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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" |
0d8c41da | 29 | #include "qcow2.h" |
a40f1c2a | 30 | #include "qemu/range.h" |
58369e22 | 31 | #include "qemu/bswap.h" |
46b732cd | 32 | #include "qemu/cutils.h" |
f7d0fe02 | 33 | |
77d6a215 EB |
34 | static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size, |
35 | uint64_t max); | |
92dcb59f | 36 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
0e06528e | 37 | int64_t offset, int64_t length, uint64_t addend, |
2aabe7c7 | 38 | bool decrease, enum qcow2_discard_type type); |
f7d0fe02 | 39 | |
59c0cb78 HR |
40 | static uint64_t get_refcount_ro0(const void *refcount_array, uint64_t index); |
41 | static uint64_t get_refcount_ro1(const void *refcount_array, uint64_t index); | |
42 | static uint64_t get_refcount_ro2(const void *refcount_array, uint64_t index); | |
43 | static uint64_t get_refcount_ro3(const void *refcount_array, uint64_t index); | |
7453c96b | 44 | static uint64_t get_refcount_ro4(const void *refcount_array, uint64_t index); |
59c0cb78 HR |
45 | static uint64_t get_refcount_ro5(const void *refcount_array, uint64_t index); |
46 | static uint64_t get_refcount_ro6(const void *refcount_array, uint64_t index); | |
7453c96b | 47 | |
59c0cb78 HR |
48 | static void set_refcount_ro0(void *refcount_array, uint64_t index, |
49 | uint64_t value); | |
50 | static void set_refcount_ro1(void *refcount_array, uint64_t index, | |
51 | uint64_t value); | |
52 | static void set_refcount_ro2(void *refcount_array, uint64_t index, | |
53 | uint64_t value); | |
54 | static void set_refcount_ro3(void *refcount_array, uint64_t index, | |
55 | uint64_t value); | |
7453c96b HR |
56 | static void set_refcount_ro4(void *refcount_array, uint64_t index, |
57 | uint64_t value); | |
59c0cb78 HR |
58 | static void set_refcount_ro5(void *refcount_array, uint64_t index, |
59 | uint64_t value); | |
60 | static void set_refcount_ro6(void *refcount_array, uint64_t index, | |
61 | uint64_t value); | |
62 | ||
63 | ||
64 | static Qcow2GetRefcountFunc *const get_refcount_funcs[] = { | |
65 | &get_refcount_ro0, | |
66 | &get_refcount_ro1, | |
67 | &get_refcount_ro2, | |
68 | &get_refcount_ro3, | |
69 | &get_refcount_ro4, | |
70 | &get_refcount_ro5, | |
71 | &get_refcount_ro6 | |
72 | }; | |
73 | ||
74 | static Qcow2SetRefcountFunc *const set_refcount_funcs[] = { | |
75 | &set_refcount_ro0, | |
76 | &set_refcount_ro1, | |
77 | &set_refcount_ro2, | |
78 | &set_refcount_ro3, | |
79 | &set_refcount_ro4, | |
80 | &set_refcount_ro5, | |
81 | &set_refcount_ro6 | |
82 | }; | |
7453c96b | 83 | |
3b88e52b | 84 | |
f7d0fe02 KW |
85 | /*********************************************************/ |
86 | /* refcount handling */ | |
87 | ||
7061a078 AG |
88 | static void update_max_refcount_table_index(BDRVQcow2State *s) |
89 | { | |
90 | unsigned i = s->refcount_table_size - 1; | |
91 | while (i > 0 && (s->refcount_table[i] & REFT_OFFSET_MASK) == 0) { | |
92 | i--; | |
93 | } | |
94 | /* Set s->max_refcount_table_index to the index of the last used entry */ | |
95 | s->max_refcount_table_index = i; | |
96 | } | |
97 | ||
ed6ccf0f | 98 | int qcow2_refcount_init(BlockDriverState *bs) |
f7d0fe02 | 99 | { |
ff99129a | 100 | BDRVQcow2State *s = bs->opaque; |
5dab2fad KW |
101 | unsigned int refcount_table_size2, i; |
102 | int ret; | |
f7d0fe02 | 103 | |
59c0cb78 HR |
104 | assert(s->refcount_order >= 0 && s->refcount_order <= 6); |
105 | ||
106 | s->get_refcount = get_refcount_funcs[s->refcount_order]; | |
107 | s->set_refcount = set_refcount_funcs[s->refcount_order]; | |
7453c96b | 108 | |
5dab2fad | 109 | assert(s->refcount_table_size <= INT_MAX / sizeof(uint64_t)); |
f7d0fe02 | 110 | refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); |
de82815d KW |
111 | s->refcount_table = g_try_malloc(refcount_table_size2); |
112 | ||
f7d0fe02 | 113 | if (s->refcount_table_size > 0) { |
de82815d | 114 | if (s->refcount_table == NULL) { |
8fcffa98 | 115 | ret = -ENOMEM; |
de82815d KW |
116 | goto fail; |
117 | } | |
66f82cee | 118 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_LOAD); |
cf2ab8fc | 119 | ret = bdrv_pread(bs->file, s->refcount_table_offset, |
f7d0fe02 | 120 | s->refcount_table, refcount_table_size2); |
8fcffa98 | 121 | if (ret < 0) { |
f7d0fe02 | 122 | goto fail; |
8fcffa98 | 123 | } |
f7d0fe02 KW |
124 | for(i = 0; i < s->refcount_table_size; i++) |
125 | be64_to_cpus(&s->refcount_table[i]); | |
7061a078 | 126 | update_max_refcount_table_index(s); |
f7d0fe02 KW |
127 | } |
128 | return 0; | |
129 | fail: | |
8fcffa98 | 130 | return ret; |
f7d0fe02 KW |
131 | } |
132 | ||
ed6ccf0f | 133 | void qcow2_refcount_close(BlockDriverState *bs) |
f7d0fe02 | 134 | { |
ff99129a | 135 | BDRVQcow2State *s = bs->opaque; |
7267c094 | 136 | g_free(s->refcount_table); |
f7d0fe02 KW |
137 | } |
138 | ||
139 | ||
59c0cb78 HR |
140 | static uint64_t get_refcount_ro0(const void *refcount_array, uint64_t index) |
141 | { | |
142 | return (((const uint8_t *)refcount_array)[index / 8] >> (index % 8)) & 0x1; | |
143 | } | |
144 | ||
145 | static void set_refcount_ro0(void *refcount_array, uint64_t index, | |
146 | uint64_t value) | |
147 | { | |
148 | assert(!(value >> 1)); | |
149 | ((uint8_t *)refcount_array)[index / 8] &= ~(0x1 << (index % 8)); | |
150 | ((uint8_t *)refcount_array)[index / 8] |= value << (index % 8); | |
151 | } | |
152 | ||
153 | static uint64_t get_refcount_ro1(const void *refcount_array, uint64_t index) | |
154 | { | |
155 | return (((const uint8_t *)refcount_array)[index / 4] >> (2 * (index % 4))) | |
156 | & 0x3; | |
157 | } | |
158 | ||
159 | static void set_refcount_ro1(void *refcount_array, uint64_t index, | |
160 | uint64_t value) | |
161 | { | |
162 | assert(!(value >> 2)); | |
163 | ((uint8_t *)refcount_array)[index / 4] &= ~(0x3 << (2 * (index % 4))); | |
164 | ((uint8_t *)refcount_array)[index / 4] |= value << (2 * (index % 4)); | |
165 | } | |
166 | ||
167 | static uint64_t get_refcount_ro2(const void *refcount_array, uint64_t index) | |
168 | { | |
169 | return (((const uint8_t *)refcount_array)[index / 2] >> (4 * (index % 2))) | |
170 | & 0xf; | |
171 | } | |
172 | ||
173 | static void set_refcount_ro2(void *refcount_array, uint64_t index, | |
174 | uint64_t value) | |
175 | { | |
176 | assert(!(value >> 4)); | |
177 | ((uint8_t *)refcount_array)[index / 2] &= ~(0xf << (4 * (index % 2))); | |
178 | ((uint8_t *)refcount_array)[index / 2] |= value << (4 * (index % 2)); | |
179 | } | |
180 | ||
181 | static uint64_t get_refcount_ro3(const void *refcount_array, uint64_t index) | |
182 | { | |
183 | return ((const uint8_t *)refcount_array)[index]; | |
184 | } | |
185 | ||
186 | static void set_refcount_ro3(void *refcount_array, uint64_t index, | |
187 | uint64_t value) | |
188 | { | |
189 | assert(!(value >> 8)); | |
190 | ((uint8_t *)refcount_array)[index] = value; | |
191 | } | |
192 | ||
7453c96b HR |
193 | static uint64_t get_refcount_ro4(const void *refcount_array, uint64_t index) |
194 | { | |
195 | return be16_to_cpu(((const uint16_t *)refcount_array)[index]); | |
196 | } | |
197 | ||
198 | static void set_refcount_ro4(void *refcount_array, uint64_t index, | |
199 | uint64_t value) | |
200 | { | |
201 | assert(!(value >> 16)); | |
202 | ((uint16_t *)refcount_array)[index] = cpu_to_be16(value); | |
203 | } | |
204 | ||
59c0cb78 HR |
205 | static uint64_t get_refcount_ro5(const void *refcount_array, uint64_t index) |
206 | { | |
207 | return be32_to_cpu(((const uint32_t *)refcount_array)[index]); | |
208 | } | |
209 | ||
210 | static void set_refcount_ro5(void *refcount_array, uint64_t index, | |
211 | uint64_t value) | |
212 | { | |
213 | assert(!(value >> 32)); | |
214 | ((uint32_t *)refcount_array)[index] = cpu_to_be32(value); | |
215 | } | |
216 | ||
217 | static uint64_t get_refcount_ro6(const void *refcount_array, uint64_t index) | |
218 | { | |
219 | return be64_to_cpu(((const uint64_t *)refcount_array)[index]); | |
220 | } | |
221 | ||
222 | static void set_refcount_ro6(void *refcount_array, uint64_t index, | |
223 | uint64_t value) | |
224 | { | |
225 | ((uint64_t *)refcount_array)[index] = cpu_to_be64(value); | |
226 | } | |
227 | ||
7453c96b | 228 | |
f7d0fe02 | 229 | static int load_refcount_block(BlockDriverState *bs, |
29c1a730 KW |
230 | int64_t refcount_block_offset, |
231 | void **refcount_block) | |
f7d0fe02 | 232 | { |
ff99129a | 233 | BDRVQcow2State *s = bs->opaque; |
3b88e52b | 234 | |
66f82cee | 235 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_LOAD); |
9be38598 EH |
236 | return qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, |
237 | refcount_block); | |
f7d0fe02 KW |
238 | } |
239 | ||
018faafd | 240 | /* |
7324c10f HR |
241 | * Retrieves the refcount of the cluster given by its index and stores it in |
242 | * *refcount. Returns 0 on success and -errno on failure. | |
018faafd | 243 | */ |
7324c10f | 244 | int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index, |
0e06528e | 245 | uint64_t *refcount) |
f7d0fe02 | 246 | { |
ff99129a | 247 | BDRVQcow2State *s = bs->opaque; |
db8a31d1 | 248 | uint64_t refcount_table_index, block_index; |
f7d0fe02 | 249 | int64_t refcount_block_offset; |
018faafd | 250 | int ret; |
7453c96b | 251 | void *refcount_block; |
f7d0fe02 | 252 | |
17bd5f47 | 253 | refcount_table_index = cluster_index >> s->refcount_block_bits; |
7324c10f HR |
254 | if (refcount_table_index >= s->refcount_table_size) { |
255 | *refcount = 0; | |
f7d0fe02 | 256 | return 0; |
7324c10f | 257 | } |
26d49c46 HR |
258 | refcount_block_offset = |
259 | s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; | |
7324c10f HR |
260 | if (!refcount_block_offset) { |
261 | *refcount = 0; | |
f7d0fe02 | 262 | return 0; |
7324c10f | 263 | } |
29c1a730 | 264 | |
a97c67ee HR |
265 | if (offset_into_cluster(s, refcount_block_offset)) { |
266 | qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#" PRIx64 | |
267 | " unaligned (reftable index: %#" PRIx64 ")", | |
268 | refcount_block_offset, refcount_table_index); | |
269 | return -EIO; | |
270 | } | |
271 | ||
29c1a730 | 272 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, |
7453c96b | 273 | &refcount_block); |
29c1a730 KW |
274 | if (ret < 0) { |
275 | return ret; | |
f7d0fe02 | 276 | } |
29c1a730 | 277 | |
17bd5f47 | 278 | block_index = cluster_index & (s->refcount_block_size - 1); |
7453c96b | 279 | *refcount = s->get_refcount(refcount_block, block_index); |
29c1a730 | 280 | |
2013c3d4 | 281 | qcow2_cache_put(s->refcount_block_cache, &refcount_block); |
29c1a730 | 282 | |
7324c10f | 283 | return 0; |
f7d0fe02 KW |
284 | } |
285 | ||
92dcb59f | 286 | /* Checks if two offsets are described by the same refcount block */ |
ff99129a | 287 | static int in_same_refcount_block(BDRVQcow2State *s, uint64_t offset_a, |
92dcb59f KW |
288 | uint64_t offset_b) |
289 | { | |
17bd5f47 HR |
290 | uint64_t block_a = offset_a >> (s->cluster_bits + s->refcount_block_bits); |
291 | uint64_t block_b = offset_b >> (s->cluster_bits + s->refcount_block_bits); | |
92dcb59f KW |
292 | |
293 | return (block_a == block_b); | |
294 | } | |
295 | ||
296 | /* | |
297 | * Loads a refcount block. If it doesn't exist yet, it is allocated first | |
298 | * (including growing the refcount table if needed). | |
299 | * | |
29c1a730 | 300 | * Returns 0 on success or -errno in error case |
92dcb59f | 301 | */ |
29c1a730 | 302 | static int alloc_refcount_block(BlockDriverState *bs, |
7453c96b | 303 | int64_t cluster_index, void **refcount_block) |
f7d0fe02 | 304 | { |
ff99129a | 305 | BDRVQcow2State *s = bs->opaque; |
92dcb59f | 306 | unsigned int refcount_table_index; |
12cc30a8 | 307 | int64_t ret; |
92dcb59f | 308 | |
66f82cee | 309 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); |
8252278a | 310 | |
92dcb59f | 311 | /* Find the refcount block for the given cluster */ |
17bd5f47 | 312 | refcount_table_index = cluster_index >> s->refcount_block_bits; |
92dcb59f KW |
313 | |
314 | if (refcount_table_index < s->refcount_table_size) { | |
315 | ||
316 | uint64_t refcount_block_offset = | |
76dc9e0c | 317 | s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; |
92dcb59f KW |
318 | |
319 | /* If it's already there, we're done */ | |
320 | if (refcount_block_offset) { | |
a97c67ee HR |
321 | if (offset_into_cluster(s, refcount_block_offset)) { |
322 | qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#" | |
323 | PRIx64 " unaligned (reftable index: " | |
324 | "%#x)", refcount_block_offset, | |
325 | refcount_table_index); | |
326 | return -EIO; | |
327 | } | |
328 | ||
29c1a730 | 329 | return load_refcount_block(bs, refcount_block_offset, |
7453c96b | 330 | refcount_block); |
92dcb59f KW |
331 | } |
332 | } | |
333 | ||
334 | /* | |
335 | * If we came here, we need to allocate something. Something is at least | |
336 | * a cluster for the new refcount block. It may also include a new refcount | |
337 | * table if the old refcount table is too small. | |
338 | * | |
339 | * Note that allocating clusters here needs some special care: | |
340 | * | |
341 | * - We can't use the normal qcow2_alloc_clusters(), it would try to | |
342 | * increase the refcount and very likely we would end up with an endless | |
343 | * recursion. Instead we must place the refcount blocks in a way that | |
344 | * they can describe them themselves. | |
345 | * | |
346 | * - We need to consider that at this point we are inside update_refcounts | |
b106ad91 KW |
347 | * and potentially doing an initial refcount increase. This means that |
348 | * some clusters have already been allocated by the caller, but their | |
349 | * refcount isn't accurate yet. If we allocate clusters for metadata, we | |
350 | * need to return -EAGAIN to signal the caller that it needs to restart | |
351 | * the search for free clusters. | |
92dcb59f KW |
352 | * |
353 | * - alloc_clusters_noref and qcow2_free_clusters may load a different | |
354 | * refcount block into the cache | |
355 | */ | |
356 | ||
29c1a730 KW |
357 | *refcount_block = NULL; |
358 | ||
359 | /* We write to the refcount table, so we might depend on L2 tables */ | |
9991923b SH |
360 | ret = qcow2_cache_flush(bs, s->l2_table_cache); |
361 | if (ret < 0) { | |
362 | return ret; | |
363 | } | |
92dcb59f KW |
364 | |
365 | /* Allocate the refcount block itself and mark it as used */ | |
77d6a215 | 366 | int64_t new_block = alloc_clusters_noref(bs, s->cluster_size, INT64_MAX); |
2eaa8f63 KW |
367 | if (new_block < 0) { |
368 | return new_block; | |
369 | } | |
f7d0fe02 | 370 | |
cdc674c7 AG |
371 | /* The offset must fit in the offset field of the refcount table entry */ |
372 | assert((new_block & REFT_OFFSET_MASK) == new_block); | |
373 | ||
6bf45d59 AG |
374 | /* If we're allocating the block at offset 0 then something is wrong */ |
375 | if (new_block == 0) { | |
376 | qcow2_signal_corruption(bs, true, -1, -1, "Preventing invalid " | |
377 | "allocation of refcount block at offset 0"); | |
378 | return -EIO; | |
379 | } | |
380 | ||
f7d0fe02 | 381 | #ifdef DEBUG_ALLOC2 |
92dcb59f KW |
382 | fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64 |
383 | " at %" PRIx64 "\n", | |
384 | refcount_table_index, cluster_index << s->cluster_bits, new_block); | |
f7d0fe02 | 385 | #endif |
92dcb59f KW |
386 | |
387 | if (in_same_refcount_block(s, new_block, cluster_index << s->cluster_bits)) { | |
25408c09 | 388 | /* Zero the new refcount block before updating it */ |
29c1a730 | 389 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
7453c96b | 390 | refcount_block); |
29c1a730 | 391 | if (ret < 0) { |
60c48a29 | 392 | goto fail; |
29c1a730 KW |
393 | } |
394 | ||
395 | memset(*refcount_block, 0, s->cluster_size); | |
25408c09 | 396 | |
92dcb59f KW |
397 | /* The block describes itself, need to update the cache */ |
398 | int block_index = (new_block >> s->cluster_bits) & | |
17bd5f47 | 399 | (s->refcount_block_size - 1); |
7453c96b | 400 | s->set_refcount(*refcount_block, block_index, 1); |
92dcb59f KW |
401 | } else { |
402 | /* Described somewhere else. This can recurse at most twice before we | |
403 | * arrive at a block that describes itself. */ | |
2aabe7c7 | 404 | ret = update_refcount(bs, new_block, s->cluster_size, 1, false, |
6cfcb9b8 | 405 | QCOW2_DISCARD_NEVER); |
92dcb59f | 406 | if (ret < 0) { |
60c48a29 | 407 | goto fail; |
92dcb59f | 408 | } |
25408c09 | 409 | |
9991923b SH |
410 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
411 | if (ret < 0) { | |
60c48a29 | 412 | goto fail; |
9991923b | 413 | } |
1c4c2814 | 414 | |
25408c09 KW |
415 | /* Initialize the new refcount block only after updating its refcount, |
416 | * update_refcount uses the refcount cache itself */ | |
29c1a730 | 417 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
7453c96b | 418 | refcount_block); |
29c1a730 | 419 | if (ret < 0) { |
60c48a29 | 420 | goto fail; |
29c1a730 KW |
421 | } |
422 | ||
423 | memset(*refcount_block, 0, s->cluster_size); | |
92dcb59f KW |
424 | } |
425 | ||
426 | /* Now the new refcount block needs to be written to disk */ | |
