1/* $NetBSD: coda_namecache.h,v 1.12 2009/03/18 15:14:30 cegger 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 (memcmp(cp->name,name,namelen) == 0))
79
80#define CODA_NC_VALID(cncp) (cncp->dcp != (struct cnode *)0)
81
82#define DATA_PART(cncp) (&((cncp)->cp))
83#define DATA_SIZE (sizeof(struct coda_cache) - offsetof(struct coda_cache, cp))
84
85/*
86 * Structure for an element in the CODA Name Cache.
87 */
88
89struct coda_cache {
90 LIST_ENTRY(coda_cache) hash; /* Hash list */
91 TAILQ_ENTRY(coda_cache) lru; /* LRU list */
92 struct cnode *cp; /* vnode of the file */
93 struct cnode *dcp; /* parent's cnode */
94 kauth_cred_t cred; /* user credentials */
95 char name[CODA_NC_NAMELEN]; /* segment name */
96 int namelen; /* length of name */
97};
98
99struct coda_lru { /* Start of LRU chain */
100 TAILQ_HEAD(,coda_cache) head;
101};
102
103
104struct coda_hash { /* Start of Hash chain */
105 LIST_HEAD(,coda_cache) head;
106 int length; /* used for tuning purposes */
107};
108
109
110/*
111 * Symbols to aid in debugging the namecache code. Assumes the existence
112 * of the variable coda_nc_debug, which is defined in cfs_namecache.c
113 */
114#define CODA_NC_DEBUG(N, STMT) { if (coda_nc_debug & (1 <<N)) { STMT } }
115
116/* Prototypes of functions exported within cfs */
117extern void coda_nc_init(void);
118extern void coda_nc_enter(struct cnode *, const char *, int,
119 kauth_cred_t, struct cnode *);
120extern struct cnode *coda_nc_lookup(struct cnode *, const char *, int,
121 kauth_cred_t);
122
123extern void coda_nc_zapParentfid(CodaFid *, enum dc_status);
124extern void coda_nc_zapfid(CodaFid *, enum dc_status);
125extern void coda_nc_zapvnode(CodaFid *, kauth_cred_t, enum dc_status);
126extern void coda_nc_zapfile(struct cnode *, const char *, int);
127extern void coda_nc_purge_user(uid_t, enum dc_status);
128extern void coda_nc_flush(enum dc_status);
129
130extern void print_coda_nc(void);
131extern void coda_nc_gather_stats(void);
132extern int coda_nc_resize(int, int, enum dc_status);
133extern void coda_nc_name(struct cnode *cp);
134
135/*
136 * Structure to contain statistics on the cache usage
137 */
138
139struct coda_nc_statistics {
140 unsigned hits;
141 unsigned misses;
142 unsigned enters;
143 unsigned dbl_enters;
144 unsigned long_name_enters;
145 unsigned long_name_lookups;
146 unsigned long_remove;
147 unsigned lru_rm;
148 unsigned zapPfids;
149 unsigned zapFids;
150 unsigned zapFile;
151 unsigned zapUsers;
152 unsigned Flushes;
153 unsigned Sum_bucket_len;
154 unsigned Sum2_bucket_len;
155 unsigned Max_bucket_len;
156 unsigned Num_zero_len;
157 unsigned Search_len;
158};
159
160#define CODA_NC_FIND ((u_long) 1)
161#define CODA_NC_REMOVE ((u_long) 2)
162#define CODA_NC_INIT ((u_long) 3)
163#define CODA_NC_ENTER ((u_long) 4)
164#define CODA_NC_LOOKUP ((u_long) 5)
165#define CODA_NC_ZAPPFID ((u_long) 6)
166#define CODA_NC_ZAPFID ((u_long) 7)
167#define CODA_NC_ZAPVNODE ((u_long) 8)
168#define CODA_NC_ZAPFILE ((u_long) 9)
169#define CODA_NC_PURGEUSER ((u_long) 10)
170#define CODA_NC_FLUSH ((u_long) 11)
171#define CODA_NC_PRINTCODA_NC ((u_long) 12)
172#define CODA_NC_PRINTSTATS ((u_long) 13)
173
174#endif /* _CFSNC_HEADER_ */
175