Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 Red Hat, Inc. |
| 3 | * |
| 4 | * This file is released under the GPL. |
| 5 | */ |
| 6 | |
| 7 | #include "dm-cache-metadata.h" |
| 8 | |
| 9 | #include "persistent-data/dm-array.h" |
| 10 | #include "persistent-data/dm-bitset.h" |
| 11 | #include "persistent-data/dm-space-map.h" |
| 12 | #include "persistent-data/dm-space-map-disk.h" |
| 13 | #include "persistent-data/dm-transaction-manager.h" |
| 14 | |
| 15 | #include <linux/device-mapper.h> |
| 16 | |
| 17 | /*----------------------------------------------------------------*/ |
| 18 | |
| 19 | #define DM_MSG_PREFIX "cache metadata" |
| 20 | |
| 21 | #define CACHE_SUPERBLOCK_MAGIC 06142003 |
| 22 | #define CACHE_SUPERBLOCK_LOCATION 0 |
Joe Thornber | 53d4981 | 2013-10-16 10:59:26 +0100 | [diff] [blame] | 23 | |
| 24 | /* |
| 25 | * defines a range of metadata versions that this module can handle. |
| 26 | */ |
| 27 | #define MIN_CACHE_VERSION 1 |
| 28 | #define MAX_CACHE_VERSION 1 |
| 29 | |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 30 | #define CACHE_METADATA_CACHE_SIZE 64 |
| 31 | |
| 32 | /* |
| 33 | * 3 for btree insert + |
| 34 | * 2 for btree lookup used within space map |
| 35 | */ |
| 36 | #define CACHE_MAX_CONCURRENT_LOCKS 5 |
| 37 | #define SPACE_MAP_ROOT_SIZE 128 |
| 38 | |
| 39 | enum superblock_flag_bits { |
| 40 | /* for spotting crashes that would invalidate the dirty bitset */ |
| 41 | CLEAN_SHUTDOWN, |
| 42 | }; |
| 43 | |
| 44 | /* |
| 45 | * Each mapping from cache block -> origin block carries a set of flags. |
| 46 | */ |
| 47 | enum mapping_bits { |
| 48 | /* |
| 49 | * A valid mapping. Because we're using an array we clear this |
| 50 | * flag for an non existant mapping. |
| 51 | */ |
| 52 | M_VALID = 1, |
| 53 | |
| 54 | /* |
| 55 | * The data on the cache is different from that on the origin. |
| 56 | */ |
| 57 | M_DIRTY = 2 |
| 58 | }; |
| 59 | |
| 60 | struct cache_disk_superblock { |
| 61 | __le32 csum; |
| 62 | __le32 flags; |
| 63 | __le64 blocknr; |
| 64 | |
| 65 | __u8 uuid[16]; |
| 66 | __le64 magic; |
| 67 | __le32 version; |
| 68 | |
| 69 | __u8 policy_name[CACHE_POLICY_NAME_SIZE]; |
| 70 | __le32 policy_hint_size; |
| 71 | |
| 72 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; |
| 73 | __le64 mapping_root; |
| 74 | __le64 hint_root; |
| 75 | |
| 76 | __le64 discard_root; |
| 77 | __le64 discard_block_size; |
| 78 | __le64 discard_nr_blocks; |
| 79 | |
| 80 | __le32 data_block_size; |
| 81 | __le32 metadata_block_size; |
| 82 | __le32 cache_blocks; |
| 83 | |
| 84 | __le32 compat_flags; |
| 85 | __le32 compat_ro_flags; |
| 86 | __le32 incompat_flags; |
| 87 | |
| 88 | __le32 read_hits; |
| 89 | __le32 read_misses; |
| 90 | __le32 write_hits; |
| 91 | __le32 write_misses; |
Mike Snitzer | 4e7f506 | 2013-03-20 17:21:27 +0000 | [diff] [blame] | 92 | |
| 93 | __le32 policy_version[CACHE_POLICY_VERSION_SIZE]; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 94 | } __packed; |
| 95 | |
| 96 | struct dm_cache_metadata { |
| 97 | struct block_device *bdev; |
| 98 | struct dm_block_manager *bm; |
| 99 | struct dm_space_map *metadata_sm; |
| 100 | struct dm_transaction_manager *tm; |
| 101 | |
| 102 | struct dm_array_info info; |
| 103 | struct dm_array_info hint_info; |
| 104 | struct dm_disk_bitset discard_info; |
| 105 | |
| 106 | struct rw_semaphore root_lock; |
| 107 | dm_block_t root; |
| 108 | dm_block_t hint_root; |
| 109 | dm_block_t discard_root; |
| 110 | |
| 111 | sector_t discard_block_size; |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 112 | dm_oblock_t discard_nr_blocks; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 113 | |
| 114 | sector_t data_block_size; |
| 115 | dm_cblock_t cache_blocks; |
| 116 | bool changed:1; |
| 117 | bool clean_when_opened:1; |
| 118 | |
| 119 | char policy_name[CACHE_POLICY_NAME_SIZE]; |
Mike Snitzer | 4e7f506 | 2013-03-20 17:21:27 +0000 | [diff] [blame] | 120 | unsigned policy_version[CACHE_POLICY_VERSION_SIZE]; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 121 | size_t policy_hint_size; |
| 122 | struct dm_cache_statistics stats; |
Joe Thornber | 5a32083 | 2014-03-27 14:13:23 +0000 | [diff] [blame] | 123 | |
| 124 | /* |
| 125 | * Reading the space map root can fail, so we read it into this |
| 126 | * buffer before the superblock is locked and updated. |
| 127 | */ |
| 128 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 129 | }; |
| 130 | |
| 131 | /*------------------------------------------------------------------- |
| 132 | * superblock validator |
| 133 | *-----------------------------------------------------------------*/ |
| 134 | |
| 135 | #define SUPERBLOCK_CSUM_XOR 9031977 |
| 136 | |
| 137 | static void sb_prepare_for_write(struct dm_block_validator *v, |
| 138 | struct dm_block *b, |
| 139 | size_t sb_block_size) |
| 140 | { |
| 141 | struct cache_disk_superblock *disk_super = dm_block_data(b); |
| 142 | |
| 143 | disk_super->blocknr = cpu_to_le64(dm_block_location(b)); |
| 144 | disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags, |
| 145 | sb_block_size - sizeof(__le32), |
| 146 | SUPERBLOCK_CSUM_XOR)); |
| 147 | } |
| 148 | |
Joe Thornber | 53d4981 | 2013-10-16 10:59:26 +0100 | [diff] [blame] | 149 | static int check_metadata_version(struct cache_disk_superblock *disk_super) |
| 150 | { |
| 151 | uint32_t metadata_version = le32_to_cpu(disk_super->version); |
| 152 | if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) { |
| 153 | DMERR("Cache metadata version %u found, but only versions between %u and %u supported.", |
| 154 | metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION); |
| 155 | return -EINVAL; |
| 156 | } |
| 157 | |
| 158 | return 0; |
| 159 | } |
| 160 | |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 161 | static int sb_check(struct dm_block_validator *v, |
| 162 | struct dm_block *b, |
| 163 | size_t sb_block_size) |
| 164 | { |
| 165 | struct cache_disk_superblock *disk_super = dm_block_data(b); |
| 166 | __le32 csum_le; |
| 167 | |
| 168 | if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) { |
| 169 | DMERR("sb_check failed: blocknr %llu: wanted %llu", |
