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45aba42f KW |
1 | /* |
2 | * Block driver for the QCOW version 2 format | |
3 | * | |
4 | * Copyright (c) 2004-2006 Fabrice Bellard | |
5 | * | |
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
7 | * of this software and associated documentation files (the "Software"), to deal | |
8 | * in the Software without restriction, including without limitation the rights | |
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
10 | * copies of the Software, and to permit persons to whom the Software is | |
11 | * furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in | |
14 | * all copies or substantial portions of the Software. | |
15 | * | |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
22 | * THE SOFTWARE. | |
23 | */ | |
24 | ||
25 | #include <zlib.h> | |
26 | ||
27 | #include "qemu-common.h" | |
28 | #include "block_int.h" | |
29 | #include "block/qcow2.h" | |
30 | ||
72893756 | 31 | int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size) |
45aba42f KW |
32 | { |
33 | BDRVQcowState *s = bs->opaque; | |
34 | int new_l1_size, new_l1_size2, ret, i; | |
35 | uint64_t *new_l1_table; | |
5d757b56 | 36 | int64_t new_l1_table_offset; |
45aba42f KW |
37 | uint8_t data[12]; |
38 | ||
72893756 | 39 | if (min_size <= s->l1_size) |
45aba42f | 40 | return 0; |
72893756 SH |
41 | |
42 | if (exact_size) { | |
43 | new_l1_size = min_size; | |
44 | } else { | |
45 | /* Bump size up to reduce the number of times we have to grow */ | |
46 | new_l1_size = s->l1_size; | |
47 | if (new_l1_size == 0) { | |
48 | new_l1_size = 1; | |
49 | } | |
50 | while (min_size > new_l1_size) { | |
51 | new_l1_size = (new_l1_size * 3 + 1) / 2; | |
52 | } | |
45aba42f | 53 | } |
72893756 | 54 | |
45aba42f | 55 | #ifdef DEBUG_ALLOC2 |
35ee5e39 | 56 | fprintf(stderr, "grow l1_table from %d to %d\n", s->l1_size, new_l1_size); |
45aba42f KW |
57 | #endif |
58 | ||
59 | new_l1_size2 = sizeof(uint64_t) * new_l1_size; | |
7267c094 | 60 | new_l1_table = g_malloc0(align_offset(new_l1_size2, 512)); |
45aba42f KW |
61 | memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t)); |
62 | ||
63 | /* write new table (align to cluster) */ | |
66f82cee | 64 | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ALLOC_TABLE); |
ed6ccf0f | 65 | new_l1_table_offset = qcow2_alloc_clusters(bs, new_l1_size2); |
5d757b56 | 66 | if (new_l1_table_offset < 0) { |
7267c094 | 67 | g_free(new_l1_table); |
5d757b56 KW |
68 | return new_l1_table_offset; |
69 | } | |
29c1a730 KW |
70 | |
71 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); | |
72 | if (ret < 0) { | |
80fa3341 | 73 | goto fail; |
29c1a730 | 74 | } |
45aba42f | 75 | |
66f82cee | 76 | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_WRITE_TABLE); |
45aba42f KW |
77 | for(i = 0; i < s->l1_size; i++) |
78 | new_l1_table[i] = cpu_to_be64(new_l1_table[i]); | |
8b3b7206 KW |
79 | ret = bdrv_pwrite_sync(bs->file, new_l1_table_offset, new_l1_table, new_l1_size2); |
80 | if (ret < 0) | |
45aba42f KW |
81 | goto fail; |
82 | for(i = 0; i < s->l1_size; i++) | |
83 | new_l1_table[i] = be64_to_cpu(new_l1_table[i]); | |
84 | ||
85 | /* set new table */ | |
66f82cee | 86 | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ACTIVATE_TABLE); |
45aba42f | 87 | cpu_to_be32w((uint32_t*)data, new_l1_size); |
653df36b | 88 | cpu_to_be64wu((uint64_t*)(data + 4), new_l1_table_offset); |
8b3b7206 KW |
89 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_size), data,sizeof(data)); |
90 | if (ret < 0) { | |
45aba42f | 91 | goto fail; |
fb8fa77c | 92 | } |
7267c094 | 93 | g_free(s->l1_table); |
ed6ccf0f | 94 | qcow2_free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t)); |
45aba42f KW |
95 | s->l1_table_offset = new_l1_table_offset; |
96 | s->l1_table = new_l1_table; | |
97 | s->l1_size = new_l1_size; | |
98 | return 0; | |
99 | fail: | |
7267c094 | 100 | g_free(new_l1_table); |
fb8fa77c | 101 | qcow2_free_clusters(bs, new_l1_table_offset, new_l1_size2); |
8b3b7206 | 102 | return ret; |
45aba42f KW |
103 | } |
104 | ||
45aba42f KW |
105 | /* |
106 | * l2_load | |
107 | * | |
108 | * Loads a L2 table into memory. If the table is in the cache, the cache | |
109 | * is used; otherwise the L2 table is loaded from the image file. | |
110 | * | |
111 | * Returns a pointer to the L2 table on success, or NULL if the read from | |
112 | * the image file failed. | |
113 | */ | |
