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Commit | Line | Data |
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c142442b 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" |
c142442b | 27 | #include "qemu-common.h" |
737e150e | 28 | #include "block/block_int.h" |
c142442b | 29 | #include "block/qcow2.h" |
d49b6836 | 30 | #include "qemu/error-report.h" |
c142442b | 31 | |
ed6ccf0f | 32 | void qcow2_free_snapshots(BlockDriverState *bs) |
c142442b | 33 | { |
ff99129a | 34 | BDRVQcow2State *s = bs->opaque; |
c142442b KW |
35 | int i; |
36 | ||
37 | for(i = 0; i < s->nb_snapshots; i++) { | |
7267c094 AL |
38 | g_free(s->snapshots[i].name); |
39 | g_free(s->snapshots[i].id_str); | |
c142442b | 40 | } |
7267c094 | 41 | g_free(s->snapshots); |
c142442b KW |
42 | s->snapshots = NULL; |
43 | s->nb_snapshots = 0; | |
44 | } | |
45 | ||
ed6ccf0f | 46 | int qcow2_read_snapshots(BlockDriverState *bs) |
c142442b | 47 | { |
ff99129a | 48 | BDRVQcow2State *s = bs->opaque; |
c142442b | 49 | QCowSnapshotHeader h; |
c2c9a466 | 50 | QCowSnapshotExtraData extra; |
c142442b KW |
51 | QCowSnapshot *sn; |
52 | int i, id_str_size, name_size; | |
53 | int64_t offset; | |
54 | uint32_t extra_data_size; | |
42deb29f | 55 | int ret; |
c142442b KW |
56 | |
57 | if (!s->nb_snapshots) { | |
58 | s->snapshots = NULL; | |
59 | s->snapshots_size = 0; | |
60 | return 0; | |
61 | } | |
62 | ||
63 | offset = s->snapshots_offset; | |
5839e53b | 64 | s->snapshots = g_new0(QCowSnapshot, s->nb_snapshots); |
42deb29f | 65 | |
c142442b | 66 | for(i = 0; i < s->nb_snapshots; i++) { |
42deb29f | 67 | /* Read statically sized part of the snapshot header */ |
c142442b | 68 | offset = align_offset(offset, 8); |
9a4f4c31 | 69 | ret = bdrv_pread(bs->file->bs, offset, &h, sizeof(h)); |
42deb29f | 70 | if (ret < 0) { |
c142442b | 71 | goto fail; |
42deb29f KW |
72 | } |
73 | ||
c142442b KW |
74 | offset += sizeof(h); |
75 | sn = s->snapshots + i; | |
76 | sn->l1_table_offset = be64_to_cpu(h.l1_table_offset); | |
77 | sn->l1_size = be32_to_cpu(h.l1_size); | |
78 | sn->vm_state_size = be32_to_cpu(h.vm_state_size); | |
79 | sn->date_sec = be32_to_cpu(h.date_sec); | |
80 | sn->date_nsec = be32_to_cpu(h.date_nsec); | |
81 | sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec); | |
82 | extra_data_size = be32_to_cpu(h.extra_data_size); | |
83 | ||
84 | id_str_size = be16_to_cpu(h.id_str_size); | |
85 | name_size = be16_to_cpu(h.name_size); | |
86 | ||
c2c9a466 | 87 | /* Read extra data */ |
9a4f4c31 | 88 | ret = bdrv_pread(bs->file->bs, offset, &extra, |
c2c9a466 KW |
89 | MIN(sizeof(extra), extra_data_size)); |
90 | if (ret < 0) { | |
91 | goto fail; | |
92 | } | |
c142442b KW |
93 | offset += extra_data_size; |
94 | ||
c2c9a466 KW |
95 | if (extra_data_size >= 8) { |
96 | sn->vm_state_size = be64_to_cpu(extra.vm_state_size_large); | |
97 | } | |
98 | ||
90b27759 KW |
99 | if (extra_data_size >= 16) { |
100 | sn->disk_size = be64_to_cpu(extra.disk_size); | |
101 | } else { | |
102 | sn->disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; | |
103 | } | |
104 | ||
42deb29f | 105 | /* Read snapshot ID */ |
7267c094 | 106 | sn->id_str = g_malloc(id_str_size + 1); |
9a4f4c31 | 107 | ret = bdrv_pread(bs->file->bs, offset, sn->id_str, id_str_size); |
42deb29f | 108 | if (ret < 0) { |
c142442b | 109 | goto fail; |
42deb29f | 110 | } |
c142442b KW |
111 | offset += id_str_size; |
