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Diffstat (limited to 'sys/fs/coda/coda_namecache.h')
| -rw-r--r-- | sys/fs/coda/coda_namecache.h | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/sys/fs/coda/coda_namecache.h b/sys/fs/coda/coda_namecache.h new file mode 100644 index 0000000..11f2e80 --- /dev/null +++ b/sys/fs/coda/coda_namecache.h @@ -0,0 +1,194 @@ +/* + * + * 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 |
