | ||
c7c0681b HR |
1902 | /* |
1903 | * Allocates clusters using an in-memory refcount table (IMRT) in contrast to | |
1904 | * the on-disk refcount structures. | |
1905 | * | |
1906 | * On input, *first_free_cluster tells where to start looking, and need not | |
1907 | * actually be a free cluster; the returned offset will not be before that | |
1908 | * cluster. On output, *first_free_cluster points to the first gap found, even | |
1909 | * if that gap was too small to be used as the returned offset. | |
1910 | * | |
1911 | * Note that *first_free_cluster is a cluster index whereas the return value is | |
1912 | * an offset. | |
1913 | */ | |
1914 | static int64_t alloc_clusters_imrt(BlockDriverState *bs, | |
1915 | int cluster_count, | |
7453c96b | 1916 | void **refcount_table, |
c7c0681b HR |
1917 | int64_t *imrt_nb_clusters, |
1918 | int64_t *first_free_cluster) | |
1919 | { | |
ff99129a | 1920 | BDRVQcow2State *s = bs->opaque; |
c7c0681b HR |
1921 | int64_t cluster = *first_free_cluster, i; |
1922 | bool first_gap = true; | |
1923 | int contiguous_free_clusters; | |
5fee192e | 1924 | int ret; |
c7c0681b HR |
1925 | |
1926 | /* Starting at *first_free_cluster, find a range of at least cluster_count | |
1927 | * continuously free clusters */ | |
1928 | for (contiguous_free_clusters = 0; | |
1929 | cluster < *imrt_nb_clusters && | |
1930 | contiguous_free_clusters < cluster_count; | |
1931 | cluster++) | |
1932 | { | |
7453c96b | 1933 | if (!s->get_refcount(*refcount_table, cluster)) { |
c7c0681b HR |
1934 | contiguous_free_clusters++; |
1935 | if (first_gap) { | |
1936 | /* If this is the first free cluster found, update | |
1937 | * *first_free_cluster accordingly */ | |
1938 | *first_free_cluster = cluster; | |
1939 | first_gap = false; | |
1940 | } | |
1941 | } else if (contiguous_free_clusters) { | |
1942 | contiguous_free_clusters = 0; | |
1943 | } | |
1944 | } | |
1945 | ||
1946 | /* If contiguous_free_clusters is greater than zero, it contains the number | |
1947 | * of continuously free clusters until the current cluster; the first free | |
1948 | * cluster in the current "gap" is therefore | |
1949 | * cluster - contiguous_free_clusters */ | |
1950 | ||
1951 | /* If no such range could be found, grow the in-memory refcount table | |
1952 | * accordingly to append free clusters at the end of the image */ | |
1953 | if (contiguous_free_clusters < cluster_count) { | |
c7c0681b HR |
1954 | /* contiguous_free_clusters clusters are already empty at the image end; |
1955 | * we need cluster_count clusters; therefore, we have to allocate | |
1956 | * cluster_count - contiguous_free_clusters new clusters at the end of | |
1957 | * the image (which is the current value of cluster; note that cluster | |
1958 | * may exceed old_imrt_nb_clusters if *first_free_cluster pointed beyond | |
1959 | * the image end) */ | |
5fee192e HR |
1960 | ret = realloc_refcount_array(s, refcount_table, imrt_nb_clusters, |
1961 | cluster + cluster_count | |
1962 | - contiguous_free_clusters); | |
1963 | if (ret < 0) { | |
1964 | return ret; | |
c7c0681b | 1965 | } |
c7c0681b HR |
1966 | } |
1967 | ||
1968 | /* Go back to the first free cluster */ | |
