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c1d7c514 1// SPDX-License-Identifier: GPL-2.0
6cbd5570
CM
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
6cbd5570
CM
4 */
5
62e2749e
CM
6#include "ctree.h"
7#include "disk-io.h"
e089f05c 8#include "transaction.h"
62e2749e 9
d352ac68
CM
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 */
35b7e476
CM
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,
e06afa83
CM
23 u32 data_size,
24 const char *name,
25 int name_len)
7fcde0e3 26{
2ff7e61e 27 struct btrfs_fs_info *fs_info = root->fs_info;
7fcde0e3 28 int ret;
7e38180e
CM
29 char *ptr;
30 struct btrfs_item *item;
5f39d397 31 struct extent_buffer *leaf;
7fcde0e3
CM
32
33 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
7e38180e 34 if (ret == -EEXIST) {
e06afa83 35 struct btrfs_dir_item *di;
2ff7e61e 36 di = btrfs_match_dir_item_name(fs_info, path, name, name_len);
e06afa83
CM
37 if (di)
38 return ERR_PTR(-EEXIST);
c71dd880 39 btrfs_extend_item(path, data_size);
143bede5 40 } else if (ret < 0)
54aa1f4d 41 return ERR_PTR(ret);
7e38180e 42 WARN_ON(ret > 0);
5f39d397 43 leaf = path->nodes[0];
dd3cc16b 44 item = btrfs_item_nr(path->slots[0]);
7e38180e 45 ptr = btrfs_item_ptr(leaf, path->slots[0], char);
5f39d397
CM
46 BUG_ON(data_size > btrfs_item_size(leaf, item));
47 ptr += btrfs_item_size(leaf, item) - data_size;
7e38180e 48 return (struct btrfs_dir_item *)ptr;
7fcde0e3
CM
49}
50
d352ac68
CM
51/*
52 * xattrs work a lot like directories, this inserts an xattr item
53 * into the tree
54 */
5103e947 55int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
f34f57a3
YZ
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)
5103e947
JB
60{
61 int ret = 0;
5103e947
JB
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
b9d04c60
DS
69 if (name_len + data_len > BTRFS_MAX_XATTR_SIZE(root->fs_info))
70 return -ENOSPC;
f34f57a3
YZ
71
72 key.objectid = objectid;
962a298f 73 key.type = BTRFS_XATTR_ITEM_KEY;
df68b8a7 74 key.offset = btrfs_name_hash(name, name_len);
5103e947
JB
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);
fa09200b
JB
79 if (IS_ERR(dir_item))
80 return PTR_ERR(dir_item);
5103e947
JB
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);
e02119d5 88 btrfs_set_dir_transid(leaf, dir_item, trans->transid);
5103e947
JB
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
5103e947
JB
97 return ret;
98}
99
d352ac68
CM
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).
79787eaa 106 * Will return 0 or -ENOMEM
d352ac68 107 */
684572df
LF
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)
62e2749e
CM
111{
112 int ret = 0;
e06afa83 113 int ret2 = 0;
684572df 114 struct btrfs_root *root = dir->root;
5caf2a00 115 struct btrfs_path *path;
62e2749e 116 struct btrfs_dir_item *dir_item;
5f39d397
CM
117 struct extent_buffer *leaf;
118 unsigned long name_ptr;
62e2749e 119 struct btrfs_key key;
5f39d397 120 struct btrfs_disk_key disk_key;
62e2749e
CM
121 u32 data_size;
122
8e7611cf 123 key.objectid = btrfs_ino(dir);
962a298f 124 key.type = BTRFS_DIR_ITEM_KEY;
df68b8a7 125 key.offset = btrfs_name_hash(name, name_len);
b9473439 126
5caf2a00 127 path = btrfs_alloc_path();
16cdcec7
MX
128 if (!path)
129 return -ENOMEM;
b9473439 130
16cdcec7
MX
131 btrfs_cpu_key_to_disk(&disk_key, location);
132
62e2749e 133 data_size = sizeof(*dir_item) + name_len;
e06afa83
CM
134 dir_item = insert_with_overflow(trans, root, path, &key, data_size,
135 name, name_len);
7e38180e
CM
136 if (IS_ERR(dir_item)) {
137 ret = PTR_ERR(dir_item);
e06afa83
CM
138 if (ret == -EEXIST)
139 goto second_insert;
c2db1073 140 goto out_free;
7e38180e 141 }
62e2749e 142
5f39d397 143 leaf = path->nodes[0];
5f39d397
CM
144 btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
