/*
|
* 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;
|
struct mutex open_mutex;
|
};
|
|
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;
|
}
|
|
/*
|
* This function relies on the fact that dentry_path_raw() will place
|
* the path name at the end of the provided buffer.
|
*/
|
BUG_ON(p + strlen(p) + 1 != name + PATH_MAX);
|
|
strlcpy(name, root, PATH_MAX);
|
if (len > p - name) {
|
__putname(name);
|
return NULL;
|
}
|
|
if (p > name + len)
|
strcpy(name + len, p);
|
|
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)
|
{
|
char *name, *resolved, *end;
|
int n;
|
|
name = kmalloc(PATH_MAX, GFP_KERNEL);
|
if (!name) {
|
n = -ENOMEM;
|
goto out_free;
|
}
|
|
n = hostfs_do_readlink(link, name, PATH_MAX);
|
if (n < 0)
|
goto out_free;
|
else if (n == PATH_MAX) {
|
n = -E2BIG;
|
goto out_free;
|
}
|
|
if (*name == '/')
|
return name;
|
|
end = strrchr(link, '/');
|
if (end == NULL)
|
return name;
|
|
*(end + 1) = '\0';
|
|
resolved = kasprintf(GFP_KERNEL, "%s%s", link, name);
|
if (resolved == NULL) {
|
n = -ENOMEM;
|
goto out_free;
|
}
|
|
kfree(name);
|
return resolved;
|
|
out_free:
|
kfree(name);
|
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_ACCOUNT);
|
if (hi == NULL)
|
return NULL;
|
hi->fd = -1;
|
hi->mode = 0;
|
inode_init_once(&hi->vfs_inode);
|
mutex_init(&hi->open_mutex);
|
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_free_inode(struct inode *inode)
|
{
|
kfree(HOSTFS_I(inode));
|
}
|
|
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_show_option(seq, root_path + offset, NULL);
|
|
if (append)
|
seq_puts(seq, ",append");
|
|
return 0;
|
}
|
|
static const struct super_operations hostfs_sbops = {
|
.alloc_inode = hostfs_alloc_inode,
|
.free_inode = hostfs_free_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;
|
seek_dir(dir, next);
|
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_open(struct inode *ino, struct file *file)
|
{
|
char *name;
|
fmode_t mode;
|
int err;
|
int r, w, fd;
|
|
mode = file->f_mode & (FMODE_READ | FMODE_WRITE);
|
if ((mode & HOSTFS_I(ino)->mode) == mode)
|
return 0;
|
|
mode |= HOSTFS_I(ino)->mode;
|
|
retry:
|
r = w = 0;
|
|
if (mode & FMODE_READ)
|
r = 1;
|
if (mode & FMODE_WRITE)
|
r = w = 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(&HOSTFS_I(ino)->open_mutex);
|
/* somebody else had handled it first? */
|
if ((mode & HOSTFS_I(ino)->mode) == mode) {
|
mutex_unlock(&HOSTFS_I(ino)->open_mutex);
|
close_file(&fd);
|
return 0;
|
}
|
if ((mode | HOSTFS_I(ino)->mode) != mode) {
|
mode |= HOSTFS_I(ino)->mode;
|
mutex_unlock(&HOSTFS_I(ino)->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(&HOSTFS_I(ino)->open_mutex);
|
return err;
|
}
|
}
|
HOSTFS_I(ino)->mode = mode;
|
mutex_unlock(&HOSTFS_I(ino)->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 = file_write_and_wait_range(file, start, end);
|
if (ret)
|
return ret;
|
|
inode_lock(inode);
|
ret = fsync_file(HOSTFS_I(inode)->fd, datasync);
|
inode_unlock(inode);
|
|
return ret;
|
}
|
|
static const struct file_operations hostfs_file_fops = {
|
.llseek = generic_file_llseek,
|
.splice_read = generic_file_splice_read,
|
.read_iter = generic_file_read_iter,
|
.write_iter = generic_file_write_iter,
|
.mmap = generic_file_mmap,
|
.open = hostfs_open,
|
.release = hostfs_file_release,
|
.fsync = hostfs_fsync,
|
};
|
|
static const struct file_operations hostfs_dir_fops = {
|
.llseek = generic_file_llseek,
|
.iterate_shared = hostfs_readdir,
|
.read = generic_read_dir,
|
.open = hostfs_open,
|
.fsync = hostfs_fsync,
|
};
|
|
static int hostfs_writepage(struct page *page, struct writeback_control *wbc)
|
{
|
struct address_space *mapping = page->mapping;
|
struct inode *inode = mapping->host;
|
char *buffer;
|
