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 #define BTRFS_ROOT_TRANS_TAG 0
13 #define TRANS_MAGIC 0xE1E10E
14 static void put_transaction(struct btrfs_transaction *transaction)
16 WARN_ON(transaction->use_count == 0);
17 transaction->use_count--;
18 WARN_ON(transaction->magic != TRANS_MAGIC);
19 if (transaction->use_count == 0) {
20 WARN_ON(total_trans == 0);
22 memset(transaction, 0, sizeof(*transaction));
23 kmem_cache_free(btrfs_transaction_cachep, transaction);
27 static int join_transaction(struct btrfs_root *root)
29 struct btrfs_transaction *cur_trans;
30 cur_trans = root->fs_info->running_transaction;
32 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
36 root->fs_info->generation++;
37 root->fs_info->running_transaction = cur_trans;
38 cur_trans->num_writers = 0;
39 cur_trans->transid = root->fs_info->generation;
40 init_waitqueue_head(&cur_trans->writer_wait);
41 init_waitqueue_head(&cur_trans->commit_wait);
42 cur_trans->magic = TRANS_MAGIC;
43 cur_trans->in_commit = 0;
44 cur_trans->use_count = 1;
45 cur_trans->commit_done = 0;
47 cur_trans->num_writers++;
51 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
54 struct btrfs_trans_handle *h =
55 kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
59 mutex_lock(&root->fs_info->trans_mutex);
60 ret = join_transaction(root);
62 running_trans_id = root->fs_info->running_transaction->transid;
64 if (root != root->fs_info->tree_root && root->last_trans <
66 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
67 (unsigned long)root->root_key.objectid,
68 BTRFS_ROOT_TRANS_TAG);
69 root->commit_root = root->node;
72 root->last_trans = running_trans_id;
73 h->transid = running_trans_id;
74 h->transaction = root->fs_info->running_transaction;
75 h->blocks_reserved = num_blocks;
77 root->fs_info->running_transaction->use_count++;
78 mutex_unlock(&root->fs_info->trans_mutex);
79 h->magic = h->magic2 = TRANS_MAGIC;
83 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
84 struct btrfs_root *root)
86 struct btrfs_transaction *cur_trans;
88 WARN_ON(trans->magic != TRANS_MAGIC);
89 WARN_ON(trans->magic2 != TRANS_MAGIC);
90 mutex_lock(&root->fs_info->trans_mutex);
91 cur_trans = root->fs_info->running_transaction;
92 WARN_ON(cur_trans->num_writers < 1);
93 if (waitqueue_active(&cur_trans->writer_wait))
94 wake_up(&cur_trans->writer_wait);
95 cur_trans->num_writers--;
96 put_transaction(cur_trans);
97 mutex_unlock(&root->fs_info->trans_mutex);
98 memset(trans, 0, sizeof(*trans));
99 kmem_cache_free(btrfs_trans_handle_cachep, trans);
104 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
105 struct btrfs_root *root)
107 filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
111 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
112 struct btrfs_root *root)
115 u64 old_extent_block;
116 struct btrfs_fs_info *fs_info = root->fs_info;
117 struct btrfs_root *tree_root = fs_info->tree_root;
118 struct btrfs_root *extent_root = fs_info->extent_root;
121 old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
122 if (old_extent_block == extent_root->node->b_blocknr)
124 btrfs_set_root_blocknr(&extent_root->root_item,
125 extent_root->node->b_blocknr);
126 ret = btrfs_update_root(trans, tree_root,
127 &extent_root->root_key,
128 &extent_root->root_item);
134 static int wait_for_commit(struct btrfs_root *root,
135 struct btrfs_transaction *commit)
138 while(!commit->commit_done) {
139 prepare_to_wait(&commit->commit_wait, &wait,
140 TASK_UNINTERRUPTIBLE);
141 if (commit->commit_done)
143 mutex_unlock(&root->fs_info->trans_mutex);
145 mutex_lock(&root->fs_info->trans_mutex);
