Commit | Line | Data |
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79154b1b CM |
1 | #include <linux/module.h> |
2 | #include <linux/fs.h> | |
3 | #include "ctree.h" | |
4 | #include "disk-io.h" | |
5 | #include "transaction.h" | |
6 | ||
78fae27e | 7 | static int total_trans = 0; |
2c90e5d6 CM |
8 | extern struct kmem_cache *btrfs_trans_handle_cachep; |
9 | extern struct kmem_cache *btrfs_transaction_cachep; | |
10 | ||
0f7d52f4 CM |
11 | #define BTRFS_ROOT_TRANS_TAG 0 |
12 | ||
2c90e5d6 | 13 | #define TRANS_MAGIC 0xE1E10E |
79154b1b CM |
14 | static void put_transaction(struct btrfs_transaction *transaction) |
15 | { | |
2c90e5d6 | 16 | WARN_ON(transaction->use_count == 0); |
79154b1b | 17 | transaction->use_count--; |
2c90e5d6 | 18 | WARN_ON(transaction->magic != TRANS_MAGIC); |
78fae27e CM |
19 | if (transaction->use_count == 0) { |
20 | WARN_ON(total_trans == 0); | |
21 | total_trans--; | |
8fd17795 | 22 | list_del_init(&transaction->list); |
2c90e5d6 CM |
23 | memset(transaction, 0, sizeof(*transaction)); |
24 | kmem_cache_free(btrfs_transaction_cachep, transaction); | |
78fae27e | 25 | } |
79154b1b CM |
26 | } |
27 | ||
28 | static int join_transaction(struct btrfs_root *root) | |
29 | { | |
30 | struct btrfs_transaction *cur_trans; | |
31 | cur_trans = root->fs_info->running_transaction; | |
32 | if (!cur_trans) { | |
2c90e5d6 CM |
33 | cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, |
34 | GFP_NOFS); | |
78fae27e | 35 | total_trans++; |
79154b1b | 36 | BUG_ON(!cur_trans); |
0f7d52f4 | 37 | root->fs_info->generation++; |
79154b1b CM |
38 | root->fs_info->running_transaction = cur_trans; |
39 | cur_trans->num_writers = 0; | |
0f7d52f4 | 40 | cur_trans->transid = root->fs_info->generation; |
79154b1b CM |
41 | init_waitqueue_head(&cur_trans->writer_wait); |
42 | init_waitqueue_head(&cur_trans->commit_wait); | |
2c90e5d6 | 43 | cur_trans->magic = TRANS_MAGIC; |
79154b1b | 44 | cur_trans->in_commit = 0; |
d5719762 | 45 | cur_trans->use_count = 1; |
79154b1b | 46 | cur_trans->commit_done = 0; |
8fd17795 | 47 | list_add_tail(&cur_trans->list, &root->fs_info->trans_list); |
79154b1b CM |
48 | } |
49 | cur_trans->num_writers++; | |
50 | return 0; | |
51 | } | |
52 | ||
53 | struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, | |
54 | int num_blocks) | |
55 | { | |
2c90e5d6 CM |
56 | struct btrfs_trans_handle *h = |
57 | kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); | |
79154b1b | 58 | int ret; |
0f7d52f4 | 59 | u64 running_trans_id; |
79154b1b CM |
60 | |
61 | mutex_lock(&root->fs_info->trans_mutex); | |
62 | ret = join_transaction(root); | |
63 | BUG_ON(ret); | |
0f7d52f4 CM |
64 | running_trans_id = root->fs_info->running_transaction->transid; |
65 | ||
66 | if (root != root->fs_info->tree_root && root->last_trans < | |
67 | running_trans_id) { | |
68 | radix_tree_tag_set(&root->fs_info->fs_roots_radix, | |
2619ba1f CM |
69 | (unsigned long)root->root_key.objectid, |
70 | BTRFS_ROOT_TRANS_TAG); | |
0f7d52f4 CM |
71 | root->commit_root = root->node; |
72 | get_bh(root->node); | |
73 | } | |
74 | root->last_trans = running_trans_id; | |
75 | h->transid = running_trans_id; | |
