Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 Red Hat, Inc. |
| 3 | * |
| 4 | * This file is released under the GPL. |
| 5 | */ |
| 6 | #include "dm-transaction-manager.h" |
| 7 | #include "dm-space-map.h" |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 8 | #include "dm-space-map-disk.h" |
| 9 | #include "dm-space-map-metadata.h" |
| 10 | #include "dm-persistent-data-internal.h" |
| 11 | |
Paul Gortmaker | 1944ce6 | 2011-09-28 18:29:32 -0400 | [diff] [blame] | 12 | #include <linux/export.h> |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 13 | #include <linux/slab.h> |
| 14 | #include <linux/device-mapper.h> |
| 15 | |
| 16 | #define DM_MSG_PREFIX "transaction manager" |
| 17 | |
| 18 | /*----------------------------------------------------------------*/ |
| 19 | |
| 20 | struct shadow_info { |
| 21 | struct hlist_node hlist; |
| 22 | dm_block_t where; |
| 23 | }; |
| 24 | |
| 25 | /* |
| 26 | * It would be nice if we scaled with the size of transaction. |
| 27 | */ |
Andrew Morton | df85579 | 2013-02-22 16:32:03 -0800 | [diff] [blame] | 28 | #define DM_HASH_SIZE 256 |
| 29 | #define DM_HASH_MASK (DM_HASH_SIZE - 1) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 30 | |
| 31 | struct dm_transaction_manager { |
| 32 | int is_clone; |
| 33 | struct dm_transaction_manager *real; |
| 34 | |
| 35 | struct dm_block_manager *bm; |
| 36 | struct dm_space_map *sm; |
| 37 | |
| 38 | spinlock_t lock; |
Andrew Morton | df85579 | 2013-02-22 16:32:03 -0800 | [diff] [blame] | 39 | struct hlist_head buckets[DM_HASH_SIZE]; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 40 | }; |
| 41 | |
| 42 | /*----------------------------------------------------------------*/ |
| 43 | |
| 44 | static int is_shadow(struct dm_transaction_manager *tm, dm_block_t b) |
| 45 | { |
| 46 | int r = 0; |
Andrew Morton | df85579 | 2013-02-22 16:32:03 -0800 | [diff] [blame] | 47 | unsigned bucket = dm_hash_block(b, DM_HASH_MASK); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 48 | struct shadow_info *si; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 49 | |
| 50 | spin_lock(&tm->lock); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame^] | 51 | hlist_for_each_entry(si, tm->buckets + bucket, hlist) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 52 | if (si->where == b) { |
| 53 | r = 1; |
| 54 | break; |
| 55 | } |
| 56 | spin_unlock(&tm->lock); |
| 57 | |
| 58 | return r; |
| 59 | } |
| 60 | |
| 61 | /* |
| 62 | * This can silently fail if there's no memory. We're ok with this since |
| 63 | * creating redundant shadows causes no harm. |
| 64 | */ |
| 65 | static void insert_shadow(struct dm_transaction_manager *tm, dm_block_t b) |
| 66 | { |
| 67 | unsigned bucket; |
| 68 | struct shadow_info *si; |
| 69 | |
| 70 | si = kmalloc(sizeof(*si), GFP_NOIO); |
| 71 | if (si) { |
| 72 | si->where = b; |
Andrew Morton | df85579 | 2013-02-22 16:32:03 -0800 | [diff] [blame] | 73 | bucket = dm_hash_block(b, DM_HASH_MASK); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 74 | spin_lock(&tm->lock); |
| 75 | hlist_add_head(&si->hlist, tm->buckets + bucket); |
| 76 | spin_unlock(&tm->lock); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | static void wipe_shadow_table(struct dm_transaction_manager *tm) |
| 81 | { |
| 82 | struct shadow_info *si; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame^] | 83 | struct hlist_node *tmp; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 84 | struct hlist_head *bucket; |
| 85 | int i; |
| 86 | |
| 87 | spin_lock(&tm->lock); |
Andrew Morton | df85579 | 2013-02-22 16:32:03 -0800 | [diff] [blame] | 88 | for (i = 0; i < DM_HASH_SIZE; i++) { |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 89 | bucket = tm->buckets + i; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame^] | 90 | hlist_for_each_entry_safe(si, tmp, bucket, hlist) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 91 | kfree(si); |
