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 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(atomic_read(&transaction->use_count) == 0); 64 if (atomic_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 while (!list_empty(&transaction->pending_chunks)) { 68 struct extent_map *em; 69 70 em = list_first_entry(&transaction->pending_chunks, 71 struct extent_map, list); 72 list_del_init(&em->list); 73 free_extent_map(em); 74 } 75 kmem_cache_free(btrfs_transaction_cachep, transaction); 76 } 77 } 78 79 static void clear_btree_io_tree(struct extent_io_tree *tree) 80 { 81 spin_lock(&tree->lock); 82 while (!RB_EMPTY_ROOT(&tree->state)) { 83 struct rb_node *node; 84 struct extent_state *state; 85 86 node = rb_first(&tree->state); 87 state = rb_entry(node, struct extent_state, rb_node); 88 rb_erase(&state->rb_node, &tree->state); 89 RB_CLEAR_NODE(&state->rb_node); 90 /* 91 * btree io trees aren't supposed to have tasks waiting for 92 * changes in the flags of extent states ever. 93 */ 94 ASSERT(!waitqueue_active(&state->wq)); 95 free_extent_state(state); 96 if (need_resched()) { 97 spin_unlock(&tree->lock); 98 cond_resched(); 99 spin_lock(&tree->lock); 100 } 101 } 102 spin_unlock(&tree->lock); 103 } 104 105 static noinline void switch_commit_roots(struct btrfs_transaction *trans, 106 struct btrfs_fs_info *fs_info) 107 { 108 struct btrfs_root *root, *tmp; 109 110 down_write(&fs_info->commit_root_sem); 111 list_for_each_entry_safe(root, tmp, &trans->switch_commits, 112 dirty_list) { 113 list_del_init(&root->dirty_list); 114 free_extent_buffer(root->commit_root); 115 root->commit_root = btrfs_root_node(root); 116 if (is_fstree(root->objectid)) 117 btrfs_unpin_free_ino(root); 118 clear_btree_io_tree(&root->dirty_log_pages); 119 } 120 up_write(&fs_info->commit_root_sem); 121 } 122 123 static inline void extwriter_counter_inc(struct btrfs_transaction *trans, 124 unsigned int type) 125 { 126 if (type & TRANS_EXTWRITERS) 127 atomic_inc(&trans->num_extwriters); 128 } 129 130 static inline void extwriter_counter_dec(struct btrfs_transaction *trans, 131 unsigned int type) 132 { 133 if (type & TRANS_EXTWRITERS) 134 atomic_dec(&trans->num_extwriters); 135 } 136 137 static inline void extwriter_counter_init(struct btrfs_transaction *trans, 138 unsigned int type) 139 { 140 atomic_set(&trans->num_extwriters, ((type & TRANS_EXTWRITERS) ? 1 : 0)); 141 } 142 143 static inline int extwriter_counter_read(struct btrfs_transaction *trans) 144 { 145 return atomic_read(&trans->num_extwriters); 146 } 147 148 /* 149 * either allocate a new transaction or hop into the existing one 150 */ 151 static noinline int join_transaction(struct btrfs_root *root, unsigned int type) 152 { 153 struct btrfs_transaction *cur_trans; 154 struct btrfs_fs_info *fs_info = root->fs_info; 155 156 spin_lock(&fs_info->trans_lock); 157 loop: 158 /* The file system has been taken offline. No new transactions. */ 159 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { 160 spin_unlock(&fs_info->trans_lock); 161 return -EROFS; 162 } 163 164 cur_trans = fs_info->running_transaction; 165 if (cur_trans) { 166 if (cur_trans->aborted) { 167 spin_unlock(&fs_info->trans_lock); 168 return cur_trans->aborted; 169 } 170 if (btrfs_blocked_trans_types[cur_trans->state] & type) { 171 spin_unlock(&fs_info->trans_lock); 172 return -EBUSY; 173 } 174 atomic_inc(&cur_trans->use_count); 175 atomic_inc(&cur_trans->num_writers); 176 extwriter_counter_inc(cur_trans, type); 177 spin_unlock(&fs_info->trans_lock); 178 return 0; 179 } 180 spin_unlock(&fs_info->trans_lock); 181 182 /* 183 * If we are ATTACH, we just want to catch the current transaction, 184 * and commit it. If there is no transaction, just return ENOENT. 185 */ 186 if (type == TRANS_ATTACH) 187 return -ENOENT; 188 189 /* 190 * JOIN_NOLOCK only happens during the transaction commit, so 191 * it is impossible that ->running_transaction is NULL 192 */ 193 BUG_ON(type == TRANS_JOIN_NOLOCK); 194 195 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS); 196 if (!cur_trans) 197 return -ENOMEM; 198 199 spin_lock(&fs_info->trans_lock); 200 if (fs_info->running_transaction) { 201 /* 202 * someone started a transaction after we unlocked. Make sure 203 * to redo the checks above 204 */ 205 kmem_cache_free(btrfs_transaction_cachep, cur_trans); 206 goto loop; 207 } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { 208 spin_unlock(&fs_info->trans_lock); 209 kmem_cache_free(btrfs_transaction_cachep, cur_trans); 210 return -EROFS; 211 } 212 213 atomic_set(&cur_trans->num_writers, 1); 214 extwriter_counter_init(cur_trans, type); 215 init_waitqueue_head(&cur_trans->writer_wait); 216 init_waitqueue_head(&cur_trans->commit_wait); 217 cur_trans->state = TRANS_STATE_RUNNING; 218 /* 219 * One for this trans handle, one so it will live on until we 220 * commit the transaction. 221 */ 222 atomic_set(&cur_trans->use_count, 2); 223 cur_trans->have_free_bgs = 0; 224 cur_trans->start_time = get_seconds(); 225 226 cur_trans->delayed_refs.href_root = RB_ROOT; 227 atomic_set(&cur_trans->delayed_refs.num_entries, 0); 228 cur_trans->delayed_refs.num_heads_ready = 0; 229 cur_trans->delayed_refs.num_heads = 0; 230 cur_trans->delayed_refs.flushing = 0; 231 cur_trans->delayed_refs.run_delayed_start = 0; 232 233 /* 234 * although the tree mod log is per file system and not per transaction, 235 * the log must never go across transaction boundaries. 236 */ 237 smp_mb(); 238 if (!list_empty(&fs_info->tree_mod_seq_list)) 239 WARN(1, KERN_ERR "BTRFS: tree_mod_seq_list not empty when " 240 "creating a fresh transaction\n"); 241 if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log)) 242 WARN(1, KERN_ERR "BTRFS: tree_mod_log rb tree not empty when " 243 "creating a fresh transaction\n"); 244 atomic64_set(&fs_info->tree_mod_seq, 0); 245 246 spin_lock_init(&cur_trans->delayed_refs.lock); 247 248 INIT_LIST_HEAD(&cur_trans->pending_snapshots); 249 INIT_LIST_HEAD(&cur_trans->pending_chunks); 250 INIT_LIST_HEAD(&cur_trans->switch_commits); 251 INIT_LIST_HEAD(&cur_trans->pending_ordered); 252 INIT_LIST_HEAD(&cur_trans->dirty_bgs); 253 spin_lock_init(&cur_trans->dirty_bgs_lock); 254 list_add_tail(&cur_trans->list, &fs_info->trans_list); 255 extent_io_tree_init(&cur_trans->dirty_pages, 256 fs_info->btree_inode->i_mapping); 257 fs_info->generation++; 258 cur_trans->transid = fs_info->generation; 259 fs_info->running_transaction = cur_trans; 260 cur_trans->aborted = 0; 261 spin_unlock(&fs_info->trans_lock); 262 263 return 0; 264 } 265 266 /* 267 * this does all the record keeping required to make sure that a reference 268 * counted root is properly recorded in a given transaction. This is required 269 * to make sure the old root from before we joined the transaction is deleted 270 * when the transaction commits 271 */ 272 static int record_root_in_trans(struct btrfs_trans_handle *trans, 273 struct btrfs_root *root) 274 { 275 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && 276 root->last_trans < trans->transid) { 277 WARN_ON(root == root->fs_info->extent_root); 278 WARN_ON(root->commit_root != root->node); 279 280 /* 281 * see below for IN_TRANS_SETUP usage rules 282 * we have the reloc mutex held now, so there 283 * is only one writer in this function 284 */ 285 set_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state); 286 287 /* make sure readers find IN_TRANS_SETUP before 288 * they find our root->last_trans update 289 */ 290 smp_wmb(); 291 292 spin_lock(&root->fs_info->fs_roots_radix_lock); 293 if (root->last_trans == trans->transid) { 294 spin_unlock(&root->fs_info->fs_roots_radix_lock); 295 return 0; 296 } 297 radix_tree_tag_set(&root->fs_info->fs_roots_radix, 298 (unsigned long)root->root_key.objectid, 299 BTRFS_ROOT_TRANS_TAG); 300 spin_unlock(&root->fs_info->fs_roots_radix_lock); 301 root->last_trans = trans->transid; 302 303 /* this is pretty tricky. We don't want to 304 * take the relocation lock in btrfs_record_root_in_trans 305 * unless we're really doing the first setup for this root in 306 * this transaction. 