114 | ||
55c17e98 KW |
115 | static int l2_load(BlockDriverState *bs, uint64_t l2_offset, |
116 | uint64_t **l2_table) | |
45aba42f KW |
117 | { |
118 | BDRVQcowState *s = bs->opaque; | |
55c17e98 | 119 | int ret; |
45aba42f | 120 | |
29c1a730 | 121 | ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, (void**) l2_table); |
45aba42f | 122 | |
29c1a730 | 123 | return ret; |
45aba42f KW |
124 | } |
125 | ||
6583e3c7 KW |
126 | /* |
127 | * Writes one sector of the L1 table to the disk (can't update single entries | |
128 | * and we really don't want bdrv_pread to perform a read-modify-write) | |
129 | */ | |
130 | #define L1_ENTRIES_PER_SECTOR (512 / 8) | |
66f82cee | 131 | static int write_l1_entry(BlockDriverState *bs, int l1_index) |
6583e3c7 | 132 | { |
66f82cee | 133 | BDRVQcowState *s = bs->opaque; |
6583e3c7 KW |
134 | uint64_t buf[L1_ENTRIES_PER_SECTOR]; |
135 | int l1_start_index; | |
f7defcb6 | 136 | int i, ret; |
6583e3c7 KW |
137 | |
138 | l1_start_index = l1_index & ~(L1_ENTRIES_PER_SECTOR - 1); | |
139 | for (i = 0; i < L1_ENTRIES_PER_SECTOR; i++) { | |
140 | buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]); | |
141 | } | |
142 | ||
66f82cee | 143 | BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); |
8b3b7206 | 144 | ret = bdrv_pwrite_sync(bs->file, s->l1_table_offset + 8 * l1_start_index, |
f7defcb6 KW |
145 | buf, sizeof(buf)); |
146 | if (ret < 0) { | |
147 | return ret; | |
6583e3c7 KW |
148 | } |
149 | ||
150 | return 0; | |
151 | } | |
152 | ||
45aba42f KW |
153 | /* |
154 | * l2_allocate | |
155 | * | |
156 | * Allocate a new l2 entry in the file. If l1_index points to an already | |
157 | * used entry in the L2 table (i.e. we are doing a copy on write for the L2 | |
158 | * table) copy the contents of the old L2 table into the newly allocated one. | |
159 | * Otherwise the new table is initialized with zeros. | |
160 | * | |
161 | */ | |
162 | ||
c46e1167 | 163 | static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) |
45aba42f KW |
164 | { |
165 | BDRVQcowState *s = bs->opaque; | |
6583e3c7 | 166 | uint64_t old_l2_offset; |
f4f0d391 KW |
167 | uint64_t *l2_table; |
168 | int64_t l2_offset; | |
c46e1167 | 169 | int ret; |
45aba42f KW |
170 | |
171 | old_l2_offset = s->l1_table[l1_index]; | |
172 | ||
173 | /* allocate a new l2 entry */ | |
174 | ||
ed6ccf0f | 175 | l2_offset = qcow2_alloc_clusters(bs, s->l2_size * sizeof(uint64_t)); |
5d757b56 | 176 | if (l2_offset < 0) { |
c46e1167 | 177 | return l2_offset; |
5d757b56 | 178 | } |
29c1a730 KW |
179 | |
180 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); | |
181 | if (ret < 0) { | |
182 | goto fail; | |
183 | } | |
45aba42f | 184 | |
45aba42f KW |
185 | /* allocate a new entry in the l2 cache */ |
186 | ||
29c1a730 KW |
187 | ret = qcow2_cache_get_empty(bs, s->l2_table_cache, l2_offset, (void**) table); |
188 | if (ret < 0) { | |
189 | return ret; | |
190 | } | |
191 | ||
192 | l2_table = *table; | |
45aba42f KW |
193 | |
194 | if (old_l2_offset == 0) { | |
195 | /* if there was no old l2 table, clear the new table */ | |
196 | memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); | |
197 | } else { | |
29c1a730 KW |
198 | uint64_t* old_table; |
199 | ||
45aba42f | 200 | /* if there was an old l2 table, read it from the disk */ |
66f82cee | 201 | BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_COW_READ); |
29c1a730 KW |
202 | ret = qcow2_cache_get(bs, s->l2_table_cache, old_l2_offset, |
203 | (void**) &old_table); | |
204 | if (ret < 0) { | |
205 | goto fail; | |
206 | } | |
207 | ||
208 | memcpy(l2_table, old_table, s->cluster_size); | |
209 | ||
210 | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &old_table); | |
c46e1167 | 211 | if (ret < 0) { |
175e1152 | 212 | goto fail; |
c46e1167 | 213 | } |
45aba42f | 214 | } |
29c1a730 | 215 | |
45aba42f | 216 | /* write the l2 table to the file */ |
66f82cee | 217 | BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_WRITE); |
29c1a730 KW |
218 | |
219 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); | |
220 | ret = qcow2_cache_flush(bs, s->l2_table_cache); | |
c46e1167 | 221 | if (ret < 0) { |
175e1152 KW |
222 | goto fail; |
223 | } | |
224 | ||
225 | /* update the L1 entry */ | |
226 | s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; | |
227 | ret = write_l1_entry(bs, l1_index); | |
228 | if (ret < 0) { | |
229 | goto fail; | |
