fs/xfs/xfs_ag.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_AG_H__
  19 #define __XFS_AG_H__
  20
  21 /*
  22  * Allocation group header
  23  * This is divided into three structures, placed in sequential 512-byte
  24  * buffers after a copy of the superblock (also in a 512-byte buffer).
  25  */
  26
  27 struct xfs_buf;
  28 struct xfs_mount;
  29 struct xfs_trans;
  30
  31 #define XFS_AGF_MAGIC   0x58414746      /* 'XAGF' */
  32 #define XFS_AGI_MAGIC   0x58414749      /* 'XAGI' */
  33 #define XFS_AGF_VERSION 1
  34 #define XFS_AGI_VERSION 1
  35
  36 #define XFS_AGF_GOOD_VERSION(v) ((v) == XFS_AGF_VERSION)
  37 #define XFS_AGI_GOOD_VERSION(v) ((v) == XFS_AGI_VERSION)
  38
  39 /*
  40  * Btree number 0 is bno, 1 is cnt.  This value gives the size of the
  41  * arrays below.
  42  */
  43 #define XFS_BTNUM_AGF   ((int)XFS_BTNUM_CNTi + 1)
  44
  45 /*
  46  * The second word of agf_levels in the first a.g. overlaps the EFS
  47  * superblock's magic number.  Since the magic numbers valid for EFS
  48  * are > 64k, our value cannot be confused for an EFS superblock's.
  49  */
  50
  51 typedef struct xfs_agf {
  52         /*
  53          * Common allocation group header information
  54          */
  55         __be32          agf_magicnum;   /* magic number == XFS_AGF_MAGIC */
  56         __be32          agf_versionnum; /* header version == XFS_AGF_VERSION */
  57         __be32          agf_seqno;      /* sequence # starting from 0 */
  58         __be32          agf_length;     /* size in blocks of a.g. */
  59         /*
  60          * Freespace information
  61          */
  62         __be32          agf_roots[XFS_BTNUM_AGF];       /* root blocks */
  63         __be32          agf_spare0;     /* spare field */
  64         __be32          agf_levels[XFS_BTNUM_AGF];      /* btree levels */
  65         __be32          agf_spare1;     /* spare field */
  66         __be32          agf_flfirst;    /* first freelist block's index */
  67         __be32          agf_fllast;     /* last freelist block's index */
  68         __be32          agf_flcount;    /* count of blocks in freelist */
  69         __be32          agf_freeblks;   /* total free blocks */
  70         __be32          agf_longest;    /* longest free space */
  71 } xfs_agf_t;
  72
  73 #define XFS_AGF_MAGICNUM        0x00000001
  74 #define XFS_AGF_VERSIONNUM      0x00000002
  75 #define XFS_AGF_SEQNO           0x00000004
  76 #define XFS_AGF_LENGTH          0x00000008
  77 #define XFS_AGF_ROOTS           0x00000010
  78 #define XFS_AGF_LEVELS          0x00000020
  79 #define XFS_AGF_FLFIRST         0x00000040
  80 #define XFS_AGF_FLLAST          0x00000080
  81 #define XFS_AGF_FLCOUNT         0x00000100
  82 #define XFS_AGF_FREEBLKS        0x00000200
  83 #define XFS_AGF_LONGEST         0x00000400
  84 #define XFS_AGF_NUM_BITS        11
  85 #define XFS_AGF_ALL_BITS        ((1 << XFS_AGF_NUM_BITS) - 1)
  86
  87 /* disk block (xfs_daddr_t) in the AG */
  88 #define XFS_AGF_DADDR(mp)       ((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
  89 #define XFS_AGF_BLOCK(mp)       XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
  90 #define XFS_BUF_TO_AGF(bp)      ((xfs_agf_t *)XFS_BUF_PTR(bp))
  91
  92
  93 /*
  94  * Size of the unlinked inode hash table in the agi.
