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