c46e1167 | 230 | } |
45aba42f | 231 | |
c46e1167 KW |
232 | *table = l2_table; |
233 | return 0; | |
175e1152 KW |
234 | |
235 | fail: | |
29c1a730 | 236 | qcow2_cache_put(bs, s->l2_table_cache, (void**) table); |
68dba0bf | 237 | s->l1_table[l1_index] = old_l2_offset; |
175e1152 | 238 | return ret; |
45aba42f KW |
239 | } |
240 | ||
241 | static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, | |
242 | uint64_t *l2_table, uint64_t start, uint64_t mask) | |
243 | { | |
244 | int i; | |
245 | uint64_t offset = be64_to_cpu(l2_table[0]) & ~mask; | |
246 | ||
247 | if (!offset) | |
248 | return 0; | |
249 | ||
250 | for (i = start; i < start + nb_clusters; i++) | |
80ee15a6 | 251 | if (offset + (uint64_t) i * cluster_size != (be64_to_cpu(l2_table[i]) & ~mask)) |
45aba42f KW |
252 | break; |
253 | ||
254 | return (i - start); | |
255 | } | |
256 | ||
257 | static int count_contiguous_free_clusters(uint64_t nb_clusters, uint64_t *l2_table) | |
258 | { | |
259 | int i = 0; | |
260 | ||
261 | while(nb_clusters-- && l2_table[i] == 0) | |
262 | i++; | |
263 | ||
264 | return i; | |
265 | } | |
266 | ||
267 | /* The crypt function is compatible with the linux cryptoloop | |
268 | algorithm for < 4 GB images. NOTE: out_buf == in_buf is | |
269 | supported */ | |
ed6ccf0f KW |
270 | void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
271 | uint8_t *out_buf, const uint8_t *in_buf, | |
272 | int nb_sectors, int enc, | |
273 | const AES_KEY *key) | |
45aba42f KW |
274 | { |
275 | union { | |
276 | uint64_t ll[2]; | |
277 | uint8_t b[16]; | |
278 | } ivec; | |
279 | int i; | |
280 | ||
281 | for(i = 0; i < nb_sectors; i++) { | |
282 | ivec.ll[0] = cpu_to_le64(sector_num); | |
283 | ivec.ll[1] = 0; | |
284 | AES_cbc_encrypt(in_buf, out_buf, 512, key, | |
285 | ivec.b, enc); | |
286 | sector_num++; | |
287 | in_buf += 512; | |
288 | out_buf += 512; | |
289 | } | |
290 | } | |
291 | ||
aef4acb6 SH |
292 | static int coroutine_fn copy_sectors(BlockDriverState *bs, |
293 | uint64_t start_sect, | |
294 | uint64_t cluster_offset, | |
295 | int n_start, int n_end) | |
45aba42f KW |
296 | { |
297 | BDRVQcowState *s = bs->opaque; | |
aef4acb6 SH |
298 | QEMUIOVector qiov; |
299 | struct iovec iov; | |
45aba42f | 300 | int n, ret; |
1b9f1491 KW |
301 | |
302 | /* | |
303 | * If this is the last cluster and it is only partially used, we must only | |
304 | * copy until the end of the image, or bdrv_check_request will fail for the | |
305 | * bdrv_read/write calls below. | |
306 | */ | |
307 | if (start_sect + n_end > bs->total_sectors) { | |
308 | n_end = bs->total_sectors - start_sect; | |
309 | } | |
45aba42f KW |
310 | |
311 | n = n_end - n_start; | |
1b9f1491 | 312 | if (n <= 0) { |
45aba42f | 313 | return 0; |
1b9f1491 KW |
314 | } |
315 | ||
aef4acb6 SH |
316 | iov.iov_len = n * BDRV_SECTOR_SIZE; |
317 | iov.iov_base = qemu_blockalign(bs, iov.iov_len); | |
318 | ||
319 | qemu_iovec_init_external(&qiov, &iov, 1); | |
1b9f1491 | 320 | |
66f82cee | 321 | BLKDBG_EVENT(bs->file, BLKDBG_COW_READ); |
aef4acb6 SH |
322 | |
323 | /* Call .bdrv_co_readv() directly instead of using the public block-layer | |
324 | * interface. This avoids double I/O throttling and request tracking, | |
325 | * which can lead to deadlock when block layer copy-on-read is enabled. | |
326 | */ | |
327 | ret = bs->drv->bdrv_co_readv(bs, start_sect + n_start, n, &qiov); | |
1b9f1491 KW |
328 | if (ret < 0) { |
329 | goto out; | |
330 | } | |
331 | ||
45aba42f | 332 | if (s->crypt_method) { |
ed6ccf0f | 333 | qcow2_encrypt_sectors(s, start_sect + n_start, |
aef4acb6 | 334 | iov.iov_base, iov.iov_base, n, 1, |
45aba42f KW |
335 | &s->aes_encrypt_key); |
336 | } | |
1b9f1491 | 337 | |
66f82cee | 338 | BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE); |
aef4acb6 | 339 | ret = bdrv_co_writev(bs->file, (cluster_offset >> 9) + n_start, n, &qiov); |
1b9f1491 KW |
340 | if (ret < 0) { |
341 | goto out; | |
342 | } | |
343 | ||
344 | ret = 0; | |
345 | out: | |
aef4acb6 | 346 | qemu_vfree(iov.iov_base); |
1b9f1491 | 347 | return ret; |
45aba42f KW |
348 | } |
349 | ||
350 | ||
351 | /* | |
352 | * get_cluster_offset | |
353 | * | |
1c46efaa KW |
354 | * For a given offset of the disk image, find the cluster offset in |
355 | * qcow2 file. The offset is stored in *cluster_offset. | |
45aba42f | 356 | * |
d57237f2 | 357 | * on entry, *num is the number of contiguous sectors we'd like to |
