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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 | ||
80c71a24 | 25 | #include "qemu/osdep.h" |
da34e65c | 26 | #include "qapi/error.h" |
f7d0fe02 | 27 | #include "qemu-common.h" |
737e150e | 28 | #include "block/block_int.h" |
f7d0fe02 | 29 | #include "block/qcow2.h" |
a40f1c2a | 30 | #include "qemu/range.h" |
f7d0fe02 | 31 | |
bb572aef | 32 | static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size); |
92dcb59f | 33 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
0e06528e | 34 | int64_t offset, int64_t length, uint64_t addend, |
2aabe7c7 | 35 | bool decrease, enum qcow2_discard_type type); |
f7d0fe02 | 36 | |
59c0cb78 HR |
37 | static uint64_t get_refcount_ro0(const void *refcount_array, uint64_t index); |
38 | static uint64_t get_refcount_ro1(const void *refcount_array, uint64_t index); | |
39 | static uint64_t get_refcount_ro2(const void *refcount_array, uint64_t index); | |
40 | static uint64_t get_refcount_ro3(const void *refcount_array, uint64_t index); | |
7453c96b | 41 | static uint64_t get_refcount_ro4(const void *refcount_array, uint64_t index); |
59c0cb78 HR |
42 | static uint64_t get_refcount_ro5(const void *refcount_array, uint64_t index); |
43 | static uint64_t get_refcount_ro6(const void *refcount_array, uint64_t index); | |
7453c96b | 44 | |
59c0cb78 HR |
45 | static void set_refcount_ro0(void *refcount_array, uint64_t index, |
46 | uint64_t value); | |
47 | static void set_refcount_ro1(void *refcount_array, uint64_t index, | |
48 | uint64_t value); | |
49 | static void set_refcount_ro2(void *refcount_array, uint64_t index, | |
50 | uint64_t value); | |
51 | static void set_refcount_ro3(void *refcount_array, uint64_t index, | |
52 | uint64_t value); | |
7453c96b HR |
53 | static void set_refcount_ro4(void *refcount_array, uint64_t index, |
54 | uint64_t value); | |
59c0cb78 HR |
55 | static void set_refcount_ro5(void *refcount_array, uint64_t index, |
56 | uint64_t value); | |
57 | static void set_refcount_ro6(void *refcount_array, uint64_t index, | |
58 | uint64_t value); | |
59 | ||
60 | ||
61 | static Qcow2GetRefcountFunc *const get_refcount_funcs[] = { | |
62 | &get_refcount_ro0, | |
63 | &get_refcount_ro1, | |
64 | &get_refcount_ro2, | |
65 | &get_refcount_ro3, | |
66 | &get_refcount_ro4, | |
67 | &get_refcount_ro5, | |
68 | &get_refcount_ro6 | |
69 | }; | |
70 | ||
71 | static Qcow2SetRefcountFunc *const set_refcount_funcs[] = { | |
72 | &set_refcount_ro0, | |
73 | &set_refcount_ro1, | |
74 | &set_refcount_ro2, | |
75 | &set_refcount_ro3, | |
76 | &set_refcount_ro4, | |
77 | &set_refcount_ro5, | |
78 | &set_refcount_ro6 | |
79 | }; | |
7453c96b | 80 | |
3b88e52b | 81 | |
f7d0fe02 KW |
82 | /*********************************************************/ |
83 | /* refcount handling */ | |
84 | ||
ed6ccf0f | 85 | int qcow2_refcount_init(BlockDriverState *bs) |
f7d0fe02 | 86 | { |
ff99129a | 87 | BDRVQcow2State *s = bs->opaque; |
5dab2fad KW |
88 | unsigned int refcount_table_size2, i; |
89 | int ret; | |
f7d0fe02 | 90 | |
59c0cb78 HR |
91 | assert(s->refcount_order >= 0 && s->refcount_order <= 6); |
92 | ||
93 | s->get_refcount = get_refcount_funcs[s->refcount_order]; | |
94 | s->set_refcount = set_refcount_funcs[s->refcount_order]; | |
7453c96b | 95 | |
5dab2fad | 96 | assert(s->refcount_table_size <= INT_MAX / sizeof(uint64_t)); |
f7d0fe02 | 97 | refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); |
de82815d KW |
98 | s->refcount_table = g_try_malloc(refcount_table_size2); |
99 | ||
f7d0fe02 | 100 | if (s->refcount_table_size > 0) { |
de82815d | 101 | if (s->refcount_table == NULL) { |
8fcffa98 | 102 | ret = -ENOMEM; |
de82815d KW |
103 | goto fail; |
104 | } | |
66f82cee | 105 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_LOAD); |
9a4f4c31 | 106 | ret = bdrv_pread(bs->file->bs, s->refcount_table_offset, |
f7d0fe02 | 107 | s->refcount_table, refcount_table_size2); |
8fcffa98 | 108 | if (ret < 0) { |
f7d0fe02 | 109 | goto fail; |
8fcffa98 | 110 | } |
f7d0fe02 KW |
111 | for(i = 0; i < s->refcount_table_size; i++) |
112 | be64_to_cpus(&s->refcount_table[i]); | |
113 | } | |
114 | return 0; | |
115 | fail: | |
8fcffa98 | 116 | return ret; |
f7d0fe02 KW |
117 | } |
118 | ||
ed6ccf0f | 119 | void qcow2_refcount_close(BlockDriverState *bs) |
f7d0fe02 | 120 | { |
ff99129a | 121 | BDRVQcow2State *s = bs->opaque; |
7267c094 | 122 | g_free(s->refcount_table); |
f7d0fe02 KW |
123 | } |
124 | ||
125 | ||
59c0cb78 HR |
126 | static uint64_t get_refcount_ro0(const void *refcount_array, uint64_t index) |
127 | { | |
128 | return (((const uint8_t *)refcount_array)[index / 8] >> (index % 8)) & 0x1; | |
129 | } | |
130 | ||
131 | static void set_refcount_ro0(void *refcount_array, uint64_t index, | |
132 | uint64_t value) | |
133 | { | |
134 | assert(!(value >> 1)); | |
135 | ((uint8_t *)refcount_array)[index / 8] &= ~(0x1 << (index % 8)); | |
136 | ((uint8_t *)refcount_array)[index / 8] |= value << (index % 8); | |
137 | } | |
138 | ||
139 | static uint64_t get_refcount_ro1(const void *refcount_array, uint64_t index) | |
140 | { | |
141 | return (((const uint8_t *)refcount_array)[index / 4] >> (2 * (index % 4))) | |
142 | & 0x3; | |
143 | } | |
144 | ||
145 | static void set_refcount_ro1(void *refcount_array, uint64_t index, | |
146 | uint64_t value) | |
147 | { | |
148 | assert(!(value >> 2)); | |
149 | ((uint8_t *)refcount_array)[index / 4] &= ~(0x3 << (2 * (index % 4))); | |
150 | ((uint8_t *)refcount_array)[index / 4] |= value << (2 * (index % 4)); | |
151 | } | |
152 | ||
153 | static uint64_t get_refcount_ro2(const void *refcount_array, uint64_t index) | |
154 | { | |
155 | return (((const uint8_t *)refcount_array)[index / 2] >> (4 * (index % 2))) | |
156 | & 0xf; | |
157 | } | |
158 | ||
159 | static void set_refcount_ro2(void *refcount_array, uint64_t index, | |
160 | uint64_t value) | |
161 | { | |
162 | assert(!(value >> 4)); | |
163 | ((uint8_t *)refcount_array)[index / 2] &= ~(0xf << (4 * (index % 2))); | |
164 | ((uint8_t *)refcount_array)[index / 2] |= value << (4 * (index % 2)); | |
165 | } | |
166 | ||
167 | static uint64_t get_refcount_ro3(const void *refcount_array, uint64_t index) | |
168 | { | |
169 | return ((const uint8_t *)refcount_array)[index]; | |
170 | } | |
171 | ||
172 | static void set_refcount_ro3(void *refcount_array, uint64_t index, | |
173 | uint64_t value) | |
174 | { | |
175 | assert(!(value >> 8)); | |
176 | ((uint8_t *)refcount_array)[index] = value; | |
177 | } | |
178 | ||
7453c96b HR |
179 | static uint64_t get_refcount_ro4(const void *refcount_array, uint64_t index) |
180 | { | |
181 | return be16_to_cpu(((const uint16_t *)refcount_array)[index]); | |
182 | } | |
183 | ||
184 | static void set_refcount_ro4(void *refcount_array, uint64_t index, | |
185 | uint64_t value) | |
186 | { | |
187 | assert(!(value >> 16)); | |
188 | ((uint16_t *)refcount_array)[index] = cpu_to_be16(value); | |
189 | } | |
190 | ||
59c0cb78 HR |
191 | static uint64_t get_refcount_ro5(const void *refcount_array, uint64_t index) |
192 | { | |
193 | return be32_to_cpu(((const uint32_t *)refcount_array)[index]); | |
194 | } | |
195 | ||
196 | static void set_refcount_ro5(void *refcount_array, uint64_t index, | |
197 | uint64_t value) | |
198 | { | |
199 | assert(!(value >> 32)); | |
200 | ((uint32_t *)refcount_array)[index] = cpu_to_be32(value); | |
201 | } | |
202 | ||
203 | static uint64_t get_refcount_ro6(const void *refcount_array, uint64_t index) | |
204 | { | |
205 | return be64_to_cpu(((const uint64_t *)refcount_array)[index]); | |
206 | } | |
207 | ||
208 | static void set_refcount_ro6(void *refcount_array, uint64_t index, | |
209 | uint64_t value) | |
210 | { | |
211 | ((uint64_t *)refcount_array)[index] = cpu_to_be64(value); | |
212 | } | |
213 | ||
7453c96b | 214 | |
f7d0fe02 | 215 | static int load_refcount_block(BlockDriverState *bs, |
29c1a730 KW |
216 | int64_t refcount_block_offset, |
217 | void **refcount_block) | |
f7d0fe02 | 218 | { |
ff99129a | 219 | BDRVQcow2State *s = bs->opaque; |
f7d0fe02 | 220 | int ret; |
3b88e52b | 221 | |
66f82cee | 222 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_LOAD); |
29c1a730 KW |
223 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, |
224 | refcount_block); | |
e14e8ba5 | 225 | |
29c1a730 | 226 | return ret; |
f7d0fe02 KW |
227 | } |
228 | ||
018faafd | 229 | /* |
7324c10f HR |
230 | * Retrieves the refcount of the cluster given by its index and stores it in |
231 | * *refcount. Returns 0 on success and -errno on failure. | |
018faafd | 232 | */ |
7324c10f | 233 | int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index, |
0e06528e | 234 | uint64_t *refcount) |
f7d0fe02 | 235 | { |
ff99129a | 236 | BDRVQcow2State *s = bs->opaque; |
db8a31d1 | 237 | uint64_t refcount_table_index, block_index; |
f7d0fe02 | 238 | int64_t refcount_block_offset; |
018faafd | 239 | int ret; |
7453c96b | 240 | void *refcount_block; |
f7d0fe02 | 241 | |
17bd5f47 | 242 | refcount_table_index = cluster_index >> s->refcount_block_bits; |
7324c10f HR |
243 | if (refcount_table_index >= s->refcount_table_size) { |
244 | *refcount = 0; | |
f7d0fe02 | 245 | return 0; |
7324c10f | 246 | } |
26d49c46 HR |
247 | refcount_block_offset = |
248 | s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; | |
7324c10f HR |
249 | if (!refcount_block_offset) { |
250 | *refcount = 0; | |
f7d0fe02 | 251 | return 0; |
7324c10f | 252 | } |
29c1a730 | 253 | |
a97c67ee HR |
254 | if (offset_into_cluster(s, refcount_block_offset)) { |
255 | qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#" PRIx64 | |
256 | " unaligned (reftable index: %#" PRIx64 ")", | |
257 | refcount_block_offset, refcount_table_index); | |
258 | return -EIO; | |
259 | } | |
260 | ||
29c1a730 | 261 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, |
7453c96b | 262 | &refcount_block); |
29c1a730 KW |
263 | if (ret < 0) { |
264 | return ret; | |
f7d0fe02 | 265 | } |
29c1a730 | 266 | |
17bd5f47 | 267 | block_index = cluster_index & (s->refcount_block_size - 1); |
7453c96b | 268 | *refcount = s->get_refcount(refcount_block, block_index); |
29c1a730 | 269 | |
a3f1afb4 | 270 | qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); |
29c1a730 | 271 | |
7324c10f | 272 | return 0; |
f7d0fe02 KW |
273 | } |
274 | ||
05121aed KW |
275 | /* |
276 | * Rounds the refcount table size up to avoid growing the table for each single | |
277 | * refcount block that is allocated. | |
278 | */ | |
ff99129a | 279 | static unsigned int next_refcount_table_size(BDRVQcow2State *s, |
05121aed KW |
280 | unsigned int min_size) |
281 | { | |
282 | unsigned int min_clusters = (min_size >> (s->cluster_bits - 3)) + 1; | |
283 | unsigned int refcount_table_clusters = | |
284 | MAX(1, s->refcount_table_size >> (s->cluster_bits - 3)); | |
285 | ||
286 | while (min_clusters > refcount_table_clusters) { | |
287 | refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; | |
288 | } | |
289 | ||
290 | return refcount_table_clusters << (s->cluster_bits - 3); | |
291 | } | |
292 | ||
92dcb59f KW |
293 | |
294 | /* Checks if two offsets are described by the same refcount block */ | |
ff99129a | 295 | static int in_same_refcount_block(BDRVQcow2State *s, uint64_t offset_a, |
92dcb59f KW |
296 | uint64_t offset_b) |
297 | { | |
17bd5f47 HR |
298 | uint64_t block_a = offset_a >> (s->cluster_bits + s->refcount_block_bits); |
299 | uint64_t block_b = offset_b >> (s->cluster_bits + s->refcount_block_bits); | |
92dcb59f KW |
300 | |
301 | return (block_a == block_b); | |
302 | } | |
303 | ||
304 | /* | |
305 | * Loads a refcount block. If it doesn't exist yet, it is allocated first | |
306 | * (including growing the refcount table if needed). | |
307 | * | |
29c1a730 | 308 | * Returns 0 on success or -errno in error case |
92dcb59f | 309 | */ |
29c1a730 | 310 | static int alloc_refcount_block(BlockDriverState *bs, |
7453c96b | 311 | int64_t cluster_index, void **refcount_block) |
f7d0fe02 | 312 | { |
ff99129a | 313 | BDRVQcow2State *s = bs->opaque; |
92dcb59f KW |
314 | unsigned int refcount_table_index; |
315 | int ret; | |
316 | ||
66f82cee | 317 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); |
8252278a | 318 | |
92dcb59f | 319 | /* Find the refcount block for the given cluster */ |
17bd5f47 | 320 | refcount_table_index = cluster_index >> s->refcount_block_bits; |
92dcb59f KW |
321 | |
322 | if (refcount_table_index < s->refcount_table_size) { | |
323 | ||
324 | uint64_t refcount_block_offset = | |
76dc9e0c | 325 | s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; |
92dcb59f KW |
326 | |
327 | /* If it's already there, we're done */ | |
328 | if (refcount_block_offset) { | |
a97c67ee HR |
329 | if (offset_into_cluster(s, refcount_block_offset)) { |
330 | qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#" | |
331 | PRIx64 " unaligned (reftable index: " | |
332 | "%#x)", refcount_block_offset, | |
333 | refcount_table_index); | |
334 | return -EIO; | |
335 | } | |
336 | ||
29c1a730 | 337 | return load_refcount_block(bs, refcount_block_offset, |
7453c96b | 338 | refcount_block); |
92dcb59f KW |
339 | } |
340 | } | |
341 | ||
342 | /* | |
343 | * If we came here, we need to allocate something. Something is at least | |
344 | * a cluster for the new refcount block. It may also include a new refcount | |
345 | * table if the old refcount table is too small. | |
346 | * | |
347 | * Note that allocating clusters here needs some special care: | |
348 | * | |
349 | * - We can't use the normal qcow2_alloc_clusters(), it would try to | |
350 | * increase the refcount and very likely we would end up with an endless | |
351 | * recursion. Instead we must place the refcount blocks in a way that | |
352 | * they can describe them themselves. | |
353 | * | |
354 | * - We need to consider that at this point we are inside update_refcounts | |
b106ad91 KW |
355 | * and potentially doing an initial refcount increase. This means that |
356 | * some clusters have already been allocated by the caller, but their | |
357 | * refcount isn't accurate yet. If we allocate clusters for metadata, we | |
358 | * need to return -EAGAIN to signal the caller that it needs to restart | |
359 | * the search for free clusters. | |
92dcb59f KW |
360 | * |
361 | * - alloc_clusters_noref and qcow2_free_clusters may load a different | |
362 | * refcount block into the cache | |
