xref: /src/sys/coda/coda_namecache.h

/*

            Coda: an Experimental Distributed File System
                             Release 3.1

          Copyright (c) 1987-1998 Carnegie Mellon University
                         All Rights Reserved

Permission  to  use, copy, modify and distribute this software and its
documentation is hereby granted,  provided  that  both  the  copyright
notice  and  this  permission  notice  appear  in  all  copies  of the
software, derivative works or  modified  versions,  and  any  portions
thereof, and that both notices appear in supporting documentation, and
that credit is given to Carnegie Mellon University  in  all  documents
and publicity pertaining to direct or indirect use of this code or its
derivatives.

CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS  KNOWN  TO  HAVE  BUGS,
SOME  OF  WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON ALLOWS
FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION.   CARNEGIE  MELLON
DISCLAIMS  ANY  LIABILITY  OF  ANY  KIND  FOR  ANY  DAMAGES WHATSOEVER
RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE  OR  OF
ANY DERIVATIVE WORK.

Carnegie  Mellon  encourages  users  of  this  software  to return any
improvements or extensions that  they  make,  and  to  grant  Carnegie
Mellon the rights to redistribute these changes without encumbrance.
*/

/* $Header: /tank/opengrok/rsync2/NetBSD/src/sys/coda/coda_namecache.h,v 1.1 1998/08/29 21:26:46 rvb Exp $ */

/*
 * Mach Operating System
 * Copyright (c) 1990 Carnegie-Mellon University
 * Copyright (c) 1989 Carnegie-Mellon University
 * All rights reserved.  The CMU software License Agreement specifies
 * the terms and conditions for use and redistribution.
 */

/*
 * This code was written for the Coda file system at Carnegie Mellon University.
 * Contributers include David Steere, James Kistler, and M. Satyanarayanan.
 */

/*
 * HISTORY
 * $Log: coda_namecache.h,v $
 * Revision 1.1  1998/08/29 21:26:46  rvb
 * Initial revision
 *
 * Revision 1.8  1998/08/28 18:12:25  rvb
 * Now it also works on FreeBSD -current.  This code will be
 * committed to the FreeBSD -current and NetBSD -current
 * trees.  It will then be tailored to the particular platform
 * by flushing conditional code.
 *
 * Revision 1.7  1998/08/18 17:05:24  rvb
 * Don't use __RCSID now
 *
 * Revision 1.6  1998/08/18 16:31:49  rvb
 * Sync the code for NetBSD -current; test on 1.3 later
 *
 * Revision 1.5  98/01/23  11:53:51  rvb
 * Bring RVB_CFS1_1 to HEAD
 *
 * Revision 1.4.2.1  97/12/16  12:40:23  rvb
 * Sync with 1.3
 *
 * Revision 1.4  97/12/05  10:39:29  rvb
 * Read CHANGES
 *
 * Revision 1.3.4.3  97/11/24  15:44:51  rvb
 * Final cfs_venus.c w/o macros, but one locking bug
 *
 * Revision 1.3.4.2  97/11/12  12:09:44  rvb
 * reorg pass1
 *
 * Revision 1.3.4.1  97/11/06  21:06:05  rvb
 * don't include headers in headers
 *
 * Revision 1.3  97/08/05  11:08:19  lily
 * Removed cfsnc_replace, replaced it with a cfs_find, unhash, and
 * rehash.  This fixes a cnode leak and a bug in which the fid is
 * not actually replaced.  (cfs_namecache.c, cfsnc.h, cfs_subr.c)
 *
 * Revision 1.2  96/01/02  16:57:19  bnoble
 * Added support for Coda MiniCache and raw inode calls (final commit)
 *
 * Revision 1.1.2.1  1995/12/20 01:57:45  bnoble
 * Added CFS-specific files
 *
 * Revision 3.1.1.1  1995/03/04  19:08:22  bnoble
 * Branch for NetBSD port revisions
 *
 * Revision 3.1  1995/03/04  19:08:21  bnoble
 * Bump to major revision 3 to prepare for NetBSD port
 *
 * Revision 2.2  1994/08/28  19:37:39  luqi
 * Add a new CFS_REPLACE call to allow venus to replace a ViceFid in the
 * mini-cache.
 *
 * In "cfs.h":
 * Add CFS_REPLACE decl.
 *
 * In "cfs_namecache.c":
 * Add routine cfsnc_replace.
 *
 * In "cfs_subr.c":
 * Add case-statement to process CFS_REPLACE.
 *
 * In "cfsnc.h":
 * Add decl for CFSNC_REPLACE.
 *
 * Revision 2.1  94/07/21  16:25:27  satya
 * Conversion to C++ 3.0; start of Coda Release 2.0
 *
 * Revision 1.2  92/10/27  17:58:34  lily
 * merge kernel/latest and alpha/src/cfs
 *
 * Revision 2.2  90/07/05  11:27:04  mrt
 * 	Created for the Coda File System.
 * 	[90/05/23            dcs]
 *
 * Revision 1.4  90/05/31  17:02:12  dcs
 * Prepare for merge with facilities kernel.
 *
 *
 */
#ifndef _CFSNC_HEADER_
#define _CFSNC_HEADER_

/*
 * Cfs constants
 */
#define CFSNC_NAMELEN	15		/* longest name stored in cache */
#define CFSNC_CACHESIZE 256		/* Default cache size */
#define CFSNC_HASHSIZE	64		/* Must be multiple of 2 */

/*
 * Hash function for the primary hash.
 */

/*
 * First try -- (first + last letters + length + (int)cp) mod size
 * 2nd try -- same, except dir fid.vnode instead of cp
 */

