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

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

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

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

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

struct btrfs_inode_ref *
btrfs_lookup_inode_ref(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 mod)
{
	struct btrfs_key key;
	struct btrfs_inode_ref *ref;
	int ins_len = mod < 0 ? -1 : 0;
	int cow = mod != 0;
	int ret;

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

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

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 del_len = name_len + sizeof(*ref);

	key.objectid = inode_objectid;
	key.offset = ref_objectid;
	btrfs_set_key_type(&key, 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;
		goto out;
	} else if (ret < 0) {
		goto out;
	}
	if (!find_name_in_backref(path, name, name_len, &ref)) {
		ret = -ENOENT;
		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(trans, root, path,
				  item_size - sub_item_len, 1);
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_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;
	btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);

	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) {
		u32 old_size;

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

		old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
		btrfs_extend_item(trans, root, 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)
			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);
	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;
	btrfs_set_key_type(&key, 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 && btrfs_key_type(location) == 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 &&
		    btrfs_key_type(&found_key) == btrfs_key_type(location)) {
			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
b2950863	24	static int find_name_in_backref(struct btrfs_path path, const char name,
3954401f CM	25	int name_len, struct btrfs_inode_ref **ref_ret)
	26	{
	27	struct extent_buffer *leaf;
	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
	35	leaf = path->nodes[0];
	36	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	37	ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
	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) {
	46	*ref_ret = ref;
	47	return 1;
	48	}
	49	}
	50	return 0;
	51	}
	52
a22285a6 YZ	53	struct btrfs_inode_ref *
	54	btrfs_lookup_inode_ref(struct btrfs_trans_handle *trans,
	55	struct btrfs_root *root,
	56	struct btrfs_path *path,
	57	const char *name, int name_len,
	58	u64 inode_objectid, u64 ref_objectid, int mod)
	59	{
	60	struct btrfs_key key;
	61	struct btrfs_inode_ref *ref;
	62	int ins_len = mod < 0 ? -1 : 0;
	63	int cow = mod != 0;
	64	int ret;
	65
	66	key.objectid = inode_objectid;
	67	key.type = BTRFS_INODE_REF_KEY;
	68	key.offset = ref_objectid;
	69
	70	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
	71	if (ret < 0)
	72	return ERR_PTR(ret);
	73	if (ret > 0)
	74	return NULL;
	75	if (!find_name_in_backref(path, name, name_len, &ref))
	76	return NULL;
	77	return ref;
	78	}
	79
3954401f CM	80	int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
	81	struct btrfs_root *root,
	82	const char *name, int name_len,
aec7477b	83	u64 inode_objectid, u64 ref_objectid, u64 *index)
3954401f CM	84	{
	85	struct btrfs_path *path;
	86	struct btrfs_key key;
	87	struct btrfs_inode_ref *ref;
	88	struct extent_buffer *leaf;
	89	unsigned long ptr;
	90	unsigned long item_start;
	91	u32 item_size;
	92	u32 sub_item_len;
	93	int ret;
	94	int del_len = name_len + sizeof(*ref);
	95
	96	key.objectid = inode_objectid;
	97	key.offset = ref_objectid;
	98	btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
	99
	100	path = btrfs_alloc_path();
	101	if (!path)
	102	return -ENOMEM;
	103
b9473439 CM	104	path->leave_spinning = 1;
b9473439 CM	105
3954401f CM	106	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	107	if (ret > 0) {
	108	ret = -ENOENT;
	109	goto out;
	110	} else if (ret < 0) {
	111	goto out;
	112	}
	113	if (!find_name_in_backref(path, name, name_len, &ref)) {
