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 struct inode
*xenfs_make_inode(struct super_block
*sb
, int mode
)
27 struct inode
*ret
= new_inode(sb
);
31 ret
->i_uid
= ret
->i_gid
= 0;
33 ret
->i_atime
= ret
->i_mtime
= ret
->i_ctime
= CURRENT_TIME
;
38 static struct dentry
*xenfs_create_file(struct super_block
*sb
,
39 struct dentry
*parent
,
41 const struct file_operations
*fops
,
45 struct dentry
*dentry
;
48 dentry
= d_alloc_name(parent
, name
);
52 inode
= xenfs_make_inode(sb
, S_IFREG
| mode
);
59 inode
->i_private
= data
;
65 static ssize_t
capabilities_read(struct file
*file
, char __user
*buf
,
66 size_t size
, loff_t
*off
)
70 if (xen_initial_domain())
73 return simple_read_from_buffer(buf
, size
, off
, tmp
, strlen(tmp
));
76 static const struct file_operations capabilities_file_ops
= {
77 .read
= capabilities_read
,
78 .llseek
= default_llseek
,
81 static int xenfs_fill_super(struct super_block
*sb
, void *data
, int silent
)
83 static struct tree_descr xenfs_files
[] = {
85 { "xenbus", &xenbus_file_ops
, S_IRUSR
|S_IWUSR
},
86 { "capabilities", &capabilities_file_ops
, S_IRUGO
},
87 { "privcmd", &privcmd_file_ops
, S_IRUSR
|S_IWUSR
},
92 rc
= simple_fill_super(sb
, XENFS_SUPER_MAGIC
, xenfs_files
);
96 if (xen_initial_domain()) {
97 xenfs_create_file(sb
, sb
->s_root
, "xsd_kva",
98 &xsd_kva_file_ops
, NULL
, S_IRUSR
|S_IWUSR
);
99 xenfs_create_file(sb
, sb
->s_root
, "xsd_port",
100 &xsd_port_file_ops
, NULL
, S_IRUSR
|S_IWUSR
);
106 static struct dentry
*xenfs_mount(struct file_system_type
*fs_type
,
107 int flags
, const char *dev_name
,
110 return mount_single(fs_type
, flags
, data
, xenfs_fill_super
);
113 static struct file_system_type xenfs_type
= {
114 .owner
= THIS_MODULE
,
116 .mount
= xenfs_mount
,
117 .kill_sb
= kill_litter_super
,
120 static int __init
xenfs_init(void)
123 return register_filesystem(&xenfs_type
);
125 printk(KERN_INFO
"XENFS: not registering filesystem on non-xen platform\n");
129 static void __exit
xenfs_exit(void)
132 unregister_filesystem(&xenfs_type
);
135 module_init(xenfs_init
);
136 module_exit(xenfs_exit
);