[mirror_ubuntu-artful-kernel.git] / fs / btrfs / inode-item.c

/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include "ctree.h"
#include "disk-io.h"
#include "hash.h"
#include "transaction.h"
#include "print-tree.h"

static int find_name_in_backref(struct btrfs_path *path, const char *name,
			 int name_len, struct btrfs_inode_ref **ref_ret)
{
	struct extent_buffer *leaf;
	struct btrfs_inode_ref *ref;
	unsigned long ptr;
	unsigned long name_ptr;
	u32 item_size;
	u32 cur_offset = 0;
	int len;

	leaf = path->nodes[0];
	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
	while (cur_offset < item_size) {
		ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
		len = btrfs_inode_ref_name_len(leaf, ref);
		name_ptr = (unsigned long)(ref + 1);
		cur_offset += len + sizeof(*ref);
		if (len != name_len)
			continue;
		if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
			*ref_ret = ref;
			return 1;
		}
	}
	return 0;
}

int btrfs_find_name_in_ext_backref(struct btrfs_path *path, u64 ref_objectid,
				   const char *name, int name_len,
				   struct btrfs_inode_extref **extref_ret)
{
	struct extent_buffer *leaf;
	struct btrfs_inode_extref *extref;
	unsigned long ptr;
	unsigned long name_ptr;
	u32 item_size;
	u32 cur_offset = 0;
	int ref_name_len;

	leaf = path->nodes[0];
	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);

	/*
	 * Search all extended backrefs in this item. We're only
	 * looking through any collisions so most of the time this is
	 * just going to compare against one buffer. If all is well,
	 * we'll return success and the inode ref object.
	 */
	while (cur_offset < item_size) {
		extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
		name_ptr = (unsigned long)(&extref->name);
		ref_name_len = btrfs_inode_extref_name_len(leaf, extref);

		if (ref_name_len == name_len &&
		    btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
		    (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
			if (extref_ret)
				*extref_ret = extref;
			return 1;
		}

		cur_offset += ref_name_len + sizeof(*extref);
	}
	return 0;
}

/* Returns NULL if no extref found */
struct btrfs_inode_extref *
btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
			  struct btrfs_root *root,
			  struct btrfs_path *path,
			  const char *name, int name_len,
			  u64 inode_objectid, u64 ref_objectid, int ins_len,
			  int cow)
{
	int ret;
	struct btrfs_key key;
	struct btrfs_inode_extref *extref;

	key.objectid = inode_objectid;
	key.type = BTRFS_INODE_EXTREF_KEY;
	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);

	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
	if (ret < 0)
		return ERR_PTR(ret);
	if (ret > 0)
		return NULL;
	if (!btrfs_find_name_in_ext_backref(path, ref_objectid, name, name_len, &extref))
		return NULL;
	return extref;
}

static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
				  struct btrfs_root *root,
				  const char *name, int name_len,
				  u64 inode_objectid, u64 ref_objectid,
				  u64 *index)
{
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_inode_extref *extref;
	struct extent_buffer *leaf;
	int ret;
	int del_len = name_len + sizeof(*extref);
	unsigned long ptr;
	unsigned long item_start;
	u32 item_size;

	key.objectid = inode_objectid;
	key.type = BTRFS_INODE_EXTREF_KEY;
	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);

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

	path->leave_spinning = 1;

	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	if (ret > 0)
		ret = -ENOENT;
	if (ret < 0)
		goto out;

	/*
	 * Sanity check - did we find the right item for this name?
	 * This should always succeed so error here will make the FS
	 * readonly.
	 */
	if (!btrfs_find_name_in_ext_backref(path, ref_objectid,
					    name, name_len, &extref)) {
		btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
		ret = -EROFS;
		goto out;
	}

	leaf = path->nodes[0];
	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	if (index)
		*index = btrfs_inode_extref_index(leaf, extref);

	if (del_len == item_size) {
		/*
		 * Common case only one ref in the item, remove the
		 * whole item.
		 */
		ret = btrfs_del_item(trans, root, path);
		goto out;
	}

	ptr = (unsigned long)extref;
	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);

	memmove_extent_buffer(leaf, ptr, ptr + del_len,
			      item_size - (ptr + del_len - item_start));

