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 | ||
1e1d2701 CM |
19 | #include "ctree.h" |
20 | #include "disk-io.h" | |
f186373f | 21 | #include "hash.h" |
e089f05c | 22 | #include "transaction.h" |
727011e0 | 23 | #include "print-tree.h" |
1e1d2701 | 24 | |
b2950863 | 25 | static int find_name_in_backref(struct btrfs_path *path, const char *name, |
3954401f CM |
26 | int name_len, struct btrfs_inode_ref **ref_ret) |
27 | { | |
28 | struct extent_buffer *leaf; | |
29 | struct btrfs_inode_ref *ref; | |
30 | unsigned long ptr; | |
31 | unsigned long name_ptr; | |
32 | u32 item_size; | |
33 | u32 cur_offset = 0; | |
34 | int len; | |
35 | ||
36 | leaf = path->nodes[0]; | |
37 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
38 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
39 | while (cur_offset < item_size) { | |
40 | ref = (struct btrfs_inode_ref *)(ptr + cur_offset); | |
41 | len = btrfs_inode_ref_name_len(leaf, ref); | |
42 | name_ptr = (unsigned long)(ref + 1); | |
43 | cur_offset += len + sizeof(*ref); | |
44 | if (len != name_len) | |
45 | continue; | |
46 | if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) { | |
47 | *ref_ret = ref; | |
48 | return 1; | |
49 | } | |
50 | } | |
51 | return 0; | |
52 | } | |
53 | ||
f186373f MF |
54 | int btrfs_find_name_in_ext_backref(struct btrfs_path *path, u64 ref_objectid, |
55 | const char *name, int name_len, | |
56 | struct btrfs_inode_extref **extref_ret) | |
57 | { | |
58 | struct extent_buffer *leaf; | |
59 | struct btrfs_inode_extref *extref; | |
60 | unsigned long ptr; | |
61 | unsigned long name_ptr; | |
62 | u32 item_size; | |
63 | u32 cur_offset = 0; | |
64 | int ref_name_len; | |
65 | ||
66 | leaf = path->nodes[0]; | |
67 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
68 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
69 | ||
70 | /* | |
71 | * Search all extended backrefs in this item. We're only | |
72 | * looking through any collisions so most of the time this is | |
73 | * just going to compare against one buffer. If all is well, | |
74 | * we'll return success and the inode ref object. | |
75 | */ | |
76 | while (cur_offset < item_size) { | |
77 | extref = (struct btrfs_inode_extref *) (ptr + cur_offset); | |
78 | name_ptr = (unsigned long)(&extref->name); | |
79 | ref_name_len = btrfs_inode_extref_name_len(leaf, extref); | |
80 | ||
81 | if (ref_name_len == name_len && | |
82 | btrfs_inode_extref_parent(leaf, extref) == ref_objectid && | |
83 | (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) { | |
84 | if (extref_ret) | |
85 | *extref_ret = extref; | |
86 | return 1; | |
87 | } | |
88 | ||
89 | cur_offset += ref_name_len + sizeof(*extref); | |
90 | } | |
91 | return 0; | |
92 | } | |
93 | ||
94 | static struct btrfs_inode_ref * | |
a22285a6 | 95 | btrfs_lookup_inode_ref(struct btrfs_trans_handle *trans, |
f186373f MF |
96 | struct btrfs_root *root, |
97 | struct btrfs_path *path, | |
98 | const char *name, int name_len, | |
99 | u64 inode_objectid, u64 ref_objectid, int ins_len, | |
100 | int cow) | |
a22285a6 | 101 | { |
f186373f | 102 | int ret; |
a22285a6 YZ |
103 | struct btrfs_key key; |
104 | struct btrfs_inode_ref *ref; | |
a22285a6 YZ |
105 | |
106 | key.objectid = inode_objectid; | |
107 | key.type = BTRFS_INODE_REF_KEY; | |
108 | key.offset = ref_objectid; | |
109 | ||
110 | ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow); | |
111 | if (ret < 0) | |
112 | return ERR_PTR(ret); | |
