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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include "ctree.h"
7#include "disk-io.h"
8#include "transaction.h"
9#include "print-tree.h"
10
11struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
12 int slot, const char *name,
13 int name_len)
14{
15 struct btrfs_inode_ref *ref;
16 unsigned long ptr;
17 unsigned long name_ptr;
18 u32 item_size;
19 u32 cur_offset = 0;
20 int len;
21
22 item_size = btrfs_item_size_nr(leaf, slot);
23 ptr = btrfs_item_ptr_offset(leaf, slot);
24 while (cur_offset < item_size) {
25 ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
26 len = btrfs_inode_ref_name_len(leaf, ref);
27 name_ptr = (unsigned long)(ref + 1);
28 cur_offset += len + sizeof(*ref);
29 if (len != name_len)
30 continue;
31 if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
32 return ref;
33 }
34 return NULL;
35}
36
37struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
38 struct extent_buffer *leaf, int slot, u64 ref_objectid,
39 const char *name, int name_len)
40{
41 struct btrfs_inode_extref *extref;
42 unsigned long ptr;
43 unsigned long name_ptr;
44 u32 item_size;
45 u32 cur_offset = 0;
46 int ref_name_len;
47
48 item_size = btrfs_item_size_nr(leaf, slot);
49 ptr = btrfs_item_ptr_offset(leaf, slot);
50
51 /*
52 * Search all extended backrefs in this item. We're only
53 * looking through any collisions so most of the time this is
54 * just going to compare against one buffer. If all is well,
55 * we'll return success and the inode ref object.
56 */
57 while (cur_offset < item_size) {
58 extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
59 name_ptr = (unsigned long)(&extref->name);
60 ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
61
62 if (ref_name_len == name_len &&
63 btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
64 (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0))
65 return extref;
66
67 cur_offset += ref_name_len + sizeof(*extref);
68 }
69 return NULL;
70}
71
72/* Returns NULL if no extref found */
73struct btrfs_inode_extref *
74btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
75 struct btrfs_root *root,
76 struct btrfs_path *path,
77 const char *name, int name_len,
78 u64 inode_objectid, u64 ref_objectid, int ins_len,
79 int cow)
80{
81 int ret;
82 struct btrfs_key key;
83
84 key.objectid = inode_objectid;
85 key.type = BTRFS_INODE_EXTREF_KEY;
86 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
87
88 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
89 if (ret < 0)
90 return ERR_PTR(ret);
91 if (ret > 0)
92 return NULL;
93 return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
94 ref_objectid, name, name_len);
95
96}
97
98static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
99 struct btrfs_root *root,
100 const char *name, int name_len,
101 u64 inode_objectid, u64 ref_objectid,
102 u64 *index)
103{
104 struct btrfs_path *path;
105 struct btrfs_key key;
106 struct btrfs_inode_extref *extref;
107 struct extent_buffer *leaf;
108 int ret;
109 int del_len = name_len + sizeof(*extref);
110 unsigned long ptr;
111 unsigned long item_start;
112 u32 item_size;
113
114 key.objectid = inode_objectid;
115 key.type = BTRFS_INODE_EXTREF_KEY;
116 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
117
118 path = btrfs_alloc_path();
119 if (!path)
120 return -ENOMEM;
121
122 path->leave_spinning = 1;
123
124 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
125 if (ret > 0)
126 ret = -ENOENT;
127 if (ret < 0)
128 goto out;
129
130 /*
131 * Sanity check - did we find the right item for this name?
132 * This should always succeed so error here will make the FS
133 * readonly.
134 */
135 extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
136 ref_objectid, name, name_len);
137 if (!extref) {
138 btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
139 ret = -EROFS;
140 goto out;
141 }
142
143 leaf = path->nodes[0];
144 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
145 if (index)
146 *index = btrfs_inode_extref_index(leaf, extref);
147
148 if (del_len == item_size) {
149 /*
150 * Common case only one ref in the item, remove the
151 * whole item.
