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      1 /* SPDX-License-Identifier: GPL-2.0+ */
      2 /*
      3  *  GRUB  --  GRand Unified Bootloader
      4  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
      5  */
      6 /*
      7  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
      8  * Use is subject to license terms.
      9  */
     10 
     11 #ifndef	_SYS_DNODE_H
     12 #define	_SYS_DNODE_H
     13 
     14 #include <zfs/spa.h>
     15 
     16 /*
     17  * Fixed constants.
     18  */
     19 #define	DNODE_SHIFT		9	/* 512 bytes */
     20 #define	DN_MIN_INDBLKSHIFT	10	/* 1k */
     21 #define	DN_MAX_INDBLKSHIFT	14	/* 16k */
     22 #define	DNODE_BLOCK_SHIFT	14	/* 16k */
     23 #define	DNODE_CORE_SIZE		64	/* 64 bytes for dnode sans blkptrs */
     24 #define	DN_MAX_OBJECT_SHIFT	48	/* 256 trillion (zfs_fid_t limit) */
     25 #define	DN_MAX_OFFSET_SHIFT	64	/* 2^64 bytes in a dnode */
     26 
     27 /*
     28  * Derived constants.
     29  */
     30 #define	DNODE_SIZE	(1 << DNODE_SHIFT)
     31 #define	DN_MAX_NBLKPTR	((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
     32 #define	DN_MAX_BONUSLEN	(DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
     33 #define	DN_MAX_OBJECT	(1ULL << DN_MAX_OBJECT_SHIFT)
     34 
     35 #define	DNODES_PER_BLOCK_SHIFT	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)
     36 #define	DNODES_PER_BLOCK	(1ULL << DNODES_PER_BLOCK_SHIFT)
     37 #define	DNODES_PER_LEVEL_SHIFT	(DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
     38 
     39 #define	DNODE_FLAG_SPILL_BLKPTR (1<<2)
     40 
     41 #define	DN_BONUS(dnp)	((void *)((dnp)->dn_bonus + \
     42 	(((dnp)->dn_nblkptr - 1) * sizeof(blkptr_t))))
     43 
     44 typedef struct dnode_phys {
     45 	uint8_t dn_type;		/* dmu_object_type_t */
     46 	uint8_t dn_indblkshift;		/* ln2(indirect block size) */
     47 	uint8_t dn_nlevels;		/* 1=dn_blkptr->data blocks */
     48 	uint8_t dn_nblkptr;		/* length of dn_blkptr */
     49 	uint8_t dn_bonustype;		/* type of data in bonus buffer */
     50 	uint8_t	dn_checksum;		/* ZIO_CHECKSUM type */
     51 	uint8_t	dn_compress;		/* ZIO_COMPRESS type */
     52 	uint8_t dn_flags;		/* DNODE_FLAG_* */
     53 	uint16_t dn_datablkszsec;	/* data block size in 512b sectors */
     54 	uint16_t dn_bonuslen;		/* length of dn_bonus */
     55 	uint8_t dn_pad2[4];
     56 
     57 	/* accounting is protected by dn_dirty_mtx */
     58 	uint64_t dn_maxblkid;		/* largest allocated block ID */
     59 	uint64_t dn_used;		/* bytes (or sectors) of disk space */
     60 
     61 	uint64_t dn_pad3[4];
     62 
     63 	blkptr_t dn_blkptr[1];
     64 	uint8_t dn_bonus[DN_MAX_BONUSLEN - sizeof(blkptr_t)];
     65 	blkptr_t dn_spill;
     66 } dnode_phys_t;
     67 
     68 #endif	/* _SYS_DNODE_H */
     69