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 TRANS_MAGIC 0xE1E10E
12 static void put_transaction(struct btrfs_transaction *transaction)
14 WARN_ON(transaction->use_count == 0);
15 transaction->use_count--;
16 WARN_ON(transaction->magic != TRANS_MAGIC);
17 if (transaction->use_count == 0) {
18 WARN_ON(total_trans == 0);
20 memset(transaction, 0, sizeof(*transaction));
21 kmem_cache_free(btrfs_transaction_cachep, transaction);
25 static int join_transaction(struct btrfs_root *root)
27 struct btrfs_transaction *cur_trans;
28 cur_trans = root->fs_info->running_transaction;
30 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
34 root->fs_info->running_transaction = cur_trans;
35 cur_trans->num_writers = 0;
36 cur_trans->transid = root->root_key.offset + 1;
37 init_waitqueue_head(&cur_trans->writer_wait);
38 init_waitqueue_head(&cur_trans->commit_wait);
39 cur_trans->magic = TRANS_MAGIC;
40 cur_trans->in_commit = 0;
41 cur_trans->use_count = 1;
42 cur_trans->commit_done = 0;
44 cur_trans->num_writers++;
48 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
51 struct btrfs_trans_handle *h =
52 kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
55 /* FIXME, use the right root */
56 root = root->fs_info->fs_root;
57 mutex_lock(&root->fs_info->trans_mutex);
58 ret = join_transaction(root);
60 h->transid = root->fs_info->running_transaction->transid;
61 h->transaction = root->fs_info->running_transaction;
62 h->blocks_reserved = num_blocks;
64 root->fs_info->running_transaction->use_count++;
65 mutex_unlock(&root->fs_info->trans_mutex);
66 h->magic = h->magic2 = TRANS_MAGIC;
70 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
71 struct btrfs_root *root)
73 struct btrfs_transaction *cur_trans;
75 /* FIXME, use the right root */
76 root = root->fs_info->fs_root;
78 WARN_ON(trans->magic != TRANS_MAGIC);
79 WARN_ON(trans->magic2 != TRANS_MAGIC);
80 mutex_lock(&root->fs_info->trans_mutex);
81 cur_trans = root->fs_info->running_transaction;
82 WARN_ON(cur_trans->num_writers < 1);
83 if (waitqueue_active(&cur_trans->writer_wait))
84 wake_up(&cur_trans->writer_wait);
85 cur_trans->num_writers--;
86 put_transaction(cur_trans);
87 mutex_unlock(&root->fs_info->trans_mutex);
88 memset(trans, 0, sizeof(*trans));
89 kmem_cache_free(btrfs_trans_handle_cachep, trans);
94 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
95 struct btrfs_root *root)
97 filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
101 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
102 struct btrfs_root *root)
105 u64 old_extent_block;
106 struct btrfs_fs_info *fs_info = root->fs_info;
107 struct btrfs_root *tree_root = fs_info->tree_root;
108 struct btrfs_root *extent_root = fs_info->extent_root;
109 struct btrfs_root *inode_root = fs_info->inode_root;
111 btrfs_set_root_blocknr(&inode_root->root_item,
112 inode_root->node->b_blocknr);
113 ret = btrfs_update_root(trans, tree_root,
114 &inode_root->root_key,
115 &inode_root->root_item);
118 old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
119 if (old_extent_block == extent_root->node->b_blocknr)
121 btrfs_set_root_blocknr(&extent_root->root_item,
122 extent_root->node->b_blocknr);
123 ret = btrfs_update_root(trans, tree_root,
124 &extent_root->root_key,
125 &extent_root->root_item);
131 static int wait_for_commit(struct btrfs_root *root,
132 struct btrfs_transaction *commit)
135 while(!commit->commit_done) {
136 prepare_to_wait(&commit->commit_wait, &wait,
137 TASK_UNINTERRUPTIBLE);
138 if (commit->commit_done)
140 mutex_unlock(&root->fs_info->trans_mutex);
142 mutex_lock(&root->fs_info->trans_mutex);
144 finish_wait(&commit->commit_wait, &wait);
148 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
149 struct btrfs_root *root)
152 struct buffer_head *snap;
153 struct btrfs_key snap_key;
154 struct btrfs_transaction *cur_trans;
157 /* FIXME, use the right root */
158 root = root->fs_info->fs_root;
160 mutex_lock(&root->fs_info->trans_mutex);
161 if (trans->transaction->in_commit) {
162 printk("already in commit!, waiting\n");
163 cur_trans = trans->transaction;
164 trans->transaction->use_count++;
165 btrfs_end_transaction(trans, root);
166 ret = wait_for_commit(root, cur_trans);
168 put_transaction(cur_trans);
169 mutex_unlock(&root->fs_info->trans_mutex);
172 cur_trans = trans->transaction;
173 trans->transaction->in_commit = 1;
174 while (trans->transaction->num_writers > 1) {
175 WARN_ON(cur_trans != trans->transaction);
176 prepare_to_wait(&trans->transaction->writer_wait, &wait,
177 TASK_UNINTERRUPTIBLE);
178 if (trans->transaction->num_writers <= 1)
180 mutex_unlock(&root->fs_info->trans_mutex);
182 mutex_lock(&root->fs_info->trans_mutex);
183 finish_wait(&trans->transaction->writer_wait, &wait);
185 finish_wait(&trans->transaction->writer_wait, &wait);
186 WARN_ON(cur_trans != trans->transaction);
187 if (root->node != root->commit_root) {
188 memcpy(&snap_key, &root->root_key, sizeof(snap_key));
189 root->root_key.offset++;
192 if (btrfs_root_blocknr(&root->root_item) != root->node->b_blocknr) {
193 btrfs_set_root_blocknr(&root->root_item, root->node->b_blocknr);
194 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
195 &root->root_key, &root->root_item);
199 ret = btrfs_commit_tree_roots(trans, root);
201 cur_trans = root->fs_info->running_transaction;
202 root->fs_info->running_transaction = NULL;
203 mutex_unlock(&root->fs_info->trans_mutex);
204 ret = btrfs_write_and_wait_transaction(trans, root);
207 write_ctree_super(trans, root);
208 btrfs_finish_extent_commit(trans, root);
209 mutex_lock(&root->fs_info->trans_mutex);
210 cur_trans->commit_done = 1;
211 wake_up(&cur_trans->commit_wait);
212 put_transaction(cur_trans);
213 put_transaction(cur_trans);
214 mutex_unlock(&root->fs_info->trans_mutex);
215 kmem_cache_free(btrfs_trans_handle_cachep, trans);
216 if (root->node != root->commit_root) {
217 trans = btrfs_start_transaction(root, 1);
218 snap = root->commit_root;
219 root->commit_root = root->node;
221 ret = btrfs_drop_snapshot(trans, root, snap);
224 ret = btrfs_del_root(trans, root->fs_info->tree_root,
227 root->fs_info->generation = root->root_key.offset + 1;
228 ret = btrfs_end_transaction(trans, root);