| 1 | /* |
| 2 | * Copyright (C) 2007 Oracle. All rights reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public |
| 6 | * License v2 as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 11 | * General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public |
| 14 | * License along with this program; if not, write to the |
| 15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| 16 | * Boston, MA 021110-1307, USA. |
| 17 | */ |
| 18 | |
| 19 | #include <linux/fs.h> |
| 20 | #include <linux/slab.h> |
| 21 | #include <linux/sched.h> |
| 22 | #include <linux/writeback.h> |
| 23 | #include <linux/pagemap.h> |
| 24 | #include <linux/blkdev.h> |
| 25 | #include <linux/uuid.h> |
| 26 | #include "ctree.h" |
| 27 | #include "disk-io.h" |
| 28 | #include "transaction.h" |
| 29 | #include "locking.h" |
| 30 | #include "tree-log.h" |
| 31 | #include "inode-map.h" |
| 32 | #include "volumes.h" |
| 33 | #include "dev-replace.h" |
| 34 | #include "qgroup.h" |
| 35 | |
| 36 | #define BTRFS_ROOT_TRANS_TAG 0 |
| 37 | |
| 38 | static const unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = { |
| 39 | [TRANS_STATE_RUNNING] = 0U, |
| 40 | [TRANS_STATE_BLOCKED] = (__TRANS_USERSPACE | |
| 41 | __TRANS_START), |
| 42 | [TRANS_STATE_COMMIT_START] = (__TRANS_USERSPACE | |
| 43 | __TRANS_START | |
| 44 | __TRANS_ATTACH), |
| 45 | [TRANS_STATE_COMMIT_DOING] = (__TRANS_USERSPACE | |
| 46 | __TRANS_START | |
| 47 | __TRANS_ATTACH | |
| 48 | __TRANS_JOIN), |
| 49 | [TRANS_STATE_UNBLOCKED] = (__TRANS_USERSPACE | |
| 50 | __TRANS_START | |
| 51 | __TRANS_ATTACH | |
| 52 | __TRANS_JOIN | |
| 53 | __TRANS_JOIN_NOLOCK), |
| 54 | [TRANS_STATE_COMPLETED] = (__TRANS_USERSPACE | |
| 55 | __TRANS_START | |
| 56 | __TRANS_ATTACH | |
| 57 | __TRANS_JOIN | |
| 58 | __TRANS_JOIN_NOLOCK), |
| 59 | }; |
| 60 | |
| 61 | void btrfs_put_transaction(struct btrfs_transaction *transaction) |
| 62 | { |
| 63 | WARN_ON(refcount_read(&transaction->use_count) == 0); |
| 64 | if (refcount_dec_and_test(&transaction->use_count)) { |
| 65 | BUG_ON(!list_empty(&transaction->list)); |
| 66 | WARN_ON(!RB_EMPTY_ROOT(&transaction->delayed_refs.href_root)); |
| 67 | if (transaction->delayed_refs.pending_csums) |
| 68 | btrfs_err(transaction->fs_info, |
| 69 | "pending csums is %llu", |
| 70 | transaction->delayed_refs.pending_csums); |
| 71 | while (!list_empty(&transaction->pending_chunks)) { |
| 72 | struct extent_map *em; |
| 73 | |
| 74 | em = list_first_entry(&transaction->pending_chunks, |
| 75 | struct extent_map, list); |
| 76 | list_del_init(&em->list); |
| 77 | free_extent_map(em); |
| 78 | } |
| 79 | /* |
| 80 | * If any block groups are found in ->deleted_bgs then it's |
| 81 | * because the transaction was aborted and a commit did not |
| 82 | * happen (things failed before writing the new superblock |
| 83 | * and calling btrfs_finish_extent_commit()), so we can not |
| 84 | * discard the physical locations of the block groups. |
| 85 | */ |
| 86 | while (!list_empty(&transaction->deleted_bgs)) { |
| 87 | struct btrfs_block_group_cache *cache; |
| 88 | |
| 89 | cache = list_first_entry(&transaction->deleted_bgs, |
| 90 | struct btrfs_block_group_cache, |
| 91 | bg_list); |
| 92 | list_del_init(&cache->bg_list); |
| 93 | btrfs_put_block_group_trimming(cache); |
| 94 | btrfs_put_block_group(cache); |
| 95 | } |
| 96 | kmem_cache_free(btrfs_transaction_cachep, transaction); |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | static void clear_btree_io_tree(struct extent_io_tree *tree) |
| 101 | { |
| 102 | spin_lock(&tree->lock); |
| 103 | /* |
| 104 | * Do a single barrier for the waitqueue_active check here, the state |
| 105 | * of the waitqueue should not change once clear_btree_io_tree is |
| 106 | * called. |
| 107 | */ |
| 108 | smp_mb(); |
| 109 | while (!RB_EMPTY_ROOT(&tree->state)) { |
| 110 | struct rb_node *node; |
| 111 | struct extent_state *state; |
| 112 | |
| 113 | node = rb_first(&tree->state); |
| 114 | state = rb_entry(node, struct extent_state, rb_node); |
| 115 | rb_erase(&state->rb_node, &tree->state); |
| 116 | RB_CLEAR_NODE(&state->rb_node); |
| 117 | /* |
| 118 | * btree io trees aren't supposed to have tasks waiting for |
| 119 | * changes in the flags of extent states ever. |
| 120 | */ |
| 121 | ASSERT(!waitqueue_active(&state->wq)); |
| 122 | free_extent_state(state); |
| 123 | |
| 124 | cond_resched_lock(&tree->lock); |
| 125 | } |
| 126 | spin_unlock(&tree->lock); |
| 127 | } |
| 128 | |
| 129 | static noinline void switch_commit_roots(struct btrfs_transaction *trans, |
| 130 | struct btrfs_fs_info *fs_info) |
| 131 | { |
| 132 | struct btrfs_root *root, *tmp; |
| 133 | |
| 134 | down_write(&fs_info->commit_root_sem); |
| 135 | list_for_each_entry_safe(root, tmp, &trans->switch_commits, |
| 136 | dirty_list) { |
| 137 | list_del_init(&root->dirty_list); |
| 138 | free_extent_buffer(root->commit_root); |
| 139 | root->commit_root = btrfs_root_node(root); |
| 140 | if (is_fstree(root->objectid)) |
| 141 | btrfs_unpin_free_ino(root); |
| 142 | clear_btree_io_tree(&root->dirty_log_pages); |
| 143 | } |
| 144 | |
| 145 | /* We can free old roots now. */ |
| 146 | spin_lock(&trans->dropped_roots_lock); |
| 147 | while (!list_empty(&trans->dropped_roots)) { |
| 148 | root = list_first_entry(&trans->dropped_roots, |
| 149 | struct btrfs_root, root_list); |
| 150 | list_del_init(&root->root_list); |
| 151 | spin_unlock(&trans->dropped_roots_lock); |
| 152 | btrfs_drop_and_free_fs_root(fs_info, root); |
| 153 | spin_lock(&trans->dropped_roots_lock); |
| 154 | } |
| 155 | spin_unlock(&trans->dropped_roots_lock); |
| 156 | up_write(&fs_info->commit_root_sem); |
| 157 | } |
| 158 | |
| 159 | static inline void extwriter_counter_inc(struct btrfs_transaction *trans, |
| 160 | unsigned int type) |
| 161 | { |
| 162 | if (type & TRANS_EXTWRITERS) |
| 163 | atomic_inc(&trans->num_extwriters); |
| 164 | } |
| 165 | |
| 166 | static inline void extwriter_counter_dec(struct btrfs_transaction *trans, |
| 167 | unsigned int type) |
| 168 | { |
| 169 | if (type & TRANS_EXTWRITERS) |
| 170 | atomic_dec(&trans->num_extwriters); |
| 171 | } |
| 172 | |
| 173 | static inline void extwriter_counter_init(struct btrfs_transaction *trans, |
| 174 | unsigned int type) |
| 175 | { |
| 176 | atomic_set(&trans->num_extwriters, ((type & TRANS_EXTWRITERS) ? 1 : 0)); |
| 177 | } |
| 178 | |
| 179 | static inline int extwriter_counter_read(struct btrfs_transaction *trans) |
| 180 | { |
| 181 | return atomic_read(&trans->num_extwriters); |
| 182 | } |
| 183 | |
| 184 | /* |
| 185 | * either allocate a new transaction or hop into the existing one |
| 186 | */ |
| 187 | static noinline int join_transaction(struct btrfs_fs_info *fs_info, |
| 188 | unsigned int type) |
| 189 | { |
| 190 | struct btrfs_transaction *cur_trans; |
| 191 | |
| 192 | spin_lock(&fs_info->trans_lock); |
| 193 | loop: |
| 194 | /* The file system has been taken offline. No new transactions. */ |
| 195 | if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { |
| 196 | spin_unlock(&fs_info->trans_lock); |
| 197 | return -EROFS; |
| 198 | } |
| 199 | |
| 200 | cur_trans = fs_info->running_transaction; |
| 201 | if (cur_trans) { |
| 202 | if (cur_trans->aborted) { |
| 203 | spin_unlock(&fs_info->trans_lock); |
| 204 | return cur_trans->aborted; |
| 205 | } |
| 206 | if (btrfs_blocked_trans_types[cur_trans->state] & type) { |
| 207 | spin_unlock(&fs_info->trans_lock); |
| 208 | return -EBUSY; |
| 209 | } |
| 210 | refcount_inc(&cur_trans->use_count); |
| 211 | atomic_inc(&cur_trans->num_writers); |
| 212 | extwriter_counter_inc(cur_trans, type); |
| 213 | spin_unlock(&fs_info->trans_lock); |
| 214 | return 0; |
| 215 | } |
| 216 | spin_unlock(&fs_info->trans_lock); |
| 217 | |
| 218 | /* |
| 219 | * If we are ATTACH, we just want to catch the current transaction, |
| 220 | * and commit it. If there is no transaction, just return ENOENT. |
| 221 | */ |
| 222 | if (type == TRANS_ATTACH) |
| 223 | return -ENOENT; |
| 224 | |
| 225 | /* |
| 226 | * JOIN_NOLOCK only happens during the transaction commit, so |
| 227 | * it is impossible that ->running_transaction is NULL |
| 228 | */ |
| 229 | BUG_ON(type == TRANS_JOIN_NOLOCK); |
| 230 | |
| 231 | cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS); |
| 232 | if (!cur_trans) |
| 233 | return -ENOMEM; |
| 234 | |
| 235 | spin_lock(&fs_info->trans_lock); |
| 236 | if (fs_info->running_transaction) { |
| 237 | /* |
| 238 | * someone started a transaction after we unlocked. Make sure |
| 239 | * to redo the checks above |
| 240 | */ |
| 241 | kmem_cache_free(btrfs_transaction_cachep, cur_trans); |
| 242 | goto loop; |
| 243 | } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { |
| 244 | spin_unlock(&fs_info->trans_lock); |
| 245 | kmem_cache_free(btrfs_transaction_cachep, cur_trans); |
| 246 | return -EROFS; |
| 247 | } |
| 248 | |
| 249 | cur_trans->fs_info = fs_info; |
| 250 | atomic_set(&cur_trans->num_writers, 1); |
| 251 | extwriter_counter_init(cur_trans, type); |
| 252 | init_waitqueue_head(&cur_trans->writer_wait); |
| 253 | init_waitqueue_head(&cur_trans->commit_wait); |
| 254 | init_waitqueue_head(&cur_trans->pending_wait); |
| 255 | cur_trans->state = TRANS_STATE_RUNNING; |
| 256 | /* |
| 257 | * One for this trans handle, one so it will live on until we |
| 258 | * commit the transaction. |
| 259 | */ |
| 260 | refcount_set(&cur_trans->use_count, 2); |
| 261 | atomic_set(&cur_trans->pending_ordered, 0); |
| 262 | cur_trans->flags = 0; |
| 263 | cur_trans->start_time = get_seconds(); |
| 264 | |
| 265 | memset(&cur_trans->delayed_refs, 0, sizeof(cur_trans->delayed_refs)); |
| 266 | |
| 267 | cur_trans->delayed_refs.href_root = RB_ROOT; |
| 268 | cur_trans->delayed_refs.dirty_extent_root = RB_ROOT; |
| 269 | atomic_set(&cur_trans->delayed_refs.num_entries, 0); |
| 270 | |
| 271 | /* |
| 272 | * although the tree mod log is per file system and not per transaction, |
| 273 | * the log must never go across transaction boundaries. |
| 274 | */ |
| 275 | smp_mb(); |
| 276 | if (!list_empty(&fs_info->tree_mod_seq_list)) |
| 277 | WARN(1, KERN_ERR "BTRFS: tree_mod_seq_list not empty when creating a fresh transaction\n"); |
| 278 | if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log)) |
| 279 | WARN(1, KERN_ERR "BTRFS: tree_mod_log rb tree not empty when creating a fresh transaction\n"); |
| 280 | atomic64_set(&fs_info->tree_mod_seq, 0); |
| 281 | |
| 282 | spin_lock_init(&cur_trans->delayed_refs.lock); |
| 283 | |
| 284 | INIT_LIST_HEAD(&cur_trans->pending_snapshots); |
| 285 | INIT_LIST_HEAD(&cur_trans->pending_chunks); |
| 286 | INIT_LIST_HEAD(&cur_trans->switch_commits); |
| 287 | INIT_LIST_HEAD(&cur_trans->dirty_bgs); |
| 288 | INIT_LIST_HEAD(&cur_trans->io_bgs); |
| 289 | INIT_LIST_HEAD(&cur_trans->dropped_roots); |
| 290 | mutex_init(&cur_trans->cache_write_mutex); |
| 291 | cur_trans->num_dirty_bgs = 0; |
| 292 | spin_lock_init(&cur_trans->dirty_bgs_lock); |
| 293 | INIT_LIST_HEAD(&cur_trans->deleted_bgs); |
| 294 | spin_lock_init(&cur_trans->dropped_roots_lock); |