145 btrfs_set_dir_type(leaf, dir_item, type);
5103e947 146 btrfs_set_dir_data_len(leaf, dir_item, 0);
5f39d397 147 btrfs_set_dir_name_len(leaf, dir_item, name_len);
e02119d5 148 btrfs_set_dir_transid(leaf, dir_item, trans->transid);
5f39d397 149 name_ptr = (unsigned long)(dir_item + 1);
c5739bba 150
5f39d397
CM
151 write_extent_buffer(leaf, name, name_ptr, name_len);
152 btrfs_mark_buffer_dirty(leaf);
7e38180e 153
e06afa83 154second_insert:
7e38180e
CM
155 /* FIXME, use some real flag for selecting the extra index */
156 if (root == root->fs_info->tree_root) {
157 ret = 0;
c2db1073 158 goto out_free;
7e38180e 159 }
b3b4aa74 160 btrfs_release_path(path);
7e38180e 161
4465c8b4
LF
162 ret2 = btrfs_insert_delayed_dir_index(trans, name, name_len, dir,
163 &disk_key, type, index);
c2db1073 164out_free:
5caf2a00 165 btrfs_free_path(path);
e06afa83
CM
166 if (ret)
167 return ret;
168 if (ret2)
169 return ret2;
170 return 0;
62e2749e
CM
171}
172
d352ac68
CM
173/*
174 * lookup a directory item based on name. 'dir' is the objectid
175 * we're searching in, and 'mod' tells us if you plan on deleting the
176 * item (use mod < 0) or changing the options (use mod > 0)
177 */
7e38180e
CM
178struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
179 struct btrfs_root *root,
180 struct btrfs_path *path, u64 dir,
181 const char *name, int name_len,
182 int mod)
62e2749e 183{
1d4f6404 184 int ret;
62e2749e 185 struct btrfs_key key;
1d4f6404
CM
186 int ins_len = mod < 0 ? -1 : 0;
187 int cow = mod != 0;
62e2749e
CM
188
189 key.objectid = dir;
962a298f 190 key.type = BTRFS_DIR_ITEM_KEY;
5f39d397 191
df68b8a7 192 key.offset = btrfs_name_hash(name, name_len);
5f39d397 193
7e38180e
CM
194 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
195 if (ret < 0)
196 return ERR_PTR(ret);
85d85a74 197 if (ret > 0)
7e38180e
CM
198 return NULL;
199
2ff7e61e 200 return btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
62e2749e
CM
201}
202
9c52057c
CM
203int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
204 const char *name, int name_len)
205{
206 int ret;
207 struct btrfs_key key;
208 struct btrfs_dir_item *di;
209 int data_size;
210 struct extent_buffer *leaf;
211 int slot;
212 struct btrfs_path *path;
213
214
215 path = btrfs_alloc_path();
216 if (!path)
217 return -ENOMEM;
218
219 key.objectid = dir;
962a298f 220 key.type = BTRFS_DIR_ITEM_KEY;
9c52057c
CM
221 key.offset = btrfs_name_hash(name, name_len);
222
223 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
224
225 /* return back any errors */
226 if (ret < 0)
227 goto out;
228
229 /* nothing found, we're safe */
230 if (ret > 0) {
231 ret = 0;
232 goto out;
233 }
234
235 /* we found an item, look for our name in the item */
2ff7e61e 236 di = btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
9c52057c
CM
237 if (di) {
238 /* our exact name was found */
239 ret = -EEXIST;
240 goto out;
241 }
242
243 /*
244 * see if there is room in the item to insert this
245 * name
246 */
878f2d2c 247 data_size = sizeof(*di) + name_len;
9c52057c
CM
248 leaf = path->nodes[0];
249 slot = path->slots[0];
250 if (data_size + btrfs_item_size_nr(leaf, slot) +
da17066c 251 sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root->fs_info)) {
9c52057c
CM
252 ret = -EOVERFLOW;
253 } else {
254 /* plenty of insertion room */
255 ret = 0;
256 }
257out:
258 btrfs_free_path(path);
259 return ret;
260}
261
d352ac68
CM
262/*
263 * lookup a directory item based on index. 'dir' is the objectid
264 * we're searching in, and 'mod' tells us if you plan on deleting the
265 * item (use mod < 0) or changing the options (use mod > 0)
266 *
267 * The name is used to make sure the index really points to the name you were
268 * looking for.
