2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
20 #include <linux/sched.h>
23 #include "transaction.h"
25 static int total_trans = 0;
26 extern struct kmem_cache *btrfs_trans_handle_cachep;
27 extern struct kmem_cache *btrfs_transaction_cachep;
29 static struct workqueue_struct *trans_wq;
31 #define BTRFS_ROOT_TRANS_TAG 0
32 #define BTRFS_ROOT_DEFRAG_TAG 1
34 static void put_transaction(struct btrfs_transaction *transaction)
36 WARN_ON(transaction->use_count == 0);
37 transaction->use_count--;
38 if (transaction->use_count == 0) {
39 WARN_ON(total_trans == 0);
41 list_del_init(&transaction->list);
42 memset(transaction, 0, sizeof(*transaction));
43 kmem_cache_free(btrfs_transaction_cachep, transaction);
47 static int join_transaction(struct btrfs_root *root)
49 struct btrfs_transaction *cur_trans;
50 cur_trans = root->fs_info->running_transaction;
52 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
56 root->fs_info->generation++;
57 root->fs_info->running_transaction = cur_trans;
58 cur_trans->num_writers = 1;
59 cur_trans->num_joined = 0;
60 cur_trans->transid = root->fs_info->generation;
61 init_waitqueue_head(&cur_trans->writer_wait);
62 init_waitqueue_head(&cur_trans->commit_wait);
63 cur_trans->in_commit = 0;
64 cur_trans->use_count = 1;
65 cur_trans->commit_done = 0;
66 cur_trans->start_time = get_seconds();
67 list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
68 init_bit_radix(&cur_trans->dirty_pages);
70 cur_trans->num_writers++;
71 cur_trans->num_joined++;
77 static int record_root_in_trans(struct btrfs_root *root)
79 u64 running_trans_id = root->fs_info->running_transaction->transid;
80 if (root->ref_cows && root->last_trans < running_trans_id) {
81 WARN_ON(root == root->fs_info->extent_root);
82 if (root->root_item.refs != 0) {
83 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
84 (unsigned long)root->root_key.objectid,
85 BTRFS_ROOT_TRANS_TAG);
86 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
87 (unsigned long)root->root_key.objectid,
88 BTRFS_ROOT_DEFRAG_TAG);
89 root->commit_root = root->node;
94 root->last_trans = running_trans_id;
99 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
102 struct btrfs_trans_handle *h =
103 kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
106 mutex_lock(&root->fs_info->trans_mutex);
107 ret = join_transaction(root);
110 record_root_in_trans(root);
111 h->transid = root->fs_info->running_transaction->transid;
112 h->transaction = root->fs_info->running_transaction;
113 h->blocks_reserved = num_blocks;
115 h->block_group = NULL;
116 h->alloc_exclude_nr = 0;
117 h->alloc_exclude_start = 0;
118 root->fs_info->running_transaction->use_count++;
119 mutex_unlock(&root->fs_info->trans_mutex);
123 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
124 struct btrfs_root *root)
126 struct btrfs_transaction *cur_trans;
128 mutex_lock(&root->fs_info->trans_mutex);
129 cur_trans = root->fs_info->running_transaction;
130 WARN_ON(cur_trans != trans->transaction);
131 WARN_ON(cur_trans->num_writers < 1);
132 cur_trans->num_writers--;
133 if (waitqueue_active(&cur_trans->writer_wait))
134 wake_up(&cur_trans->writer_wait);
135 put_transaction(cur_trans);
136 mutex_unlock(&root->fs_info->trans_mutex);
137 memset(trans, 0, sizeof(*trans));
138 kmem_cache_free(btrfs_trans_handle_cachep, trans);
143 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
144 struct btrfs_root *root)
146 unsigned long gang[16];
152 struct radix_tree_root *dirty_pages;
153 struct inode *btree_inode = root->fs_info->btree_inode;
155 if (!trans || !trans->transaction) {
156 return filemap_write_and_wait(btree_inode->i_mapping);
158 dirty_pages = &trans->transaction->dirty_pages;
