include/zfs/dnode.h

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