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 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->magic = TRANS_MAGIC;
44 cur_trans->in_commit = 0;
45 cur_trans->use_count = 1;
46 cur_trans->commit_done = 0;
47 list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
49 cur_trans->num_writers++;
53 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
56 struct btrfs_trans_handle *h =
57 kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
61 mutex_lock(&root->fs_info->trans_mutex);
62 ret = join_transaction(root);
64 running_trans_id = root->fs_info->running_transaction->transid;
66 if (root != root->fs_info->tree_root && root->last_trans <
68 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
69 (unsigned long)root->root_key.objectid,
70 BTRFS_ROOT_TRANS_TAG);
71 root->commit_root = root->node;
74 root->last_trans = running_trans_id;
75 h->transid = running_trans_id;
76 h->transaction = root->fs_info->running_transaction;
77 h->blocks_reserved = num_blocks;
79 root->fs_info->running_transaction->use_count++;
80 mutex_unlock(&root->fs_info->trans_mutex);
81 h->magic = h->magic2 = TRANS_MAGIC;
85 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
86 struct btrfs_root *root)
88 struct btrfs_transaction *cur_trans;
90 WARN_ON(trans->magic != TRANS_MAGIC);
91 WARN_ON(trans->magic2 != TRANS_MAGIC);
92 mutex_lock(&root->fs_info->trans_mutex);
93 cur_trans = root->fs_info->running_transaction;
94 WARN_ON(cur_trans->num_writers < 1);
95 if (waitqueue_active(&cur_trans->writer_wait))
96 wake_up(&cur_trans->writer_wait);
97 cur_trans->num_writers--;
98 put_transaction(cur_trans);
99 mutex_unlock(&root->fs_info->trans_mutex);
100 memset(trans, 0, sizeof(*trans));
101 kmem_cache_free(btrfs_trans_handle_cachep, trans);
106 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
107 struct btrfs_root *root)
109 filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
113 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
114 struct btrfs_root *root)
117 u64 old_extent_block;
118 struct btrfs_fs_info *fs_info = root->fs_info;
119 struct btrfs_root *tree_root = fs_info->tree_root;
120 struct btrfs_root *extent_root = fs_info->extent_root;
121 struct btrfs_root *dev_root = fs_info->dev_root;
123 if (btrfs_super_device_root(fs_info->disk_super) !=
124 bh_blocknr(dev_root->node)) {
125 btrfs_set_super_device_root(fs_info->disk_super,
126 bh_blocknr(dev_root->node));
129 old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
130 if (old_extent_block == bh_blocknr(extent_root->node))
132 btrfs_set_root_blocknr(&extent_root->root_item,
133 bh_blocknr(extent_root->node));
134 ret = btrfs_update_root(trans, tree_root,
135 &extent_root->root_key,
136 &extent_root->root_item);
142 static int wait_for_commit(struct btrfs_root *root,
143 struct btrfs_transaction *commit)
146 while(!commit->commit_done) {
147 prepare_to_wait(&commit->commit_wait, &wait,
148 TASK_UNINTERRUPTIBLE);
149 if (commit->commit_done)
151 mutex_unlock(&root->fs_info->trans_mutex);
153 mutex_lock(&root->fs_info->trans_mutex);
155 finish_wait(&commit->commit_wait, &wait);
160 struct list_head list;
161 struct btrfs_key snap_key;
162 struct buffer_head *commit_root;
163 struct btrfs_root *root;
166 int add_dirty_roots(struct btrfs_trans_handle *trans,
167 struct radix_tree_root *radix, struct list_head *list)
169 struct dirty_root *dirty;
170 struct btrfs_root *gang[8];
171 struct btrfs_root *root;
176 ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
178 BTRFS_ROOT_TRANS_TAG);
181 for (i = 0; i < ret; i++) {
183 radix_tree_tag_clear(radix,
