/*
   *  linux/include/linux/ext2_fs_sb.h
   *
   * Copyright (C) 1992, 1993, 1994, 1995
   * Remy Card (card@masi.ibp.fr)
   * Laboratoire MASI - Institut Blaise Pascal
   * Universite Pierre et Marie Curie (Paris VI)
   *
   *  from
   *
   *  linux/include/linux/minix_fs_sb.h
   *
   *  Copyright (C) 1991, 1992  Linus Torvalds
   */
  
  #ifndef _LINUX_EXT2_FS_SB
  #define _LINUX_EXT2_FS_SB
  
  #include <linux/blockgroup_lock.h>
  #include <linux/percpu_counter.h>

  #include <linux/rbtree.h>
  
  /* XXX Here for now... not interested in restructing headers JUST now */
  
  /* data type for block offset of block group */
  typedef int ext2_grpblk_t;
  
  /* data type for filesystem-wide blocks number */
  typedef unsigned long ext2_fsblk_t;
  
  #define E2FSBLK "%lu"
  
  struct ext2_reserve_window {
  	ext2_fsblk_t		_rsv_start;	/* First byte reserved */
  	ext2_fsblk_t		_rsv_end;	/* Last byte reserved or 0 */
  };
  
  struct ext2_reserve_window_node {
  	struct rb_node	 	rsv_node;
  	__u32			rsv_goal_size;
  	__u32			rsv_alloc_hit;
  	struct ext2_reserve_window	rsv_window;
  };
  
  struct ext2_block_alloc_info {
  	/* information about reservation window */
  	struct ext2_reserve_window_node	rsv_window_node;
  	/*
  	 * was i_next_alloc_block in ext2_inode_info
  	 * is the logical (file-relative) number of the
  	 * most-recently-allocated block in this file.
  	 * We use this for detecting linearly ascending allocation requests.
  	 */
  	__u32			last_alloc_logical_block;
  	/*
  	 * Was i_next_alloc_goal in ext2_inode_info
  	 * is the *physical* companion to i_next_alloc_block.
  	 * it the the physical block number of the block which was most-recentl
  	 * allocated to this file.  This give us the goal (target) for the next
  	 * allocation when we detect linearly ascending requests.
  	 */
  	ext2_fsblk_t		last_alloc_physical_block;
  };
  
  #define rsv_start rsv_window._rsv_start
  #define rsv_end rsv_window._rsv_end

  
  /*
   * second extended-fs super-block data in memory
   */
  struct ext2_sb_info {
  	unsigned long s_frag_size;	/* Size of a fragment in bytes */
  	unsigned long s_frags_per_block;/* Number of fragments per block */
  	unsigned long s_inodes_per_block;/* Number of inodes per block */
  	unsigned long s_frags_per_group;/* Number of fragments in a group */
  	unsigned long s_blocks_per_group;/* Number of blocks in a group */
  	unsigned long s_inodes_per_group;/* Number of inodes in a group */
  	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
  	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
  	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
  	unsigned long s_groups_count;	/* Number of groups in the fs */

  	unsigned long s_overhead_last;  /* Last calculated overhead */
  	unsigned long s_blocks_last;    /* Last seen block count */

  	struct buffer_head * s_sbh;	/* Buffer containing the super block */
  	struct ext2_super_block * s_es;	/* Pointer to the super block in the buffer */
  	struct buffer_head ** s_group_desc;
  	unsigned long  s_mount_opt;

  	unsigned long s_sb_block;

  	uid_t s_resuid;
  	gid_t s_resgid;
  	unsigned short s_mount_state;
  	unsigned short s_pad;
  	int s_addr_per_block_bits;
  	int s_desc_per_block_bits;
  	int s_inode_size;
  	int s_first_ino;
  	spinlock_t s_next_gen_lock;
  	u32 s_next_generation;
  	unsigned long s_dir_count;
  	u8 *s_debts;
  	struct percpu_counter s_freeblocks_counter;
  	struct percpu_counter s_freeinodes_counter;
  	struct percpu_counter s_dirs_counter;

  	struct blockgroup_lock *s_blockgroup_lock;

  	/* root of the per fs reservation window tree */
  	spinlock_t s_rsv_window_lock;
  	struct rb_root s_rsv_window_root;
  	struct ext2_reserve_window_node s_rsv_window_head;

  	/*
  	 * s_lock protects against concurrent modifications of s_mount_state,
  	 * s_blocks_last, s_overhead_last and the content of superblock's
  	 * buffer pointed to by sbi->s_es.
  	 *
  	 * Note: It is used in ext2_show_options() to provide a consistent view
  	 * of the mount options.
  	 */
  	spinlock_t s_lock;

  };

  static inline spinlock_t *
  sb_bgl_lock(struct ext2_sb_info *sbi, unsigned int block_group)
  {

  	return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);

  }

  #endif	/* _LINUX_EXT2_FS_SB */