loff_t base = page_offset(page);
|
int count = PAGE_SIZE;
|
int end_index = inode->i_size >> PAGE_SHIFT;
|
int err;
|
|
if (page->index >= end_index)
|
count = inode->i_size & (PAGE_SIZE-1);
|
|
buffer = kmap(page);
|
|
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;
|
loff_t start = page_offset(page);
|
int bytes_read, ret = 0;
|
|
buffer = kmap(page);
|
bytes_read = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer,
|
PAGE_SIZE);
|
if (bytes_read < 0) {
|
ClearPageUptodate(page);
|
SetPageError(page);
|
ret = bytes_read;
|
goto out;
|
}
|
|
memset(buffer + bytes_read, 0, PAGE_SIZE - bytes_read);
|
|
ClearPageError(page);
|
SetPageUptodate(page);
|
|
out:
|
flush_dcache_page(page);
|
kunmap(page);
|
unlock_page(page);
|
return ret;
|
}
|
|
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_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_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_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);
|
put_page(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;
|
case S_IFREG:
|
ino->i_op = &hostfs_iops;
|
ino->i_fop = &hostfs_file_fops;
|
ino->i_mapping->a_ops = &hostfs_aops;
|
break;
|
default:
|
return -EIO;
|
}
|
|
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 = (struct timespec64){ st.atime.tv_sec, st.atime.tv_nsec };
|
ino->i_mtime = (struct timespec64){ st.mtime.tv_sec, st.mtime.tv_nsec };
|
ino->i_ctime = (struct timespec64){ st.ctime.tv_sec, st.ctime.tv_nsec };
|
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 & 0777);
|
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))
|
goto out;
|
|
err = -ENOMEM;
|
name = dentry_name(dentry);
|
if (name) {
|
err = read_name(inode, name);
|
__putname(name);
|
}
|
if (err) {
|
iput(inode);
|
inode = (err == -ENOENT) ? NULL : ERR_PTR(err);
|
}
|
out:
|
return d_splice_alias(inode, dentry);
|
}
|
|
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 = hostfs_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;
|
|
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 = d_inode(dentry);
|
struct hostfs_iattr attrs;
|
char *name;
|
int err;
|
|
int fd = HOSTFS_I(inode)->fd;
|
|
err = setattr_prepare(dentry, 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 = (struct hostfs_timespec)
|
{ attr->ia_atime.tv_sec, attr->ia_atime.tv_nsec };
|
}
|
if (attr->ia_valid & ATTR_MTIME) {
|
attrs.ia_valid |= HOSTFS_ATTR_MTIME;
|
attrs.ia_mtime = (struct hostfs_timespec)
|
{ attr->ia_mtime.tv_sec, attr->ia_mtime.tv_nsec };
|
}
|
if (attr->ia_valid & ATTR_CTIME) {
|
attrs.ia_valid |= HOSTFS_ATTR_CTIME;
|
attrs.ia_ctime = (struct hostfs_timespec)
|
{ attr->ia_ctime.tv_sec, attr->ia_ctime.tv_nsec };
|
}
|
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,
|
.rename = hostfs_rename2,
|
.permission = hostfs_permission,
|
.setattr = hostfs_setattr,
|
};
|
|
static const char *hostfs_get_link(struct dentry *dentry,
|
struct inode *inode,
|
struct delayed_call *done)
|
{
|
char *link;
|
if (!dentry)
|
return ERR_PTR(-ECHILD);
|
link = kmalloc(PATH_MAX, GFP_KERNEL);
|
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) {
|
kfree(link);
|
return ERR_PTR(err);
|
}
|
} else {
|
return ERR_PTR(-ENOMEM);
|
}
|
|
set_delayed_call(done, kfree_link, link);
|
return link;
|
}
|
|
static const struct inode_operations hostfs_link_iops = {
|
.get_link = hostfs_get_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 printf(): avoid that. */
|
if (req_root == NULL)
|
req_root = "";
|
|
err = -ENOMEM;
|
sb->s_fs_info = host_root_path =
|
kasprintf(GFP_KERNEL, "%s/%s", root_ino, req_root);
|
if (host_root_path == NULL)
|
goto out;
|
|
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);
|
goto out_put;
|
}
|
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");
|
