/*
   * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
   * 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 as
   * published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it would 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 the Free Software Foundation,
   * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   */
  #ifndef __XFS_BTREE_H__
  #define	__XFS_BTREE_H__
  
  struct xfs_buf;
  struct xfs_bmap_free;
  struct xfs_inode;
  struct xfs_mount;
  struct xfs_trans;
  
  extern kmem_zone_t	*xfs_btree_cur_zone;
  
  /*
   * Generic key, ptr and record wrapper structures.
   *
   * These are disk format structures, and are converted where necessary
   * by the btree specific code that needs to interpret them.
   */
  union xfs_btree_ptr {
  	__be32			s;	/* short form ptr */
  	__be64			l;	/* long form ptr */
  };
  
  union xfs_btree_key {
  	xfs_bmbt_key_t		bmbt;
  	xfs_bmdr_key_t		bmbr;	/* bmbt root block */
  	xfs_alloc_key_t		alloc;
  	xfs_inobt_key_t		inobt;
  };
  
  union xfs_btree_rec {
  	xfs_bmbt_rec_t		bmbt;
  	xfs_bmdr_rec_t		bmbr;	/* bmbt root block */
  	xfs_alloc_rec_t		alloc;
  	xfs_inobt_rec_t		inobt;
  };
  
  /*
   * This nonsense is to make -wlint happy.
   */
  #define	XFS_LOOKUP_EQ	((xfs_lookup_t)XFS_LOOKUP_EQi)
  #define	XFS_LOOKUP_LE	((xfs_lookup_t)XFS_LOOKUP_LEi)
  #define	XFS_LOOKUP_GE	((xfs_lookup_t)XFS_LOOKUP_GEi)
  
  #define	XFS_BTNUM_BNO	((xfs_btnum_t)XFS_BTNUM_BNOi)
  #define	XFS_BTNUM_CNT	((xfs_btnum_t)XFS_BTNUM_CNTi)
  #define	XFS_BTNUM_BMAP	((xfs_btnum_t)XFS_BTNUM_BMAPi)
  #define	XFS_BTNUM_INO	((xfs_btnum_t)XFS_BTNUM_INOi)
  
  /*
   * For logging record fields.
   */
  #define	XFS_BB_MAGIC		(1 << 0)
  #define	XFS_BB_LEVEL		(1 << 1)
  #define	XFS_BB_NUMRECS		(1 << 2)
  #define	XFS_BB_LEFTSIB		(1 << 3)
  #define	XFS_BB_RIGHTSIB		(1 << 4)
  #define	XFS_BB_BLKNO		(1 << 5)
  #define	XFS_BB_LSN		(1 << 6)
  #define	XFS_BB_UUID		(1 << 7)
  #define	XFS_BB_OWNER		(1 << 8)
  #define	XFS_BB_NUM_BITS		5
  #define	XFS_BB_ALL_BITS		((1 << XFS_BB_NUM_BITS) - 1)
  #define	XFS_BB_NUM_BITS_CRC	9
  #define	XFS_BB_ALL_BITS_CRC	((1 << XFS_BB_NUM_BITS_CRC) - 1)
  
  /*
   * Generic stats interface
   */
  #define __XFS_BTREE_STATS_INC(type, stat) \
  	XFS_STATS_INC(xs_ ## type ## _2_ ## stat)
  #define XFS_BTREE_STATS_INC(cur, stat)  \
  do {    \
  	switch (cur->bc_btnum) {  \
  	case XFS_BTNUM_BNO: __XFS_BTREE_STATS_INC(abtb, stat); break;	\
  	case XFS_BTNUM_CNT: __XFS_BTREE_STATS_INC(abtc, stat); break;	\
  	case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(bmbt, stat); break;	\
  	case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(ibt, stat); break;	\
  	case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;	\
  	}       \
  } while (0)
  
  #define __XFS_BTREE_STATS_ADD(type, stat, val) \
  	XFS_STATS_ADD(xs_ ## type ## _2_ ## stat, val)
  #define XFS_BTREE_STATS_ADD(cur, stat, val)  \
  do {    \
  	switch (cur->bc_btnum) {  \
  	case XFS_BTNUM_BNO: __XFS_BTREE_STATS_ADD(abtb, stat, val); break; \
  	case XFS_BTNUM_CNT: __XFS_BTREE_STATS_ADD(abtc, stat, val); break; \
  	case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_ADD(bmbt, stat, val); break; \
  	case XFS_BTNUM_INO: __XFS_BTREE_STATS_ADD(ibt, stat, val); break; \
  	case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;	\
  	}       \
  } while (0)
  
