LXR linux/fs/xfs/xfs

   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
  27struct xfs_buf;
  28struct xfs_mount;
  29struct 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
  51typedef 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        __be32          agf_btreeblks;  /* # of blocks held in AGF btrees */
  72} xfs_agf_t;
  73
  74#define XFS_AGF_MAGICNUM        0x00000001
  75#define XFS_AGF_VERSIONNUM      0x00000002
  76#define XFS_AGF_SEQNO           0x00000004
  77#define XFS_AGF_LENGTH          0x00000008
  78#define XFS_AGF_ROOTS           0x00000010
  79#define XFS_AGF_LEVELS          0x00000020
  80#define XFS_AGF_FLFIRST         0x00000040
  81#define XFS_AGF_FLLAST          0x00000080
  82#define XFS_AGF_FLCOUNT         0x00000100
  83#define XFS_AGF_FREEBLKS        0x00000200
  84#define XFS_AGF_LONGEST         0x00000400
  85#define XFS_AGF_BTREEBLKS       0x00000800
  86#define XFS_AGF_NUM_BITS        12
  87#define XFS_AGF_ALL_BITS        ((1 << XFS_AGF_NUM_BITS) - 1)
  88
  89/* disk block (xfs_daddr_t) in the AG */
  90#define XFS_AGF_DADDR(mp)       ((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
  91#define XFS_AGF_BLOCK(mp)       XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
  92#define XFS_BUF_TO_AGF(bp)      ((xfs_agf_t *)XFS_BUF_PTR(bp))
  93
  94extern int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
  95                        xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
  96
  97/*
  98 * Size of the unlinked inode hash table in the agi.
  99 */
 100#define XFS_AGI_UNLINKED_BUCKETS        64
 101
 102typedef struct xfs_agi {
 103        /*
 104         * Common allocation group header information
 105         */
 106        __be32          agi_magicnum;   /* magic number == XFS_AGI_MAGIC */
 107        __be32          agi_versionnum; /* header version == XFS_AGI_VERSION */
 108        __be32          agi_seqno;      /* sequence # starting from 0 */
 109        __be32          agi_length;     /* size in blocks of a.g. */
 110        /*
 111         * Inode information
 112         * Inodes are mapped by interpreting the inode number, so no
 113         * mapping data is needed here.
 114         */
 115        __be32          agi_count;      /* count of allocated inodes */
 116        __be32          agi_root;       /* root of inode btree */
 117        __be32          agi_level;      /* levels in inode btree */
 118        __be32          agi_freecount;  /* number of free inodes */
 119        __be32          agi_newino;     /* new inode just allocated */
 120        __be32          agi_dirino;     /* last directory inode chunk */
 121        /*
 122         * Hash table of inodes which have been unlinked but are
 123         * still being referenced.
 124         */
 125        __be32          agi_unlinked[XFS_AGI_UNLINKED_BUCKETS];
 126} xfs_agi_t;
 127
 128#define XFS_AGI_MAGICNUM        0x00000001
 129#define XFS_AGI_VERSIONNUM      0x00000002
 130#define XFS_AGI_SEQNO           0x00000004
 131#define XFS_AGI_LENGTH          0x00000008
 132#define XFS_AGI_COUNT           0x00000010
 133#define XFS_AGI_ROOT            0x00000020
 134#define XFS_AGI_LEVEL           0x00000040
 135#define XFS_AGI_FREECOUNT       0x00000080
 136#define XFS_AGI_NEWINO          0x00000100
 137#define XFS_AGI_DIRINO          0x00000200
 138#define XFS_AGI_UNLINKED        0x00000400
 139#define XFS_AGI_NUM_BITS        11
 140#define XFS_AGI_ALL_BITS        ((1 << XFS_AGI_NUM_BITS) - 1)
 141
 142/* disk block (xfs_daddr_t) in the AG */
 143#define XFS_AGI_DADDR(mp)       ((xfs_daddr_t)(2 << (mp)->m_sectbb_log))
 144#define XFS_AGI_BLOCK(mp)       XFS_HDR_BLOCK(mp, XFS_AGI_DADDR(mp))
 145#define XFS_BUF_TO_AGI(bp)      ((xfs_agi_t *)XFS_BUF_PTR(bp))
 146
 147extern int xfs_read_agi(struct xfs_mount *mp, struct xfs_trans *tp,
 148                                xfs_agnumber_t agno, struct xfs_buf **bpp);
 149
 150/*
 151 * The third a.g. block contains the a.g. freelist, an array
 152 * of block pointers to blocks owned by the allocation btree code.
 153 */
 154#define XFS_AGFL_DADDR(mp)      ((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
 155#define XFS_AGFL_BLOCK(mp)      XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
 156#define XFS_AGFL_SIZE(mp)       ((mp)->m_sb.sb_sectsize / sizeof(xfs_agblock_t))
 157#define XFS_BUF_TO_AGFL(bp)     ((xfs_agfl_t *)XFS_BUF_PTR(bp))
 158
 159typedef struct xfs_agfl {
 160        __be32          agfl_bno[1];    /* actually XFS_AGFL_SIZE(mp) */
 161} xfs_agfl_t;
 162
 163/*
 164 * Busy block/extent entry.  Used in perag to mark blocks that have been freed
 165 * but whose transactions aren't committed to disk yet.
