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>
21 #include <linux/writeback.h>
22 #include <linux/pagemap.h>
25 #include "transaction.h"
27 static int total_trans = 0;
28 extern struct kmem_cache *btrfs_trans_handle_cachep;
29 extern struct kmem_cache *btrfs_transaction_cachep;
31 static struct workqueue_struct *trans_wq;
33 #define BTRFS_ROOT_TRANS_TAG 0
34 #define BTRFS_ROOT_DEFRAG_TAG 1
36 static void put_transaction(struct btrfs_transaction *transaction)
38 WARN_ON(transaction->use_count == 0);
39 transaction->use_count--;
40 if (transaction->use_count == 0) {
41 WARN_ON(total_trans == 0);
43 list_del_init(&transaction->list);
44 memset(transaction, 0, sizeof(*transaction));
45 kmem_cache_free(btrfs_transaction_cachep, transaction);
49 static int join_transaction(struct btrfs_root *root)
51 struct btrfs_transaction *cur_trans;
52 cur_trans = root->fs_info->running_transaction;
54 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
58 root->fs_info->generation++;
59 root->fs_info->running_transaction = cur_trans;
60 cur_trans->num_writers = 1;
61 cur_trans->num_joined = 0;
62 cur_trans->transid = root->fs_info->generation;
63 init_waitqueue_head(&cur_trans->writer_wait);
64 init_waitqueue_head(&cur_trans->commit_wait);
65 cur_trans->in_commit = 0;
66 cur_trans->use_count = 1;
67 cur_trans->commit_done = 0;
68 cur_trans->start_time = get_seconds();
69 list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
70 extent_map_tree_init(&cur_trans->dirty_pages,
71 root->fs_info->btree_inode->i_mapping,
74 cur_trans->num_writers++;
75 cur_trans->num_joined++;
81 static int record_root_in_trans(struct btrfs_root *root)
83 u64 running_trans_id = root->fs_info->running_transaction->transid;
84 if (root->ref_cows && root->last_trans < running_trans_id) {
85 WARN_ON(root == root->fs_info->extent_root);
86 if (root->root_item.refs != 0) {
87 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
88 (unsigned long)root->root_key.objectid,
89 BTRFS_ROOT_TRANS_TAG);
90 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
91 (unsigned long)root->root_key.objectid,
92 BTRFS_ROOT_DEFRAG_TAG);
93 root->commit_root = root->node;
94 extent_buffer_get(root->node);
98 root->last_trans = running_trans_id;
103 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
106 struct btrfs_trans_handle *h =
107 kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
110 mutex_lock(&root->fs_info->trans_mutex);
111 ret = join_transaction(root);
114 record_root_in_trans(root);
115 h->transid = root->fs_info->running_transaction->transid;
116 h->transaction = root->fs_info->running_transaction;
117 h->blocks_reserved = num_blocks;
119 h->block_group = NULL;
120 h->alloc_exclude_nr = 0;
121 h->alloc_exclude_start = 0;
122 root->fs_info->running_transaction->use_count++;
123 mutex_unlock(&root->fs_info->trans_mutex);
127 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
128 struct btrfs_root *root)
130 struct btrfs_transaction *cur_trans;
132 mutex_lock(&root->fs_info->trans_mutex);
133 cur_trans = root->fs_info->running_transaction;
134 WARN_ON(cur_trans != trans->transaction);
135 WARN_ON(cur_trans->num_writers < 1);
136 cur_trans->num_writers--;
137 if (waitqueue_active(&cur_trans->writer_wait))
138 wake_up(&cur_trans->writer_wait);
139 put_transaction(cur_trans);
140 mutex_unlock(&root->fs_info->trans_mutex);
141 memset(trans, 0, sizeof(*trans));
142 kmem_cache_free(btrfs_trans_handle_cachep, trans);
147 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
148 struct btrfs_root *root)
153 struct extent_map_tree *dirty_pages;
155 struct inode *btree_inode = root->fs_info->btree_inode;
160 if (!trans || !trans->transaction) {
161 return filemap_write_and_wait(btree_inode->i_mapping);
163 dirty_pages = &trans->transaction->dirty_pages;
165 ret = find_first_extent_bit(dirty_pages, 0, &start, &end,
169 clear_extent_dirty(dirty_pages, start, end, GFP_NOFS);