1969 | cluster -= contiguous_free_clusters; | |
1970 | for (i = 0; i < cluster_count; i++) { | |
7453c96b | 1971 | s->set_refcount(*refcount_table, cluster + i, 1); |
c7c0681b HR |
1972 | } |
1973 | ||
1974 | return cluster << s->cluster_bits; | |
1975 | } | |
1976 | ||
1977 | /* | |
1978 | * Creates a new refcount structure based solely on the in-memory information | |
1979 | * given through *refcount_table. All necessary allocations will be reflected | |
1980 | * in that array. | |
1981 | * | |
1982 | * On success, the old refcount structure is leaked (it will be covered by the | |
1983 | * new refcount structure). | |
1984 | */ | |
1985 | static int rebuild_refcount_structure(BlockDriverState *bs, | |
1986 | BdrvCheckResult *res, | |
7453c96b | 1987 | void **refcount_table, |
c7c0681b HR |
1988 | int64_t *nb_clusters) |
1989 | { | |
ff99129a | 1990 | BDRVQcow2State *s = bs->opaque; |
c7c0681b HR |
1991 | int64_t first_free_cluster = 0, reftable_offset = -1, cluster = 0; |
1992 | int64_t refblock_offset, refblock_start, refblock_index; | |
1993 | uint32_t reftable_size = 0; | |
1994 | uint64_t *on_disk_reftable = NULL; | |
7453c96b HR |
1995 | void *on_disk_refblock; |
1996 | int ret = 0; | |
c7c0681b HR |
1997 | struct { |
1998 | uint64_t reftable_offset; | |
1999 | uint32_t reftable_clusters; | |
2000 | } QEMU_PACKED reftable_offset_and_clusters; | |
2001 | ||
2002 | qcow2_cache_empty(bs, s->refcount_block_cache); | |
2003 | ||
2004 | write_refblocks: | |
2005 | for (; cluster < *nb_clusters; cluster++) { | |
7453c96b | 2006 | if (!s->get_refcount(*refcount_table, cluster)) { |
c7c0681b HR |
2007 | continue; |
2008 | } | |
2009 | ||
2010 | refblock_index = cluster >> s->refcount_block_bits; | |
2011 | refblock_start = refblock_index << s->refcount_block_bits; | |
2012 | ||
2013 | /* Don't allocate a cluster in a refblock already written to disk */ | |
2014 | if (first_free_cluster < refblock_start) { | |
2015 | first_free_cluster = refblock_start; | |
2016 | } | |
2017 | refblock_offset = alloc_clusters_imrt(bs, 1, refcount_table, | |
2018 | nb_clusters, &first_free_cluster); | |
2019 | if (refblock_offset < 0) { | |
2020 | fprintf(stderr, "ERROR allocating refblock: %s\n", | |
2021 | strerror(-refblock_offset)); | |
2022 | res->check_errors++; | |
2023 | ret = refblock_offset; | |
2024 | goto fail; | |
2025 | } | |
2026 | ||
2027 | if (reftable_size <= refblock_index) { | |
2028 | uint32_t old_reftable_size = reftable_size; | |
2029 | uint64_t *new_on_disk_reftable; | |
2030 | ||
2031 | reftable_size = ROUND_UP((refblock_index + 1) * sizeof(uint64_t), | |
2032 | s->cluster_size) / sizeof(uint64_t); | |
2033 | new_on_disk_reftable = g_try_realloc(on_disk_reftable, | |
2034 | reftable_size * | |
2035 | sizeof(uint64_t)); | |
2036 | if (!new_on_disk_reftable) { | |
2037 | res->check_errors++; | |
2038 | ret = -ENOMEM; | |
2039 | goto fail; | |
2040 | } | |
2041 | on_disk_reftable = new_on_disk_reftable; | |
2042 | ||
2043 | memset(on_disk_reftable + old_reftable_size, 0, | |
2044 | (reftable_size - old_reftable_size) * sizeof(uint64_t)); | |
2045 | ||
2046 | /* The offset we have for the reftable is now no longer valid; | |
