forked from Minki/linux
92e5baef85
Signed-off-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
129 lines
2.9 KiB
C
129 lines
2.9 KiB
C
/*
|
|
* 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;
|
|
file_accessed(file);
|
|
return 0;
|
|
}
|