269 */
7e38180e
CM
270struct btrfs_dir_item *
271btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
272 struct btrfs_root *root,
273 struct btrfs_path *path, u64 dir,
274 u64 objectid, const char *name, int name_len,
275 int mod)
276{
277 int ret;
278 struct btrfs_key key;
279 int ins_len = mod < 0 ? -1 : 0;
280 int cow = mod != 0;
281
282 key.objectid = dir;
962a298f 283 key.type = BTRFS_DIR_INDEX_KEY;
7e38180e
CM
284 key.offset = objectid;
285
286 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
287 if (ret < 0)
288 return ERR_PTR(ret);
289 if (ret > 0)
290 return ERR_PTR(-ENOENT);
2ff7e61e 291 return btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
7e38180e
CM
292}
293
4df27c4d
YZ
294struct btrfs_dir_item *
295btrfs_search_dir_index_item(struct btrfs_root *root,
296 struct btrfs_path *path, u64 dirid,
297 const char *name, int name_len)
298{
299 struct extent_buffer *leaf;
300 struct btrfs_dir_item *di;
301 struct btrfs_key key;
302 u32 nritems;
303 int ret;
304
305 key.objectid = dirid;
306 key.type = BTRFS_DIR_INDEX_KEY;
307 key.offset = 0;
308
309 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
310 if (ret < 0)
311 return ERR_PTR(ret);
312
313 leaf = path->nodes[0];
314 nritems = btrfs_header_nritems(leaf);
315
316 while (1) {
317 if (path->slots[0] >= nritems) {
318 ret = btrfs_next_leaf(root, path);
319 if (ret < 0)
320 return ERR_PTR(ret);
321 if (ret > 0)
322 break;
323 leaf = path->nodes[0];
324 nritems = btrfs_header_nritems(leaf);
325 continue;
326 }
327
328 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
329 if (key.objectid != dirid || key.type != BTRFS_DIR_INDEX_KEY)
330 break;
331
2ff7e61e
JM
332 di = btrfs_match_dir_item_name(root->fs_info, path,
333 name, name_len);
4df27c4d
YZ
334 if (di)
335 return di;
336
337 path->slots[0]++;
338 }
339 return NULL;
340}
341
5103e947
JB
342struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
343 struct btrfs_root *root,
344 struct btrfs_path *path, u64 dir,
345 const char *name, u16 name_len,
346 int mod)
347{
348 int ret;
349 struct btrfs_key key;
350 int ins_len = mod < 0 ? -1 : 0;
351 int cow = mod != 0;
5103e947
JB
352
353 key.objectid = dir;
962a298f 354 key.type = BTRFS_XATTR_ITEM_KEY;
df68b8a7 355 key.offset = btrfs_name_hash(name, name_len);
5103e947
JB
356 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
357 if (ret < 0)
358 return ERR_PTR(ret);
85d85a74 359 if (ret > 0)
5103e947
JB
360 return NULL;
361
2ff7e61e 362 return btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
5103e947
JB
363}
364
d352ac68
CM
365/*
366 * helper function to look at the directory item pointed to by 'path'
367 * this walks through all the entries in a dir item and finds one
368 * for a specific name.
369 */
2ff7e61e 370struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_fs_info *fs_info,
5f5bc6b1
FM
371 struct btrfs_path *path,
372 const char *name, int name_len)
62e2749e 373{
62e2749e 374 struct btrfs_dir_item *dir_item;
5f39d397 375 unsigned long name_ptr;
7e38180e
CM
376 u32 total_len;
377 u32 cur = 0;
378 u32 this_len;
5f39d397 379 struct extent_buffer *leaf;
a8a2ee0c 380
5f39d397 381 leaf = path->nodes[0];
7e38180e 382 dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
22a94d44 383
5f39d397 384 total_len = btrfs_item_size_nr(leaf, path->slots[0]);
d397712b 385 while (cur < total_len) {
5f39d397 386 this_len = sizeof(*dir_item) +
5103e947
JB
387 btrfs_dir_name_len(leaf, dir_item) +
388 btrfs_dir_data_len(leaf, dir_item);
5f39d397 389 name_ptr = (unsigned long)(dir_item + 1);
7e38180e 390
5f39d397
CM
391 if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
392 memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
7e38180e
CM
393 return dir_item;
394
395 cur += this_len;
396 dir_item = (struct btrfs_dir_item *)((char *)dir_item +
397 this_len);
398 }
399 return NULL;
62e2749e 400}
7e38180e 401
d352ac68
CM
402/*
403 * given a pointer into a directory item, delete it. This
404 * handles items that have more than one entry in them.
405 */
7e38180e
CM
406int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
407 struct btrfs_root *root,
408 struct btrfs_path *path,
409 struct btrfs_dir_item *di)
410{
411
5f39d397 412 struct extent_buffer *leaf;
7e38180e
CM
413 u32 sub_item_len;
414 u32 item_len;
54aa1f4d 415 int ret = 0;
7e38180e 416
5f39d397 417 leaf = path->nodes[0];
5103e947
JB
418 sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) +
419 btrfs_dir_data_len(leaf, di);
5f39d397
CM
420 item_len = btrfs_item_size_nr(leaf, path->slots[0]);
421 if (sub_item_len == item_len) {
7e38180e 422 ret = btrfs_del_item(trans, root, path);
7e38180e 423 } else {
5f39d397
CM
424 /* MARKER */
425 unsigned long ptr = (unsigned long)di;
426 unsigned long start;
427
428 start = btrfs_item_ptr_offset(leaf, path->slots[0]);
429 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
7e38180e 430 item_len - (ptr + sub_item_len - start));
78ac4f9e 431 btrfs_truncate_item(path, item_len - sub_item_len, 1);
7e38180e 432 }
411fc6bc 433 return ret;
7e38180e 434}