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
|
/*
* linux/fs/minix/file.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* minix regular file handling primitives
*/
#include <linux/sched.h>
#include <linux/minix_fs.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/locks.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#define NBUF 32
#define MIN(a,b) (((a)<(b))?(a):(b))
#define MAX(a,b) (((a)>(b))?(a):(b))
#include <linux/fs.h>
#include <linux/minix_fs.h>
static long minix_file_write(struct inode *, struct file *, const char *, unsigned long);
/*
* We have mostly NULL's here: the current defaults are ok for
* the minix filesystem.
*/
static struct file_operations minix_file_operations = {
NULL, /* lseek - default */
generic_file_read, /* read */
minix_file_write, /* write */
NULL, /* readdir - bad */
NULL, /* poll - default */
NULL, /* ioctl - default */
generic_file_mmap, /* mmap */
NULL, /* no special open is needed */
NULL, /* release */
minix_sync_file /* fsync */
};
struct inode_operations minix_file_inode_operations = {
&minix_file_operations, /* default file operations */
NULL, /* create */
NULL, /* lookup */
NULL, /* link */
NULL, /* unlink */
NULL, /* symlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* mknod */
NULL, /* rename */
NULL, /* readlink */
generic_readpage, /* readpage */
NULL, /* writepage */
minix_bmap, /* bmap */
minix_truncate, /* truncate */
NULL /* permission */
};
static long minix_file_write(struct inode * inode, struct file * filp,
const char * buf, unsigned long count)
{
off_t pos;
int written,c;
struct buffer_head * bh;
char * p;
if (!inode) {
printk("minix_file_write: inode = NULL\n");
return -EINVAL;
}
if (!S_ISREG(inode->i_mode)) {
printk("minix_file_write: mode = %07o\n",inode->i_mode);
return -EINVAL;
}
if (filp->f_flags & O_APPEND)
pos = inode->i_size;
else
pos = filp->f_pos;
written = 0;
while (written < count) {
bh = minix_getblk(inode,pos/BLOCK_SIZE,1);
if (!bh) {
if (!written)
written = -ENOSPC;
break;
}
c = BLOCK_SIZE - (pos % BLOCK_SIZE);
if (c > count-written)
c = count-written;
if (c != BLOCK_SIZE && !buffer_uptodate(bh)) {
ll_rw_block(READ, 1, &bh);
wait_on_buffer(bh);
if (!buffer_uptodate(bh)) {
brelse(bh);
if (!written)
written = -EIO;
break;
}
}
p = (pos % BLOCK_SIZE) + bh->b_data;
copy_from_user(p,buf,c);
update_vm_cache(inode, pos, p, c);
mark_buffer_uptodate(bh, 1);
mark_buffer_dirty(bh, 0);
brelse(bh);
pos += c;
written += c;
buf += c;
}
if (pos > inode->i_size)
inode->i_size = pos;
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
filp->f_pos = pos;
inode->i_dirt = 1;
return written;
}
|
