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6#include <linux/err.h>
7#include <linux/uuid.h>
8#include "ctree.h"
9#include "transaction.h"
10#include "disk-io.h"
11#include "print-tree.h"
12
13
14
15
16
17
18
19
20static void btrfs_read_root_item(struct extent_buffer *eb, int slot,
21 struct btrfs_root_item *item)
22{
23 uuid_le uuid;
24 u32 len;
25 int need_reset = 0;
26
27 len = btrfs_item_size_nr(eb, slot);
28 read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot),
29 min_t(u32, len, sizeof(*item)));
30 if (len < sizeof(*item))
31 need_reset = 1;
32 if (!need_reset && btrfs_root_generation(item)
33 != btrfs_root_generation_v2(item)) {
34 if (btrfs_root_generation_v2(item) != 0) {
35 btrfs_warn(eb->fs_info,
36 "mismatching generation and generation_v2 found in root item. This root was probably mounted with an older kernel. Resetting all new fields.");
37 }
38 need_reset = 1;
39 }
40 if (need_reset) {
41 memset(&item->generation_v2, 0,
42 sizeof(*item) - offsetof(struct btrfs_root_item,
43 generation_v2));
44
45 uuid_le_gen(&uuid);
46 memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE);
47 }
48}
49
50
51
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54
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60
61
62
63
64int btrfs_find_root(struct btrfs_root *root, const struct btrfs_key *search_key,
65 struct btrfs_path *path, struct btrfs_root_item *root_item,
66 struct btrfs_key *root_key)
67{
68 struct btrfs_key found_key;
69 struct extent_buffer *l;
70 int ret;
71 int slot;
72
73 ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0);
74 if (ret < 0)
75 return ret;
76
77 if (search_key->offset != -1ULL) {
78 if (ret > 0)
79 goto out;
80 } else {
81 BUG_ON(ret == 0);
82 if (path->slots[0] == 0)
83 goto out;
84 path->slots[0]--;
85 ret = 0;
86 }
87
88 l = path->nodes[0];
89 slot = path->slots[0];
90
91 btrfs_item_key_to_cpu(l, &found_key, slot);
92 if (found_key.objectid != search_key->objectid ||
93 found_key.type != BTRFS_ROOT_ITEM_KEY) {
94 ret = 1;
95 goto out;
96 }
97
98 if (root_item)
99 btrfs_read_root_item(l, slot, root_item);
100 if (root_key)
101 memcpy(root_key, &found_key, sizeof(found_key));
102out:
103 btrfs_release_path(path);
104 return ret;
105}
106
107void btrfs_set_root_node(struct btrfs_root_item *item,
108 struct extent_buffer *node)
109{
110 btrfs_set_root_bytenr(item, node->start);
111 btrfs_set_root_level(item, btrfs_header_level(node));
112 btrfs_set_root_generation(item, btrfs_header_generation(node));
113}
114
115
116
117
118int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
119 *root, struct btrfs_key *key, struct btrfs_root_item
120 *item)
121{
122 struct btrfs_fs_info *fs_info = root->fs_info;
123 struct btrfs_path *path;
124 struct extent_buffer *l;
125 int ret;
126 int slot;
127 unsigned long ptr;
128 u32 old_len;
129
130 path = btrfs_alloc_path();
131 if (!path)
132 return -ENOMEM;
133
134 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
135 if (ret < 0)
136 goto out;
137
138 if (ret > 0) {
139 btrfs_crit(fs_info,
140 "unable to find root key (%llu %u %llu) in tree %llu",
141 key->objectid, key->type, key->offset,
142 root->root_key.objectid);
143 ret = -EUCLEAN;
144 btrfs_abort_transaction(trans, ret);
145 goto out;
146 }
147
148 l = path->nodes[0];
149 slot = path->slots[0];
150 ptr = btrfs_item_ptr_offset(l, slot);
151 old_len = btrfs_item_size_nr(l, slot);
152
153
154
155
156
157
158 if (old_len < sizeof(*item)) {
159 btrfs_release_path(path);
160 ret = btrfs_search_slot(trans, root, key, path,
161 -1, 1);
162 if (ret < 0) {
163 btrfs_abort_transaction(trans, ret);
164 goto out;
165 }
166
167 ret = btrfs_del_item(trans, root, path);
168 if (ret < 0) {
169 btrfs_abort_transaction(trans, ret);
170 goto out;
171 }
172 btrfs_release_path(path);
