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.
19 #include <linux/module.h>
21 #include <linux/sched.h>
24 #include "transaction.h"
26 static int total_trans = 0;
27 extern struct kmem_cache *btrfs_trans_handle_cachep;
28 extern struct kmem_cache *btrfs_transaction_cachep;
30 static struct workqueue_struct *trans_wq;
32 #define BTRFS_ROOT_TRANS_TAG 0
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 = 0;
59 cur_trans->transid = root->fs_info->generation;
60 init_waitqueue_head(&cur_trans->writer_wait);
61 init_waitqueue_head(&cur_trans->commit_wait);
62 cur_trans->in_commit = 0;
63 cur_trans->use_count = 1;
64 cur_trans->commit_done = 0;
65 cur_trans->start_time = get_seconds();
66 list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
67 init_bit_radix(&cur_trans->dirty_pages);
69 cur_trans->num_writers++;
73 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
76 struct btrfs_trans_handle *h =
77 kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
81 mutex_lock(&root->fs_info->trans_mutex);
82 ret = join_transaction(root);
84 running_trans_id = root->fs_info->running_transaction->transid;
86 if (root != root->fs_info->tree_root && root->last_trans <
88 if (root->root_item.refs != 0) {
89 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
90 (unsigned long)root->root_key.objectid,
91 BTRFS_ROOT_TRANS_TAG);
92 root->commit_root = root->node;
98 root->last_trans = running_trans_id;
99 h->transid = running_trans_id;
100 h->transaction = root->fs_info->running_transaction;
101 h->blocks_reserved = num_blocks;
103 h->block_group = NULL;
104 root->fs_info->running_transaction->use_count++;
105 mutex_unlock(&root->fs_info->trans_mutex);
109 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
110 struct btrfs_root *root)
112 struct btrfs_transaction *cur_trans;
114 mutex_lock(&root->fs_info->trans_mutex);
115 cur_trans = root->fs_info->running_transaction;
116 WARN_ON(cur_trans->num_writers < 1);
117 if (waitqueue_active(&cur_trans->writer_wait))
118 wake_up(&cur_trans->writer_wait);
119 cur_trans->num_writers--;
120 put_transaction(cur_trans);
121 mutex_unlock(&root->fs_info->trans_mutex);
122 memset(trans, 0, sizeof(*trans));
123 kmem_cache_free(btrfs_trans_handle_cachep, trans);
128 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
129 struct btrfs_root *root)
131 unsigned long gang[16];
137 struct radix_tree_root *dirty_pages;
138 struct inode *btree_inode = root->fs_info->btree_inode;
140 if (!trans || !trans->transaction) {
141 return filemap_write_and_wait(btree_inode->i_mapping);
143 dirty_pages = &trans->transaction->dirty_pages;
145 ret = find_first_radix_bit(dirty_pages, gang,
146 0, ARRAY_SIZE(gang));
149 for (i = 0; i < ret; i++) {
151 clear_radix_bit(dirty_pages, gang[i]);
152 page = find_lock_page(btree_inode->i_mapping,
156 err = write_one_page(page, 0);
159 page_cache_release(page);
162 err = filemap_fdatawait(btree_inode->i_mapping);
168 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
169 struct btrfs_root *root)
172 u64 old_extent_block;
173 struct btrfs_fs_info *fs_info = root->fs_info;
174 struct btrfs_root *tree_root = fs_info->tree_root;
175 struct btrfs_root *extent_root = fs_info->extent_root;
177 btrfs_write_dirty_block_groups(trans, extent_root);
179 old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
180 if (old_extent_block == bh_blocknr(extent_root->node))
182 btrfs_set_root_blocknr(&extent_root->root_item,
183 bh_blocknr(extent_root->node));
184 ret = btrfs_update_root(trans, tree_root,
185 &extent_root->root_key,
186 &extent_root->root_item);
188 btrfs_write_dirty_block_groups(trans, extent_root);
