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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
32static void 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
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70
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74
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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 key->objectid, key->type, key->offset);
159 BUG_ON(1);
160 }
161
162 l = path->nodes[0];
163 slot = path->slots[0];
164 ptr = btrfs_item_ptr_offset(l, slot);
165 old_len = btrfs_item_size_nr(l, slot);
166
167
168
169
170
171
172 if (old_len < sizeof(*item)) {
173 btrfs_release_path(path);
174 ret = btrfs_search_slot(trans, root, key, path,
175 -1, 1);
176 if (ret < 0) {
177 btrfs_abort_transaction(trans, root, ret);
178 goto out;
179 }
180
181 ret = btrfs_del_item(trans, root, path);
182 if (ret < 0) {
183 btrfs_abort_transaction(trans, root, ret);
184 goto out;
185 }
186 btrfs_release_path(path);
187 ret = btrfs_insert_empty_item(trans, root, path,
188 key, sizeof(*item));
189 if (ret < 0) {
190 btrfs_abort_transaction(trans, root, ret);
191 goto out;
192 }
193 l = path->nodes[0];
194 slot = path->slots[0];
195 ptr = btrfs_item_ptr_offset(l, slot);
196 }
197
198
199
200
201
202 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
203
204 write_extent_buffer(l, item, ptr, sizeof(*item));
205 btrfs_mark_buffer_dirty(path->nodes[0]);
206out:
207 btrfs_free_path(path);
208 return ret;
209}
210
211int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
212 struct btrfs_key *key, struct btrfs_root_item *item)
213{
214
215
216
217 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
218 return btrfs_insert_item(trans, root, key, item, sizeof(*item));
219}
220
221int btrfs_find_orphan_roots(struct btrfs_root *tree_root)
222{
223 struct extent_buffer *leaf;
224 struct btrfs_path *path;
225 struct btrfs_key key;
226 struct btrfs_key root_key;
227 struct btrfs_root *root;
228 int err = 0;
229 int ret;
230 bool can_recover = true;
231
232 if (tree_root->fs_info->sb->s_flags & MS_RDONLY)
233 can_recover = false;
234
235 path = btrfs_alloc_path();
236 if (!path)
237 return -ENOMEM;
238
239 key.objectid = BTRFS_ORPHAN_OBJECTID;
240 key.type = BTRFS_ORPHAN_ITEM_KEY;
241 key.offset = 0;
242
243 root_key.type = BTRFS_ROOT_ITEM_KEY;
244 root_key.offset = (u64)-1;
245
246 while (1) {
247 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
248 if (ret < 0) {
249 err = ret;
250 break;
251 }
252
253 leaf = path->nodes[0];
254 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
255 ret = btrfs_next_leaf(tree_root, path);
256 if (ret < 0)
257 err = ret;
258 if (ret != 0)
259 break;
260 leaf = path->nodes[0];
261 }
262
263 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
264 btrfs_release_path(path);
265
266 if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
267 key.type != BTRFS_ORPHAN_ITEM_KEY)
268 break;
269
270 root_key.objectid = key.offset;
271 key.offset++;
272
273 root = btrfs_read_fs_root(tree_root, &root_key);
274 err = PTR_RET(root);
275 if (err && err != -ENOENT) {
276 break;
277 } else if (err == -ENOENT) {
278 struct btrfs_trans_handle *trans;
279
280 btrfs_release_path(path);
281
282 trans = btrfs_join_transaction(tree_root);
283 if (IS_ERR(trans)) {
284 err = PTR_ERR(trans);
285 btrfs_error(tree_root->fs_info, err,
286 "Failed to start trans to delete "
287 "orphan item");
288 break;
289 }
290 err = btrfs_del_orphan_item(trans, tree_root,
291 root_key.objectid);
292 btrfs_end_transaction(trans, tree_root);
293 if (err) {
294 btrfs_error(tree_root->fs_info, err,
295 "Failed to delete root orphan "
296 "item");
297 break;
298 }
299 continue;
300 }
301
302 err = btrfs_init_fs_root(root);
303 if (err) {
304 btrfs_free_fs_root(root);
305 break;
306 }
307
308 root->orphan_item_inserted = 1;
309
310 err = btrfs_insert_fs_root(root->fs_info, root);
311 if (err) {
312 BUG_ON(err == -EEXIST);
313 btrfs_free_fs_root(root);
314 break;
315 }
316
317 if (btrfs_root_refs(&root->root_item) == 0)
318 btrfs_add_dead_root(root);
319 }
320
321 btrfs_free_path(path);
322 return err;
323}
324
325
326int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
327 struct btrfs_key *key)
328{
329 struct btrfs_path *path;
330 int ret;
331
332 path = btrfs_alloc_path();