2047 | * this will leak that range, but we can easily fix that by running | |
2048 | * a leak-fixing check after this rebuild operation */ | |
2049 | reftable_offset = -1; | |
2050 | } | |
2051 | on_disk_reftable[refblock_index] = refblock_offset; | |
2052 | ||
2053 | /* If this is apparently the last refblock (for now), try to squeeze the | |
2054 | * reftable in */ | |
2055 | if (refblock_index == (*nb_clusters - 1) >> s->refcount_block_bits && | |
2056 | reftable_offset < 0) | |
2057 | { | |
2058 | uint64_t reftable_clusters = size_to_clusters(s, reftable_size * | |
2059 | sizeof(uint64_t)); | |
2060 | reftable_offset = alloc_clusters_imrt(bs, reftable_clusters, | |
2061 | refcount_table, nb_clusters, | |
2062 | &first_free_cluster); | |
2063 | if (reftable_offset < 0) { | |
2064 | fprintf(stderr, "ERROR allocating reftable: %s\n", | |
2065 | strerror(-reftable_offset)); | |
2066 | res->check_errors++; | |
2067 | ret = reftable_offset; | |
2068 | goto fail; | |
2069 | } | |
2070 | } | |
2071 | ||
2072 | ret = qcow2_pre_write_overlap_check(bs, 0, refblock_offset, | |
2073 | s->cluster_size); | |
2074 | if (ret < 0) { | |
2075 | fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret)); | |
2076 | goto fail; | |
2077 | } | |
2078 | ||
7453c96b HR |
2079 | /* The size of *refcount_table is always cluster-aligned, therefore the |
2080 | * write operation will not overflow */ | |
2081 | on_disk_refblock = (void *)((char *) *refcount_table + | |
2082 | refblock_index * s->cluster_size); | |
c7c0681b HR |
2083 | |
2084 | ret = bdrv_write(bs->file, refblock_offset / BDRV_SECTOR_SIZE, | |
7453c96b | 2085 | on_disk_refblock, s->cluster_sectors); |
c7c0681b HR |
2086 | if (ret < 0) { |
2087 | fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret)); | |
2088 | goto fail; | |
2089 | } | |
2090 | ||
2091 | /* Go to the end of this refblock */ | |
2092 | cluster = refblock_start + s->refcount_block_size - 1; | |
2093 | } | |
2094 | ||
2095 | if (reftable_offset < 0) { | |
2096 | uint64_t post_refblock_start, reftable_clusters; | |
2097 | ||
2098 | post_refblock_start = ROUND_UP(*nb_clusters, s->refcount_block_size); | |
2099 | reftable_clusters = size_to_clusters(s, | |
2100 | reftable_size * sizeof(uint64_t)); | |
2101 | /* Not pretty but simple */ | |
2102 | if (first_free_cluster < post_refblock_start) { | |
2103 | first_free_cluster = post_refblock_start; | |
2104 | } | |
2105 | reftable_offset = alloc_clusters_imrt(bs, reftable_clusters, | |
2106 | refcount_table, nb_clusters, | |
2107 | &first_free_cluster); | |
2108 | if (reftable_offset < 0) { | |
2109 | fprintf(stderr, "ERROR allocating reftable: %s\n", | |
2110 | strerror(-reftable_offset)); | |
2111 | res->check_errors++; | |
2112 | ret = reftable_offset; | |
2113 | goto fail; | |
2114 | } | |
2115 | ||
2116 | goto write_refblocks; | |
2117 | } | |
2118 | ||
2119 | assert(on_disk_reftable); | |
2120 | ||
2121 | for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) { | |
2122 | cpu_to_be64s(&on_disk_reftable[refblock_index]); | |
2123 | } | |
2124 | ||
2125 | ret = qcow2_pre_write_overlap_check(bs, 0, reftable_offset, | |
2126 | reftable_size * sizeof(uint64_t)); | |
