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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - fs/btrfs/dir-item.c
2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
22 #include "transaction.h"
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
30 * The name is not copied into the dir item, you have to do that yourself.
32 static struct btrfs_dir_item
*insert_with_overflow(struct btrfs_trans_handle
34 struct btrfs_root
*root
,
35 struct btrfs_path
*path
,
36 struct btrfs_key
*cpu_key
,
43 struct btrfs_item
*item
;
44 struct extent_buffer
*leaf
;
46 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
48 struct btrfs_dir_item
*di
;
49 di
= btrfs_match_dir_item_name(root
, path
, name
, name_len
);
51 return ERR_PTR(-EEXIST
);
52 btrfs_extend_item(trans
, root
, path
, data_size
);
56 leaf
= path
->nodes
[0];
57 item
= btrfs_item_nr(leaf
, 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
;
65 * xattrs work a lot like directories, this inserts an xattr item
68 int 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
)
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
;
82 BUG_ON(name_len
+ data_len
> BTRFS_MAX_XATTR_SIZE(root
));
84 key
.objectid
= objectid
;
85 btrfs_set_key_type(&key
, BTRFS_XATTR_ITEM_KEY
);
86 key
.offset
= btrfs_name_hash(name
, name_len
);
88 data_size
= sizeof(*dir_item
) + name_len
+ data_len
;
89 dir_item
= insert_with_overflow(trans
, root
, path
, &key
, data_size
,
92 return PTR_ERR(dir_item
);
93 memset(&location
, 0, sizeof(location
));
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
);
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]);
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
120 int 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
,
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
;
135 key
.objectid
= btrfs_ino(dir
);
136 btrfs_set_key_type(&key
, BTRFS_DIR_ITEM_KEY
);
137 key
.offset
= btrfs_name_hash(name
, name_len
);
139 path
= btrfs_alloc_path();
142 path
->leave_spinning
= 1;
144 btrfs_cpu_key_to_disk(&disk_key
, location
);
146 data_size
= sizeof(*dir_item
) + name_len
;
147 dir_item
= insert_with_overflow(trans
, root
, path
, &key
, data_size
,
149 if (IS_ERR(dir_item
)) {
150 ret
= PTR_ERR(dir_item
);
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);
164 write_extent_buffer(leaf
, name
, name_ptr
, name_len
);
165 btrfs_mark_buffer_dirty(leaf
);
168 /* FIXME, use some real flag for selecting the extra index */
169 if (root
== root
->fs_info
->tree_root
) {
173 btrfs_release_path(path
);
175 ret2
= btrfs_insert_delayed_dir_index(trans
, root
, name
, name_len
, dir
,
176 &disk_key
, type
, index
);
178 btrfs_free_path(path
);
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)
191 struct 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
,
198 struct btrfs_key key
;
199 int ins_len
= mod
< 0 ? -1 : 0;
203 btrfs_set_key_type(&key
, BTRFS_DIR_ITEM_KEY
);
205 key
.offset
= btrfs_name_hash(name
, name_len
);
207 ret
= btrfs_search_slot(trans
, root
, &key
, path
, ins_len
, cow
);
213 return btrfs_match_dir_item_name(root
, path
, name
, name_len
);
217 * lookup a directory item based on index. 'dir' is the objectid
218 * we're searching in, and 'mod' tells us if you plan on deleting the
219 * item (use mod < 0) or changing the options (use mod > 0)
221 * The name is used to make sure the index really points to the name you were
224 struct btrfs_dir_item
*
225 btrfs_lookup_dir_index_item(struct btrfs_trans_handle
*trans
,
226 struct btrfs_root
*root
,
227 struct btrfs_path
*path
, u64 dir
,
228 u64 objectid
, const char *name
, int name_len
,
232 struct btrfs_key key
;
233 int ins_len
= mod
< 0 ? -1 : 0;
237 btrfs_set_key_type(&key
, BTRFS_DIR_INDEX_KEY
);
238 key
.offset
= objectid
;
240 ret
= btrfs_search_slot(trans
, root
, &key
, path
, ins_len
, cow
);
244 return ERR_PTR(-ENOENT
);
245 return btrfs_match_dir_item_name(root
, path
, name
, name_len
);
248 struct btrfs_dir_item
*
249 btrfs_search_dir_index_item(struct btrfs_root
*root
,
250 struct btrfs_path
*path
, u64 dirid
,
251 const char *name
, int name_len
)
253 struct extent_buffer
*leaf
;
254 struct btrfs_dir_item
*di
;
255 struct btrfs_key key
;
259 key
.objectid
= dirid
;
260 key
.type
= BTRFS_DIR_INDEX_KEY
;
263 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
267 leaf
= path
->nodes
[0];
268 nritems
= btrfs_header_nritems(leaf
);
271 if (path
->slots
[0] >= nritems
) {
272 ret
= btrfs_next_leaf(root
, path
);
277 leaf
= path
->nodes
[0];
278 nritems
= btrfs_header_nritems(leaf
);
282 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
283 if (key
.objectid
!= dirid
|| key
.type
!= BTRFS_DIR_INDEX_KEY
)
286 di
= btrfs_match_dir_item_name(root
, path
, name
, name_len
);
295 struct btrfs_dir_item
*btrfs_lookup_xattr(struct btrfs_trans_handle
*trans
,
296 struct btrfs_root
*root
,
297 struct btrfs_path
*path
, u64 dir
,
298 const char *name
, u16 name_len
,
302 struct btrfs_key key
;
303 int ins_len
= mod
< 0 ? -1 : 0;
307 btrfs_set_key_type(&key
, BTRFS_XATTR_ITEM_KEY
);
308 key
.offset
= btrfs_name_hash(name
, name_len
);
309 ret
= btrfs_search_slot(trans
, root
, &key
, path
, ins_len
, cow
);
315 return btrfs_match_dir_item_name(root
, path
, name
, name_len
);
319 * helper function to look at the directory item pointed to by 'path'
320 * this walks through all the entries in a dir item and finds one
321 * for a specific name.
