[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->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->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;
}

static 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;
	int index;
	int err = 0;

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

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

	index = srcu_read_lock(&fs_info->subvol_srcu);

	root = btrfs_read_fs_root_no_name(fs_info, &key);
	if (IS_ERR(root)) {
		err = PTR_ERR(root);
		goto fail;
	}

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

	inode = btrfs_iget(sb, &key, root, NULL);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto fail;
	}

	srcu_read_unlock(&fs_info->subvol_srcu, index);

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

	return d_obtain_alias(inode);
fail:
	srcu_read_unlock(&fs_info->subvol_srcu, index);
	return ERR_PTR(err);
}

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);
}

static 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, NULL));
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);
	}

	ret = btrfs_is_name_len_valid(leaf, path->slots[0], name_ptr, name_len);
	if (!ret) {
		btrfs_free_path(path);
		return -EIO;
	}
	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
be6e8dc0 BR	2	#include <linux/fs.h>
	3	#include <linux/types.h>
	4	#include "ctree.h"
	5	#include "disk-io.h"
	6	#include "btrfs_inode.h"
	7	#include "print-tree.h"
	8	#include "export.h"
be6e8dc0	9
d397712b CM	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)
be6e8dc0	15
b0b0382b AV	16	static int btrfs_encode_fh(struct inode inode, u32 fh, int *max_len,
b0b0382b AV	17	struct inode *parent)
be6e8dc0 BR	18	{
be6e8dc0 BR	19	struct btrfs_fid fid = (struct btrfs_fid )fh;
be6e8dc0 BR	20	int len = *max_len;
	21	int type;
	22
b0b0382b	23	if (parent && (len < BTRFS_FID_SIZE_CONNECTABLE)) {
5fe0c237	24	*max_len = BTRFS_FID_SIZE_CONNECTABLE;
94e07a75	25	return FILEID_INVALID;
5fe0c237 AK	26	} else if (len < BTRFS_FID_SIZE_NON_CONNECTABLE) {
5fe0c237 AK	27	*max_len = BTRFS_FID_SIZE_NON_CONNECTABLE;
94e07a75	28	return FILEID_INVALID;
5fe0c237	29	}
be6e8dc0 BR	30
	31	len = BTRFS_FID_SIZE_NON_CONNECTABLE;
	32	type = FILEID_BTRFS_WITHOUT_PARENT;
	33
4a0cc7ca	34	fid->objectid = btrfs_ino(BTRFS_I(inode));
be6e8dc0 BR	35	fid->root_objectid = BTRFS_I(inode)->root->objectid;
	36	fid->gen = inode->i_generation;
	37
b0b0382b	38	if (parent) {
be6e8dc0 BR	39	u64 parent_root_id;
be6e8dc0 BR	40
be6e8dc0 BR	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
be6e8dc0 BR	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
	59	static struct dentry btrfs_get_dentry(struct super_block sb, u64 objectid,
76dda93c YZ	60	u64 root_objectid, u32 generation,
76dda93c YZ	61	int check_generation)
be6e8dc0	62	{
815745cf	63	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
be6e8dc0 BR	64	struct btrfs_root *root;
be6e8dc0 BR	65	struct inode *inode;
be6e8dc0	66	struct btrfs_key key;
76dda93c YZ	67	int index;
	68	int err = 0;
	69
	70	if (objectid < BTRFS_FIRST_FREE_OBJECTID)
	71	return ERR_PTR(-ESTALE);
be6e8dc0	72
2d4d9fbd	73	key.objectid = root_objectid;
962a298f	74	key.type = BTRFS_ROOT_ITEM_KEY;
2d4d9fbd DW	75	key.offset = (u64)-1;
2d4d9fbd DW	76
76dda93c YZ	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
be6e8dc0	85	key.objectid = objectid;
962a298f	86	key.type = BTRFS_INODE_ITEM_KEY;
be6e8dc0 BR	87	key.offset = 0;
be6e8dc0 BR	88
73f73415	89	inode = btrfs_iget(sb, &key, root, NULL);
