Commit | Line | Data |
---|---|---|
1107ba88 AZ |
1 | /* |
2 | * xenfs.c - a filesystem for passing info between the a domain and | |
3 | * the hypervisor. | |
4 | * | |
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. | |
8 | */ | |
9 | ||
10 | #include <linux/kernel.h> | |
11 | #include <linux/errno.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/fs.h> | |
14 | #include <linux/magic.h> | |
15 | ||
1ccbf534 JF |
16 | #include <xen/xen.h> |
17 | ||
1107ba88 AZ |
18 | #include "xenfs.h" |
19 | ||
20 | #include <asm/xen/hypervisor.h> | |
21 | ||
22 | MODULE_DESCRIPTION("Xen filesystem"); | |
23 | MODULE_LICENSE("GPL"); | |
24 | ||
818fd206 JF |
25 | static ssize_t capabilities_read(struct file *file, char __user *buf, |
26 | size_t size, loff_t *off) | |
27 | { | |
28 | char *tmp = ""; | |
29 | ||
30 | if (xen_initial_domain()) | |
31 | tmp = "control_d\n"; | |
32 | ||
33 | return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp)); | |
34 | } | |
35 | ||
36 | static const struct file_operations capabilities_file_ops = { | |
37 | .read = capabilities_read, | |
6038f373 | 38 | .llseek = default_llseek, |
818fd206 JF |
39 | }; |
40 | ||
1107ba88 AZ |
41 | static int xenfs_fill_super(struct super_block *sb, void *data, int silent) |
42 | { | |
43 | static struct tree_descr xenfs_files[] = { | |
818fd206 JF |
44 | [1] = {}, |
45 | { "xenbus", &xenbus_file_ops, S_IRUSR|S_IWUSR }, | |
46 | { "capabilities", &capabilities_file_ops, S_IRUGO }, | |
1107ba88 AZ |
47 | {""}, |
48 | }; | |
49 | ||
50 | return simple_fill_super(sb, XENFS_SUPER_MAGIC, xenfs_files); | |
51 | } | |
52 | ||
53 | static int xenfs_get_sb(struct file_system_type *fs_type, | |
54 | int flags, const char *dev_name, | |
55 | void *data, struct vfsmount *mnt) | |
56 | { | |
57 | return get_sb_single(fs_type, flags, data, xenfs_fill_super, mnt); | |
58 | } | |
59 | ||
60 | static struct file_system_type xenfs_type = { | |
61 | .owner = THIS_MODULE, | |
62 | .name = "xenfs", | |
63 | .get_sb = xenfs_get_sb, | |
64 | .kill_sb = kill_litter_super, | |
65 | }; | |
66 | ||
67 | static int __init xenfs_init(void) | |
68 | { | |
43df95c4 | 69 | if (xen_domain()) |
1107ba88 AZ |
70 | return register_filesystem(&xenfs_type); |
71 | ||
72 | printk(KERN_INFO "XENFS: not registering filesystem on non-xen platform\n"); | |
73 | return 0; | |
74 | } | |
75 | ||
76 | static void __exit xenfs_exit(void) | |
77 | { | |
43df95c4 | 78 | if (xen_domain()) |
1107ba88 AZ |
79 | unregister_filesystem(&xenfs_type); |
80 | } | |
81 | ||
82 | module_init(xenfs_init); | |
83 | module_exit(xenfs_exit); | |
84 |