307 * 308 * Normally we'd use root->last_trans as a flag to decide 309 * if we want to take the expensive mutex. 310 * 311 * But, we have to set root->last_trans before we 312 * init the relocation root, otherwise, we trip over warnings 313 * in ctree.c. The solution used here is to flag ourselves 314 * with root IN_TRANS_SETUP. When this is 1, we're still 315 * fixing up the reloc trees and everyone must wait. 316 * 317 * When this is zero, they can trust root->last_trans and fly 318 * through btrfs_record_root_in_trans without having to take the 319 * lock. smp_wmb() makes sure that all the writes above are 320 * done before we pop in the zero below 321 */ 322 btrfs_init_reloc_root(trans, root); 323 smp_mb__before_atomic(); 324 clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state); 325 } 326 return 0; 327 } 328 329 330 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, 331 struct btrfs_root *root) 332 { 333 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) 334 return 0; 335 336 /* 337 * see record_root_in_trans for comments about IN_TRANS_SETUP usage 338 * and barriers 339 */ 340 smp_rmb(); 341 if (root->last_trans == trans->transid && 342 !test_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state)) 343 return 0; 344 345 mutex_lock(&root->fs_info->reloc_mutex); 346 record_root_in_trans(trans, root); 347 mutex_unlock(&root->fs_info->reloc_mutex); 348 349 return 0; 350 } 351 352 static inline int is_transaction_blocked(struct btrfs_transaction *trans) 353 { 354 return (trans->state >= TRANS_STATE_BLOCKED && 355 trans->state < TRANS_STATE_UNBLOCKED && 356 !trans->aborted); 357 } 358 359 /* wait for commit against the current transaction to become unblocked 360 * when this is done, it is safe to start a new transaction, but the current 361 * transaction might not be fully on disk. 362 */ 363 static void wait_current_trans(struct btrfs_root *root) 364 { 365 struct btrfs_transaction *cur_trans; 366 367 spin_lock(&root->fs_info->trans_lock); 368 cur_trans = root->fs_info->running_transaction; 369 if (cur_trans && is_transaction_blocked(cur_trans)) { 370 atomic_inc(&cur_trans->use_count); 371 spin_unlock(&root->fs_info->trans_lock); 372 373 wait_event(root->fs_info->transaction_wait, 374 cur_trans->state >= TRANS_STATE_UNBLOCKED || 375 cur_trans->aborted); 376 btrfs_put_transaction(cur_trans); 377 } else { 378 spin_unlock(&root->fs_info->trans_lock); 379 } 380 } 381 382 static int may_wait_transaction(struct btrfs_root *root, int type) 383 { 384 if (root->fs_info->log_root_recovering) 385 return 0; 386 387 if (type == TRANS_USERSPACE) 388 return 1; 389 390 if (type == TRANS_START && 391 !atomic_read(&root->fs_info->open_ioctl_trans)) 392 return 1; 393 394 return 0; 395 } 396 397 static inline bool need_reserve_reloc_root(struct btrfs_root *root) 398 { 399 if (!root->fs_info->reloc_ctl || 400 !test_bit(BTRFS_ROOT_REF_COWS, &root->state) || 401 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || 402 root->reloc_root) 403 return false; 404 405 return true; 406 } 407 408 static struct btrfs_trans_handle * 409 start_transaction(struct btrfs_root *root, u64 num_items, unsigned int type, 410 enum btrfs_reserve_flush_enum flush) 411 { 412 struct btrfs_trans_handle *h; 413 struct btrfs_transaction *cur_trans; 414 u64 num_bytes = 0; 415 u64 qgroup_reserved = 0; 416 bool reloc_reserved = false; 417 int ret; 418 419 /* Send isn't supposed to start transactions. */ 420 ASSERT(current->journal_info != BTRFS_SEND_TRANS_STUB); 421 422 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) 423 return ERR_PTR(-EROFS); 424 425 if (current->journal_info) { 426 WARN_ON(type & TRANS_EXTWRITERS); 427 h = current->journal_info; 428 h->use_count++; 429 WARN_ON(h->use_count > 2); 430 h->orig_rsv = h->block_rsv; 431 h->block_rsv = NULL; 432 goto got_it; 433 } 434 435 /* 436 * Do the reservation before we join the transaction so we can do all 437 * the appropriate flushing if need be. 438 */ 439 if (num_items > 0 && root != root->fs_info->chunk_root) { 440 if (root->fs_info->quota_enabled && 441 is_fstree(root->root_key.objectid)) { 442 qgroup_reserved = num_items * root->nodesize; 443 ret = btrfs_qgroup_reserve(root, qgroup_reserved); 444 if (ret) 445 return ERR_PTR(ret); 446 } 447 448 num_bytes = btrfs_calc_trans_metadata_size(root, num_items); 449 /* 450 * Do the reservation for the relocation root creation 451 */ 452 if (need_reserve_reloc_root(root)) { 453 num_bytes += root->nodesize; 454 reloc_reserved = true; 455 } 456 457 ret = btrfs_block_rsv_add(root, 458 &root->fs_info->trans_block_rsv, 459 num_bytes, flush); 460 if (ret) 461 goto reserve_fail; 462 } 463 again: 464 h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); 465 if (!h) { 466 ret = -ENOMEM; 467 goto alloc_fail; 468 } 469 470 /* 471 * If we are JOIN_NOLOCK we're already committing a transaction and 472 * waiting on this guy, so we don't need to do the sb_start_intwrite 473 * because we're already holding a ref. We need this because we could 474 * have raced in and did an fsync() on a file which can kick a commit 475 * and then we deadlock with somebody doing a freeze. 476 * 477 * If we are ATTACH, it means we just want to catch the current 478 * transaction and commit it, so we needn't do sb_start_intwrite(). 479 */ 480 if (type & __TRANS_FREEZABLE) 481 sb_start_intwrite(root->fs_info->sb); 482 483 if (may_wait_transaction(root, type)) 484 wait_current_trans(root); 485 486 do { 487 ret = join_transaction(root, type); 488 if (ret == -EBUSY) { 489 wait_current_trans(root); 490 if (unlikely(type == TRANS_ATTACH)) 491 ret = -ENOENT; 492 } 493 } while (ret == -EBUSY); 494 495 if (ret < 0) { 496 /* We must get the transaction if we are JOIN_NOLOCK. */ 497 BUG_ON(type == TRANS_JOIN_NOLOCK); 498 goto join_fail; 499 } 500 501 cur_trans = root->fs_info->running_transaction; 502 503 h->transid = cur_trans->transid; 504 h->transaction = cur_trans; 505 h->blocks_used = 0; 506 h->bytes_reserved = 0; 507 h->root = root; 508 h->delayed_ref_updates = 0; 509 h->use_count = 1; 510 h->adding_csums = 0; 511 h->block_rsv = NULL; 512 h->orig_rsv = NULL; 513 h->aborted = 0; 514 h->qgroup_reserved = 0; 515 h->delayed_ref_elem.seq = 0; 516 h->type = type; 517 h->allocating_chunk = false; 518 h->reloc_reserved = false; 519 h->sync = false; 520 INIT_LIST_HEAD(&h->qgroup_ref_list); 521 INIT_LIST_HEAD(&h->new_bgs); 522 INIT_LIST_HEAD(&h->ordered); 523 524 smp_mb(); 525 if (cur_trans->state >= TRANS_STATE_BLOCKED && 526 may_wait_transaction(root, type)) { 527 current->journal_info = h; 528 btrfs_commit_transaction(h, root); 529 goto again; 530 } 531 532 if (num_bytes) { 533 trace_btrfs_space_reservation(root->fs_info, "transaction", 534 h->transid, num_bytes, 1); 535 h->block_rsv = &root->fs_info->trans_block_rsv; 536 h->bytes_reserved = num_bytes; 537 h->reloc_reserved = reloc_reserved; 538 } 539 h->qgroup_reserved = qgroup_reserved; 540 541 got_it: 542 btrfs_record_root_in_trans(h, root); 543 544 if (!current->journal_info && type != TRANS_USERSPACE) 545 current->journal_info = h; 546 return h; 547 548 join_fail: 549 if (type & __TRANS_FREEZABLE) 550 sb_end_intwrite(root->fs_info->sb); 551 kmem_cache_free(btrfs_trans_handle_cachep, h); 552 alloc_fail: 553 if (num_bytes) 554 btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv, 555 num_bytes); 556 reserve_fail: 557 if (qgroup_reserved) 558 btrfs_qgroup_free(root, qgroup_reserved); 559 return ERR_PTR(ret); 560 } 561 562 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, 563 int num_items) 564 { 565 return start_transaction(root, num_items, TRANS_START, 566 BTRFS_RESERVE_FLUSH_ALL); 567 } 568 569 struct btrfs_trans_handle *btrfs_start_transaction_lflush( 570 struct btrfs_root *root, int num_items) 571 { 572 return start_transaction(root, num_items, TRANS_START, 573 BTRFS_RESERVE_FLUSH_LIMIT); 574 } 575 576 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root) 577 { 578 return start_transaction(root, 0, TRANS_JOIN, 0); 579 } 580 581 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root) 582 { 583 return start_transaction(root, 0, TRANS_JOIN_NOLOCK, 0); 584 } 585 586 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root) 587 { 588 return start_transaction(root, 0, TRANS_USERSPACE, 0); 589 } 590 591 /* 592 * btrfs_attach_transaction() - catch the running transaction 593 * 594 * It is used when we want to commit the current the transaction, but 595 * don't want to start a new one. 596 * 597 * Note: If this function return -ENOENT, it just means there is no 598 * running transaction. But it is possible that the inactive transaction 599 * is still in the memory, not fully on disk. If you hope there is no 600 * inactive transaction in the fs when -ENOENT is returned, you should 601 * invoke 602 * btrfs_attach_transaction_barrier() 603 */ 604 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root) 605 { 606 return start_transaction(root, 0, TRANS_ATTACH, 0); 607 } 608 609 /* 610 * btrfs_attach_transaction_barrier() - catch the running transaction 611 * 612 * It is similar to the above function, the differentia is this one 613 * will wait for all the inactive transactions until they fully 614 * complete. 