/* -*- mode: c; c-basic-offset: 8; -*-
   * vim: noexpandtab sw=8 ts=8 sts=0:
   *
   *  linux/cluster/ssi/cfs/symlink.c
   *
   *	This program is free software; you can redistribute it and/or
   *	modify it under the terms of the GNU General Public License as
   *	published by the Free Software Foundation; either version 2 of
   *	the License, or (at your option) any later version.
   *
   *	This program is distributed in the hope that it will be useful,
   *	but WITHOUT ANY WARRANTY; without even the implied warranty of
   *	MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE
   *	or NON INFRINGEMENT.  See the GNU General Public License for more
   *	details.
   *
   * 	You should have received a copy of the GNU General Public License
   * 	along with this program; if not, write to the Free Software
   * 	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   *
   *	Questions/Comments/Bugfixes to ssic-linux-devel@lists.sourceforge.net
   *
   *  Copyright (C) 1992  Rick Sladkey
   *
   *  Optimization changes Copyright (C) 1994 Florian La Roche
   *
   *  Jun 7 1999, cache symlink lookups in the page cache.  -DaveM
   *
   *  Portions Copyright (C) 2001 Compaq Computer Corporation
   *
   *  ocfs2 symlink handling code.
   *
   *  Copyright (C) 2004, 2005 Oracle.
   *
   */
  
  #include <linux/fs.h>
  #include <linux/types.h>
  #include <linux/slab.h>
  #include <linux/pagemap.h>

  #include <linux/namei.h>

  #include <cluster/masklog.h>
  
  #include "ocfs2.h"
  
  #include "alloc.h"
  #include "file.h"
  #include "inode.h"
  #include "journal.h"
  #include "symlink.h"

  #include "xattr.h"

  
  #include "buffer_head_io.h"

  
  static char *ocfs2_fast_symlink_getlink(struct inode *inode,
  					struct buffer_head **bh)
  {
  	int status;
  	char *link = NULL;
  	struct ocfs2_dinode *fe;

  	status = ocfs2_read_inode_block(inode, bh);

  	if (status < 0) {
  		mlog_errno(status);
  		link = ERR_PTR(status);
  		goto bail;
  	}
  
  	fe = (struct ocfs2_dinode *) (*bh)->b_data;
  	link = (char *) fe->id2.i_symlink;
  bail:

  
  	return link;
  }
  
  static int ocfs2_readlink(struct dentry *dentry,
  			  char __user *buffer,
  			  int buflen)
  {
  	int ret;
  	char *link;
  	struct buffer_head *bh = NULL;
  	struct inode *inode = dentry->d_inode;

  	link = ocfs2_fast_symlink_getlink(inode, &bh);
  	if (IS_ERR(link)) {
  		ret = PTR_ERR(link);
  		goto out;
  	}

  	/*
  	 * Without vfsmount we can't update atime now,
  	 * but we will update atime here ultimately.
  	 */

  	ret = vfs_readlink(dentry, buffer, buflen, link);
  
  	brelse(bh);
  out:

  	if (ret < 0)
  		mlog_errno(ret);

  	return ret;
  }

  static void *ocfs2_fast_follow_link(struct dentry *dentry,
  				    struct nameidata *nd)

  {

  	int status = 0;
  	int len;
  	char *target, *link = ERR_PTR(-ENOMEM);

  	struct inode *inode = dentry->d_inode;

  	struct buffer_head *bh = NULL;

  	BUG_ON(!ocfs2_inode_is_fast_symlink(inode));
  	target = ocfs2_fast_symlink_getlink(inode, &bh);
  	if (IS_ERR(target)) {
  		status = PTR_ERR(target);

  		mlog_errno(status);
  		goto bail;
  	}

  	/* Fast symlinks can't be large */

  	len = strnlen(target, ocfs2_fast_symlink_chars(inode->i_sb));

  	link = kzalloc(len + 1, GFP_NOFS);
  	if (!link) {
  		status = -ENOMEM;
  		mlog_errno(status);
  		goto bail;
  	}
  
  	memcpy(link, target, len);

  bail:

  	nd_set_link(nd, status ? ERR_PTR(status) : link);

  	brelse(bh);

  	if (status)
  		mlog_errno(status);

  	return NULL;

  }
  
  static void ocfs2_fast_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
  {

  	char *link = nd_get_link(nd);
  	if (!IS_ERR(link))
  		kfree(link);

  }

  const struct inode_operations ocfs2_symlink_inode_operations = {

  	.readlink	= page_readlink,

  	.follow_link	= page_follow_link_light,
  	.put_link	= page_put_link,

  	.getattr	= ocfs2_getattr,

  	.setattr	= ocfs2_setattr,

  	.setxattr	= generic_setxattr,
  	.getxattr	= generic_getxattr,
  	.listxattr	= ocfs2_listxattr,
  	.removexattr	= generic_removexattr,

  	.fiemap		= ocfs2_fiemap,

  };

  const struct inode_operations ocfs2_fast_symlink_inode_operations = {

  	.readlink	= ocfs2_readlink,

  	.follow_link	= ocfs2_fast_follow_link,
  	.put_link	= ocfs2_fast_put_link,

  	.getattr	= ocfs2_getattr,

  	.setattr	= ocfs2_setattr,

  	.setxattr	= generic_setxattr,
  	.getxattr	= generic_getxattr,
  	.listxattr	= ocfs2_listxattr,
  	.removexattr	= generic_removexattr,

  	.fiemap		= ocfs2_fiemap,

  };