66f82cee | 427 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE); |
2d135ee9 | 428 | qcow2_cache_entry_mark_dirty(s->refcount_block_cache, *refcount_block); |
29c1a730 | 429 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
92dcb59f | 430 | if (ret < 0) { |
60c48a29 | 431 | goto fail; |
92dcb59f KW |
432 | } |
433 | ||
434 | /* If the refcount table is big enough, just hook the block up there */ | |
435 | if (refcount_table_index < s->refcount_table_size) { | |
436 | uint64_t data64 = cpu_to_be64(new_block); | |
66f82cee | 437 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_HOOKUP); |
d9ca2ea2 | 438 | ret = bdrv_pwrite_sync(bs->file, |
92dcb59f KW |
439 | s->refcount_table_offset + refcount_table_index * sizeof(uint64_t), |
440 | &data64, sizeof(data64)); | |
441 | if (ret < 0) { | |
60c48a29 | 442 | goto fail; |
92dcb59f KW |
443 | } |
444 | ||
445 | s->refcount_table[refcount_table_index] = new_block; | |
7061a078 AG |
446 | /* If there's a hole in s->refcount_table then it can happen |
447 | * that refcount_table_index < s->max_refcount_table_index */ | |
448 | s->max_refcount_table_index = | |
449 | MAX(s->max_refcount_table_index, refcount_table_index); | |
b106ad91 KW |
450 | |
451 | /* The new refcount block may be where the caller intended to put its | |
452 | * data, so let it restart the search. */ | |
453 | return -EAGAIN; | |
29c1a730 KW |
454 | } |
455 | ||
2013c3d4 | 456 | qcow2_cache_put(s->refcount_block_cache, refcount_block); |
92dcb59f KW |
457 | |
458 | /* | |
459 | * If we come here, we need to grow the refcount table. Again, a new | |
460 | * refcount table needs some space and we can't simply allocate to avoid | |
461 | * endless recursion. | |
462 | * | |
463 | * Therefore let's grab new refcount blocks at the end of the image, which | |
464 | * will describe themselves and the new refcount table. This way we can | |
465 | * reference them only in the new table and do the switch to the new | |
466 | * refcount table at once without producing an inconsistent state in | |
467 | * between. | |
468 | */ | |
66f82cee | 469 | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW); |
8252278a | 470 | |
14a58a4e HR |
471 | /* Calculate the number of refcount blocks needed so far; this will be the |
472 | * basis for calculating the index of the first cluster used for the | |
473 | * self-describing refcount structures which we are about to create. | |
474 | * | |
475 | * Because we reached this point, there cannot be any refcount entries for | |
476 | * cluster_index or higher indices yet. However, because new_block has been | |
477 | * allocated to describe that cluster (and it will assume this role later | |
478 | * on), we cannot use that index; also, new_block may actually have a higher | |
479 | * cluster index than cluster_index, so it needs to be taken into account | |
480 | * here (and 1 needs to be added to its value because that cluster is used). | |
481 | */ | |
482 | uint64_t blocks_used = DIV_ROUND_UP(MAX(cluster_index + 1, | |
483 | (new_block >> s->cluster_bits) + 1), | |
484 | s->refcount_block_size); | |
92dcb59f | 485 | |
12cc30a8 HR |
486 | /* Create the new refcount table and blocks */ |
487 | uint64_t meta_offset = (blocks_used * s->refcount_block_size) * | |
488 | s->cluster_size; | |
489 | ||
490 | ret = qcow2_refcount_area(bs, meta_offset, 0, false, | |
491 | refcount_table_index, new_block); | |
492 | if (ret < 0) { | |
493 | return ret; | |
2b5d5953 KW |
494 | } |
495 | ||
12cc30a8 HR |
496 | ret = load_refcount_block(bs, new_block, refcount_block); |
497 | if (ret < 0) { | |
498 | return ret; | |
499 | } | |
92dcb59f | 500 | |
12cc30a8 HR |
501 | /* If we were trying to do the initial refcount update for some cluster |
502 | * allocation, we might have used the same clusters to store newly | |
503 | * allocated metadata. Make the caller search some new space. */ | |
504 | return -EAGAIN; | |
92dcb59f | 505 | |
60c48a29 | 506 | fail: |
12cc30a8 | 507 | if (*refcount_block != NULL) { |
2013c3d4 | 508 | qcow2_cache_put(s->refcount_block_cache, refcount_block); |
12cc30a8 HR |
509 | } |
510 | return ret; | |
511 | } | |
92dcb59f | 512 | |
12cc30a8 HR |
513 | /* |
514 | * Starting at @start_offset, this function creates new self-covering refcount | |
515 | * structures: A new refcount table and refcount blocks which cover all of | |
516 | * themselves, and a number of @additional_clusters beyond their end. | |
517 | * @start_offset must be at the end of the image file, that is, there must be | |
518 | * only empty space beyond it. | |
519 | * If @exact_size is false, the refcount table will have 50 % more entries than | |
520 | * necessary so it will not need to grow again soon. | |
521 | * If @new_refblock_offset is not zero, it contains the offset of a refcount | |
522 | * block that should be entered into the new refcount table at index | |
523 | * @new_refblock_index. | |
524 | * | |
525 | * Returns: The offset after the new refcount structures (i.e. where the | |
526 | * @additional_clusters may be placed) on success, -errno on error. | |
527 | */ | |
772d1f97 HR |
528 | int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t start_offset, |
529 | uint64_t additional_clusters, bool exact_size, | |
530 | int new_refblock_index, | |
531 | uint64_t new_refblock_offset) | |
12cc30a8 HR |
532 | { |
533 | BDRVQcow2State *s = bs->opaque; | |
534 | uint64_t total_refblock_count_u64, additional_refblock_count; | |
535 | int total_refblock_count, table_size, area_reftable_index, table_clusters; | |
536 | int i; | |
537 | uint64_t table_offset, block_offset, end_offset; | |
538 | int ret; | |
539 | uint64_t *new_table; | |
92dcb59f | 540 | |
12cc30a8 | 541 | assert(!(start_offset % s->cluster_size)); |
de82815d | 542 | |
12cc30a8 HR |
543 | qcow2_refcount_metadata_size(start_offset / s->cluster_size + |
544 | additional_clusters, | |
545 | s->cluster_size, s->refcount_order, | |
546 | !exact_size, &total_refblock_count_u64); | |
547 | if (total_refblock_count_u64 > QCOW_MAX_REFTABLE_SIZE) { | |
548 | return -EFBIG; | |
549 | } | |
550 | total_refblock_count = total_refblock_count_u64; | |
551 | ||
552 | /* Index in the refcount table of the first refcount block to cover the area | |
553 | * of refcount structures we are about to create; we know that | |
554 | * @total_refblock_count can cover @start_offset, so this will definitely | |
555 | * fit into an int. */ | |
556 | area_reftable_index = (start_offset / s->cluster_size) / | |
557 | s->refcount_block_size; | |
558 | ||
559 | if (exact_size) { | |
560 | table_size = total_refblock_count; | |
561 | } else { | |
562 | table_size = total_refblock_count + | |
563 | DIV_ROUND_UP(total_refblock_count, 2); | |
564 | } | |
565 | /* The qcow2 file can only store the reftable size in number of clusters */ | |
566 | table_size = ROUND_UP(table_size, s->cluster_size / sizeof(uint64_t)); | |
567 | table_clusters = (table_size * sizeof(uint64_t)) / s->cluster_size; | |
568 | ||
569 | if (table_size > QCOW_MAX_REFTABLE_SIZE) { | |
570 | return -EFBIG; | |
571 | } | |
572 | ||
573 | new_table = g_try_new0(uint64_t, table_size); | |
574 | ||
575 | assert(table_size > 0); | |
576 | if (new_table == NULL) { | |
de82815d | 577 | ret = -ENOMEM; |
12cc30a8 | 578 | goto fail; |
de82815d | 579 | } |
92dcb59f | 580 | |
92dcb59f | 581 | /* Fill the new refcount table */ |
12cc30a8 HR |
582 | if (table_size > s->max_refcount_table_index) { |
583 | /* We're actually growing the reftable */ | |
584 | memcpy(new_table, s->refcount_table, | |
585 | (s->max_refcount_table_index + 1) * sizeof(uint64_t)); | |
586 | } else { | |
587 | /* Improbable case: We're shrinking the reftable. However, the caller | |
588 | * has assured us that there is only empty space beyond @start_offset, | |
589 | * so we can simply drop all of the refblocks that won't fit into the | |
590 | * new reftable. */ | |
591 | memcpy(new_table, s->refcount_table, table_size * sizeof(uint64_t)); | |
592 | } | |
92dcb59f | 593 | |
12cc30a8 HR |
594 | if (new_refblock_offset) { |
595 | assert(new_refblock_index < total_refblock_count); | |
596 | new_table[new_refblock_index] = new_refblock_offset; | |
597 | } | |
598 | ||
599 | /* Count how many new refblocks we have to create */ | |
600 | additional_refblock_count = 0; | |
601 | for (i = area_reftable_index; i < total_refblock_count; i++) { | |
602 | if (!new_table[i]) { | |
603 | additional_refblock_count++; | |
604 | } | |
92dcb59f KW |
605 | } |
606 | ||
12cc30a8 HR |
607 | table_offset = start_offset + additional_refblock_count * s->cluster_size; |
608 | end_offset = table_offset + table_clusters * s->cluster_size; | |
609 | ||
610 | /* Fill the refcount blocks, and create new ones, if necessary */ | |
611 | block_offset = start_offset; | |
612 | for (i = area_reftable_index; i < total_refblock_count; i++) { | |
613 | void *refblock_data; | |
614 | uint64_t first_offset_covered; | |
615 | ||
616 | /* Reuse an existing refblock if possible, create a new one otherwise */ | |
617 | if (new_table[i]) { | |
618 | ret = qcow2_cache_get(bs, s->refcount_block_cache, new_table[i], | |
619 | &refblock_data); | |
620 | if (ret < 0) { | |
621 | goto fail; | |
622 | } | |
623 | } else { | |
624 | ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, | |
625 | block_offset, &refblock_data); | |
626 | if (ret < 0) { | |
627 | goto fail; | |
628 | } | |
629 | memset(refblock_data, 0, s->cluster_size); | |
2d135ee9 | 630 | qcow2_cache_entry_mark_dirty(s->refcount_block_cache, |
12cc30a8 HR |
631 | refblock_data); |
632 | ||
633 | new_table[i] = block_offset; | |
634 | block_offset += s->cluster_size; | |
635 | } | |
636 | ||
637 | /* First host offset covered by this refblock */ | |
638 | first_offset_covered = (uint64_t)i * s->refcount_block_size * | |
639 | s->cluster_size; | |
640 | if (first_offset_covered < end_offset) { | |
641 | int j, end_index; | |
642 | ||
643 | /* Set the refcount of all of the new refcount structures to 1 */ | |
644 | ||
645 | if (first_offset_covered < start_offset) { | |
646 | assert(i == area_reftable_index); | |
647 | j = (start_offset - first_offset_covered) / s->cluster_size; | |
648 | assert(j < s->refcount_block_size); | |
649 | } else { | |
650 | j = 0; | |
651 | } | |
652 | ||
653 | end_index = MIN((end_offset - first_offset_covered) / | |
654 | s->cluster_size, | |
655 | s->refcount_block_size); | |
656 | ||
657 | for (; j < end_index; j++) { | |
658 | /* The caller guaranteed us this space would be empty */ | |
659 | assert(s->get_refcount(refblock_data, j) == 0); | |
660 | s->set_refcount(refblock_data, j, 1); | |
661 | } | |
662 | ||
2d135ee9 | 663 | qcow2_cache_entry_mark_dirty(s->refcount_block_cache, |
12cc30a8 HR |
664 | refblock_data); |
665 | } | |
666 | ||
2013c3d4 | 667 | qcow2_cache_put(s->refcount_block_cache, &refblock_data); |
92dcb59f KW |
668 | } |
669 | ||
12cc30a8 HR |
670 | assert(block_offset == table_offset); |
671 | ||
92dcb59f | 672 | /* Write refcount blocks to disk */ |
66f82cee | 673 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS); |
12cc30a8 | 674 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
92dcb59f | 675 | if (ret < 0) { |
12cc30a8 | 676 | goto fail; |
92dcb59f KW |
677 | } |
678 | ||
679 | /* Write refcount table to disk */ | |
12cc30a8 | 680 | for (i = 0; i < total_refblock_count; i++) { |
92dcb59f KW |
681 | cpu_to_be64s(&new_table[i]); |
682 | } | |
683 | ||
66f82cee | 684 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE); |
d9ca2ea2 | 685 | ret = bdrv_pwrite_sync(bs->file, table_offset, new_table, |
92dcb59f KW |
686 | table_size * sizeof(uint64_t)); |
687 | if (ret < 0) { | |
12cc30a8 | 688 | goto fail; |
92dcb59f KW |
689 | } |
690 | ||
12cc30a8 | 691 | for (i = 0; i < total_refblock_count; i++) { |
87267753 | 692 | be64_to_cpus(&new_table[i]); |
92dcb59f | 693 | } |
f7d0fe02 | 694 | |
92dcb59f | 695 | /* Hook up the new refcount table in the qcow2 header */ |
95334230 JS |
696 | struct QEMU_PACKED { |
697 | uint64_t d64; | |
698 | uint32_t d32; | |
699 | } data; | |
f1f7a1dd PM |
700 | data.d64 = cpu_to_be64(table_offset); |
701 | data.d32 = cpu_to_be32(table_clusters); | |
66f82cee | 702 | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE); |
d9ca2ea2 | 703 | ret = bdrv_pwrite_sync(bs->file, |
9a4f4c31 | 704 | offsetof(QCowHeader, refcount_table_offset), |
95334230 | 705 | &data, sizeof(data)); |
92dcb59f | 706 | if (ret < 0) { |
12cc30a8 | 707 | goto fail; |
f2b7c8b3 KW |
708 | } |
709 | ||
92dcb59f KW |
710 | /* And switch it in memory */ |
711 | uint64_t old_table_offset = s->refcount_table_offset; | |
712 | uint64_t old_table_size = s->refcount_table_size; | |
713 | ||
7267c094 | 714 | g_free(s->refcount_table); |
f7d0fe02 | 715 | s->refcount_table = new_table; |
92dcb59f | 716 | s->refcount_table_size = table_size; |
f7d0fe02 | 717 | s->refcount_table_offset = table_offset; |
7061a078 | 718 | update_max_refcount_table_index(s); |
f7d0fe02 | 719 | |
b106ad91 | 720 | /* Free old table. */ |
6cfcb9b8 KW |
721 | qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t), |
722 | QCOW2_DISCARD_OTHER); | |
f7d0fe02 | 723 | |
12cc30a8 | 724 | return end_offset; |
f7d0fe02 | 725 | |
12cc30a8 | 726 | fail: |
7267c094 | 727 | g_free(new_table); |
29c1a730 | 728 | return ret; |
9923e05e KW |
729 | } |
730 | ||
0b919fae KW |
731 | void qcow2_process_discards(BlockDriverState *bs, int ret) |
732 | { | |
ff99129a | 733 | BDRVQcow2State *s = bs->opaque; |
0b919fae KW |
734 | Qcow2DiscardRegion *d, *next; |
735 | ||
736 | QTAILQ_FOREACH_SAFE(d, &s->discards, next, next) { | |
737 | QTAILQ_REMOVE(&s->discards, d, next); | |
738 | ||
739 | /* Discard is optional, ignore the return value */ | |
740 | if (ret >= 0) { | |
0b9fd3f4 | 741 | bdrv_pdiscard(bs->file, d->offset, d->bytes); |
0b919fae KW |
742 | } |
743 | ||
744 | g_free(d); | |
745 | } | |
746 | } | |
747 | ||
748 | static void update_refcount_discard(BlockDriverState *bs, | |
749 | uint64_t offset, uint64_t length) | |
750 | { | |
ff99129a | 751 | BDRVQcow2State *s = bs->opaque; |
0b919fae KW |
752 | Qcow2DiscardRegion *d, *p, *next; |
753 | ||
754 | QTAILQ_FOREACH(d, &s->discards, next) { | |
755 | uint64_t new_start = MIN(offset, d->offset); | |
756 | uint64_t new_end = MAX(offset + length, d->offset + d->bytes); | |
757 | ||
758 | if (new_end - new_start <= length + d->bytes) { | |
759 | /* There can't be any overlap, areas ending up here have no | |
760 | * references any more and therefore shouldn't get freed another | |
761 | * time. */ | |
762 | assert(d->bytes + length == new_end - new_start); | |
763 | d->offset = new_start; | |
764 | d->bytes = new_end - new_start; | |
765 | goto found; | |
766 | } | |
767 | } | |
768 | ||
769 | d = g_malloc(sizeof(*d)); | |
770 | *d = (Qcow2DiscardRegion) { | |
771 | .bs = bs, | |
772 | .offset = offset, | |
773 | .bytes = length, | |
774 | }; | |
775 | QTAILQ_INSERT_TAIL(&s->discards, d, next); | |
776 | ||
777 | found: | |
778 | /* Merge discard requests if they are adjacent now */ | |
779 | QTAILQ_FOREACH_SAFE(p, &s->discards, next, next) { | |
780 | if (p == d | |
781 | || p->offset > d->offset + d->bytes | |
782 | || d->offset > p->offset + p->bytes) | |
783 | { | |
784 | continue; | |
785 | } | |
786 | ||
787 | /* Still no overlap possible */ | |
788 | assert(p->offset == d->offset + d->bytes | |
789 | || d->offset == p->offset + p->bytes); | |
790 | ||
791 | QTAILQ_REMOVE(&s->discards, p, next); | |
792 | d->offset = MIN(d->offset, p->offset); | |
793 | d->bytes += p->bytes; | |
d8bb71b6 | 794 | g_free(p); |
0b919fae KW |
795 | } |
796 | } | |
797 | ||
f7d0fe02 | 798 | /* XXX: cache several refcount block clusters ? */ |
2aabe7c7 HR |
799 | /* @addend is the absolute value of the addend; if @decrease is set, @addend |
800 | * will be subtracted from the current refcount, otherwise it will be added */ | |
db3a964f | 801 | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
2aabe7c7 HR |
802 | int64_t offset, |
803 | int64_t length, | |
0e06528e | 804 | uint64_t addend, |
2aabe7c7 HR |
805 | bool decrease, |
806 | enum qcow2_discard_type type) | |
f7d0fe02 | 807 | { |
ff99129a | 808 | BDRVQcow2State *s = bs->opaque; |
f7d0fe02 | 809 | int64_t start, last, cluster_offset; |
7453c96b | 810 | void *refcount_block = NULL; |
29c1a730 | 811 | int64_t old_table_index = -1; |
09508d13 | 812 | int ret; |
f7d0fe02 KW |
813 | |
814 | #ifdef DEBUG_ALLOC2 | |
2aabe7c7 | 815 | fprintf(stderr, "update_refcount: offset=%" PRId64 " size=%" PRId64 |
0e06528e | 816 | " addend=%s%" PRIu64 "\n", offset, length, decrease ? "-" : "", |
2aabe7c7 | 817 | addend); |
f7d0fe02 | 818 | #endif |
7322afe7 | 819 | if (length < 0) { |
f7d0fe02 | 820 | return -EINVAL; |
7322afe7 KW |
821 | } else if (length == 0) { |
822 | return 0; | |
823 | } | |
824 | ||
2aabe7c7 | 825 | if (decrease) { |
29c1a730 KW |
826 | qcow2_cache_set_dependency(bs, s->refcount_block_cache, |
827 | s->l2_table_cache); | |
828 | } | |
829 | ||
ac95acdb HT |
830 | start = start_of_cluster(s, offset); |
831 | last = start_of_cluster(s, offset + length - 1); | |
