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.
21 #include "transaction.h"
24 static int find_name_in_backref(struct btrfs_path
*path
, const char * name
,
25 int name_len
, struct btrfs_inode_ref
**ref_ret
)
27 struct extent_buffer
*leaf
;
28 struct btrfs_inode_ref
*ref
;
30 unsigned long name_ptr
;
35 leaf
= path
->nodes
[0];
36 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
37 ptr
= btrfs_item_ptr_offset(leaf
, path
->slots
[0]);
38 while (cur_offset
< item_size
) {
39 ref
= (struct btrfs_inode_ref
*)(ptr
+ cur_offset
);
40 len
= btrfs_inode_ref_name_len(leaf
, ref
);
41 name_ptr
= (unsigned long)(ref
+ 1);
42 cur_offset
+= len
+ sizeof(*ref
);
45 if (memcmp_extent_buffer(leaf
, name
, name_ptr
, name_len
) == 0) {
53 int btrfs_insert_inode_ref(struct btrfs_trans_handle
*trans
,
54 struct btrfs_root
*root
,
55 const char *name
, int name_len
,
56 u64 inode_objectid
, u64 ref_objectid
, u64 index
)
58 struct btrfs_path
*path
;
60 struct btrfs_inode_ref
*ref
;
63 int ins_len
= name_len
+ sizeof(*ref
);
65 key
.objectid
= inode_objectid
;
66 key
.offset
= ref_objectid
;
67 btrfs_set_key_type(&key
, BTRFS_INODE_REF_KEY
);
69 path
= btrfs_alloc_path();
73 ret
= btrfs_insert_empty_item(trans
, root
, path
, &key
,
78 if (find_name_in_backref(path
, name
, name_len
, &ref
))
81 old_size
= btrfs_item_size_nr(path
->nodes
[0], path
->slots
[0]);
82 ret
= btrfs_extend_item(trans
, root
, path
, ins_len
);
84 ref
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
85 struct btrfs_inode_ref
);
86 ref
= (struct btrfs_inode_ref
*)((unsigned long)ref
+ old_size
);
87 btrfs_set_inode_ref_name_len(path
->nodes
[0], ref
, name_len
);
88 btrfs_set_inode_ref_index(path
->nodes
[0], ref
, index
);
89 ptr
= (unsigned long)(ref
+ 1);
92 if (ret
== -EOVERFLOW
)
96 ref
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
97 struct btrfs_inode_ref
);
98 btrfs_set_inode_ref_name_len(path
->nodes
[0], ref
, name_len
);
99 btrfs_set_inode_ref_index(path
->nodes
[0], ref
, index
);
100 ptr
= (unsigned long)(ref
+ 1);
102 write_extent_buffer(path
->nodes
[0], name
, ptr
, name_len
);
103 btrfs_mark_buffer_dirty(path
->nodes
[0]);
106 btrfs_free_path(path
);
108 if (ret
== -EMLINK
) {
109 if (btrfs_fs_incompat(root
->fs_info
,
110 BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF
))
111 ret
= btrfs_insert_inode_extref(trans
, root
, name
,
114 ref_objectid
, index
);
119 int btrfs_lookup_inode(struct btrfs_trans_handle
*trans
, struct btrfs_root
120 *root
, struct btrfs_path
*path
,
121 struct btrfs_key
*location
, int mod
)
123 int ins_len
= mod
< 0 ? -1 : 0;
127 struct extent_buffer
*leaf
;
128 struct btrfs_key found_key
;
130 ret
= btrfs_search_slot(trans
, root
, location
, path
, ins_len
, cow
);
131 if (ret
> 0 && btrfs_key_type(location
) == BTRFS_ROOT_ITEM_KEY
&&
132 location
->offset
== (u64
)-1 && path
->slots
[0] != 0) {
133 slot
= path
->slots
[0] - 1;
134 leaf
= path
->nodes
[0];
135 btrfs_item_key_to_cpu(leaf
, &found_key
, slot
);
136 if (found_key
.objectid
== location
->objectid
&&
137 btrfs_key_type(&found_key
) == btrfs_key_type(location
)) {
145 int btrfs_insert_inode(struct btrfs_trans_handle
*trans
, struct btrfs_root
146 *root
, u64 objectid
, struct btrfs_inode_item
150 struct btrfs_key key
;
152 key
.objectid
= objectid
;
153 key
.type
= BTRFS_INODE_ITEM_KEY
;
156 ret
= btrfs_insert_item(trans
, root
, &key
, inode_item
,
157 sizeof(*inode_item
));
161 struct btrfs_inode_ref
