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, BTRFS_ROOT_TRANS_TAG);
68 root->commit_root = root->node;
71 root->last_trans = running_trans_id;
72 h->transid = running_trans_id;
73 h->transaction = root->fs_info->running_transaction;
74 h->blocks_reserved = num_blocks;
76 root->fs_info->running_transaction->use_count++;
77 mutex_unlock(&root->fs_info->trans_mutex);
78 h->magic = h->magic2 = TRANS_MAGIC;
82 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
83 struct btrfs_root *root)
85 struct btrfs_transaction *cur_trans;
87 WARN_ON(trans->magic != TRANS_MAGIC);
88 WARN_ON(trans->magic2 != TRANS_MAGIC);
89 mutex_lock(&root->fs_info->trans_mutex);
90 cur_trans = root->fs_info->running_transaction;
91 WARN_ON(cur_trans->num_writers < 1);
92 if (waitqueue_active(&cur_trans->writer_wait))
93 wake_up(&cur_trans->writer_wait);
94 cur_trans->num_writers--;
95 put_transaction(cur_trans);
96 mutex_unlock(&root->fs_info->trans_mutex);
97 memset(trans, 0, sizeof(*trans));
98 kmem_cache_free(btrfs_trans_handle_cachep, trans);
103 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
104 struct btrfs_root *root)
106 filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
110 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
111 struct btrfs_root *root)
114 u64 old_extent_block;
115 struct btrfs_fs_info *fs_info = root->fs_info;
116 struct btrfs_root *tree_root = fs_info->tree_root;
117 struct btrfs_root *extent_root = fs_info->extent_root;
120 old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
121 if (old_extent_block == extent_root->node->b_blocknr)
123 btrfs_set_root_blocknr(&extent_root->root_item,
124 extent_root->node->b_blocknr);
125 ret = btrfs_update_root(trans, tree_root,
126 &extent_root->root_key,
127 &extent_root->root_item);
133 static int wait_for_commit(struct btrfs_root *root,
134 struct btrfs_transaction *commit)
137 while(!commit->commit_done) {
138 prepare_to_wait(&commit->commit_wait, &wait,
139 TASK_UNINTERRUPTIBLE);
140 if (commit->commit_done)
142 mutex_unlock(&root->fs_info->trans_mutex);
144 mutex_lock(&root->fs_info->trans_mutex);
146 finish_wait(&commit->commit_wait, &wait);
151 struct list_head list;
152 struct btrfs_key snap_key;
153 struct buffer_head *commit_root;
154 struct btrfs_root *root;
157 int add_dirty_roots(struct btrfs_trans_handle *trans,
158 struct radix_tree_root *radix, struct list_head *list)
160 struct dirty_root *dirty;
161 struct btrfs_root *gang[8];
162 struct btrfs_root *root;
166 printk("add dirty\n");
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, (unsigned long)root,
176 BTRFS_ROOT_TRANS_TAG);
177 if (root->commit_root == root->node) {
178 WARN_ON(root->node->b_blocknr !=
179 btrfs_root_blocknr(&root->root_item));
180 brelse(root->commit_root);
181 root->commit_root = NULL;
184 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
186 memcpy(&dirty->snap_key, &root->root_key,
187 sizeof(root->root_key));
188 dirty->commit_root = root->commit_root;
189 root->commit_root = NULL;
191 printk("adding dirty root %Lu gen %Lu blocknr %Lu\n", root->root_key.objectid, root->root_key.offset, dirty->commit_root->b_blocknr);
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);
202 printk("add dirty done\n");
206 int drop_dirty_roots(struct btrfs_root *tree_root, struct list_head *list)
208 struct dirty_root *dirty;
209 struct btrfs_trans_handle *trans;
212 while(!list_empty(list)) {
213 dirty = list_entry(list->next, struct dirty_root, list);
214 list_del_init(&dirty->list);
215 trans = btrfs_start_transaction(tree_root, 1);
216 printk("drop snapshot root %p, commit_root blocknr %Lu generation %Lu\n", dirty->root, dirty->commit_root->b_blocknr, dirty->snap_key.offset);
217 ret = btrfs_drop_snapshot(trans, dirty->root,
221 printk("del root objectid %Lu, offset %Lu\n", dirty->snap_key.objectid, dirty->snap_key.offset);
222 ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
224 ret = btrfs_end_transaction(trans, tree_root);
231 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
232 struct btrfs_root *root)
235 struct btrfs_transaction *cur_trans;
236 struct list_head dirty_fs_roots;
239 INIT_LIST_HEAD(&dirty_fs_roots);
241 mutex_lock(&root->fs_info->trans_mutex);
242 if (trans->transaction->in_commit) {
243 printk("already in commit!, waiting\n");
244 cur_trans = trans->transaction;
245 trans->transaction->use_count++;
246 btrfs_end_transaction(trans, root);
247 ret = wait_for_commit(root, cur_trans);
249 put_transaction(cur_trans);
250 mutex_unlock(&root->fs_info->trans_mutex);
253 cur_trans = trans->transaction;
254 trans->transaction->in_commit = 1;
255 while (trans->transaction->num_writers > 1) {
256 WARN_ON(cur_trans != trans->transaction);
257 prepare_to_wait(&trans->transaction->writer_wait, &wait,
258 TASK_UNINTERRUPTIBLE);
259 if (trans->transaction->num_writers <= 1)
261 mutex_unlock(&root->fs_info->trans_mutex);
263 mutex_lock(&root->fs_info->trans_mutex);
264 finish_wait(&trans->transaction->writer_wait, &wait);
266 finish_wait(&trans->transaction->writer_wait, &wait);
267 WARN_ON(cur_trans != trans->transaction);
268 add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots);
269 ret = btrfs_commit_tree_roots(trans, root);
271 cur_trans = root->fs_info->running_transaction;
272 root->fs_info->running_transaction = NULL;
273 btrfs_set_super_generation(root->fs_info->disk_super,
274 root->fs_info->generation + 1);
275 mutex_unlock(&root->fs_info->trans_mutex);
276 ret = btrfs_write_and_wait_transaction(trans, root);
279 write_ctree_super(trans, root);
280 btrfs_finish_extent_commit(trans, root);
281 mutex_lock(&root->fs_info->trans_mutex);
282 cur_trans->commit_done = 1;
283 wake_up(&cur_trans->commit_wait);
284 put_transaction(cur_trans);
285 put_transaction(cur_trans);
286 mutex_unlock(&root->fs_info->trans_mutex);
287 kmem_cache_free(btrfs_trans_handle_cachep, trans);
289 drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);