Loading...
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
10/*
11 * insert a name into a directory, doing overflow properly if there is a hash
12 * collision. data_size indicates how big the item inserted should be. On
13 * success a struct btrfs_dir_item pointer is returned, otherwise it is
14 * an ERR_PTR.
15 *
16 * The name is not copied into the dir item, you have to do that yourself.
17 */
18static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
19 *trans,
20 struct btrfs_root *root,
21 struct btrfs_path *path,
22 struct btrfs_key *cpu_key,
23 u32 data_size,
24 const char *name,
25 int name_len)
26{
27 struct btrfs_fs_info *fs_info = root->fs_info;
28 int ret;
29 char *ptr;
30 struct btrfs_item *item;
31 struct extent_buffer *leaf;
32
33 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
34 if (ret == -EEXIST) {
35 struct btrfs_dir_item *di;
36 di = btrfs_match_dir_item_name(fs_info, path, name, name_len);
37 if (di)
38 return ERR_PTR(-EEXIST);
39 btrfs_extend_item(path, data_size);
40 } else if (ret < 0)
41 return ERR_PTR(ret);
42 WARN_ON(ret > 0);
43 leaf = path->nodes[0];
44 item = btrfs_item_nr(path->slots[0]);
45 ptr = btrfs_item_ptr(leaf, path->slots[0], char);
46 BUG_ON(data_size > btrfs_item_size(leaf, item));
47 ptr += btrfs_item_size(leaf, item) - data_size;
48 return (struct btrfs_dir_item *)ptr;
49}
50
51/*
52 * xattrs work a lot like directories, this inserts an xattr item
53 * into the tree
54 */
55int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
56 struct btrfs_root *root,
57 struct btrfs_path *path, u64 objectid,
58 const char *name, u16 name_len,
59 const void *data, u16 data_len)
60{
61 int ret = 0;
62 struct btrfs_dir_item *dir_item;
63 unsigned long name_ptr, data_ptr;
64 struct btrfs_key key, location;
65 struct btrfs_disk_key disk_key;
66 struct extent_buffer *leaf;
67 u32 data_size;
68
69 if (name_len + data_len > BTRFS_MAX_XATTR_SIZE(root->fs_info))
70 return -ENOSPC;
71
72 key.objectid = objectid;
73 key.type = BTRFS_XATTR_ITEM_KEY;
74 key.offset = btrfs_name_hash(name, name_len);
75
76 data_size = sizeof(*dir_item) + name_len + data_len;
77 dir_item = insert_with_overflow(trans, root, path, &key, data_size,
78 name, name_len);
79 if (IS_ERR(dir_item))
80 return PTR_ERR(dir_item);
81 memset(&location, 0, sizeof(location));
82
83 leaf = path->nodes[0];
84 btrfs_cpu_key_to_disk(&disk_key, &location);
85 btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
86 btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR);
87 btrfs_set_dir_name_len(leaf, dir_item, name_len);
88 btrfs_set_dir_transid(leaf, dir_item, trans->transid);
89 btrfs_set_dir_data_len(leaf, dir_item, data_len);
90 name_ptr = (unsigned long)(dir_item + 1);
91 data_ptr = (unsigned long)((char *)name_ptr + name_len);
92
93 write_extent_buffer(leaf, name, name_ptr, name_len);
94 write_extent_buffer(leaf, data, data_ptr, data_len);
95 btrfs_mark_buffer_dirty(path->nodes[0]);
96
97 return ret;
98}
99
100/*
101 * insert a directory item in the tree, doing all the magic for
102 * both indexes. 'dir' indicates which objectid to insert it into,
103 * 'location' is the key to stuff into the directory item, 'type' is the
104 * type of the inode we're pointing to, and 'index' is the sequence number
105 * to use for the second index (if one is created).
