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 ssize_t capabilities_read(struct file *file, char __user *buf,
28 size_t size, loff_t *off)
32 if (xen_initial_domain())
35 return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp));
38 static const struct file_operations capabilities_file_ops = {
39 .read = capabilities_read,
40 .llseek = default_llseek,
43 static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
45 static struct tree_descr xenfs_files[] = {
46 [2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
47 { "capabilities", &capabilities_file_ops, S_IRUGO },
48 { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
52 static struct tree_descr xenfs_init_files[] = {
53 [2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
54 { "capabilities", &capabilities_file_ops, S_IRUGO },
55 { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
56 { "xsd_kva", &xsd_kva_file_ops, S_IRUSR|S_IWUSR},
57 { "xsd_port", &xsd_port_file_ops, S_IRUSR|S_IWUSR},
61 return simple_fill_super(sb, XENFS_SUPER_MAGIC,
62 xen_initial_domain() ? xenfs_init_files : xenfs_files);
65 static struct dentry *xenfs_mount(struct file_system_type *fs_type,
66 int flags, const char *dev_name,
69 return mount_single(fs_type, flags, data, xenfs_fill_super);
72 static struct file_system_type xenfs_type = {
76 .kill_sb = kill_litter_super,
78 MODULE_ALIAS_FS("xenfs");
80 static int __init xenfs_init(void)
83 return register_filesystem(&xenfs_type);
85 printk(KERN_INFO "XENFS: not registering filesystem on non-xen platform\n");
89 static void __exit xenfs_exit(void)
92 unregister_filesystem(&xenfs_type);
95 module_init(xenfs_init);
96 module_exit(xenfs_exit);