[linux.git] / fs / sysfs / mount.c

/*
 * fs/sysfs/symlink.c - operations for initializing and mounting sysfs
 *
 * Copyright (c) 2001-3 Patrick Mochel
 * Copyright (c) 2007 SUSE Linux Products GmbH
 * Copyright (c) 2007 Tejun Heo <[email protected]>
 *
 * This file is released under the GPLv2.
 *
 * Please see Documentation/filesystems/sysfs.txt for more information.
 */

#define DEBUG 

#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/module.h>

#include "sysfs.h"

/* Random magic number */
#define SYSFS_MAGIC 0x62656572

static struct vfsmount *sysfs_mount;
struct super_block * sysfs_sb = NULL;
struct kmem_cache *sysfs_dir_cachep;

static const struct super_operations sysfs_ops = {
	.statfs		= simple_statfs,
	.drop_inode	= generic_delete_inode,
};

struct sysfs_dirent sysfs_root = {
	.s_name		= "",
	.s_count	= ATOMIC_INIT(1),
	.s_flags	= SYSFS_DIR,
	.s_mode		= S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
	.s_ino		= 1,
};

static int sysfs_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 = SYSFS_MAGIC;
	sb->s_op = &sysfs_ops;
	sb->s_time_gran = 1;
	sysfs_sb = sb;

	/* get root inode, initialize and unlock it */
	inode = sysfs_get_inode(&sysfs_root);
	if (!inode) {
		pr_debug("sysfs: could not get root inode\n");
		return -ENOMEM;
	}

	/* instantiate and link root dentry */
	root = d_alloc_root(inode);
	if (!root) {
		pr_debug("%s: could not get root dentry!\n",__func__);
		iput(inode);
		return -ENOMEM;
	}
	root->d_fsdata = &sysfs_root;
	sb->s_root = root;
	return 0;
}

static int sysfs_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
	return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt);
}

static struct file_system_type sysfs_fs_type = {
	.name		= "sysfs",
	.get_sb		= sysfs_get_sb,
	.kill_sb	= kill_anon_super,
};

int __init sysfs_init(void)
{
	int err = -ENOMEM;

	sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
					      sizeof(struct sysfs_dirent),
					      0, 0, NULL);
	if (!sysfs_dir_cachep)
		goto out;

	err = sysfs_inode_init();
	if (err)
		goto out_err;

	err = register_filesystem(&sysfs_fs_type);
	if (!err) {
		sysfs_mount = kern_mount(&sysfs_fs_type);
		if (IS_ERR(sysfs_mount)) {
			printk(KERN_ERR "sysfs: could not mount!\n");
			err = PTR_ERR(sysfs_mount);
			sysfs_mount = NULL;
			unregister_filesystem(&sysfs_fs_type);
			goto out_err;
		}
	} else
		goto out_err;
out:
	return err;
out_err:
	kmem_cache_destroy(sysfs_dir_cachep);
	sysfs_dir_cachep = NULL;
	goto out;
}

#undef sysfs_get
struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd)
{
	return __sysfs_get(sd);
}
EXPORT_SYMBOL_GPL(sysfs_get);

