1 #include <linux/module.h>
5 #include "transaction.h"
7 static int total_trans = 0;
8 extern struct kmem_cache *btrfs_trans_handle_cachep;
9 extern struct kmem_cache *btrfs_transaction_cachep;
11 static struct workqueue_struct *trans_wq;
13 #define BTRFS_ROOT_TRANS_TAG 0
15 static void put_transaction(struct btrfs_transaction *transaction)
17 WARN_ON(transaction->use_count == 0);
18 transaction->use_count--;
19 if (transaction->use_count == 0) {
20 WARN_ON(total_trans == 0);
22 list_del_init(&transaction->list);
23 memset(transaction, 0, sizeof(*transaction));
24 kmem_cache_free(btrfs_transaction_cachep, transaction);
28 static int join_transaction(struct btrfs_root *root)
30 struct btrfs_transaction *cur_trans;
31 cur_trans = root->fs_info->running_transaction;
33 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
37 root->fs_info->generation++;
38 root->fs_info->running_transaction = cur_trans;
39 cur_trans->num_writers = 0;
40 cur_trans->transid = root->fs_info->generation;
41 init_waitqueue_head(&cur_trans->writer_wait);
42 init_waitqueue_head(&cur_trans->commit_wait);
43 cur_trans->in_commit = 0;
44 cur_trans->use_count = 1;
45 cur_trans->commit_done = 0;
46 cur_trans->start_time = get_seconds();
47 list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
48 init_bit_radix(&cur_trans->dirty_pages);
50 cur_trans->num_writers++;
54 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
57 struct btrfs_trans_handle *h =
58 kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
62 mutex_lock(&root->fs_info->trans_mutex);
63 ret = join_transaction(root);
65 running_trans_id = root->fs_info->running_transaction->transid;
67 if (root != root->fs_info->tree_root && root->last_trans <
69 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
70 (unsigned long)root->root_key.objectid,
71 BTRFS_ROOT_TRANS_TAG);
72 root->commit_root = root->node;
75 root->last_trans = running_trans_id;
76 h->transid = running_trans_id;
77 h->transaction = root->fs_info->running_transaction;
78 h->blocks_reserved = num_blocks;
80 h->block_group = NULL;
81 root->fs_info->running_transaction->use_count++;
82 mutex_unlock(&root->fs_info->trans_mutex);
86 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
87 struct btrfs_root *root)
89 struct btrfs_transaction *cur_trans;
91 mutex_lock(&root->fs_info->trans_mutex);
92 cur_trans = root->fs_info->running_transaction;
93 WARN_ON(cur_trans->num_writers < 1);
94 if (waitqueue_active(&cur_trans->writer_wait))
95 wake_up(&cur_trans->writer_wait);
96 cur_trans->num_writers--;
97 put_transaction(cur_trans);
98 mutex_unlock(&root->fs_info->trans_mutex);
99 memset(trans, 0, sizeof(*trans));
100 kmem_cache_free(btrfs_trans_handle_cachep, trans);
105 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
106 struct btrfs_root *root)
108 unsigned long gang[16];
114 struct radix_tree_root *dirty_pages;
115 struct inode *btree_inode = root->fs_info->btree_inode;
117 if (!trans || !trans->transaction) {
118 return filemap_write_and_wait(btree_inode->i_mapping);
120 dirty_pages = &trans->transaction->dirty_pages;
122 ret = find_first_radix_bit(dirty_pages, gang,
123 0, ARRAY_SIZE(gang));
126 for (i = 0; i < ret; i++) {
128 clear_radix_bit(dirty_pages, gang[i]);
129 page = find_lock_page(btree_inode->i_mapping,
133 err = write_one_page(page, 0);
136 page_cache_release(page);
139 err = filemap_fdatawait(btree_inode->i_mapping);
145 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
146 struct btrfs_root *root)
149 u64 old_extent_block;
