1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2007 Oracle. All rights reserved.
8 #include "transaction.h"
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
16 * The name is not copied into the dir item, you have to do that yourself.
18 static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
20 struct btrfs_root *root,
21 struct btrfs_path *path,
22 struct btrfs_key *cpu_key,
27 struct btrfs_fs_info *fs_info = root->fs_info;
30 struct btrfs_item *item;
31 struct extent_buffer *leaf;
33 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
35 struct btrfs_dir_item *di;
36 di = btrfs_match_dir_item_name(fs_info, path, name, name_len);
38 return ERR_PTR(-EEXIST);
39 btrfs_extend_item(path, data_size);
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;
52 * xattrs work a lot like directories, this inserts an xattr item
55 int 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)
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;
69 if (name_len + data_len > BTRFS_MAX_XATTR_SIZE(root->fs_info))
72 key.objectid = objectid;
73 key.type = BTRFS_XATTR_ITEM_KEY;
74 key.offset = btrfs_name_hash(name, name_len);
76 data_size = sizeof(*dir_item) + name_len + data_len;
77 dir_item = insert_with_overflow(trans, root, path, &key, data_size,
80 return PTR_ERR(dir_item);
81 memset(&location, 0, sizeof(location));
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);
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]);
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
108 int 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)
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;
123 key.objectid = btrfs_ino(dir);
124 key.type = BTRFS_DIR_ITEM_KEY;
125 key.offset = btrfs_name_hash(name, name_len);
127 path = btrfs_alloc_path();
131 btrfs_cpu_key_to_disk(&disk_key, location);
133 data_size = sizeof(*dir_item) + name_len;
134 dir_item = insert_with_overflow(trans, root, path, &key, data_size,
136 if (IS_ERR(dir_item)) {
137 ret = PTR_ERR(dir_item);
143 leaf = path->nodes[0];
144 btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
145 btrfs_set_dir_type(leaf, dir_item, type);
146 btrfs_set_dir_data_len(leaf, dir_item, 0);
147 btrfs_set_dir_name_len(leaf, dir_item, name_len);
148 btrfs_set_dir_transid(leaf, dir_item, trans->transid);
149 name_ptr = (unsigned long)(dir_item + 1);
151 write_extent_buffer(leaf, name, name_ptr, name_len);
152 btrfs_mark_buffer_dirty(leaf);
155 /* FIXME, use some real flag for selecting the extra index */
156 if (root == root->fs_info->tree_root) {
160 btrfs_release_path(path);
162 ret2 = btrfs_insert_delayed_dir_index(trans, name, name_len, dir,
163 &disk_key, type, index);
165 btrfs_free_path(path);
173 static struct btrfs_dir_item *btrfs_lookup_match_dir(
174 struct btrfs_trans_handle *trans,
175 struct btrfs_root *root, struct btrfs_path *path,
176 struct btrfs_key *key, const char *name,
177 int name_len, int mod)
179 const int ins_len = (mod < 0 ? -1 : 0);
180 const int cow = (mod != 0);
183 ret = btrfs_search_slot(trans, root, key, path, ins_len, cow);
187 return ERR_PTR(-ENOENT);
189 return btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
193 * lookup a directory item based on name. 'dir' is the objectid
194 * we're searching in, and 'mod' tells us if you plan on deleting the
195 * item (use mod < 0) or changing the options (use mod > 0)
197 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
198 struct btrfs_root *root,
199 struct btrfs_path *path, u64 dir,
200 const char *name, int name_len,
203 struct btrfs_key key;
204 struct btrfs_dir_item *di;
207 key.type = BTRFS_DIR_ITEM_KEY;
208 key.offset = btrfs_name_hash(name, name_len);
210 di = btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod);
211 if (IS_ERR(di) && PTR_ERR(di) == -ENOENT)
217 int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
218 const char *name, int name_len)
221 struct btrfs_key key;
222 struct btrfs_dir_item *di;
