path: root/fs/xfs/xfs_buf_item.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
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_buf_item.h"
#include "xfs_trans_priv.h"
#include "xfs_error.h"
#include "xfs_trace.h"


kmem_zone_t	*xfs_buf_item_zone;

#ifdef XFS_TRANS_DEBUG
/*
 * This function uses an alternate strategy for tracking the bytes
 * that the user requests to be logged.  This can then be used
 * in conjunction with the bli_orig array in the buf log item to
 * catch bugs in our callers' code.
 *
 * We also double check the bits set in xfs_buf_item_log using a
 * simple algorithm to check that every byte is accounted for.
 */
STATIC void
xfs_buf_item_log_debug(
	xfs_buf_log_item_t	*bip,
	uint			first,
	uint			last)
{
	uint	x;
	uint	byte;
	uint	nbytes;
	uint	chunk_num;
	uint	word_num;
	uint	bit_num;
	uint	bit_set;
	uint	*wordp;

	ASSERT(bip->bli_logged != NULL);
	byte = first;
	nbytes = last - first + 1;
	bfset(bip->bli_logged, first, nbytes);
	for (x = 0; x < nbytes; x++) {
		chunk_num = byte >> XFS_BLI_SHIFT;
		word_num = chunk_num >> BIT_TO_WORD_SHIFT;
		bit_num = chunk_num & (NBWORD - 1);
		wordp = &(bip->bli_format.blf_data_map[word_num]);
		bit_set = *wordp & (1 << bit_num);
		ASSERT(bit_set);
		byte++;
	}
}

/*
 * This function is called when we flush something into a buffer without
 * logging it.  This happens for things like inodes which are logged
 * separately from the buffer.
 */
void
xfs_buf_item_flush_log_debug(
	xfs_buf_t	*bp,
	uint		first,
	uint		last)
{
	xfs_buf_log_item_t	*bip;
	uint			nbytes;

	bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t*);
	if ((bip == NULL) || (bip->bli_item.li_type != XFS_LI_BUF)) {
		return;
	}

	ASSERT(bip->bli_logged != NULL);
	nbytes = last - first + 1;
	bfset(bip->bli_logged, first, nbytes);
}

/*
 * This function is called to verify that our callers have logged
 * all the bytes that they changed.
 *
 * It does this by comparing the original copy of the buffer stored in
 * the buf log item's bli_orig array to the current copy of the buffer
 * and ensuring that all bytes which mismatch are set in the bli_logged
 * array of the buf log item.
 */
STATIC void
xfs_buf_item_log_check(
	xfs_buf_log_item_t	*bip)
{
	char		*orig;
	char		*buffer;
	int		x;
	xfs_buf_t	*bp;

	ASSERT(bip->bli_orig != NULL);
	ASSERT(bip->bli_logged != NULL);

	bp = bip->bli_buf;
	ASSERT(XFS_BUF_COUNT(bp) > 0);
	ASSERT(XFS_BUF_PTR(bp) != NULL);
	orig = bip->bli_orig;
	buffer = XFS_BUF_PTR(bp);
	for (x = 0; x < XFS_BUF_COUNT(bp); x++) {
		if (orig[x] != buffer[x] && !btst(bip->bli_logged, x))
			cmn_err(CE_PANIC,
	"xfs_buf_item_log_check bip %x buffer %x orig %x index %d",
				bip, bp, orig, x);
	}
}
#else
#define		xfs_buf_item_log_debug(x,y,z)
#define		xfs_buf_item_log_check(x)
#endif

STATIC void	xfs_buf_error_relse(xfs_buf_t *bp);
STATIC void	xfs_buf_do_callbacks(xfs_buf_t *bp, xfs_log_item_t *lip);

/*
 * This returns the number of log iovecs needed to