WSL2-Linux-Kernel/fs/ncpfs/file.c

264 строки
5.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* file.c
*
* Copyright (C) 1995, 1996 by Volker Lendecke
* Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/uaccess.h>
#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/sched.h>
#include "ncp_fs.h"
static int ncp_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
return file_write_and_wait_range(file, start, end);
}
/*
* Open a file with the specified read/write mode.
*/
int ncp_make_open(struct inode *inode, int right)
{
int error;
int access;
error = -EINVAL;
if (!inode) {
pr_err("%s: got NULL inode\n", __func__);
goto out;
}
ncp_dbg(1, "opened=%d, volume # %u, dir entry # %u\n",
atomic_read(&NCP_FINFO(inode)->opened),
NCP_FINFO(inode)->volNumber,
NCP_FINFO(inode)->dirEntNum);
error = -EACCES;
mutex_lock(&NCP_FINFO(inode)->open_mutex);
if (!atomic_read(&NCP_FINFO(inode)->opened)) {
struct ncp_entry_info finfo;
int result;
/* tries max. rights */
finfo.access = O_RDWR;
result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
inode, NULL, OC_MODE_OPEN,
0, AR_READ | AR_WRITE, &finfo);
if (!result)
goto update;
/* RDWR did not succeeded, try readonly or writeonly as requested */
switch (right) {
case O_RDONLY:
finfo.access = O_RDONLY;
result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
inode, NULL, OC_MODE_OPEN,
0, AR_READ, &finfo);
break;
case O_WRONLY:
finfo.access = O_WRONLY;
result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
inode, NULL, OC_MODE_OPEN,
0, AR_WRITE, &finfo);
break;
}
if (result) {
ncp_vdbg("failed, result=%d\n", result);
goto out_unlock;
}
/*
* Update the inode information.
*/
update:
ncp_update_inode(inode, &finfo);
atomic_set(&NCP_FINFO(inode)->opened, 1);
}
access = NCP_FINFO(inode)->access;
ncp_vdbg("file open, access=%x\n", access);
if (access == right || access == O_RDWR) {
atomic_inc(&NCP_FINFO(inode)->opened);
error = 0;
}
out_unlock:
mutex_unlock(&NCP_FINFO(inode)->open_mutex);
out:
return error;
}
static ssize_t
ncp_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
size_t already_read = 0;
off_t pos = iocb->ki_pos;
size_t bufsize;
int error;
void *freepage;
size_t freelen;
ncp_dbg(1, "enter %pD2\n", file);
if (!iov_iter_count(to))
return 0;
if (pos > inode->i_sb->s_maxbytes)
return 0;
iov_iter_truncate(to, inode->i_sb->s_maxbytes - pos);
error = ncp_make_open(inode, O_RDONLY);
if (error) {
ncp_dbg(1, "open failed, error=%d\n", error);
return error;
}
bufsize = NCP_SERVER(inode)->buffer_size;
error = -EIO;
freelen = ncp_read_bounce_size(bufsize);
freepage = vmalloc(freelen);
if (!freepage)
goto outrel;
error = 0;
/* First read in as much as possible for each bufsize. */
while (iov_iter_count(to)) {
int read_this_time;
size_t to_read = min_t(size_t,
bufsize - (pos % bufsize),
iov_iter_count(to));
error = ncp_read_bounce(NCP_SERVER(inode),
NCP_FINFO(inode)->file_handle,
pos, to_read, to, &read_this_time,
freepage, freelen);
if (error) {
error = -EIO; /* NW errno -> Linux errno */
break;
}
pos += read_this_time;
already_read += read_this_time;
if (read_this_time != to_read)
break;
}
vfree(freepage);
iocb->ki_pos = pos;
file_accessed(file);
ncp_dbg(1, "exit %pD2\n", file);
outrel:
ncp_inode_close(inode);
return already_read ? already_read : error;
}
static ssize_t
ncp_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
size_t already_written = 0;
size_t bufsize;
int errno;
void *bouncebuffer;
off_t pos;
ncp_dbg(1, "enter %pD2\n", file);
errno = generic_write_checks(iocb, from);
if (errno <= 0)
return errno;
errno = ncp_make_open(inode, O_WRONLY);
if (errno) {
ncp_dbg(1, "open failed, error=%d\n", errno);
return errno;
}
bufsize = NCP_SERVER(inode)->buffer_size;
errno = file_update_time(file);
if (errno)
goto outrel;
bouncebuffer = vmalloc(bufsize);
if (!bouncebuffer) {
errno = -EIO; /* -ENOMEM */
goto outrel;
}
pos = iocb->ki_pos;
while (iov_iter_count(from)) {
int written_this_time;
size_t to_write = min_t(size_t,
bufsize - (pos % bufsize),
iov_iter_count(from));
if (!copy_from_iter_full(bouncebuffer, to_write, from)) {
errno = -EFAULT;
break;
}
if (ncp_write_kernel(NCP_SERVER(inode),
NCP_FINFO(inode)->file_handle,
pos, to_write, bouncebuffer, &written_this_time) != 0) {
errno = -EIO;
break;
}
pos += written_this_time;
already_written += written_this_time;
if (written_this_time != to_write)
break;
}
vfree(bouncebuffer);
iocb->ki_pos = pos;
if (pos > i_size_read(inode)) {
inode_lock(inode);
if (pos > i_size_read(inode))
i_size_write(inode, pos);
inode_unlock(inode);
}
ncp_dbg(1, "exit %pD2\n", file);
outrel:
ncp_inode_close(inode);
return already_written ? already_written : errno;
}
static int ncp_release(struct inode *inode, struct file *file) {
if (ncp_make_closed(inode)) {
ncp_dbg(1, "failed to close\n");
}
return 0;
}
const struct file_operations ncp_file_operations =
{
.llseek = generic_file_llseek,
.read_iter = ncp_file_read_iter,
.write_iter = ncp_file_write_iter,
.unlocked_ioctl = ncp_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ncp_compat_ioctl,
#endif
.mmap = ncp_mmap,
.release = ncp_release,
.fsync = ncp_fsync,
};
const struct inode_operations ncp_file_inode_operations =
{
.setattr = ncp_notify_change,
};