615 */ 616 struct btrfs_trans_handle * 617 btrfs_attach_transaction_barrier(struct btrfs_root *root) 618 { 619 struct btrfs_trans_handle *trans; 620 621 trans = start_transaction(root, 0, TRANS_ATTACH, 0); 622 if (IS_ERR(trans) && PTR_ERR(trans) == -ENOENT) 623 btrfs_wait_for_commit(root, 0); 624 625 return trans; 626 } 627 628 /* wait for a transaction commit to be fully complete */ 629 static noinline void wait_for_commit(struct btrfs_root *root, 630 struct btrfs_transaction *commit) 631 { 632 wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED); 633 } 634 635 int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid) 636 { 637 struct btrfs_transaction *cur_trans = NULL, *t; 638 int ret = 0; 639 640 if (transid) { 641 if (transid <= root->fs_info->last_trans_committed) 642 goto out; 643 644 /* find specified transaction */ 645 spin_lock(&root->fs_info->trans_lock); 646 list_for_each_entry(t, &root->fs_info->trans_list, list) { 647 if (t->transid == transid) { 648 cur_trans = t; 649 atomic_inc(&cur_trans->use_count); 650 ret = 0; 651 break; 652 } 653 if (t->transid > transid) { 654 ret = 0; 655 break; 656 } 657 } 658 spin_unlock(&root->fs_info->trans_lock); 659 660 /* 661 * The specified transaction doesn't exist, or we 662 * raced with btrfs_commit_transaction 663 */ 664 if (!cur_trans) { 665 if (transid > root->fs_info->last_trans_committed) 666 ret = -EINVAL; 667 goto out; 668 } 669 } else { 670 /* find newest transaction that is committing | committed */ 671 spin_lock(&root->fs_info->trans_lock); 672 list_for_each_entry_reverse(t, &root->fs_info->trans_list, 673 list) { 674 if (t->state >= TRANS_STATE_COMMIT_START) { 675 if (t->state == TRANS_STATE_COMPLETED) 676 break; 677 cur_trans = t; 678 atomic_inc(&cur_trans->use_count); 679 break; 680 } 681 } 682 spin_unlock(&root->fs_info->trans_lock); 683 if (!cur_trans) 684 goto out; /* nothing committing|committed */ 685 } 686 687 wait_for_commit(root, cur_trans); 688 btrfs_put_transaction(cur_trans); 689 out: 690 return ret; 691 } 692 693 void btrfs_throttle(struct btrfs_root *root) 694 { 695 if (!atomic_read(&root->fs_info->open_ioctl_trans)) 696 wait_current_trans(root); 697 } 698 699 static int should_end_transaction(struct btrfs_trans_handle *trans, 700 struct btrfs_root *root) 701 { 702 if (root->fs_info->global_block_rsv.space_info->full && 703 btrfs_check_space_for_delayed_refs(trans, root)) 704 return 1; 705 706 return !!btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5); 707 } 708 709 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans, 710 struct btrfs_root *root) 711 { 712 struct btrfs_transaction *cur_trans = trans->transaction; 713 int updates; 714 int err; 715 716 smp_mb(); 717 if (cur_trans->state >= TRANS_STATE_BLOCKED || 718 cur_trans->delayed_refs.flushing) 719 return 1; 720 721 updates = trans->delayed_ref_updates; 722 trans->delayed_ref_updates = 0; 723 if (updates) { 724 err = btrfs_run_delayed_refs(trans, root, updates); 725 if (err) /* Error code will also eval true */ 726 return err; 727 } 728 729 return should_end_transaction(trans, root); 730 } 731 732 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, 733 struct btrfs_root *root, int throttle) 734 { 735 struct btrfs_transaction *cur_trans = trans->transaction; 736 struct btrfs_fs_info *info = root->fs_info; 737 unsigned long cur = trans->delayed_ref_updates; 738 int lock = (trans->type != TRANS_JOIN_NOLOCK); 739 int err = 0; 740 int must_run_delayed_refs = 0; 741 742 if (trans->use_count > 1) { 743 trans->use_count--; 744 trans->block_rsv = trans->orig_rsv; 745 return 0; 746 } 747 748 btrfs_trans_release_metadata(trans, root); 749 trans->block_rsv = NULL; 750 751 if (!list_empty(&trans->new_bgs)) 752 btrfs_create_pending_block_groups(trans, root); 753 754 if (!list_empty(&trans->ordered)) { 755 spin_lock(&info->trans_lock); 756 list_splice(&trans->ordered, &cur_trans->pending_ordered); 757 spin_unlock(&info->trans_lock); 758 } 759 760 trans->delayed_ref_updates = 0; 761 if (!trans->sync) { 762 must_run_delayed_refs = 763 btrfs_should_throttle_delayed_refs(trans, root); 764 cur = max_t(unsigned long, cur, 32); 765 766 /* 767 * don't make the caller wait if they are from a NOLOCK 768 * or ATTACH transaction, it will deadlock with commit 769 */ 770 if (must_run_delayed_refs == 1 && 771 (trans->type & (__TRANS_JOIN_NOLOCK | __TRANS_ATTACH))) 772 must_run_delayed_refs = 2; 773 } 774 775 if (trans->qgroup_reserved) { 776 /* 777 * the same root has to be passed here between start_transaction 778 * and end_transaction. Subvolume quota depends on this. 779 */ 780 btrfs_qgroup_free(trans->root, trans->qgroup_reserved); 781 trans->qgroup_reserved = 0; 782 } 783 784 btrfs_trans_release_metadata(trans, root); 785 trans->block_rsv = NULL; 786 787 if (!list_empty(&trans->new_bgs)) 788 btrfs_create_pending_block_groups(trans, root); 789 790 if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) && 791 should_end_transaction(trans, root) && 792 ACCESS_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) { 793 spin_lock(&info->trans_lock); 794 if (cur_trans->state == TRANS_STATE_RUNNING) 795 cur_trans->state = TRANS_STATE_BLOCKED; 796 spin_unlock(&info->trans_lock); 797 } 798 799 if (lock && ACCESS_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) { 800 if (throttle) 801 return btrfs_commit_transaction(trans, root); 802 else 803 wake_up_process(info->transaction_kthread); 804 } 805 806 if (trans->type & __TRANS_FREEZABLE) 807 sb_end_intwrite(root->fs_info->sb); 808 809 WARN_ON(cur_trans != info->running_transaction); 810 WARN_ON(atomic_read(&cur_trans->num_writers) < 1); 811 atomic_dec(&cur_trans->num_writers); 812 extwriter_counter_dec(cur_trans, trans->type); 813 814 smp_mb(); 815 if (waitqueue_active(&cur_trans->writer_wait)) 816 wake_up(&cur_trans->writer_wait); 817 btrfs_put_transaction(cur_trans); 818 819 if (current->journal_info == trans) 820 current->journal_info = NULL; 821 822 if (throttle) 823 btrfs_run_delayed_iputs(root); 824 825 if (trans->aborted || 826 test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) { 827 wake_up_process(info->transaction_kthread); 828 err = -EIO; 829 } 830 assert_qgroups_uptodate(trans); 831 832 kmem_cache_free(btrfs_trans_handle_cachep, trans); 833 if (must_run_delayed_refs) { 834 btrfs_async_run_delayed_refs(root, cur, 835 must_run_delayed_refs == 1); 836 } 837 return err; 838 } 839 840 int btrfs_end_transaction(struct btrfs_trans_handle *trans, 841 struct btrfs_root *root) 842 { 843 return __btrfs_end_transaction(trans, root, 0); 844 } 845 846 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans, 847 struct btrfs_root *root) 848 { 849 return __btrfs_end_transaction(trans, root, 1); 850 } 851 852 /* 853 * when btree blocks are allocated, they have some corresponding bits set for 854 * them in one of two extent_io trees. This is used to make sure all of 855 * those extents are sent to disk but does not wait on them 856 */ 857 int btrfs_write_marked_extents(struct btrfs_root *root, 858 struct extent_io_tree *dirty_pages, int mark) 859 { 860 int err = 0; 861 int werr = 0; 862 struct address_space *mapping = root->fs_info->btree_inode->i_mapping; 863 struct extent_state *cached_state = NULL; 864 u64 start = 0; 865 u64 end; 866 867 while (!find_first_extent_bit(dirty_pages, start, &start, &end, 868 mark, &cached_state)) { 869 bool wait_writeback = false; 870 871 err = convert_extent_bit(dirty_pages, start, end, 872 EXTENT_NEED_WAIT, 873 mark, &cached_state, GFP_NOFS); 874 /* 875 * convert_extent_bit can return -ENOMEM, which is most of the 876 * time a temporary error. So when it happens, ignore the error 877 * and wait for writeback of this range to finish - because we 878 * failed to set the bit EXTENT_NEED_WAIT for the range, a call 879 * to btrfs_wait_marked_extents() would not know that writeback 880 * for this range started and therefore wouldn't wait for it to 881 * finish - we don't want to commit a superblock that points to 882 * btree nodes/leafs for which writeback hasn't finished yet 883 * (and without errors). 