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/*
* mmap.c
*
* Copyright (C) 1995, 1996 by Paal-Kr. Engstad and 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/smb_fs.h>
#include <linux/fcntl.h>
#include <asm/segment.h>
#include <asm/system.h>
/*
* Fill in the supplied page for mmap
*/
static unsigned long
smb_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 n;
int i;
int pos;
page = __get_free_page(GFP_KERNEL);
if (!page)
return 0;
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 */
n = SMB_SERVER(inode)->max_xmit - SMB_HEADER_LEN - 5 * 2 - 3 - 10;
if (smb_make_open(inode, O_RDONLY) < 0)
{
clear = PAGE_SIZE;
} else
{
for (i = 0; i < (PAGE_SIZE - clear); i += n)
{
int hunk, result;
hunk = PAGE_SIZE - i;
if (hunk > n)
hunk = n;
DDPRINTK("smb_file_mmap_nopage: reading\n");
DDPRINTK("smb_file_mmap_nopage: pos = %d\n", pos);
result = smb_proc_read(SMB_SERVER(inode),
SMB_FINFO(inode), pos, hunk,
(char *) (page + i), 0);
DDPRINTK("smb_file_mmap_nopage: result= %d\n", result);
if (result < 0)
break;
pos += result;
if (result < n)
{
i += result;
break;
}
}
}
tmp = page + PAGE_SIZE;
while (clear--)
{
*(char *) --tmp = 0;
}
return page;
}
struct vm_operations_struct smb_file_mmap =
{
NULL, /* open */
NULL, /* close */
NULL, /* unmap */
NULL, /* protect */
NULL, /* sync */
NULL, /* advise */
smb_file_mmap_nopage, /* nopage */
NULL, /* wppage */
NULL, /* swapout */
NULL, /* swapin */
};
/* This is used for a general mmap of a smb file */
int
smb_mmap(struct inode *inode, struct file *file, struct vm_area_struct *vma)
{
DPRINTK("smb_mmap: called\n");
/* 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_inode = inode;
inode->i_count++;
vma->vm_ops = &smb_file_mmap;
return 0;
}
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