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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
/*
* linux/fs/nfs/file.c
*
* Copyright (C) 1992 Rick Sladkey
*
* Changes Copyright (C) 1994 by Florian La Roche
* - Do not copy data too often around in the kernel.
* - In nfs_file_read the return value of kmalloc wasn't checked.
* - Put in a better version of read look-ahead buffering. Original idea
* and implementation by Wai S Kok elekokws@ee.nus.sg.
*
* Expire cache on write to a file by Wai S Kok (Oct 1994).
*
* Total rewrite of read side for new NFS buffer cache.. Linus.
*
* nfs regular file handling functions
*/
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/mm.h>
#include <linux/nfs_fs.h>
#include <linux/malloc.h>
#include <linux/pagemap.h>
#include <asm/segment.h>
#include <asm/system.h>
static int nfs_file_mmap(struct inode *, struct file *, struct vm_area_struct *);
static int nfs_file_read(struct inode *, struct file *, char *, int);
static int nfs_file_write(struct inode *, struct file *, const char *, int);
static int nfs_fsync(struct inode *, struct file *);
static struct file_operations nfs_file_operations = {
NULL, /* lseek - default */
nfs_file_read, /* read */
nfs_file_write, /* write */
NULL, /* readdir - bad */
NULL, /* select - default */
NULL, /* ioctl - default */
nfs_file_mmap, /* mmap */
NULL, /* no special open is needed */
NULL, /* release */
nfs_fsync, /* fsync */
};
struct inode_operations nfs_file_inode_operations = {
&nfs_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 */
NULL, /* follow_link */
nfs_readpage, /* readpage */
NULL, /* writepage */
NULL, /* bmap */
NULL /* truncate */
};
static inline void revalidate_inode(struct nfs_server * server, struct inode * inode)
{
struct nfs_fattr fattr;
if (jiffies - NFS_READTIME(inode) < NFS_ATTRTIMEO(inode))
return;
NFS_READTIME(inode) = jiffies;
if (nfs_proc_getattr(server, NFS_FH(inode), &fattr) == 0) {
nfs_refresh_inode(inode, &fattr);
if (fattr.mtime.seconds == NFS_OLDMTIME(inode)) {
if ((NFS_ATTRTIMEO(inode) <<= 1) > server->acregmax)
NFS_ATTRTIMEO(inode) = server->acregmax;
return;
}
NFS_OLDMTIME(inode) = fattr.mtime.seconds;
}
invalidate_inode_pages(inode);
}
static int nfs_file_read(struct inode * inode, struct file * file,
char * buf, int count)
{
revalidate_inode(NFS_SERVER(inode), inode);
return generic_file_read(inode, file, buf, count);
}
static int nfs_file_mmap(struct inode * inode, struct file * file, struct vm_area_struct * vma)
{
revalidate_inode(NFS_SERVER(inode), inode);
return generic_file_mmap(inode, file, vma);
}
static int nfs_fsync(struct inode *inode, struct file *file)
{
return 0;
}
static int nfs_file_write(struct inode *inode, struct file *file, const char *buf,
int count)
{
int result, written, wsize;
struct nfs_fattr fattr;
unsigned long pos;
if (!inode) {
printk("nfs_file_write: inode = NULL\n");
return -EINVAL;
}
if (!S_ISREG(inode->i_mode)) {
printk("nfs_file_write: write to non-file, mode %07o\n",
inode->i_mode);
return -EINVAL;
}
if (count <= 0)
return 0;
pos = file->f_pos;
if (file->f_flags & O_APPEND)
pos = inode->i_size;
wsize = NFS_SERVER(inode)->wsize;
result = 0;
written = 0;
while (written < count) {
int hunk = count - written;
if (hunk >= wsize)
hunk = wsize;
result = nfs_proc_write(inode,
pos, hunk, buf, &fattr);
if (result < 0)
break;
pos += hunk;
buf += hunk;
written += hunk;
if (hunk < wsize)
break;
}
if (!written)
return result;
file->f_pos = pos;
if (pos > inode->i_size)
inode->i_size = pos;
/* Avoid possible Solaris 2.5 nfsd bug */
if (inode->i_ino == fattr.fileid)
nfs_refresh_inode(inode, &fattr);
return written;
}
|