| 295 | list_add_tail(&cur_trans->list, &fs_info->trans_list); |
| 296 | extent_io_tree_init(&cur_trans->dirty_pages, |
| 297 | fs_info->btree_inode->i_mapping); |
| 298 | fs_info->generation++; |
| 299 | cur_trans->transid = fs_info->generation; |
| 300 | fs_info->running_transaction = cur_trans; |
| 301 | cur_trans->aborted = 0; |
| 302 | spin_unlock(&fs_info->trans_lock); |
| 303 | |
| 304 | return 0; |
| 305 | } |
| 306 | |
| 307 | /* |
| 308 | * this does all the record keeping required to make sure that a reference |
| 309 | * counted root is properly recorded in a given transaction. This is required |
| 310 | * to make sure the old root from before we joined the transaction is deleted |
| 311 | * when the transaction commits |
| 312 | */ |
| 313 | static int record_root_in_trans(struct btrfs_trans_handle *trans, |
| 314 | struct btrfs_root *root, |
| 315 | int force) |
| 316 | { |
| 317 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 318 | |
| 319 | if ((test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
| 320 | root->last_trans < trans->transid) || force) { |
| 321 | WARN_ON(root == fs_info->extent_root); |
| 322 | WARN_ON(root->commit_root != root->node); |
| 323 | |
| 324 | /* |
| 325 | * see below for IN_TRANS_SETUP usage rules |
| 326 | * we have the reloc mutex held now, so there |
| 327 | * is only one writer in this function |
| 328 | */ |
| 329 | set_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state); |
| 330 | |
| 331 | /* make sure readers find IN_TRANS_SETUP before |
| 332 | * they find our root->last_trans update |
| 333 | */ |
| 334 | smp_wmb(); |
| 335 | |
| 336 | spin_lock(&fs_info->fs_roots_radix_lock); |
| 337 | if (root->last_trans == trans->transid && !force) { |
| 338 | spin_unlock(&fs_info->fs_roots_radix_lock); |
| 339 | return 0; |
| 340 | } |
| 341 | radix_tree_tag_set(&fs_info->fs_roots_radix, |
| 342 | (unsigned long)root->root_key.objectid, |
| 343 | BTRFS_ROOT_TRANS_TAG); |
| 344 | spin_unlock(&fs_info->fs_roots_radix_lock); |
| 345 | root->last_trans = trans->transid; |
| 346 | |
| 347 | /* this is pretty tricky. We don't want to |
| 348 | * take the relocation lock in btrfs_record_root_in_trans |
| 349 | * unless we're really doing the first setup for this root in |
| 350 | * this transaction. |
| 351 | * |
| 352 | * Normally we'd use root->last_trans as a flag to decide |
| 353 | * if we want to take the expensive mutex. |
| 354 | * |
| 355 | * But, we have to set root->last_trans before we |
| 356 | * init the relocation root, otherwise, we trip over warnings |
| 357 | * in ctree.c. The solution used here is to flag ourselves |
| 358 | * with root IN_TRANS_SETUP. When this is 1, we're still |
| 359 | * fixing up the reloc trees and everyone must wait. |
| 360 | * |
| 361 | * When this is zero, they can trust root->last_trans and fly |
| 362 | * through btrfs_record_root_in_trans without having to take the |
| 363 | * lock. smp_wmb() makes sure that all the writes above are |
| 364 | * done before we pop in the zero below |
| 365 | */ |
| 366 | btrfs_init_reloc_root(trans, root); |
| 367 | smp_mb__before_atomic(); |
| 368 | clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state); |
| 369 | } |
| 370 | return 0; |
| 371 | } |
| 372 | |
| 373 | |
| 374 | void btrfs_add_dropped_root(struct btrfs_trans_handle *trans, |
| 375 | struct btrfs_root *root) |
| 376 | { |
| 377 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 378 | struct btrfs_transaction *cur_trans = trans->transaction; |
| 379 | |
| 380 | /* Add ourselves to the transaction dropped list */ |
| 381 | spin_lock(&cur_trans->dropped_roots_lock); |
| 382 | list_add_tail(&root->root_list, &cur_trans->dropped_roots); |
| 383 | spin_unlock(&cur_trans->dropped_roots_lock); |
| 384 | |
| 385 | /* Make sure we don't try to update the root at commit time */ |
| 386 | spin_lock(&fs_info->fs_roots_radix_lock); |
| 387 | radix_tree_tag_clear(&fs_info->fs_roots_radix, |
| 388 | (unsigned long)root->root_key.objectid, |
| 389 | BTRFS_ROOT_TRANS_TAG); |
| 390 | spin_unlock(&fs_info->fs_roots_radix_lock); |
| 391 | } |
| 392 | |
| 393 | int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, |
| 394 | struct btrfs_root *root) |
| 395 | { |
| 396 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 397 | |
| 398 | if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) |
| 399 | return 0; |
| 400 | |
| 401 | /* |
| 402 | * see record_root_in_trans for comments about IN_TRANS_SETUP usage |
| 403 | * and barriers |
| 404 | */ |
| 405 | smp_rmb(); |
| 406 | if (root->last_trans == trans->transid && |
| 407 | !test_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state)) |
| 408 | return 0; |
| 409 | |
| 410 | mutex_lock(&fs_info->reloc_mutex); |
| 411 | record_root_in_trans(trans, root, 0); |
| 412 | mutex_unlock(&fs_info->reloc_mutex); |
| 413 | |
| 414 | return 0; |
| 415 | } |
| 416 | |
| 417 | static inline int is_transaction_blocked(struct btrfs_transaction *trans) |
| 418 | { |
| 419 | return (trans->state >= TRANS_STATE_BLOCKED && |
| 420 | trans->state < TRANS_STATE_UNBLOCKED && |
| 421 | !trans->aborted); |
| 422 | } |
| 423 | |
| 424 | /* wait for commit against the current transaction to become unblocked |
| 425 | * when this is done, it is safe to start a new transaction, but the current |
| 426 | * transaction might not be fully on disk. |
| 427 | */ |
| 428 | static void wait_current_trans(struct btrfs_fs_info *fs_info) |
| 429 | { |
| 430 | struct btrfs_transaction *cur_trans; |
| 431 | |
| 432 | spin_lock(&fs_info->trans_lock); |
| 433 | cur_trans = fs_info->running_transaction; |
| 434 | if (cur_trans && is_transaction_blocked(cur_trans)) { |
| 435 | refcount_inc(&cur_trans->use_count); |
| 436 | spin_unlock(&fs_info->trans_lock); |
| 437 | |
| 438 | wait_event(fs_info->transaction_wait, |
| 439 | cur_trans->state >= TRANS_STATE_UNBLOCKED || |
| 440 | cur_trans->aborted); |
| 441 | btrfs_put_transaction(cur_trans); |
| 442 | } else { |
| 443 | spin_unlock(&fs_info->trans_lock); |
| 444 | } |
| 445 | } |
| 446 | |
| 447 | static int may_wait_transaction(struct btrfs_fs_info *fs_info, int type) |
| 448 | { |
| 449 | if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) |
| 450 | return 0; |
| 451 | |
| 452 | if (type == TRANS_USERSPACE) |
| 453 | return 1; |
| 454 | |
| 455 | if (type == TRANS_START && |
| 456 | !atomic_read(&fs_info->open_ioctl_trans)) |
| 457 | return 1; |
| 458 | |
| 459 | return 0; |
| 460 | } |
| 461 | |
| 462 | static inline bool need_reserve_reloc_root(struct btrfs_root *root) |
| 463 | { |
| 464 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 465 | |
| 466 | if (!fs_info->reloc_ctl || |
| 467 | !test_bit(BTRFS_ROOT_REF_COWS, &root->state) || |
| 468 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
| 469 | root->reloc_root) |
| 470 | return false; |
| 471 | |
| 472 | return true; |
| 473 | } |
| 474 | |
| 475 | static struct btrfs_trans_handle * |
| 476 | start_transaction(struct btrfs_root *root, unsigned int num_items, |
| 477 | unsigned int type, enum btrfs_reserve_flush_enum flush, |
| 478 | bool enforce_qgroups) |
| 479 | { |
| 480 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 481 | |
| 482 | struct btrfs_trans_handle *h; |
| 483 | struct btrfs_transaction *cur_trans; |
| 484 | u64 num_bytes = 0; |
| 485 | u64 qgroup_reserved = 0; |
| 486 | bool reloc_reserved = false; |
| 487 | int ret; |
| 488 | |
| 489 | /* Send isn't supposed to start transactions. */ |
| 490 | ASSERT(current->journal_info != BTRFS_SEND_TRANS_STUB); |
| 491 | |
| 492 | if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) |
| 493 | return ERR_PTR(-EROFS); |
| 494 | |
| 495 | if (current->journal_info) { |
| 496 | WARN_ON(type & TRANS_EXTWRITERS); |
| 497 | h = current->journal_info; |
| 498 | h->use_count++; |
| 499 | WARN_ON(h->use_count > 2); |
| 500 | h->orig_rsv = h->block_rsv; |
| 501 | h->block_rsv = NULL; |
| 502 | goto got_it; |
| 503 | } |
| 504 | |
| 505 | /* |
| 506 | * Do the reservation before we join the transaction so we can do all |
| 507 | * the appropriate flushing if need be. |
| 508 | */ |
| 509 | if (num_items && root != fs_info->chunk_root) { |
| 510 | qgroup_reserved = num_items * fs_info->nodesize; |
| 511 | ret = btrfs_qgroup_reserve_meta(root, qgroup_reserved, |
| 512 | enforce_qgroups); |
| 513 | if (ret) |
| 514 | return ERR_PTR(ret); |
| 515 | |
| 516 | num_bytes = btrfs_calc_trans_metadata_size(fs_info, num_items); |
| 517 | /* |
| 518 | * Do the reservation for the relocation root creation |
| 519 | */ |
| 520 | if (need_reserve_reloc_root(root)) { |
| 521 | num_bytes += fs_info->nodesize; |
| 522 | reloc_reserved = true; |
| 523 | } |
| 524 | |
| 525 | ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv, |
| 526 | num_bytes, flush); |
| 527 | if (ret) |
| 528 | goto reserve_fail; |
| 529 | } |
| 530 | again: |
| 531 | h = kmem_cache_zalloc(btrfs_trans_handle_cachep, GFP_NOFS); |
| 532 | if (!h) { |
| 533 | ret = -ENOMEM; |
| 534 | goto alloc_fail; |
| 535 | } |
| 536 | |
| 537 | /* |
| 538 | * If we are JOIN_NOLOCK we're already committing a transaction and |
| 539 | * waiting on this guy, so we don't need to do the sb_start_intwrite |
| 540 | * because we're already holding a ref. We need this because we could |
| 541 | * have raced in and did an fsync() on a file which can kick a commit |
| 542 | * and then we deadlock with somebody doing a freeze. |
| 543 | * |
| 544 | * If we are ATTACH, it means we just want to catch the current |
| 545 | * transaction and commit it, so we needn't do sb_start_intwrite(). |
| 546 | */ |
| 547 | if (type & __TRANS_FREEZABLE) |
| 548 | sb_start_intwrite(fs_info->sb); |
| 549 | |
| 550 | if (may_wait_transaction(fs_info, type)) |
| 551 | wait_current_trans(fs_info); |
| 552 | |
| 553 | do { |
| 554 | ret = join_transaction(fs_info, type); |
| 555 | if (ret == -EBUSY) { |
| 556 | wait_current_trans(fs_info); |
| 557 | if (unlikely(type == TRANS_ATTACH)) |
| 558 | ret = -ENOENT; |
| 559 | } |
| 560 | } while (ret == -EBUSY); |
| 561 | |
| 562 | if (ret < 0) |
| 563 | goto join_fail; |
| 564 | |
| 565 | cur_trans = fs_info->running_transaction; |
| 566 | |
| 567 | h->transid = cur_trans->transid; |
| 568 | h->transaction = cur_trans; |
| 569 | h->root = root; |
| 570 | h->use_count = 1; |
| 571 | h->fs_info = root->fs_info; |
| 572 | |
| 573 | h->type = type; |
| 574 | h->can_flush_pending_bgs = true; |
| 575 | INIT_LIST_HEAD(&h->new_bgs); |
| 576 | |
| 577 | smp_mb(); |
| 578 | if (cur_trans->state >= TRANS_STATE_BLOCKED && |
| 579 | may_wait_transaction(fs_info, type)) { |
| 580 | current->journal_info = h; |
| 581 | btrfs_commit_transaction(h); |
| 582 | goto again; |
| 583 | } |
| 584 | |
| 585 | if (num_bytes) { |
| 586 | trace_btrfs_space_reservation(fs_info, "transaction", |
| 587 | h->transid, num_bytes, 1); |
| 588 | h->block_rsv = &fs_info->trans_block_rsv; |
| 589 | h->bytes_reserved = num_bytes; |
| 590 | h->reloc_reserved = reloc_reserved; |
| 591 | } |
| 592 | |
| 593 | got_it: |
