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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" |
0d8c41da | 27 | #include "qcow2.h" |
58369e22 | 28 | #include "qemu/bswap.h" |
d49b6836 | 29 | #include "qemu/error-report.h" |
f348b6d1 | 30 | #include "qemu/cutils.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); | |
fcf9a6b7 | 40 | g_free(s->snapshots[i].unknown_extra_data); |
c142442b | 41 | } |
7267c094 | 42 | g_free(s->snapshots); |
c142442b KW |
43 | s->snapshots = NULL; |
44 | s->nb_snapshots = 0; | |
45 | } | |
46 | ||
ecf6c7c0 | 47 | int qcow2_read_snapshots(BlockDriverState *bs, Error **errp) |
c142442b | 48 | { |
ff99129a | 49 | BDRVQcow2State *s = bs->opaque; |
c142442b | 50 | QCowSnapshotHeader h; |
c2c9a466 | 51 | QCowSnapshotExtraData extra; |
c142442b KW |
52 | QCowSnapshot *sn; |
53 | int i, id_str_size, name_size; | |
54 | int64_t offset; | |
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 */ |
9e029689 | 68 | offset = ROUND_UP(offset, 8); |
cf2ab8fc | 69 | ret = bdrv_pread(bs->file, offset, &h, sizeof(h)); |
42deb29f | 70 | if (ret < 0) { |
ecf6c7c0 | 71 | error_setg_errno(errp, -ret, "Failed to read snapshot table"); |
c142442b | 72 | goto fail; |
42deb29f KW |
73 | } |
74 | ||
c142442b KW |
75 | offset += sizeof(h); |
76 | sn = s->snapshots + i; | |
77 | sn->l1_table_offset = be64_to_cpu(h.l1_table_offset); | |
78 | sn->l1_size = be32_to_cpu(h.l1_size); | |
79 | sn->vm_state_size = be32_to_cpu(h.vm_state_size); | |
80 | sn->date_sec = be32_to_cpu(h.date_sec); | |
81 | sn->date_nsec = be32_to_cpu(h.date_nsec); | |
82 | sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec); | |
fcf9a6b7 | 83 | sn->extra_data_size = be32_to_cpu(h.extra_data_size); |
c142442b KW |
84 | |
85 | id_str_size = be16_to_cpu(h.id_str_size); | |
86 | name_size = be16_to_cpu(h.name_size); | |
87 | ||
fcf9a6b7 HR |
88 | if (sn->extra_data_size > QCOW_MAX_SNAPSHOT_EXTRA_DATA) { |
89 | ret = -EFBIG; | |
90 | error_setg(errp, "Too much extra metadata in snapshot table " | |
91 | "entry %i", i); | |
92 | goto fail; | |
93 | } | |
94 | ||
95 | /* Read known extra data */ | |
cf2ab8fc | 96 | ret = bdrv_pread(bs->file, offset, &extra, |
fcf9a6b7 | 97 | MIN(sizeof(extra), sn->extra_data_size)); |
c2c9a466 | 98 | if (ret < 0) { |
ecf6c7c0 | 99 | error_setg_errno(errp, -ret, "Failed to read snapshot table"); |
c2c9a466 KW |
100 | goto fail; |
101 | } | |
fcf9a6b7 | 102 | offset += MIN(sizeof(extra), sn->extra_data_size); |
c142442b | 103 | |
fcf9a6b7 HR |
104 | if (sn->extra_data_size >= endof(QCowSnapshotExtraData, |
105 | vm_state_size_large)) { | |
c2c9a466 KW |
106 | sn->vm_state_size = be64_to_cpu(extra.vm_state_size_large); |
107 | } | |
108 | ||
fcf9a6b7 | 109 | if (sn->extra_data_size >= endof(QCowSnapshotExtraData, disk_size)) { |
90b27759 KW |
110 | sn->disk_size = be64_to_cpu(extra.disk_size); |
111 | } else { | |
112 | sn->disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; | |
113 | } | |
114 | ||
fcf9a6b7 HR |
115 | if (sn->extra_data_size > sizeof(extra)) { |
116 | /* Store unknown extra data */ | |
117 | size_t unknown_extra_data_size = | |
118 | sn->extra_data_size - sizeof(extra); | |
119 | ||
120 | sn->unknown_extra_data = g_malloc(unknown_extra_data_size); | |
121 | ret = bdrv_pread(bs->file, offset, sn->unknown_extra_data, | |
122 | unknown_extra_data_size); | |
123 | if (ret < 0) { | |
124 | error_setg_errno(errp, -ret, "Failed to read snapshot table"); | |
125 | goto fail; | |
126 | } | |
127 | offset += unknown_extra_data_size; | |
128 | } | |
129 | ||
42deb29f | 130 | /* Read snapshot ID */ |
7267c094 | 131 | sn->id_str = g_malloc(id_str_size + 1); |
