Wenchao Xia | de08c60 | 2013-05-25 11:09:43 +0800 | [diff] [blame] | 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 | |
| 51 | int bdrv_can_snapshot(BlockDriverState *bs) |
| 52 | { |
| 53 | BlockDriver *drv = bs->drv; |
| 54 | if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { |
| 55 | return 0; |
| 56 | } |
| 57 | |
| 58 | if (!drv->bdrv_snapshot_create) { |
| 59 | if (bs->file != NULL) { |
| 60 | return bdrv_can_snapshot(bs->file); |
| 61 | } |
| 62 | return 0; |
| 63 | } |
| 64 | |
| 65 | return 1; |
| 66 | } |
| 67 | |
| 68 | int bdrv_snapshot_create(BlockDriverState *bs, |
| 69 | QEMUSnapshotInfo *sn_info) |
| 70 | { |
| 71 | BlockDriver *drv = bs->drv; |
| 72 | if (!drv) { |
| 73 | return -ENOMEDIUM; |
| 74 | } |
| 75 | if (drv->bdrv_snapshot_create) { |
| 76 | return drv->bdrv_snapshot_create(bs, sn_info); |
| 77 | } |
| 78 | if (bs->file) { |
| 79 | return bdrv_snapshot_create(bs->file, sn_info); |
| 80 | } |
| 81 | return -ENOTSUP; |
| 82 | } |
| 83 | |
| 84 | int bdrv_snapshot_goto(BlockDriverState *bs, |
| 85 | const char *snapshot_id) |
| 86 | { |
| 87 | BlockDriver *drv = bs->drv; |
| 88 | int ret, open_ret; |
| 89 | |
| 90 | if (!drv) { |
| 91 | return -ENOMEDIUM; |
| 92 | } |
| 93 | if (drv->bdrv_snapshot_goto) { |
| 94 | return drv->bdrv_snapshot_goto(bs, snapshot_id); |
| 95 | } |
| 96 | |
| 97 | if (bs->file) { |
| 98 | drv->bdrv_close(bs); |
| 99 | ret = bdrv_snapshot_goto(bs->file, snapshot_id); |
| 100 | open_ret = drv->bdrv_open(bs, NULL, bs->open_flags); |
| 101 | if (open_ret < 0) { |
| 102 | bdrv_delete(bs->file); |
| 103 | bs->drv = NULL; |
| 104 | return open_ret; |
| 105 | } |
| 106 | return ret; |
| 107 | } |
| 108 | |
| 109 | return -ENOTSUP; |
| 110 | } |
| 111 | |
| 112 | int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) |
| 113 | { |
| 114 | BlockDriver *drv = bs->drv; |
| 115 | if (!drv) { |
| 116 | return -ENOMEDIUM; |
| 117 | } |
| 118 | if (drv->bdrv_snapshot_delete) { |
| 119 | return drv->bdrv_snapshot_delete(bs, snapshot_id); |
| 120 | } |
| 121 | if (bs->file) { |
| 122 | return bdrv_snapshot_delete(bs->file, snapshot_id); |
| 123 | } |
| 124 | return -ENOTSUP; |
| 125 | } |
| 126 | |
| 127 | int bdrv_snapshot_list(BlockDriverState *bs, |
| 128 | QEMUSnapshotInfo **psn_info) |
| 129 | { |
| 130 | BlockDriver *drv = bs->drv; |
| 131 | if (!drv) { |
| 132 | return -ENOMEDIUM; |
| 133 | } |
| 134 | if (drv->bdrv_snapshot_list) { |
| 135 | return drv->bdrv_snapshot_list(bs, psn_info); |
| 136 | } |
| 137 | if (bs->file) { |
| 138 | return bdrv_snapshot_list(bs->file, psn_info); |
| 139 | } |
| 140 | return -ENOTSUP; |
| 141 | } |
| 142 | |
| 143 | int bdrv_snapshot_load_tmp(BlockDriverState *bs, |
| 144 | const char *snapshot_name) |
| 145 | { |
| 146 | BlockDriver *drv = bs->drv; |
| 147 | if (!drv) { |
| 148 | return -ENOMEDIUM; |
| 149 | } |
| 150 | if (!bs->read_only) { |
| 151 | return -EINVAL; |
| 152 | } |
| 153 | if (drv->bdrv_snapshot_load_tmp) { |
| 154 | return drv->bdrv_snapshot_load_tmp(bs, snapshot_name); |
| 155 | } |
| 156 | return -ENOTSUP; |
| 157 | } |