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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 | ||
3768f368 | 19 | #include "ctree.h" |
5eda7b5e | 20 | #include "transaction.h" |
3768f368 CM |
21 | #include "disk-io.h" |
22 | #include "print-tree.h" | |
23 | ||
bf4ef679 | 24 | /* |
d352ac68 CM |
25 | * search forward for a root, starting with objectid 'search_start' |
26 | * if a root key is found, the objectid we find is filled into 'found_objectid' | |
27 | * and 0 is returned. < 0 is returned on error, 1 if there is nothing | |
28 | * left in the tree. | |
bf4ef679 CM |
29 | */ |
30 | int btrfs_search_root(struct btrfs_root *root, u64 search_start, | |
31 | u64 *found_objectid) | |
32 | { | |
33 | struct btrfs_path *path; | |
34 | struct btrfs_key search_key; | |
35 | int ret; | |
36 | ||
37 | root = root->fs_info->tree_root; | |
38 | search_key.objectid = search_start; | |
39 | search_key.type = (u8)-1; | |
40 | search_key.offset = (u64)-1; | |
41 | ||
42 | path = btrfs_alloc_path(); | |
43 | BUG_ON(!path); | |
44 | again: | |
45 | ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); | |
46 | if (ret < 0) | |
47 | goto out; | |
48 | if (ret == 0) { | |
49 | ret = 1; | |
50 | goto out; | |
51 | } | |
52 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { | |
53 | ret = btrfs_next_leaf(root, path); | |
54 | if (ret) | |
55 | goto out; | |
56 | } | |
57 | btrfs_item_key_to_cpu(path->nodes[0], &search_key, path->slots[0]); | |
58 | if (search_key.type != BTRFS_ROOT_ITEM_KEY) { | |
59 | search_key.offset++; | |
60 | btrfs_release_path(root, path); | |
61 | goto again; | |
62 | } | |
63 | ret = 0; | |
64 | *found_objectid = search_key.objectid; | |
65 | ||
66 | out: | |
67 | btrfs_free_path(path); | |
68 | return ret; | |
69 | } | |
70 | ||
d352ac68 CM |
71 | /* |
72 | * lookup the root with the highest offset for a given objectid. The key we do | |
73 | * find is copied into 'key'. If we find something return 0, otherwise 1, < 0 | |
74 | * on error. | |
75 | */ | |
3768f368 CM |
76 | int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, |
77 | struct btrfs_root_item *item, struct btrfs_key *key) | |
78 | { | |
5caf2a00 | 79 | struct btrfs_path *path; |
3768f368 | 80 | struct btrfs_key search_key; |
5f39d397 CM |
81 | struct btrfs_key found_key; |
82 | struct extent_buffer *l; | |
3768f368 CM |
83 | int ret; |
84 | int slot; | |
85 | ||
86 | search_key.objectid = objectid; | |
0660b5af | 87 | search_key.type = BTRFS_ROOT_ITEM_KEY; |
5eda7b5e | 88 | search_key.offset = (u64)-1; |
3768f368 | 89 | |
5caf2a00 CM |
90 | path = btrfs_alloc_path(); |
91 | BUG_ON(!path); | |
5caf2a00 | 92 | ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); |
3768f368 CM |
93 | if (ret < 0) |
94 | goto out; | |
5f39d397 | 95 | |
3768f368 | 96 | BUG_ON(ret == 0); |
5f39d397 | 97 | l = path->nodes[0]; |
5caf2a00 CM |
98 | BUG_ON(path->slots[0] == 0); |
99 | slot = path->slots[0] - 1; | |
5f39d397 CM |
100 | btrfs_item_key_to_cpu(l, &found_key, slot); |
101 | if (found_key.objectid != objectid) { | |
3768f368 CM |
102 | ret = 1; |
103 | goto out; | |
104 | } | |
5f39d397 CM |