cf2ab8fc | 132 | ret = bdrv_pread(bs->file, offset, sn->id_str, id_str_size); |
42deb29f | 133 | if (ret < 0) { |
ecf6c7c0 | 134 | error_setg_errno(errp, -ret, "Failed to read snapshot table"); |
c142442b | 135 | goto fail; |
42deb29f | 136 | } |
c142442b KW |
137 | offset += id_str_size; |
138 | sn->id_str[id_str_size] = '\0'; | |
139 | ||
42deb29f | 140 | /* Read snapshot name */ |
7267c094 | 141 | sn->name = g_malloc(name_size + 1); |
cf2ab8fc | 142 | ret = bdrv_pread(bs->file, offset, sn->name, name_size); |
42deb29f | 143 | if (ret < 0) { |
ecf6c7c0 | 144 | error_setg_errno(errp, -ret, "Failed to read snapshot table"); |
c142442b | 145 | goto fail; |
42deb29f | 146 | } |
c142442b KW |
147 | offset += name_size; |
148 | sn->name[name_size] = '\0'; | |
5dae6e30 KW |
149 | |
150 | if (offset - s->snapshots_offset > QCOW_MAX_SNAPSHOTS_SIZE) { | |
151 | ret = -EFBIG; | |
ecf6c7c0 | 152 | error_setg(errp, "Snapshot table is too big"); |
5dae6e30 KW |
153 | goto fail; |
154 | } | |
c142442b | 155 | } |
42deb29f | 156 | |
5dae6e30 | 157 | assert(offset - s->snapshots_offset <= INT_MAX); |
c142442b KW |
158 | s->snapshots_size = offset - s->snapshots_offset; |
159 | return 0; | |
42deb29f KW |
160 | |
161 | fail: | |
ed6ccf0f | 162 | qcow2_free_snapshots(bs); |
42deb29f | 163 | return ret; |
c142442b KW |
164 | } |
165 | ||
166 | /* add at the end of the file a new list of snapshots */ | |
7c80ab3f | 167 | static int qcow2_write_snapshots(BlockDriverState *bs) |
c142442b | 168 | { |
ff99129a | 169 | BDRVQcow2State *s = bs->opaque; |
c142442b KW |
170 | QCowSnapshot *sn; |
171 | QCowSnapshotHeader h; | |
c2c9a466 | 172 | QCowSnapshotExtraData extra; |
c142442b | 173 | int i, name_size, id_str_size, snapshots_size; |
d69969c4 KW |
174 | struct { |
175 | uint32_t nb_snapshots; | |
176 | uint64_t snapshots_offset; | |
177 | } QEMU_PACKED header_data; | |
5dae6e30 | 178 | int64_t offset, snapshots_offset = 0; |
07fd8779 | 179 | int ret; |
c142442b KW |
180 | |
181 | /* compute the size of the snapshots */ | |
182 | offset = 0; | |
183 | for(i = 0; i < s->nb_snapshots; i++) { | |
184 | sn = s->snapshots + i; | |
9e029689 | 185 | offset = ROUND_UP(offset, 8); |
c142442b | 186 | offset += sizeof(h); |
fcf9a6b7 | 187 | offset += MAX(sizeof(extra), sn->extra_data_size); |
c142442b KW |
188 | offset += strlen(sn->id_str); |
189 | offset += strlen(sn->name); | |
5dae6e30 KW |
190 | |
191 | if (offset > QCOW_MAX_SNAPSHOTS_SIZE) { | |
192 | ret = -EFBIG; | |
193 | goto fail; | |
194 | } | |
c142442b | 195 | } |
5dae6e30 KW |
196 | |
197 | assert(offset <= INT_MAX); | |
c142442b KW |
198 | snapshots_size = offset; |
199 | ||
07fd8779 | 200 | /* Allocate space for the new snapshot list */ |
ed6ccf0f | 201 | snapshots_offset = qcow2_alloc_clusters(bs, snapshots_size); |
c142442b | 202 | offset = snapshots_offset; |
5d757b56 | 203 | if (offset < 0) { |
37d41f0a HR |
204 | ret = offset; |
205 | goto fail; | |
5d757b56 | 206 | } |
f6977f15 SH |
207 | ret = bdrv_flush(bs); |
208 | if (ret < 0) { | |
37d41f0a | 209 | goto fail; |
f6977f15 | 210 | } |
c142442b | 211 | |
cf93980e HR |
212 | /* The snapshot list position has not yet been updated, so these clusters |
213 | * must indeed be completely free */ | |
966b000f | 214 | ret = qcow2_pre_write_overlap_check(bs, 0, offset, snapshots_size, false); |
cf93980e | 215 | if (ret < 0) { |
37d41f0a | 216 | goto fail; |
cf93980e HR |
217 | } |
218 | ||
219 | ||
07fd8779 | 220 | /* Write all snapshots to the new list */ |
c142442b KW |
221 | for(i = 0; i < s->nb_snapshots; i++) { |
222 | sn = s->snapshots + i; | |
223 | memset(&h, 0, sizeof(h)); | |
224 | h.l1_table_offset = cpu_to_be64(sn->l1_table_offset); | |
225 | h.l1_size = cpu_to_be32(sn->l1_size); | |
