/*
   * 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 and all fields used to determine if the inode is in
  	 * the log or not (last_trans, last_sub_trans, last_log_commit,
  	 * logged_trans).
  	 */

  	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;

  	/* 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;

  
  	/*

  	 * transid that last logged this inode

  	 */

  	u64 logged_trans;

  	/*

  	 * log transid when this inode was last modified

  	 */

  	int last_sub_trans;
  
  	/* a local copy of root's last_log_commit */
  	int last_log_commit;

  	/* total number of bytes pending delalloc, used by stat to calc the
  	 * real block usage of the file
  	 */

  	u64 delalloc_bytes;

  
  	/*

  	 * Total number of bytes pending delalloc that fall within a file
  	 * range that is either a hole or beyond EOF (and no prealloc extent
  	 * exists in the range). This is always <= delalloc_bytes.
  	 */
  	u64 new_delalloc_bytes;
  
  	/*

  	 * total number of bytes pending defrag, used by stat to check whether
  	 * it needs COW.
  	 */
  	u64 defrag_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;

  	/*

  	 * Track the transaction id of the last transaction used to create a
  	 * hard link for the inode. This is used by the log tree (fsync).
  	 */
  	u64 last_link_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;

  	/*

  	 * 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;

  
  	/*

  	 * Cached values of inode properties

  	 */

  	unsigned prop_compress;		/* per-file compression algorithm */

  	/*
  	 * Force compression on the file using the defrag ioctl, could be
  	 * different from prop_compress and takes precedence if set
  	 */
  	unsigned defrag_compress;

  	struct btrfs_delayed_node *delayed_node;

  	/* File creation time. */
  	struct timespec i_otime;

  	/* Hook into fs_info->delayed_iputs */
  	struct list_head delayed_iput;
  	long delayed_iput_count;

  	/*
  	 * To avoid races between lockless (i_mutex not held) direct IO writes
  	 * and concurrent fsync requests. Direct IO writes must acquire read
  	 * access on this semaphore for creating an extent map and its
  	 * corresponding ordered extent. The fast fsync path must acquire write
  	 * access on this semaphore before it collects ordered extents and
  	 * extent maps.
  	 */
  	struct rw_semaphore dio_sem;

  	struct inode vfs_inode;

  };

  extern unsigned char btrfs_filetype_table[];

  static inline struct btrfs_inode *BTRFS_I(const 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(const struct btrfs_inode *inode)

  {

  	u64 ino = inode->location.objectid;

  	/*
  	 * !ino: btree_inode
  	 * type == BTRFS_ROOT_ITEM_KEY: subvol dir
  	 */

  	if (!ino || inode->location.type == BTRFS_ROOT_ITEM_KEY)
  		ino = inode->vfs_inode.i_ino;

  	return ino;
  }

  static inline void btrfs_i_size_write(struct btrfs_inode *inode, u64 size)

  {

  	i_size_write(&inode->vfs_inode, size);
  	inode->disk_i_size = size;

  }

  static inline bool btrfs_is_free_space_inode(struct btrfs_inode *inode)

  {

  	struct btrfs_root *root = inode->root;

  	if (root == root->fs_info->tree_root &&

  	    btrfs_ino(inode) != BTRFS_BTREE_INODE_OBJECTID)

  		return true;

  	if (inode->location.objectid == BTRFS_FREE_INO_OBJECTID)

  		return true;
  	return false;
  }

  static inline int btrfs_inode_in_log(struct btrfs_inode *inode, u64 generation)

  {

  	int ret = 0;

  	spin_lock(&inode->lock);
  	if (inode->logged_trans == generation &&
  	    inode->last_sub_trans <= inode->last_log_commit &&
  	    inode->last_sub_trans <= inode->root->last_log_commit) {

  		/*
  		 * After a ranged fsync we might have left some extent maps
  		 * (that fall outside the fsync's range). So return false
  		 * here if the list isn't empty, to make sure btrfs_log_inode()
  		 * will be called and process those extent maps.
  		 */
  		smp_mb();

  		if (list_empty(&inode->extent_tree.modified_extents))

  			ret = 1;

  	}

  	spin_unlock(&inode->lock);

  	return ret;

  }

  #define BTRFS_DIO_ORIG_BIO_SUBMITTED	0x1

  struct btrfs_dio_private {
  	struct inode *inode;

  	unsigned long flags;

  	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;

  
  	/*

  	 * The original bio may be split to several sub-bios, this is

  	 * done during endio of sub-bios
  	 */

  	blk_status_t (*subio_endio)(struct inode *, struct btrfs_io_bio *,
  			blk_status_t);

  };

  /*
   * 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 btrfs_inode *inode)

  {

  	set_bit(BTRFS_INODE_READDIO_NEED_LOCK, &inode->runtime_flags);

  	smp_mb();
  }

  static inline void btrfs_inode_resume_unlocked_dio(struct btrfs_inode *inode)

  {

  	smp_mb__before_atomic();

  	clear_bit(BTRFS_INODE_READDIO_NEED_LOCK, &inode->runtime_flags);

  }

  static inline void btrfs_print_data_csum_error(struct btrfs_inode *inode,

  		u64 logical_start, u32 csum, u32 csum_expected, int mirror_num)
  {

  	struct btrfs_root *root = inode->root;

  
  	/* Output minus objectid, which is more meaningful */
  	if (root->objectid >= BTRFS_LAST_FREE_OBJECTID)
  		btrfs_warn_rl(root->fs_info,
  	"csum failed root %lld ino %lld off %llu csum 0x%08x expected csum 0x%08x mirror %d",

  			root->objectid, btrfs_ino(inode),

  			logical_start, csum, csum_expected, mirror_num);
  	else
  		btrfs_warn_rl(root->fs_info,
  	"csum failed root %llu ino %llu off %llu csum 0x%08x expected csum 0x%08x mirror %d",

  			root->objectid, btrfs_ino(inode),

  			logical_start, csum, csum_expected, mirror_num);
  }

  bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end);

  #endif