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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 | ||
8ea05e3a | 19 | #include <linux/uuid.h> |
3768f368 | 20 | #include "ctree.h" |
5eda7b5e | 21 | #include "transaction.h" |
3768f368 CM |
22 | #include "disk-io.h" |
23 | #include "print-tree.h" | |
24 | ||
8ea05e3a AB |
25 | /* |
26 | * Read a root item from the tree. In case we detect a root item smaller then | |
27 | * sizeof(root_item), we know it's an old version of the root structure and | |
28 | * initialize all new fields to zero. The same happens if we detect mismatching | |
29 | * generation numbers as then we know the root was once mounted with an older | |
30 | * kernel that was not aware of the root item structure change. | |
31 | */ | |
5fbf83c1 SB |
32 | void btrfs_read_root_item(struct extent_buffer *eb, int slot, |
33 | struct btrfs_root_item *item) | |
8ea05e3a AB |
34 | { |
35 | uuid_le uuid; | |
36 | int len; | |
37 | int need_reset = 0; | |
38 | ||
39 | len = btrfs_item_size_nr(eb, slot); | |
40 | read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot), | |
41 | min_t(int, len, (int)sizeof(*item))); | |
42 | if (len < sizeof(*item)) | |
43 | need_reset = 1; | |
44 | if (!need_reset && btrfs_root_generation(item) | |
45 | != btrfs_root_generation_v2(item)) { | |
46 | if (btrfs_root_generation_v2(item) != 0) { | |
47 | printk(KERN_WARNING "btrfs: mismatching " | |
48 | "generation and generation_v2 " | |
49 | "found in root item. This root " | |
50 | "was probably mounted with an " | |
51 | "older kernel. Resetting all " | |
52 | "new fields.\n"); | |
53 | } | |
54 | need_reset = 1; | |
55 | } | |
56 | if (need_reset) { | |
57 | memset(&item->generation_v2, 0, | |
58 | sizeof(*item) - offsetof(struct btrfs_root_item, | |
59 | generation_v2)); | |
60 | ||
61 | uuid_le_gen(&uuid); | |
62 | memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE); | |
63 | } | |
64 | } | |
65 | ||
d352ac68 | 66 | /* |
cb517eab MX |
67 | * btrfs_find_root - lookup the root by the key. |
68 | * root: the root of the root tree | |
69 | * search_key: the key to search | |
70 | * path: the path we search | |
71 | * root_item: the root item of the tree we look for | |
72 | * root_key: the reak key of the tree we look for | |
73 | * | |
74 | * If ->offset of 'seach_key' is -1ULL, it means we are not sure the offset | |
75 | * of the search key, just lookup the root with the highest offset for a | |
76 | * given objectid. | |
77 | * | |
78 | * If we find something return 0, otherwise > 0, < 0 on error. | |
d352ac68 | 79 | */ |
cb517eab MX |
80 | int btrfs_find_root(struct btrfs_root *root, struct btrfs_key *search_key, |
81 | struct btrfs_path *path, struct btrfs_root_item *root_item, | |
82 | struct btrfs_key *root_key) | |
3768f368 | 83 | { |
5f39d397 CM |
84 | struct btrfs_key found_key; |
85 | struct extent_buffer *l; | |
3768f368 CM |
86 | int ret; |
87 | int slot; | |
88 | ||
cb517eab | 89 | ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0); |
3768f368 | 90 | if (ret < 0) |
cb517eab | 91 | return ret; |
5f39d397 | 92 | |
cb517eab MX |
93 | if (search_key->offset != -1ULL) { /* the search key is exact */ |
94 | if (ret > 0) | |
95 | goto out; | |
96 | } else { | |
97 | BUG_ON(ret == 0); /* Logical error */ | |
98 | if (path->slots[0] == 0) | |
99 | goto out; | |
100 | path->slots[0]--; | |
101 | ret = 0; | |
76dda93c | 102 | } |
cb517eab | 103 | |
5f39d397 | 104 | l = path->nodes[0]; |
cb517eab MX |
105 | slot = path->slots[0]; |
106 | ||
5f39d397 | 107 | btrfs_item_key_to_cpu(l, &found_key, slot); |
cb517eab | 108 | if (found_key.objectid != search_key->objectid || |
76dda93c | 109 | found_key.type != BTRFS_ROOT_ITEM_KEY) { |
