namei.h revision 84061
1/* 2 * Copyright (c) 1985, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)namei.h 8.5 (Berkeley) 1/9/95 34 * $FreeBSD: head/sys/sys/namei.h 84061 2001-09-28 00:05:11Z luigi $ 35 */ 36 37#ifndef _SYS_NAMEI_H_ 38#define _SYS_NAMEI_H_ 39 40#include <sys/queue.h> 41#include <sys/uio.h> 42 43struct componentname { 44 /* 45 * Arguments to lookup. 46 */ 47 u_long cn_nameiop; /* namei operation */ 48 u_long cn_flags; /* flags to namei */ 49 struct thread *cn_thread;/* thread requesting lookup */ 50 struct ucred *cn_cred; /* credentials */ 51 /* 52 * Shared between lookup and commit routines. 53 */ 54 char *cn_pnbuf; /* pathname buffer */ 55 char *cn_nameptr; /* pointer to looked up name */ 56 long cn_namelen; /* length of looked up component */ 57 long cn_consume; /* chars to consume in lookup() */ 58}; 59 60/* 61 * Encapsulation of namei parameters. 62 */ 63struct nameidata { 64 /* 65 * Arguments to namei/lookup. 66 */ 67 const char *ni_dirp; /* pathname pointer */ 68 enum uio_seg ni_segflg; /* location of pathname */ 69 /* u_long ni_nameiop; namei operation */ 70 /* u_long ni_flags; flags to namei */ 71 /* struct proc *ni_proc; process requesting lookup */ 72 /* 73 * Arguments to lookup. 74 */ 75 /* struct ucred *ni_cred; credentials */ 76 struct vnode *ni_startdir; /* starting directory */ 77 struct vnode *ni_rootdir; /* logical root directory */ 78 struct vnode *ni_topdir; /* logical top directory */ 79 /* 80 * Results: returned from/manipulated by lookup 81 */ 82 struct vnode *ni_vp; /* vnode of result */ 83 struct vnode *ni_dvp; /* vnode of intermediate directory */ 84 /* 85 * Shared between namei and lookup/commit routines. 86 */ 87 size_t ni_pathlen; /* remaining chars in path */ 88 char *ni_next; /* next location in pathname */ 89 u_long ni_loopcnt; /* count of symlinks encountered */ 90 /* 91 * Lookup parameters: this structure describes the subset of 92 * information from the nameidata structure that is passed 93 * through the VOP interface. 94 */ 95 struct componentname ni_cnd; 96}; 97 98#ifdef _KERNEL 99/* 100 * namei operations 101 */ 102#define LOOKUP 0 /* perform name lookup only */ 103#define CREATE 1 /* setup for file creation */ 104#define DELETE 2 /* setup for file deletion */ 105#define RENAME 3 /* setup for file renaming */ 106#define OPMASK 3 /* mask for operation */ 107/* 108 * namei operational modifier flags, stored in ni_cnd.flags 109 */ 110#define LOCKLEAF 0x0004 /* lock inode on return */ 111#define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 112#define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 113#define NOCACHE 0x0020 /* name must not be left in cache */ 114#define FOLLOW 0x0040 /* follow symbolic links */ 115#define NOOBJ 0x0080 /* don't create object */ 116#define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 117#define MODMASK 0x00fc /* mask of operational modifiers */ 118/* 119 * Namei parameter descriptors. 120 * 121 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP. 122 * If the caller of namei sets the flag (for example execve wants to 123 * know the name of the program that is being executed), then it must 124 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must 125 * be freed by either the commit routine or the VOP_ABORT routine. 126 * SAVESTART is set only by the callers of namei. It implies SAVENAME 127 * plus the addition of saving the parent directory that contains the 128 * name in ni_startdir. It allows repeated calls to lookup for the 129 * name being sought. The caller is responsible for releasing the 130 * buffer and for vrele'ing ni_startdir. 131 */ 132#define NOCROSSMOUNT 0x000100 /* do not cross mount points */ 133#define RDONLY 0x000200 /* lookup with read-only semantics */ 134#define HASBUF 0x000400 /* has allocated pathname buffer */ 135#define SAVENAME 0x000800 /* save pathname buffer */ 136#define SAVESTART 0x001000 /* save starting directory */ 137#define ISDOTDOT 0x002000 /* current component name is .. */ 138#define MAKEENTRY 0x004000 /* entry is to be added to name cache */ 139#define ISLASTCN 0x008000 /* this is last component of pathname */ 140#define ISSYMLINK 0x010000 /* symlink needs interpretation */ 141#define ISWHITEOUT 0x020000 /* found whiteout */ 142#define DOWHITEOUT 0x040000 /* do whiteouts */ 143#define WILLBEDIR 0x080000 /* new files will be dirs; allow trailing / */ 144#define ISUNICODE 0x100000 /* current component name is unicode*/ 145#define PDIRUNLOCK 0x200000 /* file system lookup() unlocked parent dir */ 146#define PARAMASK 0x1fff00 /* mask of parameter descriptors */ 147 148/* 149 * Initialization of an nameidata structure. 150 */ 151static void NDINIT __P((struct nameidata *, u_long, u_long, enum uio_seg, 152 const char *, struct thread *)); 153static __inline void 154#if defined(__STDC__) || defined(__cplusplus) 155NDINIT(struct nameidata *ndp, 156 u_long op, u_long flags, 157 enum uio_seg segflg, 158 const char *namep, 159 struct thread *td) 160#else 161NDINIT(ndp, op, flags, segflg, namep, td) 162 struct nameidata *ndp; 163 u_long op, flags; 164 enum uio_seg segflg; 165 const char *namep; 166 struct thread *td; 167#endif 168{ 169 ndp->ni_cnd.cn_nameiop = op; 170 ndp->ni_cnd.cn_flags = flags; 171 ndp->ni_segflg = segflg; 172 ndp->ni_dirp = namep; 173 ndp->ni_cnd.cn_thread = td; 174} 175 176#define NDF_NO_DVP_RELE 0x00000001 177#define NDF_NO_DVP_UNLOCK 0x00000002 178#define NDF_NO_DVP_PUT 0x00000003 179#define NDF_NO_VP_RELE 0x00000004 180#define NDF_NO_VP_UNLOCK 0x00000008 181#define NDF_NO_VP_PUT 0x0000000c 182#define NDF_NO_STARTDIR_RELE 0x00000010 183#define NDF_NO_FREE_PNBUF 0x00000020 184#define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF) 185 186void NDFREE __P((struct nameidata *, const uint)); 187 188int namei __P((struct nameidata *ndp)); 189int lookup __P((struct nameidata *ndp)); 190int relookup __P((struct vnode *dvp, struct vnode **vpp, 191 struct componentname *cnp)); 192#endif 193 194/* 195 * Stats on usefulness of namei caches. 196 */ 197struct nchstats { 198 long ncs_goodhits; /* hits that we can really use */ 199 long ncs_neghits; /* negative hits that we can use */ 200 long ncs_badhits; /* hits we must drop */ 201 long ncs_falsehits; /* hits with id mismatch */ 202 long ncs_miss; /* misses */ 203 long ncs_long; /* long names that ignore cache */ 204 long ncs_pass2; /* names found with passes == 2 */ 205 long ncs_2passes; /* number of times we attempt it */ 206}; 207 208extern struct nchstats nchstats; 209 210#endif /* !_SYS_NAMEI_H_ */ 211