152 */
153 ret = btrfs_del_item(trans, root, path);
154 goto out;
155 }
156
157 ptr = (unsigned long)extref;
158 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
159
160 memmove_extent_buffer(leaf, ptr, ptr + del_len,
161 item_size - (ptr + del_len - item_start));
162
163 btrfs_truncate_item(path, item_size - del_len, 1);
164
165out:
166 btrfs_free_path(path);
167
168 return ret;
169}
170
171int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
172 struct btrfs_root *root,
173 const char *name, int name_len,
174 u64 inode_objectid, u64 ref_objectid, u64 *index)
175{
176 struct btrfs_path *path;
177 struct btrfs_key key;
178 struct btrfs_inode_ref *ref;
179 struct extent_buffer *leaf;
180 unsigned long ptr;
181 unsigned long item_start;
182 u32 item_size;
183 u32 sub_item_len;
184 int ret;
185 int search_ext_refs = 0;
186 int del_len = name_len + sizeof(*ref);
187
188 key.objectid = inode_objectid;
189 key.offset = ref_objectid;
190 key.type = BTRFS_INODE_REF_KEY;
191
192 path = btrfs_alloc_path();
193 if (!path)
194 return -ENOMEM;
195
196 path->leave_spinning = 1;
197
198 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
199 if (ret > 0) {
200 ret = -ENOENT;
201 search_ext_refs = 1;
202 goto out;
203 } else if (ret < 0) {
204 goto out;
205 }
206
207 ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name,
208 name_len);
209 if (!ref) {
210 ret = -ENOENT;
211 search_ext_refs = 1;
212 goto out;
213 }
214 leaf = path->nodes[0];
215 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
216
217 if (index)
218 *index = btrfs_inode_ref_index(leaf, ref);
219
220 if (del_len == item_size) {
221 ret = btrfs_del_item(trans, root, path);
222 goto out;
223 }
224 ptr = (unsigned long)ref;
225 sub_item_len = name_len + sizeof(*ref);
226 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
227 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
228 item_size - (ptr + sub_item_len - item_start));
229 btrfs_truncate_item(path, item_size - sub_item_len, 1);
230out:
231 btrfs_free_path(path);
232
233 if (search_ext_refs) {
234 /*
235 * No refs were found, or we could not find the
236 * name in our ref array. Find and remove the extended
237 * inode ref then.
238 */
239 return btrfs_del_inode_extref(trans, root, name, name_len,
240 inode_objectid, ref_objectid, index);
241 }
242
243 return ret;
244}
245
246/*
247 * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
248 *
249 * The caller must have checked against BTRFS_LINK_MAX already.
250 */
251static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
252 struct btrfs_root *root,
253 const char *name, int name_len,
254 u64 inode_objectid, u64 ref_objectid, u64 index)
255{
256 struct btrfs_inode_extref *extref;
257 int ret;
258 int ins_len = name_len + sizeof(*extref);
259 unsigned long ptr;
260 struct btrfs_path *path;
261 struct btrfs_key key;
262 struct extent_buffer *leaf;
263 struct btrfs_item *item;
264
265 key.objectid = inode_objectid;
266 key.type = BTRFS_INODE_EXTREF_KEY;
267 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
268
269 path = btrfs_alloc_path();
270 if (!path)
271 return -ENOMEM;
272
273 path->leave_spinning = 1;
274 ret = btrfs_insert_empty_item(trans, root, path, &key,
275 ins_len);
276 if (ret == -EEXIST) {
277 if (btrfs_find_name_in_ext_backref(path->nodes[0],
278 path->slots[0],
279 ref_objectid,
280 name, name_len))
281 goto out;
282
283 btrfs_extend_item(path, ins_len);
284 ret = 0;
285 }
286 if (ret < 0)
287 goto out;
288
289 leaf = path->nodes[0];
290 item = btrfs_item_nr(path->slots[0]);
291 ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
292 ptr += btrfs_item_size(leaf, item) - ins_len;
293 extref = (struct btrfs_inode_extref *)ptr;
294
295 btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
296 btrfs_set_inode_extref_index(path->nodes[0], extref, index);
297 btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
298
299 ptr = (unsigned long)&extref->name;
300 write_extent_buffer(path->nodes[0], name, ptr, name_len);
