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Commit | Line | Data |
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de08c606 WX |
1 | /* |
2 | * Block layer snapshot related functions | |
3 | * | |
4 | * Copyright (c) 2003-2008 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" |
de08c606 WX |
26 | #include "block/snapshot.h" |
27 | #include "block/block_int.h" | |
da34e65c | 28 | #include "qapi/error.h" |
cc7a8ea7 | 29 | #include "qapi/qmp/qerror.h" |
de08c606 | 30 | |
8c116b0e WX |
31 | QemuOptsList internal_snapshot_opts = { |
32 | .name = "snapshot", | |
33 | .head = QTAILQ_HEAD_INITIALIZER(internal_snapshot_opts.head), | |
34 | .desc = { | |
35 | { | |
36 | .name = SNAPSHOT_OPT_ID, | |
37 | .type = QEMU_OPT_STRING, | |
38 | .help = "snapshot id" | |
39 | },{ | |
40 | .name = SNAPSHOT_OPT_NAME, | |
41 | .type = QEMU_OPT_STRING, | |
42 | .help = "snapshot name" | |
43 | },{ | |
44 | /* end of list */ | |
45 | } | |
46 | }, | |
47 | }; | |
48 | ||
de08c606 WX |
49 | int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info, |
50 | const char *name) | |
51 | { | |
52 | QEMUSnapshotInfo *sn_tab, *sn; | |
53 | int nb_sns, i, ret; | |
54 | ||
55 | ret = -ENOENT; | |
56 | nb_sns = bdrv_snapshot_list(bs, &sn_tab); | |
57 | if (nb_sns < 0) { | |
58 | return ret; | |
59 | } | |
60 | for (i = 0; i < nb_sns; i++) { | |
61 | sn = &sn_tab[i]; | |
62 | if (!strcmp(sn->id_str, name) || !strcmp(sn->name, name)) { | |
63 | *sn_info = *sn; | |
64 | ret = 0; | |
65 | break; | |
66 | } | |
67 | } | |
68 | g_free(sn_tab); | |
69 | return ret; | |
70 | } | |
71 | ||
2ea1dd75 WX |
72 | /** |
73 | * Look up an internal snapshot by @id and @name. | |
74 | * @bs: block device to search | |
75 | * @id: unique snapshot ID, or NULL | |
76 | * @name: snapshot name, or NULL | |
77 | * @sn_info: location to store information on the snapshot found | |
78 | * @errp: location to store error, will be set only for exception | |
79 | * | |
80 | * This function will traverse snapshot list in @bs to search the matching | |
81 | * one, @id and @name are the matching condition: | |
82 | * If both @id and @name are specified, find the first one with id @id and | |
83 | * name @name. | |
84 | * If only @id is specified, find the first one with id @id. | |
85 | * If only @name is specified, find the first one with name @name. | |
86 | * if none is specified, abort(). | |
87 | * | |
88 | * Returns: true when a snapshot is found and @sn_info will be filled, false | |
89 | * when error or not found. If all operation succeed but no matching one is | |
90 | * found, @errp will NOT be set. | |
91 | */ | |
92 | bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs, | |
93 | const char *id, | |
94 | const char *name, | |
95 | QEMUSnapshotInfo *sn_info, | |
96 | Error **errp) | |
97 | { | |
98 | QEMUSnapshotInfo *sn_tab, *sn; | |
99 | int nb_sns, i; | |
100 | bool ret = false; | |
101 | ||
102 | assert(id || name); | |
103 | ||
104 | nb_sns = bdrv_snapshot_list(bs, &sn_tab); | |
105 | if (nb_sns < 0) { | |
106 | error_setg_errno(errp, -nb_sns, "Failed to get a snapshot list"); | |
107 | return false; | |
108 | } else if (nb_sns == 0) { | |
109 | return false; | |
110 | } | |
111 | ||
112 | if (id && name) { | |
113 | for (i = 0; i < nb_sns; i++) { | |
114 | sn = &sn_tab[i]; | |
115 | if (!strcmp(sn->id_str, id) && !strcmp(sn->name, name)) { | |
116 | *sn_info = *sn; | |
117 | ret = true; | |
118 | break; | |
119 | } | |
120 | } | |
121 | } else if (id) { | |