150 struct btrfs_fs_info *fs_info = root->fs_info;
151 struct btrfs_root *tree_root = fs_info->tree_root;
152 struct btrfs_root *extent_root = fs_info->extent_root;
154 btrfs_write_dirty_block_groups(trans, extent_root);
156 old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
157 if (old_extent_block == bh_blocknr(extent_root->node))
159 btrfs_set_root_blocknr(&extent_root->root_item,
160 bh_blocknr(extent_root->node));
161 ret = btrfs_update_root(trans, tree_root,
162 &extent_root->root_key,
163 &extent_root->root_item);
165 btrfs_write_dirty_block_groups(trans, extent_root);
170 static int wait_for_commit(struct btrfs_root *root,
171 struct btrfs_transaction *commit)
174 while(!commit->commit_done) {
175 prepare_to_wait(&commit->commit_wait, &wait,
176 TASK_UNINTERRUPTIBLE);
177 if (commit->commit_done)
179 mutex_unlock(&root->fs_info->trans_mutex);
181 mutex_lock(&root->fs_info->trans_mutex);
183 finish_wait(&commit->commit_wait, &wait);
188 struct list_head list;
189 struct btrfs_key snap_key;
190 struct buffer_head *commit_root;
191 struct btrfs_root *root;
194 static int add_dirty_roots(struct btrfs_trans_handle *trans,
195 struct radix_tree_root *radix,
196 struct list_head *list)
198 struct dirty_root *dirty;
199 struct btrfs_root *gang[8];
200 struct btrfs_root *root;
205 ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
207 BTRFS_ROOT_TRANS_TAG);
210 for (i = 0; i < ret; i++) {
212 radix_tree_tag_clear(radix,
213 (unsigned long)root->root_key.objectid,
214 BTRFS_ROOT_TRANS_TAG);
215 if (root->commit_root == root->node) {
216 WARN_ON(bh_blocknr(root->node) !=
217 btrfs_root_blocknr(&root->root_item));
218 brelse(root->commit_root);
219 root->commit_root = NULL;
222 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
224 memcpy(&dirty->snap_key, &root->root_key,
225 sizeof(root->root_key));
226 dirty->commit_root = root->commit_root;
227 root->commit_root = NULL;
229 root->root_key.offset = root->fs_info->generation;
230 btrfs_set_root_blocknr(&root->root_item,
231 bh_blocknr(root->node));
232 err = btrfs_insert_root(trans, root->fs_info->tree_root,
236 list_add(&dirty->list, list);
242 static int drop_dirty_roots(struct btrfs_root *tree_root,
243 struct list_head *list)
245 struct dirty_root *dirty;
246 struct btrfs_trans_handle *trans;
248 while(!list_empty(list)) {
249 mutex_lock(&tree_root->fs_info->fs_mutex);
250 dirty = list_entry(list->next, struct dirty_root, list);
251 list_del_init(&dirty->list);
252 trans = btrfs_start_transaction(tree_root, 1);
253 ret = btrfs_drop_snapshot(trans, dirty->root,
257 ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
259 ret = btrfs_end_transaction(trans, tree_root);
262 mutex_unlock(&tree_root->fs_info->fs_mutex);
267 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
268 struct btrfs_root *root)
271 struct btrfs_transaction *cur_trans;
272 struct btrfs_transaction *prev_trans = NULL;
273 struct list_head dirty_fs_roots;
276 INIT_LIST_HEAD(&dirty_fs_roots);
278 mutex_lock(&root->fs_info->trans_mutex);
279 if (trans->transaction->in_commit) {
280 cur_trans = trans->transaction;
281 trans->transaction->use_count++;
282 btrfs_end_transaction(trans, root);
283 ret = wait_for_commit(root, cur_trans);
285 put_transaction(cur_trans);
286 mutex_unlock(&root->fs_info->trans_mutex);
289 cur_trans = trans->transaction;
290 trans->transaction->in_commit = 1;
291 while (trans->transaction->num_writers > 1) {
292 WARN_ON(cur_trans != trans->transaction);
