[linux-2.6-block.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"

struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
						   int slot, const char *name,
						   int name_len)
{
	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)
			return ref;
	}
	return NULL;
}

struct btrfs_inode_extref *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;
	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))
			return extref;

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

/* 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;

	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;
	return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
					      ref_objectid, name, name_len);

}

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.
	 */
	extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
						ref_objectid, name, name_len);
	if (!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(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;
	}

	ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name,
					 name_len);
	if (!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(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))
			goto out;

		btrfs_extend_item(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;
		ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
						 name, name_len);
		if (ref)
			goto out;

		old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
		btrfs_extend_item(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))
				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
9bb8407f NB	11	struct btrfs_inode_ref btrfs_find_name_in_backref(struct extent_buffer leaf,
	12	int slot, const char *name,
	13	int name_len)
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;
9bb8407f NB	31	if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
9bb8407f NB	32	return ref;
3954401f	33	}
9bb8407f	34	return NULL;
3954401f CM	35	}
3954401f CM	36
6ff49c6a NB	37	struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
	38	struct extent_buffer *leaf, int slot, u64 ref_objectid,
	39	const char *name, int name_len)
f186373f	40	{
f186373f MF	41	struct btrfs_inode_extref *extref;
	42	unsigned long ptr;
	43	unsigned long name_ptr;
	44	u32 item_size;
	45	u32 cur_offset = 0;
	46	int ref_name_len;
	47
1f250e92 FM	48	item_size = btrfs_item_size_nr(leaf, slot);
1f250e92 FM	49	ptr = btrfs_item_ptr_offset(leaf, slot);
f186373f MF	50
	51	/*
	52	* Search all extended backrefs in this item. We're only
	53	* looking through any collisions so most of the time this is
	54	* just going to compare against one buffer. If all is well,
	55	* we'll return success and the inode ref object.
	56	*/
	57	while (cur_offset < item_size) {
	58	extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
	59	name_ptr = (unsigned long)(&extref->name);
	60	ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
	61
	62	if (ref_name_len == name_len &&
	63	btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
6ff49c6a NB	64	(memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0))
6ff49c6a NB	65	return extref;
f186373f MF	66
	67	cur_offset += ref_name_len + sizeof(*extref);
	68	}
6ff49c6a	69	return NULL;
f186373f MF	70	}
f186373f MF	71
f186373f MF	72	/* Returns NULL if no extref found */
	73	struct btrfs_inode_extref *
	74	btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
	75	struct btrfs_root *root,
	76	struct btrfs_path *path,
	77	const char *name, int name_len,
	78	u64 inode_objectid, u64 ref_objectid, int ins_len,
	79	int cow)
	80	{
	81	int ret;
	82	struct btrfs_key key;
f186373f MF	83
	84	key.objectid = inode_objectid;
	85	key.type = BTRFS_INODE_EXTREF_KEY;
	86	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	87
	88	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
	89	if (ret < 0)
	90	return ERR_PTR(ret);
	91	if (ret > 0)
	92	return NULL;
6ff49c6a NB	93	return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
	94	ref_objectid, name, name_len);
	95
f186373f MF	96	}
f186373f MF	97
48a3b636 ES	98	static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
	99	struct btrfs_root *root,
	100	const char *name, int name_len,
	101	u64 inode_objectid, u64 ref_objectid,
	102	u64 *index)
f186373f MF	103	{
	104	struct btrfs_path *path;
	105	struct btrfs_key key;
	106	struct btrfs_inode_extref *extref;
	107	struct extent_buffer *leaf;
	108	int ret;
	109	int del_len = name_len + sizeof(*extref);
	110	unsigned long ptr;
	111	unsigned long item_start;
	112	u32 item_size;
	113
	114	key.objectid = inode_objectid;
962a298f	115	key.type = BTRFS_INODE_EXTREF_KEY;
f186373f MF	116	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	117
	118	path = btrfs_alloc_path();
	119	if (!path)
	120	return -ENOMEM;
	121
	122	path->leave_spinning = 1;
	123