112 | sn->id_str[id_str_size] = '\0'; | |
113 | ||
42deb29f | 114 | /* Read snapshot name */ |
7267c094 | 115 | sn->name = g_malloc(name_size + 1); |
9a4f4c31 | 116 | ret = bdrv_pread(bs->file->bs, offset, sn->name, name_size); |
42deb29f | 117 | if (ret < 0) { |
c142442b | 118 | goto fail; |
42deb29f | 119 | } |
c142442b KW |
120 | offset += name_size; |
121 | sn->name[name_size] = '\0'; | |
5dae6e30 KW |
122 | |
123 | if (offset - s->snapshots_offset > QCOW_MAX_SNAPSHOTS_SIZE) { | |
124 | ret = -EFBIG; | |
125 | goto fail; | |
126 | } | |
c142442b | 127 | } |
42deb29f | 128 | |
5dae6e30 | 129 | assert(offset - s->snapshots_offset <= INT_MAX); |
c142442b KW |
130 | s->snapshots_size = offset - s->snapshots_offset; |
131 | return 0; | |
42deb29f KW |
132 | |
133 | fail: | |
ed6ccf0f | 134 | qcow2_free_snapshots(bs); |
42deb29f | 135 | return ret; |
c142442b KW |
136 | } |
137 | ||
138 | /* add at the end of the file a new list of snapshots */ | |
7c80ab3f | 139 | static int qcow2_write_snapshots(BlockDriverState *bs) |
c142442b | 140 | { |
ff99129a | 141 | BDRVQcow2State *s = bs->opaque; |
c142442b KW |
142 | QCowSnapshot *sn; |
143 | QCowSnapshotHeader h; | |
c2c9a466 | 144 | QCowSnapshotExtraData extra; |
c142442b | 145 | int i, name_size, id_str_size, snapshots_size; |
d69969c4 KW |
146 | struct { |
147 | uint32_t nb_snapshots; | |
148 | uint64_t snapshots_offset; | |
149 | } QEMU_PACKED header_data; | |
5dae6e30 | 150 | int64_t offset, snapshots_offset = 0; |
07fd8779 | 151 | int ret; |
c142442b KW |
152 | |
153 | /* compute the size of the snapshots */ | |
154 | offset = 0; | |
155 | for(i = 0; i < s->nb_snapshots; i++) { | |
156 | sn = s->snapshots + i; | |
157 | offset = align_offset(offset, 8); | |
158 | offset += sizeof(h); | |
c2c9a466 | 159 | offset += sizeof(extra); |
c142442b KW |
160 | offset += strlen(sn->id_str); |
161 | offset += strlen(sn->name); | |
5dae6e30 KW |
162 | |
163 | if (offset > QCOW_MAX_SNAPSHOTS_SIZE) { | |
164 | ret = -EFBIG; | |
165 | goto fail; | |
166 | } | |
c142442b | 167 | } |
5dae6e30 KW |
168 | |
169 | assert(offset <= INT_MAX); | |
c142442b KW |
170 | snapshots_size = offset; |
171 | ||
07fd8779 | 172 | /* Allocate space for the new snapshot list */ |
ed6ccf0f | 173 | snapshots_offset = qcow2_alloc_clusters(bs, snapshots_size); |
c142442b | 174 | offset = snapshots_offset; |
5d757b56 | 175 | if (offset < 0) { |
37d41f0a HR |
176 | ret = offset; |
177 | goto fail; | |
5d757b56 | 178 | } |
f6977f15 SH |
179 | ret = bdrv_flush(bs); |
180 | if (ret < 0) { | |
37d41f0a | 181 | goto fail; |
f6977f15 | 182 | } |
c142442b | 183 | |
cf93980e HR |
184 | /* The snapshot list position has not yet been updated, so these clusters |
185 | * must indeed be completely free */ | |
231bb267 | 186 | ret = qcow2_pre_write_overlap_check(bs, 0, offset, snapshots_size); |
cf93980e | 187 | if (ret < 0) { |
37d41f0a | 188 | goto fail; |
cf93980e HR |
189 | } |
190 | ||
191 | ||
07fd8779 | 192 | /* Write all snapshots to the new list */ |
c142442b KW |
193 | for(i = 0; i < s->nb_snapshots; i++) { |
194 | sn = s->snapshots + i; | |
195 | memset(&h, 0, sizeof(h)); | |
196 | h.l1_table_offset = cpu_to_be64(sn->l1_table_offset); | |
197 | h.l1_size = cpu_to_be32(sn->l1_size); | |
c2c9a466 KW |
198 | /* If it doesn't fit in 32 bit, older implementations should treat it |
199 | * as a disk-only snapshot rather than truncate the VM state */ | |