184 (unsigned long)root->root_key.objectid,
185 BTRFS_ROOT_TRANS_TAG);
186 if (root->commit_root == root->node) {
187 WARN_ON(bh_blocknr(root->node) !=
188 btrfs_root_blocknr(&root->root_item));
189 brelse(root->commit_root);
190 root->commit_root = NULL;
193 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
195 memcpy(&dirty->snap_key, &root->root_key,
196 sizeof(root->root_key));
197 dirty->commit_root = root->commit_root;
198 root->commit_root = NULL;
200 root->root_key.offset = root->fs_info->generation;
201 btrfs_set_root_blocknr(&root->root_item,
202 bh_blocknr(root->node));
203 err = btrfs_insert_root(trans, root->fs_info->tree_root,
207 list_add(&dirty->list, list);
213 int drop_dirty_roots(struct btrfs_root *tree_root, struct list_head *list)
215 struct dirty_root *dirty;
216 struct btrfs_trans_handle *trans;
219 while(!list_empty(list)) {
220 dirty = list_entry(list->next, struct dirty_root, list);
221 list_del_init(&dirty->list);
222 trans = btrfs_start_transaction(tree_root, 1);
223 ret = btrfs_drop_snapshot(trans, dirty->root,
227 ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
229 ret = btrfs_end_transaction(trans, tree_root);
236 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
237 struct btrfs_root *root)
240 struct btrfs_transaction *cur_trans;
241 struct btrfs_transaction *prev_trans = NULL;
242 struct list_head dirty_fs_roots;
245 INIT_LIST_HEAD(&dirty_fs_roots);
247 mutex_lock(&root->fs_info->trans_mutex);
248 if (trans->transaction->in_commit) {
249 cur_trans = trans->transaction;
250 trans->transaction->use_count++;
251 btrfs_end_transaction(trans, root);
252 ret = wait_for_commit(root, cur_trans);
254 put_transaction(cur_trans);
255 mutex_unlock(&root->fs_info->trans_mutex);
258 cur_trans = trans->transaction;
259 trans->transaction->in_commit = 1;
260 while (trans->transaction->num_writers > 1) {
261 WARN_ON(cur_trans != trans->transaction);
262 prepare_to_wait(&trans->transaction->writer_wait, &wait,
263 TASK_UNINTERRUPTIBLE);
264 if (trans->transaction->num_writers <= 1)
266 mutex_unlock(&root->fs_info->trans_mutex);
268 mutex_lock(&root->fs_info->trans_mutex);
269 finish_wait(&trans->transaction->writer_wait, &wait);
271 finish_wait(&trans->transaction->writer_wait, &wait);
272 WARN_ON(cur_trans != trans->transaction);
273 add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots);
274 ret = btrfs_commit_tree_roots(trans, root);
276 cur_trans = root->fs_info->running_transaction;
277 root->fs_info->running_transaction = NULL;
278 if (cur_trans->list.prev != &root->fs_info->trans_list) {
279 prev_trans = list_entry(cur_trans->list.prev,
280 struct btrfs_transaction, list);
281 if (prev_trans->commit_done)
284 prev_trans->use_count++;
286 mutex_unlock(&root->fs_info->trans_mutex);
287 mutex_unlock(&root->fs_info->fs_mutex);
288 ret = btrfs_write_and_wait_transaction(trans, root);
290 mutex_lock(&root->fs_info->trans_mutex);
291 wait_for_commit(root, prev_trans);
292 put_transaction(prev_trans);
293 mutex_unlock(&root->fs_info->trans_mutex);
295 btrfs_set_super_generation(root->fs_info->disk_super,
298 write_ctree_super(trans, root);
300 mutex_lock(&root->fs_info->fs_mutex);
301 btrfs_finish_extent_commit(trans, root);
302 mutex_lock(&root->fs_info->trans_mutex);
303 cur_trans->commit_done = 1;
304 wake_up(&cur_trans->commit_wait);
305 put_transaction(cur_trans);
306 put_transaction(cur_trans);
307 mutex_unlock(&root->fs_info->trans_mutex);
308 kmem_cache_free(btrfs_trans_handle_cachep, trans);
310 drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);