1#include <linux/fs.h>
  2#include <linux/types.h>
  3#include "ctree.h"
  4#include "disk-io.h"
  5#include "btrfs_inode.h"
  6#include "print-tree.h"
  7#include "export.h"
 
  8
  9#define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, \
 10						 parent_objectid) / 4)
 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)
 14
 15static int btrfs_encode_fh(struct inode *inode, u32 *fh, int *max_len,
 16			   struct inode *parent)
 17{
 18	struct btrfs_fid *fid = (struct btrfs_fid *)fh;
 19	int len = *max_len;
 20	int type;
 21
 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;
 28	}
 29
 30	len  = BTRFS_FID_SIZE_NON_CONNECTABLE;
 31	type = FILEID_BTRFS_WITHOUT_PARENT;
 32
 33	fid->objectid = btrfs_ino(inode);
 34	fid->root_objectid = BTRFS_I(inode)->root->objectid;
 35	fid->gen = inode->i_generation;
 36
 37	if (parent) {
 38		u64 parent_root_id;
 39
 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;
 43
 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;
 48		} else {
 49			len = BTRFS_FID_SIZE_CONNECTABLE;
 50			type = FILEID_BTRFS_WITH_PARENT;
 51		}
 52	}
 53
 54	*max_len = len;
 55	return type;
 56}
 57
 58static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
 59				       u64 root_objectid, u32 generation,
 60				       int check_generation)
 61{
 62	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 63	struct btrfs_root *root;
 64	struct inode *inode;
 65	struct btrfs_key key;
 66	int index;
 67	int err = 0;
 68
 69	if (objectid < BTRFS_FIRST_FREE_OBJECTID)
 70		return ERR_PTR(-ESTALE);
 71
 72	key.objectid = root_objectid;
 73	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 74	key.offset = (u64)-1;
 75
 76	index = srcu_read_lock(&fs_info->subvol_srcu);
 77
 78	root = btrfs_read_fs_root_no_name(fs_info, &key);
 79	if (IS_ERR(root)) {
 80		err = PTR_ERR(root);
 
 
 
 
 
 81		goto fail;
 82	}
 83
 84	key.objectid = objectid;
 85	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
 86	key.offset = 0;
 87
 88	inode = btrfs_iget(sb, &key, root, NULL);
 89	if (IS_ERR(inode)) {
 90		err = PTR_ERR(inode);
 91		goto fail;
 92	}
 93
 94	srcu_read_unlock(&fs_info->subvol_srcu, index);
 95
 96	if (check_generation && generation != inode->i_generation) {
 97		iput(inode);
 98		return ERR_PTR(-ESTALE);
 99	}
100
101	return d_obtain_alias(inode);
102fail:
103	srcu_read_unlock(&fs_info->subvol_srcu, index);
104	return ERR_PTR(err);
105}
106
107static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
108					 int fh_len, int fh_type)
109{
110	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
111	u64 objectid, root_objectid;
112	u32 generation;
113
114	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
115		if (fh_len !=  BTRFS_FID_SIZE_CONNECTABLE)
116			return NULL;
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)
120			return NULL;
121		root_objectid = fid->parent_root_objectid;
122	} else
123		return NULL;
124
125	objectid = fid->parent_objectid;
126	generation = fid->parent_gen;
127
128	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
129}
130
131static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
132					 int fh_len, int fh_type)
133{
134	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
135	u64 objectid, root_objectid;
136	u32 generation;
137
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))
144		return NULL;
145
146	objectid = fid->objectid;
147	root_objectid = fid->root_objectid;
148	generation = fid->gen;
149
150	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
151}
152
153static struct dentry *btrfs_get_parent(struct dentry *child)
154{
155	struct inode *dir = child->d_inode;
156	struct btrfs_root *root = BTRFS_I(dir)->root;
157	struct btrfs_path *path;
158	struct extent_buffer *leaf;
159	struct btrfs_root_ref *ref;
160	struct btrfs_key key;
161	struct btrfs_key found_key;
162	int ret;
163
164	path = btrfs_alloc_path();
165	if (!path)
166		return ERR_PTR(-ENOMEM);
167
168	if (btrfs_ino(dir) == BTRFS_FIRST_FREE_OBJECTID) {
169		key.objectid = root->root_key.objectid;
170		key.type = BTRFS_ROOT_BACKREF_KEY;
