mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
183 lines
4.7 KiB
C
183 lines
4.7 KiB
C
/* -*- 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 <linux/fs.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/configfs.h>
|
|
#include "configfs_internal.h"
|
|
|
|
/* Random magic number */
|
|
#define CONFIGFS_MAGIC 0x62656570
|
|
|
|
static struct vfsmount *configfs_mount = NULL;
|
|
struct kmem_cache *configfs_dir_cachep;
|
|
static int configfs_mnt_count = 0;
|
|
|
|
static const 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,
|
|
.s_iattr = NULL,
|
|
};
|
|
|
|
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;
|
|
sb->s_time_gran = 1;
|
|
|
|
inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
|
|
&configfs_root, sb);
|
|
if (inode) {
|
|
inode->i_op = &configfs_root_inode_operations;
|
|
inode->i_fop = &configfs_dir_operations;
|
|
/* directory inodes start off with i_nlink == 2 (for "." entry) */
|
|
inc_nlink(inode);
|
|
} else {
|
|
pr_debug("configfs: could not get root inode\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
root = d_make_root(inode);
|
|
if (!root) {
|
|
pr_debug("%s: could not get root dentry!\n",__func__);
|
|
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;
|
|
sb->s_d_op = &configfs_dentry_ops; /* the rest get that */
|
|
return 0;
|
|
}
|
|
|
|
static struct dentry *configfs_do_mount(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name, void *data)
|
|
{
|
|
return mount_single(fs_type, flags, data, configfs_fill_super);
|
|
}
|
|
|
|
static struct file_system_type configfs_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "configfs",
|
|
.mount = configfs_do_mount,
|
|
.kill_sb = kill_litter_super,
|
|
};
|
|
|
|
struct dentry *configfs_pin_fs(void)
|
|
{
|
|
int err = simple_pin_fs(&configfs_fs_type, &configfs_mount,
|
|
&configfs_mnt_count);
|
|
return err ? ERR_PTR(err) : configfs_mount->mnt_root;
|
|
}
|
|
|
|
void configfs_release_fs(void)
|
|
{
|
|
simple_release_fs(&configfs_mount, &configfs_mnt_count);
|
|
}
|
|
|
|
|
|
static struct kobject *config_kobj;
|
|
|
|
static int __init configfs_init(void)
|
|
{
|
|
int err = -ENOMEM;
|
|
|
|
configfs_dir_cachep = kmem_cache_create("configfs_dir_cache",
|
|
sizeof(struct configfs_dirent),
|
|
0, 0, NULL);
|
|
if (!configfs_dir_cachep)
|
|
goto out;
|
|
|
|
config_kobj = kobject_create_and_add("config", kernel_kobj);
|
|
if (!config_kobj)
|
|
goto out2;
|
|
|
|
err = configfs_inode_init();
|
|
if (err)
|
|
goto out3;
|
|
|
|
err = register_filesystem(&configfs_fs_type);
|
|
if (err)
|
|
goto out4;
|
|
|
|
return 0;
|
|
out4:
|
|
printk(KERN_ERR "configfs: Unable to register filesystem!\n");
|
|
configfs_inode_exit();
|
|
out3:
|
|
kobject_put(config_kobj);
|
|
out2:
|
|
kmem_cache_destroy(configfs_dir_cachep);
|
|
configfs_dir_cachep = NULL;
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static void __exit configfs_exit(void)
|
|
{
|
|
unregister_filesystem(&configfs_fs_type);
|
|
kobject_put(config_kobj);
|
|
kmem_cache_destroy(configfs_dir_cachep);
|
|
configfs_dir_cachep = NULL;
|
|
configfs_inode_exit();
|
|
}
|
|
|
|
MODULE_AUTHOR("Oracle");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION("0.0.2");
|
|
MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration.");
|
|
|
|
module_init(configfs_init);
|
|
module_exit(configfs_exit);
|