xref: /netbsd-src/sys/sys/namei.h (revision 274254cdae52594c1aa480a736aef78313d15c9c)
1 /*	$NetBSD: namei.h,v 1.64 2009/02/11 00:20:18 enami Exp $	*/
2 
3 
4 /*
5  * WARNING: GENERATED FILE.  DO NOT EDIT
6  * (edit namei.src and run make namei in src/sys/sys)
7  *   by:   NetBSD: gennameih.awk,v 1.4 2008/12/03 10:54:27 ad Exp
8  *   from: NetBSD: namei.src,v 1.10 2009/02/11 00:19:11 enami Exp
9  */
10 
11 /*
12  * Copyright (c) 1985, 1989, 1991, 1993
13  *	The Regents of the University of California.  All rights reserved.
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in the
22  *    documentation and/or other materials provided with the distribution.
23  * 3. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  *
39  *	@(#)namei.h	8.5 (Berkeley) 8/20/94
40  */
41 
42 #ifndef _SYS_NAMEI_H_
43 #define	_SYS_NAMEI_H_
44 
45 #include <sys/queue.h>
46 #include <sys/mutex.h>
47 
48 #ifdef _KERNEL
49 #include <sys/kauth.h>
50 
51 /*
52  * Encapsulation of namei parameters.
53  */
54 struct nameidata {
55 	/*
56 	 * Arguments to namei/lookup.
57 	 */
58 	const char *ni_dirp;		/* pathname pointer */
59 	enum	uio_seg ni_segflg;	/* location of pathname */
60 	/*
61 	 * Arguments to lookup.
62 	 */
63 	struct	vnode *ni_startdir;	/* starting directory */
64 	struct	vnode *ni_rootdir;	/* logical root directory */
65 	struct	vnode *ni_erootdir;	/* emulation root directory */
66 	/*
67 	 * Results: returned from/manipulated by lookup
68 	 */
69 	struct	vnode *ni_vp;		/* vnode of result */
70 	struct	vnode *ni_dvp;		/* vnode of intermediate directory */
71 	/*
72 	 * Shared between namei and lookup/commit routines.
73 	 */
74 	size_t		ni_pathlen;	/* remaining chars in path */
75 	const char	*ni_next;	/* next location in pathname */
76 	unsigned int	ni_loopcnt;	/* count of symlinks encountered */
77 	/*
78 	 * Lookup parameters: this structure describes the subset of
79 	 * information from the nameidata structure that is passed
80 	 * through the VOP interface.
81 	 */
82 	struct componentname {
83 		/*
84 		 * Arguments to lookup.
85 		 */
86 		uint32_t	cn_nameiop;	/* namei operation */
87 		uint32_t	cn_flags;	/* flags to namei */
88 		kauth_cred_t 	cn_cred;	/* credentials */
89 		/*
90 		 * Shared between lookup and commit routines.
91 		 */
92 		char		*cn_pnbuf;	/* pathname buffer */
93 		const char 	*cn_nameptr;	/* pointer to looked up name */
94 		size_t		cn_namelen;	/* length of looked up comp */
95 		u_long		cn_hash;	/* hash val of looked up name */
96 		size_t		cn_consume;	/* chars to consume in lookup */
97 	} ni_cnd;
98 };
99 
100 /*
101  * namei operations
102  */
103 #define	LOOKUP		0	/* perform name lookup only */
104 #define	CREATE		1	/* setup for file creation */
105 #define	DELETE		2	/* setup for file deletion */
106 #define	RENAME		3	/* setup for file renaming */
107 #define	OPMASK		3	/* mask for operation */
108 /*
109  * namei operational modifier flags, stored in ni_cnd.cn_flags
110  */
111 #define	LOCKLEAF	0x00000004	/* lock inode on return */
112 #define	LOCKPARENT	0x00000008	/* want parent vnode returned locked */
113 #define	TRYEMULROOT	0x00000010	/* try relative to emulation root
114 					   first */
115 #define	NOCACHE		0x00000020	/* name must not be left in cache */
116 #define	FOLLOW		0x00000040	/* follow symbolic links */
117 #define	NOFOLLOW	0x00000000	/* do not follow symbolic links
118 					   (pseudo) */
119 #define	EMULROOTSET	0x00000080	/* emulation root already
120 					   in ni_erootdir */
121 #define	NOCHROOT	0x01000000	/* no chroot on abs path lookups */
122 #define	MODMASK		0x010000fc	/* mask of operational modifiers */
123 /*
124  * Namei parameter descriptors.