193 static int wait_for_commit(struct btrfs_root *root,
194 struct btrfs_transaction *commit)
197 while(!commit->commit_done) {
198 prepare_to_wait(&commit->commit_wait, &wait,
199 TASK_UNINTERRUPTIBLE);
200 if (commit->commit_done)
202 mutex_unlock(&root->fs_info->trans_mutex);
204 mutex_lock(&root->fs_info->trans_mutex);
206 finish_wait(&commit->commit_wait, &wait);
211 struct list_head list;
212 struct btrfs_key snap_key;
213 struct buffer_head *commit_root;
214 struct btrfs_root *root;
218 int btrfs_add_dead_root(struct btrfs_root *root, struct list_head *dead_list)
220 struct dirty_root *dirty;
222 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
225 memcpy(&dirty->snap_key, &root->root_key, sizeof(root->root_key));
226 dirty->commit_root = root->node;
228 dirty->free_on_drop = 1;
229 list_add(&dirty->list, dead_list);
233 static int add_dirty_roots(struct btrfs_trans_handle *trans,
234 struct radix_tree_root *radix,
235 struct list_head *list)
237 struct dirty_root *dirty;
238 struct btrfs_root *gang[8];
239 struct btrfs_root *root;
240 struct btrfs_root_item tmp_item;
247 ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
249 BTRFS_ROOT_TRANS_TAG);
252 for (i = 0; i < ret; i++) {
254 radix_tree_tag_clear(radix,
255 (unsigned long)root->root_key.objectid,
256 BTRFS_ROOT_TRANS_TAG);
257 if (root->commit_root == root->node) {
258 WARN_ON(bh_blocknr(root->node) !=
259 btrfs_root_blocknr(&root->root_item));
260 brelse(root->commit_root);
261 root->commit_root = NULL;
264 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
266 memcpy(&dirty->snap_key, &root->root_key,
267 sizeof(root->root_key));
268 dirty->commit_root = root->commit_root;
269 root->commit_root = NULL;
271 dirty->free_on_drop = 0;
272 memcpy(&tmp_item, &root->root_item, sizeof(tmp_item));
274 root->root_key.offset = root->fs_info->generation;
275 btrfs_set_root_blocknr(&root->root_item,
276 bh_blocknr(root->node));
277 err = btrfs_insert_root(trans, root->fs_info->tree_root,
283 refs = btrfs_root_refs(&tmp_item);
284 btrfs_set_root_refs(&tmp_item, refs - 1);
285 err = btrfs_update_root(trans, root->fs_info->tree_root,
291 list_add(&dirty->list, list);
299 static int drop_dirty_roots(struct btrfs_root *tree_root,
300 struct list_head *list)
302 struct dirty_root *dirty;
303 struct btrfs_trans_handle *trans;
305 while(!list_empty(list)) {
306 mutex_lock(&tree_root->fs_info->fs_mutex);
307 dirty = list_entry(list->next, struct dirty_root, list);
308 list_del_init(&dirty->list);
310 trans = btrfs_start_transaction(tree_root, 1);
311 printk("deleting root %Lu %u %Lu\n", dirty->snap_key.objectid, dirty->snap_key.flags, dirty->snap_key.offset);
312 ret = btrfs_drop_snapshot(trans, dirty->root,
315 ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
318 ret = btrfs_end_transaction(trans, tree_root);
321 if (dirty->free_on_drop)
324 mutex_unlock(&tree_root->fs_info->fs_mutex);
325 btrfs_btree_balance_dirty(tree_root);
330 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
331 struct btrfs_root *root)
334 struct btrfs_transaction *cur_trans;
335 struct btrfs_transaction *prev_trans = NULL;
336 struct list_head dirty_fs_roots;
339 INIT_LIST_HEAD(&dirty_fs_roots);
341 mutex_lock(&root->fs_info->trans_mutex);
342 if (trans->transaction->in_commit) {
343 cur_trans = trans->transaction;
344 trans->transaction->use_count++;
345 btrfs_end_transaction(trans, root);
346 ret = wait_for_commit(root, cur_trans);
348 put_transaction(cur_trans);
349 mutex_unlock(&root->fs_info->trans_mutex);
352 cur_trans = trans->transaction;
353 trans->transaction->in_commit = 1;