f7d0fe02 KW |
832 | for(cluster_offset = start; cluster_offset <= last; |
833 | cluster_offset += s->cluster_size) | |
834 | { | |
2aabe7c7 | 835 | int block_index; |
0e06528e | 836 | uint64_t refcount; |
f7d0fe02 | 837 | int64_t cluster_index = cluster_offset >> s->cluster_bits; |
17bd5f47 | 838 | int64_t table_index = cluster_index >> s->refcount_block_bits; |
f7d0fe02 | 839 | |
29c1a730 KW |
840 | /* Load the refcount block and allocate it if needed */ |
841 | if (table_index != old_table_index) { | |
842 | if (refcount_block) { | |
2013c3d4 | 843 | qcow2_cache_put(s->refcount_block_cache, &refcount_block); |
29c1a730 | 844 | } |
29c1a730 | 845 | ret = alloc_refcount_block(bs, cluster_index, &refcount_block); |
abf754fe AG |
846 | /* If the caller needs to restart the search for free clusters, |
847 | * try the same ones first to see if they're still free. */ | |
848 | if (ret == -EAGAIN) { | |
849 | if (s->free_cluster_index > (start >> s->cluster_bits)) { | |
850 | s->free_cluster_index = (start >> s->cluster_bits); | |
851 | } | |
852 | } | |
ed0df867 | 853 | if (ret < 0) { |
29c1a730 | 854 | goto fail; |
f7d0fe02 | 855 | } |
f7d0fe02 | 856 | } |
29c1a730 | 857 | old_table_index = table_index; |
f7d0fe02 | 858 | |
2d135ee9 | 859 | qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refcount_block); |
f7d0fe02 KW |
860 | |
861 | /* we can update the count and save it */ | |
17bd5f47 | 862 | block_index = cluster_index & (s->refcount_block_size - 1); |
f7d0fe02 | 863 | |
7453c96b | 864 | refcount = s->get_refcount(refcount_block, block_index); |
0e06528e HR |
865 | if (decrease ? (refcount - addend > refcount) |
866 | : (refcount + addend < refcount || | |
867 | refcount + addend > s->refcount_max)) | |
2aabe7c7 | 868 | { |
09508d13 KW |
869 | ret = -EINVAL; |
870 | goto fail; | |
871 | } | |
2aabe7c7 HR |
872 | if (decrease) { |
873 | refcount -= addend; | |
874 | } else { | |
875 | refcount += addend; | |
876 | } | |
f7d0fe02 KW |
877 | if (refcount == 0 && cluster_index < s->free_cluster_index) { |
878 | s->free_cluster_index = cluster_index; | |
879 | } | |
7453c96b | 880 | s->set_refcount(refcount_block, block_index, refcount); |
0b919fae | 881 | |
f71c08ea PB |
882 | if (refcount == 0) { |
883 | void *table; | |
884 | ||
6e6fa760 | 885 | table = qcow2_cache_is_table_offset(s->refcount_block_cache, |
f71c08ea PB |
886 | offset); |
887 | if (table != NULL) { | |
2013c3d4 | 888 | qcow2_cache_put(s->refcount_block_cache, &refcount_block); |
77aadd7b | 889 | qcow2_cache_discard(s->refcount_block_cache, table); |
f71c08ea PB |
890 | } |
891 | ||
6e6fa760 | 892 | table = qcow2_cache_is_table_offset(s->l2_table_cache, offset); |
f71c08ea | 893 | if (table != NULL) { |
77aadd7b | 894 | qcow2_cache_discard(s->l2_table_cache, table); |
f71c08ea PB |
895 | } |
896 | ||
897 | if (s->discard_passthrough[type]) { | |
898 | update_refcount_discard(bs, cluster_offset, s->cluster_size); | |
899 | } | |
67af674e | 900 | } |
f7d0fe02 KW |
901 | } |
902 | ||
09508d13 KW |
903 | ret = 0; |
904 | fail: | |
0b919fae KW |
905 | if (!s->cache_discards) { |
906 | qcow2_process_discards(bs, ret); | |
907 | } | |
908 | ||
f7d0fe02 | 909 | /* Write last changed block to disk */ |
29c1a730 | 910 | if (refcount_block) { |
2013c3d4 | 911 | qcow2_cache_put(s->refcount_block_cache, &refcount_block); |
f7d0fe02 KW |
912 | } |
913 | ||
09508d13 KW |
914 | /* |
915 | * Try do undo any updates if an error is returned (This may succeed in | |
916 | * some cases like ENOSPC for allocating a new refcount block) | |
917 | */ | |
918 | if (ret < 0) { | |
919 | int dummy; | |
2aabe7c7 HR |
920 | dummy = update_refcount(bs, offset, cluster_offset - offset, addend, |
921 | !decrease, QCOW2_DISCARD_NEVER); | |
83e3f76c | 922 | (void)dummy; |
09508d13 KW |
923 | } |
924 | ||
925 | return ret; | |
f7d0fe02 KW |
926 | } |
927 | ||
018faafd | 928 | /* |
44751917 | 929 | * Increases or decreases the refcount of a given cluster. |
018faafd | 930 | * |
2aabe7c7 HR |
931 | * @addend is the absolute value of the addend; if @decrease is set, @addend |
932 | * will be subtracted from the current refcount, otherwise it will be added. | |
933 | * | |
c6e9d8ae | 934 | * On success 0 is returned; on failure -errno is returned. |
018faafd | 935 | */ |
32b6444d HR |
936 | int qcow2_update_cluster_refcount(BlockDriverState *bs, |
937 | int64_t cluster_index, | |
0e06528e | 938 | uint64_t addend, bool decrease, |
32b6444d | 939 | enum qcow2_discard_type type) |
f7d0fe02 | 940 | { |
ff99129a | 941 | BDRVQcow2State *s = bs->opaque; |
f7d0fe02 KW |
942 | int ret; |
943 | ||
6cfcb9b8 | 944 | ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend, |
2aabe7c7 | 945 | decrease, type); |
f7d0fe02 KW |
946 | if (ret < 0) { |
947 | return ret; | |
948 | } | |
949 | ||
c6e9d8ae | 950 | return 0; |
f7d0fe02 KW |
951 | } |
952 | ||
953 | ||
954 | ||
955 | /*********************************************************/ | |
956 | /* cluster allocation functions */ | |
957 | ||
958 | ||
959 | ||
960 | /* return < 0 if error */ | |
77d6a215 EB |
961 | static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size, |
962 | uint64_t max) | |
f7d0fe02 | 963 | { |
ff99129a | 964 | BDRVQcow2State *s = bs->opaque; |
0e06528e | 965 | uint64_t i, nb_clusters, refcount; |
7324c10f | 966 | int ret; |
f7d0fe02 | 967 | |
ecbda7a2 KW |
968 | /* We can't allocate clusters if they may still be queued for discard. */ |
969 | if (s->cache_discards) { | |
970 | qcow2_process_discards(bs, 0); | |
971 | } | |
972 | ||
f7d0fe02 KW |
973 | nb_clusters = size_to_clusters(s, size); |
974 | retry: | |
975 | for(i = 0; i < nb_clusters; i++) { | |
bb572aef | 976 | uint64_t next_cluster_index = s->free_cluster_index++; |
7324c10f | 977 | ret = qcow2_get_refcount(bs, next_cluster_index, &refcount); |
2eaa8f63 | 978 | |
7324c10f HR |
979 | if (ret < 0) { |
980 | return ret; | |
2eaa8f63 | 981 | } else if (refcount != 0) { |
f7d0fe02 | 982 | goto retry; |
2eaa8f63 | 983 | } |
f7d0fe02 | 984 | } |
91f827dc HR |
985 | |
986 | /* Make sure that all offsets in the "allocated" range are representable | |
77d6a215 | 987 | * in the requested max */ |
65f33bc0 | 988 | if (s->free_cluster_index > 0 && |
77d6a215 | 989 | s->free_cluster_index - 1 > (max >> s->cluster_bits)) |
65f33bc0 | 990 | { |
91f827dc HR |
991 | return -EFBIG; |
992 | } | |
993 | ||
f7d0fe02 | 994 | #ifdef DEBUG_ALLOC2 |
35ee5e39 | 995 | fprintf(stderr, "alloc_clusters: size=%" PRId64 " -> %" PRId64 "\n", |
f7d0fe02 KW |
996 | size, |
997 | (s->free_cluster_index - nb_clusters) << s->cluster_bits); | |
998 | #endif | |
999 | return (s->free_cluster_index - nb_clusters) << s->cluster_bits; | |
1000 | } | |
1001 | ||
bb572aef | 1002 | int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size) |
f7d0fe02 KW |
1003 | { |
1004 | int64_t offset; | |
db3a964f | 1005 | int ret; |
f7d0fe02 | 1006 | |
66f82cee | 1007 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC); |
b106ad91 | 1008 | do { |
77d6a215 | 1009 | offset = alloc_clusters_noref(bs, size, QCOW_MAX_CLUSTER_OFFSET); |
b106ad91 KW |
1010 | if (offset < 0) { |
1011 | return offset; | |
1012 | } | |
1013 | ||
2aabe7c7 | 1014 | ret = update_refcount(bs, offset, size, 1, false, QCOW2_DISCARD_NEVER); |
b106ad91 | 1015 | } while (ret == -EAGAIN); |
2eaa8f63 | 1016 | |
db3a964f KW |
1017 | if (ret < 0) { |
1018 | return ret; | |
1019 | } | |
1c4c2814 | 1020 | |
f7d0fe02 KW |
1021 | return offset; |
1022 | } | |
1023 | ||
b6d36def HR |
1024 | int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, |
1025 | int64_t nb_clusters) | |
256900b1 | 1026 | { |
ff99129a | 1027 | BDRVQcow2State *s = bs->opaque; |
0e06528e | 1028 | uint64_t cluster_index, refcount; |
33304ec9 | 1029 | uint64_t i; |
7324c10f | 1030 | int ret; |
33304ec9 HT |
1031 | |
1032 | assert(nb_clusters >= 0); | |
1033 | if (nb_clusters == 0) { | |
1034 | return 0; | |
1035 | } | |
256900b1 | 1036 | |
b106ad91 KW |
1037 | do { |
1038 | /* Check how many clusters there are free */ | |
1039 | cluster_index = offset >> s->cluster_bits; | |
1040 | for(i = 0; i < nb_clusters; i++) { | |
7324c10f HR |
1041 | ret = qcow2_get_refcount(bs, cluster_index++, &refcount); |
1042 | if (ret < 0) { | |
1043 | return ret; | |
b106ad91 KW |
1044 | } else if (refcount != 0) { |
1045 | break; | |
1046 | } | |
256900b1 | 1047 | } |
256900b1 | 1048 | |
b106ad91 | 1049 | /* And then allocate them */ |
2aabe7c7 | 1050 | ret = update_refcount(bs, offset, i << s->cluster_bits, 1, false, |
b106ad91 KW |
1051 | QCOW2_DISCARD_NEVER); |
1052 | } while (ret == -EAGAIN); | |
f24423bd | 1053 | |
256900b1 KW |
1054 | if (ret < 0) { |
1055 | return ret; | |
1056 | } | |
1057 | ||
1058 | return i; | |
1059 | } | |
1060 | ||
f7d0fe02 KW |
1061 | /* only used to allocate compressed sectors. We try to allocate |
1062 | contiguous sectors. size must be <= cluster_size */ | |
ed6ccf0f | 1063 | int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size) |
f7d0fe02 | 1064 | { |
ff99129a | 1065 | BDRVQcow2State *s = bs->opaque; |
8c44dfbc HR |
1066 | int64_t offset; |
1067 | size_t free_in_cluster; | |
1068 | int ret; | |
f7d0fe02 | 1069 | |
66f82cee | 1070 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_BYTES); |
f7d0fe02 | 1071 | assert(size > 0 && size <= s->cluster_size); |
8c44dfbc HR |
1072 | assert(!s->free_byte_offset || offset_into_cluster(s, s->free_byte_offset)); |
1073 | ||
1074 | offset = s->free_byte_offset; | |
1075 | ||
1076 | if (offset) { | |
0e06528e | 1077 | uint64_t refcount; |
7324c10f HR |
1078 | ret = qcow2_get_refcount(bs, offset >> s->cluster_bits, &refcount); |
1079 | if (ret < 0) { | |
1080 | return ret; | |
5d757b56 | 1081 | } |
8c44dfbc | 1082 | |
346a53df | 1083 | if (refcount == s->refcount_max) { |
8c44dfbc | 1084 | offset = 0; |
5d757b56 | 1085 | } |
8c44dfbc HR |
1086 | } |
1087 | ||
1088 | free_in_cluster = s->cluster_size - offset_into_cluster(s, offset); | |
3e5feb62 JM |
1089 | do { |
1090 | if (!offset || free_in_cluster < size) { | |
77d6a215 EB |
1091 | int64_t new_cluster; |
1092 | ||
1093 | new_cluster = alloc_clusters_noref(bs, s->cluster_size, | |
1094 | MIN(s->cluster_offset_mask, | |
1095 | QCOW_MAX_CLUSTER_OFFSET)); | |
3e5feb62 JM |
1096 | if (new_cluster < 0) { |
1097 | return new_cluster; | |
1098 | } | |
8c44dfbc | 1099 | |
8aa34834 AG |
1100 | if (new_cluster == 0) { |
1101 | qcow2_signal_corruption(bs, true, -1, -1, "Preventing invalid " | |
1102 | "allocation of compressed cluster " | |
1103 | "at offset 0"); | |
1104 | return -EIO; | |
1105 | } | |
1106 | ||
3e5feb62 JM |
1107 | if (!offset || ROUND_UP(offset, s->cluster_size) != new_cluster) { |
1108 | offset = new_cluster; | |
2ac01520 HR |
1109 | free_in_cluster = s->cluster_size; |
1110 | } else { | |
1111 | free_in_cluster += s->cluster_size; | |
3e5feb62 | 1112 | } |
f7d0fe02 | 1113 | } |
29216ed1 | 1114 | |
3e5feb62 JM |
1115 | assert(offset); |
1116 | ret = update_refcount(bs, offset, size, 1, false, QCOW2_DISCARD_NEVER); | |
2ac01520 HR |
1117 | if (ret < 0) { |
1118 | offset = 0; | |
1119 | } | |
3e5feb62 | 1120 | } while (ret == -EAGAIN); |
8c44dfbc HR |
1121 | if (ret < 0) { |
1122 | return ret; | |
1123 | } | |
1124 | ||
1125 | /* The cluster refcount was incremented; refcount blocks must be flushed | |
1126 | * before the caller's L2 table updates. */ | |
c1f5bafd | 1127 | qcow2_cache_set_dependency(bs, s->l2_table_cache, s->refcount_block_cache); |
8c44dfbc HR |
1128 | |
1129 | s->free_byte_offset = offset + size; | |
1130 | if (!offset_into_cluster(s, s->free_byte_offset)) { | |
1131 | s->free_byte_offset = 0; | |
1132 | } | |
1133 | ||
f7d0fe02 KW |
1134 | return offset; |
1135 | } | |
1136 | ||
ed6ccf0f | 1137 | void qcow2_free_clusters(BlockDriverState *bs, |
6cfcb9b8 KW |
1138 | int64_t offset, int64_t size, |
1139 | enum qcow2_discard_type type) | |
f7d0fe02 | 1140 | { |
db3a964f KW |
1141 | int ret; |
1142 | ||
66f82cee | 1143 | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_FREE); |
2aabe7c7 | 1144 | ret = update_refcount(bs, offset, size, 1, true, type); |
db3a964f KW |
1145 | if (ret < 0) { |
1146 | fprintf(stderr, "qcow2_free_clusters failed: %s\n", strerror(-ret)); | |
003fad6e | 1147 | /* TODO Remember the clusters to free them later and avoid leaking */ |
db3a964f | 1148 | } |
f7d0fe02 KW |
1149 | } |
1150 | ||
45aba42f | 1151 | /* |
c7a4c37a KW |
1152 | * Free a cluster using its L2 entry (handles clusters of all types, e.g. |
1153 | * normal cluster, compressed cluster, etc.) | |
45aba42f | 1154 | */ |
6cfcb9b8 KW |
1155 | void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry, |
1156 | int nb_clusters, enum qcow2_discard_type type) | |
45aba42f | 1157 | { |
ff99129a | 1158 | BDRVQcow2State *s = bs->opaque; |
966b000f | 1159 | QCow2ClusterType ctype = qcow2_get_cluster_type(bs, l2_entry); |
45aba42f | 1160 | |
966b000f KW |
1161 | if (has_data_file(bs)) { |
1162 | if (s->discard_passthrough[type] && | |
1163 | (ctype == QCOW2_CLUSTER_NORMAL || | |
1164 | ctype == QCOW2_CLUSTER_ZERO_ALLOC)) | |
1165 | { | |
1166 | bdrv_pdiscard(s->data_file, l2_entry & L2E_OFFSET_MASK, | |
1167 | nb_clusters << s->cluster_bits); | |
1168 | } | |
1169 | return; | |
1170 | } | |
1171 | ||
1172 | switch (ctype) { | |
c7a4c37a KW |
1173 | case QCOW2_CLUSTER_COMPRESSED: |
1174 | { | |
1175 | int nb_csectors; | |
1176 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
1177 | s->csize_mask) + 1; | |
1178 | qcow2_free_clusters(bs, | |
1179 | (l2_entry & s->cluster_offset_mask) & ~511, | |
6cfcb9b8 | 1180 | nb_csectors * 512, type); |
c7a4c37a KW |
1181 | } |
1182 | break; | |
1183 | case QCOW2_CLUSTER_NORMAL: | |
fdfab37d EB |
1184 | case QCOW2_CLUSTER_ZERO_ALLOC: |
1185 | if (offset_into_cluster(s, l2_entry & L2E_OFFSET_MASK)) { | |
1186 | qcow2_signal_corruption(bs, false, -1, -1, | |
1187 | "Cannot free unaligned cluster %#llx", | |
1188 | l2_entry & L2E_OFFSET_MASK); | |
1189 | } else { | |
1190 | qcow2_free_clusters(bs, l2_entry & L2E_OFFSET_MASK, | |
1191 | nb_clusters << s->cluster_bits, type); | |
8f730dd2 | 1192 | } |
c7a4c37a | 1193 | break; |
fdfab37d | 1194 | case QCOW2_CLUSTER_ZERO_PLAIN: |
c7a4c37a KW |
1195 | case QCOW2_CLUSTER_UNALLOCATED: |
1196 | break; | |
1197 | default: | |
1198 | abort(); | |
45aba42f | 1199 | } |
45aba42f KW |
1200 | } |
1201 | ||
8b220eb7 PB |
1202 | int coroutine_fn qcow2_write_caches(BlockDriverState *bs) |
1203 | { | |
1204 | BDRVQcow2State *s = bs->opaque; | |
1205 | int ret; | |
f7d0fe02 | 1206 | |
8b220eb7 PB |
1207 | ret = qcow2_cache_write(bs, s->l2_table_cache); |
1208 | if (ret < 0) { | |
1209 | return ret; | |
1210 | } | |
1211 | ||
1212 | if (qcow2_need_accurate_refcounts(s)) { | |
1213 | ret = qcow2_cache_write(bs, s->refcount_block_cache); | |
1214 | if (ret < 0) { | |
1215 | return ret; | |
1216 | } | |
1217 | } | |
1218 | ||
1219 | return 0; | |
1220 | } | |
1221 | ||
1222 | int coroutine_fn qcow2_flush_caches(BlockDriverState *bs) | |
1223 | { | |
1224 | int ret = qcow2_write_caches(bs); | |
1225 | if (ret < 0) { | |
1226 | return ret; | |
1227 | } | |
1228 | ||
1229 | return bdrv_flush(bs->file->bs); | |
1230 | } | |
f7d0fe02 KW |
1231 | |
1232 | /*********************************************************/ | |
1233 | /* snapshots and image creation */ | |
1234 | ||
1235 | ||
1236 | ||
f7d0fe02 | 1237 | /* update the refcounts of snapshots and the copied flag */ |
ed6ccf0f KW |
1238 | int qcow2_update_snapshot_refcount(BlockDriverState *bs, |
1239 | int64_t l1_table_offset, int l1_size, int addend) | |
f7d0fe02 | 1240 | { |
ff99129a | 1241 | BDRVQcow2State *s = bs->opaque; |
83ad165b | 1242 | uint64_t *l1_table, *l2_slice, l2_offset, entry, l1_size2, refcount; |
de82815d | 1243 | bool l1_allocated = false; |
b32cbae1 | 1244 | int64_t old_entry, old_l2_offset; |
83ad165b | 1245 | unsigned slice, slice_size2, n_slices; |
7324c10f | 1246 | int i, j, l1_modified = 0, nb_csectors; |
29c1a730 | 1247 | int ret; |
f7d0fe02 | 1248 | |
2aabe7c7 HR |
1249 | assert(addend >= -1 && addend <= 1); |
1250 | ||
83ad165b | 1251 | l2_slice = NULL; |
f7d0fe02 KW |
1252 | l1_table = NULL; |
1253 | l1_size2 = l1_size * sizeof(uint64_t); | |
83ad165b AG |
1254 | slice_size2 = s->l2_slice_size * sizeof(uint64_t); |
1255 | n_slices = s->cluster_size / slice_size2; | |
43a0cac4 | 1256 | |
0b919fae KW |
1257 | s->cache_discards = true; |
1258 | ||
43a0cac4 KW |
1259 | /* WARNING: qcow2_snapshot_goto relies on this function not using the |
1260 | * l1_table_offset when it is the current s->l1_table_offset! Be careful | |
1261 | * when changing this! */ | |
f7d0fe02 | 1262 | if (l1_table_offset != s->l1_table_offset) { |
9e029689 | 1263 | l1_table = g_try_malloc0(ROUND_UP(l1_size2, 512)); |
de82815d KW |
1264 | if (l1_size2 && l1_table == NULL) { |
1265 | ret = -ENOMEM; | |
1266 | goto fail; | |
1267 | } | |
1268 | l1_allocated = true; | |
c2bc78b6 | 1269 | |
cf2ab8fc | 1270 | ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2); |
c2bc78b6 | 1271 | if (ret < 0) { |
f7d0fe02 | 1272 | goto fail; |
93913dfd KW |
1273 | } |
1274 | ||
b32cbae1 | 1275 | for (i = 0; i < l1_size; i++) { |