45aba42f KW |
358 | * access following offset. |
359 | * | |
d57237f2 | 360 | * on exit, *num is the number of contiguous sectors we can read. |
45aba42f | 361 | * |
1c46efaa KW |
362 | * Return 0, if the offset is found |
363 | * Return -errno, otherwise. | |
45aba42f KW |
364 | * |
365 | */ | |
366 | ||
1c46efaa KW |
367 | int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, |
368 | int *num, uint64_t *cluster_offset) | |
45aba42f KW |
369 | { |
370 | BDRVQcowState *s = bs->opaque; | |
80ee15a6 | 371 | unsigned int l1_index, l2_index; |
1c46efaa | 372 | uint64_t l2_offset, *l2_table; |
45aba42f | 373 | int l1_bits, c; |
80ee15a6 KW |
374 | unsigned int index_in_cluster, nb_clusters; |
375 | uint64_t nb_available, nb_needed; | |
55c17e98 | 376 | int ret; |
45aba42f KW |
377 | |
378 | index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1); | |
379 | nb_needed = *num + index_in_cluster; | |
380 | ||
381 | l1_bits = s->l2_bits + s->cluster_bits; | |
382 | ||
383 | /* compute how many bytes there are between the offset and | |
384 | * the end of the l1 entry | |
385 | */ | |
386 | ||
80ee15a6 | 387 | nb_available = (1ULL << l1_bits) - (offset & ((1ULL << l1_bits) - 1)); |
45aba42f KW |
388 | |
389 | /* compute the number of available sectors */ | |
390 | ||
391 | nb_available = (nb_available >> 9) + index_in_cluster; | |
392 | ||
393 | if (nb_needed > nb_available) { | |
394 | nb_needed = nb_available; | |
395 | } | |
396 | ||
1c46efaa | 397 | *cluster_offset = 0; |
45aba42f KW |
398 | |
399 | /* seek the the l2 offset in the l1 table */ | |
400 | ||
401 | l1_index = offset >> l1_bits; | |
402 | if (l1_index >= s->l1_size) | |
403 | goto out; | |
404 | ||
405 | l2_offset = s->l1_table[l1_index]; | |
406 | ||
407 | /* seek the l2 table of the given l2 offset */ | |
408 | ||
409 | if (!l2_offset) | |
410 | goto out; | |
411 | ||
412 | /* load the l2 table in memory */ | |
413 | ||
414 | l2_offset &= ~QCOW_OFLAG_COPIED; | |
55c17e98 KW |
415 | ret = l2_load(bs, l2_offset, &l2_table); |
416 | if (ret < 0) { | |
417 | return ret; | |
1c46efaa | 418 | } |
45aba42f KW |
419 | |
420 | /* find the cluster offset for the given disk offset */ | |
421 | ||
422 | l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1); | |
1c46efaa | 423 | *cluster_offset = be64_to_cpu(l2_table[l2_index]); |
45aba42f KW |
424 | nb_clusters = size_to_clusters(s, nb_needed << 9); |
425 | ||
1c46efaa | 426 | if (!*cluster_offset) { |
45aba42f KW |
427 | /* how many empty clusters ? */ |
428 | c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]); | |
429 | } else { | |
430 | /* how many allocated clusters ? */ | |
431 | c = count_contiguous_clusters(nb_clusters, s->cluster_size, | |
432 | &l2_table[l2_index], 0, QCOW_OFLAG_COPIED); | |
433 | } | |
434 | ||
29c1a730 KW |
435 | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); |
436 | ||
45aba42f KW |
437 | nb_available = (c * s->cluster_sectors); |
438 | out: | |
439 | if (nb_available > nb_needed) | |
440 | nb_available = nb_needed; | |
441 | ||
442 | *num = nb_available - index_in_cluster; | |
443 | ||
1c46efaa KW |
444 | *cluster_offset &=~QCOW_OFLAG_COPIED; |
445 | return 0; | |
45aba42f KW |
446 | } |
447 | ||
448 | /* | |
449 | * get_cluster_table | |
450 | * | |
451 | * for a given disk offset, load (and allocate if needed) | |
452 | * the l2 table. | |
453 | * | |
454 | * the l2 table offset in the qcow2 file and the cluster index | |
455 | * in the l2 table are given to the caller. | |
456 | * | |
1e3e8f1a | 457 | * Returns 0 on success, -errno in failure case |
45aba42f | 458 | */ |
45aba42f KW |
459 | static int get_cluster_table(BlockDriverState *bs, uint64_t offset, |
460 | uint64_t **new_l2_table, | |
461 | uint64_t *new_l2_offset, | |
462 | int *new_l2_index) | |
463 | { | |
464 | BDRVQcowState *s = bs->opaque; | |
80ee15a6 | 465 | unsigned int l1_index, l2_index; |
c46e1167 KW |
466 | uint64_t l2_offset; |
467 | uint64_t *l2_table = NULL; | |
80ee15a6 | 468 | int ret; |
45aba42f KW |
469 | |
470 | /* seek the the l2 offset in the l1 table */ | |
471 | ||
472 | l1_index = offset >> (s->l2_bits + s->cluster_bits); | |
473 | if (l1_index >= s->l1_size) { | |
72893756 | 474 | ret = qcow2_grow_l1_table(bs, l1_index + 1, false); |
1e3e8f1a KW |
475 | if (ret < 0) { |
476 | return ret; | |
477 | } | |
45aba42f KW |
478 | } |
479 | l2_offset = s->l1_table[l1_index]; | |
