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19#include <linux/uuid.h>
20#include "ctree.h"
21#include "transaction.h"
22#include "disk-io.h"
23#include "print-tree.h"
24
25
26
27
28
29
30
31
32void btrfs_read_root_item(struct extent_buffer *eb, int slot,
33 struct btrfs_root_item *item)
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
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80int 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)
83{
84 struct btrfs_key found_key;
85 struct extent_buffer *l;
86 int ret;
87 int slot;
88
89 ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0);
90 if (ret < 0)
91 return ret;
92
93 if (search_key->offset != -1ULL) {
94 if (ret > 0)
95 goto out;
96 } else {
97 BUG_ON(ret == 0);
98 if (path->slots[0] == 0)
99 goto out;
100 path->slots[0]--;
101 ret = 0;
102 }
103
104 l = path->nodes[0];
105 slot = path->slots[0];
106
107 btrfs_item_key_to_cpu(l, &found_key, slot);
108 if (found_key.objectid != search_key->objectid ||
109 found_key.type != BTRFS_ROOT_ITEM_KEY) {
110 ret = 1;
111 goto out;
112 }
113
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));
118out:
119 btrfs_release_path(path);
120 return ret;
121}
122
123void btrfs_set_root_node(struct btrfs_root_item *item,
124 struct extent_buffer *node)
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));
129}
130
131
132
133
134int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
135 *root, struct btrfs_key *key, struct btrfs_root_item
136 *item)
137{
138 struct btrfs_path *path;
139 struct extent_buffer *l;
140 int ret;
141 int slot;
142 unsigned long ptr;
143 int old_len;
144
145 path = btrfs_alloc_path();
146 if (!path)
147 return -ENOMEM;
148
149 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
150 if (ret < 0) {
151 btrfs_abort_transaction(trans, root, ret);
152 goto out;
153 }
154
155 if (ret != 0) {
156 btrfs_print_leaf(root, path->nodes[0]);
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);
160 BUG_ON(1);
161 }
162
163 l = path->nodes[0];
164 slot = path->slots[0];
165 ptr = btrfs_item_ptr_offset(l, slot);
166 old_len = btrfs_item_size_nr(l, slot);
167
168
169
170
171
172
173 if (old_len < sizeof(*item)) {
174 btrfs_release_path(path);
175 ret = btrfs_search_slot(trans, root, key, path,
176 -1, 1);
177 if (ret < 0) {
178 btrfs_abort_transaction(trans, root, ret);
179 goto out;
180 }
181
182 ret = btrfs_del_item(trans, root, path);
183 if (ret < 0) {
184 btrfs_abort_transaction(trans, root, ret);
185 goto out;
186 }
187 btrfs_release_path(path);
188 ret = btrfs_insert_empty_item(trans, root, path,
189 key, sizeof(*item));
190 if (ret < 0) {
191 btrfs_abort_transaction(trans, root, ret);
192 goto out;
193 }
194 l = path->nodes[0];
195 slot = path->slots[0];
196 ptr = btrfs_item_ptr_offset(l, slot);
197 }
198
199
200
201
202
203 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
204
205 write_extent_buffer(l, item, ptr, sizeof(*item));
206 btrfs_mark_buffer_dirty(path->nodes[0]);
207out:
208 btrfs_free_path(path);
209 return ret;
210}
211
212int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
213 struct btrfs_key *key, struct btrfs_root_item *item)
214{
215
216
217
218 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
219 return btrfs_insert_item(trans, root, key, item, sizeof(*item));
220}
221
222int 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;
227 struct btrfs_key root_key;
228 struct btrfs_root *root;
229 int err = 0;
230 int ret;
231 bool can_recover = true;
232
233 if (tree_root->fs_info->sb->s_flags & MS_RDONLY)
234 can_recover = false;
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
244 root_key.type = BTRFS_ROOT_ITEM_KEY;
245 root_key.offset = (u64)-1;
246
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]);
265 btrfs_release_path(path);
266
267 if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
268 key.type != BTRFS_ORPHAN_ITEM_KEY)
269 break;
270
271 root_key.objectid = key.offset;
272 key.offset++;
273
274 root = btrfs_read_fs_root(tree_root, &root_key);
275 err = PTR_RET(root);
276 if (err && err != -ENOENT) {
277 break;
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;
301 }
302
303 if (btrfs_root_refs(&root->root_item) == 0) {
304 btrfs_add_dead_root(root);
305 continue;
306 }
307
308 err = btrfs_init_fs_root(root);
309 if (err) {
310 btrfs_free_fs_root(root);
311 break;
312 }
313
314 root->orphan_item_inserted = 1;
315
316 err = btrfs_insert_fs_root(root->fs_info, root);
317 if (err) {
318 BUG_ON(err == -EEXIST);
319 btrfs_free_fs_root(root);