79154b1b CM |
76 | h->transaction = root->fs_info->running_transaction; |
77 | h->blocks_reserved = num_blocks; | |
78 | h->blocks_used = 0; | |
79 | root->fs_info->running_transaction->use_count++; | |
80 | mutex_unlock(&root->fs_info->trans_mutex); | |
2c90e5d6 | 81 | h->magic = h->magic2 = TRANS_MAGIC; |
79154b1b CM |
82 | return h; |
83 | } | |
84 | ||
85 | int btrfs_end_transaction(struct btrfs_trans_handle *trans, | |
86 | struct btrfs_root *root) | |
87 | { | |
88 | struct btrfs_transaction *cur_trans; | |
d6e4a428 | 89 | |
2c90e5d6 CM |
90 | WARN_ON(trans->magic != TRANS_MAGIC); |
91 | WARN_ON(trans->magic2 != TRANS_MAGIC); | |
79154b1b CM |
92 | mutex_lock(&root->fs_info->trans_mutex); |
93 | cur_trans = root->fs_info->running_transaction; | |
d5719762 | 94 | WARN_ON(cur_trans->num_writers < 1); |
79154b1b CM |
95 | if (waitqueue_active(&cur_trans->writer_wait)) |
96 | wake_up(&cur_trans->writer_wait); | |
97 | cur_trans->num_writers--; | |
98 | put_transaction(cur_trans); | |
99 | mutex_unlock(&root->fs_info->trans_mutex); | |
d6025579 | 100 | memset(trans, 0, sizeof(*trans)); |
2c90e5d6 | 101 | kmem_cache_free(btrfs_trans_handle_cachep, trans); |
79154b1b CM |
102 | return 0; |
103 | } | |
104 | ||
105 | ||
106 | int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, | |
107 | struct btrfs_root *root) | |
108 | { | |
7cfcc17e | 109 | filemap_write_and_wait(root->fs_info->btree_inode->i_mapping); |
79154b1b CM |
110 | return 0; |
111 | } | |
112 | ||
113 | int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans, | |
114 | struct btrfs_root *root) | |
115 | { | |
116 | int ret; | |
117 | u64 old_extent_block; | |
118 | struct btrfs_fs_info *fs_info = root->fs_info; | |
119 | struct btrfs_root *tree_root = fs_info->tree_root; | |
120 | struct btrfs_root *extent_root = fs_info->extent_root; | |
8352d8a4 | 121 | struct btrfs_root *dev_root = fs_info->dev_root; |
79154b1b | 122 | |
8352d8a4 CM |
123 | if (btrfs_super_device_root(fs_info->disk_super) != |
124 | bh_blocknr(dev_root->node)) { | |
125 | btrfs_set_super_device_root(fs_info->disk_super, | |
126 | bh_blocknr(dev_root->node)); | |
127 | } | |
79154b1b CM |
128 | while(1) { |
129 | old_extent_block = btrfs_root_blocknr(&extent_root->root_item); | |
7eccb903 | 130 | if (old_extent_block == bh_blocknr(extent_root->node)) |
79154b1b CM |
131 | break; |
132 | btrfs_set_root_blocknr(&extent_root->root_item, | |
7eccb903 | 133 | bh_blocknr(extent_root->node)); |
79154b1b CM |
134 | ret = btrfs_update_root(trans, tree_root, |
135 | &extent_root->root_key, | |
136 | &extent_root->root_item); | |
137 | BUG_ON(ret); | |
138 | } | |
139 | return 0; | |
140 | } | |
141 | ||
142 | static int wait_for_commit(struct btrfs_root *root, | |
143 | struct btrfs_transaction *commit) | |
144 | { | |
145 | DEFINE_WAIT(wait); | |
79154b1b CM |
146 | while(!commit->commit_done) { |
147 | prepare_to_wait(&commit->commit_wait, &wait, | |
148 | TASK_UNINTERRUPTIBLE); | |
149 | if (commit->commit_done) | |
150 | break; | |
151 | mutex_unlock(&root->fs_info->trans_mutex); | |
152 | schedule(); | |
153 | mutex_lock(&root->fs_info->trans_mutex); | |
