1 #include <linux/module.h>
5 #include "transaction.h"
7 static int total_trans = 0;
8 static void put_transaction(struct btrfs_transaction *transaction)
10 transaction->use_count--;
11 if (transaction->use_count == 0) {
12 WARN_ON(total_trans == 0);
18 static int join_transaction(struct btrfs_root *root)
20 struct btrfs_transaction *cur_trans;
21 cur_trans = root->fs_info->running_transaction;
23 cur_trans = kmalloc(sizeof(*cur_trans), GFP_NOFS);
26 root->fs_info->running_transaction = cur_trans;
27 cur_trans->num_writers = 0;
28 cur_trans->transid = root->root_key.offset + 1;
29 init_waitqueue_head(&cur_trans->writer_wait);
30 init_waitqueue_head(&cur_trans->commit_wait);
31 cur_trans->in_commit = 0;
32 cur_trans->use_count = 1;
33 cur_trans->commit_done = 0;
35 cur_trans->num_writers++;
39 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
42 struct btrfs_trans_handle *h = kmalloc(sizeof(*h), GFP_NOFS);
45 mutex_lock(&root->fs_info->trans_mutex);
46 ret = join_transaction(root);
48 h->transid = root->fs_info->running_transaction->transid;
49 h->transaction = root->fs_info->running_transaction;
50 h->blocks_reserved = num_blocks;
52 root->fs_info->running_transaction->use_count++;
53 mutex_unlock(&root->fs_info->trans_mutex);
57 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
58 struct btrfs_root *root)
60 struct btrfs_transaction *cur_trans;
61 mutex_lock(&root->fs_info->trans_mutex);
62 cur_trans = root->fs_info->running_transaction;
63 WARN_ON(cur_trans->num_writers < 1);
64 if (waitqueue_active(&cur_trans->writer_wait))
65 wake_up(&cur_trans->writer_wait);
66 cur_trans->num_writers--;
67 put_transaction(cur_trans);
68 mutex_unlock(&root->fs_info->trans_mutex);
74 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
75 struct btrfs_root *root)
77 filemap_write_and_wait(root->fs_info->sb->s_bdev->bd_inode->i_mapping);
81 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
82 struct btrfs_root *root)
86 struct btrfs_fs_info *fs_info = root->fs_info;
87 struct btrfs_root *tree_root = fs_info->tree_root;
88 struct btrfs_root *extent_root = fs_info->extent_root;
89 struct btrfs_root *inode_root = fs_info->inode_root;
91 btrfs_set_root_blocknr(&inode_root->root_item,
92 inode_root->node->b_blocknr);
93 ret = btrfs_update_root(trans, tree_root,
94 &inode_root->root_key,
95 &inode_root->root_item);
98 old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
99 if (old_extent_block == extent_root->node->b_blocknr)
101 btrfs_set_root_blocknr(&extent_root->root_item,
102 extent_root->node->b_blocknr);
103 ret = btrfs_update_root(trans, tree_root,
104 &extent_root->root_key,
105 &extent_root->root_item);
111 static int wait_for_commit(struct btrfs_root *root,
112 struct btrfs_transaction *commit)
115 while(!commit->commit_done) {
116 prepare_to_wait(&commit->commit_wait, &wait,
117 TASK_UNINTERRUPTIBLE);
118 if (commit->commit_done)
120 mutex_unlock(&root->fs_info->trans_mutex);
122 mutex_lock(&root->fs_info->trans_mutex);
124 finish_wait(&commit->commit_wait, &wait);
128 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
129 struct btrfs_root *root)
132 struct buffer_head *snap;
133 struct btrfs_key snap_key;
134 struct btrfs_transaction *cur_trans;
137 mutex_lock(&root->fs_info->trans_mutex);
138 if (trans->transaction->in_commit) {
139 cur_trans = trans->transaction;
140 trans->transaction->use_count++;
141 btrfs_end_transaction(trans, root);
142 ret = wait_for_commit(root, cur_trans);
144 put_transaction(cur_trans);
145 mutex_unlock(&root->fs_info->trans_mutex);
148 while (trans->transaction->num_writers > 1) {
149 prepare_to_wait(&trans->transaction->writer_wait, &wait,
150 TASK_UNINTERRUPTIBLE);
151 if (trans->transaction->num_writers <= 1)
153 mutex_unlock(&root->fs_info->trans_mutex);
155 mutex_lock(&root->fs_info->trans_mutex);
157 finish_wait(&trans->transaction->writer_wait, &wait);
159 if (root->node != root->commit_root) {
160 memcpy(&snap_key, &root->root_key, sizeof(snap_key));
161 root->root_key.offset++;
165 if (btrfs_root_blocknr(&root->root_item) != root->node->b_blocknr) {
166 btrfs_set_root_blocknr(&root->root_item, root->node->b_blocknr);
167 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
168 &root->root_key, &root->root_item);
172 ret = btrfs_commit_tree_roots(trans, root);
175 cur_trans = root->fs_info->running_transaction;
176 root->fs_info->running_transaction = NULL;
177 mutex_unlock(&root->fs_info->trans_mutex);
179 ret = btrfs_write_and_wait_transaction(trans, root);
182 write_ctree_super(trans, root);
183 btrfs_finish_extent_commit(trans, root);
184 mutex_lock(&root->fs_info->trans_mutex);
185 put_transaction(cur_trans);
186 put_transaction(cur_trans);
187 mutex_unlock(&root->fs_info->trans_mutex);
190 if (root->node != root->commit_root) {
191 trans = btrfs_start_transaction(root, 1);
192 snap = root->commit_root;
193 root->commit_root = root->node;
195 ret = btrfs_drop_snapshot(trans, root, snap);
198 ret = btrfs_del_root(trans, root->fs_info->tree_root,
200 BUG_ON(ret); root->fs_info->generation = root->root_key.offset + 1; ret = btrfs_end_transaction(trans, root); BUG_ON(ret);
201 printk("at free, total trans %d\n", total_trans);