323 struct btrfs_dir_item
*btrfs_match_dir_item_name(struct btrfs_root
*root
,
324 struct btrfs_path
*path
,
325 const char *name
, int name_len
)
327 struct btrfs_dir_item
*dir_item
;
328 unsigned long name_ptr
;
332 struct extent_buffer
*leaf
;
334 leaf
= path
->nodes
[0];
335 dir_item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_dir_item
);
336 if (verify_dir_item(root
, leaf
, dir_item
))
339 total_len
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
340 while (cur
< total_len
) {
341 this_len
= sizeof(*dir_item
) +
342 btrfs_dir_name_len(leaf
, dir_item
) +
343 btrfs_dir_data_len(leaf
, dir_item
);
344 name_ptr
= (unsigned long)(dir_item
+ 1);
346 if (btrfs_dir_name_len(leaf
, dir_item
) == name_len
&&
347 memcmp_extent_buffer(leaf
, name
, name_ptr
, name_len
) == 0)
351 dir_item
= (struct btrfs_dir_item
*)((char *)dir_item
+
358 * given a pointer into a directory item, delete it. This
359 * handles items that have more than one entry in them.
361 int btrfs_delete_one_dir_name(struct btrfs_trans_handle
*trans
,
362 struct btrfs_root
*root
,
363 struct btrfs_path
*path
,
364 struct btrfs_dir_item
*di
)
367 struct extent_buffer
*leaf
;
372 leaf
= path
->nodes
[0];
373 sub_item_len
= sizeof(*di
) + btrfs_dir_name_len(leaf
, di
) +
374 btrfs_dir_data_len(leaf
, di
);
375 item_len
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
376 if (sub_item_len
== item_len
) {
377 ret
= btrfs_del_item(trans
, root
, path
);
380 unsigned long ptr
= (unsigned long)di
;
383 start
= btrfs_item_ptr_offset(leaf
, path
->slots
[0]);
384 memmove_extent_buffer(leaf
, ptr
, ptr
+ sub_item_len
,
385 item_len
- (ptr
+ sub_item_len
- start
));
386 btrfs_truncate_item(trans
, root
, path
,
387 item_len
- sub_item_len
, 1);
392 int verify_dir_item(struct btrfs_root
*root
,
393 struct extent_buffer
*leaf
,
394 struct btrfs_dir_item
*dir_item
)
396 u16 namelen
= BTRFS_NAME_LEN
;
397 u8 type
= btrfs_dir_type(leaf
, dir_item
);
399 if (type
>= BTRFS_FT_MAX
) {
400 printk(KERN_CRIT
"btrfs: invalid dir item type: %d\n",
405 if (type
== BTRFS_FT_XATTR
)
406 namelen
= XATTR_NAME_MAX
;
408 if (btrfs_dir_name_len(leaf
, dir_item
) > namelen
) {
409 printk(KERN_CRIT
"btrfs: invalid dir item name len: %u\n",
410 (unsigned)btrfs_dir_data_len(leaf
, dir_item
));
414 /* BTRFS_MAX_XATTR_SIZE is the same for all dir items */
415 if (btrfs_dir_data_len(leaf
, dir_item
) > BTRFS_MAX_XATTR_SIZE(root
)) {
416 printk(KERN_CRIT
"btrfs: invalid dir item data len: %u\n",
417 (unsigned)btrfs_dir_data_len(leaf
, dir_item
));