linux/fs/xfs/xfs_ialloc_btree.h
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   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
  25struct xfs_buf;
  26struct xfs_btree_cur;
  27struct 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
  35typedef __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
  41static 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 */
  49typedef 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
  55typedef 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 */
  65typedef struct xfs_inobt_key {
  66        __be32          ir_startino;    /* starting inode number */
  67} xfs_inobt_key_t;
  68
  69/* btree pointer type */
  70typedef __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
 109extern struct xfs_btree_cur *xfs_inobt_init_cursor(struct xfs_mount *,
 110                struct xfs_trans *, struct xfs_buf *, xfs_agnumber_t);
 111extern int xfs_inobt_maxrecs(struct xfs_mount *, int, int);
 112
 113extern const struct xfs_buf_ops xfs_inobt_buf_ops;
 114
 115#endif  /* __XFS_IALLOC_BTREE_H__ */
 116
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