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_blocknr(&extent_root->root_item);
209 if (old_extent_block ==
210 extent_buffer_blocknr(extent_root->node))
212 btrfs_set_root_blocknr(&extent_root->root_item,
213 extent_buffer_blocknr(extent_root->node));
214 ret = btrfs_update_root(trans, tree_root,
215 &extent_root->root_key,
216 &extent_root->root_item);
218 btrfs_write_dirty_block_groups(trans, extent_root);
223 static int wait_for_commit(struct btrfs_root *root,
224 struct btrfs_transaction *commit)
227 mutex_lock(&root->fs_info->trans_mutex);
228 while(!commit->commit_done) {
229 prepare_to_wait(&commit->commit_wait, &wait,
230 TASK_UNINTERRUPTIBLE);
231 if (commit->commit_done)
233 mutex_unlock(&root->fs_info->trans_mutex);
235 mutex_lock(&root->fs_info->trans_mutex);
237 mutex_unlock(&root->fs_info->trans_mutex);
238 finish_wait(&commit->commit_wait, &wait);
243 struct list_head list;
244 struct btrfs_root *root;
245 struct btrfs_root *latest_root;
248 int btrfs_add_dead_root(struct btrfs_root *root,
249 struct btrfs_root *latest,
250 struct list_head *dead_list)
252 struct dirty_root *dirty;
254 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
258 dirty->latest_root = latest;
259 list_add(&dirty->list, dead_list);
263 static int add_dirty_roots(struct btrfs_trans_handle *trans,
264 struct radix_tree_root *radix,
265 struct list_head *list)
267 struct dirty_root *dirty;
268 struct btrfs_root *gang[8];
269 struct btrfs_root *root;
276 ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
278 BTRFS_ROOT_TRANS_TAG);
281 for (i = 0; i < ret; i++) {
283 radix_tree_tag_clear(radix,
284 (unsigned long)root->root_key.objectid,
285 BTRFS_ROOT_TRANS_TAG);
286 if (root->commit_root == root->node) {
287 WARN_ON(extent_buffer_blocknr(root->node) !=
288 btrfs_root_blocknr(&root->root_item));
289 free_extent_buffer(root->commit_root);
290 root->commit_root = NULL;
292 /* make sure to update the root on disk
293 * so we get any updates to the block used
296 err = btrfs_update_root(trans,
297 root->fs_info->tree_root,
302 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
304 dirty->root = kmalloc(sizeof(*dirty->root), GFP_NOFS);
305 BUG_ON(!dirty->root);
307 memset(&root->root_item.drop_progress, 0,
308 sizeof(struct btrfs_disk_key));
309 root->root_item.drop_level = 0;
311 memcpy(dirty->root, root, sizeof(*root));
312 dirty->root->node = root->commit_root;
313 dirty->latest_root = root;
314 root->commit_root = NULL;
316 root->root_key.offset = root->fs_info->generation;
317 btrfs_set_root_blocknr(&root->root_item,
318 extent_buffer_blocknr(root->node));
319 err = btrfs_insert_root(trans, root->fs_info->tree_root,
325 refs = btrfs_root_refs(&dirty->root->root_item);
326 btrfs_set_root_refs(&dirty->root->root_item, refs - 1);
327 err = btrfs_update_root(trans, root->fs_info->tree_root,
328 &dirty->root->root_key,
329 &dirty->root->root_item);
333 list_add(&dirty->list, list);
344 int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
346 struct btrfs_fs_info *info = root->fs_info;
348 struct btrfs_trans_handle *trans;
351 if (root->defrag_running)
354 trans = btrfs_start_transaction(root, 1);
356 root->defrag_running = 1;
357 ret = btrfs_defrag_leaves(trans, root, cacheonly);
358 nr = trans->blocks_used;
359 btrfs_end_transaction(trans, root);
360 mutex_unlock(&info->fs_mutex);
362 btrfs_btree_balance_dirty(info->tree_root, nr);
365 mutex_lock(&info->fs_mutex);
366 trans = btrfs_start_transaction(root, 1);
370 root->defrag_running = 0;
371 radix_tree_tag_clear(&info->fs_roots_radix,
372 (unsigned long)root->root_key.objectid,