333 if (!path)
334 return -ENOMEM;
335 ret = btrfs_search_slot(trans, root, key, path, -1, 1);
336 if (ret < 0)
337 goto out;
338
339 BUG_ON(ret != 0);
340
341 ret = btrfs_del_item(trans, root, path);
342out:
343 btrfs_free_path(path);
344 return ret;
345}
346
347int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
348 struct btrfs_root *tree_root,
349 u64 root_id, u64 ref_id, u64 dirid, u64 *sequence,
350 const char *name, int name_len)
351
352{
353 struct btrfs_path *path;
354 struct btrfs_root_ref *ref;
355 struct extent_buffer *leaf;
356 struct btrfs_key key;
357 unsigned long ptr;
358 int err = 0;
359 int ret;
360
361 path = btrfs_alloc_path();
362 if (!path)
363 return -ENOMEM;
364
365 key.objectid = root_id;
366 key.type = BTRFS_ROOT_BACKREF_KEY;
367 key.offset = ref_id;
368again:
369 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
370 BUG_ON(ret < 0);
371 if (ret == 0) {
372 leaf = path->nodes[0];
373 ref = btrfs_item_ptr(leaf, path->slots[0],
374 struct btrfs_root_ref);
375
376 WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
377 WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
378 ptr = (unsigned long)(ref + 1);
379 WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
380 *sequence = btrfs_root_ref_sequence(leaf, ref);
381
382 ret = btrfs_del_item(trans, tree_root, path);
383 if (ret) {
384 err = ret;
385 goto out;
386 }
387 } else
388 err = -ENOENT;
389
390 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
391 btrfs_release_path(path);
392 key.objectid = ref_id;
393 key.type = BTRFS_ROOT_REF_KEY;
394 key.offset = root_id;
395 goto again;
396 }
397
398out:
399 btrfs_free_path(path);
400 return err;
401}
402
403int btrfs_find_root_ref(struct btrfs_root *tree_root,
404 struct btrfs_path *path,
405 u64 root_id, u64 ref_id)
406{
407 struct btrfs_key key;
408 int ret;
409
410 key.objectid = root_id;
411 key.type = BTRFS_ROOT_REF_KEY;
412 key.offset = ref_id;
413
414 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
415 return ret;
416}
417
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431
432
433int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
434 struct btrfs_root *tree_root,
435 u64 root_id, u64 ref_id, u64 dirid, u64 sequence,
436 const char *name, int name_len)
437{
438 struct btrfs_key key;
439 int ret;
440 struct btrfs_path *path;
441 struct btrfs_root_ref *ref;
442 struct extent_buffer *leaf;
443 unsigned long ptr;
444
445 path = btrfs_alloc_path();
446 if (!path)
447 return -ENOMEM;
448
449 key.objectid = root_id;
450 key.type = BTRFS_ROOT_BACKREF_KEY;
451 key.offset = ref_id;
452again:
453 ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
454 sizeof(*ref) + name_len);
455 if (ret) {
456 btrfs_abort_transaction(trans, tree_root, ret);
457 btrfs_free_path(path);
458 return ret;
459 }
460
461 leaf = path->nodes[0];
462 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
463 btrfs_set_root_ref_dirid(leaf, ref, dirid);
464 btrfs_set_root_ref_sequence(leaf, ref, sequence);
465 btrfs_set_root_ref_name_len(leaf, ref, name_len);
466 ptr = (unsigned long)(ref + 1);
467 write_extent_buffer(leaf, name, ptr, name_len);
468 btrfs_mark_buffer_dirty(leaf);
469
470 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
471 btrfs_release_path(path);
472 key.objectid = ref_id;
473 key.type = BTRFS_ROOT_REF_KEY;
474 key.offset = root_id;
475 goto again;
476 }
477
478 btrfs_free_path(path);
479 return 0;
480}
481
482
483
484
485
486
487
488void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
489{
490 u64 inode_flags = btrfs_stack_inode_flags(&root_item->inode);
491
492 if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
493 inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
494 btrfs_set_stack_inode_flags(&root_item->inode, inode_flags);
495 btrfs_set_root_flags(root_item, 0);
496 btrfs_set_root_limit(root_item, 0);
497 }
498}
499
500void btrfs_update_root_times(struct btrfs_trans_handle *trans,
501 struct btrfs_root *root)
502{
503 struct btrfs_root_item *item = &root->root_item;
504 struct timespec ct = CURRENT_TIME;
505
506 spin_lock(&root->root_item_lock);
507 btrfs_set_root_ctransid(item, trans->transid);
508 btrfs_set_stack_timespec_sec(&item->ctime, ct.tv_sec);
509 btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec);
510 spin_unlock(&root->root_item_lock);
511}
512