160 ret = find_first_radix_bit(dirty_pages, gang,
161 0, ARRAY_SIZE(gang));
164 for (i = 0; i < ret; i++) {
166 clear_radix_bit(dirty_pages, gang[i]);
167 page = find_lock_page(btree_inode->i_mapping,
171 if (PageWriteback(page)) {
173 wait_on_page_writeback(page);
176 page_cache_release(page);
180 err = write_one_page(page, 0);
183 page_cache_release(page);
186 err = filemap_fdatawait(btree_inode->i_mapping);
192 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
193 struct btrfs_root *root)
196 u64 old_extent_block;
197 struct btrfs_fs_info *fs_info = root->fs_info;
198 struct btrfs_root *tree_root = fs_info->tree_root;
199 struct btrfs_root *extent_root = fs_info->extent_root;
201 btrfs_write_dirty_block_groups(trans, extent_root);
203 old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
204 if (old_extent_block == bh_blocknr(extent_root->node))
206 btrfs_set_root_blocknr(&extent_root->root_item,
207 bh_blocknr(extent_root->node));
208 ret = btrfs_update_root(trans, tree_root,
209 &extent_root->root_key,
210 &extent_root->root_item);
212 btrfs_write_dirty_block_groups(trans, extent_root);
217 static int wait_for_commit(struct btrfs_root *root,
218 struct btrfs_transaction *commit)
221 mutex_lock(&root->fs_info->trans_mutex);
222 while(!commit->commit_done) {
223 prepare_to_wait(&commit->commit_wait, &wait,
224 TASK_UNINTERRUPTIBLE);
225 if (commit->commit_done)
227 mutex_unlock(&root->fs_info->trans_mutex);
229 mutex_lock(&root->fs_info->trans_mutex);
231 mutex_unlock(&root->fs_info->trans_mutex);
232 finish_wait(&commit->commit_wait, &wait);
237 struct list_head list;
238 struct btrfs_root *root;
239 struct btrfs_root *latest_root;
242 int btrfs_add_dead_root(struct btrfs_root *root, struct list_head *dead_list)
244 struct dirty_root *dirty;
246 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
250 list_add(&dirty->list, dead_list);
254 static int add_dirty_roots(struct btrfs_trans_handle *trans,
255 struct radix_tree_root *radix,
256 struct list_head *list)
258 struct dirty_root *dirty;
259 struct btrfs_root *gang[8];
260 struct btrfs_root *root;
267 ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
269 BTRFS_ROOT_TRANS_TAG);
272 for (i = 0; i < ret; i++) {
274 radix_tree_tag_clear(radix,
275 (unsigned long)root->root_key.objectid,
276 BTRFS_ROOT_TRANS_TAG);
277 if (root->commit_root == root->node) {
278 WARN_ON(bh_blocknr(root->node) !=
279 btrfs_root_blocknr(&root->root_item));
280 brelse(root->commit_root);
281 root->commit_root = NULL;
283 /* make sure to update the root on disk
284 * so we get any updates to the block used
287 err = btrfs_update_root(trans,
288 root->fs_info->tree_root,
293 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
295 dirty->root = kmalloc(sizeof(*dirty->root), GFP_NOFS);
296 BUG_ON(!dirty->root);
298 memset(&root->root_item.drop_progress, 0,
299 sizeof(struct btrfs_disk_key));
300 root->root_item.drop_level = 0;
302 memcpy(dirty->root, root, sizeof(*root));
303 dirty->root->node = root->commit_root;
304 dirty->latest_root = root;
305 root->commit_root = NULL;
307 root->root_key.offset = root->fs_info->generation;
308 btrfs_set_root_blocknr(&root->root_item,
309 bh_blocknr(root->node));
310 err = btrfs_insert_root(trans, root->fs_info->tree_root,
316 refs = btrfs_root_refs(&dirty->root->root_item);
317 btrfs_set_root_refs(&dirty->root->root_item, refs - 1);
318 err = btrfs_update_root(trans, root->fs_info->tree_root,
319 &dirty->root->root_key,
320 &dirty->root->root_item);
324 list_add(&dirty->list, list);
335 int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
337 struct btrfs_fs_info *info = root->fs_info;
339 struct btrfs_trans_handle *trans;
341 if (root->defrag_running)
344 trans = btrfs_start_transaction(root, 1);