2127 | if (ret < 0) { | |
2128 | fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret)); | |
2129 | goto fail; | |
2130 | } | |
2131 | ||
2132 | assert(reftable_size < INT_MAX / sizeof(uint64_t)); | |
2133 | ret = bdrv_pwrite(bs->file, reftable_offset, on_disk_reftable, | |
2134 | reftable_size * sizeof(uint64_t)); | |
2135 | if (ret < 0) { | |
2136 | fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret)); | |
2137 | goto fail; | |
2138 | } | |
2139 | ||
2140 | /* Enter new reftable into the image header */ | |
2141 | cpu_to_be64w(&reftable_offset_and_clusters.reftable_offset, | |
2142 | reftable_offset); | |
2143 | cpu_to_be32w(&reftable_offset_and_clusters.reftable_clusters, | |
2144 | size_to_clusters(s, reftable_size * sizeof(uint64_t))); | |
2145 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, | |
2146 | refcount_table_offset), | |
2147 | &reftable_offset_and_clusters, | |
2148 | sizeof(reftable_offset_and_clusters)); | |
2149 | if (ret < 0) { | |
2150 | fprintf(stderr, "ERROR setting reftable: %s\n", strerror(-ret)); | |
2151 | goto fail; | |
2152 | } | |
2153 | ||
2154 | for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) { | |
2155 | be64_to_cpus(&on_disk_reftable[refblock_index]); | |
2156 | } | |
2157 | s->refcount_table = on_disk_reftable; | |
2158 | s->refcount_table_offset = reftable_offset; | |
2159 | s->refcount_table_size = reftable_size; | |
2160 | ||
2161 | return 0; | |
2162 | ||
2163 | fail: | |
2164 | g_free(on_disk_reftable); | |
2165 | return ret; | |
2166 | } | |
2167 | ||
6ca56bf5 HR |
2168 | /* |
2169 | * Checks an image for refcount consistency. | |
2170 | * | |
2171 | * Returns 0 if no errors are found, the number of errors in case the image is | |
2172 | * detected as corrupted, and -errno when an internal error occurred. | |
2173 | */ | |
2174 | int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
2175 | BdrvCheckMode fix) | |
2176 | { | |
ff99129a | 2177 | BDRVQcow2State *s = bs->opaque; |
c7c0681b | 2178 | BdrvCheckResult pre_compare_res; |
6ca56bf5 | 2179 | int64_t size, highest_cluster, nb_clusters; |
7453c96b | 2180 | void *refcount_table = NULL; |
f307b255 | 2181 | bool rebuild = false; |
6ca56bf5 HR |
2182 | int ret; |
2183 | ||
2184 | size = bdrv_getlength(bs->file); | |
2185 | if (size < 0) { | |
2186 | res->check_errors++; | |
2187 | return size; | |
2188 | } | |
2189 | ||
2190 | nb_clusters = size_to_clusters(s, size); | |
2191 | if (nb_clusters > INT_MAX) { | |
2192 | res->check_errors++; | |
2193 | return -EFBIG; | |
2194 | } | |
2195 | ||
2196 | res->bfi.total_clusters = | |
2197 | size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE); | |
2198 | ||
f307b255 HR |
2199 | ret = calculate_refcounts(bs, res, fix, &rebuild, &refcount_table, |
2200 | &nb_clusters); | |
6ca56bf5 HR |
2201 | if (ret < 0) { |
2202 | goto fail; | |
2203 | } | |
2204 | ||
c7c0681b HR |
2205 | /* In case we don't need to rebuild the refcount structure (but want to fix |
2206 | * something), this function is immediately called again, in which case the | |
2207 | * result should be ignored */ | |
2208 | pre_compare_res = *res; | |
2209 | compare_refcounts(bs, res, 0, &rebuild, &highest_cluster, refcount_table, | |
