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      1 /*	$NetBSD: coda_namecache.h,v 1.12 2009/03/18 15:14:30 cegger Exp $	*/
      2 
      3 /*
      4  *
      5  *             Coda: an Experimental Distributed File System
      6  *                              Release 3.1
      7  *
      8  *           Copyright (c) 1987-1998 Carnegie Mellon University
      9  *                          All Rights Reserved
     10  *
     11  * Permission  to  use, copy, modify and distribute this software and its
     12  * documentation is hereby granted,  provided  that  both  the  copyright
     13  * notice  and  this  permission  notice  appear  in  all  copies  of the
     14  * software, derivative works or  modified  versions,  and  any  portions
     15  * thereof, and that both notices appear in supporting documentation, and
     16  * that credit is given to Carnegie Mellon University  in  all  documents
     17  * and publicity pertaining to direct or indirect use of this code or its
     18  * derivatives.
     19  *
     20  * CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS  KNOWN  TO  HAVE  BUGS,
     21  * SOME  OF  WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON ALLOWS
     22  * FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION.   CARNEGIE  MELLON
     23  * DISCLAIMS  ANY  LIABILITY  OF  ANY  KIND  FOR  ANY  DAMAGES WHATSOEVER
     24  * RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE  OR  OF
     25  * ANY DERIVATIVE WORK.
     26  *
     27  * Carnegie  Mellon  encourages  users  of  this  software  to return any
     28  * improvements or extensions that  they  make,  and  to  grant  Carnegie
     29  * Mellon the rights to redistribute these changes without encumbrance.
     30  *
     31  * 	@(#) coda/coda_namecache.h,v 1.1.1.1 1998/08/29 21:26:46 rvb Exp $
     32  */
     33 
     34 /*
     35  * Mach Operating System
     36  * Copyright (c) 1990 Carnegie-Mellon University
     37  * Copyright (c) 1989 Carnegie-Mellon University
     38  * All rights reserved.  The CMU software License Agreement specifies
     39  * the terms and conditions for use and redistribution.
     40  */
     41 
     42 /*
     43  * This code was written for the Coda file system at Carnegie Mellon University.
     44  * Contributers include David Steere, James Kistler, and M. Satyanarayanan.
     45  */
     46 
     47 #ifndef _CODA_NC_HEADER_
     48 #define _CODA_NC_HEADER_
     49 
     50 /*
     51  * Coda constants
     52  */
     53 #define CODA_NC_NAMELEN		15		/* longest name stored in cache */
     54 #define CODA_NC_CACHESIZE	 256		/* Default cache size */
     55 #define CODA_NC_HASHSIZE	64		/* Must be multiple of 2 */
     56 
     57 /*
     58  * Hash function for the primary hash.
     59  */
     60 
     61 /*
     62  * First try -- (first + last letters + length + (int)cp) mod size
     63  * 2nd try -- same, except dir fid.vnode instead of cp
     64  */
     65 
     66 #ifdef	oldhash
     67 #define CODA_NC_HASH(name, namelen, cp) \
     68 	((name[0] + name[namelen-1] + namelen + (int)(long)(cp)) \
     69 	  & (coda_nc_hashsize-1))
     70 #else
     71 #define CODA_NC_HASH(name, namelen, cp) \
     72 	((name[0] + (name[namelen-1]<<4) + namelen + (((int)(long)cp)>>8)) \
     73 	  & (coda_nc_hashsize-1))
     74 #endif
     75 
     76 #define CODA_NAMEMATCH(cp, name, namelen, dcp) \
     77 	((namelen == cp->namelen) && (dcp == cp->dcp) && \
     78 		 (memcmp(cp->name,name,namelen) == 0))
     79 
     80 #define CODA_NC_VALID(cncp)	(cncp->dcp != (struct cnode *)0)
     81 
     82 #define DATA_PART(cncp)	(&((cncp)->cp))
     83 #define DATA_SIZE	(sizeof(struct coda_cache) - offsetof(struct coda_cache, cp))
     84 
     85 /*
     86  * Structure for an element in the CODA Name Cache.
