3 * Coda: an Experimental Distributed File System
6 * Copyright (c) 1987-1998 Carnegie Mellon University
9 * Permission to use, copy, modify and distribute this software and its
10 * documentation is hereby granted, provided that both the copyright
11 * notice and this permission notice appear in all copies of the
12 * software, derivative works or modified versions, and any portions
13 * thereof, and that both notices appear in supporting documentation, and
14 * that credit is given to Carnegie Mellon University in all documents
15 * and publicity pertaining to direct or indirect use of this code or its
18 * CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS KNOWN TO HAVE BUGS,
19 * SOME OF WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON ALLOWS
20 * FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION. CARNEGIE MELLON
21 * DISCLAIMS ANY LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER
22 * RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE OR OF
23 * ANY DERIVATIVE WORK.
25 * Carnegie Mellon encourages users of this software to return any
26 * improvements or extensions that they make, and to grant Carnegie
27 * Mellon the rights to redistribute these changes without encumbrance.
29 * @(#) src/sys/coda/coda_namecache.h,v 1.1.1.1 1998/08/29 21:14:52 rvb Exp $
30 * $FreeBSD: src/sys/coda/coda_namecache.h,v 1.6 1999/08/28 00:40:53 peter Exp $
31 * $DragonFly: src/sys/vfs/coda/Attic/coda_namecache.h,v 1.2 2003/06/17 04:28:19 dillon Exp $
36 * Mach Operating System
37 * Copyright (c) 1990 Carnegie-Mellon University
38 * Copyright (c) 1989 Carnegie-Mellon University
39 * All rights reserved. The CMU software License Agreement specifies
40 * the terms and conditions for use and redistribution.
44 * This code was written for the Coda file system at Carnegie Mellon University.
45 * Contributers include David Steere, James Kistler, and M. Satyanarayanan.
48 #ifndef _CODA_NC_HEADER_
49 #define _CODA_NC_HEADER_
54 #define CODA_NC_NAMELEN 15 /* longest name stored in cache */
55 #define CODA_NC_CACHESIZE 256 /* Default cache size */
56 #define CODA_NC_HASHSIZE 64 /* Must be multiple of 2 */
59 * Hash function for the primary hash.
63 * First try -- (first + last letters + length + (int)cp) mod size
64 * 2nd try -- same, except dir fid.vnode instead of cp
68 #define CODA_NC_HASH(name, namelen, cp) \
69 ((name[0] + name[namelen-1] + namelen + (int)(cp)) & (coda_nc_hashsize-1))
71 #define CODA_NC_HASH(name, namelen, cp) \
72 ((name[0] + (name[namelen-1]<<4) + namelen + (((int)cp)>>8)) & (coda_nc_hashsize-1))
75 #define CODA_NAMEMATCH(cp, name, namelen, dcp) \
76 ((namelen == cp->namelen) && (dcp == cp->dcp) && \
77 (bcmp(cp->name,name,namelen) == 0))
80 * Functions to modify the hash and lru chains.
81 * insque and remque assume that the pointers are the first thing
82 * in the list node, thus the trickery for lru.
85 #define CODA_NC_HSHINS(elem, pred) insque(elem,pred)
86 #define CODA_NC_HSHREM(elem) remque(elem)
87 #define CODA_NC_HSHNUL(elem) (elem)->hash_next = \
88 (elem)->hash_prev = (elem)
90 #define CODA_NC_LRUINS(elem, pred) insque(LRU_PART(elem), LRU_PART(pred))
91 #define CODA_NC_LRUREM(elem) remque(LRU_PART(elem));
92 #define CODA_NC_LRUGET(lruhead) LRU_TOP((lruhead).lru_prev)
94 #define CODA_NC_VALID(cncp) (cncp->dcp != (struct cnode *)0)
96 #define LRU_PART(cncp) (struct coda_cache *) \
97 ((char *)cncp + (2*sizeof(struct coda_cache *)))
98 #define LRU_TOP(cncp) (struct coda_cache *) \
99 ((char *)cncp - (2*sizeof(struct coda_cache *)))
100 #define DATA_PART(cncp) (struct coda_cache *) \
101 ((char *)cncp + (4*sizeof(struct coda_cache *)))
102 #define DATA_SIZE (sizeof(struct coda_cache)-(4*sizeof(struct coda_cache *)))
105 * Structure for an element in the CODA Name Cache.