170 while(start <= end) {
171 index = start >> PAGE_CACHE_SHIFT;
172 start = (index + 1) << PAGE_CACHE_SHIFT;
173 page = find_lock_page(btree_inode->i_mapping, index);
176 if (PageWriteback(page)) {
178 wait_on_page_writeback(page);
181 page_cache_release(page);
185 err = write_one_page(page, 0);
188 page_cache_release(page);
191 err = filemap_fdatawait(btree_inode->i_mapping);
197 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
198 struct btrfs_root *root)
201 u64 old_extent_block;
202 struct btrfs_fs_info *fs_info = root->fs_info;
203 struct btrfs_root *tree_root = fs_info->tree_root;
204 struct btrfs_root *extent_root = fs_info->extent_root;
206 btrfs_write_dirty_block_groups(trans, extent_root);
208 old_extent_block = btrfs_root_bytenr(&extent_root->root_item);
209 if (old_extent_block == extent_root->node->start)
211 btrfs_set_root_bytenr(&extent_root->root_item,
212 extent_root->node->start);
213 btrfs_set_root_level(&extent_root->root_item,
214 btrfs_header_level(extent_root->node));
215 ret = btrfs_update_root(trans, tree_root,
216 &extent_root->root_key,
217 &extent_root->root_item);
219 btrfs_write_dirty_block_groups(trans, extent_root);
224 static int wait_for_commit(struct btrfs_root *root,
225 struct btrfs_transaction *commit)
228 mutex_lock(&root->fs_info->trans_mutex);
229 while(!commit->commit_done) {
230 prepare_to_wait(&commit->commit_wait, &wait,
231 TASK_UNINTERRUPTIBLE);
232 if (commit->commit_done)
234 mutex_unlock(&root->fs_info->trans_mutex);
236 mutex_lock(&root->fs_info->trans_mutex);
238 mutex_unlock(&root->fs_info->trans_mutex);
239 finish_wait(&commit->commit_wait, &wait);
244 struct list_head list;
245 struct btrfs_root *root;
246 struct btrfs_root *latest_root;
249 int btrfs_add_dead_root(struct btrfs_root *root,
250 struct btrfs_root *latest,
251 struct list_head *dead_list)
253 struct dirty_root *dirty;
255 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
259 dirty->latest_root = latest;
260 list_add(&dirty->list, dead_list);
264 static int add_dirty_roots(struct btrfs_trans_handle *trans,
265 struct radix_tree_root *radix,
266 struct list_head *list)
268 struct dirty_root *dirty;
269 struct btrfs_root *gang[8];
270 struct btrfs_root *root;
277 ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
279 BTRFS_ROOT_TRANS_TAG);
282 for (i = 0; i < ret; i++) {
284 radix_tree_tag_clear(radix,
285 (unsigned long)root->root_key.objectid,
286 BTRFS_ROOT_TRANS_TAG);
287 if (root->commit_root == root->node) {
288 WARN_ON(root->node->start !=
289 btrfs_root_bytenr(&root->root_item));
290 free_extent_buffer(root->commit_root);
291 root->commit_root = NULL;
293 /* make sure to update the root on disk
294 * so we get any updates to the block used
297 err = btrfs_update_root(trans,
298 root->fs_info->tree_root,
303 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
305 dirty->root = kmalloc(sizeof(*dirty->root), GFP_NOFS);
306 BUG_ON(!dirty->root);
308 memset(&root->root_item.drop_progress, 0,
309 sizeof(struct btrfs_disk_key));
310 root->root_item.drop_level = 0;
312 memcpy(dirty->root, root, sizeof(*root));
313 dirty->root->node = root->commit_root;
314 dirty->latest_root = root;
315 root->commit_root = NULL;
317 root->root_key.offset = root->fs_info->generation;
318 btrfs_set_root_bytenr(&root->root_item,
320 btrfs_set_root_level(&root->root_item,
321 btrfs_header_level(root->node));
322 err = btrfs_insert_root(trans, root->fs_info->tree_root,
328 refs = btrfs_root_refs(&dirty->root->root_item);
329 btrfs_set_root_refs(&dirty->root->root_item, refs - 1);
330 err = btrfs_update_root(trans, root->fs_info->tree_root,
331 &dirty->root->root_key,
332 &dirty->root->root_item);
336 list_add(&dirty->list, list);
347 int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
349 struct btrfs_fs_info *info = root->fs_info;
351 struct btrfs_trans_handle *trans;
354 if (root->defrag_running)