76dda93c YZ	90	if (IS_ERR(inode)) {
	91	err = PTR_ERR(inode);
	92	goto fail;
	93	}
	94
	95	srcu_read_unlock(&fs_info->subvol_srcu, index);
be6e8dc0	96
76dda93c	97	if (check_generation && generation != inode->i_generation) {
be6e8dc0 BR	98	iput(inode);
	99	return ERR_PTR(-ESTALE);
	100	}
	101
af53d29a	102	return d_obtain_alias(inode);
76dda93c YZ	103	fail:
	104	srcu_read_unlock(&fs_info->subvol_srcu, index);
	105	return ERR_PTR(err);
be6e8dc0 BR	106	}
	107
	108	static struct dentry btrfs_fh_to_parent(struct super_block sb, struct fid *fh,
	109	int fh_len, int fh_type)
	110	{
	111	struct btrfs_fid fid = (struct btrfs_fid ) fh;
	112	u64 objectid, root_objectid;
	113	u32 generation;
	114
	115	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
7d35199e	116	if (fh_len < BTRFS_FID_SIZE_CONNECTABLE)
be6e8dc0 BR	117	return NULL;
	118	root_objectid = fid->root_objectid;
	119	} else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) {
7d35199e	120	if (fh_len < BTRFS_FID_SIZE_CONNECTABLE_ROOT)
be6e8dc0 BR	121	return NULL;
	122	root_objectid = fid->parent_root_objectid;
	123	} else
	124	return NULL;
	125
	126	objectid = fid->parent_objectid;
	127	generation = fid->parent_gen;
	128
76dda93c	129	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
be6e8dc0 BR	130	}
	131
	132	static struct dentry btrfs_fh_to_dentry(struct super_block sb, struct fid *fh,
	133	int fh_len, int fh_type)
	134	{
	135	struct btrfs_fid fid = (struct btrfs_fid ) fh;
	136	u64 objectid, root_objectid;
	137	u32 generation;
	138
	139	if ((fh_type != FILEID_BTRFS_WITH_PARENT \|\|
7d35199e	140	fh_len < BTRFS_FID_SIZE_CONNECTABLE) &&
be6e8dc0	141	(fh_type != FILEID_BTRFS_WITH_PARENT_ROOT \|\|
7d35199e	142	fh_len < BTRFS_FID_SIZE_CONNECTABLE_ROOT) &&
be6e8dc0	143	(fh_type != FILEID_BTRFS_WITHOUT_PARENT \|\|
7d35199e	144	fh_len < BTRFS_FID_SIZE_NON_CONNECTABLE))
be6e8dc0 BR	145	return NULL;
	146
	147	objectid = fid->objectid;
	148	root_objectid = fid->root_objectid;
	149	generation = fid->gen;
	150
76dda93c	151	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
be6e8dc0 BR	152	}
	153
	154	static struct dentry btrfs_get_parent(struct dentry child)
	155	{
2b0143b5	156	struct inode *dir = d_inode(child);
0b246afa	157	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
be6e8dc0	158	struct btrfs_root *root = BTRFS_I(dir)->root;
be6e8dc0 BR	159	struct btrfs_path *path;
be6e8dc0 BR	160	struct extent_buffer *leaf;
76dda93c YZ	161	struct btrfs_root_ref *ref;
	162	struct btrfs_key key;
	163	struct btrfs_key found_key;
be6e8dc0 BR	164	int ret;
	165
	166	path = btrfs_alloc_path();
2a29edc6	167	if (!path)
2a29edc6	168	return ERR_PTR(-ENOMEM);
be6e8dc0	169
4a0cc7ca	170	if (btrfs_ino(BTRFS_I(dir)) == BTRFS_FIRST_FREE_OBJECTID) {
76dda93c YZ	171	key.objectid = root->root_key.objectid;
	172	key.type = BTRFS_ROOT_BACKREF_KEY;
	173	key.offset = (u64)-1;
0b246afa	174	root = fs_info->tree_root;
76dda93c	175	} else {
4a0cc7ca	176	key.objectid = btrfs_ino(BTRFS_I(dir));
76dda93c YZ	177	key.type = BTRFS_INODE_REF_KEY;
	178	key.offset = (u64)-1;
	179	}
be6e8dc0	180
87acb4ef	181	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
76dda93c YZ	182	if (ret < 0)
	183	goto fail;
	184
79787eaa	185	BUG_ON(ret == 0); /* Key with offset of -1 found */
76dda93c YZ	186	if (path->slots[0] == 0) {
	187	ret = -ENOENT;
	188	goto fail;
d54a8390	189	}
76dda93c YZ	190
76dda93c YZ	191	path->slots[0]--;
be6e8dc0	192	leaf = path->nodes[0];
76dda93c YZ	193
	194	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
