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);