373 BTRFS_ROOT_DEFRAG_TAG);
374 btrfs_end_transaction(trans, root);
378 int btrfs_defrag_dirty_roots(struct btrfs_fs_info *info)
380 struct btrfs_root *gang[1];
381 struct btrfs_root *root;
388 ret = radix_tree_gang_lookup_tag(&info->fs_roots_radix,
391 BTRFS_ROOT_DEFRAG_TAG);
394 for (i = 0; i < ret; i++) {
396 last = root->root_key.objectid + 1;
397 btrfs_defrag_root(root, 1);
400 // btrfs_defrag_root(info->extent_root, 1);
404 static int drop_dirty_roots(struct btrfs_root *tree_root,
405 struct list_head *list)
407 struct dirty_root *dirty;
408 struct btrfs_trans_handle *trans;
415 while(!list_empty(list)) {
416 struct btrfs_root *root;
418 mutex_lock(&tree_root->fs_info->fs_mutex);
419 dirty = list_entry(list->next, struct dirty_root, list);
420 list_del_init(&dirty->list);
422 num_blocks = btrfs_root_used(&dirty->root->root_item);
423 root = dirty->latest_root;
426 trans = btrfs_start_transaction(tree_root, 1);
427 ret = btrfs_drop_snapshot(trans, dirty->root);
428 if (ret != -EAGAIN) {
432 err = btrfs_update_root(trans,
434 &dirty->root->root_key,
435 &dirty->root->root_item);
438 nr = trans->blocks_used;
439 ret = btrfs_end_transaction(trans, tree_root);
441 mutex_unlock(&tree_root->fs_info->fs_mutex);
442 btrfs_btree_balance_dirty(tree_root, nr);
445 mutex_lock(&tree_root->fs_info->fs_mutex);
449 num_blocks -= btrfs_root_used(&dirty->root->root_item);
450 blocks_used = btrfs_root_used(&root->root_item);
452 record_root_in_trans(root);
453 btrfs_set_root_used(&root->root_item,
454 blocks_used - num_blocks);
456 ret = btrfs_del_root(trans, tree_root, &dirty->root->root_key);
461 nr = trans->blocks_used;
462 ret = btrfs_end_transaction(trans, tree_root);
465 free_extent_buffer(dirty->root->node);
468 mutex_unlock(&tree_root->fs_info->fs_mutex);
470 btrfs_btree_balance_dirty(tree_root, nr);
476 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
477 struct btrfs_root *root)
479 unsigned long joined = 0;
480 unsigned long timeout = 1;
481 struct btrfs_transaction *cur_trans;
482 struct btrfs_transaction *prev_trans = NULL;
483 struct list_head dirty_fs_roots;
484 struct extent_map_tree pinned_copy;
488 extent_map_tree_init(&pinned_copy,
489 root->fs_info->btree_inode->i_mapping, GFP_NOFS);
490 INIT_LIST_HEAD(&dirty_fs_roots);
492 mutex_lock(&root->fs_info->trans_mutex);
493 if (trans->transaction->in_commit) {
494 cur_trans = trans->transaction;
495 trans->transaction->use_count++;
496 mutex_unlock(&root->fs_info->trans_mutex);
497 btrfs_end_transaction(trans, root);
499 mutex_unlock(&root->fs_info->fs_mutex);
500 ret = wait_for_commit(root, cur_trans);
503 mutex_lock(&root->fs_info->trans_mutex);
504 put_transaction(cur_trans);
505 mutex_unlock(&root->fs_info->trans_mutex);
507 mutex_lock(&root->fs_info->fs_mutex);
510 trans->transaction->in_commit = 1;
511 cur_trans = trans->transaction;
512 if (cur_trans->list.prev != &root->fs_info->trans_list) {
513 prev_trans = list_entry(cur_trans->list.prev,
514 struct btrfs_transaction, list);
515 if (!prev_trans->commit_done) {
516 prev_trans->use_count++;
517 mutex_unlock(&root->fs_info->fs_mutex);
518 mutex_unlock(&root->fs_info->trans_mutex);
520 wait_for_commit(root, prev_trans);
522 mutex_lock(&root->fs_info->fs_mutex);
523 mutex_lock(&root->fs_info->trans_mutex);
524 put_transaction(prev_trans);
529 joined = cur_trans->num_joined;
530 WARN_ON(cur_trans != trans->transaction);
531 prepare_to_wait(&cur_trans->writer_wait, &wait,
532 TASK_UNINTERRUPTIBLE);
534 if (cur_trans->num_writers > 1)
535 timeout = MAX_SCHEDULE_TIMEOUT;
539 mutex_unlock(&root->fs_info->fs_mutex);
