[linux.git] / fs / btrfs / inode-item.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 */

#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
c1d7c514	1	// SPDX-License-Identifier: GPL-2.0
6cbd5570 CM	2	/*
6cbd5570 CM	3	* Copyright (C) 2007 Oracle. All rights reserved.
6cbd5570 CM	4	*/
6cbd5570 CM	5
1e1d2701 CM	6	#include "ctree.h"
1e1d2701 CM	7	#include "disk-io.h"
e089f05c	8	#include "transaction.h"
727011e0	9	#include "print-tree.h"
1e1d2701	10
1f250e92 FM	11	int btrfs_find_name_in_backref(struct extent_buffer *leaf, int slot,
	12	const char *name,
	13	int name_len, struct btrfs_inode_ref **ref_ret)
3954401f	14	{
3954401f CM	15	struct btrfs_inode_ref *ref;
	16	unsigned long ptr;
	17	unsigned long name_ptr;
	18	u32 item_size;
	19	u32 cur_offset = 0;
	20	int len;
	21
1f250e92 FM	22	item_size = btrfs_item_size_nr(leaf, slot);
1f250e92 FM	23	ptr = btrfs_item_ptr_offset(leaf, slot);
3954401f CM	24	while (cur_offset < item_size) {
	25	ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
	26	len = btrfs_inode_ref_name_len(leaf, ref);
	27	name_ptr = (unsigned long)(ref + 1);
	28	cur_offset += len + sizeof(*ref);
	29	if (len != name_len)
	30	continue;
	31	if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
1f250e92 FM	32	if (ref_ret)
1f250e92 FM	33	*ref_ret = ref;
3954401f CM	34	return 1;
	35	}
	36	}
	37	return 0;
	38	}
	39
1f250e92 FM	40	int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
1f250e92 FM	41	u64 ref_objectid,
f186373f MF	42	const char *name, int name_len,
	43	struct btrfs_inode_extref **extref_ret)
	44	{
f186373f MF	45	struct btrfs_inode_extref *extref;
	46	unsigned long ptr;
	47	unsigned long name_ptr;
	48	u32 item_size;
	49	u32 cur_offset = 0;
	50	int ref_name_len;
	51
1f250e92 FM	52	item_size = btrfs_item_size_nr(leaf, slot);
1f250e92 FM	53	ptr = btrfs_item_ptr_offset(leaf, slot);
f186373f MF	54
	55	/*
	56	* Search all extended backrefs in this item. We're only
	57	* looking through any collisions so most of the time this is
	58	* just going to compare against one buffer. If all is well,
	59	* we'll return success and the inode ref object.
	60	*/
	61	while (cur_offset < item_size) {
	62	extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
	63	name_ptr = (unsigned long)(&extref->name);
	64	ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
	65
	66	if (ref_name_len == name_len &&
	67	btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
	68	(memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
	69	if (extref_ret)
	70	*extref_ret = extref;
	71	return 1;
	72	}
	73
	74	cur_offset += ref_name_len + sizeof(*extref);
	75	}
	76	return 0;
	77	}
	78
f186373f MF	79	/* Returns NULL if no extref found */
	80	struct btrfs_inode_extref *
	81	btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
	82	struct btrfs_root *root,
	83	struct btrfs_path *path,
	84	const char *name, int name_len,
	85	u64 inode_objectid, u64 ref_objectid, int ins_len,
	86	int cow)
	87	{
	88	int ret;
	89	struct btrfs_key key;
	90	struct btrfs_inode_extref *extref;
	91
	92	key.objectid = inode_objectid;
	93	key.type = BTRFS_INODE_EXTREF_KEY;
	94	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	95
	96	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
	97	if (ret < 0)
	98	return ERR_PTR(ret);
	99	if (ret > 0)
	100	return NULL;
1f250e92 FM	101	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
	102	ref_objectid, name, name_len,
	103	&extref))
f186373f MF	104	return NULL;
	105	return extref;
	106	}
	107
48a3b636 ES	108	static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
	109	struct btrfs_root *root,
	110	const char *name, int name_len,
	111	u64 inode_objectid, u64 ref_objectid,
	112	u64 *index)
f186373f MF	113	{
	114	struct btrfs_path *path;
	115	struct btrfs_key key;
	116	struct btrfs_inode_extref *extref;
	117	struct extent_buffer *leaf;
	118	int ret;
	119	int del_len = name_len + sizeof(*extref);
	120	unsigned long ptr;
	121	unsigned long item_start;
	122	u32 item_size;
	123
	124	key.objectid = inode_objectid;
962a298f	125	key.type = BTRFS_INODE_EXTREF_KEY;
f186373f MF	126	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	127
	128	path = btrfs_alloc_path();
	129	if (!path)
	130	return -ENOMEM;
	131
	132	path->leave_spinning = 1;
	133
	134	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	135	if (ret > 0)
	136	ret = -ENOENT;
	137	if (ret < 0)
	138	goto out;
	139
	140	/*
	141	* Sanity check - did we find the right item for this name?