884 * We cleanup any entries left in the io tree when committing 885 * the transaction (through clear_btree_io_tree()). 886 */ 887 if (err == -ENOMEM) { 888 err = 0; 889 wait_writeback = true; 890 } 891 if (!err) 892 err = filemap_fdatawrite_range(mapping, start, end); 893 if (err) 894 werr = err; 895 else if (wait_writeback) 896 werr = filemap_fdatawait_range(mapping, start, end); 897 free_extent_state(cached_state); 898 cached_state = NULL; 899 cond_resched(); 900 start = end + 1; 901 } 902 return werr; 903 } 904 905 /* 906 * when btree blocks are allocated, they have some corresponding bits set for 907 * them in one of two extent_io trees. This is used to make sure all of 908 * those extents are on disk for transaction or log commit. We wait 909 * on all the pages and clear them from the dirty pages state tree 910 */ 911 int btrfs_wait_marked_extents(struct btrfs_root *root, 912 struct extent_io_tree *dirty_pages, int mark) 913 { 914 int err = 0; 915 int werr = 0; 916 struct address_space *mapping = root->fs_info->btree_inode->i_mapping; 917 struct extent_state *cached_state = NULL; 918 u64 start = 0; 919 u64 end; 920 struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode); 921 bool errors = false; 922 923 while (!find_first_extent_bit(dirty_pages, start, &start, &end, 924 EXTENT_NEED_WAIT, &cached_state)) { 925 /* 926 * Ignore -ENOMEM errors returned by clear_extent_bit(). 927 * When committing the transaction, we'll remove any entries 928 * left in the io tree. For a log commit, we don't remove them 929 * after committing the log because the tree can be accessed 930 * concurrently - we do it only at transaction commit time when 931 * it's safe to do it (through clear_btree_io_tree()). 932 */ 933 err = clear_extent_bit(dirty_pages, start, end, 934 EXTENT_NEED_WAIT, 935 0, 0, &cached_state, GFP_NOFS); 936 if (err == -ENOMEM) 937 err = 0; 938 if (!err) 939 err = filemap_fdatawait_range(mapping, start, end); 940 if (err) 941 werr = err; 942 free_extent_state(cached_state); 943 cached_state = NULL; 944 cond_resched(); 945 start = end + 1; 946 } 947 if (err) 948 werr = err; 949 950 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { 951 if ((mark & EXTENT_DIRTY) && 952 test_and_clear_bit(BTRFS_INODE_BTREE_LOG1_ERR, 953 &btree_ino->runtime_flags)) 954 errors = true; 955 956 if ((mark & EXTENT_NEW) && 957 test_and_clear_bit(BTRFS_INODE_BTREE_LOG2_ERR, 958 &btree_ino->runtime_flags)) 959 errors = true; 960 } else { 961 if (test_and_clear_bit(BTRFS_INODE_BTREE_ERR, 962 &btree_ino->runtime_flags)) 963 errors = true; 964 } 965 966 if (errors && !werr) 967 werr = -EIO; 968 969 return werr; 970 } 971 972 /* 973 * when btree blocks are allocated, they have some corresponding bits set for 974 * them in one of two extent_io trees. This is used to make sure all of 975 * those extents are on disk for transaction or log commit 976 */ 977 static int btrfs_write_and_wait_marked_extents(struct btrfs_root *root, 978 struct extent_io_tree *dirty_pages, int mark) 979 { 980 int ret; 981 int ret2; 982 struct blk_plug plug; 983 984 blk_start_plug(&plug); 985 ret = btrfs_write_marked_extents(root, dirty_pages, mark); 986 blk_finish_plug(&plug); 987 ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark); 988 989 if (ret) 990 return ret; 991 if (ret2) 992 return ret2; 993 return 0; 994 } 995 996 static int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, 997 struct btrfs_root *root) 998 { 999 int ret; 1000 1001 ret = btrfs_write_and_wait_marked_extents(root, 1002 &trans->transaction->dirty_pages, 1003 EXTENT_DIRTY); 1004 clear_btree_io_tree(&trans->transaction->dirty_pages); 1005 1006 return ret; 1007 } 1008 1009 /* 1010 * this is used to update the root pointer in the tree of tree roots. 1011 * 1012 * But, in the case of the extent allocation tree, updating the root 1013 * pointer may allocate blocks which may change the root of the extent 1014 * allocation tree. 1015 * 1016 * So, this loops and repeats and makes sure the cowonly root didn't 1017 * change while the root pointer was being updated in the metadata. 1018 */ 1019 static int update_cowonly_root(struct btrfs_trans_handle *trans, 1020 struct btrfs_root *root) 1021 { 1022 int ret; 1023 u64 old_root_bytenr; 1024 u64 old_root_used; 1025 struct btrfs_root *tree_root = root->fs_info->tree_root; 1026 1027 old_root_used = btrfs_root_used(&root->root_item); 1028 1029 while (1) { 1030 old_root_bytenr = btrfs_root_bytenr(&root->root_item); 1031 if (old_root_bytenr == root->node->start && 1032 old_root_used == btrfs_root_used(&root->root_item)) 1033 break; 1034 1035 btrfs_set_root_node(&root->root_item, root->node); 1036 ret = btrfs_update_root(trans, tree_root, 1037 &root->root_key, 1038 &root->root_item); 1039 if (ret) 1040 return ret; 1041 1042 old_root_used = btrfs_root_used(&root->root_item); 1043 } 1044 1045 return 0; 1046 } 1047 1048 /* 1049 * update all the cowonly tree roots on disk 1050 * 1051 * The error handling in this function may not be obvious. Any of the 1052 * failures will cause the file system to go offline. We still need 1053 * to clean up the delayed refs. 1054 */ 1055 static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans, 1056 struct btrfs_root *root) 1057 { 1058 struct btrfs_fs_info *fs_info = root->fs_info; 1059 struct list_head *dirty_bgs = &trans->transaction->dirty_bgs; 1060 struct list_head *next; 1061 struct extent_buffer *eb; 1062 int ret; 1063 1064 eb = btrfs_lock_root_node(fs_info->tree_root); 1065 ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 1066 0, &eb); 1067 btrfs_tree_unlock(eb); 1068 free_extent_buffer(eb); 1069 1070 if (ret) 1071 return ret; 1072 1073 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); 1074 if (ret) 1075 return ret; 1076 1077 ret = btrfs_run_dev_stats(trans, root->fs_info); 1078 if (ret) 1079 return ret; 1080 ret = btrfs_run_dev_replace(trans, root->fs_info); 1081 if (ret) 1082 return ret; 1083 ret = btrfs_run_qgroups(trans, root->fs_info); 1084 if (ret) 1085 return ret; 1086 1087 ret = btrfs_setup_space_cache(trans, root); 1088 if (ret) 1089 return ret; 1090 1091 /* run_qgroups might have added some more refs */ 1092 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); 1093 if (ret) 1094 return ret; 1095 again: 1096 while (!list_empty(&fs_info->dirty_cowonly_roots)) { 1097 next = fs_info->dirty_cowonly_roots.next; 1098 list_del_init(next); 1099 root = list_entry(next, struct btrfs_root, dirty_list); 1100 clear_bit(BTRFS_ROOT_DIRTY, &root->state); 1101 1102 if (root != fs_info->extent_root) 1103 list_add_tail(&root->dirty_list, 1104 &trans->transaction->switch_commits); 1105 ret = update_cowonly_root(trans, root); 1106 if (ret) 1107 return ret; 1108 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); 1109 if (ret) 1110 return ret; 1111 } 1112 1113 while (!list_empty(dirty_bgs)) { 1114 ret = btrfs_write_dirty_block_groups(trans, root); 1115 if (ret) 1116 return ret; 1117 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); 1118 if (ret) 1119 return ret; 