2 #include <linux/types.h>
5 #include "btrfs_inode.h"
6 #include "print-tree.h"
9 #define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, \
11 #define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, \
12 parent_root_objectid) / 4)
13 #define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid) / 4)
15 static int btrfs_encode_fh(struct inode
*inode
, u32
*fh
, int *max_len
,
18 struct btrfs_fid
*fid
= (struct btrfs_fid
*)fh
;
22 if (parent
&& (len
< BTRFS_FID_SIZE_CONNECTABLE
)) {
23 *max_len
= BTRFS_FID_SIZE_CONNECTABLE
;
24 return FILEID_INVALID
;
25 } else if (len
< BTRFS_FID_SIZE_NON_CONNECTABLE
) {
26 *max_len
= BTRFS_FID_SIZE_NON_CONNECTABLE
;
27 return FILEID_INVALID
;
30 len
= BTRFS_FID_SIZE_NON_CONNECTABLE
;
31 type
= FILEID_BTRFS_WITHOUT_PARENT
;
33 fid
->objectid
= btrfs_ino(BTRFS_I(inode
));
34 fid
->root_objectid
= BTRFS_I(inode
)->root
->objectid
;
35 fid
->gen
= inode
->i_generation
;
40 fid
->parent_objectid
= BTRFS_I(parent
)->location
.objectid
;
41 fid
->parent_gen
= parent
->i_generation
;
42 parent_root_id
= BTRFS_I(parent
)->root
->objectid
;
44 if (parent_root_id
!= fid
->root_objectid
) {
45 fid
->parent_root_objectid
= parent_root_id
;
46 len
= BTRFS_FID_SIZE_CONNECTABLE_ROOT
;
47 type
= FILEID_BTRFS_WITH_PARENT_ROOT
;
49 len
= BTRFS_FID_SIZE_CONNECTABLE
;
50 type
= FILEID_BTRFS_WITH_PARENT
;
58 static struct dentry
*btrfs_get_dentry(struct super_block
*sb
, u64 objectid
,
59 u64 root_objectid
, u32 generation
,
62 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
63 struct btrfs_root
*root
;
69 if (objectid
< BTRFS_FIRST_FREE_OBJECTID
)
70 return ERR_PTR(-ESTALE
);
72 key
.objectid
= root_objectid
;
73 key
.type
= BTRFS_ROOT_ITEM_KEY
;
76 index
= srcu_read_lock(&fs_info
->subvol_srcu
);
78 root
= btrfs_read_fs_root_no_name(fs_info
, &key
);
84 key
.objectid
= objectid
;
85 key
.type
= BTRFS_INODE_ITEM_KEY
;
88 inode
= btrfs_iget(sb
, &key
, root
, NULL
);
94 srcu_read_unlock(&fs_info
->subvol_srcu
, index
);
96 if (check_generation
&& generation
!= inode
->i_generation
) {
98 return ERR_PTR(-ESTALE
);
101 return d_obtain_alias(inode
);
103 srcu_read_unlock(&fs_info
->subvol_srcu
, index
);
107 static struct dentry
*btrfs_fh_to_parent(struct super_block
*sb
, struct fid
*fh
,
108 int fh_len
, int fh_type
)
110 struct btrfs_fid
*fid
= (struct btrfs_fid
*) fh
;
111 u64 objectid
, root_objectid
;
114 if (fh_type
== FILEID_BTRFS_WITH_PARENT
) {
115 if (fh_len
< BTRFS_FID_SIZE_CONNECTABLE
)
117 root_objectid
= fid
->root_objectid
;
118 } else if (fh_type
== FILEID_BTRFS_WITH_PARENT_ROOT
) {
119 if (fh_len
< BTRFS_FID_SIZE_CONNECTABLE_ROOT
)
121 root_objectid
= fid
->parent_root_objectid
;
125 objectid
= fid
->parent_objectid
;
126 generation
= fid
->parent_gen
;
128 return btrfs_get_dentry(sb
, objectid
, root_objectid
, generation
, 1);
131 static struct dentry
*btrfs_fh_to_dentry(struct super_block
*sb
, struct fid
*fh
,
132 int fh_len
, int fh_type
)
134 struct btrfs_fid
*fid
= (struct btrfs_fid
*) fh
;
135 u64 objectid
, root_objectid
;
138 if ((fh_type
!= FILEID_BTRFS_WITH_PARENT
||
139 fh_len
< BTRFS_FID_SIZE_CONNECTABLE
) &&
140 (fh_type
!= FILEID_BTRFS_WITH_PARENT_ROOT
||
141 fh_len
< BTRFS_FID_SIZE_CONNECTABLE_ROOT
) &&
142 (fh_type
!= FILEID_BTRFS_WITHOUT_PARENT
||
143 fh_len
< BTRFS_FID_SIZE_NON_CONNECTABLE
))
146 objectid
= fid
->objectid
;
147 root_objectid
= fid
->root_objectid
;
148 generation
= fid
->gen
;
150 return btrfs_get_dentry(sb
, objectid
, root_objectid
, generation
, 1);
153 static struct dentry
*btrfs_get_parent(struct dentry
