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/*
* mmap.c
*
* Copyright (C) 1995, 1996 by Volker Lendecke
* Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
*
*/
#include <linux/stat.h>
#include <linux/time.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/slab.h>
#include <linux/fcntl.h>
#include <linux/ncp_fs.h>
#include "ncplib_kernel.h"
#include <asm/uaccess.h>
#include <asm/system.h>
/*
* Fill in the supplied page for mmap
*/
static struct page* ncp_file_mmap_nopage(struct vm_area_struct *area,
unsigned long address, int *type)
{
struct file *file = area->vm_file;
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = dentry->d_inode;
struct page* page;
char *pg_addr;
unsigned int already_read;
unsigned int count;
int bufsize;
int pos;
page = alloc_page(GFP_HIGHUSER); /* ncpfs has nothing against high pages
as long as recvmsg and memset works on it */
if (!page)
return page;
pg_addr = kmap(page);
address &= PAGE_MASK;
pos = address - area->vm_start + (area->vm_pgoff << PAGE_SHIFT);
count = PAGE_SIZE;
if (address + PAGE_SIZE > area->vm_end) {
count = area->vm_end - address;
}
/* what we can read in one go */
bufsize = NCP_SERVER(inode)->buffer_size;
already_read = 0;
if (ncp_make_open(inode, O_RDONLY) >= 0) {
while (already_read < count) {
int read_this_time;
int to_read;
to_read = bufsize - (pos % bufsize);
to_read = min_t(unsigned int, to_read, count - already_read);
if (ncp_read_kernel(NCP_SERVER(inode),
NCP_FINFO(inode)->file_handle,
pos, to_read,
pg_addr + 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;
}
}
ncp_inode_close(inode);
}
if (already_read < PAGE_SIZE)
memset(pg_addr + already_read, 0, PAGE_SIZE - already_read);
flush_dcache_page(page);
kunmap(page);
/*
* If I understand ncp_read_kernel() properly, the above always
* fetches from the network, here the analogue of disk.
* -- wli
*/
if (type)
*type = VM_FAULT_MAJOR;
count_vm_event(PGMAJFAULT);
return page;
}
static struct vm_operations_struct ncp_file_mmap =
{
.nopage = ncp_file_mmap_nopage,
};
/* This is used for a general mmap of a ncp file */
int ncp_mmap(struct file *file, struct vm_area_struct *vma)
{
struct inode *inode = file->f_path.dentry->d_inode;
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;
/* we do not support files bigger than 4GB... We eventually
supports just 4GB... */
if (((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff
> (1U << (32 - PAGE_SHIFT)))
return -EFBIG;
vma->vm_ops = &ncp_file_mmap;
vma->vm_flags |= VM_CAN_INVALIDATE;
file_accessed(file);
return 0;
}
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