| 594 | btrfs_record_root_in_trans(h, root); |
| 595 | |
| 596 | if (!current->journal_info && type != TRANS_USERSPACE) |
| 597 | current->journal_info = h; |
| 598 | return h; |
| 599 | |
| 600 | join_fail: |
| 601 | if (type & __TRANS_FREEZABLE) |
| 602 | sb_end_intwrite(fs_info->sb); |
| 603 | kmem_cache_free(btrfs_trans_handle_cachep, h); |
| 604 | alloc_fail: |
| 605 | if (num_bytes) |
| 606 | btrfs_block_rsv_release(fs_info, &fs_info->trans_block_rsv, |
| 607 | num_bytes); |
| 608 | reserve_fail: |
| 609 | btrfs_qgroup_free_meta(root, qgroup_reserved); |
| 610 | return ERR_PTR(ret); |
| 611 | } |
| 612 | |
| 613 | struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, |
| 614 | unsigned int num_items) |
| 615 | { |
| 616 | return start_transaction(root, num_items, TRANS_START, |
| 617 | BTRFS_RESERVE_FLUSH_ALL, true); |
| 618 | } |
| 619 | |
| 620 | struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv( |
| 621 | struct btrfs_root *root, |
| 622 | unsigned int num_items, |
| 623 | int min_factor) |
| 624 | { |
| 625 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 626 | struct btrfs_trans_handle *trans; |
| 627 | u64 num_bytes; |
| 628 | int ret; |
| 629 | |
| 630 | /* |
| 631 | * We have two callers: unlink and block group removal. The |
| 632 | * former should succeed even if we will temporarily exceed |
| 633 | * quota and the latter operates on the extent root so |
| 634 | * qgroup enforcement is ignored anyway. |
| 635 | */ |
| 636 | trans = start_transaction(root, num_items, TRANS_START, |
| 637 | BTRFS_RESERVE_FLUSH_ALL, false); |
| 638 | if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC) |
| 639 | return trans; |
| 640 | |
| 641 | trans = btrfs_start_transaction(root, 0); |
| 642 | if (IS_ERR(trans)) |
| 643 | return trans; |
| 644 | |
| 645 | num_bytes = btrfs_calc_trans_metadata_size(fs_info, num_items); |
| 646 | ret = btrfs_cond_migrate_bytes(fs_info, &fs_info->trans_block_rsv, |
| 647 | num_bytes, min_factor); |
| 648 | if (ret) { |
| 649 | btrfs_end_transaction(trans); |
| 650 | return ERR_PTR(ret); |
| 651 | } |
| 652 | |
| 653 | trans->block_rsv = &fs_info->trans_block_rsv; |
| 654 | trans->bytes_reserved = num_bytes; |
| 655 | trace_btrfs_space_reservation(fs_info, "transaction", |
| 656 | trans->transid, num_bytes, 1); |
| 657 | |
| 658 | return trans; |
| 659 | } |
| 660 | |
| 661 | struct btrfs_trans_handle *btrfs_start_transaction_lflush( |
| 662 | struct btrfs_root *root, |
| 663 | unsigned int num_items) |
| 664 | { |
| 665 | return start_transaction(root, num_items, TRANS_START, |
| 666 | BTRFS_RESERVE_FLUSH_LIMIT, true); |
| 667 | } |
| 668 | |
| 669 | struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root) |
| 670 | { |
| 671 | return start_transaction(root, 0, TRANS_JOIN, BTRFS_RESERVE_NO_FLUSH, |
| 672 | true); |
| 673 | } |
| 674 | |
| 675 | struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root) |
| 676 | { |
| 677 | return start_transaction(root, 0, TRANS_JOIN_NOLOCK, |
| 678 | BTRFS_RESERVE_NO_FLUSH, true); |
| 679 | } |
| 680 | |
| 681 | struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root) |
| 682 | { |
| 683 | return start_transaction(root, 0, TRANS_USERSPACE, |
| 684 | BTRFS_RESERVE_NO_FLUSH, true); |
| 685 | } |
| 686 | |
| 687 | /* |
| 688 | * btrfs_attach_transaction() - catch the running transaction |
| 689 | * |
| 690 | * It is used when we want to commit the current the transaction, but |
| 691 | * don't want to start a new one. |
| 692 | * |
| 693 | * Note: If this function return -ENOENT, it just means there is no |
| 694 | * running transaction. But it is possible that the inactive transaction |
| 695 | * is still in the memory, not fully on disk. If you hope there is no |
| 696 | * inactive transaction in the fs when -ENOENT is returned, you should |
| 697 | * invoke |
| 698 | * btrfs_attach_transaction_barrier() |
| 699 | */ |
| 700 | struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root) |
| 701 | { |
| 702 | return start_transaction(root, 0, TRANS_ATTACH, |
| 703 | BTRFS_RESERVE_NO_FLUSH, true); |
| 704 | } |
| 705 | |
| 706 | /* |
| 707 | * btrfs_attach_transaction_barrier() - catch the running transaction |
| 708 | * |
| 709 | * It is similar to the above function, the differentia is this one |
| 710 | * will wait for all the inactive transactions until they fully |
| 711 | * complete. |
| 712 | */ |
| 713 | struct btrfs_trans_handle * |
| 714 | btrfs_attach_transaction_barrier(struct btrfs_root *root) |
| 715 | { |
| 716 | struct btrfs_trans_handle *trans; |
| 717 | |
| 718 | trans = start_transaction(root, 0, TRANS_ATTACH, |
| 719 | BTRFS_RESERVE_NO_FLUSH, true); |
| 720 | if (IS_ERR(trans) && PTR_ERR(trans) == -ENOENT) |
| 721 | btrfs_wait_for_commit(root->fs_info, 0); |
| 722 | |
| 723 | return trans; |
| 724 | } |
| 725 | |
| 726 | /* wait for a transaction commit to be fully complete */ |
| 727 | static noinline void wait_for_commit(struct btrfs_transaction *commit) |
| 728 | { |
| 729 | wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED); |
| 730 | } |
| 731 | |
| 732 | int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid) |
| 733 | { |
| 734 | struct btrfs_transaction *cur_trans = NULL, *t; |
| 735 | int ret = 0; |
| 736 | |
| 737 | if (transid) { |
| 738 | if (transid <= fs_info->last_trans_committed) |
| 739 | goto out; |
| 740 | |
| 741 | /* find specified transaction */ |
| 742 | spin_lock(&fs_info->trans_lock); |
| 743 | list_for_each_entry(t, &fs_info->trans_list, list) { |
| 744 | if (t->transid == transid) { |
| 745 | cur_trans = t; |
| 746 | refcount_inc(&cur_trans->use_count); |
| 747 | ret = 0; |
| 748 | break; |
| 749 | } |
| 750 | if (t->transid > transid) { |
| 751 | ret = 0; |
| 752 | break; |
| 753 | } |
| 754 | } |
| 755 | spin_unlock(&fs_info->trans_lock); |
| 756 | |
| 757 | /* |
| 758 | * The specified transaction doesn't exist, or we |
| 759 | * raced with btrfs_commit_transaction |
| 760 | */ |
| 761 | if (!cur_trans) { |
| 762 | if (transid > fs_info->last_trans_committed) |
| 763 | ret = -EINVAL; |
| 764 | goto out; |
| 765 | } |
| 766 | } else { |
| 767 | /* find newest transaction that is committing | committed */ |
| 768 | spin_lock(&fs_info->trans_lock); |
| 769 | list_for_each_entry_reverse(t, &fs_info->trans_list, |
| 770 | list) { |
| 771 | if (t->state >= TRANS_STATE_COMMIT_START) { |
| 772 | if (t->state == TRANS_STATE_COMPLETED) |
| 773 | break; |
| 774 | cur_trans = t; |
| 775 | refcount_inc(&cur_trans->use_count); |
| 776 | break; |
| 777 | } |
| 778 | } |
| 779 | spin_unlock(&fs_info->trans_lock); |
| 780 | if (!cur_trans) |
| 781 | goto out; /* nothing committing|committed */ |
| 782 | } |
| 783 | |
| 784 | wait_for_commit(cur_trans); |
| 785 | btrfs_put_transaction(cur_trans); |
| 786 | out: |
| 787 | return ret; |
| 788 | } |
| 789 | |
| 790 | void btrfs_throttle(struct btrfs_fs_info *fs_info) |
| 791 | { |
| 792 | if (!atomic_read(&fs_info->open_ioctl_trans)) |
| 793 | wait_current_trans(fs_info); |
| 794 | } |
| 795 | |
| 796 | static int should_end_transaction(struct btrfs_trans_handle *trans) |
| 797 | { |
| 798 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 799 | |
| 800 | if (fs_info->global_block_rsv.space_info->full && |
| 801 | btrfs_check_space_for_delayed_refs(trans, fs_info)) |
| 802 | return 1; |
| 803 | |
| 804 | return !!btrfs_block_rsv_check(&fs_info->global_block_rsv, 5); |
| 805 | } |
| 806 | |
| 807 | int btrfs_should_end_transaction(struct btrfs_trans_handle *trans) |
| 808 | { |
| 809 | struct btrfs_transaction *cur_trans = trans->transaction; |
| 810 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 811 | int updates; |
| 812 | int err; |
| 813 | |
| 814 | smp_mb(); |
| 815 | if (cur_trans->state >= TRANS_STATE_BLOCKED || |
| 816 | cur_trans->delayed_refs.flushing) |
| 817 | return 1; |
| 818 | |
| 819 | updates = trans->delayed_ref_updates; |
| 820 | trans->delayed_ref_updates = 0; |
| 821 | if (updates) { |
| 822 | err = btrfs_run_delayed_refs(trans, fs_info, updates * 2); |
| 823 | if (err) /* Error code will also eval true */ |
| 824 | return err; |
| 825 | } |
| 826 | |
| 827 | return should_end_transaction(trans); |
| 828 | } |
| 829 | |
| 830 | static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, |
| 831 | int throttle) |
| 832 | { |
| 833 | struct btrfs_fs_info *info = trans->fs_info; |
| 834 | struct btrfs_transaction *cur_trans = trans->transaction; |
| 835 | u64 transid = trans->transid; |
| 836 | unsigned long cur = trans->delayed_ref_updates; |
| 837 | int lock = (trans->type != TRANS_JOIN_NOLOCK); |
| 838 | int err = 0; |
| 839 | int must_run_delayed_refs = 0; |
| 840 | |
| 841 | if (trans->use_count > 1) { |
| 842 | trans->use_count--; |
| 843 | trans->block_rsv = trans->orig_rsv; |
| 844 | return 0; |
| 845 | } |
| 846 | |
| 847 | btrfs_trans_release_metadata(trans, info); |
| 848 | trans->block_rsv = NULL; |
| 849 | |
| 850 | if (!list_empty(&trans->new_bgs)) |
| 851 | btrfs_create_pending_block_groups(trans, info); |
| 852 | |
| 853 | trans->delayed_ref_updates = 0; |
| 854 | if (!trans->sync) { |
| 855 | must_run_delayed_refs = |
| 856 | btrfs_should_throttle_delayed_refs(trans, info); |
| 857 | cur = max_t(unsigned long, cur, 32); |
| 858 | |
| 859 | /* |
| 860 | * don't make the caller wait if they are from a NOLOCK |
| 861 | * or ATTACH transaction, it will deadlock with commit |
| 862 | */ |
| 863 | if (must_run_delayed_refs == 1 && |
| 864 | (trans->type & (__TRANS_JOIN_NOLOCK | __TRANS_ATTACH))) |
| 865 | must_run_delayed_refs = 2; |
| 866 | } |
| 867 | |
| 868 | btrfs_trans_release_metadata(trans, info); |
| 869 | trans->block_rsv = NULL; |
| 870 | |
| 871 | if (!list_empty(&trans->new_bgs)) |
| 872 | btrfs_create_pending_block_groups(trans, info); |
| 873 | |
| 874 | btrfs_trans_release_chunk_metadata(trans); |
| 875 | |
| 876 | if (lock && !atomic_read(&info->open_ioctl_trans) && |
| 877 | should_end_transaction(trans) && |
| 878 | READ_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) { |
| 879 | spin_lock(&info->trans_lock); |
| 880 | if (cur_trans->state == TRANS_STATE_RUNNING) |
| 881 | cur_trans->state = TRANS_STATE_BLOCKED; |
| 882 | spin_unlock(&info->trans_lock); |
| 883 | } |
| 884 | |
| 885 | if (lock && READ_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) { |
| 886 | if (throttle) |
| 887 | return btrfs_commit_transaction(trans); |
| 888 | else |
| 889 | wake_up_process(info->transaction_kthread); |
| 890 | } |
| 891 | |
| 892 | if (trans->type & __TRANS_FREEZABLE) |
| 893 | sb_end_intwrite(info->sb); |
| 894 | |
| 895 | WARN_ON(cur_trans != info->running_transaction); |
| 896 | WARN_ON(atomic_read(&cur_trans->num_writers) < 1); |
| 897 | atomic_dec(&cur_trans->num_writers); |
| 898 | extwriter_counter_dec(cur_trans, trans->type); |
| 899 | |
| 900 | /* |
| 901 | * Make sure counter is updated before we wake up waiters. |
| 902 | */ |
| 903 | smp_mb(); |
| 904 | if (waitqueue_active(&cur_trans->writer_wait)) |
| 905 | wake_up(&cur_trans->writer_wait); |
| 906 | btrfs_put_transaction(cur_trans); |
