4 * Copyright (C) 1995, 1996 by Volker Lendecke
5 * Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
9 #include <linux/stat.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
13 #include <linux/shm.h>
14 #include <linux/errno.h>
15 #include <linux/mman.h>
16 #include <linux/string.h>
17 #include <linux/malloc.h>
18 #include <linux/fcntl.h>
19 #include <linux/ncp_fs.h>
21 #include "ncplib_kernel.h"
22 #include <asm/uaccess.h>
23 #include <asm/system.h>
25 static inline int min(int a
, int b
)
31 * Fill in the supplied page for mmap
33 static struct page
* ncp_file_mmap_nopage(struct vm_area_struct
*area
,
34 unsigned long address
, int write_access
)
36 struct file
*file
= area
->vm_file
;
37 struct dentry
*dentry
= file
->f_dentry
;
38 struct inode
*inode
= dentry
->d_inode
;
40 unsigned long pg_addr
;
41 unsigned int already_read
;
46 page
= alloc_page(GFP_HIGHMEM
); /* ncpfs has nothing against GFP_HIGHMEM
47 as long as recvmsg and memset works on it */
52 pos
= address
- area
->vm_start
+ (area
->vm_pgoff
<< PAGE_SHIFT
);
55 if (address
+ PAGE_SIZE
> area
->vm_end
) {
56 count
= area
->vm_end
- address
;
58 /* what we can read in one go */
59 bufsize
= NCP_SERVER(inode
)->buffer_size
;
62 if (ncp_make_open(inode
, O_RDONLY
) >= 0) {
63 while (already_read
< count
) {
67 to_read
= bufsize
- (pos
% bufsize
);
69 to_read
= min(to_read
, count
- already_read
);
71 if (ncp_read_kernel(NCP_SERVER(inode
),
72 NCP_FINFO(inode
)->file_handle
,
74 (char *) (pg_addr
+ already_read
),
75 &read_this_time
) != 0) {
78 pos
+= read_this_time
;
79 already_read
+= read_this_time
;
81 if (read_this_time
< to_read
) {
85 ncp_inode_close(inode
);
89 if (already_read
< PAGE_SIZE
)
90 memset((char*)(pg_addr
+ already_read
), 0,
91 PAGE_SIZE
- already_read
);
92 flush_dcache_page(page
);
97 static struct vm_operations_struct ncp_file_mmap
=
99 nopage
: ncp_file_mmap_nopage
,
103 /* This is used for a general mmap of a ncp file */
104 int ncp_mmap(struct file
*file
, struct vm_area_struct
*vma
)
106 struct inode
*inode
= file
->f_dentry
->d_inode
;
108 DPRINTK("ncp_mmap: called\n");
110 if (!ncp_conn_valid(NCP_SERVER(inode
))) {
113 /* only PAGE_COW or read-only supported now */
114 if (vma
->vm_flags
& VM_SHARED
)
116 if (!inode
->i_sb
|| !S_ISREG(inode
->i_mode
))
118 /* we do not support files bigger than 4GB... We eventually
119 supports just 4GB... */
120 if (((vma
->vm_end
- vma
->vm_start
) >> PAGE_SHIFT
) + vma
->vm_pgoff
121 > (1U << (32 - PAGE_SHIFT
)))
123 if (!IS_RDONLY(inode
)) {
124 inode
->i_atime
= CURRENT_TIME
;
127 vma
->vm_ops
= &ncp_file_mmap
;