- 根目录:
- fs
- hostfs
- hostfs_kern.c
/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*
* Ported the filesystem routines to 2.5.
* 2003-02-10 Petr Baudis <pasky@ucw.cz>
*/
#include <linux/fs.h>
#include <linux/magic.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/statfs.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include "hostfs.h"
#include <init.h>
#include <kern.h>
struct hostfs_inode_info {
int fd;
fmode_t mode;
struct inode vfs_inode;
};
static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode)
{
return list_entry(inode, struct hostfs_inode_info, vfs_inode);
}
#define FILE_HOSTFS_I(file) HOSTFS_I(file_inode(file))
/* Changed in hostfs_args before the kernel starts running */
static char *root_ino = "";
static int append = 0;
static const struct inode_operations hostfs_iops;
static const struct inode_operations hostfs_dir_iops;
static const struct inode_operations hostfs_link_iops;
#ifndef MODULE
static int __init hostfs_args(char *options, int *add)
{
char *ptr;
ptr = strchr(options, ',');
if (ptr != NULL)
*ptr++ = '\0';
if (*options != '\0')
root_ino = options;
options = ptr;
while (options) {
ptr = strchr(options, ',');
if (ptr != NULL)
*ptr++ = '\0';
if (*options != '\0') {
if (!strcmp(options, "append"))
append = 1;
else printf("hostfs_args - unsupported option - %s\n",
options);
}
options = ptr;
}
return 0;
}
__uml_setup("hostfs=", hostfs_args,
"hostfs=<root dir>,<flags>,...\n"
" This is used to set hostfs parameters. The root directory argument\n"
" is used to confine all hostfs mounts to within the specified directory\n"
" tree on the host. If this isn't specified, then a user inside UML can\n"
" mount anything on the host that's accessible to the user that's running\n"
" it.\n"
" The only flag currently supported is 'append', which specifies that all\n"
" files opened by hostfs will be opened in append mode.\n\n"
);
#endif
static char *__dentry_name(struct dentry *dentry, char *name)
{
char *p = dentry_path_raw(dentry, name, PATH_MAX);
char *root;
size_t len;
root = dentry->d_sb->s_fs_info;
len = strlen(root);
if (IS_ERR(p)) {
__putname(name);
return NULL;
}
strlcpy(name, root, PATH_MAX);
if (len > p - name) {
__putname(name);
return NULL;
}
if (p > name + len) {
char *s = name + len;
while ((*s++ = *p++) != '\0')
;
}
return name;
}
static char *dentry_name(struct dentry *dentry)
{
char *name = __getname();
if (!name)
return NULL;
return __dentry_name(dentry, name);
}
static char *inode_name(struct inode *ino)
{
struct dentry *dentry;
char *name;
dentry = d_find_alias(ino);
if (!dentry)
return NULL;
name = dentry_name(dentry);
dput(dentry);
return name;
}
static char *follow_link(char *link)
{
int len, n;
char *name, *resolved, *end;
len = 64;
while (1) {
n = -ENOMEM;
name = kmalloc(len, GFP_KERNEL);
if (name == NULL)
goto out;
n = hostfs_do_readlink(link, name, len);
if (n < len)
break;
len *= 2;
kfree(name);
}
if (n < 0)
goto out_free;
if (*name == '/')
return name;
end = strrchr(link, '/');
if (end == NULL)
return name;
*(end + 1) = '\0';
len = strlen(link) + strlen(name) + 1;
resolved = kmalloc(len, GFP_KERNEL);
if (resolved == NULL) {
n = -ENOMEM;
goto out_free;
}
sprintf(resolved, "%s%s", link, name);
kfree(name);
kfree(link);
return resolved;
out_free:
kfree(name);
out:
return ERR_PTR(n);
}
static struct inode *hostfs_iget(struct super_block *sb)
{
struct inode *inode = new_inode(sb);
if (!inode)
return ERR_PTR(-ENOMEM);
return inode;
}
static int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf)
{
/*
* do_statfs uses struct statfs64 internally, but the linux kernel
* struct statfs still has 32-bit versions for most of these fields,
* so we convert them here
*/
int err;
long long f_blocks;
long long f_bfree;
long long f_bavail;
long long f_files;
long long f_ffree;
err = do_statfs(dentry->d_sb->s_fs_info,
&sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files,