*child
)
155 struct inode
*dir
= d_inode(child
);
156 struct btrfs_fs_info
*fs_info
= btrfs_sb(dir
->i_sb
);
157 struct btrfs_root
*root
= BTRFS_I(dir
)->root
;
158 struct btrfs_path
*path
;
159 struct extent_buffer
*leaf
;
160 struct btrfs_root_ref
*ref
;
161 struct btrfs_key key
;
162 struct btrfs_key found_key
;
165 path
= btrfs_alloc_path();
167 return ERR_PTR(-ENOMEM
);
169 if (btrfs_ino(BTRFS_I(dir
)) == BTRFS_FIRST_FREE_OBJECTID
) {
170 key
.objectid
= root
->root_key
.objectid
;
171 key
.type
= BTRFS_ROOT_BACKREF_KEY
;
172 key
.offset
= (u64
)-1;
173 root
= fs_info
->tree_root
;
175 key
.objectid
= btrfs_ino(BTRFS_I(dir
));
176 key
.type
= BTRFS_INODE_REF_KEY
;
177 key
.offset
= (u64
)-1;
180 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
184 BUG_ON(ret
== 0); /* Key with offset of -1 found */
185 if (path
->slots
[0] == 0) {
191 leaf
= path
->nodes
[0];
193 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
194 if (found_key
.objectid
!= key
.objectid
|| found_key
.type
!= key
.type
) {
199 if (found_key
.type
== BTRFS_ROOT_BACKREF_KEY
) {
200 ref
= btrfs_item_ptr(leaf
, path
->slots
[0],
201 struct btrfs_root_ref
);
202 key
.objectid
= btrfs_root_ref_dirid(leaf
, ref
);
204 key
.objectid
= found_key
.offset
;
206 btrfs_free_path(path
);
208 if (found_key
.type
== BTRFS_ROOT_BACKREF_KEY
) {
209 return btrfs_get_dentry(fs_info
->sb
, key
.objectid
,
210 found_key
.offset
, 0, 0);
213 key
.type
= BTRFS_INODE_ITEM_KEY
;
215 return d_obtain_alias(btrfs_iget(fs_info
->sb
, &key
, root
, NULL
));
217 btrfs_free_path(path
);
221 static int btrfs_get_name(struct dentry
*parent
, char *name
,
222 struct dentry
*child
)
224 struct inode
*inode
= d_inode(child
);
225 struct inode
*dir
= d_inode(parent
);
226 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
227 struct btrfs_path
*path
;
228 struct btrfs_root
*root
= BTRFS_I(dir
)->root
;
229 struct btrfs_inode_ref
*iref
;
230 struct btrfs_root_ref
*rref
;
231 struct extent_buffer
*leaf
;
232 unsigned long name_ptr
;
233 struct btrfs_key key
;
238 if (!S_ISDIR(dir
->i_mode
))
241 ino
= btrfs_ino(BTRFS_I(inode
));
243 path
= btrfs_alloc_path();
246 path
->leave_spinning
= 1;
248 if (ino
== BTRFS_FIRST_FREE_OBJECTID
) {
249 key
.objectid
= BTRFS_I(inode
)->root
->root_key
.objectid
;
250 key
.type
= BTRFS_ROOT_BACKREF_KEY
;
251 key
.offset
= (u64
)-1;
252 root
= fs_info
->tree_root
;
255 key
.offset
= btrfs_ino(BTRFS_I(dir
));
256 key
.type
= BTRFS_INODE_REF_KEY
;
259 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
261 btrfs_free_path(path
);
263 } else if (ret
> 0) {
264 if (ino
== BTRFS_FIRST_FREE_OBJECTID
) {
267 btrfs_free_path(path
);
271 leaf
= path
->nodes
[0];
273 if (ino
== BTRFS_FIRST_FREE_OBJECTID
) {
274 rref
= btrfs_item_ptr(leaf
, path
->slots
[0],
275 struct btrfs_root_ref
);
276 name_ptr
= (unsigned long)(rref
+ 1);
277 name_len
= btrfs_root_ref_name_len(leaf
, rref
);
279 iref
= btrfs_item_ptr(leaf
, path
->slots
[0],
280 struct btrfs_inode_ref
);
281 name_ptr
= (unsigned long)(iref
+ 1);
282 name_len
= btrfs_inode_ref_name_len(leaf
, iref
);
285 read_extent_buffer(leaf
, name
, name_ptr
, name_len
);
286 btrfs_free_path(path
);
289 * have to add the null termination to make sure that reconnect_path
290 * gets the right len for strlen
292 name
[name_len
] = '\0';
297 const struct export_operations btrfs_export_ops
= {
298 .encode_fh
= btrfs_encode_fh
,
299 .fh_to_dentry
= btrfs_fh_to_dentry
,
300 .fh_to_parent
= btrfs_fh_to_parent
,
301 .get_parent
= btrfs_get_parent
,
302 .get_name
= btrfs_get_name
,