113 | if (ret > 0) | |
114 | return NULL; | |
115 | if (!find_name_in_backref(path, name, name_len, &ref)) | |
116 | return NULL; | |
117 | return ref; | |
118 | } | |
119 | ||
f186373f MF |
120 | /* Returns NULL if no extref found */ |
121 | struct btrfs_inode_extref * | |
122 | btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans, | |
123 | struct btrfs_root *root, | |
124 | struct btrfs_path *path, | |
125 | const char *name, int name_len, | |
126 | u64 inode_objectid, u64 ref_objectid, int ins_len, | |
127 | int cow) | |
128 | { | |
129 | int ret; | |
130 | struct btrfs_key key; | |
131 | struct btrfs_inode_extref *extref; | |
132 | ||
133 | key.objectid = inode_objectid; | |
134 | key.type = BTRFS_INODE_EXTREF_KEY; | |
135 | key.offset = btrfs_extref_hash(ref_objectid, name, name_len); | |
136 | ||
137 | ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow); | |
138 | if (ret < 0) | |
139 | return ERR_PTR(ret); | |
140 | if (ret > 0) | |
141 | return NULL; | |
142 | if (!btrfs_find_name_in_ext_backref(path, ref_objectid, name, name_len, &extref)) | |
143 | return NULL; | |
144 | return extref; | |
145 | } | |
146 | ||
147 | int btrfs_get_inode_ref_index(struct btrfs_trans_handle *trans, | |
148 | struct btrfs_root *root, | |
149 | struct btrfs_path *path, | |
150 | const char *name, int name_len, | |
151 | u64 inode_objectid, u64 ref_objectid, int mod, | |
152 | u64 *ret_index) | |
153 | { | |
154 | struct btrfs_inode_ref *ref; | |
155 | struct btrfs_inode_extref *extref; | |
156 | int ins_len = mod < 0 ? -1 : 0; | |
157 | int cow = mod != 0; | |
158 | ||
159 | ref = btrfs_lookup_inode_ref(trans, root, path, name, name_len, | |
160 | inode_objectid, ref_objectid, ins_len, | |
161 | cow); | |
162 | if (IS_ERR(ref)) | |
163 | return PTR_ERR(ref); | |
164 | ||
165 | if (ref != NULL) { | |
166 | *ret_index = btrfs_inode_ref_index(path->nodes[0], ref); | |
167 | return 0; | |
168 | } | |
169 | ||
170 | btrfs_release_path(path); | |
171 | ||
172 | extref = btrfs_lookup_inode_extref(trans, root, path, name, | |
173 | name_len, inode_objectid, | |
174 | ref_objectid, ins_len, cow); | |
175 | if (IS_ERR(extref)) | |
176 | return PTR_ERR(extref); | |
177 | ||
178 | if (extref) { | |
179 | *ret_index = btrfs_inode_extref_index(path->nodes[0], extref); | |
180 | return 0; | |
181 | } | |
182 | ||
183 | return -ENOENT; | |
184 | } | |
185 | ||
186 | int btrfs_del_inode_extref(struct btrfs_trans_handle *trans, | |
3954401f CM |
187 | struct btrfs_root *root, |
188 | const char *name, int name_len, | |
aec7477b | 189 | u64 inode_objectid, u64 ref_objectid, u64 *index) |
f186373f MF |
190 | { |
191 | struct btrfs_path *path; | |
192 | struct btrfs_key key; | |
193 | struct btrfs_inode_extref *extref; | |
194 | struct extent_buffer *leaf; | |
195 | int ret; | |
196 | int del_len = name_len + sizeof(*extref); | |
197 | unsigned long ptr; | |
198 | unsigned long item_start; | |
199 | u32 item_size; | |
200 | ||
201 | key.objectid = inode_objectid; | |
202 | btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY); | |
203 | key.offset = btrfs_extref_hash(ref_objectid, name, name_len); | |
204 | ||
205 | path = btrfs_alloc_path(); | |
206 | if (!path) | |
207 | return -ENOMEM; | |
208 | ||
209 | path->leave_spinning = 1; | |
210 | ||
211 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); | |
212 | if (ret > 0) | |
213 | ret = -ENOENT; | |
214 | if (ret < 0) | |
215 | goto out; | |
216 | ||