363 | */ | |
364 | ||
29c1a730 KW |
365 | *refcount_block = NULL; |
366 | ||
367 | /* We write to the refcount table, so we might depend on L2 tables */ | |
9991923b SH |
368 | ret = qcow2_cache_flush(bs, s->l2_table_cache); |
369 | if (ret < 0) { | |
370 | return ret; | |
371 | } | |
92dcb59f KW |
372 | |
373 | /* Allocate the refcount block itself and mark it as used */ | |
2eaa8f63 KW |
374 | int64_t new_block = alloc_clusters_noref(bs, s->cluster_size); |
375 | if (new_block < 0) { | |
376 | return new_block; | |
377 | } | |
f7d0fe02 | 378 | |
f7d0fe02 | 379 | #ifdef DEBUG_ALLOC2 |
92dcb59f KW |
380 | fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64 |
381 | " at %" PRIx64 "\n", | |
382 | refcount_table_index, cluster_index << s->cluster_bits, new_block); | |
f7d0fe02 | 383 | #endif |
92dcb59f KW |
384 | |
385 | if (in_same_refcount_block(s, new_block, cluster_index << s->cluster_bits)) { | |
25408c09 | 386 | /* Zero the new refcount block before updating it */ |
29c1a730 | 387 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
7453c96b | 388 | refcount_block); |
29c1a730 KW |
389 | if (ret < 0) { |
390 | goto fail_block; | |
391 | } | |
392 | ||
393 | memset(*refcount_block, 0, s->cluster_size); | |
25408c09 | 394 | |
92dcb59f KW |
395 | /* The block describes itself, need to update the cache */ |
396 | int block_index = (new_block >> s->cluster_bits) & | |
17bd5f47 | 397 | (s->refcount_block_size - 1); |
7453c96b | 398 | s->set_refcount(*refcount_block, block_index, 1); |
92dcb59f KW |
399 | } else { |
400 | /* Described somewhere else. This can recurse at most twice before we | |
401 | * arrive at a block that describes itself. */ | |
2aabe7c7 | 402 | ret = update_refcount(bs, new_block, s->cluster_size, 1, false, |
6cfcb9b8 | 403 | QCOW2_DISCARD_NEVER); |
92dcb59f KW |
404 | if (ret < 0) { |
405 | goto fail_block; | |
406 | } | |
25408c09 | 407 | |
9991923b SH |
408 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
409 | if (ret < 0) { | |
410 | goto fail_block; | |
411 | } | |
1c4c2814 | 412 | |
25408c09 KW |
413 | /* Initialize the new refcount block only after updating its refcount, |
414 | * update_refcount uses the refcount cache itself */ | |
29c1a730 | 415 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
7453c96b | 416 | refcount_block); |
29c1a730 KW |
417 | if (ret < 0) { |
418 | goto fail_block; | |
419 | } | |
420 | ||
421 | memset(*refcount_block, 0, s->cluster_size); | |
92dcb59f KW |
422 | } |
423 | ||
424 | /* Now the new refcount block needs to be written to disk */ | |
66f82cee | 425 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE); |
72e80b89 | 426 | qcow2_cache_entry_mark_dirty(bs, s->refcount_block_cache, *refcount_block); |
29c1a730 | 427 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
92dcb59f KW |
428 | if (ret < 0) { |
429 | goto fail_block; | |
430 | } | |
431 | ||
432 | /* If the refcount table is big enough, just hook the block up there */ | |
433 | if (refcount_table_index < s->refcount_table_size) { | |
434 | uint64_t data64 = cpu_to_be64(new_block); | |
66f82cee | 435 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_HOOKUP); |
9a4f4c31 | 436 | ret = bdrv_pwrite_sync(bs->file->bs, |
92dcb59f KW |
437 | s->refcount_table_offset + refcount_table_index * sizeof(uint64_t), |
438 | &data64, sizeof(data64)); | |
439 | if (ret < 0) { | |
440 | goto fail_block; | |
441 | } | |
442 | ||
443 | s->refcount_table[refcount_table_index] = new_block; | |
b106ad91 KW |
444 | |
445 | /* The new refcount block may be where the caller intended to put its | |
446 | * data, so let it restart the search. */ | |
447 | return -EAGAIN; | |
29c1a730 KW |
448 | } |
449 | ||
a3f1afb4 | 450 | qcow2_cache_put(bs, s->refcount_block_cache, refcount_block); |
92dcb59f KW |
451 | |
452 | /* | |
453 | * If we come here, we need to grow the refcount table. Again, a new | |
454 | * refcount table needs some space and we can't simply allocate to avoid | |
455 | * endless recursion. | |
456 | * | |
457 | * Therefore let's grab new refcount blocks at the end of the image, which | |
458 | * will describe themselves and the new refcount table. This way we can | |
459 | * reference them only in the new table and do the switch to the new | |
460 | * refcount table at once without producing an inconsistent state in | |
461 | * between. | |
462 | */ | |
66f82cee | 463 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW); |
8252278a | 464 | |
14a58a4e HR |
465 | /* Calculate the number of refcount blocks needed so far; this will be the |
466 | * basis for calculating the index of the first cluster used for the | |
467 | * self-describing refcount structures which we are about to create. | |
468 | * | |
469 | * Because we reached this point, there cannot be any refcount entries for | |
470 | * cluster_index or higher indices yet. However, because new_block has been | |
471 | * allocated to describe that cluster (and it will assume this role later | |
472 | * on), we cannot use that index; also, new_block may actually have a higher | |
473 | * cluster index than cluster_index, so it needs to be taken into account | |
474 | * here (and 1 needs to be added to its value because that cluster is used). | |
475 | */ | |
476 | uint64_t blocks_used = DIV_ROUND_UP(MAX(cluster_index + 1, | |
477 | (new_block >> s->cluster_bits) + 1), | |
478 | s->refcount_block_size); | |
92dcb59f | 479 | |
2b5d5953 KW |
480 | if (blocks_used > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) { |
481 | return -EFBIG; | |
482 | } | |
483 | ||
92dcb59f KW |
484 | /* And now we need at least one block more for the new metadata */ |
485 | uint64_t table_size = next_refcount_table_size(s, blocks_used + 1); | |
486 | uint64_t last_table_size; | |
487 | uint64_t blocks_clusters; | |
488 | do { | |
a3548077 KW |
489 | uint64_t table_clusters = |
490 | size_to_clusters(s, table_size * sizeof(uint64_t)); | |
92dcb59f | 491 | blocks_clusters = 1 + |
17bd5f47 HR |
492 | ((table_clusters + s->refcount_block_size - 1) |
493 | / s->refcount_block_size); | |
92dcb59f KW |
494 | uint64_t meta_clusters = table_clusters + blocks_clusters; |
495 | ||
496 | last_table_size = table_size; | |
497 | table_size = next_refcount_table_size(s, blocks_used + | |
17bd5f47 HR |
498 | ((meta_clusters + s->refcount_block_size - 1) |
499 | / s->refcount_block_size)); | |
92dcb59f KW |
500 | |
501 | } while (last_table_size != table_size); | |
502 | ||
503 | #ifdef DEBUG_ALLOC2 | |
504 | fprintf(stderr, "qcow2: Grow refcount table %" PRId32 " => %" PRId64 "\n", | |
505 | s->refcount_table_size, table_size); | |
506 | #endif | |
507 | ||
508 | /* Create the new refcount table and blocks */ | |
17bd5f47 | 509 | uint64_t meta_offset = (blocks_used * s->refcount_block_size) * |
92dcb59f KW |
510 | s->cluster_size; |
511 | uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size; | |
5839e53b | 512 | uint64_t *new_table = g_try_new0(uint64_t, table_size); |
7453c96b | 513 | void *new_blocks = g_try_malloc0(blocks_clusters * s->cluster_size); |
de82815d KW |
514 | |
515 | assert(table_size > 0 && blocks_clusters > 0); | |
516 | if (new_table == NULL || new_blocks == NULL) { | |
517 | ret = -ENOMEM; | |
518 | goto fail_table; | |
519 | } | |
92dcb59f | 520 | |
92dcb59f | 521 | /* Fill the new refcount table */ |
f7d0fe02 | 522 | memcpy(new_table, s->refcount_table, |
92dcb59f KW |
523 | s->refcount_table_size * sizeof(uint64_t)); |
524 | new_table[refcount_table_index] = new_block; | |
525 | ||
526 | int i; | |
527 | for (i = 0; i < blocks_clusters; i++) { | |
528 | new_table[blocks_used + i] = meta_offset + (i * s->cluster_size); | |
529 | } | |
530 | ||
531 | /* Fill the refcount blocks */ | |
532 | uint64_t table_clusters = size_to_clusters(s, table_size * sizeof(uint64_t)); | |
533 | int block = 0; | |
534 | for (i = 0; i < table_clusters + blocks_clusters; i++) { | |
7453c96b | 535 | s->set_refcount(new_blocks, block++, 1); |
92dcb59f KW |
536 | } |
537 | ||
538 | /* Write refcount blocks to disk */ | |
66f82cee | 539 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS); |
9a4f4c31 | 540 | ret = bdrv_pwrite_sync(bs->file->bs, meta_offset, new_blocks, |
92dcb59f | 541 | blocks_clusters * s->cluster_size); |
7267c094 | 542 | g_free(new_blocks); |
39ba3bf6 | 543 | new_blocks = NULL; |
92dcb59f KW |
544 | if (ret < 0) { |
545 | goto fail_table; | |
546 | } | |
547 | ||
548 | /* Write refcount table to disk */ | |
549 | for(i = 0; i < table_size; i++) { | |
550 | cpu_to_be64s(&new_table[i]); | |
551 | } | |
552 | ||
66f82cee | 553 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE); |
9a4f4c31 | 554 | ret = bdrv_pwrite_sync(bs->file->bs, table_offset, new_table, |
92dcb59f KW |
555 | table_size * sizeof(uint64_t)); |
556 | if (ret < 0) { | |
557 | goto fail_table; | |
558 | } | |
559 | ||
560 | for(i = 0; i < table_size; i++) { | |
87267753 | 561 | be64_to_cpus(&new_table[i]); |
92dcb59f | 562 | } |
f7d0fe02 | 563 | |
92dcb59f | 564 | /* Hook up the new refcount table in the qcow2 header */ |
95334230 JS |
565 | struct QEMU_PACKED { |
566 | uint64_t d64; | |
567 | uint32_t d32; | |
568 | } data; | |
569 | cpu_to_be64w(&data.d64, table_offset); | |
570 | cpu_to_be32w(&data.d32, table_clusters); | |
66f82cee | 571 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE); |
9a4f4c31 KW |
572 | ret = bdrv_pwrite_sync(bs->file->bs, |
573 | offsetof(QCowHeader, refcount_table_offset), | |
95334230 | 574 | &data, sizeof(data)); |
92dcb59f KW |
575 | if (ret < 0) { |
576 | goto fail_table; | |
f2b7c8b3 KW |
577 | } |
578 | ||
92dcb59f KW |
579 | /* And switch it in memory */ |
580 | uint64_t old_table_offset = s->refcount_table_offset; | |
581 | uint64_t old_table_size = s->refcount_table_size; | |
582 | ||
7267c094 | 583 | g_free(s->refcount_table); |
f7d0fe02 | 584 | s->refcount_table = new_table; |
92dcb59f | 585 | s->refcount_table_size = table_size; |
f7d0fe02 KW |
586 | s->refcount_table_offset = table_offset; |
587 | ||
b106ad91 | 588 | /* Free old table. */ |
6cfcb9b8 KW |
589 | qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t), |
590 | QCOW2_DISCARD_OTHER); | |
f7d0fe02 | 591 | |
7453c96b | 592 | ret = load_refcount_block(bs, new_block, refcount_block); |
92dcb59f | 593 | if (ret < 0) { |
29c1a730 | 594 | return ret; |
f7d0fe02 KW |
595 | } |
596 | ||
b106ad91 KW |
597 | /* If we were trying to do the initial refcount update for some cluster |
598 | * allocation, we might have used the same clusters to store newly | |
599 | * allocated metadata. Make the caller search some new space. */ | |
600 | return -EAGAIN; | |
f7d0fe02 | 601 | |
92dcb59f | 602 | fail_table: |
de82815d | 603 | g_free(new_blocks); |
7267c094 | 604 | g_free(new_table); |
92dcb59f | 605 | fail_block: |
29c1a730 | 606 | if (*refcount_block != NULL) { |
7453c96b | 607 | qcow2_cache_put(bs, s->refcount_block_cache, refcount_block); |
3b88e52b | 608 | } |
29c1a730 | 609 | return ret; |
9923e05e KW |
610 | } |
611 | ||
0b919fae KW |
612 | void qcow2_process_discards(BlockDriverState *bs, int ret) |
613 | { | |
ff99129a | 614 | BDRVQcow2State *s = bs->opaque; |
0b919fae KW |
615 | Qcow2DiscardRegion *d, *next; |
616 | ||
617 | QTAILQ_FOREACH_SAFE(d, &s->discards, next, next) { | |
618 | QTAILQ_REMOVE(&s->discards, d, next); | |
619 | ||
620 | /* Discard is optional, ignore the return value */ | |
621 | if (ret >= 0) { | |
9a4f4c31 | 622 | bdrv_discard(bs->file->bs, |
0b919fae KW |
623 | d->offset >> BDRV_SECTOR_BITS, |
624 | d->bytes >> BDRV_SECTOR_BITS); | |
625 | } | |
626 | ||
627 | g_free(d); | |
628 | } | |
629 | } | |
630 | ||
631 | static void update_refcount_discard(BlockDriverState *bs, | |
632 | uint64_t offset, uint64_t length) | |
633 | { | |
ff99129a | 634 | BDRVQcow2State *s = bs->opaque; |
0b919fae KW |
635 | Qcow2DiscardRegion *d, *p, *next; |
636 | ||
637 | QTAILQ_FOREACH(d, &s->discards, next) { | |
638 | uint64_t new_start = MIN(offset, d->offset); | |
639 | uint64_t new_end = MAX(offset + length, d->offset + d->bytes); | |
640 | ||
641 | if (new_end - new_start <= length + d->bytes) { | |
642 | /* There can't be any overlap, areas ending up here have no | |
643 | * references any more and therefore shouldn't get freed another | |
644 | * time. */ | |
645 | assert(d->bytes + length == new_end - new_start); | |
646 | d->offset = new_start; | |
647 | d->bytes = new_end - new_start; | |
648 | goto found; | |
649 | } | |
650 | } | |
651 | ||
652 | d = g_malloc(sizeof(*d)); | |
653 | *d = (Qcow2DiscardRegion) { | |
654 | .bs = bs, | |
655 | .offset = offset, | |
656 | .bytes = length, | |
657 | }; | |
658 | QTAILQ_INSERT_TAIL(&s->discards, d, next); | |
659 | ||
660 | found: | |
661 | /* Merge discard requests if they are adjacent now */ | |
662 | QTAILQ_FOREACH_SAFE(p, &s->discards, next, next) { | |
663 | if (p == d | |
664 | || p->offset > d->offset + d->bytes | |
665 | || d->offset > p->offset + p->bytes) | |
666 | { | |
667 | continue; | |
668 | } | |
669 | ||
670 | /* Still no overlap possible */ | |
671 | assert(p->offset == d->offset + d->bytes | |
672 | || d->offset == p->offset + p->bytes); | |
673 | ||
674 | QTAILQ_REMOVE(&s->discards, p, next); | |
675 | d->offset = MIN(d->offset, p->offset); | |
676 | d->bytes += p->bytes; | |
d8bb71b6 | 677 | g_free(p); |
0b919fae KW |
678 | } |
679 | } | |
680 | ||
f7d0fe02 | 681 | /* XXX: cache several refcount block clusters ? */ |
2aabe7c7 HR |
682 | /* @addend is the absolute value of the addend; if @decrease is set, @addend |
683 | * will be subtracted from the current refcount, otherwise it will be added */ | |
db3a964f | 684 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
2aabe7c7 HR |
685 | int64_t offset, |
686 | int64_t length, | |
0e06528e | 687 | uint64_t addend, |
2aabe7c7 HR |
688 | bool decrease, |
689 | enum qcow2_discard_type type) | |
f7d0fe02 | 690 | { |
ff99129a | 691 | BDRVQcow2State *s = bs->opaque; |
f7d0fe02 | 692 | int64_t start, last, cluster_offset; |
7453c96b | 693 | void *refcount_block = NULL; |
29c1a730 | 694 | int64_t old_table_index = -1; |
09508d13 | 695 | int ret; |
f7d0fe02 KW |
696 | |
697 | #ifdef DEBUG_ALLOC2 | |
2aabe7c7 | 698 | fprintf(stderr, "update_refcount: offset=%" PRId64 " size=%" PRId64 |
0e06528e | 699 | " addend=%s%" PRIu64 "\n", offset, length, decrease ? "-" : "", |
2aabe7c7 | 700 | addend); |
f7d0fe02 | 701 | #endif |