| 170 | le64_to_cpu(disk_super->blocknr), |
| 171 | (unsigned long long)dm_block_location(b)); |
| 172 | return -ENOTBLK; |
| 173 | } |
| 174 | |
| 175 | if (le64_to_cpu(disk_super->magic) != CACHE_SUPERBLOCK_MAGIC) { |
| 176 | DMERR("sb_check failed: magic %llu: wanted %llu", |
| 177 | le64_to_cpu(disk_super->magic), |
| 178 | (unsigned long long)CACHE_SUPERBLOCK_MAGIC); |
| 179 | return -EILSEQ; |
| 180 | } |
| 181 | |
| 182 | csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags, |
| 183 | sb_block_size - sizeof(__le32), |
| 184 | SUPERBLOCK_CSUM_XOR)); |
| 185 | if (csum_le != disk_super->csum) { |
| 186 | DMERR("sb_check failed: csum %u: wanted %u", |
| 187 | le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum)); |
| 188 | return -EILSEQ; |
| 189 | } |
| 190 | |
Joe Thornber | 53d4981 | 2013-10-16 10:59:26 +0100 | [diff] [blame] | 191 | return check_metadata_version(disk_super); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 192 | } |
| 193 | |
| 194 | static struct dm_block_validator sb_validator = { |
| 195 | .name = "superblock", |
| 196 | .prepare_for_write = sb_prepare_for_write, |
| 197 | .check = sb_check |
| 198 | }; |
| 199 | |
| 200 | /*----------------------------------------------------------------*/ |
| 201 | |
| 202 | static int superblock_read_lock(struct dm_cache_metadata *cmd, |
| 203 | struct dm_block **sblock) |
| 204 | { |
| 205 | return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION, |
| 206 | &sb_validator, sblock); |
| 207 | } |
| 208 | |
| 209 | static int superblock_lock_zero(struct dm_cache_metadata *cmd, |
| 210 | struct dm_block **sblock) |
| 211 | { |
| 212 | return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION, |
| 213 | &sb_validator, sblock); |
| 214 | } |
| 215 | |
| 216 | static int superblock_lock(struct dm_cache_metadata *cmd, |
| 217 | struct dm_block **sblock) |
| 218 | { |
| 219 | return dm_bm_write_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION, |
| 220 | &sb_validator, sblock); |
| 221 | } |
| 222 | |
| 223 | /*----------------------------------------------------------------*/ |
| 224 | |
Joe Thornber | dd8b0c2 | 2013-10-24 14:10:28 -0400 | [diff] [blame] | 225 | static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result) |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 226 | { |
| 227 | int r; |
| 228 | unsigned i; |
| 229 | struct dm_block *b; |
| 230 | __le64 *data_le, zero = cpu_to_le64(0); |
| 231 | unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64); |
| 232 | |
| 233 | /* |
| 234 | * We can't use a validator here - it may be all zeroes. |
| 235 | */ |
| 236 | r = dm_bm_read_lock(bm, CACHE_SUPERBLOCK_LOCATION, NULL, &b); |
| 237 | if (r) |
| 238 | return r; |
| 239 | |
| 240 | data_le = dm_block_data(b); |
Joe Thornber | dd8b0c2 | 2013-10-24 14:10:28 -0400 | [diff] [blame] | 241 | *result = true; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 242 | for (i = 0; i < sb_block_size; i++) { |
| 243 | if (data_le[i] != zero) { |
Joe Thornber | dd8b0c2 | 2013-10-24 14:10:28 -0400 | [diff] [blame] | 244 | *result = false; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 245 | break; |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | return dm_bm_unlock(b); |
| 250 | } |
| 251 | |
| 252 | static void __setup_mapping_info(struct dm_cache_metadata *cmd) |
| 253 | { |
| 254 | struct dm_btree_value_type vt; |
| 255 | |
| 256 | vt.context = NULL; |
| 257 | vt.size = sizeof(__le64); |
| 258 | vt.inc = NULL; |
| 259 | vt.dec = NULL; |
| 260 | vt.equal = NULL; |
| 261 | dm_array_info_init(&cmd->info, cmd->tm, &vt); |
| 262 | |
| 263 | if (cmd->policy_hint_size) { |
| 264 | vt.size = sizeof(__le32); |
| 265 | dm_array_info_init(&cmd->hint_info, cmd->tm, &vt); |
| 266 | } |
| 267 | } |
| 268 | |
Joe Thornber | 5a32083 | 2014-03-27 14:13:23 +0000 | [diff] [blame] | 269 | static int __save_sm_root(struct dm_cache_metadata *cmd) |
| 270 | { |
| 271 | int r; |
| 272 | size_t metadata_len; |
| 273 | |
| 274 | r = dm_sm_root_size(cmd->metadata_sm, &metadata_len); |
| 275 | if (r < 0) |
| 276 | return r; |
| 277 | |
| 278 | return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root, |
| 279 | metadata_len); |
| 280 | } |
| 281 | |
| 282 | static void __copy_sm_root(struct dm_cache_metadata *cmd, |
| 283 | struct cache_disk_superblock *disk_super) |
| 284 | { |
| 285 | memcpy(&disk_super->metadata_space_map_root, |
| 286 | &cmd->metadata_space_map_root, |
| 287 | sizeof(cmd->metadata_space_map_root)); |
| 288 | } |
| 289 | |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 290 | static int __write_initial_superblock(struct dm_cache_metadata *cmd) |
| 291 | { |
| 292 | int r; |
| 293 | struct dm_block *sblock; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 294 | struct cache_disk_superblock *disk_super; |
| 295 | sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT; |
| 296 | |
| 297 | /* FIXME: see if we can lose the max sectors limit */ |
| 298 | if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS) |
| 299 | bdev_size = DM_CACHE_METADATA_MAX_SECTORS; |
| 300 | |
Joe Thornber | 5a32083 | 2014-03-27 14:13:23 +0000 | [diff] [blame] | 301 | r = dm_tm_pre_commit(cmd->tm); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 302 | if (r < 0) |
| 303 | return r; |
| 304 | |
Joe Thornber | 5a32083 | 2014-03-27 14:13:23 +0000 | [diff] [blame] | 305 | /* |
| 306 | * dm_sm_copy_root() can fail. So we need to do it before we start |
| 307 | * updating the superblock. |
| 308 | */ |
| 309 | r = __save_sm_root(cmd); |
| 310 | if (r) |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 311 | return r; |
| 312 | |
| 313 | r = superblock_lock_zero(cmd, &sblock); |
| 314 | if (r) |
| 315 | return r; |
| 316 | |
| 317 | disk_super = dm_block_data(sblock); |
| 318 | disk_super->flags = 0; |
| 319 | memset(disk_super->uuid, 0, sizeof(disk_super->uuid)); |
| 320 | disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC); |
Joe Thornber | 53d4981 | 2013-10-16 10:59:26 +0100 | [diff] [blame] | 321 | disk_super->version = cpu_to_le32(MAX_CACHE_VERSION); |