106 * Will return 0 or -ENOMEM
107 */
108int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, const char *name,
109 int name_len, struct btrfs_inode *dir,
110 struct btrfs_key *location, u8 type, u64 index)
111{
112 int ret = 0;
113 int ret2 = 0;
114 struct btrfs_root *root = dir->root;
115 struct btrfs_path *path;
116 struct btrfs_dir_item *dir_item;
117 struct extent_buffer *leaf;
118 unsigned long name_ptr;
119 struct btrfs_key key;
120 struct btrfs_disk_key disk_key;
121 u32 data_size;
122
123 key.objectid = btrfs_ino(dir);
124 key.type = BTRFS_DIR_ITEM_KEY;
125 key.offset = btrfs_name_hash(name, name_len);
126
127 path = btrfs_alloc_path();
128 if (!path)
129 return -ENOMEM;
130 path->leave_spinning = 1;
131
132 btrfs_cpu_key_to_disk(&disk_key, location);
133
134 data_size = sizeof(*dir_item) + name_len;
135 dir_item = insert_with_overflow(trans, root, path, &key, data_size,
136 name, name_len);
137 if (IS_ERR(dir_item)) {
138 ret = PTR_ERR(dir_item);
139 if (ret == -EEXIST)
140 goto second_insert;
141 goto out_free;
142 }
143
144 leaf = path->nodes[0];
145 btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
146 btrfs_set_dir_type(leaf, dir_item, type);
147 btrfs_set_dir_data_len(leaf, dir_item, 0);
148 btrfs_set_dir_name_len(leaf, dir_item, name_len);
149 btrfs_set_dir_transid(leaf, dir_item, trans->transid);
150 name_ptr = (unsigned long)(dir_item + 1);
151
152 write_extent_buffer(leaf, name, name_ptr, name_len);
153 btrfs_mark_buffer_dirty(leaf);
154
155second_insert:
156 /* FIXME, use some real flag for selecting the extra index */
157 if (root == root->fs_info->tree_root) {
158 ret = 0;
159 goto out_free;
160 }
161 btrfs_release_path(path);
162
163 ret2 = btrfs_insert_delayed_dir_index(trans, name, name_len, dir,
164 &disk_key, type, index);
165out_free:
166 btrfs_free_path(path);
167 if (ret)
168 return ret;
169 if (ret2)
170 return ret2;
171 return 0;
172}
173
174/*
175 * lookup a directory item based on name. 'dir' is the objectid
176 * we're searching in, and 'mod' tells us if you plan on deleting the
177 * item (use mod < 0) or changing the options (use mod > 0)
178 */
179struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
180 struct btrfs_root *root,
181 struct btrfs_path *path, u64 dir,
182 const char *name, int name_len,
183 int mod)
184{
185 int ret;
186 struct btrfs_key key;
187 int ins_len = mod < 0 ? -1 : 0;
188 int cow = mod != 0;
189
190 key.objectid = dir;
191 key.type = BTRFS_DIR_ITEM_KEY;
192
193 key.offset = btrfs_name_hash(name, name_len);
194
195 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
196 if (ret < 0)
197 return ERR_PTR(ret);
198 if (ret > 0)
199 return NULL;
200
201 return btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
202}
203
204int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
205 const char *name, int name_len)
206{
207 int ret;
208 struct btrfs_key key;
209 struct btrfs_dir_item *di;
210 int data_size;
211 struct extent_buffer *leaf;
212 int slot;
213 struct btrfs_path *path;
214
215
216 path = btrfs_alloc_path();
217 if (!path)
218 return -ENOMEM;
219
220 key.objectid = dir;
221 key.type = BTRFS_DIR_ITEM_KEY;
222 key.offset = btrfs_name_hash(name, name_len);
223
224 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
225
226 /* return back any errors */
227 if (ret < 0)
228 goto out;
229
230 /* nothing found, we're safe */
231 if (ret > 0) {
232 ret = 0;
233 goto out;
234 }
235
236 /* we found an item, look for our name in the item */
237 di = btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
238 if (di) {
239 /* our exact name was found */
240 ret = -EEXIST;
241 goto out;
242 }
243
244 /*
245 * see if there is room in the item to insert this
246 * name
247 */
248 data_size = sizeof(*di) + name_len;
249 leaf = path->nodes[0];
250 slot = path->slots[0];
251 if (data_size + btrfs_item_size_nr(leaf, slot) +
252 sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root->fs_info)) {
253 ret = -EOVERFLOW;
254 } else {
255 /* plenty of insertion room */
256 ret = 0;
257 }
258out:
259 btrfs_free_path(path);
260 return ret;
261}
262
263/*
264 * lookup a directory item based on index. 'dir' is the objectid
265 * we're searching in, and 'mod' tells us if you plan on deleting the
266 * item (use mod < 0) or changing the options (use mod > 0)
267 *
268 * The name is used to make sure the index really points to the name you were
269 * looking for.
