linux/fs/ocfs2/buffer_head_io.h
Joel Becker 970e4936d7 ocfs2: Validate metadata only when it's read from disk.
Add an optional validation hook to ocfs2_read_blocks().  Now the
validation function is only called when a block was actually read off of
disk.  It is not called when the buffer was in cache.

We add a buffer state bit BH_NeedsValidate to flag these buffers.  It
must always be one higher than the last JBD2 buffer state bit.

The dinode, dirblock, extent_block, and xattr_block validators are
lifted to this scheme directly.  The group_descriptor validator needs to
be split into two pieces.  The first part only needs the gd buffer and
is passed to ocfs2_read_block().  The second part requires the dinode as
well, and is called every time.  It's only 3 compares, so it's tiny.
This also allows us to clean up the non-fatal gd check used by resize.c.
It now has no magic argument.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:36:53 -08:00

78 lines
2.4 KiB
C

/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* ocfs2_buffer_head.h
*
* Buffer cache handling functions defined
*
* Copyright (C) 2002, 2004 Oracle. 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; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will 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 to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#ifndef OCFS2_BUFFER_HEAD_IO_H
#define OCFS2_BUFFER_HEAD_IO_H
#include <linux/buffer_head.h>
void ocfs2_end_buffer_io_sync(struct buffer_head *bh,
int uptodate);
int ocfs2_write_block(struct ocfs2_super *osb,
struct buffer_head *bh,
struct inode *inode);
int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
unsigned int nr, struct buffer_head *bhs[]);
/*
* If not NULL, validate() will be called on a buffer that is freshly
* read from disk. It will not be called if the buffer was in cache.
* Note that if validate() is being used for this buffer, it needs to
* be set even for a READAHEAD call, as it marks the buffer for later
* validation.
*/
int ocfs2_read_blocks(struct inode *inode, u64 block, int nr,
struct buffer_head *bhs[], int flags,
int (*validate)(struct super_block *sb,
struct buffer_head *bh));
int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
struct buffer_head *bh);
#define OCFS2_BH_IGNORE_CACHE 1
#define OCFS2_BH_READAHEAD 8
static inline int ocfs2_read_block(struct inode *inode, u64 off,
struct buffer_head **bh,
int (*validate)(struct super_block *sb,
struct buffer_head *bh))
{
int status = 0;
if (bh == NULL) {
printk("ocfs2: bh == NULL\n");
status = -EINVAL;
goto bail;
}
status = ocfs2_read_blocks(inode, off, 1, bh, 0, validate);
bail:
return status;
}
#endif /* OCFS2_BUFFER_HEAD_IO_H */