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
btrfs_find_highest_inode(struct btrfs_root * root,u64 * objectid)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 */
btrfs_find_free_objectid(struct btrfs_trans_handle * trans,struct btrfs_root * root,u64 dirid,u64 * objectid)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 start_found = 0;
88 ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
89 if (ret < 0)
90 goto error;
91
92 while (1) {
93 l = path->nodes[0];
94 slot = path->slots[0];
95 if (slot >= btrfs_header_nritems(l)) {
96 ret = btrfs_next_leaf(root, path);
97 if (ret == 0)
98 continue;
99 if (ret < 0)
100 goto error;
101 if (!start_found) {
102 *objectid = search_start;
103 start_found = 1;
104 goto found;
105 }
106 *objectid = last_ino > search_start ?
107 last_ino : search_start;
108 goto found;
109 }
110 btrfs_item_key_to_cpu(l, &key, slot);
111 if (key.objectid >= search_start) {
112 if (start_found) {
113 if (last_ino < search_start)
114 last_ino = search_start;
115 if (key.objectid > last_ino) {
116 *objectid = last_ino;
117 goto found;
118 }
119 } else if (key.objectid > search_start) {
120 *objectid = search_start;
121 goto found;
122 }
123 }
124 if (key.objectid >= BTRFS_LAST_FREE_OBJECTID)
125 break;
126
127 start_found = 1;
128 last_ino = key.objectid + 1;
129 path->slots[0]++;
130 }
131 BUG_ON(1);
132 found:
133 btrfs_release_path(root, path);
134 btrfs_free_path(path);
135 BUG_ON(*objectid < search_start);
136 mutex_unlock(&root->objectid_mutex);
137 return 0;
138 error:
139 btrfs_release_path(root, path);
140 btrfs_free_path(path);
141 mutex_unlock(&root->objectid_mutex);
142 return ret;
143 }
144