linux/fs/gfs2/lops.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

116 lines
3.0 KiB
C

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2008 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 __LOPS_DOT_H__
#define __LOPS_DOT_H__
#include <linux/list.h>
#include "incore.h"
#define BUF_OFFSET \
((sizeof(struct gfs2_log_descriptor) + sizeof(__be64) - 1) & \
~(sizeof(__be64) - 1))
#define DATABUF_OFFSET \
((sizeof(struct gfs2_log_descriptor) + (2 * sizeof(__be64) - 1)) & \
~(2 * sizeof(__be64) - 1))
extern const struct gfs2_log_operations gfs2_glock_lops;
extern const struct gfs2_log_operations gfs2_buf_lops;
extern const struct gfs2_log_operations gfs2_revoke_lops;
extern const struct gfs2_log_operations gfs2_rg_lops;
extern const struct gfs2_log_operations gfs2_databuf_lops;
extern const struct gfs2_log_operations *gfs2_log_ops[];
extern void gfs2_log_write_page(struct gfs2_sbd *sdp, struct page *page);
extern void gfs2_log_flush_bio(struct gfs2_sbd *sdp, int rw);
static inline unsigned int buf_limit(struct gfs2_sbd *sdp)
{
unsigned int limit;
limit = (sdp->sd_sb.sb_bsize - BUF_OFFSET) / sizeof(__be64);
return limit;
}
static inline unsigned int databuf_limit(struct gfs2_sbd *sdp)
{
unsigned int limit;
limit = (sdp->sd_sb.sb_bsize - DATABUF_OFFSET) / (2 * sizeof(__be64));
return limit;
}
static inline void lops_init_le(struct gfs2_log_element *le,
const struct gfs2_log_operations *lops)
{
INIT_LIST_HEAD(&le->le_list);
le->le_ops = lops;
}
static inline void lops_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
{
if (le->le_ops->lo_add)
le->le_ops->lo_add(sdp, le);
}
static inline void lops_before_commit(struct gfs2_sbd *sdp)
{
int x;
for (x = 0; gfs2_log_ops[x]; x++)
if (gfs2_log_ops[x]->lo_before_commit)
gfs2_log_ops[x]->lo_before_commit(sdp);
}
static inline void lops_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
{
int x;
for (x = 0; gfs2_log_ops[x]; x++)
if (gfs2_log_ops[x]->lo_after_commit)
gfs2_log_ops[x]->lo_after_commit(sdp, ai);
}
static inline void lops_before_scan(struct gfs2_jdesc *jd,
struct gfs2_log_header_host *head,
unsigned int pass)
{
int x;
for (x = 0; gfs2_log_ops[x]; x++)
if (gfs2_log_ops[x]->lo_before_scan)
gfs2_log_ops[x]->lo_before_scan(jd, head, pass);
}
static inline int lops_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
struct gfs2_log_descriptor *ld,
__be64 *ptr,
unsigned int pass)
{
int x, error;
for (x = 0; gfs2_log_ops[x]; x++)
if (gfs2_log_ops[x]->lo_scan_elements) {
error = gfs2_log_ops[x]->lo_scan_elements(jd, start,
ld, ptr, pass);
if (error)
return error;
}
return 0;
}
static inline void lops_after_scan(struct gfs2_jdesc *jd, int error,
unsigned int pass)
{
int x;
for (x = 0; gfs2_log_ops[x]; x++)
if (gfs2_log_ops[x]->lo_before_scan)
gfs2_log_ops[x]->lo_after_scan(jd, error, pass);
}
#endif /* __LOPS_DOT_H__ */