/* -*- mode: c; c-basic-offset: 8; -*-
   * vim: noexpandtab sw=8 ts=8 sts=0:
   *
   * suballoc.h
   *
   * Defines sub allocator api
   *
   * Copyright (C) 2003, 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.
   */
  
  #ifndef _CHAINALLOC_H_
  #define _CHAINALLOC_H_

  struct ocfs2_suballoc_result;

  typedef int (group_search_t)(struct inode *,
  			     struct buffer_head *,

  			     u32,			/* bits_wanted */
  			     u32,			/* min_bits */
  			     u64,			/* max_block */

  			     struct ocfs2_suballoc_result *);
  							/* found bits */

  
  struct ocfs2_alloc_context {
  	struct inode *ac_inode;    /* which bitmap are we allocating from? */
  	struct buffer_head *ac_bh; /* file entry bh */

  	u32    ac_alloc_slot;   /* which slot are we allocating from? */

  	u32    ac_bits_wanted;
  	u32    ac_bits_given;
  #define OCFS2_AC_USE_LOCAL 1
  #define OCFS2_AC_USE_MAIN  2
  #define OCFS2_AC_USE_INODE 3
  #define OCFS2_AC_USE_META  4
  	u32    ac_which;

  
  	/* these are used by the chain search */
  	u16    ac_chain;
  	int    ac_allow_chain_relink;
  	group_search_t *ac_group_search;

  
  	u64    ac_last_group;

  	u64    ac_max_block;  /* Highest block number to allocate. 0 is
  				 is the same as ~0 - unlimited */

  	int    ac_find_loc_only;  /* hack for reflink operation ordering */
  	struct ocfs2_suballoc_result *ac_find_loc_priv; /* */

  	struct ocfs2_alloc_reservation	*ac_resv;

  };

  void ocfs2_init_steal_slots(struct ocfs2_super *osb);

  void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac);
  static inline int ocfs2_alloc_context_bits_left(struct ocfs2_alloc_context *ac)
  {
  	return ac->ac_bits_wanted - ac->ac_bits_given;
  }

  /*
   * Please note that the caller must make sure that root_el is the root
   * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
   * the result may be wrong.
   */

  int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,

  			       struct ocfs2_extent_list *root_el,

  			       struct ocfs2_alloc_context **ac);

  int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
  				      int blocks,
  				      struct ocfs2_alloc_context **ac);

  int ocfs2_reserve_new_inode(struct ocfs2_super *osb,

  			    struct ocfs2_alloc_context **ac);
  int ocfs2_reserve_clusters(struct ocfs2_super *osb,

  			   u32 bits_wanted,
  			   struct ocfs2_alloc_context **ac);

  int ocfs2_claim_metadata(handle_t *handle,

  			 struct ocfs2_alloc_context *ac,
  			 u32 bits_wanted,

  			 u64 *suballoc_loc,

  			 u16 *suballoc_bit_start,
  			 u32 *num_bits,
  			 u64 *blkno_start);

  int ocfs2_claim_new_inode(handle_t *handle,

  			  struct inode *dir,
  			  struct buffer_head *parent_fe_bh,

  			  struct ocfs2_alloc_context *ac,

  			  u64 *suballoc_loc,

  			  u16 *suballoc_bit,
  			  u64 *fe_blkno);

  int ocfs2_claim_clusters(handle_t *handle,

  			 struct ocfs2_alloc_context *ac,
  			 u32 min_clusters,
  			 u32 *cluster_start,
  			 u32 *num_clusters);

  /*
   * Use this variant of ocfs2_claim_clusters to specify a maxiumum
   * number of clusters smaller than the allocation reserved.
   */

  int __ocfs2_claim_clusters(handle_t *handle,

  			   struct ocfs2_alloc_context *ac,
  			   u32 min_clusters,
  			   u32 max_clusters,
  			   u32 *cluster_start,
  			   u32 *num_clusters);

  int ocfs2_free_suballoc_bits(handle_t *handle,
  			     struct inode *alloc_inode,
  			     struct buffer_head *alloc_bh,
  			     unsigned int start_bit,
  			     u64 bg_blkno,
  			     unsigned int count);

  int ocfs2_free_dinode(handle_t *handle,

  		      struct inode *inode_alloc_inode,
  		      struct buffer_head *inode_alloc_bh,
  		      struct ocfs2_dinode *di);

  int ocfs2_free_clusters(handle_t *handle,

  			struct inode *bitmap_inode,
  			struct buffer_head *bitmap_bh,
  			u64 start_blk,
  			unsigned int num_clusters);

  int ocfs2_release_clusters(handle_t *handle,
  			   struct inode *bitmap_inode,
  			   struct buffer_head *bitmap_bh,
  			   u64 start_blk,
  			   unsigned int num_clusters);

  static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
  {
  	u64 group = block - (u64) bit;
  
  	return group;
  }

  static inline u32 ocfs2_cluster_from_desc(struct ocfs2_super *osb,
  					  u64 bg_blkno)
  {
  	/* This should work for all block group descriptors as only
  	 * the 1st group descriptor of the cluster bitmap is
  	 * different. */
  
  	if (bg_blkno == osb->first_cluster_group_blkno)
  		return 0;
  
  	/* the rest of the block groups are located at the beginning
  	 * of their 1st cluster, so a direct translation just
  	 * works. */
  	return ocfs2_blocks_to_clusters(osb->sb, bg_blkno);
  }
  
  static inline int ocfs2_is_cluster_bitmap(struct inode *inode)
  {
  	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
  	return osb->bitmap_blkno == OCFS2_I(inode)->ip_blkno;
  }
  
  /* This is for local alloc ONLY. Others should use the task-specific
   * apis above. */
  int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
  				      struct ocfs2_alloc_context *ac);

  void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac);

  /* given a cluster offset, calculate which block group it belongs to
   * and return that block offset. */
  u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster);

  /*

   * By default, ocfs2_read_group_descriptor() calls ocfs2_error() when it

   * finds a problem.  A caller that wants to check a group descriptor

   * without going readonly should read the block with ocfs2_read_block[s]()
   * and then checking it with this function.  This is only resize, really.
   * Everyone else should be using ocfs2_read_group_descriptor().

   */

  int ocfs2_check_group_descriptor(struct super_block *sb,
  				 struct ocfs2_dinode *di,
  				 struct buffer_head *bh);

  /*
   * Read a group descriptor block into *bh.  If *bh is NULL, a bh will be
   * allocated.  This is a cached read.  The descriptor will be validated with
   * ocfs2_validate_group_descriptor().
   */
  int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
  				u64 gd_blkno, struct buffer_head **bh);

  int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_extent_tree *et,

  			  u32 clusters_to_add, u32 extents_to_split,
  			  struct ocfs2_alloc_context **data_ac,

  			  struct ocfs2_alloc_context **meta_ac);

  
  int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res);

  
  
  
  /*
   * The following two interfaces are for ocfs2_create_inode_in_orphan().
   */
  int ocfs2_find_new_inode_loc(struct inode *dir,
  			     struct buffer_head *parent_fe_bh,
  			     struct ocfs2_alloc_context *ac,
  			     u64 *fe_blkno);
  
  int ocfs2_claim_new_inode_at_loc(handle_t *handle,
  				 struct inode *dir,
  				 struct ocfs2_alloc_context *ac,
  				 u64 *suballoc_loc,
  				 u16 *suballoc_bit,
  				 u64 di_blkno);

  #endif /* _CHAINALLOC_H_ */