480 | ||
481 | /* seek the l2 table of the given l2 offset */ | |
482 | ||
483 | if (l2_offset & QCOW_OFLAG_COPIED) { | |
484 | /* load the l2 table in memory */ | |
485 | l2_offset &= ~QCOW_OFLAG_COPIED; | |
55c17e98 KW |
486 | ret = l2_load(bs, l2_offset, &l2_table); |
487 | if (ret < 0) { | |
488 | return ret; | |
1e3e8f1a | 489 | } |
45aba42f | 490 | } else { |
16fde5f2 | 491 | /* First allocate a new L2 table (and do COW if needed) */ |
c46e1167 KW |
492 | ret = l2_allocate(bs, l1_index, &l2_table); |
493 | if (ret < 0) { | |
494 | return ret; | |
1e3e8f1a | 495 | } |
16fde5f2 KW |
496 | |
497 | /* Then decrease the refcount of the old table */ | |
498 | if (l2_offset) { | |
499 | qcow2_free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t)); | |
500 | } | |
45aba42f KW |
501 | l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED; |
502 | } | |
503 | ||
504 | /* find the cluster offset for the given disk offset */ | |
505 | ||
506 | l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1); | |
507 | ||
508 | *new_l2_table = l2_table; | |
509 | *new_l2_offset = l2_offset; | |
510 | *new_l2_index = l2_index; | |
511 | ||
1e3e8f1a | 512 | return 0; |
45aba42f KW |
513 | } |
514 | ||
515 | /* | |
516 | * alloc_compressed_cluster_offset | |
517 | * | |
518 | * For a given offset of the disk image, return cluster offset in | |
519 | * qcow2 file. | |
520 | * | |
521 | * If the offset is not found, allocate a new compressed cluster. | |
522 | * | |
523 | * Return the cluster offset if successful, | |
524 | * Return 0, otherwise. | |
525 | * | |
526 | */ | |
527 | ||
ed6ccf0f KW |
528 | uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, |
529 | uint64_t offset, | |
530 | int compressed_size) | |
45aba42f KW |
531 | { |
532 | BDRVQcowState *s = bs->opaque; | |
533 | int l2_index, ret; | |
f4f0d391 KW |
534 | uint64_t l2_offset, *l2_table; |
535 | int64_t cluster_offset; | |
45aba42f KW |
536 | int nb_csectors; |
537 | ||
538 | ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); | |
1e3e8f1a | 539 | if (ret < 0) { |
45aba42f | 540 | return 0; |
1e3e8f1a | 541 | } |
45aba42f KW |
542 | |
543 | cluster_offset = be64_to_cpu(l2_table[l2_index]); | |
8f1efd00 KW |
544 | if (cluster_offset & QCOW_OFLAG_COPIED) { |
545 | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); | |
546 | return 0; | |
547 | } | |
45aba42f KW |
548 | |
549 | if (cluster_offset) | |
ed6ccf0f | 550 | qcow2_free_any_clusters(bs, cluster_offset, 1); |
45aba42f | 551 | |
ed6ccf0f | 552 | cluster_offset = qcow2_alloc_bytes(bs, compressed_size); |
5d757b56 | 553 | if (cluster_offset < 0) { |
29c1a730 | 554 | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); |
5d757b56 KW |
555 | return 0; |
556 | } | |
557 | ||
45aba42f KW |
558 | nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) - |
559 | (cluster_offset >> 9); | |
560 | ||
561 | cluster_offset |= QCOW_OFLAG_COMPRESSED | | |
562 | ((uint64_t)nb_csectors << s->csize_shift); | |
563 | ||
564 | /* update L2 table */ | |
565 | ||
566 | /* compressed clusters never have the copied flag */ | |
567 | ||
66f82cee | 568 | BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED); |
29c1a730 | 569 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); |
45aba42f | 570 | l2_table[l2_index] = cpu_to_be64(cluster_offset); |
29c1a730 | 571 | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); |
79a31189 | 572 | if (ret < 0) { |
29c1a730 | 573 | return 0; |
4c1612d9 KW |
574 | } |
575 | ||
29c1a730 | 576 | return cluster_offset; |
4c1612d9 KW |
577 | } |
578 | ||
148da7ea | 579 | int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m) |
45aba42f KW |
580 | { |
581 | BDRVQcowState *s = bs->opaque; | |
582 | int i, j = 0, l2_index, ret; | |
583 | uint64_t *old_cluster, start_sect, l2_offset, *l2_table; | |
148da7ea | 584 | uint64_t cluster_offset = m->cluster_offset; |
29c1a730 | 585 | bool cow = false; |
45aba42f KW |
586 | |
587 | if (m->nb_clusters == 0) | |
588 | return 0; | |
589 | ||
7267c094 | 590 | old_cluster = g_malloc(m->nb_clusters * sizeof(uint64_t)); |
45aba42f KW |
591 | |
592 | /* copy content of unmodified sectors */ | |
593 | start_sect = (m->offset & ~(s->cluster_size - 1)) >> 9; | |
594 | if (m->n_start) { | |
29c1a730 | 595 | cow = true; |
1b9f1491 | 596 | qemu_co_mutex_unlock(&s->lock); |
45aba42f | 597 | ret = copy_sectors(bs, start_sect, cluster_offset, 0, m->n_start); |
