Commit | Line | Data |
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6cbd5570 CM |
1 | /* |
2 | * Copyright (C) 2007 Oracle. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
886322e8 | 19 | #include <linux/err.h> |
8ea05e3a | 20 | #include <linux/uuid.h> |
3768f368 | 21 | #include "ctree.h" |
5eda7b5e | 22 | #include "transaction.h" |
3768f368 CM |
23 | #include "disk-io.h" |
24 | #include "print-tree.h" | |
25 | ||
8ea05e3a AB |
26 | /* |
27 | * Read a root item from the tree. In case we detect a root item smaller then | |
28 | * sizeof(root_item), we know it's an old version of the root structure and | |
29 | * initialize all new fields to zero. The same happens if we detect mismatching | |
30 | * generation numbers as then we know the root was once mounted with an older | |
31 | * kernel that was not aware of the root item structure change. | |
32 | */ | |
171170c1 ST |
33 | static void btrfs_read_root_item(struct extent_buffer *eb, int slot, |
34 | struct btrfs_root_item *item) | |
8ea05e3a AB |
35 | { |
36 | uuid_le uuid; | |
37 | int len; | |
38 | int need_reset = 0; | |
39 | ||
40 | len = btrfs_item_size_nr(eb, slot); | |
41 | read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot), | |
42 | min_t(int, len, (int)sizeof(*item))); | |
43 | if (len < sizeof(*item)) | |
44 | need_reset = 1; | |
45 | if (!need_reset && btrfs_root_generation(item) | |
46 | != btrfs_root_generation_v2(item)) { | |
47 | if (btrfs_root_generation_v2(item) != 0) { | |
efe120a0 | 48 | printk(KERN_WARNING "BTRFS: mismatching " |
8ea05e3a AB |
49 | "generation and generation_v2 " |
50 | "found in root item. This root " | |
51 | "was probably mounted with an " | |
52 | "older kernel. Resetting all " | |
53 | "new fields.\n"); | |
54 | } | |
55 | need_reset = 1; | |
56 | } | |
57 | if (need_reset) { | |
58 | memset(&item->generation_v2, 0, | |
59 | sizeof(*item) - offsetof(struct btrfs_root_item, | |
60 | generation_v2)); | |
61 | ||
62 | uuid_le_gen(&uuid); | |
63 | memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE); | |
64 | } | |
65 | } | |
66 | ||
d352ac68 | 67 | /* |
cb517eab MX |
68 | * btrfs_find_root - lookup the root by the key. |
69 | * root: the root of the root tree | |
70 | * search_key: the key to search | |
71 | * path: the path we search | |
72 | * root_item: the root item of the tree we look for | |
73 | * root_key: the reak key of the tree we look for | |
74 | * | |
75 | * If ->offset of 'seach_key' is -1ULL, it means we are not sure the offset | |
76 | * of the search key, just lookup the root with the highest offset for a | |
77 | * given objectid. | |
78 | * | |
79 | * If we find something return 0, otherwise > 0, < 0 on error. | |
d352ac68 | 80 | */ |
cb517eab MX |
81 | int btrfs_find_root(struct btrfs_root *root, struct btrfs_key *search_key, |
82 | struct btrfs_path *path, struct btrfs_root_item *root_item, | |
83 | struct btrfs_key *root_key) | |
3768f368 | 84 | { |
5f39d397 CM |
85 | struct btrfs_key found_key; |
86 | struct extent_buffer *l; | |
3768f368 CM |
87 | int ret; |
88 | int slot; | |
89 | ||
cb517eab | 90 | ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0); |
3768f368 | 91 | if (ret < 0) |
cb517eab | 92 | return ret; |
5f39d397 | 93 | |
cb517eab MX |
94 | if (search_key->offset != -1ULL) { /* the search key is exact */ |
95 | if (ret > 0) | |
96 | goto out; | |
97 | } else { | |
98 | BUG_ON(ret == 0); /* Logical error */ | |
99 | if (path->slots[0] == 0) | |
100 | goto out; | |
101 | path->slots[0]--; | |
102 | ret = 0; | |
76dda93c | 103 | } |
cb517eab | 104 | |