c2c9a466 KW |
226 | /* If it doesn't fit in 32 bit, older implementations should treat it |
227 | * as a disk-only snapshot rather than truncate the VM state */ | |
228 | if (sn->vm_state_size <= 0xffffffff) { | |
229 | h.vm_state_size = cpu_to_be32(sn->vm_state_size); | |
230 | } | |
c142442b KW |
231 | h.date_sec = cpu_to_be32(sn->date_sec); |
232 | h.date_nsec = cpu_to_be32(sn->date_nsec); | |
233 | h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec); | |
fcf9a6b7 HR |
234 | h.extra_data_size = cpu_to_be32(MAX(sizeof(extra), |
235 | sn->extra_data_size)); | |
c2c9a466 KW |
236 | |
237 | memset(&extra, 0, sizeof(extra)); | |
238 | extra.vm_state_size_large = cpu_to_be64(sn->vm_state_size); | |
90b27759 | 239 | extra.disk_size = cpu_to_be64(sn->disk_size); |
c142442b KW |
240 | |
241 | id_str_size = strlen(sn->id_str); | |
242 | name_size = strlen(sn->name); | |
88fb1535 | 243 | assert(id_str_size <= UINT16_MAX && name_size <= UINT16_MAX); |
c142442b KW |
244 | h.id_str_size = cpu_to_be16(id_str_size); |
245 | h.name_size = cpu_to_be16(name_size); | |
9e029689 | 246 | offset = ROUND_UP(offset, 8); |
07fd8779 | 247 | |
d9ca2ea2 | 248 | ret = bdrv_pwrite(bs->file, offset, &h, sizeof(h)); |
07fd8779 | 249 | if (ret < 0) { |
c142442b | 250 | goto fail; |
07fd8779 | 251 | } |
c142442b | 252 | offset += sizeof(h); |
07fd8779 | 253 | |
d9ca2ea2 | 254 | ret = bdrv_pwrite(bs->file, offset, &extra, sizeof(extra)); |
c2c9a466 KW |
255 | if (ret < 0) { |
256 | goto fail; | |
257 | } | |
258 | offset += sizeof(extra); | |
259 | ||
fcf9a6b7 HR |
260 | if (sn->extra_data_size > sizeof(extra)) { |
261 | size_t unknown_extra_data_size = | |
262 | sn->extra_data_size - sizeof(extra); | |
263 | ||
264 | /* qcow2_read_snapshots() ensures no unbounded allocation */ | |
265 | assert(unknown_extra_data_size <= BDRV_REQUEST_MAX_BYTES); | |
266 | assert(sn->unknown_extra_data); | |
267 | ||
268 | ret = bdrv_pwrite(bs->file, offset, sn->unknown_extra_data, | |
269 | unknown_extra_data_size); | |
270 | if (ret < 0) { | |
271 | goto fail; | |
272 | } | |
273 | offset += unknown_extra_data_size; | |
274 | } | |
275 | ||
d9ca2ea2 | 276 | ret = bdrv_pwrite(bs->file, offset, sn->id_str, id_str_size); |
07fd8779 | 277 | if (ret < 0) { |
c142442b | 278 | goto fail; |
07fd8779 | 279 | } |
c142442b | 280 | offset += id_str_size; |
07fd8779 | 281 | |
d9ca2ea2 | 282 | ret = bdrv_pwrite(bs->file, offset, sn->name, name_size); |
07fd8779 | 283 | if (ret < 0) { |
c142442b | 284 | goto fail; |
07fd8779 | 285 | } |
c142442b KW |
286 | offset += name_size; |
287 | } | |
288 | ||
07fd8779 KW |
289 | /* |
290 | * Update the header to point to the new snapshot table. This requires the | |
291 | * new table and its refcounts to be stable on disk. | |
07fd8779 KW |
292 | */ |
293 | ret = bdrv_flush(bs); | |
294 | if (ret < 0) { | |
295 | goto fail; | |
296 | } | |
297 | ||
d69969c4 | 298 | QEMU_BUILD_BUG_ON(offsetof(QCowHeader, snapshots_offset) != |
d8fa8442 | 299 | endof(QCowHeader, nb_snapshots)); |
d69969c4 KW |
300 | |
301 | header_data.nb_snapshots = cpu_to_be32(s->nb_snapshots); | |
302 | header_data.snapshots_offset = cpu_to_be64(snapshots_offset); | |
07fd8779 | 303 | |
d9ca2ea2 | 304 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, nb_snapshots), |
d69969c4 | 305 | &header_data, sizeof(header_data)); |
07fd8779 | 306 | if (ret < 0) { |
c142442b | 307 | goto fail; |
07fd8779 | 308 | } |
c142442b KW |
309 | |
310 | /* free the old snapshot table */ | |
6cfcb9b8 KW |
311 | qcow2_free_clusters(bs, s->snapshots_offset, s->snapshots_size, |
312 | QCOW2_DISCARD_SNAPSHOT); | |
c142442b KW |
313 | s->snapshots_offset = snapshots_offset; |
