FreeBSD/Linux Kernel Cross Reference
sys/sys/namei.h
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: releng/5.4/sys/sys/namei.h 145335 2005-04-20 19:11:07Z cvs2svn $
31 */
32
33 #ifndef _SYS_NAMEI_H_
34 #define _SYS_NAMEI_H_
35
36 #include <sys/queue.h>
37 #include <sys/uio.h>
38
39 struct 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 /*
48 * Shared between lookup and commit routines.
49 */
50 char *cn_pnbuf; /* pathname buffer */
51 char *cn_nameptr; /* pointer to looked up name */
52 long cn_namelen; /* length of looked up component */
53 long cn_consume; /* chars to consume in lookup() */
54 };
55
56 /*
57 * Encapsulation of namei parameters.
58 */
59 struct nameidata {
60 /*
61 * Arguments to namei/lookup.
62 */
63 const char *ni_dirp; /* pathname pointer */
64 enum uio_seg ni_segflg; /* location of pathname */
65 /*
66 * Arguments to lookup.
67 */
68 struct vnode *ni_startdir; /* starting directory */
69 struct vnode *ni_rootdir; /* logical root directory */
70 struct vnode *ni_topdir; /* logical top directory */
71 /*
72 * Results: returned from/manipulated by lookup
73 */
74 struct vnode *ni_vp; /* vnode of result */
75 struct vnode *ni_dvp; /* vnode of intermediate directory */
76 /*
77 * Shared between namei and lookup/commit routines.
78 */
79 size_t ni_pathlen; /* remaining chars in path */
80 char *ni_next; /* next location in pathname */
81 u_long ni_loopcnt; /* count of symlinks encountered */
82 /*
83 * Lookup parameters: this structure describes the subset of
84 * information from the nameidata structure that is passed
85 * through the VOP interface.
86 */
87 struct componentname ni_cnd;
88 };
89
90 #ifdef _KERNEL
91 /*
92 * namei operations
93 */
94 #define LOOKUP 0 /* perform name lookup only */
95 #define CREATE 1 /* setup for file creation */
96 #define DELETE 2 /* setup for file deletion */
97 #define RENAME 3 /* setup for file renaming */
98 #define OPMASK 3 /* mask for operation */
99 /*
100 * namei operational modifier flags, stored in ni_cnd.flags
101 */
102 #define LOCKLEAF 0x0004 /* lock inode on return */
103 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */
104 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
105 #define NOCACHE 0x0020 /* name must not be left in cache */
106 #define FOLLOW 0x0040 /* follow symbolic links */
107 #define NOOBJ 0x0080 /* don't create object */
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 0x000200 /* lookup with read-only semantics */
126 #define HASBUF 0x000400 /* has allocated pathname buffer */
127 #define SAVENAME 0x000800 /* save pathname buffer */
128 #define SAVESTART 0x001000 /* save starting directory */
129 #define ISDOTDOT 0x002000 /* current component name is .. */
130 #define MAKEENTRY 0x004000 /* entry is to be added to name cache */
131 #define ISLASTCN 0x008000 /* this is last component of pathname */
132 #define ISSYMLINK 0x010000 /* symlink needs interpretation */
133 #define ISWHITEOUT 0x020000 /* found whiteout */
134 #define DOWHITEOUT 0x040000 /* do whiteouts */
135 #define WILLBEDIR 0x080000 /* new files will be dirs; allow trailing / */
136 #define ISUNICODE 0x100000 /* current component name is unicode*/
137 #define PDIRUNLOCK 0x200000 /* filesystem lookup() unlocked parent dir */
138 #define NOCROSSMOUNT 0x400000 /* do not cross mount points */
139 #define NOMACCHECK 0x800000 /* do not perform MAC checks */
140 #define PARAMASK 0xfffe00 /* mask of parameter descriptors */
141
142 /*
143 * Initialization of a nameidata structure.
144 */
145 static void NDINIT(struct nameidata *, u_long, u_long, enum uio_seg,
146 const char *, struct thread *);
147 static __inline void
148 NDINIT(struct nameidata *ndp,
149 u_long op, u_long flags,
150 enum uio_seg segflg,
151 const char *namep,
152 struct thread *td)
153 {
154 ndp->ni_cnd.cn_nameiop = op;
155 ndp->ni_cnd.cn_flags = flags;
156 ndp->ni_segflg = segflg;
157 ndp->ni_dirp = namep;
158 ndp->ni_cnd.cn_thread = td;
159 }
160
161 #define NDF_NO_DVP_RELE 0x00000001
162 #define NDF_NO_DVP_UNLOCK 0x00000002
163 #define NDF_NO_DVP_PUT 0x00000003
164 #define NDF_NO_VP_RELE 0x00000004
165 #define NDF_NO_VP_UNLOCK 0x00000008
166 #define NDF_NO_VP_PUT 0x0000000c
167 #define NDF_NO_STARTDIR_RELE 0x00000010
168 #define NDF_NO_FREE_PNBUF 0x00000020
169 #define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF)
170
171 void NDFREE(struct nameidata *, const u_int);
172
173 int namei(struct nameidata *ndp);
174 int lookup(struct nameidata *ndp);
175 int relookup(struct vnode *dvp, struct vnode **vpp,
176 struct componentname *cnp);
177 #endif
178
179 /*
180 * Stats on usefulness of namei caches.
181 */
182 struct nchstats {
183 long ncs_goodhits; /* hits that we can really use */
184 long ncs_neghits; /* negative hits that we can use */
185 long ncs_badhits; /* hits we must drop */
186 long ncs_falsehits; /* hits with id mismatch */
187 long ncs_miss; /* misses */
188 long ncs_long; /* long names that ignore cache */
189 long ncs_pass2; /* names found with passes == 2 */
190 long ncs_2passes; /* number of times we attempt it */
191 };
192
193 extern struct nchstats nchstats;
194
195 #endif /* !_SYS_NAMEI_H_ */
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