summaryrefslogtreecommitdiffstats
path: root/fs/btrfs/inode-map.c
blob: 80038c5ef7cf8678fc6d70f172fee2129eb0d4f7 (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
/*
 * 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"

int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid)
{
	struct btrfs_path *path;
	int ret;
	struct extent_buffer *l;
	struct btrfs_key search_key;
	struct btrfs_key found_key;
	int slot;

	path = btrfs_alloc_path();
	BUG_ON(!path);

	search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
	search_key.type = -1;
	search_key.offset = (u64)-1;
	ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
	if (ret < 0)
		goto error;
	BUG_ON(ret == 0);
	if (path->slots[0] > 0) {
		slot = path->slots[0] - 1;
		l = path->nodes[0];
		btrfs_item_key_to_cpu(l, &found_key, slot);
		*objectid = found_key.objectid;
	} else {
		*objectid = BTRFS_FIRST_FREE_OBJECTID;
	}
	ret = 0;
error:
	btrfs_free_path(path);
	return ret;
}

/*
 * walks the btree of allocated inodes and find a hole.
 */
int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
			     struct btrfs_root *root,
			     u64 dirid, u64 *objectid)
{
	struct btrfs_path *path;
	struct btrfs_key key;
	int ret;
	int slot = 0;
	u64 last_ino = 0;
	int start_found;
	struct extent_buffer *l;
	struct btrfs_key search_key;
	u64 search_start = dirid;

	mutex_lock(&root->objectid_mutex);
	if (root->last_inode_alloc >= BTRFS_FIRST_FREE_OBJECTID &&
	    root->last_inode_alloc < BTRFS_LAST_FREE_OBJECTID) {
		*objectid = ++root->last_inode_alloc;
		mutex_unlock(&root->objectid_mutex);
		return 0;
	}
	path = btrfs_alloc_path();
	BUG_ON(!path);
	search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
	search_key.objectid = search_start;
	search_key.type = 0;
	search_key.offset = 0;

	btrfs_init_path(path);
	start_found = 0;
	ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
	if (ret < 0)
		goto error;

	while (1) {
		l = path->nodes[0];
		slot = path->slots[0];
		if (slot >= btrfs_header_nritems(l)) {
			ret = btrfs_next_leaf(root, path);
			if (ret == 0)
				continue;
			if (ret < 0)
				goto error;
			if (!start_found) {
				*objectid = search_start;
				start_found = 1;
				goto found;
			}
			*objectid = last_ino > search_start ?
				last_ino : search_start;
			goto found;
		}
		btrfs_item_key_to_cpu(l, &key, slot);
		if (key.objectid >= search_start) {
			if (start_found) {
				if (last_ino < search_start)
					last_ino = search_start;
				if (key.objectid > last_ino) {
					*objectid = last_ino;
					goto found;
				}
			} else if (key.objectid > search_start) {
				*objectid = search_start;
				goto found;
			}
		}
		if (key.objectid >= BTRFS_LAST_FREE_OBJECTID)
			break;

		start_found = 1;
		last_ino = key.objectid + 1;
		path->slots[0]++;
	}
	// FIXME -ENOSPC
	BUG_ON(1);
found:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	BUG_ON(*objectid < search_start);
	mutex_unlock(&root->objectid_mutex);
	return 0;
error:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	mutex_unlock(&root->objectid_mutex);
	return ret;
}