/*
   *  GRUB  --  GRand Unified Bootloader
   *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  /*
   * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
  #ifndef	_SYS_DNODE_H
  #define	_SYS_DNODE_H
  
  #include <zfs/spa.h>
  
  /*
   * Fixed constants.
   */
  #define	DNODE_SHIFT		9	/* 512 bytes */
  #define	DN_MIN_INDBLKSHIFT	10	/* 1k */
  #define	DN_MAX_INDBLKSHIFT	14	/* 16k */
  #define	DNODE_BLOCK_SHIFT	14	/* 16k */
  #define	DNODE_CORE_SIZE		64	/* 64 bytes for dnode sans blkptrs */
  #define	DN_MAX_OBJECT_SHIFT	48	/* 256 trillion (zfs_fid_t limit) */
  #define	DN_MAX_OFFSET_SHIFT	64	/* 2^64 bytes in a dnode */
  
  /*
   * Derived constants.
   */
  #define	DNODE_SIZE	(1 << DNODE_SHIFT)
  #define	DN_MAX_NBLKPTR	((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
  #define	DN_MAX_BONUSLEN	(DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
  #define	DN_MAX_OBJECT	(1ULL << DN_MAX_OBJECT_SHIFT)
  
  #define	DNODES_PER_BLOCK_SHIFT	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)
  #define	DNODES_PER_BLOCK	(1ULL << DNODES_PER_BLOCK_SHIFT)
  #define	DNODES_PER_LEVEL_SHIFT	(DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
  
  #define	DNODE_FLAG_SPILL_BLKPTR (1<<2)
  
  #define	DN_BONUS(dnp)	((void *)((dnp)->dn_bonus + \
  	(((dnp)->dn_nblkptr - 1) * sizeof(blkptr_t))))
  
  typedef struct dnode_phys {
  	uint8_t dn_type;		/* dmu_object_type_t */
  	uint8_t dn_indblkshift;		/* ln2(indirect block size) */
  	uint8_t dn_nlevels;		/* 1=dn_blkptr->data blocks */
  	uint8_t dn_nblkptr;		/* length of dn_blkptr */
  	uint8_t dn_bonustype;		/* type of data in bonus buffer */
  	uint8_t	dn_checksum;		/* ZIO_CHECKSUM type */
  	uint8_t	dn_compress;		/* ZIO_COMPRESS type */
  	uint8_t dn_flags;		/* DNODE_FLAG_* */
  	uint16_t dn_datablkszsec;	/* data block size in 512b sectors */
  	uint16_t dn_bonuslen;		/* length of dn_bonus */
  	uint8_t dn_pad2[4];
  
  	/* accounting is protected by dn_dirty_mtx */
  	uint64_t dn_maxblkid;		/* largest allocated block ID */
  	uint64_t dn_used;		/* bytes (or sectors) of disk space */
  
  	uint64_t dn_pad3[4];
  
  	blkptr_t dn_blkptr[1];
  	uint8_t dn_bonus[DN_MAX_BONUSLEN - sizeof(blkptr_t)];
  	blkptr_t dn_spill;
  } dnode_phys_t;
  
  #endif	/* _SYS_DNODE_H */