#ifdef	oldhash
#define CFSNC_HASH(name, namelen, cp) \
	((name[0] + name[namelen-1] + namelen + (int)(cp)) & (cfsnc_hashsize-1))
#else
#define CFSNC_HASH(name, namelen, cp) \
	((name[0] + (name[namelen-1]<<4) + namelen + (((int)cp)>>8)) & (cfsnc_hashsize-1))
#endif

#define CFS_NAMEMATCH(cp, name, namelen, dcp) \
	((namelen == cp->namelen) && (dcp == cp->dcp) && \
		 (bcmp(cp->name,name,namelen) == 0))

/*
 * Functions to modify the hash and lru chains.
 * insque and remque assume that the pointers are the first thing
 * in the list node, thus the trickery for lru.
 */

#define CFSNC_HSHINS(elem, pred)	insque(elem,pred)
#define CFSNC_HSHREM(elem)		remque(elem)
#define CFSNC_HSHNUL(elem)		(elem)->hash_next = \
					(elem)->hash_prev = (elem)

#define CFSNC_LRUINS(elem, pred)	insque(LRU_PART(elem), LRU_PART(pred))
#define CFSNC_LRUREM(elem)		remque(LRU_PART(elem));
#define CFSNC_LRUGET(lruhead)		LRU_TOP((lruhead).lru_prev)

#define CFSNC_VALID(cncp)	(cncp->dcp != (struct cnode *)0)

#define LRU_PART(cncp)			(struct cfscache *) \
				((char *)cncp + (2*sizeof(struct cfscache *)))
#define LRU_TOP(cncp)				(struct cfscache *) \
			((char *)cncp - (2*sizeof(struct cfscache *)))
#define DATA_PART(cncp)				(struct cfscache *) \
			((char *)cncp + (4*sizeof(struct cfscache *)))
#define DATA_SIZE	(sizeof(struct cfscache)-(4*sizeof(struct cfscache *)))

/*
 * Structure for an element in the CFS Name Cache.
 * NOTE: I use the position of arguments and their size in the
 * implementation of the functions CFSNC_LRUINS, CFSNC_LRUREM, and
 * DATA_PART.
 */

struct cfscache {
	struct cfscache	*hash_next,*hash_prev;	/* Hash list */
	struct cfscache	*lru_next, *lru_prev;	/* LRU list */
	struct cnode	*cp;			/* vnode of the file */
	struct cnode	*dcp;			/* parent's cnode */
	struct ucred	*cred;			/* user credentials */
	char		name[CFSNC_NAMELEN];	/* segment name */
	int		namelen;		/* length of name */
};

struct	cfslru {		/* Start of LRU chain */
	char *dummy1, *dummy2;			/* place holders */
	struct cfscache *lru_next, *lru_prev;   /* position of pointers is important */
};


struct cfshash {		/* Start of Hash chain */
	struct cfscache *hash_next, *hash_prev; /* NOTE: chain pointers must be first */
        int length;                             /* used for tuning purposes */
};


/*
 * Symbols to aid in debugging the namecache code. Assumes the existence
 * of the variable cfsnc_debug, which is defined in cfs_namecache.c
 */
#define CFSNC_DEBUG(N, STMT)     { if (cfsnc_debug & (1 <<N)) { STMT } }

/* Prototypes of functions exported within cfs */
extern void cfsnc_init(void);
extern void cfsnc_enter(struct cnode *, const char *, int, struct ucred *, struct cnode *);
extern struct cnode *cfsnc_lookup(struct cnode *, const char *, int, struct ucred *);

extern void cfsnc_zapParentfid(ViceFid *, enum dc_status);
extern void cfsnc_zapfid(ViceFid *, enum dc_status);
extern void cfsnc_zapvnode(ViceFid *, struct ucred *, enum dc_status);
extern void cfsnc_zapfile(struct cnode *, const char *, int);
extern void cfsnc_purge_user(vuid_t, enum dc_status);
extern void cfsnc_flush(enum dc_status);

extern void print_cfsnc(void);
extern void cfsnc_gather_stats(void);
extern int  cfsnc_resize(int, int, enum dc_status);
extern void cfsnc_name(struct cnode *cp);

/*
 * Structure to contain statistics on the cache usage
 */

struct cfsnc_statistics {
	unsigned	hits;
	unsigned	misses;
	unsigned	enters;
	unsigned	dbl_enters;
	unsigned	long_name_enters;
	unsigned	long_name_lookups;
	unsigned	long_remove;
	unsigned	lru_rm;
	unsigned	zapPfids;
	unsigned	zapFids;
	unsigned	zapFile;
	unsigned	zapUsers;
	unsigned	Flushes;
	unsigned        Sum_bucket_len;
	unsigned        Sum2_bucket_len;
	unsigned        Max_bucket_len;
	unsigned        Num_zero_len;
	unsigned        Search_len;
};

#define CFSNC_FIND		((u_long) 1)
#define CFSNC_REMOVE		((u_long) 2)
#define CFSNC_INIT		((u_long) 3)
#define CFSNC_ENTER		((u_long) 4)
#define CFSNC_LOOKUP		((u_long) 5)
#define CFSNC_ZAPPFID		((u_long) 6)
#define CFSNC_ZAPFID		((u_long) 7)
#define CFSNC_ZAPVNODE		((u_long) 8)
#define CFSNC_ZAPFILE		((u_long) 9)
#define CFSNC_PURGEUSER		((u_long) 10)
#define CFSNC_FLUSH		((u_long) 11)
#define CFSNC_PRINTCFSNC	((u_long) 12)
#define CFSNC_PRINTSTATS	((u_long) 13)

#endif /* _CFSNC_HEADER_ */