| 92 | |
| 93 | INIT_HLIST_HEAD(bucket); |
| 94 | } |
| 95 | |
| 96 | spin_unlock(&tm->lock); |
| 97 | } |
| 98 | |
| 99 | /*----------------------------------------------------------------*/ |
| 100 | |
| 101 | static struct dm_transaction_manager *dm_tm_create(struct dm_block_manager *bm, |
| 102 | struct dm_space_map *sm) |
| 103 | { |
| 104 | int i; |
| 105 | struct dm_transaction_manager *tm; |
| 106 | |
| 107 | tm = kmalloc(sizeof(*tm), GFP_KERNEL); |
| 108 | if (!tm) |
| 109 | return ERR_PTR(-ENOMEM); |
| 110 | |
| 111 | tm->is_clone = 0; |
| 112 | tm->real = NULL; |
| 113 | tm->bm = bm; |
| 114 | tm->sm = sm; |
| 115 | |
| 116 | spin_lock_init(&tm->lock); |
Andrew Morton | df85579 | 2013-02-22 16:32:03 -0800 | [diff] [blame] | 117 | for (i = 0; i < DM_HASH_SIZE; i++) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 118 | INIT_HLIST_HEAD(tm->buckets + i); |
| 119 | |
| 120 | return tm; |
| 121 | } |
| 122 | |
| 123 | struct dm_transaction_manager *dm_tm_create_non_blocking_clone(struct dm_transaction_manager *real) |
| 124 | { |
| 125 | struct dm_transaction_manager *tm; |
| 126 | |
| 127 | tm = kmalloc(sizeof(*tm), GFP_KERNEL); |
| 128 | if (tm) { |
| 129 | tm->is_clone = 1; |
| 130 | tm->real = real; |
| 131 | } |
| 132 | |
| 133 | return tm; |
| 134 | } |
| 135 | EXPORT_SYMBOL_GPL(dm_tm_create_non_blocking_clone); |
| 136 | |
| 137 | void dm_tm_destroy(struct dm_transaction_manager *tm) |
| 138 | { |
Mike Snitzer | 25d7cd6 | 2012-07-03 12:55:33 +0100 | [diff] [blame] | 139 | if (!tm->is_clone) |
| 140 | wipe_shadow_table(tm); |
| 141 | |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 142 | kfree(tm); |
| 143 | } |
| 144 | EXPORT_SYMBOL_GPL(dm_tm_destroy); |
| 145 | |
| 146 | int dm_tm_pre_commit(struct dm_transaction_manager *tm) |
| 147 | { |
| 148 | int r; |
| 149 | |
| 150 | if (tm->is_clone) |
| 151 | return -EWOULDBLOCK; |
| 152 | |
| 153 | r = dm_sm_commit(tm->sm); |
| 154 | if (r < 0) |
| 155 | return r; |
| 156 | |
| 157 | return 0; |
| 158 | } |
| 159 | EXPORT_SYMBOL_GPL(dm_tm_pre_commit); |
| 160 | |
| 161 | int dm_tm_commit(struct dm_transaction_manager *tm, struct dm_block *root) |
| 162 | { |
| 163 | if (tm->is_clone) |
| 164 | return -EWOULDBLOCK; |
| 165 | |
| 166 | wipe_shadow_table(tm); |
| 167 | |
| 168 | return dm_bm_flush_and_unlock(tm->bm, root); |
| 169 | } |
| 170 | EXPORT_SYMBOL_GPL(dm_tm_commit); |
| 171 | |
| 172 | int dm_tm_new_block(struct dm_transaction_manager *tm, |
| 173 | struct dm_block_validator *v, |
| 174 | struct dm_block **result) |
| 175 | { |
| 176 | int r; |
| 177 | dm_block_t new_block; |
| 178 | |
| 179 | if (tm->is_clone) |
| 180 | return -EWOULDBLOCK; |
| 181 | |
| 182 | r = dm_sm_new_block(tm->sm, &new_block); |
| 183 | if (r < 0) |
| 184 | return r; |
| 185 | |
| 186 | r = dm_bm_write_lock_zero(tm->bm, new_block, v, result); |
| 187 | if (r < 0) { |
| 188 | dm_sm_dec_block(tm->sm, new_block); |
| 189 | return r; |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * New blocks count as shadows in that they don't need to be |
| 194 | * shadowed again. |
| 195 | */ |
| 196 | insert_shadow(tm, new_block); |
| 197 | |
| 198 | return 0; |
| 199 | } |
| 200 | |
| 201 | static int __shadow_block(struct dm_transaction_manager *tm, dm_block_t orig, |
| 202 | struct dm_block_validator *v, |
| 203 | struct dm_block **result) |
| 204 | { |
| 205 | int r; |
| 206 | dm_block_t new; |
| 207 | struct dm_block *orig_block; |
| 208 | |
| 209 | r = dm_sm_new_block(tm->sm, &new); |
| 210 | if (r < 0) |
| 211 | return r; |
| 212 | |
| 213 | r = dm_sm_dec_block(tm->sm, orig); |
| 214 | if (r < 0) |
| 215 | return r; |
| 216 | |
| 217 | r = dm_bm_read_lock(tm->bm, orig, v, &orig_block); |
| 218 | if (r < 0) |
| 219 | return r; |
| 220 | |