1b9f1491 | 598 | qemu_co_mutex_lock(&s->lock); |
45aba42f KW |
599 | if (ret < 0) |
600 | goto err; | |
601 | } | |
602 | ||
603 | if (m->nb_available & (s->cluster_sectors - 1)) { | |
604 | uint64_t end = m->nb_available & ~(uint64_t)(s->cluster_sectors - 1); | |
29c1a730 | 605 | cow = true; |
1b9f1491 | 606 | qemu_co_mutex_unlock(&s->lock); |
45aba42f KW |
607 | ret = copy_sectors(bs, start_sect + end, cluster_offset + (end << 9), |
608 | m->nb_available - end, s->cluster_sectors); | |
1b9f1491 | 609 | qemu_co_mutex_lock(&s->lock); |
45aba42f KW |
610 | if (ret < 0) |
611 | goto err; | |
612 | } | |
613 | ||
29c1a730 KW |
614 | /* |
615 | * Update L2 table. | |
616 | * | |
617 | * Before we update the L2 table to actually point to the new cluster, we | |
618 | * need to be sure that the refcounts have been increased and COW was | |
619 | * handled. | |
620 | */ | |
621 | if (cow) { | |
3de0a294 | 622 | qcow2_cache_depends_on_flush(s->l2_table_cache); |
29c1a730 KW |
623 | } |
624 | ||
625 | qcow2_cache_set_dependency(bs, s->l2_table_cache, s->refcount_block_cache); | |
1e3e8f1a KW |
626 | ret = get_cluster_table(bs, m->offset, &l2_table, &l2_offset, &l2_index); |
627 | if (ret < 0) { | |
45aba42f | 628 | goto err; |
1e3e8f1a | 629 | } |
29c1a730 | 630 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); |
45aba42f KW |
631 | |
632 | for (i = 0; i < m->nb_clusters; i++) { | |
633 | /* if two concurrent writes happen to the same unallocated cluster | |
634 | * each write allocates separate cluster and writes data concurrently. | |
635 | * The first one to complete updates l2 table with pointer to its | |
636 | * cluster the second one has to do RMW (which is done above by | |
637 | * copy_sectors()), update l2 table with its cluster pointer and free | |
638 | * old cluster. This is what this loop does */ | |
639 | if(l2_table[l2_index + i] != 0) | |
640 | old_cluster[j++] = l2_table[l2_index + i]; | |
641 | ||
642 | l2_table[l2_index + i] = cpu_to_be64((cluster_offset + | |
643 | (i << s->cluster_bits)) | QCOW_OFLAG_COPIED); | |
644 | } | |
645 | ||
9f8e668e | 646 | |
29c1a730 | 647 | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); |
c835d00f | 648 | if (ret < 0) { |
45aba42f | 649 | goto err; |
4c1612d9 | 650 | } |
45aba42f | 651 | |
7ec5e6a4 KW |
652 | /* |
653 | * If this was a COW, we need to decrease the refcount of the old cluster. | |
654 | * Also flush bs->file to get the right order for L2 and refcount update. | |
655 | */ | |
656 | if (j != 0) { | |
7ec5e6a4 KW |
657 | for (i = 0; i < j; i++) { |
658 | qcow2_free_any_clusters(bs, | |
659 | be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED, 1); | |
660 | } | |
661 | } | |
45aba42f KW |
662 | |
663 | ret = 0; | |
664 | err: | |
7267c094 | 665 | g_free(old_cluster); |
45aba42f KW |
666 | return ret; |
667 | } | |
668 | ||
669 | /* | |
670 | * alloc_cluster_offset | |
671 | * | |
148da7ea | 672 | * For a given offset of the disk image, return cluster offset in qcow2 file. |
45aba42f KW |
673 | * If the offset is not found, allocate a new cluster. |
674 | * | |
148da7ea | 675 | * If the cluster was already allocated, m->nb_clusters is set to 0, |
a7912369 | 676 | * other fields in m are meaningless. |
148da7ea KW |
677 | * |
678 | * If the cluster is newly allocated, m->nb_clusters is set to the number of | |
68d100e9 KW |
679 | * contiguous clusters that have been allocated. In this case, the other |
680 | * fields of m are valid and contain information about the first allocated | |
681 | * cluster. | |
45aba42f | 682 | * |
68d100e9 KW |
683 | * If the request conflicts with another write request in flight, the coroutine |
684 | * is queued and will be reentered when the dependency has completed. | |
148da7ea KW |
685 | * |
686 | * Return 0 on success and -errno in error cases | |
45aba42f | 687 | */ |
f4f0d391 KW |
688 | int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, |
689 | int n_start, int n_end, int *num, QCowL2Meta *m) | |
45aba42f KW |
690 | { |
691 | BDRVQcowState *s = bs->opaque; | |
692 | int l2_index, ret; | |
5d757b56 KW |
693 | uint64_t l2_offset, *l2_table; |
694 | int64_t cluster_offset; | |
80ee15a6 | 695 | unsigned int nb_clusters, i = 0; |
f214978a | 696 | QCowL2Meta *old_alloc; |
45aba42f KW |
697 | |
698 | ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); | |
1e3e8f1a | 699 | if (ret < 0) { |
148da7ea | 700 | return ret; |