  #define	XFS_BTREE_MAXLEVELS	8	/* max of all btrees */
  
  struct xfs_btree_ops {
  	/* size of the key and record structures */
  	size_t	key_len;
  	size_t	rec_len;
  
  	/* cursor operations */
  	struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
  	void	(*update_cursor)(struct xfs_btree_cur *src,
  				 struct xfs_btree_cur *dst);
  
  	/* update btree root pointer */
  	void	(*set_root)(struct xfs_btree_cur *cur,
  			    union xfs_btree_ptr *nptr, int level_change);
  
  	/* block allocation / freeing */
  	int	(*alloc_block)(struct xfs_btree_cur *cur,
  			       union xfs_btree_ptr *start_bno,
  			       union xfs_btree_ptr *new_bno,
  			       int length, int *stat);
  	int	(*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
  
  	/* update last record information */
  	void	(*update_lastrec)(struct xfs_btree_cur *cur,
  				  struct xfs_btree_block *block,
  				  union xfs_btree_rec *rec,
  				  int ptr, int reason);
  
  	/* records in block/level */
  	int	(*get_minrecs)(struct xfs_btree_cur *cur, int level);
  	int	(*get_maxrecs)(struct xfs_btree_cur *cur, int level);
  
  	/* records on disk.  Matter for the root in inode case. */
  	int	(*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
  
  	/* init values of btree structures */
  	void	(*init_key_from_rec)(union xfs_btree_key *key,
  				     union xfs_btree_rec *rec);
  	void	(*init_rec_from_key)(union xfs_btree_key *key,
  				     union xfs_btree_rec *rec);
  	void	(*init_rec_from_cur)(struct xfs_btree_cur *cur,
  				     union xfs_btree_rec *rec);
  	void	(*init_ptr_from_cur)(struct xfs_btree_cur *cur,
  				     union xfs_btree_ptr *ptr);
  
  	/* difference between key value and cursor value */
  	__int64_t (*key_diff)(struct xfs_btree_cur *cur,
  			      union xfs_btree_key *key);
  
  	const struct xfs_buf_ops	*buf_ops;
  
  #if defined(DEBUG) || defined(XFS_WARN)
  	/* check that k1 is lower than k2 */
  	int	(*keys_inorder)(struct xfs_btree_cur *cur,
  				union xfs_btree_key *k1,
  				union xfs_btree_key *k2);
  
  	/* check that r1 is lower than r2 */
  	int	(*recs_inorder)(struct xfs_btree_cur *cur,
  				union xfs_btree_rec *r1,
  				union xfs_btree_rec *r2);
  #endif
  };
  
  /*
   * Reasons for the update_lastrec method to be called.
   */
  #define LASTREC_UPDATE	0
  #define LASTREC_INSREC	1
  #define LASTREC_DELREC	2
  
  
  /*
   * Btree cursor structure.
   * This collects all information needed by the btree code in one place.
   */
  typedef struct xfs_btree_cur
  {
  	struct xfs_trans	*bc_tp;	/* transaction we're in, if any */
  	struct xfs_mount	*bc_mp;	/* file system mount struct */
  	const struct xfs_btree_ops *bc_ops;
  	uint			bc_flags; /* btree features - below */
  	union {
  		xfs_alloc_rec_incore_t	a;
  		xfs_bmbt_irec_t		b;
  		xfs_inobt_rec_incore_t	i;
  	}		bc_rec;		/* current insert/search record value */
  	struct xfs_buf	*bc_bufs[XFS_BTREE_MAXLEVELS];	/* buf ptr per level */
  	int		bc_ptrs[XFS_BTREE_MAXLEVELS];	/* key/record # */
  	__uint8_t	bc_ra[XFS_BTREE_MAXLEVELS];	/* readahead bits */
  #define	XFS_BTCUR_LEFTRA	1	/* left sibling has been read-ahead */
  #define	XFS_BTCUR_RIGHTRA	2	/* right sibling has been read-ahead */
  	__uint8_t	bc_nlevels;	/* number of levels in the tree */
  	__uint8_t	bc_blocklog;	/* log2(blocksize) of btree blocks */
  	xfs_btnum_t	bc_btnum;	/* identifies which btree type */
  	union {
  		struct {			/* needed for BNO, CNT, INO */
  			struct xfs_buf	*agbp;	/* agf/agi buffer pointer */
  			xfs_agnumber_t	agno;	/* ag number */
  		} a;
  		struct {			/* needed for BMAP */
  			struct xfs_inode *ip;	/* pointer to our inode */
  			struct xfs_bmap_free *flist;	/* list to free after */
  			xfs_fsblock_t	firstblock;	/* 1st blk allocated */
  			int		allocated;	/* count of alloced */
  			short		forksize;	/* fork's inode space */
  			char		whichfork;	/* data or attr fork */
  			char		flags;		/* flags */
  #define	XFS_BTCUR_BPRV_WASDEL	1			/* was delayed */
  		} b;
  	}		bc_private;	/* per-btree type data */
  } xfs_btree_cur_t;
  