105 | read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot), |
106 | sizeof(*item)); | |
107 | memcpy(key, &found_key, sizeof(found_key)); | |
3768f368 CM |
108 | ret = 0; |
109 | out: | |
5caf2a00 | 110 | btrfs_free_path(path); |
3768f368 CM |
111 | return ret; |
112 | } | |
113 | ||
d352ac68 CM |
114 | /* |
115 | * copy the data in 'item' into the btree | |
116 | */ | |
e089f05c CM |
117 | int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root |
118 | *root, struct btrfs_key *key, struct btrfs_root_item | |
119 | *item) | |
3768f368 | 120 | { |
5caf2a00 | 121 | struct btrfs_path *path; |
5f39d397 | 122 | struct extent_buffer *l; |
3768f368 CM |
123 | int ret; |
124 | int slot; | |
5f39d397 | 125 | unsigned long ptr; |
3768f368 | 126 | |
5caf2a00 CM |
127 | path = btrfs_alloc_path(); |
128 | BUG_ON(!path); | |
5caf2a00 | 129 | ret = btrfs_search_slot(trans, root, key, path, 0, 1); |
3768f368 CM |
130 | if (ret < 0) |
131 | goto out; | |
d6667462 CM |
132 | |
133 | if (ret != 0) { | |
134 | btrfs_print_leaf(root, path->nodes[0]); | |
135 | printk("unable to update root key %Lu %u %Lu\n", | |
136 | key->objectid, key->type, key->offset); | |
137 | BUG_ON(1); | |
138 | } | |
139 | ||
5f39d397 | 140 | l = path->nodes[0]; |
5caf2a00 | 141 | slot = path->slots[0]; |
5f39d397 CM |
142 | ptr = btrfs_item_ptr_offset(l, slot); |
143 | write_extent_buffer(l, item, ptr, sizeof(*item)); | |
5caf2a00 | 144 | btrfs_mark_buffer_dirty(path->nodes[0]); |
3768f368 | 145 | out: |
5caf2a00 CM |
146 | btrfs_release_path(root, path); |
147 | btrfs_free_path(path); | |
3768f368 CM |
148 | return ret; |
149 | } | |
150 | ||
e089f05c CM |
151 | int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root |
152 | *root, struct btrfs_key *key, struct btrfs_root_item | |
153 | *item) | |
3768f368 CM |
154 | { |
155 | int ret; | |
e089f05c | 156 | ret = btrfs_insert_item(trans, root, key, item, sizeof(*item)); |
3768f368 CM |
157 | return ret; |
158 | } | |
159 | ||
d352ac68 CM |
160 | /* |
161 | * at mount time we want to find all the old transaction snapshots that were in | |
162 | * the process of being deleted if we crashed. This is any root item with an offset | |
163 | * lower than the latest root. They need to be queued for deletion to finish | |
164 | * what was happening when we crashed. | |
165 | */ | |
5ce14bbc CM |
166 | int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid, |
167 | struct btrfs_root *latest) | |
5eda7b5e CM |
168 | { |
169 | struct btrfs_root *dead_root; | |
170 | struct btrfs_item *item; | |
171 | struct btrfs_root_item *ri; | |
172 | struct btrfs_key key; | |
a7a16fd7 | 173 | struct btrfs_key found_key; |
5eda7b5e CM |
174 | struct btrfs_path *path; |
175 | int ret; | |
176 | u32 nritems; | |
5f39d397 | 177 | struct extent_buffer *leaf; |
5eda7b5e CM |
178 | int slot; |
179 | ||
5ce14bbc | 180 | key.objectid = objectid; |
5eda7b5e CM |
181 | btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); |
182 | key.offset = 0; | |
183 | path = btrfs_alloc_path(); | |
184 | if (!path) | |
185 | return -ENOMEM; | |
a7a16fd7 CM |
186 | |
187 | again: | |
5eda7b5e CM |