7322afe7 | 702 | if (length < 0) { |
f7d0fe02 | 703 | return -EINVAL; |
7322afe7 KW |
704 | } else if (length == 0) { |
705 | return 0; | |
706 | } | |
707 | ||
2aabe7c7 | 708 | if (decrease) { |
29c1a730 KW |
709 | qcow2_cache_set_dependency(bs, s->refcount_block_cache, |
710 | s->l2_table_cache); | |
711 | } | |
712 | ||
ac95acdb HT |
713 | start = start_of_cluster(s, offset); |
714 | last = start_of_cluster(s, offset + length - 1); | |
f7d0fe02 KW |
715 | for(cluster_offset = start; cluster_offset <= last; |
716 | cluster_offset += s->cluster_size) | |
717 | { | |
2aabe7c7 | 718 | int block_index; |
0e06528e | 719 | uint64_t refcount; |
f7d0fe02 | 720 | int64_t cluster_index = cluster_offset >> s->cluster_bits; |
17bd5f47 | 721 | int64_t table_index = cluster_index >> s->refcount_block_bits; |
f7d0fe02 | 722 | |
29c1a730 KW |
723 | /* Load the refcount block and allocate it if needed */ |
724 | if (table_index != old_table_index) { | |
725 | if (refcount_block) { | |
a3f1afb4 | 726 | qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); |
29c1a730 | 727 | } |
29c1a730 | 728 | ret = alloc_refcount_block(bs, cluster_index, &refcount_block); |
ed0df867 | 729 | if (ret < 0) { |
29c1a730 | 730 | goto fail; |
f7d0fe02 | 731 | } |
f7d0fe02 | 732 | } |
29c1a730 | 733 | old_table_index = table_index; |
f7d0fe02 | 734 | |
72e80b89 AG |
735 | qcow2_cache_entry_mark_dirty(bs, s->refcount_block_cache, |
736 | refcount_block); | |
f7d0fe02 KW |
737 | |
738 | /* we can update the count and save it */ | |
17bd5f47 | 739 | block_index = cluster_index & (s->refcount_block_size - 1); |
f7d0fe02 | 740 | |
7453c96b | 741 | refcount = s->get_refcount(refcount_block, block_index); |
0e06528e HR |
742 | if (decrease ? (refcount - addend > refcount) |
743 | : (refcount + addend < refcount || | |
744 | refcount + addend > s->refcount_max)) | |
2aabe7c7 | 745 | { |
09508d13 KW |
746 | ret = -EINVAL; |
747 | goto fail; | |
748 | } | |
2aabe7c7 HR |
749 | if (decrease) { |
750 | refcount -= addend; | |
751 | } else { | |
752 | refcount += addend; | |
753 | } | |
f7d0fe02 KW |
754 | if (refcount == 0 && cluster_index < s->free_cluster_index) { |
755 | s->free_cluster_index = cluster_index; | |
756 | } | |
7453c96b | 757 | s->set_refcount(refcount_block, block_index, refcount); |
0b919fae | 758 | |
67af674e | 759 | if (refcount == 0 && s->discard_passthrough[type]) { |
0b919fae | 760 | update_refcount_discard(bs, cluster_offset, s->cluster_size); |
67af674e | 761 | } |
f7d0fe02 KW |
762 | } |
763 | ||
09508d13 KW |
764 | ret = 0; |
765 | fail: | |
0b919fae KW |
766 | if (!s->cache_discards) { |
767 | qcow2_process_discards(bs, ret); | |
768 | } | |
769 | ||
f7d0fe02 | 770 | /* Write last changed block to disk */ |
29c1a730 | 771 | if (refcount_block) { |
a3f1afb4 | 772 | qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); |
f7d0fe02 KW |
773 | } |
774 | ||
09508d13 KW |
775 | /* |
776 | * Try do undo any updates if an error is returned (This may succeed in | |
777 | * some cases like ENOSPC for allocating a new refcount block) | |
778 | */ | |
779 | if (ret < 0) { | |
780 | int dummy; | |
2aabe7c7 HR |
781 | dummy = update_refcount(bs, offset, cluster_offset - offset, addend, |
782 | !decrease, QCOW2_DISCARD_NEVER); | |
83e3f76c | 783 | (void)dummy; |
09508d13 KW |
784 | } |
785 | ||
786 | return ret; | |
f7d0fe02 KW |
787 | } |
788 | ||
018faafd | 789 | /* |
44751917 | 790 | * Increases or decreases the refcount of a given cluster. |
018faafd | 791 | * |
2aabe7c7 HR |
792 | * @addend is the absolute value of the addend; if @decrease is set, @addend |
793 | * will be subtracted from the current refcount, otherwise it will be added. | |
794 | * | |
c6e9d8ae | 795 | * On success 0 is returned; on failure -errno is returned. |
018faafd | 796 | */ |
32b6444d HR |
797 | int qcow2_update_cluster_refcount(BlockDriverState *bs, |
798 | int64_t cluster_index, | |
0e06528e | 799 | uint64_t addend, bool decrease, |
32b6444d | 800 | enum qcow2_discard_type type) |
f7d0fe02 | 801 | { |
ff99129a | 802 | BDRVQcow2State *s = bs->opaque; |
f7d0fe02 KW |
803 | int ret; |
804 | ||
6cfcb9b8 | 805 | ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend, |
2aabe7c7 | 806 | decrease, type); |
f7d0fe02 KW |
807 | if (ret < 0) { |
808 | return ret; | |
809 | } | |
810 | ||
c6e9d8ae | 811 | return 0; |
f7d0fe02 KW |
812 | } |
813 | ||
814 | ||
815 | ||
816 | /*********************************************************/ | |
817 | /* cluster allocation functions */ | |
818 | ||
819 | ||
820 | ||
821 | /* return < 0 if error */ | |
bb572aef | 822 | static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size) |
f7d0fe02 | 823 | { |
ff99129a | 824 | BDRVQcow2State *s = bs->opaque; |
0e06528e | 825 | uint64_t i, nb_clusters, refcount; |
7324c10f | 826 | int ret; |
f7d0fe02 | 827 | |
ecbda7a2 KW |
828 | /* We can't allocate clusters if they may still be queued for discard. */ |
829 | if (s->cache_discards) { | |
830 | qcow2_process_discards(bs, 0); | |
831 | } | |
832 | ||
f7d0fe02 KW |
833 | nb_clusters = size_to_clusters(s, size); |
834 | retry: | |
835 | for(i = 0; i < nb_clusters; i++) { | |
bb572aef | 836 | uint64_t next_cluster_index = s->free_cluster_index++; |
7324c10f | 837 | ret = qcow2_get_refcount(bs, next_cluster_index, &refcount); |
2eaa8f63 | 838 | |
7324c10f HR |
839 | if (ret < 0) { |
840 | return ret; | |
2eaa8f63 | 841 | } else if (refcount != 0) { |
f7d0fe02 | 842 | goto retry; |
2eaa8f63 | 843 | } |
f7d0fe02 | 844 | } |
91f827dc HR |
845 | |
846 | /* Make sure that all offsets in the "allocated" range are representable | |
847 | * in an int64_t */ | |
65f33bc0 HR |
848 | if (s->free_cluster_index > 0 && |
849 | s->free_cluster_index - 1 > (INT64_MAX >> s->cluster_bits)) | |
850 | { | |
91f827dc HR |
851 | return -EFBIG; |
852 | } | |
853 | ||
f7d0fe02 | 854 | #ifdef DEBUG_ALLOC2 |
35ee5e39 | 855 | fprintf(stderr, "alloc_clusters: size=%" PRId64 " -> %" PRId64 "\n", |
f7d0fe02 KW |
856 | size, |
857 | (s->free_cluster_index - nb_clusters) << s->cluster_bits); | |
858 | #endif | |
859 | return (s->free_cluster_index - nb_clusters) << s->cluster_bits; | |
860 | } | |
861 | ||
bb572aef | 862 | int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size) |
f7d0fe02 KW |
863 | { |
864 | int64_t offset; | |
db3a964f | 865 | int ret; |
f7d0fe02 | 866 | |
66f82cee | 867 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC); |
b106ad91 KW |
868 | do { |
869 | offset = alloc_clusters_noref(bs, size); | |
870 | if (offset < 0) { | |
871 | return offset; | |
872 | } | |
873 | ||
2aabe7c7 | 874 | ret = update_refcount(bs, offset, size, 1, false, QCOW2_DISCARD_NEVER); |
b106ad91 | 875 | } while (ret == -EAGAIN); |
2eaa8f63 | 876 | |
db3a964f KW |
877 | if (ret < 0) { |
878 | return ret; | |
879 | } | |
1c4c2814 | 880 | |
f7d0fe02 KW |
881 | return offset; |
882 | } | |
883 | ||
b6d36def HR |
884 | int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, |
885 | int64_t nb_clusters) | |
256900b1 | 886 | { |
ff99129a | 887 | BDRVQcow2State *s = bs->opaque; |
0e06528e | 888 | uint64_t cluster_index, refcount; |
33304ec9 | 889 | uint64_t i; |
7324c10f | 890 | int ret; |
33304ec9 HT |
891 | |
892 | assert(nb_clusters >= 0); | |
893 | if (nb_clusters == 0) { | |
894 | return 0; | |
895 | } | |
256900b1 | 896 | |
b106ad91 KW |
897 | do { |
898 | /* Check how many clusters there are free */ | |
899 | cluster_index = offset >> s->cluster_bits; | |
900 | for(i = 0; i < nb_clusters; i++) { | |
7324c10f HR |
901 | ret = qcow2_get_refcount(bs, cluster_index++, &refcount); |
902 | if (ret < 0) { | |
903 | return ret; | |
b106ad91 KW |
904 | } else if (refcount != 0) { |
905 | break; | |
906 | } | |
256900b1 | 907 | } |
256900b1 | 908 | |
b106ad91 | 909 | /* And then allocate them */ |
2aabe7c7 | 910 | ret = update_refcount(bs, offset, i << s->cluster_bits, 1, false, |
b106ad91 KW |
911 | QCOW2_DISCARD_NEVER); |
912 | } while (ret == -EAGAIN); | |
f24423bd | 913 | |
256900b1 KW |
914 | if (ret < 0) { |
915 | return ret; | |
916 | } | |
917 | ||
918 | return i; | |
919 | } | |
920 | ||
f7d0fe02 KW |
921 | /* only used to allocate compressed sectors. We try to allocate |
922 | contiguous sectors. size must be <= cluster_size */ | |
ed6ccf0f | 923 | int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size) |
f7d0fe02 | 924 | { |
ff99129a | 925 | BDRVQcow2State *s = bs->opaque; |
8c44dfbc HR |
926 | int64_t offset; |
927 | size_t free_in_cluster; | |
928 | int ret; | |
f7d0fe02 | 929 | |
66f82cee | 930 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_BYTES); |
f7d0fe02 | 931 | assert(size > 0 && size <= s->cluster_size); |
8c44dfbc HR |
932 | assert(!s->free_byte_offset || offset_into_cluster(s, s->free_byte_offset)); |
933 | ||
934 | offset = s->free_byte_offset; | |
935 | ||
936 | if (offset) { | |
0e06528e | 937 | uint64_t refcount; |
7324c10f HR |
938 | ret = qcow2_get_refcount(bs, offset >> s->cluster_bits, &refcount); |
939 | if (ret < 0) { | |
940 | return ret; | |
5d757b56 | 941 | } |
8c44dfbc | 942 | |
346a53df | 943 | if (refcount == s->refcount_max) { |
8c44dfbc | 944 | offset = 0; |
5d757b56 | 945 | } |
8c44dfbc HR |
946 | } |
947 | ||
948 | free_in_cluster = s->cluster_size - offset_into_cluster(s, offset); | |
3e5feb62 JM |
949 | do { |
950 | if (!offset || free_in_cluster < size) { | |
951 | int64_t new_cluster = alloc_clusters_noref(bs, s->cluster_size); | |
952 | if (new_cluster < 0) { | |
953 | return new_cluster; | |
954 | } | |
8c44dfbc | 955 | |
3e5feb62 JM |
956 | if (!offset || ROUND_UP(offset, s->cluster_size) != new_cluster) { |
957 | offset = new_cluster; | |
2ac01520 HR |
958 | free_in_cluster = s->cluster_size; |
959 | } else { | |
960 | free_in_cluster += s->cluster_size; | |
3e5feb62 | 961 | } |
f7d0fe02 | 962 | } |
29216ed1 | 963 | |
3e5feb62 JM |
964 | assert(offset); |
965 | ret = update_refcount(bs, offset, size, 1, false, QCOW2_DISCARD_NEVER); | |
2ac01520 HR |
966 | if (ret < 0) { |
967 | offset = 0; | |
968 | } | |
3e5feb62 | 969 | } while (ret == -EAGAIN); |
8c44dfbc HR |
970 | if (ret < 0) { |
971 | return ret; | |
972 | } | |
973 | ||
974 | /* The cluster refcount was incremented; refcount blocks must be flushed | |
975 | * before the caller's L2 table updates. */ | |
c1f5bafd | 976 | qcow2_cache_set_dependency(bs, s->l2_table_cache, s->refcount_block_cache); |
8c44dfbc HR |
977 | |
978 | s->free_byte_offset = offset + size; | |
979 | if (!offset_into_cluster(s, s->free_byte_offset)) { | |
980 | s->free_byte_offset = 0; | |
981 | } | |
982 | ||
f7d0fe02 KW |
983 | return offset; |
984 | } | |
985 | ||
ed6ccf0f | 986 | void qcow2_free_clusters(BlockDriverState *bs, |
6cfcb9b8 KW |
987 | int64_t offset, int64_t size, |
988 | enum qcow2_discard_type type) | |
f7d0fe02 | 989 | { |
db3a964f KW |
990 | int ret; |
991 | ||
66f82cee | 992 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_FREE); |
2aabe7c7 | 993 | ret = update_refcount(bs, offset, size, 1, true, type); |
db3a964f KW |
994 | if (ret < 0) { |
995 | fprintf(stderr, "qcow2_free_clusters failed: %s\n", strerror(-ret)); | |
003fad6e | 996 | /* TODO Remember the clusters to free them later and avoid leaking */ |
db3a964f | 997 | } |
f7d0fe02 KW |
998 | } |
999 | ||
45aba42f | 1000 | /* |
c7a4c37a KW |
1001 | * Free a cluster using its L2 entry (handles clusters of all types, e.g. |
1002 | * normal cluster, compressed cluster, etc.) | |
45aba42f | 1003 | */ |
6cfcb9b8 KW |
1004 | void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry, |
1005 | int nb_clusters, enum qcow2_discard_type type) | |
45aba42f | 1006 | { |
ff99129a | 1007 | BDRVQcow2State *s = bs->opaque; |
45aba42f | 1008 | |
c7a4c37a KW |
1009 | switch (qcow2_get_cluster_type(l2_entry)) { |
1010 | case QCOW2_CLUSTER_COMPRESSED: | |
1011 | { | |
1012 | int nb_csectors; | |
1013 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
1014 | s->csize_mask) + 1; | |
1015 | qcow2_free_clusters(bs, | |
1016 | (l2_entry & s->cluster_offset_mask) & ~511, | |
6cfcb9b8 | 1017 | nb_csectors * 512, type); |
c7a4c37a KW |
1018 | } |
1019 | break; | |
1020 | case QCOW2_CLUSTER_NORMAL: | |
8f730dd2 HR |
1021 | case QCOW2_CLUSTER_ZERO: |
1022 | if (l2_entry & L2E_OFFSET_MASK) { | |
a97c67ee HR |
1023 | if (offset_into_cluster(s, l2_entry & L2E_OFFSET_MASK)) { |
1024 | qcow2_signal_corruption(bs, false, -1, -1, | |
1025 | "Cannot free unaligned cluster %#llx", | |
1026 | l2_entry & L2E_OFFSET_MASK); | |
1027 | } else { | |
1028 | qcow2_free_clusters(bs, l2_entry & L2E_OFFSET_MASK, | |
1029 | nb_clusters << s->cluster_bits, type); | |
1030 | } | |
8f730dd2 | 1031 | } |
c7a4c37a KW |
1032 | break; |
1033 | case QCOW2_CLUSTER_UNALLOCATED: | |
1034 | break; | |
1035 | default: | |
1036 | abort(); | |
45aba42f | 1037 | } |
45aba42f KW |
1038 | } |
1039 | ||
f7d0fe02 KW |
1040 | |
1041 | ||
1042 | /*********************************************************/ | |
1043 | /* snapshots and image creation */ | |
1044 | ||
1045 | ||
1046 | ||
f7d0fe02 | 1047 | /* update the refcounts of snapshots and the copied flag */ |
ed6ccf0f KW |
1048 | int qcow2_update_snapshot_refcount(BlockDriverState *bs, |
1049 | int64_t l1_table_offset, int l1_size, int addend) | |
f7d0fe02 | 1050 | { |
ff99129a | 1051 | BDRVQcow2State *s = bs->opaque; |
0e06528e | 1052 | uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, refcount; |
de82815d | 1053 | bool l1_allocated = false; |
f7d0fe02 | 1054 | int64_t old_offset, old_l2_offset; |
7324c10f | 1055 | int i, j, l1_modified = 0, nb_csectors; |
29c1a730 | 1056 | int ret; |
f7d0fe02 | 1057 | |
2aabe7c7 HR |
1058 | assert(addend >= -1 && addend <= 1); |
1059 | ||
f7d0fe02 KW |
1060 | l2_table = NULL; |
1061 | l1_table = NULL; | |
1062 | l1_size2 = l1_size * sizeof(uint64_t); | |
43a0cac4 | 1063 | |
0b919fae KW |
1064 | s->cache_discards = true; |
1065 | ||
43a0cac4 KW |
1066 | /* WARNING: qcow2_snapshot_goto relies on this function not using the |
1067 | * l1_table_offset when it is the current s->l1_table_offset! Be careful | |
1068 | * when changing this! */ | |
f7d0fe02 | 1069 | if (l1_table_offset != s->l1_table_offset) { |
de82815d KW |
1070 | l1_table = g_try_malloc0(align_offset(l1_size2, 512)); |
1071 | if (l1_size2 && l1_table == NULL) { | |
1072 | ret = -ENOMEM; | |
1073 | goto fail; | |
1074 | } | |
1075 | l1_allocated = true; | |
c2bc78b6 | 1076 | |
9a4f4c31 | 1077 | ret = bdrv_pread(bs->file->bs, l1_table_offset, l1_table, l1_size2); |