173 ret = btrfs_insert_empty_item(trans, root, path,
174 key, sizeof(*item));
175 if (ret < 0) {
176 btrfs_abort_transaction(trans, ret);
177 goto out;
178 }
179 l = path->nodes[0];
180 slot = path->slots[0];
181 ptr = btrfs_item_ptr_offset(l, slot);
182 }
183
184
185
186
187
188 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
189
190 write_extent_buffer(l, item, ptr, sizeof(*item));
191 btrfs_mark_buffer_dirty(path->nodes[0]);
192out:
193 btrfs_free_path(path);
194 return ret;
195}
196
197int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
198 const struct btrfs_key *key, struct btrfs_root_item *item)
199{
200
201
202
203 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
204 return btrfs_insert_item(trans, root, key, item, sizeof(*item));
205}
206
207int btrfs_find_orphan_roots(struct btrfs_fs_info *fs_info)
208{
209 struct btrfs_root *tree_root = fs_info->tree_root;
210 struct extent_buffer *leaf;
211 struct btrfs_path *path;
212 struct btrfs_key key;
213 struct btrfs_key root_key;
214 struct btrfs_root *root;
215 int err = 0;
216 int ret;
217
218 path = btrfs_alloc_path();
219 if (!path)
220 return -ENOMEM;
221
222 key.objectid = BTRFS_ORPHAN_OBJECTID;
223 key.type = BTRFS_ORPHAN_ITEM_KEY;
224 key.offset = 0;
225
226 root_key.type = BTRFS_ROOT_ITEM_KEY;
227 root_key.offset = (u64)-1;
228
229 while (1) {
230 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
231 if (ret < 0) {
232 err = ret;
233 break;
234 }
235
236 leaf = path->nodes[0];
237 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
238 ret = btrfs_next_leaf(tree_root, path);
239 if (ret < 0)
240 err = ret;
241 if (ret != 0)
242 break;
243 leaf = path->nodes[0];
244 }
245
246 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
247 btrfs_release_path(path);
248
249 if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
250 key.type != BTRFS_ORPHAN_ITEM_KEY)
251 break;
252
253 root_key.objectid = key.offset;
254 key.offset++;
255
256
257
258
259
260
261
262
263 root = btrfs_lookup_fs_root(fs_info, root_key.objectid);
264 if (root) {
265 WARN_ON(!test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
266 &root->state));
267 if (btrfs_root_refs(&root->root_item) == 0) {
268 set_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
269 btrfs_add_dead_root(root);
270 }
271 continue;
272 }
273
274 root = btrfs_read_fs_root(tree_root, &root_key);
275 err = PTR_ERR_OR_ZERO(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_handle_fs_error(fs_info, err,
287 "Failed to start trans to delete orphan item");
288 break;
289 }
290 err = btrfs_del_orphan_item(trans, tree_root,
291 root_key.objectid);
292 btrfs_end_transaction(trans);
293 if (err) {
294 btrfs_handle_fs_error(fs_info, err,
295 "Failed to delete root orphan item");
296 break;
297 }
298 continue;
299 }
300
301 err = btrfs_init_fs_root(root);
302 if (err) {
303 btrfs_free_fs_root(root);
304 break;
305 }
306
307 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
308
309 err = btrfs_insert_fs_root(fs_info, root);
310 if (err) {
311 BUG_ON(err == -EEXIST);
312 btrfs_free_fs_root(root);
313 break;
314 }
315
316 if (btrfs_root_refs(&root->root_item) == 0) {
317 set_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
318 btrfs_add_dead_root(root);
319 }
320 }
321
322 btrfs_free_path(path);
323 return err;
324}
325
326
327int btrfs_del_root(struct btrfs_trans_handle *trans,
328 const struct btrfs_key *key)
329{
330 struct btrfs_root *root = trans->fs_info->tree_root;
331 struct btrfs_path *path;
332 int ret;
333
334 path = btrfs_alloc_path();
335 if (!path)
336 return -ENOMEM;
337 ret = btrfs_search_slot(trans, root, key, path, -1, 1);
338 if (ret < 0)
339 goto out;
340
341 BUG_ON(ret != 0);
342
343 ret = btrfs_del_item(trans, root, path);
344out:
345 btrfs_free_path(path);
346 return ret;