  /* cursor flags */
  #define XFS_BTREE_LONG_PTRS		(1<<0)	/* pointers are 64bits long */
  #define XFS_BTREE_ROOT_IN_INODE		(1<<1)	/* root may be variable size */
  #define XFS_BTREE_LASTREC_UPDATE	(1<<2)	/* track last rec externally */
  #define XFS_BTREE_CRC_BLOCKS		(1<<3)	/* uses extended btree blocks */
  
  
  #define	XFS_BTREE_NOERROR	0
  #define	XFS_BTREE_ERROR		1
  
  /*
   * Convert from buffer to btree block header.
   */
  #define	XFS_BUF_TO_BLOCK(bp)	((struct xfs_btree_block *)((bp)->b_addr))
  
  
  /*
   * Check that block header is ok.
   */
  int
  xfs_btree_check_block(
  	struct xfs_btree_cur	*cur,	/* btree cursor */
  	struct xfs_btree_block	*block,	/* generic btree block pointer */
  	int			level,	/* level of the btree block */
  	struct xfs_buf		*bp);	/* buffer containing block, if any */
  
  /*
   * Check that (long) pointer is ok.
   */
  int					/* error (0 or EFSCORRUPTED) */
  xfs_btree_check_lptr(
  	struct xfs_btree_cur	*cur,	/* btree cursor */
  	xfs_dfsbno_t		ptr,	/* btree block disk address */
  	int			level);	/* btree block level */
  
  /*
   * Delete the btree cursor.
   */
  void
  xfs_btree_del_cursor(
  	xfs_btree_cur_t		*cur,	/* btree cursor */
  	int			error);	/* del because of error */
  
  /*
   * Duplicate the btree cursor.
   * Allocate a new one, copy the record, re-get the buffers.
   */
  int					/* error */
  xfs_btree_dup_cursor(
  	xfs_btree_cur_t		*cur,	/* input cursor */
  	xfs_btree_cur_t		**ncur);/* output cursor */
  
  /*
   * Get a buffer for the block, return it with no data read.
   * Long-form addressing.
   */
  struct xfs_buf *				/* buffer for fsbno */
  xfs_btree_get_bufl(
  	struct xfs_mount	*mp,	/* file system mount point */
  	struct xfs_trans	*tp,	/* transaction pointer */
  	xfs_fsblock_t		fsbno,	/* file system block number */
  	uint			lock);	/* lock flags for get_buf */
  
  /*
   * Get a buffer for the block, return it with no data read.
   * Short-form addressing.
   */
  struct xfs_buf *				/* buffer for agno/agbno */
  xfs_btree_get_bufs(
  	struct xfs_mount	*mp,	/* file system mount point */
  	struct xfs_trans	*tp,	/* transaction pointer */
  	xfs_agnumber_t		agno,	/* allocation group number */
  	xfs_agblock_t		agbno,	/* allocation group block number */
  	uint			lock);	/* lock flags for get_buf */
  
  /*
   * Check for the cursor referring to the last block at the given level.
   */
  int					/* 1=is last block, 0=not last block */
  xfs_btree_islastblock(
  	xfs_btree_cur_t		*cur,	/* btree cursor */
  	int			level);	/* level to check */
  
  /*
   * Compute first and last byte offsets for the fields given.
   * Interprets the offsets table, which contains struct field offsets.
   */
  void
  xfs_btree_offsets(
  	__int64_t		fields,	/* bitmask of fields */
  	const short		*offsets,/* table of field offsets */
  	int			nbits,	/* number of bits to inspect */
  	int			*first,	/* output: first byte offset */
  	int			*last);	/* output: last byte offset */
  
  /*
   * Get a buffer for the block, return it read in.
   * Long-form addressing.
   */
  int					/* error */
  xfs_btree_read_bufl(
  	struct xfs_mount	*mp,	/* file system mount point */
  	struct xfs_trans	*tp,	/* transaction pointer */
  	xfs_fsblock_t		fsbno,	/* file system block number */
  	uint			lock,	/* lock flags for read_buf */
  	struct xfs_buf		**bpp,	/* buffer for fsbno */
  	int			refval,	/* ref count value for buffer */
  	const struct xfs_buf_ops *ops);
  