&f_ffree, &sf->f_fsid, sizeof(sf->f_fsid),
&sf->f_namelen);
if (err)
return err;
sf->f_blocks = f_blocks;
sf->f_bfree = f_bfree;
sf->f_bavail = f_bavail;
sf->f_files = f_files;
sf->f_ffree = f_ffree;
sf->f_type = HOSTFS_SUPER_MAGIC;
return 0;
}
static struct inode *hostfs_alloc_inode(struct super_block *sb)
{
struct hostfs_inode_info *hi;
hi = kmalloc(sizeof(*hi), GFP_KERNEL);
if (hi == NULL)
return NULL;
hi->fd = -1;
hi->mode = 0;
inode_init_once(&hi->vfs_inode);
return &hi->vfs_inode;
}
static void hostfs_evict_inode(struct inode *inode)
{
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
if (HOSTFS_I(inode)->fd != -1) {
close_file(&HOSTFS_I(inode)->fd);
HOSTFS_I(inode)->fd = -1;
}
}
static void hostfs_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kfree(HOSTFS_I(inode));
}
static void hostfs_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, hostfs_i_callback);
}
static int hostfs_show_options(struct seq_file *seq, struct dentry *root)
{
const char *root_path = root->d_sb->s_fs_info;
size_t offset = strlen(root_ino) + 1;
if (strlen(root_path) > offset)
seq_printf(seq, ",%s", root_path + offset);
return 0;
}
static const struct super_operations hostfs_sbops = {
.alloc_inode = hostfs_alloc_inode,
.destroy_inode = hostfs_destroy_inode,
.evict_inode = hostfs_evict_inode,
.statfs = hostfs_statfs,
.show_options = hostfs_show_options,
};
static int hostfs_readdir(struct file *file, struct dir_context *ctx)
{
void *dir;
char *name;
unsigned long long next, ino;
int error, len;
unsigned int type;
name = dentry_name(file->f_path.dentry);
if (name == NULL)
return -ENOMEM;
dir = open_dir(name, &error);
__putname(name);
if (dir == NULL)
return -error;
next = ctx->pos;
while ((name = read_dir(dir, &next, &ino, &len, &type)) != NULL) {
if (!dir_emit(ctx, name, len, ino, type))
break;
ctx->pos = next;
}
close_dir(dir);
return 0;
}
static int hostfs_file_open(struct inode *ino, struct file *file)
{
static DEFINE_MUTEX(open_mutex);
char *name;
fmode_t mode = 0;
int err;
int r = 0, w = 0, fd;
mode = file->f_mode & (FMODE_READ | FMODE_WRITE);
if ((mode & HOSTFS_I(ino)->mode) == mode)
return 0;
mode |= HOSTFS_I(ino)->mode;
retry:
if (mode & FMODE_READ)
r = 1;
if (mode & FMODE_WRITE)
w = 1;
if (w)
r = 1;
name = dentry_name(file->f_path.dentry);
if (name == NULL)
return -ENOMEM;
fd = open_file(name, r, w, append);
__putname(name);
if (fd < 0)
return fd;
mutex_lock(&open_mutex);
/* somebody else had handled it first? */
if ((mode & HOSTFS_I(ino)->mode) == mode) {
mutex_unlock(&open_mutex);
return 0;
}
if ((mode | HOSTFS_I(ino)->mode) != mode) {
mode |= HOSTFS_I(ino)->mode;
mutex_unlock(&open_mutex);
close_file(&fd);
goto retry;
}
if (HOSTFS_I(ino)->fd == -1) {
HOSTFS_I(ino)->fd = fd;
} else {
err = replace_file(fd, HOSTFS_I(ino)->fd);
close_file(&fd);
if (err < 0) {
mutex_unlock(&open_mutex);
return err;
}
}
HOSTFS_I(ino)->mode = mode;
mutex_unlock(&open_mutex);
return 0;
}
static int hostfs_file_release(struct inode *inode, struct file *file)
{
filemap_write_and_wait(inode->i_mapping);
return 0;
}
static int hostfs_fsync(struct file *file, loff_t start, loff_t end,
int datasync)
{
struct inode *inode = file->f_mapping->host;
int ret;
ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
if (ret)
return ret;
mutex_lock(&inode->i_mutex);
ret = fsync_file(HOSTFS_I(inode)->fd, datasync);
mutex_unlock(&inode->i_mutex);
return ret;
}
static const struct file_operations hostfs_file_fops = {
.llseek = generic_file_llseek,
.read = new_sync_read,
.splice_read = generic_file_splice_read,
.read_iter = generic_file_read_iter,
.write_iter = generic_file_write_iter,
.write = new_sync_write,
.mmap = generic_file_mmap,
.open = hostfs_file_open,
.release = hostfs_file_release,
.fsync = hostfs_fsync,
};
static const struct file_operations hostfs_dir_fops = {
.llseek = generic_file_llseek,
.iterate = hostfs_readdir,
.read = generic_read_dir,