f7d0fe02 | 1276 | be64_to_cpus(&l1_table[i]); |
b32cbae1 | 1277 | } |
f7d0fe02 KW |
1278 | } else { |
1279 | assert(l1_size == s->l1_size); | |
1280 | l1_table = s->l1_table; | |
de82815d | 1281 | l1_allocated = false; |
f7d0fe02 KW |
1282 | } |
1283 | ||
b32cbae1 | 1284 | for (i = 0; i < l1_size; i++) { |
f7d0fe02 KW |
1285 | l2_offset = l1_table[i]; |
1286 | if (l2_offset) { | |
1287 | old_l2_offset = l2_offset; | |
8e37f681 | 1288 | l2_offset &= L1E_OFFSET_MASK; |
29c1a730 | 1289 | |
a97c67ee HR |
1290 | if (offset_into_cluster(s, l2_offset)) { |
1291 | qcow2_signal_corruption(bs, true, -1, -1, "L2 table offset %#" | |
1292 | PRIx64 " unaligned (L1 index: %#x)", | |
1293 | l2_offset, i); | |
1294 | ret = -EIO; | |
1295 | goto fail; | |
1296 | } | |
1297 | ||
83ad165b | 1298 | for (slice = 0; slice < n_slices; slice++) { |
ca62dd5c | 1299 | ret = qcow2_cache_get(bs, s->l2_table_cache, |
83ad165b AG |
1300 | l2_offset + slice * slice_size2, |
1301 | (void **) &l2_slice); | |
ca62dd5c AG |
1302 | if (ret < 0) { |
1303 | goto fail; | |
1304 | } | |
29c1a730 | 1305 | |
83ad165b | 1306 | for (j = 0; j < s->l2_slice_size; j++) { |
ca62dd5c AG |
1307 | uint64_t cluster_index; |
1308 | uint64_t offset; | |
1309 | ||
83ad165b | 1310 | entry = be64_to_cpu(l2_slice[j]); |
ca62dd5c AG |
1311 | old_entry = entry; |
1312 | entry &= ~QCOW_OFLAG_COPIED; | |
1313 | offset = entry & L2E_OFFSET_MASK; | |
1314 | ||
808c2bb4 | 1315 | switch (qcow2_get_cluster_type(bs, entry)) { |
ca62dd5c AG |
1316 | case QCOW2_CLUSTER_COMPRESSED: |
1317 | nb_csectors = ((entry >> s->csize_shift) & | |
1318 | s->csize_mask) + 1; | |
1319 | if (addend != 0) { | |
1320 | ret = update_refcount( | |
1321 | bs, (entry & s->cluster_offset_mask) & ~511, | |
2aabe7c7 | 1322 | nb_csectors * 512, abs(addend), addend < 0, |
6cfcb9b8 | 1323 | QCOW2_DISCARD_SNAPSHOT); |
ca62dd5c AG |
1324 | if (ret < 0) { |
1325 | goto fail; | |
1326 | } | |
1327 | } | |
1328 | /* compressed clusters are never modified */ | |
1329 | refcount = 2; | |
1330 | break; | |
1331 | ||
1332 | case QCOW2_CLUSTER_NORMAL: | |
1333 | case QCOW2_CLUSTER_ZERO_ALLOC: | |
1334 | if (offset_into_cluster(s, offset)) { | |
83ad165b AG |
1335 | /* Here l2_index means table (not slice) index */ |
1336 | int l2_index = slice * s->l2_slice_size + j; | |
ca62dd5c AG |
1337 | qcow2_signal_corruption( |
1338 | bs, true, -1, -1, "Cluster " | |
1339 | "allocation offset %#" PRIx64 | |
1340 | " unaligned (L2 offset: %#" | |
1341 | PRIx64 ", L2 index: %#x)", | |
83ad165b | 1342 | offset, l2_offset, l2_index); |
ca62dd5c | 1343 | ret = -EIO; |
a97c67ee HR |
1344 | goto fail; |
1345 | } | |
1346 | ||
ca62dd5c AG |
1347 | cluster_index = offset >> s->cluster_bits; |
1348 | assert(cluster_index); | |
1349 | if (addend != 0) { | |
1350 | ret = qcow2_update_cluster_refcount( | |
1351 | bs, cluster_index, abs(addend), addend < 0, | |
1352 | QCOW2_DISCARD_SNAPSHOT); | |
1353 | if (ret < 0) { | |
1354 | goto fail; | |
1355 | } | |
1356 | } | |
1357 | ||
1358 | ret = qcow2_get_refcount(bs, cluster_index, &refcount); | |
7324c10f | 1359 | if (ret < 0) { |
018faafd KW |
1360 | goto fail; |
1361 | } | |
ca62dd5c | 1362 | break; |
bbd995d8 | 1363 | |
ca62dd5c AG |
1364 | case QCOW2_CLUSTER_ZERO_PLAIN: |
1365 | case QCOW2_CLUSTER_UNALLOCATED: | |
1366 | refcount = 0; | |
1367 | break; | |
8b81a7b6 | 1368 | |
ca62dd5c AG |
1369 | default: |
1370 | abort(); | |
1371 | } | |
8b81a7b6 | 1372 | |
ca62dd5c AG |
1373 | if (refcount == 1) { |
1374 | entry |= QCOW_OFLAG_COPIED; | |
1375 | } | |
1376 | if (entry != old_entry) { | |
1377 | if (addend > 0) { | |
1378 | qcow2_cache_set_dependency(bs, s->l2_table_cache, | |
1379 | s->refcount_block_cache); | |
1380 | } | |
83ad165b | 1381 | l2_slice[j] = cpu_to_be64(entry); |
ca62dd5c | 1382 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, |
83ad165b | 1383 | l2_slice); |
f7d0fe02 KW |
1384 | } |
1385 | } | |
29c1a730 | 1386 | |
83ad165b | 1387 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
ca62dd5c | 1388 | } |
29c1a730 | 1389 | |
f7d0fe02 | 1390 | if (addend != 0) { |
c6e9d8ae HR |
1391 | ret = qcow2_update_cluster_refcount(bs, l2_offset >> |
1392 | s->cluster_bits, | |
2aabe7c7 | 1393 | abs(addend), addend < 0, |
c6e9d8ae HR |
1394 | QCOW2_DISCARD_SNAPSHOT); |
1395 | if (ret < 0) { | |
1396 | goto fail; | |
1397 | } | |
f7d0fe02 | 1398 | } |
7324c10f HR |
1399 | ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, |
1400 | &refcount); | |
1401 | if (ret < 0) { | |
018faafd KW |
1402 | goto fail; |
1403 | } else if (refcount == 1) { | |
f7d0fe02 KW |
1404 | l2_offset |= QCOW_OFLAG_COPIED; |
1405 | } | |
1406 | if (l2_offset != old_l2_offset) { | |
1407 | l1_table[i] = l2_offset; | |
1408 | l1_modified = 1; | |
1409 | } | |
1410 | } | |
1411 | } | |
93913dfd | 1412 | |
2154f24e | 1413 | ret = bdrv_flush(bs); |
93913dfd | 1414 | fail: |
83ad165b AG |
1415 | if (l2_slice) { |
1416 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); | |
93913dfd KW |
1417 | } |
1418 | ||
0b919fae KW |
1419 | s->cache_discards = false; |
1420 | qcow2_process_discards(bs, ret); | |
1421 | ||
43a0cac4 | 1422 | /* Update L1 only if it isn't deleted anyway (addend = -1) */ |
c2b6ff51 KW |
1423 | if (ret == 0 && addend >= 0 && l1_modified) { |
1424 | for (i = 0; i < l1_size; i++) { | |
f7d0fe02 | 1425 | cpu_to_be64s(&l1_table[i]); |
c2b6ff51 KW |
1426 | } |
1427 | ||
d9ca2ea2 | 1428 | ret = bdrv_pwrite_sync(bs->file, l1_table_offset, |
9a4f4c31 | 1429 | l1_table, l1_size2); |
c2b6ff51 KW |
1430 | |
1431 | for (i = 0; i < l1_size; i++) { | |
f7d0fe02 | 1432 | be64_to_cpus(&l1_table[i]); |
c2b6ff51 | 1433 | } |
f7d0fe02 KW |
1434 | } |
1435 | if (l1_allocated) | |
7267c094 | 1436 | g_free(l1_table); |
93913dfd | 1437 | return ret; |
f7d0fe02 KW |
1438 | } |
1439 | ||
1440 | ||
1441 | ||
1442 | ||
1443 | /*********************************************************/ | |
1444 | /* refcount checking functions */ | |
1445 | ||
1446 | ||
c2551b47 | 1447 | static uint64_t refcount_array_byte_size(BDRVQcow2State *s, uint64_t entries) |
5fee192e HR |
1448 | { |
1449 | /* This assertion holds because there is no way we can address more than | |
1450 | * 2^(64 - 9) clusters at once (with cluster size 512 = 2^9, and because | |
1451 | * offsets have to be representable in bytes); due to every cluster | |
1452 | * corresponding to one refcount entry, we are well below that limit */ | |
1453 | assert(entries < (UINT64_C(1) << (64 - 9))); | |
1454 | ||
1455 | /* Thanks to the assertion this will not overflow, because | |
1456 | * s->refcount_order < 7. | |
1457 | * (note: x << s->refcount_order == x * s->refcount_bits) */ | |
1458 | return DIV_ROUND_UP(entries << s->refcount_order, 8); | |
1459 | } | |
1460 | ||
1461 | /** | |
1462 | * Reallocates *array so that it can hold new_size entries. *size must contain | |
1463 | * the current number of entries in *array. If the reallocation fails, *array | |
1464 | * and *size will not be modified and -errno will be returned. If the | |
1465 | * reallocation is successful, *array will be set to the new buffer, *size | |
1466 | * will be set to new_size and 0 will be returned. The size of the reallocated | |
1467 | * refcount array buffer will be aligned to a cluster boundary, and the newly | |
1468 | * allocated area will be zeroed. | |
1469 | */ | |
ff99129a | 1470 | static int realloc_refcount_array(BDRVQcow2State *s, void **array, |
5fee192e HR |
1471 | int64_t *size, int64_t new_size) |
1472 | { | |
b6d36def | 1473 | int64_t old_byte_size, new_byte_size; |
7453c96b | 1474 | void *new_ptr; |
5fee192e HR |
1475 | |
1476 | /* Round to clusters so the array can be directly written to disk */ | |
1477 | old_byte_size = size_to_clusters(s, refcount_array_byte_size(s, *size)) | |
1478 | * s->cluster_size; | |
1479 | new_byte_size = size_to_clusters(s, refcount_array_byte_size(s, new_size)) | |
1480 | * s->cluster_size; | |
1481 | ||
1482 | if (new_byte_size == old_byte_size) { | |
1483 | *size = new_size; | |
1484 | return 0; | |
1485 | } | |
1486 | ||
1487 | assert(new_byte_size > 0); | |
1488 | ||
b6d36def HR |
1489 | if (new_byte_size > SIZE_MAX) { |
1490 | return -ENOMEM; | |
1491 | } | |
1492 | ||
5fee192e HR |
1493 | new_ptr = g_try_realloc(*array, new_byte_size); |
1494 | if (!new_ptr) { | |
1495 | return -ENOMEM; | |
1496 | } | |
1497 | ||
1498 | if (new_byte_size > old_byte_size) { | |
b6d36def | 1499 | memset((char *)new_ptr + old_byte_size, 0, |
5fee192e HR |
1500 | new_byte_size - old_byte_size); |
1501 | } | |
1502 | ||
1503 | *array = new_ptr; | |
1504 | *size = new_size; | |
1505 | ||
1506 | return 0; | |
1507 | } | |
f7d0fe02 KW |
1508 | |
1509 | /* | |
1510 | * Increases the refcount for a range of clusters in a given refcount table. | |
1511 | * This is used to construct a temporary refcount table out of L1 and L2 tables | |
b6af0975 | 1512 | * which can be compared to the refcount table saved in the image. |
f7d0fe02 | 1513 | * |
9ac228e0 | 1514 | * Modifies the number of errors in res. |
f7d0fe02 | 1515 | */ |
8a5bb1f1 VSO |
1516 | int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res, |
1517 | void **refcount_table, | |
1518 | int64_t *refcount_table_size, | |
1519 | int64_t offset, int64_t size) | |
f7d0fe02 | 1520 | { |
ff99129a | 1521 | BDRVQcow2State *s = bs->opaque; |
7453c96b | 1522 | uint64_t start, last, cluster_offset, k, refcount; |
a5fff8d4 | 1523 | int64_t file_len; |
5fee192e | 1524 | int ret; |
f7d0fe02 | 1525 | |
fef4d3d5 HR |
1526 | if (size <= 0) { |
1527 | return 0; | |
1528 | } | |
f7d0fe02 | 1529 | |
a5fff8d4 VSO |
1530 | file_len = bdrv_getlength(bs->file->bs); |
1531 | if (file_len < 0) { | |
1532 | return file_len; | |
1533 | } | |
1534 | ||
1535 | /* | |
1536 | * Last cluster of qcow2 image may be semi-allocated, so it may be OK to | |
1537 | * reference some space after file end but it should be less than one | |
1538 | * cluster. | |
1539 | */ | |
1540 | if (offset + size - file_len >= s->cluster_size) { | |
1541 | fprintf(stderr, "ERROR: counting reference for region exceeding the " | |
1542 | "end of the file by one cluster or more: offset 0x%" PRIx64 | |
1543 | " size 0x%" PRIx64 "\n", offset, size); | |
1544 | res->corruptions++; | |
1545 | return 0; | |
1546 | } | |
1547 | ||
ac95acdb HT |
1548 | start = start_of_cluster(s, offset); |
1549 | last = start_of_cluster(s, offset + size - 1); | |
f7d0fe02 KW |
1550 | for(cluster_offset = start; cluster_offset <= last; |
1551 | cluster_offset += s->cluster_size) { | |
1552 | k = cluster_offset >> s->cluster_bits; | |
641bb63c | 1553 | if (k >= *refcount_table_size) { |
5fee192e HR |
1554 | ret = realloc_refcount_array(s, refcount_table, |
1555 | refcount_table_size, k + 1); | |
1556 | if (ret < 0) { | |
641bb63c | 1557 | res->check_errors++; |
5fee192e | 1558 | return ret; |
f7d0fe02 | 1559 | } |
641bb63c HR |
1560 | } |
1561 | ||
7453c96b HR |
1562 | refcount = s->get_refcount(*refcount_table, k); |
1563 | if (refcount == s->refcount_max) { | |
641bb63c HR |
1564 | fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64 |
1565 | "\n", cluster_offset); | |
03bb78ed HR |
1566 | fprintf(stderr, "Use qemu-img amend to increase the refcount entry " |
1567 | "width or qemu-img convert to create a clean copy if the " | |
1568 | "image cannot be opened for writing\n"); | |
641bb63c | 1569 | res->corruptions++; |
7453c96b | 1570 | continue; |
f7d0fe02 | 1571 | } |
7453c96b | 1572 | s->set_refcount(*refcount_table, k, refcount + 1); |
f7d0fe02 | 1573 | } |
fef4d3d5 HR |
1574 | |
1575 | return 0; | |
f7d0fe02 KW |
1576 | } |
1577 | ||
801f7044 SH |
1578 | /* Flags for check_refcounts_l1() and check_refcounts_l2() */ |
1579 | enum { | |
fba31bae | 1580 | CHECK_FRAG_INFO = 0x2, /* update BlockFragInfo counters */ |
801f7044 SH |
1581 | }; |
1582 | ||
f7d0fe02 KW |
1583 | /* |
1584 | * Increases the refcount in the given refcount table for the all clusters | |
1585 | * referenced in the L2 table. While doing so, performs some checks on L2 | |
1586 | * entries. | |
1587 | * | |
1588 | * Returns the number of errors found by the checks or -errno if an internal | |
1589 | * error occurred. | |
1590 | */ | |
9ac228e0 | 1591 | static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, |
7453c96b HR |
1592 | void **refcount_table, |
1593 | int64_t *refcount_table_size, int64_t l2_offset, | |
1ef337b7 | 1594 | int flags, BdrvCheckMode fix, bool active) |
f7d0fe02 | 1595 | { |
ff99129a | 1596 | BDRVQcow2State *s = bs->opaque; |
afdf0abe | 1597 | uint64_t *l2_table, l2_entry; |
fba31bae | 1598 | uint64_t next_contiguous_offset = 0; |
ad27390c | 1599 | int i, l2_size, nb_csectors, ret; |
f7d0fe02 KW |
1600 | |
1601 | /* Read L2 table from disk */ | |
1602 | l2_size = s->l2_size * sizeof(uint64_t); | |
7267c094 | 1603 | l2_table = g_malloc(l2_size); |
f7d0fe02 | 1604 | |
cf2ab8fc | 1605 | ret = bdrv_pread(bs->file, l2_offset, l2_table, l2_size); |
ad27390c HR |
1606 | if (ret < 0) { |
1607 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l2\n"); | |
1608 | res->check_errors++; | |
f7d0fe02 | 1609 | goto fail; |
ad27390c | 1610 | } |
f7d0fe02 KW |
1611 | |
1612 | /* Do the actual checks */ | |
1613 | for(i = 0; i < s->l2_size; i++) { | |
afdf0abe KW |
1614 | l2_entry = be64_to_cpu(l2_table[i]); |
1615 | ||
808c2bb4 | 1616 | switch (qcow2_get_cluster_type(bs, l2_entry)) { |
afdf0abe KW |
1617 | case QCOW2_CLUSTER_COMPRESSED: |
1618 | /* Compressed clusters don't have QCOW_OFLAG_COPIED */ | |
1619 | if (l2_entry & QCOW_OFLAG_COPIED) { | |
74c44a59 | 1620 | fprintf(stderr, "ERROR: coffset=0x%" PRIx64 ": " |
afdf0abe | 1621 | "copied flag must never be set for compressed " |
74c44a59 | 1622 | "clusters\n", l2_entry & s->cluster_offset_mask); |
afdf0abe KW |
1623 | l2_entry &= ~QCOW_OFLAG_COPIED; |
1624 | res->corruptions++; | |
1625 | } | |
f7d0fe02 | 1626 | |
e9f5b6de KW |
1627 | if (has_data_file(bs)) { |
1628 | fprintf(stderr, "ERROR compressed cluster %d with data file, " | |
1629 | "entry=0x%" PRIx64 "\n", i, l2_entry); | |
1630 | res->corruptions++; | |
1631 | break; | |
1632 | } | |
1633 | ||
afdf0abe KW |
1634 | /* Mark cluster as used */ |
1635 | nb_csectors = ((l2_entry >> s->csize_shift) & | |
1636 | s->csize_mask) + 1; | |
1637 | l2_entry &= s->cluster_offset_mask; | |
8a5bb1f1 VSO |
1638 | ret = qcow2_inc_refcounts_imrt(bs, res, |
1639 | refcount_table, refcount_table_size, | |
1640 | l2_entry & ~511, nb_csectors * 512); | |
fef4d3d5 HR |
1641 | if (ret < 0) { |
1642 | goto fail; | |
1643 | } | |
fba31bae SH |
1644 | |
1645 | if (flags & CHECK_FRAG_INFO) { | |
1646 | res->bfi.allocated_clusters++; | |
4db35162 | 1647 | res->bfi.compressed_clusters++; |
fba31bae SH |
1648 | |
1649 | /* Compressed clusters are fragmented by nature. Since they | |
1650 | * take up sub-sector space but we only have sector granularity | |
1651 | * I/O we need to re-read the same sectors even for adjacent | |
1652 | * compressed clusters. | |
1653 | */ | |
1654 | res->bfi.fragmented_clusters++; | |
1655 | } | |
afdf0abe | 1656 | break; |
f7d0fe02 | 1657 | |
fdfab37d | 1658 | case QCOW2_CLUSTER_ZERO_ALLOC: |
afdf0abe KW |
1659 | case QCOW2_CLUSTER_NORMAL: |
1660 | { | |
afdf0abe | 1661 | uint64_t offset = l2_entry & L2E_OFFSET_MASK; |
f7d0fe02 | 1662 | |
fba31bae SH |
1663 | if (flags & CHECK_FRAG_INFO) { |
1664 | res->bfi.allocated_clusters++; | |
1665 | if (next_contiguous_offset && | |
1666 | offset != next_contiguous_offset) { | |
1667 | res->bfi.fragmented_clusters++; | |
1668 | } | |
1669 | next_contiguous_offset = offset + s->cluster_size; | |
1670 | } | |
1671 | ||
ac5b787a HR |
1672 | /* Correct offsets are cluster aligned */ |
1673 | if (offset_into_cluster(s, offset)) { | |
808c2bb4 | 1674 | if (qcow2_get_cluster_type(bs, l2_entry) == |
ac5b787a HR |
1675 | QCOW2_CLUSTER_ZERO_ALLOC) |
1676 | { | |
1677 | fprintf(stderr, "%s offset=%" PRIx64 ": Preallocated zero " | |
1678 | "cluster is not properly aligned; L2 entry " | |
1679 | "corrupted.\n", | |
1680 | fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", | |
1681 | offset); | |
1682 | if (fix & BDRV_FIX_ERRORS) { | |
1683 | uint64_t l2e_offset = | |
1684 | l2_offset + (uint64_t)i * sizeof(uint64_t); | |
1ef337b7 VSO |
1685 | int ign = active ? QCOW2_OL_ACTIVE_L2 : |
1686 | QCOW2_OL_INACTIVE_L2; | |
ac5b787a HR |
1687 | |
1688 | l2_entry = QCOW_OFLAG_ZERO; | |
1689 | l2_table[i] = cpu_to_be64(l2_entry); | |
1ef337b7 | 1690 | ret = qcow2_pre_write_overlap_check(bs, ign, |
966b000f | 1691 | l2e_offset, sizeof(uint64_t), false); |
ac5b787a HR |
1692 | if (ret < 0) { |
1693 | fprintf(stderr, "ERROR: Overlap check failed\n"); | |
1694 | res->check_errors++; | |
1695 | /* Something is seriously wrong, so abort checking | |
1696 | * this L2 table */ | |
1697 | goto fail; | |
1698 | } | |
1699 | ||
1700 | ret = bdrv_pwrite_sync(bs->file, l2e_offset, | |
1701 | &l2_table[i], sizeof(uint64_t)); | |
1702 | if (ret < 0) { | |
1703 | fprintf(stderr, "ERROR: Failed to overwrite L2 " | |
1704 | "table entry: %s\n", strerror(-ret)); | |
1705 | res->check_errors++; | |