3768f368 CM |
110 | ret = 1; |
111 | goto out; | |
112 | } | |
8ea05e3a | 113 | |
cb517eab MX |
114 | if (root_item) |
115 | btrfs_read_root_item(l, slot, root_item); | |
116 | if (root_key) | |
117 | memcpy(root_key, &found_key, sizeof(found_key)); | |
3768f368 | 118 | out: |
cb517eab | 119 | btrfs_release_path(path); |
3768f368 CM |
120 | return ret; |
121 | } | |
122 | ||
bf5f32ec MF |
123 | void btrfs_set_root_node(struct btrfs_root_item *item, |
124 | struct extent_buffer *node) | |
5d4f98a2 YZ |
125 | { |
126 | btrfs_set_root_bytenr(item, node->start); | |
127 | btrfs_set_root_level(item, btrfs_header_level(node)); | |
128 | btrfs_set_root_generation(item, btrfs_header_generation(node)); | |
5d4f98a2 YZ |
129 | } |
130 | ||
d352ac68 CM |
131 | /* |
132 | * copy the data in 'item' into the btree | |
133 | */ | |
e089f05c CM |
134 | int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root |
135 | *root, struct btrfs_key *key, struct btrfs_root_item | |
136 | *item) | |
3768f368 | 137 | { |
5caf2a00 | 138 | struct btrfs_path *path; |
5f39d397 | 139 | struct extent_buffer *l; |
3768f368 CM |
140 | int ret; |
141 | int slot; | |
5f39d397 | 142 | unsigned long ptr; |
8ea05e3a | 143 | int old_len; |
3768f368 | 144 | |
5caf2a00 | 145 | path = btrfs_alloc_path(); |
b45a9d8b JM |
146 | if (!path) |
147 | return -ENOMEM; | |
148 | ||
5caf2a00 | 149 | ret = btrfs_search_slot(trans, root, key, path, 0, 1); |
005d6427 DS |
150 | if (ret < 0) { |
151 | btrfs_abort_transaction(trans, root, ret); | |
152 | goto out; | |
153 | } | |
d6667462 CM |
154 | |
155 | if (ret != 0) { | |
156 | btrfs_print_leaf(root, path->nodes[0]); | |
d397712b CM |
157 | printk(KERN_CRIT "unable to update root key %llu %u %llu\n", |
158 | (unsigned long long)key->objectid, key->type, | |
159 | (unsigned long long)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; | |
231 | ||
232 | path = btrfs_alloc_path(); | |
233 | if (!path) | |
234 | return -ENOMEM; | |
235 | ||
236 | key.objectid = BTRFS_ORPHAN_OBJECTID; | |
237 | key.type = BTRFS_ORPHAN_ITEM_KEY; | |
238 | key.offset = 0; | |
239 | ||
d68fc57b YZ |
240 | root_key.type = BTRFS_ROOT_ITEM_KEY; |
241 | root_key.offset = (u64)-1; | |
242 | ||
76dda93c YZ |
243 | while (1) { |
244 | ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); | |
245 | if (ret < 0) { | |
246 | err = ret; | |
247 | break; | |
248 | } | |
249 | ||
250 | leaf = path->nodes[0]; | |
251 | if (path->slots[0] >= btrfs_header_nritems(leaf)) { | |
252 | ret = btrfs_next_leaf(tree_root, path); | |
253 | if (ret < 0) | |
254 | err = ret; | |
255 | if (ret != 0) | |
256 | break; | |
257 | leaf = path->nodes[0]; | |
258 | } | |
259 | ||
260 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); | |
b3b4aa74 | 261 | btrfs_release_path(path); |
76dda93c YZ |
262 | |
263 | if (key.objectid != BTRFS_ORPHAN_OBJECTID || | |
264 | key.type != BTRFS_ORPHAN_ITEM_KEY) | |
265 | break; | |
266 | ||
d68fc57b YZ |
267 | root_key.objectid = key.offset; |
268 | key.offset++; | |
269 | ||
cb517eab MX |
270 | root = btrfs_read_fs_root(tree_root, &root_key); |
271 | if (IS_ERR(root)) { | |
272 | err = PTR_ERR(root); | |
273 | break; | |
274 | } | |
275 | ||
276 | if (btrfs_root_refs(&root->root_item) == 0) { | |
277 | btrfs_add_dead_root(root); | |
d68fc57b | 278 | continue; |
cb517eab | 279 | } |
d68fc57b | 280 | |
cb517eab MX |
281 | err = btrfs_init_fs_root(root); |
282 | if (err) { | |
283 | btrfs_free_fs_root(root); | |
76dda93c YZ |
284 | break; |
285 | } | |
286 | ||
cb517eab MX |
287 | root->orphan_item_inserted = 1; |
288 | ||
289 | err = btrfs_insert_fs_root(root->fs_info, root); | |
290 | if (err) { | |
291 | BUG_ON(err == -EEXIST); | |
292 | btrfs_free_fs_root(root); | |
