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7063fbf2 JB |
1 | /* -*- mode: c; c-basic-offset: 8; -*- |
2 | * vim: noexpandtab sw=8 ts=8 sts=0: | |
3 | * | |
4 | * mount.c - operations for initializing and mounting configfs. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public | |
8 | * License as published by the Free Software Foundation; either | |
9 | * version 2 of the License, or (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public | |
17 | * License along with this program; if not, write to the | |
18 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
19 | * Boston, MA 021110-1307, USA. | |
20 | * | |
21 | * Based on sysfs: | |
22 | * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel | |
23 | * | |
24 | * configfs Copyright (C) 2005 Oracle. All rights reserved. | |
25 | */ | |
26 | ||
27 | #include <linux/fs.h> | |
28 | #include <linux/module.h> | |
29 | #include <linux/mount.h> | |
30 | #include <linux/pagemap.h> | |
31 | #include <linux/init.h> | |
32 | ||
33 | #include <linux/configfs.h> | |
34 | #include "configfs_internal.h" | |
35 | ||
36 | /* Random magic number */ | |
37 | #define CONFIGFS_MAGIC 0x62656570 | |
38 | ||
39 | struct vfsmount * configfs_mount = NULL; | |
40 | struct super_block * configfs_sb = NULL; | |
e18b890b | 41 | struct kmem_cache *configfs_dir_cachep; |
7063fbf2 JB |
42 | static int configfs_mnt_count = 0; |
43 | ||
ee9b6d61 | 44 | static const struct super_operations configfs_ops = { |
7063fbf2 JB |
45 | .statfs = simple_statfs, |
46 | .drop_inode = generic_delete_inode, | |
47 | }; | |
48 | ||
49 | static struct config_group configfs_root_group = { | |
50 | .cg_item = { | |
51 | .ci_namebuf = "root", | |
52 | .ci_name = configfs_root_group.cg_item.ci_namebuf, | |
53 | }, | |
54 | }; | |
55 | ||
56 | int configfs_is_root(struct config_item *item) | |
57 | { | |
58 | return item == &configfs_root_group.cg_item; | |
59 | } | |
60 | ||
61 | static struct configfs_dirent configfs_root = { | |
62 | .s_sibling = LIST_HEAD_INIT(configfs_root.s_sibling), | |
63 | .s_children = LIST_HEAD_INIT(configfs_root.s_children), | |
64 | .s_element = &configfs_root_group.cg_item, | |
65 | .s_type = CONFIGFS_ROOT, | |
3d0f89bb | 66 | .s_iattr = NULL, |
7063fbf2 JB |
67 | }; |
68 | ||
69 | static int configfs_fill_super(struct super_block *sb, void *data, int silent) | |
70 | { | |
71 | struct inode *inode; | |
72 | struct dentry *root; | |
73 | ||
74 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
75 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
76 | sb->s_magic = CONFIGFS_MAGIC; | |
77 | sb->s_op = &configfs_ops; | |
3d0f89bb | 78 | sb->s_time_gran = 1; |
7063fbf2 JB |
79 | configfs_sb = sb; |
80 | ||
3d0f89bb JB |
81 | inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, |
82 | &configfs_root); | |
7063fbf2 JB |
83 | if (inode) { |
84 | inode->i_op = &configfs_dir_inode_operations; | |
85 | inode->i_fop = &configfs_dir_operations; | |
86 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
d8c76e6f | 87 | inc_nlink(inode); |
7063fbf2 JB |
88 | } else { |
89 | pr_debug("configfs: could not get root inode\n"); | |
90 | return -ENOMEM; | |
91 | } | |
92 | ||
93 | root = d_alloc_root(inode); | |
94 | if (!root) { | |
95 | pr_debug("%s: could not get root dentry!\n",__FUNCTION__); | |
96 | iput(inode); | |
97 | return -ENOMEM; | |
98 | } | |
99 | config_group_init(&configfs_root_group); | |
100 | configfs_root_group.cg_item.ci_dentry = root; | |
101 | root->d_fsdata = &configfs_root; | |
102 | sb->s_root = root; | |
103 | return 0; | |
104 | } | |
105 | ||
454e2398 DH |
106 | static int configfs_get_sb(struct file_system_type *fs_type, |
107 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
7063fbf2 | 108 | { |
454e2398 | 109 | return get_sb_single(fs_type, flags, data, configfs_fill_super, mnt); |
7063fbf2 JB |
110 | } |
111 | ||
112 | static struct file_system_type configfs_fs_type = { | |
113 | .owner = THIS_MODULE, | |
114 | .name = "configfs", | |
115 | .get_sb = configfs_get_sb, | |
116 | .kill_sb = kill_litter_super, | |
117 | }; | |
118 | ||
119 | int configfs_pin_fs(void) | |
120 | { | |
1f5ce9e9 | 121 | return simple_pin_fs(&configfs_fs_type, &configfs_mount, |
7063fbf2 JB |
122 | &configfs_mnt_count); |
123 | } | |
124 | ||
125 | void configfs_release_fs(void) | |
126 | { | |
127 | simple_release_fs(&configfs_mount, &configfs_mnt_count); | |
128 | } | |
129 | ||
130 | ||
131 | static decl_subsys(config, NULL, NULL); | |
132 | ||
133 | static int __init configfs_init(void) | |
134 | { | |
3d0f89bb JB |
135 | int err = -ENOMEM; |
136 | ||
137 | configfs_dir_cachep = kmem_cache_create("configfs_dir_cache", | |
138 | sizeof(struct configfs_dirent), | |
139 | 0, 0, NULL, NULL); | |
140 | if (!configfs_dir_cachep) | |
141 | goto out; | |
7063fbf2 | 142 | |
823bccfc | 143 | kobj_set_kset_s(&config_subsys, kernel_subsys); |
7063fbf2 | 144 | err = subsystem_register(&config_subsys); |
3d0f89bb JB |
145 | if (err) { |
146 | kmem_cache_destroy(configfs_dir_cachep); | |
147 | configfs_dir_cachep = NULL; | |
148 | goto out; | |
149 | } | |
7063fbf2 JB |
150 | |
151 | err = register_filesystem(&configfs_fs_type); | |
152 | if (err) { | |
153 | printk(KERN_ERR "configfs: Unable to register filesystem!\n"); | |
154 | subsystem_unregister(&config_subsys); | |
3d0f89bb JB |
155 | kmem_cache_destroy(configfs_dir_cachep); |
156 | configfs_dir_cachep = NULL; | |
7063fbf2 JB |
157 | } |
158 | ||
3d0f89bb | 159 | out: |
7063fbf2 JB |
160 | return err; |
161 | } | |
162 | ||
163 | static void __exit configfs_exit(void) | |
164 | { | |
165 | unregister_filesystem(&configfs_fs_type); | |
166 | subsystem_unregister(&config_subsys); | |
3d0f89bb JB |
167 | kmem_cache_destroy(configfs_dir_cachep); |
168 | configfs_dir_cachep = NULL; | |
7063fbf2 JB |
169 | } |
170 | ||
171 | MODULE_AUTHOR("Oracle"); | |
172 | MODULE_LICENSE("GPL"); | |
3d0f89bb | 173 | MODULE_VERSION("0.0.2"); |
7063fbf2 JB |
174 | MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration."); |
175 | ||
176 | module_init(configfs_init); | |
177 | module_exit(configfs_exit); |