core/fs/xfs/xfs_ag.h

   1 /*
   2  * Taken from Linux kernel tree (linux/fs/xfs)
   3  *
   4  * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
   5  * All Rights Reserved.
   6  *
   7  * Copyright (c) 2012 Paulo Alcantara <pcacjr@zytor.com>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it would be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write the Free Software Foundation,
  20  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21  */
  22
  23 #ifndef XFS_AG_H_
  24 #define XFS_AG_H_
  25
  26 #include "xfs_types.h"
  27
  28 /*
  29  * Allocation group header
  30  * This is divided into three structures, placed in sequential 512-byte
  31  * buffers after a copy of the superblock (also in a 512-byte buffer).
  32  */
  33
  34 typedef uint32_t xfs_agino_t;
  35
  36 struct xfs_buf;
  37 struct xfs_mount;
  38 struct xfs_trans;
  39
  40 #define XFS_AGF_MAGIC   "XAGF"
  41 #define XFS_AGF_VERSION 1
  42 #define XFS_AGI_VERSION 1
  43
  44 #define XFS_AGF_GOOD_VERSION(v) ((v) == XFS_AGF_VERSION)
  45 #define XFS_AGI_GOOD_VERSION(v) ((v) == XFS_AGI_VERSION)
  46
  47 /*
  48  * Btree number 0 is bno, 1 is cnt.  This value gives the size of the
  49  * arrays below.
  50  */
  51 #define XFS_BTNUM_AGF   ((int)XFS_BTNUM_CNTi + 1)
  52
  53 /*
  54  * The second word of agf_levels in the first a.g. overlaps the EFS
  55  * superblock's magic number.  Since the magic numbers valid for EFS
  56  * are > 64k, our value cannot be confused for an EFS superblock's.
  57  */
  58
  59 typedef struct xfs_agf {
  60         /*
  61          * Common allocation group header information
  62          */
  63         uint32_t                agf_magicnum;   /* magic number == XFS_AGF_MAGIC */
  64         uint32_t                agf_versionnum; /* header version == XFS_AGF_VERSION */
  65         uint32_t                agf_seqno;      /* sequence # starting from 0 */
  66         uint32_t                agf_length;     /* size in blocks of a.g. */
  67         /*
  68          * Freespace information
  69          */
  70         uint32_t                agf_roots[XFS_BTNUM_AGF];       /* root blocks */
  71         uint32_t                agf_spare0;     /* spare field */
  72         uint32_t                agf_levels[XFS_BTNUM_AGF];      /* btree levels */
  73         uint32_t                agf_spare1;     /* spare field */
  74         uint32_t                agf_flfirst;    /* first freelist block's index */
  75         uint32_t                agf_fllast;     /* last freelist block's index */
  76         uint32_t                agf_flcount;    /* count of blocks in freelist */
  77         uint32_t                agf_freeblks;   /* total free blocks */
  78         uint32_t                agf_longest;    /* longest free space */
  79         uint32_t                agf_btreeblks;  /* # of blocks held in AGF btrees */
  80 } xfs_agf_t;
  81
  82 #define XFS_AGF_MAGICNUM        0x00000001
  83 #define XFS_AGF_VERSIONNUM      0x00000002
  84 #define XFS_AGF_SEQNO           0x00000004
  85 #define XFS_AGF_LENGTH          0x00000008
  86 #define XFS_AGF_ROOTS           0x00000010
  87 #define XFS_AGF_LEVELS          0x00000020
  88 #define XFS_AGF_FLFIRST         0x00000040
  89 #define XFS_AGF_FLLAST          0x00000080
  90 #define XFS_AGF_FLCOUNT         0x00000100
  91 #define XFS_AGF_FREEBLKS        0x00000200
  92 #define XFS_AGF_LONGEST         0x00000400
  93 #define XFS_AGF_BTREEBLKS       0x00000800
  94 #define XFS_AGF_NUM_BITS        12
  95 #define XFS_AGF_ALL_BITS        ((1 << XFS_AGF_NUM_BITS) - 1)
  96
  97 #define XFS_AGF_FLAGS \
  98         { XFS_AGF_MAGICNUM,     "MAGICNUM" }, \
  99         { XFS_AGF_VERSIONNUM,   "VERSIONNUM" }, \
 100         { XFS_AGF_SEQNO,        "SEQNO" }, \
 101         { XFS_AGF_LENGTH,       "LENGTH" }, \
 102         { XFS_AGF_ROOTS,        "ROOTS" }, \
 103         { XFS_AGF_LEVELS,       "LEVELS" }, \
 104         { XFS_AGF_FLFIRST,      "FLFIRST" }, \
 105         { XFS_AGF_FLLAST,       "FLLAST" }, \
 106         { XFS_AGF_FLCOUNT,      "FLCOUNT" }, \
 107         { XFS_AGF_FREEBLKS,     "FREEBLKS" }, \
 108         { XFS_AGF_LONGEST,      "LONGEST" }, \
 109         { XFS_AGF_BTREEBLKS,    "BTREEBLKS" }
 110
 111 /* disk block (xfs_daddr_t) in the AG */
 112 #define XFS_AGF_DADDR(mp)       ((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
 113 #define XFS_AGF_BLOCK(mp)       XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
 114 #define XFS_BUF_TO_AGF(bp)      ((xfs_agf_t *)((bp)->b_addr))
 115
 116 extern int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
 117                         xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
 118
 119 /*
 120  * Size of the unlinked inode hash table in the agi.