301 btrfs_mark_buffer_dirty(path->nodes[0]);
302
303out:
304 btrfs_free_path(path);
305 return ret;
306}
307
308/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
309int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
310 struct btrfs_root *root,
311 const char *name, int name_len,
312 u64 inode_objectid, u64 ref_objectid, u64 index)
313{
314 struct btrfs_fs_info *fs_info = root->fs_info;
315 struct btrfs_path *path;
316 struct btrfs_key key;
317 struct btrfs_inode_ref *ref;
318 unsigned long ptr;
319 int ret;
320 int ins_len = name_len + sizeof(*ref);
321
322 key.objectid = inode_objectid;
323 key.offset = ref_objectid;
324 key.type = BTRFS_INODE_REF_KEY;
325
326 path = btrfs_alloc_path();
327 if (!path)
328 return -ENOMEM;
329
330 path->leave_spinning = 1;
331 path->skip_release_on_error = 1;
332 ret = btrfs_insert_empty_item(trans, root, path, &key,
333 ins_len);
334 if (ret == -EEXIST) {
335 u32 old_size;
336 ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
337 name, name_len);
338 if (ref)
339 goto out;
340
341 old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
342 btrfs_extend_item(path, ins_len);
343 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
344 struct btrfs_inode_ref);
345 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
346 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
347 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
348 ptr = (unsigned long)(ref + 1);
349 ret = 0;
350 } else if (ret < 0) {
351 if (ret == -EOVERFLOW) {
352 if (btrfs_find_name_in_backref(path->nodes[0],
353 path->slots[0],
354 name, name_len))
355 ret = -EEXIST;
356 else
357 ret = -EMLINK;
358 }
359 goto out;
360 } else {
361 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
362 struct btrfs_inode_ref);
363 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
364 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
365 ptr = (unsigned long)(ref + 1);
366 }
367 write_extent_buffer(path->nodes[0], name, ptr, name_len);
368 btrfs_mark_buffer_dirty(path->nodes[0]);
369
370out:
371 btrfs_free_path(path);
372
373 if (ret == -EMLINK) {
374 struct btrfs_super_block *disk_super = fs_info->super_copy;
375 /* We ran out of space in the ref array. Need to
376 * add an extended ref. */
377 if (btrfs_super_incompat_flags(disk_super)
378 & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
379 ret = btrfs_insert_inode_extref(trans, root, name,
380 name_len,
381 inode_objectid,
382 ref_objectid, index);
383 }
384
385 return ret;
386}
387
388int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
389 struct btrfs_root *root,
390 struct btrfs_path *path, u64 objectid)
391{
392 struct btrfs_key key;
393 int ret;
394 key.objectid = objectid;
395 key.type = BTRFS_INODE_ITEM_KEY;
396 key.offset = 0;
397
398 ret = btrfs_insert_empty_item(trans, root, path, &key,
399 sizeof(struct btrfs_inode_item));
400 return ret;
401}
402
403int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
404 *root, struct btrfs_path *path,
405 struct btrfs_key *location, int mod)
406{
407 int ins_len = mod < 0 ? -1 : 0;
408 int cow = mod != 0;
409 int ret;
410 int slot;
411 struct extent_buffer *leaf;
412 struct btrfs_key found_key;
413
414 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
415 if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
416 location->offset == (u64)-1 && path->slots[0] != 0) {
417 slot = path->slots[0] - 1;
418 leaf = path->nodes[0];
419 btrfs_item_key_to_cpu(leaf, &found_key, slot);
420 if (found_key.objectid == location->objectid &&
421 found_key.type == location->type) {
422 path->slots[0]--;
423 return 0;
424 }
425 }
426 return ret;
427}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include "ctree.h"
7#include "disk-io.h"
8#include "transaction.h"
9#include "print-tree.h"
10
11int btrfs_find_name_in_backref(struct extent_buffer *leaf, int slot,
12 const char *name,
13 int name_len, struct btrfs_inode_ref **ref_ret)
14{
15 struct btrfs_inode_ref *ref;
