84 lines
1.9 KiB
C
84 lines
1.9 KiB
C
/*
|
|
* xenfs.c - a filesystem for passing info between the a domain and
|
|
* the hypervisor.
|
|
*
|
|
* 2008-10-07 Alex Zeffertt Replaced /proc/xen/xenbus with xenfs filesystem
|
|
* and /proc/xen compatibility mount point.
|
|
* Turned xenfs into a loadable module.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/module.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/magic.h>
|
|
|
|
#include <xen/xen.h>
|
|
|
|
#include "xenfs.h"
|
|
|
|
#include <asm/xen/hypervisor.h>
|
|
|
|
MODULE_DESCRIPTION("Xen filesystem");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
static ssize_t capabilities_read(struct file *file, char __user *buf,
|
|
size_t size, loff_t *off)
|
|
{
|
|
char *tmp = "";
|
|
|
|
if (xen_initial_domain())
|
|
tmp = "control_d\n";
|
|
|
|
return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp));
|
|
}
|
|
|
|
static const struct file_operations capabilities_file_ops = {
|
|
.read = capabilities_read,
|
|
};
|
|
|
|
static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
|
|
{
|
|
static struct tree_descr xenfs_files[] = {
|
|
[1] = {},
|
|
{ "xenbus", &xenbus_file_ops, S_IRUSR|S_IWUSR },
|
|
{ "capabilities", &capabilities_file_ops, S_IRUGO },
|
|
{""},
|
|
};
|
|
|
|
return simple_fill_super(sb, XENFS_SUPER_MAGIC, xenfs_files);
|
|
}
|
|
|
|
static int xenfs_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, xenfs_fill_super, mnt);
|
|
}
|
|
|
|
static struct file_system_type xenfs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "xenfs",
|
|
.get_sb = xenfs_get_sb,
|
|
.kill_sb = kill_litter_super,
|
|
};
|
|
|
|
static int __init xenfs_init(void)
|
|
{
|
|
if (xen_pv_domain())
|
|
return register_filesystem(&xenfs_type);
|
|
|
|
printk(KERN_INFO "XENFS: not registering filesystem on non-xen platform\n");
|
|
return 0;
|
|
}
|
|
|
|
static void __exit xenfs_exit(void)
|
|
{
|
|
if (xen_pv_domain())
|
|
unregister_filesystem(&xenfs_type);
|
|
}
|
|
|
|
module_init(xenfs_init);
|
|
module_exit(xenfs_exit);
|
|
|