alistair23-linux/fs/xfs/xfs_alloc_btree.h
Dave Chinner 1813dd6405 xfs: convert buffer verifiers to an ops structure.
To separate the verifiers from iodone functions and associate read
and write verifiers at the same time, introduce a buffer verifier
operations structure to the xfs_buf.

This avoids the need for assigning the write verifier, clearing the
iodone function and re-running ioend processing in the read
verifier, and gets rid of the nasty "b_pre_io" name for the write
verifier function pointer. If we ever need to, it will also be
easier to add further content specific callbacks to a buffer with an
ops structure in place.

We also avoid needing to export verifier functions, instead we
can simply export the ops structures for those that are needed
outside the function they are defined in.

This patch also fixes a directory block readahead verifier issue
it exposed.

This patch also adds ops callbacks to the inode/alloc btree blocks
initialised by growfs. These will need more work before they will
work with CRCs.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:35:12 -06:00

99 lines
3 KiB
C

/*
* Copyright (c) 2000,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __XFS_ALLOC_BTREE_H__
#define __XFS_ALLOC_BTREE_H__
/*
* Freespace on-disk structures
*/
struct xfs_buf;
struct xfs_btree_cur;
struct xfs_mount;
/*
* There are two on-disk btrees, one sorted by blockno and one sorted
* by blockcount and blockno. All blocks look the same to make the code
* simpler; if we have time later, we'll make the optimizations.
*/
#define XFS_ABTB_MAGIC 0x41425442 /* 'ABTB' for bno tree */
#define XFS_ABTC_MAGIC 0x41425443 /* 'ABTC' for cnt tree */
/*
* Data record/key structure
*/
typedef struct xfs_alloc_rec {
__be32 ar_startblock; /* starting block number */
__be32 ar_blockcount; /* count of free blocks */
} xfs_alloc_rec_t, xfs_alloc_key_t;
typedef struct xfs_alloc_rec_incore {
xfs_agblock_t ar_startblock; /* starting block number */
xfs_extlen_t ar_blockcount; /* count of free blocks */
} xfs_alloc_rec_incore_t;
/* btree pointer type */
typedef __be32 xfs_alloc_ptr_t;
/*
* Block numbers in the AG:
* SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3.
*/
#define XFS_BNO_BLOCK(mp) ((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
#define XFS_CNT_BLOCK(mp) ((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))
/*
* Btree block header size depends on a superblock flag.
*
* (not quite yet, but soon)
*/
#define XFS_ALLOC_BLOCK_LEN(mp) XFS_BTREE_SBLOCK_LEN
/*
* Record, key, and pointer address macros for btree blocks.
*
* (note that some of these may appear unused, but they are used in userspace)
*/
#define XFS_ALLOC_REC_ADDR(mp, block, index) \
((xfs_alloc_rec_t *) \
((char *)(block) + \
XFS_ALLOC_BLOCK_LEN(mp) + \
(((index) - 1) * sizeof(xfs_alloc_rec_t))))
#define XFS_ALLOC_KEY_ADDR(mp, block, index) \
((xfs_alloc_key_t *) \
((char *)(block) + \
XFS_ALLOC_BLOCK_LEN(mp) + \
((index) - 1) * sizeof(xfs_alloc_key_t)))
#define XFS_ALLOC_PTR_ADDR(mp, block, index, maxrecs) \
((xfs_alloc_ptr_t *) \
((char *)(block) + \
XFS_ALLOC_BLOCK_LEN(mp) + \
(maxrecs) * sizeof(xfs_alloc_key_t) + \
((index) - 1) * sizeof(xfs_alloc_ptr_t)))
extern struct xfs_btree_cur *xfs_allocbt_init_cursor(struct xfs_mount *,
struct xfs_trans *, struct xfs_buf *,
xfs_agnumber_t, xfs_btnum_t);
extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int);
extern const struct xfs_buf_ops xfs_allocbt_buf_ops;
#endif /* __XFS_ALLOC_BTREE_H__ */