1120 } 1121 1122 if (!list_empty(&fs_info->dirty_cowonly_roots)) 1123 goto again; 1124 1125 list_add_tail(&fs_info->extent_root->dirty_list, 1126 &trans->transaction->switch_commits); 1127 btrfs_after_dev_replace_commit(fs_info); 1128 1129 return 0; 1130 } 1131 1132 /* 1133 * dead roots are old snapshots that need to be deleted. This allocates 1134 * a dirty root struct and adds it into the list of dead roots that need to 1135 * be deleted 1136 */ 1137 void btrfs_add_dead_root(struct btrfs_root *root) 1138 { 1139 spin_lock(&root->fs_info->trans_lock); 1140 if (list_empty(&root->root_list)) 1141 list_add_tail(&root->root_list, &root->fs_info->dead_roots); 1142 spin_unlock(&root->fs_info->trans_lock); 1143 } 1144 1145 /* 1146 * update all the cowonly tree roots on disk 1147 */ 1148 static noinline int commit_fs_roots(struct btrfs_trans_handle *trans, 1149 struct btrfs_root *root) 1150 { 1151 struct btrfs_root *gang[8]; 1152 struct btrfs_fs_info *fs_info = root->fs_info; 1153 int i; 1154 int ret; 1155 int err = 0; 1156 1157 spin_lock(&fs_info->fs_roots_radix_lock); 1158 while (1) { 1159 ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix, 1160 (void **)gang, 0, 1161 ARRAY_SIZE(gang), 1162 BTRFS_ROOT_TRANS_TAG); 1163 if (ret == 0) 1164 break; 1165 for (i = 0; i < ret; i++) { 1166 root = gang[i]; 1167 radix_tree_tag_clear(&fs_info->fs_roots_radix, 1168 (unsigned long)root->root_key.objectid, 1169 BTRFS_ROOT_TRANS_TAG); 1170 spin_unlock(&fs_info->fs_roots_radix_lock); 1171 1172 btrfs_free_log(trans, root); 1173 btrfs_update_reloc_root(trans, root); 1174 btrfs_orphan_commit_root(trans, root); 1175 1176 btrfs_save_ino_cache(root, trans); 1177 1178 /* see comments in should_cow_block() */ 1179 clear_bit(BTRFS_ROOT_FORCE_COW, &root->state); 1180 smp_mb__after_atomic(); 1181 1182 if (root->commit_root != root->node) { 1183 list_add_tail(&root->dirty_list, 1184 &trans->transaction->switch_commits); 1185 btrfs_set_root_node(&root->root_item, 1186 root->node); 1187 } 1188 1189 err = btrfs_update_root(trans, fs_info->tree_root, 1190 &root->root_key, 1191 &root->root_item); 1192 spin_lock(&fs_info->fs_roots_radix_lock); 1193 if (err) 1194 break; 1195 } 1196 } 1197 spin_unlock(&fs_info->fs_roots_radix_lock); 1198 return err; 1199 } 1200 1201 /* 1202 * defrag a given btree. 1203 * Every leaf in the btree is read and defragged. 1204 */ 1205 int btrfs_defrag_root(struct btrfs_root *root) 1206 { 1207 struct btrfs_fs_info *info = root->fs_info; 1208 struct btrfs_trans_handle *trans; 1209 int ret; 1210 1211 if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state)) 1212 return 0; 1213 1214 while (1) { 1215 trans = btrfs_start_transaction(root, 0); 1216 if (IS_ERR(trans)) 1217 return PTR_ERR(trans); 1218 1219 ret = btrfs_defrag_leaves(trans, root); 1220 1221 btrfs_end_transaction(trans, root); 1222 btrfs_btree_balance_dirty(info->tree_root); 1223 cond_resched(); 1224 1225 if (btrfs_fs_closing(root->fs_info) || ret != -EAGAIN) 1226 break; 1227 1228 if (btrfs_defrag_cancelled(root->fs_info)) { 1229 pr_debug("BTRFS: defrag_root cancelled\n"); 1230 ret = -EAGAIN; 1231 break; 1232 } 1233 } 1234 clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state); 1235 return ret; 1236 } 1237 1238 /* 1239 * new snapshots need to be created at a very specific time in the 1240 * transaction commit. This does the actual creation. 1241 * 1242 * Note: 1243 * If the error which may affect the commitment of the current transaction 1244 * happens, we should return the error number. If the error which just affect 1245 * the creation of the pending snapshots, just return 0. 1246 */ 1247 static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 1248 struct btrfs_fs_info *fs_info, 1249 struct btrfs_pending_snapshot *pending) 1250 { 1251 struct btrfs_key key; 1252 struct btrfs_root_item *new_root_item; 1253 struct btrfs_root *tree_root = fs_info->tree_root; 1254 struct btrfs_root *root = pending->root; 1255 struct btrfs_root *parent_root; 1256 struct btrfs_block_rsv *rsv; 1257 struct inode *parent_inode; 1258 struct btrfs_path *path; 1259 struct btrfs_dir_item *dir_item; 1260 struct dentry *dentry; 1261 struct extent_buffer *tmp; 1262 struct extent_buffer *old; 1263 struct timespec cur_time = CURRENT_TIME; 1264 int ret = 0; 1265 u64 to_reserve = 0; 1266 u64 index = 0; 1267 u64 objectid; 1268 u64 root_flags; 1269 uuid_le new_uuid; 1270 1271 path = btrfs_alloc_path(); 1272 if (!path) { 1273 pending->error = -ENOMEM; 1274 return 0; 1275 } 1276 1277 new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS); 1278 if (!new_root_item) { 1279 pending->error = -ENOMEM; 1280 goto root_item_alloc_fail; 1281 } 1282 1283 pending->error = btrfs_find_free_objectid(tree_root, &objectid); 1284 if (pending->error) 1285 goto no_free_objectid; 1286 1287 btrfs_reloc_pre_snapshot(trans, pending, &to_reserve); 1288 1289 if (to_reserve > 0) { 1290 pending->error = btrfs_block_rsv_add(root, 1291 &pending->block_rsv, 1292 to_reserve, 1293 BTRFS_RESERVE_NO_FLUSH); 1294 if (pending->error) 1295 goto no_free_objectid; 1296 } 1297 1298 key.objectid = objectid; 1299 key.offset = (u64)-1; 1300 key.type = BTRFS_ROOT_ITEM_KEY; 1301 1302 rsv = trans->block_rsv; 1303 trans->block_rsv = &pending->block_rsv; 1304 trans->bytes_reserved = trans->block_rsv->reserved; 1305 1306 dentry = pending->dentry; 1307 parent_inode = pending->dir; 1308 parent_root = BTRFS_I(parent_inode)->root; 1309 record_root_in_trans(trans, parent_root); 1310 1311 /* 1312 * insert the directory item 1313 */ 1314 ret = btrfs_set_inode_index(parent_inode, &index); 1315 BUG_ON(ret); /* -ENOMEM */ 1316 1317 /* check if there is a file/dir which has the same name. */ 1318 dir_item = btrfs_lookup_dir_item(NULL, parent_root, path, 1319 btrfs_ino(parent_inode), 1320 dentry->d_name.name, 1321 dentry->d_name.len, 0); 1322 if (dir_item != NULL && !IS_ERR(dir_item)) { 1323 pending->error = -EEXIST; 1324 goto dir_item_existed; 1325 } else if (IS_ERR(dir_item)) { 1326 ret = PTR_ERR(dir_item); 1327 btrfs_abort_transaction(trans, root, ret); 1328 goto fail; 1329 } 1330 btrfs_release_path(path); 1331 1332 /* 1333 * pull in the delayed directory update 1334 * and the delayed inode item 1335 * otherwise we corrupt the FS during 1336 * snapshot 1337 */ 1338 ret = btrfs_run_delayed_items(trans, root); 1339 if (ret) { /* Transaction aborted */ 1340 btrfs_abort_transaction(trans, root, ret); 1341 goto fail; 1342 } 1343 1344 record_root_in_trans(trans, root); 1345 btrfs_set_root_last_snapshot(&root->root_item, trans->transid); 1346 memcpy(new_root_item, &root->root_item, sizeof(*new_root_item)); 1347 btrfs_check_and_init_root_item(new_root_item); 1348 1349 root_flags = btrfs_root_flags(new_root_item); 1350 if (pending->readonly) 1351 root_flags |= BTRFS_ROOT_SUBVOL_RDONLY; 1352 else 1353 root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY; 1354 btrfs_set_root_flags(new_root_item, root_flags); 1355 1356 btrfs_set_root_generation_v2(new_root_item, 1357 trans->transid); 1358 uuid_le_gen(&new_uuid); 1359 memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE); 1360 memcpy(new_root_item->parent_uuid, root->root_item.uuid, 1361 BTRFS_UUID_SIZE); 1362 if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) { 1363 memset(new_root_item->received_uuid, 0, 1364 sizeof(new_root_item->received_uuid)); 1365 memset(&new_root_item->stime, 0, sizeof(new_root_item->stime)); 1366 memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime)); 1367 btrfs_set_root_stransid(new_root_item, 0); 1368 btrfs_set_root_rtransid(new_root_item, 0); 1369 } 1370 btrfs_set_stack_timespec_sec(&new_root_item->otime, cur_time.tv_sec); 1371 btrfs_set_stack_timespec_nsec(&new_root_item->otime, cur_time.tv_nsec); 1372 btrfs_set_root_otransid(new_root_item, trans->transid); 1373 1374 old = btrfs_lock_root_node(root); 1375 ret = btrfs_cow_block(trans, root, old, NULL, 0, &old); 1376 if (ret) { 1377 btrfs_tree_unlock(old); 1378 free_extent_buffer(old); 1379 btrfs_abort_transaction(trans, root, ret); 1380 goto fail; 1381 } 1382 1383 btrfs_set_lock_blocking(old); 1384 1385 ret = btrfs_copy_root(trans, root, old, &tmp, objectid); 1386 /* clean up in any case */ 1387 btrfs_tree_unlock(old); 1388 free_extent_buffer(old); 1389 if (ret) { 1390 btrfs_abort_transaction(trans, root, ret); 1391 goto fail; 1392 } 1393 1394 /* 1395 * We need to flush delayed refs in order to make sure all of our quota 1396 * operations have been done before we call btrfs_qgroup_inherit. 