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>
19 #include "../privcmd.h"
20 #include "../xenbus/xenbus_comms.h"
22 #include <asm/xen/hypervisor.h>
24 MODULE_DESCRIPTION("Xen filesystem");
25 MODULE_LICENSE("GPL");
27 static struct inode
*xenfs_make_inode(struct super_block
*sb
, int mode
)
29 struct inode
*ret
= new_inode(sb
);
33 ret
->i_uid
= ret
->i_gid
= 0;
35 ret
->i_atime
= ret
->i_mtime
= ret
->i_ctime
= CURRENT_TIME
;
40 static struct dentry
*xenfs_create_file(struct super_block
*sb
,
41 struct dentry
*parent
,
43 const struct file_operations
*fops
,
47 struct dentry
*dentry
;
50 dentry
= d_alloc_name(parent
, name
);
54 inode
= xenfs_make_inode(sb
, S_IFREG
| mode
);
61 inode
->i_private
= data
;
67 static ssize_t
capabilities_read(struct file
*file
, char __user
*buf
,
68 size_t size
, loff_t
*off
)
72 if (xen_initial_domain())
75 return simple_read_from_buffer(buf
, size
, off
, tmp
, strlen(tmp
));
78 static const struct file_operations capabilities_file_ops
= {
79 .read
= capabilities_read
,
80 .llseek
= default_llseek
,
83 static int xenfs_fill_super(struct super_block
*sb
, void *data
, int silent
)
85 static struct tree_descr xenfs_files
[] = {
87 { "xenbus", &xen_xenbus_fops
, S_IRUSR
|S_IWUSR
},
88 { "capabilities", &capabilities_file_ops
, S_IRUGO
},
89 { "privcmd", &xen_privcmd_fops
, S_IRUSR
|S_IWUSR
},
94 rc
= simple_fill_super(sb
, XENFS_SUPER_MAGIC
, xenfs_files
);
98 if (xen_initial_domain()) {
99 xenfs_create_file(sb
, sb
->s_root
, "xsd_kva",
100 &xsd_kva_file_ops
, NULL
, S_IRUSR
|S_IWUSR
);
101 xenfs_create_file(sb
, sb
->s_root
, "xsd_port",
102 &xsd_port_file_ops
, NULL
, S_IRUSR
|S_IWUSR
);
108 static struct dentry
*xenfs_mount(struct file_system_type
*fs_type
,
109 int flags
, const char *dev_name
,
112 return mount_single(fs_type
, flags
, data
, xenfs_fill_super
);
115 static struct file_system_type xenfs_type
= {
116 .owner
= THIS_MODULE
,
118 .mount
= xenfs_mount
,
119 .kill_sb
= kill_litter_super
,
122 static int __init
xenfs_init(void)
125 return register_filesystem(&xenfs_type
);
127 printk(KERN_INFO
"XENFS: not registering filesystem on non-xen platform\n");
131 static void __exit
xenfs_exit(void)
134 unregister_filesystem(&xenfs_type
);
137 module_init(xenfs_init
);
138 module_exit(xenfs_exit
);