16 unsigned long ptr;
17 unsigned long name_ptr;
18 u32 item_size;
19 u32 cur_offset = 0;
20 int len;
21
22 item_size = btrfs_item_size_nr(leaf, slot);
23 ptr = btrfs_item_ptr_offset(leaf, slot);
24 while (cur_offset < item_size) {
25 ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
26 len = btrfs_inode_ref_name_len(leaf, ref);
27 name_ptr = (unsigned long)(ref + 1);
28 cur_offset += len + sizeof(*ref);
29 if (len != name_len)
30 continue;
31 if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
32 if (ref_ret)
33 *ref_ret = ref;
34 return 1;
35 }
36 }
37 return 0;
38}
39
40int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
41 u64 ref_objectid,
42 const char *name, int name_len,
43 struct btrfs_inode_extref **extref_ret)
44{
45 struct btrfs_inode_extref *extref;
46 unsigned long ptr;
47 unsigned long name_ptr;
48 u32 item_size;
49 u32 cur_offset = 0;
50 int ref_name_len;
51
52 item_size = btrfs_item_size_nr(leaf, slot);
53 ptr = btrfs_item_ptr_offset(leaf, slot);
54
55 /*
56 * Search all extended backrefs in this item. We're only
57 * looking through any collisions so most of the time this is
58 * just going to compare against one buffer. If all is well,
59 * we'll return success and the inode ref object.
60 */
61 while (cur_offset < item_size) {
62 extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
63 name_ptr = (unsigned long)(&extref->name);
64 ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
65
66 if (ref_name_len == name_len &&
67 btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
68 (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
69 if (extref_ret)
70 *extref_ret = extref;
71 return 1;
72 }
73
74 cur_offset += ref_name_len + sizeof(*extref);
75 }
76 return 0;
77}
78
79/* Returns NULL if no extref found */
80struct btrfs_inode_extref *
81btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
82 struct btrfs_root *root,
83 struct btrfs_path *path,
84 const char *name, int name_len,
85 u64 inode_objectid, u64 ref_objectid, int ins_len,
86 int cow)
87{
88 int ret;
89 struct btrfs_key key;
90 struct btrfs_inode_extref *extref;
91
92 key.objectid = inode_objectid;
93 key.type = BTRFS_INODE_EXTREF_KEY;
94 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
95
96 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
97 if (ret < 0)
98 return ERR_PTR(ret);
99 if (ret > 0)
100 return NULL;
101 if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
102 ref_objectid, name, name_len,
103 &extref))
104 return NULL;
105 return extref;
106}
107
108static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
109 struct btrfs_root *root,
110 const char *name, int name_len,
111 u64 inode_objectid, u64 ref_objectid,
112 u64 *index)
113{
114 struct btrfs_path *path;
115 struct btrfs_key key;
116 struct btrfs_inode_extref *extref;
117 struct extent_buffer *leaf;
118 int ret;
119 int del_len = name_len + sizeof(*extref);
120 unsigned long ptr;
121 unsigned long item_start;
122 u32 item_size;
123
124 key.objectid = inode_objectid;
125 key.type = BTRFS_INODE_EXTREF_KEY;
126 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
127
128 path = btrfs_alloc_path();
129 if (!path)
130 return -ENOMEM;
131
132 path->leave_spinning = 1;
133
134 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
135 if (ret > 0)
136 ret = -ENOENT;
137 if (ret < 0)
138 goto out;
139
140 /*
141 * Sanity check - did we find the right item for this name?
142 * This should always succeed so error here will make the FS
143 * readonly.
144 */
145 if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
146 ref_objectid,
147 name, name_len, &extref)) {
148 btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
149 ret = -EROFS;
150 goto out;
151 }
152
153 leaf = path->nodes[0];
154 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
155 if (index)
156 *index = btrfs_inode_extref_index(leaf, extref);
157
158 if (del_len == item_size) {
159 /*
160 * Common case only one ref in the item, remove the
161 * whole item.