1397 */ 1398 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); 1399 if (ret) { 1400 btrfs_abort_transaction(trans, root, ret); 1401 goto fail; 1402 } 1403 1404 ret = btrfs_qgroup_inherit(trans, fs_info, 1405 root->root_key.objectid, 1406 objectid, pending->inherit); 1407 if (ret) { 1408 btrfs_abort_transaction(trans, root, ret); 1409 goto fail; 1410 } 1411 1412 /* see comments in should_cow_block() */ 1413 set_bit(BTRFS_ROOT_FORCE_COW, &root->state); 1414 smp_wmb(); 1415 1416 btrfs_set_root_node(new_root_item, tmp); 1417 /* record when the snapshot was created in key.offset */ 1418 key.offset = trans->transid; 1419 ret = btrfs_insert_root(trans, tree_root, &key, new_root_item); 1420 btrfs_tree_unlock(tmp); 1421 free_extent_buffer(tmp); 1422 if (ret) { 1423 btrfs_abort_transaction(trans, root, ret); 1424 goto fail; 1425 } 1426 1427 /* 1428 * insert root back/forward references 1429 */ 1430 ret = btrfs_add_root_ref(trans, tree_root, objectid, 1431 parent_root->root_key.objectid, 1432 btrfs_ino(parent_inode), index, 1433 dentry->d_name.name, dentry->d_name.len); 1434 if (ret) { 1435 btrfs_abort_transaction(trans, root, ret); 1436 goto fail; 1437 } 1438 1439 key.offset = (u64)-1; 1440 pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key); 1441 if (IS_ERR(pending->snap)) { 1442 ret = PTR_ERR(pending->snap); 1443 btrfs_abort_transaction(trans, root, ret); 1444 goto fail; 1445 } 1446 1447 ret = btrfs_reloc_post_snapshot(trans, pending); 1448 if (ret) { 1449 btrfs_abort_transaction(trans, root, ret); 1450 goto fail; 1451 } 1452 1453 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); 1454 if (ret) { 1455 btrfs_abort_transaction(trans, root, ret); 1456 goto fail; 1457 } 1458 1459 ret = btrfs_insert_dir_item(trans, parent_root, 1460 dentry->d_name.name, dentry->d_name.len, 1461 parent_inode, &key, 1462 BTRFS_FT_DIR, index); 1463 /* We have check then name at the beginning, so it is impossible. */ 1464 BUG_ON(ret == -EEXIST || ret == -EOVERFLOW); 1465 if (ret) { 1466 btrfs_abort_transaction(trans, root, ret); 1467 goto fail; 1468 } 1469 1470 btrfs_i_size_write(parent_inode, parent_inode->i_size + 1471 dentry->d_name.len * 2); 1472 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; 1473 ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode); 1474 if (ret) { 1475 btrfs_abort_transaction(trans, root, ret); 1476 goto fail; 1477 } 1478 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, new_uuid.b, 1479 BTRFS_UUID_KEY_SUBVOL, objectid); 1480 if (ret) { 1481 btrfs_abort_transaction(trans, root, ret); 1482 goto fail; 1483 } 1484 if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) { 1485 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, 1486 new_root_item->received_uuid, 1487 BTRFS_UUID_KEY_RECEIVED_SUBVOL, 1488 objectid); 1489 if (ret && ret != -EEXIST) { 1490 btrfs_abort_transaction(trans, root, ret); 1491 goto fail; 1492 } 1493 } 1494 fail: 1495 pending->error = ret; 1496 dir_item_existed: 1497 trans->block_rsv = rsv; 1498 trans->bytes_reserved = 0; 1499 no_free_objectid: 1500 kfree(new_root_item); 1501 root_item_alloc_fail: 1502 btrfs_free_path(path); 1503 return ret; 1504 } 1505 1506 /* 1507 * create all the snapshots we've scheduled for creation 1508 */ 1509 static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans, 1510 struct btrfs_fs_info *fs_info) 1511 { 1512 struct btrfs_pending_snapshot *pending, *next; 1513 struct list_head *head = &trans->transaction->pending_snapshots; 1514 int ret = 0; 1515 1516 list_for_each_entry_safe(pending, next, head, list) { 1517 list_del(&pending->list); 1518 ret = create_pending_snapshot(trans, fs_info, pending); 1519 if (ret) 1520 break; 1521 } 1522 return ret; 1523 } 1524 1525 static void update_super_roots(struct btrfs_root *root) 1526 { 1527 struct btrfs_root_item *root_item; 1528 struct btrfs_super_block *super; 1529 1530 super = root->fs_info->super_copy; 1531 1532 root_item = &root->fs_info->chunk_root->root_item; 1533 super->chunk_root = root_item->bytenr; 1534 super->chunk_root_generation = root_item->generation; 1535 super->chunk_root_level = root_item->level; 1536 1537 root_item = &root->fs_info->tree_root->root_item; 1538 super->root = root_item->bytenr; 1539 super->generation = root_item->generation; 1540 super->root_level = root_item->level; 1541 if (btrfs_test_opt(root, SPACE_CACHE)) 1542 super->cache_generation = root_item->generation; 1543 if (root->fs_info->update_uuid_tree_gen) 1544 super->uuid_tree_generation = root_item->generation; 1545 } 1546 1547 int btrfs_transaction_in_commit(struct btrfs_fs_info *info) 1548 { 1549 struct btrfs_transaction *trans; 1550 int ret = 0; 1551 1552 spin_lock(&info->trans_lock); 1553 trans = info->running_transaction; 1554 if (trans) 1555 ret = (trans->state >= TRANS_STATE_COMMIT_START); 1556 spin_unlock(&info->trans_lock); 1557 return ret; 1558 } 1559 1560 int btrfs_transaction_blocked(struct btrfs_fs_info *info) 1561 { 1562 struct btrfs_transaction *trans; 1563 int ret = 0; 1564 1565 spin_lock(&info->trans_lock); 1566 trans = info->running_transaction; 1567 if (trans) 1568 ret = is_transaction_blocked(trans); 1569 spin_unlock(&info->trans_lock); 1570 return ret; 1571 } 1572 1573 /* 1574 * wait for the current transaction commit to start and block subsequent 1575 * transaction joins 1576 */ 1577 static void wait_current_trans_commit_start(struct btrfs_root *root, 1578 struct btrfs_transaction *trans) 1579 { 1580 wait_event(root->fs_info->transaction_blocked_wait, 1581 trans->state >= TRANS_STATE_COMMIT_START || 1582 trans->aborted); 1583 } 1584 1585 /* 1586 * wait for the current transaction to start and then become unblocked. 1587 * caller holds ref. 1588 */ 1589 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root, 1590 struct btrfs_transaction *trans) 1591 { 1592 wait_event(root->fs_info->transaction_wait, 1593 trans->state >= TRANS_STATE_UNBLOCKED || 1594 trans->aborted); 1595 } 1596 1597 /* 1598 * commit transactions asynchronously. once btrfs_commit_transaction_async 1599 * returns, any subsequent transaction will not be allowed to join. 1600 */ 1601 struct btrfs_async_commit { 1602 struct btrfs_trans_handle *newtrans; 1603 struct btrfs_root *root; 1604 struct work_struct work; 1605 }; 1606 1607 static void do_async_commit(struct work_struct *work) 1608 { 1609 struct btrfs_async_commit *ac = 1610 container_of(work, struct btrfs_async_commit, work); 1611 1612 /* 1613 * We've got freeze protection passed with the transaction. 1614 * Tell lockdep about it. 1615 */ 1616 if (ac->newtrans->type & __TRANS_FREEZABLE) 1617 rwsem_acquire_read( 1618 &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1], 1619 0, 1, _THIS_IP_); 1620 1621 current->journal_info = ac->newtrans; 1622 1623 btrfs_commit_transaction(ac->newtrans, ac->root); 1624 kfree(ac); 1625 } 1626 1627 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans, 1628 struct btrfs_root *root, 1629 int wait_for_unblock) 1630 { 1631 struct btrfs_async_commit *ac; 1632 struct btrfs_transaction *cur_trans; 1633 1634 ac = kmalloc(sizeof(*ac), GFP_NOFS); 1635 if (!ac) 1636 return -ENOMEM; 1637 1638 INIT_WORK(&ac->work, do_async_commit); 1639 ac->root = root; 1640 ac->newtrans = btrfs_join_transaction(root); 1641 if (IS_ERR(ac->newtrans)) { 1642 int err = PTR_ERR(ac->newtrans); 1643 kfree(ac); 1644 return err; 1645 } 1646 1647 /* take transaction reference */ 1648 cur_trans = trans->transaction; 1649 atomic_inc(&cur_trans->use_count); 1650 1651 btrfs_end_transaction(trans, root); 1652 1653 /* 1654 * Tell lockdep we've released the freeze rwsem, since the 1655 * async commit thread will be the one to unlock it. 1656 */ 1657 if (ac->newtrans->type & __TRANS_FREEZABLE) 1658 rwsem_release( 1659 &root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1], 1660 1, _THIS_IP_); 1661 1662 schedule_work(&ac->work); 1663 1664 /* wait for transaction to start and unblock */ 1665 if (wait_for_unblock) 1666 wait_current_trans_commit_start_and_unblock(root, cur_trans); 1667 else 1668 wait_current_trans_commit_start(root, cur_trans); 1669 1670 if (current->journal_info == trans) 1671 current->journal_info = NULL; 1672 1673 btrfs_put_transaction(cur_trans); 1674 return 0; 1675 } 1676 1677 1678 static void cleanup_transaction(struct btrfs_trans_handle *trans, 1679 struct btrfs_root *root, int err) 1680 { 1681 struct btrfs_transaction *cur_trans = trans->transaction; 1682 DEFINE_WAIT(wait); 1683 1684 WARN_ON(trans->use_count > 1); 1685 1686 btrfs_abort_transaction(trans, root, err); 1687 1688 spin_lock(&root->fs_info->trans_lock); 1689 1690 /* 1691 * If the transaction is removed from the list, it means this 1692 * transaction has been committed successfully, so it is impossible 1693 * to call the cleanup function. 