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/*
* mmap.c
*
* Copyright (C) 1995, 1996 by Volker Lendecke
*
*/
#include <linux/stat.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/shm.h>
#include <linux/errno.h>
#include <linux/mman.h>
#include <linux/string.h>
#include <linux/malloc.h>
#include <linux/fcntl.h>
#include <linux/ncp_fs.h>
#include "ncplib_kernel.h"
#include <asm/uaccess.h>
#include <asm/system.h>
static inline int min(int a, int b)
{
return a < b ? a : b;
}
/*
* Fill in the supplied page for mmap
*/
static unsigned long ncp_file_mmap_nopage(struct vm_area_struct *area,
unsigned long address, int no_share)
{
struct inode *inode = area->vm_inode;
unsigned long page;
unsigned int clear;
unsigned long tmp;
int bufsize;
int pos;
unsigned short fs;
page = __get_free_page(GFP_KERNEL);
if (!page)
return page;
address &= PAGE_MASK;
pos = address - area->vm_start + area->vm_offset;
clear = 0;
if (address + PAGE_SIZE > area->vm_end) {
clear = address + PAGE_SIZE - area->vm_end;
}
/* what we can read in one go */
bufsize = NCP_SERVER(inode)->buffer_size;
fs = get_fs();
set_fs(get_ds());
if (ncp_make_open(inode, O_RDONLY) < 0) {
clear = PAGE_SIZE;
} else {
int already_read = 0;
int count = PAGE_SIZE - clear;
int to_read;
while (already_read < count) {
int read_this_time;
if ((pos % bufsize) != 0) {
to_read = bufsize - (pos % bufsize);
} else {
to_read = bufsize;
}
to_read = min(to_read, count - already_read);
if (ncp_read(NCP_SERVER(inode),
NCP_FINFO(inode)->file_handle,
pos, to_read,
(char *) (page + already_read),
&read_this_time) != 0) {
read_this_time = 0;
}
pos += read_this_time;
already_read += read_this_time;
if (read_this_time < to_read) {
break;
}
}
}
set_fs(fs);
tmp = page + PAGE_SIZE;
while (clear--) {
*(char *) --tmp = 0;
}
return page;
}
struct vm_operations_struct ncp_file_mmap =
{
NULL, /* open */
NULL, /* close */
NULL, /* unmap */
NULL, /* protect */
NULL, /* sync */
NULL, /* advise */
ncp_file_mmap_nopage, /* nopage */
NULL, /* wppage */
NULL, /* swapout */
NULL, /* swapin */
};
/* This is used for a general mmap of a ncp file */
int ncp_mmap(struct inode *inode, struct file *file, struct vm_area_struct *vma)
{
DPRINTK("ncp_mmap: called\n");
if (!ncp_conn_valid(NCP_SERVER(inode))) {
return -EIO;
}
/* only PAGE_COW or read-only supported now */
if (vma->vm_flags & VM_SHARED)
return -EINVAL;
if (!inode->i_sb || !S_ISREG(inode->i_mode))
return -EACCES;
if (!IS_RDONLY(inode)) {
inode->i_atime = CURRENT_TIME;
inode->i_dirt = 1;
}
vma->vm_dentry = dget(file->f_dentry);
vma->vm_ops = &ncp_file_mmap;
return 0;
}
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