1 /* 2 * Copyright (c) 1985, 1989 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 * 17 * @(#)namei.h 7.5 (Berkeley) 06/06/89 18 */ 19 20 #ifndef _NAMEI_ 21 #define _NAMEI_ 22 23 #ifdef KERNEL 24 #include "../ufs/dir.h" 25 #include "uio.h" 26 #else 27 #include <sys/uio.h> 28 #include <ufs/dir.h> 29 #endif 30 31 /* 32 * Encapsulation of namei parameters. 33 * One of these is located in the u. area to 34 * minimize space allocated on the kernel stack. 35 */ 36 struct nameidata { 37 /* arguments to namei and related context: */ 38 caddr_t ni_dirp; /* pathname pointer */ 39 enum uio_seg ni_segflg; /* location of pathname */ 40 short ni_nameiop; /* see below */ 41 struct vnode *ni_cdir; /* current directory */ 42 struct vnode *ni_rdir; /* root directory, if not normal root */ 43 struct ucred *ni_cred; /* credentials */ 44 45 /* shared between namei, lookup routines and commit routines: */ 46 caddr_t ni_pnbuf; /* pathname buffer */ 47 char *ni_ptr; /* current location in pathname */ 48 char *ni_next; /* next location in pathname */ 49 u_int ni_pathlen; /* remaining chars in path */ 50 short ni_namelen; /* length of current component */ 51 short ni_loopcnt; /* count of symlinks encountered */ 52 char ni_makeentry; /* 1 => add entry to name cache */ 53 char ni_isdotdot; /* 1 => current component name is .. */ 54 55 /* results: */ 56 struct vnode *ni_vp; /* vnode of result */ 57 struct vnode *ni_dvp; /* vnode of intermediate directory */ 58 59 /* side effects: */ 60 struct direct ni_dent; /* current directory entry */ 61 62 /* BEGIN UFS SPECIFIC */ 63 off_t ni_endoff; /* end of useful directory contents */ 64 struct ndirinfo { /* saved info for new dir entry */ 65 struct iovec nd_iovec; /* pointed to by ni_iov */ 66 struct uio nd_uio; /* directory I/O parameters */ 67 u_long nd_hash; /* hash value of nd_dent */ 68 } ni_nd; 69 /* END UFS SPECIFIC */ 70 }; 71 72 #define ni_base ni_nd.nd_iovec.iov_base 73 #define ni_count ni_nd.nd_iovec.iov_len 74 #define ni_segflg ni_nd.nd_uio.uio_segflg 75 #define ni_iov ni_nd.nd_uio.uio_iov 76 #define ni_iovcnt ni_nd.nd_uio.uio_iovcnt 77 #define ni_offset ni_nd.nd_uio.uio_offset 78 #define ni_resid ni_nd.nd_uio.uio_resid 79 #define ni_rw ni_nd.nd_uio.uio_rw 80 #define ni_uio ni_nd.nd_uio 81 #define ni_hash ni_nd.nd_hash 82 83 #ifdef KERNEL 84 /* 85 * namei operations and modifiers 86 */ 87 #define LOOKUP 0 /* perform name lookup only */ 88 #define CREATE 1 /* setup for file creation */ 89 #define DELETE 2 /* setup for file deletion */ 90 #define RENAME 3 /* setup for file renaming */ 91 #define OPFLAG 3 /* mask for operation */ 92 #define LOCKLEAF 0x04 /* lock inode on return */ 93 #define LOCKPARENT 0x08 /* want parent vnode returned locked */ 94 #define WANTPARENT 0x10 /* want parent vnode returned unlocked */ 95 #define NOCACHE 0x20 /* name must not be left in cache */ 96 #define FOLLOW 0x40 /* follow symbolic links */ 97 #define NOFOLLOW 0x0 /* don't follow symbolic links (pseudo) */ 98 #define NOMOUNT 0x80 /* don't cross mount points */ 99 #endif 100 101 /* 102 * This structure describes the elements in the cache of recent 103 * names looked up by namei. 104 */ 105 106 #define NCHNAMLEN 15 /* maximum name segment length we bother with */ 107 108 struct namecache { 109 struct namecache *nc_forw; /* hash chain, MUST BE FIRST */ 110 struct namecache *nc_back; /* hash chain, MUST BE FIRST */ 111 struct namecache *nc_nxt; /* LRU chain */ 112 struct namecache **nc_prev; /* LRU chain */ 113 struct vnode *nc_vp; /* vnode the name refers to */ 114 struct vnode *nc_dp; /* vnode of parent of name */ 115 char nc_nlen; /* length of name */ 116 char nc_name[NCHNAMLEN]; /* segment name */ 117 struct ucred *nc_cred; /* ??? credentials */ 118 }; 119 120 #define ANYCRED ((struct ucred *) -1) 121 #define NOCRED ((struct ucred *) 0) 122 123 #ifdef KERNEL 124 struct namecache *namecache; 125 int nchsize; 126 #endif 127 128 /* 129 * Stats on usefulness of namei caches. 130 */ 131 struct nchstats { 132 long ncs_goodhits; /* hits that we can reall use */ 133 long ncs_badhits; /* hits we must drop */ 134 long ncs_falsehits; /* hits with id mismatch */ 135 long ncs_miss; /* misses */ 136 long ncs_long; /* long names that ignore cache */ 137 long ncs_pass2; /* names found with passes == 2 */ 138 long ncs_2passes; /* number of times we attempt it */ 139 }; 140 #endif 141