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);
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);
83 h->magic = h->magic2 = TRANS_MAGIC;
87 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
88 struct btrfs_root *root)
90 struct btrfs_transaction *cur_trans;
92 WARN_ON(trans->magic != TRANS_MAGIC);
93 WARN_ON(trans->magic2 != TRANS_MAGIC);
94 mutex_lock(&root->fs_info->trans_mutex);
95 cur_trans = root->fs_info->running_transaction;
96 WARN_ON(cur_trans->num_writers < 1);
97 if (waitqueue_active(&cur_trans->writer_wait))
98 wake_up(&cur_trans->writer_wait);
99 cur_trans->num_writers--;
100 put_transaction(cur_trans);
101 mutex_unlock(&root->fs_info->trans_mutex);
102 memset(trans, 0, sizeof(*trans));
103 kmem_cache_free(btrfs_trans_handle_cachep, trans);
108 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
109 struct btrfs_root *root)
111 unsigned long gang[16];
117 struct radix_tree_root *dirty_pages;
118 struct inode *btree_inode = root->fs_info->btree_inode;
120 if (!trans || !trans->transaction) {
121 return filemap_write_and_wait(btree_inode->i_mapping);
123 dirty_pages = &trans->transaction->dirty_pages;
125 ret = find_first_radix_bit(dirty_pages, gang, ARRAY_SIZE(gang));
128 for (i = 0; i < ret; i++) {
130 clear_radix_bit(dirty_pages, gang[i]);
131 page = find_lock_page(btree_inode->i_mapping,
135 err = write_one_page(page, 0);
138 page_cache_release(page);
141 err = filemap_fdatawait(btree_inode->i_mapping);
147 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
148 struct btrfs_root *root)
151 u64 old_extent_block;
152 struct btrfs_fs_info *fs_info = root->fs_info;
153 struct btrfs_root *tree_root = fs_info->tree_root;
154 struct btrfs_root *extent_root = fs_info->extent_root;
155 struct btrfs_root *dev_root = fs_info->dev_root;
157 if (btrfs_super_device_root(fs_info->disk_super) !=
158 bh_blocknr(dev_root->node)) {
159 btrfs_set_super_device_root(fs_info->disk_super,
160 bh_blocknr(dev_root->node));
162 btrfs_write_dirty_block_groups(trans, extent_root);
164 old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
165 if (old_extent_block == bh_blocknr(extent_root->node))
167 btrfs_set_root_blocknr(&extent_root->root_item,
168 bh_blocknr(extent_root->node));
169 ret = btrfs_update_root(trans, tree_root,
170 &extent_root->root_key,
171 &extent_root->root_item);
173 btrfs_write_dirty_block_groups(trans, extent_root);
178 static int wait_for_commit(struct btrfs_root *root,
179 struct btrfs_transaction *commit)
182 while(!commit->commit_done) {
183 prepare_to_wait(&commit->commit_wait, &wait,
184 TASK_UNINTERRUPTIBLE);
185 if (commit->commit_done)
187 mutex_unlock(&root->fs_info->trans_mutex);
189 mutex_lock(&root->fs_info->trans_mutex);
191 finish_wait(&commit->commit_wait, &wait);
196 struct list_head list;
197 struct btrfs_key snap_key;
198 struct buffer_head *commit_root;
199 struct btrfs_root *root;
202 static int add_dirty_roots(struct btrfs_trans_handle *trans,
203 struct radix_tree_root *radix,
204 struct list_head *list)
206 struct dirty_root *dirty;
207 struct btrfs_root *gang[8];
208 struct btrfs_root *root;
213 ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
215 BTRFS_ROOT_TRANS_TAG);
218 for (i = 0; i < ret; i++) {
220 radix_tree_tag_clear(radix,
221 (unsigned long)root->root_key.objectid,
222 BTRFS_ROOT_TRANS_TAG);
223 if (root->commit_root == root->node) {
224 WARN_ON(bh_blocknr(root->node) !=
