Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 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; |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 41 | kmem_cache_t *configfs_dir_cachep; |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 42 | static int configfs_mnt_count = 0; |
| 43 | |
| 44 | static struct super_operations configfs_ops = { |
| 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, |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 66 | .s_iattr = NULL, |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 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; |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 78 | sb->s_time_gran = 1; |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 79 | configfs_sb = sb; |
| 80 | |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 81 | inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, |
| 82 | &configfs_root); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 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 | } |
| 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 | |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 106 | static int configfs_get_sb(struct file_system_type *fs_type, |
| 107 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 108 | { |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 109 | return get_sb_single(fs_type, flags, data, configfs_fill_super, mnt); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 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 | { |
| 121 | return simple_pin_fs("configfs", &configfs_mount, |
| 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 | { |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 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; |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 142 | |
| 143 | kset_set_kset_s(&config_subsys, kernel_subsys); |
| 144 | err = subsystem_register(&config_subsys); |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 145 | if (err) { |
| 146 | kmem_cache_destroy(configfs_dir_cachep); |
| 147 | configfs_dir_cachep = NULL; |
| 148 | goto out; |
| 149 | } |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 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); |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 155 | kmem_cache_destroy(configfs_dir_cachep); |
| 156 | configfs_dir_cachep = NULL; |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 157 | } |
| 158 | |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 159 | out: |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 160 | return err; |
| 161 | } |
| 162 | |
| 163 | static void __exit configfs_exit(void) |
| 164 | { |
| 165 | unregister_filesystem(&configfs_fs_type); |
| 166 | subsystem_unregister(&config_subsys); |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 167 | kmem_cache_destroy(configfs_dir_cachep); |
| 168 | configfs_dir_cachep = NULL; |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 169 | } |
| 170 | |
| 171 | MODULE_AUTHOR("Oracle"); |
| 172 | MODULE_LICENSE("GPL"); |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 173 | MODULE_VERSION("0.0.2"); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 174 | MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration."); |
| 175 | |
| 176 | module_init(configfs_init); |
| 177 | module_exit(configfs_exit); |