[linux-block.git] / fs / btrfs / export.c

// SPDX-License-Identifier: GPL-2.0

#include <linux/fs.h>
#include <linux/types.h>
#include "ctree.h"
#include "disk-io.h"
#include "btrfs_inode.h"
#include "print-tree.h"
#include "export.h"

#define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, \
						 parent_objectid) / 4)
#define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, \
					     parent_root_objectid) / 4)
#define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid) / 4)

static int btrfs_encode_fh(struct inode *inode, u32 *fh, int *max_len,
			   struct inode *parent)
{
	struct btrfs_fid *fid = (struct btrfs_fid *)fh;
	int len = *max_len;
	int type;

	if (parent && (len < BTRFS_FID_SIZE_CONNECTABLE)) {
		*max_len = BTRFS_FID_SIZE_CONNECTABLE;
		return FILEID_INVALID;
	} else if (len < BTRFS_FID_SIZE_NON_CONNECTABLE) {
		*max_len = BTRFS_FID_SIZE_NON_CONNECTABLE;
		return FILEID_INVALID;
	}

	len  = BTRFS_FID_SIZE_NON_CONNECTABLE;
	type = FILEID_BTRFS_WITHOUT_PARENT;

	fid->objectid = btrfs_ino(BTRFS_I(inode));
	fid->root_objectid = BTRFS_I(inode)->root->root_key.objectid;
	fid->gen = inode->i_generation;

	if (parent) {
		u64 parent_root_id;

		fid->parent_objectid = BTRFS_I(parent)->location.objectid;
		fid->parent_gen = parent->i_generation;
		parent_root_id = BTRFS_I(parent)->root->root_key.objectid;

		if (parent_root_id != fid->root_objectid) {
			fid->parent_root_objectid = parent_root_id;
			len = BTRFS_FID_SIZE_CONNECTABLE_ROOT;
			type = FILEID_BTRFS_WITH_PARENT_ROOT;
		} else {
			len = BTRFS_FID_SIZE_CONNECTABLE;
			type = FILEID_BTRFS_WITH_PARENT;
		}
	}

	*max_len = len;
	return type;
}

struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
				u64 root_objectid, u32 generation,
				int check_generation)
{
	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
	struct btrfs_root *root;
	struct inode *inode;
	struct btrfs_key key;

	if (objectid < BTRFS_FIRST_FREE_OBJECTID)
		return ERR_PTR(-ESTALE);

	key.objectid = root_objectid;
	key.type = BTRFS_ROOT_ITEM_KEY;
	key.offset = (u64)-1;

	root = btrfs_get_fs_root(fs_info, &key, true);
	if (IS_ERR(root))
		return ERR_CAST(root);

	key.objectid = objectid;
	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;

	inode = btrfs_iget(sb, &key, root);
	btrfs_put_root(root);
	if (IS_ERR(inode))
		return ERR_CAST(inode);

	if (check_generation && generation != inode->i_generation) {
		iput(inode);
		return ERR_PTR(-ESTALE);
	}

	return d_obtain_alias(inode);
}

static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
					 int fh_len, int fh_type)
{
	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
	u64 objectid, root_objectid;
	u32 generation;

	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
		if (fh_len <  BTRFS_FID_SIZE_CONNECTABLE)
			return NULL;
		root_objectid = fid->root_objectid;
	} else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) {
		if (fh_len < BTRFS_FID_SIZE_CONNECTABLE_ROOT)
			return NULL;
		root_objectid = fid->parent_root_objectid;
	} else
		return NULL;

	objectid = fid->parent_objectid;
	generation = fid->parent_gen;

	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
}

static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
					 int fh_len, int fh_type)
{
	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
	u64 objectid, root_objectid;
	u32 generation;

	if ((fh_type != FILEID_BTRFS_WITH_PARENT ||
	     fh_len < BTRFS_FID_SIZE_CONNECTABLE) &&
	    (fh_type != FILEID_BTRFS_WITH_PARENT_ROOT ||
	     fh_len < BTRFS_FID_SIZE_CONNECTABLE_ROOT) &&
	    (fh_type != FILEID_BTRFS_WITHOUT_PARENT ||
	     fh_len < BTRFS_FID_SIZE_NON_CONNECTABLE))
		return NULL;

	objectid = fid->objectid;
	root_objectid = fid->root_objectid;
	generation = fid->gen;