	btrfs_truncate_item(root->fs_info, path, item_size - del_len, 1);

out:
	btrfs_free_path(path);

	return ret;
}

int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
			struct btrfs_root *root,
			const char *name, int name_len,
			u64 inode_objectid, u64 ref_objectid, u64 *index)
{
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_inode_ref *ref;
	struct extent_buffer *leaf;
	unsigned long ptr;
	unsigned long item_start;
	u32 item_size;
	u32 sub_item_len;
	int ret;
	int search_ext_refs = 0;
	int del_len = name_len + sizeof(*ref);

	key.objectid = inode_objectid;
	key.offset = ref_objectid;
	key.type = BTRFS_INODE_REF_KEY;

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

	path->leave_spinning = 1;

	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	if (ret > 0) {
		ret = -ENOENT;
		search_ext_refs = 1;
		goto out;
	} else if (ret < 0) {
		goto out;
	}
	if (!find_name_in_backref(path, name, name_len, &ref)) {
		ret = -ENOENT;
		search_ext_refs = 1;
		goto out;
	}
	leaf = path->nodes[0];
	item_size = btrfs_item_size_nr(leaf, path->slots[0]);

	if (index)
		*index = btrfs_inode_ref_index(leaf, ref);

	if (del_len == item_size) {
		ret = btrfs_del_item(trans, root, path);
		goto out;
	}
	ptr = (unsigned long)ref;
	sub_item_len = name_len + sizeof(*ref);
	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
			      item_size - (ptr + sub_item_len - item_start));
	btrfs_truncate_item(root->fs_info, path, item_size - sub_item_len, 1);
out:
	btrfs_free_path(path);

	if (search_ext_refs) {
		/*
		 * No refs were found, or we could not find the
		 * name in our ref array. Find and remove the extended
		 * inode ref then.
		 */
		return btrfs_del_inode_extref(trans, root, name, name_len,
					      inode_objectid, ref_objectid, index);
	}

	return ret;
}

/*
 * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
 *
 * The caller must have checked against BTRFS_LINK_MAX already.
 */
static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
				     struct btrfs_root *root,
				     const char *name, int name_len,
				     u64 inode_objectid, u64 ref_objectid, u64 index)
{
	struct btrfs_inode_extref *extref;
	int ret;
	int ins_len = name_len + sizeof(*extref);
	unsigned long ptr;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct extent_buffer *leaf;
	struct btrfs_item *item;

	key.objectid = inode_objectid;
	key.type = BTRFS_INODE_EXTREF_KEY;
	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);

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

	path->leave_spinning = 1;
	ret = btrfs_insert_empty_item(trans, root, path, &key,
				      ins_len);
	if (ret == -EEXIST) {
		if (btrfs_find_name_in_ext_backref(path, ref_objectid,
						   name, name_len, NULL))
			goto out;

		btrfs_extend_item(root->fs_info, path, ins_len);
		ret = 0;
	}
	if (ret < 0)
		goto out;

	leaf = path->nodes[0];
	item = btrfs_item_nr(path->slots[0]);
	ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
	ptr += btrfs_item_size(leaf, item) - ins_len;
	extref = (struct btrfs_inode_extref *)ptr;

	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
	btrfs_set_inode_extref_index(path->nodes[0], extref, index);
	btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);

	ptr = (unsigned long)&extref->name;
	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	btrfs_mark_buffer_dirty(path->nodes[0]);

out:
	btrfs_free_path(path);
	return ret;
}

/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root,
			   const char *name, int name_len,
			   u64 inode_objectid, u64 ref_objectid, u64 index)
{
	struct btrfs_fs_info *fs_info = root->fs_info;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_inode_ref *ref;
	unsigned long ptr;
	int ret;
	int ins_len = name_len + sizeof(*ref);

	key.objectid = inode_objectid;
	key.offset = ref_objectid;
	key.type = BTRFS_INODE_REF_KEY;

