fs/xfs/xfs_alloc_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_ALLOC_BTREE_H__
  19 #define __XFS_ALLOC_BTREE_H__
  20
  21 /*
  22  * Freespace on-disk structures
  23  */
  24
  25 struct xfs_buf;
  26 struct xfs_btree_cur;
  27 struct xfs_mount;
  28
  29 /*
  30  * Btree block header size depends on a superblock flag.
  31  */
  32 #define XFS_ALLOC_BLOCK_LEN(mp) \
  33         (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
  34                 XFS_BTREE_SBLOCK_CRC_LEN : XFS_BTREE_SBLOCK_LEN)
  35
  36 /*
  37  * Record, key, and pointer address macros for btree blocks.
  38  *
  39  * (note that some of these may appear unused, but they are used in userspace)
  40  */
  41 #define XFS_ALLOC_REC_ADDR(mp, block, index) \
  42         ((xfs_alloc_rec_t *) \
  43                 ((char *)(block) + \
  44                  XFS_ALLOC_BLOCK_LEN(mp) + \
  45                  (((index) - 1) * sizeof(xfs_alloc_rec_t))))
  46
  47 #define XFS_ALLOC_KEY_ADDR(mp, block, index) \
  48         ((xfs_alloc_key_t *) \
  49                 ((char *)(block) + \
  50                  XFS_ALLOC_BLOCK_LEN(mp) + \
  51                  ((index) - 1) * sizeof(xfs_alloc_key_t)))
  52
  53 #define XFS_ALLOC_PTR_ADDR(mp, block, index, maxrecs) \
  54         ((xfs_alloc_ptr_t *) \
  55                 ((char *)(block) + \
  56                  XFS_ALLOC_BLOCK_LEN(mp) + \
  57                  (maxrecs) * sizeof(xfs_alloc_key_t) + \
  58                  ((index) - 1) * sizeof(xfs_alloc_ptr_t)))
  59
  60 extern struct xfs_btree_cur *xfs_allocbt_init_cursor(struct xfs_mount *,
  61                 struct xfs_trans *, struct xfs_buf *,
  62                 xfs_agnumber_t, xfs_btnum_t);
  63 extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int);
  64
  65 #endif  /* __XFS_ALLOC_BTREE_H__ */