1706 | /* Do not abort, continue checking the rest of this | |
1707 | * L2 table's entries */ | |
1708 | } else { | |
1709 | res->corruptions_fixed++; | |
1710 | /* Skip marking the cluster as used | |
1711 | * (it is unused now) */ | |
1712 | continue; | |
1713 | } | |
1714 | } else { | |
1715 | res->corruptions++; | |
1716 | } | |
1717 | } else { | |
1718 | fprintf(stderr, "ERROR offset=%" PRIx64 ": Data cluster is " | |
1719 | "not properly aligned; L2 entry corrupted.\n", offset); | |
1720 | res->corruptions++; | |
1721 | } | |
1722 | } | |
1723 | ||
afdf0abe | 1724 | /* Mark cluster as used */ |
e9f5b6de KW |
1725 | if (!has_data_file(bs)) { |
1726 | ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, | |
1727 | refcount_table_size, | |
1728 | offset, s->cluster_size); | |
1729 | if (ret < 0) { | |
1730 | goto fail; | |
1731 | } | |
fef4d3d5 | 1732 | } |
afdf0abe KW |
1733 | break; |
1734 | } | |
1735 | ||
fdfab37d | 1736 | case QCOW2_CLUSTER_ZERO_PLAIN: |
afdf0abe KW |
1737 | case QCOW2_CLUSTER_UNALLOCATED: |
1738 | break; | |
1739 | ||
1740 | default: | |
1741 | abort(); | |
f7d0fe02 KW |
1742 | } |
1743 | } | |
1744 | ||
7267c094 | 1745 | g_free(l2_table); |
9ac228e0 | 1746 | return 0; |
f7d0fe02 KW |
1747 | |
1748 | fail: | |
7267c094 | 1749 | g_free(l2_table); |
ad27390c | 1750 | return ret; |
f7d0fe02 KW |
1751 | } |
1752 | ||
1753 | /* | |
1754 | * Increases the refcount for the L1 table, its L2 tables and all referenced | |
1755 | * clusters in the given refcount table. While doing so, performs some checks | |
1756 | * on L1 and L2 entries. | |
1757 | * | |
1758 | * Returns the number of errors found by the checks or -errno if an internal | |
1759 | * error occurred. | |
1760 | */ | |
1761 | static int check_refcounts_l1(BlockDriverState *bs, | |
9ac228e0 | 1762 | BdrvCheckResult *res, |
7453c96b | 1763 | void **refcount_table, |
641bb63c | 1764 | int64_t *refcount_table_size, |
f7d0fe02 | 1765 | int64_t l1_table_offset, int l1_size, |
1ef337b7 | 1766 | int flags, BdrvCheckMode fix, bool active) |
f7d0fe02 | 1767 | { |
ff99129a | 1768 | BDRVQcow2State *s = bs->opaque; |
fef4d3d5 | 1769 | uint64_t *l1_table = NULL, l2_offset, l1_size2; |
4f6ed88c | 1770 | int i, ret; |
f7d0fe02 KW |
1771 | |
1772 | l1_size2 = l1_size * sizeof(uint64_t); | |
1773 | ||
1774 | /* Mark L1 table as used */ | |
8a5bb1f1 VSO |
1775 | ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, refcount_table_size, |
1776 | l1_table_offset, l1_size2); | |
fef4d3d5 HR |
1777 | if (ret < 0) { |
1778 | goto fail; | |
1779 | } | |
f7d0fe02 KW |
1780 | |
1781 | /* Read L1 table entries from disk */ | |
fef4d3d5 | 1782 | if (l1_size2 > 0) { |
de82815d KW |
1783 | l1_table = g_try_malloc(l1_size2); |
1784 | if (l1_table == NULL) { | |
1785 | ret = -ENOMEM; | |
ad27390c | 1786 | res->check_errors++; |
de82815d KW |
1787 | goto fail; |
1788 | } | |
cf2ab8fc | 1789 | ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2); |
ad27390c HR |
1790 | if (ret < 0) { |
1791 | fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); | |
1792 | res->check_errors++; | |
702ef63f | 1793 | goto fail; |
ad27390c | 1794 | } |
702ef63f KW |
1795 | for(i = 0;i < l1_size; i++) |
1796 | be64_to_cpus(&l1_table[i]); | |
1797 | } | |
f7d0fe02 KW |
1798 | |
1799 | /* Do the actual checks */ | |
1800 | for(i = 0; i < l1_size; i++) { | |
1801 | l2_offset = l1_table[i]; | |
1802 | if (l2_offset) { | |
f7d0fe02 | 1803 | /* Mark L2 table as used */ |
afdf0abe | 1804 | l2_offset &= L1E_OFFSET_MASK; |
8a5bb1f1 VSO |
1805 | ret = qcow2_inc_refcounts_imrt(bs, res, |
1806 | refcount_table, refcount_table_size, | |
1807 | l2_offset, s->cluster_size); | |
fef4d3d5 HR |
1808 | if (ret < 0) { |
1809 | goto fail; | |
1810 | } | |
f7d0fe02 KW |
1811 | |
1812 | /* L2 tables are cluster aligned */ | |
ac95acdb | 1813 | if (offset_into_cluster(s, l2_offset)) { |
f7d0fe02 KW |
1814 | fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " |
1815 | "cluster aligned; L1 entry corrupted\n", l2_offset); | |
9ac228e0 | 1816 | res->corruptions++; |
f7d0fe02 KW |
1817 | } |
1818 | ||
1819 | /* Process and check L2 entries */ | |
9ac228e0 | 1820 | ret = check_refcounts_l2(bs, res, refcount_table, |
ac5b787a | 1821 | refcount_table_size, l2_offset, flags, |
1ef337b7 | 1822 | fix, active); |
f7d0fe02 KW |
1823 | if (ret < 0) { |
1824 | goto fail; | |
1825 | } | |
f7d0fe02 KW |
1826 | } |
1827 | } | |
7267c094 | 1828 | g_free(l1_table); |
9ac228e0 | 1829 | return 0; |
f7d0fe02 KW |
1830 | |
1831 | fail: | |
7267c094 | 1832 | g_free(l1_table); |
ad27390c | 1833 | return ret; |
f7d0fe02 KW |
1834 | } |
1835 | ||
4f6ed88c HR |
1836 | /* |
1837 | * Checks the OFLAG_COPIED flag for all L1 and L2 entries. | |
1838 | * | |
1839 | * This function does not print an error message nor does it increment | |
44751917 HR |
1840 | * check_errors if qcow2_get_refcount fails (this is because such an error will |
1841 | * have been already detected and sufficiently signaled by the calling function | |
4f6ed88c HR |
1842 | * (qcow2_check_refcounts) by the time this function is called). |
1843 | */ | |
e23e400e HR |
1844 | static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res, |
1845 | BdrvCheckMode fix) | |
4f6ed88c | 1846 | { |
ff99129a | 1847 | BDRVQcow2State *s = bs->opaque; |
4f6ed88c HR |
1848 | uint64_t *l2_table = qemu_blockalign(bs, s->cluster_size); |
1849 | int ret; | |
0e06528e | 1850 | uint64_t refcount; |
4f6ed88c | 1851 | int i, j; |
3cce51c9 HR |
1852 | bool repair; |
1853 | ||
1854 | if (fix & BDRV_FIX_ERRORS) { | |
1855 | /* Always repair */ | |
1856 | repair = true; | |
1857 | } else if (fix & BDRV_FIX_LEAKS) { | |
1858 | /* Repair only if that seems safe: This function is always | |
1859 | * called after the refcounts have been fixed, so the refcount | |
1860 | * is accurate if that repair was successful */ | |
1861 | repair = !res->check_errors && !res->corruptions && !res->leaks; | |
1862 | } else { | |
1863 | repair = false; | |
1864 | } | |
4f6ed88c HR |
1865 | |
1866 | for (i = 0; i < s->l1_size; i++) { | |
1867 | uint64_t l1_entry = s->l1_table[i]; | |
1868 | uint64_t l2_offset = l1_entry & L1E_OFFSET_MASK; | |
7e3e736c | 1869 | int l2_dirty = 0; |
4f6ed88c HR |
1870 | |
1871 | if (!l2_offset) { | |
1872 | continue; | |
1873 | } | |
1874 | ||
7324c10f HR |
1875 | ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, |
1876 | &refcount); | |
1877 | if (ret < 0) { | |
4f6ed88c HR |
1878 | /* don't print message nor increment check_errors */ |
1879 | continue; | |
1880 | } | |
1881 | if ((refcount == 1) != ((l1_entry & QCOW_OFLAG_COPIED) != 0)) { | |
e23e400e | 1882 | fprintf(stderr, "%s OFLAG_COPIED L2 cluster: l1_index=%d " |
0e06528e | 1883 | "l1_entry=%" PRIx64 " refcount=%" PRIu64 "\n", |
3cce51c9 HR |
1884 | repair ? "Repairing" : "ERROR", i, l1_entry, refcount); |
1885 | if (repair) { | |
e23e400e HR |
1886 | s->l1_table[i] = refcount == 1 |
1887 | ? l1_entry | QCOW_OFLAG_COPIED | |
1888 | : l1_entry & ~QCOW_OFLAG_COPIED; | |
1889 | ret = qcow2_write_l1_entry(bs, i); | |
1890 | if (ret < 0) { | |
1891 | res->check_errors++; | |
1892 | goto fail; | |
1893 | } | |
1894 | res->corruptions_fixed++; | |
1895 | } else { | |
1896 | res->corruptions++; | |
1897 | } | |
4f6ed88c HR |
1898 | } |
1899 | ||
cf2ab8fc | 1900 | ret = bdrv_pread(bs->file, l2_offset, l2_table, |
4f6ed88c HR |
1901 | s->l2_size * sizeof(uint64_t)); |
1902 | if (ret < 0) { | |
1903 | fprintf(stderr, "ERROR: Could not read L2 table: %s\n", | |
1904 | strerror(-ret)); | |
1905 | res->check_errors++; | |
1906 | goto fail; | |
1907 | } | |
1908 | ||
1909 | for (j = 0; j < s->l2_size; j++) { | |
1910 | uint64_t l2_entry = be64_to_cpu(l2_table[j]); | |
1911 | uint64_t data_offset = l2_entry & L2E_OFFSET_MASK; | |
808c2bb4 | 1912 | QCow2ClusterType cluster_type = qcow2_get_cluster_type(bs, l2_entry); |
4f6ed88c | 1913 | |
fdfab37d EB |
1914 | if (cluster_type == QCOW2_CLUSTER_NORMAL || |
1915 | cluster_type == QCOW2_CLUSTER_ZERO_ALLOC) { | |
e9f5b6de KW |
1916 | if (has_data_file(bs)) { |
1917 | refcount = 1; | |
1918 | } else { | |
1919 | ret = qcow2_get_refcount(bs, | |
1920 | data_offset >> s->cluster_bits, | |
1921 | &refcount); | |
1922 | if (ret < 0) { | |
1923 | /* don't print message nor increment check_errors */ | |
1924 | continue; | |
1925 | } | |
4f6ed88c HR |
1926 | } |
1927 | if ((refcount == 1) != ((l2_entry & QCOW_OFLAG_COPIED) != 0)) { | |
e23e400e | 1928 | fprintf(stderr, "%s OFLAG_COPIED data cluster: " |
0e06528e | 1929 | "l2_entry=%" PRIx64 " refcount=%" PRIu64 "\n", |
3cce51c9 HR |
1930 | repair ? "Repairing" : "ERROR", l2_entry, refcount); |
1931 | if (repair) { | |
e23e400e HR |
1932 | l2_table[j] = cpu_to_be64(refcount == 1 |
1933 | ? l2_entry | QCOW_OFLAG_COPIED | |
1934 | : l2_entry & ~QCOW_OFLAG_COPIED); | |
7e3e736c | 1935 | l2_dirty++; |
e23e400e HR |
1936 | } else { |
1937 | res->corruptions++; | |
1938 | } | |
4f6ed88c HR |
1939 | } |
1940 | } | |
1941 | } | |
e23e400e | 1942 | |
7e3e736c | 1943 | if (l2_dirty > 0) { |
231bb267 | 1944 | ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L2, |
966b000f KW |
1945 | l2_offset, s->cluster_size, |
1946 | false); | |
e23e400e HR |
1947 | if (ret < 0) { |
1948 | fprintf(stderr, "ERROR: Could not write L2 table; metadata " | |
1949 | "overlap check failed: %s\n", strerror(-ret)); | |
1950 | res->check_errors++; | |
1951 | goto fail; | |
1952 | } | |
1953 | ||
d9ca2ea2 | 1954 | ret = bdrv_pwrite(bs->file, l2_offset, l2_table, |
9a4f4c31 | 1955 | s->cluster_size); |
e23e400e HR |
1956 | if (ret < 0) { |
1957 | fprintf(stderr, "ERROR: Could not write L2 table: %s\n", | |
1958 | strerror(-ret)); | |
1959 | res->check_errors++; | |
1960 | goto fail; | |
1961 | } | |
7e3e736c | 1962 | res->corruptions_fixed += l2_dirty; |
e23e400e | 1963 | } |
4f6ed88c HR |
1964 | } |
1965 | ||
1966 | ret = 0; | |
1967 | ||
1968 | fail: | |
1969 | qemu_vfree(l2_table); | |
1970 | return ret; | |
1971 | } | |
1972 | ||
6ca56bf5 HR |
1973 | /* |
1974 | * Checks consistency of refblocks and accounts for each refblock in | |
1975 | * *refcount_table. | |
1976 | */ | |
1977 | static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 | 1978 | BdrvCheckMode fix, bool *rebuild, |
7453c96b | 1979 | void **refcount_table, int64_t *nb_clusters) |
6ca56bf5 | 1980 | { |
ff99129a | 1981 | BDRVQcow2State *s = bs->opaque; |
001c158d | 1982 | int64_t i, size; |
fef4d3d5 | 1983 | int ret; |
6ca56bf5 | 1984 | |
f7d0fe02 | 1985 | for(i = 0; i < s->refcount_table_size; i++) { |
6882c8fa | 1986 | uint64_t offset, cluster; |
f7d0fe02 | 1987 | offset = s->refcount_table[i]; |
6882c8fa | 1988 | cluster = offset >> s->cluster_bits; |
746c3cb5 KW |
1989 | |
1990 | /* Refcount blocks are cluster aligned */ | |
ac95acdb | 1991 | if (offset_into_cluster(s, offset)) { |
166acf54 | 1992 | fprintf(stderr, "ERROR refcount block %" PRId64 " is not " |
746c3cb5 | 1993 | "cluster aligned; refcount table entry corrupted\n", i); |
9ac228e0 | 1994 | res->corruptions++; |
f307b255 | 1995 | *rebuild = true; |
6882c8fa KW |
1996 | continue; |
1997 | } | |
1998 | ||
6ca56bf5 | 1999 | if (cluster >= *nb_clusters) { |
001c158d HR |
2000 | fprintf(stderr, "%s refcount block %" PRId64 " is outside image\n", |
2001 | fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i); | |
2002 | ||
2003 | if (fix & BDRV_FIX_ERRORS) { | |
5fee192e | 2004 | int64_t new_nb_clusters; |
ed3d2ec9 | 2005 | Error *local_err = NULL; |
001c158d HR |
2006 | |
2007 | if (offset > INT64_MAX - s->cluster_size) { | |
2008 | ret = -EINVAL; | |
2009 | goto resize_fail; | |
2010 | } | |
2011 | ||
ed3d2ec9 | 2012 | ret = bdrv_truncate(bs->file, offset + s->cluster_size, |
7ea37c30 | 2013 | PREALLOC_MODE_OFF, &local_err); |
001c158d | 2014 | if (ret < 0) { |
ed3d2ec9 | 2015 | error_report_err(local_err); |
001c158d HR |
2016 | goto resize_fail; |
2017 | } | |
9a4f4c31 | 2018 | size = bdrv_getlength(bs->file->bs); |
001c158d HR |
2019 | if (size < 0) { |
2020 | ret = size; | |
2021 | goto resize_fail; | |
2022 | } | |
2023 | ||
5fee192e HR |
2024 | new_nb_clusters = size_to_clusters(s, size); |
2025 | assert(new_nb_clusters >= *nb_clusters); | |
001c158d | 2026 | |
5fee192e HR |
2027 | ret = realloc_refcount_array(s, refcount_table, |
2028 | nb_clusters, new_nb_clusters); | |
2029 | if (ret < 0) { | |
001c158d | 2030 | res->check_errors++; |
5fee192e | 2031 | return ret; |
001c158d | 2032 | } |
001c158d HR |
2033 | |
2034 | if (cluster >= *nb_clusters) { | |
2035 | ret = -EINVAL; | |
2036 | goto resize_fail; | |
2037 | } | |
2038 | ||
2039 | res->corruptions_fixed++; | |
8a5bb1f1 VSO |
2040 | ret = qcow2_inc_refcounts_imrt(bs, res, |
2041 | refcount_table, nb_clusters, | |
2042 | offset, s->cluster_size); | |
001c158d HR |
2043 | if (ret < 0) { |
2044 | return ret; | |
2045 | } | |
2046 | /* No need to check whether the refcount is now greater than 1: | |
2047 | * This area was just allocated and zeroed, so it can only be | |
8a5bb1f1 | 2048 | * exactly 1 after qcow2_inc_refcounts_imrt() */ |
001c158d HR |
2049 | continue; |
2050 | ||
2051 | resize_fail: | |
2052 | res->corruptions++; | |
f307b255 | 2053 | *rebuild = true; |
001c158d HR |
2054 | fprintf(stderr, "ERROR could not resize image: %s\n", |
2055 | strerror(-ret)); | |
2056 | } else { | |
2057 | res->corruptions++; | |
2058 | } | |
6882c8fa | 2059 | continue; |
746c3cb5 KW |
2060 | } |
2061 | ||
f7d0fe02 | 2062 | if (offset != 0) { |
8a5bb1f1 VSO |
2063 | ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, nb_clusters, |
2064 | offset, s->cluster_size); | |
fef4d3d5 HR |
2065 | if (ret < 0) { |
2066 | return ret; | |
2067 | } | |
7453c96b | 2068 | if (s->get_refcount(*refcount_table, cluster) != 1) { |
f307b255 | 2069 | fprintf(stderr, "ERROR refcount block %" PRId64 |
7453c96b HR |
2070 | " refcount=%" PRIu64 "\n", i, |
2071 | s->get_refcount(*refcount_table, cluster)); | |
f307b255 HR |
2072 | res->corruptions++; |
2073 | *rebuild = true; | |
746c3cb5 | 2074 | } |
f7d0fe02 KW |
2075 | } |
2076 | } | |
2077 | ||
6ca56bf5 HR |
2078 | return 0; |
2079 | } | |
2080 | ||
057a3fe5 HR |
2081 | /* |
2082 | * Calculates an in-memory refcount table. | |
2083 | */ | |
2084 | static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 | 2085 | BdrvCheckMode fix, bool *rebuild, |
7453c96b | 2086 | void **refcount_table, int64_t *nb_clusters) |
057a3fe5 | 2087 | { |
ff99129a | 2088 | BDRVQcow2State *s = bs->opaque; |
057a3fe5 HR |
2089 | int64_t i; |
2090 | QCowSnapshot *sn; | |
2091 | int ret; | |
2092 | ||
9696df21 | 2093 | if (!*refcount_table) { |
5fee192e HR |
2094 | int64_t old_size = 0; |
2095 | ret = realloc_refcount_array(s, refcount_table, | |
2096 | &old_size, *nb_clusters); | |
2097 | if (ret < 0) { | |
9696df21 | 2098 | res->check_errors++; |
5fee192e | 2099 | return ret; |
9696df21 | 2100 | } |
057a3fe5 HR |
2101 | } |
2102 | ||
2103 | /* header */ | |
8a5bb1f1 VSO |
2104 | ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, nb_clusters, |
2105 | 0, s->cluster_size); | |
fef4d3d5 HR |
2106 | if (ret < 0) { |
2107 | return ret; | |
2108 | } | |
057a3fe5 HR |
2109 | |
2110 | /* current L1 table */ | |
641bb63c | 2111 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
ac5b787a | 2112 | s->l1_table_offset, s->l1_size, CHECK_FRAG_INFO, |
1ef337b7 | 2113 | fix, true); |
057a3fe5 HR |
2114 | if (ret < 0) { |
2115 | return ret; | |
2116 | } | |
2117 | ||
2118 | /* snapshots */ | |
e9f5b6de KW |
2119 | if (has_data_file(bs) && s->nb_snapshots) { |
2120 | fprintf(stderr, "ERROR %d snapshots in image with data file\n", | |
2121 | s->nb_snapshots); | |
2122 | res->corruptions++; | |
2123 | } | |
2124 | ||
057a3fe5 HR |
2125 | for (i = 0; i < s->nb_snapshots; i++) { |
2126 | sn = s->snapshots + i; | |
0c2ada81 AG |
2127 | if (offset_into_cluster(s, sn->l1_table_offset)) { |
2128 | fprintf(stderr, "ERROR snapshot %s (%s) l1_offset=%#" PRIx64 ": " | |
2129 | "L1 table is not cluster aligned; snapshot table entry " | |
2130 | "corrupted\n", sn->id_str, sn->name, sn->l1_table_offset); | |
2131 | res->corruptions++; | |
2132 | continue; | |
2133 | } | |
2134 | if (sn->l1_size > QCOW_MAX_L1_SIZE / sizeof(uint64_t)) { | |
2135 | fprintf(stderr, "ERROR snapshot %s (%s) l1_size=%#" PRIx32 ": " | |
2136 | "L1 table is too large; snapshot table entry corrupted\n", | |
2137 | sn->id_str, sn->name, sn->l1_size); | |
2138 | res->corruptions++; | |
2139 | continue; | |
2140 | } | |
641bb63c | 2141 | ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
1ef337b7 VSO |
2142 | sn->l1_table_offset, sn->l1_size, 0, fix, |
2143 | false); | |
057a3fe5 HR |
2144 | if (ret < 0) { |
2145 | return ret; | |
2146 | } | |
2147 | } | |
8a5bb1f1 VSO |
2148 | ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, nb_clusters, |
2149 | s->snapshots_offset, s->snapshots_size); | |
fef4d3d5 HR |
2150 | if (ret < 0) { |
2151 | return ret; | |
2152 | } | |
057a3fe5 HR |
2153 | |
2154 | /* refcount data */ | |
8a5bb1f1 VSO |
2155 | ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, nb_clusters, |
2156 | s->refcount_table_offset, | |
