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 | 18 | #include "xenfs.h" |
d8414d3c | 19 | #include "../privcmd.h" |
2fb3683e | 20 | #include "../xenbus/xenbus_comms.h" |
1107ba88 AZ |
21 | |
22 | #include <asm/xen/hypervisor.h> | |
23 | ||
24 | MODULE_DESCRIPTION("Xen filesystem"); | |
25 | MODULE_LICENSE("GPL"); | |
26 | ||
655d406a IC |
27 | static struct inode *xenfs_make_inode(struct super_block *sb, int mode) |
28 | { | |
29 | struct inode *ret = new_inode(sb); | |
30 | ||
31 | if (ret) { | |
32 | ret->i_mode = mode; | |
9a11f451 EB |
33 | ret->i_uid = GLOBAL_ROOT_UID; |
34 | ret->i_gid = GLOBAL_ROOT_GID; | |
655d406a IC |
35 | ret->i_blocks = 0; |
36 | ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME; | |
37 | } | |
38 | return ret; | |
39 | } | |
40 | ||
41 | static struct dentry *xenfs_create_file(struct super_block *sb, | |
42 | struct dentry *parent, | |
43 | const char *name, | |
44 | const struct file_operations *fops, | |
45 | void *data, | |
46 | int mode) | |
47 | { | |
48 | struct dentry *dentry; | |
49 | struct inode *inode; | |
50 | ||
51 | dentry = d_alloc_name(parent, name); | |
52 | if (!dentry) | |
53 | return NULL; | |
54 | ||
55 | inode = xenfs_make_inode(sb, S_IFREG | mode); | |
56 | if (!inode) { | |
57 | dput(dentry); | |
58 | return NULL; | |
59 | } | |
60 | ||
61 | inode->i_fop = fops; | |
62 | inode->i_private = data; | |
63 | ||
64 | d_add(dentry, inode); | |
65 | return dentry; | |
66 | } | |
67 | ||
818fd206 JF |
68 | static ssize_t capabilities_read(struct file *file, char __user *buf, |
69 | size_t size, loff_t *off) | |
70 | { | |
71 | char *tmp = ""; | |
72 | ||
73 | if (xen_initial_domain()) | |
74 | tmp = "control_d\n"; | |
75 | ||
76 | return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp)); | |
77 | } | |
78 | ||
79 | static const struct file_operations capabilities_file_ops = { | |
80 | .read = capabilities_read, | |
6038f373 | 81 | .llseek = default_llseek, |
818fd206 JF |
82 | }; |
83 | ||
1107ba88 AZ |
84 | static int xenfs_fill_super(struct super_block *sb, void *data, int silent) |
85 | { | |
86 | static struct tree_descr xenfs_files[] = { | |
818fd206 | 87 | [1] = {}, |
2fb3683e | 88 | { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR }, |
818fd206 | 89 | { "capabilities", &capabilities_file_ops, S_IRUGO }, |
d8414d3c | 90 | { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR }, |
1107ba88 AZ |
91 | {""}, |
92 | }; | |
655d406a | 93 | int rc; |
1107ba88 | 94 | |
655d406a IC |
95 | rc = simple_fill_super(sb, XENFS_SUPER_MAGIC, xenfs_files); |
96 | if (rc < 0) | |
97 | return rc; | |
98 | ||
99 | if (xen_initial_domain()) { | |
100 | xenfs_create_file(sb, sb->s_root, "xsd_kva", | |
101 | &xsd_kva_file_ops, NULL, S_IRUSR|S_IWUSR); | |
102 | xenfs_create_file(sb, sb->s_root, "xsd_port", | |
103 | &xsd_port_file_ops, NULL, S_IRUSR|S_IWUSR); | |
104 | } | |
1107ba88 | 105 | |
655d406a | 106 | return rc; |
1107ba88 AZ |
107 | } |
108 | ||
fe61f1d7 JF |
109 | static struct dentry *xenfs_mount(struct file_system_type *fs_type, |
110 | int flags, const char *dev_name, | |
111 | void *data) | |
1107ba88 | 112 | { |
fc14f2fe | 113 | return mount_single(fs_type, flags, data, xenfs_fill_super); |
1107ba88 AZ |
114 | } |
115 | ||
116 | static struct file_system_type xenfs_type = { | |
117 | .owner = THIS_MODULE, | |
118 | .name = "xenfs", | |
fc14f2fe | 119 | .mount = xenfs_mount, |
1107ba88 AZ |
120 | .kill_sb = kill_litter_super, |
121 | }; | |
122 | ||
123 | static int __init xenfs_init(void) | |
124 | { | |
9045d47e JF |
125 | if (xen_domain()) |
126 | return register_filesystem(&xenfs_type); | |
1107ba88 | 127 | |
9045d47e JF |
128 | printk(KERN_INFO "XENFS: not registering filesystem on non-xen platform\n"); |
129 | return 0; | |
1107ba88 AZ |
130 | } |
131 | ||
132 | static void __exit xenfs_exit(void) | |
133 | { | |
43df95c4 | 134 | if (xen_domain()) |
1107ba88 AZ |
135 | unregister_filesystem(&xenfs_type); |
136 | } | |
137 | ||
138 | module_init(xenfs_init); | |
139 | module_exit(xenfs_exit); | |
140 |