  /*
   * Read-ahead the block, don't wait for it, don't return a buffer.
   * Long-form addressing.
   */
  void					/* error */
  xfs_btree_reada_bufl(
  	struct xfs_mount	*mp,	/* file system mount point */
  	xfs_fsblock_t		fsbno,	/* file system block number */
  	xfs_extlen_t		count,	/* count of filesystem blocks */
  	const struct xfs_buf_ops *ops);
  
  /*
   * Read-ahead the block, don't wait for it, don't return a buffer.
   * Short-form addressing.
   */
  void					/* error */
  xfs_btree_reada_bufs(
  	struct xfs_mount	*mp,	/* file system mount point */
  	xfs_agnumber_t		agno,	/* allocation group number */
  	xfs_agblock_t		agbno,	/* allocation group block number */
  	xfs_extlen_t		count,	/* count of filesystem blocks */
  	const struct xfs_buf_ops *ops);
  
  /*
   * Initialise a new btree block header
   */
  void
  xfs_btree_init_block(
  	struct xfs_mount *mp,
  	struct xfs_buf	*bp,
  	__u32		magic,
  	__u16		level,
  	__u16		numrecs,
  	__u64		owner,
  	unsigned int	flags);
  
  void
  xfs_btree_init_block_int(
  	struct xfs_mount	*mp,
  	struct xfs_btree_block	*buf,
  	xfs_daddr_t		blkno,
  	__u32			magic,
  	__u16			level,
  	__u16			numrecs,
  	__u64			owner,
  	unsigned int		flags);
  
  /*
   * Common btree core entry points.
   */
  int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
  int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
  int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
  int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
  int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
  int xfs_btree_insert(struct xfs_btree_cur *, int *);
  int xfs_btree_delete(struct xfs_btree_cur *, int *);
  int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
  int xfs_btree_change_owner(struct xfs_btree_cur *cur, __uint64_t new_owner,
  			   struct list_head *buffer_list);
  
  /*
   * btree block CRC helpers
   */
  void xfs_btree_lblock_calc_crc(struct xfs_buf *);
  bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
  void xfs_btree_sblock_calc_crc(struct xfs_buf *);
  bool xfs_btree_sblock_verify_crc(struct xfs_buf *);
  
  /*
   * Internal btree helpers also used by xfs_bmap.c.
   */
  void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
  void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
  
  /*
   * Helpers.
   */
  static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
  {
  	return be16_to_cpu(block->bb_numrecs);
  }
  
  static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
  		__uint16_t numrecs)
  {
  	block->bb_numrecs = cpu_to_be16(numrecs);
  }
  
  static inline int xfs_btree_get_level(struct xfs_btree_block *block)
  {
  	return be16_to_cpu(block->bb_level);
  }
  
  
  /*
   * Min and max functions for extlen, agblock, fileoff, and filblks types.
   */
  #define	XFS_EXTLEN_MIN(a,b)	min_t(xfs_extlen_t, (a), (b))
  #define	XFS_EXTLEN_MAX(a,b)	max_t(xfs_extlen_t, (a), (b))
  #define	XFS_AGBLOCK_MIN(a,b)	min_t(xfs_agblock_t, (a), (b))
  #define	XFS_AGBLOCK_MAX(a,b)	max_t(xfs_agblock_t, (a), (b))
  #define	XFS_FILEOFF_MIN(a,b)	min_t(xfs_fileoff_t, (a), (b))
  #define	XFS_FILEOFF_MAX(a,b)	max_t(xfs_fileoff_t, (a), (b))
  #define	XFS_FILBLKS_MIN(a,b)	min_t(xfs_filblks_t, (a), (b))
  #define	XFS_FILBLKS_MAX(a,b)	max_t(xfs_filblks_t, (a), (b))
  
  #define	XFS_FSB_SANITY_CHECK(mp,fsb)	\
  	(XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
  		XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
  
  /*
   * Trace hooks.  Currently not implemented as they need to be ported
   * over to the generic tracing functionality, which is some effort.
   *
   * i,j = integer (32 bit)
   * b = btree block buffer (xfs_buf_t)
   * p = btree ptr
   * r = btree record
   * k = btree key
   */
  #define	XFS_BTREE_TRACE_ARGBI(c, b, i)
  #define	XFS_BTREE_TRACE_ARGBII(c, b, i, j)
  #define	XFS_BTREE_TRACE_ARGI(c, i)
  #define	XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
  #define	XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
  #define	XFS_BTREE_TRACE_ARGIK(c, i, k)
  #define XFS_BTREE_TRACE_ARGR(c, r)
  #define	XFS_BTREE_TRACE_CURSOR(c, t)
  
  #endif	/* __XFS_BTREE_H__ */