171		key.offset = (u64)-1;
172		root = root->fs_info->tree_root;
173	} else {
174		key.objectid = btrfs_ino(dir);
175		key.type = BTRFS_INODE_REF_KEY;
176		key.offset = (u64)-1;
177	}
178
179	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
180	if (ret < 0)
181		goto fail;
182
183	BUG_ON(ret == 0); /* Key with offset of -1 found */
184	if (path->slots[0] == 0) {
185		ret = -ENOENT;
186		goto fail;
187	}
188
189	path->slots[0]--;
190	leaf = path->nodes[0];
191
192	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
193	if (found_key.objectid != key.objectid || found_key.type != key.type) {
194		ret = -ENOENT;
195		goto fail;
196	}
197
198	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
199		ref = btrfs_item_ptr(leaf, path->slots[0],
200				     struct btrfs_root_ref);
201		key.objectid = btrfs_root_ref_dirid(leaf, ref);
202	} else {
203		key.objectid = found_key.offset;
204	}
205	btrfs_free_path(path);
206
207	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
208		return btrfs_get_dentry(root->fs_info->sb, key.objectid,
209					found_key.offset, 0, 0);
210	}
211
212	key.type = BTRFS_INODE_ITEM_KEY;
213	key.offset = 0;
214	return d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL));
215fail:
216	btrfs_free_path(path);
217	return ERR_PTR(ret);
218}
219
220static int btrfs_get_name(struct dentry *parent, char *name,
221			  struct dentry *child)
222{
223	struct inode *inode = child->d_inode;
224	struct inode *dir = parent->d_inode;
225	struct btrfs_path *path;
226	struct btrfs_root *root = BTRFS_I(dir)->root;
227	struct btrfs_inode_ref *iref;
228	struct btrfs_root_ref *rref;
229	struct extent_buffer *leaf;
230	unsigned long name_ptr;
231	struct btrfs_key key;
232	int name_len;
233	int ret;
234	u64 ino;
235
236	if (!dir || !inode)
237		return -EINVAL;
238
239	if (!S_ISDIR(dir->i_mode))
240		return -EINVAL;
241
242	ino = btrfs_ino(inode);
243
244	path = btrfs_alloc_path();
245	if (!path)
246		return -ENOMEM;
247	path->leave_spinning = 1;
248
249	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
250		key.objectid = BTRFS_I(inode)->root->root_key.objectid;
251		key.type = BTRFS_ROOT_BACKREF_KEY;
252		key.offset = (u64)-1;
253		root = root->fs_info->tree_root;
254	} else {
255		key.objectid = ino;
256		key.offset = btrfs_ino(dir);
257		key.type = BTRFS_INODE_REF_KEY;
258	}
259
260	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
261	if (ret < 0) {
262		btrfs_free_path(path);
263		return ret;
264	} else if (ret > 0) {
265		if (ino == BTRFS_FIRST_FREE_OBJECTID) {
266			path->slots[0]--;
267		} else {
268			btrfs_free_path(path);
269			return -ENOENT;
270		}
271	}
272	leaf = path->nodes[0];
273
274	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
275		rref = btrfs_item_ptr(leaf, path->slots[0],
276				     struct btrfs_root_ref);
277		name_ptr = (unsigned long)(rref + 1);
278		name_len = btrfs_root_ref_name_len(leaf, rref);
279	} else {
280		iref = btrfs_item_ptr(leaf, path->slots[0],
281				      struct btrfs_inode_ref);
282		name_ptr = (unsigned long)(iref + 1);
283		name_len = btrfs_inode_ref_name_len(leaf, iref);
284	}
285
286	read_extent_buffer(leaf, name, name_ptr, name_len);
287	btrfs_free_path(path);
288
289	/*
290	 * have to add the null termination to make sure that reconnect_path
291	 * gets the right len for strlen
292	 */
293	name[name_len] = '\0';
294
295	return 0;
296}
297
298const struct export_operations btrfs_export_ops = {
299	.encode_fh	= btrfs_encode_fh,
300	.fh_to_dentry	= btrfs_fh_to_dentry,
301	.fh_to_parent	= btrfs_fh_to_parent,
302	.get_parent	= btrfs_get_parent,
303	.get_name	= btrfs_get_name,
304};

  1#include <linux/fs.h>
  2#include <linux/types.h>
  3#include "ctree.h"
  4#include "disk-io.h"
  5#include "btrfs_inode.h"
  6#include "print-tree.h"
  7#include "export.h"
  8#include "compat.h"
  9
 10#define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, \
 11						 parent_objectid) / 4)
 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)
 15
 16static int btrfs_encode_fh(struct inode *inode, u32 *fh, int *max_len,
 17			   struct inode *parent)