314 | s->snapshots_size = snapshots_size; | |
315 | return 0; | |
07fd8779 KW |
316 | |
317 | fail: | |
9186ad96 HR |
318 | if (snapshots_offset > 0) { |
319 | qcow2_free_clusters(bs, snapshots_offset, snapshots_size, | |
320 | QCOW2_DISCARD_ALWAYS); | |
321 | } | |
07fd8779 | 322 | return ret; |
c142442b KW |
323 | } |
324 | ||
325 | static void find_new_snapshot_id(BlockDriverState *bs, | |
326 | char *id_str, int id_str_size) | |
327 | { | |
ff99129a | 328 | BDRVQcow2State *s = bs->opaque; |
c142442b | 329 | QCowSnapshot *sn; |
00c49b21 HR |
330 | int i; |
331 | unsigned long id, id_max = 0; | |
c142442b KW |
332 | |
333 | for(i = 0; i < s->nb_snapshots; i++) { | |
334 | sn = s->snapshots + i; | |
335 | id = strtoul(sn->id_str, NULL, 10); | |
336 | if (id > id_max) | |
337 | id_max = id; | |
338 | } | |
00c49b21 | 339 | snprintf(id_str, id_str_size, "%lu", id_max + 1); |
c142442b KW |
340 | } |
341 | ||
a89d89d3 WX |
342 | static int find_snapshot_by_id_and_name(BlockDriverState *bs, |
343 | const char *id, | |
344 | const char *name) | |
c142442b | 345 | { |
ff99129a | 346 | BDRVQcow2State *s = bs->opaque; |
c142442b KW |
347 | int i; |
348 | ||
a89d89d3 WX |
349 | if (id && name) { |
350 | for (i = 0; i < s->nb_snapshots; i++) { | |
351 | if (!strcmp(s->snapshots[i].id_str, id) && | |
352 | !strcmp(s->snapshots[i].name, name)) { | |
353 | return i; | |
354 | } | |
355 | } | |
356 | } else if (id) { | |
357 | for (i = 0; i < s->nb_snapshots; i++) { | |
358 | if (!strcmp(s->snapshots[i].id_str, id)) { | |
359 | return i; | |
360 | } | |
361 | } | |
362 | } else if (name) { | |
363 | for (i = 0; i < s->nb_snapshots; i++) { | |
364 | if (!strcmp(s->snapshots[i].name, name)) { | |
365 | return i; | |
366 | } | |
367 | } | |
c142442b | 368 | } |
a89d89d3 | 369 | |
c142442b KW |
370 | return -1; |
371 | } | |
372 | ||
a89d89d3 WX |
373 | static int find_snapshot_by_id_or_name(BlockDriverState *bs, |
374 | const char *id_or_name) | |
c142442b | 375 | { |
a89d89d3 | 376 | int ret; |
c142442b | 377 | |
a89d89d3 WX |
378 | ret = find_snapshot_by_id_and_name(bs, id_or_name, NULL); |
379 | if (ret >= 0) { | |
c142442b | 380 | return ret; |
c142442b | 381 | } |
a89d89d3 | 382 | return find_snapshot_by_id_and_name(bs, NULL, id_or_name); |
c142442b KW |
383 | } |
384 | ||
385 | /* if no id is provided, a new one is constructed */ | |
ed6ccf0f | 386 | int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info) |
c142442b | 387 | { |
ff99129a | 388 | BDRVQcow2State *s = bs->opaque; |
d1ea98d5 KW |
389 | QCowSnapshot *new_snapshot_list = NULL; |
390 | QCowSnapshot *old_snapshot_list = NULL; | |
391 | QCowSnapshot sn1, *sn = &sn1; | |
c142442b KW |
392 | int i, ret; |
393 | uint64_t *l1_table = NULL; | |
5d757b56 | 394 | int64_t l1_table_offset; |
c142442b | 395 | |
ce48f2f4 KW |
396 | if (s->nb_snapshots >= QCOW_MAX_SNAPSHOTS) { |
397 | return -EFBIG; | |
398 | } | |
399 | ||
aa8b34c1 KW |
400 | if (has_data_file(bs)) { |
401 | return -ENOTSUP; | |
402 | } | |
403 | ||
c142442b KW |
404 | memset(sn, 0, sizeof(*sn)); |
405 | ||
407bc150 YW |
406 | /* Generate an ID */ |
407 | find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str)); | |
c142442b | 408 | |
03343166 | 409 | /* Populate sn with passed data */ |
7267c094 | 410 | sn->id_str = g_strdup(sn_info->id_str); |
7267c094 | 411 | sn->name = g_strdup(sn_info->name); |
03343166 | 412 | |
90b27759 | 413 | sn->disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; |
c142442b KW |
414 | sn->vm_state_size = sn_info->vm_state_size; |
415 | sn->date_sec = sn_info->date_sec; | |
416 | sn->date_nsec = sn_info->date_nsec; | |
417 | sn->vm_clock_nsec = sn_info->vm_clock_nsec; | |