217 | /* | |
218 | * Sanity check - did we find the right item for this name? | |
219 | * This should always succeed so error here will make the FS | |
220 | * readonly. | |
221 | */ | |
222 | if (!btrfs_find_name_in_ext_backref(path, ref_objectid, | |
223 | name, name_len, &extref)) { | |
224 | btrfs_std_error(root->fs_info, -ENOENT); | |
225 | ret = -EROFS; | |
226 | goto out; | |
227 | } | |
228 | ||
229 | leaf = path->nodes[0]; | |
230 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
231 | if (index) | |
232 | *index = btrfs_inode_extref_index(leaf, extref); | |
233 | ||
234 | if (del_len == item_size) { | |
235 | /* | |
236 | * Common case only one ref in the item, remove the | |
237 | * whole item. | |
238 | */ | |
239 | ret = btrfs_del_item(trans, root, path); | |
240 | goto out; | |
241 | } | |
242 | ||
243 | ptr = (unsigned long)extref; | |
244 | item_start = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
245 | ||
246 | memmove_extent_buffer(leaf, ptr, ptr + del_len, | |
247 | item_size - (ptr + del_len - item_start)); | |
248 | ||
249 | btrfs_truncate_item(trans, root, path, item_size - del_len, 1); | |
250 | ||
251 | out: | |
252 | btrfs_free_path(path); | |
253 | ||
254 | return ret; | |
255 | } | |
256 | ||
257 | int btrfs_del_inode_ref(struct btrfs_trans_handle *trans, | |
258 | struct btrfs_root *root, | |
259 | const char *name, int name_len, | |
260 | u64 inode_objectid, u64 ref_objectid, u64 *index) | |
3954401f CM |
261 | { |
262 | struct btrfs_path *path; | |
263 | struct btrfs_key key; | |
264 | struct btrfs_inode_ref *ref; | |
265 | struct extent_buffer *leaf; | |
266 | unsigned long ptr; | |
267 | unsigned long item_start; | |
268 | u32 item_size; | |
269 | u32 sub_item_len; | |
270 | int ret; | |
f186373f | 271 | int search_ext_refs = 0; |
3954401f CM |
272 | int del_len = name_len + sizeof(*ref); |
273 | ||
274 | key.objectid = inode_objectid; | |
275 | key.offset = ref_objectid; | |
276 | btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY); | |
277 | ||
278 | path = btrfs_alloc_path(); | |
279 | if (!path) | |
280 | return -ENOMEM; | |
281 | ||
b9473439 CM |
282 | path->leave_spinning = 1; |
283 | ||
3954401f CM |
284 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
285 | if (ret > 0) { | |
286 | ret = -ENOENT; | |
f186373f | 287 | search_ext_refs = 1; |
3954401f CM |
288 | goto out; |
289 | } else if (ret < 0) { | |
290 | goto out; | |
291 | } | |
292 | if (!find_name_in_backref(path, name, name_len, &ref)) { | |
293 | ret = -ENOENT; | |
f186373f | 294 | search_ext_refs = 1; |
3954401f CM |
295 | goto out; |
296 | } | |
297 | leaf = path->nodes[0]; | |
298 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
aec7477b JB |
299 | |
300 | if (index) | |
301 | *index = btrfs_inode_ref_index(leaf, ref); | |
302 | ||
3954401f CM |
303 | if (del_len == item_size) { |
304 | ret = btrfs_del_item(trans, root, path); | |
305 | goto out; | |
306 | } | |
307 | ptr = (unsigned long)ref; | |
308 | sub_item_len = name_len + sizeof(*ref); | |
309 | item_start = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
310 | memmove_extent_buffer(leaf, ptr, ptr + sub_item_len, | |
311 | item_size - (ptr + sub_item_len - item_start)); | |
f186373f MF |
312 | btrfs_truncate_item(trans, root, path, item_size - sub_item_len, 1); |
313 | out: | |
314 | btrfs_free_path(path); | |
315 | ||
316 | if (search_ext_refs) { | |
317 | /* | |
318 | * No refs were found, or we could not find the | |
