include/xfs_rtalloc.h

   1 /*
   2  * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32 #ifndef __XFS_RTALLOC_H__
  33 #define __XFS_RTALLOC_H__
  34
  35 struct xfs_mount;
  36 struct xfs_trans;
  37
  38 /* Min and max rt extent sizes, specified in bytes */
  39 #define XFS_MAX_RTEXTSIZE       (1024 * 1024 * 1024)    /* 1GB */
  40 #define XFS_DFL_RTEXTSIZE       (64 * 1024)             /* 64KB */
  41 #define XFS_MIN_RTEXTSIZE       (4 * 1024)              /* 4KB */
  42
  43 /*
  44  * Constants for bit manipulations.
  45  */
  46 #define XFS_NBBYLOG     3               /* log2(NBBY) */
  47 #define XFS_WORDLOG     2               /* log2(sizeof(xfs_rtword_t)) */
  48 #define XFS_NBWORDLOG   (XFS_NBBYLOG + XFS_WORDLOG)
  49 #define XFS_NBWORD      (1 << XFS_NBWORDLOG)
  50 #define XFS_WORDMASK    ((1 << XFS_WORDLOG) - 1)
  51
  52 #define XFS_BLOCKSIZE(mp)       ((mp)->m_sb.sb_blocksize)
  53 #define XFS_BLOCKMASK(mp)       ((mp)->m_blockmask)
  54 #define XFS_BLOCKWSIZE(mp)      ((mp)->m_blockwsize)
  55 #define XFS_BLOCKWMASK(mp)      ((mp)->m_blockwmask)
  56
  57 /*
  58  * Summary and bit manipulation macros.
  59  */
  60 #define XFS_SUMOFFS(mp,ls,bb)   ((int)((ls) * (mp)->m_sb.sb_rbmblocks + (bb)))
  61 #define XFS_SUMOFFSTOBLOCK(mp,s)        \
  62         (((s) * (uint)sizeof(xfs_suminfo_t)) >> (mp)->m_sb.sb_blocklog)
  63 #define XFS_SUMPTR(mp,bp,so)    \
  64         ((xfs_suminfo_t *)((char *)XFS_BUF_PTR(bp) + \
  65                 (((so) * (uint)sizeof(xfs_suminfo_t)) & XFS_BLOCKMASK(mp))))
  66
  67 #define XFS_BITTOBLOCK(mp,bi)   ((bi) >> (mp)->m_blkbit_log)
  68 #define XFS_BLOCKTOBIT(mp,bb)   ((bb) << (mp)->m_blkbit_log)
  69 #define XFS_BITTOWORD(mp,bi)    \
  70         ((int)(((bi) >> XFS_NBWORDLOG) & XFS_BLOCKWMASK(mp)))
  71
  72 #define XFS_RTMIN(a,b)  ((a) < (b) ? (a) : (b))
  73 #define XFS_RTMAX(a,b)  ((a) > (b) ? (a) : (b))
  74
  75 #define XFS_RTLOBIT(w)  xfs_lowbit32(w)
  76 #define XFS_RTHIBIT(w)  xfs_highbit32(w)
  77
  78 #if XFS_BIG_FILESYSTEMS
  79 #define XFS_RTBLOCKLOG(b)       xfs_highbit64(b)
  80 #else
  81 #define XFS_RTBLOCKLOG(b)       xfs_highbit32(b)
  82 #endif
  83
  84 /*
  85  * Function prototypes for exported functions.
  86  */
  87
  88 /*
  89  * Allocate an extent in the realtime subvolume, with the usual allocation
  90  * parameters.  The length units are all in realtime extents, as is the
  91  * result block number.
  92  */
  93 int                                     /* error */
  94 xfs_rtallocate_extent(
  95         struct xfs_trans        *tp,    /* transaction pointer */
  96         xfs_rtblock_t           bno,    /* starting block number to allocate */
  97         xfs_extlen_t            minlen, /* minimum length to allocate */
  98         xfs_extlen_t            maxlen, /* maximum length to allocate */
  99         xfs_extlen_t            *len,   /* out: actual length allocated */
 100         xfs_alloctype_t         type,   /* allocation type XFS_ALLOCTYPE... */
 101         int                     wasdel, /* was a delayed allocation extent */
 102         xfs_extlen_t            prod,   /* extent product factor */
 103         xfs_rtblock_t           *rtblock); /* out: start block allocated */
 104
 105 /*
 106  * Free an extent in the realtime subvolume.  Length is expressed in
 107  * realtime extents, as is the block number.
 108  */
 109 int                                     /* error */
 110 xfs_rtfree_extent(
 111         struct xfs_trans        *tp,    /* transaction pointer */
 112         xfs_rtblock_t           bno,    /* starting block number to free */
 113         xfs_extlen_t            len);   /* length of extent freed */
 114
 115 /*
 116  * Initialize realtime fields in the mount structure.
 117  */
 118 int                                     /* error */
 119 xfs_rtmount_init(
 120         struct xfs_mount        *mp);   /* file system mount structure */
 121
 122 /*
 123  * Get the bitmap and summary inodes into the mount structure
 124  * at mount time.
 125  */
 126 int                                     /* error */
 127 xfs_rtmount_inodes(
 128         struct xfs_mount        *mp);   /* file system mount structure */
 129
 130 /*
 131  * Pick an extent for allocation at the start of a new realtime file.
 132  * Use the sequence number stored in the atime field of the bitmap inode.
 133  * Translate this to a fraction of the rtextents, and return the product
 134  * of rtextents and the fraction.
 135  * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
 136  */
 137 int                                     /* error */
 138 xfs_rtpick_extent(
 139         struct xfs_mount        *mp,    /* file system mount point */
 140         struct xfs_trans        *tp,    /* transaction pointer */
 141         xfs_extlen_t            len,    /* allocation length (rtextents) */
 142         xfs_rtblock_t           *pick); /* result rt extent */
 143
 144 #ifdef XFSDEBUG
 145 /*
 146  * Debug code: print out the value of a range in the bitmap.
 147  */
 148 void
 149 xfs_rtprint_range(
 150         struct xfs_mount        *mp,    /* file system mount structure */
 151         struct xfs_trans        *tp,    /* transaction pointer */
 152         xfs_rtblock_t           start,  /* starting block to print */
 153         xfs_extlen_t            len);   /* length to print */
 154
 155 /*
 156  * Debug code: print the summary file.
 157  */
 158 void
 159 xfs_rtprint_summary(
 160         struct xfs_mount        *mp,    /* file system mount structure */
 161         struct xfs_trans        *tp);   /* transaction pointer */
 162 #endif  /* XFSDEBUG */
 163
 164 #endif  /* __XFS_RTALLOC_H__ */