ia64/linux-2.6.18-xen.hg

view fs/configfs/mount.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
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 */
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>
33 #include <linux/configfs.h>
34 #include "configfs_internal.h"
36 /* Random magic number */
37 #define CONFIGFS_MAGIC 0x62656570
39 struct vfsmount * configfs_mount = NULL;
40 struct super_block * configfs_sb = NULL;
41 kmem_cache_t *configfs_dir_cachep;
42 static int configfs_mnt_count = 0;
44 static struct super_operations configfs_ops = {
45 .statfs = simple_statfs,
46 .drop_inode = generic_delete_inode,
47 };
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 };
56 int configfs_is_root(struct config_item *item)
57 {
58 return item == &configfs_root_group.cg_item;
59 }
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,
66 .s_iattr = NULL,
67 };
69 static int configfs_fill_super(struct super_block *sb, void *data, int silent)
70 {
71 struct inode *inode;
72 struct dentry *root;
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;
78 sb->s_time_gran = 1;
79 configfs_sb = sb;
81 inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
82 &configfs_root);
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) */
87 inode->i_nlink++;
88 } else {
89 pr_debug("configfs: could not get root inode\n");
90 return -ENOMEM;
91 }
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 }
106 static int configfs_get_sb(struct file_system_type *fs_type,
107 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
108 {
109 return get_sb_single(fs_type, flags, data, configfs_fill_super, mnt);
110 }
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 };
119 int configfs_pin_fs(void)
120 {
121 return simple_pin_fs(&configfs_fs_type, &configfs_mount,
122 &configfs_mnt_count);
123 }
125 void configfs_release_fs(void)
126 {
127 simple_release_fs(&configfs_mount, &configfs_mnt_count);
128 }
131 static decl_subsys(config, NULL, NULL);
133 static int __init configfs_init(void)
134 {
135 int err = -ENOMEM;
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;
143 kset_set_kset_s(&config_subsys, kernel_subsys);
144 err = subsystem_register(&config_subsys);
145 if (err) {
146 kmem_cache_destroy(configfs_dir_cachep);
147 configfs_dir_cachep = NULL;
148 goto out;
149 }
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);
155 kmem_cache_destroy(configfs_dir_cachep);
156 configfs_dir_cachep = NULL;
157 }
159 out:
160 return err;
161 }
163 static void __exit configfs_exit(void)
164 {
165 unregister_filesystem(&configfs_fs_type);
166 subsystem_unregister(&config_subsys);
167 kmem_cache_destroy(configfs_dir_cachep);
168 configfs_dir_cachep = NULL;
169 }
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);