200 | if (sn->vm_state_size <= 0xffffffff) { | |
201 | h.vm_state_size = cpu_to_be32(sn->vm_state_size); | |
202 | } | |
c142442b KW |
203 | h.date_sec = cpu_to_be32(sn->date_sec); |
204 | h.date_nsec = cpu_to_be32(sn->date_nsec); | |
205 | h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec); | |
c2c9a466 KW |
206 | h.extra_data_size = cpu_to_be32(sizeof(extra)); |
207 | ||
208 | memset(&extra, 0, sizeof(extra)); | |
209 | extra.vm_state_size_large = cpu_to_be64(sn->vm_state_size); | |
90b27759 | 210 | extra.disk_size = cpu_to_be64(sn->disk_size); |
c142442b KW |
211 | |
212 | id_str_size = strlen(sn->id_str); | |
213 | name_size = strlen(sn->name); | |
88fb1535 | 214 | assert(id_str_size <= UINT16_MAX && name_size <= UINT16_MAX); |
c142442b KW |
215 | h.id_str_size = cpu_to_be16(id_str_size); |
216 | h.name_size = cpu_to_be16(name_size); | |
217 | offset = align_offset(offset, 8); | |
07fd8779 | 218 | |
9a4f4c31 | 219 | ret = bdrv_pwrite(bs->file->bs, offset, &h, sizeof(h)); |
07fd8779 | 220 | if (ret < 0) { |
c142442b | 221 | goto fail; |
07fd8779 | 222 | } |
c142442b | 223 | offset += sizeof(h); |
07fd8779 | 224 | |
9a4f4c31 | 225 | ret = bdrv_pwrite(bs->file->bs, offset, &extra, sizeof(extra)); |
c2c9a466 KW |
226 | if (ret < 0) { |
227 | goto fail; | |
228 | } | |
229 | offset += sizeof(extra); | |
230 | ||
9a4f4c31 | 231 | ret = bdrv_pwrite(bs->file->bs, offset, sn->id_str, id_str_size); |
07fd8779 | 232 | if (ret < 0) { |
c142442b | 233 | goto fail; |
07fd8779 | 234 | } |
c142442b | 235 | offset += id_str_size; |
07fd8779 | 236 | |
9a4f4c31 | 237 | ret = bdrv_pwrite(bs->file->bs, offset, sn->name, name_size); |
07fd8779 | 238 | if (ret < 0) { |
c142442b | 239 | goto fail; |
07fd8779 | 240 | } |
c142442b KW |
241 | offset += name_size; |
242 | } | |
243 | ||
07fd8779 KW |
244 | /* |
245 | * Update the header to point to the new snapshot table. This requires the | |
246 | * new table and its refcounts to be stable on disk. | |
07fd8779 KW |
247 | */ |
248 | ret = bdrv_flush(bs); | |
249 | if (ret < 0) { | |
250 | goto fail; | |
251 | } | |
252 | ||
d69969c4 KW |
253 | QEMU_BUILD_BUG_ON(offsetof(QCowHeader, snapshots_offset) != |
254 | offsetof(QCowHeader, nb_snapshots) + sizeof(header_data.nb_snapshots)); | |
255 | ||
256 | header_data.nb_snapshots = cpu_to_be32(s->nb_snapshots); | |
257 | header_data.snapshots_offset = cpu_to_be64(snapshots_offset); | |
07fd8779 | 258 | |
9a4f4c31 | 259 | ret = bdrv_pwrite_sync(bs->file->bs, offsetof(QCowHeader, nb_snapshots), |
d69969c4 | 260 | &header_data, sizeof(header_data)); |
07fd8779 | 261 | if (ret < 0) { |
c142442b | 262 | goto fail; |
07fd8779 | 263 | } |
c142442b KW |
264 | |
265 | /* free the old snapshot table */ | |
6cfcb9b8 KW |
266 | qcow2_free_clusters(bs, s->snapshots_offset, s->snapshots_size, |
267 | QCOW2_DISCARD_SNAPSHOT); | |
c142442b KW |
268 | s->snapshots_offset = snapshots_offset; |
269 | s->snapshots_size = snapshots_size; | |
270 | return 0; | |
07fd8779 KW |
271 | |
272 | fail: | |
9186ad96 HR |
273 | if (snapshots_offset > 0) { |
274 | qcow2_free_clusters(bs, snapshots_offset, snapshots_size, | |
275 | QCOW2_DISCARD_ALWAYS); | |
276 | } | |
07fd8779 | 277 | return ret; |
c142442b KW |
278 | } |
279 | ||
280 | static void find_new_snapshot_id(BlockDriverState *bs, | |
281 | char *id_str, int id_str_size) | |
282 | { | |