293 prepare_to_wait(&trans->transaction->writer_wait, &wait,
294 TASK_UNINTERRUPTIBLE);
295 if (trans->transaction->num_writers <= 1)
297 mutex_unlock(&root->fs_info->trans_mutex);
299 mutex_lock(&root->fs_info->trans_mutex);
300 finish_wait(&trans->transaction->writer_wait, &wait);
302 finish_wait(&trans->transaction->writer_wait, &wait);
303 WARN_ON(cur_trans != trans->transaction);
304 add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots);
305 ret = btrfs_commit_tree_roots(trans, root);
307 cur_trans = root->fs_info->running_transaction;
308 root->fs_info->running_transaction = NULL;
309 if (cur_trans->list.prev != &root->fs_info->trans_list) {
310 prev_trans = list_entry(cur_trans->list.prev,
311 struct btrfs_transaction, list);
312 if (prev_trans->commit_done)
315 prev_trans->use_count++;
317 mutex_unlock(&root->fs_info->trans_mutex);
318 mutex_unlock(&root->fs_info->fs_mutex);
319 ret = btrfs_write_and_wait_transaction(trans, root);
321 mutex_lock(&root->fs_info->trans_mutex);
322 wait_for_commit(root, prev_trans);
323 put_transaction(prev_trans);
324 mutex_unlock(&root->fs_info->trans_mutex);
326 btrfs_set_super_generation(root->fs_info->disk_super,
329 write_ctree_super(trans, root);
331 mutex_lock(&root->fs_info->fs_mutex);
332 btrfs_finish_extent_commit(trans, root);
333 mutex_lock(&root->fs_info->trans_mutex);
334 cur_trans->commit_done = 1;
335 wake_up(&cur_trans->commit_wait);
336 put_transaction(cur_trans);
337 put_transaction(cur_trans);
338 if (root->fs_info->closing)
339 list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
341 list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
342 mutex_unlock(&root->fs_info->trans_mutex);
343 kmem_cache_free(btrfs_trans_handle_cachep, trans);
345 if (root->fs_info->closing) {
346 mutex_unlock(&root->fs_info->fs_mutex);
347 drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
348 mutex_lock(&root->fs_info->fs_mutex);
353 void btrfs_transaction_cleaner(struct work_struct *work)
355 struct btrfs_fs_info *fs_info = container_of(work,
356 struct btrfs_fs_info,
359 struct btrfs_root *root = fs_info->tree_root;
360 struct btrfs_transaction *cur;
361 struct btrfs_trans_handle *trans;
362 struct list_head dirty_roots;
364 unsigned long delay = HZ * 30;
367 INIT_LIST_HEAD(&dirty_roots);
368 mutex_lock(&root->fs_info->fs_mutex);
369 mutex_lock(&root->fs_info->trans_mutex);
370 cur = root->fs_info->running_transaction;
372 mutex_unlock(&root->fs_info->trans_mutex);
376 if (now < cur->start_time || now - cur->start_time < 30) {
377 mutex_unlock(&root->fs_info->trans_mutex);
381 mutex_unlock(&root->fs_info->trans_mutex);
382 trans = btrfs_start_transaction(root, 1);
383 ret = btrfs_commit_transaction(trans, root);
385 mutex_unlock(&root->fs_info->fs_mutex);
387 mutex_lock(&root->fs_info->trans_mutex);
388 list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
389 mutex_unlock(&root->fs_info->trans_mutex);
391 if (!list_empty(&dirty_roots)) {
392 drop_dirty_roots(root, &dirty_roots);
394 btrfs_transaction_queue_work(root, delay);
397 void btrfs_transaction_queue_work(struct btrfs_root *root, int delay)
399 queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
402 void btrfs_transaction_flush_work(struct btrfs_root *root)
404 cancel_rearming_delayed_workqueue(trans_wq, &root->fs_info->trans_work);
405 flush_workqueue(trans_wq);
408 void __init btrfs_init_transaction_sys(void)
410 trans_wq = create_workqueue("btrfs");
413 void __exit btrfs_exit_transaction_sys(void)
415 destroy_workqueue(trans_wq);