 18{
 19	struct btrfs_fid *fid = (struct btrfs_fid *)fh;
 20	int len = *max_len;
 21	int type;
 22
 23	if (parent && (len < BTRFS_FID_SIZE_CONNECTABLE)) {
 24		*max_len = BTRFS_FID_SIZE_CONNECTABLE;
 25		return 255;
 26	} else if (len < BTRFS_FID_SIZE_NON_CONNECTABLE) {
 27		*max_len = BTRFS_FID_SIZE_NON_CONNECTABLE;
 28		return 255;
 29	}
 30
 31	len  = BTRFS_FID_SIZE_NON_CONNECTABLE;
 32	type = FILEID_BTRFS_WITHOUT_PARENT;
 33
 34	fid->objectid = btrfs_ino(inode);
 35	fid->root_objectid = BTRFS_I(inode)->root->objectid;
 36	fid->gen = inode->i_generation;
 37
 38	if (parent) {
 39		u64 parent_root_id;
 40
 41		fid->parent_objectid = BTRFS_I(parent)->location.objectid;
 42		fid->parent_gen = parent->i_generation;
 43		parent_root_id = BTRFS_I(parent)->root->objectid;
 44
 45		if (parent_root_id != fid->root_objectid) {
 46			fid->parent_root_objectid = parent_root_id;
 47			len = BTRFS_FID_SIZE_CONNECTABLE_ROOT;
 48			type = FILEID_BTRFS_WITH_PARENT_ROOT;
 49		} else {
 50			len = BTRFS_FID_SIZE_CONNECTABLE;
 51			type = FILEID_BTRFS_WITH_PARENT;
 52		}
 53	}
 54
 55	*max_len = len;
 56	return type;
 57}
 58
 59static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
 60				       u64 root_objectid, u32 generation,
 61				       int check_generation)
 62{
 63	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 64	struct btrfs_root *root;
 65	struct inode *inode;
 66	struct btrfs_key key;
 67	int index;
 68	int err = 0;
 69
 70	if (objectid < BTRFS_FIRST_FREE_OBJECTID)
 71		return ERR_PTR(-ESTALE);
 72
 73	key.objectid = root_objectid;
 74	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 75	key.offset = (u64)-1;
 76
 77	index = srcu_read_lock(&fs_info->subvol_srcu);
 78
 79	root = btrfs_read_fs_root_no_name(fs_info, &key);
 80	if (IS_ERR(root)) {
 81		err = PTR_ERR(root);
 82		goto fail;
 83	}
 84
 85	if (btrfs_root_refs(&root->root_item) == 0) {
 86		err = -ENOENT;
 87		goto fail;
 88	}
 89
 90	key.objectid = objectid;
 91	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
 92	key.offset = 0;
 93
 94	inode = btrfs_iget(sb, &key, root, NULL);
 95	if (IS_ERR(inode)) {
 96		err = PTR_ERR(inode);
 97		goto fail;
 98	}
 99
100	srcu_read_unlock(&fs_info->subvol_srcu, index);
101
102	if (check_generation && generation != inode->i_generation) {
103		iput(inode);
104		return ERR_PTR(-ESTALE);
105	}
106
107	return d_obtain_alias(inode);
108fail:
109	srcu_read_unlock(&fs_info->subvol_srcu, index);
110	return ERR_PTR(err);
111}
112
113static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
114					 int fh_len, int fh_type)
115{
116	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
117	u64 objectid, root_objectid;
118	u32 generation;
119
120	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
121		if (fh_len !=  BTRFS_FID_SIZE_CONNECTABLE)
122			return NULL;
123		root_objectid = fid->root_objectid;
124	} else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) {
125		if (fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT)
126			return NULL;
127		root_objectid = fid->parent_root_objectid;
128	} else
129		return NULL;
130
131	objectid = fid->parent_objectid;
132	generation = fid->parent_gen;
133
134	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
135}
136
137static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
138					 int fh_len, int fh_type)
139{
140	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
141	u64 objectid, root_objectid;
142	u32 generation;
143
144	if ((fh_type != FILEID_BTRFS_WITH_PARENT ||
145	     fh_len != BTRFS_FID_SIZE_CONNECTABLE) &&
146	    (fh_type != FILEID_BTRFS_WITH_PARENT_ROOT ||
147	     fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT) &&
148	    (fh_type != FILEID_BTRFS_WITHOUT_PARENT ||
149	     fh_len != BTRFS_FID_SIZE_NON_CONNECTABLE))
150		return NULL;
151
152	objectid = fid->objectid;
153	root_objectid = fid->root_objectid;
154	generation = fid->gen;
155
156	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
157}
158
159static struct dentry *btrfs_get_parent(struct dentry *child)
160{
161	struct inode *dir = child->d_inode;