ff99129a | 283 | BDRVQcow2State *s = bs->opaque; |
c142442b | 284 | QCowSnapshot *sn; |
00c49b21 HR |
285 | int i; |
286 | unsigned long id, id_max = 0; | |
c142442b KW |
287 | |
288 | for(i = 0; i < s->nb_snapshots; i++) { | |
289 | sn = s->snapshots + i; | |
290 | id = strtoul(sn->id_str, NULL, 10); | |
291 | if (id > id_max) | |
292 | id_max = id; | |
293 | } | |
00c49b21 | 294 | snprintf(id_str, id_str_size, "%lu", id_max + 1); |
c142442b KW |
295 | } |
296 | ||
a89d89d3 WX |
297 | static int find_snapshot_by_id_and_name(BlockDriverState *bs, |
298 | const char *id, | |
299 | const char *name) | |
c142442b | 300 | { |
ff99129a | 301 | BDRVQcow2State *s = bs->opaque; |
c142442b KW |
302 | int i; |
303 | ||
a89d89d3 WX |
304 | if (id && name) { |
305 | for (i = 0; i < s->nb_snapshots; i++) { | |
306 | if (!strcmp(s->snapshots[i].id_str, id) && | |
307 | !strcmp(s->snapshots[i].name, name)) { | |
308 | return i; | |
309 | } | |
310 | } | |
311 | } else if (id) { | |
312 | for (i = 0; i < s->nb_snapshots; i++) { | |
313 | if (!strcmp(s->snapshots[i].id_str, id)) { | |
314 | return i; | |
315 | } | |
316 | } | |
317 | } else if (name) { | |
318 | for (i = 0; i < s->nb_snapshots; i++) { | |
319 | if (!strcmp(s->snapshots[i].name, name)) { | |
320 | return i; | |
321 | } | |
322 | } | |
c142442b | 323 | } |
a89d89d3 | 324 | |
c142442b KW |
325 | return -1; |
326 | } | |
327 | ||
a89d89d3 WX |
328 | static int find_snapshot_by_id_or_name(BlockDriverState *bs, |
329 | const char *id_or_name) | |
c142442b | 330 | { |
a89d89d3 | 331 | int ret; |
c142442b | 332 | |
a89d89d3 WX |
333 | ret = find_snapshot_by_id_and_name(bs, id_or_name, NULL); |
334 | if (ret >= 0) { | |
c142442b | 335 | return ret; |
c142442b | 336 | } |
a89d89d3 | 337 | return find_snapshot_by_id_and_name(bs, NULL, id_or_name); |
c142442b KW |
338 | } |
339 | ||
340 | /* if no id is provided, a new one is constructed */ | |
ed6ccf0f | 341 | int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info) |
c142442b | 342 | { |
ff99129a | 343 | BDRVQcow2State *s = bs->opaque; |
d1ea98d5 KW |
344 | QCowSnapshot *new_snapshot_list = NULL; |
345 | QCowSnapshot *old_snapshot_list = NULL; | |
346 | QCowSnapshot sn1, *sn = &sn1; | |
c142442b KW |
347 | int i, ret; |
348 | uint64_t *l1_table = NULL; | |
5d757b56 | 349 | int64_t l1_table_offset; |
c142442b | 350 | |
ce48f2f4 KW |
351 | if (s->nb_snapshots >= QCOW_MAX_SNAPSHOTS) { |
352 | return -EFBIG; | |
353 | } | |
354 | ||
c142442b KW |
355 | memset(sn, 0, sizeof(*sn)); |
356 | ||
407bc150 YW |
357 | /* Generate an ID */ |
358 | find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str)); | |
c142442b | 359 | |
03343166 | 360 | /* Check that the ID is unique */ |
a89d89d3 | 361 | if (find_snapshot_by_id_and_name(bs, sn_info->id_str, NULL) >= 0) { |
647cc472 | 362 | return -EEXIST; |
03343166 | 363 | } |
c142442b | 364 | |
03343166 | 365 | /* Populate sn with passed data */ |
7267c094 | 366 | sn->id_str = g_strdup(sn_info->id_str); |
7267c094 | 367 | sn->name = g_strdup(sn_info->name); |
03343166 | 368 | |
90b27759 | 369 | sn->disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; |
c142442b KW |
370 | sn->vm_state_size = sn_info->vm_state_size; |
371 | sn->date_sec = sn_info->date_sec; | |
372 | sn->date_nsec = sn_info->date_nsec; | |
373 | sn->vm_clock_nsec = sn_info->vm_clock_nsec; | |
374 | ||
03343166 | 375 | /* Allocate the L1 table of the snapshot and copy the current one there. */ |