347}
348
349int btrfs_del_root_ref(struct btrfs_trans_handle *trans, u64 root_id,
350 u64 ref_id, u64 dirid, u64 *sequence, const char *name,
351 int name_len)
352
353{
354 struct btrfs_root *tree_root = trans->fs_info->tree_root;
355 struct btrfs_path *path;
356 struct btrfs_root_ref *ref;
357 struct extent_buffer *leaf;
358 struct btrfs_key key;
359 unsigned long ptr;
360 int err = 0;
361 int ret;
362
363 path = btrfs_alloc_path();
364 if (!path)
365 return -ENOMEM;
366
367 key.objectid = root_id;
368 key.type = BTRFS_ROOT_BACKREF_KEY;
369 key.offset = ref_id;
370again:
371 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
372 BUG_ON(ret < 0);
373 if (ret == 0) {
374 leaf = path->nodes[0];
375 ref = btrfs_item_ptr(leaf, path->slots[0],
376 struct btrfs_root_ref);
377
378 WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
379 WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
380 ptr = (unsigned long)(ref + 1);
381 WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
382 *sequence = btrfs_root_ref_sequence(leaf, ref);
383
384 ret = btrfs_del_item(trans, tree_root, path);
385 if (ret) {
386 err = ret;
387 goto out;
388 }
389 } else
390 err = -ENOENT;
391
392 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
393 btrfs_release_path(path);
394 key.objectid = ref_id;
395 key.type = BTRFS_ROOT_REF_KEY;
396 key.offset = root_id;
397 goto again;
398 }
399
400out:
401 btrfs_free_path(path);
402 return err;
403}
404
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418
419
420int btrfs_add_root_ref(struct btrfs_trans_handle *trans, u64 root_id,
421 u64 ref_id, u64 dirid, u64 sequence, const char *name,
422 int name_len)
423{
424 struct btrfs_root *tree_root = trans->fs_info->tree_root;
425 struct btrfs_key key;
426 int ret;
427 struct btrfs_path *path;
428 struct btrfs_root_ref *ref;
429 struct extent_buffer *leaf;
430 unsigned long ptr;
431
432 path = btrfs_alloc_path();
433 if (!path)
434 return -ENOMEM;
435
436 key.objectid = root_id;
437 key.type = BTRFS_ROOT_BACKREF_KEY;
438 key.offset = ref_id;
439again:
440 ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
441 sizeof(*ref) + name_len);
442 if (ret) {
443 btrfs_abort_transaction(trans, ret);
444 btrfs_free_path(path);
445 return ret;
446 }
447
448 leaf = path->nodes[0];
449 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
450 btrfs_set_root_ref_dirid(leaf, ref, dirid);
451 btrfs_set_root_ref_sequence(leaf, ref, sequence);
452 btrfs_set_root_ref_name_len(leaf, ref, name_len);
453 ptr = (unsigned long)(ref + 1);
454 write_extent_buffer(leaf, name, ptr, name_len);
455 btrfs_mark_buffer_dirty(leaf);
456
457 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
458 btrfs_release_path(path);
459 key.objectid = ref_id;
460 key.type = BTRFS_ROOT_REF_KEY;
461 key.offset = root_id;
462 goto again;
463 }
464
465 btrfs_free_path(path);
466 return 0;
467}
468
469
470
471
472
473
474
475void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
476{
477 u64 inode_flags = btrfs_stack_inode_flags(&root_item->inode);
478
479 if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
480 inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
481 btrfs_set_stack_inode_flags(&root_item->inode, inode_flags);
482 btrfs_set_root_flags(root_item, 0);
483 btrfs_set_root_limit(root_item, 0);
484 }
485}
486
487void btrfs_update_root_times(struct btrfs_trans_handle *trans,
488 struct btrfs_root *root)
489{
490 struct btrfs_root_item *item = &root->root_item;
491 struct timespec64 ct;
492
493 ktime_get_real_ts64(&ct);
494 spin_lock(&root->root_item_lock);
495 btrfs_set_root_ctransid(item, trans->transid);
496 btrfs_set_stack_timespec_sec(&item->ctime, ct.tv_sec);
497 btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec);
498 spin_unlock(&root->root_item_lock);
499}
500