| 907 | |
| 908 | if (current->journal_info == trans) |
| 909 | current->journal_info = NULL; |
| 910 | |
| 911 | if (throttle) |
| 912 | btrfs_run_delayed_iputs(info); |
| 913 | |
| 914 | if (trans->aborted || |
| 915 | test_bit(BTRFS_FS_STATE_ERROR, &info->fs_state)) { |
| 916 | wake_up_process(info->transaction_kthread); |
| 917 | err = -EIO; |
| 918 | } |
| 919 | |
| 920 | kmem_cache_free(btrfs_trans_handle_cachep, trans); |
| 921 | if (must_run_delayed_refs) { |
| 922 | btrfs_async_run_delayed_refs(info, cur, transid, |
| 923 | must_run_delayed_refs == 1); |
| 924 | } |
| 925 | return err; |
| 926 | } |
| 927 | |
| 928 | int btrfs_end_transaction(struct btrfs_trans_handle *trans) |
| 929 | { |
| 930 | return __btrfs_end_transaction(trans, 0); |
| 931 | } |
| 932 | |
| 933 | int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans) |
| 934 | { |
| 935 | return __btrfs_end_transaction(trans, 1); |
| 936 | } |
| 937 | |
| 938 | /* |
| 939 | * when btree blocks are allocated, they have some corresponding bits set for |
| 940 | * them in one of two extent_io trees. This is used to make sure all of |
| 941 | * those extents are sent to disk but does not wait on them |
| 942 | */ |
| 943 | int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info, |
| 944 | struct extent_io_tree *dirty_pages, int mark) |
| 945 | { |
| 946 | int err = 0; |
| 947 | int werr = 0; |
| 948 | struct address_space *mapping = fs_info->btree_inode->i_mapping; |
| 949 | struct extent_state *cached_state = NULL; |
| 950 | u64 start = 0; |
| 951 | u64 end; |
| 952 | |
| 953 | while (!find_first_extent_bit(dirty_pages, start, &start, &end, |
| 954 | mark, &cached_state)) { |
| 955 | bool wait_writeback = false; |
| 956 | |
| 957 | err = convert_extent_bit(dirty_pages, start, end, |
| 958 | EXTENT_NEED_WAIT, |
| 959 | mark, &cached_state); |
| 960 | /* |
| 961 | * convert_extent_bit can return -ENOMEM, which is most of the |
| 962 | * time a temporary error. So when it happens, ignore the error |
| 963 | * and wait for writeback of this range to finish - because we |
| 964 | * failed to set the bit EXTENT_NEED_WAIT for the range, a call |
| 965 | * to __btrfs_wait_marked_extents() would not know that |
| 966 | * writeback for this range started and therefore wouldn't |
| 967 | * wait for it to finish - we don't want to commit a |
| 968 | * superblock that points to btree nodes/leafs for which |
| 969 | * writeback hasn't finished yet (and without errors). |
| 970 | * We cleanup any entries left in the io tree when committing |
| 971 | * the transaction (through clear_btree_io_tree()). |
| 972 | */ |
| 973 | if (err == -ENOMEM) { |
| 974 | err = 0; |
| 975 | wait_writeback = true; |
| 976 | } |
| 977 | if (!err) |
| 978 | err = filemap_fdatawrite_range(mapping, start, end); |
| 979 | if (err) |
| 980 | werr = err; |
| 981 | else if (wait_writeback) |
| 982 | werr = filemap_fdatawait_range(mapping, start, end); |
| 983 | free_extent_state(cached_state); |
| 984 | cached_state = NULL; |
| 985 | cond_resched(); |
| 986 | start = end + 1; |
| 987 | } |
| 988 | return werr; |
| 989 | } |
| 990 | |
| 991 | /* |
| 992 | * when btree blocks are allocated, they have some corresponding bits set for |
| 993 | * them in one of two extent_io trees. This is used to make sure all of |
| 994 | * those extents are on disk for transaction or log commit. We wait |
| 995 | * on all the pages and clear them from the dirty pages state tree |
| 996 | */ |
| 997 | static int __btrfs_wait_marked_extents(struct btrfs_fs_info *fs_info, |
| 998 | struct extent_io_tree *dirty_pages) |
| 999 | { |
| 1000 | int err = 0; |
| 1001 | int werr = 0; |
| 1002 | struct address_space *mapping = fs_info->btree_inode->i_mapping; |
| 1003 | struct extent_state *cached_state = NULL; |
| 1004 | u64 start = 0; |
| 1005 | u64 end; |
| 1006 | |
| 1007 | while (!find_first_extent_bit(dirty_pages, start, &start, &end, |
| 1008 | EXTENT_NEED_WAIT, &cached_state)) { |
| 1009 | /* |
| 1010 | * Ignore -ENOMEM errors returned by clear_extent_bit(). |
| 1011 | * When committing the transaction, we'll remove any entries |
| 1012 | * left in the io tree. For a log commit, we don't remove them |
| 1013 | * after committing the log because the tree can be accessed |
| 1014 | * concurrently - we do it only at transaction commit time when |
| 1015 | * it's safe to do it (through clear_btree_io_tree()). |
| 1016 | */ |
| 1017 | err = clear_extent_bit(dirty_pages, start, end, |
| 1018 | EXTENT_NEED_WAIT, |
| 1019 | 0, 0, &cached_state, GFP_NOFS); |
| 1020 | if (err == -ENOMEM) |
| 1021 | err = 0; |
| 1022 | if (!err) |
| 1023 | err = filemap_fdatawait_range(mapping, start, end); |
| 1024 | if (err) |
| 1025 | werr = err; |
| 1026 | free_extent_state(cached_state); |
| 1027 | cached_state = NULL; |
| 1028 | cond_resched(); |
| 1029 | start = end + 1; |
| 1030 | } |
| 1031 | if (err) |
| 1032 | werr = err; |
| 1033 | return werr; |
| 1034 | } |
| 1035 | |
| 1036 | int btrfs_wait_extents(struct btrfs_fs_info *fs_info, |
| 1037 | struct extent_io_tree *dirty_pages) |
| 1038 | { |
| 1039 | bool errors = false; |
| 1040 | int err; |
| 1041 | |
| 1042 | err = __btrfs_wait_marked_extents(fs_info, dirty_pages); |
| 1043 | if (test_and_clear_bit(BTRFS_FS_BTREE_ERR, &fs_info->flags)) |
| 1044 | errors = true; |
| 1045 | |
| 1046 | if (errors && !err) |
| 1047 | err = -EIO; |
| 1048 | return err; |
| 1049 | } |
| 1050 | |
| 1051 | int btrfs_wait_tree_log_extents(struct btrfs_root *log_root, int mark) |
| 1052 | { |
| 1053 | struct btrfs_fs_info *fs_info = log_root->fs_info; |
| 1054 | struct extent_io_tree *dirty_pages = &log_root->dirty_log_pages; |
| 1055 | bool errors = false; |
| 1056 | int err; |
| 1057 | |
| 1058 | ASSERT(log_root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID); |
| 1059 | |
| 1060 | err = __btrfs_wait_marked_extents(fs_info, dirty_pages); |
| 1061 | if ((mark & EXTENT_DIRTY) && |
| 1062 | test_and_clear_bit(BTRFS_FS_LOG1_ERR, &fs_info->flags)) |
| 1063 | errors = true; |
| 1064 | |
| 1065 | if ((mark & EXTENT_NEW) && |
| 1066 | test_and_clear_bit(BTRFS_FS_LOG2_ERR, &fs_info->flags)) |
| 1067 | errors = true; |
| 1068 | |
| 1069 | if (errors && !err) |
| 1070 | err = -EIO; |
| 1071 | return err; |
| 1072 | } |
| 1073 | |
| 1074 | /* |
| 1075 | * when btree blocks are allocated, they have some corresponding bits set for |
| 1076 | * them in one of two extent_io trees. This is used to make sure all of |
| 1077 | * those extents are on disk for transaction or log commit |
| 1078 | */ |
| 1079 | static int btrfs_write_and_wait_marked_extents(struct btrfs_fs_info *fs_info, |
| 1080 | struct extent_io_tree *dirty_pages, int mark) |
| 1081 | { |
| 1082 | int ret; |
| 1083 | int ret2; |
| 1084 | struct blk_plug plug; |
| 1085 | |
| 1086 | blk_start_plug(&plug); |
| 1087 | ret = btrfs_write_marked_extents(fs_info, dirty_pages, mark); |
| 1088 | blk_finish_plug(&plug); |
| 1089 | ret2 = btrfs_wait_extents(fs_info, dirty_pages); |
| 1090 | |
| 1091 | if (ret) |
| 1092 | return ret; |
| 1093 | if (ret2) |
| 1094 | return ret2; |
| 1095 | return 0; |
| 1096 | } |
| 1097 | |
| 1098 | static int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, |
| 1099 | struct btrfs_fs_info *fs_info) |
| 1100 | { |
| 1101 | int ret; |
| 1102 | |
| 1103 | ret = btrfs_write_and_wait_marked_extents(fs_info, |
| 1104 | &trans->transaction->dirty_pages, |
| 1105 | EXTENT_DIRTY); |
| 1106 | clear_btree_io_tree(&trans->transaction->dirty_pages); |
| 1107 | |
| 1108 | return ret; |
| 1109 | } |
| 1110 | |
| 1111 | /* |
| 1112 | * this is used to update the root pointer in the tree of tree roots. |
| 1113 | * |
| 1114 | * But, in the case of the extent allocation tree, updating the root |
| 1115 | * pointer may allocate blocks which may change the root of the extent |
| 1116 | * allocation tree. |
| 1117 | * |
| 1118 | * So, this loops and repeats and makes sure the cowonly root didn't |
| 1119 | * change while the root pointer was being updated in the metadata. |
| 1120 | */ |
| 1121 | static int update_cowonly_root(struct btrfs_trans_handle *trans, |
| 1122 | struct btrfs_root *root) |
| 1123 | { |
| 1124 | int ret; |
| 1125 | u64 old_root_bytenr; |
| 1126 | u64 old_root_used; |
| 1127 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 1128 | struct btrfs_root *tree_root = fs_info->tree_root; |
| 1129 | |
| 1130 | old_root_used = btrfs_root_used(&root->root_item); |
| 1131 | |
| 1132 | while (1) { |
| 1133 | old_root_bytenr = btrfs_root_bytenr(&root->root_item); |
| 1134 | if (old_root_bytenr == root->node->start && |
| 1135 | old_root_used == btrfs_root_used(&root->root_item)) |
| 1136 | break; |
| 1137 | |
| 1138 | btrfs_set_root_node(&root->root_item, root->node); |
| 1139 | ret = btrfs_update_root(trans, tree_root, |
| 1140 | &root->root_key, |
| 1141 | &root->root_item); |
| 1142 | if (ret) |
| 1143 | return ret; |
| 1144 | |
| 1145 | old_root_used = btrfs_root_used(&root->root_item); |
| 1146 | } |
| 1147 | |
| 1148 | return 0; |
| 1149 | } |
| 1150 | |
| 1151 | /* |
| 1152 | * update all the cowonly tree roots on disk |
| 1153 | * |
| 1154 | * The error handling in this function may not be obvious. Any of the |
| 1155 | * failures will cause the file system to go offline. We still need |
| 1156 | * to clean up the delayed refs. |
| 1157 | */ |
| 1158 | static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans, |
| 1159 | struct btrfs_fs_info *fs_info) |
| 1160 | { |
| 1161 | struct list_head *dirty_bgs = &trans->transaction->dirty_bgs; |
| 1162 | struct list_head *io_bgs = &trans->transaction->io_bgs; |
| 1163 | struct list_head *next; |
| 1164 | struct extent_buffer *eb; |
| 1165 | int ret; |
| 1166 | |
| 1167 | eb = btrfs_lock_root_node(fs_info->tree_root); |
| 1168 | ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, |
| 1169 | 0, &eb); |
| 1170 | btrfs_tree_unlock(eb); |
| 1171 | free_extent_buffer(eb); |
| 1172 | |
| 1173 | if (ret) |
| 1174 | return ret; |
| 1175 | |
| 1176 | ret = btrfs_run_delayed_refs(trans, fs_info, (unsigned long)-1); |
| 1177 | if (ret) |
| 1178 | return ret; |
| 1179 | |
| 1180 | ret = btrfs_run_dev_stats(trans, fs_info); |
| 1181 | if (ret) |
| 1182 | return ret; |
| 1183 | ret = btrfs_run_dev_replace(trans, fs_info); |
| 1184 | if (ret) |
| 1185 | return ret; |
| 1186 | ret = btrfs_run_qgroups(trans, fs_info); |
| 1187 | if (ret) |
| 1188 | return ret; |
| 1189 | |
| 1190 | ret = btrfs_setup_space_cache(trans, fs_info); |
| 1191 | if (ret) |
| 1192 | return ret; |
| 1193 | |
| 1194 | /* run_qgroups might have added some more refs */ |
| 1195 | ret = btrfs_run_delayed_refs(trans, fs_info, (unsigned long)-1); |
| 1196 | if (ret) |
| 1197 | return ret; |
| 1198 | again: |
| 1199 | while (!list_empty(&fs_info->dirty_cowonly_roots)) { |
| 1200 | struct btrfs_root *root; |
| 1201 | next = fs_info->dirty_cowonly_roots.next; |
| 1202 | list_del_init(next); |
| 1203 | root = list_entry(next, struct btrfs_root, dirty_list); |
| 1204 | clear_bit(BTRFS_ROOT_DIRTY, &root->state); |
| 1205 | |