*btrfs_lookup_inode_ref(struct btrfs_trans_handle
*trans
,
162 struct btrfs_root
*root
, struct btrfs_path
*path
,
163 const char *name
, int namelen
, u64 ino
, u64 parent_ino
,
164 u64 index
, int ins_len
)
166 struct btrfs_key key
;
167 struct btrfs_inode_ref
*ret_inode_ref
= NULL
;
171 key
.type
= BTRFS_INODE_REF_KEY
;
172 key
.offset
= parent_ino
;
174 ret
= btrfs_search_slot(trans
, root
, &key
, path
, ins_len
,
179 find_name_in_backref(path
, name
, namelen
, &ret_inode_ref
);
184 return ret_inode_ref
;
187 static inline u64
btrfs_extref_hash(u64 parent_ino
, const char *name
,
190 return (u64
)btrfs_crc32c(parent_ino
, name
, namelen
);
193 static int btrfs_find_name_in_ext_backref(struct btrfs_path
*path
,
194 u64 parent_ino
, const char *name
, int namelen
,
195 struct btrfs_inode_extref
**extref_ret
)
197 struct extent_buffer
*node
;
198 struct btrfs_inode_extref
*extref
;
200 unsigned long name_ptr
;
206 node
= path
->nodes
[0];
207 slot
= path
->slots
[0];
208 item_size
= btrfs_item_size_nr(node
, slot
);
209 ptr
= btrfs_item_ptr_offset(node
, slot
);
212 * Search all extended backrefs in this item. We're only looking
213 * through any collisions so most of the time this is just going to
214 * compare against one buffer. If all is well, we'll return success and
215 * the inode ref object.
217 while (cur_offset
< item_size
) {
218 extref
= (struct btrfs_inode_extref
*) (ptr
+ cur_offset
);
219 name_ptr
= (unsigned long)(&extref
->name
);
220 ref_name_len
= btrfs_inode_extref_name_len(node
, extref
);
222 if (ref_name_len
== namelen
&&
223 btrfs_inode_extref_parent(node
, extref
) == parent_ino
&&
224 (memcmp_extent_buffer(node
, name
, name_ptr
, namelen
) == 0))
227 *extref_ret
= extref
;
231 cur_offset
+= ref_name_len
+ sizeof(*extref
);
237 struct btrfs_inode_extref
*btrfs_lookup_inode_extref(struct btrfs_trans_handle
238 *trans
, struct btrfs_path
*path
, struct btrfs_root
*root
,
239 u64 ino
, u64 parent_ino
, u64 index
, const char *name
,
240 int namelen
, int ins_len
)
242 struct btrfs_key key
;
243 struct btrfs_inode_extref
*extref
;
247 key
.type
= BTRFS_INODE_EXTREF_KEY
;
248 key
.offset
= btrfs_extref_hash(parent_ino
, name
, namelen
);
250 ret
= btrfs_search_slot(trans
, root
, &key
, path
, ins_len
,
256 if (!btrfs_find_name_in_ext_backref(path
, parent_ino
, name
,
263 int btrfs_del_inode_extref(struct btrfs_trans_handle
*trans
,
264 struct btrfs_root
*root
,
265 const char *name
, int name_len
,
266 u64 inode_objectid
, u64 ref_objectid
,
269 struct btrfs_path
*path
;
270 struct btrfs_key key
;
271 struct btrfs_inode_extref
*extref
;
272 struct extent_buffer
*leaf
;
274 int del_len
= name_len
+ sizeof(*extref
);
276 unsigned long item_start
;
279 key
.objectid
= inode_objectid
;
280 key
.type
= BTRFS_INODE_EXTREF_KEY
;
281 key
.offset
= btrfs_extref_hash(ref_objectid
, name
, name_len
);
283 path
= btrfs_alloc_path();
287 ret
= btrfs_search_slot(trans
, root
, &key
, path
, -1, 1);
294 * Sanity check - did we find the right item for this name? This
295 * should always succeed so error here will make the FS readonly.
297 if (!btrfs_find_name_in_ext_backref(path
, ref_objectid
,
298 name
, name_len
, &extref
)) {
303 leaf
= path
->nodes
[0];
304 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
306 *index
= btrfs_inode_extref_index(leaf
, extref
);
308 if (del_len
== item_size
) {
310 * Common case only one ref in the item, remove the whole item.