1e3e8f1a | 701 | } |
45aba42f | 702 | |
68d100e9 | 703 | again: |
45aba42f KW |
704 | nb_clusters = size_to_clusters(s, n_end << 9); |
705 | ||
706 | nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); | |
707 | ||
708 | cluster_offset = be64_to_cpu(l2_table[l2_index]); | |
709 | ||
710 | /* We keep all QCOW_OFLAG_COPIED clusters */ | |
711 | ||
712 | if (cluster_offset & QCOW_OFLAG_COPIED) { | |
713 | nb_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size, | |
714 | &l2_table[l2_index], 0, 0); | |
715 | ||
716 | cluster_offset &= ~QCOW_OFLAG_COPIED; | |
717 | m->nb_clusters = 0; | |
718 | ||
719 | goto out; | |
720 | } | |
721 | ||
722 | /* for the moment, multiple compressed clusters are not managed */ | |
723 | ||
724 | if (cluster_offset & QCOW_OFLAG_COMPRESSED) | |
725 | nb_clusters = 1; | |
726 | ||
727 | /* how many available clusters ? */ | |
728 | ||
729 | while (i < nb_clusters) { | |
730 | i += count_contiguous_clusters(nb_clusters - i, s->cluster_size, | |
731 | &l2_table[l2_index], i, 0); | |
4805bb66 | 732 | if ((i >= nb_clusters) || be64_to_cpu(l2_table[l2_index + i])) { |
45aba42f | 733 | break; |
4805bb66 | 734 | } |
45aba42f KW |
735 | |
736 | i += count_contiguous_free_clusters(nb_clusters - i, | |
737 | &l2_table[l2_index + i]); | |
4805bb66 KW |
738 | if (i >= nb_clusters) { |
739 | break; | |
740 | } | |
45aba42f KW |
741 | |
742 | cluster_offset = be64_to_cpu(l2_table[l2_index + i]); | |
743 | ||
744 | if ((cluster_offset & QCOW_OFLAG_COPIED) || | |
745 | (cluster_offset & QCOW_OFLAG_COMPRESSED)) | |
746 | break; | |
747 | } | |
4805bb66 | 748 | assert(i <= nb_clusters); |
45aba42f KW |
749 | nb_clusters = i; |
750 | ||
f214978a KW |
751 | /* |
752 | * Check if there already is an AIO write request in flight which allocates | |
753 | * the same cluster. In this case we need to wait until the previous | |
754 | * request has completed and updated the L2 table accordingly. | |
755 | */ | |
72cf2d4f | 756 | QLIST_FOREACH(old_alloc, &s->cluster_allocs, next_in_flight) { |
f214978a | 757 | |
ee18e730 FZ |
758 | uint64_t start = offset >> s->cluster_bits; |
759 | uint64_t end = start + nb_clusters; | |
760 | uint64_t old_start = old_alloc->offset >> s->cluster_bits; | |
761 | uint64_t old_end = old_start + old_alloc->nb_clusters; | |
f214978a | 762 | |
ee18e730 | 763 | if (end < old_start || start > old_end) { |
f214978a KW |
764 | /* No intersection */ |
765 | } else { | |
ee18e730 | 766 | if (start < old_start) { |
f214978a | 767 | /* Stop at the start of a running allocation */ |
ee18e730 | 768 | nb_clusters = old_start - start; |
f214978a KW |
769 | } else { |
770 | nb_clusters = 0; | |
771 | } | |
772 | ||
773 | if (nb_clusters == 0) { | |
68d100e9 KW |
774 | /* Wait for the dependency to complete. We need to recheck |
775 | * the free/allocated clusters when we continue. */ | |
776 | qemu_co_mutex_unlock(&s->lock); | |
777 | qemu_co_queue_wait(&old_alloc->dependent_requests); | |
778 | qemu_co_mutex_lock(&s->lock); | |
779 | goto again; | |
f214978a KW |
780 | } |
781 | } | |
782 | } | |
783 | ||
784 | if (!nb_clusters) { | |
785 | abort(); | |
786 | } | |
787 | ||
05140499 FZ |
788 | /* save info needed for meta data update */ |
789 | m->offset = offset; | |
790 | m->n_start = n_start; | |
791 | m->nb_clusters = nb_clusters; | |
792 | ||
72cf2d4f | 793 | QLIST_INSERT_HEAD(&s->cluster_allocs, m, next_in_flight); |
f214978a | 794 | |
45aba42f KW |
795 | /* allocate a new cluster */ |
796 | ||
ed6ccf0f | 797 | cluster_offset = qcow2_alloc_clusters(bs, nb_clusters * s->cluster_size); |
5d757b56 | 798 | if (cluster_offset < 0) { |
29c1a730 KW |
799 | ret = cluster_offset; |
800 | goto fail; | |
5d757b56 | 801 | } |
45aba42f | 802 | |
45aba42f | 803 | out: |
29c1a730 KW |
804 | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); |
805 | if (ret < 0) { | |
9e2a3701 | 806 | goto fail_put; |
29c1a730 KW |
807 | } |
808 | ||
45aba42f | 809 | m->nb_available = MIN(nb_clusters << (s->cluster_bits - 9), n_end); |
148da7ea | 810 | m->cluster_offset = cluster_offset; |
45aba42f KW |
811 | |
812 | *num = m->nb_available - n_start; | |
813 | ||
148da7ea | 814 | return 0; |
29c1a730 KW |
815 | |
816 | fail: | |
817 | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); | |
9e2a3701 KW |
818 | fail_put: |
819 | QLIST_REMOVE(m, next_in_flight); | |
29c1a730 | 820 | return ret; |
45aba42f KW |
