1/*	$NetBSD: coda_namecache.h,v 1.11 2007/11/22 22:26:19 plunky 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