/*

   *   Copyright (C) International Business Machines Corp., 2000-2002

   *
   *   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; either version 2 of the License, or

   *   (at your option) any later version.

   *

   *   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 02111-1307 USA
   */
  #ifndef _H_JFS_XTREE
  #define _H_JFS_XTREE
  
  /*

   *	jfs_xtree.h: extent allocation descriptor B+-tree manager

   */
  
  #include "jfs_btree.h"
  
  
  /*

   *	extent allocation descriptor (xad)

   */
  typedef struct xad {
  	unsigned flag:8;	/* 1: flag */
  	unsigned rsvrd:16;	/* 2: reserved */
  	unsigned off1:8;	/* 1: offset in unit of fsblksize */
  	__le32 off2;		/* 4: offset in unit of fsblksize */
  	unsigned len:24;	/* 3: length in unit of fsblksize */
  	unsigned addr1:8;	/* 1: address in unit of fsblksize */
  	__le32 addr2;		/* 4: address in unit of fsblksize */
  } xad_t;			/* (16) */

  #define MAXXLEN		((1 << 24) - 1)

  #define XTSLOTSIZE	16
  #define L2XTSLOTSIZE	4

  
  /* xad_t field construction */
  #define XADoffset(xad, offset64)\
  {\

  	(xad)->off1 = ((u64)offset64) >> 32;\
  	(xad)->off2 = __cpu_to_le32((offset64) & 0xffffffff);\

  }
  #define XADaddress(xad, address64)\
  {\

  	(xad)->addr1 = ((u64)address64) >> 32;\
  	(xad)->addr2 = __cpu_to_le32((address64) & 0xffffffff);\

  }

  #define XADlength(xad, length32)	(xad)->len = __cpu_to_le24(length32)

  
  /* xad_t field extraction */
  #define offsetXAD(xad)\

  	( ((s64)((xad)->off1)) << 32 | __le32_to_cpu((xad)->off2))

  #define addressXAD(xad)\

  	( ((s64)((xad)->addr1)) << 32 | __le32_to_cpu((xad)->addr2))
  #define lengthXAD(xad)	__le24_to_cpu((xad)->len)

  
  /* xad list */
  struct xadlist {
  	s16 maxnxad;
  	s16 nxad;
  	xad_t *xad;
  };
  
  /* xad_t flags */

  #define XAD_NEW		0x01	/* new */
  #define XAD_EXTENDED	0x02	/* extended */
  #define XAD_COMPRESSED	0x04	/* compressed with recorded length */

  #define XAD_NOTRECORDED 0x08	/* allocated but not recorded */

  #define XAD_COW		0x10	/* copy-on-write */

  
  
  /* possible values for maxentry */

  #define XTROOTINITSLOT_DIR 6
  #define XTROOTINITSLOT	10
  #define XTROOTMAXSLOT	18
  #define XTPAGEMAXSLOT	256
  #define XTENTRYSTART	2

  
  /*

   *	xtree page:

   */
  typedef union {
  	struct xtheader {
  		__le64 next;	/* 8: */
  		__le64 prev;	/* 8: */
  
  		u8 flag;	/* 1: */
  		u8 rsrvd1;	/* 1: */
  		__le16 nextindex;	/* 2: next index = number of entries */
  		__le16 maxentry;	/* 2: max number of entries */
  		__le16 rsrvd2;	/* 2: */
  
  		pxd_t self;	/* 8: self */
  	} header;		/* (32) */
  
  	xad_t xad[XTROOTMAXSLOT];	/* 16 * maxentry: xad array */
  } xtpage_t;
  
  /*

   *	external declaration

   */
  extern int xtLookup(struct inode *ip, s64 lstart, s64 llen,
  		    int *pflag, s64 * paddr, int *plen, int flag);

  extern void xtInitRoot(tid_t tid, struct inode *ip);
  extern int xtInsert(tid_t tid, struct inode *ip,
  		    int xflag, s64 xoff, int xlen, s64 * xaddrp, int flag);
  extern int xtExtend(tid_t tid, struct inode *ip, s64 xoff, int xlen,
  		    int flag);
  #ifdef _NOTYET
  extern int xtTailgate(tid_t tid, struct inode *ip,
  		      s64 xoff, int xlen, s64 xaddr, int flag);
  #endif
  extern int xtUpdate(tid_t tid, struct inode *ip, struct xad *nxad);
  extern int xtDelete(tid_t tid, struct inode *ip, s64 xoff, int xlen,
  		    int flag);
  extern s64 xtTruncate(tid_t tid, struct inode *ip, s64 newsize, int type);
  extern s64 xtTruncate_pmap(tid_t tid, struct inode *ip, s64 committed_size);
  extern int xtRelocate(tid_t tid, struct inode *ip,
  		      xad_t * oxad, s64 nxaddr, int xtype);
  extern int xtAppend(tid_t tid,
  		    struct inode *ip, int xflag, s64 xoff, int maxblocks,
  		    int *xlenp, s64 * xaddrp, int flag);

  #endif				/* !_H_JFS_XTREE */