File: [cvs.NetBSD.org] / src / sys / sys / namei.src (download)
Revision 1.8.4.2, Sat Jul 18 14:53:27 2009 UTC (14 years, 9 months ago) by yamt
Branch: yamt-nfs-mp
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/* $NetBSD: namei.src,v 1.8.4.2 2009/07/18 14:53:27 yamt Exp $ */
/*
* Copyright (c) 1985, 1989, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)namei.h 8.5 (Berkeley) 8/20/94
*/
#ifndef _SYS_NAMEI_H_
#define _SYS_NAMEI_H_
#include <sys/queue.h>
#include <sys/mutex.h>
#ifdef _KERNEL
#include <sys/kauth.h>
/*
* Encapsulation of namei parameters.
*/
struct nameidata {
/*
* Arguments to namei/lookup.
*/
const char *ni_dirp; /* pathname pointer */
enum uio_seg ni_segflg; /* location of pathname */
/*
* Arguments to lookup.
*/
struct vnode *ni_startdir; /* starting directory */
struct vnode *ni_rootdir; /* logical root directory */
struct vnode *ni_erootdir; /* emulation root directory */
/*
* Results: returned from/manipulated by lookup
*/
struct vnode *ni_vp; /* vnode of result */
struct vnode *ni_dvp; /* vnode of intermediate directory */
/*
* Shared between namei and lookup/commit routines.
*/
size_t ni_pathlen; /* remaining chars in path */
const char *ni_next; /* next location in pathname */
unsigned int ni_loopcnt; /* count of symlinks encountered */
/*
* Lookup parameters: this structure describes the subset of
* information from the nameidata structure that is passed
* through the VOP interface.
*/
struct componentname {
/*
* Arguments to lookup.
*/
uint32_t cn_nameiop; /* namei operation */
uint32_t cn_flags; /* flags to namei */
kauth_cred_t cn_cred; /* credentials */
/*
* Shared between lookup and commit routines.
*/
char *cn_pnbuf; /* pathname buffer */
const char *cn_nameptr; /* pointer to looked up name */
size_t cn_namelen; /* length of looked up comp */
u_long cn_hash; /* hash val of looked up name */
size_t cn_consume; /* chars to consume in lookup */
} ni_cnd;
};
/*
* namei operations
*/
NAMEIFL LOOKUP 0 /* perform name lookup only */
NAMEIFL CREATE 1 /* setup for file creation */
NAMEIFL DELETE 2 /* setup for file deletion */
NAMEIFL RENAME 3 /* setup for file renaming */
NAMEIFL OPMASK 3 /* mask for operation */
/*
* namei operational modifier flags, stored in ni_cnd.cn_flags
*/
NAMEIFL LOCKLEAF 0x00000004 /* lock inode on return */
NAMEIFL LOCKPARENT 0x00000008 /* want parent vnode returned locked */
NAMEIFL TRYEMULROOT 0x00000010 /* try relative to emulation root
first */
NAMEIFL NOCACHE 0x00000020 /* name must not be left in cache */
NAMEIFL FOLLOW 0x00000040 /* follow symbolic links */
NAMEIFL NOFOLLOW 0x00000000 /* do not follow symbolic links
(pseudo) */
NAMEIFL EMULROOTSET 0x00000080 /* emulation root already
in ni_erootdir */
NAMEIFL NOCHROOT 0x01000000 /* no chroot on abs path lookups */
NAMEIFL MODMASK 0x010000fc /* mask of operational modifiers */
/*
* Namei parameter descriptors.
*
* SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
* If the caller of namei sets the flag (for example execve wants to
* know the name of the program that is being executed), then it must
* free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
* be freed by either the commit routine or the VOP_ABORT routine.
* SAVESTART is set only by the callers of namei. It implies SAVENAME
* plus the addition of saving the parent directory that contains the
* name in ni_startdir. It allows repeated calls to lookup for the
* name being sought. The caller is responsible for releasing the
* buffer and for vrele'ing ni_startdir.
*/
NAMEIFL NOCROSSMOUNT 0x0000100 /* do not cross mount points */
NAMEIFL RDONLY 0x0000200 /* lookup with read-only semantics */
NAMEIFL HASBUF 0x0000400 /* has allocated pathname buffer */
NAMEIFL SAVENAME 0x0000800 /* save pathname buffer */
NAMEIFL SAVESTART 0x0001000 /* save starting directory */
NAMEIFL ISDOTDOT 0x0002000 /* current component name is .. */
NAMEIFL MAKEENTRY 0x0004000 /* entry is to be added to name cache */
NAMEIFL ISLASTCN 0x0008000 /* this is last component of pathname */
NAMEIFL ISSYMLINK 0x0010000 /* symlink needs interpretation */
NAMEIFL ISWHITEOUT 0x0020000 /* found whiteout */
NAMEIFL DOWHITEOUT 0x0040000 /* do whiteouts */
NAMEIFL REQUIREDIR 0x0080000 /* must be a directory */
NAMEIFL CREATEDIR 0x0200000 /* trailing slashes are ok */
NAMEIFL PARAMASK 0x02fff00 /* mask of parameter descriptors */
/*
* Initialization of an nameidata structure.
