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 return ERR_PTR(-ENOMEM);
182 if (dir->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
183 key.objectid = root->root_key.objectid;
184 key.type = BTRFS_ROOT_BACKREF_KEY;
185 key.offset = (u64)-1;
186 root = root->fs_info->tree_root;
188 key.objectid = dir->i_ino;
189 key.type = BTRFS_INODE_REF_KEY;
190 key.offset = (u64)-1;
193 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
198 if (path->slots[0] == 0) {
204 leaf = path->nodes[0];
206 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
207 if (found_key.objectid != key.objectid || found_key.type != key.type) {
212 if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
213 ref = btrfs_item_ptr(leaf, path->slots[0],
214 struct btrfs_root_ref);
215 key.objectid = btrfs_root_ref_dirid(leaf, ref);
217 key.objectid = found_key.offset;
219 btrfs_free_path(path);
221 if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
222 return btrfs_get_dentry(root->fs_info->sb, key.objectid,
223 found_key.offset, 0, 0);
226 key.type = BTRFS_INODE_ITEM_KEY;
228 dentry = d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL));
230 dentry->d_op = &btrfs_dentry_operations;
233 btrfs_free_path(path);
237 static int btrfs_get_name(struct dentry *parent, char *name,
238 struct dentry *child)
240 struct inode *inode = child->d_inode;
241 struct inode *dir = parent->d_inode;
242 struct btrfs_path *path;
243 struct btrfs_root *root = BTRFS_I(dir)->root;
244 struct btrfs_inode_ref *iref;
245 struct btrfs_root_ref *rref;
246 struct extent_buffer *leaf;
247 unsigned long name_ptr;
248 struct btrfs_key key;
255 if (!S_ISDIR(dir->i_mode))
258 path = btrfs_alloc_path();
261 path->leave_spinning = 1;
263 if (inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
264 key.objectid = BTRFS_I(inode)->root->root_key.objectid;
265 key.type = BTRFS_ROOT_BACKREF_KEY;
266 key.offset = (u64)-1;
267 root = root->fs_info->tree_root;
269 key.objectid = inode->i_ino;
270 key.offset = dir->i_ino;
271 key.type = BTRFS_INODE_REF_KEY;
274 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
276 btrfs_free_path(path);
278 } else if (ret > 0) {
279 if (inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
282 btrfs_free_path(path);
286 leaf = path->nodes[0];
288 if (inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
289 rref = btrfs_item_ptr(leaf, path->slots[0],
290 struct btrfs_root_ref);
291 name_ptr = (unsigned long)(rref + 1);
292 name_len = btrfs_root_ref_name_len(leaf, rref);
294 iref = btrfs_item_ptr(leaf, path->slots[0],
295 struct btrfs_inode_ref);
296 name_ptr = (unsigned long)(iref + 1);
297 name_len = btrfs_inode_ref_name_len(leaf, iref);
300 read_extent_buffer(leaf, name, name_ptr, name_len);
301 btrfs_free_path(path);
304 * have to add the null termination to make sure that reconnect_path
305 * gets the right len for strlen
307 name[name_len] = '\0';
312 const struct export_operations btrfs_export_ops = {
313 .encode_fh = btrfs_encode_fh,
314 .fh_to_dentry = btrfs_fh_to_dentry,
315 .fh_to_parent = btrfs_fh_to_parent,
316 .get_parent = btrfs_get_parent,
317 .get_name = btrfs_get_name,