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

	path->leave_spinning = 1;
	path->skip_release_on_error = 1;
	ret = btrfs_insert_empty_item(trans, root, path, &key,
				      ins_len);
	if (ret == -EEXIST) {
		u32 old_size;

		if (find_name_in_backref(path, name, name_len, &ref))
			goto out;

		old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
		btrfs_extend_item(fs_info, path, ins_len);
		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
				     struct btrfs_inode_ref);
		ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
		btrfs_set_inode_ref_index(path->nodes[0], ref, index);
		ptr = (unsigned long)(ref + 1);
		ret = 0;
	} else if (ret < 0) {
		if (ret == -EOVERFLOW) {
			if (find_name_in_backref(path, name, name_len, &ref))
				ret = -EEXIST;
			else
				ret = -EMLINK;
		}
		goto out;
	} else {
		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
				     struct btrfs_inode_ref);
		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
		btrfs_set_inode_ref_index(path->nodes[0], ref, index);
		ptr = (unsigned long)(ref + 1);
	}
	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	btrfs_mark_buffer_dirty(path->nodes[0]);

out:
	btrfs_free_path(path);

	if (ret == -EMLINK) {
		struct btrfs_super_block *disk_super = fs_info->super_copy;
		/* We ran out of space in the ref array. Need to
		 * add an extended ref. */
		if (btrfs_super_incompat_flags(disk_super)
		    & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
			ret = btrfs_insert_inode_extref(trans, root, name,
							name_len,
							inode_objectid,
							ref_objectid, index);
	}

	return ret;
}

int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
			     struct btrfs_root *root,
			     struct btrfs_path *path, u64 objectid)
{
	struct btrfs_key key;
	int ret;
	key.objectid = objectid;
	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;

	ret = btrfs_insert_empty_item(trans, root, path, &key,
				      sizeof(struct btrfs_inode_item));
	return ret;
}

int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
		       *root, struct btrfs_path *path,
		       struct btrfs_key *location, int mod)
{
	int ins_len = mod < 0 ? -1 : 0;
	int cow = mod != 0;
	int ret;
	int slot;
	struct extent_buffer *leaf;
	struct btrfs_key found_key;

	ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
	if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
	    location->offset == (u64)-1 && path->slots[0] != 0) {
		slot = path->slots[0] - 1;
		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &found_key, slot);
		if (found_key.objectid == location->objectid &&
		    found_key.type == location->type) {
			path->slots[0]--;
			return 0;
		}
	}
	return ret;
}
Commit	Line	Data
6cbd5570 CM	1	/*
	2	* Copyright (C) 2007 Oracle. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public
	6	* License v2 as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public
	14	* License along with this program; if not, write to the
	15	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	16	* Boston, MA 021110-1307, USA.
	17	*/
	18
1e1d2701 CM	19	#include "ctree.h"
1e1d2701 CM	20	#include "disk-io.h"
f186373f	21	#include "hash.h"
e089f05c	22	#include "transaction.h"
727011e0	23	#include "print-tree.h"
1e1d2701	24
b2950863	25	static int find_name_in_backref(struct btrfs_path path, const char name,
3954401f CM	26	int name_len, struct btrfs_inode_ref **ref_ret)
	27	{
	28	struct extent_buffer *leaf;
	29	struct btrfs_inode_ref *ref;
	30	unsigned long ptr;
	31	unsigned long name_ptr;
	32	u32 item_size;
	33	u32 cur_offset = 0;
	34	int len;
	35
	36	leaf = path->nodes[0];
	37	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	38	ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
	39	while (cur_offset < item_size) {
	40	ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
	41	len = btrfs_inode_ref_name_len(leaf, ref);
	42	name_ptr = (unsigned long)(ref + 1);
	43	cur_offset += len + sizeof(*ref);
	44	if (len != name_len)
	45	continue;
	46	if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
	47	*ref_ret = ref;
	48	return 1;
	49	}
	50	}
	51	return 0;
	52	}
	53
f186373f MF	54	int btrfs_find_name_in_ext_backref(struct btrfs_path *path, u64 ref_objectid,
	55	const char *name, int name_len,
	56	struct btrfs_inode_extref **extref_ret)
	57	{
	58	struct extent_buffer *leaf;
	59	struct btrfs_inode_extref *extref;
	60	unsigned long ptr;
	61	unsigned long name_ptr;
	62	u32 item_size;
	63	u32 cur_offset = 0;
	64	int ref_name_len;
	65
	66	leaf = path->nodes[0];
	67	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	68	ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
	69
	70	/*
	71	* Search all extended backrefs in this item. We're only
	72	* looking through any collisions so most of the time this is
	73	* just going to compare against one buffer. If all is well,
	74	* we'll return success and the inode ref object.
	75	*/
	76	while (cur_offset < item_size) {
	77	extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
	78	name_ptr = (unsigned long)(&extref->name);
	79	ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
	80
	81	if (ref_name_len == name_len &&
	82	btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
	83	(memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
	84	if (extref_ret)
	85	*extref_ret = extref;
	86	return 1;
	87	}
	88
	89	cur_offset += ref_name_len + sizeof(*extref);
	90	}
	91	return 0;
	92	}
	93
f186373f MF	94	/* Returns NULL if no extref found */
	95	struct btrfs_inode_extref *
	96	btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
	97	struct btrfs_root *root,
	98	struct btrfs_path *path,
	99	const char *name, int name_len,
	100	u64 inode_objectid, u64 ref_objectid, int ins_len,
	101	int cow)
	102	{
	103	int ret;
	104	struct btrfs_key key;
	105	struct btrfs_inode_extref *extref;
	106
	107	key.objectid = inode_objectid;
	108	key.type = BTRFS_INODE_EXTREF_KEY;
	109	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	110
	111	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
	112	if (ret < 0)
	113	return ERR_PTR(ret);
	114	if (ret > 0)
	115	return NULL;
	116	if (!btrfs_find_name_in_ext_backref(path, ref_objectid, name, name_len, &extref))
	117	return NULL;
	118	return extref;
	119	}
	120
48a3b636 ES	121	static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
	122	struct btrfs_root *root,
	123	const char *name, int name_len,
	124	u64 inode_objectid, u64 ref_objectid,
	125	u64 *index)
f186373f MF	126	{
	127	struct btrfs_path *path;
	128	struct btrfs_key key;
	129	struct btrfs_inode_extref *extref;
	130	struct extent_buffer *leaf;
	131	int ret;
	132	int del_len = name_len + sizeof(*extref);
	133	unsigned long ptr;
	134	unsigned long item_start;
	135	u32 item_size;
	136
	137	key.objectid = inode_objectid;
962a298f	138	key.type = BTRFS_INODE_EXTREF_KEY;
f186373f MF	139	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	140
	141	path = btrfs_alloc_path();
	142	if (!path)
	143	return -ENOMEM;
	144