fcf9a6b7 | 418 | sn->extra_data_size = sizeof(QCowSnapshotExtraData); |
c142442b | 419 | |
03343166 | 420 | /* Allocate the L1 table of the snapshot and copy the current one there. */ |
5d757b56 KW |
421 | l1_table_offset = qcow2_alloc_clusters(bs, s->l1_size * sizeof(uint64_t)); |
422 | if (l1_table_offset < 0) { | |
d1ea98d5 | 423 | ret = l1_table_offset; |
5d757b56 KW |
424 | goto fail; |
425 | } | |
426 | ||
427 | sn->l1_table_offset = l1_table_offset; | |
c142442b KW |
428 | sn->l1_size = s->l1_size; |
429 | ||
5839e53b | 430 | l1_table = g_try_new(uint64_t, s->l1_size); |
de82815d KW |
431 | if (s->l1_size && l1_table == NULL) { |
432 | ret = -ENOMEM; | |
433 | goto fail; | |
434 | } | |
435 | ||
c142442b KW |
436 | for(i = 0; i < s->l1_size; i++) { |
437 | l1_table[i] = cpu_to_be64(s->l1_table[i]); | |
438 | } | |
d1ea98d5 | 439 | |
231bb267 | 440 | ret = qcow2_pre_write_overlap_check(bs, 0, sn->l1_table_offset, |
966b000f | 441 | s->l1_size * sizeof(uint64_t), false); |
cf93980e HR |
442 | if (ret < 0) { |
443 | goto fail; | |
444 | } | |
445 | ||
d9ca2ea2 | 446 | ret = bdrv_pwrite(bs->file, sn->l1_table_offset, l1_table, |
d1ea98d5 KW |
447 | s->l1_size * sizeof(uint64_t)); |
448 | if (ret < 0) { | |
c142442b | 449 | goto fail; |
d1ea98d5 KW |
450 | } |
451 | ||
7267c094 | 452 | g_free(l1_table); |
c142442b KW |
453 | l1_table = NULL; |
454 | ||
d1ea98d5 KW |
455 | /* |
456 | * Increase the refcounts of all clusters and make sure everything is | |
457 | * stable on disk before updating the snapshot table to contain a pointer | |
458 | * to the new L1 table. | |
459 | */ | |
460 | ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1); | |
461 | if (ret < 0) { | |
462 | goto fail; | |
463 | } | |
464 | ||
d1ea98d5 | 465 | /* Append the new snapshot to the snapshot list */ |
5839e53b | 466 | new_snapshot_list = g_new(QCowSnapshot, s->nb_snapshots + 1); |
c142442b | 467 | if (s->snapshots) { |
d1ea98d5 KW |
468 | memcpy(new_snapshot_list, s->snapshots, |
469 | s->nb_snapshots * sizeof(QCowSnapshot)); | |
470 | old_snapshot_list = s->snapshots; | |
c142442b | 471 | } |
d1ea98d5 | 472 | s->snapshots = new_snapshot_list; |
c142442b KW |
473 | s->snapshots[s->nb_snapshots++] = *sn; |
474 | ||
d1ea98d5 KW |
475 | ret = qcow2_write_snapshots(bs); |
476 | if (ret < 0) { | |
477 | g_free(s->snapshots); | |
478 | s->snapshots = old_snapshot_list; | |
84757f7e | 479 | s->nb_snapshots--; |
c142442b | 480 | goto fail; |
d1ea98d5 KW |
481 | } |
482 | ||
483 | g_free(old_snapshot_list); | |
484 | ||
1ebf561c KW |
485 | /* The VM state isn't needed any more in the active L1 table; in fact, it |
486 | * hurts by causing expensive COW for the next snapshot. */ | |
d2cb36af | 487 | qcow2_cluster_discard(bs, qcow2_vm_state_offset(s), |
9e029689 | 488 | ROUND_UP(sn->vm_state_size, s->cluster_size), |
d2cb36af | 489 | QCOW2_DISCARD_NEVER, false); |
1ebf561c | 490 | |
c142442b | 491 | #ifdef DEBUG_ALLOC |
6cbc3031 PH |
492 | { |
493 | BdrvCheckResult result = {0}; | |
b35278f7 | 494 | qcow2_check_refcounts(bs, &result, 0); |
6cbc3031 | 495 | } |
c142442b KW |
496 | #endif |
497 | return 0; | |
03343166 KW |
498 | |
499 | fail: | |
500 | g_free(sn->id_str); | |
7267c094 AL |
501 | g_free(sn->name); |
502 | g_free(l1_table); | |
d1ea98d5 KW |
503 | |
504 | return ret; | |
c142442b KW |
505 | } |
506 | ||
507 | /* copy the snapshot 'snapshot_name' into the current disk image */ | |
ed6ccf0f | 508 | int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id) |
c142442b | 509 | { |
ff99129a | 510 | BDRVQcow2State *s = bs->opaque; |
c142442b | 511 | QCowSnapshot *sn; |
a8475d75 | 512 | Error *local_err = NULL; |
35d7ace7 KW |