6ca56bf5 | 2210 | nb_clusters); |
f7d0fe02 | 2211 | |
c7c0681b | 2212 | if (rebuild && (fix & BDRV_FIX_ERRORS)) { |
791230d8 HR |
2213 | BdrvCheckResult old_res = *res; |
2214 | int fresh_leaks = 0; | |
2215 | ||
c7c0681b HR |
2216 | fprintf(stderr, "Rebuilding refcount structure\n"); |
2217 | ret = rebuild_refcount_structure(bs, res, &refcount_table, | |
2218 | &nb_clusters); | |
2219 | if (ret < 0) { | |
2220 | goto fail; | |
2221 | } | |
791230d8 HR |
2222 | |
2223 | res->corruptions = 0; | |
2224 | res->leaks = 0; | |
2225 | ||
2226 | /* Because the old reftable has been exchanged for a new one the | |
2227 | * references have to be recalculated */ | |
2228 | rebuild = false; | |
7453c96b | 2229 | memset(refcount_table, 0, refcount_array_byte_size(s, nb_clusters)); |
791230d8 HR |
2230 | ret = calculate_refcounts(bs, res, 0, &rebuild, &refcount_table, |
2231 | &nb_clusters); | |
2232 | if (ret < 0) { | |
2233 | goto fail; | |
2234 | } | |
2235 | ||
2236 | if (fix & BDRV_FIX_LEAKS) { | |
2237 | /* The old refcount structures are now leaked, fix it; the result | |
2238 | * can be ignored, aside from leaks which were introduced by | |
2239 | * rebuild_refcount_structure() that could not be fixed */ | |
2240 | BdrvCheckResult saved_res = *res; | |
2241 | *res = (BdrvCheckResult){ 0 }; | |
2242 | ||
2243 | compare_refcounts(bs, res, BDRV_FIX_LEAKS, &rebuild, | |
2244 | &highest_cluster, refcount_table, nb_clusters); | |
2245 | if (rebuild) { | |
2246 | fprintf(stderr, "ERROR rebuilt refcount structure is still " | |
2247 | "broken\n"); | |
2248 | } | |
2249 | ||
2250 | /* Any leaks accounted for here were introduced by | |
2251 | * rebuild_refcount_structure() because that function has created a | |
2252 | * new refcount structure from scratch */ | |
2253 | fresh_leaks = res->leaks; | |
2254 | *res = saved_res; | |
2255 | } | |
2256 | ||
2257 | if (res->corruptions < old_res.corruptions) { | |
2258 | res->corruptions_fixed += old_res.corruptions - res->corruptions; | |
2259 | } | |
2260 | if (res->leaks < old_res.leaks) { | |
2261 | res->leaks_fixed += old_res.leaks - res->leaks; | |
2262 | } | |
2263 | res->leaks += fresh_leaks; | |
c7c0681b HR |
2264 | } else if (fix) { |
2265 | if (rebuild) { | |
2266 | fprintf(stderr, "ERROR need to rebuild refcount structures\n"); | |
2267 | res->check_errors++; | |
2268 | ret = -EIO; | |
2269 | goto fail; | |
2270 | } | |
2271 | ||
2272 | if (res->leaks || res->corruptions) { | |
2273 | *res = pre_compare_res; | |
2274 | compare_refcounts(bs, res, fix, &rebuild, &highest_cluster, | |
2275 | refcount_table, nb_clusters); | |
2276 | } | |
f307b255 HR |
2277 | } |
2278 | ||
4f6ed88c | 2279 | /* check OFLAG_COPIED */ |
e23e400e | 2280 | ret = check_oflag_copied(bs, res, fix); |
4f6ed88c HR |
2281 | if (ret < 0) { |
2282 | goto fail; | |
2283 | } | |
2284 | ||
c6bb9ad1 | 2285 | res->image_end_offset = (highest_cluster + 1) * s->cluster_size; |
80fa3341 KW |
2286 | ret = 0; |
2287 | ||
2288 | fail: | |
7267c094 | 2289 | g_free(refcount_table); |
f7d0fe02 | 2290 | |
80fa3341 | 2291 | return ret; |
f7d0fe02 KW |
2292 | } |
2293 | ||
a40f1c2a HR |
2294 | #define overlaps_with(ofs, sz) \ |
