linux/fs/gfs2/rgrp.h
Steven Whitehouse 6dbd822487 [GFS2] Reduce inode size by moving i_alloc out of line
It is possible to reduce the size of GFS2 inodes by taking the i_alloc
structure out of the gfs2_inode. This patch allocates the i_alloc
structure whenever its needed, and frees it afterward. This decreases
the amount of low memory we use at the expense of requiring a memory
allocation for each page or partial page that we write. A quick test
with postmark shows that the overhead is not measurable and I also note
that OCFS2 use the same approach.

In the future I'd like to solve the problem by shrinking down the size
of the members of the i_alloc structure, but for now, this reduces the
immediate problem of using too much low-memory on x86 and doesn't add
too much overhead.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:18:25 +00:00

73 lines
2.3 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 __RGRP_DOT_H__
#define __RGRP_DOT_H__
struct gfs2_rgrpd;
struct gfs2_sbd;
struct gfs2_holder;
void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd);
struct gfs2_rgrpd *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, u64 blk);
struct gfs2_rgrpd *gfs2_rgrpd_get_first(struct gfs2_sbd *sdp);
struct gfs2_rgrpd *gfs2_rgrpd_get_next(struct gfs2_rgrpd *rgd);
void gfs2_clear_rgrpd(struct gfs2_sbd *sdp);
int gfs2_rindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ri_gh);
int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd);
void gfs2_rgrp_bh_hold(struct gfs2_rgrpd *rgd);
void gfs2_rgrp_bh_put(struct gfs2_rgrpd *rgd);
void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd);
struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip);
static inline void gfs2_alloc_put(struct gfs2_inode *ip)
{
BUG_ON(ip->i_alloc == NULL);
kfree(ip->i_alloc);
ip->i_alloc = NULL;
}
int gfs2_inplace_reserve_i(struct gfs2_inode *ip,
char *file, unsigned int line);
#define gfs2_inplace_reserve(ip) \
gfs2_inplace_reserve_i((ip), __FILE__, __LINE__)
void gfs2_inplace_release(struct gfs2_inode *ip);
unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, u64 block);
u64 gfs2_alloc_data(struct gfs2_inode *ip);
u64 gfs2_alloc_meta(struct gfs2_inode *ip);
u64 gfs2_alloc_di(struct gfs2_inode *ip, u64 *generation);
void gfs2_free_data(struct gfs2_inode *ip, u64 bstart, u32 blen);
void gfs2_free_meta(struct gfs2_inode *ip, u64 bstart, u32 blen);
void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip);
void gfs2_unlink_di(struct inode *inode);
struct gfs2_rgrp_list {
unsigned int rl_rgrps;
unsigned int rl_space;
struct gfs2_rgrpd **rl_rgd;
struct gfs2_holder *rl_ghs;
};
void gfs2_rlist_add(struct gfs2_sbd *sdp, struct gfs2_rgrp_list *rlist,
u64 block);
void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist, unsigned int state,
int flags);
void gfs2_rlist_free(struct gfs2_rgrp_list *rlist);
u64 gfs2_ri_total(struct gfs2_sbd *sdp);
#endif /* __RGRP_DOT_H__ */