346 root->defrag_running = 1;
347 ret = btrfs_defrag_leaves(trans, root, cacheonly);
348 btrfs_end_transaction(trans, root);
349 mutex_unlock(&info->fs_mutex);
351 btrfs_btree_balance_dirty(root);
354 mutex_lock(&info->fs_mutex);
355 trans = btrfs_start_transaction(root, 1);
359 root->defrag_running = 0;
360 radix_tree_tag_clear(&info->fs_roots_radix,
361 (unsigned long)root->root_key.objectid,
362 BTRFS_ROOT_DEFRAG_TAG);
363 btrfs_end_transaction(trans, root);
367 int btrfs_defrag_dirty_roots(struct btrfs_fs_info *info)
369 struct btrfs_root *gang[1];
370 struct btrfs_root *root;
377 ret = radix_tree_gang_lookup_tag(&info->fs_roots_radix,
380 BTRFS_ROOT_DEFRAG_TAG);
383 for (i = 0; i < ret; i++) {
385 last = root->root_key.objectid + 1;
386 btrfs_defrag_root(root, 1);
389 btrfs_defrag_root(info->extent_root, 1);
393 static int drop_dirty_roots(struct btrfs_root *tree_root,
394 struct list_head *list)
396 struct dirty_root *dirty;
397 struct btrfs_trans_handle *trans;
403 while(!list_empty(list)) {
404 struct btrfs_root *root;
406 mutex_lock(&tree_root->fs_info->fs_mutex);
407 dirty = list_entry(list->next, struct dirty_root, list);
408 list_del_init(&dirty->list);
410 num_blocks = btrfs_root_blocks_used(&dirty->root->root_item);
411 root = dirty->latest_root;
414 trans = btrfs_start_transaction(tree_root, 1);
416 ret = btrfs_drop_snapshot(trans, dirty->root);
417 if (ret != -EAGAIN) {
421 err = btrfs_update_root(trans,
423 &dirty->root->root_key,
424 &dirty->root->root_item);
427 ret = btrfs_end_transaction(trans, tree_root);
429 mutex_unlock(&tree_root->fs_info->fs_mutex);
431 btrfs_btree_balance_dirty(tree_root);
434 mutex_lock(&tree_root->fs_info->fs_mutex);
438 num_blocks -= btrfs_root_blocks_used(&dirty->root->root_item);
439 blocks_used = btrfs_root_blocks_used(&root->root_item);
441 record_root_in_trans(root);
442 btrfs_set_root_blocks_used(&root->root_item,
443 blocks_used - num_blocks);
445 ret = btrfs_del_root(trans, tree_root, &dirty->root->root_key);
450 ret = btrfs_end_transaction(trans, tree_root);
455 mutex_unlock(&tree_root->fs_info->fs_mutex);
456 btrfs_btree_balance_dirty(tree_root);
462 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
463 struct btrfs_root *root)
465 unsigned long joined = 0;
466 unsigned long timeout = 1;
467 struct btrfs_transaction *cur_trans;
468 struct btrfs_transaction *prev_trans = NULL;
469 struct list_head dirty_fs_roots;
470 struct radix_tree_root pinned_copy;
474 init_bit_radix(&pinned_copy);
475 INIT_LIST_HEAD(&dirty_fs_roots);
477 mutex_lock(&root->fs_info->trans_mutex);
478 if (trans->transaction->in_commit) {
479 cur_trans = trans->transaction;
480 trans->transaction->use_count++;
481 mutex_unlock(&root->fs_info->trans_mutex);
482 btrfs_end_transaction(trans, root);
484 mutex_unlock(&root->fs_info->fs_mutex);
485 ret = wait_for_commit(root, cur_trans);
488 mutex_lock(&root->fs_info->trans_mutex);
489 put_transaction(cur_trans);
490 mutex_unlock(&root->fs_info->trans_mutex);
492 mutex_lock(&root->fs_info->fs_mutex);
495 trans->transaction->in_commit = 1;
496 cur_trans = trans->transaction;
497 if (cur_trans->list.prev != &root->fs_info->trans_list) {
498 prev_trans = list_entry(cur_trans->list.prev,
499 struct btrfs_transaction, list);
500 if (!prev_trans->commit_done) {
501 prev_trans->use_count++;
502 mutex_unlock(&root->fs_info->fs_mutex);
503 mutex_unlock(&root->fs_info->trans_mutex);
505 wait_for_commit(root, prev_trans);
507 mutex_lock(&root->fs_info->fs_mutex);
508 mutex_lock(&root->fs_info->trans_mutex);
509 put_transaction(prev_trans);
514 joined = cur_trans->num_joined;
515 WARN_ON(cur_trans != trans->transaction);
516 prepare_to_wait(&cur_trans->writer_wait, &wait,