2157 | s->refcount_table_size * sizeof(uint64_t)); | |
fef4d3d5 HR |
2158 | if (ret < 0) { |
2159 | return ret; | |
2160 | } | |
057a3fe5 | 2161 | |
4652b8f3 DB |
2162 | /* encryption */ |
2163 | if (s->crypto_header.length) { | |
8a5bb1f1 VSO |
2164 | ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, nb_clusters, |
2165 | s->crypto_header.offset, | |
2166 | s->crypto_header.length); | |
4652b8f3 DB |
2167 | if (ret < 0) { |
2168 | return ret; | |
2169 | } | |
2170 | } | |
2171 | ||
88ddffae VSO |
2172 | /* bitmaps */ |
2173 | ret = qcow2_check_bitmaps_refcounts(bs, res, refcount_table, nb_clusters); | |
2174 | if (ret < 0) { | |
2175 | return ret; | |
2176 | } | |
2177 | ||
f307b255 | 2178 | return check_refblocks(bs, res, fix, rebuild, refcount_table, nb_clusters); |
057a3fe5 HR |
2179 | } |
2180 | ||
6ca56bf5 HR |
2181 | /* |
2182 | * Compares the actual reference count for each cluster in the image against the | |
2183 | * refcount as reported by the refcount structures on-disk. | |
2184 | */ | |
2185 | static void compare_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
f307b255 HR |
2186 | BdrvCheckMode fix, bool *rebuild, |
2187 | int64_t *highest_cluster, | |
7453c96b | 2188 | void *refcount_table, int64_t nb_clusters) |
6ca56bf5 | 2189 | { |
ff99129a | 2190 | BDRVQcow2State *s = bs->opaque; |
6ca56bf5 | 2191 | int64_t i; |
0e06528e | 2192 | uint64_t refcount1, refcount2; |
7324c10f | 2193 | int ret; |
6ca56bf5 HR |
2194 | |
2195 | for (i = 0, *highest_cluster = 0; i < nb_clusters; i++) { | |
7324c10f HR |
2196 | ret = qcow2_get_refcount(bs, i, &refcount1); |
2197 | if (ret < 0) { | |
166acf54 | 2198 | fprintf(stderr, "Can't get refcount for cluster %" PRId64 ": %s\n", |
7324c10f | 2199 | i, strerror(-ret)); |
9ac228e0 | 2200 | res->check_errors++; |
f74550fd | 2201 | continue; |
018faafd KW |
2202 | } |
2203 | ||
7453c96b | 2204 | refcount2 = s->get_refcount(refcount_table, i); |
c6bb9ad1 FS |
2205 | |
2206 | if (refcount1 > 0 || refcount2 > 0) { | |
6ca56bf5 | 2207 | *highest_cluster = i; |
c6bb9ad1 FS |
2208 | } |
2209 | ||
f7d0fe02 | 2210 | if (refcount1 != refcount2) { |
166acf54 KW |
2211 | /* Check if we're allowed to fix the mismatch */ |
2212 | int *num_fixed = NULL; | |
f307b255 HR |
2213 | if (refcount1 == 0) { |
2214 | *rebuild = true; | |
2215 | } else if (refcount1 > refcount2 && (fix & BDRV_FIX_LEAKS)) { | |
166acf54 KW |
2216 | num_fixed = &res->leaks_fixed; |
2217 | } else if (refcount1 < refcount2 && (fix & BDRV_FIX_ERRORS)) { | |
2218 | num_fixed = &res->corruptions_fixed; | |
2219 | } | |
2220 | ||
0e06528e HR |
2221 | fprintf(stderr, "%s cluster %" PRId64 " refcount=%" PRIu64 |
2222 | " reference=%" PRIu64 "\n", | |
166acf54 KW |
2223 | num_fixed != NULL ? "Repairing" : |
2224 | refcount1 < refcount2 ? "ERROR" : | |
2225 | "Leaked", | |
f7d0fe02 | 2226 | i, refcount1, refcount2); |
166acf54 KW |
2227 | |
2228 | if (num_fixed) { | |
2229 | ret = update_refcount(bs, i << s->cluster_bits, 1, | |
2aabe7c7 HR |
2230 | refcount_diff(refcount1, refcount2), |
2231 | refcount1 > refcount2, | |
6cfcb9b8 | 2232 | QCOW2_DISCARD_ALWAYS); |
166acf54 KW |
2233 | if (ret >= 0) { |
2234 | (*num_fixed)++; | |
2235 | continue; | |
2236 | } | |
2237 | } | |
2238 | ||
2239 | /* And if we couldn't, print an error */ | |
9ac228e0 KW |
2240 | if (refcount1 < refcount2) { |
2241 | res->corruptions++; | |
2242 | } else { | |
2243 | res->leaks++; | |
2244 | } | |
f7d0fe02 KW |
2245 | } |
2246 | } | |
6ca56bf5 HR |
2247 | } |
2248 | ||
c7c0681b HR |
2249 | /* |
2250 | * Allocates clusters using an in-memory refcount table (IMRT) in contrast to | |
2251 | * the on-disk refcount structures. | |
2252 | * | |
2253 | * On input, *first_free_cluster tells where to start looking, and need not | |
2254 | * actually be a free cluster; the returned offset will not be before that | |
2255 | * cluster. On output, *first_free_cluster points to the first gap found, even | |
2256 | * if that gap was too small to be used as the returned offset. | |
2257 | * | |
2258 | * Note that *first_free_cluster is a cluster index whereas the return value is | |
2259 | * an offset. | |
2260 | */ | |
2261 | static int64_t alloc_clusters_imrt(BlockDriverState *bs, | |
2262 | int cluster_count, | |
7453c96b | 2263 | void **refcount_table, |
c7c0681b HR |
2264 | int64_t *imrt_nb_clusters, |
2265 | int64_t *first_free_cluster) | |
2266 | { | |
ff99129a | 2267 | BDRVQcow2State *s = bs->opaque; |
c7c0681b HR |
2268 | int64_t cluster = *first_free_cluster, i; |
2269 | bool first_gap = true; | |
2270 | int contiguous_free_clusters; | |
5fee192e | 2271 | int ret; |
c7c0681b HR |
2272 | |
2273 | /* Starting at *first_free_cluster, find a range of at least cluster_count | |
2274 | * continuously free clusters */ | |
2275 | for (contiguous_free_clusters = 0; | |
2276 | cluster < *imrt_nb_clusters && | |
2277 | contiguous_free_clusters < cluster_count; | |
2278 | cluster++) | |
2279 | { | |
7453c96b | 2280 | if (!s->get_refcount(*refcount_table, cluster)) { |
c7c0681b HR |
2281 | contiguous_free_clusters++; |
2282 | if (first_gap) { | |
2283 | /* If this is the first free cluster found, update | |
2284 | * *first_free_cluster accordingly */ | |
2285 | *first_free_cluster = cluster; | |
2286 | first_gap = false; | |
2287 | } | |
2288 | } else if (contiguous_free_clusters) { | |
2289 | contiguous_free_clusters = 0; | |
2290 | } | |
2291 | } | |
2292 | ||
2293 | /* If contiguous_free_clusters is greater than zero, it contains the number | |
2294 | * of continuously free clusters until the current cluster; the first free | |
2295 | * cluster in the current "gap" is therefore | |
2296 | * cluster - contiguous_free_clusters */ | |
2297 | ||
2298 | /* If no such range could be found, grow the in-memory refcount table | |
2299 | * accordingly to append free clusters at the end of the image */ | |
2300 | if (contiguous_free_clusters < cluster_count) { | |
c7c0681b HR |
2301 | /* contiguous_free_clusters clusters are already empty at the image end; |
2302 | * we need cluster_count clusters; therefore, we have to allocate | |
2303 | * cluster_count - contiguous_free_clusters new clusters at the end of | |
2304 | * the image (which is the current value of cluster; note that cluster | |
2305 | * may exceed old_imrt_nb_clusters if *first_free_cluster pointed beyond | |
2306 | * the image end) */ | |
5fee192e HR |
2307 | ret = realloc_refcount_array(s, refcount_table, imrt_nb_clusters, |
2308 | cluster + cluster_count | |
2309 | - contiguous_free_clusters); | |
2310 | if (ret < 0) { | |
2311 | return ret; | |
c7c0681b | 2312 | } |
c7c0681b HR |
2313 | } |
2314 | ||
2315 | /* Go back to the first free cluster */ | |
2316 | cluster -= contiguous_free_clusters; | |
2317 | for (i = 0; i < cluster_count; i++) { | |
7453c96b | 2318 | s->set_refcount(*refcount_table, cluster + i, 1); |
c7c0681b HR |
2319 | } |
2320 | ||
2321 | return cluster << s->cluster_bits; | |
2322 | } | |
2323 | ||
2324 | /* | |
2325 | * Creates a new refcount structure based solely on the in-memory information | |
2326 | * given through *refcount_table. All necessary allocations will be reflected | |
2327 | * in that array. | |
2328 | * | |
2329 | * On success, the old refcount structure is leaked (it will be covered by the | |
2330 | * new refcount structure). | |
2331 | */ | |
2332 | static int rebuild_refcount_structure(BlockDriverState *bs, | |
2333 | BdrvCheckResult *res, | |
7453c96b | 2334 | void **refcount_table, |
c7c0681b HR |
2335 | int64_t *nb_clusters) |
2336 | { | |
ff99129a | 2337 | BDRVQcow2State *s = bs->opaque; |
c7c0681b HR |
2338 | int64_t first_free_cluster = 0, reftable_offset = -1, cluster = 0; |
2339 | int64_t refblock_offset, refblock_start, refblock_index; | |
2340 | uint32_t reftable_size = 0; | |
2341 | uint64_t *on_disk_reftable = NULL; | |
7453c96b HR |
2342 | void *on_disk_refblock; |
2343 | int ret = 0; | |
c7c0681b HR |
2344 | struct { |
2345 | uint64_t reftable_offset; | |
2346 | uint32_t reftable_clusters; | |
2347 | } QEMU_PACKED reftable_offset_and_clusters; | |
2348 | ||
2349 | qcow2_cache_empty(bs, s->refcount_block_cache); | |
2350 | ||
2351 | write_refblocks: | |
2352 | for (; cluster < *nb_clusters; cluster++) { | |
7453c96b | 2353 | if (!s->get_refcount(*refcount_table, cluster)) { |
c7c0681b HR |
2354 | continue; |
2355 | } | |
2356 | ||
2357 | refblock_index = cluster >> s->refcount_block_bits; | |
2358 | refblock_start = refblock_index << s->refcount_block_bits; | |
2359 | ||
2360 | /* Don't allocate a cluster in a refblock already written to disk */ | |
2361 | if (first_free_cluster < refblock_start) { | |
2362 | first_free_cluster = refblock_start; | |
2363 | } | |
2364 | refblock_offset = alloc_clusters_imrt(bs, 1, refcount_table, | |
2365 | nb_clusters, &first_free_cluster); | |
2366 | if (refblock_offset < 0) { | |
2367 | fprintf(stderr, "ERROR allocating refblock: %s\n", | |
2368 | strerror(-refblock_offset)); | |
2369 | res->check_errors++; | |
2370 | ret = refblock_offset; | |
2371 | goto fail; | |
2372 | } | |
2373 | ||
2374 | if (reftable_size <= refblock_index) { | |
2375 | uint32_t old_reftable_size = reftable_size; | |
2376 | uint64_t *new_on_disk_reftable; | |
2377 | ||
2378 | reftable_size = ROUND_UP((refblock_index + 1) * sizeof(uint64_t), | |
2379 | s->cluster_size) / sizeof(uint64_t); | |
2380 | new_on_disk_reftable = g_try_realloc(on_disk_reftable, | |
2381 | reftable_size * | |
2382 | sizeof(uint64_t)); | |
2383 | if (!new_on_disk_reftable) { | |
2384 | res->check_errors++; | |
2385 | ret = -ENOMEM; | |
2386 | goto fail; | |
2387 | } | |
2388 | on_disk_reftable = new_on_disk_reftable; | |
2389 | ||
2390 | memset(on_disk_reftable + old_reftable_size, 0, | |
2391 | (reftable_size - old_reftable_size) * sizeof(uint64_t)); | |
2392 | ||
2393 | /* The offset we have for the reftable is now no longer valid; | |
2394 | * this will leak that range, but we can easily fix that by running | |
2395 | * a leak-fixing check after this rebuild operation */ | |
2396 | reftable_offset = -1; | |
f80ac75d PMD |
2397 | } else { |
2398 | assert(on_disk_reftable); | |
c7c0681b HR |
2399 | } |
2400 | on_disk_reftable[refblock_index] = refblock_offset; | |
2401 | ||
2402 | /* If this is apparently the last refblock (for now), try to squeeze the | |
2403 | * reftable in */ | |
2404 | if (refblock_index == (*nb_clusters - 1) >> s->refcount_block_bits && | |
2405 | reftable_offset < 0) | |
2406 | { | |
2407 | uint64_t reftable_clusters = size_to_clusters(s, reftable_size * | |
2408 | sizeof(uint64_t)); | |
2409 | reftable_offset = alloc_clusters_imrt(bs, reftable_clusters, | |
2410 | refcount_table, nb_clusters, | |
2411 | &first_free_cluster); | |
2412 | if (reftable_offset < 0) { | |
2413 | fprintf(stderr, "ERROR allocating reftable: %s\n", | |
2414 | strerror(-reftable_offset)); | |
2415 | res->check_errors++; | |
2416 | ret = reftable_offset; | |
2417 | goto fail; | |
2418 | } | |
2419 | } | |
2420 | ||
2421 | ret = qcow2_pre_write_overlap_check(bs, 0, refblock_offset, | |
966b000f | 2422 | s->cluster_size, false); |
c7c0681b HR |
2423 | if (ret < 0) { |
2424 | fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret)); | |
2425 | goto fail; | |
2426 | } | |
2427 | ||
7453c96b HR |
2428 | /* The size of *refcount_table is always cluster-aligned, therefore the |
2429 | * write operation will not overflow */ | |
2430 | on_disk_refblock = (void *)((char *) *refcount_table + | |
2431 | refblock_index * s->cluster_size); | |
c7c0681b | 2432 | |
18d51c4b | 2433 | ret = bdrv_write(bs->file, refblock_offset / BDRV_SECTOR_SIZE, |
7453c96b | 2434 | on_disk_refblock, s->cluster_sectors); |
c7c0681b HR |
2435 | if (ret < 0) { |
2436 | fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret)); | |
2437 | goto fail; | |
2438 | } | |
2439 | ||
2440 | /* Go to the end of this refblock */ | |
2441 | cluster = refblock_start + s->refcount_block_size - 1; | |
2442 | } | |
2443 | ||
2444 | if (reftable_offset < 0) { | |
2445 | uint64_t post_refblock_start, reftable_clusters; | |
2446 | ||
2447 | post_refblock_start = ROUND_UP(*nb_clusters, s->refcount_block_size); | |
2448 | reftable_clusters = size_to_clusters(s, | |
2449 | reftable_size * sizeof(uint64_t)); | |
2450 | /* Not pretty but simple */ | |
2451 | if (first_free_cluster < post_refblock_start) { | |
2452 | first_free_cluster = post_refblock_start; | |
2453 | } | |
2454 | reftable_offset = alloc_clusters_imrt(bs, reftable_clusters, | |
2455 | refcount_table, nb_clusters, | |
2456 | &first_free_cluster); | |
2457 | if (reftable_offset < 0) { | |
2458 | fprintf(stderr, "ERROR allocating reftable: %s\n", | |
2459 | strerror(-reftable_offset)); | |
2460 | res->check_errors++; | |
2461 | ret = reftable_offset; | |
2462 | goto fail; | |
2463 | } | |
2464 | ||
2465 | goto write_refblocks; | |
2466 | } | |
2467 | ||
c7c0681b HR |
2468 | for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) { |
2469 | cpu_to_be64s(&on_disk_reftable[refblock_index]); | |
2470 | } | |
2471 | ||
2472 | ret = qcow2_pre_write_overlap_check(bs, 0, reftable_offset, | |
966b000f KW |
2473 | reftable_size * sizeof(uint64_t), |
2474 | false); | |
c7c0681b HR |
2475 | if (ret < 0) { |
2476 | fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret)); | |
2477 | goto fail; | |
2478 | } | |
2479 | ||
2480 | assert(reftable_size < INT_MAX / sizeof(uint64_t)); | |
d9ca2ea2 | 2481 | ret = bdrv_pwrite(bs->file, reftable_offset, on_disk_reftable, |
c7c0681b HR |
2482 | reftable_size * sizeof(uint64_t)); |
2483 | if (ret < 0) { | |
2484 | fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret)); | |
2485 | goto fail; | |
2486 | } | |
2487 | ||
2488 | /* Enter new reftable into the image header */ | |
f1f7a1dd PM |
2489 | reftable_offset_and_clusters.reftable_offset = cpu_to_be64(reftable_offset); |
2490 | reftable_offset_and_clusters.reftable_clusters = | |
2491 | cpu_to_be32(size_to_clusters(s, reftable_size * sizeof(uint64_t))); | |
d9ca2ea2 KW |
2492 | ret = bdrv_pwrite_sync(bs->file, |
2493 | offsetof(QCowHeader, refcount_table_offset), | |
c7c0681b HR |
2494 | &reftable_offset_and_clusters, |
2495 | sizeof(reftable_offset_and_clusters)); | |
2496 | if (ret < 0) { | |
2497 | fprintf(stderr, "ERROR setting reftable: %s\n", strerror(-ret)); | |
2498 | goto fail; | |
2499 | } | |
2500 | ||
2501 | for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) { | |
2502 | be64_to_cpus(&on_disk_reftable[refblock_index]); | |
2503 | } | |
2504 | s->refcount_table = on_disk_reftable; | |
2505 | s->refcount_table_offset = reftable_offset; | |
2506 | s->refcount_table_size = reftable_size; | |
7061a078 | 2507 | update_max_refcount_table_index(s); |
c7c0681b HR |
2508 | |
2509 | return 0; | |
2510 | ||
2511 | fail: | |
2512 | g_free(on_disk_reftable); | |
2513 | return ret; | |
2514 | } | |
2515 | ||
6ca56bf5 HR |
2516 | /* |
2517 | * Checks an image for refcount consistency. | |
2518 | * | |
2519 | * Returns 0 if no errors are found, the number of errors in case the image is | |
2520 | * detected as corrupted, and -errno when an internal error occurred. | |
2521 | */ | |
2522 | int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, | |
2523 | BdrvCheckMode fix) | |
2524 | { | |
ff99129a | 2525 | BDRVQcow2State *s = bs->opaque; |
c7c0681b | 2526 | BdrvCheckResult pre_compare_res; |
6ca56bf5 | 2527 | int64_t size, highest_cluster, nb_clusters; |
7453c96b | 2528 | void *refcount_table = NULL; |
f307b255 | 2529 | bool rebuild = false; |
6ca56bf5 HR |
2530 | int ret; |
2531 | ||
9a4f4c31 | 2532 | size = bdrv_getlength(bs->file->bs); |
6ca56bf5 HR |
2533 | if (size < 0) { |
2534 | res->check_errors++; | |
2535 | return size; | |
2536 | } | |
2537 | ||
2538 | nb_clusters = size_to_clusters(s, size); | |
2539 | if (nb_clusters > INT_MAX) { | |
2540 | res->check_errors++; | |
2541 | return -EFBIG; | |
2542 | } | |
2543 | ||
2544 | res->bfi.total_clusters = | |
2545 | size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE); | |
2546 | ||
f307b255 HR |
2547 | ret = calculate_refcounts(bs, res, fix, &rebuild, &refcount_table, |
2548 | &nb_clusters); | |
6ca56bf5 HR |
2549 | if (ret < 0) { |
2550 | goto fail; | |
2551 | } | |
2552 | ||
c7c0681b HR |
2553 | /* In case we don't need to rebuild the refcount structure (but want to fix |
2554 | * something), this function is immediately called again, in which case the | |
2555 | * result should be ignored */ | |
2556 | pre_compare_res = *res; | |
2557 | compare_refcounts(bs, res, 0, &rebuild, &highest_cluster, refcount_table, | |
6ca56bf5 | 2558 | nb_clusters); |
f7d0fe02 | 2559 | |
c7c0681b | 2560 | if (rebuild && (fix & BDRV_FIX_ERRORS)) { |
791230d8 HR |
2561 | BdrvCheckResult old_res = *res; |
2562 | int fresh_leaks = 0; | |
2563 | ||
c7c0681b HR |
2564 | fprintf(stderr, "Rebuilding refcount structure\n"); |
2565 | ret = rebuild_refcount_structure(bs, res, &refcount_table, | |
2566 | &nb_clusters); | |
2567 | if (ret < 0) { | |
2568 | goto fail; | |
2569 | } | |
791230d8 HR |
2570 | |
2571 | res->corruptions = 0; | |
2572 | res->leaks = 0; | |
2573 | ||
