[linux-block.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"

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

	item_size = btrfs_item_size_nr(leaf, slot);
	ptr = btrfs_item_ptr_offset(leaf, slot);
	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) {
			if (ref_ret)
				*ref_ret = ref;
			return 1;
		}
	}
	return 0;
}

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

	item_size = btrfs_item_size_nr(leaf, slot);
	ptr = btrfs_item_ptr_offset(leaf, slot);

	/*
	 * 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->nodes[0], path->slots[0],
					    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->nodes[0], path->slots[0],
					    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 (!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
					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->nodes[0],
						   path->slots[0],
						   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 (btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
					       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 (btrfs_find_name_in_backref(path->nodes[0],
						       path->slots[0],
						       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
1f250e92 FM	25	int btrfs_find_name_in_backref(struct extent_buffer *leaf, int slot,
	26	const char *name,
	27	int name_len, struct btrfs_inode_ref **ref_ret)
3954401f	28	{
3954401f CM	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
1f250e92 FM	36	item_size = btrfs_item_size_nr(leaf, slot);
1f250e92 FM	37	ptr = btrfs_item_ptr_offset(leaf, slot);
3954401f CM	38	while (cur_offset < item_size) {
	39	ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
	40	len = btrfs_inode_ref_name_len(leaf, ref);
	41	name_ptr = (unsigned long)(ref + 1);
	42	cur_offset += len + sizeof(*ref);
	43	if (len != name_len)
	44	continue;
	45	if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
1f250e92 FM	46	if (ref_ret)
1f250e92 FM	47	*ref_ret = ref;
3954401f CM	48	return 1;
	49	}
	50	}
	51	return 0;
	52	}
	53
1f250e92 FM	54	int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
1f250e92 FM	55	u64 ref_objectid,
f186373f MF	56	const char *name, int name_len,
	57	struct btrfs_inode_extref **extref_ret)
	58	{
f186373f MF	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
1f250e92 FM	66	item_size = btrfs_item_size_nr(leaf, slot);
1f250e92 FM	67	ptr = btrfs_item_ptr_offset(leaf, slot);
f186373f MF	68
	69	/*
	70	* Search all extended backrefs in this item. We're only
	71	* looking through any collisions so most of the time this is
	72	* just going to compare against one buffer. If all is well,
	73	* we'll return success and the inode ref object.
	74	*/
	75	while (cur_offset < item_size) {
	76	extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
	77	name_ptr = (unsigned long)(&extref->name);
	78	ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
	79
	80	if (ref_name_len == name_len &&
	81	btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
	82	(memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
	83	if (extref_ret)
	84	*extref_ret = extref;
	85	return 1;
	86	}
	87
	88	cur_offset += ref_name_len + sizeof(*extref);
	89	}
	90	return 0;
	91	}
	92
f186373f MF	93	/* Returns NULL if no extref found */
	94	struct btrfs_inode_extref *
	95	btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
	96	struct btrfs_root *root,
	97	struct btrfs_path *path,
	98	const char *name, int name_len,
	99	u64 inode_objectid, u64 ref_objectid, int ins_len,
	100	int cow)
	101	{
	102	int ret;
	103	struct btrfs_key key;
	104	struct btrfs_inode_extref *extref;
	105
	106	key.objectid = inode_objectid;
	107	key.type = BTRFS_INODE_EXTREF_KEY;
	108	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	109
	110	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
	111	if (ret < 0)
	112	return ERR_PTR(ret);
	113	if (ret > 0)
	114	return NULL;
1f250e92 FM	115	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
	116	ref_objectid, name, name_len,
	117	&extref))
f186373f MF	118	return NULL;
	119	return extref;
	120	}
	121
48a3b636 ES	122	static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
	123	struct btrfs_root *root,
	124	const char *name, int name_len,
	125	u64 inode_objectid, u64 ref_objectid,
	126	u64 *index)
f186373f MF	127	{
	128	struct btrfs_path *path;
	129	struct btrfs_key key;
	130	struct btrfs_inode_extref *extref;
	131	struct extent_buffer *leaf;
	132	int ret;
	133	int del_len = name_len + sizeof(*extref);
	134	unsigned long ptr;
	135	unsigned long item_start;
	136	u32 item_size;
	137
	138	key.objectid = inode_objectid;
962a298f	139	key.type = BTRFS_INODE_EXTREF_KEY;
f186373f MF	140	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	141
	142	path = btrfs_alloc_path();
	143	if (!path)
	144	return -ENOMEM;
	145
	146	path->leave_spinning = 1;
	147