270 */
271struct btrfs_dir_item *
272btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
273 struct btrfs_root *root,
274 struct btrfs_path *path, u64 dir,
275 u64 objectid, const char *name, int name_len,
276 int mod)
277{
278 int ret;
279 struct btrfs_key key;
280 int ins_len = mod < 0 ? -1 : 0;
281 int cow = mod != 0;
282
283 key.objectid = dir;
284 key.type = BTRFS_DIR_INDEX_KEY;
285 key.offset = objectid;
286
287 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
288 if (ret < 0)
289 return ERR_PTR(ret);
290 if (ret > 0)
291 return ERR_PTR(-ENOENT);
292 return btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
293}
294
295struct btrfs_dir_item *
296btrfs_search_dir_index_item(struct btrfs_root *root,
297 struct btrfs_path *path, u64 dirid,
298 const char *name, int name_len)
299{
300 struct extent_buffer *leaf;
301 struct btrfs_dir_item *di;
302 struct btrfs_key key;
303 u32 nritems;
304 int ret;
305
306 key.objectid = dirid;
307 key.type = BTRFS_DIR_INDEX_KEY;
308 key.offset = 0;
309
310 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
311 if (ret < 0)
312 return ERR_PTR(ret);
313
314 leaf = path->nodes[0];
315 nritems = btrfs_header_nritems(leaf);
316
317 while (1) {
318 if (path->slots[0] >= nritems) {
319 ret = btrfs_next_leaf(root, path);
320 if (ret < 0)
321 return ERR_PTR(ret);
322 if (ret > 0)
323 break;
324 leaf = path->nodes[0];
325 nritems = btrfs_header_nritems(leaf);
326 continue;
327 }
328
329 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
330 if (key.objectid != dirid || key.type != BTRFS_DIR_INDEX_KEY)
331 break;
332
333 di = btrfs_match_dir_item_name(root->fs_info, path,
334 name, name_len);
335 if (di)
336 return di;
337
338 path->slots[0]++;
339 }
340 return NULL;
341}
342
343struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
344 struct btrfs_root *root,
345 struct btrfs_path *path, u64 dir,
346 const char *name, u16 name_len,
347 int mod)
348{
349 int ret;
350 struct btrfs_key key;
351 int ins_len = mod < 0 ? -1 : 0;
352 int cow = mod != 0;
353
354 key.objectid = dir;
355 key.type = BTRFS_XATTR_ITEM_KEY;
356 key.offset = btrfs_name_hash(name, name_len);
357 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
358 if (ret < 0)
359 return ERR_PTR(ret);
360 if (ret > 0)
361 return NULL;
362
363 return btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
364}
365
366/*
367 * helper function to look at the directory item pointed to by 'path'
368 * this walks through all the entries in a dir item and finds one
369 * for a specific name.
370 */
371struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_fs_info *fs_info,
372 struct btrfs_path *path,
373 const char *name, int name_len)
374{
375 struct btrfs_dir_item *dir_item;
376 unsigned long name_ptr;
377 u32 total_len;
378 u32 cur = 0;
379 u32 this_len;
380 struct extent_buffer *leaf;
381
382 leaf = path->nodes[0];
383 dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
384
385 total_len = btrfs_item_size_nr(leaf, path->slots[0]);
386 while (cur < total_len) {
387 this_len = sizeof(*dir_item) +
388 btrfs_dir_name_len(leaf, dir_item) +
389 btrfs_dir_data_len(leaf, dir_item);
390 name_ptr = (unsigned long)(dir_item + 1);
391
392 if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
393 memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
394 return dir_item;
395
396 cur += this_len;
397 dir_item = (struct btrfs_dir_item *)((char *)dir_item +
398 this_len);
399 }
400 return NULL;
401}
402
403/*
404 * given a pointer into a directory item, delete it. This
405 * handles items that have more than one entry in them.