122 | for (i = 0; i < nb_sns; i++) { | |
123 | sn = &sn_tab[i]; | |
124 | if (!strcmp(sn->id_str, id)) { | |
125 | *sn_info = *sn; | |
126 | ret = true; | |
127 | break; | |
128 | } | |
129 | } | |
130 | } else if (name) { | |
131 | for (i = 0; i < nb_sns; i++) { | |
132 | sn = &sn_tab[i]; | |
133 | if (!strcmp(sn->name, name)) { | |
134 | *sn_info = *sn; | |
135 | ret = true; | |
136 | break; | |
137 | } | |
138 | } | |
139 | } | |
140 | ||
141 | g_free(sn_tab); | |
142 | return ret; | |
143 | } | |
144 | ||
de08c606 WX |
145 | int bdrv_can_snapshot(BlockDriverState *bs) |
146 | { | |
147 | BlockDriver *drv = bs->drv; | |
148 | if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { | |
149 | return 0; | |
150 | } | |
151 | ||
152 | if (!drv->bdrv_snapshot_create) { | |
153 | if (bs->file != NULL) { | |
9a4f4c31 | 154 | return bdrv_can_snapshot(bs->file->bs); |
de08c606 WX |
155 | } |
156 | return 0; | |
157 | } | |
158 | ||
159 | return 1; | |
160 | } | |
161 | ||
162 | int bdrv_snapshot_create(BlockDriverState *bs, | |
163 | QEMUSnapshotInfo *sn_info) | |
164 | { | |
165 | BlockDriver *drv = bs->drv; | |
166 | if (!drv) { | |
167 | return -ENOMEDIUM; | |
168 | } | |
169 | if (drv->bdrv_snapshot_create) { | |
170 | return drv->bdrv_snapshot_create(bs, sn_info); | |
171 | } | |
172 | if (bs->file) { | |
9a4f4c31 | 173 | return bdrv_snapshot_create(bs->file->bs, sn_info); |
de08c606 WX |
174 | } |
175 | return -ENOTSUP; | |
176 | } | |
177 | ||
178 | int bdrv_snapshot_goto(BlockDriverState *bs, | |
179 | const char *snapshot_id) | |
180 | { | |
181 | BlockDriver *drv = bs->drv; | |
182 | int ret, open_ret; | |
183 | ||
184 | if (!drv) { | |
185 | return -ENOMEDIUM; | |
186 | } | |
187 | if (drv->bdrv_snapshot_goto) { | |
188 | return drv->bdrv_snapshot_goto(bs, snapshot_id); | |
189 | } | |
190 | ||
191 | if (bs->file) { | |
192 | drv->bdrv_close(bs); | |
9a4f4c31 | 193 | ret = bdrv_snapshot_goto(bs->file->bs, snapshot_id); |
015a1036 | 194 | open_ret = drv->bdrv_open(bs, NULL, bs->open_flags, NULL); |
de08c606 | 195 | if (open_ret < 0) { |
9a4f4c31 | 196 | bdrv_unref(bs->file->bs); |
de08c606 WX |
197 | bs->drv = NULL; |
198 | return open_ret; | |
199 | } | |
200 | return ret; | |
201 | } | |
202 | ||
203 | return -ENOTSUP; | |
204 | } | |
205 | ||
a89d89d3 WX |
206 | /** |
207 | * Delete an internal snapshot by @snapshot_id and @name. | |
208 | * @bs: block device used in the operation | |
209 | * @snapshot_id: unique snapshot ID, or NULL | |
210 | * @name: snapshot name, or NULL | |
211 | * @errp: location to store error | |
212 | * | |
213 | * If both @snapshot_id and @name are specified, delete the first one with | |
214 | * id @snapshot_id and name @name. | |
215 | * If only @snapshot_id is specified, delete the first one with id | |
216 | * @snapshot_id. | |
217 | * If only @name is specified, delete the first one with name @name. | |
7b4c4781 | 218 | * if none is specified, return -EINVAL. |
a89d89d3 WX |
219 | * |
220 | * Returns: 0 on success, -errno on failure. If @bs is not inserted, return | |
221 | * -ENOMEDIUM. If @snapshot_id and @name are both NULL, return -EINVAL. If @bs | |
222 | * does not support internal snapshot deletion, return -ENOTSUP. If @bs does | |
223 | * not support parameter @snapshot_id or @name, or one of them is not correctly | |
224 | * specified, return -EINVAL. If @bs can't find one matching @id and @name, | |
225 | * return -ENOENT. If @errp != NULL, it will always be filled with error | |