188 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
189 | if (ret < 0) | |
190 | goto err; | |
191 | while(1) { | |
5f39d397 CM |
192 | leaf = path->nodes[0]; |
193 | nritems = btrfs_header_nritems(leaf); | |
5eda7b5e CM |
194 | slot = path->slots[0]; |
195 | if (slot >= nritems) { | |
196 | ret = btrfs_next_leaf(root, path); | |
197 | if (ret) | |
198 | break; | |
5f39d397 CM |
199 | leaf = path->nodes[0]; |
200 | nritems = btrfs_header_nritems(leaf); | |
5eda7b5e CM |
201 | slot = path->slots[0]; |
202 | } | |
5f39d397 CM |
203 | item = btrfs_item_nr(leaf, slot); |
204 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
5eda7b5e CM |
205 | if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY) |
206 | goto next; | |
5ce14bbc CM |
207 | |
208 | if (key.objectid < objectid) | |
209 | goto next; | |
210 | ||
211 | if (key.objectid > objectid) | |
212 | break; | |
213 | ||
5eda7b5e | 214 | ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item); |
5f39d397 | 215 | if (btrfs_disk_root_refs(leaf, ri) != 0) |
5eda7b5e | 216 | goto next; |
5ce14bbc | 217 | |
a7a16fd7 CM |
218 | memcpy(&found_key, &key, sizeof(key)); |
219 | key.offset++; | |
220 | btrfs_release_path(root, path); | |
e02119d5 CM |
221 | dead_root = |
222 | btrfs_read_fs_root_no_radix(root->fs_info->tree_root, | |
223 | &found_key); | |
a1f39630 A |
224 | if (IS_ERR(dead_root)) { |
225 | ret = PTR_ERR(dead_root); | |
5eda7b5e CM |
226 | goto err; |
227 | } | |
5ce14bbc | 228 | |
1a40e23b ZY |
229 | if (objectid == BTRFS_TREE_RELOC_OBJECTID) |
230 | ret = btrfs_add_dead_reloc_root(dead_root); | |
231 | else | |
232 | ret = btrfs_add_dead_root(dead_root, latest); | |
5eda7b5e CM |
233 | if (ret) |
234 | goto err; | |
a7a16fd7 | 235 | goto again; |
5eda7b5e CM |
236 | next: |
237 | slot++; | |
238 | path->slots[0]++; | |
239 | } | |
240 | ret = 0; | |
241 | err: | |
242 | btrfs_free_path(path); | |
243 | return ret; | |
244 | } | |
245 | ||
d352ac68 | 246 | /* drop the root item for 'key' from 'root' */ |
e089f05c CM |
247 | int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
248 | struct btrfs_key *key) | |
3768f368 | 249 | { |
5caf2a00 | 250 | struct btrfs_path *path; |
3768f368 | 251 | int ret; |
c5739bba CM |
252 | u32 refs; |
253 | struct btrfs_root_item *ri; | |
5f39d397 | 254 | struct extent_buffer *leaf; |
3768f368 | 255 | |
5caf2a00 CM |
256 | path = btrfs_alloc_path(); |
257 | BUG_ON(!path); | |
5caf2a00 | 258 | ret = btrfs_search_slot(trans, root, key, path, -1, 1); |
3768f368 CM |
259 | if (ret < 0) |
260 | goto out; | |
edbd8d4e CM |
261 | if (ret) { |
262 | btrfs_print_leaf(root, path->nodes[0]); | |
263 | printk("failed to del %Lu %u %Lu\n", key->objectid, key->type, key->offset); | |
264 | ||
265 | } | |
3768f368 | 266 | BUG_ON(ret != 0); |
5f39d397 CM |
267 | leaf = path->nodes[0]; |
268 | ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item); | |
c5739bba | 269 | |
5f39d397 | 270 | refs = btrfs_disk_root_refs(leaf, ri); |
5eda7b5e CM |
271 | BUG_ON(refs != 0); |
272 | ret = btrfs_del_item(trans, root, path); | |
3768f368 | 273 | out: |
5caf2a00 CM |
274 | btrfs_release_path(root, path); |