	124	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	125	if (ret > 0)
	126	ret = -ENOENT;
	127	if (ret < 0)
	128	goto out;
	129
	130	/*
	131	* Sanity check - did we find the right item for this name?
	132	* This should always succeed so error here will make the FS
	133	* readonly.
	134	*/
6ff49c6a NB	135	extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
	136	ref_objectid, name, name_len);
	137	if (!extref) {
34d97007	138	btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
f186373f MF	139	ret = -EROFS;
	140	goto out;
	141	}
	142
	143	leaf = path->nodes[0];
	144	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	145	if (index)
	146	*index = btrfs_inode_extref_index(leaf, extref);
	147
	148	if (del_len == item_size) {
	149	/*
	150	* Common case only one ref in the item, remove the
	151	* whole item.
	152	*/
	153	ret = btrfs_del_item(trans, root, path);
	154	goto out;
	155	}
	156
	157	ptr = (unsigned long)extref;
	158	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	159
	160	memmove_extent_buffer(leaf, ptr, ptr + del_len,
	161	item_size - (ptr + del_len - item_start));
	162
78ac4f9e	163	btrfs_truncate_item(path, item_size - del_len, 1);
f186373f MF	164
	165	out:
	166	btrfs_free_path(path);
	167
	168	return ret;
	169	}
	170
	171	int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
	172	struct btrfs_root *root,
	173	const char *name, int name_len,
	174	u64 inode_objectid, u64 ref_objectid, u64 *index)
3954401f CM	175	{
	176	struct btrfs_path *path;
	177	struct btrfs_key key;
	178	struct btrfs_inode_ref *ref;
	179	struct extent_buffer *leaf;
	180	unsigned long ptr;
	181	unsigned long item_start;
	182	u32 item_size;
	183	u32 sub_item_len;
	184	int ret;
f186373f	185	int search_ext_refs = 0;
3954401f CM	186	int del_len = name_len + sizeof(*ref);
	187
	188	key.objectid = inode_objectid;
	189	key.offset = ref_objectid;
962a298f	190	key.type = BTRFS_INODE_REF_KEY;
3954401f CM	191
	192	path = btrfs_alloc_path();
	193	if (!path)
	194	return -ENOMEM;
	195
b9473439 CM	196	path->leave_spinning = 1;
b9473439 CM	197
3954401f CM	198	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	199	if (ret > 0) {
	200	ret = -ENOENT;
f186373f	201	search_ext_refs = 1;
3954401f CM	202	goto out;
	203	} else if (ret < 0) {
	204	goto out;
	205	}
9bb8407f NB	206
	207	ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name,
	208	name_len);
	209	if (!ref) {
3954401f	210	ret = -ENOENT;
f186373f	211	search_ext_refs = 1;
3954401f CM	212	goto out;
	213	}
	214	leaf = path->nodes[0];
	215	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
aec7477b JB	216
	217	if (index)
	218	*index = btrfs_inode_ref_index(leaf, ref);
	219
3954401f CM	220	if (del_len == item_size) {
	221	ret = btrfs_del_item(trans, root, path);
	222	goto out;
	223	}
	224	ptr = (unsigned long)ref;
	225	sub_item_len = name_len + sizeof(*ref);
	226	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	227	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
	228	item_size - (ptr + sub_item_len - item_start));
78ac4f9e	229	btrfs_truncate_item(path, item_size - sub_item_len, 1);
f186373f MF	230	out:
	231	btrfs_free_path(path);
	232
	233	if (search_ext_refs) {
	234	/*
	235	* No refs were found, or we could not find the
	236	* name in our ref array. Find and remove the extended
	237	* inode ref then.
	238	*/
	239	return btrfs_del_inode_extref(trans, root, name, name_len,
	240	inode_objectid, ref_objectid, index);
	241	}
	242
	243	return ret;
	244	}
	245
	246	/*
	247	* btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
	248	*
	249	* The caller must have checked against BTRFS_LINK_MAX already.
	250	*/
	251	static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
	252	struct btrfs_root *root,
	253	const char *name, int name_len,
	254	u64 inode_objectid, u64 ref_objectid, u64 index)
	255	{
	256	struct btrfs_inode_extref *extref;
	257	int ret;
	258	int ins_len = name_len + sizeof(*extref);
	259	unsigned long ptr;
	260	struct btrfs_path *path;
	261	struct btrfs_key key;
	262	struct extent_buffer *leaf;
	263	struct btrfs_item *item;
	264
	265	key.objectid = inode_objectid;
	266	key.type = BTRFS_INODE_EXTREF_KEY;
	267	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
	268
	269	path = btrfs_alloc_path();
	270	if (!path)
	271	return -ENOMEM;
	272
	273	path->leave_spinning = 1;
	274	ret = btrfs_insert_empty_item(trans, root, path, &key,
	275	ins_len);
	276	if (ret == -EEXIST) {
1f250e92 FM	277	if (btrfs_find_name_in_ext_backref(path->nodes[0],
	278	path->slots[0],
	279	ref_objectid,
6ff49c6a	280	name, name_len))
f186373f MF	281	goto out;
f186373f MF	282
c71dd880	283	btrfs_extend_item(path, ins_len);
f186373f MF	284	ret = 0;
	285	}
	286	if (ret < 0)
	287	goto out;
	288
	289	leaf = path->nodes[0];
dd3cc16b	290	item = btrfs_item_nr(path->slots[0]);