125  *
126  * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
127  * If the caller of namei sets the flag (for example execve wants to
128  * know the name of the program that is being executed), then it must
129  * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
130  * be freed by either the commit routine or the VOP_ABORT routine.
131  * SAVESTART is set only by the callers of namei. It implies SAVENAME
132  * plus the addition of saving the parent directory that contains the
133  * name in ni_startdir. It allows repeated calls to lookup for the
134  * name being sought. The caller is responsible for releasing the
135  * buffer and for vrele'ing ni_startdir.
136  */
137 #define	NOCROSSMOUNT	0x0000100	/* do not cross mount points */
138 #define	RDONLY		0x0000200	/* lookup with read-only semantics */
139 #define	HASBUF		0x0000400	/* has allocated pathname buffer */
140 #define	SAVENAME	0x0000800	/* save pathname buffer */
141 #define	SAVESTART	0x0001000	/* save starting directory */
142 #define	ISDOTDOT	0x0002000	/* current component name is .. */
143 #define	MAKEENTRY	0x0004000	/* entry is to be added to name cache */
144 #define	ISLASTCN	0x0008000	/* this is last component of pathname */
145 #define	ISSYMLINK	0x0010000	/* symlink needs interpretation */
146 #define	ISWHITEOUT	0x0020000	/* found whiteout */
147 #define	DOWHITEOUT	0x0040000	/* do whiteouts */
148 #define	REQUIREDIR	0x0080000	/* must be a directory */
149 #define	CREATEDIR	0x0200000	/* trailing slashes are ok */
150 #define	PARAMASK	0x02fff00	/* mask of parameter descriptors */
151 
152 /*
153  * Initialization of an nameidata structure.
154  */
155 #define NDINIT(ndp, op, flags, segflg, namep) { \
156 	(ndp)->ni_cnd.cn_nameiop = op; \
157 	(ndp)->ni_cnd.cn_flags = flags; \
158 	(ndp)->ni_segflg = segflg; \
159 	(ndp)->ni_dirp = namep; \
160 	(ndp)->ni_cnd.cn_cred = kauth_cred_get(); \
161 }
162 #endif
163 
164 /*
165  * This structure describes the elements in the cache of recent
166  * names looked up by namei. NCHNAMLEN is sized to make structure
167  * size a power of two to optimize malloc's. Minimum reasonable
168  * size is 15.
169  */
170 
171 #define	NCHNAMLEN	31	/* maximum name segment length we bother with */
172 
173 /*
174  * Namecache entry.  This structure is arranged so that frequently
175  * accessed and mostly read-only data is toward the front, with
176  * infrequently accessed data and the lock towards the rear.  The
177  * lock is then more likely to be in a seperate cache line.
