summaryrefslogtreecommitdiff
path: root/fs/btrfs/root-tree.c
blob: 271dd2b5c3215b4aaaad8322b8420aa3afad5efd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/*
 * 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 "transaction.h"
#include "disk-io.h"
#include "print-tree.h"

int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
			struct btrfs_root_item *item, struct btrfs_key *key)
{
	struct btrfs_path *path;
	struct btrfs_key search_key;
	struct btrfs_leaf *l;
	int ret;
	int slot;

	search_key.objectid = objectid;
	search_key.flags = (u32)-1;
	search_key.offset = (u64)-1;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
	if (ret < 0)
		goto out;
	BUG_ON(ret == 0);
	l = btrfs_buffer_leaf(path->nodes[0]);
	BUG_ON(path->slots[0] == 0);
	slot = path->slots[0] - 1;
	if (btrfs_disk_key_objectid(&l->items[slot].key) != objectid) {
		ret = 1;
		goto out;
	}
	memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item),
		sizeof(*item));
	btrfs_disk_key_to_cpu(key, &l->items[slot].key);
	ret = 0;
out:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	return ret;
}

int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
		      *root, struct btrfs_key *key, struct btrfs_root_item
		      *item)
{
	struct btrfs_path *path;
	struct btrfs_leaf *l;
	int ret;
	int slot;
	struct btrfs_root_item *update_item;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	ret = btrfs_search_slot(trans, root, key, path, 0, 1);
	if (ret < 0)
		goto out;
	BUG_ON(ret != 0);
	l = btrfs_buffer_leaf(path->nodes[0]);
	slot = path->slots[0];
	update_item = btrfs_item_ptr(l, slot, struct btrfs_root_item);
	btrfs_memcpy(root, l, update_item, item, sizeof(*item));
	btrfs_mark_buffer_dirty(path->nodes[0]);
out:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	return ret;
}

int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
		      *root, struct btrfs_key *key, struct btrfs_root_item
		      *item)
{
	int ret;
	ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
	return ret;
}

int btrfs_find_dead_roots(struct btrfs_root *root)
{
	struct btrfs_root *dead_root;
	struct btrfs_item *item;
	struct btrfs_root_item *ri;
	struct btrfs_key key;
	struct btrfs_path *path;
	int ret;
	u32 nritems;
	struct btrfs_leaf *leaf;
	int slot;

	key.objectid = 0;
	key.flags = 0;
	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
	key.offset = 0;
	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto err;
	while(1) {
		leaf = btrfs_buffer_leaf(path->nodes[0]);
		nritems = btrfs_header_nritems(&leaf->header);
		slot = path->slots[0];
		if (slot >= nritems) {
			ret = btrfs_next_leaf(root, path);
			if (ret)
				break;
			leaf = btrfs_buffer_leaf(path->nodes[0]);
			nritems = btrfs_header_nritems(&leaf->header);
			slot = path->slots[0];
		}
		item = leaf->items + slot;
		btrfs_disk_key_to_cpu(&key, &item->key);
		if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
			goto next;
		ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
		if (btrfs_root_refs(ri) != 0)
			goto next;
		dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key);
		if (IS_ERR(root)) {
			ret = PTR_ERR(root);
			goto err;
		}
		ret = btrfs_add_dead_root(dead_root,
					  &root->fs_info->dead_roots);
		if (ret)
			goto err;
next:
		slot++;
		path->slots[0]++;
	}
	ret = 0;
err:
	btrfs_free_path(path);
	return ret;
}

int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
		   struct btrfs_key *key)
{
	struct btrfs_path *path;
	int ret;
	u32 refs;
	struct btrfs_root_item *ri;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	ret = btrfs_search_slot(trans, root, key, path, -1, 1);
	if (ret < 0)
		goto out;
	BUG_ON(ret != 0);
	ri = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
			    path->slots[0], struct btrfs_root_item);

	refs = btrfs_root_refs(ri);
	BUG_ON(refs != 0);
	ret = btrfs_del_item(trans, root, path);
out:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	return ret;
}