540 mutex_unlock(&root->fs_info->trans_mutex);
542 schedule_timeout(timeout);
544 mutex_lock(&root->fs_info->fs_mutex);
545 mutex_lock(&root->fs_info->trans_mutex);
546 finish_wait(&cur_trans->writer_wait, &wait);
547 } while (cur_trans->num_writers > 1 ||
548 (cur_trans->num_joined != joined));
550 WARN_ON(cur_trans != trans->transaction);
551 ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
555 ret = btrfs_commit_tree_roots(trans, root);
558 cur_trans = root->fs_info->running_transaction;
559 root->fs_info->running_transaction = NULL;
560 btrfs_set_super_generation(&root->fs_info->super_copy,
562 btrfs_set_super_root(&root->fs_info->super_copy,
563 extent_buffer_blocknr(root->fs_info->tree_root->node));
565 write_extent_buffer(root->fs_info->sb_buffer,
566 &root->fs_info->super_copy, 0,
567 sizeof(root->fs_info->super_copy));
569 btrfs_copy_pinned(root, &pinned_copy);
571 mutex_unlock(&root->fs_info->trans_mutex);
572 mutex_unlock(&root->fs_info->fs_mutex);
573 ret = btrfs_write_and_wait_transaction(trans, root);
575 write_ctree_super(trans, root);
576 mutex_lock(&root->fs_info->fs_mutex);
577 btrfs_finish_extent_commit(trans, root, &pinned_copy);
578 mutex_lock(&root->fs_info->trans_mutex);
579 cur_trans->commit_done = 1;
580 root->fs_info->last_trans_committed = cur_trans->transid;
581 wake_up(&cur_trans->commit_wait);
582 put_transaction(cur_trans);
583 put_transaction(cur_trans);
585 if (root->fs_info->closing)
586 list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
588 list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
590 mutex_unlock(&root->fs_info->trans_mutex);
591 kmem_cache_free(btrfs_trans_handle_cachep, trans);
593 if (root->fs_info->closing) {
594 mutex_unlock(&root->fs_info->fs_mutex);
595 drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
596 mutex_lock(&root->fs_info->fs_mutex);
601 int btrfs_clean_old_snapshots(struct btrfs_root *root)
603 struct list_head dirty_roots;
604 INIT_LIST_HEAD(&dirty_roots);
606 mutex_lock(&root->fs_info->trans_mutex);
607 list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
608 mutex_unlock(&root->fs_info->trans_mutex);
610 if (!list_empty(&dirty_roots)) {
611 drop_dirty_roots(root, &dirty_roots);
615 void btrfs_transaction_cleaner(struct work_struct *work)
617 struct btrfs_fs_info *fs_info = container_of(work,
618 struct btrfs_fs_info,
621 struct btrfs_root *root = fs_info->tree_root;
622 struct btrfs_transaction *cur;
623 struct btrfs_trans_handle *trans;
625 unsigned long delay = HZ * 30;
628 mutex_lock(&root->fs_info->fs_mutex);
629 mutex_lock(&root->fs_info->trans_mutex);
630 cur = root->fs_info->running_transaction;
632 mutex_unlock(&root->fs_info->trans_mutex);
636 if (now < cur->start_time || now - cur->start_time < 30) {
637 mutex_unlock(&root->fs_info->trans_mutex);
641 mutex_unlock(&root->fs_info->trans_mutex);
642 btrfs_defrag_dirty_roots(root->fs_info);
643 trans = btrfs_start_transaction(root, 1);
644 ret = btrfs_commit_transaction(trans, root);
646 mutex_unlock(&root->fs_info->fs_mutex);
647 btrfs_clean_old_snapshots(root);
648 btrfs_transaction_queue_work(root, delay);
651 void btrfs_transaction_queue_work(struct btrfs_root *root, int delay)
653 queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
656 void btrfs_transaction_flush_work(struct btrfs_root *root)
658 cancel_rearming_delayed_workqueue(trans_wq, &root->fs_info->trans_work);
659 flush_workqueue(trans_wq);
662 void __init btrfs_init_transaction_sys(void)
664 trans_wq = create_workqueue("btrfs");
667 void __exit btrfs_exit_transaction_sys(void)
669 destroy_workqueue(trans_wq);