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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
16#include <xen/xen.h>
17
18#include "xenfs.h"
19
20#include <asm/xen/hypervisor.h>
21
22MODULE_DESCRIPTION("Xen filesystem");
23MODULE_LICENSE("GPL");
24
25static struct inode *xenfs_make_inode(struct super_block *sb, int mode)
26{
27 struct inode *ret = new_inode(sb);
28
29 if (ret) {
30 ret->i_mode = mode;
31 ret->i_uid = ret->i_gid = 0;
32 ret->i_blocks = 0;
33 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
34 }
35 return ret;
36}
37
38static struct dentry *xenfs_create_file(struct super_block *sb,
39 struct dentry *parent,
40 const char *name,
41 const struct file_operations *fops,
42 void *data,
43 int mode)
44{
45 struct dentry *dentry;
46 struct inode *inode;
47
48 dentry = d_alloc_name(parent, name);
49 if (!dentry)
50 return NULL;
51
52 inode = xenfs_make_inode(sb, S_IFREG | mode);
53 if (!inode) {
54 dput(dentry);
55 return NULL;
56 }
57
58 inode->i_fop = fops;
59 inode->i_private = data;
60
61 d_add(dentry, inode);
62 return dentry;
63}
64
65static ssize_t capabilities_read(struct file *file, char __user *buf,
66 size_t size, loff_t *off)
67{
68 char *tmp = "";
69
70 if (xen_initial_domain())
71 tmp = "control_d\n";
72
73 return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp));
74}
75
76static const struct file_operations capabilities_file_ops = {
77 .read = capabilities_read,
78 .llseek = default_llseek,
79};
80
81static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
82{
83 static struct tree_descr xenfs_files[] = {
84 [1] = {},
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 },
88 {""},
89 };
90 int rc;
91
92 rc = simple_fill_super(sb, XENFS_SUPER_MAGIC, xenfs_files);
93 if (rc < 0)
94 return rc;
95
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);
101 }
102
103 return rc;
104}
105
106static struct dentry *xenfs_mount(struct file_system_type *fs_type,
107 int flags, const char *dev_name,
108 void *data)
109{
110 return mount_single(fs_type, flags, data, xenfs_fill_super);
111}
112
113static struct file_system_type xenfs_type = {
114 .owner = THIS_MODULE,
115 .name = "xenfs",
116 .mount = xenfs_mount,
117 .kill_sb = kill_litter_super,
118};
119
120static int __init xenfs_init(void)
121{
122 if (xen_domain())
123 return register_filesystem(&xenfs_type);
124
125 printk(KERN_INFO "XENFS: not registering filesystem on non-xen platform\n");
126 return 0;
127}
128
129static void __exit xenfs_exit(void)
130{
131 if (xen_domain())
132 unregister_filesystem(&xenfs_type);
133}
134
135module_init(xenfs_init);
136module_exit(xenfs_exit);
137
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/kernel.h>
13#include <linux/errno.h>
14#include <linux/module.h>
15#include <linux/fs.h>
16#include <linux/magic.h>
17
18#include <xen/xen.h>
19
20#include "xenfs.h"
21#include "../privcmd.h"
22#include "../xenbus/xenbus_comms.h"
23
24#include <asm/xen/hypervisor.h>
25
26MODULE_DESCRIPTION("Xen filesystem");
27MODULE_LICENSE("GPL");
28
29static ssize_t capabilities_read(struct file *file, char __user *buf,
30 size_t size, loff_t *off)
31{
32 char *tmp = "";
33
34 if (xen_initial_domain())
35 tmp = "control_d\n";
36
37 return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp));
38}
39
40static const struct file_operations capabilities_file_ops = {
41 .read = capabilities_read,
42 .llseek = default_llseek,
43};
44
45static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
46{
47 static struct tree_descr xenfs_files[] = {
48 [2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
49 { "capabilities", &capabilities_file_ops, S_IRUGO },
50 { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
51 {""},
52 };
53
54 static struct tree_descr xenfs_init_files[] = {
55 [2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
56 { "capabilities", &capabilities_file_ops, S_IRUGO },
57 { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
58 { "xsd_kva", &xsd_kva_file_ops, S_IRUSR|S_IWUSR},
59 { "xsd_port", &xsd_port_file_ops, S_IRUSR|S_IWUSR},
60#ifdef CONFIG_XEN_SYMS
61 { "xensyms", &xensyms_ops, S_IRUSR},
62#endif
63 {""},
64 };
65
66 return simple_fill_super(sb, XENFS_SUPER_MAGIC,
67 xen_initial_domain() ? xenfs_init_files : xenfs_files);
68}
69
70static struct dentry *xenfs_mount(struct file_system_type *fs_type,
71 int flags, const char *dev_name,
72 void *data)
73{
74 return mount_single(fs_type, flags, data, xenfs_fill_super);
75}
76
77static struct file_system_type xenfs_type = {
78 .owner = THIS_MODULE,
79 .name = "xenfs",
80 .mount = xenfs_mount,
81 .kill_sb = kill_litter_super,
82};
83MODULE_ALIAS_FS("xenfs");
84
85static int __init xenfs_init(void)
86{
87 if (xen_domain())
88 return register_filesystem(&xenfs_type);
89
90 pr_info("not registering filesystem on non-xen platform\n");
91 return 0;
92}
93
94static void __exit xenfs_exit(void)
95{
96 if (xen_domain())
97 unregister_filesystem(&xenfs_type);
98}
99
100module_init(xenfs_init);
101module_exit(xenfs_exit);
102