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/*
* 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/nfs_fs.h>
#include <linux/mm.h>
#include <linux/malloc.h>
#include <linux/pagemap.h>
#include <linux/lockd/bind.h>
#include <asm/segment.h>
#include <asm/system.h>
#define NFSDBG_FACILITY NFSDBG_FILE
static int nfs_file_mmap(struct file *, struct vm_area_struct *);
static long nfs_file_read(struct inode *, struct file *, char *, unsigned long);
static long nfs_file_write(struct inode *, struct file *,
const char *, unsigned long);
static int nfs_file_close(struct inode *, struct file *);
static int nfs_fsync(struct file *, struct dentry *dentry);
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 */
nfs_file_close, /* release */
nfs_fsync, /* fsync */
NULL, /* fasync */
NULL, /* check_media_change */
NULL, /* revalidate */
nfs_lock, /* lock */
};
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 */
nfs_writepage, /* writepage */
NULL, /* bmap */
NULL, /* truncate */
NULL, /* permission */
NULL, /* smap */
nfs_updatepage, /* updatepage */
nfs_revalidate, /* revalidate */
};
/* Hack for future NFS swap support */
#ifndef IS_SWAPFILE
# define IS_SWAPFILE(inode) (0)
#endif
static int
nfs_file_close(struct inode *inode, struct file *file)
{
int status;
dfprintk(VFS, "nfs: close(%x/%ld)\n", inode->i_dev, inode->i_ino);
if ((status = nfs_flush_dirty_pages(inode, 0, 0)) < 0)
return status;
return nfs_write_error(inode);
}
static long
nfs_file_read(struct inode * inode, struct file * file,
char * buf, unsigned long count)
{
int status;
dfprintk(VFS, "nfs: read(%x/%ld, %lu@%lu)\n",
inode->i_dev, inode->i_ino, count,
(unsigned long) file->f_pos);
if ((status = nfs_revalidate_inode(NFS_SERVER(inode), inode)) < 0)
return status;
return generic_file_read(inode, file, buf, count);
}
static int
nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
{
int status;
struct inode *inode = file->f_dentry->d_inode;
dfprintk(VFS, "nfs: mmap(%x/%ld)\n", inode->i_dev, inode->i_ino);
if ((status = nfs_revalidate_inode(NFS_SERVER(inode), inode)) < 0)
return status;
return generic_file_mmap(file, vma);
}
static int nfs_fsync(struct file *file, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
dfprintk(VFS, "nfs: fsync(%x/%ld)\n", inode->i_dev, inode->i_ino);
return nfs_flush_dirty_pages(inode, 0, 0);
}
/*
* Write to a file (through the page cache).
*/
static long
nfs_file_write(struct inode *inode, struct file *file,
const char *buf, unsigned long count)
{
int result;
dfprintk(VFS, "nfs: write(%x/%ld (%d), %lu@%lu)\n",
inode->i_dev, inode->i_ino, inode->i_count,
count, (unsigned long) file->f_pos);
if (!inode) {
printk("nfs_file_write: inode = NULL\n");
return -EINVAL;
}
if (IS_SWAPFILE(inode)) {
printk("NFS: attempt to write to active swap file!\n");
return -EBUSY;
}
if ((result = nfs_revalidate_inode(NFS_SERVER(inode), inode)) < 0)
return result;
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;
/* Return error from previous async call */
if ((result = nfs_write_error(inode)) < 0)
return result;
return generic_file_write(inode, file, buf, count);
}
/*
* Lock a (portion of) a file
*/
int
nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
{
int status;
struct inode * inode;
dprintk("NFS: nfs_lock(f=%4x/%ld, t=%x, fl=%x, r=%ld:%ld)\n",
filp->f_dentry->d_inode->i_dev, filp->f_dentry->d_inode->i_ino,
fl->fl_type, fl->fl_flags,
fl->fl_start, fl->fl_end);
if (!(inode = filp->f_dentry->d_inode))
return -EINVAL;
/* No mandatory locks over NFS */
if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
return -ENOLCK;
/* Fake OK code if mounted without NLM support */
if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)
return 0;
/*
* No BSD flocks over NFS allowed.
* Note: we could try to fake a POSIX lock request here by
* using ((u32) filp | 0x80000000) or some such as the pid.
* Not sure whether that would be unique, though, or whether
* that would break in other places.
*/
if (!fl->fl_owner || (fl->fl_flags & (FL_POSIX|FL_BROKEN)) != FL_POSIX)
return -ENOLCK;
/* If unlocking a file region, flush dirty pages (unless we've
* been killed by a signal, that is). */
if (cmd == F_SETLK && fl->fl_type == F_UNLCK
&& !(current->signal & ~current->blocked)) {
status = nfs_flush_dirty_pages(inode,
fl->fl_start, fl->fl_end == NLM_OFFSET_MAX? 0 :
fl->fl_end - fl->fl_start + 1);
if (status < 0)
return status;
}
if ((status = nlmclnt_proc(inode, cmd, fl)) < 0)
return status;
/* Here, we could turn off write-back of pages in the
* locked file region */
return 0;
}
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