5f39d397 | 105 | l = path->nodes[0]; |
cb517eab MX |
106 | slot = path->slots[0]; |
107 | ||
5f39d397 | 108 | btrfs_item_key_to_cpu(l, &found_key, slot); |
cb517eab | 109 | if (found_key.objectid != search_key->objectid || |
76dda93c | 110 | found_key.type != BTRFS_ROOT_ITEM_KEY) { |
3768f368 CM |
111 | ret = 1; |
112 | goto out; | |
113 | } | |
8ea05e3a | 114 | |
cb517eab MX |
115 | if (root_item) |
116 | btrfs_read_root_item(l, slot, root_item); | |
117 | if (root_key) | |
118 | memcpy(root_key, &found_key, sizeof(found_key)); | |
3768f368 | 119 | out: |
cb517eab | 120 | btrfs_release_path(path); |
3768f368 CM |
121 | return ret; |
122 | } | |
123 | ||
bf5f32ec MF |
124 | void btrfs_set_root_node(struct btrfs_root_item *item, |
125 | struct extent_buffer *node) | |
5d4f98a2 YZ |
126 | { |
127 | btrfs_set_root_bytenr(item, node->start); | |
128 | btrfs_set_root_level(item, btrfs_header_level(node)); | |
129 | btrfs_set_root_generation(item, btrfs_header_generation(node)); | |
5d4f98a2 YZ |
130 | } |
131 | ||
d352ac68 CM |
132 | /* |
133 | * copy the data in 'item' into the btree | |
134 | */ | |
e089f05c CM |
135 | int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root |
136 | *root, struct btrfs_key *key, struct btrfs_root_item | |
137 | *item) | |
3768f368 | 138 | { |
5caf2a00 | 139 | struct btrfs_path *path; |
5f39d397 | 140 | struct extent_buffer *l; |
3768f368 CM |
141 | int ret; |
142 | int slot; | |
5f39d397 | 143 | unsigned long ptr; |
8ea05e3a | 144 | int old_len; |
3768f368 | 145 | |
5caf2a00 | 146 | path = btrfs_alloc_path(); |
b45a9d8b JM |
147 | if (!path) |
148 | return -ENOMEM; | |
149 | ||
5caf2a00 | 150 | ret = btrfs_search_slot(trans, root, key, path, 0, 1); |
005d6427 DS |
151 | if (ret < 0) { |
152 | btrfs_abort_transaction(trans, root, ret); | |
153 | goto out; | |
154 | } | |
d6667462 CM |
155 | |
156 | if (ret != 0) { | |
157 | btrfs_print_leaf(root, path->nodes[0]); | |
efe120a0 | 158 | btrfs_crit(root->fs_info, "unable to update root key %llu %u %llu", |
c1c9ff7c | 159 | key->objectid, key->type, key->offset); |
d6667462 CM |
160 | BUG_ON(1); |
161 | } | |
162 | ||
5f39d397 | 163 | l = path->nodes[0]; |
5caf2a00 | 164 | slot = path->slots[0]; |
5f39d397 | 165 | ptr = btrfs_item_ptr_offset(l, slot); |
8ea05e3a AB |
166 | old_len = btrfs_item_size_nr(l, slot); |
167 | ||
168 | /* | |
169 | * If this is the first time we update the root item which originated | |
170 | * from an older kernel, we need to enlarge the item size to make room | |
171 | * for the added fields. | |
172 | */ | |
173 | if (old_len < sizeof(*item)) { | |
174 | btrfs_release_path(path); | |
175 | ret = btrfs_search_slot(trans, root, key, path, | |
176 | -1, 1); | |
005d6427 DS |
177 | if (ret < 0) { |
178 | btrfs_abort_transaction(trans, root, ret); | |
179 | goto out; | |
180 | } | |
181 | ||
8ea05e3a | 182 | ret = btrfs_del_item(trans, root, path); |
005d6427 DS |
183 | if (ret < 0) { |
184 | btrfs_abort_transaction(trans, root, ret); | |
185 | goto out; | |
186 | } | |
8ea05e3a AB |
187 | btrfs_release_path(path); |
188 | ret = btrfs_insert_empty_item(trans, root, path, | |
189 | key, sizeof(*item)); | |
005d6427 DS |
190 | if (ret < 0) { |
191 | btrfs_abort_transaction(trans, root, ret); | |
192 | goto out; | |
193 | } | |
8ea05e3a AB |
194 | l = path->nodes[0]; |
195 | slot = path->slots[0]; | |
196 | ptr = btrfs_item_ptr_offset(l, slot); | |
197 | } | |
198 | ||
199 | /* | |
200 | * Update generation_v2 so at the next mount we know the new root | |
201 | * fields are valid. | |
202 | */ | |
