/*
   * Copyright (C) 2007 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 v2 as published by the Free Software Foundation.
   *
   * 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 __BTRFS_ORDERED_DATA__
  #define __BTRFS_ORDERED_DATA__

  /* one of these per inode */

  struct btrfs_ordered_inode_tree {

  	spinlock_t lock;

  	struct rb_root tree;

  	struct rb_node *last;

  };

  /*
   * these are used to collect checksums done just before bios submission.
   * They are attached via a list into the ordered extent, and
   * checksum items are inserted into the tree after all the blocks in
   * the ordered extent are on disk
   */

  struct btrfs_sector_sum {

  	/* bytenr on disk */
  	u64 bytenr;

  	u32 sum;
  };
  
  struct btrfs_ordered_sum {

  	/* bytenr is the start of this extent on disk */
  	u64 bytenr;

  	/*
  	 * this is the length in bytes covered by the sums array below.

  	 */
  	unsigned long len;

  	struct list_head list;

  	/* last field is a variable length array of btrfs_sector_sums */

  	struct btrfs_sector_sum sums[];

  };

  /*
   * bits for the flags field:
   *
   * BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
   * It is used to make sure metadata is inserted into the tree only once
   * per extent.
   *
   * BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
   * rbtree, just before waking any waiters.  It is used to indicate the
   * IO is done and any metadata is inserted into the tree.
   */

  #define BTRFS_ORDERED_IO_DONE 0 /* set when all the pages are written */

  #define BTRFS_ORDERED_COMPLETE 1 /* set when removed from the tree */

  #define BTRFS_ORDERED_NOCOW 2 /* set when we want to write in place */

  #define BTRFS_ORDERED_COMPRESSED 3 /* writing a zlib compressed extent */

  #define BTRFS_ORDERED_PREALLOC 4 /* set when writing to prealloced extent */

  #define BTRFS_ORDERED_DIRECT 5 /* set when we're doing DIO with this extent */

  struct btrfs_ordered_extent {

  	/* logical offset in the file */

  	u64 file_offset;

  
  	/* disk byte number */

  	u64 start;

  	/* ram length of the extent in bytes */

  	u64 len;

  	/* extent length on disk */
  	u64 disk_len;

  	/* number of bytes that still need writing */
  	u64 bytes_left;

  	/* flags (described above) */

  	unsigned long flags;

  	/* compression algorithm */
  	int compress_type;

  	/* reference count */

  	atomic_t refs;

  	/* the inode we belong to */
  	struct inode *inode;

  	/* list of checksums for insertion when the extent io is done */

  	struct list_head list;

  
  	/* used to wait for the BTRFS_ORDERED_COMPLETE bit */

  	wait_queue_head_t wait;

  
  	/* our friendly rbtree entry */

  	struct rb_node rb_node;

  
  	/* a per root list of all the pending ordered extents */
  	struct list_head root_extent_list;

  };

  /*
   * calculates the total size you need to allocate for an ordered sum
   * structure spanning 'bytes' in the file
   */

  static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
  					 unsigned long bytes)

  {
  	unsigned long num_sectors = (bytes + root->sectorsize - 1) /
  		root->sectorsize;

  	num_sectors++;

  	return sizeof(struct btrfs_ordered_sum) +
  		num_sectors * sizeof(struct btrfs_sector_sum);
  }

  static inline void
  btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
  {

  	spin_lock_init(&t->lock);

  	t->tree = RB_ROOT;

  	t->last = NULL;

  }

  int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
  int btrfs_remove_ordered_extent(struct inode *inode,
  				struct btrfs_ordered_extent *entry);
  int btrfs_dec_test_ordered_pending(struct inode *inode,

  				   struct btrfs_ordered_extent **cached,
  				   u64 file_offset, u64 io_size);

  int btrfs_dec_test_first_ordered_pending(struct inode *inode,
  				   struct btrfs_ordered_extent **cached,
  				   u64 *file_offset, u64 io_size);

  int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,

  			     u64 start, u64 len, u64 disk_len, int type);
  int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
  				 u64 start, u64 len, u64 disk_len, int type);

  int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
  				      u64 start, u64 len, u64 disk_len,
  				      int type, int compress_type);

  int btrfs_add_ordered_sum(struct inode *inode,
  			  struct btrfs_ordered_extent *entry,
  			  struct btrfs_ordered_sum *sum);

  struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
  							 u64 file_offset);

  void btrfs_start_ordered_extent(struct inode *inode,
  				struct btrfs_ordered_extent *entry, int wait);

  int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);

  struct btrfs_ordered_extent *
  btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);

  struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
  							u64 file_offset,
  							u64 len);

  int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,

  				struct btrfs_ordered_extent *ordered);

  int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum);

  int btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
  int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
  				struct btrfs_root *root,
  				struct inode *inode);

  int btrfs_wait_ordered_extents(struct btrfs_root *root,
  			       int nocow_only, int delay_iput);

  #endif