357 trans = btrfs_start_transaction(root, 1);
359 root->defrag_running = 1;
360 ret = btrfs_defrag_leaves(trans, root, cacheonly);
361 nr = trans->blocks_used;
362 btrfs_end_transaction(trans, root);
363 mutex_unlock(&info->fs_mutex);
365 btrfs_btree_balance_dirty(info->tree_root, nr);
368 mutex_lock(&info->fs_mutex);
369 trans = btrfs_start_transaction(root, 1);
373 root->defrag_running = 0;
374 radix_tree_tag_clear(&info->fs_roots_radix,
375 (unsigned long)root->root_key.objectid,
376 BTRFS_ROOT_DEFRAG_TAG);
377 btrfs_end_transaction(trans, root);
381 int btrfs_defrag_dirty_roots(struct btrfs_fs_info *info)
383 struct btrfs_root *gang[1];
384 struct btrfs_root *root;
391 ret = radix_tree_gang_lookup_tag(&info->fs_roots_radix,
394 BTRFS_ROOT_DEFRAG_TAG);
397 for (i = 0; i < ret; i++) {
399 last = root->root_key.objectid + 1;
400 btrfs_defrag_root(root, 1);
403 btrfs_defrag_root(info->extent_root, 1);
407 static int drop_dirty_roots(struct btrfs_root *tree_root,
408 struct list_head *list)
410 struct dirty_root *dirty;
411 struct btrfs_trans_handle *trans;
418 while(!list_empty(list)) {
419 struct btrfs_root *root;
421 mutex_lock(&tree_root->fs_info->fs_mutex);
422 dirty = list_entry(list->next, struct dirty_root, list);
423 list_del_init(&dirty->list);
425 num_bytes = btrfs_root_used(&dirty->root->root_item);
426 root = dirty->latest_root;
429 trans = btrfs_start_transaction(tree_root, 1);
430 ret = btrfs_drop_snapshot(trans, dirty->root);
431 if (ret != -EAGAIN) {
435 err = btrfs_update_root(trans,
437 &dirty->root->root_key,
438 &dirty->root->root_item);
441 nr = trans->blocks_used;
442 ret = btrfs_end_transaction(trans, tree_root);
444 mutex_unlock(&tree_root->fs_info->fs_mutex);
445 btrfs_btree_balance_dirty(tree_root, nr);
448 mutex_lock(&tree_root->fs_info->fs_mutex);
452 num_bytes -= btrfs_root_used(&dirty->root->root_item);
453 bytes_used = btrfs_root_used(&root->root_item);
455 record_root_in_trans(root);
456 btrfs_set_root_used(&root->root_item,
457 bytes_used - num_bytes);
459 ret = btrfs_del_root(trans, tree_root, &dirty->root->root_key);
464 nr = trans->blocks_used;
465 ret = btrfs_end_transaction(trans, tree_root);
468 free_extent_buffer(dirty->root->node);
471 mutex_unlock(&tree_root->fs_info->fs_mutex);
473 btrfs_btree_balance_dirty(tree_root, nr);
479 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
480 struct btrfs_root *root)
482 unsigned long joined = 0;
483 unsigned long timeout = 1;
484 struct btrfs_transaction *cur_trans;
485 struct btrfs_transaction *prev_trans = NULL;
486 struct list_head dirty_fs_roots;
487 struct extent_map_tree pinned_copy;
491 extent_map_tree_init(&pinned_copy,
492 root->fs_info->btree_inode->i_mapping, GFP_NOFS);
493 INIT_LIST_HEAD(&dirty_fs_roots);
495 mutex_lock(&root->fs_info->trans_mutex);
496 if (trans->transaction->in_commit) {
497 cur_trans = trans->transaction;
498 trans->transaction->use_count++;
499 mutex_unlock(&root->fs_info->trans_mutex);
500 btrfs_end_transaction(trans, root);
502 mutex_unlock(&root->fs_info->fs_mutex);
503 ret = wait_for_commit(root, cur_trans);
506 mutex_lock(&root->fs_info->trans_mutex);
507 put_transaction(cur_trans);
508 mutex_unlock(&root->fs_info->trans_mutex);
510 mutex_lock(&root->fs_info->fs_mutex);
513 trans->transaction->in_commit = 1;
514 cur_trans = trans->transaction;
515 if (cur_trans->list.prev != &root->fs_info->trans_list) {
516 prev_trans = list_entry(cur_trans->list.prev,
517 struct btrfs_transaction, list);
518 if (!prev_trans->commit_done) {
519 prev_trans->use_count++;
520 mutex_unlock(&root->fs_info->fs_mutex);
521 mutex_unlock(&root->fs_info->trans_mutex);
523 wait_for_commit(root, prev_trans);
525 mutex_lock(&root->fs_info->fs_mutex);
526 mutex_lock(&root->fs_info->trans_mutex);
527 put_transaction(prev_trans);
532 joined = cur_trans->num_joined;
533 WARN_ON(cur_trans != trans->transaction);