517 TASK_UNINTERRUPTIBLE);
519 if (cur_trans->num_writers > 1)
520 timeout = MAX_SCHEDULE_TIMEOUT;
524 mutex_unlock(&root->fs_info->fs_mutex);
525 mutex_unlock(&root->fs_info->trans_mutex);
527 schedule_timeout(timeout);
529 mutex_lock(&root->fs_info->fs_mutex);
530 mutex_lock(&root->fs_info->trans_mutex);
531 finish_wait(&cur_trans->writer_wait, &wait);
532 } while (cur_trans->num_writers > 1 ||
533 (cur_trans->num_joined != joined));
535 WARN_ON(cur_trans != trans->transaction);
536 ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
540 ret = btrfs_commit_tree_roots(trans, root);
543 cur_trans = root->fs_info->running_transaction;
544 root->fs_info->running_transaction = NULL;
545 btrfs_set_super_generation(&root->fs_info->super_copy,
547 btrfs_set_super_root(&root->fs_info->super_copy,
548 bh_blocknr(root->fs_info->tree_root->node));
549 memcpy(root->fs_info->disk_super, &root->fs_info->super_copy,
550 sizeof(root->fs_info->super_copy));
552 btrfs_copy_pinned(root, &pinned_copy);
554 mutex_unlock(&root->fs_info->trans_mutex);
555 mutex_unlock(&root->fs_info->fs_mutex);
556 ret = btrfs_write_and_wait_transaction(trans, root);
558 write_ctree_super(trans, root);
559 mutex_lock(&root->fs_info->fs_mutex);
560 btrfs_finish_extent_commit(trans, root, &pinned_copy);
561 mutex_lock(&root->fs_info->trans_mutex);
562 cur_trans->commit_done = 1;
563 root->fs_info->last_trans_committed = cur_trans->transid;
564 wake_up(&cur_trans->commit_wait);
565 put_transaction(cur_trans);
566 put_transaction(cur_trans);
568 if (root->fs_info->closing)
569 list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
571 list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
573 mutex_unlock(&root->fs_info->trans_mutex);
574 kmem_cache_free(btrfs_trans_handle_cachep, trans);
576 if (root->fs_info->closing) {
577 mutex_unlock(&root->fs_info->fs_mutex);
578 drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
579 mutex_lock(&root->fs_info->fs_mutex);
584 int btrfs_clean_old_snapshots(struct btrfs_root *root)
586 struct list_head dirty_roots;
587 INIT_LIST_HEAD(&dirty_roots);
589 mutex_lock(&root->fs_info->trans_mutex);
590 list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
591 mutex_unlock(&root->fs_info->trans_mutex);
593 if (!list_empty(&dirty_roots)) {
594 drop_dirty_roots(root, &dirty_roots);
598 void btrfs_transaction_cleaner(struct work_struct *work)
600 struct btrfs_fs_info *fs_info = container_of(work,
601 struct btrfs_fs_info,
604 struct btrfs_root *root = fs_info->tree_root;
605 struct btrfs_transaction *cur;
606 struct btrfs_trans_handle *trans;
608 unsigned long delay = HZ * 30;
611 mutex_lock(&root->fs_info->fs_mutex);
612 mutex_lock(&root->fs_info->trans_mutex);
613 cur = root->fs_info->running_transaction;
615 mutex_unlock(&root->fs_info->trans_mutex);
619 if (now < cur->start_time || now - cur->start_time < 30) {
620 mutex_unlock(&root->fs_info->trans_mutex);
624 mutex_unlock(&root->fs_info->trans_mutex);
625 btrfs_defrag_dirty_roots(root->fs_info);
626 trans = btrfs_start_transaction(root, 1);
627 ret = btrfs_commit_transaction(trans, root);
629 mutex_unlock(&root->fs_info->fs_mutex);
630 btrfs_clean_old_snapshots(root);
631 btrfs_transaction_queue_work(root, delay);
634 void btrfs_transaction_queue_work(struct btrfs_root *root, int delay)
636 queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
639 void btrfs_transaction_flush_work(struct btrfs_root *root)
641 cancel_rearming_delayed_workqueue(trans_wq, &root->fs_info->trans_work);
642 flush_workqueue(trans_wq);
645 void __init btrfs_init_transaction_sys(void)
647 trans_wq = create_workqueue("btrfs");
650 void __exit btrfs_exit_transaction_sys(void)
652 destroy_workqueue(trans_wq);