203 | btrfs_set_root_generation_v2(item, btrfs_root_generation(item)); | |
204 | ||
5f39d397 | 205 | write_extent_buffer(l, item, ptr, sizeof(*item)); |
5caf2a00 | 206 | btrfs_mark_buffer_dirty(path->nodes[0]); |
3768f368 | 207 | out: |
5caf2a00 | 208 | btrfs_free_path(path); |
3768f368 CM |
209 | return ret; |
210 | } | |
211 | ||
d16cb050 JM |
212 | int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
213 | struct btrfs_key *key, struct btrfs_root_item *item) | |
3768f368 | 214 | { |
8ea05e3a AB |
215 | /* |
216 | * Make sure generation v1 and v2 match. See update_root for details. | |
217 | */ | |
218 | btrfs_set_root_generation_v2(item, btrfs_root_generation(item)); | |
d16cb050 | 219 | return btrfs_insert_item(trans, root, key, item, sizeof(*item)); |
3768f368 CM |
220 | } |
221 | ||
76dda93c YZ |
222 | int btrfs_find_orphan_roots(struct btrfs_root *tree_root) |
223 | { | |
224 | struct extent_buffer *leaf; | |
225 | struct btrfs_path *path; | |
226 | struct btrfs_key key; | |
d68fc57b YZ |
227 | struct btrfs_key root_key; |
228 | struct btrfs_root *root; | |
76dda93c YZ |
229 | int err = 0; |
230 | int ret; | |
68a7342c JB |
231 | bool can_recover = true; |
232 | ||
233 | if (tree_root->fs_info->sb->s_flags & MS_RDONLY) | |
234 | can_recover = false; | |
76dda93c YZ |
235 | |
236 | path = btrfs_alloc_path(); | |
237 | if (!path) | |
238 | return -ENOMEM; | |
239 | ||
240 | key.objectid = BTRFS_ORPHAN_OBJECTID; | |
241 | key.type = BTRFS_ORPHAN_ITEM_KEY; | |
242 | key.offset = 0; | |
243 | ||
d68fc57b YZ |
244 | root_key.type = BTRFS_ROOT_ITEM_KEY; |
245 | root_key.offset = (u64)-1; | |
246 | ||
76dda93c YZ |
247 | while (1) { |
248 | ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); | |
249 | if (ret < 0) { | |
250 | err = ret; | |
251 | break; | |
252 | } | |
253 | ||
254 | leaf = path->nodes[0]; | |
255 | if (path->slots[0] >= btrfs_header_nritems(leaf)) { | |
256 | ret = btrfs_next_leaf(tree_root, path); | |
257 | if (ret < 0) | |
258 | err = ret; | |
259 | if (ret != 0) | |
260 | break; | |
261 | leaf = path->nodes[0]; | |
262 | } | |
263 | ||
264 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); | |
b3b4aa74 | 265 | btrfs_release_path(path); |
76dda93c YZ |
266 | |
267 | if (key.objectid != BTRFS_ORPHAN_OBJECTID || | |
268 | key.type != BTRFS_ORPHAN_ITEM_KEY) | |
269 | break; | |
270 | ||
d68fc57b YZ |
271 | root_key.objectid = key.offset; |
272 | key.offset++; | |
273 | ||
cb517eab | 274 | root = btrfs_read_fs_root(tree_root, &root_key); |
886322e8 | 275 | err = PTR_ERR_OR_ZERO(root); |
68a7342c | 276 | if (err && err != -ENOENT) { |
cb517eab | 277 | break; |
68a7342c JB |
278 | } else if (err == -ENOENT) { |
279 | struct btrfs_trans_handle *trans; | |
280 | ||
281 | btrfs_release_path(path); | |
282 | ||
283 | trans = btrfs_join_transaction(tree_root); | |
284 | if (IS_ERR(trans)) { | |
285 | err = PTR_ERR(trans); | |
286 | btrfs_error(tree_root->fs_info, err, | |
287 | "Failed to start trans to delete " | |
288 | "orphan item"); | |
289 | break; | |
290 | } | |
291 | err = btrfs_del_orphan_item(trans, tree_root, | |
292 | root_key.objectid); | |
293 | btrfs_end_transaction(trans, tree_root); | |
294 | if (err) { | |
295 | btrfs_error(tree_root->fs_info, err, | |
296 | "Failed to delete root orphan " | |
297 | "item"); | |
298 | break; | |
299 | } | |
300 | continue; | |
cb517eab MX |
301 | } |
302 | ||
cb517eab MX |
303 | err = btrfs_init_fs_root(root); |
304 | if (err) { | |
305 | btrfs_free_fs_root(root); | |
76dda93c YZ |
306 | break; |
307 | } | |
308 | ||
27cdeb70 | 309 | set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state); |
