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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 | ||
25 | #include "block/snapshot.h" | |
26 | #include "block/block_int.h" | |
27 | ||
28 | int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info, | |
29 | const char *name) | |
30 | { | |
31 | QEMUSnapshotInfo *sn_tab, *sn; | |
32 | int nb_sns, i, ret; | |
33 | ||
34 | ret = -ENOENT; | |
35 | nb_sns = bdrv_snapshot_list(bs, &sn_tab); | |
36 | if (nb_sns < 0) { | |
37 | return ret; | |
38 | } | |
39 | for (i = 0; i < nb_sns; i++) { | |
40 | sn = &sn_tab[i]; | |
41 | if (!strcmp(sn->id_str, name) || !strcmp(sn->name, name)) { | |
42 | *sn_info = *sn; | |
43 | ret = 0; | |
44 | break; | |
45 | } | |
46 | } | |
47 | g_free(sn_tab); | |
48 | return ret; | |
49 | } | |
50 | ||
2ea1dd75 WX |
51 | /** |
52 | * Look up an internal snapshot by @id and @name. | |
53 | * @bs: block device to search | |
54 | * @id: unique snapshot ID, or NULL | |
55 | * @name: snapshot name, or NULL | |
56 | * @sn_info: location to store information on the snapshot found | |
57 | * @errp: location to store error, will be set only for exception | |
58 | * | |
59 | * This function will traverse snapshot list in @bs to search the matching | |
60 | * one, @id and @name are the matching condition: | |
61 | * If both @id and @name are specified, find the first one with id @id and | |
62 | * name @name. | |
63 | * If only @id is specified, find the first one with id @id. | |
64 | * If only @name is specified, find the first one with name @name. | |
65 | * if none is specified, abort(). | |
66 | * | |
67 | * Returns: true when a snapshot is found and @sn_info will be filled, false | |
68 | * when error or not found. If all operation succeed but no matching one is | |
69 | * found, @errp will NOT be set. | |
70 | */ | |
71 | bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs, | |
72 | const char *id, | |
73 | const char *name, | |
74 | QEMUSnapshotInfo *sn_info, | |
75 | Error **errp) | |
76 | { | |
77 | QEMUSnapshotInfo *sn_tab, *sn; | |
78 | int nb_sns, i; | |
79 | bool ret = false; | |
80 | ||
81 | assert(id || name); | |
82 | ||
83 | nb_sns = bdrv_snapshot_list(bs, &sn_tab); | |
84 | if (nb_sns < 0) { | |
85 | error_setg_errno(errp, -nb_sns, "Failed to get a snapshot list"); | |
86 | return false; | |
87 | } else if (nb_sns == 0) { | |
88 | return false; | |
89 | } | |
90 | ||
91 | if (id && name) { | |
92 | for (i = 0; i < nb_sns; i++) { | |
93 | sn = &sn_tab[i]; | |
94 | if (!strcmp(sn->id_str, id) && !strcmp(sn->name, name)) { | |
95 | *sn_info = *sn; | |
96 | ret = true; | |
97 | break; | |
98 | } | |
99 | } | |
100 | } else if (id) { | |
101 | for (i = 0; i < nb_sns; i++) { | |
102 | sn = &sn_tab[i]; | |
103 | if (!strcmp(sn->id_str, id)) { | |
104 | *sn_info = *sn; | |
105 | ret = true; | |
106 | break; | |
107 | } | |
108 | } | |
109 | } else if (name) { | |
110 | for (i = 0; i < nb_sns; i++) { | |
111 | sn = &sn_tab[i]; | |
112 | if (!strcmp(sn->name, name)) { | |
113 | *sn_info = *sn; | |
114 | ret = true; | |
115 | break; | |
116 | } | |
117 | } | |
118 | } | |
119 | ||
120 | g_free(sn_tab); | |
121 | return ret; | |
122 | } | |
123 | ||
de08c606 WX |
124 | int bdrv_can_snapshot(BlockDriverState *bs) |
125 | { | |
126 | BlockDriver *drv = bs->drv; | |
127 | if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { | |
128 | return 0; | |
129 | } | |
130 | ||
131 | if (!drv->bdrv_snapshot_create) { | |
132 | if (bs->file != NULL) { | |
133 | return bdrv_can_snapshot(bs->file); | |
134 | } | |
135 | return 0; | |
136 | } | |
137 | ||
138 | return 1; | |
139 | } | |
140 | ||
141 | int bdrv_snapshot_create(BlockDriverState *bs, | |
142 | QEMUSnapshotInfo *sn_info) | |
143 | { | |
144 | BlockDriver *drv = bs->drv; | |
145 | if (!drv) { | |
146 | return -ENOMEDIUM; | |
147 | } | |
148 | if (drv->bdrv_snapshot_create) { | |
149 | return drv->bdrv_snapshot_create(bs, sn_info); | |
150 | } | |
151 | if (bs->file) { | |
152 | return bdrv_snapshot_create(bs->file, sn_info); | |
153 | } | |
154 | return -ENOTSUP; | |
155 | } | |
156 | ||
157 | int bdrv_snapshot_goto(BlockDriverState *bs, | |
158 | const char *snapshot_id) | |
159 | { | |
160 | BlockDriver *drv = bs->drv; | |
161 | int ret, open_ret; | |
162 | ||
163 | if (!drv) { | |
164 | return -ENOMEDIUM; | |
165 | } | |
