linux/fs/gfs2/rgrp.h
Bob Peterson 8e2e004735 GFS2: Reduce file fragmentation
This patch reduces GFS2 file fragmentation by pre-reserving blocks. The
resulting improved on disk layout greatly speeds up operations in cases
which would have resulted in interlaced allocation of blocks previously.
A typical example of this is 10 parallel dd processes, each writing to a
file in a common dirctory.

The implementation uses an rbtree of reservations attached to each
resource group (and each inode).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-07-19 14:51:08 +01:00

102 lines
3.6 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 __RGRP_DOT_H__
#define __RGRP_DOT_H__
#include <linux/slab.h>
#include <linux/uaccess.h>
/* Since each block in the file system is represented by two bits in the
* bitmap, one 64-bit word in the bitmap will represent 32 blocks.
* By reserving 32 blocks at a time, we can optimize / shortcut how we search
* through the bitmaps by looking a word at a time.
*/
#define RGRP_RSRV_MINBYTES 8
#define RGRP_RSRV_MINBLKS ((u32)(RGRP_RSRV_MINBYTES * GFS2_NBBY))
struct gfs2_rgrpd;
struct gfs2_sbd;
struct gfs2_holder;
extern void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd);
extern struct gfs2_rgrpd *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, u64 blk, bool exact);
extern struct gfs2_rgrpd *gfs2_rgrpd_get_first(struct gfs2_sbd *sdp);
extern struct gfs2_rgrpd *gfs2_rgrpd_get_next(struct gfs2_rgrpd *rgd);
extern void gfs2_clear_rgrpd(struct gfs2_sbd *sdp);
extern int gfs2_rindex_update(struct gfs2_sbd *sdp);
extern void gfs2_free_clones(struct gfs2_rgrpd *rgd);
extern int gfs2_rgrp_go_lock(struct gfs2_holder *gh);
extern void gfs2_rgrp_go_unlock(struct gfs2_holder *gh);
extern struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip);
extern int gfs2_inplace_reserve(struct gfs2_inode *ip, u32 requested);
extern void gfs2_inplace_release(struct gfs2_inode *ip);
extern int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *n,
bool dinode, u64 *generation);
extern int gfs2_rs_alloc(struct gfs2_inode *ip);
extern void gfs2_rs_deltree(struct gfs2_blkreserv *rs);
extern void gfs2_rs_delete(struct gfs2_inode *ip);
extern void __gfs2_free_blocks(struct gfs2_inode *ip, u64 bstart, u32 blen, int meta);
extern void gfs2_free_meta(struct gfs2_inode *ip, u64 bstart, u32 blen);
extern void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip);
extern void gfs2_unlink_di(struct inode *inode);
extern int gfs2_check_blk_type(struct gfs2_sbd *sdp, u64 no_addr,
unsigned int type);
struct gfs2_rgrp_list {
unsigned int rl_rgrps;
unsigned int rl_space;
struct gfs2_rgrpd **rl_rgd;
struct gfs2_holder *rl_ghs;
};
extern void gfs2_rlist_add(struct gfs2_inode *ip, struct gfs2_rgrp_list *rlist,
u64 block);
extern void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist, unsigned int state);
extern void gfs2_rlist_free(struct gfs2_rgrp_list *rlist);
extern u64 gfs2_ri_total(struct gfs2_sbd *sdp);
extern int gfs2_rgrp_dump(struct seq_file *seq, const struct gfs2_glock *gl);
extern int gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
struct buffer_head *bh,
const struct gfs2_bitmap *bi, unsigned minlen, u64 *ptrimmed);
extern int gfs2_fitrim(struct file *filp, void __user *argp);
/* This is how to tell if a multi-block reservation is "inplace" reserved: */
static inline int gfs2_mb_reserved(struct gfs2_inode *ip)
{
if (ip->i_res && ip->i_res->rs_requested)
return 1;
return 0;
}
/* This is how to tell if a multi-block reservation is in the rgrp tree: */
static inline int gfs2_rs_active(struct gfs2_blkreserv *rs)
{
if (rs && rs->rs_bi)
return 1;
return 0;
}
static inline u32 gfs2_bi2rgd_blk(const struct gfs2_bitmap *bi, u32 blk)
{
return (bi->bi_start * GFS2_NBBY) + blk;
}
static inline u64 gfs2_rs_startblk(const struct gfs2_blkreserv *rs)
{
return gfs2_bi2rgd_blk(rs->rs_bi, rs->rs_biblk) + rs->rs_rgd->rd_data0;
}
#endif /* __RGRP_DOT_H__ */