  95  */
  96 #define XFS_AGI_UNLINKED_BUCKETS        64
  97
  98 typedef struct xfs_agi {
  99         /*
 100          * Common allocation group header information
 101          */
 102         __be32          agi_magicnum;   /* magic number == XFS_AGI_MAGIC */
 103         __be32          agi_versionnum; /* header version == XFS_AGI_VERSION */
 104         __be32          agi_seqno;      /* sequence # starting from 0 */
 105         __be32          agi_length;     /* size in blocks of a.g. */
 106         /*
 107          * Inode information
 108          * Inodes are mapped by interpreting the inode number, so no
 109          * mapping data is needed here.
 110          */
 111         __be32          agi_count;      /* count of allocated inodes */
 112         __be32          agi_root;       /* root of inode btree */
 113         __be32          agi_level;      /* levels in inode btree */
 114         __be32          agi_freecount;  /* number of free inodes */
 115         __be32          agi_newino;     /* new inode just allocated */
 116         __be32          agi_dirino;     /* last directory inode chunk */
 117         /*
 118          * Hash table of inodes which have been unlinked but are
 119          * still being referenced.
 120          */
 121         __be32          agi_unlinked[XFS_AGI_UNLINKED_BUCKETS];
 122 } xfs_agi_t;
 123
 124 #define XFS_AGI_MAGICNUM        0x00000001
 125 #define XFS_AGI_VERSIONNUM      0x00000002
 126 #define XFS_AGI_SEQNO           0x00000004
 127 #define XFS_AGI_LENGTH          0x00000008
 128 #define XFS_AGI_COUNT           0x00000010
 129 #define XFS_AGI_ROOT            0x00000020
 130 #define XFS_AGI_LEVEL           0x00000040
 131 #define XFS_AGI_FREECOUNT       0x00000080
 132 #define XFS_AGI_NEWINO          0x00000100
 133 #define XFS_AGI_DIRINO          0x00000200
 134 #define XFS_AGI_UNLINKED        0x00000400
 135 #define XFS_AGI_NUM_BITS        11
 136 #define XFS_AGI_ALL_BITS        ((1 << XFS_AGI_NUM_BITS) - 1)
 137
 138 /* disk block (xfs_daddr_t) in the AG */
 139 #define XFS_AGI_DADDR(mp)       ((xfs_daddr_t)(2 << (mp)->m_sectbb_log))
 140 #define XFS_AGI_BLOCK(mp)       XFS_HDR_BLOCK(mp, XFS_AGI_DADDR(mp))
 141 #define XFS_BUF_TO_AGI(bp)      ((xfs_agi_t *)XFS_BUF_PTR(bp))
 142
 143 /*
 144  * The third a.g. block contains the a.g. freelist, an array
 145  * of block pointers to blocks owned by the allocation btree code.
 146  */
 147 #define XFS_AGFL_DADDR(mp)      ((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
 148 #define XFS_AGFL_BLOCK(mp)      XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
 149 #define XFS_AGFL_SIZE(mp)       ((mp)->m_sb.sb_sectsize / sizeof(xfs_agblock_t))
 150 #define XFS_BUF_TO_AGFL(bp)     ((xfs_agfl_t *)XFS_BUF_PTR(bp))
 151
 152 typedef struct xfs_agfl {
 153         __be32          agfl_bno[1];    /* actually XFS_AGFL_SIZE(mp) */
 154 } xfs_agfl_t;
 155
 156 /*
 157  * Busy block/extent entry.  Used in perag to mark blocks that have been freed
 158  * but whose transactions aren't committed to disk yet.
 159  */
 160 typedef struct xfs_perag_busy {
 161         xfs_agblock_t   busy_start;
 162         xfs_extlen_t    busy_length;
 163         struct xfs_trans *busy_tp;      /* transaction that did the free */
 164 } xfs_perag_busy_t;
 165
 166 /*
 167  * Per-ag incore structure, copies of information in agf and agi,
 168  * to improve the performance of allocation group selection.