};
static int hostfs_writepage(struct page *page, struct writeback_control *wbc)
{
struct address_space *mapping = page->mapping;
struct inode *inode = mapping->host;
char *buffer;
unsigned long long base;
int count = PAGE_CACHE_SIZE;
int end_index = inode->i_size >> PAGE_CACHE_SHIFT;
int err;
if (page->index >= end_index)
count = inode->i_size & (PAGE_CACHE_SIZE-1);
buffer = kmap(page);
base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT;
err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count);
if (err != count) {
ClearPageUptodate(page);
goto out;
}
if (base > inode->i_size)
inode->i_size = base;
if (PageError(page))
ClearPageError(page);
err = 0;
out:
kunmap(page);
unlock_page(page);
return err;
}
static int hostfs_readpage(struct file *file, struct page *page)
{
char *buffer;
long long start;
int err = 0;
start = (long long) page->index << PAGE_CACHE_SHIFT;
buffer = kmap(page);
err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer,
PAGE_CACHE_SIZE);
if (err < 0)
goto out;
memset(&buffer[err], 0, PAGE_CACHE_SIZE - err);
flush_dcache_page(page);
SetPageUptodate(page);
if (PageError(page)) ClearPageError(page);
err = 0;
out:
kunmap(page);
unlock_page(page);
return err;
}
static int hostfs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
*pagep = grab_cache_page_write_begin(mapping, index, flags);
if (!*pagep)
return -ENOMEM;
return 0;
}
static int hostfs_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
struct inode *inode = mapping->host;
void *buffer;
unsigned from = pos & (PAGE_CACHE_SIZE - 1);
int err;
buffer = kmap(page);
err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied);
kunmap(page);
if (!PageUptodate(page) && err == PAGE_CACHE_SIZE)
SetPageUptodate(page);
/*
* If err > 0, write_file has added err to pos, so we are comparing
* i_size against the last byte written.
*/
if (err > 0 && (pos > inode->i_size))
inode->i_size = pos;
unlock_page(page);
page_cache_release(page);
return err;
}
static const struct address_space_operations hostfs_aops = {
.writepage = hostfs_writepage,
.readpage = hostfs_readpage,
.set_page_dirty = __set_page_dirty_nobuffers,
.write_begin = hostfs_write_begin,
.write_end = hostfs_write_end,
};
static int read_name(struct inode *ino, char *name)
{
dev_t rdev;
struct hostfs_stat st;
int err = stat_file(name, &st, -1);
if (err)
return err;
/* Reencode maj and min with the kernel encoding.*/
rdev = MKDEV(st.maj, st.min);
switch (st.mode & S_IFMT) {
case S_IFLNK:
ino->i_op = &hostfs_link_iops;
break;
case S_IFDIR:
ino->i_op = &hostfs_dir_iops;
ino->i_fop = &hostfs_dir_fops;
break;
case S_IFCHR:
case S_IFBLK:
case S_IFIFO:
case S_IFSOCK:
init_special_inode(ino, st.mode & S_IFMT, rdev);
ino->i_op = &hostfs_iops;
break;
default:
ino->i_op = &hostfs_iops;
ino->i_fop = &hostfs_file_fops;
ino->i_mapping->a_ops = &hostfs_aops;
}
ino->i_ino = st.ino;
ino->i_mode = st.mode;
set_nlink(ino, st.nlink);
i_uid_write(ino, st.uid);
i_gid_write(ino, st.gid);
ino->i_atime = st.atime;
ino->i_mtime = st.mtime;
ino->i_ctime = st.ctime;
ino->i_size = st.size;
ino->i_blocks = st.blocks;
return 0;
}
static int hostfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
struct inode *inode;
char *name;
int error, fd;
inode = hostfs_iget(dir->i_sb);
if (IS_ERR(inode)) {
error = PTR_ERR(inode);
goto out;
}
error = -ENOMEM;
name = dentry_name(dentry);
if (name == NULL)
goto out_put;
fd = file_create(name,
mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR,
mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP,
mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH);
if (fd < 0)
error = fd;
else
error = read_name(inode, name);
__putname(name);
if (error)
goto out_put;
HOSTFS_I(inode)->fd = fd;
HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE;
d_instantiate(dentry, inode);
return 0;
out_put:
iput(inode);
out:
return error;
}
static struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode;