275 | btrfs_free_path(path); | |
3768f368 CM |
276 | return ret; |
277 | } | |
0660b5af | 278 | |
b2950863 | 279 | #if 0 /* this will get used when snapshot deletion is implemented */ |
0660b5af CM |
280 | int btrfs_del_root_ref(struct btrfs_trans_handle *trans, |
281 | struct btrfs_root *tree_root, | |
282 | u64 root_id, u8 type, u64 ref_id) | |
283 | { | |
284 | struct btrfs_key key; | |
285 | int ret; | |
286 | struct btrfs_path *path; | |
287 | ||
288 | path = btrfs_alloc_path(); | |
289 | ||
290 | key.objectid = root_id; | |
291 | key.type = type; | |
292 | key.offset = ref_id; | |
293 | ||
294 | ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1); | |
295 | BUG_ON(ret); | |
296 | ||
297 | ret = btrfs_del_item(trans, tree_root, path); | |
298 | BUG_ON(ret); | |
299 | ||
300 | btrfs_free_path(path); | |
301 | return ret; | |
302 | } | |
b2950863 | 303 | #endif |
0660b5af | 304 | |
ea9e8b11 CM |
305 | int btrfs_find_root_ref(struct btrfs_root *tree_root, |
306 | struct btrfs_path *path, | |
307 | u64 root_id, u64 ref_id) | |
308 | { | |
309 | struct btrfs_key key; | |
310 | int ret; | |
311 | ||
312 | key.objectid = root_id; | |
313 | key.type = BTRFS_ROOT_REF_KEY; | |
314 | key.offset = ref_id; | |
315 | ||
316 | ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); | |
317 | return ret; | |
318 | } | |
319 | ||
320 | ||
0660b5af CM |
321 | /* |
322 | * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY | |
323 | * or BTRFS_ROOT_BACKREF_KEY. | |
324 | * | |
325 | * The dirid, sequence, name and name_len refer to the directory entry | |
326 | * that is referencing the root. | |
327 | * | |
328 | * For a forward ref, the root_id is the id of the tree referencing | |
329 | * the root and ref_id is the id of the subvol or snapshot. | |
330 | * | |
331 | * For a back ref the root_id is the id of the subvol or snapshot and | |
332 | * ref_id is the id of the tree referencing it. | |
333 | */ | |
334 | int btrfs_add_root_ref(struct btrfs_trans_handle *trans, | |
335 | struct btrfs_root *tree_root, | |
336 | u64 root_id, u8 type, u64 ref_id, | |
337 | u64 dirid, u64 sequence, | |
338 | const char *name, int name_len) | |
339 | { | |
340 | struct btrfs_key key; | |
341 | int ret; | |
342 | struct btrfs_path *path; | |
343 | struct btrfs_root_ref *ref; | |
344 | struct extent_buffer *leaf; | |
345 | unsigned long ptr; | |
346 | ||
347 | ||
348 | path = btrfs_alloc_path(); | |
349 | ||
350 | key.objectid = root_id; | |
351 | key.type = type; | |
352 | key.offset = ref_id; | |
353 | ||
354 | ret = btrfs_insert_empty_item(trans, tree_root, path, &key, | |
355 | sizeof(*ref) + name_len); | |
356 | BUG_ON(ret); | |
357 | ||
358 | leaf = path->nodes[0]; | |
359 | ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); | |
360 | btrfs_set_root_ref_dirid(leaf, ref, dirid); | |
361 | btrfs_set_root_ref_sequence(leaf, ref, sequence); | |
362 | btrfs_set_root_ref_name_len(leaf, ref, name_len); | |
363 | ptr = (unsigned long)(ref + 1); | |
364 | write_extent_buffer(leaf, name, ptr, name_len); | |
365 | btrfs_mark_buffer_dirty(leaf); | |
366 | ||
367 | btrfs_free_path(path); | |
368 | return ret; | |
369 | } |