	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
}

struct dentry *btrfs_get_parent(struct dentry *child)
{
	struct inode *dir = d_inode(child);
	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_root_ref *ref;
	struct btrfs_key key;
	struct btrfs_key found_key;
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return ERR_PTR(-ENOMEM);

	if (btrfs_ino(BTRFS_I(dir)) == BTRFS_FIRST_FREE_OBJECTID) {
		key.objectid = root->root_key.objectid;
		key.type = BTRFS_ROOT_BACKREF_KEY;
		key.offset = (u64)-1;
		root = fs_info->tree_root;
	} else {
		key.objectid = btrfs_ino(BTRFS_I(dir));
		key.type = BTRFS_INODE_REF_KEY;
		key.offset = (u64)-1;
	}

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto fail;

	BUG_ON(ret == 0); /* Key with offset of -1 found */
	if (path->slots[0] == 0) {
		ret = -ENOENT;
		goto fail;
	}

	path->slots[0]--;
	leaf = path->nodes[0];

	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
	if (found_key.objectid != key.objectid || found_key.type != key.type) {
		ret = -ENOENT;
		goto fail;
	}

	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
		ref = btrfs_item_ptr(leaf, path->slots[0],
				     struct btrfs_root_ref);
		key.objectid = btrfs_root_ref_dirid(leaf, ref);
	} else {
		key.objectid = found_key.offset;
	}
	btrfs_free_path(path);

	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
		return btrfs_get_dentry(fs_info->sb, key.objectid,
					found_key.offset, 0, 0);
	}

	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;
	return d_obtain_alias(btrfs_iget(fs_info->sb, &key, root));
fail:
	btrfs_free_path(path);
	return ERR_PTR(ret);
}

static int btrfs_get_name(struct dentry *parent, char *name,
			  struct dentry *child)
{
	struct inode *inode = d_inode(child);
	struct inode *dir = d_inode(parent);
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	struct btrfs_path *path;
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct btrfs_inode_ref *iref;
	struct btrfs_root_ref *rref;
	struct extent_buffer *leaf;
	unsigned long name_ptr;
	struct btrfs_key key;
	int name_len;
	int ret;
	u64 ino;

	if (!S_ISDIR(dir->i_mode))
		return -EINVAL;

	ino = btrfs_ino(BTRFS_I(inode));

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
	path->leave_spinning = 1;

	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
		key.objectid = BTRFS_I(inode)->root->root_key.objectid;
		key.type = BTRFS_ROOT_BACKREF_KEY;
		key.offset = (u64)-1;
		root = fs_info->tree_root;
	} else {
		key.objectid = ino;
		key.offset = btrfs_ino(BTRFS_I(dir));
		key.type = BTRFS_INODE_REF_KEY;
	}

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0) {
		btrfs_free_path(path);
		return ret;
	} else if (ret > 0) {
		if (ino == BTRFS_FIRST_FREE_OBJECTID) {
			path->slots[0]--;
		} else {
			btrfs_free_path(path);
			return -ENOENT;
		}
	}
	leaf = path->nodes[0];

	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
		rref = btrfs_item_ptr(leaf, path->slots[0],
				     struct btrfs_root_ref);
		name_ptr = (unsigned long)(rref + 1);
		name_len = btrfs_root_ref_name_len(leaf, rref);
	} else {
		iref = btrfs_item_ptr(leaf, path->slots[0],
				      struct btrfs_inode_ref);
		name_ptr = (unsigned long)(iref + 1);
		name_len = btrfs_inode_ref_name_len(leaf, iref);
	}

	read_extent_buffer(leaf, name, name_ptr, name_len);
	btrfs_free_path(path);

	/*
	 * have to add the null termination to make sure that reconnect_path
	 * gets the right len for strlen
	 */
	name[name_len] = '\0';