354 while (trans->transaction->num_writers > 1) {
355 WARN_ON(cur_trans != trans->transaction);
356 prepare_to_wait(&trans->transaction->writer_wait, &wait,
357 TASK_UNINTERRUPTIBLE);
358 if (trans->transaction->num_writers <= 1)
360 mutex_unlock(&root->fs_info->trans_mutex);
362 mutex_lock(&root->fs_info->trans_mutex);
363 finish_wait(&trans->transaction->writer_wait, &wait);
365 finish_wait(&trans->transaction->writer_wait, &wait);
366 WARN_ON(cur_trans != trans->transaction);
367 ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
371 ret = btrfs_commit_tree_roots(trans, root);
374 cur_trans = root->fs_info->running_transaction;
375 root->fs_info->running_transaction = NULL;
376 if (cur_trans->list.prev != &root->fs_info->trans_list) {
377 prev_trans = list_entry(cur_trans->list.prev,
378 struct btrfs_transaction, list);
379 if (prev_trans->commit_done)
382 prev_trans->use_count++;
384 mutex_unlock(&root->fs_info->trans_mutex);
385 mutex_unlock(&root->fs_info->fs_mutex);
386 ret = btrfs_write_and_wait_transaction(trans, root);
388 mutex_lock(&root->fs_info->trans_mutex);
389 wait_for_commit(root, prev_trans);
390 put_transaction(prev_trans);
391 mutex_unlock(&root->fs_info->trans_mutex);
393 btrfs_set_super_generation(root->fs_info->disk_super,
396 write_ctree_super(trans, root);
398 mutex_lock(&root->fs_info->fs_mutex);
399 btrfs_finish_extent_commit(trans, root);
400 mutex_lock(&root->fs_info->trans_mutex);
401 cur_trans->commit_done = 1;
402 wake_up(&cur_trans->commit_wait);
403 put_transaction(cur_trans);
404 put_transaction(cur_trans);
405 if (root->fs_info->closing)
406 list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
408 list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
409 mutex_unlock(&root->fs_info->trans_mutex);
410 kmem_cache_free(btrfs_trans_handle_cachep, trans);
412 if (root->fs_info->closing) {
413 mutex_unlock(&root->fs_info->fs_mutex);
414 drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
415 mutex_lock(&root->fs_info->fs_mutex);
420 void btrfs_transaction_cleaner(struct work_struct *work)
422 struct btrfs_fs_info *fs_info = container_of(work,
423 struct btrfs_fs_info,
426 struct btrfs_root *root = fs_info->tree_root;
427 struct btrfs_transaction *cur;
428 struct btrfs_trans_handle *trans;
429 struct list_head dirty_roots;
431 unsigned long delay = HZ * 30;
434 INIT_LIST_HEAD(&dirty_roots);
435 mutex_lock(&root->fs_info->fs_mutex);
436 mutex_lock(&root->fs_info->trans_mutex);
437 cur = root->fs_info->running_transaction;
439 mutex_unlock(&root->fs_info->trans_mutex);
443 if (now < cur->start_time || now - cur->start_time < 30) {
444 mutex_unlock(&root->fs_info->trans_mutex);
448 mutex_unlock(&root->fs_info->trans_mutex);
449 trans = btrfs_start_transaction(root, 1);
450 ret = btrfs_commit_transaction(trans, root);
452 mutex_unlock(&root->fs_info->fs_mutex);
454 mutex_lock(&root->fs_info->trans_mutex);
455 list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
456 mutex_unlock(&root->fs_info->trans_mutex);
458 if (!list_empty(&dirty_roots)) {
459 drop_dirty_roots(root, &dirty_roots);
461 btrfs_transaction_queue_work(root, delay);
464 void btrfs_transaction_queue_work(struct btrfs_root *root, int delay)
466 queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
469 void btrfs_transaction_flush_work(struct btrfs_root *root)
471 cancel_rearming_delayed_workqueue(trans_wq, &root->fs_info->trans_work);
472 flush_workqueue(trans_wq);
475 void __init btrfs_init_transaction_sys(void)
477 trans_wq = create_workqueue("btrfs");
480 void __exit btrfs_exit_transaction_sys(void)
482 destroy_workqueue(trans_wq);