319 | * name in our ref array. Find and remove the extended | |
320 | * inode ref then. | |
321 | */ | |
322 | return btrfs_del_inode_extref(trans, root, name, name_len, | |
323 | inode_objectid, ref_objectid, index); | |
324 | } | |
325 | ||
326 | return ret; | |
327 | } | |
328 | ||
329 | /* | |
330 | * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree. | |
331 | * | |
332 | * The caller must have checked against BTRFS_LINK_MAX already. | |
333 | */ | |
334 | static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans, | |
335 | struct btrfs_root *root, | |
336 | const char *name, int name_len, | |
337 | u64 inode_objectid, u64 ref_objectid, u64 index) | |
338 | { | |
339 | struct btrfs_inode_extref *extref; | |
340 | int ret; | |
341 | int ins_len = name_len + sizeof(*extref); | |
342 | unsigned long ptr; | |
343 | struct btrfs_path *path; | |
344 | struct btrfs_key key; | |
345 | struct extent_buffer *leaf; | |
346 | struct btrfs_item *item; | |
347 | ||
348 | key.objectid = inode_objectid; | |
349 | key.type = BTRFS_INODE_EXTREF_KEY; | |
350 | key.offset = btrfs_extref_hash(ref_objectid, name, name_len); | |
351 | ||
352 | path = btrfs_alloc_path(); | |
353 | if (!path) | |
354 | return -ENOMEM; | |
355 | ||
356 | path->leave_spinning = 1; | |
357 | ret = btrfs_insert_empty_item(trans, root, path, &key, | |
358 | ins_len); | |
359 | if (ret == -EEXIST) { | |
360 | if (btrfs_find_name_in_ext_backref(path, ref_objectid, | |
361 | name, name_len, NULL)) | |
362 | goto out; | |
363 | ||
364 | btrfs_extend_item(trans, root, path, ins_len); | |
365 | ret = 0; | |
366 | } | |
367 | if (ret < 0) | |
368 | goto out; | |
369 | ||
370 | leaf = path->nodes[0]; | |
371 | item = btrfs_item_nr(leaf, path->slots[0]); | |
372 | ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char); | |
373 | ptr += btrfs_item_size(leaf, item) - ins_len; | |
374 | extref = (struct btrfs_inode_extref *)ptr; | |
375 | ||
376 | btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len); | |
377 | btrfs_set_inode_extref_index(path->nodes[0], extref, index); | |
378 | btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid); | |
379 | ||
380 | ptr = (unsigned long)&extref->name; | |
381 | write_extent_buffer(path->nodes[0], name, ptr, name_len); | |
382 | btrfs_mark_buffer_dirty(path->nodes[0]); | |
383 | ||
3954401f CM |
384 | out: |
385 | btrfs_free_path(path); | |
386 | return ret; | |
387 | } | |
388 | ||
79787eaa | 389 | /* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */ |
3954401f CM |
390 | int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans, |
391 | struct btrfs_root *root, | |
392 | const char *name, int name_len, | |
aec7477b | 393 | u64 inode_objectid, u64 ref_objectid, u64 index) |
3954401f CM |
394 | { |
395 | struct btrfs_path *path; | |
396 | struct btrfs_key key; | |
397 | struct btrfs_inode_ref *ref; | |
398 | unsigned long ptr; | |
399 | int ret; | |
400 | int ins_len = name_len + sizeof(*ref); | |
401 | ||
402 | key.objectid = inode_objectid; | |
403 | key.offset = ref_objectid; | |
404 | btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY); | |
405 | ||
406 | path = btrfs_alloc_path(); | |
407 | if (!path) | |
408 | return -ENOMEM; | |
409 | ||
b9473439 | 410 | path->leave_spinning = 1; |
3954401f CM |
411 | ret = btrfs_insert_empty_item(trans, root, path, &key, |
412 | ins_len); | |
413 | if (ret == -EEXIST) { | |
414 | u32 old_size; | |
415 | ||
