text: /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   * vim:expandtab:shiftwidth=8:tabstop=8:
   *
   *  Copyright (C) 1998 Peter J. Braam <braam@clusterfs.com>
   *
   *   This file is part of InterMezzo, http://www.inter-mezzo.org.
   *
   *   InterMezzo is free software; you can redistribute it and/or
   *   modify it under the terms of version 2 of the GNU General Public
   *   License as published by the Free Software Foundation.
   *
   *   InterMezzo 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.  See the
   *   GNU General Public License for more details.
   *
   *   You should have received a copy of the GNU General Public License
   *   along with InterMezzo; if not, write to the Free Software
   *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/sched.h>
  #include <linux/fs.h>
  #include <linux/slab.h>
  #include <linux/vmalloc.h>
  #include <linux/stat.h>
  #include <linux/errno.h>
  #include <asm/segment.h>
  #include <asm/uaccess.h>
  #include <linux/string.h>
  #include <linux/ext2_fs.h> 
  
  #include "intermezzo_fs.h"
  #include "intermezzo_psdev.h"
  
  #if defined(CONFIG_EXT2_FS)
  
  /* EXT2 has no journalling, so these functions do nothing */
  static loff_t presto_e2_freespace(struct presto_cache *cache,
                                           struct super_block *sb)
  {
          unsigned long freebl = le32_to_cpu(EXT2_SB(sb)->s_es->s_free_blocks_count);
          unsigned long avail =   freebl - le32_to_cpu(EXT2_SB(sb)->s_es->s_r_blocks_count);
  	return (avail <<  EXT2_BLOCK_SIZE_BITS(sb));
  }
  
  /* start the filesystem journal operations */
  static void *presto_e2_trans_start(struct presto_file_set *fset, struct inode *inode, int op)
  {
          __u32 avail_kmlblocks;
  
          if ( presto_no_journal(fset) ||
               strcmp(fset->fset_cache->cache_type, "ext2"))
                  return NULL;
  
          avail_kmlblocks = EXT2_SB(inode->i_sb)->s_es->s_free_blocks_count;
          
          if ( avail_kmlblocks < 3 ) {
                  return ERR_PTR(-ENOSPC);
          }
          
          if (  (op != KML_OPCODE_UNLINK && op != KML_OPCODE_RMDIR)
                && avail_kmlblocks < 6 ) {
                  return ERR_PTR(-ENOSPC);
          }            
  	return (void *) 1;
  }
  
  static void presto_e2_trans_commit(struct presto_file_set *fset, void *handle)
  {
          do {} while (0);
  }
  
  static int presto_e2_has_all_data(struct inode *inode)
  {
          BUG();
          return 0;
  }
  
  struct journal_ops presto_ext2_journal_ops = {
          .tr_all_data            = presto_e2_has_all_data,
          .tr_avail               = presto_e2_freespace,
          .tr_start               = presto_e2_trans_start,
          .tr_commit              = presto_e2_trans_commit,
          .tr_journal_data        = NULL
  };
  
  #endif /* CONFIG_EXT2_FS */
  