char *name;
int err;
inode = hostfs_iget(ino->i_sb);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out;
}
err = -ENOMEM;
name = dentry_name(dentry);
if (name == NULL)
goto out_put;
err = read_name(inode, name);
__putname(name);
if (err == -ENOENT) {
iput(inode);
inode = NULL;
}
else if (err)
goto out_put;
d_add(dentry, inode);
return NULL;
out_put:
iput(inode);
out:
return ERR_PTR(err);
}
static int hostfs_link(struct dentry *to, struct inode *ino,
struct dentry *from)
{
char *from_name, *to_name;
int err;
if ((from_name = dentry_name(from)) == NULL)
return -ENOMEM;
to_name = dentry_name(to);
if (to_name == NULL) {
__putname(from_name);
return -ENOMEM;
}
err = link_file(to_name, from_name);
__putname(from_name);
__putname(to_name);
return err;
}
static int hostfs_unlink(struct inode *ino, struct dentry *dentry)
{
char *file;
int err;
if (append)
return -EPERM;
if ((file = dentry_name(dentry)) == NULL)
return -ENOMEM;
err = unlink_file(file);
__putname(file);
return err;
}
static int hostfs_symlink(struct inode *ino, struct dentry *dentry,
const char *to)
{
char *file;
int err;
if ((file = dentry_name(dentry)) == NULL)
return -ENOMEM;
err = make_symlink(file, to);
__putname(file);
return err;
}
static int hostfs_mkdir(struct inode *ino, struct dentry *dentry, umode_t mode)
{
char *file;
int err;
if ((file = dentry_name(dentry)) == NULL)
return -ENOMEM;
err = do_mkdir(file, mode);
__putname(file);
return err;
}
static int hostfs_rmdir(struct inode *ino, struct dentry *dentry)
{
char *file;
int err;
if ((file = dentry_name(dentry)) == NULL)
return -ENOMEM;
err = do_rmdir(file);
__putname(file);
return err;
}
static int hostfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
{
struct inode *inode;
char *name;
int err;
inode = hostfs_iget(dir->i_sb);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out;
}
err = -ENOMEM;
name = dentry_name(dentry);
if (name == NULL)
goto out_put;
init_special_inode(inode, mode, dev);
err = do_mknod(name, mode, MAJOR(dev), MINOR(dev));
if (!err)
goto out_free;
err = read_name(inode, name);
__putname(name);
if (err)
goto out_put;
if (err)
goto out_put;
d_instantiate(dentry, inode);
return 0;
out_free:
__putname(name);
out_put:
iput(inode);
out:
return err;
}
static int hostfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
char *old_name, *new_name;
int err;
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
return -EINVAL;
old_name = dentry_name(old_dentry);
if (old_name == NULL)
return -ENOMEM;
new_name = dentry_name(new_dentry);
if (new_name == NULL) {
__putname(old_name);
return -ENOMEM;
}
if (!flags)
err = rename_file(old_name, new_name);
else
err = rename2_file(old_name, new_name, flags);
__putname(old_name);
__putname(new_name);
return err;
}
static int hostfs_permission(struct inode *ino, int desired)
{
char *name;
int r = 0, w = 0, x = 0, err;
if (desired & MAY_NOT_BLOCK)
return -ECHILD;
if (desired & MAY_READ) r = 1;
if (desired & MAY_WRITE) w = 1;
if (desired & MAY_EXEC) x = 1;
name = inode_name(ino);
if (name == NULL)
return -ENOMEM;
if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) ||
S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode))
err = 0;
else
err = access_file(name, r, w, x);
__putname(name);
if (!err)
err = generic_permission(ino, desired);
return err;
}
static int hostfs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
struct hostfs_iattr attrs;
char *name;
int err;
int fd = HOSTFS_I(inode)->fd;
err = inode_change_ok(inode, attr);
if (err)
return err;
if (append)
attr->ia_valid &= ~ATTR_SIZE;
attrs.ia_valid = 0;
if (attr->ia_valid & ATTR_MODE) {
attrs.ia_valid |= HOSTFS_ATTR_MODE;
attrs.ia_mode = attr->ia_mode;
}
if (attr->ia_valid & ATTR_UID) {
attrs.ia_valid |= HOSTFS_ATTR_UID;
attrs.ia_uid = from_kuid(&init_user_ns, attr->ia_uid);
}
if (attr->ia_valid & ATTR_GID) {
attrs.ia_valid |= HOSTFS_ATTR_GID;