| 1206 | if (root != fs_info->extent_root) |
| 1207 | list_add_tail(&root->dirty_list, |
| 1208 | &trans->transaction->switch_commits); |
| 1209 | ret = update_cowonly_root(trans, root); |
| 1210 | if (ret) |
| 1211 | return ret; |
| 1212 | ret = btrfs_run_delayed_refs(trans, fs_info, (unsigned long)-1); |
| 1213 | if (ret) |
| 1214 | return ret; |
| 1215 | } |
| 1216 | |
| 1217 | while (!list_empty(dirty_bgs) || !list_empty(io_bgs)) { |
| 1218 | ret = btrfs_write_dirty_block_groups(trans, fs_info); |
| 1219 | if (ret) |
| 1220 | return ret; |
| 1221 | ret = btrfs_run_delayed_refs(trans, fs_info, (unsigned long)-1); |
| 1222 | if (ret) |
| 1223 | return ret; |
| 1224 | } |
| 1225 | |
| 1226 | if (!list_empty(&fs_info->dirty_cowonly_roots)) |
| 1227 | goto again; |
| 1228 | |
| 1229 | list_add_tail(&fs_info->extent_root->dirty_list, |
| 1230 | &trans->transaction->switch_commits); |
| 1231 | btrfs_after_dev_replace_commit(fs_info); |
| 1232 | |
| 1233 | return 0; |
| 1234 | } |
| 1235 | |
| 1236 | /* |
| 1237 | * dead roots are old snapshots that need to be deleted. This allocates |
| 1238 | * a dirty root struct and adds it into the list of dead roots that need to |
| 1239 | * be deleted |
| 1240 | */ |
| 1241 | void btrfs_add_dead_root(struct btrfs_root *root) |
| 1242 | { |
| 1243 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 1244 | |
| 1245 | spin_lock(&fs_info->trans_lock); |
| 1246 | if (list_empty(&root->root_list)) |
| 1247 | list_add_tail(&root->root_list, &fs_info->dead_roots); |
| 1248 | spin_unlock(&fs_info->trans_lock); |
| 1249 | } |
| 1250 | |
| 1251 | /* |
| 1252 | * update all the cowonly tree roots on disk |
| 1253 | */ |
| 1254 | static noinline int commit_fs_roots(struct btrfs_trans_handle *trans, |
| 1255 | struct btrfs_fs_info *fs_info) |
| 1256 | { |
| 1257 | struct btrfs_root *gang[8]; |
| 1258 | int i; |
| 1259 | int ret; |
| 1260 | int err = 0; |
| 1261 | |
| 1262 | spin_lock(&fs_info->fs_roots_radix_lock); |
| 1263 | while (1) { |
| 1264 | ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix, |
| 1265 | (void **)gang, 0, |
| 1266 | ARRAY_SIZE(gang), |
| 1267 | BTRFS_ROOT_TRANS_TAG); |
| 1268 | if (ret == 0) |
| 1269 | break; |
| 1270 | for (i = 0; i < ret; i++) { |
| 1271 | struct btrfs_root *root = gang[i]; |
| 1272 | radix_tree_tag_clear(&fs_info->fs_roots_radix, |
| 1273 | (unsigned long)root->root_key.objectid, |
| 1274 | BTRFS_ROOT_TRANS_TAG); |
| 1275 | spin_unlock(&fs_info->fs_roots_radix_lock); |
| 1276 | |
| 1277 | btrfs_free_log(trans, root); |
| 1278 | btrfs_update_reloc_root(trans, root); |
| 1279 | btrfs_orphan_commit_root(trans, root); |
| 1280 | |
| 1281 | btrfs_save_ino_cache(root, trans); |
| 1282 | |
| 1283 | /* see comments in should_cow_block() */ |
| 1284 | clear_bit(BTRFS_ROOT_FORCE_COW, &root->state); |
| 1285 | smp_mb__after_atomic(); |
| 1286 | |
| 1287 | if (root->commit_root != root->node) { |
| 1288 | list_add_tail(&root->dirty_list, |
| 1289 | &trans->transaction->switch_commits); |
| 1290 | btrfs_set_root_node(&root->root_item, |
| 1291 | root->node); |
| 1292 | } |
| 1293 | |
| 1294 | err = btrfs_update_root(trans, fs_info->tree_root, |
| 1295 | &root->root_key, |
| 1296 | &root->root_item); |
| 1297 | spin_lock(&fs_info->fs_roots_radix_lock); |
| 1298 | if (err) |
| 1299 | break; |
| 1300 | btrfs_qgroup_free_meta_all(root); |
| 1301 | } |
| 1302 | } |
| 1303 | spin_unlock(&fs_info->fs_roots_radix_lock); |
| 1304 | return err; |
| 1305 | } |
| 1306 | |
| 1307 | /* |
| 1308 | * defrag a given btree. |
| 1309 | * Every leaf in the btree is read and defragged. |
| 1310 | */ |
| 1311 | int btrfs_defrag_root(struct btrfs_root *root) |
| 1312 | { |
| 1313 | struct btrfs_fs_info *info = root->fs_info; |
| 1314 | struct btrfs_trans_handle *trans; |
| 1315 | int ret; |
| 1316 | |
| 1317 | if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state)) |
| 1318 | return 0; |
| 1319 | |
| 1320 | while (1) { |
| 1321 | trans = btrfs_start_transaction(root, 0); |
| 1322 | if (IS_ERR(trans)) |
| 1323 | return PTR_ERR(trans); |
| 1324 | |
| 1325 | ret = btrfs_defrag_leaves(trans, root); |
| 1326 | |
| 1327 | btrfs_end_transaction(trans); |
| 1328 | btrfs_btree_balance_dirty(info); |
| 1329 | cond_resched(); |
| 1330 | |
| 1331 | if (btrfs_fs_closing(info) || ret != -EAGAIN) |
| 1332 | break; |
| 1333 | |
| 1334 | if (btrfs_defrag_cancelled(info)) { |
| 1335 | btrfs_debug(info, "defrag_root cancelled"); |
| 1336 | ret = -EAGAIN; |
| 1337 | break; |
| 1338 | } |
| 1339 | } |
| 1340 | clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state); |
| 1341 | return ret; |
| 1342 | } |
| 1343 | |
| 1344 | /* |
| 1345 | * Do all special snapshot related qgroup dirty hack. |
| 1346 | * |
| 1347 | * Will do all needed qgroup inherit and dirty hack like switch commit |
| 1348 | * roots inside one transaction and write all btree into disk, to make |
| 1349 | * qgroup works. |
| 1350 | */ |
| 1351 | static int qgroup_account_snapshot(struct btrfs_trans_handle *trans, |
| 1352 | struct btrfs_root *src, |
| 1353 | struct btrfs_root *parent, |
| 1354 | struct btrfs_qgroup_inherit *inherit, |
| 1355 | u64 dst_objectid) |
| 1356 | { |
| 1357 | struct btrfs_fs_info *fs_info = src->fs_info; |
| 1358 | int ret; |
| 1359 | |
| 1360 | /* |
| 1361 | * Save some performance in the case that qgroups are not |
| 1362 | * enabled. If this check races with the ioctl, rescan will |
| 1363 | * kick in anyway. |
| 1364 | */ |
| 1365 | if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) |
| 1366 | return 0; |
| 1367 | |
| 1368 | /* |
| 1369 | * We are going to commit transaction, see btrfs_commit_transaction() |
| 1370 | * comment for reason locking tree_log_mutex |
| 1371 | */ |
| 1372 | mutex_lock(&fs_info->tree_log_mutex); |
| 1373 | |
| 1374 | ret = commit_fs_roots(trans, fs_info); |
| 1375 | if (ret) |
| 1376 | goto out; |
| 1377 | ret = btrfs_qgroup_prepare_account_extents(trans, fs_info); |
| 1378 | if (ret < 0) |
| 1379 | goto out; |
| 1380 | ret = btrfs_qgroup_account_extents(trans, fs_info); |
| 1381 | if (ret < 0) |
| 1382 | goto out; |
| 1383 | |
| 1384 | /* Now qgroup are all updated, we can inherit it to new qgroups */ |
| 1385 | ret = btrfs_qgroup_inherit(trans, fs_info, |
| 1386 | src->root_key.objectid, dst_objectid, |
| 1387 | inherit); |
| 1388 | if (ret < 0) |
| 1389 | goto out; |
| 1390 | |
| 1391 | /* |
| 1392 | * Now we do a simplified commit transaction, which will: |
| 1393 | * 1) commit all subvolume and extent tree |
| 1394 | * To ensure all subvolume and extent tree have a valid |
| 1395 | * commit_root to accounting later insert_dir_item() |
| 1396 | * 2) write all btree blocks onto disk |
| 1397 | * This is to make sure later btree modification will be cowed |
| 1398 | * Or commit_root can be populated and cause wrong qgroup numbers |
| 1399 | * In this simplified commit, we don't really care about other trees |
| 1400 | * like chunk and root tree, as they won't affect qgroup. |
| 1401 | * And we don't write super to avoid half committed status. |
| 1402 | */ |
| 1403 | ret = commit_cowonly_roots(trans, fs_info); |
| 1404 | if (ret) |
| 1405 | goto out; |
| 1406 | switch_commit_roots(trans->transaction, fs_info); |
| 1407 | ret = btrfs_write_and_wait_transaction(trans, fs_info); |
| 1408 | if (ret) |
| 1409 | btrfs_handle_fs_error(fs_info, ret, |
| 1410 | "Error while writing out transaction for qgroup"); |
| 1411 | |
| 1412 | out: |
| 1413 | mutex_unlock(&fs_info->tree_log_mutex); |
| 1414 | |
| 1415 | /* |
| 1416 | * Force parent root to be updated, as we recorded it before so its |
| 1417 | * last_trans == cur_transid. |
| 1418 | * Or it won't be committed again onto disk after later |
| 1419 | * insert_dir_item() |
| 1420 | */ |
| 1421 | if (!ret) |
| 1422 | record_root_in_trans(trans, parent, 1); |
| 1423 | return ret; |
| 1424 | } |
| 1425 | |
| 1426 | /* |
| 1427 | * new snapshots need to be created at a very specific time in the |
| 1428 | * transaction commit. This does the actual creation. |
| 1429 | * |
| 1430 | * Note: |
| 1431 | * If the error which may affect the commitment of the current transaction |
| 1432 | * happens, we should return the error number. If the error which just affect |
| 1433 | * the creation of the pending snapshots, just return 0. |
| 1434 | */ |
| 1435 | static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, |
| 1436 | struct btrfs_fs_info *fs_info, |
| 1437 | struct btrfs_pending_snapshot *pending) |
| 1438 | { |
| 1439 | struct btrfs_key key; |
| 1440 | struct btrfs_root_item *new_root_item; |
| 1441 | struct btrfs_root *tree_root = fs_info->tree_root; |
| 1442 | struct btrfs_root *root = pending->root; |
| 1443 | struct btrfs_root *parent_root; |
| 1444 | struct btrfs_block_rsv *rsv; |
| 1445 | struct inode *parent_inode; |
| 1446 | struct btrfs_path *path; |
| 1447 | struct btrfs_dir_item *dir_item; |
| 1448 | struct dentry *dentry; |
| 1449 | struct extent_buffer *tmp; |
| 1450 | struct extent_buffer *old; |
| 1451 | struct timespec cur_time; |
| 1452 | int ret = 0; |
| 1453 | u64 to_reserve = 0; |
| 1454 | u64 index = 0; |
| 1455 | u64 objectid; |
| 1456 | u64 root_flags; |
| 1457 | uuid_le new_uuid; |
| 1458 | |
| 1459 | ASSERT(pending->path); |
| 1460 | path = pending->path; |
| 1461 | |
| 1462 | ASSERT(pending->root_item); |
| 1463 | new_root_item = pending->root_item; |
| 1464 | |
| 1465 | pending->error = btrfs_find_free_objectid(tree_root, &objectid); |
| 1466 | if (pending->error) |
| 1467 | goto no_free_objectid; |
| 1468 | |
| 1469 | /* |
| 1470 | * Make qgroup to skip current new snapshot's qgroupid, as it is |
| 1471 | * accounted by later btrfs_qgroup_inherit(). |
| 1472 | */ |
| 1473 | btrfs_set_skip_qgroup(trans, objectid); |
| 1474 | |
| 1475 | btrfs_reloc_pre_snapshot(pending, &to_reserve); |
| 1476 | |
| 1477 | if (to_reserve > 0) { |
| 1478 | pending->error = btrfs_block_rsv_add(root, |
| 1479 | &pending->block_rsv, |
| 1480 | to_reserve, |
| 1481 | BTRFS_RESERVE_NO_FLUSH); |
| 1482 | if (pending->error) |
| 1483 | goto clear_skip_qgroup; |
| 1484 | } |
| 1485 | |
| 1486 | key.objectid = objectid; |
| 1487 | key.offset = (u64)-1; |
| 1488 | key.type = BTRFS_ROOT_ITEM_KEY; |
| 1489 | |
| 1490 | rsv = trans->block_rsv; |
| 1491 | trans->block_rsv = &pending->block_rsv; |
| 1492 | trans->bytes_reserved = trans->block_rsv->reserved; |
| 1493 | trace_btrfs_space_reservation(fs_info, "transaction", |
| 1494 | trans->transid, |
| 1495 | trans->bytes_reserved, 1); |
| 1496 | dentry = pending->dentry; |
| 1497 | parent_inode = pending->dir; |
| 1498 | parent_root = BTRFS_I(parent_inode)->root; |
| 1499 | record_root_in_trans(trans, parent_root, 0); |
| 1500 | |
| 1501 | cur_time = current_time(parent_inode); |
| 1502 | |
| 1503 | /* |
| 1504 | * insert the directory item |
| 1505 | */ |
| 1506 | ret = btrfs_set_inode_index(BTRFS_I(parent_inode), &index); |
| 1507 | BUG_ON(ret); /* -ENOMEM */ |
| 1508 | |
| 1509 | /* check if there is a file/dir which has the same name. */ |
| 1510 | dir_item = btrfs_lookup_dir_item(NULL, parent_root, path, |