	return 0;
}

const struct export_operations btrfs_export_ops = {
	.encode_fh	= btrfs_encode_fh,
	.fh_to_dentry	= btrfs_fh_to_dentry,
	.fh_to_parent	= btrfs_fh_to_parent,
	.get_parent	= btrfs_get_parent,
	.get_name	= btrfs_get_name,
};
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
c1d7c514	2
be6e8dc0 BR	3	#include <linux/fs.h>
	4	#include <linux/types.h>
	5	#include "ctree.h"
	6	#include "disk-io.h"
	7	#include "btrfs_inode.h"
	8	#include "print-tree.h"
	9	#include "export.h"
be6e8dc0	10
d397712b CM	11	#define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, \
	12	parent_objectid) / 4)
	13	#define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, \
	14	parent_root_objectid) / 4)
	15	#define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid) / 4)
be6e8dc0	16
b0b0382b AV	17	static int btrfs_encode_fh(struct inode inode, u32 fh, int *max_len,
b0b0382b AV	18	struct inode *parent)
be6e8dc0 BR	19	{
be6e8dc0 BR	20	struct btrfs_fid fid = (struct btrfs_fid )fh;
be6e8dc0 BR	21	int len = *max_len;
	22	int type;
	23
b0b0382b	24	if (parent && (len < BTRFS_FID_SIZE_CONNECTABLE)) {
5fe0c237	25	*max_len = BTRFS_FID_SIZE_CONNECTABLE;
94e07a75	26	return FILEID_INVALID;
5fe0c237 AK	27	} else if (len < BTRFS_FID_SIZE_NON_CONNECTABLE) {
5fe0c237 AK	28	*max_len = BTRFS_FID_SIZE_NON_CONNECTABLE;
94e07a75	29	return FILEID_INVALID;
5fe0c237	30	}
be6e8dc0 BR	31
	32	len = BTRFS_FID_SIZE_NON_CONNECTABLE;
	33	type = FILEID_BTRFS_WITHOUT_PARENT;
	34
4a0cc7ca	35	fid->objectid = btrfs_ino(BTRFS_I(inode));
4fd786e6	36	fid->root_objectid = BTRFS_I(inode)->root->root_key.objectid;
be6e8dc0 BR	37	fid->gen = inode->i_generation;
be6e8dc0 BR	38
b0b0382b	39	if (parent) {
be6e8dc0 BR	40	u64 parent_root_id;
be6e8dc0 BR	41
be6e8dc0 BR	42	fid->parent_objectid = BTRFS_I(parent)->location.objectid;
be6e8dc0 BR	43	fid->parent_gen = parent->i_generation;
4fd786e6	44	parent_root_id = BTRFS_I(parent)->root->root_key.objectid;
be6e8dc0	45
be6e8dc0 BR	46	if (parent_root_id != fid->root_objectid) {
	47	fid->parent_root_objectid = parent_root_id;
	48	len = BTRFS_FID_SIZE_CONNECTABLE_ROOT;
	49	type = FILEID_BTRFS_WITH_PARENT_ROOT;
	50	} else {
	51	len = BTRFS_FID_SIZE_CONNECTABLE;
	52	type = FILEID_BTRFS_WITH_PARENT;
	53	}
	54	}
	55
	56	*max_len = len;
	57	return type;
	58	}
	59
c0c907a4 MPS	60	struct dentry btrfs_get_dentry(struct super_block sb, u64 objectid,
	61	u64 root_objectid, u32 generation,
	62	int check_generation)
be6e8dc0	63	{
815745cf	64	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
be6e8dc0 BR	65	struct btrfs_root *root;
be6e8dc0 BR	66	struct inode *inode;
be6e8dc0	67	struct btrfs_key key;
76dda93c YZ	68
	69	if (objectid < BTRFS_FIRST_FREE_OBJECTID)
	70	return ERR_PTR(-ESTALE);
be6e8dc0	71
2d4d9fbd	72	key.objectid = root_objectid;
962a298f	73	key.type = BTRFS_ROOT_ITEM_KEY;
2d4d9fbd DW	74	key.offset = (u64)-1;
2d4d9fbd DW	75
3619c94f	76	root = btrfs_get_fs_root(fs_info, &key, true);
c75e8394 JB	77	if (IS_ERR(root))
c75e8394 JB	78	return ERR_CAST(root);
76dda93c	79
be6e8dc0	80	key.objectid = objectid;
962a298f	81	key.type = BTRFS_INODE_ITEM_KEY;
be6e8dc0 BR	82	key.offset = 0;
be6e8dc0 BR	83
4c66e0d4	84	inode = btrfs_iget(sb, &key, root);
00246528	85	btrfs_put_root(root);
c75e8394 JB	86	if (IS_ERR(inode))
c75e8394 JB	87	return ERR_CAST(inode);
be6e8dc0	88
76dda93c	89	if (check_generation && generation != inode->i_generation) {
