linux/drivers/xen/xenfs/super.c
Eric Biggers cda37124f4 fs: constify tree_descr arrays passed to simple_fill_super()
simple_fill_super() is passed an array of tree_descr structures which
describe the files to create in the filesystem's root directory.  Since
these arrays are never modified intentionally, they should be 'const' so
that they are placed in .rodata and benefit from memory protection.
This patch updates the function signature and all users, and also
constifies tree_descr.name.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-26 23:54:06 -04:00

103 lines
2.5 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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 <xen/xenbus.h>
#include "xenfs.h"
#include "../privcmd.h"
#include <asm/xen/hypervisor.h>
MODULE_DESCRIPTION("Xen filesystem");
MODULE_LICENSE("GPL");
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 const struct tree_descr xenfs_files[] = {
[2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
{ "capabilities", &capabilities_file_ops, S_IRUGO },
{ "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
{""},
};
static const struct tree_descr xenfs_init_files[] = {
[2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
{ "capabilities", &capabilities_file_ops, S_IRUGO },
{ "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
{ "xsd_kva", &xsd_kva_file_ops, S_IRUSR|S_IWUSR},
{ "xsd_port", &xsd_port_file_ops, S_IRUSR|S_IWUSR},
#ifdef CONFIG_XEN_SYMS
{ "xensyms", &xensyms_ops, S_IRUSR},
#endif
{""},
};
return simple_fill_super(sb, XENFS_SUPER_MAGIC,
xen_initial_domain() ? xenfs_init_files : xenfs_files);
}
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,
};
MODULE_ALIAS_FS("xenfs");
static int __init xenfs_init(void)
{
if (xen_domain())
return register_filesystem(&xenfs_type);
pr_info("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);