 166 */
 167typedef struct xfs_perag_busy {
 168        xfs_agblock_t   busy_start;
 169        xfs_extlen_t    busy_length;
 170        struct xfs_trans *busy_tp;      /* transaction that did the free */
 171} xfs_perag_busy_t;
 172
 173/*
 174 * Per-ag incore structure, copies of information in agf and agi,
 175 * to improve the performance of allocation group selection.
 176 *
 177 * pick sizes which fit in allocation buckets well
 178 */
 179#if (BITS_PER_LONG == 32)
 180#define XFS_PAGB_NUM_SLOTS      84
 181#elif (BITS_PER_LONG == 64)
 182#define XFS_PAGB_NUM_SLOTS      128
 183#endif
 184
 185typedef struct xfs_perag
 186{
 187        char            pagf_init;      /* this agf's entry is initialized */
 188        char            pagi_init;      /* this agi's entry is initialized */
 189        char            pagf_metadata;  /* the agf is preferred to be metadata */
 190        char            pagi_inodeok;   /* The agi is ok for inodes */
 191        __uint8_t       pagf_levels[XFS_BTNUM_AGF];
 192                                        /* # of levels in bno & cnt btree */
 193        __uint32_t      pagf_flcount;   /* count of blocks in freelist */
 194        xfs_extlen_t    pagf_freeblks;  /* total free blocks */
 195        xfs_extlen_t    pagf_longest;   /* longest free space */
 196        __uint32_t      pagf_btreeblks; /* # of blocks held in AGF btrees */
 197        xfs_agino_t     pagi_freecount; /* number of free inodes */
 198        xfs_agino_t     pagi_count;     /* number of allocated inodes */
 199        int             pagb_count;     /* pagb slots in use */
 200        xfs_perag_busy_t *pagb_list;    /* unstable blocks */
 201
 202        /*
 203         * Inode allocation search lookup optimisation.
 204         * If the pagino matches, the search for new inodes
 205         * doesn't need to search the near ones again straight away
 206         */
 207        xfs_agino_t     pagl_pagino;
 208        xfs_agino_t     pagl_leftrec;
 209        xfs_agino_t     pagl_rightrec;
 210#ifdef __KERNEL__
 211        spinlock_t      pagb_lock;      /* lock for pagb_list */
 212
 213        atomic_t        pagf_fstrms;    /* # of filestreams active in this AG */
 214
 215        int             pag_ici_init;   /* incore inode cache initialised */
 216        rwlock_t        pag_ici_lock;   /* incore inode lock */
 217        struct radix_tree_root pag_ici_root;    /* incore inode cache root */
 218#endif
 219} xfs_perag_t;
 220
 221/*
 222 * tags for inode radix tree
 223 */
 224#define XFS_ICI_NO_TAG          (-1)    /* special flag for an untagged lookup
 225                                           in xfs_inode_ag_iterator */
 226#define XFS_ICI_RECLAIM_TAG     0       /* inode is to be reclaimed */
 227
 228#define XFS_AG_MAXLEVELS(mp)            ((mp)->m_ag_maxlevels)
 229#define XFS_MIN_FREELIST_RAW(bl,cl,mp)  \
 230        (MIN(bl + 1, XFS_AG_MAXLEVELS(mp)) + MIN(cl + 1, XFS_AG_MAXLEVELS(mp)))
 231#define XFS_MIN_FREELIST(a,mp)          \
 232        (XFS_MIN_FREELIST_RAW(          \
 233                be32_to_cpu((a)->agf_levels[XFS_BTNUM_BNOi]), \
 234                be32_to_cpu((a)->agf_levels[XFS_BTNUM_CNTi]), mp))
 235#define XFS_MIN_FREELIST_PAG(pag,mp)    \
 236        (XFS_MIN_FREELIST_RAW(          \
 237                (unsigned int)(pag)->pagf_levels[XFS_BTNUM_BNOi], \
 238                (unsigned int)(pag)->pagf_levels[XFS_BTNUM_CNTi], mp))
 239
 240#define XFS_AGB_TO_FSB(mp,agno,agbno)   \
 241        (((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) | (agbno))
 242#define XFS_FSB_TO_AGNO(mp,fsbno)       \
 243        ((xfs_agnumber_t)((fsbno) >> (mp)->m_sb.sb_agblklog))
 244#define XFS_FSB_TO_AGBNO(mp,fsbno)      \
 245        ((xfs_agblock_t)((fsbno) & xfs_mask32lo((mp)->m_sb.sb_agblklog)))
 246#define XFS_AGB_TO_DADDR(mp,agno,agbno) \
 247        ((xfs_daddr_t)XFS_FSB_TO_BB(mp, \
 248                (xfs_fsblock_t)(agno) * (mp)->m_sb.sb_agblocks + (agbno)))
 249#define XFS_AG_DADDR(mp,agno,d)         (XFS_AGB_TO_DADDR(mp, agno, 0) + (d))
 250
 251/*
 252 * For checking for bad ranges of xfs_daddr_t's, covering multiple
 253 * allocation groups or a single xfs_daddr_t that's a superblock copy.
 254 */
 255#define XFS_AG_CHECK_DADDR(mp,d,len)    \
 256        ((len) == 1 ? \
 257            ASSERT((d) == XFS_SB_DADDR || \
 258                   xfs_daddr_to_agbno(mp, d) != XFS_SB_DADDR) : \
 259            ASSERT(xfs_daddr_to_agno(mp, d) == \
 260                   xfs_daddr_to_agno(mp, (d) + (len) - 1)))
 261
 262#endif  /* __XFS_AG_H__ */
 263