f186373f MF	291	ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
	292	ptr += btrfs_item_size(leaf, item) - ins_len;
	293	extref = (struct btrfs_inode_extref *)ptr;
	294
	295	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
	296	btrfs_set_inode_extref_index(path->nodes[0], extref, index);
	297	btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
	298
	299	ptr = (unsigned long)&extref->name;
	300	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	301	btrfs_mark_buffer_dirty(path->nodes[0]);
	302
3954401f CM	303	out:
	304	btrfs_free_path(path);
	305	return ret;
	306	}
	307
79787eaa	308	/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
3954401f CM	309	int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
	310	struct btrfs_root *root,
	311	const char *name, int name_len,
aec7477b	312	u64 inode_objectid, u64 ref_objectid, u64 index)
3954401f	313	{
0b246afa	314	struct btrfs_fs_info *fs_info = root->fs_info;
3954401f CM	315	struct btrfs_path *path;
	316	struct btrfs_key key;
	317	struct btrfs_inode_ref *ref;
	318	unsigned long ptr;
	319	int ret;
	320	int ins_len = name_len + sizeof(*ref);
	321
	322	key.objectid = inode_objectid;
	323	key.offset = ref_objectid;
962a298f	324	key.type = BTRFS_INODE_REF_KEY;
3954401f CM	325
	326	path = btrfs_alloc_path();
	327	if (!path)
	328	return -ENOMEM;
	329
b9473439	330	path->leave_spinning = 1;
df8d116f	331	path->skip_release_on_error = 1;
3954401f CM	332	ret = btrfs_insert_empty_item(trans, root, path, &key,
	333	ins_len);
	334	if (ret == -EEXIST) {
	335	u32 old_size;
9bb8407f NB	336	ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
	337	name, name_len);
	338	if (ref)
3954401f CM	339	goto out;
	340
	341	old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
c71dd880	342	btrfs_extend_item(path, ins_len);
3954401f CM	343	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	344	struct btrfs_inode_ref);
	345	ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
	346	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	347	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	348	ptr = (unsigned long)(ref + 1);
	349	ret = 0;
	350	} else if (ret < 0) {
df8d116f	351	if (ret == -EOVERFLOW) {
1f250e92 FM	352	if (btrfs_find_name_in_backref(path->nodes[0],
1f250e92 FM	353	path->slots[0],
9bb8407f	354	name, name_len))
df8d116f FM	355	ret = -EEXIST;
	356	else
	357	ret = -EMLINK;
	358	}
3954401f CM	359	goto out;
	360	} else {
	361	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	362	struct btrfs_inode_ref);
	363	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	364	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	365	ptr = (unsigned long)(ref + 1);
	366	}
	367	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	368	btrfs_mark_buffer_dirty(path->nodes[0]);
	369
	370	out:
	371	btrfs_free_path(path);
f186373f MF	372
f186373f MF	373	if (ret == -EMLINK) {
0b246afa	374	struct btrfs_super_block *disk_super = fs_info->super_copy;
f186373f MF	375	/* We ran out of space in the ref array. Need to
	376	* add an extended ref. */
	377	if (btrfs_super_incompat_flags(disk_super)
	378	& BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
	379	ret = btrfs_insert_inode_extref(trans, root, name,
	380	name_len,
	381	inode_objectid,
	382	ref_objectid, index);
	383	}
	384
3954401f CM	385	return ret;
	386	}
	387
5f39d397 CM	388	int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
	389	struct btrfs_root *root,
	390	struct btrfs_path *path, u64 objectid)
1e1d2701	391	{
1e1d2701 CM	392	struct btrfs_key key;
	393	int ret;
	394	key.objectid = objectid;
962a298f	395	key.type = BTRFS_INODE_ITEM_KEY;
1e1d2701 CM	396	key.offset = 0;
1e1d2701 CM	397
5f39d397 CM	398	ret = btrfs_insert_empty_item(trans, root, path, &key,
5f39d397 CM	399	sizeof(struct btrfs_inode_item));
1e1d2701 CM	400	return ret;
	401	}
	402
e089f05c	403	int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
d6e4a428 CM	404	root, struct btrfs_path path,
d6e4a428 CM	405	struct btrfs_key *location, int mod)
1e1d2701	406	{
1e1d2701 CM	407	int ins_len = mod < 0 ? -1 : 0;
1e1d2701 CM	408	int cow = mod != 0;
d6e4a428 CM	409	int ret;
d6e4a428 CM	410	int slot;
5f39d397	411	struct extent_buffer *leaf;
d6e4a428	412	struct btrfs_key found_key;
1e1d2701	413
d6e4a428	414	ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
962a298f	415	if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
d6e4a428 CM	416	location->offset == (u64)-1 && path->slots[0] != 0) {
d6e4a428 CM	417	slot = path->slots[0] - 1;
5f39d397 CM	418	leaf = path->nodes[0];
5f39d397 CM	419	btrfs_item_key_to_cpu(leaf, &found_key, slot);
d6e4a428	420	if (found_key.objectid == location->objectid &&
962a298f	421	found_key.type == location->type) {
d6e4a428 CM	422	path->slots[0]--;
	423	return 0;
	424	}
	425	}
	426	return ret;
1e1d2701	427	}