2295 | ranges_overlap(offset, size, ofs, sz) | |
2296 | ||
2297 | /* | |
2298 | * Checks if the given offset into the image file is actually free to use by | |
2299 | * looking for overlaps with important metadata sections (L1/L2 tables etc.), | |
2300 | * i.e. a sanity check without relying on the refcount tables. | |
2301 | * | |
231bb267 HR |
2302 | * The ign parameter specifies what checks not to perform (being a bitmask of |
2303 | * QCow2MetadataOverlap values), i.e., what sections to ignore. | |
a40f1c2a HR |
2304 | * |
2305 | * Returns: | |
2306 | * - 0 if writing to this offset will not affect the mentioned metadata | |
2307 | * - a positive QCow2MetadataOverlap value indicating one overlapping section | |
2308 | * - a negative value (-errno) indicating an error while performing a check, | |
2309 | * e.g. when bdrv_read failed on QCOW2_OL_INACTIVE_L2 | |
2310 | */ | |
231bb267 | 2311 | int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset, |
a40f1c2a HR |
2312 | int64_t size) |
2313 | { | |
ff99129a | 2314 | BDRVQcow2State *s = bs->opaque; |
3e355390 | 2315 | int chk = s->overlap_check & ~ign; |
a40f1c2a HR |
2316 | int i, j; |
2317 | ||
2318 | if (!size) { | |
2319 | return 0; | |
2320 | } | |
2321 | ||
2322 | if (chk & QCOW2_OL_MAIN_HEADER) { | |
2323 | if (offset < s->cluster_size) { | |
2324 | return QCOW2_OL_MAIN_HEADER; | |
2325 | } | |
2326 | } | |
2327 | ||
2328 | /* align range to test to cluster boundaries */ | |
2329 | size = align_offset(offset_into_cluster(s, offset) + size, s->cluster_size); | |
2330 | offset = start_of_cluster(s, offset); | |
2331 | ||
2332 | if ((chk & QCOW2_OL_ACTIVE_L1) && s->l1_size) { | |
2333 | if (overlaps_with(s->l1_table_offset, s->l1_size * sizeof(uint64_t))) { | |
2334 | return QCOW2_OL_ACTIVE_L1; | |
2335 | } | |
2336 | } | |
2337 | ||
2338 | if ((chk & QCOW2_OL_REFCOUNT_TABLE) && s->refcount_table_size) { | |
2339 | if (overlaps_with(s->refcount_table_offset, | |
2340 | s->refcount_table_size * sizeof(uint64_t))) { | |
2341 | return QCOW2_OL_REFCOUNT_TABLE; | |
2342 | } | |
2343 | } | |
2344 | ||
2345 | if ((chk & QCOW2_OL_SNAPSHOT_TABLE) && s->snapshots_size) { | |
2346 | if (overlaps_with(s->snapshots_offset, s->snapshots_size)) { | |
2347 | return QCOW2_OL_SNAPSHOT_TABLE; | |
2348 | } | |
2349 | } | |
2350 | ||
2351 | if ((chk & QCOW2_OL_INACTIVE_L1) && s->snapshots) { | |
2352 | for (i = 0; i < s->nb_snapshots; i++) { | |
2353 | if (s->snapshots[i].l1_size && | |
2354 | overlaps_with(s->snapshots[i].l1_table_offset, | |
2355 | s->snapshots[i].l1_size * sizeof(uint64_t))) { | |
2356 | return QCOW2_OL_INACTIVE_L1; | |
2357 | } | |
2358 | } | |
2359 | } | |
2360 | ||
2361 | if ((chk & QCOW2_OL_ACTIVE_L2) && s->l1_table) { | |
2362 | for (i = 0; i < s->l1_size; i++) { | |
2363 | if ((s->l1_table[i] & L1E_OFFSET_MASK) && | |
2364 | overlaps_with(s->l1_table[i] & L1E_OFFSET_MASK, | |
2365 | s->cluster_size)) { | |
2366 | return QCOW2_OL_ACTIVE_L2; | |
2367 | } | |
2368 | } | |
2369 | } | |
2370 | ||
2371 | if ((chk & QCOW2_OL_REFCOUNT_BLOCK) && s->refcount_table) { | |
2372 | for (i = 0; i < s->refcount_table_size; i++) { | |
2373 | if ((s->refcount_table[i] & REFT_OFFSET_MASK) && | |