226 | * message on failure. | |
227 | */ | |
228 | int bdrv_snapshot_delete(BlockDriverState *bs, | |
229 | const char *snapshot_id, | |
230 | const char *name, | |
231 | Error **errp) | |
de08c606 WX |
232 | { |
233 | BlockDriver *drv = bs->drv; | |
27a7649a PB |
234 | int ret; |
235 | ||
de08c606 | 236 | if (!drv) { |
c6bd8c70 | 237 | error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs)); |
de08c606 WX |
238 | return -ENOMEDIUM; |
239 | } | |
a89d89d3 WX |
240 | if (!snapshot_id && !name) { |
241 | error_setg(errp, "snapshot_id and name are both NULL"); | |
242 | return -EINVAL; | |
243 | } | |
3432a192 ZH |
244 | |
245 | /* drain all pending i/o before deleting snapshot */ | |
27a7649a | 246 | bdrv_drained_begin(bs); |
3432a192 | 247 | |
de08c606 | 248 | if (drv->bdrv_snapshot_delete) { |
27a7649a PB |
249 | ret = drv->bdrv_snapshot_delete(bs, snapshot_id, name, errp); |
250 | } else if (bs->file) { | |
251 | ret = bdrv_snapshot_delete(bs->file->bs, snapshot_id, name, errp); | |
252 | } else { | |
253 | error_setg(errp, "Block format '%s' used by device '%s' " | |
254 | "does not support internal snapshot deletion", | |
255 | drv->format_name, bdrv_get_device_name(bs)); | |
256 | ret = -ENOTSUP; | |
de08c606 | 257 | } |
27a7649a PB |
258 | |
259 | bdrv_drained_end(bs); | |
260 | return ret; | |
de08c606 WX |
261 | } |
262 | ||
25af925f DL |
263 | int bdrv_snapshot_delete_by_id_or_name(BlockDriverState *bs, |
264 | const char *id_or_name, | |
265 | Error **errp) | |
a89d89d3 WX |
266 | { |
267 | int ret; | |
268 | Error *local_err = NULL; | |
269 | ||
270 | ret = bdrv_snapshot_delete(bs, id_or_name, NULL, &local_err); | |
271 | if (ret == -ENOENT || ret == -EINVAL) { | |
272 | error_free(local_err); | |
273 | local_err = NULL; | |
274 | ret = bdrv_snapshot_delete(bs, NULL, id_or_name, &local_err); | |
275 | } | |
276 | ||
277 | if (ret < 0) { | |
278 | error_propagate(errp, local_err); | |
279 | } | |
25af925f | 280 | return ret; |
a89d89d3 WX |
281 | } |
282 | ||
de08c606 WX |
283 | int bdrv_snapshot_list(BlockDriverState *bs, |
284 | QEMUSnapshotInfo **psn_info) | |
285 | { | |
286 | BlockDriver *drv = bs->drv; | |
287 | if (!drv) { | |
288 | return -ENOMEDIUM; | |
289 | } | |
290 | if (drv->bdrv_snapshot_list) { | |
291 | return drv->bdrv_snapshot_list(bs, psn_info); | |
292 | } | |
293 | if (bs->file) { | |
9a4f4c31 | 294 | return bdrv_snapshot_list(bs->file->bs, psn_info); |
de08c606 WX |
295 | } |
296 | return -ENOTSUP; | |
297 | } | |
298 | ||
7b4c4781 WX |
299 | /** |
300 | * Temporarily load an internal snapshot by @snapshot_id and @name. | |
301 | * @bs: block device used in the operation | |
302 | * @snapshot_id: unique snapshot ID, or NULL | |
303 | * @name: snapshot name, or NULL | |
304 | * @errp: location to store error | |
305 | * | |
306 | * If both @snapshot_id and @name are specified, load the first one with | |
307 | * id @snapshot_id and name @name. | |
308 | * If only @snapshot_id is specified, load the first one with id | |
309 | * @snapshot_id. | |
310 | * If only @name is specified, load the first one with name @name. | |
311 | * if none is specified, return -EINVAL. | |
312 | * | |
313 | * Returns: 0 on success, -errno on fail. If @bs is not inserted, return | |
314 | * -ENOMEDIUM. If @bs is not readonly, return -EINVAL. If @bs did not support | |
315 | * internal snapshot, return -ENOTSUP. If qemu can't find a matching @id and | |
316 | * @name, return -ENOENT. If @errp != NULL, it will always be filled on | |
