| 1 | /* |
| 2 | * QEMU block dirty bitmap QMP commands |
| 3 | * |
| 4 | * Copyright (c) 2003-2008 Fabrice Bellard |
| 5 | * |
| 6 | * This work is licensed under the terms of the GNU GPL, version 2 or |
| 7 | * later. See the COPYING file in the top-level directory. |
| 8 | * |
| 9 | * This file incorporates work covered by the following copyright and |
| 10 | * permission notice: |
| 11 | * |
| 12 | * Copyright (c) 2003-2008 Fabrice Bellard |
| 13 | * |
| 14 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 15 | * of this software and associated documentation files (the "Software"), to deal |
| 16 | * in the Software without restriction, including without limitation the rights |
| 17 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 18 | * copies of the Software, and to permit persons to whom the Software is |
| 19 | * furnished to do so, subject to the following conditions: |
| 20 | * |
| 21 | * The above copyright notice and this permission notice shall be included in |
| 22 | * all copies or substantial portions of the Software. |
| 23 | * |
| 24 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 25 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 26 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 27 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 28 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 29 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 30 | * THE SOFTWARE. |
| 31 | */ |
| 32 | |
| 33 | #include "qemu/osdep.h" |
| 34 | |
| 35 | #include "block/block-io.h" |
| 36 | #include "block/block_int.h" |
| 37 | #include "block/dirty-bitmap.h" |
| 38 | #include "qapi/qapi-commands-block.h" |
| 39 | #include "qapi/error.h" |
| 40 | |
| 41 | /** |
| 42 | * block_dirty_bitmap_lookup: |
| 43 | * Return a dirty bitmap (if present), after validating |
| 44 | * the node reference and bitmap names. |
| 45 | * |
| 46 | * @node: The name of the BDS node to search for bitmaps |
| 47 | * @name: The name of the bitmap to search for |
| 48 | * @pbs: Output pointer for BDS lookup, if desired. Can be NULL. |
| 49 | * @errp: Output pointer for error information. Can be NULL. |
| 50 | * |
| 51 | * @return: A bitmap object on success, or NULL on failure. |
| 52 | */ |
| 53 | BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node, |
| 54 | const char *name, |
| 55 | BlockDriverState **pbs, |
| 56 | Error **errp) |
| 57 | { |
| 58 | BlockDriverState *bs; |
| 59 | BdrvDirtyBitmap *bitmap; |
| 60 | |
| 61 | GLOBAL_STATE_CODE(); |
| 62 | |
| 63 | if (!node) { |
| 64 | error_setg(errp, "Node cannot be NULL"); |
| 65 | return NULL; |
| 66 | } |
| 67 | if (!name) { |
| 68 | error_setg(errp, "Bitmap name cannot be NULL"); |
| 69 | return NULL; |
| 70 | } |
| 71 | bs = bdrv_lookup_bs(node, node, NULL); |
| 72 | if (!bs) { |
| 73 | error_setg(errp, "Node '%s' not found", node); |
| 74 | return NULL; |
| 75 | } |
| 76 | |
| 77 | bitmap = bdrv_find_dirty_bitmap(bs, name); |
| 78 | if (!bitmap) { |
| 79 | error_setg(errp, "Dirty bitmap '%s' not found", name); |
| 80 | return NULL; |
| 81 | } |
| 82 | |
| 83 | if (pbs) { |
| 84 | *pbs = bs; |
| 85 | } |
| 86 | |
| 87 | return bitmap; |
| 88 | } |
| 89 | |
| 90 | void qmp_block_dirty_bitmap_add(const char *node, const char *name, |
| 91 | bool has_granularity, uint32_t granularity, |
| 92 | bool has_persistent, bool persistent, |
| 93 | bool has_disabled, bool disabled, |
