Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm
[linux-2.6] / fs / btrfs / inode-map.c
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
19 #include "ctree.h"
20 #include "disk-io.h"
21 #include "transaction.h"
22
23 int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid)
24 {
25         struct btrfs_path *path;
26         int ret;
27         struct extent_buffer *l;
28         struct btrfs_key search_key;
29         struct btrfs_key found_key;
30         int slot;
31
32         path = btrfs_alloc_path();
33         BUG_ON(!path);
34
35         search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
36         search_key.type = -1;
37         search_key.offset = (u64)-1;
38         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
39         if (ret < 0)
40                 goto error;
41         BUG_ON(ret == 0);
42         if (path->slots[0] > 0) {
43                 slot = path->slots[0] - 1;
44                 l = path->nodes[0];
45                 btrfs_item_key_to_cpu(l, &found_key, slot);
46                 *objectid = found_key.objectid;
47         } else {
48                 *objectid = BTRFS_FIRST_FREE_OBJECTID;
49         }
50         ret = 0;
51 error:
52         btrfs_free_path(path);
53         return ret;
54 }
55
56 /*
57  * walks the btree of allocated inodes and find a hole.
58  */
59 int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
60                              struct btrfs_root *root,
61                              u64 dirid, u64 *objectid)
62 {
63         struct btrfs_path *path;
64         struct btrfs_key key;
65         int ret;
66         int slot = 0;
67         u64 last_ino = 0;
68         int start_found;
69         struct extent_buffer *l;
70         struct btrfs_key search_key;
71         u64 search_start = dirid;
72
73         mutex_lock(&root->objectid_mutex);
74         if (root->last_inode_alloc >= BTRFS_FIRST_FREE_OBJECTID &&
75             root->last_inode_alloc < BTRFS_LAST_FREE_OBJECTID) {
76                 *objectid = ++root->last_inode_alloc;
77                 mutex_unlock(&root->objectid_mutex);
78                 return 0;
79         }
80         path = btrfs_alloc_path();
81         BUG_ON(!path);
82         search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
83         search_key.objectid = search_start;
84         search_key.type = 0;
85         search_key.offset = 0;
86
87         btrfs_init_path(path);
88         start_found = 0;
89         ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
90         if (ret < 0)
91                 goto error;
92
93         while (1) {
94                 l = path->nodes[0];
95                 slot = path->slots[0];
96                 if (slot >= btrfs_header_nritems(l)) {
97                         ret = btrfs_next_leaf(root, path);
98                         if (ret == 0)
99                                 continue;
100                         if (ret < 0)
101                                 goto error;
102                         if (!start_found) {
103                                 *objectid = search_start;
104                                 start_found = 1;
105                                 goto found;
106                         }
107                         *objectid = last_ino > search_start ?
108                                 last_ino : search_start;
109                         goto found;
110                 }
111                 btrfs_item_key_to_cpu(l, &key, slot);
112                 if (key.objectid >= search_start) {
113                         if (start_found) {
114                                 if (last_ino < search_start)
115                                         last_ino = search_start;
116                                 if (key.objectid > last_ino) {
117                                         *objectid = last_ino;
118                                         goto found;
119                                 }
120                         } else if (key.objectid > search_start) {
121                                 *objectid = search_start;
122                                 goto found;
123                         }
124                 }
125                 if (key.objectid >= BTRFS_LAST_FREE_OBJECTID)
126                         break;
127
128                 start_found = 1;
129                 last_ino = key.objectid + 1;
130                 path->slots[0]++;
131         }
132         BUG_ON(1);
133 found:
134         btrfs_release_path(root, path);
135         btrfs_free_path(path);
136         BUG_ON(*objectid < search_start);
137         mutex_unlock(&root->objectid_mutex);
138         return 0;
139 error:
140         btrfs_release_path(root, path);
141         btrfs_free_path(path);
142         mutex_unlock(&root->objectid_mutex);
143         return ret;
144 }