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 mutex_lock(&root->fs_info->trans_mutex);
56 ret = join_transaction(root);
58 h->transid = root->fs_info->running_transaction->transid;
59 h->transaction = root->fs_info->running_transaction;
60 h->blocks_reserved = num_blocks;
62 root->fs_info->running_transaction->use_count++;
63 mutex_unlock(&root->fs_info->trans_mutex);
64 h->magic = h->magic2 = TRANS_MAGIC;
68 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
69 struct btrfs_root *root)
71 struct btrfs_transaction *cur_trans;
72 WARN_ON(trans->magic != TRANS_MAGIC);
73 WARN_ON(trans->magic2 != TRANS_MAGIC);
74 mutex_lock(&root->fs_info->trans_mutex);
75 cur_trans = root->fs_info->running_transaction;
76 WARN_ON(cur_trans->num_writers < 1);
77 if (waitqueue_active(&cur_trans->writer_wait))
78 wake_up(&cur_trans->writer_wait);
79 cur_trans->num_writers--;
80 put_transaction(cur_trans);
81 mutex_unlock(&root->fs_info->trans_mutex);
82 memset(trans, 0, sizeof(*trans));
83 kmem_cache_free(btrfs_trans_handle_cachep, trans);
88 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
89 struct btrfs_root *root)
91 filemap_write_and_wait(root->fs_info->sb->s_bdev->bd_inode->i_mapping);
95 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
96 struct btrfs_root *root)
100 struct btrfs_fs_info *fs_info = root->fs_info;
101 struct btrfs_root *tree_root = fs_info->tree_root;
102 struct btrfs_root *extent_root = fs_info->extent_root;
103 struct btrfs_root *inode_root = fs_info->inode_root;
105 btrfs_set_root_blocknr(&inode_root->root_item,
106 inode_root->node->b_blocknr);
107 ret = btrfs_update_root(trans, tree_root,
108 &inode_root->root_key,
109 &inode_root->root_item);
112 old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
113 if (old_extent_block == extent_root->node->b_blocknr)
115 btrfs_set_root_blocknr(&extent_root->root_item,
116 extent_root->node->b_blocknr);
117 ret = btrfs_update_root(trans, tree_root,
118 &extent_root->root_key,
119 &extent_root->root_item);
125 static int wait_for_commit(struct btrfs_root *root,
126 struct btrfs_transaction *commit)
129 while(!commit->commit_done) {
130 prepare_to_wait(&commit->commit_wait, &wait,
131 TASK_UNINTERRUPTIBLE);
132 if (commit->commit_done)
134 mutex_unlock(&root->fs_info->trans_mutex);
136 mutex_lock(&root->fs_info->trans_mutex);
138 finish_wait(&commit->commit_wait, &wait);
142 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
143 struct btrfs_root *root)
146 struct buffer_head *snap;
147 struct btrfs_key snap_key;
148 struct btrfs_transaction *cur_trans;
151 mutex_lock(&root->fs_info->trans_mutex);
152 if (trans->transaction->in_commit) {
153 printk("already in commit!, waiting\n");
154 cur_trans = trans->transaction;
155 trans->transaction->use_count++;
156 btrfs_end_transaction(trans, root);
157 ret = wait_for_commit(root, cur_trans);
159 put_transaction(cur_trans);
160 mutex_unlock(&root->fs_info->trans_mutex);
163 cur_trans = trans->transaction;
164 trans->transaction->in_commit = 1;
165 while (trans->transaction->num_writers > 1) {
166 WARN_ON(cur_trans != trans->transaction);
167 prepare_to_wait(&trans->transaction->writer_wait, &wait,
168 TASK_UNINTERRUPTIBLE);
169 if (trans->transaction->num_writers <= 1)
171 mutex_unlock(&root->fs_info->trans_mutex);
173 mutex_lock(&root->fs_info->trans_mutex);
174 finish_wait(&trans->transaction->writer_wait, &wait);
176 finish_wait(&trans->transaction->writer_wait, &wait);
177 WARN_ON(cur_trans != trans->transaction);
178 if (root->node != root->commit_root) {
179 memcpy(&snap_key, &root->root_key, sizeof(snap_key));
180 root->root_key.offset++;
183 if (btrfs_root_blocknr(&root->root_item) != root->node->b_blocknr) {
184 btrfs_set_root_blocknr(&root->root_item, root->node->b_blocknr);
185 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
186 &root->root_key, &root->root_item);
190 ret = btrfs_commit_tree_roots(trans, root);
192 cur_trans = root->fs_info->running_transaction;
193 root->fs_info->running_transaction = NULL;
194 mutex_unlock(&root->fs_info->trans_mutex);
195 ret = btrfs_write_and_wait_transaction(trans, root);
198 write_ctree_super(trans, root);
199 btrfs_finish_extent_commit(trans, root);
200 mutex_lock(&root->fs_info->trans_mutex);
201 cur_trans->commit_done = 1;
202 wake_up(&cur_trans->commit_wait);
203 put_transaction(cur_trans);
204 put_transaction(cur_trans);
205 mutex_unlock(&root->fs_info->trans_mutex);
206 kmem_cache_free(btrfs_trans_handle_cachep, trans);
207 if (root->node != root->commit_root) {
208 trans = btrfs_start_transaction(root, 1);
209 snap = root->commit_root;
210 root->commit_root = root->node;
212 ret = btrfs_drop_snapshot(trans, root, snap);
215 ret = btrfs_del_root(trans, root->fs_info->tree_root,
218 root->fs_info->generation = root->root_key.offset + 1;
219 ret = btrfs_end_transaction(trans, root);