[linux-2.6-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 "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"
e089f05c	21	#include "transaction.h"
727011e0	22	#include "print-tree.h"
1e1d2701	23
1f250e92 FM	24	int btrfs_find_name_in_backref(struct extent_buffer *leaf, int slot,
	25	const char *name,
	26	int name_len, struct btrfs_inode_ref **ref_ret)
3954401f	27	{
3954401f CM	28	struct btrfs_inode_ref *ref;
	29	unsigned long ptr;
	30	unsigned long name_ptr;
	31	u32 item_size;
	32	u32 cur_offset = 0;
	33	int len;
	34
1f250e92 FM	35	item_size = btrfs_item_size_nr(leaf, slot);
1f250e92 FM	36	ptr = btrfs_item_ptr_offset(leaf, slot);
3954401f CM	37	while (cur_offset < item_size) {
	38	ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
	39	len = btrfs_inode_ref_name_len(leaf, ref);
	40	name_ptr = (unsigned long)(ref + 1);
	41	cur_offset += len + sizeof(*ref);
	42	if (len != name_len)
	43	continue;
	44	if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
1f250e92 FM	45	if (ref_ret)
1f250e92 FM	46	*ref_ret = ref;
3954401f CM	47	return 1;
	48	}
	49	}
	50	return 0;
	51	}
	52
1f250e92 FM	53	int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
1f250e92 FM	54	u64 ref_objectid,
f186373f MF	55	const char *name, int name_len,
	56	struct btrfs_inode_extref **extref_ret)
	57	{
f186373f MF	58	struct btrfs_inode_extref *extref;
	59	unsigned long ptr;
	60	unsigned long name_ptr;
	61	u32 item_size;
	62	u32 cur_offset = 0;
	63	int ref_name_len;
	64
1f250e92 FM	65	item_size = btrfs_item_size_nr(leaf, slot);
1f250e92 FM	66	ptr = btrfs_item_ptr_offset(leaf, slot);
f186373f MF	67
	68	/*
	69	* Search all extended backrefs in this item. We're only
	70	* looking through any collisions so most of the time this is
	71	* just going to compare against one buffer. If all is well,
	72	* we'll return success and the inode ref object.
	73	*/
	74	while (cur_offset < item_size) {
	75	extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
	76	name_ptr = (unsigned long)(&extref->name);
	77	ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
	78
	79	if (ref_name_len == name_len &&
	80	btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
	81	(memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
	82	if (extref_ret)
	83	*extref_ret = extref;
	84	return 1;
	85	}
	86
	87	cur_offset += ref_name_len + sizeof(*extref);
	88	}
	89	return 0;
	90	}
	91
f186373f MF	92	/* Returns NULL if no extref found */
	93	struct btrfs_inode_extref *
	94	btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
	95	struct btrfs_root *root,
	96	struct btrfs_path *path,
	97	const char *name, int name_len,
	98	u64 inode_objectid, u64 ref_objectid, int ins_len,
	99	int cow)
	100	{
	101	int ret;
	102	struct btrfs_key key;
	103	struct btrfs_inode_extref *extref;
	104
	105	key.objectid = inode_objectid;
	106	key.type = BTRFS_INODE_EXTREF_KEY;
	107	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	108
	109	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
	110	if (ret < 0)
	111	return ERR_PTR(ret);
	112	if (ret > 0)
	113	return NULL;
1f250e92 FM	114	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
	115	ref_objectid, name, name_len,
	116	&extref))
f186373f MF	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	*/
1f250e92 FM	158	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
1f250e92 FM	159	ref_objectid,
f186373f	160	name, name_len, &extref)) {
34d97007	161	btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
f186373f MF	162	ret = -EROFS;
	163	goto out;
	164	}
	165
	166	leaf = path->nodes[0];
	167	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	168	if (index)
	169	*index = btrfs_inode_extref_index(leaf, extref);
	170
	171	if (del_len == item_size) {
	172	/*
	173	* Common case only one ref in the item, remove the
	174	* whole item.