312 ret
= btrfs_del_item(trans
, root
, path
);
316 ptr
= (unsigned long)extref
;
317 item_start
= btrfs_item_ptr_offset(leaf
, path
->slots
[0]);
319 memmove_extent_buffer(leaf
, ptr
, ptr
+ del_len
,
320 item_size
- (ptr
+ del_len
- item_start
));
322 btrfs_truncate_item(trans
, root
, path
, item_size
- del_len
, 1);
325 btrfs_free_path(path
);
331 * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
333 * The caller must have checked against BTRFS_LINK_MAX already.
335 int btrfs_insert_inode_extref(struct btrfs_trans_handle
*trans
,
336 struct btrfs_root
*root
,
337 const char *name
, int name_len
,
338 u64 inode_objectid
, u64 ref_objectid
, u64 index
)
340 struct btrfs_inode_extref
*extref
;
342 int ins_len
= name_len
+ sizeof(*extref
);
344 struct btrfs_path
*path
;
345 struct btrfs_key key
;
346 struct extent_buffer
*leaf
;
347 struct btrfs_item
*item
;
349 key
.objectid
= inode_objectid
;
350 key
.type
= BTRFS_INODE_EXTREF_KEY
;
351 key
.offset
= btrfs_extref_hash(ref_objectid
, name
, name_len
);
353 path
= btrfs_alloc_path();
357 ret
= btrfs_insert_empty_item(trans
, root
, path
, &key
,
359 if (ret
== -EEXIST
) {
360 if (btrfs_find_name_in_ext_backref(path
, ref_objectid
,
361 name
, name_len
, NULL
))
364 btrfs_extend_item(trans
, root
, path
, ins_len
);
371 leaf
= path
->nodes
[0];
372 item
= btrfs_item_nr(path
->slots
[0]);
373 ptr
= (unsigned long)btrfs_item_ptr(leaf
, path
->slots
[0], char);
374 ptr
+= btrfs_item_size(leaf
, item
) - ins_len
;
375 extref
= (struct btrfs_inode_extref
*)ptr
;
377 btrfs_set_inode_extref_name_len(path
->nodes
[0], extref
, name_len
);
378 btrfs_set_inode_extref_index(path
->nodes
[0], extref
, index
);
379 btrfs_set_inode_extref_parent(path
->nodes
[0], extref
, ref_objectid
);
381 ptr
= (unsigned long)&extref
->name
;
382 write_extent_buffer(path
->nodes
[0], name
, ptr
, name_len
);
383 btrfs_mark_buffer_dirty(path
->nodes
[0]);
386 btrfs_free_path(path
);
391 int btrfs_del_inode_ref(struct btrfs_trans_handle
*trans
,
392 struct btrfs_root
*root
, const char *name
, int name_len
,
393 u64 ino
, u64 parent_ino
, u64
*index
)
395 struct btrfs_path
*path
;
396 struct btrfs_key key
;
397 struct btrfs_inode_ref
*ref
;
398 struct extent_buffer
*leaf
;
400 unsigned long item_start
;
404 int search_ext_refs
= 0;
405 int del_len
= name_len
+ sizeof(*ref
);
408 key
.offset
= parent_ino
;
409 key
.type
= BTRFS_INODE_REF_KEY
;
411 path
= btrfs_alloc_path();
415 ret
= btrfs_search_slot(trans
, root
, &key
, path
, -1, 1);
420 } else if (ret
< 0) {
423 if (!find_name_in_backref(path
, name
, name_len
, &ref
)) {
428 leaf
= path
->nodes
[0];
429 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
432 *index
= btrfs_inode_ref_index(leaf
, ref
);
434 if (del_len
== item_size
) {
435 ret
= btrfs_del_item(trans
, root
, path
);
438 ptr
= (unsigned long)ref
;
439 sub_item_len
= name_len
+ sizeof(*ref
);
440 item_start
= btrfs_item_ptr_offset(leaf
, path
->slots
[0]);
441 memmove_extent_buffer(leaf
, ptr
, ptr
+ sub_item_len
,
442 item_size
- (ptr
+ sub_item_len
- item_start
));
443 btrfs_truncate_item(trans
, root
, path
, item_size
- sub_item_len
, 1);
444 btrfs_mark_buffer_dirty(path
->nodes
[0]);
446 btrfs_free_path(path
);
448 if (search_ext_refs
&&
449 btrfs_fs_incompat(root
->fs_info
,
450 BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF
)) {
452 * No refs were found, or we could not find the name in our ref
453 * array. Find and remove the extended inode ref then.
455 return btrfs_del_inode_extref(trans
, root
, name
, name_len
,
456 ino
, parent_ino
, index
);