Mike Snitzer | 4e7f506 | 2013-03-20 17:21:27 +0000 | [diff] [blame] | 322 | memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name)); |
| 323 | memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version)); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 324 | disk_super->policy_hint_size = 0; |
| 325 | |
Joe Thornber | 5a32083 | 2014-03-27 14:13:23 +0000 | [diff] [blame] | 326 | __copy_sm_root(cmd, disk_super); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 327 | |
| 328 | disk_super->mapping_root = cpu_to_le64(cmd->root); |
| 329 | disk_super->hint_root = cpu_to_le64(cmd->hint_root); |
| 330 | disk_super->discard_root = cpu_to_le64(cmd->discard_root); |
| 331 | disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size); |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 332 | disk_super->discard_nr_blocks = cpu_to_le64(from_oblock(cmd->discard_nr_blocks)); |
Mike Snitzer | 895b47d | 2014-07-14 15:37:18 -0400 | [diff] [blame] | 333 | disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 334 | disk_super->data_block_size = cpu_to_le32(cmd->data_block_size); |
| 335 | disk_super->cache_blocks = cpu_to_le32(0); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 336 | |
| 337 | disk_super->read_hits = cpu_to_le32(0); |
| 338 | disk_super->read_misses = cpu_to_le32(0); |
| 339 | disk_super->write_hits = cpu_to_le32(0); |
| 340 | disk_super->write_misses = cpu_to_le32(0); |
| 341 | |
| 342 | return dm_tm_commit(cmd->tm, sblock); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 343 | } |
| 344 | |
| 345 | static int __format_metadata(struct dm_cache_metadata *cmd) |
| 346 | { |
| 347 | int r; |
| 348 | |
| 349 | r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION, |
| 350 | &cmd->tm, &cmd->metadata_sm); |
| 351 | if (r < 0) { |
| 352 | DMERR("tm_create_with_sm failed"); |
| 353 | return r; |
| 354 | } |
| 355 | |
| 356 | __setup_mapping_info(cmd); |
| 357 | |
| 358 | r = dm_array_empty(&cmd->info, &cmd->root); |
| 359 | if (r < 0) |
| 360 | goto bad; |
| 361 | |
| 362 | dm_disk_bitset_init(cmd->tm, &cmd->discard_info); |
| 363 | |
| 364 | r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root); |
| 365 | if (r < 0) |
| 366 | goto bad; |
| 367 | |
| 368 | cmd->discard_block_size = 0; |
| 369 | cmd->discard_nr_blocks = 0; |
| 370 | |
| 371 | r = __write_initial_superblock(cmd); |
| 372 | if (r) |
| 373 | goto bad; |
| 374 | |
| 375 | cmd->clean_when_opened = true; |
| 376 | return 0; |
| 377 | |
| 378 | bad: |
| 379 | dm_tm_destroy(cmd->tm); |
| 380 | dm_sm_destroy(cmd->metadata_sm); |
| 381 | |
| 382 | return r; |
| 383 | } |
| 384 | |
| 385 | static int __check_incompat_features(struct cache_disk_superblock *disk_super, |
| 386 | struct dm_cache_metadata *cmd) |
| 387 | { |
| 388 | uint32_t features; |
| 389 | |
| 390 | features = le32_to_cpu(disk_super->incompat_flags) & ~DM_CACHE_FEATURE_INCOMPAT_SUPP; |
| 391 | if (features) { |
| 392 | DMERR("could not access metadata due to unsupported optional features (%lx).", |
| 393 | (unsigned long)features); |
| 394 | return -EINVAL; |
| 395 | } |
| 396 | |
| 397 | /* |
| 398 | * Check for read-only metadata to skip the following RDWR checks. |
| 399 | */ |
| 400 | if (get_disk_ro(cmd->bdev->bd_disk)) |
| 401 | return 0; |
| 402 | |
| 403 | features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP; |
| 404 | if (features) { |
| 405 | DMERR("could not access metadata RDWR due to unsupported optional features (%lx).", |
| 406 | (unsigned long)features); |
| 407 | return -EINVAL; |
| 408 | } |
| 409 | |
| 410 | return 0; |
| 411 | } |
| 412 | |
| 413 | static int __open_metadata(struct dm_cache_metadata *cmd) |
| 414 | { |
| 415 | int r; |
| 416 | struct dm_block *sblock; |
| 417 | struct cache_disk_superblock *disk_super; |
| 418 | unsigned long sb_flags; |
| 419 | |
| 420 | r = superblock_read_lock(cmd, &sblock); |
| 421 | if (r < 0) { |
| 422 | DMERR("couldn't read lock superblock"); |
| 423 | return r; |
| 424 | } |
| 425 | |
| 426 | disk_super = dm_block_data(sblock); |
| 427 | |
Mike Snitzer | 048e5a0 | 2014-07-14 16:59:39 -0400 | [diff] [blame] | 428 | /* Verify the data block size hasn't changed */ |
| 429 | if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) { |
| 430 | DMERR("changing the data block size (from %u to %llu) is not supported", |
| 431 | le32_to_cpu(disk_super->data_block_size), |
| 432 | (unsigned long long)cmd->data_block_size); |
| 433 | r = -EINVAL; |
| 434 | goto bad; |
| 435 | } |
| 436 | |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 437 | r = __check_incompat_features(disk_super, cmd); |
| 438 | if (r < 0) |
| 439 | goto bad; |
| 440 | |
| 441 | r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION, |
| 442 | disk_super->metadata_space_map_root, |
| 443 | sizeof(disk_super->metadata_space_map_root), |
| 444 | &cmd->tm, &cmd->metadata_sm); |
| 445 | if (r < 0) { |
| 446 | DMERR("tm_open_with_sm failed"); |
| 447 | goto bad; |
| 448 | } |
| 449 | |
| 450 | __setup_mapping_info(cmd); |
| 451 | dm_disk_bitset_init(cmd->tm, &cmd->discard_info); |
| 452 | sb_flags = le32_to_cpu(disk_super->flags); |
| 453 | cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags); |
| 454 | return dm_bm_unlock(sblock); |
| 455 | |
| 456 | bad: |
| 457 | dm_bm_unlock(sblock); |
| 458 | return r; |
| 459 | } |
| 460 | |
| 461 | static int __open_or_format_metadata(struct dm_cache_metadata *cmd, |
| 462 | bool format_device) |
| 463 | { |
Joe Thornber | dd8b0c2 | 2013-10-24 14:10:28 -0400 | [diff] [blame] | 464 | int r; |
| 465 | bool unformatted = false; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 466 | |
| 467 | r = __superblock_all_zeroes(cmd->bm, &unformatted); |
| 468 | if (r) |
| 469 | return r; |
| 470 | |
| 471 | if (unformatted) |
| 472 | return format_device ? __format_metadata(cmd) : -EPERM; |
| 473 | |
| 474 | return __open_metadata(cmd); |
| 475 | } |
| 476 | |
| 477 | static int __create_persistent_data_objects(struct dm_cache_metadata *cmd, |
| 478 | bool may_format_device) |
| 479 | { |
| 480 | int r; |
Mike Snitzer | 895b47d | 2014-07-14 15:37:18 -0400 | [diff] [blame] | 481 | cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT, |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 482 | CACHE_METADATA_CACHE_SIZE, |