416 | if (find_name_in_backref(path, name, name_len, &ref)) | |
417 | goto out; | |
418 | ||
419 | old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]); | |
143bede5 | 420 | btrfs_extend_item(trans, root, path, ins_len); |
3954401f CM |
421 | ref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
422 | struct btrfs_inode_ref); | |
423 | ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size); | |
424 | btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); | |
aec7477b | 425 | btrfs_set_inode_ref_index(path->nodes[0], ref, index); |
3954401f CM |
426 | ptr = (unsigned long)(ref + 1); |
427 | ret = 0; | |
428 | } else if (ret < 0) { | |
a5719521 YZ |
429 | if (ret == -EOVERFLOW) |
430 | ret = -EMLINK; | |
3954401f CM |
431 | goto out; |
432 | } else { | |
433 | ref = btrfs_item_ptr(path->nodes[0], path->slots[0], | |
434 | struct btrfs_inode_ref); | |
435 | btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); | |
aec7477b | 436 | btrfs_set_inode_ref_index(path->nodes[0], ref, index); |
3954401f CM |
437 | ptr = (unsigned long)(ref + 1); |
438 | } | |
439 | write_extent_buffer(path->nodes[0], name, ptr, name_len); | |
440 | btrfs_mark_buffer_dirty(path->nodes[0]); | |
441 | ||
442 | out: | |
443 | btrfs_free_path(path); | |
f186373f MF |
444 | |
445 | if (ret == -EMLINK) { | |
446 | struct btrfs_super_block *disk_super = root->fs_info->super_copy; | |
447 | /* We ran out of space in the ref array. Need to | |
448 | * add an extended ref. */ | |
449 | if (btrfs_super_incompat_flags(disk_super) | |
450 | & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF) | |
451 | ret = btrfs_insert_inode_extref(trans, root, name, | |
452 | name_len, | |
453 | inode_objectid, | |
454 | ref_objectid, index); | |
455 | } | |
456 | ||
3954401f CM |
457 | return ret; |
458 | } | |
459 | ||
5f39d397 CM |
460 | int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans, |
461 | struct btrfs_root *root, | |
462 | struct btrfs_path *path, u64 objectid) | |
1e1d2701 | 463 | { |
1e1d2701 CM |
464 | struct btrfs_key key; |
465 | int ret; | |
466 | key.objectid = objectid; | |
1e1d2701 CM |
467 | btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); |
468 | key.offset = 0; | |
469 | ||
5f39d397 CM |
470 | ret = btrfs_insert_empty_item(trans, root, path, &key, |
471 | sizeof(struct btrfs_inode_item)); | |
1e1d2701 CM |
472 | return ret; |
473 | } | |
474 | ||
e089f05c | 475 | int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root |
d6e4a428 CM |
476 | *root, struct btrfs_path *path, |
477 | struct btrfs_key *location, int mod) | |
1e1d2701 | 478 | { |
1e1d2701 CM |
479 | int ins_len = mod < 0 ? -1 : 0; |
480 | int cow = mod != 0; | |
d6e4a428 CM |
481 | int ret; |
482 | int slot; | |
5f39d397 | 483 | struct extent_buffer *leaf; |
d6e4a428 | 484 | struct btrfs_key found_key; |
1e1d2701 | 485 | |
d6e4a428 CM |
486 | ret = btrfs_search_slot(trans, root, location, path, ins_len, cow); |
487 | if (ret > 0 && btrfs_key_type(location) == BTRFS_ROOT_ITEM_KEY && | |
488 | location->offset == (u64)-1 && path->slots[0] != 0) { | |
489 | slot = path->slots[0] - 1; | |
5f39d397 CM |
490 | leaf = path->nodes[0]; |
491 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
d6e4a428 CM |
492 | if (found_key.objectid == location->objectid && |
493 | btrfs_key_type(&found_key) == btrfs_key_type(location)) { | |
494 | path->slots[0]--; | |
495 | return 0; | |
496 | } | |
497 | } | |
498 | return ret; | |
1e1d2701 | 499 | } |