147 finish_wait(&commit->commit_wait, &wait);
152 struct list_head list;
153 struct btrfs_key snap_key;
154 struct buffer_head *commit_root;
155 struct btrfs_root *root;
158 int add_dirty_roots(struct btrfs_trans_handle *trans,
159 struct radix_tree_root *radix, struct list_head *list)
161 struct dirty_root *dirty;
162 struct btrfs_root *gang[8];
163 struct btrfs_root *root;
168 ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
170 BTRFS_ROOT_TRANS_TAG);
173 for (i = 0; i < ret; i++) {
175 radix_tree_tag_clear(radix,
176 (unsigned long)root->root_key.objectid,
177 BTRFS_ROOT_TRANS_TAG);
178 if (root->commit_root == root->node) {
179 WARN_ON(root->node->b_blocknr !=
180 btrfs_root_blocknr(&root->root_item));
181 brelse(root->commit_root);
182 root->commit_root = NULL;
185 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
187 memcpy(&dirty->snap_key, &root->root_key,
188 sizeof(root->root_key));
189 dirty->commit_root = root->commit_root;
190 root->commit_root = NULL;
192 root->root_key.offset = root->fs_info->generation;
193 btrfs_set_root_blocknr(&root->root_item,
194 root->node->b_blocknr);
195 err = btrfs_insert_root(trans, root->fs_info->tree_root,
199 list_add(&dirty->list, list);
205 int drop_dirty_roots(struct btrfs_root *tree_root, struct list_head *list)
207 struct dirty_root *dirty;
208 struct btrfs_trans_handle *trans;
211 while(!list_empty(list)) {
212 dirty = list_entry(list->next, struct dirty_root, list);
213 list_del_init(&dirty->list);
214 trans = btrfs_start_transaction(tree_root, 1);
215 ret = btrfs_drop_snapshot(trans, dirty->root,
219 ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
221 ret = btrfs_end_transaction(trans, tree_root);
228 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
229 struct btrfs_root *root)
232 struct btrfs_transaction *cur_trans;
233 struct list_head dirty_fs_roots;
236 INIT_LIST_HEAD(&dirty_fs_roots);
238 mutex_lock(&root->fs_info->trans_mutex);
239 if (trans->transaction->in_commit) {
240 cur_trans = trans->transaction;
241 trans->transaction->use_count++;
242 btrfs_end_transaction(trans, root);
243 ret = wait_for_commit(root, cur_trans);
245 put_transaction(cur_trans);
246 mutex_unlock(&root->fs_info->trans_mutex);
249 cur_trans = trans->transaction;
250 trans->transaction->in_commit = 1;
251 while (trans->transaction->num_writers > 1) {
252 WARN_ON(cur_trans != trans->transaction);
253 prepare_to_wait(&trans->transaction->writer_wait, &wait,
254 TASK_UNINTERRUPTIBLE);
255 if (trans->transaction->num_writers <= 1)
257 mutex_unlock(&root->fs_info->trans_mutex);
259 mutex_lock(&root->fs_info->trans_mutex);
260 finish_wait(&trans->transaction->writer_wait, &wait);
262 finish_wait(&trans->transaction->writer_wait, &wait);
263 WARN_ON(cur_trans != trans->transaction);
264 add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots);
265 ret = btrfs_commit_tree_roots(trans, root);
267 cur_trans = root->fs_info->running_transaction;
268 root->fs_info->running_transaction = NULL;
269 btrfs_set_super_generation(root->fs_info->disk_super,
270 root->fs_info->generation + 1);
271 mutex_unlock(&root->fs_info->trans_mutex);
272 ret = btrfs_write_and_wait_transaction(trans, root);
275 write_ctree_super(trans, root);
276 btrfs_finish_extent_commit(trans, root);
277 mutex_lock(&root->fs_info->trans_mutex);
278 cur_trans->commit_done = 1;
279 wake_up(&cur_trans->commit_wait);
280 put_transaction(cur_trans);
281 put_transaction(cur_trans);
282 mutex_unlock(&root->fs_info->trans_mutex);
283 kmem_cache_free(btrfs_trans_handle_cachep, trans);
285 drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);