225 btrfs_root_blocknr(&root->root_item));
226 brelse(root->commit_root);
227 root->commit_root = NULL;
230 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
232 memcpy(&dirty->snap_key, &root->root_key,
233 sizeof(root->root_key));
234 dirty->commit_root = root->commit_root;
235 root->commit_root = NULL;
237 root->root_key.offset = root->fs_info->generation;
238 btrfs_set_root_blocknr(&root->root_item,
239 bh_blocknr(root->node));
240 err = btrfs_insert_root(trans, root->fs_info->tree_root,
244 list_add(&dirty->list, list);
250 static int drop_dirty_roots(struct btrfs_root *tree_root,
251 struct list_head *list)
253 struct dirty_root *dirty;
254 struct btrfs_trans_handle *trans;
257 while(!list_empty(list)) {
258 dirty = list_entry(list->next, struct dirty_root, list);
259 list_del_init(&dirty->list);
260 trans = btrfs_start_transaction(tree_root, 1);
261 ret = btrfs_drop_snapshot(trans, dirty->root,
265 ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
267 ret = btrfs_end_transaction(trans, tree_root);
274 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
275 struct btrfs_root *root)
278 struct btrfs_transaction *cur_trans;
279 struct btrfs_transaction *prev_trans = NULL;
280 struct list_head dirty_fs_roots;
283 INIT_LIST_HEAD(&dirty_fs_roots);
285 mutex_lock(&root->fs_info->trans_mutex);
286 if (trans->transaction->in_commit) {
287 cur_trans = trans->transaction;
288 trans->transaction->use_count++;
289 btrfs_end_transaction(trans, root);
290 ret = wait_for_commit(root, cur_trans);
292 put_transaction(cur_trans);
293 mutex_unlock(&root->fs_info->trans_mutex);
296 cur_trans = trans->transaction;
297 trans->transaction->in_commit = 1;
298 while (trans->transaction->num_writers > 1) {
299 WARN_ON(cur_trans != trans->transaction);
300 prepare_to_wait(&trans->transaction->writer_wait, &wait,
301 TASK_UNINTERRUPTIBLE);
302 if (trans->transaction->num_writers <= 1)
304 mutex_unlock(&root->fs_info->trans_mutex);
306 mutex_lock(&root->fs_info->trans_mutex);
307 finish_wait(&trans->transaction->writer_wait, &wait);
309 finish_wait(&trans->transaction->writer_wait, &wait);
310 WARN_ON(cur_trans != trans->transaction);
311 add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots);
312 ret = btrfs_commit_tree_roots(trans, root);
314 cur_trans = root->fs_info->running_transaction;
315 root->fs_info->running_transaction = NULL;
316 if (cur_trans->list.prev != &root->fs_info->trans_list) {
317 prev_trans = list_entry(cur_trans->list.prev,
318 struct btrfs_transaction, list);
319 if (prev_trans->commit_done)
322 prev_trans->use_count++;
324 mutex_unlock(&root->fs_info->trans_mutex);
325 mutex_unlock(&root->fs_info->fs_mutex);
326 ret = btrfs_write_and_wait_transaction(trans, root);
328 mutex_lock(&root->fs_info->trans_mutex);
329 wait_for_commit(root, prev_trans);
330 put_transaction(prev_trans);
331 mutex_unlock(&root->fs_info->trans_mutex);
333 btrfs_set_super_generation(root->fs_info->disk_super,
336 write_ctree_super(trans, root);
338 mutex_lock(&root->fs_info->fs_mutex);
339 btrfs_finish_extent_commit(trans, root);
340 mutex_lock(&root->fs_info->trans_mutex);
341 cur_trans->commit_done = 1;
342 wake_up(&cur_trans->commit_wait);
343 put_transaction(cur_trans);
344 put_transaction(cur_trans);
345 mutex_unlock(&root->fs_info->trans_mutex);
346 kmem_cache_free(btrfs_trans_handle_cachep, trans);
348 drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);