| 94 | Error **errp) |
| 95 | { |
| 96 | BlockDriverState *bs; |
| 97 | BdrvDirtyBitmap *bitmap; |
| 98 | |
| 99 | if (!name || name[0] == '\0') { |
| 100 | error_setg(errp, "Bitmap name cannot be empty"); |
| 101 | return; |
| 102 | } |
| 103 | |
| 104 | bs = bdrv_lookup_bs(node, node, errp); |
| 105 | if (!bs) { |
| 106 | return; |
| 107 | } |
| 108 | |
| 109 | if (has_granularity) { |
| 110 | if (granularity < 512 || !is_power_of_2(granularity)) { |
| 111 | error_setg(errp, "Granularity must be power of 2 " |
| 112 | "and at least 512"); |
| 113 | return; |
| 114 | } |
| 115 | } else { |
| 116 | /* Default to cluster size, if available: */ |
| 117 | granularity = bdrv_get_default_bitmap_granularity(bs); |
| 118 | } |
| 119 | |
| 120 | if (!has_persistent) { |
| 121 | persistent = false; |
| 122 | } |
| 123 | |
| 124 | if (!has_disabled) { |
| 125 | disabled = false; |
| 126 | } |
| 127 | |
| 128 | if (persistent) { |
| 129 | if (!bdrv_is_writable(bs)) { |
| 130 | error_setg(errp, "Cannot add a persistent bitmap to " |
| 131 | "read-only or inactive node '%s'", |
| 132 | bdrv_get_node_name(bs)); |
| 133 | return; |
| 134 | } |
| 135 | |
| 136 | if (!bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp)) { |
| 137 | return; |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | bitmap = bdrv_create_dirty_bitmap(bs, granularity, name, errp); |
| 142 | if (bitmap == NULL) { |
| 143 | return; |
| 144 | } |
| 145 | |
| 146 | if (disabled) { |
| 147 | bdrv_disable_dirty_bitmap(bitmap); |
| 148 | } |
| 149 | |
| 150 | bdrv_dirty_bitmap_set_persistence(bitmap, persistent); |
| 151 | } |
| 152 | |
| 153 | BdrvDirtyBitmap *block_dirty_bitmap_remove(const char *node, const char *name, |
| 154 | bool release, |
| 155 | BlockDriverState **bitmap_bs, |
| 156 | Error **errp) |
| 157 | { |
| 158 | BlockDriverState *bs; |
| 159 | BdrvDirtyBitmap *bitmap; |
| 160 | |
| 161 | GLOBAL_STATE_CODE(); |
| 162 | |
| 163 | bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp); |
| 164 | if (!bitmap || !bs) { |
| 165 | return NULL; |
| 166 | } |
| 167 | |
| 168 | if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_BUSY, errp)) { |
| 169 | return NULL; |
| 170 | } |
| 171 | |
| 172 | /* Dropping a bitmap needs no write access unless it is actually stored. */ |
| 173 | if (bdrv_dirty_bitmap_get_persistence(bitmap) && |
| 174 | bdrv_remove_persistent_dirty_bitmap(bs, name, errp) < 0) |
| 175 | { |
| 176 | return NULL; |
| 177 | } |
| 178 | |
| 179 | if (release) { |
| 180 | bdrv_release_dirty_bitmap(bitmap); |
| 181 | } |
| 182 | |
| 183 | if (bitmap_bs) { |
| 184 | *bitmap_bs = bs; |
| 185 | } |
| 186 | |
| 187 | return release ? NULL : bitmap; |
| 188 | } |
| 189 | |
| 190 | void qmp_block_dirty_bitmap_remove(const char *node, const char *name, |
| 191 | Error **errp) |
| 192 | { |
| 193 | block_dirty_bitmap_remove(node, name, true, NULL, errp); |
| 194 | } |
| 195 | |
| 196 | /** |
| 197 | * Completely clear a bitmap, for the purposes of synchronizing a bitmap |
| 198 | * immediately after a full backup operation. |
| 199 | */ |
| 200 | void qmp_block_dirty_bitmap_clear(const char *node, const char *name, |
| 201 | Error **errp) |
| 202 | { |
| 203 | BdrvDirtyBitmap *bitmap; |
| 204 | BlockDriverState *bs; |
| 205 | |
| 206 | bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp); |
| 207 | if (!bitmap || !bs) { |