 121  */
 122 #define XFS_AGI_UNLINKED_BUCKETS        64
 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 *)((bp)->b_addr))
 142
 143 extern int xfs_read_agi(struct xfs_mount *mp, struct xfs_trans *tp,
 144                                 xfs_agnumber_t agno, struct xfs_buf **bpp);
 145
 146 /*
 147  * The third a.g. block contains the a.g. freelist, an array
 148  * of block pointers to blocks owned by the allocation btree code.
 149  */
 150 #define XFS_AGFL_DADDR(mp)      ((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
 151 #define XFS_AGFL_BLOCK(mp)      XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
 152 #define XFS_AGFL_SIZE(mp)       ((mp)->m_sb.sb_sectsize / sizeof(xfs_agblock_t))
 153 #define XFS_BUF_TO_AGFL(bp)     ((xfs_agfl_t *)((bp)->b_addr))
 154
 155 typedef struct xfs_agfl {
 156         uint32_t                agfl_bno[1];    /* actually XFS_AGFL_SIZE(mp) */
 157 } xfs_agfl_t;
 158
 159 /*
 160  * tags for inode radix tree
 161  */
 162 #define XFS_ICI_NO_TAG          (-1)    /* special flag for an untagged lookup
 163                                            in xfs_inode_ag_iterator */
 164 #define XFS_ICI_RECLAIM_TAG     0       /* inode is to be reclaimed */
 165
 166 #define XFS_AG_MAXLEVELS(mp)            ((mp)->m_ag_maxlevels)
 167 #define XFS_MIN_FREELIST_RAW(bl,cl,mp)  \
 168         (MIN(bl + 1, XFS_AG_MAXLEVELS(mp)) + MIN(cl + 1, XFS_AG_MAXLEVELS(mp)))
 169 #define XFS_MIN_FREELIST(a,mp)          \
 170         (XFS_MIN_FREELIST_RAW(          \
 171                 be32_to_cpu((a)->agf_levels[XFS_BTNUM_BNOi]), \
 172                 be32_to_cpu((a)->agf_levels[XFS_BTNUM_CNTi]), mp))
 173 #define XFS_MIN_FREELIST_PAG(pag,mp)    \
 174         (XFS_MIN_FREELIST_RAW(          \
 175                 (unsigned int)(pag)->pagf_levels[XFS_BTNUM_BNOi], \
 176                 (unsigned int)(pag)->pagf_levels[XFS_BTNUM_CNTi], mp))
 177
 178 /*
 179  * For checking for bad ranges of xfs_daddr_t's, covering multiple
 180  * allocation groups or a single xfs_daddr_t that's a superblock copy.
 181  */
 182 #define XFS_AG_CHECK_DADDR(mp,d,len)    \
 183         ((len) == 1 ? \
 184             ASSERT((d) == XFS_SB_DADDR || \
 185                    xfs_daddr_to_agbno(mp, d) != XFS_SB_DADDR) : \
 186             ASSERT(xfs_daddr_to_agno(mp, d) == \
 187                    xfs_daddr_to_agno(mp, (d) + (len) - 1)))
 188
 189 #endif  /* XFS_AG_H_ */