c2bc78b6 | 1078 | if (ret < 0) { |
f7d0fe02 | 1079 | goto fail; |
93913dfd KW |
1080 | } |
1081 | ||
f7d0fe02 KW |
1082 | for(i = 0;i < l1_size; i++) |
1083 | be64_to_cpus(&l1_table[i]); | |
1084 | } else { | |
1085 | assert(l1_size == s->l1_size); | |
1086 | l1_table = s->l1_table; | |
de82815d | 1087 | l1_allocated = false; |
f7d0fe02 KW |
1088 | } |
1089 | ||
f7d0fe02 KW |
1090 | for(i = 0; i < l1_size; i++) { |
1091 | l2_offset = l1_table[i]; | |
1092 | if (l2_offset) { | |
1093 | old_l2_offset = l2_offset; | |
8e37f681 | 1094 | l2_offset &= L1E_OFFSET_MASK; |
29c1a730 | 1095 | |
a97c67ee HR |
1096 | if (offset_into_cluster(s, l2_offset)) { |
1097 | qcow2_signal_corruption(bs, true, -1, -1, "L2 table offset %#" | |
1098 | PRIx64 " unaligned (L1 index: %#x)", | |
1099 | l2_offset, i); | |
1100 | ret = -EIO; | |
1101 | goto fail; | |
1102 | } | |
1103 | ||
29c1a730 KW |
1104 | ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, |
1105 | (void**) &l2_table); | |
1106 | if (ret < 0) { | |
f7d0fe02 | 1107 | goto fail; |
29c1a730 KW |
1108 | } |
1109 | ||
f7d0fe02 | 1110 | for(j = 0; j < s->l2_size; j++) { |
8b81a7b6 HR |
1111 | uint64_t cluster_index; |
1112 | ||
f7d0fe02 | 1113 | offset = be64_to_cpu(l2_table[j]); |
8b81a7b6 HR |
1114 | old_offset = offset; |
1115 | offset &= ~QCOW_OFLAG_COPIED; | |
1116 | ||
1117 | switch (qcow2_get_cluster_type(offset)) { | |
1118 | case QCOW2_CLUSTER_COMPRESSED: | |
f7d0fe02 KW |
1119 | nb_csectors = ((offset >> s->csize_shift) & |
1120 | s->csize_mask) + 1; | |
db3a964f | 1121 | if (addend != 0) { |
db3a964f KW |
1122 | ret = update_refcount(bs, |
1123 | (offset & s->cluster_offset_mask) & ~511, | |
2aabe7c7 | 1124 | nb_csectors * 512, abs(addend), addend < 0, |
6cfcb9b8 | 1125 | QCOW2_DISCARD_SNAPSHOT); |
db3a964f KW |
1126 | if (ret < 0) { |
1127 | goto fail; | |
1128 | } | |
1129 | } | |
f7d0fe02 KW |
1130 | /* compressed clusters are never modified */ |
1131 | refcount = 2; | |
8b81a7b6 HR |
1132 | break; |
1133 | ||
1134 | case QCOW2_CLUSTER_NORMAL: | |
1135 | case QCOW2_CLUSTER_ZERO: | |
a97c67ee HR |
1136 | if (offset_into_cluster(s, offset & L2E_OFFSET_MASK)) { |
1137 | qcow2_signal_corruption(bs, true, -1, -1, "Data " | |
1138 | "cluster offset %#llx " | |
1139 | "unaligned (L2 offset: %#" | |
1140 | PRIx64 ", L2 index: %#x)", | |
1141 | offset & L2E_OFFSET_MASK, | |
1142 | l2_offset, j); | |
1143 | ret = -EIO; | |
1144 | goto fail; | |
1145 | } | |
1146 | ||
8b81a7b6 HR |
1147 | cluster_index = (offset & L2E_OFFSET_MASK) >> s->cluster_bits; |
1148 | if (!cluster_index) { | |
1149 | /* unallocated */ | |
1150 | refcount = 0; | |
1151 | break; | |
1152 | } | |
f7d0fe02 | 1153 | if (addend != 0) { |
c6e9d8ae | 1154 | ret = qcow2_update_cluster_refcount(bs, |
2aabe7c7 | 1155 | cluster_index, abs(addend), addend < 0, |
32b6444d | 1156 | QCOW2_DISCARD_SNAPSHOT); |
c6e9d8ae HR |
1157 | if (ret < 0) { |
1158 | goto fail; | |
1159 | } | |
f7d0fe02 | 1160 | } |
018faafd | 1161 | |
7324c10f HR |
1162 | ret = qcow2_get_refcount(bs, cluster_index, &refcount); |
1163 | if (ret < 0) { | |
018faafd KW |
1164 | goto fail; |
1165 | } | |
8b81a7b6 | 1166 | break; |
f7d0fe02 | 1167 | |
8b81a7b6 HR |
1168 | case QCOW2_CLUSTER_UNALLOCATED: |
1169 | refcount = 0; | |
1170 | break; | |
1171 | ||
1172 | default: | |
1173 | abort(); | |
1174 | } | |
1175 | ||
1176 | if (refcount == 1) { | |
1177 | offset |= QCOW_OFLAG_COPIED; | |
1178 | } | |
1179 | if (offset != old_offset) { | |
1180 | if (addend > 0) { | |
1181 | qcow2_cache_set_dependency(bs, s->l2_table_cache, | |
1182 | s->refcount_block_cache); | |
f7d0fe02 | 1183 | } |
8b81a7b6 | 1184 | l2_table[j] = cpu_to_be64(offset); |
72e80b89 AG |
1185 | qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, |
1186 | l2_table); | |
f7d0fe02 KW |
1187 | } |
1188 | } | |
29c1a730 | 1189 | |
a3f1afb4 | 1190 | qcow2_cache_put(bs, s->l2_table_cache, (void **) &l2_table); |
29c1a730 | 1191 | |
f7d0fe02 | 1192 | if (addend != 0) { |
c6e9d8ae HR |
1193 | ret = qcow2_update_cluster_refcount(bs, l2_offset >> |
1194 | s->cluster_bits, | |
2aabe7c7 | 1195 | abs(addend), addend < 0, |
c6e9d8ae HR |
1196 | QCOW2_DISCARD_SNAPSHOT); |
1197 | if (ret < 0) { | |
1198 | goto fail; | |
1199 | } | |
f7d0fe02 | 1200 | } |
7324c10f HR |
1201 | ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, |
1202 | &refcount); | |
1203 | if (ret < 0) { | |
018faafd KW |
1204 | goto fail; |
1205 | } else if (refcount == 1) { | |
f7d0fe02 KW |
1206 | l2_offset |= QCOW_OFLAG_COPIED; |
1207 | } | |
1208 | if (l2_offset != old_l2_offset) { | |
1209 | l1_table[i] = l2_offset; | |
1210 | l1_modified = 1; | |
1211 | } | |
1212 | } | |
1213 | } | |
93913dfd | 1214 | |
2154f24e | 1215 | ret = bdrv_flush(bs); |
93913dfd KW |
1216 | fail: |
1217 | if (l2_table) { | |
1218 | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); | |
1219 | } | |
1220 | ||
0b919fae KW |
1221 | s->cache_discards = false; |
1222 | qcow2_process_discards(bs, ret); | |
1223 | ||
43a0cac4 | 1224 | /* Update L1 only if it isn't deleted anyway (addend = -1) */ |
c2b6ff51 KW |
1225 | if (ret == 0 && addend >= 0 && l1_modified) { |
1226 | for (i = 0; i < l1_size; i++) { | |
f7d0fe02 | 1227 | cpu_to_be64s(&l1_table[i]); |
c2b6ff51 KW |
1228 | } |
1229 | ||
9a4f4c31 KW |
1230 | ret = bdrv_pwrite_sync(bs->file->bs, l1_table_offset, |
1231 | l1_table, l1_size2); | |
c2b6ff51 KW |
1232 | |
1233 | for (i = 0; i < l1_size; i++) { | |
f7d0fe02 | 1234 | be64_to_cpus(&l1_table[i]); |
c2b6ff51 | 1235 | } |
f7d0fe02 KW |
1236 | } |
1237 | if (l1_allocated) | |
7267c094 | 1238 | g_free(l1_table); |
93913dfd | 1239 | return ret; |
f7d0fe02 KW |
1240 | } |
1241 | ||
1242 | ||
1243 | ||
1244 | ||
1245 | /*********************************************************/ | |
1246 | /* refcount checking functions */ | |
1247 | ||
1248 | ||
c2551b47 | 1249 | static uint64_t refcount_array_byte_size(BDRVQcow2State *s, uint64_t entries) |
5fee192e HR |
1250 | { |
1251 | /* This assertion holds because there is no way we can address more than | |
1252 | * 2^(64 - 9) clusters at once (with cluster size 512 = 2^9, and because | |
1253 | * offsets have to be representable in bytes); due to every cluster | |
1254 | * corresponding to one refcount entry, we are well below that limit */ | |
1255 | assert(entries < (UINT64_C(1) << (64 - 9))); | |
1256 | ||
1257 | /* Thanks to the assertion this will not overflow, because | |
1258 | * s->refcount_order < 7. | |
1259 | * (note: x << s->refcount_order == x * s->refcount_bits) */ | |
1260 | return DIV_ROUND_UP(entries << s->refcount_order, 8); | |
1261 | } | |
1262 | ||
1263 | /** | |
1264 | * Reallocates *array so that it can hold new_size entries. *size must contain | |
1265 | * the current number of entries in *array. If the reallocation fails, *array | |
1266 | * and *size will not be modified and -errno will be returned. If the | |
1267 | * reallocation is successful, *array will be set to the new buffer, *size | |
1268 | * will be set to new_size and 0 will be returned. The size of the reallocated | |
1269 | * refcount array buffer will be aligned to a cluster boundary, and the newly | |
1270 | * allocated area will be zeroed. | |
1271 | */ | |
ff99129a | 1272 | static int realloc_refcount_array(BDRVQcow2State *s, void **array, |
5fee192e HR |
1273 | int64_t *size, int64_t new_size) |
1274 | { | |
b6d36def | 1275 | int64_t old_byte_size, new_byte_size; |
7453c96b | 1276 | void *new_ptr; |
5fee192e HR |
1277 | |
1278 | /* Round to clusters so the array can be directly written to disk */ | |
1279 | old_byte_size = size_to_clusters(s, refcount_array_byte_size(s, *size)) | |
1280 | * s->cluster_size; | |
1281 | new_byte_size = size_to_clusters(s, refcount_array_byte_size(s, new_size)) | |
1282 | * s->cluster_size; | |
1283 | ||
1284 | if (new_byte_size == old_byte_size) { | |
1285 | *size = new_size; | |
1286 | return 0; | |
1287 | } | |
1288 | ||
1289 | assert(new_byte_size > 0); | |
1290 | ||
b6d36def HR |
1291 | if (new_byte_size > SIZE_MAX) { |
1292 | return -ENOMEM; | |
1293 | } | |
1294 | ||
5fee192e HR |
1295 | new_ptr = g_try_realloc(*array, new_byte_size); |
1296 | if (!new_ptr) { | |
1297 | return -ENOMEM; | |
1298 | } | |
1299 | ||
1300 | if (new_byte_size > old_byte_size) { | |
b6d36def | 1301 | memset((char *)new_ptr + old_byte_size, 0, |
5fee192e HR |
1302 | new_byte_size - old_byte_size); |
1303 | } | |
1304 | ||
1305 | *array = new_ptr; | |
1306 | *size = new_size; | |
1307 | ||
1308 | return 0; | |
1309 | } | |
f7d0fe02 KW |
1310 | |
1311 | /* | |
1312 | * Increases the refcount for a range of clusters in a given refcount table. | |
1313 | * This is used to construct a temporary refcount table out of L1 and L2 tables | |
b6af0975 | 1314 | * which can be compared to the refcount table saved in the image. |
f7d0fe02 | 1315 | * |
9ac228e0 | 1316 | * Modifies the number of errors in res. |
f7d0fe02 | 1317 | */ |
fef4d3d5 HR |
1318 | static int inc_refcounts(BlockDriverState *bs, |
1319 | BdrvCheckResult *res, | |
7453c96b | 1320 | void **refcount_table, |
641bb63c | 1321 | int64_t *refcount_table_size, |
fef4d3d5 | 1322 | int64_t offset, int64_t size) |
f7d0fe02 | 1323 | { |
ff99129a | 1324 | BDRVQcow2State *s = bs->opaque; |
7453c96b | 1325 | uint64_t start, last, cluster_offset, k, refcount; |
5fee192e | 1326 | int ret; |
f7d0fe02 | 1327 | |
fef4d3d5 HR |
1328 | if (size <= 0) { |
1329 | return 0; | |
1330 | } | |
f7d0fe02 | 1331 | |
ac95acdb HT |
1332 | start = start_of_cluster(s, offset); |
1333 | last = start_of_cluster(s, offset + size - 1); | |
f7d0fe02 KW |
1334 | for(cluster_offset = start; cluster_offset <= last; |
1335 | cluster_offset += s->cluster_size) { | |
1336 | k = cluster_offset >> s->cluster_bits; | |
641bb63c | 1337 | if (k >= *refcount_table_size) { |
5fee192e HR |
1338 | ret = realloc_refcount_array(s, refcount_table, |
1339 | refcount_table_size, k + 1); | |
1340 | if (ret < 0) { | |
641bb63c | 1341 | res->check_errors++; |
5fee192e | 1342 | return ret; |
f7d0fe02 | 1343 | } |
641bb63c HR |
1344 | } |
1345 | ||
7453c96b HR |
1346 | refcount = s->get_refcount(*refcount_table, k); |
1347 | if (refcount == s->refcount_max) { | |
641bb63c HR |
1348 | fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64 |
1349 | "\n", cluster_offset); | |
03bb78ed HR |
1350 | fprintf(stderr, "Use qemu-img amend to increase the refcount entry " |
1351 | "width or qemu-img convert to create a clean copy if the " | |
1352 | "image cannot be opened for writing\n"); | |
641bb63c | 1353 | res->corruptions++; |
7453c96b | 1354 | continue; |
f7d0fe02 | 1355 | } |
7453c96b | 1356 | s->set_refcount(*refcount_table, k, refcount + 1); |
f7d0fe02 | 1357 | } |
fef4d3d5 HR |
1358 | |
1359 | return 0; | |
f7d0fe02 KW |
1360 | } |
1361 | ||
801f7044 SH |
1362 | /* Flags for check_refcounts_l1() and check_refcounts_l2() */ |
1363 | enum { | |
fba31bae | 1364 | CHECK_FRAG_INFO = 0x2, /* update BlockFragInfo counters */ |
801f7044 SH |
1365 | }; |
1366 | ||
f7d0fe02 KW |
1367 | /* |
1368 | * Increases the refcount in the given refcount table for the all clusters | |
1369 | * referenced in the L2 table. While doing so, performs some checks on L2 | |
1370 | * entries. | |
1371 | * | |
1372 | * Returns the number of errors found by the checks or -errno if an internal | |
1373 | * error occurred. | |
1374 | */ | |
9ac228e0 | 1375 | static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, |
7453c96b HR |
1376 | void **refcount_table, |
1377 | int64_t *refcount_table_size, int64_t l2_offset, | |
1378 | int flags) | |
f7d0fe02 | 1379 | { |
ff99129a | 1380 | BDRVQcow2State *s = bs->opaque; |
afdf0abe | 1381 | uint64_t *l2_table, l2_entry; |
fba31bae | 1382 | uint64_t next_contiguous_offset = 0; |
ad27390c | 1383 | int i, l2_size, nb_csectors, ret; |
f7d0fe02 KW |
1384 | |
1385 | /* Read L2 table from disk */ | |
1386 | l2_size = s->l2_size * sizeof(uint64_t); | |
7267c094 | 1387 | l2_table = g_malloc(l2_size); |
f7d0fe02 | 1388 | |
9a4f4c31 | 1389 | ret = bdrv_pread(bs->file->bs, l2_offset, l2_table, l2_size); |
ad27390c HR |
1390 | if (ret < 0) { |
1391 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l2\n"); | |
1392 | res->check_errors++; | |
f7d0fe02 | 1393 | goto fail; |
ad27390c | 1394 | } |
f7d0fe02 KW |
1395 | |
1396 | /* Do the actual checks */ | |
1397 | for(i = 0; i < s->l2_size; i++) { | |
afdf0abe KW |
1398 | l2_entry = be64_to_cpu(l2_table[i]); |
1399 | ||
1400 | switch (qcow2_get_cluster_type(l2_entry)) { | |
1401 | case QCOW2_CLUSTER_COMPRESSED: | |
1402 | /* Compressed clusters don't have QCOW_OFLAG_COPIED */ | |
1403 | if (l2_entry & QCOW_OFLAG_COPIED) { | |
1404 | fprintf(stderr, "ERROR: cluster %" PRId64 ": " | |
1405 | "copied flag must never be set for compressed " | |
1406 | "clusters\n", l2_entry >> s->cluster_bits); | |
1407 | l2_entry &= ~QCOW_OFLAG_COPIED; | |
1408 | res->corruptions++; | |
1409 | } | |
f7d0fe02 | 1410 | |
afdf0abe KW |
1411 | /* Mark cluster as used */ |
1412 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
1413 | s->csize_mask) + 1; | |
1414 | l2_entry &= s->cluster_offset_mask; | |
fef4d3d5 HR |
1415 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1416 | l2_entry & ~511, nb_csectors * 512); | |
1417 | if (ret < 0) { | |
1418 | goto fail; | |
1419 | } | |
fba31bae SH |
1420 | |
1421 | if (flags & CHECK_FRAG_INFO) { | |
1422 | res->bfi.allocated_clusters++; | |
4db35162 | 1423 | res->bfi.compressed_clusters++; |
fba31bae SH |
1424 | |
1425 | /* Compressed clusters are fragmented by nature. Since they | |
1426 | * take up sub-sector space but we only have sector granularity | |
1427 | * I/O we need to re-read the same sectors even for adjacent | |
1428 | * compressed clusters. | |
1429 | */ | |
1430 | res->bfi.fragmented_clusters++; | |
1431 | } | |
afdf0abe | 1432 | break; |
f7d0fe02 | 1433 | |
6377af48 KW |
1434 | case QCOW2_CLUSTER_ZERO: |
1435 | if ((l2_entry & L2E_OFFSET_MASK) == 0) { | |
1436 | break; | |
1437 | } | |
1438 | /* fall through */ | |
1439 | ||
afdf0abe KW |
1440 | case QCOW2_CLUSTER_NORMAL: |
1441 | { | |
afdf0abe | 1442 | uint64_t offset = l2_entry & L2E_OFFSET_MASK; |
f7d0fe02 | 1443 | |
fba31bae SH |
1444 | if (flags & CHECK_FRAG_INFO) { |
1445 | res->bfi.allocated_clusters++; | |
1446 | if (next_contiguous_offset && | |
1447 | offset != next_contiguous_offset) { | |