320 break;
321 }
322 }
323
324 btrfs_free_path(path);
325 return err;
326}
327
328
329int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
330 struct btrfs_key *key)
331{
332 struct btrfs_path *path;
333 int ret;
334
335 path = btrfs_alloc_path();
336 if (!path)
337 return -ENOMEM;
338 ret = btrfs_search_slot(trans, root, key, path, -1, 1);
339 if (ret < 0)
340 goto out;
341
342 BUG_ON(ret != 0);
343
344 ret = btrfs_del_item(trans, root, path);
345out:
346 btrfs_free_path(path);
347 return ret;
348}
349
350int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
351 struct btrfs_root *tree_root,
352 u64 root_id, u64 ref_id, u64 dirid, u64 *sequence,
353 const char *name, int name_len)
354
355{
356 struct btrfs_path *path;
357 struct btrfs_root_ref *ref;
358 struct extent_buffer *leaf;
359 struct btrfs_key key;
360 unsigned long ptr;
361 int err = 0;
362 int ret;
363
364 path = btrfs_alloc_path();
365 if (!path)
366 return -ENOMEM;
367
368 key.objectid = root_id;
369 key.type = BTRFS_ROOT_BACKREF_KEY;
370 key.offset = ref_id;
371again:
372 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
373 BUG_ON(ret < 0);
374 if (ret == 0) {
375 leaf = path->nodes[0];
376 ref = btrfs_item_ptr(leaf, path->slots[0],
377 struct btrfs_root_ref);
378
379 WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
380 WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
381 ptr = (unsigned long)(ref + 1);
382 WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
383 *sequence = btrfs_root_ref_sequence(leaf, ref);
384
385 ret = btrfs_del_item(trans, tree_root, path);
386 if (ret) {
387 err = ret;
388 goto out;
389 }
390 } else
391 err = -ENOENT;
392
393 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
394 btrfs_release_path(path);
395 key.objectid = ref_id;
396 key.type = BTRFS_ROOT_REF_KEY;
397 key.offset = root_id;
398 goto again;
399 }
400
401out:
402 btrfs_free_path(path);
403 return err;
404}
405
406int btrfs_find_root_ref(struct btrfs_root *tree_root,
407 struct btrfs_path *path,
408 u64 root_id, u64 ref_id)
409{
410 struct btrfs_key key;
411 int ret;
412
413 key.objectid = root_id;
414 key.type = BTRFS_ROOT_REF_KEY;
415 key.offset = ref_id;
416
417 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
418 return ret;
419}
420
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430
431
432
433
434
435
436int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
437 struct btrfs_root *tree_root,
438 u64 root_id, u64 ref_id, u64 dirid, u64 sequence,
439 const char *name, int name_len)
440{
441 struct btrfs_key key;
442 int ret;
443 struct btrfs_path *path;
444 struct btrfs_root_ref *ref;
445 struct extent_buffer *leaf;
446 unsigned long ptr;
447
448 path = btrfs_alloc_path();
449 if (!path)
450 return -ENOMEM;
451
452 key.objectid = root_id;
453 key.type = BTRFS_ROOT_BACKREF_KEY;
454 key.offset = ref_id;
455again:
456 ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
457 sizeof(*ref) + name_len);
458 if (ret) {
459 btrfs_abort_transaction(trans, tree_root, ret);
460 btrfs_free_path(path);
461 return ret;
462 }
463
464 leaf = path->nodes[0];
465 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
466 btrfs_set_root_ref_dirid(leaf, ref, dirid);
467 btrfs_set_root_ref_sequence(leaf, ref, sequence);
468 btrfs_set_root_ref_name_len(leaf, ref, name_len);
469 ptr = (unsigned long)(ref + 1);
470 write_extent_buffer(leaf, name, ptr, name_len);
471 btrfs_mark_buffer_dirty(leaf);
472
473 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
474 btrfs_release_path(path);
475 key.objectid = ref_id;
476 key.type = BTRFS_ROOT_REF_KEY;
477 key.offset = root_id;
478 goto again;
479 }
480
481 btrfs_free_path(path);
482 return 0;
483}
484
485
486
487
488
489
490
491void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
492{
493 u64 inode_flags = le64_to_cpu(root_item->inode.flags);
494
495 if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
496 inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
497 root_item->inode.flags = cpu_to_le64(inode_flags);
498 root_item->flags = 0;
499 root_item->byte_limit = 0;
500 }
501}
502
503void btrfs_update_root_times(struct btrfs_trans_handle *trans,
504 struct btrfs_root *root)
505{
506 struct btrfs_root_item *item = &root->root_item;
507 struct timespec ct = CURRENT_TIME;
508
509 spin_lock(&root->root_item_lock);
510 item->ctransid = cpu_to_le64(trans->transid);
511 item->ctime.sec = cpu_to_le64(ct.tv_sec);
512 item->ctime.nsec = cpu_to_le32(ct.tv_nsec);
513 spin_unlock(&root->root_item_lock);
514}
515