	142	* This should always succeed so error here will make the FS
	143	* readonly.
	144	*/
1f250e92 FM	145	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
1f250e92 FM	146	ref_objectid,
f186373f	147	name, name_len, &extref)) {
34d97007	148	btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
f186373f MF	149	ret = -EROFS;
	150	goto out;
	151	}
	152
	153	leaf = path->nodes[0];
	154	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	155	if (index)
	156	*index = btrfs_inode_extref_index(leaf, extref);
	157
	158	if (del_len == item_size) {
	159	/*
	160	* Common case only one ref in the item, remove the
	161	* whole item.
	162	*/
	163	ret = btrfs_del_item(trans, root, path);
	164	goto out;
	165	}
	166
	167	ptr = (unsigned long)extref;
	168	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	169
	170	memmove_extent_buffer(leaf, ptr, ptr + del_len,
	171	item_size - (ptr + del_len - item_start));
	172
2ff7e61e	173	btrfs_truncate_item(root->fs_info, path, item_size - del_len, 1);
f186373f MF	174
	175	out:
	176	btrfs_free_path(path);
	177
	178	return ret;
	179	}
	180
	181	int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
	182	struct btrfs_root *root,
	183	const char *name, int name_len,
	184	u64 inode_objectid, u64 ref_objectid, u64 *index)
3954401f CM	185	{
	186	struct btrfs_path *path;
	187	struct btrfs_key key;
	188	struct btrfs_inode_ref *ref;
	189	struct extent_buffer *leaf;
	190	unsigned long ptr;
	191	unsigned long item_start;
	192	u32 item_size;
	193	u32 sub_item_len;
	194	int ret;
f186373f	195	int search_ext_refs = 0;
3954401f CM	196	int del_len = name_len + sizeof(*ref);
	197
	198	key.objectid = inode_objectid;
	199	key.offset = ref_objectid;
962a298f	200	key.type = BTRFS_INODE_REF_KEY;
3954401f CM	201
	202	path = btrfs_alloc_path();
	203	if (!path)
	204	return -ENOMEM;
	205
b9473439 CM	206	path->leave_spinning = 1;
b9473439 CM	207
3954401f CM	208	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	209	if (ret > 0) {
	210	ret = -ENOENT;
f186373f	211	search_ext_refs = 1;
3954401f CM	212	goto out;
	213	} else if (ret < 0) {
	214	goto out;
	215	}
1f250e92 FM	216	if (!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
1f250e92 FM	217	name, name_len, &ref)) {
3954401f	218	ret = -ENOENT;
f186373f	219	search_ext_refs = 1;
3954401f CM	220	goto out;
	221	}
	222	leaf = path->nodes[0];
	223	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
aec7477b JB	224
	225	if (index)
	226	*index = btrfs_inode_ref_index(leaf, ref);
	227
3954401f CM	228	if (del_len == item_size) {
	229	ret = btrfs_del_item(trans, root, path);
	230	goto out;
	231	}
	232	ptr = (unsigned long)ref;
	233	sub_item_len = name_len + sizeof(*ref);
	234	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	235	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
	236	item_size - (ptr + sub_item_len - item_start));
2ff7e61e	237	btrfs_truncate_item(root->fs_info, path, item_size - sub_item_len, 1);
f186373f MF	238	out:
	239	btrfs_free_path(path);
	240
	241	if (search_ext_refs) {
	242	/*
	243	* No refs were found, or we could not find the
	244	* name in our ref array. Find and remove the extended
	245	* inode ref then.
