[linux-2.6-block.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 <teheo@suse.de>
 *
 * 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 <linux/magic.h>

#include "sysfs.h"


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,
	.delete_inode	= sysfs_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 */
	mutex_lock(&sysfs_mutex);
	inode = sysfs_get_inode(&sysfs_root);
	mutex_unlock(&sysfs_mutex);
	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 <teheo@suse.de>
	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>
8231f2f9	20	#include <linux/magic.h>
1da177e4 LT	21
	22	#include "sysfs.h"
	23
1da177e4	24
7d0c7d67	25	static struct vfsmount *sysfs_mount;
1da177e4	26	struct super_block * sysfs_sb = NULL;
e18b890b	27	struct kmem_cache *sysfs_dir_cachep;
1da177e4	28
ee9b6d61	29	static const struct super_operations sysfs_ops = {
1da177e4	30	.statfs = simple_statfs,
90bc6135	31	.drop_inode = generic_delete_inode,
04256b4a	32	.delete_inode = sysfs_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	55	/* get root inode, initialize and unlock it */
4a67a1bc	56	mutex_lock(&sysfs_mutex);
e080e436	57	inode = sysfs_get_inode(&sysfs_root);
4a67a1bc	58	mutex_unlock(&sysfs_mutex);
fc9f54b9	59	if (!inode) {
1da177e4 LT	60	pr_debug("sysfs: could not get root inode\n");
	61	return -ENOMEM;
	62	}
	63
e080e436	64	/* instantiate and link root dentry */
1da177e4 LT	65	root = d_alloc_root(inode);
1da177e4 LT	66	if (!root) {
8e24eea7	67	pr_debug("%s: could not get root dentry!\n",__func__);
1da177e4 LT	68	iput(inode);
	69	return -ENOMEM;
	70	}
	71	root->d_fsdata = &sysfs_root;
	72	sb->s_root = root;
	73	return 0;
	74	}
	75
454e2398 DH	76	static int sysfs_get_sb(struct file_system_type *fs_type,
454e2398 DH	77	int flags, const char dev_name, void data, struct vfsmount *mnt)
1da177e4	78	{
454e2398	79	return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt);
1da177e4 LT	80	}
	81
	82	static struct file_system_type sysfs_fs_type = {
	83	.name = "sysfs",
	84	.get_sb = sysfs_get_sb,
0333cd8a	85	.kill_sb = kill_anon_super,
1da177e4 LT	86	};
	87
	88	int __init sysfs_init(void)
	89	{
	90	int err = -ENOMEM;
	91
	92	sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
	93	sizeof(struct sysfs_dirent),
20c2df83	94	0, 0, NULL);
1da177e4 LT	95	if (!sysfs_dir_cachep)
	96	goto out;
	97
e0bf68dd PZ	98	err = sysfs_inode_init();
	99	if (err)
	100	goto out_err;
	101
1da177e4 LT	102	err = register_filesystem(&sysfs_fs_type);
	103	if (!err) {
	104	sysfs_mount = kern_mount(&sysfs_fs_type);
	105	if (IS_ERR(sysfs_mount)) {
	106	printk(KERN_ERR "sysfs: could not mount!\n");
	107	err = PTR_ERR(sysfs_mount);
	108	sysfs_mount = NULL;
	109	unregister_filesystem(&sysfs_fs_type);
	110	goto out_err;
	111	}
	112	} else
	113	goto out_err;
	114	out:
	115	return err;
	116	out_err:
	117	kmem_cache_destroy(sysfs_dir_cachep);
	118	sysfs_dir_cachep = NULL;
	119	goto out;
	120	}
f1282c84 NB	121
	122	#undef sysfs_get
	123	struct sysfs_dirent sysfs_get(struct sysfs_dirent sd)
	124	{
	125	return __sysfs_get(sd);
	126	}
	127	EXPORT_SYMBOL_GPL(sysfs_get);
	128
	129	#undef sysfs_put
	130	void sysfs_put(struct sysfs_dirent *sd)
	131	{
	132	__sysfs_put(sd);
	133	}
	134	EXPORT_SYMBOL_GPL(sysfs_put);