| 483 | CACHE_MAX_CONCURRENT_LOCKS); |
| 484 | if (IS_ERR(cmd->bm)) { |
| 485 | DMERR("could not create block manager"); |
| 486 | return PTR_ERR(cmd->bm); |
| 487 | } |
| 488 | |
| 489 | r = __open_or_format_metadata(cmd, may_format_device); |
| 490 | if (r) |
| 491 | dm_block_manager_destroy(cmd->bm); |
| 492 | |
| 493 | return r; |
| 494 | } |
| 495 | |
| 496 | static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd) |
| 497 | { |
| 498 | dm_sm_destroy(cmd->metadata_sm); |
| 499 | dm_tm_destroy(cmd->tm); |
| 500 | dm_block_manager_destroy(cmd->bm); |
| 501 | } |
| 502 | |
| 503 | typedef unsigned long (*flags_mutator)(unsigned long); |
| 504 | |
| 505 | static void update_flags(struct cache_disk_superblock *disk_super, |
| 506 | flags_mutator mutator) |
| 507 | { |
| 508 | uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags)); |
| 509 | disk_super->flags = cpu_to_le32(sb_flags); |
| 510 | } |
| 511 | |
| 512 | static unsigned long set_clean_shutdown(unsigned long flags) |
| 513 | { |
| 514 | set_bit(CLEAN_SHUTDOWN, &flags); |
| 515 | return flags; |
| 516 | } |
| 517 | |
| 518 | static unsigned long clear_clean_shutdown(unsigned long flags) |
| 519 | { |
| 520 | clear_bit(CLEAN_SHUTDOWN, &flags); |
| 521 | return flags; |
| 522 | } |
| 523 | |
| 524 | static void read_superblock_fields(struct dm_cache_metadata *cmd, |
| 525 | struct cache_disk_superblock *disk_super) |
| 526 | { |
| 527 | cmd->root = le64_to_cpu(disk_super->mapping_root); |
| 528 | cmd->hint_root = le64_to_cpu(disk_super->hint_root); |
| 529 | cmd->discard_root = le64_to_cpu(disk_super->discard_root); |
| 530 | cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size); |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 531 | cmd->discard_nr_blocks = to_oblock(le64_to_cpu(disk_super->discard_nr_blocks)); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 532 | cmd->data_block_size = le32_to_cpu(disk_super->data_block_size); |
| 533 | cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks)); |
| 534 | strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name)); |
Mike Snitzer | 4e7f506 | 2013-03-20 17:21:27 +0000 | [diff] [blame] | 535 | cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]); |
| 536 | cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]); |
| 537 | cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 538 | cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size); |
| 539 | |
| 540 | cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits); |
| 541 | cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses); |
| 542 | cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits); |
| 543 | cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses); |
| 544 | |
| 545 | cmd->changed = false; |
| 546 | } |
| 547 | |
| 548 | /* |
| 549 | * The mutator updates the superblock flags. |
| 550 | */ |
| 551 | static int __begin_transaction_flags(struct dm_cache_metadata *cmd, |
| 552 | flags_mutator mutator) |
| 553 | { |
| 554 | int r; |
| 555 | struct cache_disk_superblock *disk_super; |
| 556 | struct dm_block *sblock; |
| 557 | |
| 558 | r = superblock_lock(cmd, &sblock); |
| 559 | if (r) |
| 560 | return r; |
| 561 | |
| 562 | disk_super = dm_block_data(sblock); |
| 563 | update_flags(disk_super, mutator); |
| 564 | read_superblock_fields(cmd, disk_super); |
Joe Thornber | a9d4539 | 2014-03-27 14:13:20 +0000 | [diff] [blame] | 565 | dm_bm_unlock(sblock); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 566 | |
Joe Thornber | a9d4539 | 2014-03-27 14:13:20 +0000 | [diff] [blame] | 567 | return dm_bm_flush(cmd->bm); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 568 | } |
| 569 | |
| 570 | static int __begin_transaction(struct dm_cache_metadata *cmd) |
| 571 | { |
| 572 | int r; |
| 573 | struct cache_disk_superblock *disk_super; |
| 574 | struct dm_block *sblock; |
| 575 | |
| 576 | /* |
| 577 | * We re-read the superblock every time. Shouldn't need to do this |
| 578 | * really. |
| 579 | */ |
| 580 | r = superblock_read_lock(cmd, &sblock); |
| 581 | if (r) |
| 582 | return r; |
| 583 | |
| 584 | disk_super = dm_block_data(sblock); |
| 585 | read_superblock_fields(cmd, disk_super); |
| 586 | dm_bm_unlock(sblock); |
| 587 | |
| 588 | return 0; |
| 589 | } |
| 590 | |
| 591 | static int __commit_transaction(struct dm_cache_metadata *cmd, |
| 592 | flags_mutator mutator) |
| 593 | { |
| 594 | int r; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 595 | struct cache_disk_superblock *disk_super; |
| 596 | struct dm_block *sblock; |
| 597 | |
| 598 | /* |
| 599 | * We need to know if the cache_disk_superblock exceeds a 512-byte sector. |
| 600 | */ |
| 601 | BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512); |
| 602 | |
| 603 | r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, |
| 604 | &cmd->discard_root); |
| 605 | if (r) |
| 606 | return r; |
| 607 | |
| 608 | r = dm_tm_pre_commit(cmd->tm); |
| 609 | if (r < 0) |
| 610 | return r; |
| 611 | |
Joe Thornber | 5a32083 | 2014-03-27 14:13:23 +0000 | [diff] [blame] | 612 | r = __save_sm_root(cmd); |
| 613 | if (r) |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 614 | return r; |
| 615 | |
| 616 | r = superblock_lock(cmd, &sblock); |
| 617 | if (r) |
| 618 | return r; |
| 619 | |
| 620 | disk_super = dm_block_data(sblock); |
| 621 | |
| 622 | if (mutator) |
| 623 | update_flags(disk_super, mutator); |
| 624 | |
| 625 | disk_super->mapping_root = cpu_to_le64(cmd->root); |
| 626 | disk_super->hint_root = cpu_to_le64(cmd->hint_root); |
| 627 | disk_super->discard_root = cpu_to_le64(cmd->discard_root); |
| 628 | disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size); |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 629 | disk_super->discard_nr_blocks = cpu_to_le64(from_oblock(cmd->discard_nr_blocks)); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 630 | disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks)); |
| 631 | strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name)); |