406 */
407int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
408 struct btrfs_root *root,
409 struct btrfs_path *path,
410 struct btrfs_dir_item *di)
411{
412
413 struct extent_buffer *leaf;
414 u32 sub_item_len;
415 u32 item_len;
416 int ret = 0;
417
418 leaf = path->nodes[0];
419 sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) +
420 btrfs_dir_data_len(leaf, di);
421 item_len = btrfs_item_size_nr(leaf, path->slots[0]);
422 if (sub_item_len == item_len) {
423 ret = btrfs_del_item(trans, root, path);
424 } else {
425 /* MARKER */
426 unsigned long ptr = (unsigned long)di;
427 unsigned long start;
428
429 start = btrfs_item_ptr_offset(leaf, path->slots[0]);
430 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
431 item_len - (ptr + sub_item_len - start));
432 btrfs_truncate_item(path, item_len - sub_item_len, 1);
433 }
434 return ret;
435}
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
19#include "ctree.h"
20#include "disk-io.h"
21#include "hash.h"
22#include "transaction.h"
23
24/*
25 * insert a name into a directory, doing overflow properly if there is a hash
26 * collision. data_size indicates how big the item inserted should be. On
27 * success a struct btrfs_dir_item pointer is returned, otherwise it is
28 * an ERR_PTR.
29 *
30 * The name is not copied into the dir item, you have to do that yourself.
31 */
32static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
33 *trans,
34 struct btrfs_root *root,
35 struct btrfs_path *path,
36 struct btrfs_key *cpu_key,
37 u32 data_size,
38 const char *name,
39 int name_len)
40{
41 int ret;
42 char *ptr;
43 struct btrfs_item *item;
44 struct extent_buffer *leaf;
45
46 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
47 if (ret == -EEXIST) {
48 struct btrfs_dir_item *di;
49 di = btrfs_match_dir_item_name(root, path, name, name_len);
50 if (di)
51 return ERR_PTR(-EEXIST);
52 btrfs_extend_item(root, path, data_size);
53 } else if (ret < 0)
54 return ERR_PTR(ret);
55 WARN_ON(ret > 0);
56 leaf = path->nodes[0];
57 item = btrfs_item_nr(path->slots[0]);
58 ptr = btrfs_item_ptr(leaf, path->slots[0], char);
59 BUG_ON(data_size > btrfs_item_size(leaf, item));
60 ptr += btrfs_item_size(leaf, item) - data_size;
61 return (struct btrfs_dir_item *)ptr;
62}
63
64/*
65 * xattrs work a lot like directories, this inserts an xattr item
66 * into the tree
67 */
68int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
69 struct btrfs_root *root,
70 struct btrfs_path *path, u64 objectid,
71 const char *name, u16 name_len,
72 const void *data, u16 data_len)
73{
74 int ret = 0;
75 struct btrfs_dir_item *dir_item;
76 unsigned long name_ptr, data_ptr;
77 struct btrfs_key key, location;
78 struct btrfs_disk_key disk_key;
79 struct extent_buffer *leaf;
80 u32 data_size;
81
82 BUG_ON(name_len + data_len > BTRFS_MAX_XATTR_SIZE(root));
83
84 key.objectid = objectid;
85 key.type = BTRFS_XATTR_ITEM_KEY;
86 key.offset = btrfs_name_hash(name, name_len);
87
88 data_size = sizeof(*dir_item) + name_len + data_len;
89 dir_item = insert_with_overflow(trans, root, path, &key, data_size,
90 name, name_len);
91 if (IS_ERR(dir_item))
92 return PTR_ERR(dir_item);
93 memset(&location, 0, sizeof(location));
94
95 leaf = path->nodes[0];
96 btrfs_cpu_key_to_disk(&disk_key, &location);
97 btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
98 btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR);
99 btrfs_set_dir_name_len(leaf, dir_item, name_len);
100 btrfs_set_dir_transid(leaf, dir_item, trans->transid);
101 btrfs_set_dir_data_len(leaf, dir_item, data_len);
102 name_ptr = (unsigned long)(dir_item + 1);
103 data_ptr = (unsigned long)((char *)name_ptr + name_len);
104
105 write_extent_buffer(leaf, name, name_ptr, name_len);
106 write_extent_buffer(leaf, data, data_ptr, data_len);
107 btrfs_mark_buffer_dirty(path->nodes[0]);
108
109 return ret;
110}
111
112/*
113 * insert a directory item in the tree, doing all the magic for
114 * both indexes. 'dir' indicates which objectid to insert it into,
115 * 'location' is the key to stuff into the directory item, 'type' is the
116 * type of the inode we're pointing to, and 'index' is the sequence number
117 * to use for the second index (if one is created).