5d757b56 KW |
376 | l1_table_offset = qcow2_alloc_clusters(bs, s->l1_size * sizeof(uint64_t)); |
377 | if (l1_table_offset < 0) { | |
d1ea98d5 | 378 | ret = l1_table_offset; |
5d757b56 KW |
379 | goto fail; |
380 | } | |
381 | ||
382 | sn->l1_table_offset = l1_table_offset; | |
c142442b KW |
383 | sn->l1_size = s->l1_size; |
384 | ||
5839e53b | 385 | l1_table = g_try_new(uint64_t, s->l1_size); |
de82815d KW |
386 | if (s->l1_size && l1_table == NULL) { |
387 | ret = -ENOMEM; | |
388 | goto fail; | |
389 | } | |
390 | ||
c142442b KW |
391 | for(i = 0; i < s->l1_size; i++) { |
392 | l1_table[i] = cpu_to_be64(s->l1_table[i]); | |
393 | } | |
d1ea98d5 | 394 | |
231bb267 HR |
395 | ret = qcow2_pre_write_overlap_check(bs, 0, sn->l1_table_offset, |
396 | s->l1_size * sizeof(uint64_t)); | |
cf93980e HR |
397 | if (ret < 0) { |
398 | goto fail; | |
399 | } | |
400 | ||
9a4f4c31 | 401 | ret = bdrv_pwrite(bs->file->bs, sn->l1_table_offset, l1_table, |
d1ea98d5 KW |
402 | s->l1_size * sizeof(uint64_t)); |
403 | if (ret < 0) { | |
c142442b | 404 | goto fail; |
d1ea98d5 KW |
405 | } |
406 | ||
7267c094 | 407 | g_free(l1_table); |
c142442b KW |
408 | l1_table = NULL; |
409 | ||
d1ea98d5 KW |
410 | /* |
411 | * Increase the refcounts of all clusters and make sure everything is | |
412 | * stable on disk before updating the snapshot table to contain a pointer | |
413 | * to the new L1 table. | |
414 | */ | |
415 | ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1); | |
416 | if (ret < 0) { | |
417 | goto fail; | |
418 | } | |
419 | ||
d1ea98d5 | 420 | /* Append the new snapshot to the snapshot list */ |
5839e53b | 421 | new_snapshot_list = g_new(QCowSnapshot, s->nb_snapshots + 1); |
c142442b | 422 | if (s->snapshots) { |
d1ea98d5 KW |
423 | memcpy(new_snapshot_list, s->snapshots, |
424 | s->nb_snapshots * sizeof(QCowSnapshot)); | |
425 | old_snapshot_list = s->snapshots; | |
c142442b | 426 | } |
d1ea98d5 | 427 | s->snapshots = new_snapshot_list; |
c142442b KW |
428 | s->snapshots[s->nb_snapshots++] = *sn; |
429 | ||
d1ea98d5 KW |
430 | ret = qcow2_write_snapshots(bs); |
431 | if (ret < 0) { | |
432 | g_free(s->snapshots); | |
433 | s->snapshots = old_snapshot_list; | |
84757f7e | 434 | s->nb_snapshots--; |
c142442b | 435 | goto fail; |
d1ea98d5 KW |
436 | } |
437 | ||
438 | g_free(old_snapshot_list); | |
439 | ||
1ebf561c KW |
440 | /* The VM state isn't needed any more in the active L1 table; in fact, it |
441 | * hurts by causing expensive COW for the next snapshot. */ | |
442 | qcow2_discard_clusters(bs, qcow2_vm_state_offset(s), | |
443 | align_offset(sn->vm_state_size, s->cluster_size) | |
444 | >> BDRV_SECTOR_BITS, | |
808c4b6f | 445 | QCOW2_DISCARD_NEVER, false); |
1ebf561c | 446 | |
c142442b | 447 | #ifdef DEBUG_ALLOC |
6cbc3031 PH |
448 | { |
449 | BdrvCheckResult result = {0}; | |
b35278f7 | 450 | qcow2_check_refcounts(bs, &result, 0); |
6cbc3031 | 451 | } |
c142442b KW |
452 | #endif |
453 | return 0; | |
03343166 KW |
454 | |
455 | fail: | |
456 | g_free(sn->id_str); | |
7267c094 AL |
457 | g_free(sn->name); |
458 | g_free(l1_table); | |
d1ea98d5 KW |
459 | |
460 | return ret; | |
c142442b KW |
461 | } |
462 | ||
463 | /* copy the snapshot 'snapshot_name' into the current disk image */ | |
ed6ccf0f | 464 | int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id) |
c142442b | 465 | { |