1448 | res->bfi.fragmented_clusters++; | |
1449 | } | |
1450 | next_contiguous_offset = offset + s->cluster_size; | |
1451 | } | |
1452 | ||
afdf0abe | 1453 | /* Mark cluster as used */ |
fef4d3d5 HR |
1454 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1455 | offset, s->cluster_size); | |
1456 | if (ret < 0) { | |
1457 | goto fail; | |
1458 | } | |
afdf0abe KW |
1459 | |
1460 | /* Correct offsets are cluster aligned */ | |
ac95acdb | 1461 | if (offset_into_cluster(s, offset)) { |
afdf0abe KW |
1462 | fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " |
1463 | "properly aligned; L2 entry corrupted.\n", offset); | |
1464 | res->corruptions++; | |
1465 | } | |
1466 | break; | |
1467 | } | |
1468 | ||
1469 | case QCOW2_CLUSTER_UNALLOCATED: | |
1470 | break; | |
1471 | ||
1472 | default: | |
1473 | abort(); | |
f7d0fe02 KW |
1474 | } |
1475 | } | |
1476 | ||
7267c094 | 1477 | g_free(l2_table); |
9ac228e0 | 1478 | return 0; |
f7d0fe02 KW |
1479 | |
1480 | fail: | |
7267c094 | 1481 | g_free(l2_table); |
ad27390c | 1482 | return ret; |
f7d0fe02 KW |
1483 | } |
1484 | ||
1485 | /* | |
1486 | * Increases the refcount for the L1 table, its L2 tables and all referenced | |
1487 | * clusters in the given refcount table. While doing so, performs some checks | |
1488 | * on L1 and L2 entries. | |
1489 | * | |
1490 | * Returns the number of errors found by the checks or -errno if an internal | |
1491 | * error occurred. | |
1492 | */ | |
1493 | static int check_refcounts_l1(BlockDriverState *bs, | |
9ac228e0 | 1494 | BdrvCheckResult *res, |
7453c96b | 1495 | void **refcount_table, |
641bb63c | 1496 | int64_t *refcount_table_size, |
f7d0fe02 | 1497 | int64_t l1_table_offset, int l1_size, |
801f7044 | 1498 | int flags) |
f7d0fe02 | 1499 | { |
ff99129a | 1500 | BDRVQcow2State *s = bs->opaque; |
fef4d3d5 | 1501 | uint64_t *l1_table = NULL, l2_offset, l1_size2; |
4f6ed88c | 1502 | int i, ret; |
f7d0fe02 KW |
1503 | |
1504 | l1_size2 = l1_size * sizeof(uint64_t); | |
1505 | ||
1506 | /* Mark L1 table as used */ | |
fef4d3d5 HR |
1507 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1508 | l1_table_offset, l1_size2); | |
1509 | if (ret < 0) { | |
1510 | goto fail; | |
1511 | } | |
f7d0fe02 KW |
1512 | |
1513 | /* Read L1 table entries from disk */ | |
fef4d3d5 | 1514 | if (l1_size2 > 0) { |
de82815d KW |
1515 | l1_table = g_try_malloc(l1_size2); |
1516 | if (l1_table == NULL) { | |
1517 | ret = -ENOMEM; | |
ad27390c | 1518 | res->check_errors++; |
de82815d KW |
1519 | goto fail; |
1520 | } | |
9a4f4c31 | 1521 | ret = bdrv_pread(bs->file->bs, l1_table_offset, l1_table, l1_size2); |
ad27390c HR |
1522 | if (ret < 0) { |
1523 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); | |
1524 | res->check_errors++; | |
702ef63f | 1525 | goto fail; |
ad27390c | 1526 | } |
702ef63f KW |
1527 | for(i = 0;i < l1_size; i++) |
1528 | be64_to_cpus(&l1_table[i]); | |
1529 | } | |
f7d0fe02 KW |
1530 | |
1531 | /* Do the actual checks */ | |
1532 | for(i = 0; i < l1_size; i++) { | |
1533 | l2_offset = l1_table[i]; | |
1534 | if (l2_offset) { | |
f7d0fe02 | 1535 | /* Mark L2 table as used */ |
afdf0abe | 1536 | l2_offset &= L1E_OFFSET_MASK; |
fef4d3d5 HR |
1537 | ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1538 | l2_offset, s->cluster_size); | |
1539 | if (ret < 0) { | |
1540 | goto fail; | |
1541 | } | |
f7d0fe02 KW |
1542 | |
1543 | /* L2 tables are cluster aligned */ | |
ac95acdb | 1544 | if (offset_into_cluster(s, l2_offset)) { |
f7d0fe02 KW |
1545 | fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " |
1546 | "cluster aligned; L1 entry corrupted\n", l2_offset); | |
9ac228e0 | 1547 | res->corruptions++; |
f7d0fe02 KW |
1548 | } |
1549 | ||
1550 | /* Process and check L2 entries */ | |
9ac228e0 | 1551 | ret = check_refcounts_l2(bs, res, refcount_table, |
801f7044 | 1552 | refcount_table_size, l2_offset, flags); |
f7d0fe02 KW |
1553 | if (ret < 0) { |
1554 | goto fail; | |
1555 | } | |
f7d0fe02 KW |
1556 | } |
1557 | } | |
7267c094 | 1558 | g_free(l1_table); |
9ac228e0 | 1559 | return 0; |
f7d0fe02 KW |
1560 | |
1561 | fail: | |
7267c094 | 1562 | g_free(l1_table); |
ad27390c | 1563 | return ret; |
f7d0fe02 KW |
1564 | } |
1565 | ||
4f6ed88c HR |
1566 | /* |
1567 | * Checks the OFLAG_COPIED flag for all L1 and L2 entries. | |
1568 | * | |
1569 | * This function does not print an error message nor does it increment | |
44751917 HR |
1570 | * check_errors if qcow2_get_refcount fails (this is because such an error will |
1571 | * have been already detected and sufficiently signaled by the calling function | |
4f6ed88c HR |
1572 | * (qcow2_check_refcounts) by the time this function is called). |
1573 | */ | |
e23e400e HR |
1574 | static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res, |
1575 | BdrvCheckMode fix) | |
4f6ed88c | 1576 | { |
ff99129a | 1577 | BDRVQcow2State *s = bs->opaque; |
4f6ed88c HR |
1578 | uint64_t *l2_table = qemu_blockalign(bs, s->cluster_size); |
1579 | int ret; | |
0e06528e | 1580 | uint64_t refcount; |
4f6ed88c HR |
1581 | int i, j; |
1582 | ||
1583 | for (i = 0; i < s->l1_size; i++) { | |
1584 | uint64_t l1_entry = s->l1_table[i]; | |
1585 | uint64_t l2_offset = l1_entry & L1E_OFFSET_MASK; | |
e23e400e | 1586 | bool l2_dirty = false; |
4f6ed88c HR |
1587 | |
1588 | if (!l2_offset) { | |
1589 | continue; | |
1590 | } | |
1591 | ||
7324c10f HR |
1592 | ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, |
1593 | &refcount); | |
1594 | if (ret < 0) { | |
4f6ed88c HR |
1595 | /* don't print message nor increment check_errors */ |
1596 | continue; | |
1597 | } | |
1598 | if ((refcount == 1) != ((l1_entry & QCOW_OFLAG_COPIED) != 0)) { | |
e23e400e | 1599 | fprintf(stderr, "%s OFLAG_COPIED L2 cluster: l1_index=%d " |
0e06528e | 1600 | "l1_entry=%" PRIx64 " refcount=%" PRIu64 "\n", |
e23e400e HR |
1601 | fix & BDRV_FIX_ERRORS ? "Repairing" : |
1602 | "ERROR", | |
4f6ed88c | 1603 | i, l1_entry, refcount); |
e23e400e HR |
1604 | if (fix & BDRV_FIX_ERRORS) { |
1605 | s->l1_table[i] = refcount == 1 | |
1606 | ? l1_entry | QCOW_OFLAG_COPIED | |
1607 | : l1_entry & ~QCOW_OFLAG_COPIED; | |
1608 | ret = qcow2_write_l1_entry(bs, i); | |
1609 | if (ret < 0) { | |
1610 | res->check_errors++; | |
1611 | goto fail; | |
1612 | } | |
1613 | res->corruptions_fixed++; | |
1614 | } else { | |
1615 | res->corruptions++; | |
1616 | } | |
4f6ed88c HR |
1617 | } |
1618 | ||
9a4f4c31 | 1619 | ret = bdrv_pread(bs->file->bs, l2_offset, l2_table, |
4f6ed88c HR |
1620 | s->l2_size * sizeof(uint64_t)); |
1621 | if (ret < 0) { | |
1622 | fprintf(stderr, "ERROR: Could not read L2 table: %s\n", | |
1623 | strerror(-ret)); | |
1624 | res->check_errors++; | |
1625 | goto fail; | |
1626 | } | |
1627 | ||
1628 | for (j = 0; j < s->l2_size; j++) { | |
1629 | uint64_t l2_entry = be64_to_cpu(l2_table[j]); | |
1630 | uint64_t data_offset = l2_entry & L2E_OFFSET_MASK; | |
1631 | int cluster_type = qcow2_get_cluster_type(l2_entry); | |
1632 | ||
1633 | if ((cluster_type == QCOW2_CLUSTER_NORMAL) || | |
1634 | ((cluster_type == QCOW2_CLUSTER_ZERO) && (data_offset != 0))) { | |
7324c10f HR |
1635 | ret = qcow2_get_refcount(bs, |
1636 | data_offset >> s->cluster_bits, | |
1637 | &refcount); | |
1638 | if (ret < 0) { | |
4f6ed88c HR |
1639 | /* don't print message nor increment check_errors */ |
1640 | continue; | |
1641 | } | |
1642 | if ((refcount == 1) != ((l2_entry & QCOW_OFLAG_COPIED) != 0)) { | |
e23e400e | 1643 | fprintf(stderr, "%s OFLAG_COPIED data cluster: " |
0e06528e | 1644 | "l2_entry=%" PRIx64 " refcount=%" PRIu64 "\n", |
e23e400e HR |
1645 | fix & BDRV_FIX_ERRORS ? "Repairing" : |
1646 | "ERROR", | |
4f6ed88c | 1647 | l2_entry, refcount); |
e23e400e HR |
1648 | if (fix & BDRV_FIX_ERRORS) { |
1649 | l2_table[j] = cpu_to_be64(refcount == 1 | |
1650 | ? l2_entry | QCOW_OFLAG_COPIED | |
1651 | : l2_entry & ~QCOW_OFLAG_COPIED); | |
1652 | l2_dirty = true; | |
1653 | res->corruptions_fixed++; | |
1654 | } else { | |
1655 | res->corruptions++; | |
1656 | } | |
4f6ed88c HR |
1657 | } |
1658 | } | |
1659 | } | |
e23e400e HR |
1660 | |
1661 | if (l2_dirty) { | |
231bb267 HR |
1662 | ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L2, |
1663 | l2_offset, s->cluster_size); | |
e23e400e HR |
1664 | if (ret < 0) { |
1665 | fprintf(stderr, "ERROR: Could not write L2 table; metadata " | |
1666 | "overlap check failed: %s\n", strerror(-ret)); | |
1667 | res->check_errors++; | |
1668 | goto fail; | |
1669 | } | |
1670 | ||
9a4f4c31 KW |
1671 | ret = bdrv_pwrite(bs->file->bs, l2_offset, l2_table, |
1672 | s->cluster_size); | |
e23e400e HR |
1673 | if (ret < 0) { |
1674 | fprintf(stderr, "ERROR: Could not write L2 table: %s\n", | |
1675 | strerror(-ret)); | |
1676 | res->check_errors++; | |
1677 | goto fail; | |
1678 | } | |
1679 | } | |
4f6ed88c HR |
1680 | } |
1681 | ||
1682 | ret = 0; | |
1683 | ||
1684 | fail: | |
1685 | qemu_vfree(l2_table); | |
1686 | return ret; | |
1687 | } | |
1688 | ||
6ca56bf5 HR |
1689 | /* |
1690 | * Checks consistency of refblocks and accounts for each refblock in | |
1691 | * *refcount_table. | |
1692 | */ | |
1693 | static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 | 1694 | BdrvCheckMode fix, bool *rebuild, |
7453c96b | 1695 | void **refcount_table, int64_t *nb_clusters) |
6ca56bf5 | 1696 | { |
ff99129a | 1697 | BDRVQcow2State *s = bs->opaque; |
001c158d | 1698 | int64_t i, size; |
fef4d3d5 | 1699 | int ret; |
6ca56bf5 | 1700 | |
f7d0fe02 | 1701 | for(i = 0; i < s->refcount_table_size; i++) { |
6882c8fa | 1702 | uint64_t offset, cluster; |
f7d0fe02 | 1703 | offset = s->refcount_table[i]; |
6882c8fa | 1704 | cluster = offset >> s->cluster_bits; |
746c3cb5 KW |
1705 | |
1706 | /* Refcount blocks are cluster aligned */ | |
ac95acdb | 1707 | if (offset_into_cluster(s, offset)) { |
166acf54 | 1708 | fprintf(stderr, "ERROR refcount block %" PRId64 " is not " |
746c3cb5 | 1709 | "cluster aligned; refcount table entry corrupted\n", i); |
9ac228e0 | 1710 | res->corruptions++; |
f307b255 | 1711 | *rebuild = true; |
6882c8fa KW |
1712 | continue; |
1713 | } | |
1714 | ||
6ca56bf5 | 1715 | if (cluster >= *nb_clusters) { |
001c158d HR |
1716 | fprintf(stderr, "%s refcount block %" PRId64 " is outside image\n", |
1717 | fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i); | |
1718 | ||
1719 | if (fix & BDRV_FIX_ERRORS) { | |
5fee192e | 1720 | int64_t new_nb_clusters; |
001c158d HR |
1721 | |
1722 | if (offset > INT64_MAX - s->cluster_size) { | |
1723 | ret = -EINVAL; | |
1724 | goto resize_fail; | |
1725 | } | |
1726 | ||
9a4f4c31 | 1727 | ret = bdrv_truncate(bs->file->bs, offset + s->cluster_size); |
001c158d HR |
1728 | if (ret < 0) { |
1729 | goto resize_fail; | |
1730 | } | |
9a4f4c31 | 1731 | size = bdrv_getlength(bs->file->bs); |
001c158d HR |
1732 | if (size < 0) { |
1733 | ret = size; | |
1734 | goto resize_fail; | |
1735 | } | |
1736 | ||
5fee192e HR |
1737 | new_nb_clusters = size_to_clusters(s, size); |
1738 | assert(new_nb_clusters >= *nb_clusters); | |
001c158d | 1739 | |
5fee192e HR |
1740 | ret = realloc_refcount_array(s, refcount_table, |
1741 | nb_clusters, new_nb_clusters); | |
1742 | if (ret < 0) { | |
001c158d | 1743 | res->check_errors++; |
5fee192e | 1744 | return ret; |
001c158d | 1745 | } |
001c158d HR |
1746 | |
1747 | if (cluster >= *nb_clusters) { | |
1748 | ret = -EINVAL; | |
1749 | goto resize_fail; | |
1750 | } | |
1751 | ||
1752 | res->corruptions_fixed++; | |
1753 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, | |
1754 | offset, s->cluster_size); | |
1755 | if (ret < 0) { | |
1756 | return ret; | |
1757 | } | |
1758 | /* No need to check whether the refcount is now greater than 1: | |
1759 | * This area was just allocated and zeroed, so it can only be | |
1760 | * exactly 1 after inc_refcounts() */ | |
1761 | continue; | |
1762 | ||
1763 | resize_fail: | |
1764 | res->corruptions++; | |
f307b255 | 1765 | *rebuild = true; |
001c158d HR |
1766 | fprintf(stderr, "ERROR could not resize image: %s\n", |
1767 | strerror(-ret)); | |
1768 | } else { | |
1769 | res->corruptions++; | |
1770 | } | |
6882c8fa | 1771 | continue; |
746c3cb5 KW |
1772 | } |
1773 | ||
f7d0fe02 | 1774 | if (offset != 0) { |
641bb63c | 1775 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1776 | offset, s->cluster_size); |
1777 | if (ret < 0) { | |
1778 | return ret; | |
1779 | } | |
7453c96b | 1780 | if (s->get_refcount(*refcount_table, cluster) != 1) { |
f307b255 | 1781 | fprintf(stderr, "ERROR refcount block %" PRId64 |
7453c96b HR |
1782 | " refcount=%" PRIu64 "\n", i, |
1783 | s->get_refcount(*refcount_table, cluster)); | |
f307b255 HR |
1784 | res->corruptions++; |
1785 | *rebuild = true; | |
746c3cb5 | 1786 | } |
f7d0fe02 KW |
1787 | } |
1788 | } | |
1789 | ||
6ca56bf5 HR |
1790 | return 0; |
1791 | } | |
1792 | ||
057a3fe5 HR |
1793 | /* |
1794 | * Calculates an in-memory refcount table. | |
1795 | */ | |
1796 | static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 | 1797 | BdrvCheckMode fix, bool *rebuild, |
7453c96b | 1798 | void **refcount_table, int64_t *nb_clusters) |
057a3fe5 | 1799 | { |
ff99129a | 1800 | BDRVQcow2State *s = bs->opaque; |
057a3fe5 HR |
1801 | int64_t i; |
1802 | QCowSnapshot *sn; | |
1803 | int ret; | |
1804 | ||
9696df21 | 1805 | if (!*refcount_table) { |
5fee192e HR |
1806 | int64_t old_size = 0; |
1807 | ret = realloc_refcount_array(s, refcount_table, | |
1808 | &old_size, *nb_clusters); | |
1809 | if (ret < 0) { | |
9696df21 | 1810 | res->check_errors++; |
5fee192e | 1811 | return ret; |
9696df21 | 1812 | } |
057a3fe5 HR |
1813 | } |
1814 | ||
1815 | /* header */ | |
641bb63c | 1816 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1817 | 0, s->cluster_size); |
1818 | if (ret < 0) { | |
1819 | return ret; | |
1820 | } | |
057a3fe5 HR |
1821 | |
1822 | /* current L1 table */ | |
641bb63c | 1823 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
057a3fe5 HR |
1824 | s->l1_table_offset, s->l1_size, CHECK_FRAG_INFO); |
1825 | if (ret < 0) { | |
1826 | return ret; | |
1827 | } | |
1828 | ||
1829 | /* snapshots */ | |
1830 | for (i = 0; i < s->nb_snapshots; i++) { | |
1831 | sn = s->snapshots + i; | |
641bb63c | 1832 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
fef4d3d5 | 1833 | sn->l1_table_offset, sn->l1_size, 0); |
057a3fe5 HR |
1834 | if (ret < 0) { |
1835 | return ret; | |
1836 | } | |
1837 | } | |
