/*

   *  linux/include/linux/ext4_fs_i.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_i.h
   *
   *  Copyright (C) 1991, 1992  Linus Torvalds
   */

  #ifndef _LINUX_EXT4_FS_I
  #define _LINUX_EXT4_FS_I

  
  #include <linux/rwsem.h>
  #include <linux/rbtree.h>
  #include <linux/seqlock.h>
  #include <linux/mutex.h>
  
  /* data type for block offset of block group */

  typedef int ext4_grpblk_t;

  
  /* data type for filesystem-wide blocks number */

  typedef unsigned long long ext4_fsblk_t;

  struct ext4_reserve_window {
  	ext4_fsblk_t	_rsv_start;	/* First byte reserved */
  	ext4_fsblk_t	_rsv_end;	/* Last byte reserved or 0 */

  };

  struct ext4_reserve_window_node {

  	struct rb_node		rsv_node;
  	__u32			rsv_goal_size;
  	__u32			rsv_alloc_hit;

  	struct ext4_reserve_window	rsv_window;

  };

  struct ext4_block_alloc_info {

  	/* information about reservation window */

  	struct ext4_reserve_window_node rsv_window_node;

  	/*

  	 * was i_next_alloc_block in ext4_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 ext4_inode_info

  	 * is the *physical* companion to i_next_alloc_block.

  	 * it 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.
  	 */

  	ext4_fsblk_t last_alloc_physical_block;

  };
  
  #define rsv_start rsv_window._rsv_start
  #define rsv_end rsv_window._rsv_end
  
  /*

   * storage for cached extent
   */
  struct ext4_ext_cache {

  	ext4_fsblk_t	ec_start;
  	__u32		ec_block;
  	__u32		ec_len; /* must be 32bit to return holes */
  	__u32		ec_type;

  };
  
  /*

   * third extended file system inode data in memory
   */

  struct ext4_inode_info {

  	__le32	i_data[15];	/* unconverted */
  	__u32	i_flags;

  #ifdef EXT4_FRAGMENTS

  	__u32	i_faddr;
  	__u8	i_frag_no;
  	__u8	i_frag_size;
  #endif

  	ext4_fsblk_t	i_file_acl;

  	__u32	i_dir_acl;
  	__u32	i_dtime;
  
  	/*
  	 * i_block_group is the number of the block group which contains
  	 * this file's inode.  Constant across the lifetime of the inode,
  	 * it is ued for making block allocation decisions - we try to
  	 * place a file's data blocks near its inode block, and new inodes
  	 * near to their parent directory's inode.
  	 */
  	__u32	i_block_group;

  	__u32	i_state;		/* Dynamic state flags for ext4 */

  
  	/* block reservation info */

  	struct ext4_block_alloc_info *i_block_alloc_info;

  
  	__u32	i_dir_start_lookup;

  #ifdef CONFIG_EXT4DEV_FS_XATTR

  	/*
  	 * Extended attributes can be read independently of the main file
  	 * data. Taking i_mutex even when reading would cause contention
  	 * between readers of EAs and writers of regular file data, so
  	 * instead we synchronize on xattr_sem when reading or changing
  	 * EAs.
  	 */
  	struct rw_semaphore xattr_sem;
  #endif

  #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL

  	struct posix_acl	*i_acl;
  	struct posix_acl	*i_default_acl;
  #endif
  
  	struct list_head i_orphan;	/* unlinked but open inodes */
  
  	/*
  	 * i_disksize keeps track of what the inode size is ON DISK, not
  	 * in memory.  During truncate, i_size is set to the new size by

  	 * the VFS prior to calling ext4_truncate(), but the filesystem won't

  	 * set i_disksize to 0 until the truncate is actually under way.
  	 *
  	 * The intent is that i_disksize always represents the blocks which
  	 * are used by this file.  This allows recovery to restart truncate
  	 * on orphans if we crash during truncate.  We actually write i_disksize
  	 * into the on-disk inode when writing inodes out, instead of i_size.
  	 *
  	 * The only time when i_disksize and i_size may be different is when
  	 * a truncate is in progress.  The only things which change i_disksize

  	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).

  	 */
  	loff_t	i_disksize;
  
  	/* on-disk additional length */
  	__u16 i_extra_isize;
  
  	/*

  	 * truncate_mutex is for serialising ext4_truncate() against
  	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's

  	 * data tree are chopped off during truncate. We can't do that in

  	 * ext4 because whenever we perform intermediate commits during

  	 * truncate, the inode and all the metadata blocks *must* be in a
  	 * consistent state which allows truncation of the orphans to restart
  	 * during recovery.  Hence we must fix the get_block-vs-truncate race
  	 * by other means, so we have truncate_mutex.
  	 */
  	struct mutex truncate_mutex;
  	struct inode vfs_inode;

  
  	unsigned long i_ext_generation;
  	struct ext4_ext_cache i_cached_extent;

  	/*
  	 * File creation time. Its function is same as that of
  	 * struct timespec i_{a,c,m}time in the generic inode.
  	 */
  	struct timespec i_crtime;

  };

  #endif	/* _LINUX_EXT4_FS_I */