d68fc57b YZ |
293 | break; |
294 | } | |
76dda93c YZ |
295 | } |
296 | ||
297 | btrfs_free_path(path); | |
298 | return err; | |
299 | } | |
300 | ||
d352ac68 | 301 | /* drop the root item for 'key' from 'root' */ |
e089f05c CM |
302 | int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
303 | struct btrfs_key *key) | |
3768f368 | 304 | { |
5caf2a00 | 305 | struct btrfs_path *path; |
3768f368 | 306 | int ret; |
c5739bba | 307 | struct btrfs_root_item *ri; |
5f39d397 | 308 | struct extent_buffer *leaf; |
3768f368 | 309 | |
5caf2a00 | 310 | path = btrfs_alloc_path(); |
db5b493a TI |
311 | if (!path) |
312 | return -ENOMEM; | |
5caf2a00 | 313 | ret = btrfs_search_slot(trans, root, key, path, -1, 1); |
3768f368 CM |
314 | if (ret < 0) |
315 | goto out; | |
edbd8d4e | 316 | |
3768f368 | 317 | BUG_ON(ret != 0); |
5f39d397 CM |
318 | leaf = path->nodes[0]; |
319 | ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item); | |
c5739bba | 320 | |
5eda7b5e | 321 | ret = btrfs_del_item(trans, root, path); |
3768f368 | 322 | out: |
5caf2a00 | 323 | btrfs_free_path(path); |
3768f368 CM |
324 | return ret; |
325 | } | |
0660b5af CM |
326 | |
327 | int btrfs_del_root_ref(struct btrfs_trans_handle *trans, | |
328 | struct btrfs_root *tree_root, | |
4df27c4d YZ |
329 | u64 root_id, u64 ref_id, u64 dirid, u64 *sequence, |
330 | const char *name, int name_len) | |
331 | ||
0660b5af | 332 | { |
4df27c4d YZ |
333 | struct btrfs_path *path; |
334 | struct btrfs_root_ref *ref; | |
335 | struct extent_buffer *leaf; | |
0660b5af | 336 | struct btrfs_key key; |
4df27c4d YZ |
337 | unsigned long ptr; |
338 | int err = 0; | |
0660b5af | 339 | int ret; |
0660b5af CM |
340 | |
341 | path = btrfs_alloc_path(); | |
4df27c4d YZ |
342 | if (!path) |
343 | return -ENOMEM; | |
0660b5af CM |
344 | |
345 | key.objectid = root_id; | |
4df27c4d | 346 | key.type = BTRFS_ROOT_BACKREF_KEY; |
0660b5af | 347 | key.offset = ref_id; |
4df27c4d | 348 | again: |
0660b5af | 349 | ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1); |
4df27c4d YZ |
350 | BUG_ON(ret < 0); |
351 | if (ret == 0) { | |
352 | leaf = path->nodes[0]; | |
353 | ref = btrfs_item_ptr(leaf, path->slots[0], | |
354 | struct btrfs_root_ref); | |
355 | ||
356 | WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid); | |
357 | WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len); | |
358 | ptr = (unsigned long)(ref + 1); | |
359 | WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len)); | |
360 | *sequence = btrfs_root_ref_sequence(leaf, ref); | |
361 | ||
362 | ret = btrfs_del_item(trans, tree_root, path); | |
65a246c5 TI |
363 | if (ret) { |
364 | err = ret; | |
365 | goto out; | |
366 | } | |
4df27c4d YZ |
367 | } else |
368 | err = -ENOENT; | |
369 | ||
370 | if (key.type == BTRFS_ROOT_BACKREF_KEY) { | |
b3b4aa74 | 371 | btrfs_release_path(path); |
4df27c4d YZ |
372 | key.objectid = ref_id; |
373 | key.type = BTRFS_ROOT_REF_KEY; | |
374 | key.offset = root_id; | |
375 | goto again; | |
376 | } | |
0660b5af | 377 | |
65a246c5 | 378 | out: |
0660b5af | 379 | btrfs_free_path(path); |
4df27c4d | 380 | return err; |
0660b5af CM |
381 | } |
382 | ||
ea9e8b11 CM |
383 | int btrfs_find_root_ref(struct btrfs_root *tree_root, |
384 | struct btrfs_path *path, | |
385 | u64 root_id, u64 ref_id) | |
386 | { | |
387 | struct btrfs_key key; | |
388 | int ret; | |
389 | ||
390 | key.objectid = root_id; | |
391 | key.type = BTRFS_ROOT_REF_KEY; | |
392 | key.offset = ref_id; | |
393 | ||
394 | ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); | |
395 | return ret; | |
396 | } | |
397 | ||
0660b5af CM |
398 | /* |
399 | * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY | |
400 | * or BTRFS_ROOT_BACKREF_KEY. | |
