1 /*
2 *
3 * Coda: an Experimental Distributed File System
4 * Release 3.1
5 *
6 * Copyright (c) 1987-1998 Carnegie Mellon University
7 * All Rights Reserved
8 *
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
16 * derivatives.
17 *
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.
24 *
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.
28 *
29 * @(#) src/sys/coda/coda_namecache.h,v 1.1.1.1 1998/08/29 21:14:52 rvb Exp $
30 * $FreeBSD$
31 *
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)(cp)) & (coda_nc_hashsize-1))
69 #else
70 #define CODA_NC_HASH(name, namelen, cp) \
71 ((name[0] + (name[namelen-1]<<4) + namelen + (((int)cp)>>8)) & (coda_nc_hashsize-1))
72 #endif
73
74 #define CODA_NAMEMATCH(cp, name, namelen, dcp) \
75 ((namelen == cp->namelen) && (dcp == cp->dcp) && \
76 (bcmp(cp->name,name,namelen) == 0))
77
78 /*
79 * Functions to modify the hash and lru chains.
80 * insque and remque assume that the pointers are the first thing
81 * in the list node, thus the trickery for lru.
82 */
83
84 #define CODA_NC_HSHINS(elem, pred) insque(elem,pred)
85 #define CODA_NC_HSHREM(elem) remque(elem)
86 #define CODA_NC_HSHNUL(elem) (elem)->hash_next = \
87 (elem)->hash_prev = (elem)
88
89 #define CODA_NC_LRUINS(elem, pred) insque(LRU_PART(elem), LRU_PART(pred))
90 #define CODA_NC_LRUREM(elem) remque(LRU_PART(elem));
91 #define CODA_NC_LRUGET(lruhead) LRU_TOP((lruhead).lru_prev)
92
93 #define CODA_NC_VALID(cncp) (cncp->dcp != (struct cnode *)0)
94
95 #define LRU_PART(cncp) (struct coda_cache *) \
96 ((char *)cncp + (2*sizeof(struct coda_cache *)))
97 #define LRU_TOP(cncp) (struct coda_cache *) \
98 ((char *)cncp - (2*sizeof(struct coda_cache *)))
99 #define DATA_PART(cncp) (struct coda_cache *) \
100 ((char *)cncp + (4*sizeof(struct coda_cache *)))
101 #define DATA_SIZE (sizeof(struct coda_cache)-(4*sizeof(struct coda_cache *)))
102
103 /*
104 * Structure for an element in the CODA Name Cache.
105 * NOTE: I use the position of arguments and their size in the
106 * implementation of the functions CODA_NC_LRUINS, CODA_NC_LRUREM, and
107 * DATA_PART.
108 */
109
110 struct coda_cache {
111 struct coda_cache *hash_next,*hash_prev; /* Hash list */
112 struct coda_cache *lru_next, *lru_prev; /* LRU list */
113 struct cnode *cp; /* vnode of the file */
114 struct cnode *dcp; /* parent's cnode */
115 struct ucred *cred; /* user credentials */
116 char name[CODA_NC_NAMELEN]; /* segment name */
117 int namelen; /* length of name */
118 };
119
120 struct coda_lru { /* Start of LRU chain */
121 char *dummy1, *dummy2; /* place holders */
122 struct coda_cache *lru_next, *lru_prev; /* position of pointers is important */
123 };
124
125
126 struct coda_hash { /* Start of Hash chain */
127 struct coda_cache *hash_next, *hash_prev; /* NOTE: chain pointers must be first */
128 int length; /* used for tuning purposes */
129 };
130
131
132 /*
133 * Symbols to aid in debugging the namecache code. Assumes the existence
134 * of the variable coda_nc_debug, which is defined in cfs_namecache.c
135 */
136 #define CODA_NC_DEBUG(N, STMT) { if (coda_nc_debug & (1 <<N)) { STMT } }
137
138 /* Prototypes of functions exported within cfs */
139 extern void coda_nc_init(void);
140 extern void coda_nc_enter(struct cnode *, const char *, int, struct ucred *, struct cnode *);
141 extern struct cnode *coda_nc_lookup(struct cnode *, const char *, int, struct ucred *);
142
143 extern void coda_nc_zapParentfid(ViceFid *, enum dc_status);
144 extern void coda_nc_zapfid(ViceFid *, enum dc_status);
145 extern void coda_nc_zapvnode(ViceFid *, struct ucred *, enum dc_status);
146 extern void coda_nc_zapfile(struct cnode *, const char *, int);
147 extern void coda_nc_purge_user(vuid_t, enum dc_status);
148 extern void coda_nc_flush(enum dc_status);
149
150 extern void print_coda_nc(void);
151 extern void coda_nc_gather_stats(void);
152 extern int coda_nc_resize(int, int, enum dc_status);
153 extern void coda_nc_name(struct cnode *cp);
154
155 /*
156 * Structure to contain statistics on the cache usage
157 */
158
159 struct coda_nc_statistics {
160 unsigned hits;
161 unsigned misses;
162 unsigned enters;
163 unsigned dbl_enters;
164 unsigned long_name_enters;
165 unsigned long_name_lookups;
166 unsigned long_remove;
167 unsigned lru_rm;
168 unsigned zapPfids;
169 unsigned zapFids;
170 unsigned zapFile;
171 unsigned zapUsers;
172 unsigned Flushes;
173 unsigned Sum_bucket_len;
174 unsigned Sum2_bucket_len;
175 unsigned Max_bucket_len;
176 unsigned Num_zero_len;
177 unsigned Search_len;
178 };
179
180 #define CODA_NC_FIND ((u_long) 1)
181 #define CODA_NC_REMOVE ((u_long) 2)
182 #define CODA_NC_INIT ((u_long) 3)
183 #define CODA_NC_ENTER ((u_long) 4)
184 #define CODA_NC_LOOKUP ((u_long) 5)
185 #define CODA_NC_ZAPPFID ((u_long) 6)
186 #define CODA_NC_ZAPFID ((u_long) 7)
187 #define CODA_NC_ZAPVNODE ((u_long) 8)
188 #define CODA_NC_ZAPFILE ((u_long) 9)
189 #define CODA_NC_PURGEUSER ((u_long) 10)
190 #define CODA_NC_FLUSH ((u_long) 11)
191 #define CODA_NC_PRINTCODA_NC ((u_long) 12)
192 #define CODA_NC_PRINTSTATS ((u_long) 13)
193
194 #endif
Cache object: e10937dd0e08d2b32f5723b7dad337bd
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