ff99129a | 466 | BDRVQcow2State *s = bs->opaque; |
c142442b | 467 | QCowSnapshot *sn; |
35d7ace7 KW |
468 | int i, snapshot_index; |
469 | int cur_l1_bytes, sn_l1_bytes; | |
589f284b | 470 | int ret; |
43a0cac4 | 471 | uint64_t *sn_l1_table = NULL; |
c142442b | 472 | |
589f284b | 473 | /* Search the snapshot */ |
c142442b | 474 | snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
589f284b | 475 | if (snapshot_index < 0) { |
c142442b | 476 | return -ENOENT; |
589f284b | 477 | } |
c142442b KW |
478 | sn = &s->snapshots[snapshot_index]; |
479 | ||
90b27759 KW |
480 | if (sn->disk_size != bs->total_sectors * BDRV_SECTOR_SIZE) { |
481 | error_report("qcow2: Loading snapshots with different disk " | |
482 | "size is not implemented"); | |
483 | ret = -ENOTSUP; | |
484 | goto fail; | |
485 | } | |
486 | ||
589f284b KW |
487 | /* |
488 | * Make sure that the current L1 table is big enough to contain the whole | |
489 | * L1 table of the snapshot. If the snapshot L1 table is smaller, the | |
490 | * current one must be padded with zeros. | |
491 | */ | |
492 | ret = qcow2_grow_l1_table(bs, sn->l1_size, true); | |
493 | if (ret < 0) { | |
c142442b | 494 | goto fail; |
589f284b | 495 | } |
c142442b | 496 | |
35d7ace7 KW |
497 | cur_l1_bytes = s->l1_size * sizeof(uint64_t); |
498 | sn_l1_bytes = sn->l1_size * sizeof(uint64_t); | |
499 | ||
589f284b KW |
500 | /* |
501 | * Copy the snapshot L1 table to the current L1 table. | |
502 | * | |
503 | * Before overwriting the old current L1 table on disk, make sure to | |
504 | * increase all refcounts for the clusters referenced by the new one. | |
43a0cac4 KW |
505 | * Decrease the refcount referenced by the old one only when the L1 |
506 | * table is overwritten. | |
589f284b | 507 | */ |
de82815d KW |
508 | sn_l1_table = g_try_malloc0(cur_l1_bytes); |
509 | if (cur_l1_bytes && sn_l1_table == NULL) { | |
510 | ret = -ENOMEM; | |
511 | goto fail; | |
512 | } | |
43a0cac4 | 513 | |
9a4f4c31 KW |
514 | ret = bdrv_pread(bs->file->bs, sn->l1_table_offset, |
515 | sn_l1_table, sn_l1_bytes); | |
43a0cac4 KW |
516 | if (ret < 0) { |
517 | goto fail; | |
518 | } | |
519 | ||
520 | ret = qcow2_update_snapshot_refcount(bs, sn->l1_table_offset, | |
521 | sn->l1_size, 1); | |
589f284b | 522 | if (ret < 0) { |
c142442b | 523 | goto fail; |
589f284b KW |
524 | } |
525 | ||
231bb267 HR |
526 | ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L1, |
527 | s->l1_table_offset, cur_l1_bytes); | |
cf93980e HR |
528 | if (ret < 0) { |
529 | goto fail; | |
530 | } | |
531 | ||
9a4f4c31 | 532 | ret = bdrv_pwrite_sync(bs->file->bs, s->l1_table_offset, sn_l1_table, |
589f284b KW |
533 | cur_l1_bytes); |
534 | if (ret < 0) { | |
c142442b | 535 | goto fail; |
589f284b KW |
536 | } |
537 | ||
43a0cac4 KW |
538 | /* |
539 | * Decrease refcount of clusters of current L1 table. | |
540 | * | |
541 | * At this point, the in-memory s->l1_table points to the old L1 table, | |
542 | * whereas on disk we already have the new one. | |
543 | * | |
544 | * qcow2_update_snapshot_refcount special cases the current L1 table to use | |
545 | * the in-memory data instead of really using the offset to load a new one, | |
546 | * which is why this works. | |
547 | */ | |
548 | ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, | |
549 | s->l1_size, -1); | |
550 | ||
551 | /* | |
552 | * Now update the in-memory L1 table to be in sync with the on-disk one. We | |
