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/*
*
* 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.
*
* @(#) src/sys/coda/coda_namecache.h,v 1.1.1.1 1998/08/29 21:14:52 rvb Exp $
* $FreeBSD$
*
*/
/*
* 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.
*/
#ifndef _CODA_NC_HEADER_
#define _CODA_NC_HEADER_
/*
* Coda constants
*/
#define CODA_NC_NAMELEN 15 /* longest name stored in cache */
#define CODA_NC_CACHESIZE 256 /* Default cache size */
#define CODA_NC_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 CODA_NC_HASH(name, namelen, cp) \
((name[0] + name[namelen-1] + namelen + (int)(cp)) & (coda_nc_hashsize-1))
#else
#define CODA_NC_HASH(name, namelen, cp) \
((name[0] + (name[namelen-1]<<4) + namelen + (((int)cp)>>8)) & (coda_nc_hashsize-1))
#endif
#define CODA_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 CODA_NC_HSHINS(elem, pred) insque(elem,pred)
#define CODA_NC_HSHREM(elem) remque(elem)
#define CODA_NC_HSHNUL(elem) (elem)->hash_next = \
(elem)->hash_prev = (elem)
#define CODA_NC_LRUINS(elem, pred) insque(LRU_PART(elem), LRU_PART(pred))
#define CODA_NC_LRUREM(elem) remque(LRU_PART(elem));
#define CODA_NC_LRUGET(lruhead) LRU_TOP((lruhead).lru_prev)
#define CODA_NC_VALID(cncp) (cncp->dcp != (struct cnode *)0)
#define LRU_PART(cncp) (struct coda_cache *) \
((char *)cncp + (2*sizeof(struct coda_cache *)))
#define LRU_TOP(cncp) (struct coda_cache *) \
((char *)cncp - (2*sizeof(struct coda_cache *)))
#define DATA_PART(cncp) (struct coda_cache *) \
((char *)cncp + (4*sizeof(struct coda_cache *)))
#define DATA_SIZE (sizeof(struct coda_cache)-(4*sizeof(struct coda_cache *)))
/*
* Structure for an element in the CODA Name Cache.
* NOTE: I use the position of arguments and their size in the
* implementation of the functions CODA_NC_LRUINS, CODA_NC_LRUREM, and
* DATA_PART.
*/
struct coda_cache {
struct coda_cache *hash_next,*hash_prev; /* Hash list */
struct coda_cache *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[CODA_NC_NAMELEN]; /* segment name */
int namelen; /* length of name */
};
struct coda_lru { /* Start of LRU chain */
char *dummy1, *dummy2; /* place holders */
struct coda_cache *lru_next, *lru_prev; /* position of pointers is important */
};
struct coda_hash { /* Start of Hash chain */
struct coda_cache *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 coda_nc_debug, which is defined in cfs_namecache.c
*/
#define CODA_NC_DEBUG(N, STMT) { if (coda_nc_debug & (1 <<N)) { STMT } }
/* Prototypes of functions exported within cfs */
extern void coda_nc_init(void);
extern void coda_nc_enter(struct cnode *, const char *, int, struct ucred *, struct cnode *);
extern struct cnode *coda_nc_lookup(struct cnode *, const char *, int, struct ucred *);
extern void coda_nc_zapParentfid(ViceFid *, enum dc_status);
extern void coda_nc_zapfid(ViceFid *, enum dc_status);
extern void coda_nc_zapvnode(ViceFid *, struct ucred *, enum dc_status);
extern void coda_nc_zapfile(struct cnode *, const char *, int);
extern void coda_nc_purge_user(vuid_t, enum dc_status);
extern void coda_nc_flush(enum dc_status);
extern void print_coda_nc(void);
extern void coda_nc_gather_stats(void);
extern int coda_nc_resize(int, int, enum dc_status);
extern void coda_nc_name(struct cnode *cp);
/*
* Structure to contain statistics on the cache usage
*/
struct coda_nc_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 CODA_NC_FIND ((u_long) 1)
#define CODA_NC_REMOVE ((u_long) 2)
#define CODA_NC_INIT ((u_long) 3)
#define CODA_NC_ENTER ((u_long) 4)
#define CODA_NC_LOOKUP ((u_long) 5)
#define CODA_NC_ZAPPFID ((u_long) 6)
#define CODA_NC_ZAPFID ((u_long) 7)
#define CODA_NC_ZAPVNODE ((u_long) 8)
#define CODA_NC_ZAPFILE ((u_long) 9)
#define CODA_NC_PURGEUSER ((u_long) 10)
#define CODA_NC_FLUSH ((u_long) 11)
#define CODA_NC_PRINTCODA_NC ((u_long) 12)
#define CODA_NC_PRINTSTATS ((u_long) 13)
#endif
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