162	struct btrfs_root *root = BTRFS_I(dir)->root;
163	struct btrfs_path *path;
164	struct extent_buffer *leaf;
165	struct btrfs_root_ref *ref;
166	struct btrfs_key key;
167	struct btrfs_key found_key;
168	int ret;
169
170	path = btrfs_alloc_path();
171	if (!path)
172		return ERR_PTR(-ENOMEM);
173
174	if (btrfs_ino(dir) == BTRFS_FIRST_FREE_OBJECTID) {
175		key.objectid = root->root_key.objectid;
176		key.type = BTRFS_ROOT_BACKREF_KEY;
177		key.offset = (u64)-1;
178		root = root->fs_info->tree_root;
179	} else {
180		key.objectid = btrfs_ino(dir);
181		key.type = BTRFS_INODE_REF_KEY;
182		key.offset = (u64)-1;
183	}
184
185	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
186	if (ret < 0)
187		goto fail;
188
189	BUG_ON(ret == 0); /* Key with offset of -1 found */
190	if (path->slots[0] == 0) {
191		ret = -ENOENT;
192		goto fail;
193	}
194
195	path->slots[0]--;
196	leaf = path->nodes[0];
197
198	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
199	if (found_key.objectid != key.objectid || found_key.type != key.type) {
200		ret = -ENOENT;
201		goto fail;
202	}
203
204	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
205		ref = btrfs_item_ptr(leaf, path->slots[0],
206				     struct btrfs_root_ref);
207		key.objectid = btrfs_root_ref_dirid(leaf, ref);
208	} else {
209		key.objectid = found_key.offset;
210	}
211	btrfs_free_path(path);
212
213	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
214		return btrfs_get_dentry(root->fs_info->sb, key.objectid,
215					found_key.offset, 0, 0);
216	}
217
218	key.type = BTRFS_INODE_ITEM_KEY;
219	key.offset = 0;
220	return d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL));
221fail:
222	btrfs_free_path(path);
223	return ERR_PTR(ret);
224}
225
226static int btrfs_get_name(struct dentry *parent, char *name,
227			  struct dentry *child)
228{
229	struct inode *inode = child->d_inode;
230	struct inode *dir = parent->d_inode;
231	struct btrfs_path *path;
232	struct btrfs_root *root = BTRFS_I(dir)->root;
233	struct btrfs_inode_ref *iref;
234	struct btrfs_root_ref *rref;
235	struct extent_buffer *leaf;
236	unsigned long name_ptr;
237	struct btrfs_key key;
238	int name_len;
239	int ret;
240	u64 ino;
241
242	if (!dir || !inode)
243		return -EINVAL;
244
245	if (!S_ISDIR(dir->i_mode))
246		return -EINVAL;
247
248	ino = btrfs_ino(inode);
249
250	path = btrfs_alloc_path();
251	if (!path)
252		return -ENOMEM;
253	path->leave_spinning = 1;
254
255	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
256		key.objectid = BTRFS_I(inode)->root->root_key.objectid;
257		key.type = BTRFS_ROOT_BACKREF_KEY;
258		key.offset = (u64)-1;
259		root = root->fs_info->tree_root;
260	} else {
261		key.objectid = ino;
262		key.offset = btrfs_ino(dir);
263		key.type = BTRFS_INODE_REF_KEY;
264	}
265
266	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
267	if (ret < 0) {
268		btrfs_free_path(path);
269		return ret;
270	} else if (ret > 0) {
271		if (ino == BTRFS_FIRST_FREE_OBJECTID) {
272			path->slots[0]--;
273		} else {
274			btrfs_free_path(path);
275			return -ENOENT;
276		}
277	}
278	leaf = path->nodes[0];
279
280	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
281		rref = btrfs_item_ptr(leaf, path->slots[0],
282				     struct btrfs_root_ref);
283		name_ptr = (unsigned long)(rref + 1);
284		name_len = btrfs_root_ref_name_len(leaf, rref);
285	} else {
286		iref = btrfs_item_ptr(leaf, path->slots[0],
287				      struct btrfs_inode_ref);
288		name_ptr = (unsigned long)(iref + 1);
289		name_len = btrfs_inode_ref_name_len(leaf, iref);
290	}
291
292	read_extent_buffer(leaf, name, name_ptr, name_len);
293	btrfs_free_path(path);
294
295	/*
296	 * have to add the null termination to make sure that reconnect_path
297	 * gets the right len for strlen
298	 */
299	name[name_len] = '\0';
300
301	return 0;
302}
303
304const struct export_operations btrfs_export_ops = {
305	.encode_fh	= btrfs_encode_fh,
306	.fh_to_dentry	= btrfs_fh_to_dentry,
307	.fh_to_parent	= btrfs_fh_to_parent,
308	.get_parent	= btrfs_get_parent,
309	.get_name	= btrfs_get_name,
310};