	246	*/
	247	return btrfs_del_inode_extref(trans, root, name, name_len,
	248	inode_objectid, ref_objectid, index);
	249	}
	250
	251	return ret;
	252	}
	253
	254	/*
	255	* btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
	256	*
	257	* The caller must have checked against BTRFS_LINK_MAX already.
	258	*/
	259	static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
	260	struct btrfs_root *root,
	261	const char *name, int name_len,
	262	u64 inode_objectid, u64 ref_objectid, u64 index)
	263	{
	264	struct btrfs_inode_extref *extref;
	265	int ret;
	266	int ins_len = name_len + sizeof(*extref);
	267	unsigned long ptr;
	268	struct btrfs_path *path;
	269	struct btrfs_key key;
	270	struct extent_buffer *leaf;
	271	struct btrfs_item *item;
	272
	273	key.objectid = inode_objectid;
	274	key.type = BTRFS_INODE_EXTREF_KEY;
	275	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	276
	277	path = btrfs_alloc_path();
	278	if (!path)
	279	return -ENOMEM;
	280
	281	path->leave_spinning = 1;
	282	ret = btrfs_insert_empty_item(trans, root, path, &key,
	283	ins_len);
	284	if (ret == -EEXIST) {
1f250e92 FM	285	if (btrfs_find_name_in_ext_backref(path->nodes[0],
	286	path->slots[0],
	287	ref_objectid,
f186373f MF	288	name, name_len, NULL))
	289	goto out;
	290
2ff7e61e	291	btrfs_extend_item(root->fs_info, path, ins_len);
f186373f MF	292	ret = 0;
	293	}
	294	if (ret < 0)
	295	goto out;
	296
	297	leaf = path->nodes[0];
dd3cc16b	298	item = btrfs_item_nr(path->slots[0]);
f186373f MF	299	ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
	300	ptr += btrfs_item_size(leaf, item) - ins_len;
	301	extref = (struct btrfs_inode_extref *)ptr;
	302
	303	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
	304	btrfs_set_inode_extref_index(path->nodes[0], extref, index);
	305	btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
	306
	307	ptr = (unsigned long)&extref->name;
	308	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	309	btrfs_mark_buffer_dirty(path->nodes[0]);
	310
3954401f CM	311	out:
	312	btrfs_free_path(path);
	313	return ret;
	314	}
	315
79787eaa	316	/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
3954401f CM	317	int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
	318	struct btrfs_root *root,
	319	const char *name, int name_len,
aec7477b	320	u64 inode_objectid, u64 ref_objectid, u64 index)
3954401f	321	{
0b246afa	322	struct btrfs_fs_info *fs_info = root->fs_info;
3954401f CM	323	struct btrfs_path *path;
	324	struct btrfs_key key;
	325	struct btrfs_inode_ref *ref;
	326	unsigned long ptr;
	327	int ret;
	328	int ins_len = name_len + sizeof(*ref);
	329
	330	key.objectid = inode_objectid;
	331	key.offset = ref_objectid;
962a298f	332	key.type = BTRFS_INODE_REF_KEY;
3954401f CM	333
	334	path = btrfs_alloc_path();
	335	if (!path)
	336	return -ENOMEM;
	337
b9473439	338	path->leave_spinning = 1;
df8d116f	339	path->skip_release_on_error = 1;
3954401f CM	340	ret = btrfs_insert_empty_item(trans, root, path, &key,
	341	ins_len);
	342	if (ret == -EEXIST) {
	343	u32 old_size;
	344
1f250e92 FM	345	if (btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
1f250e92 FM	346	name, name_len, &ref))
