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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 filesystem 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
*/
#define CODA_NC_HASH(name, namelen, cp) \
((name[0] + (name[namelen-1]<<4) + namelen + \
(((int)(intptr_t)cp)>>8)) & (coda_nc_hashsize-1))
#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 */
};
/*
* Start of an LRU chain -- notice position of pointers.
*/
struct coda_lru {
char *dummy1, *dummy2;
struct coda_cache *lru_next, *lru_prev;
};
/*
* Start of Hash chain -- notice position of pointers -- chain pointers must
* be first.
*/
struct coda_hash {
struct coda_cache *hash_next, *hash_prev;
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) do { \
if (coda_nc_debug & (1 << N)) { \
STMT \
} \
} while (0)
/*
* Prototypes of functions exported within cfs.
*/
void coda_nc_init(void);
void coda_nc_enter(struct cnode *, const char *, int, struct ucred *,
struct cnode *);
struct cnode *coda_nc_lookup(struct cnode *, const char *, int,
struct ucred *);
void coda_nc_zapParentfid(CodaFid *, enum dc_status);
void coda_nc_zapfid(CodaFid *, enum dc_status);
void coda_nc_zapvnode(CodaFid *, struct ucred *, enum dc_status);
void coda_nc_zapfile(struct cnode *, const char *, int);
void coda_nc_purge_user(uid_t, enum dc_status);
void coda_nc_flush(enum dc_status);
void print_coda_nc(void);
void coda_nc_gather_stats(void);
int coda_nc_resize(int, int, enum dc_status);
void coda_nc_name(struct cnode *cp);
/*
* Global variables tracking and controlling Coda namecache operation.
*/
extern int coda_nc_debug; /* Set to enable debugging printfs */
extern int coda_nc_initialized; /* Set if cache has been initialized */
extern int coda_nc_use; /* Indicate use of CODA Name Cache */
/*
* Structure to contain statistics on the cache usage.
*/
struct coda_nc_statistics {
u_int hits;
u_int misses;
u_int enters;
u_int dbl_enters;
u_int long_name_enters;
u_int long_name_lookups;
u_int long_remove;
u_int lru_rm;
u_int zapPfids;
u_int zapFids;
u_int zapFile;
u_int zapUsers;
u_int Flushes;
u_int Sum_bucket_len;
u_int Sum2_bucket_len;
u_int Max_bucket_len;
u_int Num_zero_len;
u_int 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 /* !_CODA_NC_HEADER_ */
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