2574 | /* Because the old reftable has been exchanged for a new one the | |
2575 | * references have to be recalculated */ | |
2576 | rebuild = false; | |
7453c96b | 2577 | memset(refcount_table, 0, refcount_array_byte_size(s, nb_clusters)); |
791230d8 HR |
2578 | ret = calculate_refcounts(bs, res, 0, &rebuild, &refcount_table, |
2579 | &nb_clusters); | |
2580 | if (ret < 0) { | |
2581 | goto fail; | |
2582 | } | |
2583 | ||
2584 | if (fix & BDRV_FIX_LEAKS) { | |
2585 | /* The old refcount structures are now leaked, fix it; the result | |
2586 | * can be ignored, aside from leaks which were introduced by | |
2587 | * rebuild_refcount_structure() that could not be fixed */ | |
2588 | BdrvCheckResult saved_res = *res; | |
2589 | *res = (BdrvCheckResult){ 0 }; | |
2590 | ||
2591 | compare_refcounts(bs, res, BDRV_FIX_LEAKS, &rebuild, | |
2592 | &highest_cluster, refcount_table, nb_clusters); | |
2593 | if (rebuild) { | |
2594 | fprintf(stderr, "ERROR rebuilt refcount structure is still " | |
2595 | "broken\n"); | |
2596 | } | |
2597 | ||
2598 | /* Any leaks accounted for here were introduced by | |
2599 | * rebuild_refcount_structure() because that function has created a | |
2600 | * new refcount structure from scratch */ | |
2601 | fresh_leaks = res->leaks; | |
2602 | *res = saved_res; | |
2603 | } | |
2604 | ||
2605 | if (res->corruptions < old_res.corruptions) { | |
2606 | res->corruptions_fixed += old_res.corruptions - res->corruptions; | |
2607 | } | |
2608 | if (res->leaks < old_res.leaks) { | |
2609 | res->leaks_fixed += old_res.leaks - res->leaks; | |
2610 | } | |
2611 | res->leaks += fresh_leaks; | |
c7c0681b HR |
2612 | } else if (fix) { |
2613 | if (rebuild) { | |
2614 | fprintf(stderr, "ERROR need to rebuild refcount structures\n"); | |
2615 | res->check_errors++; | |
2616 | ret = -EIO; | |
2617 | goto fail; | |
2618 | } | |
2619 | ||
2620 | if (res->leaks || res->corruptions) { | |
2621 | *res = pre_compare_res; | |
2622 | compare_refcounts(bs, res, fix, &rebuild, &highest_cluster, | |
2623 | refcount_table, nb_clusters); | |
2624 | } | |
f307b255 HR |
2625 | } |
2626 | ||
4f6ed88c | 2627 | /* check OFLAG_COPIED */ |
e23e400e | 2628 | ret = check_oflag_copied(bs, res, fix); |
4f6ed88c HR |
2629 | if (ret < 0) { |
2630 | goto fail; | |
2631 | } | |
2632 | ||
c6bb9ad1 | 2633 | res->image_end_offset = (highest_cluster + 1) * s->cluster_size; |
80fa3341 KW |
2634 | ret = 0; |
2635 | ||
2636 | fail: | |
7267c094 | 2637 | g_free(refcount_table); |
f7d0fe02 | 2638 | |
80fa3341 | 2639 | return ret; |
f7d0fe02 KW |
2640 | } |
2641 | ||
a40f1c2a HR |
2642 | #define overlaps_with(ofs, sz) \ |
2643 | ranges_overlap(offset, size, ofs, sz) | |
2644 | ||
2645 | /* | |
2646 | * Checks if the given offset into the image file is actually free to use by | |
2647 | * looking for overlaps with important metadata sections (L1/L2 tables etc.), | |
2648 | * i.e. a sanity check without relying on the refcount tables. | |
2649 | * | |
231bb267 HR |
2650 | * The ign parameter specifies what checks not to perform (being a bitmask of |
2651 | * QCow2MetadataOverlap values), i.e., what sections to ignore. | |
a40f1c2a HR |
2652 | * |
2653 | * Returns: | |
2654 | * - 0 if writing to this offset will not affect the mentioned metadata | |
2655 | * - a positive QCow2MetadataOverlap value indicating one overlapping section | |
2656 | * - a negative value (-errno) indicating an error while performing a check, | |
2657 | * e.g. when bdrv_read failed on QCOW2_OL_INACTIVE_L2 | |
2658 | */ | |
231bb267 | 2659 | int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset, |
a40f1c2a HR |
2660 | int64_t size) |
2661 | { | |
ff99129a | 2662 | BDRVQcow2State *s = bs->opaque; |
3e355390 | 2663 | int chk = s->overlap_check & ~ign; |
a40f1c2a HR |
2664 | int i, j; |
2665 | ||
2666 | if (!size) { | |
2667 | return 0; | |
2668 | } | |
2669 | ||
2670 | if (chk & QCOW2_OL_MAIN_HEADER) { | |
2671 | if (offset < s->cluster_size) { | |
2672 | return QCOW2_OL_MAIN_HEADER; | |
2673 | } | |
2674 | } | |
2675 | ||
2676 | /* align range to test to cluster boundaries */ | |
9e029689 | 2677 | size = ROUND_UP(offset_into_cluster(s, offset) + size, s->cluster_size); |
a40f1c2a HR |
2678 | offset = start_of_cluster(s, offset); |
2679 | ||
2680 | if ((chk & QCOW2_OL_ACTIVE_L1) && s->l1_size) { | |
2681 | if (overlaps_with(s->l1_table_offset, s->l1_size * sizeof(uint64_t))) { | |
2682 | return QCOW2_OL_ACTIVE_L1; | |
2683 | } | |
2684 | } | |
2685 | ||
2686 | if ((chk & QCOW2_OL_REFCOUNT_TABLE) && s->refcount_table_size) { | |
2687 | if (overlaps_with(s->refcount_table_offset, | |
2688 | s->refcount_table_size * sizeof(uint64_t))) { | |
2689 | return QCOW2_OL_REFCOUNT_TABLE; | |
2690 | } | |
2691 | } | |
2692 | ||
2693 | if ((chk & QCOW2_OL_SNAPSHOT_TABLE) && s->snapshots_size) { | |
2694 | if (overlaps_with(s->snapshots_offset, s->snapshots_size)) { | |
2695 | return QCOW2_OL_SNAPSHOT_TABLE; | |
2696 | } | |
2697 | } | |
2698 | ||
2699 | if ((chk & QCOW2_OL_INACTIVE_L1) && s->snapshots) { | |
2700 | for (i = 0; i < s->nb_snapshots; i++) { | |
2701 | if (s->snapshots[i].l1_size && | |
2702 | overlaps_with(s->snapshots[i].l1_table_offset, | |
2703 | s->snapshots[i].l1_size * sizeof(uint64_t))) { | |
2704 | return QCOW2_OL_INACTIVE_L1; | |
2705 | } | |
2706 | } | |
2707 | } | |
2708 | ||
2709 | if ((chk & QCOW2_OL_ACTIVE_L2) && s->l1_table) { | |
2710 | for (i = 0; i < s->l1_size; i++) { | |
2711 | if ((s->l1_table[i] & L1E_OFFSET_MASK) && | |
2712 | overlaps_with(s->l1_table[i] & L1E_OFFSET_MASK, | |
2713 | s->cluster_size)) { | |
2714 | return QCOW2_OL_ACTIVE_L2; | |
2715 | } | |
2716 | } | |
2717 | } | |
2718 | ||
2719 | if ((chk & QCOW2_OL_REFCOUNT_BLOCK) && s->refcount_table) { | |
7061a078 AG |
2720 | unsigned last_entry = s->max_refcount_table_index; |
2721 | assert(last_entry < s->refcount_table_size); | |
2722 | assert(last_entry + 1 == s->refcount_table_size || | |
2723 | (s->refcount_table[last_entry + 1] & REFT_OFFSET_MASK) == 0); | |
2724 | for (i = 0; i <= last_entry; i++) { | |
a40f1c2a HR |
2725 | if ((s->refcount_table[i] & REFT_OFFSET_MASK) && |
2726 | overlaps_with(s->refcount_table[i] & REFT_OFFSET_MASK, | |
2727 | s->cluster_size)) { | |
2728 | return QCOW2_OL_REFCOUNT_BLOCK; | |
2729 | } | |
2730 | } | |
2731 | } | |
2732 | ||
2733 | if ((chk & QCOW2_OL_INACTIVE_L2) && s->snapshots) { | |
2734 | for (i = 0; i < s->nb_snapshots; i++) { | |
2735 | uint64_t l1_ofs = s->snapshots[i].l1_table_offset; | |
2736 | uint32_t l1_sz = s->snapshots[i].l1_size; | |
998b959c | 2737 | uint64_t l1_sz2 = l1_sz * sizeof(uint64_t); |
c7a9d81d | 2738 | uint64_t *l1; |
a40f1c2a HR |
2739 | int ret; |
2740 | ||
c7a9d81d AG |
2741 | ret = qcow2_validate_table(bs, l1_ofs, l1_sz, sizeof(uint64_t), |
2742 | QCOW_MAX_L1_SIZE, "", NULL); | |
2743 | if (ret < 0) { | |
2744 | return ret; | |
2745 | } | |
2746 | ||
2747 | l1 = g_try_malloc(l1_sz2); | |
2748 | ||
de82815d KW |
2749 | if (l1_sz2 && l1 == NULL) { |
2750 | return -ENOMEM; | |
2751 | } | |
2752 | ||
cf2ab8fc | 2753 | ret = bdrv_pread(bs->file, l1_ofs, l1, l1_sz2); |
a40f1c2a HR |
2754 | if (ret < 0) { |
2755 | g_free(l1); | |
2756 | return ret; | |
2757 | } | |
2758 | ||
2759 | for (j = 0; j < l1_sz; j++) { | |
1e242b55 HR |
2760 | uint64_t l2_ofs = be64_to_cpu(l1[j]) & L1E_OFFSET_MASK; |
2761 | if (l2_ofs && overlaps_with(l2_ofs, s->cluster_size)) { | |
a40f1c2a HR |
2762 | g_free(l1); |
2763 | return QCOW2_OL_INACTIVE_L2; | |
2764 | } | |
2765 | } | |
2766 | ||
2767 | g_free(l1); | |
2768 | } | |
2769 | } | |
2770 | ||
0e4e4318 VSO |
2771 | if ((chk & QCOW2_OL_BITMAP_DIRECTORY) && |
2772 | (s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) | |
2773 | { | |
2774 | if (overlaps_with(s->bitmap_directory_offset, | |
2775 | s->bitmap_directory_size)) | |
2776 | { | |
2777 | return QCOW2_OL_BITMAP_DIRECTORY; | |
2778 | } | |
2779 | } | |
2780 | ||
a40f1c2a HR |
2781 | return 0; |
2782 | } | |
2783 | ||
2784 | static const char *metadata_ol_names[] = { | |
7cb6d3c9 LM |
2785 | [QCOW2_OL_MAIN_HEADER_BITNR] = "qcow2_header", |
2786 | [QCOW2_OL_ACTIVE_L1_BITNR] = "active L1 table", | |
2787 | [QCOW2_OL_ACTIVE_L2_BITNR] = "active L2 table", | |
2788 | [QCOW2_OL_REFCOUNT_TABLE_BITNR] = "refcount table", | |
2789 | [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = "refcount block", | |
2790 | [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = "snapshot table", | |
2791 | [QCOW2_OL_INACTIVE_L1_BITNR] = "inactive L1 table", | |
2792 | [QCOW2_OL_INACTIVE_L2_BITNR] = "inactive L2 table", | |
2793 | [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = "bitmap directory", | |
a40f1c2a | 2794 | }; |
7cb6d3c9 | 2795 | QEMU_BUILD_BUG_ON(QCOW2_OL_MAX_BITNR != ARRAY_SIZE(metadata_ol_names)); |
a40f1c2a HR |
2796 | |
2797 | /* | |
2798 | * First performs a check for metadata overlaps (through | |
2799 | * qcow2_check_metadata_overlap); if that fails with a negative value (error | |
2800 | * while performing a check), that value is returned. If an impending overlap | |
2801 | * is detected, the BDS will be made unusable, the qcow2 file marked corrupt | |
2802 | * and -EIO returned. | |
2803 | * | |
2804 | * Returns 0 if there were neither overlaps nor errors while checking for | |
2805 | * overlaps; or a negative value (-errno) on error. | |
2806 | */ | |
231bb267 | 2807 | int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset, |
966b000f | 2808 | int64_t size, bool data_file) |
a40f1c2a | 2809 | { |
966b000f KW |
2810 | int ret; |
2811 | ||
2812 | if (data_file && has_data_file(bs)) { | |
2813 | return 0; | |
2814 | } | |
a40f1c2a | 2815 | |
966b000f | 2816 | ret = qcow2_check_metadata_overlap(bs, ign, offset, size); |
a40f1c2a HR |
2817 | if (ret < 0) { |
2818 | return ret; | |
2819 | } else if (ret > 0) { | |
786a4ea8 | 2820 | int metadata_ol_bitnr = ctz32(ret); |
a40f1c2a HR |
2821 | assert(metadata_ol_bitnr < QCOW2_OL_MAX_BITNR); |
2822 | ||
adb43552 HR |
2823 | qcow2_signal_corruption(bs, true, offset, size, "Preventing invalid " |
2824 | "write on metadata (overlaps with %s)", | |
2825 | metadata_ol_names[metadata_ol_bitnr]); | |
a40f1c2a HR |
2826 | return -EIO; |
2827 | } | |
2828 | ||
2829 | return 0; | |
2830 | } | |
791c9a00 HR |
2831 | |
2832 | /* A pointer to a function of this type is given to walk_over_reftable(). That | |
2833 | * function will create refblocks and pass them to a RefblockFinishOp once they | |
2834 | * are completed (@refblock). @refblock_empty is set if the refblock is | |
2835 | * completely empty. | |
2836 | * | |
2837 | * Along with the refblock, a corresponding reftable entry is passed, in the | |
2838 | * reftable @reftable (which may be reallocated) at @reftable_index. | |
2839 | * | |
2840 | * @allocated should be set to true if a new cluster has been allocated. | |
2841 | */ | |
2842 | typedef int (RefblockFinishOp)(BlockDriverState *bs, uint64_t **reftable, | |
2843 | uint64_t reftable_index, uint64_t *reftable_size, | |
2844 | void *refblock, bool refblock_empty, | |
2845 | bool *allocated, Error **errp); | |
2846 | ||
2847 | /** | |
2848 | * This "operation" for walk_over_reftable() allocates the refblock on disk (if | |
2849 | * it is not empty) and inserts its offset into the new reftable. The size of | |
2850 | * this new reftable is increased as required. | |
2851 | */ | |
2852 | static int alloc_refblock(BlockDriverState *bs, uint64_t **reftable, | |
2853 | uint64_t reftable_index, uint64_t *reftable_size, | |
2854 | void *refblock, bool refblock_empty, bool *allocated, | |
2855 | Error **errp) | |
2856 | { | |
2857 | BDRVQcow2State *s = bs->opaque; | |
2858 | int64_t offset; | |
2859 | ||
2860 | if (!refblock_empty && reftable_index >= *reftable_size) { | |
2861 | uint64_t *new_reftable; | |
2862 | uint64_t new_reftable_size; | |
2863 | ||
2864 | new_reftable_size = ROUND_UP(reftable_index + 1, | |
2865 | s->cluster_size / sizeof(uint64_t)); | |
2866 | if (new_reftable_size > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) { | |
2867 | error_setg(errp, | |
2868 | "This operation would make the refcount table grow " | |
2869 | "beyond the maximum size supported by QEMU, aborting"); | |
2870 | return -ENOTSUP; | |
2871 | } | |
2872 | ||
2873 | new_reftable = g_try_realloc(*reftable, new_reftable_size * | |
2874 | sizeof(uint64_t)); | |
2875 | if (!new_reftable) { | |
2876 | error_setg(errp, "Failed to increase reftable buffer size"); | |
2877 | return -ENOMEM; | |
2878 | } | |
2879 | ||
2880 | memset(new_reftable + *reftable_size, 0, | |
2881 | (new_reftable_size - *reftable_size) * sizeof(uint64_t)); | |
2882 | ||
2883 | *reftable = new_reftable; | |
2884 | *reftable_size = new_reftable_size; | |
2885 | } | |
2886 | ||
2887 | if (!refblock_empty && !(*reftable)[reftable_index]) { | |
2888 | offset = qcow2_alloc_clusters(bs, s->cluster_size); | |
2889 | if (offset < 0) { | |
2890 | error_setg_errno(errp, -offset, "Failed to allocate refblock"); | |
2891 | return offset; | |
2892 | } | |
2893 | (*reftable)[reftable_index] = offset; | |
2894 | *allocated = true; | |
2895 | } | |
2896 | ||
2897 | return 0; | |
2898 | } | |
2899 | ||
2900 | /** | |
2901 | * This "operation" for walk_over_reftable() writes the refblock to disk at the | |
2902 | * offset specified by the new reftable's entry. It does not modify the new | |
2903 | * reftable or change any refcounts. | |
2904 | */ | |
2905 | static int flush_refblock(BlockDriverState *bs, uint64_t **reftable, | |
2906 | uint64_t reftable_index, uint64_t *reftable_size, | |
2907 | void *refblock, bool refblock_empty, bool *allocated, | |
2908 | Error **errp) | |
2909 | { | |
2910 | BDRVQcow2State *s = bs->opaque; | |
2911 | int64_t offset; | |
2912 | int ret; | |
2913 | ||
2914 | if (reftable_index < *reftable_size && (*reftable)[reftable_index]) { | |
2915 | offset = (*reftable)[reftable_index]; | |
2916 | ||
966b000f KW |
2917 | ret = qcow2_pre_write_overlap_check(bs, 0, offset, s->cluster_size, |
2918 | false); | |
791c9a00 HR |
2919 | if (ret < 0) { |
2920 | error_setg_errno(errp, -ret, "Overlap check failed"); | |
2921 | return ret; | |
2922 | } | |
2923 | ||
d9ca2ea2 | 2924 | ret = bdrv_pwrite(bs->file, offset, refblock, s->cluster_size); |
791c9a00 HR |
2925 | if (ret < 0) { |
2926 | error_setg_errno(errp, -ret, "Failed to write refblock"); | |
2927 | return ret; | |
2928 | } | |
2929 | } else { | |
2930 | assert(refblock_empty); | |
2931 | } | |
2932 | ||
2933 | return 0; | |
2934 | } | |
2935 | ||
2936 | /** | |
2937 | * This function walks over the existing reftable and every referenced refblock; | |
2938 | * if @new_set_refcount is non-NULL, it is called for every refcount entry to | |
2939 | * create an equal new entry in the passed @new_refblock. Once that | |
2940 | * @new_refblock is completely filled, @operation will be called. | |
2941 | * | |
2942 | * @status_cb and @cb_opaque are used for the amend operation's status callback. | |
2943 | * @index is the index of the walk_over_reftable() calls and @total is the total | |
2944 | * number of walk_over_reftable() calls per amend operation. Both are used for | |
2945 | * calculating the parameters for the status callback. | |
2946 | * | |
2947 | * @allocated is set to true if a new cluster has been allocated. | |
2948 | */ | |
2949 | static int walk_over_reftable(BlockDriverState *bs, uint64_t **new_reftable, | |
2950 | uint64_t *new_reftable_index, | |
2951 | uint64_t *new_reftable_size, | |
2952 | void *new_refblock, int new_refblock_size, | |
2953 | int new_refcount_bits, | |
2954 | RefblockFinishOp *operation, bool *allocated, | |
2955 | Qcow2SetRefcountFunc *new_set_refcount, | |
2956 | BlockDriverAmendStatusCB *status_cb, | |
2957 | void *cb_opaque, int index, int total, | |
2958 | Error **errp) | |
2959 | { | |
2960 | BDRVQcow2State *s = bs->opaque; | |
2961 | uint64_t reftable_index; | |
2962 | bool new_refblock_empty = true; | |
2963 | int refblock_index; | |
2964 | int new_refblock_index = 0; | |
2965 | int ret; | |
2966 | ||
2967 | for (reftable_index = 0; reftable_index < s->refcount_table_size; | |
2968 | reftable_index++) | |
2969 | { | |
2970 | uint64_t refblock_offset = s->refcount_table[reftable_index] | |
2971 | & REFT_OFFSET_MASK; | |
2972 | ||
2973 | status_cb(bs, (uint64_t)index * s->refcount_table_size + reftable_index, | |
2974 | (uint64_t)total * s->refcount_table_size, cb_opaque); | |
2975 | ||
2976 | if (refblock_offset) { | |
2977 | void *refblock; | |
2978 | ||
2979 | if (offset_into_cluster(s, refblock_offset)) { | |
2980 | qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#" | |
2981 | PRIx64 " unaligned (reftable index: %#" | |
2982 | PRIx64 ")", refblock_offset, | |
2983 | reftable_index); | |
2984 | error_setg(errp, | |
2985 | "Image is corrupt (unaligned refblock offset)"); | |
2986 | return -EIO; | |
2987 | } | |
2988 | ||
2989 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refblock_offset, | |
2990 | &refblock); | |
2991 | if (ret < 0) { | |
2992 | error_setg_errno(errp, -ret, "Failed to retrieve refblock"); | |
2993 | return ret; | |
2994 | } | |
2995 | ||