	175	*/
	176	ret = btrfs_del_item(trans, root, path);
	177	goto out;
	178	}
	179
	180	ptr = (unsigned long)extref;
	181	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	182
	183	memmove_extent_buffer(leaf, ptr, ptr + del_len,
	184	item_size - (ptr + del_len - item_start));
	185
2ff7e61e	186	btrfs_truncate_item(root->fs_info, path, item_size - del_len, 1);
f186373f MF	187
	188	out:
	189	btrfs_free_path(path);
	190
	191	return ret;
	192	}
	193
	194	int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
	195	struct btrfs_root *root,
	196	const char *name, int name_len,
	197	u64 inode_objectid, u64 ref_objectid, u64 *index)
3954401f CM	198	{
	199	struct btrfs_path *path;
	200	struct btrfs_key key;
	201	struct btrfs_inode_ref *ref;
	202	struct extent_buffer *leaf;
	203	unsigned long ptr;
	204	unsigned long item_start;
	205	u32 item_size;
	206	u32 sub_item_len;
	207	int ret;
f186373f	208	int search_ext_refs = 0;
3954401f CM	209	int del_len = name_len + sizeof(*ref);
	210
	211	key.objectid = inode_objectid;
	212	key.offset = ref_objectid;
962a298f	213	key.type = BTRFS_INODE_REF_KEY;
3954401f CM	214
	215	path = btrfs_alloc_path();
	216	if (!path)
	217	return -ENOMEM;
	218
b9473439 CM	219	path->leave_spinning = 1;
b9473439 CM	220
3954401f CM	221	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	222	if (ret > 0) {
	223	ret = -ENOENT;
f186373f	224	search_ext_refs = 1;
3954401f CM	225	goto out;
	226	} else if (ret < 0) {
	227	goto out;
	228	}
1f250e92 FM	229	if (!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
1f250e92 FM	230	name, name_len, &ref)) {
3954401f	231	ret = -ENOENT;
f186373f	232	search_ext_refs = 1;
3954401f CM	233	goto out;
	234	}
	235	leaf = path->nodes[0];
	236	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
aec7477b JB	237
	238	if (index)
	239	*index = btrfs_inode_ref_index(leaf, ref);
	240
3954401f CM	241	if (del_len == item_size) {
	242	ret = btrfs_del_item(trans, root, path);
	243	goto out;
	244	}
	245	ptr = (unsigned long)ref;
	246	sub_item_len = name_len + sizeof(*ref);
	247	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	248	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
	249	item_size - (ptr + sub_item_len - item_start));
2ff7e61e	250	btrfs_truncate_item(root->fs_info, path, item_size - sub_item_len, 1);
f186373f MF	251	out:
	252	btrfs_free_path(path);
	253
	254	if (search_ext_refs) {
	255	/*
	256	* No refs were found, or we could not find the
	257	* name in our ref array. Find and remove the extended
	258	* inode ref then.
	259	*/
	260	return btrfs_del_inode_extref(trans, root, name, name_len,
	261	inode_objectid, ref_objectid, index);
	262	}
	263
	264	return ret;
	265	}
	266
	267	/*
	268	* btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
	269	*
	270	* The caller must have checked against BTRFS_LINK_MAX already.
	271	*/
	272	static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
	273	struct btrfs_root *root,
	274	const char *name, int name_len,
	275	u64 inode_objectid, u64 ref_objectid, u64 index)
	276	{
	277	struct btrfs_inode_extref *extref;
	278	int ret;
	279	int ins_len = name_len + sizeof(*extref);
	280	unsigned long ptr;
	281	struct btrfs_path *path;
	282	struct btrfs_key key;
	283	struct extent_buffer *leaf;
	284	struct btrfs_item *item;
	285
	286	key.objectid = inode_objectid;
	287	key.type = BTRFS_INODE_EXTREF_KEY;
	288	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	289
	290	path = btrfs_alloc_path();
	291	if (!path)
	292	return -ENOMEM;
	293
	294	path->leave_spinning = 1;
	295	ret = btrfs_insert_empty_item(trans, root, path, &key,
	296	ins_len);
	297	if (ret == -EEXIST) {
1f250e92 FM	298	if (btrfs_find_name_in_ext_backref(path->nodes[0],
	299	path->slots[0],
	300	ref_objectid,
f186373f MF	301	name, name_len, NULL))
	302	goto out;
	303
2ff7e61e	304	btrfs_extend_item(root->fs_info, path, ins_len);
f186373f MF	305	ret = 0;
	306	}
	307	if (ret < 0)
	308	goto out;
	309
	310	leaf = path->nodes[0];
dd3cc16b	311	item = btrfs_item_nr(path->slots[0]);
f186373f MF	312	ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
	313	ptr += btrfs_item_size(leaf, item) - ins_len;
	314	extref = (struct btrfs_inode_extref *)ptr;
	315
	316	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
	317	btrfs_set_inode_extref_index(path->nodes[0], extref, index);
	318	btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
	319
	320	ptr = (unsigned long)&extref->name;
