From 7063fbf2261194f72ee75afca67b3b38b554b5fa Mon Sep 17 00:00:00 2001 From: Joel Becker Date: Thu, 15 Dec 2005 14:29:43 -0800 Subject: [PATCH] configfs: User-driven configuration filesystem Configfs, a file system for userspace-driven kernel object configuration. The OCFS2 stack makes extensive use of this for propagation of cluster configuration information into kernel. Signed-off-by: Joel Becker --- fs/configfs/mount.c | 159 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 fs/configfs/mount.c (limited to 'fs/configfs/mount.c') diff --git a/fs/configfs/mount.c b/fs/configfs/mount.c new file mode 100644 index 00000000000000..1a2f6f6a4d917d --- /dev/null +++ b/fs/configfs/mount.c @@ -0,0 +1,159 @@ +/* -*- mode: c; c-basic-offset: 8; -*- + * vim: noexpandtab sw=8 ts=8 sts=0: + * + * mount.c - operations for initializing and mounting configfs. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + * + * Based on sysfs: + * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel + * + * configfs Copyright (C) 2005 Oracle. All rights reserved. + */ + +#include +#include +#include +#include +#include + +#include +#include "configfs_internal.h" + +/* Random magic number */ +#define CONFIGFS_MAGIC 0x62656570 + +struct vfsmount * configfs_mount = NULL; +struct super_block * configfs_sb = NULL; +static int configfs_mnt_count = 0; + +static struct super_operations configfs_ops = { + .statfs = simple_statfs, + .drop_inode = generic_delete_inode, +}; + +static struct config_group configfs_root_group = { + .cg_item = { + .ci_namebuf = "root", + .ci_name = configfs_root_group.cg_item.ci_namebuf, + }, +}; + +int configfs_is_root(struct config_item *item) +{ + return item == &configfs_root_group.cg_item; +} + +static struct configfs_dirent configfs_root = { + .s_sibling = LIST_HEAD_INIT(configfs_root.s_sibling), + .s_children = LIST_HEAD_INIT(configfs_root.s_children), + .s_element = &configfs_root_group.cg_item, + .s_type = CONFIGFS_ROOT, +}; + +static int configfs_fill_super(struct super_block *sb, void *data, int silent) +{ + struct inode *inode; + struct dentry *root; + + sb->s_blocksize = PAGE_CACHE_SIZE; + sb->s_blocksize_bits = PAGE_CACHE_SHIFT; + sb->s_magic = CONFIGFS_MAGIC; + sb->s_op = &configfs_ops; + configfs_sb = sb; + + inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO); + if (inode) { + inode->i_op = &configfs_dir_inode_operations; + inode->i_fop = &configfs_dir_operations; + /* directory inodes start off with i_nlink == 2 (for "." entry) */ + inode->i_nlink++; + } else { + pr_debug("configfs: could not get root inode\n"); + return -ENOMEM; + } + + root = d_alloc_root(inode); + if (!root) { + pr_debug("%s: could not get root dentry!\n",__FUNCTION__); + iput(inode); + return -ENOMEM; + } + config_group_init(&configfs_root_group); + configfs_root_group.cg_item.ci_dentry = root; + root->d_fsdata = &configfs_root; + sb->s_root = root; + return 0; +} + +static struct super_block *configfs_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data) +{ + return get_sb_single(fs_type, flags, data, configfs_fill_super); +} + +static struct file_system_type configfs_fs_type = { + .owner = THIS_MODULE, + .name = "configfs", + .get_sb = configfs_get_sb, + .kill_sb = kill_litter_super, +}; + +int configfs_pin_fs(void) +{ + return simple_pin_fs("configfs", &configfs_mount, + &configfs_mnt_count); +} + +void configfs_release_fs(void) +{ + simple_release_fs(&configfs_mount, &configfs_mnt_count); +} + + +static decl_subsys(config, NULL, NULL); + +static int __init configfs_init(void) +{ + int err; + + kset_set_kset_s(&config_subsys, kernel_subsys); + err = subsystem_register(&config_subsys); + if (err) + return err; + + err = register_filesystem(&configfs_fs_type); + if (err) { + printk(KERN_ERR "configfs: Unable to register filesystem!\n"); + subsystem_unregister(&config_subsys); + } + + return err; +} + +static void __exit configfs_exit(void) +{ + unregister_filesystem(&configfs_fs_type); + subsystem_unregister(&config_subsys); +} + +MODULE_AUTHOR("Oracle"); +MODULE_LICENSE("GPL"); +MODULE_VERSION("0.0.1"); +MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration."); + +module_init(configfs_init); +module_exit(configfs_exit); -- cgit 1.2.3-korg