2996 | for (refblock_index = 0; refblock_index < s->refcount_block_size; | |
2997 | refblock_index++) | |
2998 | { | |
2999 | uint64_t refcount; | |
3000 | ||
3001 | if (new_refblock_index >= new_refblock_size) { | |
3002 | /* new_refblock is now complete */ | |
3003 | ret = operation(bs, new_reftable, *new_reftable_index, | |
3004 | new_reftable_size, new_refblock, | |
3005 | new_refblock_empty, allocated, errp); | |
3006 | if (ret < 0) { | |
2013c3d4 | 3007 | qcow2_cache_put(s->refcount_block_cache, &refblock); |
791c9a00 HR |
3008 | return ret; |
3009 | } | |
3010 | ||
3011 | (*new_reftable_index)++; | |
3012 | new_refblock_index = 0; | |
3013 | new_refblock_empty = true; | |
3014 | } | |
3015 | ||
3016 | refcount = s->get_refcount(refblock, refblock_index); | |
3017 | if (new_refcount_bits < 64 && refcount >> new_refcount_bits) { | |
3018 | uint64_t offset; | |
3019 | ||
2013c3d4 | 3020 | qcow2_cache_put(s->refcount_block_cache, &refblock); |
791c9a00 HR |
3021 | |
3022 | offset = ((reftable_index << s->refcount_block_bits) | |
3023 | + refblock_index) << s->cluster_bits; | |
3024 | ||
3025 | error_setg(errp, "Cannot decrease refcount entry width to " | |
3026 | "%i bits: Cluster at offset %#" PRIx64 " has a " | |
3027 | "refcount of %" PRIu64, new_refcount_bits, | |
3028 | offset, refcount); | |
3029 | return -EINVAL; | |
3030 | } | |
3031 | ||
3032 | if (new_set_refcount) { | |
3033 | new_set_refcount(new_refblock, new_refblock_index++, | |
3034 | refcount); | |
3035 | } else { | |
3036 | new_refblock_index++; | |
3037 | } | |
3038 | new_refblock_empty = new_refblock_empty && refcount == 0; | |
3039 | } | |
3040 | ||
2013c3d4 | 3041 | qcow2_cache_put(s->refcount_block_cache, &refblock); |
791c9a00 HR |
3042 | } else { |
3043 | /* No refblock means every refcount is 0 */ | |
3044 | for (refblock_index = 0; refblock_index < s->refcount_block_size; | |
3045 | refblock_index++) | |
3046 | { | |
3047 | if (new_refblock_index >= new_refblock_size) { | |
3048 | /* new_refblock is now complete */ | |
3049 | ret = operation(bs, new_reftable, *new_reftable_index, | |
3050 | new_reftable_size, new_refblock, | |
3051 | new_refblock_empty, allocated, errp); | |
3052 | if (ret < 0) { | |
3053 | return ret; | |
3054 | } | |
3055 | ||
3056 | (*new_reftable_index)++; | |
3057 | new_refblock_index = 0; | |
3058 | new_refblock_empty = true; | |
3059 | } | |
3060 | ||
3061 | if (new_set_refcount) { | |
3062 | new_set_refcount(new_refblock, new_refblock_index++, 0); | |
3063 | } else { | |
3064 | new_refblock_index++; | |
3065 | } | |
3066 | } | |
3067 | } | |
3068 | } | |
3069 | ||
3070 | if (new_refblock_index > 0) { | |
3071 | /* Complete the potentially existing partially filled final refblock */ | |
3072 | if (new_set_refcount) { | |
3073 | for (; new_refblock_index < new_refblock_size; | |
3074 | new_refblock_index++) | |
3075 | { | |
3076 | new_set_refcount(new_refblock, new_refblock_index, 0); | |
3077 | } | |
3078 | } | |
3079 | ||
3080 | ret = operation(bs, new_reftable, *new_reftable_index, | |
3081 | new_reftable_size, new_refblock, new_refblock_empty, | |
3082 | allocated, errp); | |
3083 | if (ret < 0) { | |
3084 | return ret; | |
3085 | } | |
3086 | ||
3087 | (*new_reftable_index)++; | |
3088 | } | |
3089 | ||
3090 | status_cb(bs, (uint64_t)(index + 1) * s->refcount_table_size, | |
3091 | (uint64_t)total * s->refcount_table_size, cb_opaque); | |
3092 | ||
3093 | return 0; | |
3094 | } | |
3095 | ||
3096 | int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order, | |
3097 | BlockDriverAmendStatusCB *status_cb, | |
3098 | void *cb_opaque, Error **errp) | |
3099 | { | |
3100 | BDRVQcow2State *s = bs->opaque; | |
3101 | Qcow2GetRefcountFunc *new_get_refcount; | |
3102 | Qcow2SetRefcountFunc *new_set_refcount; | |
3103 | void *new_refblock = qemu_blockalign(bs->file->bs, s->cluster_size); | |
3104 | uint64_t *new_reftable = NULL, new_reftable_size = 0; | |
3105 | uint64_t *old_reftable, old_reftable_size, old_reftable_offset; | |
3106 | uint64_t new_reftable_index = 0; | |
3107 | uint64_t i; | |
3108 | int64_t new_reftable_offset = 0, allocated_reftable_size = 0; | |
3109 | int new_refblock_size, new_refcount_bits = 1 << refcount_order; | |
3110 | int old_refcount_order; | |
3111 | int walk_index = 0; | |
3112 | int ret; | |
3113 | bool new_allocation; | |
3114 | ||
3115 | assert(s->qcow_version >= 3); | |
3116 | assert(refcount_order >= 0 && refcount_order <= 6); | |
3117 | ||
3118 | /* see qcow2_open() */ | |
3119 | new_refblock_size = 1 << (s->cluster_bits - (refcount_order - 3)); | |
3120 | ||
3121 | new_get_refcount = get_refcount_funcs[refcount_order]; | |
3122 | new_set_refcount = set_refcount_funcs[refcount_order]; | |
3123 | ||
3124 | ||
3125 | do { | |
3126 | int total_walks; | |
3127 | ||
3128 | new_allocation = false; | |
3129 | ||
3130 | /* At least we have to do this walk and the one which writes the | |
3131 | * refblocks; also, at least we have to do this loop here at least | |
3132 | * twice (normally), first to do the allocations, and second to | |
3133 | * determine that everything is correctly allocated, this then makes | |
3134 | * three walks in total */ | |
3135 | total_walks = MAX(walk_index + 2, 3); | |
3136 | ||
3137 | /* First, allocate the structures so they are present in the refcount | |
3138 | * structures */ | |
3139 | ret = walk_over_reftable(bs, &new_reftable, &new_reftable_index, | |
3140 | &new_reftable_size, NULL, new_refblock_size, | |
3141 | new_refcount_bits, &alloc_refblock, | |
3142 | &new_allocation, NULL, status_cb, cb_opaque, | |
3143 | walk_index++, total_walks, errp); | |
3144 | if (ret < 0) { | |
3145 | goto done; | |
3146 | } | |
3147 | ||
3148 | new_reftable_index = 0; | |
3149 | ||
3150 | if (new_allocation) { | |
3151 | if (new_reftable_offset) { | |
3152 | qcow2_free_clusters(bs, new_reftable_offset, | |
3153 | allocated_reftable_size * sizeof(uint64_t), | |
3154 | QCOW2_DISCARD_NEVER); | |
3155 | } | |
3156 | ||
3157 | new_reftable_offset = qcow2_alloc_clusters(bs, new_reftable_size * | |
3158 | sizeof(uint64_t)); | |
3159 | if (new_reftable_offset < 0) { | |
3160 | error_setg_errno(errp, -new_reftable_offset, | |
3161 | "Failed to allocate the new reftable"); | |
3162 | ret = new_reftable_offset; | |
3163 | goto done; | |
3164 | } | |
3165 | allocated_reftable_size = new_reftable_size; | |
3166 | } | |
3167 | } while (new_allocation); | |
3168 | ||
3169 | /* Second, write the new refblocks */ | |
3170 | ret = walk_over_reftable(bs, &new_reftable, &new_reftable_index, | |
3171 | &new_reftable_size, new_refblock, | |
3172 | new_refblock_size, new_refcount_bits, | |
3173 | &flush_refblock, &new_allocation, new_set_refcount, | |
3174 | status_cb, cb_opaque, walk_index, walk_index + 1, | |
3175 | errp); | |
3176 | if (ret < 0) { | |
3177 | goto done; | |
3178 | } | |
3179 | assert(!new_allocation); | |
3180 | ||
3181 | ||
3182 | /* Write the new reftable */ | |
3183 | ret = qcow2_pre_write_overlap_check(bs, 0, new_reftable_offset, | |
966b000f KW |
3184 | new_reftable_size * sizeof(uint64_t), |
3185 | false); | |
791c9a00 HR |
3186 | if (ret < 0) { |
3187 | error_setg_errno(errp, -ret, "Overlap check failed"); | |
3188 | goto done; | |
3189 | } | |
3190 | ||
3191 | for (i = 0; i < new_reftable_size; i++) { | |
3192 | cpu_to_be64s(&new_reftable[i]); | |
3193 | } | |
3194 | ||
d9ca2ea2 | 3195 | ret = bdrv_pwrite(bs->file, new_reftable_offset, new_reftable, |
791c9a00 HR |
3196 | new_reftable_size * sizeof(uint64_t)); |
3197 | ||
3198 | for (i = 0; i < new_reftable_size; i++) { | |
3199 | be64_to_cpus(&new_reftable[i]); | |
3200 | } | |
3201 | ||
3202 | if (ret < 0) { | |
3203 | error_setg_errno(errp, -ret, "Failed to write the new reftable"); | |
3204 | goto done; | |
3205 | } | |
3206 | ||
3207 | ||
3208 | /* Empty the refcount cache */ | |
3209 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); | |
3210 | if (ret < 0) { | |
3211 | error_setg_errno(errp, -ret, "Failed to flush the refblock cache"); | |
3212 | goto done; | |
3213 | } | |
3214 | ||
3215 | /* Update the image header to point to the new reftable; this only updates | |
3216 | * the fields which are relevant to qcow2_update_header(); other fields | |
3217 | * such as s->refcount_table or s->refcount_bits stay stale for now | |
3218 | * (because we have to restore everything if qcow2_update_header() fails) */ | |
3219 | old_refcount_order = s->refcount_order; | |
3220 | old_reftable_size = s->refcount_table_size; | |
3221 | old_reftable_offset = s->refcount_table_offset; | |
3222 | ||
3223 | s->refcount_order = refcount_order; | |
3224 | s->refcount_table_size = new_reftable_size; | |
3225 | s->refcount_table_offset = new_reftable_offset; | |
3226 | ||
3227 | ret = qcow2_update_header(bs); | |
3228 | if (ret < 0) { | |
3229 | s->refcount_order = old_refcount_order; | |
3230 | s->refcount_table_size = old_reftable_size; | |
3231 | s->refcount_table_offset = old_reftable_offset; | |
3232 | error_setg_errno(errp, -ret, "Failed to update the qcow2 header"); | |
3233 | goto done; | |
3234 | } | |
3235 | ||
3236 | /* Now update the rest of the in-memory information */ | |
3237 | old_reftable = s->refcount_table; | |
3238 | s->refcount_table = new_reftable; | |
7061a078 | 3239 | update_max_refcount_table_index(s); |
791c9a00 HR |
3240 | |
3241 | s->refcount_bits = 1 << refcount_order; | |
3242 | s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1); | |
3243 | s->refcount_max += s->refcount_max - 1; | |
3244 | ||
3245 | s->refcount_block_bits = s->cluster_bits - (refcount_order - 3); | |
3246 | s->refcount_block_size = 1 << s->refcount_block_bits; | |
3247 | ||
3248 | s->get_refcount = new_get_refcount; | |
3249 | s->set_refcount = new_set_refcount; | |
3250 | ||
3251 | /* For cleaning up all old refblocks and the old reftable below the "done" | |
3252 | * label */ | |
3253 | new_reftable = old_reftable; | |
3254 | new_reftable_size = old_reftable_size; | |
3255 | new_reftable_offset = old_reftable_offset; | |
3256 | ||
3257 | done: | |
3258 | if (new_reftable) { | |
3259 | /* On success, new_reftable actually points to the old reftable (and | |
3260 | * new_reftable_size is the old reftable's size); but that is just | |
3261 | * fine */ | |
3262 | for (i = 0; i < new_reftable_size; i++) { | |
3263 | uint64_t offset = new_reftable[i] & REFT_OFFSET_MASK; | |
3264 | if (offset) { | |
3265 | qcow2_free_clusters(bs, offset, s->cluster_size, | |
3266 | QCOW2_DISCARD_OTHER); | |
3267 | } | |
3268 | } | |
3269 | g_free(new_reftable); | |
3270 | ||
3271 | if (new_reftable_offset > 0) { | |
3272 | qcow2_free_clusters(bs, new_reftable_offset, | |
3273 | new_reftable_size * sizeof(uint64_t), | |
3274 | QCOW2_DISCARD_OTHER); | |
3275 | } | |
3276 | } | |
3277 | ||
3278 | qemu_vfree(new_refblock); | |
3279 | return ret; | |
3280 | } | |
46b732cd | 3281 | |
23482f8a HR |
3282 | static int64_t get_refblock_offset(BlockDriverState *bs, uint64_t offset) |
3283 | { | |
3284 | BDRVQcow2State *s = bs->opaque; | |
3285 | uint32_t index = offset_to_reftable_index(s, offset); | |
3286 | int64_t covering_refblock_offset = 0; | |
3287 | ||
3288 | if (index < s->refcount_table_size) { | |
3289 | covering_refblock_offset = s->refcount_table[index] & REFT_OFFSET_MASK; | |
3290 | } | |
3291 | if (!covering_refblock_offset) { | |
3292 | qcow2_signal_corruption(bs, true, -1, -1, "Refblock at %#" PRIx64 " is " | |
3293 | "not covered by the refcount structures", | |
3294 | offset); | |
3295 | return -EIO; | |
3296 | } | |
3297 | ||
3298 | return covering_refblock_offset; | |
3299 | } | |
3300 | ||
46b732cd PB |
3301 | static int qcow2_discard_refcount_block(BlockDriverState *bs, |
3302 | uint64_t discard_block_offs) | |
3303 | { | |
3304 | BDRVQcow2State *s = bs->opaque; | |
23482f8a | 3305 | int64_t refblock_offs; |
46b732cd PB |
3306 | uint64_t cluster_index = discard_block_offs >> s->cluster_bits; |
3307 | uint32_t block_index = cluster_index & (s->refcount_block_size - 1); | |
3308 | void *refblock; | |
3309 | int ret; | |
3310 | ||
23482f8a HR |
3311 | refblock_offs = get_refblock_offset(bs, discard_block_offs); |
3312 | if (refblock_offs < 0) { | |
3313 | return refblock_offs; | |
3314 | } | |
3315 | ||
46b732cd PB |
3316 | assert(discard_block_offs != 0); |
3317 | ||
3318 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refblock_offs, | |
3319 | &refblock); | |
3320 | if (ret < 0) { | |
3321 | return ret; | |
3322 | } | |
3323 | ||
3324 | if (s->get_refcount(refblock, block_index) != 1) { | |
3325 | qcow2_signal_corruption(bs, true, -1, -1, "Invalid refcount:" | |
3326 | " refblock offset %#" PRIx64 | |
3327 | ", reftable index %u" | |
3328 | ", block offset %#" PRIx64 | |
3329 | ", refcount %#" PRIx64, | |
3330 | refblock_offs, | |
3331 | offset_to_reftable_index(s, discard_block_offs), | |
3332 | discard_block_offs, | |
3333 | s->get_refcount(refblock, block_index)); | |
2013c3d4 | 3334 | qcow2_cache_put(s->refcount_block_cache, &refblock); |
46b732cd PB |
3335 | return -EINVAL; |
3336 | } | |
3337 | s->set_refcount(refblock, block_index, 0); | |
3338 | ||
2d135ee9 | 3339 | qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refblock); |
46b732cd | 3340 | |
2013c3d4 | 3341 | qcow2_cache_put(s->refcount_block_cache, &refblock); |
46b732cd PB |
3342 | |
3343 | if (cluster_index < s->free_cluster_index) { | |
3344 | s->free_cluster_index = cluster_index; | |
3345 | } | |
3346 | ||
6e6fa760 | 3347 | refblock = qcow2_cache_is_table_offset(s->refcount_block_cache, |
46b732cd PB |
3348 | discard_block_offs); |
3349 | if (refblock) { | |
3350 | /* discard refblock from the cache if refblock is cached */ | |
77aadd7b | 3351 | qcow2_cache_discard(s->refcount_block_cache, refblock); |
46b732cd PB |
3352 | } |
3353 | update_refcount_discard(bs, discard_block_offs, s->cluster_size); | |
3354 | ||
3355 | return 0; | |
3356 | } | |
3357 | ||
3358 | int qcow2_shrink_reftable(BlockDriverState *bs) | |
3359 | { | |
3360 | BDRVQcow2State *s = bs->opaque; | |
3361 | uint64_t *reftable_tmp = | |
3362 | g_malloc(s->refcount_table_size * sizeof(uint64_t)); | |
3363 | int i, ret; | |
3364 | ||
3365 | for (i = 0; i < s->refcount_table_size; i++) { | |
3366 | int64_t refblock_offs = s->refcount_table[i] & REFT_OFFSET_MASK; | |
3367 | void *refblock; | |
3368 | bool unused_block; | |
3369 | ||
3370 | if (refblock_offs == 0) { | |
3371 | reftable_tmp[i] = 0; | |
3372 | continue; | |
3373 | } | |
3374 | ret = qcow2_cache_get(bs, s->refcount_block_cache, refblock_offs, | |
3375 | &refblock); | |
3376 | if (ret < 0) { | |
3377 | goto out; | |
3378 | } | |
3379 | ||
3380 | /* the refblock has own reference */ | |
3381 | if (i == offset_to_reftable_index(s, refblock_offs)) { | |
3382 | uint64_t block_index = (refblock_offs >> s->cluster_bits) & | |
3383 | (s->refcount_block_size - 1); | |
3384 | uint64_t refcount = s->get_refcount(refblock, block_index); | |
3385 | ||
3386 | s->set_refcount(refblock, block_index, 0); | |
3387 | ||
3388 | unused_block = buffer_is_zero(refblock, s->cluster_size); | |
3389 | ||
3390 | s->set_refcount(refblock, block_index, refcount); | |
3391 | } else { | |
3392 | unused_block = buffer_is_zero(refblock, s->cluster_size); | |
3393 | } | |
2013c3d4 | 3394 | qcow2_cache_put(s->refcount_block_cache, &refblock); |
46b732cd PB |
3395 | |
3396 | reftable_tmp[i] = unused_block ? 0 : cpu_to_be64(s->refcount_table[i]); | |
3397 | } | |
3398 | ||
3399 | ret = bdrv_pwrite_sync(bs->file, s->refcount_table_offset, reftable_tmp, | |
3400 | s->refcount_table_size * sizeof(uint64_t)); | |
3401 | /* | |
3402 | * If the write in the reftable failed the image may contain a partially | |
3403 | * overwritten reftable. In this case it would be better to clear the | |
3404 | * reftable in memory to avoid possible image corruption. | |
3405 | */ | |
3406 | for (i = 0; i < s->refcount_table_size; i++) { | |
3407 | if (s->refcount_table[i] && !reftable_tmp[i]) { | |
3408 | if (ret == 0) { | |
3409 | ret = qcow2_discard_refcount_block(bs, s->refcount_table[i] & | |
3410 | REFT_OFFSET_MASK); | |
3411 | } | |
3412 | s->refcount_table[i] = 0; | |
3413 | } | |
3414 | } | |
3415 | ||
3416 | if (!s->cache_discards) { | |
3417 | qcow2_process_discards(bs, ret); | |
3418 | } | |
3419 | ||
3420 | out: | |
3421 | g_free(reftable_tmp); | |
3422 | return ret; | |
3423 | } | |
163bc39d PB |
3424 | |
3425 | int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size) | |
3426 | { | |
3427 | BDRVQcow2State *s = bs->opaque; | |
3428 | int64_t i; | |
3429 | ||
3430 | for (i = size_to_clusters(s, size) - 1; i >= 0; i--) { | |
3431 | uint64_t refcount; | |
3432 | int ret = qcow2_get_refcount(bs, i, &refcount); | |
3433 | if (ret < 0) { | |
3434 | fprintf(stderr, "Can't get refcount for cluster %" PRId64 ": %s\n", | |
3435 | i, strerror(-ret)); | |
3436 | return ret; | |
3437 | } | |
3438 | if (refcount > 0) { | |
3439 | return i; | |
3440 | } | |
3441 | } | |
3442 | qcow2_signal_corruption(bs, true, -1, -1, | |
3443 | "There are no references in the refcount table."); | |
3444 | return -EIO; | |
3445 | } |