Joe Thornber | 3c9ad9b | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 221 | /* |
| 222 | * It would be tempting to use dm_bm_unlock_move here, but some |
| 223 | * code, such as the space maps, keeps using the old data structures |
| 224 | * secure in the knowledge they won't be changed until the next |
| 225 | * transaction. Using unlock_move would force a synchronous read |
| 226 | * since the old block would no longer be in the cache. |
| 227 | */ |
| 228 | r = dm_bm_write_lock_zero(tm->bm, new, v, result); |
| 229 | if (r) { |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 230 | dm_bm_unlock(orig_block); |
| 231 | return r; |
| 232 | } |
| 233 | |
Joe Thornber | 3c9ad9b | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 234 | memcpy(dm_block_data(*result), dm_block_data(orig_block), |
| 235 | dm_bm_block_size(tm->bm)); |
| 236 | |
| 237 | dm_bm_unlock(orig_block); |
| 238 | return r; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 239 | } |
| 240 | |
| 241 | int dm_tm_shadow_block(struct dm_transaction_manager *tm, dm_block_t orig, |
| 242 | struct dm_block_validator *v, struct dm_block **result, |
| 243 | int *inc_children) |
| 244 | { |
| 245 | int r; |
| 246 | |
| 247 | if (tm->is_clone) |
| 248 | return -EWOULDBLOCK; |
| 249 | |
| 250 | r = dm_sm_count_is_more_than_one(tm->sm, orig, inc_children); |
| 251 | if (r < 0) |
| 252 | return r; |
| 253 | |
| 254 | if (is_shadow(tm, orig) && !*inc_children) |
| 255 | return dm_bm_write_lock(tm->bm, orig, v, result); |
| 256 | |
| 257 | r = __shadow_block(tm, orig, v, result); |
| 258 | if (r < 0) |
| 259 | return r; |
| 260 | insert_shadow(tm, dm_block_location(*result)); |
| 261 | |
| 262 | return r; |
| 263 | } |
Joe Thornber | cc8394d | 2012-06-03 00:30:01 +0100 | [diff] [blame] | 264 | EXPORT_SYMBOL_GPL(dm_tm_shadow_block); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 265 | |
| 266 | int dm_tm_read_lock(struct dm_transaction_manager *tm, dm_block_t b, |
| 267 | struct dm_block_validator *v, |
| 268 | struct dm_block **blk) |
| 269 | { |
| 270 | if (tm->is_clone) |
| 271 | return dm_bm_read_try_lock(tm->real->bm, b, v, blk); |
| 272 | |
| 273 | return dm_bm_read_lock(tm->bm, b, v, blk); |
| 274 | } |
Joe Thornber | cc8394d | 2012-06-03 00:30:01 +0100 | [diff] [blame] | 275 | EXPORT_SYMBOL_GPL(dm_tm_read_lock); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 276 | |
| 277 | int dm_tm_unlock(struct dm_transaction_manager *tm, struct dm_block *b) |
| 278 | { |
| 279 | return dm_bm_unlock(b); |
| 280 | } |
| 281 | EXPORT_SYMBOL_GPL(dm_tm_unlock); |
| 282 | |
| 283 | void dm_tm_inc(struct dm_transaction_manager *tm, dm_block_t b) |
| 284 | { |
| 285 | /* |
| 286 | * The non-blocking clone doesn't support this. |
| 287 | */ |
| 288 | BUG_ON(tm->is_clone); |
| 289 | |
| 290 | dm_sm_inc_block(tm->sm, b); |
| 291 | } |
| 292 | EXPORT_SYMBOL_GPL(dm_tm_inc); |
| 293 | |
| 294 | void dm_tm_dec(struct dm_transaction_manager *tm, dm_block_t b) |
| 295 | { |
| 296 | /* |
| 297 | * The non-blocking clone doesn't support this. |
| 298 | */ |
| 299 | BUG_ON(tm->is_clone); |
| 300 | |
| 301 | dm_sm_dec_block(tm->sm, b); |
| 302 | } |
| 303 | EXPORT_SYMBOL_GPL(dm_tm_dec); |
| 304 | |
| 305 | int dm_tm_ref(struct dm_transaction_manager *tm, dm_block_t b, |
| 306 | uint32_t *result) |
| 307 | { |
| 308 | if (tm->is_clone) |
| 309 | return -EWOULDBLOCK; |
| 310 | |
| 311 | return dm_sm_get_count(tm->sm, b, result); |
| 312 | } |
| 313 | |
| 314 | struct dm_block_manager *dm_tm_get_bm(struct dm_transaction_manager *tm) |
| 315 | { |
| 316 | return tm->bm; |
| 317 | } |
| 318 | |
| 319 | /*----------------------------------------------------------------*/ |
| 320 | |
| 321 | static int dm_tm_create_internal(struct dm_block_manager *bm, |
| 322 | dm_block_t sb_location, |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 323 | struct dm_transaction_manager **tm, |