Mike Snitzer | 4e7f506 | 2013-03-20 17:21:27 +0000 | [diff] [blame] | 632 | disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]); |
| 633 | disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]); |
| 634 | disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 635 | |
| 636 | disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits); |
| 637 | disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses); |
| 638 | disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits); |
| 639 | disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses); |
Joe Thornber | 5a32083 | 2014-03-27 14:13:23 +0000 | [diff] [blame] | 640 | __copy_sm_root(cmd, disk_super); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 641 | |
| 642 | return dm_tm_commit(cmd->tm, sblock); |
| 643 | } |
| 644 | |
| 645 | /*----------------------------------------------------------------*/ |
| 646 | |
| 647 | /* |
| 648 | * The mappings are held in a dm-array that has 64-bit values stored in |
| 649 | * little-endian format. The index is the cblock, the high 48bits of the |
| 650 | * value are the oblock and the low 16 bit the flags. |
| 651 | */ |
| 652 | #define FLAGS_MASK ((1 << 16) - 1) |
| 653 | |
| 654 | static __le64 pack_value(dm_oblock_t block, unsigned flags) |
| 655 | { |
| 656 | uint64_t value = from_oblock(block); |
| 657 | value <<= 16; |
| 658 | value = value | (flags & FLAGS_MASK); |
| 659 | return cpu_to_le64(value); |
| 660 | } |
| 661 | |
| 662 | static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags) |
| 663 | { |
| 664 | uint64_t value = le64_to_cpu(value_le); |
| 665 | uint64_t b = value >> 16; |
| 666 | *block = to_oblock(b); |
| 667 | *flags = value & FLAGS_MASK; |
| 668 | } |
| 669 | |
| 670 | /*----------------------------------------------------------------*/ |
| 671 | |
| 672 | struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev, |
| 673 | sector_t data_block_size, |
| 674 | bool may_format_device, |
| 675 | size_t policy_hint_size) |
| 676 | { |
| 677 | int r; |
| 678 | struct dm_cache_metadata *cmd; |
| 679 | |
| 680 | cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); |
| 681 | if (!cmd) { |
| 682 | DMERR("could not allocate metadata struct"); |
| 683 | return NULL; |
| 684 | } |
| 685 | |
| 686 | init_rwsem(&cmd->root_lock); |
| 687 | cmd->bdev = bdev; |
| 688 | cmd->data_block_size = data_block_size; |
| 689 | cmd->cache_blocks = 0; |
| 690 | cmd->policy_hint_size = policy_hint_size; |
| 691 | cmd->changed = true; |
| 692 | |
| 693 | r = __create_persistent_data_objects(cmd, may_format_device); |
| 694 | if (r) { |
| 695 | kfree(cmd); |
| 696 | return ERR_PTR(r); |
| 697 | } |
| 698 | |
| 699 | r = __begin_transaction_flags(cmd, clear_clean_shutdown); |
| 700 | if (r < 0) { |
| 701 | dm_cache_metadata_close(cmd); |
| 702 | return ERR_PTR(r); |
| 703 | } |
| 704 | |
| 705 | return cmd; |
| 706 | } |
| 707 | |
| 708 | void dm_cache_metadata_close(struct dm_cache_metadata *cmd) |
| 709 | { |
| 710 | __destroy_persistent_data_objects(cmd); |
| 711 | kfree(cmd); |
| 712 | } |
| 713 | |
Joe Thornber | f494a9c | 2013-10-31 13:55:49 -0400 | [diff] [blame] | 714 | /* |
| 715 | * Checks that the given cache block is either unmapped or clean. |
| 716 | */ |
| 717 | static int block_unmapped_or_clean(struct dm_cache_metadata *cmd, dm_cblock_t b, |
| 718 | bool *result) |
| 719 | { |
| 720 | int r; |
| 721 | __le64 value; |
| 722 | dm_oblock_t ob; |
| 723 | unsigned flags; |
| 724 | |
| 725 | r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value); |
| 726 | if (r) { |
| 727 | DMERR("block_unmapped_or_clean failed"); |
| 728 | return r; |
| 729 | } |
| 730 | |
| 731 | unpack_value(value, &ob, &flags); |
| 732 | *result = !((flags & M_VALID) && (flags & M_DIRTY)); |
| 733 | |
| 734 | return 0; |
| 735 | } |
| 736 | |
| 737 | static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd, |
| 738 | dm_cblock_t begin, dm_cblock_t end, |
| 739 | bool *result) |
| 740 | { |
| 741 | int r; |
| 742 | *result = true; |
| 743 | |
| 744 | while (begin != end) { |
| 745 | r = block_unmapped_or_clean(cmd, begin, result); |
| 746 | if (r) |
| 747 | return r; |
| 748 | |
| 749 | if (!*result) { |
| 750 | DMERR("cache block %llu is dirty", |
| 751 | (unsigned long long) from_cblock(begin)); |
| 752 | return 0; |
| 753 | } |
| 754 | |
| 755 | begin = to_cblock(from_cblock(begin) + 1); |
| 756 | } |
| 757 | |
| 758 | return 0; |
| 759 | } |
| 760 | |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 761 | int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size) |
| 762 | { |
| 763 | int r; |
Joe Thornber | f494a9c | 2013-10-31 13:55:49 -0400 | [diff] [blame] | 764 | bool clean; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 765 | __le64 null_mapping = pack_value(0, 0); |
| 766 | |
| 767 | down_write(&cmd->root_lock); |
| 768 | __dm_bless_for_disk(&null_mapping); |
Joe Thornber | f494a9c | 2013-10-31 13:55:49 -0400 | [diff] [blame] | 769 | |
| 770 | if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) { |
| 771 | r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean); |
| 772 | if (r) { |
| 773 | __dm_unbless_for_disk(&null_mapping); |
| 774 | goto out; |
| 775 | } |
| 776 | |
| 777 | if (!clean) { |
| 778 | DMERR("unable to shrink cache due to dirty blocks"); |
| 779 | r = -EINVAL; |
| 780 | __dm_unbless_for_disk(&null_mapping); |
| 781 | goto out; |
| 782 | } |
| 783 | } |
| 784 | |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 785 | r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks), |
| 786 | from_cblock(new_cache_size), |
| 787 | &null_mapping, &cmd->root); |
| 788 | if (!r) |
| 789 | cmd->cache_blocks = new_cache_size; |
| 790 | cmd->changed = true; |
Joe Thornber | f494a9c | 2013-10-31 13:55:49 -0400 | [diff] [blame] | 791 | |
| 792 | out: |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 793 | up_write(&cmd->root_lock); |
| 794 | |
| 795 | return r; |
| 796 | } |
| 797 | |
| 798 | int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd, |
| 799 | sector_t discard_block_size, |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 800 | dm_oblock_t new_nr_entries) |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 801 | { |
