/* $OpenBSD: namei.h,v 1.21 2008/07/05 12:56:52 thib Exp $ */ /* $NetBSD: namei.h,v 1.11 1996/02/09 18:25:20 christos 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 8.4 (Berkeley) 8/20/94 */ #ifndef _SYS_NAMEI_H_ #define _SYS_NAMEI_H_ #include /* * Encapsulation of namei parameters. */ struct nameidata { /* * Arguments to namei/lookup. */ const char *ni_dirp; /* pathname pointer */ enum uio_seg ni_segflg; /* location of pathname */ /* u_long ni_nameiop; namei operation */ /* u_long ni_flags; flags to namei */ /* struct proc *ni_proc; process requesting lookup */ /* * Arguments to lookup. */ /* struct ucred *ni_cred; credentials */ struct vnode *ni_startdir; /* starting directory */ struct vnode *ni_rootdir; /* logical 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 */ char *ni_next; /* next location in pathname */ u_long 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. */ u_long cn_nameiop; /* namei operation */ u_long cn_flags; /* flags to namei */ struct proc *cn_proc; /* process requesting lookup */ struct ucred *cn_cred; /* credentials */ /* * Shared between lookup and commit routines. */ char *cn_pnbuf; /* pathname buffer */ char *cn_nameptr; /* pointer to looked up name */ long cn_namelen; /* length of looked up component */ u_int32_t cn_hash; /* hash value of looked up name */ long cn_consume; /* chars to consume in lookup() */ } ni_cnd; }; #ifdef _KERNEL /* * namei operations */ #define LOOKUP 0 /* perform name lookup only */ #define CREATE 1 /* setup for file creation */ #define DELETE 2 /* setup for file deletion */ #define RENAME 3 /* setup for file renaming */ #define OPMASK 3 /* mask for operation */ /* * namei operational modifier flags, stored in ni_cnd.flags */ #define LOCKLEAF 0x0004 /* lock inode on return */ #define LOCKPARENT 0x0008 /* want parent vnode returned locked */ #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ #define NOCACHE 0x0020 /* name must not be left in cache */ #define FOLLOW 0x0040 /* follow symbolic links */ #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ #define MODMASK 0x00fc /* 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. */ #define NOCROSSMOUNT 0x000100 /* do not cross mount points */ #define RDONLY 0x000200 /* lookup with read-only semantics */ #define HASBUF 0x000400 /* has allocated pathname buffer */ #define SAVENAME 0x000800 /* save pathanme buffer */ #define SAVESTART 0x001000 /* save starting directory */ #define ISDOTDOT 0x002000 /* current component name is .. */ #define MAKEENTRY 0x004000 /* entry is to be added to name cache */ #define ISLASTCN 0x008000 /* this is last component of pathname */ #define ISSYMLINK 0x010000 /* symlink needs interpretation */ #define REQUIREDIR 0x080000 /* must be a directory */ #define STRIPSLASHES 0x100000 /* strip trailing slashes */ #define PDIRUNLOCK 0x200000 /* vfs_lookup() unlocked parent dir */ /* * Initialization of an nameidata structure. */ #define NDINIT(ndp, op, flags, segflg, namep, p) { \ (ndp)->ni_cnd.cn_nameiop = op; \ (ndp)->ni_cnd.cn_flags = flags; \ (ndp)->ni_segflg = segflg; \ (ndp)->ni_dirp = namep; \ (ndp)->ni_cnd.cn_proc = p; \ } #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 */ struct namecache { LIST_ENTRY(namecache) nc_hash; /* hash chain */ LIST_ENTRY(namecache) nc_vhash; /* (reverse) directory hash chain */ TAILQ_ENTRY(namecache) nc_lru; /* LRU chain */ struct vnode *nc_dvp; /* vnode of parent of name */ u_long nc_dvpid; /* capability number of nc_dvp */ struct vnode *nc_vp; /* vnode the name refers to */ u_long nc_vpid; /* capability number of nc_vp */ char nc_nlen; /* length of name */ char nc_name[NCHNAMLEN]; /* segment name */ }; #ifdef _KERNEL int namei(struct nameidata *ndp); int lookup(struct nameidata *ndp); int relookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp); void cache_purge(struct vnode *); int cache_lookup(struct vnode *, struct vnode **, struct componentname *); void cache_enter(struct vnode *, struct vnode *, struct componentname *); int cache_revlookup(struct vnode *, struct vnode **, char **, char *); void nchinit(void); struct mount; void cache_purgevfs(struct mount *); extern struct pool namei_pool; #endif /* * Stats on usefulness of namei caches. */ struct nchstats { u_int64_t ncs_goodhits; /* hits that we can really use */ u_int64_t ncs_neghits; /* negative hits that we can use */ u_int64_t ncs_badhits; /* hits we must drop */ u_int64_t ncs_falsehits; /* hits with id mismatch */ u_int64_t ncs_miss; /* misses */ u_int64_t ncs_long; /* long names that ignore cache */ u_int64_t ncs_pass2; /* names found with passes == 2 */ u_int64_t ncs_2passes; /* number of times we attempt it */ u_int64_t ncs_revhits; /* reverse-cache hits */ u_int64_t ncs_revmiss; /* reverse-cache misses */ u_int64_t ncs_dothits; /* hits on '.' lookups */ u_int64_t ncs_dotdothits; /* hits on '..' lookups */ }; /* These sysctl names are only really used by sysctl(8) */ #define KERN_NCHSTATS_GOODHITS 1 #define KERN_NCHSTATS_NEGHITS 2 #define KERN_NCHSTATS_BADHITS 3 #define KERN_NCHSTATS_FALSEHITS 4 #define KERN_NCHSTATS_MISS 5 #define KERN_NCHSTATS_LONG 6 #define KERN_NCHSTATS_PASS2 7 #define KERN_NCHSTATS_2PASSES 8 #define KERN_NCHSTATS_REVHITS 9 #define KERN_NCHSTATS_REVMISS 10 #define KERN_NCHSTATS_DOTHITS 11 #define KERN_NCHSTATS_DOTDOTHITS 12 #define KERN_NCHSTATS_MAXID 13 #define CTL_KERN_NCHSTATS_NAMES { \ { 0, 0 }, \ { "good_hits", CTLTYPE_QUAD }, \ { "negative_hits", CTLTYPE_QUAD }, \ { "bad_hits", CTLTYPE_QUAD }, \ { "false_hits", CTLTYPE_QUAD }, \ { "misses", CTLTYPE_QUAD }, \ { "long_names", CTLTYPE_QUAD }, \ { "pass2", CTLTYPE_QUAD }, \ { "2passes", CTLTYPE_QUAD }, \ { "ncs_revhits", CTLTYPE_QUAD }, \ { "ncs_revmiss", CTLTYPE_QUAD }, \ { "ncs_dothits", CTLTYPE_QUAD }, \ { "nch_dotdothits", CTLTYPE_QUAD }, \ } #endif /* !_SYS_NAMEI_H_ */