/* -*- mode: c; c-basic-offset: 8; -*-
   * vim: noexpandtab sw=8 ts=8 sts=0:
   *
   * sysfile.c
   *
   * Initialize, read, write, etc. system files.
   *
   * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
   *
   * 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.  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., 59 Temple Place - Suite 330,
   * Boston, MA 021110-1307, USA.
   */
  
  #include <linux/fs.h>
  #include <linux/types.h>
  #include <linux/slab.h>
  #include <linux/highmem.h>

  #define MLOG_MASK_PREFIX ML_INODE
  #include <cluster/masklog.h>

  #include "ocfs2.h"

  #include "alloc.h"
  #include "dir.h"
  #include "inode.h"
  #include "journal.h"
  #include "sysfile.h"
  
  #include "buffer_head_io.h"
  
  static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
  						   int type,
  						   u32 slot);
  
  static inline int is_global_system_inode(int type);
  static inline int is_in_system_inode_array(struct ocfs2_super *osb,
  					   int type,
  					   u32 slot);
  
  static inline int is_global_system_inode(int type)
  {
  	return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
  		type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
  }
  
  static inline int is_in_system_inode_array(struct ocfs2_super *osb,
  					   int type,
  					   u32 slot)
  {
  	return slot == osb->slot_num || is_global_system_inode(type);
  }
  
  struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
  					  int type,
  					  u32 slot)
  {
  	struct inode *inode = NULL;
  	struct inode **arr = NULL;
  
  	/* avoid the lookup if cached in local system file array */
  	if (is_in_system_inode_array(osb, type, slot))
  		arr = &(osb->system_inodes[type]);
  
  	if (arr && ((inode = *arr) != NULL)) {
  		/* get a ref in addition to the array ref */
  		inode = igrab(inode);

  		BUG_ON(!inode);

  
  		return inode;
  	}
  
  	/* this gets one ref thru iget */
  	inode = _ocfs2_get_system_file_inode(osb, type, slot);
  
  	/* add one more if putting into array for first time */
  	if (arr && inode) {
  		*arr = igrab(inode);

  		BUG_ON(!*arr);

  	}
  	return inode;
  }
  
  static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
  						   int type,
  						   u32 slot)
  {
  	char namebuf[40];
  	struct inode *inode = NULL;
  	u64 blkno;
  	struct buffer_head *dirent_bh = NULL;
  	struct ocfs2_dir_entry *de = NULL;
  	int status = 0;
  
  	ocfs2_sprintf_system_inode_name(namebuf,
  					sizeof(namebuf),
  					type, slot);
  
  	status = ocfs2_find_files_on_disk(namebuf, strlen(namebuf),
  					  &blkno, osb->sys_root_inode,
  					  &dirent_bh, &de);
  	if (status < 0) {
  		goto bail;
  	}

  	inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE);

  	if (IS_ERR(inode)) {
  		mlog_errno(PTR_ERR(inode));
  		inode = NULL;
  		goto bail;
  	}
  bail:
  	if (dirent_bh)
  		brelse(dirent_bh);
  	return inode;
  }