	148	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	149	if (ret > 0)
	150	ret = -ENOENT;
	151	if (ret < 0)
	152	goto out;
	153
	154	/*
	155	* Sanity check - did we find the right item for this name?
	156	* This should always succeed so error here will make the FS
	157	* readonly.
	158	*/
1f250e92 FM	159	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
1f250e92 FM	160	ref_objectid,
f186373f	161	name, name_len, &extref)) {
34d97007	162	btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
f186373f MF	163	ret = -EROFS;
	164	goto out;
	165	}
	166
	167	leaf = path->nodes[0];
	168	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	169	if (index)
	170	*index = btrfs_inode_extref_index(leaf, extref);
	171
	172	if (del_len == item_size) {
	173	/*
	174	* Common case only one ref in the item, remove the
	175	* whole item.
	176	*/
	177	ret = btrfs_del_item(trans, root, path);
	178	goto out;
	179	}
	180
	181	ptr = (unsigned long)extref;
	182	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	183
	184	memmove_extent_buffer(leaf, ptr, ptr + del_len,
	185	item_size - (ptr + del_len - item_start));
	186
2ff7e61e	187	btrfs_truncate_item(root->fs_info, path, item_size - del_len, 1);
f186373f MF	188
	189	out:
	190	btrfs_free_path(path);
	191
	192	return ret;
	193	}
	194
	195	int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
	196	struct btrfs_root *root,
	197	const char *name, int name_len,
	198	u64 inode_objectid, u64 ref_objectid, u64 *index)
3954401f CM	199	{
	200	struct btrfs_path *path;
	201	struct btrfs_key key;
	202	struct btrfs_inode_ref *ref;
	203	struct extent_buffer *leaf;
	204	unsigned long ptr;
	205	unsigned long item_start;
	206	u32 item_size;
	207	u32 sub_item_len;
	208	int ret;
f186373f	209	int search_ext_refs = 0;
3954401f CM	210	int del_len = name_len + sizeof(*ref);
	211
	212	key.objectid = inode_objectid;
	213	key.offset = ref_objectid;
962a298f	214	key.type = BTRFS_INODE_REF_KEY;
3954401f CM	215
	216	path = btrfs_alloc_path();
	217	if (!path)
	218	return -ENOMEM;
	219
b9473439 CM	220	path->leave_spinning = 1;
b9473439 CM	221
3954401f CM	222	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	223	if (ret > 0) {
	224	ret = -ENOENT;
f186373f	225	search_ext_refs = 1;
3954401f CM	226	goto out;
	227	} else if (ret < 0) {
	228	goto out;
	229	}
1f250e92 FM	230	if (!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
1f250e92 FM	231	name, name_len, &ref)) {
3954401f	232	ret = -ENOENT;
f186373f	233	search_ext_refs = 1;
3954401f CM	234	goto out;
	235	}
	236	leaf = path->nodes[0];
	237	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
aec7477b JB	238
	239	if (index)
	240	*index = btrfs_inode_ref_index(leaf, ref);
	241
3954401f CM	242	if (del_len == item_size) {
	243	ret = btrfs_del_item(trans, root, path);
	244	goto out;
	245	}
	246	ptr = (unsigned long)ref;
	247	sub_item_len = name_len + sizeof(*ref);
	248	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	249	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
	250	item_size - (ptr + sub_item_len - item_start));
2ff7e61e	251	btrfs_truncate_item(root->fs_info, path, item_size - sub_item_len, 1);
f186373f MF	252	out:
	253	btrfs_free_path(path);
	254
	255	if (search_ext_refs) {
	256	/*
	257	* No refs were found, or we could not find the
	258	* name in our ref array. Find and remove the extended
	259	* inode ref then.
	260	*/
	261	return btrfs_del_inode_extref(trans, root, name, name_len,
	262	inode_objectid, ref_objectid, index);
	263	}
	264
	265	return ret;
	266	}
	267
	268	/*
	269	* btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
	270	*
	271	* The caller must have checked against BTRFS_LINK_MAX already.
	272	*/
	273	static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
	274	struct btrfs_root *root,
	275	const char *name, int name_len,
	276	u64 inode_objectid, u64 ref_objectid, u64 index)
	277	{
	278	struct btrfs_inode_extref *extref;
	279	int ret;
	280	int ins_len = name_len + sizeof(*extref);
	281	unsigned long ptr;
	282	struct btrfs_path *path;
	283	struct btrfs_key key;
	284	struct extent_buffer *leaf;
	285	struct btrfs_item *item;
	286
	287	key.objectid = inode_objectid;
	288	key.type = BTRFS_INODE_EXTREF_KEY;
	289	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	290
	291	path = btrfs_alloc_path();
	292	if (!path)
	293	return -ENOMEM;
	294
	295	path->leave_spinning = 1;
	296	ret = btrfs_insert_empty_item(trans, root, path, &key,
	297	ins_len);
	298	if (ret == -EEXIST) {
1f250e92 FM	299	if (btrfs_find_name_in_ext_backref(path->nodes[0],
	300	path->slots[0],
	301	ref_objectid,
f186373f MF	302	name, name_len, NULL))
	303	goto out;
	304
2ff7e61e	305	btrfs_extend_item(root->fs_info, path, ins_len);
f186373f MF	306	ret = 0;
	307	}
	308	if (ret < 0)
	309	goto out;
	310
	311	leaf = path->nodes[0];
dd3cc16b	312	item = btrfs_item_nr(path->slots[0]);