1694 */ 1695 BUG_ON(list_empty(&cur_trans->list)); 1696 1697 list_del_init(&cur_trans->list); 1698 if (cur_trans == root->fs_info->running_transaction) { 1699 cur_trans->state = TRANS_STATE_COMMIT_DOING; 1700 spin_unlock(&root->fs_info->trans_lock); 1701 wait_event(cur_trans->writer_wait, 1702 atomic_read(&cur_trans->num_writers) == 1); 1703 1704 spin_lock(&root->fs_info->trans_lock); 1705 } 1706 spin_unlock(&root->fs_info->trans_lock); 1707 1708 btrfs_cleanup_one_transaction(trans->transaction, root); 1709 1710 spin_lock(&root->fs_info->trans_lock); 1711 if (cur_trans == root->fs_info->running_transaction) 1712 root->fs_info->running_transaction = NULL; 1713 spin_unlock(&root->fs_info->trans_lock); 1714 1715 if (trans->type & __TRANS_FREEZABLE) 1716 sb_end_intwrite(root->fs_info->sb); 1717 btrfs_put_transaction(cur_trans); 1718 btrfs_put_transaction(cur_trans); 1719 1720 trace_btrfs_transaction_commit(root); 1721 1722 if (current->journal_info == trans) 1723 current->journal_info = NULL; 1724 btrfs_scrub_cancel(root->fs_info); 1725 1726 kmem_cache_free(btrfs_trans_handle_cachep, trans); 1727 } 1728 1729 static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info) 1730 { 1731 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT)) 1732 return btrfs_start_delalloc_roots(fs_info, 1, -1); 1733 return 0; 1734 } 1735 1736 static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info) 1737 { 1738 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT)) 1739 btrfs_wait_ordered_roots(fs_info, -1); 1740 } 1741 1742 static inline void 1743 btrfs_wait_pending_ordered(struct btrfs_transaction *cur_trans, 1744 struct btrfs_fs_info *fs_info) 1745 { 1746 struct btrfs_ordered_extent *ordered; 1747 1748 spin_lock(&fs_info->trans_lock); 1749 while (!list_empty(&cur_trans->pending_ordered)) { 1750 ordered = list_first_entry(&cur_trans->pending_ordered, 1751 struct btrfs_ordered_extent, 1752 trans_list); 1753 list_del_init(&ordered->trans_list); 1754 spin_unlock(&fs_info->trans_lock); 1755 1756 wait_event(ordered->wait, test_bit(BTRFS_ORDERED_COMPLETE, 1757 &ordered->flags)); 1758 btrfs_put_ordered_extent(ordered); 1759 spin_lock(&fs_info->trans_lock); 1760 } 1761 spin_unlock(&fs_info->trans_lock); 1762 } 1763 1764 int btrfs_commit_transaction(struct btrfs_trans_handle *trans, 1765 struct btrfs_root *root) 1766 { 1767 struct btrfs_transaction *cur_trans = trans->transaction; 1768 struct btrfs_transaction *prev_trans = NULL; 1769 struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode); 1770 int ret; 1771 1772 /* Stop the commit early if ->aborted is set */ 1773 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) { 1774 ret = cur_trans->aborted; 1775 btrfs_end_transaction(trans, root); 1776 return ret; 1777 } 1778 1779 /* make a pass through all the delayed refs we have so far 1780 * any runnings procs may add more while we are here 1781 */ 1782 ret = btrfs_run_delayed_refs(trans, root, 0); 1783 if (ret) { 1784 btrfs_end_transaction(trans, root); 1785 return ret; 1786 } 1787 1788 btrfs_trans_release_metadata(trans, root); 1789 trans->block_rsv = NULL; 1790 if (trans->qgroup_reserved) { 1791 btrfs_qgroup_free(root, trans->qgroup_reserved); 1792 trans->qgroup_reserved = 0; 1793 } 1794 1795 cur_trans = trans->transaction; 1796 1797 /* 1798 * set the flushing flag so procs in this transaction have to 1799 * start sending their work down. 1800 */ 1801 cur_trans->delayed_refs.flushing = 1; 1802 smp_wmb(); 1803 1804 if (!list_empty(&trans->new_bgs)) 1805 btrfs_create_pending_block_groups(trans, root); 1806 1807 ret = btrfs_run_delayed_refs(trans, root, 0); 1808 if (ret) { 1809 btrfs_end_transaction(trans, root); 1810 return ret; 1811 } 1812 1813 spin_lock(&root->fs_info->trans_lock); 1814 list_splice(&trans->ordered, &cur_trans->pending_ordered); 1815 if (cur_trans->state >= TRANS_STATE_COMMIT_START) { 1816 spin_unlock(&root->fs_info->trans_lock); 1817 atomic_inc(&cur_trans->use_count); 1818 ret = btrfs_end_transaction(trans, root); 1819 1820 wait_for_commit(root, cur_trans); 1821 1822 if (unlikely(cur_trans->aborted)) 1823 ret = cur_trans->aborted; 1824 1825 btrfs_put_transaction(cur_trans); 1826 1827 return ret; 1828 } 1829 1830 cur_trans->state = TRANS_STATE_COMMIT_START; 1831 wake_up(&root->fs_info->transaction_blocked_wait); 1832 1833 if (cur_trans->list.prev != &root->fs_info->trans_list) { 1834 prev_trans = list_entry(cur_trans->list.prev, 1835 struct btrfs_transaction, list); 1836 if (prev_trans->state != TRANS_STATE_COMPLETED) { 1837 atomic_inc(&prev_trans->use_count); 1838 spin_unlock(&root->fs_info->trans_lock); 1839 1840 wait_for_commit(root, prev_trans); 1841 1842 btrfs_put_transaction(prev_trans); 1843 } else { 1844 spin_unlock(&root->fs_info->trans_lock); 1845 } 1846 } else { 1847 spin_unlock(&root->fs_info->trans_lock); 1848 } 1849 1850 extwriter_counter_dec(cur_trans, trans->type); 1851 1852 ret = btrfs_start_delalloc_flush(root->fs_info); 1853 if (ret) 1854 goto cleanup_transaction; 1855 1856 ret = btrfs_run_delayed_items(trans, root); 1857 if (ret) 1858 goto cleanup_transaction; 1859 1860 wait_event(cur_trans->writer_wait, 1861 extwriter_counter_read(cur_trans) == 0); 1862 1863 /* some pending stuffs might be added after the previous flush. */ 1864 ret = btrfs_run_delayed_items(trans, root); 1865 if (ret) 1866 goto cleanup_transaction; 1867 1868 btrfs_wait_delalloc_flush(root->fs_info); 1869 1870 btrfs_wait_pending_ordered(cur_trans, root->fs_info); 1871 1872 btrfs_scrub_pause(root); 1873 /* 1874 * Ok now we need to make sure to block out any other joins while we 1875 * commit the transaction. We could have started a join before setting 1876 * COMMIT_DOING so make sure to wait for num_writers to == 1 again. 1877 */ 1878 spin_lock(&root->fs_info->trans_lock); 1879 cur_trans->state = TRANS_STATE_COMMIT_DOING; 1880 spin_unlock(&root->fs_info->trans_lock); 1881 wait_event(cur_trans->writer_wait, 1882 atomic_read(&cur_trans->num_writers) == 1); 1883 1884 /* ->aborted might be set after the previous check, so check it */ 1885 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) { 1886 ret = cur_trans->aborted; 1887 goto scrub_continue; 1888 } 1889 /* 1890 * the reloc mutex makes sure that we stop 1891 * the balancing code from coming in and moving 1892 * extents around in the middle of the commit 1893 */ 1894 mutex_lock(&root->fs_info->reloc_mutex); 1895 1896 /* 1897 * We needn't worry about the delayed items because we will 1898 * deal with them in create_pending_snapshot(), which is the 1899 * core function of the snapshot creation. 1900 */ 1901 ret = create_pending_snapshots(trans, root->fs_info); 1902 if (ret) { 1903 mutex_unlock(&root->fs_info->reloc_mutex); 1904 goto scrub_continue; 1905 } 1906 1907 /* 1908 * We insert the dir indexes of the snapshots and update the inode 1909 * of the snapshots' parents after the snapshot creation, so there 1910 * are some delayed items which are not dealt with. Now deal with 1911 * them. 1912 * 1913 * We needn't worry that this operation will corrupt the snapshots, 1914 * because all the tree which are snapshoted will be forced to COW 1915 * the nodes and leaves. 