641bb63c | 1838 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1839 | s->snapshots_offset, s->snapshots_size); |
1840 | if (ret < 0) { | |
1841 | return ret; | |
1842 | } | |
057a3fe5 HR |
1843 | |
1844 | /* refcount data */ | |
641bb63c | 1845 | ret = inc_refcounts(bs, res, refcount_table, nb_clusters, |
fef4d3d5 HR |
1846 | s->refcount_table_offset, |
1847 | s->refcount_table_size * sizeof(uint64_t)); | |
1848 | if (ret < 0) { | |
1849 | return ret; | |
1850 | } | |
057a3fe5 | 1851 | |
f307b255 | 1852 | return check_refblocks(bs, res, fix, rebuild, refcount_table, nb_clusters); |
057a3fe5 HR |
1853 | } |
1854 | ||
6ca56bf5 HR |
1855 | /* |
1856 | * Compares the actual reference count for each cluster in the image against the | |
1857 | * refcount as reported by the refcount structures on-disk. | |
1858 | */ | |
1859 | static void compare_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 HR |
1860 | BdrvCheckMode fix, bool *rebuild, |
1861 | int64_t *highest_cluster, | |
7453c96b | 1862 | void *refcount_table, int64_t nb_clusters) |
6ca56bf5 | 1863 | { |
ff99129a | 1864 | BDRVQcow2State *s = bs->opaque; |
6ca56bf5 | 1865 | int64_t i; |
0e06528e | 1866 | uint64_t refcount1, refcount2; |
7324c10f | 1867 | int ret; |
6ca56bf5 HR |
1868 | |
1869 | for (i = 0, *highest_cluster = 0; i < nb_clusters; i++) { | |
7324c10f HR |
1870 | ret = qcow2_get_refcount(bs, i, &refcount1); |
1871 | if (ret < 0) { | |
166acf54 | 1872 | fprintf(stderr, "Can't get refcount for cluster %" PRId64 ": %s\n", |
7324c10f | 1873 | i, strerror(-ret)); |
9ac228e0 | 1874 | res->check_errors++; |
f74550fd | 1875 | continue; |
018faafd KW |
1876 | } |
1877 | ||
7453c96b | 1878 | refcount2 = s->get_refcount(refcount_table, i); |
c6bb9ad1 FS |
1879 | |
1880 | if (refcount1 > 0 || refcount2 > 0) { | |
6ca56bf5 | 1881 | *highest_cluster = i; |
c6bb9ad1 FS |
1882 | } |
1883 | ||
f7d0fe02 | 1884 | if (refcount1 != refcount2) { |
166acf54 KW |
1885 | /* Check if we're allowed to fix the mismatch */ |
1886 | int *num_fixed = NULL; | |
f307b255 HR |
1887 | if (refcount1 == 0) { |
1888 | *rebuild = true; | |
1889 | } else if (refcount1 > refcount2 && (fix & BDRV_FIX_LEAKS)) { | |
166acf54 KW |
1890 | num_fixed = &res->leaks_fixed; |
1891 | } else if (refcount1 < refcount2 && (fix & BDRV_FIX_ERRORS)) { | |
1892 | num_fixed = &res->corruptions_fixed; | |
1893 | } | |
1894 | ||
0e06528e HR |
1895 | fprintf(stderr, "%s cluster %" PRId64 " refcount=%" PRIu64 |
1896 | " reference=%" PRIu64 "\n", | |
166acf54 KW |
1897 | num_fixed != NULL ? "Repairing" : |
1898 | refcount1 < refcount2 ? "ERROR" : | |
1899 | "Leaked", | |
f7d0fe02 | 1900 | i, refcount1, refcount2); |
166acf54 KW |
1901 | |
1902 | if (num_fixed) { | |
1903 | ret = update_refcount(bs, i << s->cluster_bits, 1, | |
2aabe7c7 HR |
1904 | refcount_diff(refcount1, refcount2), |
1905 | refcount1 > refcount2, | |
6cfcb9b8 | 1906 | QCOW2_DISCARD_ALWAYS); |
166acf54 KW |
1907 | if (ret >= 0) { |
1908 | (*num_fixed)++; | |
1909 | continue; | |
1910 | } | |
1911 | } | |
1912 | ||
1913 | /* And if we couldn't, print an error */ | |
9ac228e0 KW |
1914 | if (refcount1 < refcount2) { |
1915 | res->corruptions++; | |
1916 | } else { | |
1917 | res->leaks++; | |
1918 | } | |
f7d0fe02 KW |
1919 | } |
1920 | } | |
6ca56bf5 HR |
1921 | } |
1922 | ||
c7c0681b HR |
1923 | /* |
1924 | * Allocates clusters using an in-memory refcount table (IMRT) in contrast to | |
1925 | * the on-disk refcount structures. | |
1926 | * | |
1927 | * On input, *first_free_cluster tells where to start looking, and need not | |
1928 | * actually be a free cluster; the returned offset will not be before that | |
1929 | * cluster. On output, *first_free_cluster points to the first gap found, even | |
1930 | * if that gap was too small to be used as the returned offset. | |
1931 | * | |
1932 | * Note that *first_free_cluster is a cluster index whereas the return value is | |
1933 | * an offset. | |
1934 | */ | |
1935 | static int64_t alloc_clusters_imrt(BlockDriverState *bs, | |
1936 | int cluster_count, | |
7453c96b | 1937 | void **refcount_table, |
c7c0681b HR |
1938 | int64_t *imrt_nb_clusters, |
1939 | int64_t *first_free_cluster) | |
1940 | { | |
ff99129a | 1941 | BDRVQcow2State *s = bs->opaque; |
c7c0681b HR |
1942 | int64_t cluster = *first_free_cluster, i; |
1943 | bool first_gap = true; | |
1944 | int contiguous_free_clusters; | |
5fee192e | 1945 | int ret; |
c7c0681b HR |
1946 | |
1947 | /* Starting at *first_free_cluster, find a range of at least cluster_count | |
1948 | * continuously free clusters */ | |
1949 | for (contiguous_free_clusters = 0; | |
1950 | cluster < *imrt_nb_clusters && | |
1951 | contiguous_free_clusters < cluster_count; | |
1952 | cluster++) | |
1953 | { | |
7453c96b | 1954 | if (!s->get_refcount(*refcount_table, cluster)) { |
c7c0681b HR |
1955 | contiguous_free_clusters++; |
1956 | if (first_gap) { | |
1957 | /* If this is the first free cluster found, update | |
1958 | * *first_free_cluster accordingly */ | |
1959 | *first_free_cluster = cluster; | |
1960 | first_gap = false; | |
1961 | } | |
1962 | } else if (contiguous_free_clusters) { | |
1963 | contiguous_free_clusters = 0; | |
1964 | } | |
1965 | } | |
1966 | ||
1967 | /* If contiguous_free_clusters is greater than zero, it contains the number | |
1968 | * of continuously free clusters until the current cluster; the first free | |
1969 | * cluster in the current "gap" is therefore | |
1970 | * cluster - contiguous_free_clusters */ | |
1971 | ||
1972 | /* If no such range could be found, grow the in-memory refcount table | |
1973 | * accordingly to append free clusters at the end of the image */ | |
1974 | if (contiguous_free_clusters < cluster_count) { | |
c7c0681b HR |
1975 | /* contiguous_free_clusters clusters are already empty at the image end; |
1976 | * we need cluster_count clusters; therefore, we have to allocate | |
1977 | * cluster_count - contiguous_free_clusters new clusters at the end of | |
1978 | * the image (which is the current value of cluster; note that cluster | |
1979 | * may exceed old_imrt_nb_clusters if *first_free_cluster pointed beyond | |
1980 | * the image end) */ | |
5fee192e HR |
1981 | ret = realloc_refcount_array(s, refcount_table, imrt_nb_clusters, |
1982 | cluster + cluster_count | |
1983 | - contiguous_free_clusters); | |
1984 | if (ret < 0) { | |
1985 | return ret; | |
c7c0681b | 1986 | } |
c7c0681b HR |
1987 | } |
1988 | ||
1989 | /* Go back to the first free cluster */ | |
1990 | cluster -= contiguous_free_clusters; | |
1991 | for (i = 0; i < cluster_count; i++) { | |
7453c96b | 1992 | s->set_refcount(*refcount_table, cluster + i, 1); |
c7c0681b HR |
1993 | } |
1994 | ||
1995 | return cluster << s->cluster_bits; | |
1996 | } | |
1997 | ||
1998 | /* | |
1999 | * Creates a new refcount structure based solely on the in-memory information | |
2000 | * given through *refcount_table. All necessary allocations will be reflected | |
2001 | * in that array. | |
2002 | * | |
2003 | * On success, the old refcount structure is leaked (it will be covered by the | |
2004 | * new refcount structure). | |
2005 | */ | |
2006 | static int rebuild_refcount_structure(BlockDriverState *bs, | |
2007 | BdrvCheckResult *res, | |
7453c96b | 2008 | void **refcount_table, |
c7c0681b HR |
2009 | int64_t *nb_clusters) |
2010 | { | |
ff99129a | 2011 | BDRVQcow2State *s = bs->opaque; |
c7c0681b HR |
2012 | int64_t first_free_cluster = 0, reftable_offset = -1, cluster = 0; |
2013 | int64_t refblock_offset, refblock_start, refblock_index; | |
2014 | uint32_t reftable_size = 0; | |
2015 | uint64_t *on_disk_reftable = NULL; | |
7453c96b HR |
2016 | void *on_disk_refblock; |
2017 | int ret = 0; | |
c7c0681b HR |
2018 | struct { |
2019 | uint64_t reftable_offset; | |
2020 | uint32_t reftable_clusters; | |
2021 | } QEMU_PACKED reftable_offset_and_clusters; | |
2022 | ||
2023 | qcow2_cache_empty(bs, s->refcount_block_cache); | |
2024 | ||
2025 | write_refblocks: | |
2026 | for (; cluster < *nb_clusters; cluster++) { | |
7453c96b | 2027 | if (!s->get_refcount(*refcount_table, cluster)) { |
c7c0681b HR |
2028 | continue; |
2029 | } | |
2030 | ||
2031 | refblock_index = cluster >> s->refcount_block_bits; | |
2032 | refblock_start = refblock_index << s->refcount_block_bits; | |
2033 | ||
2034 | /* Don't allocate a cluster in a refblock already written to disk */ | |
2035 | if (first_free_cluster < refblock_start) { | |
2036 | first_free_cluster = refblock_start; | |
2037 | } | |
2038 | refblock_offset = alloc_clusters_imrt(bs, 1, refcount_table, | |
2039 | nb_clusters, &first_free_cluster); | |
2040 | if (refblock_offset < 0) { | |
2041 | fprintf(stderr, "ERROR allocating refblock: %s\n", | |
2042 | strerror(-refblock_offset)); | |
2043 | res->check_errors++; | |
2044 | ret = refblock_offset; | |
2045 | goto fail; | |
2046 | } | |
2047 | ||
2048 | if (reftable_size <= refblock_index) { | |
2049 | uint32_t old_reftable_size = reftable_size; | |
2050 | uint64_t *new_on_disk_reftable; | |
2051 | ||
2052 | reftable_size = ROUND_UP((refblock_index + 1) * sizeof(uint64_t), | |
2053 | s->cluster_size) / sizeof(uint64_t); | |
2054 | new_on_disk_reftable = g_try_realloc(on_disk_reftable, | |
2055 | reftable_size * | |
2056 | sizeof(uint64_t)); | |
2057 | if (!new_on_disk_reftable) { | |
2058 | res->check_errors++; | |
2059 | ret = -ENOMEM; | |
2060 | goto fail; | |
2061 | } | |
2062 | on_disk_reftable = new_on_disk_reftable; | |
2063 | ||
2064 | memset(on_disk_reftable + old_reftable_size, 0, | |
2065 | (reftable_size - old_reftable_size) * sizeof(uint64_t)); | |
2066 | ||
2067 | /* The offset we have for the reftable is now no longer valid; | |
2068 | * this will leak that range, but we can easily fix that by running | |
2069 | * a leak-fixing check after this rebuild operation */ | |
2070 | reftable_offset = -1; | |
2071 | } | |
2072 | on_disk_reftable[refblock_index] = refblock_offset; | |
2073 | ||
2074 | /* If this is apparently the last refblock (for now), try to squeeze the | |
2075 | * reftable in */ | |
2076 | if (refblock_index == (*nb_clusters - 1) >> s->refcount_block_bits && | |
2077 | reftable_offset < 0) | |
2078 | { | |
2079 | uint64_t reftable_clusters = size_to_clusters(s, reftable_size * | |
2080 | sizeof(uint64_t)); | |
2081 | reftable_offset = alloc_clusters_imrt(bs, reftable_clusters, | |
2082 | refcount_table, nb_clusters, | |
2083 | &first_free_cluster); | |
2084 | if (reftable_offset < 0) { | |
2085 | fprintf(stderr, "ERROR allocating reftable: %s\n", | |
2086 | strerror(-reftable_offset)); | |
2087 | res->check_errors++; | |
2088 | ret = reftable_offset; | |
2089 | goto fail; | |
2090 | } | |
2091 | } | |
2092 | ||
2093 | ret = qcow2_pre_write_overlap_check(bs, 0, refblock_offset, | |
2094 | s->cluster_size); | |
2095 | if (ret < 0) { | |
2096 | fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret)); | |
2097 | goto fail; | |
2098 | } | |
2099 | ||
7453c96b HR |
2100 | /* The size of *refcount_table is always cluster-aligned, therefore the |
2101 | * write operation will not overflow */ | |
2102 | on_disk_refblock = (void *)((char *) *refcount_table + | |
2103 | refblock_index * s->cluster_size); | |
c7c0681b | 2104 | |
9a4f4c31 | 2105 | ret = bdrv_write(bs->file->bs, refblock_offset / BDRV_SECTOR_SIZE, |
7453c96b | 2106 | on_disk_refblock, s->cluster_sectors); |
c7c0681b HR |
2107 | if (ret < 0) { |
2108 | fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret)); | |
2109 | goto fail; | |
2110 | } | |
2111 | ||
2112 | /* Go to the end of this refblock */ | |
2113 | cluster = refblock_start + s->refcount_block_size - 1; | |
2114 | } | |
2115 | ||
2116 | if (reftable_offset < 0) { | |
2117 | uint64_t post_refblock_start, reftable_clusters; | |
2118 | ||
2119 | post_refblock_start = ROUND_UP(*nb_clusters, s->refcount_block_size); | |
2120 | reftable_clusters = size_to_clusters(s, | |
2121 | reftable_size * sizeof(uint64_t)); | |
2122 | /* Not pretty but simple */ | |
2123 | if (first_free_cluster < post_refblock_start) { | |
2124 | first_free_cluster = post_refblock_start; | |
2125 | } | |
2126 | reftable_offset = alloc_clusters_imrt(bs, reftable_clusters, | |
2127 | refcount_table, nb_clusters, | |
2128 | &first_free_cluster); | |
2129 | if (reftable_offset < 0) { | |
2130 | fprintf(stderr, "ERROR allocating reftable: %s\n", | |
2131 | strerror(-reftable_offset)); | |
2132 | res->check_errors++; | |
2133 | ret = reftable_offset; | |
2134 | goto fail; | |
2135 | } | |
2136 | ||
2137 | goto write_refblocks; | |
2138 | } | |
2139 | ||
2140 | assert(on_disk_reftable); | |
2141 | ||
2142 | for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) { | |
2143 | cpu_to_be64s(&on_disk_reftable[refblock_index]); | |
2144 | } | |
2145 | ||
2146 | ret = qcow2_pre_write_overlap_check(bs, 0, reftable_offset, | |
2147 | reftable_size * sizeof(uint64_t)); | |
2148 | if (ret < 0) { | |
2149 | fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret)); | |
2150 | goto fail; | |
2151 | } | |
2152 | ||
2153 | assert(reftable_size < INT_MAX / sizeof(uint64_t)); | |
9a4f4c31 | 2154 | ret = bdrv_pwrite(bs->file->bs, reftable_offset, on_disk_reftable, |
c7c0681b HR |
2155 | reftable_size * sizeof(uint64_t)); |
2156 | if (ret < 0) { | |
2157 | fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret)); | |
2158 | goto fail; | |
2159 | } | |
2160 | ||
2161 | /* Enter new reftable into the image header */ | |
2162 | cpu_to_be64w(&reftable_offset_and_clusters.reftable_offset, | |
2163 | reftable_offset); | |
2164 | cpu_to_be32w(&reftable_offset_and_clusters.reftable_clusters, | |
2165 | size_to_clusters(s, reftable_size * sizeof(uint64_t))); | |
9a4f4c31 KW |
2166 | ret = bdrv_pwrite_sync(bs->file->bs, offsetof(QCowHeader, |
2167 | refcount_table_offset), | |
c7c0681b HR |
2168 | &reftable_offset_and_clusters, |
2169 | sizeof(reftable_offset_and_clusters)); | |
2170 | if (ret < 0) { | |
2171 | fprintf(stderr, "ERROR setting reftable: %s\n", strerror(-ret)); | |
2172 | goto fail; | |
2173 | } | |
2174 | ||
2175 | for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) { | |
2176 | be64_to_cpus(&on_disk_reftable[refblock_index]); | |
2177 | } | |
2178 | s->refcount_table = on_disk_reftable; | |
2179 | s->refcount_table_offset = reftable_offset; | |
2180 | s->refcount_table_size = reftable_size; | |
2181 | ||
2182 | return 0; | |
2183 | ||
2184 | fail: | |
2185 | g_free(on_disk_reftable); | |
