/*
   * 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_I__
  #define __BTRFS_I__
  
  #include <linux/hash.h>
  #include "extent_map.h"
  #include "extent_io.h"
  #include "ordered-data.h"
  #include "delayed-inode.h"
  
  /*
   * ordered_data_close is set by truncate when a file that used
   * to have good data has been truncated to zero.  When it is set
   * the btrfs file release call will add this inode to the
   * ordered operations list so that we make sure to flush out any
   * new data the application may have written before commit.
   */
  #define BTRFS_INODE_ORDERED_DATA_CLOSE		0
  #define BTRFS_INODE_ORPHAN_META_RESERVED	1
  #define BTRFS_INODE_DUMMY			2
  #define BTRFS_INODE_IN_DEFRAG			3
  #define BTRFS_INODE_DELALLOC_META_RESERVED	4
  #define BTRFS_INODE_HAS_ORPHAN_ITEM		5
  #define BTRFS_INODE_HAS_ASYNC_EXTENT		6
  #define BTRFS_INODE_NEEDS_FULL_SYNC		7
  #define BTRFS_INODE_COPY_EVERYTHING		8
  #define BTRFS_INODE_IN_DELALLOC_LIST		9
  #define BTRFS_INODE_READDIO_NEED_LOCK		10
  #define BTRFS_INODE_HAS_PROPS		        11
  
  /* in memory btrfs inode */
  struct btrfs_inode {
  	/* which subvolume this inode belongs to */
  	struct btrfs_root *root;
  
  	/* key used to find this inode on disk.  This is used by the code
  	 * to read in roots of subvolumes
  	 */
  	struct btrfs_key location;
  
  	/* Lock for counters */
  	spinlock_t lock;
  
  	/* the extent_tree has caches of all the extent mappings to disk */
  	struct extent_map_tree extent_tree;
  
  	/* the io_tree does range state (DIRTY, LOCKED etc) */
  	struct extent_io_tree io_tree;
  
  	/* special utility tree used to record which mirrors have already been
  	 * tried when checksums fail for a given block
  	 */
  	struct extent_io_tree io_failure_tree;
  
  	/* held while logging the inode in tree-log.c */
  	struct mutex log_mutex;
  
  	/* held while doing delalloc reservations */
  	struct mutex delalloc_mutex;
  
  	/* used to order data wrt metadata */
  	struct btrfs_ordered_inode_tree ordered_tree;
  
  	/* list of all the delalloc inodes in the FS.  There are times we need
  	 * to write all the delalloc pages to disk, and this list is used
  	 * to walk them all.
  	 */
  	struct list_head delalloc_inodes;
  
  	/*
  	 * list for tracking inodes that must be sent to disk before a
  	 * rename or truncate commit
  	 */
  	struct list_head ordered_operations;
  
  	/* node for the red-black tree that links inodes in subvolume root */
  	struct rb_node rb_node;
  
  	unsigned long runtime_flags;
  
  	/* Keep track of who's O_SYNC/fsyncing currently */
  	atomic_t sync_writers;
  
  	/* full 64 bit generation number, struct vfs_inode doesn't have a big
  	 * enough field for this.
  	 */
  	u64 generation;
  
  	/*
  	 * transid of the trans_handle that last modified this inode
  	 */
  	u64 last_trans;
  
  	/*
  	 * log transid when this inode was last modified
  	 */
  	u64 last_sub_trans;
  
  	/*
  	 * transid that last logged this inode
  	 */
  	u64 logged_trans;
  
  	/* total number of bytes pending delalloc, used by stat to calc the
  	 * real block usage of the file
  	 */
  	u64 delalloc_bytes;
  
  	/*
  	 * the size of the file stored in the metadata on disk.  data=ordered
  	 * means the in-memory i_size might be larger than the size on disk
  	 * because not all the blocks are written yet.
  	 */
  	u64 disk_i_size;
  
  	/*
  	 * if this is a directory then index_cnt is the counter for the index
  	 * number for new files that are created
  	 */
  	u64 index_cnt;
  
  	/* Cache the directory index number to speed the dir/file remove */
  	u64 dir_index;
  
  	/* the fsync log has some corner cases that mean we have to check
  	 * directories to see if any unlinks have been done before
  	 * the directory was logged.  See tree-log.c for all the
  	 * details
  	 */
  	u64 last_unlink_trans;
  