	321	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	322	btrfs_mark_buffer_dirty(path->nodes[0]);
	323
3954401f CM	324	out:
	325	btrfs_free_path(path);
	326	return ret;
	327	}
	328
79787eaa	329	/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
3954401f CM	330	int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
	331	struct btrfs_root *root,
	332	const char *name, int name_len,
aec7477b	333	u64 inode_objectid, u64 ref_objectid, u64 index)
3954401f	334	{
0b246afa	335	struct btrfs_fs_info *fs_info = root->fs_info;
3954401f CM	336	struct btrfs_path *path;
	337	struct btrfs_key key;
	338	struct btrfs_inode_ref *ref;
	339	unsigned long ptr;
	340	int ret;
	341	int ins_len = name_len + sizeof(*ref);
	342
	343	key.objectid = inode_objectid;
	344	key.offset = ref_objectid;
962a298f	345	key.type = BTRFS_INODE_REF_KEY;
3954401f CM	346
	347	path = btrfs_alloc_path();
	348	if (!path)
	349	return -ENOMEM;
	350
b9473439	351	path->leave_spinning = 1;
df8d116f	352	path->skip_release_on_error = 1;
3954401f CM	353	ret = btrfs_insert_empty_item(trans, root, path, &key,
	354	ins_len);
	355	if (ret == -EEXIST) {
	356	u32 old_size;
	357
1f250e92 FM	358	if (btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
1f250e92 FM	359	name, name_len, &ref))
3954401f CM	360	goto out;
	361
	362	old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
2ff7e61e	363	btrfs_extend_item(fs_info, path, ins_len);
3954401f CM	364	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	365	struct btrfs_inode_ref);
	366	ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
	367	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	368	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	369	ptr = (unsigned long)(ref + 1);
	370	ret = 0;
	371	} else if (ret < 0) {
df8d116f	372	if (ret == -EOVERFLOW) {
1f250e92 FM	373	if (btrfs_find_name_in_backref(path->nodes[0],
	374	path->slots[0],
	375	name, name_len, &ref))
df8d116f FM	376	ret = -EEXIST;
	377	else
	378	ret = -EMLINK;
	379	}
3954401f CM	380	goto out;
	381	} else {
	382	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	383	struct btrfs_inode_ref);
	384	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	385	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	386	ptr = (unsigned long)(ref + 1);
	387	}
	388	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	389	btrfs_mark_buffer_dirty(path->nodes[0]);
	390
	391	out:
	392	btrfs_free_path(path);
f186373f MF	393
f186373f MF	394	if (ret == -EMLINK) {
0b246afa	395	struct btrfs_super_block *disk_super = fs_info->super_copy;
f186373f MF	396	/* We ran out of space in the ref array. Need to
	397	* add an extended ref. */
	398	if (btrfs_super_incompat_flags(disk_super)
	399	& BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
	400	ret = btrfs_insert_inode_extref(trans, root, name,
	401	name_len,
	402	inode_objectid,
	403	ref_objectid, index);
	404	}
	405
3954401f CM	406	return ret;
	407	}
	408
5f39d397 CM	409	int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
	410	struct btrfs_root *root,
	411	struct btrfs_path *path, u64 objectid)
1e1d2701	412	{
1e1d2701 CM	413	struct btrfs_key key;
	414	int ret;
	415	key.objectid = objectid;
962a298f	416	key.type = BTRFS_INODE_ITEM_KEY;
1e1d2701 CM	417	key.offset = 0;
1e1d2701 CM	418
5f39d397 CM	419	ret = btrfs_insert_empty_item(trans, root, path, &key,
5f39d397 CM	420	sizeof(struct btrfs_inode_item));
1e1d2701 CM	421	return ret;
	422	}
	423
e089f05c	424	int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
d6e4a428 CM	425	root, struct btrfs_path path,
d6e4a428 CM	426	struct btrfs_key *location, int mod)
1e1d2701	427	{
1e1d2701 CM	428	int ins_len = mod < 0 ? -1 : 0;
1e1d2701 CM	429	int cow = mod != 0;
d6e4a428 CM	430	int ret;
d6e4a428 CM	431	int slot;
5f39d397	432	struct extent_buffer *leaf;
d6e4a428	433	struct btrfs_key found_key;
1e1d2701	434
d6e4a428	435	ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
962a298f	436	if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
d6e4a428 CM	437	location->offset == (u64)-1 && path->slots[0] != 0) {
d6e4a428 CM	438	slot = path->slots[0] - 1;
5f39d397 CM	439	leaf = path->nodes[0];
5f39d397 CM	440	btrfs_item_key_to_cpu(leaf, &found_key, slot);
d6e4a428	441	if (found_key.objectid == location->objectid &&
962a298f	442	found_key.type == location->type) {
d6e4a428 CM	443	path->slots[0]--;
	444	return 0;
	445	}
	446	}
	447	return ret;
1e1d2701	448	}