166 | if (drv->bdrv_snapshot_goto) { | |
167 | return drv->bdrv_snapshot_goto(bs, snapshot_id); | |
168 | } | |
169 | ||
170 | if (bs->file) { | |
171 | drv->bdrv_close(bs); | |
172 | ret = bdrv_snapshot_goto(bs->file, snapshot_id); | |
015a1036 | 173 | open_ret = drv->bdrv_open(bs, NULL, bs->open_flags, NULL); |
de08c606 | 174 | if (open_ret < 0) { |
4f6fd349 | 175 | bdrv_unref(bs->file); |
de08c606 WX |
176 | bs->drv = NULL; |
177 | return open_ret; | |
178 | } | |
179 | return ret; | |
180 | } | |
181 | ||
182 | return -ENOTSUP; | |
183 | } | |
184 | ||
a89d89d3 WX |
185 | /** |
186 | * Delete an internal snapshot by @snapshot_id and @name. | |
187 | * @bs: block device used in the operation | |
188 | * @snapshot_id: unique snapshot ID, or NULL | |
189 | * @name: snapshot name, or NULL | |
190 | * @errp: location to store error | |
191 | * | |
192 | * If both @snapshot_id and @name are specified, delete the first one with | |
193 | * id @snapshot_id and name @name. | |
194 | * If only @snapshot_id is specified, delete the first one with id | |
195 | * @snapshot_id. | |
196 | * If only @name is specified, delete the first one with name @name. | |
197 | * if none is specified, return -ENINVAL. | |
198 | * | |
199 | * Returns: 0 on success, -errno on failure. If @bs is not inserted, return | |
200 | * -ENOMEDIUM. If @snapshot_id and @name are both NULL, return -EINVAL. If @bs | |
201 | * does not support internal snapshot deletion, return -ENOTSUP. If @bs does | |
202 | * not support parameter @snapshot_id or @name, or one of them is not correctly | |
203 | * specified, return -EINVAL. If @bs can't find one matching @id and @name, | |
204 | * return -ENOENT. If @errp != NULL, it will always be filled with error | |
205 | * message on failure. | |
206 | */ | |
207 | int bdrv_snapshot_delete(BlockDriverState *bs, | |
208 | const char *snapshot_id, | |
209 | const char *name, | |
210 | Error **errp) | |
de08c606 WX |
211 | { |
212 | BlockDriver *drv = bs->drv; | |
213 | if (!drv) { | |
a89d89d3 | 214 | error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs)); |
de08c606 WX |
215 | return -ENOMEDIUM; |
216 | } | |
a89d89d3 WX |
217 | if (!snapshot_id && !name) { |
218 | error_setg(errp, "snapshot_id and name are both NULL"); | |
219 | return -EINVAL; | |
220 | } | |
de08c606 | 221 | if (drv->bdrv_snapshot_delete) { |
a89d89d3 | 222 | return drv->bdrv_snapshot_delete(bs, snapshot_id, name, errp); |
de08c606 WX |
223 | } |
224 | if (bs->file) { | |
a89d89d3 | 225 | return bdrv_snapshot_delete(bs->file, snapshot_id, name, errp); |
de08c606 | 226 | } |
a89d89d3 WX |
227 | error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, |
228 | drv->format_name, bdrv_get_device_name(bs), | |
229 | "internal snapshot deletion"); | |
de08c606 WX |
230 | return -ENOTSUP; |
231 | } | |
232 | ||
a89d89d3 WX |
233 | void bdrv_snapshot_delete_by_id_or_name(BlockDriverState *bs, |
234 | const char *id_or_name, | |
235 | Error **errp) | |
236 | { | |
237 | int ret; | |
238 | Error *local_err = NULL; | |
239 | ||
240 | ret = bdrv_snapshot_delete(bs, id_or_name, NULL, &local_err); | |
241 | if (ret == -ENOENT || ret == -EINVAL) { | |
242 | error_free(local_err); | |
243 | local_err = NULL; | |
244 | ret = bdrv_snapshot_delete(bs, NULL, id_or_name, &local_err); | |
245 | } | |
246 | ||
247 | if (ret < 0) { | |
248 | error_propagate(errp, local_err); | |
249 | } | |
250 | } | |
251 | ||
de08c606 WX |
252 | int bdrv_snapshot_list(BlockDriverState *bs, |
253 | QEMUSnapshotInfo **psn_info) | |
254 | { | |
255 | BlockDriver *drv = bs->drv; | |
256 | if (!drv) { | |
257 | return -ENOMEDIUM; | |
258 | } | |
259 | if (drv->bdrv_snapshot_list) { | |
260 | return drv->bdrv_snapshot_list(bs, psn_info); | |
261 | } | |
262 | if (bs->file) { | |
263 | return bdrv_snapshot_list(bs->file, psn_info); | |
264 | } | |
265 | return -ENOTSUP; | |
266 | } | |
267 | ||
268 | int bdrv_snapshot_load_tmp(BlockDriverState *bs, | |
269 | const char *snapshot_name) | |
270 | { | |
271 | BlockDriver *drv = bs->drv; | |
272 | if (!drv) { | |
273 | return -ENOMEDIUM; | |
274 | } | |
275 | if (!bs->read_only) { | |
276 | return -EINVAL; | |
277 | } | |
278 | if (drv->bdrv_snapshot_load_tmp) { | |
279 | return drv->bdrv_snapshot_load_tmp(bs, snapshot_name); | |
280 | } | |
281 | return -ENOTSUP; | |
282 | } |