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linux-next/fs/gfs2/dir.h
Bob Peterson dfe4d34b39 GFS2: Add readahead to sequential directory traversal
This patch adds read-ahead capability to GFS2's
directory hash table management.  It greatly improves
performance for some directory operations.  For example:
In one of my file systems that has 1000 directories, each
of which has 1000 files, time to execute a recursive
ls (time ls -fR /mnt/gfs2 > /dev/null) was reduced
from 2m2.814s on a stock kernel to 0m45.938s.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-08 09:52:12 +00:00

70 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 __DIR_DOT_H__
#define __DIR_DOT_H__
#include <linux/dcache.h>
#include <linux/crc32.h>
struct inode;
struct gfs2_inode;
struct gfs2_inum;
extern struct inode *gfs2_dir_search(struct inode *dir,
const struct qstr *filename);
extern int gfs2_dir_check(struct inode *dir, const struct qstr *filename,
const struct gfs2_inode *ip);
extern int gfs2_dir_add(struct inode *inode, const struct qstr *filename,
const struct gfs2_inode *ip);
extern int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry);
extern int gfs2_dir_read(struct inode *inode, u64 *offset, void *opaque,
filldir_t filldir, struct file_ra_state *f_ra);
extern int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
const struct gfs2_inode *nip, unsigned int new_type);
extern int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip);
extern int gfs2_diradd_alloc_required(struct inode *dir,
const struct qstr *filename);
extern int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
struct buffer_head **bhp);
extern void gfs2_dir_hash_inval(struct gfs2_inode *ip);
static inline u32 gfs2_disk_hash(const char *data, int len)
{
return crc32_le((u32)~0, data, len) ^ (u32)~0;
}
static inline void gfs2_str2qstr(struct qstr *name, const char *fname)
{
name->name = fname;
name->len = strlen(fname);
name->hash = gfs2_disk_hash(name->name, name->len);
}
/* N.B. This probably ought to take inum & type as args as well */
static inline void gfs2_qstr2dirent(const struct qstr *name, u16 reclen, struct gfs2_dirent *dent)
{
dent->de_inum.no_addr = cpu_to_be64(0);
dent->de_inum.no_formal_ino = cpu_to_be64(0);
dent->de_hash = cpu_to_be32(name->hash);
dent->de_rec_len = cpu_to_be16(reclen);
dent->de_name_len = cpu_to_be16(name->len);
dent->de_type = cpu_to_be16(0);
memset(dent->__pad, 0, sizeof(dent->__pad));
memcpy(dent + 1, name->name, name->len);
}
extern struct qstr gfs2_qdot;
extern struct qstr gfs2_qdotdot;
#endif /* __DIR_DOT_H__ */