f186373f MF	313	ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
	314	ptr += btrfs_item_size(leaf, item) - ins_len;
	315	extref = (struct btrfs_inode_extref *)ptr;
	316
	317	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
	318	btrfs_set_inode_extref_index(path->nodes[0], extref, index);
	319	btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
	320
	321	ptr = (unsigned long)&extref->name;
	322	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	323	btrfs_mark_buffer_dirty(path->nodes[0]);
	324
3954401f CM	325	out:
	326	btrfs_free_path(path);
	327	return ret;
	328	}
	329
79787eaa	330	/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
3954401f CM	331	int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
	332	struct btrfs_root *root,
	333	const char *name, int name_len,
aec7477b	334	u64 inode_objectid, u64 ref_objectid, u64 index)
3954401f	335	{
0b246afa	336	struct btrfs_fs_info *fs_info = root->fs_info;
3954401f CM	337	struct btrfs_path *path;
	338	struct btrfs_key key;
	339	struct btrfs_inode_ref *ref;
	340	unsigned long ptr;
	341	int ret;
	342	int ins_len = name_len + sizeof(*ref);
	343
	344	key.objectid = inode_objectid;
	345	key.offset = ref_objectid;
962a298f	346	key.type = BTRFS_INODE_REF_KEY;
3954401f CM	347
	348	path = btrfs_alloc_path();
	349	if (!path)
	350	return -ENOMEM;
	351
b9473439	352	path->leave_spinning = 1;
df8d116f	353	path->skip_release_on_error = 1;
3954401f CM	354	ret = btrfs_insert_empty_item(trans, root, path, &key,
	355	ins_len);
	356	if (ret == -EEXIST) {
	357	u32 old_size;
	358
1f250e92 FM	359	if (btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
1f250e92 FM	360	name, name_len, &ref))
3954401f CM	361	goto out;
	362
	363	old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
2ff7e61e	364	btrfs_extend_item(fs_info, path, ins_len);
3954401f CM	365	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	366	struct btrfs_inode_ref);
	367	ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
	368	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	369	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	370	ptr = (unsigned long)(ref + 1);
	371	ret = 0;
	372	} else if (ret < 0) {
df8d116f	373	if (ret == -EOVERFLOW) {
1f250e92 FM	374	if (btrfs_find_name_in_backref(path->nodes[0],
	375	path->slots[0],
	376	name, name_len, &ref))
df8d116f FM	377	ret = -EEXIST;
	378	else
	379	ret = -EMLINK;
	380	}
3954401f CM	381	goto out;
	382	} else {
	383	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	384	struct btrfs_inode_ref);
	385	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	386	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	387	ptr = (unsigned long)(ref + 1);
	388	}
	389	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	390	btrfs_mark_buffer_dirty(path->nodes[0]);
	391
	392	out:
	393	btrfs_free_path(path);
f186373f MF	394
f186373f MF	395	if (ret == -EMLINK) {
0b246afa	396	struct btrfs_super_block *disk_super = fs_info->super_copy;
f186373f MF	397	/* We ran out of space in the ref array. Need to
	398	* add an extended ref. */
	399	if (btrfs_super_incompat_flags(disk_super)
	400	& BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
	401	ret = btrfs_insert_inode_extref(trans, root, name,
	402	name_len,
	403	inode_objectid,
	404	ref_objectid, index);
	405	}
	406
3954401f CM	407	return ret;
	408	}
	409
5f39d397 CM	410	int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
	411	struct btrfs_root *root,
	412	struct btrfs_path *path, u64 objectid)
1e1d2701	413	{
1e1d2701 CM	414	struct btrfs_key key;
	415	int ret;
	416	key.objectid = objectid;
962a298f	417	key.type = BTRFS_INODE_ITEM_KEY;
1e1d2701 CM	418	key.offset = 0;
1e1d2701 CM	419
5f39d397 CM	420	ret = btrfs_insert_empty_item(trans, root, path, &key,
5f39d397 CM	421	sizeof(struct btrfs_inode_item));
1e1d2701 CM	422	return ret;
	423	}
	424
e089f05c	425	int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
d6e4a428 CM	426	root, struct btrfs_path path,
d6e4a428 CM	427	struct btrfs_key *location, int mod)
1e1d2701	428	{
1e1d2701 CM	429	int ins_len = mod < 0 ? -1 : 0;
1e1d2701 CM	430	int cow = mod != 0;
d6e4a428 CM	431	int ret;
d6e4a428 CM	432	int slot;
5f39d397	433	struct extent_buffer *leaf;
d6e4a428	434	struct btrfs_key found_key;
1e1d2701	435
d6e4a428	436	ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
962a298f	437	if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
d6e4a428 CM	438	location->offset == (u64)-1 && path->slots[0] != 0) {
d6e4a428 CM	439	slot = path->slots[0] - 1;
5f39d397 CM	440	leaf = path->nodes[0];
5f39d397 CM	441	btrfs_item_key_to_cpu(leaf, &found_key, slot);
d6e4a428	442	if (found_key.objectid == location->objectid &&
962a298f	443	found_key.type == location->type) {
d6e4a428 CM	444	path->slots[0]--;
	445	return 0;
	446	}
	447	}
	448	return ret;
1e1d2701	449	}