1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/*
* 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/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 struct page* ncp_file_mmap_nopage(struct vm_area_struct *area,
unsigned long address, int write_access)
{
struct file *file = area->vm_file;
struct dentry *dentry = file->f_dentry;
struct inode *inode = dentry->d_inode;
struct page* page;
unsigned long pg_addr;
unsigned int already_read;
unsigned int count;
int bufsize;
int pos;
page = alloc_page(GFP_KERNEL);
if (!page)
return page;
pg_addr = page_address(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(to_read, count - already_read);
if (ncp_read_kernel(NCP_SERVER(inode),
NCP_FINFO(inode)->file_handle,
pos, to_read,
(char *) (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;
}
}
}
if (already_read < PAGE_SIZE)
memset((char*)(pg_addr + already_read), 0,
PAGE_SIZE - already_read);
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 */
};
/* 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_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;
if (!inode->i_sb || !S_ISREG(inode->i_mode))
return -EACCES;
/* 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;
if (!IS_RDONLY(inode)) {
inode->i_atime = CURRENT_TIME;
}
vma->vm_ops = &ncp_file_mmap;
return 0;
}
|