513 | int i, snapshot_index; |
514 | int cur_l1_bytes, sn_l1_bytes; | |
589f284b | 515 | int ret; |
43a0cac4 | 516 | uint64_t *sn_l1_table = NULL; |
c142442b | 517 | |
aa8b34c1 KW |
518 | if (has_data_file(bs)) { |
519 | return -ENOTSUP; | |
520 | } | |
521 | ||
589f284b | 522 | /* Search the snapshot */ |
c142442b | 523 | snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
589f284b | 524 | if (snapshot_index < 0) { |
c142442b | 525 | return -ENOENT; |
589f284b | 526 | } |
c142442b KW |
527 | sn = &s->snapshots[snapshot_index]; |
528 | ||
a8475d75 AG |
529 | ret = qcow2_validate_table(bs, sn->l1_table_offset, sn->l1_size, |
530 | sizeof(uint64_t), QCOW_MAX_L1_SIZE, | |
531 | "Snapshot L1 table", &local_err); | |
532 | if (ret < 0) { | |
533 | error_report_err(local_err); | |
534 | goto fail; | |
535 | } | |
536 | ||
90b27759 KW |
537 | if (sn->disk_size != bs->total_sectors * BDRV_SECTOR_SIZE) { |
538 | error_report("qcow2: Loading snapshots with different disk " | |
539 | "size is not implemented"); | |
540 | ret = -ENOTSUP; | |
541 | goto fail; | |
542 | } | |
543 | ||
589f284b KW |
544 | /* |
545 | * Make sure that the current L1 table is big enough to contain the whole | |
546 | * L1 table of the snapshot. If the snapshot L1 table is smaller, the | |
547 | * current one must be padded with zeros. | |
548 | */ | |
549 | ret = qcow2_grow_l1_table(bs, sn->l1_size, true); | |
550 | if (ret < 0) { | |
c142442b | 551 | goto fail; |
589f284b | 552 | } |
c142442b | 553 | |
35d7ace7 KW |
554 | cur_l1_bytes = s->l1_size * sizeof(uint64_t); |
555 | sn_l1_bytes = sn->l1_size * sizeof(uint64_t); | |
556 | ||
589f284b KW |
557 | /* |
558 | * Copy the snapshot L1 table to the current L1 table. | |
559 | * | |
560 | * Before overwriting the old current L1 table on disk, make sure to | |
561 | * increase all refcounts for the clusters referenced by the new one. | |
43a0cac4 KW |
562 | * Decrease the refcount referenced by the old one only when the L1 |
563 | * table is overwritten. | |
589f284b | 564 | */ |
de82815d KW |
565 | sn_l1_table = g_try_malloc0(cur_l1_bytes); |
566 | if (cur_l1_bytes && sn_l1_table == NULL) { | |
567 | ret = -ENOMEM; | |
568 | goto fail; | |
569 | } | |
43a0cac4 | 570 | |
cf2ab8fc | 571 | ret = bdrv_pread(bs->file, sn->l1_table_offset, |
9a4f4c31 | 572 | sn_l1_table, sn_l1_bytes); |
43a0cac4 KW |
573 | if (ret < 0) { |
574 | goto fail; | |
575 | } | |
576 | ||
577 | ret = qcow2_update_snapshot_refcount(bs, sn->l1_table_offset, | |
578 | sn->l1_size, 1); | |
589f284b | 579 | if (ret < 0) { |
c142442b | 580 | goto fail; |
589f284b KW |
581 | } |
582 | ||
231bb267 | 583 | ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L1, |
966b000f KW |
584 | s->l1_table_offset, cur_l1_bytes, |
585 | false); | |
cf93980e HR |
586 | if (ret < 0) { |
587 | goto fail; | |
588 | } | |
589 | ||
d9ca2ea2 | 590 | ret = bdrv_pwrite_sync(bs->file, s->l1_table_offset, sn_l1_table, |
589f284b KW |
591 | cur_l1_bytes); |
592 | if (ret < 0) { | |
c142442b | 593 | goto fail; |
589f284b KW |
594 | } |
595 | ||
43a0cac4 KW |
596 | /* |
597 | * Decrease refcount of clusters of current L1 table. | |
598 | * | |
599 | * At this point, the in-memory s->l1_table points to the old L1 table, | |
600 | * whereas on disk we already have the new one. | |
601 | * | |
602 | * qcow2_update_snapshot_refcount special cases the current L1 table to use | |
603 | * the in-memory data instead of really using the offset to load a new one, | |
604 | * which is why this works. | |
605 | */ | |
606 | ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, | |
607 | s->l1_size, -1); | |
608 | ||
609 | /* | |
610 | * Now update the in-memory L1 table to be in sync with the on-disk one. We | |
