2 * xenfs.c - a filesystem for passing info between the a domain and
5 * 2008-10-07 Alex Zeffertt Replaced /proc/xen/xenbus with xenfs filesystem
6 * and /proc/xen compatibility mount point.
7 * Turned xenfs into a loadable module.
10 #include <linux/kernel.h>
11 #include <linux/errno.h>
12 #include <linux/module.h>
14 #include <linux/magic.h>
20 #include <asm/xen/hypervisor.h>
22 MODULE_DESCRIPTION("Xen filesystem");
23 MODULE_LICENSE("GPL");
25 static ssize_t
capabilities_read(struct file
*file
, char __user
*buf
,
26 size_t size
, loff_t
*off
)
30 if (xen_initial_domain())
33 return simple_read_from_buffer(buf
, size
, off
, tmp
, strlen(tmp
));
36 static const struct file_operations capabilities_file_ops
= {
37 .read
= capabilities_read
,
38 .llseek
= default_llseek
,
41 static int xenfs_fill_super(struct super_block
*sb
, void *data
, int silent
)
43 static struct tree_descr xenfs_files
[] = {
45 { "xenbus", &xenbus_file_ops
, S_IRUSR
|S_IWUSR
},
46 { "capabilities", &capabilities_file_ops
, S_IRUGO
},
50 return simple_fill_super(sb
, XENFS_SUPER_MAGIC
, xenfs_files
);
53 static int xenfs_get_sb(struct file_system_type
*fs_type
,
54 int flags
, const char *dev_name
,
55 void *data
, struct vfsmount
*mnt
)
57 return get_sb_single(fs_type
, flags
, data
, xenfs_fill_super
, mnt
);
60 static struct file_system_type xenfs_type
= {
63 .get_sb
= xenfs_get_sb
,
64 .kill_sb
= kill_litter_super
,
67 static int __init
xenfs_init(void)
70 return register_filesystem(&xenfs_type
);
72 printk(KERN_INFO
"XENFS: not registering filesystem on non-xen platform\n");
76 static void __exit
xenfs_exit(void)
79 unregister_filesystem(&xenfs_type
);
82 module_init(xenfs_init
);
83 module_exit(xenfs_exit
);