attrs.ia_gid = from_kgid(&init_user_ns, attr->ia_gid);
}
if (attr->ia_valid & ATTR_SIZE) {
attrs.ia_valid |= HOSTFS_ATTR_SIZE;
attrs.ia_size = attr->ia_size;
}
if (attr->ia_valid & ATTR_ATIME) {
attrs.ia_valid |= HOSTFS_ATTR_ATIME;
attrs.ia_atime = attr->ia_atime;
}
if (attr->ia_valid & ATTR_MTIME) {
attrs.ia_valid |= HOSTFS_ATTR_MTIME;
attrs.ia_mtime = attr->ia_mtime;
}
if (attr->ia_valid & ATTR_CTIME) {
attrs.ia_valid |= HOSTFS_ATTR_CTIME;
attrs.ia_ctime = attr->ia_ctime;
}
if (attr->ia_valid & ATTR_ATIME_SET) {
attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET;
}
if (attr->ia_valid & ATTR_MTIME_SET) {
attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET;
}
name = dentry_name(dentry);
if (name == NULL)
return -ENOMEM;
err = set_attr(name, &attrs, fd);
__putname(name);
if (err)
return err;
if ((attr->ia_valid & ATTR_SIZE) &&
attr->ia_size != i_size_read(inode))
truncate_setsize(inode, attr->ia_size);
setattr_copy(inode, attr);
mark_inode_dirty(inode);
return 0;
}
static const struct inode_operations hostfs_iops = {
.permission = hostfs_permission,
.setattr = hostfs_setattr,
};
static const struct inode_operations hostfs_dir_iops = {
.create = hostfs_create,
.lookup = hostfs_lookup,
.link = hostfs_link,
.unlink = hostfs_unlink,
.symlink = hostfs_symlink,
.mkdir = hostfs_mkdir,
.rmdir = hostfs_rmdir,
.mknod = hostfs_mknod,
.rename2 = hostfs_rename2,
.permission = hostfs_permission,
.setattr = hostfs_setattr,
};
static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
char *link = __getname();
if (link) {
char *path = dentry_name(dentry);
int err = -ENOMEM;
if (path) {
err = hostfs_do_readlink(path, link, PATH_MAX);
if (err == PATH_MAX)
err = -E2BIG;
__putname(path);
}
if (err < 0) {
__putname(link);
link = ERR_PTR(err);
}
} else {
link = ERR_PTR(-ENOMEM);
}
nd_set_link(nd, link);
return NULL;
}
static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
{
char *s = nd_get_link(nd);
if (!IS_ERR(s))
__putname(s);
}
static const struct inode_operations hostfs_link_iops = {
.readlink = generic_readlink,
.follow_link = hostfs_follow_link,
.put_link = hostfs_put_link,
};
static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent)
{
struct inode *root_inode;
char *host_root_path, *req_root = d;
int err;
sb->s_blocksize = 1024;
sb->s_blocksize_bits = 10;
sb->s_magic = HOSTFS_SUPER_MAGIC;
sb->s_op = &hostfs_sbops;
sb->s_d_op = &simple_dentry_operations;
sb->s_maxbytes = MAX_LFS_FILESIZE;
/* NULL is printed as <NULL> by sprintf: avoid that. */
if (req_root == NULL)
req_root = "";
err = -ENOMEM;
sb->s_fs_info = host_root_path =
kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL);
if (host_root_path == NULL)
goto out;
sprintf(host_root_path, "%s/%s", root_ino, req_root);
root_inode = new_inode(sb);
if (!root_inode)
goto out;
err = read_name(root_inode, host_root_path);
if (err)
goto out_put;
if (S_ISLNK(root_inode->i_mode)) {
char *name = follow_link(host_root_path);
if (IS_ERR(name))
err = PTR_ERR(name);
else
err = read_name(root_inode, name);
kfree(name);
if (err)
goto out_put;
}
err = -ENOMEM;
sb->s_root = d_make_root(root_inode);
if (sb->s_root == NULL)
goto out;
return 0;
out_put:
iput(root_inode);
out:
return err;
}
static struct dentry *hostfs_read_sb(struct file_system_type *type,
int flags, const char *dev_name,
void *data)
{
return mount_nodev(type, flags, data, hostfs_fill_sb_common);
}
static void hostfs_kill_sb(struct super_block *s)
{
kill_anon_super(s);
kfree(s->s_fs_info);
}
static struct file_system_type hostfs_type = {
.owner = THIS_MODULE,
.name = "hostfs",
.mount = hostfs_read_sb,
.kill_sb = hostfs_kill_sb,
.fs_flags = 0,
};
MODULE_ALIAS_FS("hostfs");
static int __init init_hostfs(void)
{
return register_filesystem(&hostfs_type);
}
static void __exit exit_hostfs(void)
{
unregister_filesystem(&hostfs_type);
}
module_init(init_hostfs)
module_exit(exit_hostfs)
MODULE_LICENSE("GPL");