	145	path->leave_spinning = 1;
	146
	147	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	148	if (ret > 0)
	149	ret = -ENOENT;
	150	if (ret < 0)
	151	goto out;
	152
	153	/*
	154	* Sanity check - did we find the right item for this name?
	155	* This should always succeed so error here will make the FS
	156	* readonly.
	157	*/
	158	if (!btrfs_find_name_in_ext_backref(path, ref_objectid,
	159	name, name_len, &extref)) {
34d97007	160	btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
f186373f MF	161	ret = -EROFS;
	162	goto out;
	163	}
	164
	165	leaf = path->nodes[0];
	166	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	167	if (index)
	168	*index = btrfs_inode_extref_index(leaf, extref);
	169
	170	if (del_len == item_size) {
	171	/*
	172	* Common case only one ref in the item, remove the
	173	* whole item.
	174	*/
	175	ret = btrfs_del_item(trans, root, path);
	176	goto out;
	177	}
	178
	179	ptr = (unsigned long)extref;
	180	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	181
	182	memmove_extent_buffer(leaf, ptr, ptr + del_len,
	183	item_size - (ptr + del_len - item_start));
	184
2ff7e61e	185	btrfs_truncate_item(root->fs_info, path, item_size - del_len, 1);
f186373f MF	186
	187	out:
	188	btrfs_free_path(path);
	189
	190	return ret;
	191	}
	192
	193	int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
	194	struct btrfs_root *root,
	195	const char *name, int name_len,
	196	u64 inode_objectid, u64 ref_objectid, u64 *index)
3954401f CM	197	{
	198	struct btrfs_path *path;
	199	struct btrfs_key key;
	200	struct btrfs_inode_ref *ref;
	201	struct extent_buffer *leaf;
	202	unsigned long ptr;
	203	unsigned long item_start;
	204	u32 item_size;
	205	u32 sub_item_len;
	206	int ret;
f186373f	207	int search_ext_refs = 0;
3954401f CM	208	int del_len = name_len + sizeof(*ref);
	209
	210	key.objectid = inode_objectid;
	211	key.offset = ref_objectid;
962a298f	212	key.type = BTRFS_INODE_REF_KEY;
3954401f CM	213
	214	path = btrfs_alloc_path();
	215	if (!path)
	216	return -ENOMEM;
	217
b9473439 CM	218	path->leave_spinning = 1;
b9473439 CM	219
3954401f CM	220	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	221	if (ret > 0) {
	222	ret = -ENOENT;
f186373f	223	search_ext_refs = 1;
3954401f CM	224	goto out;
	225	} else if (ret < 0) {
	226	goto out;
	227	}
	228	if (!find_name_in_backref(path, name, name_len, &ref)) {
	229	ret = -ENOENT;
f186373f	230	search_ext_refs = 1;
3954401f CM	231	goto out;
	232	}
	233	leaf = path->nodes[0];
	234	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
aec7477b JB	235
	236	if (index)
	237	*index = btrfs_inode_ref_index(leaf, ref);
	238
3954401f CM	239	if (del_len == item_size) {
	240	ret = btrfs_del_item(trans, root, path);
	241	goto out;
	242	}
	243	ptr = (unsigned long)ref;
	244	sub_item_len = name_len + sizeof(*ref);
	245	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	246	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
	247	item_size - (ptr + sub_item_len - item_start));
2ff7e61e	248	btrfs_truncate_item(root->fs_info, path, item_size - sub_item_len, 1);
f186373f MF	249	out:
	250	btrfs_free_path(path);
	251
	252	if (search_ext_refs) {
	253	/*
	254	* No refs were found, or we could not find the
	255	* name in our ref array. Find and remove the extended
	256	* inode ref then.
	257	*/
	258	return btrfs_del_inode_extref(trans, root, name, name_len,
	259	inode_objectid, ref_objectid, index);
	260	}
	261
	262	return ret;
	263	}
	264
	265	/*
	266	* btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
	267	*
	268	* The caller must have checked against BTRFS_LINK_MAX already.
	269	*/
	270	static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
	271	struct btrfs_root *root,
	272	const char *name, int name_len,
	273	u64 inode_objectid, u64 ref_objectid, u64 index)
	274	{
	275	struct btrfs_inode_extref *extref;
	276	int ret;
	277	int ins_len = name_len + sizeof(*extref);
	278	unsigned long ptr;
	279	struct btrfs_path *path;
	280	struct btrfs_key key;
	281	struct extent_buffer *leaf;
	282	struct btrfs_item *item;
	283
	284	key.objectid = inode_objectid;
	285	key.type = BTRFS_INODE_EXTREF_KEY;
	286	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	287
	288	path = btrfs_alloc_path();
	289	if (!path)
	290	return -ENOMEM;
	291
	292	path->leave_spinning = 1;
	293	ret = btrfs_insert_empty_item(trans, root, path, &key,
	294	ins_len);
	295	if (ret == -EEXIST) {
	296	if (btrfs_find_name_in_ext_backref(path, ref_objectid,
	297	name, name_len, NULL))
	298	goto out;
	299
2ff7e61e	300	btrfs_extend_item(root->fs_info, path, ins_len);
f186373f MF	301	ret = 0;
	302	}
	303	if (ret < 0)
	304	goto out;
	305
	306	leaf = path->nodes[0];
dd3cc16b	307	item = btrfs_item_nr(path->slots[0]);
