1 /*
2 * mmap.c
3 *
4 * Copyright (C) 1995, 1996 by Volker Lendecke
5 * Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
6 *
7 */
8
9 #include <linux/stat.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/mm.h>
13 #include <linux/shm.h>
14 #include <linux/errno.h>
15 #include <linux/mman.h>
16 #include <linux/string.h>
17 #include <linux/slab.h>
18 #include <linux/fcntl.h>
19 #include <linux/ncp_fs.h>
20
21 #include "ncplib_kernel.h"
22 #include <asm/uaccess.h>
23 #include <asm/system.h>
24
25 /*
26 * Fill in the supplied page for mmap
27 */
ncp_file_mmap_nopage(struct vm_area_struct * area,unsigned long address,int write_access)28 static struct page* ncp_file_mmap_nopage(struct vm_area_struct *area,
29 unsigned long address, int write_access)
30 {
31 struct file *file = area->vm_file;
32 struct dentry *dentry = file->f_dentry;
33 struct inode *inode = dentry->d_inode;
34 struct page* page;
35 char *pg_addr;
36 unsigned int already_read;
37 unsigned int count;
38 int bufsize;
39 int pos;
40
41 page = alloc_page(GFP_HIGHUSER); /* ncpfs has nothing against high pages
42 as long as recvmsg and memset works on it */
43 if (!page)
44 return page;
45 pg_addr = kmap(page);
46 address &= PAGE_MASK;
47 pos = address - area->vm_start + (area->vm_pgoff << PAGE_SHIFT);
48
49 count = PAGE_SIZE;
50 /* what we can read in one go */
51 bufsize = NCP_SERVER(inode)->buffer_size;
52
53 already_read = 0;
54 if (ncp_make_open(inode, O_RDONLY) >= 0) {
55 while (already_read < count) {
56 int read_this_time;
57 int to_read;
58
59 to_read = bufsize - (pos % bufsize);
60
61 to_read = min_t(unsigned int, to_read, count - already_read);
62
63 if (ncp_read_kernel(NCP_SERVER(inode),
64 NCP_FINFO(inode)->file_handle,
65 pos, to_read,
66 pg_addr + already_read,
67 &read_this_time) != 0) {
68 read_this_time = 0;
69 }
70 pos += read_this_time;
71 already_read += read_this_time;
72
73 if (read_this_time < to_read) {
74 break;
75 }
76 }
77 ncp_inode_close(inode);
78
79 }
80
81 if (already_read < PAGE_SIZE)
82 memset(pg_addr + already_read, 0, PAGE_SIZE - already_read);
83 flush_dcache_page(page);
84 kunmap(page);
85 return page;
86 }
87
88 static struct vm_operations_struct ncp_file_mmap =
89 {
90 nopage: ncp_file_mmap_nopage,
91 };
92
93
94 /* This is used for a general mmap of a ncp file */
ncp_mmap(struct file * file,struct vm_area_struct * vma)95 int ncp_mmap(struct file *file, struct vm_area_struct *vma)
96 {
97 struct inode *inode = file->f_dentry->d_inode;
98
99 DPRINTK("ncp_mmap: called\n");
100
101 if (!ncp_conn_valid(NCP_SERVER(inode))) {
102 return -EIO;
103 }
104 /* only PAGE_COW or read-only supported now */
105 if (vma->vm_flags & VM_SHARED)
106 return -EINVAL;
107 if (!inode->i_sb || !S_ISREG(inode->i_mode))
108 return -EACCES;
109 /* we do not support files bigger than 4GB... We eventually
110 supports just 4GB... */
111 if (((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff
112 > (1U << (32 - PAGE_SHIFT)))
113 return -EFBIG;
114 if (!IS_RDONLY(inode)) {
115 inode->i_atime = CURRENT_TIME;
116 }
117
118 vma->vm_ops = &ncp_file_mmap;
119 return 0;
120 }
121