#undef sysfs_put
void sysfs_put(struct sysfs_dirent *sd)
{
	__sysfs_put(sd);
}
EXPORT_SYMBOL_GPL(sysfs_put);
Commit	Line	Data
1da177e4	1	/*
6d66f5cd TH	2	* fs/sysfs/symlink.c - operations for initializing and mounting sysfs
	3	*
	4	* Copyright (c) 2001-3 Patrick Mochel
	5	* Copyright (c) 2007 SUSE Linux Products GmbH
	6	* Copyright (c) 2007 Tejun Heo <[email protected]>
	7	*
	8	* This file is released under the GPLv2.
	9	*
	10	* Please see Documentation/filesystems/sysfs.txt for more information.
1da177e4 LT	11	*/
	12
	13	#define DEBUG
	14
	15	#include <linux/fs.h>
	16	#include <linux/mount.h>
	17	#include <linux/pagemap.h>
	18	#include <linux/init.h>
f1282c84	19	#include <linux/module.h>
1da177e4 LT	20
	21	#include "sysfs.h"
	22
	23	/* Random magic number */
	24	#define SYSFS_MAGIC 0x62656572
	25
7d0c7d67	26	static struct vfsmount *sysfs_mount;
1da177e4	27	struct super_block * sysfs_sb = NULL;
e18b890b	28	struct kmem_cache *sysfs_dir_cachep;
1da177e4	29
ee9b6d61	30	static const struct super_operations sysfs_ops = {
1da177e4	31	.statfs = simple_statfs,
90bc6135	32	.drop_inode = generic_delete_inode,
1da177e4 LT	33	};
1da177e4 LT	34
51225039	35	struct sysfs_dirent sysfs_root = {
dc2f75f0	36	.s_name = "",
13b3086d	37	.s_count = ATOMIC_INIT(1),
dc2f75f0	38	.s_flags = SYSFS_DIR,
fc9f54b9	39	.s_mode = S_IFDIR \| S_IRWXU \| S_IRUGO \| S_IXUGO,
dc351252	40	.s_ino = 1,
1da177e4 LT	41	};
	42
	43	static int sysfs_fill_super(struct super_block sb, void data, int silent)
	44	{
	45	struct inode *inode;
	46	struct dentry *root;
	47
	48	sb->s_blocksize = PAGE_CACHE_SIZE;
	49	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	50	sb->s_magic = SYSFS_MAGIC;
	51	sb->s_op = &sysfs_ops;
	52	sb->s_time_gran = 1;
	53	sysfs_sb = sb;
	54
e080e436 TH	55	/* get root inode, initialize and unlock it */
e080e436 TH	56	inode = sysfs_get_inode(&sysfs_root);
fc9f54b9	57	if (!inode) {
1da177e4 LT	58	pr_debug("sysfs: could not get root inode\n");
	59	return -ENOMEM;
	60	}
	61
e080e436	62	/* instantiate and link root dentry */
1da177e4 LT	63	root = d_alloc_root(inode);
1da177e4 LT	64	if (!root) {
8e24eea7	65	pr_debug("%s: could not get root dentry!\n",__func__);
1da177e4 LT	66	iput(inode);
	67	return -ENOMEM;
	68	}
	69	root->d_fsdata = &sysfs_root;
	70	sb->s_root = root;
	71	return 0;
	72	}
	73
454e2398 DH	74	static int sysfs_get_sb(struct file_system_type *fs_type,
454e2398 DH	75	int flags, const char dev_name, void data, struct vfsmount *mnt)
1da177e4	76	{
454e2398	77	return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt);
1da177e4 LT	78	}
	79
	80	static struct file_system_type sysfs_fs_type = {
	81	.name = "sysfs",
	82	.get_sb = sysfs_get_sb,
0333cd8a	83	.kill_sb = kill_anon_super,
1da177e4 LT	84	};
	85
	86	int __init sysfs_init(void)
	87	{
	88	int err = -ENOMEM;
	89
	90	sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
	91	sizeof(struct sysfs_dirent),
20c2df83	92	0, 0, NULL);
1da177e4 LT	93	if (!sysfs_dir_cachep)
	94	goto out;
	95
e0bf68dd PZ	96	err = sysfs_inode_init();
	97	if (err)
	98	goto out_err;
	99
1da177e4 LT	100	err = register_filesystem(&sysfs_fs_type);
	101	if (!err) {
	102	sysfs_mount = kern_mount(&sysfs_fs_type);
	103	if (IS_ERR(sysfs_mount)) {
	104	printk(KERN_ERR "sysfs: could not mount!\n");
	105	err = PTR_ERR(sysfs_mount);
	106	sysfs_mount = NULL;
	107	unregister_filesystem(&sysfs_fs_type);
	108	goto out_err;
	109	}
	110	} else
	111	goto out_err;
	112	out:
	113	return err;
	114	out_err:
	115	kmem_cache_destroy(sysfs_dir_cachep);
	116	sysfs_dir_cachep = NULL;
	117	goto out;
	118	}
f1282c84 NB	119
	120	#undef sysfs_get
	121	struct sysfs_dirent sysfs_get(struct sysfs_dirent sd)
	122	{
	123	return __sysfs_get(sd);
	124	}
	125	EXPORT_SYMBOL_GPL(sysfs_get);
	126
	127	#undef sysfs_put
	128	void sysfs_put(struct sysfs_dirent *sd)
	129	{
	130	__sysfs_put(sd);
	131	}
	132	EXPORT_SYMBOL_GPL(sysfs_put);