be6e8dc0 BR	90	iput(inode);
	91	return ERR_PTR(-ESTALE);
	92	}
	93
af53d29a	94	return d_obtain_alias(inode);
be6e8dc0 BR	95	}
	96
	97	static struct dentry btrfs_fh_to_parent(struct super_block sb, struct fid *fh,
	98	int fh_len, int fh_type)
	99	{
	100	struct btrfs_fid fid = (struct btrfs_fid ) fh;
	101	u64 objectid, root_objectid;
	102	u32 generation;
	103
	104	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
7d35199e	105	if (fh_len < BTRFS_FID_SIZE_CONNECTABLE)
be6e8dc0 BR	106	return NULL;
	107	root_objectid = fid->root_objectid;
	108	} else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) {
7d35199e	109	if (fh_len < BTRFS_FID_SIZE_CONNECTABLE_ROOT)
be6e8dc0 BR	110	return NULL;
	111	root_objectid = fid->parent_root_objectid;
	112	} else
	113	return NULL;
	114
	115	objectid = fid->parent_objectid;
	116	generation = fid->parent_gen;
	117
76dda93c	118	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
be6e8dc0 BR	119	}
	120
	121	static struct dentry btrfs_fh_to_dentry(struct super_block sb, struct fid *fh,
	122	int fh_len, int fh_type)
	123	{
	124	struct btrfs_fid fid = (struct btrfs_fid ) fh;
	125	u64 objectid, root_objectid;
	126	u32 generation;
	127
	128	if ((fh_type != FILEID_BTRFS_WITH_PARENT \|\|
7d35199e	129	fh_len < BTRFS_FID_SIZE_CONNECTABLE) &&
be6e8dc0	130	(fh_type != FILEID_BTRFS_WITH_PARENT_ROOT \|\|
7d35199e	131	fh_len < BTRFS_FID_SIZE_CONNECTABLE_ROOT) &&
be6e8dc0	132	(fh_type != FILEID_BTRFS_WITHOUT_PARENT \|\|
7d35199e	133	fh_len < BTRFS_FID_SIZE_NON_CONNECTABLE))
be6e8dc0 BR	134	return NULL;
	135
	136	objectid = fid->objectid;
	137	root_objectid = fid->root_objectid;
	138	generation = fid->gen;
	139
76dda93c	140	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
be6e8dc0 BR	141	}
be6e8dc0 BR	142
c0c907a4	143	struct dentry btrfs_get_parent(struct dentry child)
be6e8dc0	144	{
2b0143b5	145	struct inode *dir = d_inode(child);
0b246afa	146	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
be6e8dc0	147	struct btrfs_root *root = BTRFS_I(dir)->root;
be6e8dc0 BR	148	struct btrfs_path *path;
be6e8dc0 BR	149	struct extent_buffer *leaf;
76dda93c YZ	150	struct btrfs_root_ref *ref;
	151	struct btrfs_key key;
	152	struct btrfs_key found_key;
be6e8dc0 BR	153	int ret;
	154
	155	path = btrfs_alloc_path();
2a29edc6	156	if (!path)
2a29edc6	157	return ERR_PTR(-ENOMEM);
be6e8dc0	158
4a0cc7ca	159	if (btrfs_ino(BTRFS_I(dir)) == BTRFS_FIRST_FREE_OBJECTID) {
76dda93c YZ	160	key.objectid = root->root_key.objectid;
	161	key.type = BTRFS_ROOT_BACKREF_KEY;
	162	key.offset = (u64)-1;
0b246afa	163	root = fs_info->tree_root;
76dda93c	164	} else {
4a0cc7ca	165	key.objectid = btrfs_ino(BTRFS_I(dir));
76dda93c YZ	166	key.type = BTRFS_INODE_REF_KEY;
	167	key.offset = (u64)-1;
	168	}
be6e8dc0	169
87acb4ef	170	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
76dda93c YZ	171	if (ret < 0)
	172	goto fail;
	173
79787eaa	174	BUG_ON(ret == 0); /* Key with offset of -1 found */
76dda93c YZ	175	if (path->slots[0] == 0) {
	176	ret = -ENOENT;
	177	goto fail;
d54a8390	178	}
76dda93c YZ	179
76dda93c YZ	180	path->slots[0]--;
be6e8dc0	181	leaf = path->nodes[0];
76dda93c YZ	182
	183	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
	184	if (found_key.objectid != key.objectid \|\| found_key.type != key.type) {
	185	ret = -ENOENT;
	186	goto fail;
be6e8dc0 BR	187	}
be6e8dc0 BR	188
76dda93c YZ	189	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