| 1511 | btrfs_ino(BTRFS_I(parent_inode)), |
| 1512 | dentry->d_name.name, |
| 1513 | dentry->d_name.len, 0); |
| 1514 | if (dir_item != NULL && !IS_ERR(dir_item)) { |
| 1515 | pending->error = -EEXIST; |
| 1516 | goto dir_item_existed; |
| 1517 | } else if (IS_ERR(dir_item)) { |
| 1518 | ret = PTR_ERR(dir_item); |
| 1519 | btrfs_abort_transaction(trans, ret); |
| 1520 | goto fail; |
| 1521 | } |
| 1522 | btrfs_release_path(path); |
| 1523 | |
| 1524 | /* |
| 1525 | * pull in the delayed directory update |
| 1526 | * and the delayed inode item |
| 1527 | * otherwise we corrupt the FS during |
| 1528 | * snapshot |
| 1529 | */ |
| 1530 | ret = btrfs_run_delayed_items(trans, fs_info); |
| 1531 | if (ret) { /* Transaction aborted */ |
| 1532 | btrfs_abort_transaction(trans, ret); |
| 1533 | goto fail; |
| 1534 | } |
| 1535 | |
| 1536 | record_root_in_trans(trans, root, 0); |
| 1537 | btrfs_set_root_last_snapshot(&root->root_item, trans->transid); |
| 1538 | memcpy(new_root_item, &root->root_item, sizeof(*new_root_item)); |
| 1539 | btrfs_check_and_init_root_item(new_root_item); |
| 1540 | |
| 1541 | root_flags = btrfs_root_flags(new_root_item); |
| 1542 | if (pending->readonly) |
| 1543 | root_flags |= BTRFS_ROOT_SUBVOL_RDONLY; |
| 1544 | else |
| 1545 | root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY; |
| 1546 | btrfs_set_root_flags(new_root_item, root_flags); |
| 1547 | |
| 1548 | btrfs_set_root_generation_v2(new_root_item, |
| 1549 | trans->transid); |
| 1550 | uuid_le_gen(&new_uuid); |
| 1551 | memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE); |
| 1552 | memcpy(new_root_item->parent_uuid, root->root_item.uuid, |
| 1553 | BTRFS_UUID_SIZE); |
| 1554 | if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) { |
| 1555 | memset(new_root_item->received_uuid, 0, |
| 1556 | sizeof(new_root_item->received_uuid)); |
| 1557 | memset(&new_root_item->stime, 0, sizeof(new_root_item->stime)); |
| 1558 | memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime)); |
| 1559 | btrfs_set_root_stransid(new_root_item, 0); |
| 1560 | btrfs_set_root_rtransid(new_root_item, 0); |
| 1561 | } |
| 1562 | btrfs_set_stack_timespec_sec(&new_root_item->otime, cur_time.tv_sec); |
| 1563 | btrfs_set_stack_timespec_nsec(&new_root_item->otime, cur_time.tv_nsec); |
| 1564 | btrfs_set_root_otransid(new_root_item, trans->transid); |
| 1565 | |
| 1566 | old = btrfs_lock_root_node(root); |
| 1567 | ret = btrfs_cow_block(trans, root, old, NULL, 0, &old); |
| 1568 | if (ret) { |
| 1569 | btrfs_tree_unlock(old); |
| 1570 | free_extent_buffer(old); |
| 1571 | btrfs_abort_transaction(trans, ret); |
| 1572 | goto fail; |
| 1573 | } |
| 1574 | |
| 1575 | btrfs_set_lock_blocking(old); |
| 1576 | |
| 1577 | ret = btrfs_copy_root(trans, root, old, &tmp, objectid); |
| 1578 | /* clean up in any case */ |
| 1579 | btrfs_tree_unlock(old); |
| 1580 | free_extent_buffer(old); |
| 1581 | if (ret) { |
| 1582 | btrfs_abort_transaction(trans, ret); |
| 1583 | goto fail; |
| 1584 | } |
| 1585 | /* see comments in should_cow_block() */ |
| 1586 | set_bit(BTRFS_ROOT_FORCE_COW, &root->state); |
| 1587 | smp_wmb(); |
| 1588 | |
| 1589 | btrfs_set_root_node(new_root_item, tmp); |
| 1590 | /* record when the snapshot was created in key.offset */ |
| 1591 | key.offset = trans->transid; |
| 1592 | ret = btrfs_insert_root(trans, tree_root, &key, new_root_item); |
| 1593 | btrfs_tree_unlock(tmp); |
| 1594 | free_extent_buffer(tmp); |
| 1595 | if (ret) { |
| 1596 | btrfs_abort_transaction(trans, ret); |
| 1597 | goto fail; |
| 1598 | } |
| 1599 | |
| 1600 | /* |
| 1601 | * insert root back/forward references |
| 1602 | */ |
| 1603 | ret = btrfs_add_root_ref(trans, fs_info, objectid, |
| 1604 | parent_root->root_key.objectid, |
| 1605 | btrfs_ino(BTRFS_I(parent_inode)), index, |
| 1606 | dentry->d_name.name, dentry->d_name.len); |
| 1607 | if (ret) { |
| 1608 | btrfs_abort_transaction(trans, ret); |
| 1609 | goto fail; |
| 1610 | } |
| 1611 | |
| 1612 | key.offset = (u64)-1; |
| 1613 | pending->snap = btrfs_read_fs_root_no_name(fs_info, &key); |
| 1614 | if (IS_ERR(pending->snap)) { |
| 1615 | ret = PTR_ERR(pending->snap); |
| 1616 | btrfs_abort_transaction(trans, ret); |
| 1617 | goto fail; |
| 1618 | } |
| 1619 | |
| 1620 | ret = btrfs_reloc_post_snapshot(trans, pending); |
| 1621 | if (ret) { |
| 1622 | btrfs_abort_transaction(trans, ret); |
| 1623 | goto fail; |
| 1624 | } |
| 1625 | |
| 1626 | ret = btrfs_run_delayed_refs(trans, fs_info, (unsigned long)-1); |
| 1627 | if (ret) { |
| 1628 | btrfs_abort_transaction(trans, ret); |
| 1629 | goto fail; |
| 1630 | } |
| 1631 | |
| 1632 | /* |
| 1633 | * Do special qgroup accounting for snapshot, as we do some qgroup |
| 1634 | * snapshot hack to do fast snapshot. |
| 1635 | * To co-operate with that hack, we do hack again. |
| 1636 | * Or snapshot will be greatly slowed down by a subtree qgroup rescan |
| 1637 | */ |
| 1638 | ret = qgroup_account_snapshot(trans, root, parent_root, |
| 1639 | pending->inherit, objectid); |
| 1640 | if (ret < 0) |
| 1641 | goto fail; |
| 1642 | |
| 1643 | ret = btrfs_insert_dir_item(trans, parent_root, |
| 1644 | dentry->d_name.name, dentry->d_name.len, |
| 1645 | BTRFS_I(parent_inode), &key, |
| 1646 | BTRFS_FT_DIR, index); |
| 1647 | /* We have check then name at the beginning, so it is impossible. */ |
| 1648 | BUG_ON(ret == -EEXIST || ret == -EOVERFLOW); |
| 1649 | if (ret) { |
| 1650 | btrfs_abort_transaction(trans, ret); |
| 1651 | goto fail; |
| 1652 | } |
| 1653 | |
| 1654 | btrfs_i_size_write(BTRFS_I(parent_inode), parent_inode->i_size + |
| 1655 | dentry->d_name.len * 2); |
| 1656 | parent_inode->i_mtime = parent_inode->i_ctime = |
| 1657 | current_time(parent_inode); |
| 1658 | ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode); |
| 1659 | if (ret) { |
| 1660 | btrfs_abort_transaction(trans, ret); |
| 1661 | goto fail; |
| 1662 | } |
| 1663 | ret = btrfs_uuid_tree_add(trans, fs_info, new_uuid.b, |
| 1664 | BTRFS_UUID_KEY_SUBVOL, objectid); |
| 1665 | if (ret) { |
| 1666 | btrfs_abort_transaction(trans, ret); |
| 1667 | goto fail; |
| 1668 | } |
| 1669 | if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) { |
| 1670 | ret = btrfs_uuid_tree_add(trans, fs_info, |
| 1671 | new_root_item->received_uuid, |
| 1672 | BTRFS_UUID_KEY_RECEIVED_SUBVOL, |
| 1673 | objectid); |
| 1674 | if (ret && ret != -EEXIST) { |
| 1675 | btrfs_abort_transaction(trans, ret); |
| 1676 | goto fail; |
| 1677 | } |
| 1678 | } |
| 1679 | |
| 1680 | ret = btrfs_run_delayed_refs(trans, fs_info, (unsigned long)-1); |
| 1681 | if (ret) { |
| 1682 | btrfs_abort_transaction(trans, ret); |
| 1683 | goto fail; |
| 1684 | } |
| 1685 | |
| 1686 | fail: |
| 1687 | pending->error = ret; |
| 1688 | dir_item_existed: |
| 1689 | trans->block_rsv = rsv; |
| 1690 | trans->bytes_reserved = 0; |
| 1691 | clear_skip_qgroup: |
| 1692 | btrfs_clear_skip_qgroup(trans); |
| 1693 | no_free_objectid: |
| 1694 | kfree(new_root_item); |
| 1695 | pending->root_item = NULL; |
| 1696 | btrfs_free_path(path); |
| 1697 | pending->path = NULL; |
| 1698 | |
| 1699 | return ret; |
| 1700 | } |
| 1701 | |
| 1702 | /* |
| 1703 | * create all the snapshots we've scheduled for creation |
| 1704 | */ |
| 1705 | static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans, |
| 1706 | struct btrfs_fs_info *fs_info) |
| 1707 | { |
| 1708 | struct btrfs_pending_snapshot *pending, *next; |
| 1709 | struct list_head *head = &trans->transaction->pending_snapshots; |
| 1710 | int ret = 0; |
| 1711 | |
| 1712 | list_for_each_entry_safe(pending, next, head, list) { |
| 1713 | list_del(&pending->list); |
| 1714 | ret = create_pending_snapshot(trans, fs_info, pending); |
| 1715 | if (ret) |
| 1716 | break; |
| 1717 | } |
| 1718 | return ret; |
| 1719 | } |
| 1720 | |
| 1721 | static void update_super_roots(struct btrfs_fs_info *fs_info) |
| 1722 | { |
| 1723 | struct btrfs_root_item *root_item; |
| 1724 | struct btrfs_super_block *super; |
| 1725 | |
| 1726 | super = fs_info->super_copy; |
| 1727 | |
| 1728 | root_item = &fs_info->chunk_root->root_item; |
| 1729 | super->chunk_root = root_item->bytenr; |
| 1730 | super->chunk_root_generation = root_item->generation; |
| 1731 | super->chunk_root_level = root_item->level; |
| 1732 | |
| 1733 | root_item = &fs_info->tree_root->root_item; |
| 1734 | super->root = root_item->bytenr; |
| 1735 | super->generation = root_item->generation; |
| 1736 | super->root_level = root_item->level; |
| 1737 | if (btrfs_test_opt(fs_info, SPACE_CACHE)) |
| 1738 | super->cache_generation = root_item->generation; |
| 1739 | if (test_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags)) |
| 1740 | super->uuid_tree_generation = root_item->generation; |
| 1741 | } |
| 1742 | |
| 1743 | int btrfs_transaction_in_commit(struct btrfs_fs_info *info) |
| 1744 | { |
| 1745 | struct btrfs_transaction *trans; |
| 1746 | int ret = 0; |
| 1747 | |
| 1748 | spin_lock(&info->trans_lock); |
| 1749 | trans = info->running_transaction; |
| 1750 | if (trans) |
| 1751 | ret = (trans->state >= TRANS_STATE_COMMIT_START); |
| 1752 | spin_unlock(&info->trans_lock); |
| 1753 | return ret; |
| 1754 | } |
| 1755 | |
| 1756 | int btrfs_transaction_blocked(struct btrfs_fs_info *info) |
| 1757 | { |
| 1758 | struct btrfs_transaction *trans; |
| 1759 | int ret = 0; |
| 1760 | |
| 1761 | spin_lock(&info->trans_lock); |
| 1762 | trans = info->running_transaction; |
| 1763 | if (trans) |
| 1764 | ret = is_transaction_blocked(trans); |
| 1765 | spin_unlock(&info->trans_lock); |
| 1766 | return ret; |
| 1767 | } |
| 1768 | |
| 1769 | /* |
| 1770 | * wait for the current transaction commit to start and block subsequent |
| 1771 | * transaction joins |
| 1772 | */ |
| 1773 | static void wait_current_trans_commit_start(struct btrfs_fs_info *fs_info, |
| 1774 | struct btrfs_transaction *trans) |
| 1775 | { |
| 1776 | wait_event(fs_info->transaction_blocked_wait, |
| 1777 | trans->state >= TRANS_STATE_COMMIT_START || trans->aborted); |
| 1778 | } |
| 1779 | |
| 1780 | /* |
| 1781 | * wait for the current transaction to start and then become unblocked. |
| 1782 | * caller holds ref. |
| 1783 | */ |
| 1784 | static void wait_current_trans_commit_start_and_unblock( |
| 1785 | struct btrfs_fs_info *fs_info, |
| 1786 | struct btrfs_transaction *trans) |
| 1787 | { |
| 1788 | wait_event(fs_info->transaction_wait, |
| 1789 | trans->state >= TRANS_STATE_UNBLOCKED || trans->aborted); |
| 1790 | } |
| 1791 | |
| 1792 | /* |
| 1793 | * commit transactions asynchronously. once btrfs_commit_transaction_async |
| 1794 | * returns, any subsequent transaction will not be allowed to join. |
| 1795 | */ |
| 1796 | struct btrfs_async_commit { |
| 1797 | struct btrfs_trans_handle *newtrans; |
| 1798 | struct work_struct work; |
| 1799 | }; |
| 1800 | |
| 1801 | static void do_async_commit(struct work_struct *work) |
| 1802 | { |
| 1803 | struct btrfs_async_commit *ac = |
| 1804 | container_of(work, struct btrfs_async_commit, work); |
| 1805 | |
| 1806 | /* |