118 * Will return 0 or -ENOMEM
119 */
120int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
121 *root, const char *name, int name_len,
122 struct inode *dir, struct btrfs_key *location,
123 u8 type, u64 index)
124{
125 int ret = 0;
126 int ret2 = 0;
127 struct btrfs_path *path;
128 struct btrfs_dir_item *dir_item;
129 struct extent_buffer *leaf;
130 unsigned long name_ptr;
131 struct btrfs_key key;
132 struct btrfs_disk_key disk_key;
133 u32 data_size;
134
135 key.objectid = btrfs_ino(dir);
136 key.type = BTRFS_DIR_ITEM_KEY;
137 key.offset = btrfs_name_hash(name, name_len);
138
139 path = btrfs_alloc_path();
140 if (!path)
141 return -ENOMEM;
142 path->leave_spinning = 1;
143
144 btrfs_cpu_key_to_disk(&disk_key, location);
145
146 data_size = sizeof(*dir_item) + name_len;
147 dir_item = insert_with_overflow(trans, root, path, &key, data_size,
148 name, name_len);
149 if (IS_ERR(dir_item)) {
150 ret = PTR_ERR(dir_item);
151 if (ret == -EEXIST)
152 goto second_insert;
153 goto out_free;
154 }
155
156 leaf = path->nodes[0];
157 btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
158 btrfs_set_dir_type(leaf, dir_item, type);
159 btrfs_set_dir_data_len(leaf, dir_item, 0);
160 btrfs_set_dir_name_len(leaf, dir_item, name_len);
161 btrfs_set_dir_transid(leaf, dir_item, trans->transid);
162 name_ptr = (unsigned long)(dir_item + 1);
163
164 write_extent_buffer(leaf, name, name_ptr, name_len);
165 btrfs_mark_buffer_dirty(leaf);
166
167second_insert:
168 /* FIXME, use some real flag for selecting the extra index */
169 if (root == root->fs_info->tree_root) {
170 ret = 0;
171 goto out_free;
172 }
173 btrfs_release_path(path);
174
175 ret2 = btrfs_insert_delayed_dir_index(trans, root, name, name_len, dir,
176 &disk_key, type, index);
177out_free:
178 btrfs_free_path(path);
179 if (ret)
180 return ret;
181 if (ret2)
182 return ret2;
183 return 0;
184}
185
186/*
187 * lookup a directory item based on name. 'dir' is the objectid
188 * we're searching in, and 'mod' tells us if you plan on deleting the
189 * item (use mod < 0) or changing the options (use mod > 0)
190 */
191struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
192 struct btrfs_root *root,
193 struct btrfs_path *path, u64 dir,
194 const char *name, int name_len,
195 int mod)
196{
197 int ret;
198 struct btrfs_key key;
199 int ins_len = mod < 0 ? -1 : 0;
200 int cow = mod != 0;
201
202 key.objectid = dir;
203 key.type = BTRFS_DIR_ITEM_KEY;
204
205 key.offset = btrfs_name_hash(name, name_len);
206
207 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
208 if (ret < 0)
209 return ERR_PTR(ret);
210 if (ret > 0)
211 return NULL;
212
213 return btrfs_match_dir_item_name(root, path, name, name_len);
214}
215
216int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
217 const char *name, int name_len)
218{
219 int ret;
220 struct btrfs_key key;
221 struct btrfs_dir_item *di;
222 int data_size;
223 struct extent_buffer *leaf;
224 int slot;
225 struct btrfs_path *path;
226
227
228 path = btrfs_alloc_path();
229 if (!path)
230 return -ENOMEM;
231
232 key.objectid = dir;
233 key.type = BTRFS_DIR_ITEM_KEY;
234 key.offset = btrfs_name_hash(name, name_len);
235
236 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
237
238 /* return back any errors */
239 if (ret < 0)
240 goto out;
241
242 /* nothing found, we're safe */
243 if (ret > 0) {
244 ret = 0;
245 goto out;
246 }
247
248 /* we found an item, look for our name in the item */
