namei.h revision 145583
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 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)namei.h 8.5 (Berkeley) 1/9/95 30 * $FreeBSD: head/sys/sys/namei.h 145583 2005-04-27 09:00:47Z jeff $ 31 */ 32 33#ifndef _SYS_NAMEI_H_ 34#define _SYS_NAMEI_H_ 35 36#include <sys/queue.h> 37#include <sys/uio.h> 38 39struct componentname { 40 /* 41 * Arguments to lookup. 42 */ 43 u_long cn_nameiop; /* namei operation */ 44 u_long cn_flags; /* flags to namei */ 45 struct thread *cn_thread;/* thread requesting lookup */ 46 struct ucred *cn_cred; /* credentials */ 47 int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */ 48 /* 49 * Shared between lookup and commit routines. 50 */ 51 char *cn_pnbuf; /* pathname buffer */ 52 char *cn_nameptr; /* pointer to looked up name */ 53 long cn_namelen; /* length of looked up component */ 54 long cn_consume; /* chars to consume in lookup() */ 55}; 56 57/* 58 * Encapsulation of namei parameters. 59 */ 60struct nameidata { 61 /* 62 * Arguments to namei/lookup. 63 */ 64 const char *ni_dirp; /* pathname pointer */ 65 enum uio_seg ni_segflg; /* location of pathname */ 66 /* 67 * Arguments to lookup. 68 */ 69 struct vnode *ni_startdir; /* starting directory */ 70 struct vnode *ni_rootdir; /* logical root directory */ 71 struct vnode *ni_topdir; /* logical top directory */ 72 /* 73 * Results: returned from/manipulated by lookup 74 */ 75 struct vnode *ni_vp; /* vnode of result */ 76 struct vnode *ni_dvp; /* vnode of intermediate directory */ 77 /* 78 * Shared between namei and lookup/commit routines. 79 */ 80 size_t ni_pathlen; /* remaining chars in path */ 81 char *ni_next; /* next location in pathname */ 82 u_long ni_loopcnt; /* count of symlinks encountered */ 83 /* 84 * Lookup parameters: this structure describes the subset of 85 * information from the nameidata structure that is passed 86 * through the VOP interface. 87 */ 88 struct componentname ni_cnd; 89}; 90 91#ifdef _KERNEL 92/* 93 * namei operations 94 */ 95#define LOOKUP 0 /* perform name lookup only */ 96#define CREATE 1 /* setup for file creation */ 97#define DELETE 2 /* setup for file deletion */ 98#define RENAME 3 /* setup for file renaming */ 99#define OPMASK 3 /* mask for operation */ 100/* 101 * namei operational modifier flags, stored in ni_cnd.flags 102 */ 103#define LOCKLEAF 0x0004 /* lock inode on return */ 104#define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 105#define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 106#define NOCACHE 0x0020 /* name must not be left in cache */ 107#define FOLLOW 0x0040 /* follow symbolic links */ 108#define LOCKSHARED 0x0100 /* Shared lock leaf */ 109#define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 110#define MODMASK 0x01fc /* mask of operational modifiers */ 111/* 112 * Namei parameter descriptors. 113 * 114 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP. 115 * If the caller of namei sets the flag (for example execve wants to 116 * know the name of the program that is being executed), then it must 117 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must 118 * be freed by either the commit routine or the VOP_ABORT routine. 119 * SAVESTART is set only by the callers of namei. It implies SAVENAME 120 * plus the addition of saving the parent directory that contains the 121 * name in ni_startdir. It allows repeated calls to lookup for the 122 * name being sought. The caller is responsible for releasing the 123 * buffer and for vrele'ing ni_startdir. 124 */ 125#define RDONLY 0x0000200 /* lookup with read-only semantics */ 126#define HASBUF 0x0000400 /* has allocated pathname buffer */ 127#define SAVENAME 0x0000800 /* save pathname buffer */ 128#define SAVESTART 0x0001000 /* save starting directory */ 129#define ISDOTDOT 0x0002000 /* current component name is .. */ 130#define MAKEENTRY 0x0004000 /* entry is to be added to name cache */ 131#define ISLASTCN 0x0008000 /* this is last component of pathname */ 132#define ISSYMLINK 0x0010000 /* symlink needs interpretation */ 133#define ISWHITEOUT 0x0020000 /* found whiteout */ 134#define DOWHITEOUT 0x0040000 /* do whiteouts */ 135#define WILLBEDIR 0x0080000 /* new files will be dirs; allow trailing / */ 136#define ISUNICODE 0x0100000 /* current component name is unicode*/ 137#define ISOPEN 0x0200000 /* caller is opening; return a real vnode. */ 138#define NOCROSSMOUNT 0x0400000 /* do not cross mount points */ 139#define NOMACCHECK 0x0800000 /* do not perform MAC checks */ 140#define MPSAFE 0x1000000 /* namei() must acquire Giant if needed. */ 141#define GIANTHELD 0x2000000 /* namei() is holding giant. */ 142#define PARAMASK 0x3fffe00 /* mask of parameter descriptors */ 143 144#define NDHASGIANT(NDP) (((NDP)->ni_cnd.cn_flags & GIANTHELD) != 0) 145 146/* 147 * Initialization of a nameidata structure. 148 */ 149static void NDINIT(struct nameidata *, u_long, u_long, enum uio_seg, 150 const char *, struct thread *); 151static __inline void 152NDINIT(struct nameidata *ndp, 153 u_long op, u_long flags, 154 enum uio_seg segflg, 155 const char *namep, 156 struct thread *td) 157{ 158 ndp->ni_cnd.cn_nameiop = op; 159 ndp->ni_cnd.cn_flags = flags; 160 ndp->ni_segflg = segflg; 161 ndp->ni_dirp = namep; 162 ndp->ni_cnd.cn_thread = td; 163} 164 165#define NDF_NO_DVP_RELE 0x00000001 166#define NDF_NO_DVP_UNLOCK 0x00000002 167#define NDF_NO_DVP_PUT 0x00000003 168#define NDF_NO_VP_RELE 0x00000004 169#define NDF_NO_VP_UNLOCK 0x00000008 170#define NDF_NO_VP_PUT 0x0000000c 171#define NDF_NO_STARTDIR_RELE 0x00000010 172#define NDF_NO_FREE_PNBUF 0x00000020 173#define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF) 174 175void NDFREE(struct nameidata *, const u_int); 176 177int namei(struct nameidata *ndp); 178int lookup(struct nameidata *ndp); 179int relookup(struct vnode *dvp, struct vnode **vpp, 180 struct componentname *cnp); 181#endif 182 183/* 184 * Stats on usefulness of namei caches. 185 */ 186struct nchstats { 187 long ncs_goodhits; /* hits that we can really use */ 188 long ncs_neghits; /* negative hits that we can use */ 189 long ncs_badhits; /* hits we must drop */ 190 long ncs_falsehits; /* hits with id mismatch */ 191 long ncs_miss; /* misses */ 192 long ncs_long; /* long names that ignore cache */ 193 long ncs_pass2; /* names found with passes == 2 */ 194 long ncs_2passes; /* number of times we attempt it */ 195}; 196 197extern struct nchstats nchstats; 198 199#endif /* !_SYS_NAMEI_H_ */ 200