| 1807 | * We've got freeze protection passed with the transaction. |
| 1808 | * Tell lockdep about it. |
| 1809 | */ |
| 1810 | if (ac->newtrans->type & __TRANS_FREEZABLE) |
| 1811 | __sb_writers_acquired(ac->newtrans->fs_info->sb, SB_FREEZE_FS); |
| 1812 | |
| 1813 | current->journal_info = ac->newtrans; |
| 1814 | |
| 1815 | btrfs_commit_transaction(ac->newtrans); |
| 1816 | kfree(ac); |
| 1817 | } |
| 1818 | |
| 1819 | int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans, |
| 1820 | int wait_for_unblock) |
| 1821 | { |
| 1822 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 1823 | struct btrfs_async_commit *ac; |
| 1824 | struct btrfs_transaction *cur_trans; |
| 1825 | |
| 1826 | ac = kmalloc(sizeof(*ac), GFP_NOFS); |
| 1827 | if (!ac) |
| 1828 | return -ENOMEM; |
| 1829 | |
| 1830 | INIT_WORK(&ac->work, do_async_commit); |
| 1831 | ac->newtrans = btrfs_join_transaction(trans->root); |
| 1832 | if (IS_ERR(ac->newtrans)) { |
| 1833 | int err = PTR_ERR(ac->newtrans); |
| 1834 | kfree(ac); |
| 1835 | return err; |
| 1836 | } |
| 1837 | |
| 1838 | /* take transaction reference */ |
| 1839 | cur_trans = trans->transaction; |
| 1840 | refcount_inc(&cur_trans->use_count); |
| 1841 | |
| 1842 | btrfs_end_transaction(trans); |
| 1843 | |
| 1844 | /* |
| 1845 | * Tell lockdep we've released the freeze rwsem, since the |
| 1846 | * async commit thread will be the one to unlock it. |
| 1847 | */ |
| 1848 | if (ac->newtrans->type & __TRANS_FREEZABLE) |
| 1849 | __sb_writers_release(fs_info->sb, SB_FREEZE_FS); |
| 1850 | |
| 1851 | schedule_work(&ac->work); |
| 1852 | |
| 1853 | /* wait for transaction to start and unblock */ |
| 1854 | if (wait_for_unblock) |
| 1855 | wait_current_trans_commit_start_and_unblock(fs_info, cur_trans); |
| 1856 | else |
| 1857 | wait_current_trans_commit_start(fs_info, cur_trans); |
| 1858 | |
| 1859 | if (current->journal_info == trans) |
| 1860 | current->journal_info = NULL; |
| 1861 | |
| 1862 | btrfs_put_transaction(cur_trans); |
| 1863 | return 0; |
| 1864 | } |
| 1865 | |
| 1866 | |
| 1867 | static void cleanup_transaction(struct btrfs_trans_handle *trans, |
| 1868 | struct btrfs_root *root, int err) |
| 1869 | { |
| 1870 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 1871 | struct btrfs_transaction *cur_trans = trans->transaction; |
| 1872 | DEFINE_WAIT(wait); |
| 1873 | |
| 1874 | WARN_ON(trans->use_count > 1); |
| 1875 | |
| 1876 | btrfs_abort_transaction(trans, err); |
| 1877 | |
| 1878 | spin_lock(&fs_info->trans_lock); |
| 1879 | |
| 1880 | /* |
| 1881 | * If the transaction is removed from the list, it means this |
| 1882 | * transaction has been committed successfully, so it is impossible |
| 1883 | * to call the cleanup function. |
| 1884 | */ |
| 1885 | BUG_ON(list_empty(&cur_trans->list)); |
| 1886 | |
| 1887 | list_del_init(&cur_trans->list); |
| 1888 | if (cur_trans == fs_info->running_transaction) { |
| 1889 | cur_trans->state = TRANS_STATE_COMMIT_DOING; |
| 1890 | spin_unlock(&fs_info->trans_lock); |
| 1891 | wait_event(cur_trans->writer_wait, |
| 1892 | atomic_read(&cur_trans->num_writers) == 1); |
| 1893 | |
| 1894 | spin_lock(&fs_info->trans_lock); |
| 1895 | } |
| 1896 | spin_unlock(&fs_info->trans_lock); |
| 1897 | |
| 1898 | btrfs_cleanup_one_transaction(trans->transaction, fs_info); |
| 1899 | |
| 1900 | spin_lock(&fs_info->trans_lock); |
| 1901 | if (cur_trans == fs_info->running_transaction) |
| 1902 | fs_info->running_transaction = NULL; |
| 1903 | spin_unlock(&fs_info->trans_lock); |
| 1904 | |
| 1905 | if (trans->type & __TRANS_FREEZABLE) |
| 1906 | sb_end_intwrite(fs_info->sb); |
| 1907 | btrfs_put_transaction(cur_trans); |
| 1908 | btrfs_put_transaction(cur_trans); |
| 1909 | |
| 1910 | trace_btrfs_transaction_commit(root); |
| 1911 | |
| 1912 | if (current->journal_info == trans) |
| 1913 | current->journal_info = NULL; |
| 1914 | btrfs_scrub_cancel(fs_info); |
| 1915 | |
| 1916 | kmem_cache_free(btrfs_trans_handle_cachep, trans); |
| 1917 | } |
| 1918 | |
| 1919 | static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info) |
| 1920 | { |
| 1921 | if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) |
| 1922 | return btrfs_start_delalloc_roots(fs_info, 1, -1); |
| 1923 | return 0; |
| 1924 | } |
| 1925 | |
| 1926 | static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info) |
| 1927 | { |
| 1928 | if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) |
| 1929 | btrfs_wait_ordered_roots(fs_info, -1, 0, (u64)-1); |
| 1930 | } |
| 1931 | |
| 1932 | static inline void |
| 1933 | btrfs_wait_pending_ordered(struct btrfs_transaction *cur_trans) |
| 1934 | { |
| 1935 | wait_event(cur_trans->pending_wait, |
| 1936 | atomic_read(&cur_trans->pending_ordered) == 0); |
| 1937 | } |
| 1938 | |
| 1939 | int btrfs_commit_transaction(struct btrfs_trans_handle *trans) |
| 1940 | { |
| 1941 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 1942 | struct btrfs_transaction *cur_trans = trans->transaction; |
| 1943 | struct btrfs_transaction *prev_trans = NULL; |
| 1944 | int ret; |
| 1945 | |
| 1946 | /* Stop the commit early if ->aborted is set */ |
| 1947 | if (unlikely(READ_ONCE(cur_trans->aborted))) { |
| 1948 | ret = cur_trans->aborted; |
| 1949 | btrfs_end_transaction(trans); |
| 1950 | return ret; |
| 1951 | } |
| 1952 | |
| 1953 | /* make a pass through all the delayed refs we have so far |
| 1954 | * any runnings procs may add more while we are here |
| 1955 | */ |
| 1956 | ret = btrfs_run_delayed_refs(trans, fs_info, 0); |
| 1957 | if (ret) { |
| 1958 | btrfs_end_transaction(trans); |
| 1959 | return ret; |
| 1960 | } |
| 1961 | |
| 1962 | btrfs_trans_release_metadata(trans, fs_info); |
| 1963 | trans->block_rsv = NULL; |
| 1964 | |
| 1965 | cur_trans = trans->transaction; |
| 1966 | |
| 1967 | /* |
| 1968 | * set the flushing flag so procs in this transaction have to |
| 1969 | * start sending their work down. |
| 1970 | */ |
| 1971 | cur_trans->delayed_refs.flushing = 1; |
| 1972 | smp_wmb(); |
| 1973 | |
| 1974 | if (!list_empty(&trans->new_bgs)) |
| 1975 | btrfs_create_pending_block_groups(trans, fs_info); |
| 1976 | |
| 1977 | ret = btrfs_run_delayed_refs(trans, fs_info, 0); |
| 1978 | if (ret) { |
| 1979 | btrfs_end_transaction(trans); |
| 1980 | return ret; |
| 1981 | } |
| 1982 | |
| 1983 | if (!test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &cur_trans->flags)) { |
| 1984 | int run_it = 0; |
| 1985 | |
| 1986 | /* this mutex is also taken before trying to set |
| 1987 | * block groups readonly. We need to make sure |
| 1988 | * that nobody has set a block group readonly |
| 1989 | * after a extents from that block group have been |
| 1990 | * allocated for cache files. btrfs_set_block_group_ro |
| 1991 | * will wait for the transaction to commit if it |
| 1992 | * finds BTRFS_TRANS_DIRTY_BG_RUN set. |
| 1993 | * |
| 1994 | * The BTRFS_TRANS_DIRTY_BG_RUN flag is also used to make sure |
| 1995 | * only one process starts all the block group IO. It wouldn't |
| 1996 | * hurt to have more than one go through, but there's no |
| 1997 | * real advantage to it either. |
| 1998 | */ |
| 1999 | mutex_lock(&fs_info->ro_block_group_mutex); |
| 2000 | if (!test_and_set_bit(BTRFS_TRANS_DIRTY_BG_RUN, |
| 2001 | &cur_trans->flags)) |
| 2002 | run_it = 1; |
| 2003 | mutex_unlock(&fs_info->ro_block_group_mutex); |
| 2004 | |
| 2005 | if (run_it) |
| 2006 | ret = btrfs_start_dirty_block_groups(trans, fs_info); |
| 2007 | } |
| 2008 | if (ret) { |
| 2009 | btrfs_end_transaction(trans); |
| 2010 | return ret; |
| 2011 | } |
| 2012 | |
| 2013 | spin_lock(&fs_info->trans_lock); |
| 2014 | if (cur_trans->state >= TRANS_STATE_COMMIT_START) { |
| 2015 | spin_unlock(&fs_info->trans_lock); |
| 2016 | refcount_inc(&cur_trans->use_count); |
| 2017 | ret = btrfs_end_transaction(trans); |
| 2018 | |
| 2019 | wait_for_commit(cur_trans); |
| 2020 | |
| 2021 | if (unlikely(cur_trans->aborted)) |
| 2022 | ret = cur_trans->aborted; |
| 2023 | |
| 2024 | btrfs_put_transaction(cur_trans); |
| 2025 | |
| 2026 | return ret; |
| 2027 | } |
| 2028 | |
| 2029 | cur_trans->state = TRANS_STATE_COMMIT_START; |
| 2030 | wake_up(&fs_info->transaction_blocked_wait); |
| 2031 | |
| 2032 | if (cur_trans->list.prev != &fs_info->trans_list) { |
| 2033 | prev_trans = list_entry(cur_trans->list.prev, |
| 2034 | struct btrfs_transaction, list); |
| 2035 | if (prev_trans->state != TRANS_STATE_COMPLETED) { |
| 2036 | refcount_inc(&prev_trans->use_count); |
| 2037 | spin_unlock(&fs_info->trans_lock); |
| 2038 | |
| 2039 | wait_for_commit(prev_trans); |
| 2040 | ret = prev_trans->aborted; |
| 2041 | |
| 2042 | btrfs_put_transaction(prev_trans); |
| 2043 | if (ret) |
| 2044 | goto cleanup_transaction; |
| 2045 | } else { |
| 2046 | spin_unlock(&fs_info->trans_lock); |
| 2047 | } |
| 2048 | } else { |
| 2049 | spin_unlock(&fs_info->trans_lock); |
| 2050 | } |
| 2051 | |
| 2052 | extwriter_counter_dec(cur_trans, trans->type); |
| 2053 | |
| 2054 | ret = btrfs_start_delalloc_flush(fs_info); |
| 2055 | if (ret) |
| 2056 | goto cleanup_transaction; |
| 2057 | |
| 2058 | ret = btrfs_run_delayed_items(trans, fs_info); |
| 2059 | if (ret) |
| 2060 | goto cleanup_transaction; |
| 2061 | |
| 2062 | wait_event(cur_trans->writer_wait, |
| 2063 | extwriter_counter_read(cur_trans) == 0); |
| 2064 | |
| 2065 | /* some pending stuffs might be added after the previous flush. */ |
| 2066 | ret = btrfs_run_delayed_items(trans, fs_info); |
| 2067 | if (ret) |
| 2068 | goto cleanup_transaction; |
| 2069 | |
| 2070 | btrfs_wait_delalloc_flush(fs_info); |
| 2071 | |
| 2072 | btrfs_wait_pending_ordered(cur_trans); |
| 2073 | |
| 2074 | btrfs_scrub_pause(fs_info); |
| 2075 | /* |
| 2076 | * Ok now we need to make sure to block out any other joins while we |
| 2077 | * commit the transaction. We could have started a join before setting |
| 2078 | * COMMIT_DOING so make sure to wait for num_writers to == 1 again. |
| 2079 | */ |
| 2080 | spin_lock(&fs_info->trans_lock); |
| 2081 | cur_trans->state = TRANS_STATE_COMMIT_DOING; |
| 2082 | spin_unlock(&fs_info->trans_lock); |
| 2083 | wait_event(cur_trans->writer_wait, |
| 2084 | atomic_read(&cur_trans->num_writers) == 1); |
| 2085 | |
| 2086 | /* ->aborted might be set after the previous check, so check it */ |
| 2087 | if (unlikely(READ_ONCE(cur_trans->aborted))) { |
| 2088 | ret = cur_trans->aborted; |
| 2089 | goto scrub_continue; |
| 2090 | } |
| 2091 | /* |
| 2092 | * the reloc mutex makes sure that we stop |
| 2093 | * the balancing code from coming in and moving |
| 2094 | * extents around in the middle of the commit |
| 2095 | */ |
| 2096 | mutex_lock(&fs_info->reloc_mutex); |
| 2097 | |
| 2098 | /* |
| 2099 | * We needn't worry about the delayed items because we will |
| 2100 | * deal with them in create_pending_snapshot(), which is the |
| 2101 | * core function of the snapshot creation. |
| 2102 | */ |
| 2103 | ret = create_pending_snapshots(trans, fs_info); |
| 2104 | if (ret) { |
| 2105 | mutex_unlock(&fs_info->reloc_mutex); |
| 2106 | goto scrub_continue; |
| 2107 | } |
| 2108 | |