| 324 | struct dm_space_map **sm, |
Joe Thornber | 384ef0e | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 325 | int create, |
| 326 | void *sm_root, size_t sm_len) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 327 | { |
| 328 | int r; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 329 | |
Joe Thornber | 3caf6d7 | 2012-07-27 15:07:58 +0100 | [diff] [blame] | 330 | *sm = dm_sm_metadata_init(); |
| 331 | if (IS_ERR(*sm)) |
| 332 | return PTR_ERR(*sm); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 333 | |
Joe Thornber | 3caf6d7 | 2012-07-27 15:07:58 +0100 | [diff] [blame] | 334 | *tm = dm_tm_create(bm, *sm); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 335 | if (IS_ERR(*tm)) { |
Joe Thornber | 3caf6d7 | 2012-07-27 15:07:58 +0100 | [diff] [blame] | 336 | dm_sm_destroy(*sm); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 337 | return PTR_ERR(*tm); |
| 338 | } |
| 339 | |
| 340 | if (create) { |
Joe Thornber | 3caf6d7 | 2012-07-27 15:07:58 +0100 | [diff] [blame] | 341 | r = dm_sm_metadata_create(*sm, *tm, dm_bm_nr_blocks(bm), |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 342 | sb_location); |
| 343 | if (r) { |
| 344 | DMERR("couldn't create metadata space map"); |
Joe Thornber | 384ef0e | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 345 | goto bad; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 346 | } |
| 347 | |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 348 | } else { |
Joe Thornber | 384ef0e | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 349 | r = dm_sm_metadata_open(*sm, *tm, sm_root, sm_len); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 350 | if (r) { |
| 351 | DMERR("couldn't open metadata space map"); |
Joe Thornber | 384ef0e | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 352 | goto bad; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 353 | } |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 354 | } |
| 355 | |
| 356 | return 0; |
| 357 | |
Joe Thornber | 384ef0e | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 358 | bad: |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 359 | dm_tm_destroy(*tm); |
Joe Thornber | 384ef0e | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 360 | dm_sm_destroy(*sm); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 361 | return r; |
| 362 | } |
| 363 | |
| 364 | int dm_tm_create_with_sm(struct dm_block_manager *bm, dm_block_t sb_location, |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 365 | struct dm_transaction_manager **tm, |
Joe Thornber | 384ef0e | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 366 | struct dm_space_map **sm) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 367 | { |
Joe Thornber | 384ef0e | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 368 | return dm_tm_create_internal(bm, sb_location, tm, sm, 1, NULL, 0); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 369 | } |
| 370 | EXPORT_SYMBOL_GPL(dm_tm_create_with_sm); |
| 371 | |
| 372 | int dm_tm_open_with_sm(struct dm_block_manager *bm, dm_block_t sb_location, |
Joe Thornber | 384ef0e | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 373 | void *sm_root, size_t root_len, |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 374 | struct dm_transaction_manager **tm, |
Joe Thornber | 384ef0e | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 375 | struct dm_space_map **sm) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 376 | { |
Joe Thornber | 384ef0e | 2012-07-27 15:08:09 +0100 | [diff] [blame] | 377 | return dm_tm_create_internal(bm, sb_location, tm, sm, 0, sm_root, root_len); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 378 | } |
| 379 | EXPORT_SYMBOL_GPL(dm_tm_open_with_sm); |
| 380 | |
| 381 | /*----------------------------------------------------------------*/ |