cb517eab MX |
310 | |
311 | err = btrfs_insert_fs_root(root->fs_info, root); | |
312 | if (err) { | |
313 | BUG_ON(err == -EEXIST); | |
314 | btrfs_free_fs_root(root); | |
d68fc57b YZ |
315 | break; |
316 | } | |
14927d95 MX |
317 | |
318 | if (btrfs_root_refs(&root->root_item) == 0) | |
319 | btrfs_add_dead_root(root); | |
76dda93c YZ |
320 | } |
321 | ||
322 | btrfs_free_path(path); | |
323 | return err; | |
324 | } | |
325 | ||
d352ac68 | 326 | /* drop the root item for 'key' from 'root' */ |
e089f05c CM |
327 | int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
328 | struct btrfs_key *key) | |
3768f368 | 329 | { |
5caf2a00 | 330 | struct btrfs_path *path; |
3768f368 CM |
331 | int ret; |
332 | ||
5caf2a00 | 333 | path = btrfs_alloc_path(); |
db5b493a TI |
334 | if (!path) |
335 | return -ENOMEM; | |
5caf2a00 | 336 | ret = btrfs_search_slot(trans, root, key, path, -1, 1); |
3768f368 CM |
337 | if (ret < 0) |
338 | goto out; | |
edbd8d4e | 339 | |
3768f368 | 340 | BUG_ON(ret != 0); |
c5739bba | 341 | |
5eda7b5e | 342 | ret = btrfs_del_item(trans, root, path); |
3768f368 | 343 | out: |
5caf2a00 | 344 | btrfs_free_path(path); |
3768f368 CM |
345 | return ret; |
346 | } | |
0660b5af CM |
347 | |
348 | int btrfs_del_root_ref(struct btrfs_trans_handle *trans, | |
349 | struct btrfs_root *tree_root, | |
4df27c4d YZ |
350 | u64 root_id, u64 ref_id, u64 dirid, u64 *sequence, |
351 | const char *name, int name_len) | |
352 | ||
0660b5af | 353 | { |
4df27c4d YZ |
354 | struct btrfs_path *path; |
355 | struct btrfs_root_ref *ref; | |
356 | struct extent_buffer *leaf; | |
0660b5af | 357 | struct btrfs_key key; |
4df27c4d YZ |
358 | unsigned long ptr; |
359 | int err = 0; | |
0660b5af | 360 | int ret; |
0660b5af CM |
361 | |
362 | path = btrfs_alloc_path(); | |
4df27c4d YZ |
363 | if (!path) |
364 | return -ENOMEM; | |
0660b5af CM |
365 | |
366 | key.objectid = root_id; | |
4df27c4d | 367 | key.type = BTRFS_ROOT_BACKREF_KEY; |
0660b5af | 368 | key.offset = ref_id; |
4df27c4d | 369 | again: |
0660b5af | 370 | ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1); |
4df27c4d YZ |
371 | BUG_ON(ret < 0); |
372 | if (ret == 0) { | |
373 | leaf = path->nodes[0]; | |
374 | ref = btrfs_item_ptr(leaf, path->slots[0], | |
375 | struct btrfs_root_ref); | |
376 | ||
377 | WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid); | |
378 | WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len); | |
379 | ptr = (unsigned long)(ref + 1); | |
380 | WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len)); | |
381 | *sequence = btrfs_root_ref_sequence(leaf, ref); | |
382 | ||
383 | ret = btrfs_del_item(trans, tree_root, path); | |
65a246c5 TI |
384 | if (ret) { |
385 | err = ret; | |
386 | goto out; | |
387 | } | |
4df27c4d YZ |
388 | } else |
389 | err = -ENOENT; | |
390 | ||
391 | if (key.type == BTRFS_ROOT_BACKREF_KEY) { | |
b3b4aa74 | 392 | btrfs_release_path(path); |
4df27c4d YZ |
393 | key.objectid = ref_id; |
394 | key.type = BTRFS_ROOT_REF_KEY; | |
395 | key.offset = root_id; | |
396 | goto again; | |
397 | } | |
0660b5af | 398 | |
65a246c5 | 399 | out: |
0660b5af | 400 | btrfs_free_path(path); |
4df27c4d | 401 | return err; |
0660b5af CM |
402 | } |
403 | ||
404 | /* | |
405 | * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY | |
406 | * or BTRFS_ROOT_BACKREF_KEY. | |
407 | * | |
408 | * The dirid, sequence, name and name_len refer to the directory entry | |
409 | * that is referencing the root. | |
410 | * | |
411 | * For a forward ref, the root_id is the id of the tree referencing | |
