fs/xfs/xfs_ialloc_btree.h

   1 /*
   2  * Copyright (c) 2000,2005 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_IALLOC_BTREE_H__
  19 #define __XFS_IALLOC_BTREE_H__
  20
  21 /*
  22  * Inode map on-disk structures
  23  */
  24
  25 struct xfs_buf;
  26 struct xfs_btree_cur;
  27 struct xfs_mount;
  28
  29 /*
  30  * There is a btree for the inode map per allocation group.
  31  */
  32 #define XFS_IBT_MAGIC           0x49414254      /* 'IABT' */
  33 #define XFS_IBT_CRC_MAGIC       0x49414233      /* 'IAB3' */
  34
  35 typedef __uint64_t      xfs_inofree_t;
  36 #define XFS_INODES_PER_CHUNK            (NBBY * sizeof(xfs_inofree_t))
  37 #define XFS_INODES_PER_CHUNK_LOG        (XFS_NBBYLOG + 3)
  38 #define XFS_INOBT_ALL_FREE              ((xfs_inofree_t)-1)
  39 #define XFS_INOBT_MASK(i)               ((xfs_inofree_t)1 << (i))
  40
  41 static inline xfs_inofree_t xfs_inobt_maskn(int i, int n)
  42 {
  43         return ((n >= XFS_INODES_PER_CHUNK ? 0 : XFS_INOBT_MASK(n)) - 1) << i;
  44 }
  45
  46 /*
  47  * Data record structure
  48  */
  49 typedef struct xfs_inobt_rec {
  50         __be32          ir_startino;    /* starting inode number */
  51         __be32          ir_freecount;   /* count of free inodes (set bits) */
  52         __be64          ir_free;        /* free inode mask */
  53 } xfs_inobt_rec_t;
  54
  55 typedef struct xfs_inobt_rec_incore {
  56         xfs_agino_t     ir_startino;    /* starting inode number */
  57         __int32_t       ir_freecount;   /* count of free inodes (set bits) */
  58         xfs_inofree_t   ir_free;        /* free inode mask */
  59 } xfs_inobt_rec_incore_t;
  60
  61
  62 /*
  63  * Key structure
  64  */
  65 typedef struct xfs_inobt_key {
  66         __be32          ir_startino;    /* starting inode number */
  67 } xfs_inobt_key_t;
  68
  69 /* btree pointer type */
  70 typedef __be32 xfs_inobt_ptr_t;
  71
  72 /*
  73  * block numbers in the AG.
  74  */
  75 #define XFS_IBT_BLOCK(mp)               ((xfs_agblock_t)(XFS_CNT_BLOCK(mp) + 1))
  76 #define XFS_PREALLOC_BLOCKS(mp)         ((xfs_agblock_t)(XFS_IBT_BLOCK(mp) + 1))
  77
  78 /*
  79  * Btree block header size depends on a superblock flag.
  80  */
  81 #define XFS_INOBT_BLOCK_LEN(mp) \
  82         (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
  83                 XFS_BTREE_SBLOCK_CRC_LEN : XFS_BTREE_SBLOCK_LEN)
  84
  85 /*
  86  * Record, key, and pointer address macros for btree blocks.
  87  *
  88  * (note that some of these may appear unused, but they are used in userspace)
  89  */
  90 #define XFS_INOBT_REC_ADDR(mp, block, index) \
  91         ((xfs_inobt_rec_t *) \
  92                 ((char *)(block) + \
  93                  XFS_INOBT_BLOCK_LEN(mp) + \
  94                  (((index) - 1) * sizeof(xfs_inobt_rec_t))))
  95
  96 #define XFS_INOBT_KEY_ADDR(mp, block, index) \
  97         ((xfs_inobt_key_t *) \
  98                 ((char *)(block) + \
  99                  XFS_INOBT_BLOCK_LEN(mp) + \
 100                  ((index) - 1) * sizeof(xfs_inobt_key_t)))
 101
 102 #define XFS_INOBT_PTR_ADDR(mp, block, index, maxrecs) \
 103         ((xfs_inobt_ptr_t *) \
 104                 ((char *)(block) + \
 105                  XFS_INOBT_BLOCK_LEN(mp) + \
 106                  (maxrecs) * sizeof(xfs_inobt_key_t) + \
 107                  ((index) - 1) * sizeof(xfs_inobt_ptr_t)))
 108
 109 extern struct xfs_btree_cur *xfs_inobt_init_cursor(struct xfs_mount *,
 110                 struct xfs_trans *, struct xfs_buf *, xfs_agnumber_t);
 111 extern int xfs_inobt_maxrecs(struct xfs_mount *, int, int);
 112
 113 extern const struct xfs_buf_ops xfs_inobt_buf_ops;
 114
 115 #endif  /* __XFS_IALLOC_BTREE_H__ */