553 | * need to do this even if updating refcounts failed. | |
554 | */ | |
c142442b | 555 | for(i = 0;i < s->l1_size; i++) { |
43a0cac4 | 556 | s->l1_table[i] = be64_to_cpu(sn_l1_table[i]); |
c142442b KW |
557 | } |
558 | ||
43a0cac4 KW |
559 | if (ret < 0) { |
560 | goto fail; | |
561 | } | |
562 | ||
563 | g_free(sn_l1_table); | |
564 | sn_l1_table = NULL; | |
565 | ||
566 | /* | |
567 | * Update QCOW_OFLAG_COPIED in the active L1 table (it may have changed | |
568 | * when we decreased the refcount of the old snapshot. | |
569 | */ | |
570 | ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0); | |
589f284b | 571 | if (ret < 0) { |
c142442b | 572 | goto fail; |
589f284b | 573 | } |
c142442b KW |
574 | |
575 | #ifdef DEBUG_ALLOC | |
6cbc3031 PH |
576 | { |
577 | BdrvCheckResult result = {0}; | |
b35278f7 | 578 | qcow2_check_refcounts(bs, &result, 0); |
6cbc3031 | 579 | } |
c142442b KW |
580 | #endif |
581 | return 0; | |
589f284b KW |
582 | |
583 | fail: | |
43a0cac4 | 584 | g_free(sn_l1_table); |
589f284b | 585 | return ret; |
c142442b KW |
586 | } |
587 | ||
a89d89d3 WX |
588 | int qcow2_snapshot_delete(BlockDriverState *bs, |
589 | const char *snapshot_id, | |
590 | const char *name, | |
591 | Error **errp) | |
c142442b | 592 | { |
ff99129a | 593 | BDRVQcow2State *s = bs->opaque; |
9a476780 | 594 | QCowSnapshot sn; |
c142442b KW |
595 | int snapshot_index, ret; |
596 | ||
9a476780 | 597 | /* Search the snapshot */ |
a89d89d3 | 598 | snapshot_index = find_snapshot_by_id_and_name(bs, snapshot_id, name); |
9a476780 | 599 | if (snapshot_index < 0) { |
a89d89d3 | 600 | error_setg(errp, "Can't find the snapshot"); |
c142442b | 601 | return -ENOENT; |
9a476780 KW |
602 | } |
603 | sn = s->snapshots[snapshot_index]; | |
c142442b | 604 | |
9a476780 KW |
605 | /* Remove it from the snapshot list */ |
606 | memmove(s->snapshots + snapshot_index, | |
607 | s->snapshots + snapshot_index + 1, | |
608 | (s->nb_snapshots - snapshot_index - 1) * sizeof(sn)); | |
609 | s->nb_snapshots--; | |
610 | ret = qcow2_write_snapshots(bs); | |
611 | if (ret < 0) { | |
39a611a3 JC |
612 | error_setg_errno(errp, -ret, |
613 | "Failed to remove snapshot from snapshot list"); | |
c142442b | 614 | return ret; |
9a476780 KW |
615 | } |
616 | ||
617 | /* | |
618 | * The snapshot is now unused, clean up. If we fail after this point, we | |
619 | * won't recover but just leak clusters. | |
620 | */ | |
621 | g_free(sn.id_str); | |
622 | g_free(sn.name); | |
623 | ||
624 | /* | |
625 | * Now decrease the refcounts of clusters referenced by the snapshot and | |
626 | * free the L1 table. | |
627 | */ | |
628 | ret = qcow2_update_snapshot_refcount(bs, sn.l1_table_offset, | |
629 | sn.l1_size, -1); | |
630 | if (ret < 0) { | |
39a611a3 | 631 | error_setg_errno(errp, -ret, "Failed to free the cluster and L1 table"); |
c142442b | 632 | return ret; |
9a476780 | 633 | } |
6cfcb9b8 KW |
634 | qcow2_free_clusters(bs, sn.l1_table_offset, sn.l1_size * sizeof(uint64_t), |
635 | QCOW2_DISCARD_SNAPSHOT); | |
c142442b | 636 | |
9a476780 KW |
637 | /* must update the copied flag on the current cluster offsets */ |
638 | ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0); | |
c142442b | 639 | if (ret < 0) { |
39a611a3 JC |
640 | error_setg_errno(errp, -ret, |
641 | "Failed to update snapshot status in disk"); | |
c142442b KW |
642 | return ret; |
643 | } | |
9a476780 | 644 | |