	190	ref = btrfs_item_ptr(leaf, path->slots[0],
	191	struct btrfs_root_ref);
	192	key.objectid = btrfs_root_ref_dirid(leaf, ref);
	193	} else {
	194	key.objectid = found_key.offset;
	195	}
be6e8dc0 BR	196	btrfs_free_path(path);
be6e8dc0 BR	197
76dda93c	198	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
0b246afa	199	return btrfs_get_dentry(fs_info->sb, key.objectid,
76dda93c YZ	200	found_key.offset, 0, 0);
76dda93c YZ	201	}
2d4d9fbd	202
76dda93c	203	key.type = BTRFS_INODE_ITEM_KEY;
be6e8dc0	204	key.offset = 0;
4c66e0d4	205	return d_obtain_alias(btrfs_iget(fs_info->sb, &key, root));
76dda93c YZ	206	fail:
	207	btrfs_free_path(path);
	208	return ERR_PTR(ret);
be6e8dc0 BR	209	}
be6e8dc0 BR	210
2ede0daf JB	211	static int btrfs_get_name(struct dentry parent, char name,
	212	struct dentry *child)
	213	{
2b0143b5 DH	214	struct inode *inode = d_inode(child);
2b0143b5 DH	215	struct inode *dir = d_inode(parent);
0b246afa	216	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2ede0daf JB	217	struct btrfs_path *path;
	218	struct btrfs_root *root = BTRFS_I(dir)->root;
	219	struct btrfs_inode_ref *iref;
	220	struct btrfs_root_ref *rref;
	221	struct extent_buffer *leaf;
	222	unsigned long name_ptr;
	223	struct btrfs_key key;
	224	int name_len;
	225	int ret;
33345d01	226	u64 ino;
2ede0daf	227
2ede0daf JB	228	if (!S_ISDIR(dir->i_mode))
	229	return -EINVAL;
	230
4a0cc7ca	231	ino = btrfs_ino(BTRFS_I(inode));
33345d01	232
2ede0daf JB	233	path = btrfs_alloc_path();
	234	if (!path)
	235	return -ENOMEM;
	236	path->leave_spinning = 1;
	237
33345d01	238	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
2ede0daf JB	239	key.objectid = BTRFS_I(inode)->root->root_key.objectid;
	240	key.type = BTRFS_ROOT_BACKREF_KEY;
	241	key.offset = (u64)-1;
0b246afa	242	root = fs_info->tree_root;
2ede0daf	243	} else {
33345d01	244	key.objectid = ino;
4a0cc7ca	245	key.offset = btrfs_ino(BTRFS_I(dir));
2ede0daf JB	246	key.type = BTRFS_INODE_REF_KEY;
	247	}
	248
	249	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	250	if (ret < 0) {
	251	btrfs_free_path(path);
	252	return ret;
	253	} else if (ret > 0) {
33345d01	254	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
2ede0daf JB	255	path->slots[0]--;
	256	} else {
	257	btrfs_free_path(path);
	258	return -ENOENT;
	259	}
	260	}
	261	leaf = path->nodes[0];
	262
33345d01 LZ	263	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
33345d01 LZ	264	rref = btrfs_item_ptr(leaf, path->slots[0],
2ede0daf	265	struct btrfs_root_ref);
33345d01 LZ	266	name_ptr = (unsigned long)(rref + 1);
33345d01 LZ	267	name_len = btrfs_root_ref_name_len(leaf, rref);
2ede0daf JB	268	} else {
	269	iref = btrfs_item_ptr(leaf, path->slots[0],
	270	struct btrfs_inode_ref);
	271	name_ptr = (unsigned long)(iref + 1);
	272	name_len = btrfs_inode_ref_name_len(leaf, iref);
	273	}
	274
	275	read_extent_buffer(leaf, name, name_ptr, name_len);
	276	btrfs_free_path(path);
	277
	278	/*
	279	* have to add the null termination to make sure that reconnect_path
	280	* gets the right len for strlen
	281	*/
	282	name[name_len] = '\0';
	283
	284	return 0;
	285	}
	286
be6e8dc0 BR	287	const struct export_operations btrfs_export_ops = {
	288	.encode_fh = btrfs_encode_fh,
	289	.fh_to_dentry = btrfs_fh_to_dentry,
	290	.fh_to_parent = btrfs_fh_to_parent,
	291	.get_parent = btrfs_get_parent,
2ede0daf	292	.get_name = btrfs_get_name,
be6e8dc0	293	};