3954401f CM	347	goto out;
	348
	349	old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
2ff7e61e	350	btrfs_extend_item(fs_info, path, ins_len);
3954401f CM	351	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	352	struct btrfs_inode_ref);
	353	ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
	354	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	355	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	356	ptr = (unsigned long)(ref + 1);
	357	ret = 0;
	358	} else if (ret < 0) {
df8d116f	359	if (ret == -EOVERFLOW) {
1f250e92 FM	360	if (btrfs_find_name_in_backref(path->nodes[0],
	361	path->slots[0],
	362	name, name_len, &ref))
df8d116f FM	363	ret = -EEXIST;
	364	else
	365	ret = -EMLINK;
	366	}
3954401f CM	367	goto out;
	368	} else {
	369	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	370	struct btrfs_inode_ref);
	371	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	372	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	373	ptr = (unsigned long)(ref + 1);
	374	}
	375	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	376	btrfs_mark_buffer_dirty(path->nodes[0]);
	377
	378	out:
	379	btrfs_free_path(path);
f186373f MF	380
f186373f MF	381	if (ret == -EMLINK) {
0b246afa	382	struct btrfs_super_block *disk_super = fs_info->super_copy;
f186373f MF	383	/* We ran out of space in the ref array. Need to
	384	* add an extended ref. */
	385	if (btrfs_super_incompat_flags(disk_super)
	386	& BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
	387	ret = btrfs_insert_inode_extref(trans, root, name,
	388	name_len,
	389	inode_objectid,
	390	ref_objectid, index);
	391	}
	392
3954401f CM	393	return ret;
	394	}
	395
5f39d397 CM	396	int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
	397	struct btrfs_root *root,
	398	struct btrfs_path *path, u64 objectid)
1e1d2701	399	{
1e1d2701 CM	400	struct btrfs_key key;
	401	int ret;
	402	key.objectid = objectid;
962a298f	403	key.type = BTRFS_INODE_ITEM_KEY;
1e1d2701 CM	404	key.offset = 0;
1e1d2701 CM	405
5f39d397 CM	406	ret = btrfs_insert_empty_item(trans, root, path, &key,
5f39d397 CM	407	sizeof(struct btrfs_inode_item));
1e1d2701 CM	408	return ret;
	409	}
	410
e089f05c	411	int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
d6e4a428 CM	412	root, struct btrfs_path path,
d6e4a428 CM	413	struct btrfs_key *location, int mod)
1e1d2701	414	{
1e1d2701 CM	415	int ins_len = mod < 0 ? -1 : 0;
1e1d2701 CM	416	int cow = mod != 0;
d6e4a428 CM	417	int ret;
d6e4a428 CM	418	int slot;
5f39d397	419	struct extent_buffer *leaf;
d6e4a428	420	struct btrfs_key found_key;
1e1d2701	421
d6e4a428	422	ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
962a298f	423	if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
d6e4a428 CM	424	location->offset == (u64)-1 && path->slots[0] != 0) {
d6e4a428 CM	425	slot = path->slots[0] - 1;
5f39d397 CM	426	leaf = path->nodes[0];
5f39d397 CM	427	btrfs_item_key_to_cpu(leaf, &found_key, slot);
d6e4a428	428	if (found_key.objectid == location->objectid &&
962a298f	429	found_key.type == location->type) {
d6e4a428 CM	430	path->slots[0]--;
	431	return 0;
	432	}
	433	}
	434	return ret;
1e1d2701	435	}