1 /* $NetBSD: coda_namecache.h,v 1.10 2006/05/14 21:24:49 elad 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 (bcmp(cp->name,name,namelen) == 0))
79
80 /*
81 * Functions to modify the hash and lru chains.
82 * insque and remque assume that the pointers are the first thing
83 * in the list node, thus the trickery for lru.
84 */
85
86 #define CODA_NC_HSHINS(elem, pred) insque(elem,pred)
87 #define CODA_NC_HSHREM(elem) remque(elem)
88 #define CODA_NC_HSHNUL(elem) (elem)->hash_next = \
89 (elem)->hash_prev = (elem)
90
91 #define CODA_NC_LRUINS(elem, pred) insque(LRU_PART(elem), LRU_PART(pred))
92 #define CODA_NC_LRUREM(elem) remque(LRU_PART(elem));
93 #define CODA_NC_LRUGET(lruhead) LRU_TOP((lruhead).lru_prev)
94
95 #define CODA_NC_VALID(cncp) (cncp->dcp != (struct cnode *)0)
96
97 #define LRU_PART(cncp) (struct coda_cache *) \
98 ((char *)cncp + (2*sizeof(struct coda_cache *)))
99 #define LRU_TOP(cncp) (struct coda_cache *) \
100 ((char *)cncp - (2*sizeof(struct coda_cache *)))
101 #define DATA_PART(cncp) (struct coda_cache *) \
102 ((char *)cncp + (4*sizeof(struct coda_cache *)))
103 #define DATA_SIZE (sizeof(struct coda_cache)-(4*sizeof(struct coda_cache *)))
104
105 /*
106 * Structure for an element in the CODA Name Cache.
107 * NOTE: I use the position of arguments and their size in the
108 * implementation of the functions CODA_NC_LRUINS, CODA_NC_LRUREM, and
109 * DATA_PART.
110 */
111
112 struct coda_cache {
113 struct coda_cache *hash_next,*hash_prev; /* Hash list */
114 struct coda_cache *lru_next, *lru_prev; /* LRU list */
115 struct cnode *cp; /* vnode of the file */
116 struct cnode *dcp; /* parent's cnode */
117 kauth_cred_t cred; /* user credentials */
118 char name[CODA_NC_NAMELEN]; /* segment name */
119 int namelen; /* length of name */
120 };
121
122 struct coda_lru { /* Start of LRU chain */
123 char *dummy1, *dummy2; /* place holders */
124 struct coda_cache *lru_next, *lru_prev; /* position of pointers is important */
125 };
126
127
128 struct coda_hash { /* Start of Hash chain */
129 struct coda_cache *hash_next, *hash_prev; /* NOTE: chain pointers must be first */
130 int length; /* used for tuning purposes */
131 };
132
133
134 /*
135 * Symbols to aid in debugging the namecache code. Assumes the existence
136 * of the variable coda_nc_debug, which is defined in cfs_namecache.c
137 */
138 #define CODA_NC_DEBUG(N, STMT) { if (coda_nc_debug & (1 <<N)) { STMT } }
139
140 /* Prototypes of functions exported within cfs */
141 extern void coda_nc_init(void);
142 extern void coda_nc_enter(struct cnode *, const char *, int,
143 kauth_cred_t, struct cnode *);
144 extern struct cnode *coda_nc_lookup(struct cnode *, const char *, int,
145 kauth_cred_t);
146
147 extern void coda_nc_zapParentfid(CodaFid *, enum dc_status);
148 extern void coda_nc_zapfid(CodaFid *, enum dc_status);
149 extern void coda_nc_zapvnode(CodaFid *, kauth_cred_t, enum dc_status);
150 extern void coda_nc_zapfile(struct cnode *, const char *, int);
151 extern void coda_nc_purge_user(uid_t, enum dc_status);
152 extern void coda_nc_flush(enum dc_status);
153
154 extern void print_coda_nc(void);
155 extern void coda_nc_gather_stats(void);
156 extern int coda_nc_resize(int, int, enum dc_status);
157 extern void coda_nc_name(struct cnode *cp);
158
159 /*
160 * Structure to contain statistics on the cache usage
161 */
162
163 struct coda_nc_statistics {
164 unsigned hits;
165 unsigned misses;
166 unsigned enters;
167 unsigned dbl_enters;
168 unsigned long_name_enters;
169 unsigned long_name_lookups;
170 unsigned long_remove;
171 unsigned lru_rm;
172 unsigned zapPfids;
173 unsigned zapFids;
174 unsigned zapFile;
175 unsigned zapUsers;
176 unsigned Flushes;
177 unsigned Sum_bucket_len;
178 unsigned Sum2_bucket_len;
179 unsigned Max_bucket_len;
180 unsigned Num_zero_len;
181 unsigned Search_len;
182 };
183
184 #define CODA_NC_FIND ((u_long) 1)
185 #define CODA_NC_REMOVE ((u_long) 2)
186 #define CODA_NC_INIT ((u_long) 3)
187 #define CODA_NC_ENTER ((u_long) 4)
188 #define CODA_NC_LOOKUP ((u_long) 5)
189 #define CODA_NC_ZAPPFID ((u_long) 6)
190 #define CODA_NC_ZAPFID ((u_long) 7)
191 #define CODA_NC_ZAPVNODE ((u_long) 8)
192 #define CODA_NC_ZAPFILE ((u_long) 9)
193 #define CODA_NC_PURGEUSER ((u_long) 10)
194 #define CODA_NC_FLUSH ((u_long) 11)
195 #define CODA_NC_PRINTCODA_NC ((u_long) 12)
196 #define CODA_NC_PRINTSTATS ((u_long) 13)
197
198 #endif /* _CFSNC_HEADER_ */
Cache object: cc96e66d135abafb9f5db253a7ea34f1
|