401 | * | |
402 | * The dirid, sequence, name and name_len refer to the directory entry | |
403 | * that is referencing the root. | |
404 | * | |
405 | * For a forward ref, the root_id is the id of the tree referencing | |
406 | * the root and ref_id is the id of the subvol or snapshot. | |
407 | * | |
408 | * For a back ref the root_id is the id of the subvol or snapshot and | |
409 | * ref_id is the id of the tree referencing it. | |
79787eaa JM |
410 | * |
411 | * Will return 0, -ENOMEM, or anything from the CoW path | |
0660b5af CM |
412 | */ |
413 | int btrfs_add_root_ref(struct btrfs_trans_handle *trans, | |
414 | struct btrfs_root *tree_root, | |
4df27c4d | 415 | u64 root_id, u64 ref_id, u64 dirid, u64 sequence, |
0660b5af CM |
416 | const char *name, int name_len) |
417 | { | |
418 | struct btrfs_key key; | |
419 | int ret; | |
420 | struct btrfs_path *path; | |
421 | struct btrfs_root_ref *ref; | |
422 | struct extent_buffer *leaf; | |
423 | unsigned long ptr; | |
424 | ||
0660b5af | 425 | path = btrfs_alloc_path(); |
4df27c4d YZ |
426 | if (!path) |
427 | return -ENOMEM; | |
0660b5af CM |
428 | |
429 | key.objectid = root_id; | |
4df27c4d | 430 | key.type = BTRFS_ROOT_BACKREF_KEY; |
0660b5af | 431 | key.offset = ref_id; |
4df27c4d | 432 | again: |
0660b5af CM |
433 | ret = btrfs_insert_empty_item(trans, tree_root, path, &key, |
434 | sizeof(*ref) + name_len); | |
79787eaa JM |
435 | if (ret) { |
436 | btrfs_abort_transaction(trans, tree_root, ret); | |
437 | btrfs_free_path(path); | |
438 | return ret; | |
439 | } | |
0660b5af CM |
440 | |
441 | leaf = path->nodes[0]; | |
442 | ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); | |
443 | btrfs_set_root_ref_dirid(leaf, ref, dirid); | |
444 | btrfs_set_root_ref_sequence(leaf, ref, sequence); | |
445 | btrfs_set_root_ref_name_len(leaf, ref, name_len); | |
446 | ptr = (unsigned long)(ref + 1); | |
447 | write_extent_buffer(leaf, name, ptr, name_len); | |
448 | btrfs_mark_buffer_dirty(leaf); | |
449 | ||
4df27c4d | 450 | if (key.type == BTRFS_ROOT_BACKREF_KEY) { |
b3b4aa74 | 451 | btrfs_release_path(path); |
4df27c4d YZ |
452 | key.objectid = ref_id; |
453 | key.type = BTRFS_ROOT_REF_KEY; | |
454 | key.offset = root_id; | |
455 | goto again; | |
456 | } | |
457 | ||
0660b5af | 458 | btrfs_free_path(path); |
4df27c4d | 459 | return 0; |
0660b5af | 460 | } |
08fe4db1 LZ |
461 | |
462 | /* | |
463 | * Old btrfs forgets to init root_item->flags and root_item->byte_limit | |
464 | * for subvolumes. To work around this problem, we steal a bit from | |
465 | * root_item->inode_item->flags, and use it to indicate if those fields | |
466 | * have been properly initialized. | |
467 | */ | |
468 | void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item) | |
469 | { | |
470 | u64 inode_flags = le64_to_cpu(root_item->inode.flags); | |
471 | ||
472 | if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) { | |
473 | inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT; | |
474 | root_item->inode.flags = cpu_to_le64(inode_flags); | |
475 | root_item->flags = 0; | |
476 | root_item->byte_limit = 0; | |
477 | } | |
478 | } | |
8ea05e3a AB |
479 | |
480 | void btrfs_update_root_times(struct btrfs_trans_handle *trans, | |
481 | struct btrfs_root *root) | |
482 | { | |
483 | struct btrfs_root_item *item = &root->root_item; | |
484 | struct timespec ct = CURRENT_TIME; | |
485 | ||
5f3ab90a | 486 | spin_lock(&root->root_item_lock); |
dadd1105 | 487 | item->ctransid = cpu_to_le64(trans->transid); |
8ea05e3a | 488 | item->ctime.sec = cpu_to_le64(ct.tv_sec); |
dadd1105 | 489 | item->ctime.nsec = cpu_to_le32(ct.tv_nsec); |
5f3ab90a | 490 | spin_unlock(&root->root_item_lock); |
8ea05e3a | 491 | } |