     87  */
     88 
     89 struct coda_cache {
     90 	LIST_ENTRY(coda_cache)	hash;		/* Hash list */
     91 	TAILQ_ENTRY(coda_cache)	lru;		/* LRU list */
     92 	struct cnode	*cp;			/* vnode of the file */
     93 	struct cnode	*dcp;			/* parent's cnode */
     94 	kauth_cred_t    cred;			/* user credentials */
     95 	char		name[CODA_NC_NAMELEN];	/* segment name */
     96 	int		namelen;		/* length of name */
     97 };
     98 
     99 struct	coda_lru {		/* Start of LRU chain */
    100 	TAILQ_HEAD(,coda_cache)	head;
    101 };
    102 
    103 
    104 struct coda_hash {		/* Start of Hash chain */
    105 	LIST_HEAD(,coda_cache)	head;
    106 	int			length;	/* used for tuning purposes */
    107 };
    108 
    109 
    110 /*
    111  * Symbols to aid in debugging the namecache code. Assumes the existence
    112  * of the variable coda_nc_debug, which is defined in cfs_namecache.c
    113  */
    114 #define CODA_NC_DEBUG(N, STMT)     { if (coda_nc_debug & (1 <<N)) { STMT } }
    115 
    116 /* Prototypes of functions exported within cfs */
    117 extern void coda_nc_init(void);
    118 extern void coda_nc_enter(struct cnode *, const char *, int,
    119     kauth_cred_t, struct cnode *);
    120 extern struct cnode *coda_nc_lookup(struct cnode *, const char *, int,
    121     kauth_cred_t);
    122 
    123 extern void coda_nc_zapParentfid(CodaFid *, enum dc_status);
    124 extern void coda_nc_zapfid(CodaFid *, enum dc_status);
    125 extern void coda_nc_zapvnode(CodaFid *, kauth_cred_t, enum dc_status);
    126 extern void coda_nc_zapfile(struct cnode *, const char *, int);
    127 extern void coda_nc_purge_user(uid_t, enum dc_status);
    128 extern void coda_nc_flush(enum dc_status);
    129 
    130 extern void print_coda_nc(void);
    131 extern void coda_nc_gather_stats(void);
    132 extern int  coda_nc_resize(int, int, enum dc_status);
    133 extern void coda_nc_name(struct cnode *cp);
    134 
    135 /*
    136  * Structure to contain statistics on the cache usage
    137  */
    138 
    139 struct coda_nc_statistics {
    140 	unsigned	hits;
    141 	unsigned	misses;
    142 	unsigned	enters;
    143 	unsigned	dbl_enters;
    144 	unsigned	long_name_enters;
    145 	unsigned	long_name_lookups;
    146 	unsigned	long_remove;
    147 	unsigned	lru_rm;
    148 	unsigned	zapPfids;
    149 	unsigned	zapFids;
    150 	unsigned	zapFile;
    151 	unsigned	zapUsers;
    152 	unsigned	Flushes;
    153 	unsigned        Sum_bucket_len;
    154 	unsigned        Sum2_bucket_len;
    155 	unsigned        Max_bucket_len;
    156 	unsigned        Num_zero_len;
    157 	unsigned        Search_len;
    158 };
    159 
    160 #define CODA_NC_FIND		((u_long) 1)
    161 #define CODA_NC_REMOVE		((u_long) 2)
    162 #define CODA_NC_INIT		((u_long) 3)
    163 #define CODA_NC_ENTER		((u_long) 4)
    164 #define CODA_NC_LOOKUP		((u_long) 5)
    165 #define CODA_NC_ZAPPFID		((u_long) 6)
    166 #define CODA_NC_ZAPFID		((u_long) 7)
    167 #define CODA_NC_ZAPVNODE		((u_long) 8)
    168 #define CODA_NC_ZAPFILE		((u_long) 9)
    169 #define CODA_NC_PURGEUSER		((u_long) 10)
    170 #define CODA_NC_FLUSH		((u_long) 11)
    171 #define CODA_NC_PRINTCODA_NC	((u_long) 12)
    172 #define CODA_NC_PRINTSTATS	((u_long) 13)
    173 
    174 #endif /* _CFSNC_HEADER_ */
    175