[unix-history] / usr / src / sys.386bsd / sys / namei.h

/*
 * Copyright (c) 1985, 1989, 1991 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)namei.h	7.15 (Berkeley) 5/15/91
 */

#ifndef _NAMEI_H_
#define	_NAMEI_H_

/*
 * Encapsulation of namei parameters.
 */
struct nameidata {
	/*
	 * Arguments to namei.
	 */
	caddr_t	ni_dirp;		/* pathname pointer */
	enum	uio_seg ni_segflg;	/* location of pathname */
	u_long	ni_nameiop;		/* see below */
	/*
	 * Arguments to lookup.
	 */
	struct	ucred *ni_cred;		/* credentials */
	struct	vnode *ni_startdir;	/* starting directory */
	struct	vnode *ni_rootdir;	/* logical root directory */
	/*
	 * Results
	 */
	struct	vnode *ni_vp;		/* vnode of result */
	struct	vnode *ni_dvp;		/* vnode of intermediate directory */
	/*
	 * Shared between namei, lookup routines, and commit routines.
	 */
	char	*ni_pnbuf;		/* pathname buffer */
	long	ni_pathlen;		/* remaining chars in path */
	char	*ni_ptr;		/* current location in pathname */
	long	ni_namelen;		/* length of current component */
	char	*ni_next;		/* next location in pathname */
	u_long	ni_hash;		/* hash value of current component */
	u_char	ni_loopcnt;		/* count of symlinks encountered */
	u_char	ni_makeentry;		/* 1 => add entry to name cache */
	u_char	ni_isdotdot;		/* 1 => current component name is .. */
	u_char	ni_more;		/* 1 => symlink needs interpretation */
	/*
	 * Side effects.
	 */
	struct ufs_specific {		/* saved info for new dir entry */
		off_t	ufs_endoff;	/* end of useful directory contents */
		long	ufs_offset;	/* offset of free space in directory */
		long	ufs_count;	/* size of free slot in directory */
		ino_t	ufs_ino;	/* inode number of found directory */
		u_long	ufs_reclen;	/* size of found directory entry */
	} ni_ufs;
};

#ifdef KERNEL
/*
 * namei operations
 */
#define	LOOKUP		0	/* perform name lookup only */
#define	CREATE		1	/* setup for file creation */
#define	DELETE		2	/* setup for file deletion */
#define	RENAME		3	/* setup for file renaming */
#define	OPMASK		3	/* mask for operation */
/*
 * namei operational modifiers
 */
#define	LOCKLEAF	0x0004	/* lock inode on return */
#define	LOCKPARENT	0x0008	/* want parent vnode returned locked */
#define	WANTPARENT	0x0010	/* want parent vnode returned unlocked */
#define	NOCACHE		0x0020	/* name must not be left in cache */
#define	FOLLOW		0x0040	/* follow symbolic links */
#define	NOFOLLOW	0x0000	/* do not follow symbolic links (pseudo) */
#define	MODMASK		0x00fc	/* mask of operational modifiers */
/*
 * Namei parameter descriptors.
 *
 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
 * If the caller of namei sets the flag (for example execve wants to
 * know the name of the program that is being executed), then it must
 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
 * be freed by either the commit routine or the VOP_ABORT routine.
 * SAVESTART is set only by the callers of namei. It implies SAVENAME
 * plus the addition of saving the parent directory that contains the
 * name in ni_startdir. It allows repeated calls to lookup for the
 * name being sought. The caller is responsible for releasing the
 * buffer and for vrele'ing ni_startdir.
 */
#define	NOCROSSMOUNT	0x0100	/* do not cross mount points */
#define	REMOTE		0x0200	/* lookup for remote filesystem servers */
#define	HASBUF		0x0400	/* has allocated pathname buffer */
#define	SAVENAME	0x0800	/* save pathanme buffer */
#define	SAVESTART	0x1000	/* save starting directory */
#define PARAMASK	0xff00	/* mask of parameter descriptors */
#endif

/*
 * This structure describes the elements in the cache of recent
 * names looked up by namei. NCHNAMLEN is sized to make structure
 * size a power of two to optimize malloc's. Minimum reasonable
 * size is 15.
 */

