2 #include <linux/types.h>
5 #include "btrfs_inode.h"
6 #include "print-tree.h"
10 #define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, \
12 #define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, \
13 parent_root_objectid) / 4)
14 #define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid) / 4)
16 static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
19 struct btrfs_fid *fid = (struct btrfs_fid *)fh;
20 struct inode *inode = dentry->d_inode;
24 if ((len < BTRFS_FID_SIZE_NON_CONNECTABLE) ||
25 (connectable && len < BTRFS_FID_SIZE_CONNECTABLE))
28 len = BTRFS_FID_SIZE_NON_CONNECTABLE;
29 type = FILEID_BTRFS_WITHOUT_PARENT;
31 fid->objectid = inode->i_ino;
32 fid->root_objectid = BTRFS_I(inode)->root->objectid;
33 fid->gen = inode->i_generation;
35 if (connectable && !S_ISDIR(inode->i_mode)) {
39 spin_lock(&dentry->d_lock);
41 parent = dentry->d_parent->d_inode;
42 fid->parent_objectid = BTRFS_I(parent)->location.objectid;
43 fid->parent_gen = parent->i_generation;
44 parent_root_id = BTRFS_I(parent)->root->objectid;
46 spin_unlock(&dentry->d_lock);
48 if (parent_root_id != fid->root_objectid) {
49 fid->parent_root_objectid = parent_root_id;
50 len = BTRFS_FID_SIZE_CONNECTABLE_ROOT;
51 type = FILEID_BTRFS_WITH_PARENT_ROOT;
53 len = BTRFS_FID_SIZE_CONNECTABLE;
54 type = FILEID_BTRFS_WITH_PARENT;
62 static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
63 u64 root_objectid, u32 generation,
66 struct btrfs_fs_info *fs_info = btrfs_sb(sb)->fs_info;
67 struct btrfs_root *root;
68 struct dentry *dentry;
74 if (objectid < BTRFS_FIRST_FREE_OBJECTID)
75 return ERR_PTR(-ESTALE);
77 key.objectid = root_objectid;
78 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
81 index = srcu_read_lock(&fs_info->subvol_srcu);
83 root = btrfs_read_fs_root_no_name(fs_info, &key);
89 if (btrfs_root_refs(&root->root_item) == 0) {
94 key.objectid = objectid;
95 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
98 inode = btrfs_iget(sb, &key, root, NULL);
100 err = PTR_ERR(inode);
104 srcu_read_unlock(&fs_info->subvol_srcu, index);
106 if (check_generation && generation != inode->i_generation) {
108 return ERR_PTR(-ESTALE);
111 dentry = d_obtain_alias(inode);
113 dentry->d_op = &btrfs_dentry_operations;
116 srcu_read_unlock(&fs_info->subvol_srcu, index);
120 static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
121 int fh_len, int fh_type)
123 struct btrfs_fid *fid = (struct btrfs_fid *) fh;
124 u64 objectid, root_objectid;
127 if (fh_type == FILEID_BTRFS_WITH_PARENT) {
128 if (fh_len != BTRFS_FID_SIZE_CONNECTABLE)
130 root_objectid = fid->root_objectid;
131 } else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) {
132 if (fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT)
134 root_objectid = fid->parent_root_objectid;
138 objectid = fid->parent_objectid;
139 generation = fid->parent_gen;
141 return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
144 static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
145 int fh_len, int fh_type)
147 struct btrfs_fid *fid = (struct btrfs_fid *) fh;
148 u64 objectid, root_objectid;
151 if ((fh_type != FILEID_BTRFS_WITH_PARENT ||
152 fh_len != BTRFS_FID_SIZE_CONNECTABLE) &&
153 (fh_type != FILEID_BTRFS_WITH_PARENT_ROOT ||
154 fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT) &&
155 (fh_type != FILEID_BTRFS_WITHOUT_PARENT ||
156 fh_len != BTRFS_FID_SIZE_NON_CONNECTABLE))
159 objectid = fid->objectid;
160 root_objectid = fid->root_objectid;
161 generation = fid->gen;
163 return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
166 static struct dentry *btrfs_get_parent(struct dentry *child)
168 struct inode *dir = child->d_inode;
169 static struct dentry *dentry;
170 struct btrfs_root *root = BTRFS_I(dir)->root;
171 struct btrfs_path *path;
172 struct extent_buffer *leaf;
173 struct btrfs_root_ref *ref;
174 struct btrfs_key key;
175 struct btrfs_key found_key;
178 path = btrfs_alloc_path();
180 if (dir->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
181 key.objectid = root->root_key.objectid;
182 key.type = BTRFS_ROOT_BACKREF_KEY;
183 key.offset = (u64)-1;
184 root = root->fs_info->tree_root;
186 key.objectid = dir->i_ino;
187 key.type = BTRFS_INODE_REF_KEY;
188 key.offset = (u64)-1;
191 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
196 if (path->slots[0] == 0) {
202 leaf = path->nodes[0];
204 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
205 if (found_key.objectid != key.objectid || found_key.type != key.type) {
210 if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
211 ref = btrfs_item_ptr(leaf, path->slots[0],
212 struct btrfs_root_ref);
213 key.objectid = btrfs_root_ref_dirid(leaf, ref);
215 key.objectid = found_key.offset;
217 btrfs_free_path(path);
219 if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
220 return btrfs_get_dentry(root->fs_info->sb, key.objectid,
221 found_key.offset, 0, 0);
224 key.type = BTRFS_INODE_ITEM_KEY;
226 dentry = d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL));
228 dentry->d_op = &btrfs_dentry_operations;
231 btrfs_free_path(path);
235 const struct export_operations btrfs_export_ops = {
236 .encode_fh = btrfs_encode_fh,
237 .fh_to_dentry = btrfs_fh_to_dentry,
238 .fh_to_parent = btrfs_fh_to_parent,
239 .get_parent = btrfs_get_parent,