611 | * need to do this even if updating refcounts failed. | |
612 | */ | |
c142442b | 613 | for(i = 0;i < s->l1_size; i++) { |
43a0cac4 | 614 | s->l1_table[i] = be64_to_cpu(sn_l1_table[i]); |
c142442b KW |
615 | } |
616 | ||
43a0cac4 KW |
617 | if (ret < 0) { |
618 | goto fail; | |
619 | } | |
620 | ||
621 | g_free(sn_l1_table); | |
622 | sn_l1_table = NULL; | |
623 | ||
624 | /* | |
625 | * Update QCOW_OFLAG_COPIED in the active L1 table (it may have changed | |
626 | * when we decreased the refcount of the old snapshot. | |
627 | */ | |
628 | ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0); | |
589f284b | 629 | if (ret < 0) { |
c142442b | 630 | goto fail; |
589f284b | 631 | } |
c142442b KW |
632 | |
633 | #ifdef DEBUG_ALLOC | |
6cbc3031 PH |
634 | { |
635 | BdrvCheckResult result = {0}; | |
b35278f7 | 636 | qcow2_check_refcounts(bs, &result, 0); |
6cbc3031 | 637 | } |
c142442b KW |
638 | #endif |
639 | return 0; | |
589f284b KW |
640 | |
641 | fail: | |
43a0cac4 | 642 | g_free(sn_l1_table); |
589f284b | 643 | return ret; |
c142442b KW |
644 | } |
645 | ||
a89d89d3 WX |
646 | int qcow2_snapshot_delete(BlockDriverState *bs, |
647 | const char *snapshot_id, | |
648 | const char *name, | |
649 | Error **errp) | |
c142442b | 650 | { |
ff99129a | 651 | BDRVQcow2State *s = bs->opaque; |
9a476780 | 652 | QCowSnapshot sn; |
c142442b KW |
653 | int snapshot_index, ret; |
654 | ||
aa8b34c1 KW |
655 | if (has_data_file(bs)) { |
656 | return -ENOTSUP; | |
657 | } | |
658 | ||
9a476780 | 659 | /* Search the snapshot */ |
a89d89d3 | 660 | snapshot_index = find_snapshot_by_id_and_name(bs, snapshot_id, name); |
9a476780 | 661 | if (snapshot_index < 0) { |
a89d89d3 | 662 | error_setg(errp, "Can't find the snapshot"); |
c142442b | 663 | return -ENOENT; |
9a476780 KW |
664 | } |
665 | sn = s->snapshots[snapshot_index]; | |
c142442b | 666 | |
db5794f1 AG |
667 | ret = qcow2_validate_table(bs, sn.l1_table_offset, sn.l1_size, |
668 | sizeof(uint64_t), QCOW_MAX_L1_SIZE, | |
669 | "Snapshot L1 table", errp); | |
670 | if (ret < 0) { | |
671 | return ret; | |
672 | } | |
673 | ||
9a476780 KW |
674 | /* Remove it from the snapshot list */ |
675 | memmove(s->snapshots + snapshot_index, | |
676 | s->snapshots + snapshot_index + 1, | |
677 | (s->nb_snapshots - snapshot_index - 1) * sizeof(sn)); | |
678 | s->nb_snapshots--; | |
679 | ret = qcow2_write_snapshots(bs); | |
680 | if (ret < 0) { | |
39a611a3 JC |
681 | error_setg_errno(errp, -ret, |
682 | "Failed to remove snapshot from snapshot list"); | |
c142442b | 683 | return ret; |
9a476780 KW |
684 | } |
685 | ||
686 | /* | |
687 | * The snapshot is now unused, clean up. If we fail after this point, we | |
688 | * won't recover but just leak clusters. | |
689 | */ | |
fcf9a6b7 | 690 | g_free(sn.unknown_extra_data); |
9a476780 KW |
691 | g_free(sn.id_str); |
692 | g_free(sn.name); | |
693 | ||
694 | /* | |
695 | * Now decrease the refcounts of clusters referenced by the snapshot and | |
696 | * free the L1 table. | |
697 | */ | |
698 | ret = qcow2_update_snapshot_refcount(bs, sn.l1_table_offset, | |
699 | sn.l1_size, -1); | |
700 | if (ret < 0) { | |
39a611a3 | 701 | error_setg_errno(errp, -ret, "Failed to free the cluster and L1 table"); |
c142442b | 702 | return ret; |
9a476780 | 703 | } |
6cfcb9b8 KW |
704 | qcow2_free_clusters(bs, sn.l1_table_offset, sn.l1_size * sizeof(uint64_t), |
705 | QCOW2_DISCARD_SNAPSHOT); | |
c142442b | 706 | |
9a476780 KW |
707 | /* must update the copied flag on the current cluster offsets */ |
708 | ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0); | |
c142442b | 709 | if (ret < 0) { |
39a611a3 JC |
710 | error_setg_errno(errp, -ret, |