| 208 | return; |
| 209 | } |
| 210 | |
| 211 | if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, errp)) { |
| 212 | return; |
| 213 | } |
| 214 | |
| 215 | bdrv_clear_dirty_bitmap(bitmap, NULL); |
| 216 | } |
| 217 | |
| 218 | void qmp_block_dirty_bitmap_enable(const char *node, const char *name, |
| 219 | Error **errp) |
| 220 | { |
| 221 | BlockDriverState *bs; |
| 222 | BdrvDirtyBitmap *bitmap; |
| 223 | |
| 224 | bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp); |
| 225 | if (!bitmap) { |
| 226 | return; |
| 227 | } |
| 228 | |
| 229 | if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_ALLOW_RO, errp)) { |
| 230 | return; |
| 231 | } |
| 232 | |
| 233 | bdrv_enable_dirty_bitmap(bitmap); |
| 234 | } |
| 235 | |
| 236 | void qmp_block_dirty_bitmap_disable(const char *node, const char *name, |
| 237 | Error **errp) |
| 238 | { |
| 239 | BlockDriverState *bs; |
| 240 | BdrvDirtyBitmap *bitmap; |
| 241 | |
| 242 | bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp); |
| 243 | if (!bitmap) { |
| 244 | return; |
| 245 | } |
| 246 | |
| 247 | if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_ALLOW_RO, errp)) { |
| 248 | return; |
| 249 | } |
| 250 | |
| 251 | bdrv_disable_dirty_bitmap(bitmap); |
| 252 | } |
| 253 | |
| 254 | BdrvDirtyBitmap *block_dirty_bitmap_merge(const char *dst_node, |
| 255 | const char *dst_bitmap, |
| 256 | BlockDirtyBitmapOrStrList *bms, |
| 257 | HBitmap **backup, Error **errp) |
| 258 | { |
| 259 | BlockDriverState *bs; |
| 260 | BdrvDirtyBitmap *dst, *src; |
| 261 | BlockDirtyBitmapOrStrList *lst; |
| 262 | const char *src_node, *src_bitmap; |
| 263 | HBitmap *local_backup = NULL; |
| 264 | |
| 265 | GLOBAL_STATE_CODE(); |
| 266 | |
| 267 | dst = block_dirty_bitmap_lookup(dst_node, dst_bitmap, &bs, errp); |
| 268 | if (!dst) { |
| 269 | return NULL; |
| 270 | } |
| 271 | |
| 272 | for (lst = bms; lst; lst = lst->next) { |
| 273 | switch (lst->value->type) { |
| 274 | case QTYPE_QSTRING: |
| 275 | src_bitmap = lst->value->u.local; |
| 276 | src = bdrv_find_dirty_bitmap(bs, src_bitmap); |
| 277 | if (!src) { |
| 278 | error_setg(errp, "Dirty bitmap '%s' not found", src_bitmap); |
| 279 | goto fail; |
| 280 | } |
| 281 | break; |
| 282 | case QTYPE_QDICT: |
| 283 | src_node = lst->value->u.external.node; |
| 284 | src_bitmap = lst->value->u.external.name; |
| 285 | src = block_dirty_bitmap_lookup(src_node, src_bitmap, NULL, errp); |
| 286 | if (!src) { |
| 287 | goto fail; |
| 288 | } |
| 289 | break; |
| 290 | default: |
| 291 | abort(); |
| 292 | } |
| 293 | |
| 294 | /* We do backup only for first merge operation */ |
| 295 | if (!bdrv_merge_dirty_bitmap(dst, src, |
| 296 | local_backup ? NULL : &local_backup, |
| 297 | errp)) |
| 298 | { |
| 299 | goto fail; |
| 300 | } |
| 301 | } |
| 302 | |
| 303 | if (backup) { |
| 304 | *backup = local_backup; |
| 305 | } else { |
| 306 | hbitmap_free(local_backup); |
| 307 | } |
| 308 | |
| 309 | return dst; |
| 310 | |
| 311 | fail: |
| 312 | if (local_backup) { |
| 313 | bdrv_restore_dirty_bitmap(dst, local_backup); |
| 314 | } |
| 315 | |
| 316 | return NULL; |
| 317 | } |
| 318 | |
| 319 | void qmp_block_dirty_bitmap_merge(const char *node, const char *target, |
| 320 | BlockDirtyBitmapOrStrList *bitmaps, |
| 321 | Error **errp) |
| 322 | { |
| 323 | block_dirty_bitmap_merge(node, target, bitmaps, NULL, errp); |
| 324 | } |