sys/coda/coda_namecache.h

   1 /*      $NetBSD: coda_namecache.h,v 1.11 2007/11/22 22:26:19 plunky 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_ */