534 prepare_to_wait(&cur_trans->writer_wait, &wait,
535 TASK_UNINTERRUPTIBLE);
537 if (cur_trans->num_writers > 1)
538 timeout = MAX_SCHEDULE_TIMEOUT;
542 mutex_unlock(&root->fs_info->fs_mutex);
543 mutex_unlock(&root->fs_info->trans_mutex);
545 schedule_timeout(timeout);
547 mutex_lock(&root->fs_info->fs_mutex);
548 mutex_lock(&root->fs_info->trans_mutex);
549 finish_wait(&cur_trans->writer_wait, &wait);
550 } while (cur_trans->num_writers > 1 ||
551 (cur_trans->num_joined != joined));
553 WARN_ON(cur_trans != trans->transaction);
554 ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
558 ret = btrfs_commit_tree_roots(trans, root);
561 cur_trans = root->fs_info->running_transaction;
562 root->fs_info->running_transaction = NULL;
563 btrfs_set_super_generation(&root->fs_info->super_copy,
565 btrfs_set_super_root(&root->fs_info->super_copy,
566 root->fs_info->tree_root->node->start);
567 btrfs_set_super_root_level(&root->fs_info->super_copy,
568 btrfs_header_level(root->fs_info->tree_root->node));
570 write_extent_buffer(root->fs_info->sb_buffer,
571 &root->fs_info->super_copy, 0,
572 sizeof(root->fs_info->super_copy));
574 btrfs_copy_pinned(root, &pinned_copy);
576 mutex_unlock(&root->fs_info->trans_mutex);
577 mutex_unlock(&root->fs_info->fs_mutex);
578 ret = btrfs_write_and_wait_transaction(trans, root);
580 write_ctree_super(trans, root);
581 mutex_lock(&root->fs_info->fs_mutex);
582 btrfs_finish_extent_commit(trans, root, &pinned_copy);
583 mutex_lock(&root->fs_info->trans_mutex);
584 cur_trans->commit_done = 1;
585 root->fs_info->last_trans_committed = cur_trans->transid;
586 wake_up(&cur_trans->commit_wait);
587 put_transaction(cur_trans);
588 put_transaction(cur_trans);
590 if (root->fs_info->closing)
591 list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
593 list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
595 mutex_unlock(&root->fs_info->trans_mutex);
596 kmem_cache_free(btrfs_trans_handle_cachep, trans);
598 if (root->fs_info->closing) {
599 mutex_unlock(&root->fs_info->fs_mutex);
600 drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
601 mutex_lock(&root->fs_info->fs_mutex);
606 int btrfs_clean_old_snapshots(struct btrfs_root *root)
608 struct list_head dirty_roots;
609 INIT_LIST_HEAD(&dirty_roots);
611 mutex_lock(&root->fs_info->trans_mutex);
612 list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
613 mutex_unlock(&root->fs_info->trans_mutex);
615 if (!list_empty(&dirty_roots)) {
616 drop_dirty_roots(root, &dirty_roots);
620 void btrfs_transaction_cleaner(struct work_struct *work)
622 struct btrfs_fs_info *fs_info = container_of(work,
623 struct btrfs_fs_info,
626 struct btrfs_root *root = fs_info->tree_root;
627 struct btrfs_transaction *cur;
628 struct btrfs_trans_handle *trans;
630 unsigned long delay = HZ * 30;
633 mutex_lock(&root->fs_info->fs_mutex);
634 mutex_lock(&root->fs_info->trans_mutex);
635 cur = root->fs_info->running_transaction;
637 mutex_unlock(&root->fs_info->trans_mutex);
641 if (now < cur->start_time || now - cur->start_time < 30) {
642 mutex_unlock(&root->fs_info->trans_mutex);
646 mutex_unlock(&root->fs_info->trans_mutex);
647 btrfs_defrag_dirty_roots(root->fs_info);
648 trans = btrfs_start_transaction(root, 1);
649 ret = btrfs_commit_transaction(trans, root);
651 mutex_unlock(&root->fs_info->fs_mutex);
652 btrfs_clean_old_snapshots(root);
653 btrfs_transaction_queue_work(root, delay);
656 void btrfs_transaction_queue_work(struct btrfs_root *root, int delay)
658 queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
661 void btrfs_transaction_flush_work(struct btrfs_root *root)
663 cancel_rearming_delayed_workqueue(trans_wq, &root->fs_info->trans_work);
664 flush_workqueue(trans_wq);
667 void __init btrfs_init_transaction_sys(void)
669 trans_wq = create_workqueue("btrfs");
672 void __exit btrfs_exit_transaction_sys(void)
674 destroy_workqueue(trans_wq);