1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
4 * mount.c - operations for initializing and mounting configfs.
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.
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.
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.
22 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
24 * configfs Copyright (C) 2005 Oracle. All rights reserved.
28 #include <linux/module.h>
29 #include <linux/mount.h>
30 #include <linux/pagemap.h>
31 #include <linux/init.h>
32 #include <linux/slab.h>
34 #include <linux/configfs.h>
35 #include "configfs_internal.h"
37 /* Random magic number */
38 #define CONFIGFS_MAGIC 0x62656570
40 static struct vfsmount *configfs_mount = NULL;
41 struct kmem_cache *configfs_dir_cachep;
42 static int configfs_mnt_count = 0;
44 static const struct super_operations configfs_ops = {
45 .statfs = simple_statfs,
46 .drop_inode = generic_delete_inode,
49 static struct config_group configfs_root_group = {
52 .ci_name = configfs_root_group.cg_item.ci_namebuf,
56 int configfs_is_root(struct config_item *item)
58 return item == &configfs_root_group.cg_item;
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,
69 static int configfs_fill_super(struct super_block *sb, void *data, int silent)
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;
80 inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
83 inode->i_op = &configfs_root_inode_operations;
84 inode->i_fop = &configfs_dir_operations;
85 /* directory inodes start off with i_nlink == 2 (for "." entry) */
88 pr_debug("could not get root inode\n");
92 root = d_make_root(inode);
94 pr_debug("%s: could not get root dentry!\n",__func__);
97 config_group_init(&configfs_root_group);
98 configfs_root_group.cg_item.ci_dentry = root;
99 root->d_fsdata = &configfs_root;
101 sb->s_d_op = &configfs_dentry_ops; /* the rest get that */
105 static struct dentry *configfs_do_mount(struct file_system_type *fs_type,
106 int flags, const char *dev_name, void *data)
108 return mount_single(fs_type, flags, data, configfs_fill_super);
111 static struct file_system_type configfs_fs_type = {
112 .owner = THIS_MODULE,
114 .mount = configfs_do_mount,
115 .kill_sb = kill_litter_super,
117 MODULE_ALIAS_FS("configfs");
119 struct dentry *configfs_pin_fs(void)
121 int err = simple_pin_fs(&configfs_fs_type, &configfs_mount,
122 &configfs_mnt_count);
123 return err ? ERR_PTR(err) : configfs_mount->mnt_root;
126 void configfs_release_fs(void)
128 simple_release_fs(&configfs_mount, &configfs_mnt_count);
132 static struct kobject *config_kobj;
134 static int __init configfs_init(void)
138 configfs_dir_cachep = kmem_cache_create("configfs_dir_cache",
139 sizeof(struct configfs_dirent),
141 if (!configfs_dir_cachep)
144 config_kobj = kobject_create_and_add("config", kernel_kobj);
148 err = register_filesystem(&configfs_fs_type);
154 pr_err("Unable to register filesystem!\n");
155 kobject_put(config_kobj);
157 kmem_cache_destroy(configfs_dir_cachep);
158 configfs_dir_cachep = NULL;
163 static void __exit configfs_exit(void)
165 unregister_filesystem(&configfs_fs_type);
166 kobject_put(config_kobj);
167 kmem_cache_destroy(configfs_dir_cachep);
168 configfs_dir_cachep = NULL;
171 MODULE_AUTHOR("Oracle");
172 MODULE_LICENSE("GPL");
173 MODULE_VERSION("0.0.2");
174 MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration.");
176 module_init(configfs_init);
177 module_exit(configfs_exit);