/*
   *  linux/fs/nfs/symlink.c
   *
   *  Copyright (C) 1992  Rick Sladkey
   *
   *  Optimization changes Copyright (C) 1994 Florian La Roche
   *
   *  Jun 7 1999, cache symlink lookups in the page cache.  -DaveM
   *
   *  nfs symlink handling code
   */

  #include <linux/time.h>
  #include <linux/errno.h>
  #include <linux/sunrpc/clnt.h>
  #include <linux/nfs.h>
  #include <linux/nfs2.h>
  #include <linux/nfs_fs.h>
  #include <linux/pagemap.h>
  #include <linux/stat.h>
  #include <linux/mm.h>

  #include <linux/string.h>

  #include <linux/namei.h>
  
  /* Symlink caching in the page cache is even more simplistic
   * and straight-forward than readdir caching.

   */

  static int nfs_symlink_filler(struct inode *inode, struct page *page)
  {

  	int error;

  	error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE);

  	if (error < 0)
  		goto error;
  	SetPageUptodate(page);
  	unlock_page(page);
  	return 0;
  
  error:
  	SetPageError(page);
  	unlock_page(page);
  	return -EIO;
  }

  static void *nfs_follow_link(struct dentry *dentry, struct nameidata *nd)

  {
  	struct inode *inode = dentry->d_inode;
  	struct page *page;

  	void *err;

  	err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));

  	if (err)
  		goto read_failed;
  	page = read_cache_page(&inode->i_data, 0,
  				(filler_t *)nfs_symlink_filler, inode);
  	if (IS_ERR(page)) {
  		err = page;
  		goto read_failed;
  	}

  	nd_set_link(nd, kmap(page));
  	return page;

  read_failed:
  	nd_set_link(nd, err);

  	return NULL;

  }

  /*
   * symlinks can't do much...
   */

  const struct inode_operations nfs_symlink_inode_operations = {

  	.readlink	= generic_readlink,
  	.follow_link	= nfs_follow_link,

  	.put_link	= page_put_link,

  	.getattr	= nfs_getattr,
  	.setattr	= nfs_setattr,
  };