178  */
179 struct	namecache {
180 	LIST_ENTRY(namecache) nc_hash;	/* hash chain */
181 	LIST_ENTRY(namecache) nc_vhash;	/* directory hash chain */
182 	struct	vnode *nc_dvp;		/* vnode of parent of name */
183 	struct	vnode *nc_vp;		/* vnode the name refers to */
184 	int	nc_flags;		/* copy of componentname's ISWHITEOUT */
185 	char	nc_nlen;		/* length of name */
186 	char	nc_name[NCHNAMLEN];	/* segment name */
187 	void	*nc_gcqueue;		/* queue for garbage collection */
188 	TAILQ_ENTRY(namecache) nc_lru;	/* psuedo-lru chain */
189 	LIST_ENTRY(namecache) nc_dvlist;
190 	LIST_ENTRY(namecache) nc_vlist;
191 	kmutex_t nc_lock;		/* lock on this entry */
192 	int	nc_hittime;		/* last time scored a hit */
193 };
194 
195 #ifdef _KERNEL
196 #include <sys/mallocvar.h>
197 #include <sys/pool.h>
198 
199 struct mount;
200 struct cpu_info;
201 
202 extern pool_cache_t pnbuf_cache;	/* pathname buffer cache */
203 
204 #define	PNBUF_GET()	pool_cache_get(pnbuf_cache, PR_WAITOK)
205 #define	PNBUF_PUT(pnb)	pool_cache_put(pnbuf_cache, (pnb))
206 
207 int	namei(struct nameidata *);
208 uint32_t namei_hash(const char *, const char **);
209 int	lookup(struct nameidata *);
210 int	relookup(struct vnode *, struct vnode **, struct componentname *);
211 void	cache_purge1(struct vnode *, const struct componentname *, int);
212 #define	PURGE_PARENTS	1
213 #define	PURGE_CHILDREN	2
214 #define	cache_purge(vp)	cache_purge1((vp), NULL, PURGE_PARENTS|PURGE_CHILDREN)
215 int	cache_lookup(struct vnode *, struct vnode **, struct componentname *);
216 int	cache_lookup_raw(struct vnode *, struct vnode **,
217 			 struct componentname *);
218 int	cache_revlookup(struct vnode *, struct vnode **, char **, char *);
219 void	cache_enter(struct vnode *, struct vnode *, struct componentname *);
220 void	nchinit(void);
221 void	nchreinit(void);
222 void	cache_cpu_init(struct cpu_info *);
223 void	cache_purgevfs(struct mount *);
224 void	namecache_print(struct vnode *, void (*)(const char *, ...));
225 
226 #endif
227 
228 /*
229  * Stats on usefulness of namei caches.
230  * XXX: should be 64-bit counters.
231  */
232 struct	nchstats {
233 	long	ncs_goodhits;		/* hits that we can really use */
234 	long	ncs_neghits;		/* negative hits that we can use */
235 	long	ncs_badhits;		/* hits we must drop */
236 	long	ncs_falsehits;		/* hits with id mismatch */
237 	long	ncs_miss;		/* misses */
238 	long	ncs_long;		/* long names that ignore cache */
239 	long	ncs_pass2;		/* names found with passes == 2 */
240 	long	ncs_2passes;		/* number of times we attempt it */
241 	long	ncs_revhits;		/* reverse-cache hits */
242 	long	ncs_revmiss;		/* reverse-cache misses */
243 };
244 
245 #ifdef _KERNEL
246 extern struct nchstats nchstats;
247 #endif
248 /* #endif !_SYS_NAMEI_H_ (generated by gennameih.awk) */
249 
250 /* Definitions match above, but with NAMEI_ prefix */
251 #define NAMEI_LOOKUP	0
252 #define NAMEI_CREATE	1
253 #define NAMEI_DELETE	2
254 #define NAMEI_RENAME	3
255 #define NAMEI_OPMASK	3
256 #define NAMEI_LOCKLEAF	0x00000004
257 #define NAMEI_LOCKPARENT	0x00000008
258 #define NAMEI_TRYEMULROOT	0x00000010
259 #define NAMEI_NOCACHE	0x00000020
260 #define NAMEI_FOLLOW	0x00000040
261 #define NAMEI_NOFOLLOW	0x00000000
262 #define NAMEI_EMULROOTSET	0x00000080
263 #define NAMEI_NOCHROOT	0x01000000
264 #define NAMEI_MODMASK	0x010000fc
265 #define NAMEI_NOCROSSMOUNT	0x0000100
266 #define NAMEI_RDONLY	0x0000200
267 #define NAMEI_HASBUF	0x0000400
268 #define NAMEI_SAVENAME	0x0000800
269 #define NAMEI_SAVESTART	0x0001000
270 #define NAMEI_ISDOTDOT	0x0002000
271 #define NAMEI_MAKEENTRY	0x0004000
272 #define NAMEI_ISLASTCN	0x0008000
273 #define NAMEI_ISSYMLINK	0x0010000
274 #define NAMEI_ISWHITEOUT	0x0020000
275 #define NAMEI_DOWHITEOUT	0x0040000
276 #define NAMEI_REQUIREDIR	0x0080000
277 #define NAMEI_CREATEDIR	0x0200000
278 #define NAMEI_PARAMASK	0x02fff00
279 
280 #endif /* !_SYS_NAMEI_H_ */
281