| 802 | int r; |
| 803 | |
| 804 | down_write(&cmd->root_lock); |
| 805 | r = dm_bitset_resize(&cmd->discard_info, |
| 806 | cmd->discard_root, |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 807 | from_oblock(cmd->discard_nr_blocks), |
| 808 | from_oblock(new_nr_entries), |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 809 | false, &cmd->discard_root); |
| 810 | if (!r) { |
| 811 | cmd->discard_block_size = discard_block_size; |
| 812 | cmd->discard_nr_blocks = new_nr_entries; |
| 813 | } |
| 814 | |
| 815 | cmd->changed = true; |
| 816 | up_write(&cmd->root_lock); |
| 817 | |
| 818 | return r; |
| 819 | } |
| 820 | |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 821 | static int __set_discard(struct dm_cache_metadata *cmd, dm_oblock_t b) |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 822 | { |
| 823 | return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root, |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 824 | from_oblock(b), &cmd->discard_root); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 825 | } |
| 826 | |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 827 | static int __clear_discard(struct dm_cache_metadata *cmd, dm_oblock_t b) |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 828 | { |
| 829 | return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root, |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 830 | from_oblock(b), &cmd->discard_root); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 831 | } |
| 832 | |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 833 | static int __is_discarded(struct dm_cache_metadata *cmd, dm_oblock_t b, |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 834 | bool *is_discarded) |
| 835 | { |
| 836 | return dm_bitset_test_bit(&cmd->discard_info, cmd->discard_root, |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 837 | from_oblock(b), &cmd->discard_root, |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 838 | is_discarded); |
| 839 | } |
| 840 | |
| 841 | static int __discard(struct dm_cache_metadata *cmd, |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 842 | dm_oblock_t dblock, bool discard) |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 843 | { |
| 844 | int r; |
| 845 | |
| 846 | r = (discard ? __set_discard : __clear_discard)(cmd, dblock); |
| 847 | if (r) |
| 848 | return r; |
| 849 | |
| 850 | cmd->changed = true; |
| 851 | return 0; |
| 852 | } |
| 853 | |
| 854 | int dm_cache_set_discard(struct dm_cache_metadata *cmd, |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 855 | dm_oblock_t dblock, bool discard) |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 856 | { |
| 857 | int r; |
| 858 | |
| 859 | down_write(&cmd->root_lock); |
| 860 | r = __discard(cmd, dblock, discard); |
| 861 | up_write(&cmd->root_lock); |
| 862 | |
| 863 | return r; |
| 864 | } |
| 865 | |
| 866 | static int __load_discards(struct dm_cache_metadata *cmd, |
| 867 | load_discard_fn fn, void *context) |
| 868 | { |
| 869 | int r = 0; |
| 870 | dm_block_t b; |
| 871 | bool discard; |
| 872 | |
Heinz Mauelshagen | 64ab346 | 2014-03-27 15:14:10 -0400 | [diff] [blame] | 873 | for (b = 0; b < from_oblock(cmd->discard_nr_blocks); b++) { |
| 874 | dm_oblock_t dblock = to_oblock(b); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 875 | |
| 876 | if (cmd->clean_when_opened) { |
| 877 | r = __is_discarded(cmd, dblock, &discard); |
| 878 | if (r) |
| 879 | return r; |
| 880 | } else |
| 881 | discard = false; |
| 882 | |
| 883 | r = fn(context, cmd->discard_block_size, dblock, discard); |
| 884 | if (r) |
| 885 | break; |
| 886 | } |
| 887 | |
| 888 | return r; |
| 889 | } |
| 890 | |
| 891 | int dm_cache_load_discards(struct dm_cache_metadata *cmd, |
| 892 | load_discard_fn fn, void *context) |
| 893 | { |
| 894 | int r; |
| 895 | |
| 896 | down_read(&cmd->root_lock); |
| 897 | r = __load_discards(cmd, fn, context); |
| 898 | up_read(&cmd->root_lock); |
| 899 | |
| 900 | return r; |
| 901 | } |
| 902 | |
| 903 | dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd) |
| 904 | { |
| 905 | dm_cblock_t r; |
| 906 | |
| 907 | down_read(&cmd->root_lock); |
| 908 | r = cmd->cache_blocks; |
| 909 | up_read(&cmd->root_lock); |
| 910 | |
| 911 | return r; |
| 912 | } |
| 913 | |
| 914 | static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock) |
| 915 | { |
| 916 | int r; |
| 917 | __le64 value = pack_value(0, 0); |
| 918 | |
| 919 | __dm_bless_for_disk(&value); |
| 920 | r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), |
| 921 | &value, &cmd->root); |
| 922 | if (r) |
| 923 | return r; |
| 924 | |
| 925 | cmd->changed = true; |
| 926 | return 0; |
| 927 | } |
| 928 | |
| 929 | int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock) |
| 930 | { |
| 931 | int r; |
| 932 | |
| 933 | down_write(&cmd->root_lock); |
| 934 | r = __remove(cmd, cblock); |
| 935 | up_write(&cmd->root_lock); |
| 936 | |
| 937 | return r; |
| 938 | } |
| 939 | |
| 940 | static int __insert(struct dm_cache_metadata *cmd, |
| 941 | dm_cblock_t cblock, dm_oblock_t oblock) |
| 942 | { |
| 943 | int r; |
| 944 | __le64 value = pack_value(oblock, M_VALID); |
| 945 | __dm_bless_for_disk(&value); |
| 946 | |
| 947 | r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), |
| 948 | &value, &cmd->root); |
| 949 | if (r) |
| 950 | return r; |
| 951 | |
| 952 | cmd->changed = true; |
| 953 | return 0; |
| 954 | } |
| 955 | |
| 956 | int dm_cache_insert_mapping(struct dm_cache_metadata *cmd, |
| 957 | dm_cblock_t cblock, dm_oblock_t oblock) |
| 958 | { |
| 959 | int r; |
| 960 | |
| 961 | down_write(&cmd->root_lock); |
| 962 | r = __insert(cmd, cblock, oblock); |
| 963 | up_write(&cmd->root_lock); |
| 964 | |
| 965 | return r; |
| 966 | } |
| 967 | |
| 968 | struct thunk { |
| 969 | load_mapping_fn fn; |
| 970 | void *context; |
| 971 | |
| 972 | struct dm_cache_metadata *cmd; |
| 973 | bool respect_dirty_flags; |
| 974 | bool hints_valid; |
| 975 | }; |
| 976 | |
Mike Snitzer | ea2dd8c | 2013-03-20 17:21:28 +0000 | [diff] [blame] | 977 | static bool policy_unchanged(struct dm_cache_metadata *cmd, |