| 2109 | /* |
| 2110 | * We insert the dir indexes of the snapshots and update the inode |
| 2111 | * of the snapshots' parents after the snapshot creation, so there |
| 2112 | * are some delayed items which are not dealt with. Now deal with |
| 2113 | * them. |
| 2114 | * |
| 2115 | * We needn't worry that this operation will corrupt the snapshots, |
| 2116 | * because all the tree which are snapshoted will be forced to COW |
| 2117 | * the nodes and leaves. |
| 2118 | */ |
| 2119 | ret = btrfs_run_delayed_items(trans, fs_info); |
| 2120 | if (ret) { |
| 2121 | mutex_unlock(&fs_info->reloc_mutex); |
| 2122 | goto scrub_continue; |
| 2123 | } |
| 2124 | |
| 2125 | ret = btrfs_run_delayed_refs(trans, fs_info, (unsigned long)-1); |
| 2126 | if (ret) { |
| 2127 | mutex_unlock(&fs_info->reloc_mutex); |
| 2128 | goto scrub_continue; |
| 2129 | } |
| 2130 | |
| 2131 | /* |
| 2132 | * make sure none of the code above managed to slip in a |
| 2133 | * delayed item |
| 2134 | */ |
| 2135 | btrfs_assert_delayed_root_empty(fs_info); |
| 2136 | |
| 2137 | WARN_ON(cur_trans != trans->transaction); |
| 2138 | |
| 2139 | /* btrfs_commit_tree_roots is responsible for getting the |
| 2140 | * various roots consistent with each other. Every pointer |
| 2141 | * in the tree of tree roots has to point to the most up to date |
| 2142 | * root for every subvolume and other tree. So, we have to keep |
| 2143 | * the tree logging code from jumping in and changing any |
| 2144 | * of the trees. |
| 2145 | * |
| 2146 | * At this point in the commit, there can't be any tree-log |
| 2147 | * writers, but a little lower down we drop the trans mutex |
| 2148 | * and let new people in. By holding the tree_log_mutex |
| 2149 | * from now until after the super is written, we avoid races |
| 2150 | * with the tree-log code. |
| 2151 | */ |
| 2152 | mutex_lock(&fs_info->tree_log_mutex); |
| 2153 | |
| 2154 | ret = commit_fs_roots(trans, fs_info); |
| 2155 | if (ret) { |
| 2156 | mutex_unlock(&fs_info->tree_log_mutex); |
| 2157 | mutex_unlock(&fs_info->reloc_mutex); |
| 2158 | goto scrub_continue; |
| 2159 | } |
| 2160 | |
| 2161 | /* |
| 2162 | * Since the transaction is done, we can apply the pending changes |
| 2163 | * before the next transaction. |
| 2164 | */ |
| 2165 | btrfs_apply_pending_changes(fs_info); |
| 2166 | |
| 2167 | /* commit_fs_roots gets rid of all the tree log roots, it is now |
| 2168 | * safe to free the root of tree log roots |
| 2169 | */ |
| 2170 | btrfs_free_log_root_tree(trans, fs_info); |
| 2171 | |
| 2172 | /* |
| 2173 | * commit_fs_roots() can call btrfs_save_ino_cache(), which generates |
| 2174 | * new delayed refs. Must handle them or qgroup can be wrong. |
| 2175 | */ |
| 2176 | ret = btrfs_run_delayed_refs(trans, fs_info, (unsigned long)-1); |
| 2177 | if (ret) { |
| 2178 | mutex_unlock(&fs_info->tree_log_mutex); |
| 2179 | mutex_unlock(&fs_info->reloc_mutex); |
| 2180 | goto scrub_continue; |
| 2181 | } |
| 2182 | |
| 2183 | ret = btrfs_qgroup_prepare_account_extents(trans, fs_info); |
| 2184 | if (ret) { |
| 2185 | mutex_unlock(&fs_info->tree_log_mutex); |
| 2186 | mutex_unlock(&fs_info->reloc_mutex); |
| 2187 | goto scrub_continue; |
| 2188 | } |
| 2189 | |
| 2190 | /* |
| 2191 | * Since fs roots are all committed, we can get a quite accurate |
| 2192 | * new_roots. So let's do quota accounting. |
| 2193 | */ |
| 2194 | ret = btrfs_qgroup_account_extents(trans, fs_info); |
| 2195 | if (ret < 0) { |
| 2196 | mutex_unlock(&fs_info->tree_log_mutex); |
| 2197 | mutex_unlock(&fs_info->reloc_mutex); |
| 2198 | goto scrub_continue; |
| 2199 | } |
| 2200 | |
| 2201 | ret = commit_cowonly_roots(trans, fs_info); |
| 2202 | if (ret) { |
| 2203 | mutex_unlock(&fs_info->tree_log_mutex); |
| 2204 | mutex_unlock(&fs_info->reloc_mutex); |
| 2205 | goto scrub_continue; |
| 2206 | } |
| 2207 | |
| 2208 | /* |
| 2209 | * The tasks which save the space cache and inode cache may also |
| 2210 | * update ->aborted, check it. |
| 2211 | */ |
| 2212 | if (unlikely(READ_ONCE(cur_trans->aborted))) { |
| 2213 | ret = cur_trans->aborted; |
| 2214 | mutex_unlock(&fs_info->tree_log_mutex); |
| 2215 | mutex_unlock(&fs_info->reloc_mutex); |
| 2216 | goto scrub_continue; |
| 2217 | } |
| 2218 | |
| 2219 | btrfs_prepare_extent_commit(fs_info); |
| 2220 | |
| 2221 | cur_trans = fs_info->running_transaction; |
| 2222 | |
| 2223 | btrfs_set_root_node(&fs_info->tree_root->root_item, |
| 2224 | fs_info->tree_root->node); |
| 2225 | list_add_tail(&fs_info->tree_root->dirty_list, |
| 2226 | &cur_trans->switch_commits); |
| 2227 | |
| 2228 | btrfs_set_root_node(&fs_info->chunk_root->root_item, |
| 2229 | fs_info->chunk_root->node); |
| 2230 | list_add_tail(&fs_info->chunk_root->dirty_list, |
| 2231 | &cur_trans->switch_commits); |
| 2232 | |
| 2233 | switch_commit_roots(cur_trans, fs_info); |
| 2234 | |
| 2235 | ASSERT(list_empty(&cur_trans->dirty_bgs)); |
| 2236 | ASSERT(list_empty(&cur_trans->io_bgs)); |
| 2237 | update_super_roots(fs_info); |
| 2238 | |
| 2239 | btrfs_set_super_log_root(fs_info->super_copy, 0); |
| 2240 | btrfs_set_super_log_root_level(fs_info->super_copy, 0); |
| 2241 | memcpy(fs_info->super_for_commit, fs_info->super_copy, |
| 2242 | sizeof(*fs_info->super_copy)); |
| 2243 | |
| 2244 | btrfs_update_commit_device_size(fs_info); |
| 2245 | btrfs_update_commit_device_bytes_used(fs_info, cur_trans); |
| 2246 | |
| 2247 | clear_bit(BTRFS_FS_LOG1_ERR, &fs_info->flags); |
| 2248 | clear_bit(BTRFS_FS_LOG2_ERR, &fs_info->flags); |
| 2249 | |
| 2250 | btrfs_trans_release_chunk_metadata(trans); |
| 2251 | |
| 2252 | spin_lock(&fs_info->trans_lock); |
| 2253 | cur_trans->state = TRANS_STATE_UNBLOCKED; |
| 2254 | fs_info->running_transaction = NULL; |
| 2255 | spin_unlock(&fs_info->trans_lock); |
| 2256 | mutex_unlock(&fs_info->reloc_mutex); |
| 2257 | |
| 2258 | wake_up(&fs_info->transaction_wait); |
| 2259 | |
| 2260 | ret = btrfs_write_and_wait_transaction(trans, fs_info); |
| 2261 | if (ret) { |
| 2262 | btrfs_handle_fs_error(fs_info, ret, |
| 2263 | "Error while writing out transaction"); |
| 2264 | mutex_unlock(&fs_info->tree_log_mutex); |
| 2265 | goto scrub_continue; |
| 2266 | } |
| 2267 | |
| 2268 | ret = write_all_supers(fs_info, 0); |
| 2269 | if (ret) { |
| 2270 | mutex_unlock(&fs_info->tree_log_mutex); |
| 2271 | goto scrub_continue; |
| 2272 | } |
| 2273 | |
| 2274 | /* |
| 2275 | * the super is written, we can safely allow the tree-loggers |
| 2276 | * to go about their business |
| 2277 | */ |
| 2278 | mutex_unlock(&fs_info->tree_log_mutex); |
| 2279 | |
| 2280 | btrfs_finish_extent_commit(trans, fs_info); |
| 2281 | |
| 2282 | if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &cur_trans->flags)) |
| 2283 | btrfs_clear_space_info_full(fs_info); |
| 2284 | |
| 2285 | fs_info->last_trans_committed = cur_trans->transid; |
| 2286 | /* |
| 2287 | * We needn't acquire the lock here because there is no other task |
| 2288 | * which can change it. |
| 2289 | */ |
| 2290 | cur_trans->state = TRANS_STATE_COMPLETED; |
| 2291 | wake_up(&cur_trans->commit_wait); |
| 2292 | |
| 2293 | spin_lock(&fs_info->trans_lock); |
| 2294 | list_del_init(&cur_trans->list); |
| 2295 | spin_unlock(&fs_info->trans_lock); |
| 2296 | |
| 2297 | btrfs_put_transaction(cur_trans); |
| 2298 | btrfs_put_transaction(cur_trans); |
| 2299 | |
| 2300 | if (trans->type & __TRANS_FREEZABLE) |
| 2301 | sb_end_intwrite(fs_info->sb); |
| 2302 | |
| 2303 | trace_btrfs_transaction_commit(trans->root); |
| 2304 | |
| 2305 | btrfs_scrub_continue(fs_info); |
| 2306 | |
| 2307 | if (current->journal_info == trans) |
| 2308 | current->journal_info = NULL; |
| 2309 | |
| 2310 | kmem_cache_free(btrfs_trans_handle_cachep, trans); |
| 2311 | |
| 2312 | /* |
| 2313 | * If fs has been frozen, we can not handle delayed iputs, otherwise |
| 2314 | * it'll result in deadlock about SB_FREEZE_FS. |
| 2315 | */ |
| 2316 | if (current != fs_info->transaction_kthread && |
| 2317 | current != fs_info->cleaner_kthread && !fs_info->fs_frozen) |
| 2318 | btrfs_run_delayed_iputs(fs_info); |
| 2319 | |
| 2320 | return ret; |
| 2321 | |
| 2322 | scrub_continue: |
| 2323 | btrfs_scrub_continue(fs_info); |
| 2324 | cleanup_transaction: |
| 2325 | btrfs_trans_release_metadata(trans, fs_info); |
| 2326 | btrfs_trans_release_chunk_metadata(trans); |
| 2327 | trans->block_rsv = NULL; |
| 2328 | btrfs_warn(fs_info, "Skipping commit of aborted transaction."); |
| 2329 | if (current->journal_info == trans) |
| 2330 | current->journal_info = NULL; |
| 2331 | cleanup_transaction(trans, trans->root, ret); |
| 2332 | |
| 2333 | return ret; |
| 2334 | } |
| 2335 | |
| 2336 | /* |
| 2337 | * return < 0 if error |
| 2338 | * 0 if there are no more dead_roots at the time of call |
| 2339 | * 1 there are more to be processed, call me again |
| 2340 | * |
| 2341 | * The return value indicates there are certainly more snapshots to delete, but |
| 2342 | * if there comes a new one during processing, it may return 0. We don't mind, |
| 2343 | * because btrfs_commit_super will poke cleaner thread and it will process it a |
| 2344 | * few seconds later. |
| 2345 | */ |
| 2346 | int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root) |
| 2347 | { |
| 2348 | int ret; |
| 2349 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 2350 | |
| 2351 | spin_lock(&fs_info->trans_lock); |
| 2352 | if (list_empty(&fs_info->dead_roots)) { |
| 2353 | spin_unlock(&fs_info->trans_lock); |
| 2354 | return 0; |
| 2355 | } |
| 2356 | root = list_first_entry(&fs_info->dead_roots, |
| 2357 | struct btrfs_root, root_list); |
| 2358 | list_del_init(&root->root_list); |
| 2359 | spin_unlock(&fs_info->trans_lock); |
| 2360 | |
| 2361 | btrfs_debug(fs_info, "cleaner removing %llu", root->objectid); |
| 2362 | |
| 2363 | btrfs_kill_all_delayed_nodes(root); |
| 2364 | |
| 2365 | if (btrfs_header_backref_rev(root->node) < |
| 2366 | BTRFS_MIXED_BACKREF_REV) |
| 2367 | ret = btrfs_drop_snapshot(root, NULL, 0, 0); |
| 2368 | else |
| 2369 | ret = btrfs_drop_snapshot(root, NULL, 1, 0); |
| 2370 | |
| 2371 | return (ret < 0) ? 0 : 1; |
| 2372 | } |
| 2373 | |
| 2374 | void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info) |
| 2375 | { |
| 2376 | unsigned long prev; |
| 2377 | unsigned long bit; |
| 2378 | |
| 2379 | prev = xchg(&fs_info->pending_changes, 0); |
| 2380 | if (!prev) |
| 2381 | return; |
| 2382 | |
| 2383 | bit = 1 << BTRFS_PENDING_SET_INODE_MAP_CACHE; |
| 2384 | if (prev & bit) |
| 2385 | btrfs_set_opt(fs_info->mount_opt, INODE_MAP_CACHE); |
| 2386 | prev &= ~bit; |
| 2387 | |
| 2388 | bit = 1 << BTRFS_PENDING_CLEAR_INODE_MAP_CACHE; |
| 2389 | if (prev & bit) |
| 2390 | btrfs_clear_opt(fs_info->mount_opt, INODE_MAP_CACHE); |
| 2391 | prev &= ~bit; |
| 2392 | |
| 2393 | bit = 1 << BTRFS_PENDING_COMMIT; |
| 2394 | if (prev & bit) |
| 2395 | btrfs_debug(fs_info, "pending commit done"); |
| 2396 | prev &= ~bit; |
| 2397 | |
| 2398 | if (prev) |
| 2399 | btrfs_warn(fs_info, |
| 2400 | "unknown pending changes left 0x%lx, ignoring", prev); |
| 2401 | } |