317 | * failure. | |
318 | */ | |
de08c606 | 319 | int bdrv_snapshot_load_tmp(BlockDriverState *bs, |
7b4c4781 WX |
320 | const char *snapshot_id, |
321 | const char *name, | |
322 | Error **errp) | |
de08c606 WX |
323 | { |
324 | BlockDriver *drv = bs->drv; | |
7b4c4781 | 325 | |
de08c606 | 326 | if (!drv) { |
c6bd8c70 | 327 | error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs)); |
de08c606 WX |
328 | return -ENOMEDIUM; |
329 | } | |
7b4c4781 WX |
330 | if (!snapshot_id && !name) { |
331 | error_setg(errp, "snapshot_id and name are both NULL"); | |
332 | return -EINVAL; | |
333 | } | |
de08c606 | 334 | if (!bs->read_only) { |
7b4c4781 | 335 | error_setg(errp, "Device is not readonly"); |
de08c606 WX |
336 | return -EINVAL; |
337 | } | |
338 | if (drv->bdrv_snapshot_load_tmp) { | |
7b4c4781 | 339 | return drv->bdrv_snapshot_load_tmp(bs, snapshot_id, name, errp); |
de08c606 | 340 | } |
81e5f78a AG |
341 | error_setg(errp, "Block format '%s' used by device '%s' " |
342 | "does not support temporarily loading internal snapshots", | |
343 | drv->format_name, bdrv_get_device_name(bs)); | |
de08c606 WX |
344 | return -ENOTSUP; |
345 | } | |
7b4c4781 WX |
346 | |
347 | int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs, | |
348 | const char *id_or_name, | |
349 | Error **errp) | |
350 | { | |
351 | int ret; | |
352 | Error *local_err = NULL; | |
353 | ||
354 | ret = bdrv_snapshot_load_tmp(bs, id_or_name, NULL, &local_err); | |
355 | if (ret == -ENOENT || ret == -EINVAL) { | |
356 | error_free(local_err); | |
357 | local_err = NULL; | |
358 | ret = bdrv_snapshot_load_tmp(bs, NULL, id_or_name, &local_err); | |
359 | } | |
360 | ||
84d18f06 | 361 | if (local_err) { |
7b4c4781 WX |
362 | error_propagate(errp, local_err); |
363 | } | |
364 | ||
365 | return ret; | |
366 | } | |
e9ff957a DL |
367 | |
368 | ||
369 | /* Group operations. All block drivers are involved. | |
370 | * These functions will properly handle dataplane (take aio_context_acquire | |
371 | * when appropriate for appropriate block drivers) */ | |
372 | ||
373 | bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs) | |
374 | { | |
375 | bool ok = true; | |
7c8eece4 | 376 | BlockDriverState *bs; |
88be7b4b | 377 | BdrvNextIterator it; |
e9ff957a | 378 | |
88be7b4b | 379 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
e9ff957a DL |
380 | AioContext *ctx = bdrv_get_aio_context(bs); |
381 | ||
382 | aio_context_acquire(ctx); | |
383 | if (bdrv_is_inserted(bs) && !bdrv_is_read_only(bs)) { | |
384 | ok = bdrv_can_snapshot(bs); | |
385 | } | |
386 | aio_context_release(ctx); | |
88be7b4b KW |
387 | if (!ok) { |
388 | goto fail; | |
389 | } | |
e9ff957a DL |
390 | } |
391 | ||
88be7b4b | 392 | fail: |
e9ff957a DL |
393 | *first_bad_bs = bs; |
394 | return ok; | |
395 | } | |
9b00ea37 DL |
396 | |
397 | int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bad_bs, | |
398 | Error **err) | |
399 | { | |
400 | int ret = 0; | |
7c8eece4 | 401 | BlockDriverState *bs; |
88be7b4b | 402 | BdrvNextIterator it; |
9b00ea37 DL |
403 | QEMUSnapshotInfo sn1, *snapshot = &sn1; |
404 | ||
88be7b4b | 405 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
9b00ea37 DL |
406 | AioContext *ctx = bdrv_get_aio_context(bs); |
407 | ||
408 | aio_context_acquire(ctx); | |
409 | if (bdrv_can_snapshot(bs) && | |
410 | bdrv_snapshot_find(bs, snapshot, name) >= 0) { | |
411 | ret = bdrv_snapshot_delete_by_id_or_name(bs, name, err); | |
88be7b4b KW |
412 | if (ret < 0) { |