412 | * the root and ref_id is the id of the subvol or snapshot. | |
413 | * | |
414 | * For a back ref the root_id is the id of the subvol or snapshot and | |
415 | * ref_id is the id of the tree referencing it. | |
79787eaa JM |
416 | * |
417 | * Will return 0, -ENOMEM, or anything from the CoW path | |
0660b5af CM |
418 | */ |
419 | int btrfs_add_root_ref(struct btrfs_trans_handle *trans, | |
420 | struct btrfs_root *tree_root, | |
4df27c4d | 421 | u64 root_id, u64 ref_id, u64 dirid, u64 sequence, |
0660b5af CM |
422 | const char *name, int name_len) |
423 | { | |
424 | struct btrfs_key key; | |
425 | int ret; | |
426 | struct btrfs_path *path; | |
427 | struct btrfs_root_ref *ref; | |
428 | struct extent_buffer *leaf; | |
429 | unsigned long ptr; | |
430 | ||
0660b5af | 431 | path = btrfs_alloc_path(); |
4df27c4d YZ |
432 | if (!path) |
433 | return -ENOMEM; | |
0660b5af CM |
434 | |
435 | key.objectid = root_id; | |
4df27c4d | 436 | key.type = BTRFS_ROOT_BACKREF_KEY; |
0660b5af | 437 | key.offset = ref_id; |
4df27c4d | 438 | again: |
0660b5af CM |
439 | ret = btrfs_insert_empty_item(trans, tree_root, path, &key, |
440 | sizeof(*ref) + name_len); | |
79787eaa JM |
441 | if (ret) { |
442 | btrfs_abort_transaction(trans, tree_root, ret); | |
443 | btrfs_free_path(path); | |
444 | return ret; | |
445 | } | |
0660b5af CM |
446 | |
447 | leaf = path->nodes[0]; | |
448 | ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); | |
449 | btrfs_set_root_ref_dirid(leaf, ref, dirid); | |
450 | btrfs_set_root_ref_sequence(leaf, ref, sequence); | |
451 | btrfs_set_root_ref_name_len(leaf, ref, name_len); | |
452 | ptr = (unsigned long)(ref + 1); | |
453 | write_extent_buffer(leaf, name, ptr, name_len); | |
454 | btrfs_mark_buffer_dirty(leaf); | |
455 | ||
4df27c4d | 456 | if (key.type == BTRFS_ROOT_BACKREF_KEY) { |
b3b4aa74 | 457 | btrfs_release_path(path); |
4df27c4d YZ |
458 | key.objectid = ref_id; |
459 | key.type = BTRFS_ROOT_REF_KEY; | |
460 | key.offset = root_id; | |
461 | goto again; | |
462 | } | |
463 | ||
0660b5af | 464 | btrfs_free_path(path); |
4df27c4d | 465 | return 0; |
0660b5af | 466 | } |
08fe4db1 LZ |
467 | |
468 | /* | |
469 | * Old btrfs forgets to init root_item->flags and root_item->byte_limit | |
470 | * for subvolumes. To work around this problem, we steal a bit from | |
471 | * root_item->inode_item->flags, and use it to indicate if those fields | |
472 | * have been properly initialized. | |
473 | */ | |
474 | void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item) | |
475 | { | |
3cae210f | 476 | u64 inode_flags = btrfs_stack_inode_flags(&root_item->inode); |
08fe4db1 LZ |
477 | |
478 | if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) { | |
479 | inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT; | |
3cae210f QW |
480 | btrfs_set_stack_inode_flags(&root_item->inode, inode_flags); |
481 | btrfs_set_root_flags(root_item, 0); | |
482 | btrfs_set_root_limit(root_item, 0); | |
08fe4db1 LZ |
483 | } |
484 | } | |
8ea05e3a AB |
485 | |
486 | void btrfs_update_root_times(struct btrfs_trans_handle *trans, | |
487 | struct btrfs_root *root) | |
488 | { | |
489 | struct btrfs_root_item *item = &root->root_item; | |
490 | struct timespec ct = CURRENT_TIME; | |
491 | ||
5f3ab90a | 492 | spin_lock(&root->root_item_lock); |
3cae210f QW |
493 | btrfs_set_root_ctransid(item, trans->transid); |
494 | btrfs_set_stack_timespec_sec(&item->ctime, ct.tv_sec); | |
495 | btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec); | |
5f3ab90a | 496 | spin_unlock(&root->root_item_lock); |
8ea05e3a | 497 | } |