2 #include <linux/types.h>
5 #include "btrfs_inode.h"
6 #include "print-tree.h"
10 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28)
11 #define FILEID_BTRFS_WITHOUT_PARENT 0x4d
12 #define FILEID_BTRFS_WITH_PARENT 0x4e
13 #define FILEID_BTRFS_WITH_PARENT_ROOT 0x4f
16 #define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, parent_objectid)/4)
17 #define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, parent_root_objectid)/4)
18 #define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid)/4)
20 static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
23 struct btrfs_fid *fid = (struct btrfs_fid *)fh;
24 struct inode *inode = dentry->d_inode;
28 if ((len < BTRFS_FID_SIZE_NON_CONNECTABLE) ||
29 (connectable && len < BTRFS_FID_SIZE_CONNECTABLE))
32 len = BTRFS_FID_SIZE_NON_CONNECTABLE;
33 type = FILEID_BTRFS_WITHOUT_PARENT;
35 fid->objectid = BTRFS_I(inode)->location.objectid;
36 fid->root_objectid = BTRFS_I(inode)->root->objectid;
37 fid->gen = inode->i_generation;
39 if (connectable && !S_ISDIR(inode->i_mode)) {
43 spin_lock(&dentry->d_lock);
45 parent = dentry->d_parent->d_inode;
46 fid->parent_objectid = BTRFS_I(parent)->location.objectid;
47 fid->parent_gen = parent->i_generation;
48 parent_root_id = BTRFS_I(parent)->root->objectid;
50 spin_unlock(&dentry->d_lock);
52 if (parent_root_id != fid->root_objectid) {
53 fid->parent_root_objectid = parent_root_id;
54 len = BTRFS_FID_SIZE_CONNECTABLE_ROOT;
55 type = FILEID_BTRFS_WITH_PARENT_ROOT;
57 len = BTRFS_FID_SIZE_CONNECTABLE;
58 type = FILEID_BTRFS_WITH_PARENT;
66 static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
67 u64 root_objectid, u32 generation)
69 struct btrfs_root *root;
71 struct dentry *result;
74 key.objectid = root_objectid;
75 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
78 root = btrfs_read_fs_root_no_name(btrfs_sb(sb)->fs_info, &key);
80 return ERR_CAST(root);
82 key.objectid = objectid;
83 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
86 inode = btrfs_iget(sb, &key, root, NULL);
90 if (generation != inode->i_generation) {
92 return ERR_PTR(-ESTALE);
95 result = d_obtain_alias(inode);
97 return ERR_PTR(-ENOMEM);
102 static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
103 int fh_len, int fh_type)
105 struct btrfs_fid *fid = (struct btrfs_fid *) fh;
106 u64 objectid, root_objectid;
109 if (fh_type == FILEID_BTRFS_WITH_PARENT) {
110 if (fh_len != BTRFS_FID_SIZE_CONNECTABLE)
112 root_objectid = fid->root_objectid;
113 } else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) {
114 if (fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT)
116 root_objectid = fid->parent_root_objectid;
120 objectid = fid->parent_objectid;
121 generation = fid->parent_gen;
123 return btrfs_get_dentry(sb, objectid, root_objectid, generation);
126 static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
127 int fh_len, int fh_type)
129 struct btrfs_fid *fid = (struct btrfs_fid *) fh;
130 u64 objectid, root_objectid;
133 if ((fh_type != FILEID_BTRFS_WITH_PARENT ||
134 fh_len != BTRFS_FID_SIZE_CONNECTABLE) &&
135 (fh_type != FILEID_BTRFS_WITH_PARENT_ROOT ||
136 fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT) &&
137 (fh_type != FILEID_BTRFS_WITHOUT_PARENT ||
138 fh_len != BTRFS_FID_SIZE_NON_CONNECTABLE))
141 objectid = fid->objectid;
142 root_objectid = fid->root_objectid;
143 generation = fid->gen;
145 return btrfs_get_dentry(sb, objectid, root_objectid, generation);
148 static struct dentry *btrfs_get_parent(struct dentry *child)
150 struct inode *dir = child->d_inode;
152 struct dentry *parent;
153 struct btrfs_root *root = BTRFS_I(dir)->root;
154 struct btrfs_key key;
155 struct btrfs_path *path;
156 struct extent_buffer *leaf;
161 path = btrfs_alloc_path();
163 key.objectid = dir->i_ino;
164 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
165 key.offset = (u64)-1;
167 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
168 leaf = path->nodes[0];
169 slot = path->slots[0];
170 if (ret < 0 || slot == 0) {
171 btrfs_free_path(path);
174 /* btrfs_search_slot() returns the slot where we'd want to insert
175 an INODE_REF_KEY for parent inode #0xFFFFFFFFFFFFFFFF. The _real_
176 one, telling us what the parent inode _actually_ is, will be in
177 the slot _before_ the one that btrfs_search_slot() returns. */
180 btrfs_item_key_to_cpu(leaf, &key, slot);
181 btrfs_free_path(path);
183 if (key.objectid != dir->i_ino || key.type != BTRFS_INODE_REF_KEY)
186 objectid = key.offset;
188 /* If we are already at the root of a subvol, return the real root */
189 if (objectid == dir->i_ino)
190 return dget(dir->i_sb->s_root);
192 /* Build a new key for the inode item */
193 key.objectid = objectid;
194 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
197 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
199 parent = d_obtain_alias(inode);
201 parent = ERR_PTR(-ENOMEM);
206 btrfs_free_path(path);
207 return ERR_PTR(-EINVAL);
210 const struct export_operations btrfs_export_ops = {
211 .encode_fh = btrfs_encode_fh,
212 .fh_to_dentry = btrfs_fh_to_dentry,
213 .fh_to_parent = btrfs_fh_to_parent,
214 .get_parent = btrfs_get_parent,