154 | } | |
155 | finish_wait(&commit->commit_wait, &wait); | |
156 | return 0; | |
157 | } | |
158 | ||
0f7d52f4 CM |
159 | struct dirty_root { |
160 | struct list_head list; | |
161 | struct btrfs_key snap_key; | |
162 | struct buffer_head *commit_root; | |
163 | struct btrfs_root *root; | |
164 | }; | |
165 | ||
166 | int add_dirty_roots(struct btrfs_trans_handle *trans, | |
167 | struct radix_tree_root *radix, struct list_head *list) | |
168 | { | |
169 | struct dirty_root *dirty; | |
170 | struct btrfs_root *gang[8]; | |
171 | struct btrfs_root *root; | |
172 | int i; | |
173 | int ret; | |
174 | int err; | |
0f7d52f4 CM |
175 | while(1) { |
176 | ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0, | |
177 | ARRAY_SIZE(gang), | |
178 | BTRFS_ROOT_TRANS_TAG); | |
179 | if (ret == 0) | |
180 | break; | |
181 | for (i = 0; i < ret; i++) { | |
182 | root = gang[i]; | |
2619ba1f CM |
183 | radix_tree_tag_clear(radix, |
184 | (unsigned long)root->root_key.objectid, | |
185 | BTRFS_ROOT_TRANS_TAG); | |
0f7d52f4 | 186 | if (root->commit_root == root->node) { |
7eccb903 | 187 | WARN_ON(bh_blocknr(root->node) != |
0f7d52f4 CM |
188 | btrfs_root_blocknr(&root->root_item)); |
189 | brelse(root->commit_root); | |
190 | root->commit_root = NULL; | |
191 | continue; | |
192 | } | |
193 | dirty = kmalloc(sizeof(*dirty), GFP_NOFS); | |
194 | BUG_ON(!dirty); | |
195 | memcpy(&dirty->snap_key, &root->root_key, | |
196 | sizeof(root->root_key)); | |
197 | dirty->commit_root = root->commit_root; | |
198 | root->commit_root = NULL; | |
199 | dirty->root = root; | |
0f7d52f4 CM |
200 | root->root_key.offset = root->fs_info->generation; |
201 | btrfs_set_root_blocknr(&root->root_item, | |
7eccb903 | 202 | bh_blocknr(root->node)); |
0f7d52f4 CM |
203 | err = btrfs_insert_root(trans, root->fs_info->tree_root, |
204 | &root->root_key, | |
205 | &root->root_item); | |
206 | BUG_ON(err); | |
207 | list_add(&dirty->list, list); | |
208 | } | |
209 | } | |
0f7d52f4 CM |
210 | return 0; |
211 | } | |
212 | ||
213 | int drop_dirty_roots(struct btrfs_root *tree_root, struct list_head *list) | |
214 | { | |
215 | struct dirty_root *dirty; | |
216 | struct btrfs_trans_handle *trans; | |
217 | int ret; | |
218 | ||
219 | while(!list_empty(list)) { | |
220 | dirty = list_entry(list->next, struct dirty_root, list); | |
221 | list_del_init(&dirty->list); | |
222 | trans = btrfs_start_transaction(tree_root, 1); | |
0f7d52f4 CM |
223 | ret = btrfs_drop_snapshot(trans, dirty->root, |
224 | dirty->commit_root); | |
225 | BUG_ON(ret); | |
226 | ||
0f7d52f4 CM |
227 | ret = btrfs_del_root(trans, tree_root, &dirty->snap_key); |
228 | BUG_ON(ret); | |
229 | ret = btrfs_end_transaction(trans, tree_root); | |
230 | BUG_ON(ret); | |
231 | kfree(dirty); | |
232 | } | |
233 | return 0; | |
234 | } | |
235 | ||
79154b1b CM |
236 | int btrfs_commit_transaction(struct btrfs_trans_handle *trans, |
237 | struct btrfs_root *root) | |
238 | { | |
239 | int ret = 0; | |
79154b1b | 240 | struct btrfs_transaction *cur_trans; |
8fd17795 | 241 | struct btrfs_transaction *prev_trans = NULL; |
0f7d52f4 | 242 | struct list_head dirty_fs_roots; |
79154b1b CM |