413 | goto fail; | |
414 | } | |
9b00ea37 DL |
415 | } |
416 | aio_context_release(ctx); | |
88be7b4b KW |
417 | if (ret < 0) { |
418 | goto fail; | |
419 | } | |
9b00ea37 DL |
420 | } |
421 | ||
88be7b4b | 422 | fail: |
9b00ea37 DL |
423 | *first_bad_bs = bs; |
424 | return ret; | |
425 | } | |
4c1cdbaa DL |
426 | |
427 | ||
428 | int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs) | |
429 | { | |
430 | int err = 0; | |
7c8eece4 | 431 | BlockDriverState *bs; |
88be7b4b | 432 | BdrvNextIterator it; |
4c1cdbaa | 433 | |
88be7b4b | 434 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
4c1cdbaa DL |
435 | AioContext *ctx = bdrv_get_aio_context(bs); |
436 | ||
437 | aio_context_acquire(ctx); | |
438 | if (bdrv_can_snapshot(bs)) { | |
439 | err = bdrv_snapshot_goto(bs, name); | |
440 | } | |
441 | aio_context_release(ctx); | |
88be7b4b KW |
442 | if (err < 0) { |
443 | goto fail; | |
444 | } | |
4c1cdbaa DL |
445 | } |
446 | ||
88be7b4b | 447 | fail: |
4c1cdbaa DL |
448 | *first_bad_bs = bs; |
449 | return err; | |
450 | } | |
723ccda1 DL |
451 | |
452 | int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs) | |
453 | { | |
454 | QEMUSnapshotInfo sn; | |
455 | int err = 0; | |
7c8eece4 | 456 | BlockDriverState *bs; |
88be7b4b | 457 | BdrvNextIterator it; |
723ccda1 | 458 | |
88be7b4b | 459 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
723ccda1 DL |
460 | AioContext *ctx = bdrv_get_aio_context(bs); |
461 | ||
462 | aio_context_acquire(ctx); | |
463 | if (bdrv_can_snapshot(bs)) { | |
464 | err = bdrv_snapshot_find(bs, &sn, name); | |
465 | } | |
466 | aio_context_release(ctx); | |
88be7b4b KW |
467 | if (err < 0) { |
468 | goto fail; | |
469 | } | |
723ccda1 DL |
470 | } |
471 | ||
88be7b4b | 472 | fail: |
723ccda1 DL |
473 | *first_bad_bs = bs; |
474 | return err; | |
475 | } | |
a9085f9b DL |
476 | |
477 | int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn, | |
478 | BlockDriverState *vm_state_bs, | |
479 | uint64_t vm_state_size, | |
480 | BlockDriverState **first_bad_bs) | |
481 | { | |
482 | int err = 0; | |
7c8eece4 | 483 | BlockDriverState *bs; |
88be7b4b | 484 | BdrvNextIterator it; |
a9085f9b | 485 | |
88be7b4b | 486 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
a9085f9b DL |
487 | AioContext *ctx = bdrv_get_aio_context(bs); |
488 | ||
489 | aio_context_acquire(ctx); | |
490 | if (bs == vm_state_bs) { | |
491 | sn->vm_state_size = vm_state_size; | |
492 | err = bdrv_snapshot_create(bs, sn); | |
493 | } else if (bdrv_can_snapshot(bs)) { | |
494 | sn->vm_state_size = 0; | |
495 | err = bdrv_snapshot_create(bs, sn); | |
496 | } | |
497 | aio_context_release(ctx); | |
88be7b4b KW |
498 | if (err < 0) { |
499 | goto fail; | |
500 | } | |
a9085f9b DL |
501 | } |
502 | ||
88be7b4b | 503 | fail: |
a9085f9b DL |
504 | *first_bad_bs = bs; |
505 | return err; | |
506 | } | |
7cb14481 DL |
507 | |
508 | BlockDriverState *bdrv_all_find_vmstate_bs(void) | |
509 | { | |
7c8eece4 | 510 | BlockDriverState *bs; |
88be7b4b | 511 | BdrvNextIterator it; |
7cb14481 | 512 | |
88be7b4b | 513 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
7cb14481 | 514 | AioContext *ctx = bdrv_get_aio_context(bs); |
88be7b4b | 515 | bool found; |
7cb14481 DL |
516 | |
517 | aio_context_acquire(ctx); | |
88be7b4b | 518 | found = bdrv_can_snapshot(bs); |
7cb14481 | 519 | aio_context_release(ctx); |
88be7b4b KW |
520 | |
521 | if (found) { | |
522 | break; | |
523 | } | |
7cb14481 DL |
524 | } |
525 | return bs; | |
526 | } |