162 */
163 ret = btrfs_del_item(trans, root, path);
164 goto out;
165 }
166
167 ptr = (unsigned long)extref;
168 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
169
170 memmove_extent_buffer(leaf, ptr, ptr + del_len,
171 item_size - (ptr + del_len - item_start));
172
173 btrfs_truncate_item(root->fs_info, path, item_size - del_len, 1);
174
175out:
176 btrfs_free_path(path);
177
178 return ret;
179}
180
181int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
182 struct btrfs_root *root,
183 const char *name, int name_len,
184 u64 inode_objectid, u64 ref_objectid, u64 *index)
185{
186 struct btrfs_path *path;
187 struct btrfs_key key;
188 struct btrfs_inode_ref *ref;
189 struct extent_buffer *leaf;
190 unsigned long ptr;
191 unsigned long item_start;
192 u32 item_size;
193 u32 sub_item_len;
194 int ret;
195 int search_ext_refs = 0;
196 int del_len = name_len + sizeof(*ref);
197
198 key.objectid = inode_objectid;
199 key.offset = ref_objectid;
200 key.type = BTRFS_INODE_REF_KEY;
201
202 path = btrfs_alloc_path();
203 if (!path)
204 return -ENOMEM;
205
206 path->leave_spinning = 1;
207
208 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
209 if (ret > 0) {
210 ret = -ENOENT;
211 search_ext_refs = 1;
212 goto out;
213 } else if (ret < 0) {
214 goto out;
215 }
216 if (!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
217 name, name_len, &ref)) {
218 ret = -ENOENT;
219 search_ext_refs = 1;
220 goto out;
221 }
222 leaf = path->nodes[0];
223 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
224
225 if (index)
226 *index = btrfs_inode_ref_index(leaf, ref);
227
228 if (del_len == item_size) {
229 ret = btrfs_del_item(trans, root, path);
230 goto out;
231 }
232 ptr = (unsigned long)ref;
233 sub_item_len = name_len + sizeof(*ref);
234 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
235 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
236 item_size - (ptr + sub_item_len - item_start));
237 btrfs_truncate_item(root->fs_info, path, item_size - sub_item_len, 1);
238out:
239 btrfs_free_path(path);
240
241 if (search_ext_refs) {
242 /*
243 * No refs were found, or we could not find the
244 * name in our ref array. Find and remove the extended
245 * inode ref then.
246 */
247 return btrfs_del_inode_extref(trans, root, name, name_len,
248 inode_objectid, ref_objectid, index);
249 }
250
251 return ret;
252}
253
254/*
255 * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
256 *
257 * The caller must have checked against BTRFS_LINK_MAX already.
258 */
259static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
260 struct btrfs_root *root,
261 const char *name, int name_len,
262 u64 inode_objectid, u64 ref_objectid, u64 index)
263{
264 struct btrfs_inode_extref *extref;
265 int ret;
266 int ins_len = name_len + sizeof(*extref);
267 unsigned long ptr;
268 struct btrfs_path *path;
269 struct btrfs_key key;
270 struct extent_buffer *leaf;
271 struct btrfs_item *item;
272
273 key.objectid = inode_objectid;
274 key.type = BTRFS_INODE_EXTREF_KEY;
275 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
276
277 path = btrfs_alloc_path();
278 if (!path)
279 return -ENOMEM;
280
281 path->leave_spinning = 1;
282 ret = btrfs_insert_empty_item(trans, root, path, &key,
283 ins_len);
284 if (ret == -EEXIST) {
285 if (btrfs_find_name_in_ext_backref(path->nodes[0],
286 path->slots[0],
287 ref_objectid,
288 name, name_len, NULL))
289 goto out;
290
291 btrfs_extend_item(root->fs_info, path, ins_len);
292 ret = 0;
293 }
294 if (ret < 0)
295 goto out;
296
297 leaf = path->nodes[0];
298 item = btrfs_item_nr(path->slots[0]);
299 ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
300 ptr += btrfs_item_size(leaf, item) - ins_len;
301 extref = (struct btrfs_inode_extref *)ptr;
302
303 btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
304 btrfs_set_inode_extref_index(path->nodes[0], extref, index);