711 | "Failed to update snapshot status in disk"); | |
c142442b KW |
712 | return ret; |
713 | } | |
9a476780 | 714 | |
c142442b | 715 | #ifdef DEBUG_ALLOC |
6cbc3031 PH |
716 | { |
717 | BdrvCheckResult result = {0}; | |
b35278f7 | 718 | qcow2_check_refcounts(bs, &result, 0); |
6cbc3031 | 719 | } |
c142442b KW |
720 | #endif |
721 | return 0; | |
722 | } | |
723 | ||
ed6ccf0f | 724 | int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab) |
c142442b | 725 | { |
ff99129a | 726 | BDRVQcow2State *s = bs->opaque; |
c142442b KW |
727 | QEMUSnapshotInfo *sn_tab, *sn_info; |
728 | QCowSnapshot *sn; | |
729 | int i; | |
730 | ||
aa8b34c1 KW |
731 | if (has_data_file(bs)) { |
732 | return -ENOTSUP; | |
733 | } | |
c142442b KW |
734 | if (!s->nb_snapshots) { |
735 | *psn_tab = NULL; | |
736 | return s->nb_snapshots; | |
737 | } | |
738 | ||
5839e53b | 739 | sn_tab = g_new0(QEMUSnapshotInfo, s->nb_snapshots); |
c142442b KW |
740 | for(i = 0; i < s->nb_snapshots; i++) { |
741 | sn_info = sn_tab + i; | |
742 | sn = s->snapshots + i; | |
743 | pstrcpy(sn_info->id_str, sizeof(sn_info->id_str), | |
744 | sn->id_str); | |
745 | pstrcpy(sn_info->name, sizeof(sn_info->name), | |
746 | sn->name); | |
747 | sn_info->vm_state_size = sn->vm_state_size; | |
748 | sn_info->date_sec = sn->date_sec; | |
749 | sn_info->date_nsec = sn->date_nsec; | |
750 | sn_info->vm_clock_nsec = sn->vm_clock_nsec; | |
751 | } | |
752 | *psn_tab = sn_tab; | |
753 | return s->nb_snapshots; | |
754 | } | |
755 | ||
7b4c4781 WX |
756 | int qcow2_snapshot_load_tmp(BlockDriverState *bs, |
757 | const char *snapshot_id, | |
758 | const char *name, | |
759 | Error **errp) | |
51ef6727 | 760 | { |
e3f652b3 | 761 | int i, snapshot_index; |
ff99129a | 762 | BDRVQcow2State *s = bs->opaque; |
51ef6727 | 763 | QCowSnapshot *sn; |
e3f652b3 KW |
764 | uint64_t *new_l1_table; |
765 | int new_l1_bytes; | |
766 | int ret; | |
51ef6727 | 767 | |
e3f652b3 KW |
768 | assert(bs->read_only); |
769 | ||
770 | /* Search the snapshot */ | |
7b4c4781 | 771 | snapshot_index = find_snapshot_by_id_and_name(bs, snapshot_id, name); |
51ef6727 | 772 | if (snapshot_index < 0) { |
7b4c4781 WX |
773 | error_setg(errp, |
774 | "Can't find snapshot"); | |
51ef6727 | 775 | return -ENOENT; |
776 | } | |
51ef6727 | 777 | sn = &s->snapshots[snapshot_index]; |
51ef6727 | 778 | |
e3f652b3 | 779 | /* Allocate and read in the snapshot's L1 table */ |
314e8d39 AG |
780 | ret = qcow2_validate_table(bs, sn->l1_table_offset, sn->l1_size, |
781 | sizeof(uint64_t), QCOW_MAX_L1_SIZE, | |
782 | "Snapshot L1 table", errp); | |
783 | if (ret < 0) { | |
784 | return ret; | |
6a83f8b5 | 785 | } |
c05e4667 | 786 | new_l1_bytes = sn->l1_size * sizeof(uint64_t); |
9a4f4c31 | 787 | new_l1_table = qemu_try_blockalign(bs->file->bs, |
9e029689 | 788 | ROUND_UP(new_l1_bytes, 512)); |
de82815d KW |
789 | if (new_l1_table == NULL) { |
790 | return -ENOMEM; | |
791 | } | |
51ef6727 | 792 | |
cf2ab8fc | 793 | ret = bdrv_pread(bs->file, sn->l1_table_offset, |
9a4f4c31 | 794 | new_l1_table, new_l1_bytes); |
e3f652b3 | 795 | if (ret < 0) { |
7b4c4781 | 796 | error_setg(errp, "Failed to read l1 table for snapshot"); |
de82815d | 797 | qemu_vfree(new_l1_table); |
e3f652b3 | 798 | return ret; |
51ef6727 | 799 | } |
800 | ||
e3f652b3 | 801 | /* Switch the L1 table */ |
de82815d | 802 | qemu_vfree(s->l1_table); |
e3f652b3 KW |
803 | |
804 | s->l1_size = sn->l1_size; | |
805 | s->l1_table_offset = sn->l1_table_offset; | |
806 | s->l1_table = new_l1_table; | |
807 | ||
51ef6727 | 808 | for(i = 0;i < s->l1_size; i++) { |
809 | be64_to_cpus(&s->l1_table[i]); | |
810 | } | |
e3f652b3 | 811 | |
51ef6727 | 812 | return 0; |
813 | } |