| 978 | struct dm_cache_policy *policy) |
| 979 | { |
| 980 | const char *policy_name = dm_cache_policy_get_name(policy); |
| 981 | const unsigned *policy_version = dm_cache_policy_get_version(policy); |
| 982 | size_t policy_hint_size = dm_cache_policy_get_hint_size(policy); |
| 983 | |
| 984 | /* |
| 985 | * Ensure policy names match. |
| 986 | */ |
| 987 | if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name))) |
| 988 | return false; |
| 989 | |
| 990 | /* |
| 991 | * Ensure policy major versions match. |
| 992 | */ |
| 993 | if (cmd->policy_version[0] != policy_version[0]) |
| 994 | return false; |
| 995 | |
| 996 | /* |
| 997 | * Ensure policy hint sizes match. |
| 998 | */ |
| 999 | if (cmd->policy_hint_size != policy_hint_size) |
| 1000 | return false; |
| 1001 | |
| 1002 | return true; |
| 1003 | } |
| 1004 | |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1005 | static bool hints_array_initialized(struct dm_cache_metadata *cmd) |
| 1006 | { |
| 1007 | return cmd->hint_root && cmd->policy_hint_size; |
| 1008 | } |
| 1009 | |
| 1010 | static bool hints_array_available(struct dm_cache_metadata *cmd, |
Mike Snitzer | ea2dd8c | 2013-03-20 17:21:28 +0000 | [diff] [blame] | 1011 | struct dm_cache_policy *policy) |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1012 | { |
Mike Snitzer | ea2dd8c | 2013-03-20 17:21:28 +0000 | [diff] [blame] | 1013 | return cmd->clean_when_opened && policy_unchanged(cmd, policy) && |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1014 | hints_array_initialized(cmd); |
| 1015 | } |
| 1016 | |
| 1017 | static int __load_mapping(void *context, uint64_t cblock, void *leaf) |
| 1018 | { |
| 1019 | int r = 0; |
| 1020 | bool dirty; |
| 1021 | __le64 value; |
| 1022 | __le32 hint_value = 0; |
| 1023 | dm_oblock_t oblock; |
| 1024 | unsigned flags; |
| 1025 | struct thunk *thunk = context; |
| 1026 | struct dm_cache_metadata *cmd = thunk->cmd; |
| 1027 | |
| 1028 | memcpy(&value, leaf, sizeof(value)); |
| 1029 | unpack_value(value, &oblock, &flags); |
| 1030 | |
| 1031 | if (flags & M_VALID) { |
| 1032 | if (thunk->hints_valid) { |
| 1033 | r = dm_array_get_value(&cmd->hint_info, cmd->hint_root, |
| 1034 | cblock, &hint_value); |
| 1035 | if (r && r != -ENODATA) |
| 1036 | return r; |
| 1037 | } |
| 1038 | |
| 1039 | dirty = thunk->respect_dirty_flags ? (flags & M_DIRTY) : true; |
| 1040 | r = thunk->fn(thunk->context, oblock, to_cblock(cblock), |
| 1041 | dirty, le32_to_cpu(hint_value), thunk->hints_valid); |
| 1042 | } |
| 1043 | |
| 1044 | return r; |
| 1045 | } |
| 1046 | |
Mike Snitzer | ea2dd8c | 2013-03-20 17:21:28 +0000 | [diff] [blame] | 1047 | static int __load_mappings(struct dm_cache_metadata *cmd, |
| 1048 | struct dm_cache_policy *policy, |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1049 | load_mapping_fn fn, void *context) |
| 1050 | { |
| 1051 | struct thunk thunk; |
| 1052 | |
| 1053 | thunk.fn = fn; |
| 1054 | thunk.context = context; |
| 1055 | |
| 1056 | thunk.cmd = cmd; |
| 1057 | thunk.respect_dirty_flags = cmd->clean_when_opened; |
Mike Snitzer | ea2dd8c | 2013-03-20 17:21:28 +0000 | [diff] [blame] | 1058 | thunk.hints_valid = hints_array_available(cmd, policy); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1059 | |
| 1060 | return dm_array_walk(&cmd->info, cmd->root, __load_mapping, &thunk); |
| 1061 | } |
| 1062 | |
Mike Snitzer | ea2dd8c | 2013-03-20 17:21:28 +0000 | [diff] [blame] | 1063 | int dm_cache_load_mappings(struct dm_cache_metadata *cmd, |
| 1064 | struct dm_cache_policy *policy, |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1065 | load_mapping_fn fn, void *context) |
| 1066 | { |
| 1067 | int r; |
| 1068 | |
| 1069 | down_read(&cmd->root_lock); |
Mike Snitzer | ea2dd8c | 2013-03-20 17:21:28 +0000 | [diff] [blame] | 1070 | r = __load_mappings(cmd, policy, fn, context); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1071 | up_read(&cmd->root_lock); |
| 1072 | |
| 1073 | return r; |
| 1074 | } |
| 1075 | |
| 1076 | static int __dump_mapping(void *context, uint64_t cblock, void *leaf) |
| 1077 | { |
| 1078 | int r = 0; |
| 1079 | __le64 value; |
| 1080 | dm_oblock_t oblock; |
| 1081 | unsigned flags; |
| 1082 | |
| 1083 | memcpy(&value, leaf, sizeof(value)); |
| 1084 | unpack_value(value, &oblock, &flags); |
| 1085 | |
| 1086 | return r; |
| 1087 | } |
| 1088 | |
| 1089 | static int __dump_mappings(struct dm_cache_metadata *cmd) |
| 1090 | { |
| 1091 | return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL); |
| 1092 | } |
| 1093 | |
| 1094 | void dm_cache_dump(struct dm_cache_metadata *cmd) |
| 1095 | { |
| 1096 | down_read(&cmd->root_lock); |
| 1097 | __dump_mappings(cmd); |
| 1098 | up_read(&cmd->root_lock); |
| 1099 | } |
| 1100 | |
| 1101 | int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd) |
| 1102 | { |
| 1103 | int r; |
| 1104 | |
| 1105 | down_read(&cmd->root_lock); |
| 1106 | r = cmd->changed; |
| 1107 | up_read(&cmd->root_lock); |
| 1108 | |
| 1109 | return r; |
| 1110 | } |
| 1111 | |
| 1112 | static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty) |
| 1113 | { |
| 1114 | int r; |
| 1115 | unsigned flags; |
| 1116 | dm_oblock_t oblock; |
| 1117 | __le64 value; |
| 1118 | |
| 1119 | r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value); |
| 1120 | if (r) |
| 1121 | return r; |
| 1122 | |
| 1123 | unpack_value(value, &oblock, &flags); |
| 1124 | |
| 1125 | if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty)) |
| 1126 | /* nothing to be done */ |
| 1127 | return 0; |
| 1128 | |
Joe Thornber | 79ed9ca | 2013-03-20 17:21:27 +0000 | [diff] [blame] | 1129 | value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0)); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1130 | __dm_bless_for_disk(&value); |
| 1131 | |
| 1132 | r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), |
| 1133 | &value, &cmd->root); |
| 1134 | if (r) |
| 1135 | return r; |
| 1136 | |
| 1137 | cmd->changed = true; |
| 1138 | return 0; |
| 1139 | |
| 1140 | } |
| 1141 | |
| 1142 | int dm_cache_set_dirty(struct dm_cache_metadata *cmd, |
| 1143 | dm_cblock_t cblock, bool dirty) |
| 1144 | { |
| 1145 | int r; |
