2 * mount.c - operations for initializing and mounting sysfs.
8 #include <linux/mount.h>
9 #include <linux/pagemap.h>
10 #include <linux/init.h>
14 /* Random magic number */
15 #define SYSFS_MAGIC 0x62656572
17 struct vfsmount
*sysfs_mount
;
18 struct super_block
* sysfs_sb
= NULL
;
19 struct kmem_cache
*sysfs_dir_cachep
;
21 static const struct super_operations sysfs_ops
= {
22 .statfs
= simple_statfs
,
23 .drop_inode
= sysfs_delete_inode
,
26 struct sysfs_dirent sysfs_root
= {
27 .s_count
= ATOMIC_INIT(1),
28 .s_flags
= SYSFS_ROOT
,
29 .s_mode
= S_IFDIR
| S_IRWXU
| S_IRUGO
| S_IXUGO
,
33 static int sysfs_fill_super(struct super_block
*sb
, void *data
, int silent
)
38 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
39 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
40 sb
->s_magic
= SYSFS_MAGIC
;
41 sb
->s_op
= &sysfs_ops
;
45 /* get root inode, initialize and unlock it */
46 inode
= sysfs_get_inode(&sysfs_root
);
48 pr_debug("sysfs: could not get root inode\n");
52 inode
->i_op
= &sysfs_dir_inode_operations
;
53 inode
->i_fop
= &sysfs_dir_operations
;
54 inc_nlink(inode
); /* directory, account for "." */
55 unlock_new_inode(inode
);
57 /* instantiate and link root dentry */
58 root
= d_alloc_root(inode
);
60 pr_debug("%s: could not get root dentry!\n",__FUNCTION__
);
64 sysfs_root
.s_dentry
= root
;
65 root
->d_fsdata
= &sysfs_root
;
70 static int sysfs_get_sb(struct file_system_type
*fs_type
,
71 int flags
, const char *dev_name
, void *data
, struct vfsmount
*mnt
)
73 return get_sb_single(fs_type
, flags
, data
, sysfs_fill_super
, mnt
);
76 static struct file_system_type sysfs_fs_type
= {
78 .get_sb
= sysfs_get_sb
,
79 .kill_sb
= kill_litter_super
,
82 int __init
sysfs_init(void)
86 sysfs_dir_cachep
= kmem_cache_create("sysfs_dir_cache",
87 sizeof(struct sysfs_dirent
),
89 if (!sysfs_dir_cachep
)
92 err
= register_filesystem(&sysfs_fs_type
);
94 sysfs_mount
= kern_mount(&sysfs_fs_type
);
95 if (IS_ERR(sysfs_mount
)) {
96 printk(KERN_ERR
"sysfs: could not mount!\n");
97 err
= PTR_ERR(sysfs_mount
);
99 unregister_filesystem(&sysfs_fs_type
);
107 kmem_cache_destroy(sysfs_dir_cachep
);
108 sysfs_dir_cachep
= NULL
;