2186 | return ret; | |
2187 | } | |
2188 | ||
6ca56bf5 HR |
2189 | /* |
2190 | * Checks an image for refcount consistency. | |
2191 | * | |
2192 | * Returns 0 if no errors are found, the number of errors in case the image is | |
2193 | * detected as corrupted, and -errno when an internal error occurred. | |
2194 | */ | |
2195 | int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
2196 | BdrvCheckMode fix) | |
2197 | { | |
ff99129a | 2198 | BDRVQcow2State *s = bs->opaque; |
c7c0681b | 2199 | BdrvCheckResult pre_compare_res; |
6ca56bf5 | 2200 | int64_t size, highest_cluster, nb_clusters; |
7453c96b | 2201 | void *refcount_table = NULL; |
f307b255 | 2202 | bool rebuild = false; |
6ca56bf5 HR |
2203 | int ret; |
2204 | ||
9a4f4c31 | 2205 | size = bdrv_getlength(bs->file->bs); |
6ca56bf5 HR |
2206 | if (size < 0) { |
2207 | res->check_errors++; | |
2208 | return size; | |
2209 | } | |
2210 | ||
2211 | nb_clusters = size_to_clusters(s, size); | |
2212 | if (nb_clusters > INT_MAX) { | |
2213 | res->check_errors++; | |
2214 | return -EFBIG; | |
2215 | } | |
2216 | ||
2217 | res->bfi.total_clusters = | |
2218 | size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE); | |
2219 | ||
f307b255 HR |
2220 | ret = calculate_refcounts(bs, res, fix, &rebuild, &refcount_table, |
2221 | &nb_clusters); | |
6ca56bf5 HR |
2222 | if (ret < 0) { |
2223 | goto fail; | |
2224 | } | |
2225 | ||
c7c0681b HR |
2226 | /* In case we don't need to rebuild the refcount structure (but want to fix |
2227 | * something), this function is immediately called again, in which case the | |
2228 | * result should be ignored */ | |
2229 | pre_compare_res = *res; | |
2230 | compare_refcounts(bs, res, 0, &rebuild, &highest_cluster, refcount_table, | |
6ca56bf5 | 2231 | nb_clusters); |
f7d0fe02 | 2232 | |
c7c0681b | 2233 | if (rebuild && (fix & BDRV_FIX_ERRORS)) { |
791230d8 HR |
2234 | BdrvCheckResult old_res = *res; |
2235 | int fresh_leaks = 0; | |
2236 | ||
c7c0681b HR |
2237 | fprintf(stderr, "Rebuilding refcount structure\n"); |
2238 | ret = rebuild_refcount_structure(bs, res, &refcount_table, | |
2239 | &nb_clusters); | |
2240 | if (ret < 0) { | |
2241 | goto fail; | |
2242 | } | |
791230d8 HR |
2243 | |
2244 | res->corruptions = 0; | |
2245 | res->leaks = 0; | |
2246 | ||
2247 | /* Because the old reftable has been exchanged for a new one the | |
2248 | * references have to be recalculated */ | |
2249 | rebuild = false; | |
7453c96b | 2250 | memset(refcount_table, 0, refcount_array_byte_size(s, nb_clusters)); |
791230d8 HR |
2251 | ret = calculate_refcounts(bs, res, 0, &rebuild, &refcount_table, |
2252 | &nb_clusters); | |
2253 | if (ret < 0) { | |
2254 | goto fail; | |
2255 | } | |
2256 | ||
2257 | if (fix & BDRV_FIX_LEAKS) { | |
2258 | /* The old refcount structures are now leaked, fix it; the result | |
2259 | * can be ignored, aside from leaks which were introduced by | |
2260 | * rebuild_refcount_structure() that could not be fixed */ | |
2261 | BdrvCheckResult saved_res = *res; | |
2262 | *res = (BdrvCheckResult){ 0 }; | |
2263 | ||
2264 | compare_refcounts(bs, res, BDRV_FIX_LEAKS, &rebuild, | |
2265 | &highest_cluster, refcount_table, nb_clusters); | |
2266 | if (rebuild) { | |
2267 | fprintf(stderr, "ERROR rebuilt refcount structure is still " | |
2268 | "broken\n"); | |
2269 | } | |
2270 | ||
2271 | /* Any leaks accounted for here were introduced by | |
2272 | * rebuild_refcount_structure() because that function has created a | |
2273 | * new refcount structure from scratch */ | |
2274 | fresh_leaks = res->leaks; | |
2275 | *res = saved_res; | |
2276 | } | |
2277 | ||
2278 | if (res->corruptions < old_res.corruptions) { | |
2279 | res->corruptions_fixed += old_res.corruptions - res->corruptions; | |
2280 | } | |
2281 | if (res->leaks < old_res.leaks) { | |
2282 | res->leaks_fixed += old_res.leaks - res->leaks; | |
2283 | } | |
2284 | res->leaks += fresh_leaks; | |
c7c0681b HR |
2285 | } else if (fix) { |
2286 | if (rebuild) { | |
2287 | fprintf(stderr, "ERROR need to rebuild refcount structures\n"); | |
2288 | res->check_errors++; | |
2289 | ret = -EIO; | |
2290 | goto fail; | |
2291 | } | |
2292 | ||
2293 | if (res->leaks || res->corruptions) { | |
2294 | *res = pre_compare_res; | |
2295 | compare_refcounts(bs, res, fix, &rebuild, &highest_cluster, | |
2296 | refcount_table, nb_clusters); | |
2297 | } | |
f307b255 HR |
2298 | } |
2299 | ||
4f6ed88c | 2300 | /* check OFLAG_COPIED */ |
e23e400e | 2301 | ret = check_oflag_copied(bs, res, fix); |
4f6ed88c HR |
2302 | if (ret < 0) { |
2303 | goto fail; | |
2304 | } | |
2305 | ||
c6bb9ad1 | 2306 | res->image_end_offset = (highest_cluster + 1) * s->cluster_size; |
80fa3341 KW |
2307 | ret = 0; |
2308 | ||
2309 | fail: | |
7267c094 | 2310 | g_free(refcount_table); |
f7d0fe02 | 2311 | |
80fa3341 | 2312 | return ret; |
f7d0fe02 KW |
2313 | } |
2314 | ||
a40f1c2a HR |
2315 | #define overlaps_with(ofs, sz) \ |
2316 | ranges_overlap(offset, size, ofs, sz) | |
2317 | ||
2318 | /* | |
2319 | * Checks if the given offset into the image file is actually free to use by | |
2320 | * looking for overlaps with important metadata sections (L1/L2 tables etc.), | |
2321 | * i.e. a sanity check without relying on the refcount tables. | |
2322 | * | |
231bb267 HR |
2323 | * The ign parameter specifies what checks not to perform (being a bitmask of |
2324 | * QCow2MetadataOverlap values), i.e., what sections to ignore. | |
a40f1c2a HR |
2325 | * |
2326 | * Returns: | |
2327 | * - 0 if writing to this offset will not affect the mentioned metadata | |
2328 | * - a positive QCow2MetadataOverlap value indicating one overlapping section | |
2329 | * - a negative value (-errno) indicating an error while performing a check, | |
2330 | * e.g. when bdrv_read failed on QCOW2_OL_INACTIVE_L2 | |
2331 | */ | |
231bb267 | 2332 | int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset, |
a40f1c2a HR |
2333 | int64_t size) |
2334 | { | |
ff99129a | 2335 | BDRVQcow2State *s = bs->opaque; |
3e355390 | 2336 | int chk = s->overlap_check & ~ign; |
a40f1c2a HR |
2337 | int i, j; |
2338 | ||
2339 | if (!size) { | |
2340 | return 0; | |
2341 | } | |
2342 | ||
2343 | if (chk & QCOW2_OL_MAIN_HEADER) { | |
2344 | if (offset < s->cluster_size) { | |
2345 | return QCOW2_OL_MAIN_HEADER; | |
2346 | } | |
2347 | } | |
2348 | ||
2349 | /* align range to test to cluster boundaries */ | |
2350 | size = align_offset(offset_into_cluster(s, offset) + size, s->cluster_size); | |
2351 | offset = start_of_cluster(s, offset); | |
2352 | ||
2353 | if ((chk & QCOW2_OL_ACTIVE_L1) && s->l1_size) { | |
2354 | if (overlaps_with(s->l1_table_offset, s->l1_size * sizeof(uint64_t))) { | |
2355 | return QCOW2_OL_ACTIVE_L1; | |
2356 | } | |
2357 | } | |
2358 | ||
2359 | if ((chk & QCOW2_OL_REFCOUNT_TABLE) && s->refcount_table_size) { | |
2360 | if (overlaps_with(s->refcount_table_offset, | |
2361 | s->refcount_table_size * sizeof(uint64_t))) { | |
2362 | return QCOW2_OL_REFCOUNT_TABLE; | |
2363 | } | |
2364 | } | |
2365 | ||
2366 | if ((chk & QCOW2_OL_SNAPSHOT_TABLE) && s->snapshots_size) { | |
2367 | if (overlaps_with(s->snapshots_offset, s->snapshots_size)) { | |
2368 | return QCOW2_OL_SNAPSHOT_TABLE; | |
2369 | } | |
2370 | } | |
2371 | ||
2372 | if ((chk & QCOW2_OL_INACTIVE_L1) && s->snapshots) { | |
2373 | for (i = 0; i < s->nb_snapshots; i++) { | |
2374 | if (s->snapshots[i].l1_size && | |
2375 | overlaps_with(s->snapshots[i].l1_table_offset, | |
2376 | s->snapshots[i].l1_size * sizeof(uint64_t))) { | |
2377 | return QCOW2_OL_INACTIVE_L1; | |
2378 | } | |
2379 | } | |
2380 | } | |
2381 | ||
2382 | if ((chk & QCOW2_OL_ACTIVE_L2) && s->l1_table) { | |
2383 | for (i = 0; i < s->l1_size; i++) { | |
2384 | if ((s->l1_table[i] & L1E_OFFSET_MASK) && | |
2385 | overlaps_with(s->l1_table[i] & L1E_OFFSET_MASK, | |
2386 | s->cluster_size)) { | |
2387 | return QCOW2_OL_ACTIVE_L2; | |
2388 | } | |
2389 | } | |
2390 | } | |
2391 | ||
2392 | if ((chk & QCOW2_OL_REFCOUNT_BLOCK) && s->refcount_table) { | |
2393 | for (i = 0; i < s->refcount_table_size; i++) { | |
2394 | if ((s->refcount_table[i] & REFT_OFFSET_MASK) && | |
2395 | overlaps_with(s->refcount_table[i] & REFT_OFFSET_MASK, | |
2396 | s->cluster_size)) { | |
2397 | return QCOW2_OL_REFCOUNT_BLOCK; | |
2398 | } | |
2399 | } | |
2400 | } | |
2401 | ||
2402 | if ((chk & QCOW2_OL_INACTIVE_L2) && s->snapshots) { | |
2403 | for (i = 0; i < s->nb_snapshots; i++) { | |
2404 | uint64_t l1_ofs = s->snapshots[i].l1_table_offset; | |
2405 | uint32_t l1_sz = s->snapshots[i].l1_size; | |
998b959c | 2406 | uint64_t l1_sz2 = l1_sz * sizeof(uint64_t); |
de82815d | 2407 | uint64_t *l1 = g_try_malloc(l1_sz2); |
a40f1c2a HR |
2408 | int ret; |
2409 | ||
de82815d KW |
2410 | if (l1_sz2 && l1 == NULL) { |
2411 | return -ENOMEM; | |
2412 | } | |
2413 | ||
9a4f4c31 | 2414 | ret = bdrv_pread(bs->file->bs, l1_ofs, l1, l1_sz2); |
a40f1c2a HR |
2415 | if (ret < 0) { |
2416 | g_free(l1); | |
2417 | return ret; | |
2418 | } | |
2419 | ||
2420 | for (j = 0; j < l1_sz; j++) { | |
1e242b55 HR |
2421 | uint64_t l2_ofs = be64_to_cpu(l1[j]) & L1E_OFFSET_MASK; |
2422 | if (l2_ofs && overlaps_with(l2_ofs, s->cluster_size)) { | |
a40f1c2a HR |
2423 | g_free(l1); |
2424 | return QCOW2_OL_INACTIVE_L2; | |
2425 | } | |
2426 | } | |
2427 | ||
2428 | g_free(l1); | |
2429 | } | |
2430 | } | |
2431 | ||
2432 | return 0; | |
2433 | } | |
2434 | ||
2435 | static const char *metadata_ol_names[] = { | |
2436 | [QCOW2_OL_MAIN_HEADER_BITNR] = "qcow2_header", | |
2437 | [QCOW2_OL_ACTIVE_L1_BITNR] = "active L1 table", | |
2438 | [QCOW2_OL_ACTIVE_L2_BITNR] = "active L2 table", | |
2439 | [QCOW2_OL_REFCOUNT_TABLE_BITNR] = "refcount table", | |
2440 | [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = "refcount block", | |
2441 | [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = "snapshot table", | |
2442 | [QCOW2_OL_INACTIVE_L1_BITNR] = "inactive L1 table", | |
2443 | [QCOW2_OL_INACTIVE_L2_BITNR] = "inactive L2 table", | |
2444 | }; | |
2445 | ||
2446 | /* | |
2447 | * First performs a check for metadata overlaps (through | |
2448 | * qcow2_check_metadata_overlap); if that fails with a negative value (error | |
2449 | * while performing a check), that value is returned. If an impending overlap | |
2450 | * is detected, the BDS will be made unusable, the qcow2 file marked corrupt | |
2451 | * and -EIO returned. | |
2452 | * | |
2453 | * Returns 0 if there were neither overlaps nor errors while checking for | |
2454 | * overlaps; or a negative value (-errno) on error. | |
2455 | */ | |
231bb267 | 2456 | int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset, |
a40f1c2a HR |
2457 | int64_t size) |
2458 | { | |
231bb267 | 2459 | int ret = qcow2_check_metadata_overlap(bs, ign, offset, size); |
a40f1c2a HR |
2460 | |
2461 | if (ret < 0) { | |
2462 | return ret; | |
2463 | } else if (ret > 0) { | |
786a4ea8 | 2464 | int metadata_ol_bitnr = ctz32(ret); |
a40f1c2a HR |
2465 | assert(metadata_ol_bitnr < QCOW2_OL_MAX_BITNR); |
2466 | ||
adb43552 HR |
2467 | qcow2_signal_corruption(bs, true, offset, size, "Preventing invalid " |
2468 | "write on metadata (overlaps with %s)", | |
2469 | metadata_ol_names[metadata_ol_bitnr]); | |
a40f1c2a HR |
2470 | return -EIO; |
2471 | } | |
2472 | ||
2473 | return 0; | |
2474 | } | |
791c9a00 HR |
2475 | |
2476 | /* A pointer to a function of this type is given to walk_over_reftable(). That | |
2477 | * function will create refblocks and pass them to a RefblockFinishOp once they | |
2478 | * are completed (@refblock). @refblock_empty is set if the refblock is | |
2479 | * completely empty. | |
2480 | * | |
2481 | * Along with the refblock, a corresponding reftable entry is passed, in the | |
2482 | * reftable @reftable (which may be reallocated) at @reftable_index. | |
2483 | * | |
2484 | * @allocated should be set to true if a new cluster has been allocated. | |
2485 | */ | |
2486 | typedef int (RefblockFinishOp)(BlockDriverState *bs, uint64_t **reftable, | |
2487 | uint64_t reftable_index, uint64_t *reftable_size, | |
2488 | void *refblock, bool refblock_empty, | |
2489 | bool *allocated, Error **errp); | |
2490 | ||
2491 | /** | |
2492 | * This "operation" for walk_over_reftable() allocates the refblock on disk (if | |
2493 | * it is not empty) and inserts its offset into the new reftable. The size of | |
2494 | * this new reftable is increased as required. | |
2495 | */ | |
2496 | static int alloc_refblock(BlockDriverState *bs, uint64_t **reftable, | |
2497 | uint64_t reftable_index, uint64_t *reftable_size, | |
2498 | void *refblock, bool refblock_empty, bool *allocated, | |
2499 | Error **errp) | |
2500 | { | |
2501 | BDRVQcow2State *s = bs->opaque; | |
2502 | int64_t offset; | |
2503 | ||
2504 | if (!refblock_empty && reftable_index >= *reftable_size) { | |
2505 | uint64_t *new_reftable; | |
2506 | uint64_t new_reftable_size; | |
2507 | ||
2508 | new_reftable_size = ROUND_UP(reftable_index + 1, | |
2509 | s->cluster_size / sizeof(uint64_t)); | |
2510 | if (new_reftable_size > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) { | |
2511 | error_setg(errp, | |
2512 | "This operation would make the refcount table grow " | |
2513 | "beyond the maximum size supported by QEMU, aborting"); | |
2514 | return -ENOTSUP; | |
2515 | } | |
2516 | ||
2517 | new_reftable = g_try_realloc(*reftable, new_reftable_size * | |
2518 | sizeof(uint64_t)); | |
2519 | if (!new_reftable) { | |
2520 | error_setg(errp, "Failed to increase reftable buffer size"); | |
2521 | return -ENOMEM; | |
2522 | } | |
2523 | ||
2524 | memset(new_reftable + *reftable_size, 0, | |
2525 | (new_reftable_size - *reftable_size) * sizeof(uint64_t)); | |
2526 | ||
2527 | *reftable = new_reftable; | |
2528 | *reftable_size = new_reftable_size; | |
2529 | } | |
2530 | ||
2531 | if (!refblock_empty && !(*reftable)[reftable_index]) { | |
2532 | offset = qcow2_alloc_clusters(bs, s->cluster_size); | |
2533 | if (offset < 0) { | |
2534 | error_setg_errno(errp, -offset, "Failed to allocate refblock"); | |
2535 | return offset; | |
2536 | } | |
2537 | (*reftable)[reftable_index] = offset; | |
2538 | *allocated = true; | |
2539 | } | |
2540 | ||
2541 | return 0; | |
2542 | } | |
2543 | ||
2544 | /** | |
2545 | * This "operation" for walk_over_reftable() writes the refblock to disk at the | |
2546 | * offset specified by the new reftable's entry. It does not modify the new | |