224 struct extent_buffer *leaf;
226 struct btrfs_path *path;
228 path = btrfs_alloc_path();
233 key.type = BTRFS_DIR_ITEM_KEY;
234 key.offset = btrfs_name_hash(name, name_len);
236 di = btrfs_lookup_match_dir(NULL, root, path, &key, name, name_len, 0);
239 /* Nothing found, we're safe */
240 if (ret == -ENOENT) {
249 /* we found an item, look for our name in the item */
251 /* our exact name was found */
257 * see if there is room in the item to insert this
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->fs_info)) {
267 /* plenty of insertion room */
271 btrfs_free_path(path);
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)
280 * The name is used to make sure the index really points to the name you were
283 struct btrfs_dir_item *
284 btrfs_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,
290 struct btrfs_key key;
293 key.type = BTRFS_DIR_INDEX_KEY;
294 key.offset = objectid;
296 return btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod);
299 struct btrfs_dir_item *
300 btrfs_search_dir_index_item(struct btrfs_root *root,
301 struct btrfs_path *path, u64 dirid,
302 const char *name, int name_len)
304 struct extent_buffer *leaf;
305 struct btrfs_dir_item *di;
306 struct btrfs_key key;
310 key.objectid = dirid;
311 key.type = BTRFS_DIR_INDEX_KEY;
314 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
318 leaf = path->nodes[0];
319 nritems = btrfs_header_nritems(leaf);
322 if (path->slots[0] >= nritems) {
323 ret = btrfs_next_leaf(root, path);
328 leaf = path->nodes[0];
329 nritems = btrfs_header_nritems(leaf);
333 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
334 if (key.objectid != dirid || key.type != BTRFS_DIR_INDEX_KEY)
337 di = btrfs_match_dir_item_name(root->fs_info, path,
347 struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
348 struct btrfs_root *root,
349 struct btrfs_path *path, u64 dir,
350 const char *name, u16 name_len,
353 struct btrfs_key key;
354 struct btrfs_dir_item *di;
357 key.type = BTRFS_XATTR_ITEM_KEY;
358 key.offset = btrfs_name_hash(name, name_len);
360 di = btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod);
361 if (IS_ERR(di) && PTR_ERR(di) == -ENOENT)
368 * helper function to look at the directory item pointed to by 'path'
369 * this walks through all the entries in a dir item and finds one
370 * for a specific name.
372 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_fs_info *fs_info,
373 struct btrfs_path *path,
374 const char *name, int name_len)
376 struct btrfs_dir_item *dir_item;
377 unsigned long name_ptr;
381 struct extent_buffer *leaf;
383 leaf = path->nodes[0];
384 dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
386 total_len = btrfs_item_size_nr(leaf, path->slots[0]);
387 while (cur < total_len) {
388 this_len = sizeof(*dir_item) +
389 btrfs_dir_name_len(leaf, dir_item) +
390 btrfs_dir_data_len(leaf, dir_item);
391 name_ptr = (unsigned long)(dir_item + 1);
393 if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
394 memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
398 dir_item = (struct btrfs_dir_item *)((char *)dir_item +
405 * given a pointer into a directory item, delete it. This
406 * handles items that have more than one entry in them.
408 int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
409 struct btrfs_root *root,
410 struct btrfs_path *path,
411 struct btrfs_dir_item *di)
414 struct extent_buffer *leaf;
419 leaf = path->nodes[0];
420 sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) +
421 btrfs_dir_data_len(leaf, di);
422 item_len = btrfs_item_size_nr(leaf, path->slots[0]);
423 if (sub_item_len == item_len) {
424 ret = btrfs_del_item(trans, root, path);
427 unsigned long ptr = (unsigned long)di;
430 start = btrfs_item_ptr_offset(leaf, path->slots[0]);
431 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
432 item_len - (ptr + sub_item_len - start));
433 btrfs_truncate_item(path, item_len - sub_item_len, 1);