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Commit | Line | Data |
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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, | |
38 | }; | |
39 | ||
1107ba88 AZ |
40 | static int xenfs_fill_super(struct super_block *sb, void *data, int silent) |
41 | { | |
42 | static struct tree_descr xenfs_files[] = { | |
818fd206 JF |
43 | [1] = {}, |
44 | { "xenbus", &xenbus_file_ops, S_IRUSR|S_IWUSR }, | |
45 | { "capabilities", &capabilities_file_ops, S_IRUGO }, | |
1107ba88 AZ |
46 | {""}, |
47 | }; | |
48 | ||
49 | return simple_fill_super(sb, XENFS_SUPER_MAGIC, xenfs_files); | |
50 | } | |
51 | ||
52 | static int xenfs_get_sb(struct file_system_type *fs_type, | |
53 | int flags, const char *dev_name, | |
54 | void *data, struct vfsmount *mnt) | |
55 | { | |
56 | return get_sb_single(fs_type, flags, data, xenfs_fill_super, mnt); | |
57 | } | |
58 | ||
59 | static struct file_system_type xenfs_type = { | |
60 | .owner = THIS_MODULE, | |
61 | .name = "xenfs", | |
62 | .get_sb = xenfs_get_sb, | |
63 | .kill_sb = kill_litter_super, | |
64 | }; | |
65 | ||
66 | static int __init xenfs_init(void) | |
67 | { | |
43df95c4 | 68 | if (xen_domain()) |
1107ba88 AZ |
69 | return register_filesystem(&xenfs_type); |
70 | ||
71 | printk(KERN_INFO "XENFS: not registering filesystem on non-xen platform\n"); | |
72 | return 0; | |
73 | } | |
74 | ||
75 | static void __exit xenfs_exit(void) | |
76 | { | |
43df95c4 | 77 | if (xen_domain()) |
1107ba88 AZ |
78 | unregister_filesystem(&xenfs_type); |
79 | } | |
80 | ||
81 | module_init(xenfs_init); | |
82 | module_exit(xenfs_exit); | |
83 |