249 di = btrfs_match_dir_item_name(root, path, name, name_len);
250 if (di) {
251 /* our exact name was found */
252 ret = -EEXIST;
253 goto out;
254 }
255
256 /*
257 * see if there is room in the item to insert this
258 * name
259 */
260 data_size = sizeof(*di) + name_len;
261 leaf = path->nodes[0];
262 slot = path->slots[0];
263 if (data_size + btrfs_item_size_nr(leaf, slot) +
264 sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) {
265 ret = -EOVERFLOW;
266 } else {
267 /* plenty of insertion room */
268 ret = 0;
269 }
270out:
271 btrfs_free_path(path);
272 return ret;
273}
274
275/*
276 * lookup a directory item based on index. 'dir' is the objectid
277 * we're searching in, and 'mod' tells us if you plan on deleting the
278 * item (use mod < 0) or changing the options (use mod > 0)
279 *
280 * The name is used to make sure the index really points to the name you were
281 * looking for.
282 */
283struct btrfs_dir_item *
284btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
285 struct btrfs_root *root,
286 struct btrfs_path *path, u64 dir,
287 u64 objectid, const char *name, int name_len,
288 int mod)
289{
290 int ret;
291 struct btrfs_key key;
292 int ins_len = mod < 0 ? -1 : 0;
293 int cow = mod != 0;
294
295 key.objectid = dir;
296 key.type = BTRFS_DIR_INDEX_KEY;
297 key.offset = objectid;
298
299 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
300 if (ret < 0)
301 return ERR_PTR(ret);
302 if (ret > 0)
303 return ERR_PTR(-ENOENT);
304 return btrfs_match_dir_item_name(root, path, name, name_len);
305}
306
307struct btrfs_dir_item *
308btrfs_search_dir_index_item(struct btrfs_root *root,
309 struct btrfs_path *path, u64 dirid,
310 const char *name, int name_len)
311{
312 struct extent_buffer *leaf;
313 struct btrfs_dir_item *di;
314 struct btrfs_key key;
315 u32 nritems;
316 int ret;
317
318 key.objectid = dirid;
319 key.type = BTRFS_DIR_INDEX_KEY;
320 key.offset = 0;
321
322 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
323 if (ret < 0)
324 return ERR_PTR(ret);
325
326 leaf = path->nodes[0];
327 nritems = btrfs_header_nritems(leaf);
328
329 while (1) {
330 if (path->slots[0] >= nritems) {
331 ret = btrfs_next_leaf(root, path);
332 if (ret < 0)
333 return ERR_PTR(ret);
334 if (ret > 0)
335 break;
336 leaf = path->nodes[0];
337 nritems = btrfs_header_nritems(leaf);
338 continue;
339 }
340
341 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
342 if (key.objectid != dirid || key.type != BTRFS_DIR_INDEX_KEY)
343 break;
344
345 di = btrfs_match_dir_item_name(root, path, name, name_len);
346 if (di)
347 return di;
348
349 path->slots[0]++;
350 }
351 return NULL;
352}
353
354struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
355 struct btrfs_root *root,
356 struct btrfs_path *path, u64 dir,
357 const char *name, u16 name_len,
358 int mod)
359{
360 int ret;
361 struct btrfs_key key;
362 int ins_len = mod < 0 ? -1 : 0;
363 int cow = mod != 0;
364
365 key.objectid = dir;
366 key.type = BTRFS_XATTR_ITEM_KEY;
367 key.offset = btrfs_name_hash(name, name_len);
368 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
369 if (ret < 0)
370 return ERR_PTR(ret);
371 if (ret > 0)
372 return NULL;
373
374 return btrfs_match_dir_item_name(root, path, name, name_len);
375}
376
377/*
378 * helper function to look at the directory item pointed to by 'path'
379 * this walks through all the entries in a dir item and finds one
380 * for a specific name.
