FreeBSD/Linux Kernel Cross Reference
sys/coda/coda_namecache.h

     /*      $NetBSD: coda_namecache.h,v 1.12 2009/03/18 15:14:30 cegger Exp $       */
     
     /*
      *
      *             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.
     *
     *      @(#) coda/coda_namecache.h,v 1.1.1.1 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.
     */
    
    #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)(long)(cp)) \
              & (coda_nc_hashsize-1))
    #else
    #define CODA_NC_HASH(name, namelen, cp) \
            ((name[0] + (name[namelen-1]<<4) + namelen + (((int)(long)cp)>>8)) \
              & (coda_nc_hashsize-1))
    #endif
    
    #define CODA_NAMEMATCH(cp, name, namelen, dcp) \
            ((namelen == cp->namelen) && (dcp == cp->dcp) && \
                     (memcmp(cp->name,name,namelen) == 0))
    
    #define CODA_NC_VALID(cncp)     (cncp->dcp != (struct cnode *)0)
    
    #define DATA_PART(cncp) (&((cncp)->cp))
    #define DATA_SIZE       (sizeof(struct coda_cache) - offsetof(struct coda_cache, cp))
    
    /*
     * Structure for an element in the CODA Name Cache.
     */
    
    struct coda_cache {
            LIST_ENTRY(coda_cache)  hash;           /* Hash list */
            TAILQ_ENTRY(coda_cache) lru;            /* LRU list */
            struct cnode    *cp;                    /* vnode of the file */
            struct cnode    *dcp;                   /* parent's cnode */
            kauth_cred_t    cred;                   /* user credentials */
            char            name[CODA_NC_NAMELEN];  /* segment name */
            int             namelen;                /* length of name */
    };
    
    struct  coda_lru {              /* Start of LRU chain */
           TAILQ_HEAD(,coda_cache) head;
   };
   
   
   struct coda_hash {              /* Start of Hash chain */
           LIST_HEAD(,coda_cache)  head;
           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,
       kauth_cred_t, struct cnode *);
   extern struct cnode *coda_nc_lookup(struct cnode *, const char *, int, 
       kauth_cred_t);
   
   extern void coda_nc_zapParentfid(CodaFid *, enum dc_status);
   extern void coda_nc_zapfid(CodaFid *, enum dc_status);
   extern void coda_nc_zapvnode(CodaFid *, kauth_cred_t, enum dc_status);
   extern void coda_nc_zapfile(struct cnode *, const char *, int);
   extern void coda_nc_purge_user(uid_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 /* _CFSNC_HEADER_ */

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