106 * NOTE: I use the position of arguments and their size in the
107 * implementation of the functions CODA_NC_LRUINS, CODA_NC_LRUREM, and
112 struct coda_cache *hash_next,*hash_prev; /* Hash list */
113 struct coda_cache *lru_next, *lru_prev; /* LRU list */
114 struct cnode *cp; /* vnode of the file */
115 struct cnode *dcp; /* parent's cnode */
116 struct ucred *cred; /* user credentials */
117 char name[CODA_NC_NAMELEN]; /* segment name */
118 int namelen; /* length of name */
121 struct coda_lru { /* Start of LRU chain */
122 char *dummy1, *dummy2; /* place holders */
123 struct coda_cache *lru_next, *lru_prev; /* position of pointers is important */
127 struct coda_hash { /* Start of Hash chain */
128 struct coda_cache *hash_next, *hash_prev; /* NOTE: chain pointers must be first */
129 int length; /* used for tuning purposes */
134 * Symbols to aid in debugging the namecache code. Assumes the existence
135 * of the variable coda_nc_debug, which is defined in cfs_namecache.c
137 #define CODA_NC_DEBUG(N, STMT) { if (coda_nc_debug & (1 <<N)) { STMT } }
139 /* Prototypes of functions exported within cfs */
140 extern void coda_nc_init(void);
141 extern void coda_nc_enter(struct cnode *, const char *, int, struct ucred *, struct cnode *);
142 extern struct cnode *coda_nc_lookup(struct cnode *, const char *, int, struct ucred *);
144 extern void coda_nc_zapParentfid(ViceFid *, enum dc_status);
145 extern void coda_nc_zapfid(ViceFid *, enum dc_status);
146 extern void coda_nc_zapvnode(ViceFid *, struct ucred *, enum dc_status);
147 extern void coda_nc_zapfile(struct cnode *, const char *, int);
148 extern void coda_nc_purge_user(vuid_t, enum dc_status);
149 extern void coda_nc_flush(enum dc_status);
151 extern void print_coda_nc(void);
152 extern void coda_nc_gather_stats(void);
153 extern int coda_nc_resize(int, int, enum dc_status);
154 extern void coda_nc_name(struct cnode *cp);
157 * Structure to contain statistics on the cache usage
160 struct coda_nc_statistics {
165 unsigned long_name_enters;
166 unsigned long_name_lookups;
167 unsigned long_remove;
174 unsigned Sum_bucket_len;
175 unsigned Sum2_bucket_len;
176 unsigned Max_bucket_len;
177 unsigned Num_zero_len;
181 #define CODA_NC_FIND ((u_long) 1)
182 #define CODA_NC_REMOVE ((u_long) 2)
183 #define CODA_NC_INIT ((u_long) 3)
184 #define CODA_NC_ENTER ((u_long) 4)
185 #define CODA_NC_LOOKUP ((u_long) 5)
186 #define CODA_NC_ZAPPFID ((u_long) 6)
187 #define CODA_NC_ZAPFID ((u_long) 7)
188 #define CODA_NC_ZAPVNODE ((u_long) 8)
189 #define CODA_NC_ZAPFILE ((u_long) 9)
190 #define CODA_NC_PURGEUSER ((u_long) 10)
191 #define CODA_NC_FLUSH ((u_long) 11)
192 #define CODA_NC_PRINTCODA_NC ((u_long) 12)
193 #define CODA_NC_PRINTSTATS ((u_long) 13)