1916 */ 1917 ret = btrfs_run_delayed_items(trans, root); 1918 if (ret) { 1919 mutex_unlock(&root->fs_info->reloc_mutex); 1920 goto scrub_continue; 1921 } 1922 1923 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); 1924 if (ret) { 1925 mutex_unlock(&root->fs_info->reloc_mutex); 1926 goto scrub_continue; 1927 } 1928 1929 /* 1930 * make sure none of the code above managed to slip in a 1931 * delayed item 1932 */ 1933 btrfs_assert_delayed_root_empty(root); 1934 1935 WARN_ON(cur_trans != trans->transaction); 1936 1937 /* btrfs_commit_tree_roots is responsible for getting the 1938 * various roots consistent with each other. Every pointer 1939 * in the tree of tree roots has to point to the most up to date 1940 * root for every subvolume and other tree. So, we have to keep 1941 * the tree logging code from jumping in and changing any 1942 * of the trees. 1943 * 1944 * At this point in the commit, there can't be any tree-log 1945 * writers, but a little lower down we drop the trans mutex 1946 * and let new people in. By holding the tree_log_mutex 1947 * from now until after the super is written, we avoid races 1948 * with the tree-log code. 1949 */ 1950 mutex_lock(&root->fs_info->tree_log_mutex); 1951 1952 ret = commit_fs_roots(trans, root); 1953 if (ret) { 1954 mutex_unlock(&root->fs_info->tree_log_mutex); 1955 mutex_unlock(&root->fs_info->reloc_mutex); 1956 goto scrub_continue; 1957 } 1958 1959 /* 1960 * Since the transaction is done, we can apply the pending changes 1961 * before the next transaction. 1962 */ 1963 btrfs_apply_pending_changes(root->fs_info); 1964 1965 /* commit_fs_roots gets rid of all the tree log roots, it is now 1966 * safe to free the root of tree log roots 1967 */ 1968 btrfs_free_log_root_tree(trans, root->fs_info); 1969 1970 ret = commit_cowonly_roots(trans, root); 1971 if (ret) { 1972 mutex_unlock(&root->fs_info->tree_log_mutex); 1973 mutex_unlock(&root->fs_info->reloc_mutex); 1974 goto scrub_continue; 1975 } 1976 1977 /* 1978 * The tasks which save the space cache and inode cache may also 1979 * update ->aborted, check it. 1980 */ 1981 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) { 1982 ret = cur_trans->aborted; 1983 mutex_unlock(&root->fs_info->tree_log_mutex); 1984 mutex_unlock(&root->fs_info->reloc_mutex); 1985 goto scrub_continue; 1986 } 1987 1988 btrfs_prepare_extent_commit(trans, root); 1989 1990 cur_trans = root->fs_info->running_transaction; 1991 1992 btrfs_set_root_node(&root->fs_info->tree_root->root_item, 1993 root->fs_info->tree_root->node); 1994 list_add_tail(&root->fs_info->tree_root->dirty_list, 1995 &cur_trans->switch_commits); 1996 1997 btrfs_set_root_node(&root->fs_info->chunk_root->root_item, 1998 root->fs_info->chunk_root->node); 1999 list_add_tail(&root->fs_info->chunk_root->dirty_list, 2000 &cur_trans->switch_commits); 2001 2002 switch_commit_roots(cur_trans, root->fs_info); 2003 2004 assert_qgroups_uptodate(trans); 2005 ASSERT(list_empty(&cur_trans->dirty_bgs)); 2006 update_super_roots(root); 2007 2008 btrfs_set_super_log_root(root->fs_info->super_copy, 0); 2009 btrfs_set_super_log_root_level(root->fs_info->super_copy, 0); 2010 memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy, 2011 sizeof(*root->fs_info->super_copy)); 2012 2013 btrfs_update_commit_device_size(root->fs_info); 2014 btrfs_update_commit_device_bytes_used(root, cur_trans); 2015 2016 clear_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags); 2017 clear_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags); 2018 2019 spin_lock(&root->fs_info->trans_lock); 2020 cur_trans->state = TRANS_STATE_UNBLOCKED; 2021 root->fs_info->running_transaction = NULL; 2022 spin_unlock(&root->fs_info->trans_lock); 2023 mutex_unlock(&root->fs_info->reloc_mutex); 2024 2025 wake_up(&root->fs_info->transaction_wait); 2026 2027 ret = btrfs_write_and_wait_transaction(trans, root); 2028 if (ret) { 2029 btrfs_error(root->fs_info, ret, 2030 "Error while writing out transaction"); 2031 mutex_unlock(&root->fs_info->tree_log_mutex); 2032 goto scrub_continue; 2033 } 2034 2035 ret = write_ctree_super(trans, root, 0); 2036 if (ret) { 2037 mutex_unlock(&root->fs_info->tree_log_mutex); 2038 goto scrub_continue; 2039 } 2040 2041 /* 2042 * the super is written, we can safely allow the tree-loggers 2043 * to go about their business 2044 */ 2045 mutex_unlock(&root->fs_info->tree_log_mutex); 2046 2047 btrfs_finish_extent_commit(trans, root); 2048 2049 if (cur_trans->have_free_bgs) 2050 btrfs_clear_space_info_full(root->fs_info); 2051 2052 root->fs_info->last_trans_committed = cur_trans->transid; 2053 /* 2054 * We needn't acquire the lock here because there is no other task 2055 * which can change it. 2056 */ 2057 cur_trans->state = TRANS_STATE_COMPLETED; 2058 wake_up(&cur_trans->commit_wait); 2059 2060 spin_lock(&root->fs_info->trans_lock); 2061 list_del_init(&cur_trans->list); 2062 spin_unlock(&root->fs_info->trans_lock); 2063 2064 btrfs_put_transaction(cur_trans); 2065 btrfs_put_transaction(cur_trans); 2066 2067 if (trans->type & __TRANS_FREEZABLE) 2068 sb_end_intwrite(root->fs_info->sb); 2069 2070 trace_btrfs_transaction_commit(root); 2071 2072 btrfs_scrub_continue(root); 2073 2074 if (current->journal_info == trans) 2075 current->journal_info = NULL; 2076 2077 kmem_cache_free(btrfs_trans_handle_cachep, trans); 2078 2079 if (current != root->fs_info->transaction_kthread) 2080 btrfs_run_delayed_iputs(root); 2081 2082 return ret; 2083 2084 scrub_continue: 2085 btrfs_scrub_continue(root); 2086 cleanup_transaction: 2087 btrfs_trans_release_metadata(trans, root); 2088 trans->block_rsv = NULL; 2089 if (trans->qgroup_reserved) { 2090 btrfs_qgroup_free(root, trans->qgroup_reserved); 2091 trans->qgroup_reserved = 0; 2092 } 2093 btrfs_warn(root->fs_info, "Skipping commit of aborted transaction."); 2094 if (current->journal_info == trans) 2095 current->journal_info = NULL; 2096 cleanup_transaction(trans, root, ret); 2097 2098 return ret; 2099 } 2100 2101 /* 2102 * return < 0 if error 2103 * 0 if there are no more dead_roots at the time of call 2104 * 1 there are more to be processed, call me again 2105 * 2106 * The return value indicates there are certainly more snapshots to delete, but 2107 * if there comes a new one during processing, it may return 0. We don't mind, 2108 * because btrfs_commit_super will poke cleaner thread and it will process it a 2109 * few seconds later. 2110 */ 2111 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root) 2112 { 2113 int ret; 2114 struct btrfs_fs_info *fs_info = root->fs_info; 2115 2116 spin_lock(&fs_info->trans_lock); 2117 if (list_empty(&fs_info->dead_roots)) { 2118 spin_unlock(&fs_info->trans_lock); 2119 return 0; 2120 } 2121 root = list_first_entry(&fs_info->dead_roots, 2122 struct btrfs_root, root_list); 2123 list_del_init(&root->root_list); 2124 spin_unlock(&fs_info->trans_lock); 2125 2126 pr_debug("BTRFS: cleaner removing %llu\n", root->objectid); 2127 2128 btrfs_kill_all_delayed_nodes(root); 2129 2130 if (btrfs_header_backref_rev(root->node) < 2131 BTRFS_MIXED_BACKREF_REV) 2132 ret = btrfs_drop_snapshot(root, NULL, 0, 0); 2133 else 2134 ret = btrfs_drop_snapshot(root, NULL, 1, 0); 2135 2136 return (ret < 0) ? 0 : 1; 2137 } 2138 2139 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info) 2140 { 2141 unsigned long prev; 2142 unsigned long bit; 2143 2144 prev = xchg(&fs_info->pending_changes, 0); 2145 if (!prev) 2146 return; 2147 2148 bit = 1 << BTRFS_PENDING_SET_INODE_MAP_CACHE; 2149 if (prev & bit) 2150 btrfs_set_opt(fs_info->mount_opt, INODE_MAP_CACHE); 2151 prev &= ~bit; 2152 2153 bit = 1 << BTRFS_PENDING_CLEAR_INODE_MAP_CACHE; 2154 if (prev & bit) 2155 btrfs_clear_opt(fs_info->mount_opt, INODE_MAP_CACHE); 2156 prev &= ~bit; 2157 2158 bit = 1 << BTRFS_PENDING_COMMIT; 2159 if (prev & bit) 2160 btrfs_debug(fs_info, "pending commit done"); 2161 prev &= ~bit; 2162 2163 if (prev) 2164 btrfs_warn(fs_info, 2165 "unknown pending changes left 0x%lx, ignoring", prev); 2166 } 2167