mirror of https://gitee.com/openkylin/linux.git
140 lines
3.0 KiB
C
140 lines
3.0 KiB
C
/*
|
|
* xenfs.c - a filesystem for passing info between the a domain and
|
|
* the hypervisor.
|
|
*
|
|
* 2008-10-07 Alex Zeffertt Replaced /proc/xen/xenbus with xenfs filesystem
|
|
* and /proc/xen compatibility mount point.
|
|
* Turned xenfs into a loadable module.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/module.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/magic.h>
|
|
|
|
#include <xen/xen.h>
|
|
|
|
#include "xenfs.h"
|
|
#include "../privcmd.h"
|
|
#include "../xenbus/xenbus_comms.h"
|
|
|
|
#include <asm/xen/hypervisor.h>
|
|
|
|
MODULE_DESCRIPTION("Xen filesystem");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
static struct inode *xenfs_make_inode(struct super_block *sb, int mode)
|
|
{
|
|
struct inode *ret = new_inode(sb);
|
|
|
|
if (ret) {
|
|
ret->i_mode = mode;
|
|
ret->i_uid = ret->i_gid = 0;
|
|
ret->i_blocks = 0;
|
|
ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static struct dentry *xenfs_create_file(struct super_block *sb,
|
|
struct dentry *parent,
|
|
const char *name,
|
|
const struct file_operations *fops,
|
|
void *data,
|
|
int mode)
|
|
{
|
|
struct dentry *dentry;
|
|
struct inode *inode;
|
|
|
|
dentry = d_alloc_name(parent, name);
|
|
if (!dentry)
|
|
return NULL;
|
|
|
|
inode = xenfs_make_inode(sb, S_IFREG | mode);
|
|
if (!inode) {
|
|
dput(dentry);
|
|
return NULL;
|
|
}
|
|
|
|
inode->i_fop = fops;
|
|
inode->i_private = data;
|
|
|
|
d_add(dentry, inode);
|
|
return dentry;
|
|
}
|
|
|
|
static ssize_t capabilities_read(struct file *file, char __user *buf,
|
|
size_t size, loff_t *off)
|
|
{
|
|
char *tmp = "";
|
|
|
|
if (xen_initial_domain())
|
|
tmp = "control_d\n";
|
|
|
|
return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp));
|
|
}
|
|
|
|
static const struct file_operations capabilities_file_ops = {
|
|
.read = capabilities_read,
|
|
.llseek = default_llseek,
|
|
};
|
|
|
|
static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
|
|
{
|
|
static struct tree_descr xenfs_files[] = {
|
|
[1] = {},
|
|
{ "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
|
|
{ "capabilities", &capabilities_file_ops, S_IRUGO },
|
|
{ "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
|
|
{""},
|
|
};
|
|
int rc;
|
|
|
|
rc = simple_fill_super(sb, XENFS_SUPER_MAGIC, xenfs_files);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
if (xen_initial_domain()) {
|
|
xenfs_create_file(sb, sb->s_root, "xsd_kva",
|
|
&xsd_kva_file_ops, NULL, S_IRUSR|S_IWUSR);
|
|
xenfs_create_file(sb, sb->s_root, "xsd_port",
|
|
&xsd_port_file_ops, NULL, S_IRUSR|S_IWUSR);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
static struct dentry *xenfs_mount(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name,
|
|
void *data)
|
|
{
|
|
return mount_single(fs_type, flags, data, xenfs_fill_super);
|
|
}
|
|
|
|
static struct file_system_type xenfs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "xenfs",
|
|
.mount = xenfs_mount,
|
|
.kill_sb = kill_litter_super,
|
|
};
|
|
|
|
static int __init xenfs_init(void)
|
|
{
|
|
if (xen_domain())
|
|
return register_filesystem(&xenfs_type);
|
|
|
|
printk(KERN_INFO "XENFS: not registering filesystem on non-xen platform\n");
|
|
return 0;
|
|
}
|
|
|
|
static void __exit xenfs_exit(void)
|
|
{
|
|
if (xen_domain())
|
|
unregister_filesystem(&xenfs_type);
|
|
}
|
|
|
|
module_init(xenfs_init);
|
|
module_exit(xenfs_exit);
|
|
|