	114	ret = -ENOENT;
	115	goto out;
	116	}
	117	leaf = path->nodes[0];
	118	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
aec7477b JB	119
	120	if (index)
	121	*index = btrfs_inode_ref_index(leaf, ref);
	122
3954401f CM	123	if (del_len == item_size) {
	124	ret = btrfs_del_item(trans, root, path);
	125	goto out;
	126	}
	127	ptr = (unsigned long)ref;
	128	sub_item_len = name_len + sizeof(*ref);
	129	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
	130	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
	131	item_size - (ptr + sub_item_len - item_start));
143bede5	132	btrfs_truncate_item(trans, root, path,
3954401f	133	item_size - sub_item_len, 1);
3954401f CM	134	out:
	135	btrfs_free_path(path);
	136	return ret;
	137	}
	138
79787eaa	139	/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
3954401f CM	140	int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
	141	struct btrfs_root *root,
	142	const char *name, int name_len,
aec7477b	143	u64 inode_objectid, u64 ref_objectid, u64 index)
3954401f CM	144	{
	145	struct btrfs_path *path;
	146	struct btrfs_key key;
	147	struct btrfs_inode_ref *ref;
	148	unsigned long ptr;
	149	int ret;
	150	int ins_len = name_len + sizeof(*ref);
	151
	152	key.objectid = inode_objectid;
	153	key.offset = ref_objectid;
	154	btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
	155
	156	path = btrfs_alloc_path();
	157	if (!path)
	158	return -ENOMEM;
	159
b9473439	160	path->leave_spinning = 1;
3954401f CM	161	ret = btrfs_insert_empty_item(trans, root, path, &key,
	162	ins_len);
	163	if (ret == -EEXIST) {
	164	u32 old_size;
	165
	166	if (find_name_in_backref(path, name, name_len, &ref))
	167	goto out;
	168
	169	old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
143bede5	170	btrfs_extend_item(trans, root, path, ins_len);
3954401f CM	171	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	172	struct btrfs_inode_ref);
	173	ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
	174	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	175	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	176	ptr = (unsigned long)(ref + 1);
	177	ret = 0;
	178	} else if (ret < 0) {
a5719521 YZ	179	if (ret == -EOVERFLOW)
a5719521 YZ	180	ret = -EMLINK;
3954401f CM	181	goto out;
	182	} else {
	183	ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
	184	struct btrfs_inode_ref);
	185	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
aec7477b	186	btrfs_set_inode_ref_index(path->nodes[0], ref, index);
3954401f CM	187	ptr = (unsigned long)(ref + 1);
	188	}
	189	write_extent_buffer(path->nodes[0], name, ptr, name_len);
	190	btrfs_mark_buffer_dirty(path->nodes[0]);
	191
	192	out:
	193	btrfs_free_path(path);
	194	return ret;
	195	}
	196
5f39d397 CM	197	int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
	198	struct btrfs_root *root,
	199	struct btrfs_path *path, u64 objectid)
1e1d2701	200	{
1e1d2701 CM	201	struct btrfs_key key;
	202	int ret;
	203	key.objectid = objectid;
1e1d2701 CM	204	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
	205	key.offset = 0;
	206
5f39d397 CM	207	ret = btrfs_insert_empty_item(trans, root, path, &key,
5f39d397 CM	208	sizeof(struct btrfs_inode_item));
1e1d2701 CM	209	return ret;
	210	}
	211
e089f05c	212	int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
d6e4a428 CM	213	root, struct btrfs_path path,
d6e4a428 CM	214	struct btrfs_key *location, int mod)
1e1d2701	215	{
1e1d2701 CM	216	int ins_len = mod < 0 ? -1 : 0;
1e1d2701 CM	217	int cow = mod != 0;
d6e4a428 CM	218	int ret;
d6e4a428 CM	219	int slot;
5f39d397	220	struct extent_buffer *leaf;
d6e4a428	221	struct btrfs_key found_key;
1e1d2701	222
d6e4a428 CM	223	ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
	224	if (ret > 0 && btrfs_key_type(location) == BTRFS_ROOT_ITEM_KEY &&
	225	location->offset == (u64)-1 && path->slots[0] != 0) {
	226	slot = path->slots[0] - 1;
5f39d397 CM	227	leaf = path->nodes[0];
5f39d397 CM	228	btrfs_item_key_to_cpu(leaf, &found_key, slot);
d6e4a428 CM	229	if (found_key.objectid == location->objectid &&
	230	btrfs_key_type(&found_key) == btrfs_key_type(location)) {
	231	path->slots[0]--;
	232	return 0;
	233	}
	234	}
	235	return ret;
1e1d2701	236	}