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