c142442b | 645 | #ifdef DEBUG_ALLOC |
6cbc3031 PH |
646 | { |
647 | BdrvCheckResult result = {0}; | |
b35278f7 | 648 | qcow2_check_refcounts(bs, &result, 0); |
6cbc3031 | 649 | } |
c142442b KW |
650 | #endif |
651 | return 0; | |
652 | } | |
653 | ||
ed6ccf0f | 654 | int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab) |
c142442b | 655 | { |
ff99129a | 656 | BDRVQcow2State *s = bs->opaque; |
c142442b KW |
657 | QEMUSnapshotInfo *sn_tab, *sn_info; |
658 | QCowSnapshot *sn; | |
659 | int i; | |
660 | ||
661 | if (!s->nb_snapshots) { | |
662 | *psn_tab = NULL; | |
663 | return s->nb_snapshots; | |
664 | } | |
665 | ||
5839e53b | 666 | sn_tab = g_new0(QEMUSnapshotInfo, s->nb_snapshots); |
c142442b KW |
667 | for(i = 0; i < s->nb_snapshots; i++) { |
668 | sn_info = sn_tab + i; | |
669 | sn = s->snapshots + i; | |
670 | pstrcpy(sn_info->id_str, sizeof(sn_info->id_str), | |
671 | sn->id_str); | |
672 | pstrcpy(sn_info->name, sizeof(sn_info->name), | |
673 | sn->name); | |
674 | sn_info->vm_state_size = sn->vm_state_size; | |
675 | sn_info->date_sec = sn->date_sec; | |
676 | sn_info->date_nsec = sn->date_nsec; | |
677 | sn_info->vm_clock_nsec = sn->vm_clock_nsec; | |
678 | } | |
679 | *psn_tab = sn_tab; | |
680 | return s->nb_snapshots; | |
681 | } | |
682 | ||
7b4c4781 WX |
683 | int qcow2_snapshot_load_tmp(BlockDriverState *bs, |
684 | const char *snapshot_id, | |
685 | const char *name, | |
686 | Error **errp) | |
51ef6727 | 687 | { |
e3f652b3 | 688 | int i, snapshot_index; |
ff99129a | 689 | BDRVQcow2State *s = bs->opaque; |
51ef6727 | 690 | QCowSnapshot *sn; |
e3f652b3 KW |
691 | uint64_t *new_l1_table; |
692 | int new_l1_bytes; | |
693 | int ret; | |
51ef6727 | 694 | |
e3f652b3 KW |
695 | assert(bs->read_only); |
696 | ||
697 | /* Search the snapshot */ | |
7b4c4781 | 698 | snapshot_index = find_snapshot_by_id_and_name(bs, snapshot_id, name); |
51ef6727 | 699 | if (snapshot_index < 0) { |
7b4c4781 WX |
700 | error_setg(errp, |
701 | "Can't find snapshot"); | |
51ef6727 | 702 | return -ENOENT; |
703 | } | |
51ef6727 | 704 | sn = &s->snapshots[snapshot_index]; |
51ef6727 | 705 | |
e3f652b3 | 706 | /* Allocate and read in the snapshot's L1 table */ |
87b86e7e | 707 | if (sn->l1_size > QCOW_MAX_L1_SIZE / sizeof(uint64_t)) { |
6a83f8b5 KW |
708 | error_setg(errp, "Snapshot L1 table too large"); |
709 | return -EFBIG; | |
710 | } | |
c05e4667 | 711 | new_l1_bytes = sn->l1_size * sizeof(uint64_t); |
9a4f4c31 | 712 | new_l1_table = qemu_try_blockalign(bs->file->bs, |
de82815d KW |
713 | align_offset(new_l1_bytes, 512)); |
714 | if (new_l1_table == NULL) { | |
715 | return -ENOMEM; | |
716 | } | |
51ef6727 | 717 | |
9a4f4c31 KW |
718 | ret = bdrv_pread(bs->file->bs, sn->l1_table_offset, |
719 | new_l1_table, new_l1_bytes); | |
e3f652b3 | 720 | if (ret < 0) { |
7b4c4781 | 721 | error_setg(errp, "Failed to read l1 table for snapshot"); |
de82815d | 722 | qemu_vfree(new_l1_table); |
e3f652b3 | 723 | return ret; |
51ef6727 | 724 | } |
725 | ||
e3f652b3 | 726 | /* Switch the L1 table */ |
de82815d | 727 | qemu_vfree(s->l1_table); |
e3f652b3 KW |
728 | |
729 | s->l1_size = sn->l1_size; | |
730 | s->l1_table_offset = sn->l1_table_offset; | |
731 | s->l1_table = new_l1_table; | |
732 | ||
51ef6727 | 733 | for(i = 0;i < s->l1_size; i++) { |
734 | be64_to_cpus(&s->l1_table[i]); | |
735 | } | |
e3f652b3 | 736 | |
51ef6727 | 737 | return 0; |
738 | } |