243 | DEFINE_WAIT(wait); |
244 | ||
0f7d52f4 | 245 | INIT_LIST_HEAD(&dirty_fs_roots); |
d6e4a428 | 246 | |
79154b1b CM |
247 | mutex_lock(&root->fs_info->trans_mutex); |
248 | if (trans->transaction->in_commit) { | |
249 | cur_trans = trans->transaction; | |
250 | trans->transaction->use_count++; | |
251 | btrfs_end_transaction(trans, root); | |
252 | ret = wait_for_commit(root, cur_trans); | |
253 | BUG_ON(ret); | |
254 | put_transaction(cur_trans); | |
255 | mutex_unlock(&root->fs_info->trans_mutex); | |
256 | return 0; | |
257 | } | |
2c90e5d6 CM |
258 | cur_trans = trans->transaction; |
259 | trans->transaction->in_commit = 1; | |
79154b1b | 260 | while (trans->transaction->num_writers > 1) { |
2c90e5d6 | 261 | WARN_ON(cur_trans != trans->transaction); |
79154b1b CM |
262 | prepare_to_wait(&trans->transaction->writer_wait, &wait, |
263 | TASK_UNINTERRUPTIBLE); | |
264 | if (trans->transaction->num_writers <= 1) | |
265 | break; | |
266 | mutex_unlock(&root->fs_info->trans_mutex); | |
267 | schedule(); | |
268 | mutex_lock(&root->fs_info->trans_mutex); | |
2c90e5d6 | 269 | finish_wait(&trans->transaction->writer_wait, &wait); |
79154b1b CM |
270 | } |
271 | finish_wait(&trans->transaction->writer_wait, &wait); | |
2c90e5d6 | 272 | WARN_ON(cur_trans != trans->transaction); |
0f7d52f4 | 273 | add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots); |
79154b1b CM |
274 | ret = btrfs_commit_tree_roots(trans, root); |
275 | BUG_ON(ret); | |
78fae27e CM |
276 | cur_trans = root->fs_info->running_transaction; |
277 | root->fs_info->running_transaction = NULL; | |
8fd17795 CM |
278 | if (cur_trans->list.prev != &root->fs_info->trans_list) { |
279 | prev_trans = list_entry(cur_trans->list.prev, | |
280 | struct btrfs_transaction, list); | |
281 | if (prev_trans->commit_done) | |
282 | prev_trans = NULL; | |
283 | else | |
284 | prev_trans->use_count++; | |
285 | } | |
78fae27e | 286 | mutex_unlock(&root->fs_info->trans_mutex); |
8fd17795 | 287 | mutex_unlock(&root->fs_info->fs_mutex); |
79154b1b | 288 | ret = btrfs_write_and_wait_transaction(trans, root); |
8fd17795 CM |
289 | if (prev_trans) { |
290 | mutex_lock(&root->fs_info->trans_mutex); | |
291 | wait_for_commit(root, prev_trans); | |
292 | put_transaction(prev_trans); | |
293 | mutex_unlock(&root->fs_info->trans_mutex); | |
294 | } | |
295 | btrfs_set_super_generation(root->fs_info->disk_super, | |
296 | cur_trans->transid); | |
79154b1b | 297 | BUG_ON(ret); |
79154b1b | 298 | write_ctree_super(trans, root); |
8fd17795 CM |
299 | |
300 | mutex_lock(&root->fs_info->fs_mutex); | |
78fae27e CM |
301 | btrfs_finish_extent_commit(trans, root); |
302 | mutex_lock(&root->fs_info->trans_mutex); | |
2c90e5d6 CM |
303 | cur_trans->commit_done = 1; |
304 | wake_up(&cur_trans->commit_wait); | |
78fae27e | 305 | put_transaction(cur_trans); |
79154b1b | 306 | put_transaction(cur_trans); |
78fae27e | 307 | mutex_unlock(&root->fs_info->trans_mutex); |
2c90e5d6 | 308 | kmem_cache_free(btrfs_trans_handle_cachep, trans); |
79154b1b | 309 | |
0f7d52f4 | 310 | drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots); |
79154b1b CM |
311 | return ret; |
312 | } | |
313 |