fs/nfs/file.c

/* */
This source file includes following definitions.
nfs_file_read
nfs_file_write
   1 /*
   2  *  linux/fs/nfs/file.c
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  *
   6  *  nfs regular file handling functions
   7  */
   8 
   9 #include <asm/segment.h>
  10 #include <asm/system.h>
  11 
  12 #include <linux/sched.h>
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/fcntl.h>
  16 #include <linux/stat.h>
  17 #include <linux/mm.h>
  18 #include <linux/nfs_fs.h>
  19 
  20 static int nfs_file_read(struct inode *, struct file *, char *, int);
  21 static int nfs_file_write(struct inode *, struct file *, char *, int);
  22 
  23 static struct file_operations nfs_file_operations = {
  24         NULL,                   /* lseek - default */
  25         nfs_file_read,          /* read */
  26         nfs_file_write,         /* write */
  27         NULL,                   /* readdir - bad */
  28         NULL,                   /* select - default */
  29         NULL,                   /* ioctl - default */
  30         NULL,                   /* mmap */
  31         NULL,                   /* no special open is needed */
  32         NULL                    /* release */
  33 };
  34 
  35 struct inode_operations nfs_file_inode_operations = {
  36         &nfs_file_operations,   /* default file operations */
  37         NULL,                   /* create */
  38         NULL,                   /* lookup */
  39         NULL,                   /* link */
  40         NULL,                   /* unlink */
  41         NULL,                   /* symlink */
  42         NULL,                   /* mkdir */
  43         NULL,                   /* rmdir */
  44         NULL,                   /* mknod */
  45         NULL,                   /* rename */
  46         NULL,                   /* readlink */
  47         NULL,                   /* follow_link */
  48         NULL,                   /* bmap */
  49         NULL                    /* truncate */
  50 };
  51 
  52 static int nfs_file_read(struct inode *inode, struct file *file, char *buf,
     /*  */
  53                          int count)
  54 {
  55         int result;
  56         int hunk;
  57         int i;
  58         int n;
  59         struct nfs_fattr fattr;
  60         char *data;
  61         off_t pos;
  62 
  63         if (!inode) {
  64                 printk("nfs_file_read: inode = NULL\n");
  65                 return -EINVAL;
  66         }
  67         if (!S_ISREG(inode->i_mode)) {
  68                 printk("nfs_file_read: read from non-file, mode %07o\n",
  69                         inode->i_mode);
  70                 return -EINVAL;
  71         }
  72         pos = file->f_pos;
  73         if (file->f_pos + count > inode->i_size)
  74                 count = inode->i_size - pos;
  75         if (count <= 0)
  76                 return 0;
  77         n = NFS_SERVER(inode)->rsize;
  78         data = (char *) kmalloc(n, GFP_KERNEL);
  79         for (i = 0; i < count; i += n) {
  80                 hunk = count - i;
  81                 if (hunk > n)
  82                         hunk = n;
  83                 result = nfs_proc_read(NFS_SERVER(inode), NFS_FH(inode), 
  84                         pos, hunk, data, &fattr);
  85                 if (result < 0) {
  86                         kfree_s(data, n);
  87                         return result;
  88                 }
  89                 memcpy_tofs(buf, data, result);
  90                 pos += result;
  91                 buf += result;
  92                 if (result < n) {
  93                         i += result;
  94                         break;
  95                 }
  96         }
  97         file->f_pos = pos;
  98         kfree_s(data, n);
  99         nfs_refresh_inode(inode, &fattr);
 100         return i;
 101 }
 102 
 103 static int nfs_file_write(struct inode *inode, struct file *file, char *buf,
     /*  */
 104                           int count)
 105 {
 106         int result;
 107         int hunk;
 108         int i;
 109         int n;
 110         struct nfs_fattr fattr;
 111         char *data;
 112         int pos;
 113 
 114         if (!inode) {
 115                 printk("nfs_file_write: inode = NULL\n");
 116                 return -EINVAL;
 117         }
 118         if (!S_ISREG(inode->i_mode)) {
 119                 printk("nfs_file_write: write to non-file, mode %07o\n",
 120                         inode->i_mode);
 121                 return -EINVAL;
 122         }
 123         if (count <= 0)
 124                 return 0;
 125         pos = file->f_pos;
 126         if (file->f_flags & O_APPEND)
 127                 pos = inode->i_size;
 128         n = NFS_SERVER(inode)->wsize;
 129         data = (char *) kmalloc(n, GFP_KERNEL);
 130         for (i = 0; i < count; i += n) {
 131                 hunk = count - i;
 132                 if (hunk >= n)
 133                         hunk = n;
 134                 memcpy_fromfs(data, buf, hunk);
 135                 result = nfs_proc_write(NFS_SERVER(inode), NFS_FH(inode), 
 136                         pos, hunk, data, &fattr);
 137                 if (result < 0) {
 138                         kfree_s(data, n);
 139                         return result;
 140                 }
 141                 pos += hunk;
 142                 buf += hunk;
 143                 if (hunk < n) {
 144                         i += hunk;
 145                         break;
 146                 }
 147         }
 148         file->f_pos = pos;
 149         kfree_s(data, n);
 150         nfs_refresh_inode(inode, &fattr);
 151         return i;
 152 }
 153
/* */
root/fs/nfs/file.c

DEFINITIONS