821 | } |
822 | ||
823 | static int decompress_buffer(uint8_t *out_buf, int out_buf_size, | |
824 | const uint8_t *buf, int buf_size) | |
825 | { | |
826 | z_stream strm1, *strm = &strm1; | |
827 | int ret, out_len; | |
828 | ||
829 | memset(strm, 0, sizeof(*strm)); | |
830 | ||
831 | strm->next_in = (uint8_t *)buf; | |
832 | strm->avail_in = buf_size; | |
833 | strm->next_out = out_buf; | |
834 | strm->avail_out = out_buf_size; | |
835 | ||
836 | ret = inflateInit2(strm, -12); | |
837 | if (ret != Z_OK) | |
838 | return -1; | |
839 | ret = inflate(strm, Z_FINISH); | |
840 | out_len = strm->next_out - out_buf; | |
841 | if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || | |
842 | out_len != out_buf_size) { | |
843 | inflateEnd(strm); | |
844 | return -1; | |
845 | } | |
846 | inflateEnd(strm); | |
847 | return 0; | |
848 | } | |
849 | ||
66f82cee | 850 | int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) |
45aba42f | 851 | { |
66f82cee | 852 | BDRVQcowState *s = bs->opaque; |
45aba42f KW |
853 | int ret, csize, nb_csectors, sector_offset; |
854 | uint64_t coffset; | |
855 | ||
856 | coffset = cluster_offset & s->cluster_offset_mask; | |
857 | if (s->cluster_cache_offset != coffset) { | |
858 | nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1; | |
859 | sector_offset = coffset & 511; | |
860 | csize = nb_csectors * 512 - sector_offset; | |
66f82cee KW |
861 | BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED); |
862 | ret = bdrv_read(bs->file, coffset >> 9, s->cluster_data, nb_csectors); | |
45aba42f | 863 | if (ret < 0) { |
8af36488 | 864 | return ret; |
45aba42f KW |
865 | } |
866 | if (decompress_buffer(s->cluster_cache, s->cluster_size, | |
867 | s->cluster_data + sector_offset, csize) < 0) { | |
8af36488 | 868 | return -EIO; |
45aba42f KW |
869 | } |
870 | s->cluster_cache_offset = coffset; | |
871 | } | |
872 | return 0; | |
873 | } | |
5ea929e3 KW |
874 | |
875 | /* | |
876 | * This discards as many clusters of nb_clusters as possible at once (i.e. | |
877 | * all clusters in the same L2 table) and returns the number of discarded | |
878 | * clusters. | |
879 | */ | |
880 | static int discard_single_l2(BlockDriverState *bs, uint64_t offset, | |
881 | unsigned int nb_clusters) | |
882 | { | |
883 | BDRVQcowState *s = bs->opaque; | |
884 | uint64_t l2_offset, *l2_table; | |
885 | int l2_index; | |
886 | int ret; | |
887 | int i; | |
888 | ||
889 | ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); | |
890 | if (ret < 0) { | |
891 | return ret; | |
892 | } | |
893 | ||
894 | /* Limit nb_clusters to one L2 table */ | |
895 | nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); | |
896 | ||
897 | for (i = 0; i < nb_clusters; i++) { | |
898 | uint64_t old_offset; | |
899 | ||
900 | old_offset = be64_to_cpu(l2_table[l2_index + i]); | |
901 | old_offset &= ~QCOW_OFLAG_COPIED; | |
902 | ||
903 | if (old_offset == 0) { | |
904 | continue; | |
905 | } | |
906 | ||
907 | /* First remove L2 entries */ | |
908 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); | |
909 | l2_table[l2_index + i] = cpu_to_be64(0); | |
910 | ||
911 | /* Then decrease the refcount */ | |
912 | qcow2_free_any_clusters(bs, old_offset, 1); | |
913 | } | |
914 | ||
915 | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); | |
916 | if (ret < 0) { | |
917 | return ret; | |
918 | } | |
919 | ||
920 | return nb_clusters; | |
921 | } | |
922 | ||
923 | int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset, | |
924 | int nb_sectors) | |
925 | { | |
926 | BDRVQcowState *s = bs->opaque; | |
927 | uint64_t end_offset; | |
928 | unsigned int nb_clusters; | |
929 | int ret; | |
930 | ||
931 | end_offset = offset + (nb_sectors << BDRV_SECTOR_BITS); | |
932 | ||
933 | /* Round start up and end down */ | |
934 | offset = align_offset(offset, s->cluster_size); | |
935 | end_offset &= ~(s->cluster_size - 1); | |
936 | ||
937 | if (offset > end_offset) { | |
938 | return 0; | |
939 | } | |
940 | ||
941 | nb_clusters = size_to_clusters(s, end_offset - offset); | |
942 | ||
943 | /* Each L2 table is handled by its own loop iteration */ | |
944 | while (nb_clusters > 0) { | |
945 | ret = discard_single_l2(bs, offset, nb_clusters); | |
946 | if (ret < 0) { | |
947 | return ret; | |
948 | } | |
949 | ||
950 | nb_clusters -= ret; | |
951 | offset += (ret * s->cluster_size); | |
952 | } | |
953 | ||
954 | return 0; | |
955 | } |