  	/*
  	 * Number of bytes outstanding that are going to need csums.  This is
  	 * used in ENOSPC accounting.
  	 */
  	u64 csum_bytes;
  
  	/* flags field from the on disk inode */
  	u32 flags;
  
  	/* a local copy of root's last_log_commit */
  	unsigned long last_log_commit;
  
  	/*
  	 * Counters to keep track of the number of extent item's we may use due
  	 * to delalloc and such.  outstanding_extents is the number of extent
  	 * items we think we'll end up using, and reserved_extents is the number
  	 * of extent items we've reserved metadata for.
  	 */
  	unsigned outstanding_extents;
  	unsigned reserved_extents;
  
  	/*
  	 * always compress this one file
  	 */
  	unsigned force_compress;
  
  	struct btrfs_delayed_node *delayed_node;
  
  	struct inode vfs_inode;
  };
  
  extern unsigned char btrfs_filetype_table[];
  
  static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
  {
  	return container_of(inode, struct btrfs_inode, vfs_inode);
  }
  
  static inline unsigned long btrfs_inode_hash(u64 objectid,
  					     const struct btrfs_root *root)
  {
  	u64 h = objectid ^ (root->objectid * GOLDEN_RATIO_PRIME);
  
  #if BITS_PER_LONG == 32
  	h = (h >> 32) ^ (h & 0xffffffff);
  #endif
  
  	return (unsigned long)h;
  }
  
  static inline void btrfs_insert_inode_hash(struct inode *inode)
  {
  	unsigned long h = btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root);
  
  	__insert_inode_hash(inode, h);
  }
  
  static inline u64 btrfs_ino(struct inode *inode)
  {
  	u64 ino = BTRFS_I(inode)->location.objectid;
  
  	/*
  	 * !ino: btree_inode
  	 * type == BTRFS_ROOT_ITEM_KEY: subvol dir
  	 */
  	if (!ino || BTRFS_I(inode)->location.type == BTRFS_ROOT_ITEM_KEY)
  		ino = inode->i_ino;
  	return ino;
  }
  
  static inline void btrfs_i_size_write(struct inode *inode, u64 size)
  {
  	i_size_write(inode, size);
  	BTRFS_I(inode)->disk_i_size = size;
  }
  
  static inline bool btrfs_is_free_space_inode(struct inode *inode)
  {
  	struct btrfs_root *root = BTRFS_I(inode)->root;
  
  	if (root == root->fs_info->tree_root &&
  	    btrfs_ino(inode) != BTRFS_BTREE_INODE_OBJECTID)
  		return true;
  	if (BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID)
  		return true;
  	return false;
  }
  
  static inline int btrfs_inode_in_log(struct inode *inode, u64 generation)
  {
  	if (BTRFS_I(inode)->logged_trans == generation &&
  	    BTRFS_I(inode)->last_sub_trans <=
  	    BTRFS_I(inode)->last_log_commit &&
  	    BTRFS_I(inode)->last_sub_trans <=
  	    BTRFS_I(inode)->root->last_log_commit)
  		return 1;
  	return 0;
  }
  
  struct btrfs_dio_private {
  	struct inode *inode;
  	u64 logical_offset;
  	u64 disk_bytenr;
  	u64 bytes;
  	void *private;
  
  	/* number of bios pending for this dio */
  	atomic_t pending_bios;
  
  	/* IO errors */
  	int errors;
  
  	/* orig_bio is our btrfs_io_bio */
  	struct bio *orig_bio;
  
  	/* dio_bio came from fs/direct-io.c */
  	struct bio *dio_bio;
  	u8 csum[0];
  };
  
  /*
   * Disable DIO read nolock optimization, so new dio readers will be forced
   * to grab i_mutex. It is used to avoid the endless truncate due to
   * nonlocked dio read.
   */
  static inline void btrfs_inode_block_unlocked_dio(struct inode *inode)
  {
  	set_bit(BTRFS_INODE_READDIO_NEED_LOCK, &BTRFS_I(inode)->runtime_flags);
  	smp_mb();
  }
  
  static inline void btrfs_inode_resume_unlocked_dio(struct inode *inode)
  {
  	smp_mb__before_clear_bit();
  	clear_bit(BTRFS_INODE_READDIO_NEED_LOCK,
  		  &BTRFS_I(inode)->runtime_flags);
  }
  
  #endif