fs/xfs/xfs_rtalloc.h

   1 /*
   2  * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #ifndef __XFS_RTALLOC_H__
  19 #define __XFS_RTALLOC_H__
  20
  21 struct xfs_mount;
  22 struct xfs_trans;
  23
  24 /* Min and max rt extent sizes, specified in bytes */
  25 #define XFS_MAX_RTEXTSIZE       (1024 * 1024 * 1024)    /* 1GB */
  26 #define XFS_DFL_RTEXTSIZE       (64 * 1024)             /* 64KB */
  27 #define XFS_MIN_RTEXTSIZE       (4 * 1024)              /* 4KB */
  28
  29 /*
  30  * Constants for bit manipulations.
  31  */
  32 #define XFS_NBBYLOG     3               /* log2(NBBY) */
  33 #define XFS_WORDLOG     2               /* log2(sizeof(xfs_rtword_t)) */
  34 #define XFS_NBWORDLOG   (XFS_NBBYLOG + XFS_WORDLOG)
  35 #define XFS_NBWORD      (1 << XFS_NBWORDLOG)
  36 #define XFS_WORDMASK    ((1 << XFS_WORDLOG) - 1)
  37
  38 #define XFS_BLOCKSIZE(mp)       ((mp)->m_sb.sb_blocksize)
  39 #define XFS_BLOCKMASK(mp)       ((mp)->m_blockmask)
  40 #define XFS_BLOCKWSIZE(mp)      ((mp)->m_blockwsize)
  41 #define XFS_BLOCKWMASK(mp)      ((mp)->m_blockwmask)
  42
  43 /*
  44  * Summary and bit manipulation macros.
  45  */
  46 #define XFS_SUMOFFS(mp,ls,bb)   ((int)((ls) * (mp)->m_sb.sb_rbmblocks + (bb)))
  47 #define XFS_SUMOFFSTOBLOCK(mp,s)        \
  48         (((s) * (uint)sizeof(xfs_suminfo_t)) >> (mp)->m_sb.sb_blocklog)
  49 #define XFS_SUMPTR(mp,bp,so)    \
  50         ((xfs_suminfo_t *)((char *)XFS_BUF_PTR(bp) + \
  51                 (((so) * (uint)sizeof(xfs_suminfo_t)) & XFS_BLOCKMASK(mp))))
  52
  53 #define XFS_BITTOBLOCK(mp,bi)   ((bi) >> (mp)->m_blkbit_log)
  54 #define XFS_BLOCKTOBIT(mp,bb)   ((bb) << (mp)->m_blkbit_log)
  55 #define XFS_BITTOWORD(mp,bi)    \
  56         ((int)(((bi) >> XFS_NBWORDLOG) & XFS_BLOCKWMASK(mp)))
  57
  58 #define XFS_RTMIN(a,b)  ((a) < (b) ? (a) : (b))
  59 #define XFS_RTMAX(a,b)  ((a) > (b) ? (a) : (b))
  60
  61 #define XFS_RTLOBIT(w)  xfs_lowbit32(w)
  62 #define XFS_RTHIBIT(w)  xfs_highbit32(w)
  63
  64 #if XFS_BIG_BLKNOS
  65 #define XFS_RTBLOCKLOG(b)       xfs_highbit64(b)
  66 #else
  67 #define XFS_RTBLOCKLOG(b)       xfs_highbit32(b)
  68 #endif
  69
  70
  71 #ifdef __KERNEL__
  72
  73 #ifdef CONFIG_XFS_RT
  74 /*
  75  * Function prototypes for exported functions.
  76  */
  77
  78 /*
  79  * Allocate an extent in the realtime subvolume, with the usual allocation
  80  * parameters.  The length units are all in realtime extents, as is the
  81  * result block number.
  82  */
  83 int                                     /* error */
  84 xfs_rtallocate_extent(
  85         struct xfs_trans        *tp,    /* transaction pointer */
  86         xfs_rtblock_t           bno,    /* starting block number to allocate */
  87         xfs_extlen_t            minlen, /* minimum length to allocate */
  88         xfs_extlen_t            maxlen, /* maximum length to allocate */
  89         xfs_extlen_t            *len,   /* out: actual length allocated */
  90         xfs_alloctype_t         type,   /* allocation type XFS_ALLOCTYPE... */
  91         int                     wasdel, /* was a delayed allocation extent */
  92         xfs_extlen_t            prod,   /* extent product factor */
  93         xfs_rtblock_t           *rtblock); /* out: start block allocated */
  94
  95 /*
  96  * Free an extent in the realtime subvolume.  Length is expressed in
  97  * realtime extents, as is the block number.
  98  */
  99 int                                     /* error */
 100 xfs_rtfree_extent(
 101         struct xfs_trans        *tp,    /* transaction pointer */
 102         xfs_rtblock_t           bno,    /* starting block number to free */
 103         xfs_extlen_t            len);   /* length of extent freed */
 104
 105 /*
 106  * Initialize realtime fields in the mount structure.
 107  */
 108 int                                     /* error */
 109 xfs_rtmount_init(
 110         struct xfs_mount        *mp);   /* file system mount structure */
 111
 112 /*
 113  * Get the bitmap and summary inodes into the mount structure
 114  * at mount time.
 115  */
 116 int                                     /* error */
 117 xfs_rtmount_inodes(
 118         struct xfs_mount        *mp);   /* file system mount structure */
 119
 120 /*
 121  * Pick an extent for allocation at the start of a new realtime file.
 122  * Use the sequence number stored in the atime field of the bitmap inode.
 123  * Translate this to a fraction of the rtextents, and return the product
 124  * of rtextents and the fraction.
 125  * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
 126  */
 127 int                                     /* error */
 128 xfs_rtpick_extent(
 129         struct xfs_mount        *mp,    /* file system mount point */
 130         struct xfs_trans        *tp,    /* transaction pointer */
 131         xfs_extlen_t            len,    /* allocation length (rtextents) */
 132         xfs_rtblock_t           *pick); /* result rt extent */
 133
 134 /*
 135  * Grow the realtime area of the filesystem.
 136  */
 137 int
 138 xfs_growfs_rt(
 139         struct xfs_mount        *mp,    /* file system mount structure */
 140         xfs_growfs_rt_t         *in);   /* user supplied growfs struct */
 141
 142 #else
 143 # define xfs_rtallocate_extent(t,b,min,max,l,a,f,p,rb)  (ENOSYS)
 144 # define xfs_rtfree_extent(t,b,l)                       (ENOSYS)
 145 # define xfs_rtpick_extent(m,t,l,rb)                    (ENOSYS)
 146 # define xfs_growfs_rt(mp,in)                           (ENOSYS)
 147 # define xfs_rtmount_init(m)    (((mp)->m_sb.sb_rblocks == 0)? 0 : (ENOSYS))
 148 # define xfs_rtmount_inodes(m)  (((mp)->m_sb.sb_rblocks == 0)? 0 : (ENOSYS))
 149 #endif  /* CONFIG_XFS_RT */
 150
 151 #endif  /* __KERNEL__ */
 152
 153 #endif  /* __XFS_RTALLOC_H__ */