305 btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
306
307 ptr = (unsigned long)&extref->name;
308 write_extent_buffer(path->nodes[0], name, ptr, name_len);
309 btrfs_mark_buffer_dirty(path->nodes[0]);
310
311out:
312 btrfs_free_path(path);
313 return ret;
314}
315
316/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
317int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
318 struct btrfs_root *root,
319 const char *name, int name_len,
320 u64 inode_objectid, u64 ref_objectid, u64 index)
321{
322 struct btrfs_fs_info *fs_info = root->fs_info;
323 struct btrfs_path *path;
324 struct btrfs_key key;
325 struct btrfs_inode_ref *ref;
326 unsigned long ptr;
327 int ret;
328 int ins_len = name_len + sizeof(*ref);
329
330 key.objectid = inode_objectid;
331 key.offset = ref_objectid;
332 key.type = BTRFS_INODE_REF_KEY;
333
334 path = btrfs_alloc_path();
335 if (!path)
336 return -ENOMEM;
337
338 path->leave_spinning = 1;
339 path->skip_release_on_error = 1;
340 ret = btrfs_insert_empty_item(trans, root, path, &key,
341 ins_len);
342 if (ret == -EEXIST) {
343 u32 old_size;
344
345 if (btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
346 name, name_len, &ref))
347 goto out;
348
349 old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
350 btrfs_extend_item(fs_info, path, ins_len);
351 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
352 struct btrfs_inode_ref);
353 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
354 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
355 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
356 ptr = (unsigned long)(ref + 1);
357 ret = 0;
358 } else if (ret < 0) {
359 if (ret == -EOVERFLOW) {
360 if (btrfs_find_name_in_backref(path->nodes[0],
361 path->slots[0],
362 name, name_len, &ref))
363 ret = -EEXIST;
364 else
365 ret = -EMLINK;
366 }
367 goto out;
368 } else {
369 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
370 struct btrfs_inode_ref);
371 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
372 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
373 ptr = (unsigned long)(ref + 1);
374 }
375 write_extent_buffer(path->nodes[0], name, ptr, name_len);
376 btrfs_mark_buffer_dirty(path->nodes[0]);
377
378out:
379 btrfs_free_path(path);
380
381 if (ret == -EMLINK) {
382 struct btrfs_super_block *disk_super = fs_info->super_copy;
383 /* We ran out of space in the ref array. Need to
384 * add an extended ref. */
385 if (btrfs_super_incompat_flags(disk_super)
386 & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
387 ret = btrfs_insert_inode_extref(trans, root, name,
388 name_len,
389 inode_objectid,
390 ref_objectid, index);
391 }
392
393 return ret;
394}
395
396int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
397 struct btrfs_root *root,
398 struct btrfs_path *path, u64 objectid)
399{
400 struct btrfs_key key;
401 int ret;
402 key.objectid = objectid;
403 key.type = BTRFS_INODE_ITEM_KEY;
404 key.offset = 0;
405
406 ret = btrfs_insert_empty_item(trans, root, path, &key,
407 sizeof(struct btrfs_inode_item));
408 return ret;
409}
410
411int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
412 *root, struct btrfs_path *path,
413 struct btrfs_key *location, int mod)
414{
415 int ins_len = mod < 0 ? -1 : 0;
416 int cow = mod != 0;
417 int ret;
418 int slot;
419 struct extent_buffer *leaf;
420 struct btrfs_key found_key;
421
422 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
423 if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
424 location->offset == (u64)-1 && path->slots[0] != 0) {
425 slot = path->slots[0] - 1;
426 leaf = path->nodes[0];
427 btrfs_item_key_to_cpu(leaf, &found_key, slot);
428 if (found_key.objectid == location->objectid &&
429 found_key.type == location->type) {
430 path->slots[0]--;
431 return 0;
432 }
433 }
434 return ret;
435}