| 1146 | |
| 1147 | down_write(&cmd->root_lock); |
| 1148 | r = __dirty(cmd, cblock, dirty); |
| 1149 | up_write(&cmd->root_lock); |
| 1150 | |
| 1151 | return r; |
| 1152 | } |
| 1153 | |
| 1154 | void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd, |
| 1155 | struct dm_cache_statistics *stats) |
| 1156 | { |
| 1157 | down_read(&cmd->root_lock); |
Joe Thornber | 8c5008f | 2013-05-10 14:37:18 +0100 | [diff] [blame] | 1158 | *stats = cmd->stats; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1159 | up_read(&cmd->root_lock); |
| 1160 | } |
| 1161 | |
| 1162 | void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd, |
| 1163 | struct dm_cache_statistics *stats) |
| 1164 | { |
| 1165 | down_write(&cmd->root_lock); |
Joe Thornber | 8c5008f | 2013-05-10 14:37:18 +0100 | [diff] [blame] | 1166 | cmd->stats = *stats; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1167 | up_write(&cmd->root_lock); |
| 1168 | } |
| 1169 | |
| 1170 | int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown) |
| 1171 | { |
| 1172 | int r; |
| 1173 | flags_mutator mutator = (clean_shutdown ? set_clean_shutdown : |
| 1174 | clear_clean_shutdown); |
| 1175 | |
| 1176 | down_write(&cmd->root_lock); |
| 1177 | r = __commit_transaction(cmd, mutator); |
| 1178 | if (r) |
| 1179 | goto out; |
| 1180 | |
| 1181 | r = __begin_transaction(cmd); |
| 1182 | |
| 1183 | out: |
| 1184 | up_write(&cmd->root_lock); |
| 1185 | return r; |
| 1186 | } |
| 1187 | |
| 1188 | int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd, |
| 1189 | dm_block_t *result) |
| 1190 | { |
| 1191 | int r = -EINVAL; |
| 1192 | |
| 1193 | down_read(&cmd->root_lock); |
| 1194 | r = dm_sm_get_nr_free(cmd->metadata_sm, result); |
| 1195 | up_read(&cmd->root_lock); |
| 1196 | |
| 1197 | return r; |
| 1198 | } |
| 1199 | |
| 1200 | int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd, |
| 1201 | dm_block_t *result) |
| 1202 | { |
| 1203 | int r = -EINVAL; |
| 1204 | |
| 1205 | down_read(&cmd->root_lock); |
| 1206 | r = dm_sm_get_nr_blocks(cmd->metadata_sm, result); |
| 1207 | up_read(&cmd->root_lock); |
| 1208 | |
| 1209 | return r; |
| 1210 | } |
| 1211 | |
| 1212 | /*----------------------------------------------------------------*/ |
| 1213 | |
| 1214 | static int begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) |
| 1215 | { |
| 1216 | int r; |
| 1217 | __le32 value; |
| 1218 | size_t hint_size; |
| 1219 | const char *policy_name = dm_cache_policy_get_name(policy); |
Mike Snitzer | 4e7f506 | 2013-03-20 17:21:27 +0000 | [diff] [blame] | 1220 | const unsigned *policy_version = dm_cache_policy_get_version(policy); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1221 | |
| 1222 | if (!policy_name[0] || |
| 1223 | (strlen(policy_name) > sizeof(cmd->policy_name) - 1)) |
| 1224 | return -EINVAL; |
| 1225 | |
Mike Snitzer | ea2dd8c | 2013-03-20 17:21:28 +0000 | [diff] [blame] | 1226 | if (!policy_unchanged(cmd, policy)) { |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1227 | strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name)); |
Mike Snitzer | 4e7f506 | 2013-03-20 17:21:27 +0000 | [diff] [blame] | 1228 | memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version)); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1229 | |
| 1230 | hint_size = dm_cache_policy_get_hint_size(policy); |
| 1231 | if (!hint_size) |
| 1232 | return 0; /* short-circuit hints initialization */ |
| 1233 | cmd->policy_hint_size = hint_size; |
| 1234 | |
| 1235 | if (cmd->hint_root) { |
| 1236 | r = dm_array_del(&cmd->hint_info, cmd->hint_root); |
| 1237 | if (r) |
| 1238 | return r; |
| 1239 | } |
| 1240 | |
| 1241 | r = dm_array_empty(&cmd->hint_info, &cmd->hint_root); |
| 1242 | if (r) |
| 1243 | return r; |
| 1244 | |
| 1245 | value = cpu_to_le32(0); |
| 1246 | __dm_bless_for_disk(&value); |
| 1247 | r = dm_array_resize(&cmd->hint_info, cmd->hint_root, 0, |
| 1248 | from_cblock(cmd->cache_blocks), |
| 1249 | &value, &cmd->hint_root); |
| 1250 | if (r) |
| 1251 | return r; |
| 1252 | } |
| 1253 | |
| 1254 | return 0; |
| 1255 | } |
| 1256 | |
Joe Thornber | 0596661 | 2014-04-03 16:16:44 +0100 | [diff] [blame] | 1257 | static int save_hint(void *context, dm_cblock_t cblock, dm_oblock_t oblock, uint32_t hint) |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1258 | { |
Joe Thornber | 0596661 | 2014-04-03 16:16:44 +0100 | [diff] [blame] | 1259 | struct dm_cache_metadata *cmd = context; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1260 | __le32 value = cpu_to_le32(hint); |
Joe Thornber | 0596661 | 2014-04-03 16:16:44 +0100 | [diff] [blame] | 1261 | int r; |
| 1262 | |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1263 | __dm_bless_for_disk(&value); |
| 1264 | |
| 1265 | r = dm_array_set_value(&cmd->hint_info, cmd->hint_root, |
| 1266 | from_cblock(cblock), &value, &cmd->hint_root); |
| 1267 | cmd->changed = true; |
| 1268 | |
| 1269 | return r; |
| 1270 | } |
| 1271 | |
Joe Thornber | 0596661 | 2014-04-03 16:16:44 +0100 | [diff] [blame] | 1272 | static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1273 | { |
| 1274 | int r; |
| 1275 | |
Joe Thornber | 0596661 | 2014-04-03 16:16:44 +0100 | [diff] [blame] | 1276 | r = begin_hints(cmd, policy); |
| 1277 | if (r) { |
| 1278 | DMERR("begin_hints failed"); |
| 1279 | return r; |
| 1280 | } |
| 1281 | |
| 1282 | return policy_walk_mappings(policy, save_hint, cmd); |
| 1283 | } |
| 1284 | |
| 1285 | int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) |
| 1286 | { |
| 1287 | int r; |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1288 | |
| 1289 | down_write(&cmd->root_lock); |
Joe Thornber | 0596661 | 2014-04-03 16:16:44 +0100 | [diff] [blame] | 1290 | r = write_hints(cmd, policy); |
Joe Thornber | c6b4fcb | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1291 | up_write(&cmd->root_lock); |
| 1292 | |
| 1293 | return r; |
| 1294 | } |
Joe Thornber | 2ee57d5 | 2013-10-24 14:10:29 -0400 | [diff] [blame] | 1295 | |
| 1296 | int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result) |
| 1297 | { |
| 1298 | return blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result); |
| 1299 | } |