 169  *
 170  * pick sizes which fit in allocation buckets well
 171  */
 172 #if (BITS_PER_LONG == 32)
 173 #define XFS_PAGB_NUM_SLOTS      84
 174 #elif (BITS_PER_LONG == 64)
 175 #define XFS_PAGB_NUM_SLOTS      128
 176 #endif
 177
 178 typedef struct xfs_perag
 179 {
 180         char            pagf_init;      /* this agf's entry is initialized */
 181         char            pagi_init;      /* this agi's entry is initialized */
 182         char            pagf_metadata;  /* the agf is preferred to be metadata */
 183         char            pagi_inodeok;   /* The agi is ok for inodes */
 184         __uint8_t       pagf_levels[XFS_BTNUM_AGF];
 185                                         /* # of levels in bno & cnt btree */
 186         __uint32_t      pagf_flcount;   /* count of blocks in freelist */
 187         xfs_extlen_t    pagf_freeblks;  /* total free blocks */
 188         xfs_extlen_t    pagf_longest;   /* longest free space */
 189         xfs_agino_t     pagi_freecount; /* number of free inodes */
 190 #ifdef __KERNEL__
 191         lock_t          pagb_lock;      /* lock for pagb_list */
 192 #endif
 193         int             pagb_count;     /* pagb slots in use */
 194         xfs_perag_busy_t *pagb_list;    /* unstable blocks */
 195 } xfs_perag_t;
 196
 197 #define XFS_AG_MAXLEVELS(mp)            ((mp)->m_ag_maxlevels)
 198 #define XFS_MIN_FREELIST_RAW(bl,cl,mp)  \
 199         (MIN(bl + 1, XFS_AG_MAXLEVELS(mp)) + MIN(cl + 1, XFS_AG_MAXLEVELS(mp)))
 200 #define XFS_MIN_FREELIST(a,mp)          \
 201         (XFS_MIN_FREELIST_RAW(          \
 202                 be32_to_cpu((a)->agf_levels[XFS_BTNUM_BNOi]), \
 203                 be32_to_cpu((a)->agf_levels[XFS_BTNUM_CNTi]), mp))
 204 #define XFS_MIN_FREELIST_PAG(pag,mp)    \
 205         (XFS_MIN_FREELIST_RAW(          \
 206                 (uint_t)(pag)->pagf_levels[XFS_BTNUM_BNOi], \
 207                 (uint_t)(pag)->pagf_levels[XFS_BTNUM_CNTi], mp))
 208
 209 #define XFS_AGB_TO_FSB(mp,agno,agbno)   \
 210         (((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) | (agbno))
 211 #define XFS_FSB_TO_AGNO(mp,fsbno)       \
 212         ((xfs_agnumber_t)((fsbno) >> (mp)->m_sb.sb_agblklog))
 213 #define XFS_FSB_TO_AGBNO(mp,fsbno)      \
 214         ((xfs_agblock_t)((fsbno) & XFS_MASK32LO((mp)->m_sb.sb_agblklog)))
 215 #define XFS_AGB_TO_DADDR(mp,agno,agbno) \
 216         ((xfs_daddr_t)XFS_FSB_TO_BB(mp, \
 217                 (xfs_fsblock_t)(agno) * (mp)->m_sb.sb_agblocks + (agbno)))
 218 #define XFS_AG_DADDR(mp,agno,d)         (XFS_AGB_TO_DADDR(mp, agno, 0) + (d))
 219
 220 /*
 221  * For checking for bad ranges of xfs_daddr_t's, covering multiple
 222  * allocation groups or a single xfs_daddr_t that's a superblock copy.
 223  */
 224 #define XFS_AG_CHECK_DADDR(mp,d,len)    \
 225         ((len) == 1 ? \
 226             ASSERT((d) == XFS_SB_DADDR || \
 227                    XFS_DADDR_TO_AGBNO(mp, d) != XFS_SB_DADDR) : \
 228             ASSERT(XFS_DADDR_TO_AGNO(mp, d) == \
 229                    XFS_DADDR_TO_AGNO(mp, (d) + (len) - 1)))
 230
 231 #endif  /* __XFS_AG_H__ */