*/
#define NDINIT(ndp, op, flags, segflg, namep) { \
(ndp)->ni_cnd.cn_nameiop = op; \
(ndp)->ni_cnd.cn_flags = flags; \
(ndp)->ni_segflg = segflg; \
(ndp)->ni_dirp = namep; \
(ndp)->ni_cnd.cn_cred = kauth_cred_get(); \
}
#endif
/*
* This structure describes the elements in the cache of recent
* names looked up by namei. NCHNAMLEN is sized to make structure
* size a power of two to optimize malloc's. Minimum reasonable
* size is 15.
*/
#define NCHNAMLEN 31 /* maximum name segment length we bother with */
/*
* Namecache entry. This structure is arranged so that frequently
* accessed and mostly read-only data is toward the front, with
* infrequently accessed data and the lock towards the rear. The
* lock is then more likely to be in a seperate cache line.
*/
struct namecache {
LIST_ENTRY(namecache) nc_hash; /* hash chain */
LIST_ENTRY(namecache) nc_vhash; /* directory hash chain */
struct vnode *nc_dvp; /* vnode of parent of name */
struct vnode *nc_vp; /* vnode the name refers to */
int nc_flags; /* copy of componentname's ISWHITEOUT */
char nc_nlen; /* length of name */
char nc_name[NCHNAMLEN]; /* segment name */
void *nc_gcqueue; /* queue for garbage collection */
TAILQ_ENTRY(namecache) nc_lru; /* psuedo-lru chain */
LIST_ENTRY(namecache) nc_dvlist;
LIST_ENTRY(namecache) nc_vlist;
kmutex_t nc_lock; /* lock on this entry */
int nc_hittime; /* last time scored a hit */
};
#ifdef _KERNEL
#include <sys/mallocvar.h>
#include <sys/pool.h>
struct mount;
struct cpu_info;
extern pool_cache_t pnbuf_cache; /* pathname buffer cache */
#define PNBUF_GET() pool_cache_get(pnbuf_cache, PR_WAITOK)
#define PNBUF_PUT(pnb) pool_cache_put(pnbuf_cache, (pnb))
/*
* Typesafe flags for namei_simple.
*
* This encoding is not optimal but serves the important purpose of
* not being type-compatible with the regular namei flags.
*/
struct namei_simple_flags_type; /* Opaque. */
typedef const struct namei_simple_flags_type *namei_simple_flags_t; /* Gross. */
extern const namei_simple_flags_t
NSM_NOFOLLOW_NOEMULROOT,
NSM_NOFOLLOW_TRYEMULROOT,
NSM_FOLLOW_NOEMULROOT,
NSM_FOLLOW_TRYEMULROOT;
/*
* namei_simple_* - the simple cases of namei, with no struct
* nameidata involved.
*
* namei_simple_kernel takes a kernel-space path as the first argument.
* namei_simple_user takes a user-space path as the first argument.
*
* A namei call can be converted to namei_simple_* if:
* - the second arg to NDINIT is LOOKUP;
* - it does not need the parent vnode, nd.ni_dvp;
* - the only flags it uses are (NO)FOLLOW and TRYEMULROOT;
* - it does not do anything else gross with the contents of nd.
*/
int namei_simple_kernel(const char *, namei_simple_flags_t, struct vnode **);
int namei_simple_user(const char *, namei_simple_flags_t, struct vnode **);
int namei(struct nameidata *);
uint32_t namei_hash(const char *, const char **);
int lookup(struct nameidata *);
int relookup(struct vnode *, struct vnode **, struct componentname *);
void cache_purge1(struct vnode *, const struct componentname *, int);
#define PURGE_PARENTS 1
#define PURGE_CHILDREN 2
#define cache_purge(vp) cache_purge1((vp), NULL, PURGE_PARENTS|PURGE_CHILDREN)
int cache_lookup(struct vnode *, struct vnode **, struct componentname *);
int cache_lookup_raw(struct vnode *, struct vnode **,
struct componentname *);
int cache_revlookup(struct vnode *, struct vnode **, char **, char *);
void cache_enter(struct vnode *, struct vnode *, struct componentname *);
void nchinit(void);
void nchreinit(void);
void cache_cpu_init(struct cpu_info *);
void cache_purgevfs(struct mount *);
void namecache_print(struct vnode *, void (*)(const char *, ...));
#endif
/*
* Stats on usefulness of namei caches.
* XXX: should be 64-bit counters.
*/
struct nchstats {
long ncs_goodhits; /* hits that we can really use */
long ncs_neghits; /* negative hits that we can use */
long ncs_badhits; /* hits we must drop */
long ncs_falsehits; /* hits with id mismatch */
long ncs_miss; /* misses */
long ncs_long; /* long names that ignore cache */
long ncs_pass2; /* names found with passes == 2 */
long ncs_2passes; /* number of times we attempt it */
long ncs_revhits; /* reverse-cache hits */
long ncs_revmiss; /* reverse-cache misses */
};
#ifdef _KERNEL
extern struct nchstats nchstats;
#endif
/* #endif !_SYS_NAMEI_H_ (generated by gennameih.awk) */