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irix-657m-src/irix/kern/sys/dnlc.h
2022-09-29 17:59:04 +03:00

132 lines
4.3 KiB
C

/*
* Directory Name Lookup Cache.
*
* Copyright 1992, Silicon Graphics, Inc.
* All Rights Reserved.
*/
/* Copyright (c) 1990, 1991 UNIX System Laboratories, Inc. */
/* Copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T */
/* All Rights Reserved */
/* THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF */
/* UNIX System Laboratories, Inc. */
/* The copyright notice above does not evidence any */
/* actual or intended publication of such source code. */
/*
* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
* PROPRIETARY NOTICE (Combined)
*
* This source code is unpublished proprietary information
* constituting, or derived under license from AT&T's UNIX(r) System V.
* In addition, portions of such source code were derived from Berkeley
* 4.3 BSD under license from the Regents of the University of
* California.
*
*
*
* Copyright Notice
*
* Notice of copyright on this source code product does not indicate
* publication.
*
* (c) 1986,1987,1988,1989 Sun Microsystems, Inc
* (c) 1983,1984,1985,1986,1987,1988,1989 AT&T.
* All rights reserved.
*
*/
#ifndef _FS_DNLC_H /* wrapper symbol for kernel use */
#define _FS_DNLC_H /* subject to change without notice */
/*#ident "@(#)uts-3b2:fs/dnlc.h 1.4"*/
#ident "$Revision: 1.12 $"
/*
* This structure describes the elements in the cache of recently
* looked up names.
*/
#define NC_NAMLEN 31 /* maximum name segment length we bother with */
struct bhv_desc;
struct cred;
struct vnode;
struct nc_hash_s;
typedef struct ncache_s {
struct ncache_s *hash_next; /* hash chain, MUST BE FIRST */
struct ncache_s **hash_prevp; /* pointer to previous hash_next */
struct ncache_s *lru_next; /* LRU chain */
struct ncache_s *lru_prev;
struct nc_hash_s *hash_chain; /* NULL if not on any */
struct vnode *vp; /* vnode the name refers to */
struct bhv_desc *bdp; /* behavior of the referred vnode */
struct vnode *dp; /* vnode of parent of name */
struct cred *cred; /* credentials */
uint64_t vp_cap; /* vnode pointer capability */
uint64_t dp_cap; /* parent directory capability */
u_char namlen; /* length of name */
char name[NC_NAMLEN]; /* segment name */
off_t offset; /* offset in directory if fast */
} ncache_t;
/*
* Stats on usefulness of name cache.
*/
typedef struct ncstats {
u_int hits; /* hits that we can really use */
u_int misses; /* cache misses */
u_int enters; /* number of enters done */
u_int dbl_enters; /* number of enters tried when already cached */
u_int long_enter; /* long names tried to enter */
u_int long_look; /* long names tried to look up */
u_int lru_empty; /* LRU list empty */
u_int purges; /* number of purges of cache */
u_int vfs_purges; /* number of filesystem purges */
u_int removes; /* number of removals by name */
u_int searches; /* number of hash lookups */
u_int stale_hits; /* hits that found old vnode stamp */
u_int steps; /* hash chain steps for all searches */
u_int neg_enters; /* number of negative entries entered */
u_int neg_hits; /* hits of negative entries */
u_int pad; /* allocated for future expansion */
} ncstats_t;
#define ANYCRED ((struct cred *)(__psint_t)-1)
#define NOCRED ((struct cred *)(__psint_t)0)
#ifdef _KERNEL
/*
* External routines.
*/
struct pathname;
struct vfs;
typedef struct ncfastdata {
char *name; /* name being operated upon */
u_short namlen; /* name length, precomputed by lookuppn */
u_char flags; /* name flags -- see pathname.h */
u_char vnowait; /* lookup failed due to vn_get nowait */
off_t offset; /* offset in directory if invariant */
void *hash; /* hash bucket pointer hint */
} ncfastdata_t;
void dnlc_enter(struct vnode *, char *, struct bhv_desc *,
struct cred *);
void dnlc_enter_fast(struct vnode *, struct ncfastdata *,
struct bhv_desc *, struct cred *);
void dnlc_init(void);
struct bhv_desc *dnlc_lookup(struct vnode *, char *, struct cred *, uint);
struct bhv_desc *dnlc_lookup_fast(struct vnode *, char *, struct pathname *,
struct ncfastdata *, struct cred *, uint);
void dnlc_purge_vp(struct vnode *);
int dnlc_purge_vfsp(struct vfs *, int);
void dnlc_remove(struct vnode *, char *);
void dnlc_remove_fast(struct vnode *, struct ncfastdata *);
void dnlc_remove_vp(struct vnode *);
#endif /* _KERNEL */
#endif /* _FS_DNLC_H */