381 */
382struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
383 struct btrfs_path *path,
384 const char *name, int name_len)
385{
386 struct btrfs_dir_item *dir_item;
387 unsigned long name_ptr;
388 u32 total_len;
389 u32 cur = 0;
390 u32 this_len;
391 struct extent_buffer *leaf;
392
393 leaf = path->nodes[0];
394 dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
395 if (verify_dir_item(root, leaf, dir_item))
396 return NULL;
397
398 total_len = btrfs_item_size_nr(leaf, path->slots[0]);
399 while (cur < total_len) {
400 this_len = sizeof(*dir_item) +
401 btrfs_dir_name_len(leaf, dir_item) +
402 btrfs_dir_data_len(leaf, dir_item);
403 name_ptr = (unsigned long)(dir_item + 1);
404
405 if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
406 memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
407 return dir_item;
408
409 cur += this_len;
410 dir_item = (struct btrfs_dir_item *)((char *)dir_item +
411 this_len);
412 }
413 return NULL;
414}
415
416/*
417 * given a pointer into a directory item, delete it. This
418 * handles items that have more than one entry in them.
419 */
420int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
421 struct btrfs_root *root,
422 struct btrfs_path *path,
423 struct btrfs_dir_item *di)
424{
425
426 struct extent_buffer *leaf;
427 u32 sub_item_len;
428 u32 item_len;
429 int ret = 0;
430
431 leaf = path->nodes[0];
432 sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) +
433 btrfs_dir_data_len(leaf, di);
434 item_len = btrfs_item_size_nr(leaf, path->slots[0]);
435 if (sub_item_len == item_len) {
436 ret = btrfs_del_item(trans, root, path);
437 } else {
438 /* MARKER */
439 unsigned long ptr = (unsigned long)di;
440 unsigned long start;
441
442 start = btrfs_item_ptr_offset(leaf, path->slots[0]);
443 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
444 item_len - (ptr + sub_item_len - start));
445 btrfs_truncate_item(root, path, item_len - sub_item_len, 1);
446 }
447 return ret;
448}
449
450int verify_dir_item(struct btrfs_root *root,
451 struct extent_buffer *leaf,
452 struct btrfs_dir_item *dir_item)
453{
454 u16 namelen = BTRFS_NAME_LEN;
455 u8 type = btrfs_dir_type(leaf, dir_item);
456
457 if (type >= BTRFS_FT_MAX) {
458 btrfs_crit(root->fs_info, "invalid dir item type: %d",
459 (int)type);
460 return 1;
461 }
462
463 if (type == BTRFS_FT_XATTR)
464 namelen = XATTR_NAME_MAX;
465
466 if (btrfs_dir_name_len(leaf, dir_item) > namelen) {
467 btrfs_crit(root->fs_info, "invalid dir item name len: %u",
468 (unsigned)btrfs_dir_data_len(leaf, dir_item));
469 return 1;
470 }
471
472 /* BTRFS_MAX_XATTR_SIZE is the same for all dir items */
473 if ((btrfs_dir_data_len(leaf, dir_item) +
474 btrfs_dir_name_len(leaf, dir_item)) > BTRFS_MAX_XATTR_SIZE(root)) {
475 btrfs_crit(root->fs_info, "invalid dir item name + data len: %u + %u",
476 (unsigned)btrfs_dir_name_len(leaf, dir_item),
477 (unsigned)btrfs_dir_data_len(leaf, dir_item));
478 return 1;
479 }
480
481 return 0;
482}