	195	if (found_key.objectid != key.objectid \|\| found_key.type != key.type) {
	196	ret = -ENOENT;
	197	goto fail;
be6e8dc0 BR	198	}
be6e8dc0 BR	199
76dda93c YZ	200	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
	201	ref = btrfs_item_ptr(leaf, path->slots[0],
	202	struct btrfs_root_ref);
	203	key.objectid = btrfs_root_ref_dirid(leaf, ref);
	204	} else {
	205	key.objectid = found_key.offset;
	206	}
be6e8dc0 BR	207	btrfs_free_path(path);
be6e8dc0 BR	208
76dda93c	209	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
0b246afa	210	return btrfs_get_dentry(fs_info->sb, key.objectid,
76dda93c YZ	211	found_key.offset, 0, 0);
76dda93c YZ	212	}
2d4d9fbd	213
76dda93c	214	key.type = BTRFS_INODE_ITEM_KEY;
be6e8dc0	215	key.offset = 0;
0b246afa	216	return d_obtain_alias(btrfs_iget(fs_info->sb, &key, root, NULL));
76dda93c YZ	217	fail:
	218	btrfs_free_path(path);
	219	return ERR_PTR(ret);
be6e8dc0 BR	220	}
be6e8dc0 BR	221
2ede0daf JB	222	static int btrfs_get_name(struct dentry parent, char name,
	223	struct dentry *child)
	224	{
2b0143b5 DH	225	struct inode *inode = d_inode(child);
2b0143b5 DH	226	struct inode *dir = d_inode(parent);
0b246afa	227	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2ede0daf JB	228	struct btrfs_path *path;
	229	struct btrfs_root *root = BTRFS_I(dir)->root;
	230	struct btrfs_inode_ref *iref;
	231	struct btrfs_root_ref *rref;
	232	struct extent_buffer *leaf;
	233	unsigned long name_ptr;
	234	struct btrfs_key key;
	235	int name_len;
	236	int ret;
33345d01	237	u64 ino;
2ede0daf	238
2ede0daf JB	239	if (!S_ISDIR(dir->i_mode))
	240	return -EINVAL;
	241
4a0cc7ca	242	ino = btrfs_ino(BTRFS_I(inode));
33345d01	243
2ede0daf JB	244	path = btrfs_alloc_path();
	245	if (!path)
	246	return -ENOMEM;
	247	path->leave_spinning = 1;
	248
33345d01	249	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
2ede0daf JB	250	key.objectid = BTRFS_I(inode)->root->root_key.objectid;
	251	key.type = BTRFS_ROOT_BACKREF_KEY;
	252	key.offset = (u64)-1;
0b246afa	253	root = fs_info->tree_root;
2ede0daf	254	} else {
33345d01	255	key.objectid = ino;
4a0cc7ca	256	key.offset = btrfs_ino(BTRFS_I(dir));
2ede0daf JB	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) {
33345d01	265	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
2ede0daf JB	266	path->slots[0]--;
	267	} else {
	268	btrfs_free_path(path);
	269	return -ENOENT;
	270	}
	271	}
	272	leaf = path->nodes[0];
	273
33345d01 LZ	274	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
33345d01 LZ	275	rref = btrfs_item_ptr(leaf, path->slots[0],
2ede0daf	276	struct btrfs_root_ref);
33345d01 LZ	277	name_ptr = (unsigned long)(rref + 1);
33345d01 LZ	278	name_len = btrfs_root_ref_name_len(leaf, rref);
2ede0daf JB	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
488d7c45 SY	286	ret = btrfs_is_name_len_valid(leaf, path->slots[0], name_ptr, name_len);
	287	if (!ret) {
	288	btrfs_free_path(path);
	289	return -EIO;
	290	}
2ede0daf JB	291	read_extent_buffer(leaf, name, name_ptr, name_len);
	292	btrfs_free_path(path);
	293
	294	/*
	295	* have to add the null termination to make sure that reconnect_path
	296	* gets the right len for strlen
	297	*/
	298	name[name_len] = '\0';
	299
	300	return 0;
	301	}
	302
be6e8dc0 BR	303	const struct export_operations btrfs_export_ops = {
	304	.encode_fh = btrfs_encode_fh,
	305	.fh_to_dentry = btrfs_fh_to_dentry,
	306	.fh_to_parent = btrfs_fh_to_parent,
	307	.get_parent = btrfs_get_parent,
2ede0daf	308	.get_name = btrfs_get_name,
be6e8dc0	309	};