2547 | * reftable or change any refcounts. | |
2548 | */ | |
2549 | static int flush_refblock(BlockDriverState *bs, uint64_t **reftable, | |
2550 | uint64_t reftable_index, uint64_t *reftable_size, | |
2551 | void *refblock, bool refblock_empty, bool *allocated, | |
2552 | Error **errp) | |
2553 | { | |
2554 | BDRVQcow2State *s = bs->opaque; | |
2555 | int64_t offset; | |
2556 | int ret; | |
2557 | ||
2558 | if (reftable_index < *reftable_size && (*reftable)[reftable_index]) { | |
2559 | offset = (*reftable)[reftable_index]; | |
2560 | ||
2561 | ret = qcow2_pre_write_overlap_check(bs, 0, offset, s->cluster_size); | |
2562 | if (ret < 0) { | |
2563 | error_setg_errno(errp, -ret, "Overlap check failed"); | |
2564 | return ret; | |
2565 | } | |
2566 | ||
2567 | ret = bdrv_pwrite(bs->file->bs, offset, refblock, s->cluster_size); | |
2568 | if (ret < 0) { | |
2569 | error_setg_errno(errp, -ret, "Failed to write refblock"); | |
2570 | return ret; | |
2571 | } | |
2572 | } else { | |
2573 | assert(refblock_empty); | |
2574 | } | |
2575 | ||
2576 | return 0; | |
2577 | } | |
2578 | ||
2579 | /** | |
2580 | * This function walks over the existing reftable and every referenced refblock; | |
2581 | * if @new_set_refcount is non-NULL, it is called for every refcount entry to | |
2582 | * create an equal new entry in the passed @new_refblock. Once that | |
2583 | * @new_refblock is completely filled, @operation will be called. | |
2584 | * | |
2585 | * @status_cb and @cb_opaque are used for the amend operation's status callback. | |
2586 | * @index is the index of the walk_over_reftable() calls and @total is the total | |
2587 | * number of walk_over_reftable() calls per amend operation. Both are used for | |
2588 | * calculating the parameters for the status callback. | |
2589 | * | |
2590 | * @allocated is set to true if a new cluster has been allocated. | |
2591 | */ | |
2592 | static int walk_over_reftable(BlockDriverState *bs, uint64_t **new_reftable, | |
2593 | uint64_t *new_reftable_index, | |
2594 | uint64_t *new_reftable_size, | |
2595 | void *new_refblock, int new_refblock_size, | |
2596 | int new_refcount_bits, | |
2597 | RefblockFinishOp *operation, bool *allocated, | |
2598 | Qcow2SetRefcountFunc *new_set_refcount, | |
2599 | BlockDriverAmendStatusCB *status_cb, | |
2600 | void *cb_opaque, int index, int total, | |
2601 | Error **errp) | |
2602 | { | |
2603 | BDRVQcow2State *s = bs->opaque; | |
2604 | uint64_t reftable_index; | |
2605 | bool new_refblock_empty = true; | |
2606 | int refblock_index; | |
2607 | int new_refblock_index = 0; | |
2608 | int ret; | |
2609 | ||
2610 | for (reftable_index = 0; reftable_index < s->refcount_table_size; | |
2611 | reftable_index++) | |
2612 | { | |
2613 | uint64_t refblock_offset = s->refcount_table[reftable_index] | |
2614 | & REFT_OFFSET_MASK; | |
2615 | ||
2616 | status_cb(bs, (uint64_t)index * s->refcount_table_size + reftable_index, | |
2617 | (uint64_t)total * s->refcount_table_size, cb_opaque); | |
2618 | ||
2619 | if (refblock_offset) { | |
2620 | void *refblock; | |
2621 | ||
2622 | if (offset_into_cluster(s, refblock_offset)) { | |
2623 | qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#" | |
2624 | PRIx64 " unaligned (reftable index: %#" | |
2625 | PRIx64 ")", refblock_offset, | |
2626 | reftable_index); | |
2627 | error_setg(errp, | |
2628 | "Image is corrupt (unaligned refblock offset)"); | |
2629 | return -EIO; | |
2630 | } | |
2631 | ||
2632 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refblock_offset, | |
2633 | &refblock); | |
2634 | if (ret < 0) { | |
2635 | error_setg_errno(errp, -ret, "Failed to retrieve refblock"); | |
2636 | return ret; | |
2637 | } | |
2638 | ||
2639 | for (refblock_index = 0; refblock_index < s->refcount_block_size; | |
2640 | refblock_index++) | |
2641 | { | |
2642 | uint64_t refcount; | |
2643 | ||
2644 | if (new_refblock_index >= new_refblock_size) { | |
2645 | /* new_refblock is now complete */ | |
2646 | ret = operation(bs, new_reftable, *new_reftable_index, | |
2647 | new_reftable_size, new_refblock, | |
2648 | new_refblock_empty, allocated, errp); | |
2649 | if (ret < 0) { | |
2650 | qcow2_cache_put(bs, s->refcount_block_cache, &refblock); | |
2651 | return ret; | |
2652 | } | |
2653 | ||
2654 | (*new_reftable_index)++; | |
2655 | new_refblock_index = 0; | |
2656 | new_refblock_empty = true; | |
2657 | } | |
2658 | ||
2659 | refcount = s->get_refcount(refblock, refblock_index); | |
2660 | if (new_refcount_bits < 64 && refcount >> new_refcount_bits) { | |
2661 | uint64_t offset; | |
2662 | ||
2663 | qcow2_cache_put(bs, s->refcount_block_cache, &refblock); | |
2664 | ||
2665 | offset = ((reftable_index << s->refcount_block_bits) | |
2666 | + refblock_index) << s->cluster_bits; | |
2667 | ||
2668 | error_setg(errp, "Cannot decrease refcount entry width to " | |
2669 | "%i bits: Cluster at offset %#" PRIx64 " has a " | |
2670 | "refcount of %" PRIu64, new_refcount_bits, | |
2671 | offset, refcount); | |
2672 | return -EINVAL; | |
2673 | } | |
2674 | ||
2675 | if (new_set_refcount) { | |
2676 | new_set_refcount(new_refblock, new_refblock_index++, | |
2677 | refcount); | |
2678 | } else { | |
2679 | new_refblock_index++; | |
2680 | } | |
2681 | new_refblock_empty = new_refblock_empty && refcount == 0; | |
2682 | } | |
2683 | ||
2684 | qcow2_cache_put(bs, s->refcount_block_cache, &refblock); | |
2685 | } else { | |
2686 | /* No refblock means every refcount is 0 */ | |
2687 | for (refblock_index = 0; refblock_index < s->refcount_block_size; | |
2688 | refblock_index++) | |
2689 | { | |
2690 | if (new_refblock_index >= new_refblock_size) { | |
2691 | /* new_refblock is now complete */ | |
2692 | ret = operation(bs, new_reftable, *new_reftable_index, | |
2693 | new_reftable_size, new_refblock, | |
2694 | new_refblock_empty, allocated, errp); | |
2695 | if (ret < 0) { | |
2696 | return ret; | |
2697 | } | |
2698 | ||
2699 | (*new_reftable_index)++; | |
2700 | new_refblock_index = 0; | |
2701 | new_refblock_empty = true; | |
2702 | } | |
2703 | ||
2704 | if (new_set_refcount) { | |
2705 | new_set_refcount(new_refblock, new_refblock_index++, 0); | |
2706 | } else { | |
2707 | new_refblock_index++; | |
2708 | } | |
2709 | } | |
2710 | } | |
2711 | } | |
2712 | ||
2713 | if (new_refblock_index > 0) { | |
2714 | /* Complete the potentially existing partially filled final refblock */ | |
2715 | if (new_set_refcount) { | |
2716 | for (; new_refblock_index < new_refblock_size; | |
2717 | new_refblock_index++) | |
2718 | { | |
2719 | new_set_refcount(new_refblock, new_refblock_index, 0); | |
2720 | } | |
2721 | } | |
2722 | ||
2723 | ret = operation(bs, new_reftable, *new_reftable_index, | |
2724 | new_reftable_size, new_refblock, new_refblock_empty, | |
2725 | allocated, errp); | |
2726 | if (ret < 0) { | |
2727 | return ret; | |
2728 | } | |
2729 | ||
2730 | (*new_reftable_index)++; | |
2731 | } | |
2732 | ||
2733 | status_cb(bs, (uint64_t)(index + 1) * s->refcount_table_size, | |
2734 | (uint64_t)total * s->refcount_table_size, cb_opaque); | |
2735 | ||
2736 | return 0; | |
2737 | } | |
2738 | ||
2739 | int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order, | |
2740 | BlockDriverAmendStatusCB *status_cb, | |
2741 | void *cb_opaque, Error **errp) | |
2742 | { | |
2743 | BDRVQcow2State *s = bs->opaque; | |
2744 | Qcow2GetRefcountFunc *new_get_refcount; | |
2745 | Qcow2SetRefcountFunc *new_set_refcount; | |
2746 | void *new_refblock = qemu_blockalign(bs->file->bs, s->cluster_size); | |
2747 | uint64_t *new_reftable = NULL, new_reftable_size = 0; | |
2748 | uint64_t *old_reftable, old_reftable_size, old_reftable_offset; | |
2749 | uint64_t new_reftable_index = 0; | |
2750 | uint64_t i; | |
2751 | int64_t new_reftable_offset = 0, allocated_reftable_size = 0; | |
2752 | int new_refblock_size, new_refcount_bits = 1 << refcount_order; | |
2753 | int old_refcount_order; | |
2754 | int walk_index = 0; | |
2755 | int ret; | |
2756 | bool new_allocation; | |
2757 | ||
2758 | assert(s->qcow_version >= 3); | |
2759 | assert(refcount_order >= 0 && refcount_order <= 6); | |
2760 | ||
2761 | /* see qcow2_open() */ | |
2762 | new_refblock_size = 1 << (s->cluster_bits - (refcount_order - 3)); | |
2763 | ||
2764 | new_get_refcount = get_refcount_funcs[refcount_order]; | |
2765 | new_set_refcount = set_refcount_funcs[refcount_order]; | |
2766 | ||
2767 | ||
2768 | do { | |
2769 | int total_walks; | |
2770 | ||
2771 | new_allocation = false; | |
2772 | ||
2773 | /* At least we have to do this walk and the one which writes the | |
2774 | * refblocks; also, at least we have to do this loop here at least | |
2775 | * twice (normally), first to do the allocations, and second to | |
2776 | * determine that everything is correctly allocated, this then makes | |
2777 | * three walks in total */ | |
2778 | total_walks = MAX(walk_index + 2, 3); | |
2779 | ||
2780 | /* First, allocate the structures so they are present in the refcount | |
2781 | * structures */ | |
2782 | ret = walk_over_reftable(bs, &new_reftable, &new_reftable_index, | |
2783 | &new_reftable_size, NULL, new_refblock_size, | |
2784 | new_refcount_bits, &alloc_refblock, | |
2785 | &new_allocation, NULL, status_cb, cb_opaque, | |
2786 | walk_index++, total_walks, errp); | |
2787 | if (ret < 0) { | |
2788 | goto done; | |
2789 | } | |
2790 | ||
2791 | new_reftable_index = 0; | |
2792 | ||
2793 | if (new_allocation) { | |
2794 | if (new_reftable_offset) { | |
2795 | qcow2_free_clusters(bs, new_reftable_offset, | |
2796 | allocated_reftable_size * sizeof(uint64_t), | |
2797 | QCOW2_DISCARD_NEVER); | |
2798 | } | |
2799 | ||
2800 | new_reftable_offset = qcow2_alloc_clusters(bs, new_reftable_size * | |
2801 | sizeof(uint64_t)); | |
2802 | if (new_reftable_offset < 0) { | |
2803 | error_setg_errno(errp, -new_reftable_offset, | |
2804 | "Failed to allocate the new reftable"); | |
2805 | ret = new_reftable_offset; | |
2806 | goto done; | |
2807 | } | |
2808 | allocated_reftable_size = new_reftable_size; | |
2809 | } | |
2810 | } while (new_allocation); | |
2811 | ||
2812 | /* Second, write the new refblocks */ | |
2813 | ret = walk_over_reftable(bs, &new_reftable, &new_reftable_index, | |
2814 | &new_reftable_size, new_refblock, | |
2815 | new_refblock_size, new_refcount_bits, | |
2816 | &flush_refblock, &new_allocation, new_set_refcount, | |
2817 | status_cb, cb_opaque, walk_index, walk_index + 1, | |
2818 | errp); | |
2819 | if (ret < 0) { | |
2820 | goto done; | |
2821 | } | |
2822 | assert(!new_allocation); | |
2823 | ||
2824 | ||
2825 | /* Write the new reftable */ | |
2826 | ret = qcow2_pre_write_overlap_check(bs, 0, new_reftable_offset, | |
2827 | new_reftable_size * sizeof(uint64_t)); | |
2828 | if (ret < 0) { | |
2829 | error_setg_errno(errp, -ret, "Overlap check failed"); | |
2830 | goto done; | |
2831 | } | |
2832 | ||
2833 | for (i = 0; i < new_reftable_size; i++) { | |
2834 | cpu_to_be64s(&new_reftable[i]); | |
2835 | } | |
2836 | ||
2837 | ret = bdrv_pwrite(bs->file->bs, new_reftable_offset, new_reftable, | |
2838 | new_reftable_size * sizeof(uint64_t)); | |
2839 | ||
2840 | for (i = 0; i < new_reftable_size; i++) { | |
2841 | be64_to_cpus(&new_reftable[i]); | |
2842 | } | |
2843 | ||
2844 | if (ret < 0) { | |
2845 | error_setg_errno(errp, -ret, "Failed to write the new reftable"); | |
2846 | goto done; | |
2847 | } | |
2848 | ||
2849 | ||
2850 | /* Empty the refcount cache */ | |
2851 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); | |
2852 | if (ret < 0) { | |
2853 | error_setg_errno(errp, -ret, "Failed to flush the refblock cache"); | |
2854 | goto done; | |
2855 | } | |
2856 | ||
2857 | /* Update the image header to point to the new reftable; this only updates | |
2858 | * the fields which are relevant to qcow2_update_header(); other fields | |
2859 | * such as s->refcount_table or s->refcount_bits stay stale for now | |
2860 | * (because we have to restore everything if qcow2_update_header() fails) */ | |
2861 | old_refcount_order = s->refcount_order; | |
2862 | old_reftable_size = s->refcount_table_size; | |
2863 | old_reftable_offset = s->refcount_table_offset; | |
2864 | ||
2865 | s->refcount_order = refcount_order; | |
2866 | s->refcount_table_size = new_reftable_size; | |
2867 | s->refcount_table_offset = new_reftable_offset; | |
2868 | ||
2869 | ret = qcow2_update_header(bs); | |
2870 | if (ret < 0) { | |
2871 | s->refcount_order = old_refcount_order; | |
2872 | s->refcount_table_size = old_reftable_size; | |
2873 | s->refcount_table_offset = old_reftable_offset; | |
2874 | error_setg_errno(errp, -ret, "Failed to update the qcow2 header"); | |
2875 | goto done; | |
2876 | } | |
2877 | ||
2878 | /* Now update the rest of the in-memory information */ | |
2879 | old_reftable = s->refcount_table; | |
2880 | s->refcount_table = new_reftable; | |
2881 | ||
2882 | s->refcount_bits = 1 << refcount_order; | |
2883 | s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1); | |
2884 | s->refcount_max += s->refcount_max - 1; | |
2885 | ||
2886 | s->refcount_block_bits = s->cluster_bits - (refcount_order - 3); | |
2887 | s->refcount_block_size = 1 << s->refcount_block_bits; | |
2888 | ||
2889 | s->get_refcount = new_get_refcount; | |
2890 | s->set_refcount = new_set_refcount; | |
2891 | ||
2892 | /* For cleaning up all old refblocks and the old reftable below the "done" | |
2893 | * label */ | |
2894 | new_reftable = old_reftable; | |
2895 | new_reftable_size = old_reftable_size; | |
2896 | new_reftable_offset = old_reftable_offset; | |
2897 | ||
2898 | done: | |
2899 | if (new_reftable) { | |
2900 | /* On success, new_reftable actually points to the old reftable (and | |
2901 | * new_reftable_size is the old reftable's size); but that is just | |
2902 | * fine */ | |
2903 | for (i = 0; i < new_reftable_size; i++) { | |
2904 | uint64_t offset = new_reftable[i] & REFT_OFFSET_MASK; | |
2905 | if (offset) { | |
2906 | qcow2_free_clusters(bs, offset, s->cluster_size, | |
2907 | QCOW2_DISCARD_OTHER); | |
2908 | } | |
2909 | } | |
2910 | g_free(new_reftable); | |
2911 | ||
2912 | if (new_reftable_offset > 0) { | |
2913 | qcow2_free_clusters(bs, new_reftable_offset, | |
2914 | new_reftable_size * sizeof(uint64_t), | |
2915 | QCOW2_DISCARD_OTHER); | |
2916 | } | |
2917 | } | |
2918 | ||
2919 | qemu_vfree(new_refblock); | |
2920 | return ret; | |
2921 | } |