2374 | overlaps_with(s->refcount_table[i] & REFT_OFFSET_MASK, | |
2375 | s->cluster_size)) { | |
2376 | return QCOW2_OL_REFCOUNT_BLOCK; | |
2377 | } | |
2378 | } | |
2379 | } | |
2380 | ||
2381 | if ((chk & QCOW2_OL_INACTIVE_L2) && s->snapshots) { | |
2382 | for (i = 0; i < s->nb_snapshots; i++) { | |
2383 | uint64_t l1_ofs = s->snapshots[i].l1_table_offset; | |
2384 | uint32_t l1_sz = s->snapshots[i].l1_size; | |
998b959c | 2385 | uint64_t l1_sz2 = l1_sz * sizeof(uint64_t); |
de82815d | 2386 | uint64_t *l1 = g_try_malloc(l1_sz2); |
a40f1c2a HR |
2387 | int ret; |
2388 | ||
de82815d KW |
2389 | if (l1_sz2 && l1 == NULL) { |
2390 | return -ENOMEM; | |
2391 | } | |
2392 | ||
998b959c | 2393 | ret = bdrv_pread(bs->file, l1_ofs, l1, l1_sz2); |
a40f1c2a HR |
2394 | if (ret < 0) { |
2395 | g_free(l1); | |
2396 | return ret; | |
2397 | } | |
2398 | ||
2399 | for (j = 0; j < l1_sz; j++) { | |
1e242b55 HR |
2400 | uint64_t l2_ofs = be64_to_cpu(l1[j]) & L1E_OFFSET_MASK; |
2401 | if (l2_ofs && overlaps_with(l2_ofs, s->cluster_size)) { | |
a40f1c2a HR |
2402 | g_free(l1); |
2403 | return QCOW2_OL_INACTIVE_L2; | |
2404 | } | |
2405 | } | |
2406 | ||
2407 | g_free(l1); | |
2408 | } | |
2409 | } | |
2410 | ||
2411 | return 0; | |
2412 | } | |
2413 | ||
2414 | static const char *metadata_ol_names[] = { | |
2415 | [QCOW2_OL_MAIN_HEADER_BITNR] = "qcow2_header", | |
2416 | [QCOW2_OL_ACTIVE_L1_BITNR] = "active L1 table", | |
2417 | [QCOW2_OL_ACTIVE_L2_BITNR] = "active L2 table", | |
2418 | [QCOW2_OL_REFCOUNT_TABLE_BITNR] = "refcount table", | |
2419 | [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = "refcount block", | |
2420 | [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = "snapshot table", | |
2421 | [QCOW2_OL_INACTIVE_L1_BITNR] = "inactive L1 table", | |
2422 | [QCOW2_OL_INACTIVE_L2_BITNR] = "inactive L2 table", | |
2423 | }; | |
2424 | ||
2425 | /* | |
2426 | * First performs a check for metadata overlaps (through | |
2427 | * qcow2_check_metadata_overlap); if that fails with a negative value (error | |
2428 | * while performing a check), that value is returned. If an impending overlap | |
2429 | * is detected, the BDS will be made unusable, the qcow2 file marked corrupt | |
2430 | * and -EIO returned. | |
2431 | * | |
2432 | * Returns 0 if there were neither overlaps nor errors while checking for | |
2433 | * overlaps; or a negative value (-errno) on error. | |
2434 | */ | |
231bb267 | 2435 | int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset, |
a40f1c2a HR |
2436 | int64_t size) |
2437 | { | |
231bb267 | 2438 | int ret = qcow2_check_metadata_overlap(bs, ign, offset, size); |
a40f1c2a HR |
2439 | |
2440 | if (ret < 0) { | |
2441 | return ret; | |
2442 | } else if (ret > 0) { | |
786a4ea8 | 2443 | int metadata_ol_bitnr = ctz32(ret); |
a40f1c2a HR |
2444 | assert(metadata_ol_bitnr < QCOW2_OL_MAX_BITNR); |
2445 | ||
adb43552 HR |
2446 | qcow2_signal_corruption(bs, true, offset, size, "Preventing invalid " |
2447 | "write on metadata (overlaps with %s)", | |
2448 | metadata_ol_names[metadata_ol_bitnr]); | |
a40f1c2a HR |
2449 | return -EIO; |
2450 | } | |
2451 | ||
2452 | return 0; | |
2453 | } |