f186373f MF	308	ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
	309	ptr += btrfs_item_size(leaf, item) - ins_len;
	310	extref = (struct btrfs_inode_extref *)ptr;
	311
	312	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
	313	btrfs_set_inode_extref_index(path->nodes[0], extref, index);
	314	btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
	315
	316	ptr = (unsigned long)&extref->name;
	317	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	318	btrfs_mark_buffer_dirty(path->nodes[0]);
	319
3954401f CM	320	out:
	321	btrfs_free_path(path);
	322	return ret;
	323	}
	324
79787eaa	325	/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
3954401f CM	326	int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
	327	struct btrfs_root *root,
	328	const char *name, int name_len,
aec7477b	329	u64 inode_objectid, u64 ref_objectid, u64 index)
3954401f	330	{
0b246afa	331	struct btrfs_fs_info *fs_info = root->fs_info;
3954401f CM	332	struct btrfs_path *path;
	333	struct btrfs_key key;
	334	struct btrfs_inode_ref *ref;
	335	unsigned long ptr;
	336	int ret;
	337	int ins_len = name_len + sizeof(*ref);
	338
	339	key.objectid = inode_objectid;
	340	key.offset = ref_objectid;
962a298f	341	key.type = BTRFS_INODE_REF_KEY;
3954401f CM	342
	343	path = btrfs_alloc_path();
	344	if (!path)
	345	return -ENOMEM;
	346
b9473439	347	path->leave_spinning = 1;
df8d116f	348	path->skip_release_on_error = 1;
3954401f CM	349	ret = btrfs_insert_empty_item(trans, root, path, &key,
	350	ins_len);
	351	if (ret == -EEXIST) {
	352	u32 old_size;
	353
	354	if (find_name_in_backref(path, name, name_len, &ref))
	355	goto out;
	356
	357	old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
2ff7e61e	358	btrfs_extend_item(fs_info, path, ins_len);
3954401f CM	359	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	360	struct btrfs_inode_ref);
	361	ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
	362	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	363	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	364	ptr = (unsigned long)(ref + 1);
	365	ret = 0;
	366	} else if (ret < 0) {
df8d116f FM	367	if (ret == -EOVERFLOW) {
	368	if (find_name_in_backref(path, name, name_len, &ref))
	369	ret = -EEXIST;
	370	else
	371	ret = -EMLINK;
	372	}
3954401f CM	373	goto out;
	374	} else {
	375	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	376	struct btrfs_inode_ref);
	377	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	378	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	379	ptr = (unsigned long)(ref + 1);
	380	}
	381	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	382	btrfs_mark_buffer_dirty(path->nodes[0]);
	383
	384	out:
	385	btrfs_free_path(path);
f186373f MF	386
f186373f MF	387	if (ret == -EMLINK) {
0b246afa	388	struct btrfs_super_block *disk_super = fs_info->super_copy;
f186373f MF	389	/* We ran out of space in the ref array. Need to
	390	* add an extended ref. */
	391	if (btrfs_super_incompat_flags(disk_super)
	392	& BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
	393	ret = btrfs_insert_inode_extref(trans, root, name,
	394	name_len,
	395	inode_objectid,
	396	ref_objectid, index);
	397	}
	398
3954401f CM	399	return ret;
	400	}
	401
5f39d397 CM	402	int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
	403	struct btrfs_root *root,
	404	struct btrfs_path *path, u64 objectid)
1e1d2701	405	{
1e1d2701 CM	406	struct btrfs_key key;
	407	int ret;
	408	key.objectid = objectid;
962a298f	409	key.type = BTRFS_INODE_ITEM_KEY;
1e1d2701 CM	410	key.offset = 0;
1e1d2701 CM	411
5f39d397 CM	412	ret = btrfs_insert_empty_item(trans, root, path, &key,
5f39d397 CM	413	sizeof(struct btrfs_inode_item));
1e1d2701 CM	414	return ret;
	415	}
	416
e089f05c	417	int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
d6e4a428 CM	418	root, struct btrfs_path path,
d6e4a428 CM	419	struct btrfs_key *location, int mod)
1e1d2701	420	{
1e1d2701 CM	421	int ins_len = mod < 0 ? -1 : 0;
1e1d2701 CM	422	int cow = mod != 0;
d6e4a428 CM	423	int ret;
d6e4a428 CM	424	int slot;
5f39d397	425	struct extent_buffer *leaf;
d6e4a428	426	struct btrfs_key found_key;
1e1d2701	427
d6e4a428	428	ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
962a298f	429	if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
d6e4a428 CM	430	location->offset == (u64)-1 && path->slots[0] != 0) {
d6e4a428 CM	431	slot = path->slots[0] - 1;
5f39d397 CM	432	leaf = path->nodes[0];
5f39d397 CM	433	btrfs_item_key_to_cpu(leaf, &found_key, slot);
d6e4a428	434	if (found_key.objectid == location->objectid &&
962a298f	435	found_key.type == location->type) {
d6e4a428 CM	436	path->slots[0]--;
	437	return 0;
	438	}
	439	}
	440	return ret;
1e1d2701	441	}