alistair23-linux/fs/gfs2/log.h
Steven Whitehouse e8c92ed769 GFS2: Clean up log write code path
Prior to this patch, we have two ways of sending i/o to the log.
One of those is used when we need to allocate both the data
to be written itself and also a buffer head to submit it. This
is done via sb_getblk and friends. This is used mostly for writing
log headers.

The other method is used when writing blocks which have some
in-place counterpart. This is the case for all the metadata
blocks which are journalled, and when journaled data is in use,
for unescaped journalled data blocks.

This patch replaces both of those two methods, and about half
a dozen separate i/o submission points with a single i/o
submission function. We also go direct to bio rather than
using buffer heads, since this allows us to build i/o
requests of the maximum size for the block device in
question. It also reduces the memory required for flushing
the log, which can be very useful in low memory situations.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-04-24 16:44:34 +01:00

65 lines
1.7 KiB
C

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License version 2.
*/
#ifndef __LOG_DOT_H__
#define __LOG_DOT_H__
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/writeback.h>
#include "incore.h"
/**
* gfs2_log_lock - acquire the right to mess with the log manager
* @sdp: the filesystem
*
*/
static inline void gfs2_log_lock(struct gfs2_sbd *sdp)
__acquires(&sdp->sd_log_lock)
{
spin_lock(&sdp->sd_log_lock);
}
/**
* gfs2_log_unlock - release the right to mess with the log manager
* @sdp: the filesystem
*
*/
static inline void gfs2_log_unlock(struct gfs2_sbd *sdp)
__releases(&sdp->sd_log_lock)
{
spin_unlock(&sdp->sd_log_lock);
}
static inline void gfs2_log_pointers_init(struct gfs2_sbd *sdp,
unsigned int value)
{
if (++value == sdp->sd_jdesc->jd_blocks) {
value = 0;
}
sdp->sd_log_head = sdp->sd_log_tail = value;
}
extern unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
unsigned int ssize);
extern int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks);
extern void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl);
extern void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *trans);
extern void gfs2_remove_from_ail(struct gfs2_bufdata *bd);
extern void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc);
extern void gfs2_log_shutdown(struct gfs2_sbd *sdp);
extern void gfs2_meta_syncfs(struct gfs2_sbd *sdp);
extern int gfs2_logd(void *data);
#endif /* __LOG_DOT_H__ */