#define	NCHNAMLEN	31	/* maximum name segment length we bother with */

struct	namecache {
	struct	namecache *nc_forw;	/* hash chain, MUST BE FIRST */
	struct	namecache *nc_back;	/* hash chain, MUST BE FIRST */
	struct	namecache *nc_nxt;	/* LRU chain */
	struct	namecache **nc_prev;	/* LRU chain */
	struct	vnode *nc_dvp;		/* vnode of parent of name */
	u_long	nc_dvpid;		/* capability number of nc_dvp */
	struct	vnode *nc_vp;		/* vnode the name refers to */
	u_long	nc_vpid;		/* capability number of nc_vp */
	char	nc_nlen;		/* length of name */
	char	nc_name[NCHNAMLEN];	/* segment name */
};

#ifdef KERNEL
u_long	nextvnodeid;
int	namei __P((struct nameidata *ndp, struct proc *p));
int	lookup __P((struct nameidata *ndp, struct proc *p));
#endif

/*
 * Stats on usefulness of namei caches.
 */
struct	nchstats {
	long	ncs_goodhits;		/* hits that we can really use */
	long	ncs_neghits;		/* negative hits that we can use */
	long	ncs_badhits;		/* hits we must drop */
	long	ncs_falsehits;		/* hits with id mismatch */
	long	ncs_miss;		/* misses */
	long	ncs_long;		/* long names that ignore cache */
	long	ncs_pass2;		/* names found with passes == 2 */
	long	ncs_2passes;		/* number of times we attempt it */
};
#endif /* !_NAMEI_H_ */
Commit	Line	Data
b688fc87 WJ	1	/*
	2	* Copyright (c) 1985, 1989, 1991 Regents of the University of California.
	3	* 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 7.15 (Berkeley) 5/15/91
	34	*/
	35
	36	#ifndef _NAMEI_H_
	37	#define _NAMEI_H_
	38
	39	/*
	40	* Encapsulation of namei parameters.
	41	*/
	42	struct nameidata {
	43	/*
	44	* Arguments to namei.
	45	*/
	46	caddr_t ni_dirp; /* pathname pointer */
	47	enum uio_seg ni_segflg; /* location of pathname */
	48	u_long ni_nameiop; /* see below */
	49	/*
	50	* Arguments to lookup.
	51	*/
	52	struct ucred ni_cred; / credentials */
	53	struct vnode ni_startdir; / starting directory */
	54	struct vnode ni_rootdir; / logical root directory */
	55	/*
	56	* Results
	57	*/
	58	struct vnode ni_vp; / vnode of result */
	59	struct vnode ni_dvp; / vnode of intermediate directory */
	60	/*
	61	* Shared between namei, lookup routines, and commit routines.
	62	*/
	63	char ni_pnbuf; / pathname buffer */
	64	long ni_pathlen; /* remaining chars in path */
65	char ni_ptr; / current location in pathname */
66	long ni_namelen; /* length of current component */
67	char ni_next; / next location in pathname */
68	u_long ni_hash; /* hash value of current component */
69	u_char ni_loopcnt; /* count of symlinks encountered */
70	u_char ni_makeentry; /* 1 => add entry to name cache */
71	u_char ni_isdotdot; /* 1 => current component name is .. */
72	u_char ni_more; /* 1 => symlink needs interpretation */
73	/*
74	* Side effects.
75	*/
76	struct ufs_specific { /* saved info for new dir entry */
77	off_t ufs_endoff; /* end of useful directory contents */
78	long ufs_offset; /* offset of free space in directory */
79	long ufs_count; /* size of free slot in directory */
80	ino_t ufs_ino; /* inode number of found directory */
81	u_long ufs_reclen; /* size of found directory entry */
82	} ni_ufs;
83	};
84
85	#ifdef KERNEL
86	/*
87	* namei operations
88	*/
89	#define LOOKUP 0 /* perform name lookup only */
90	#define CREATE 1 /* setup for file creation */
91	#define DELETE 2 /* setup for file deletion */
92	#define RENAME 3 /* setup for file renaming */
93	#define OPMASK 3 /* mask for operation */
94	/*
95	* namei operational modifiers
96	*/
97	#define LOCKLEAF 0x0004 /* lock inode on return */
98	#define LOCKPARENT 0x0008 /* want parent vnode returned locked */
99	#define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
100	#define NOCACHE 0x0020 /* name must not be left in cache */
101	#define FOLLOW 0x0040 /* follow symbolic links */
102	#define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */
103	#define MODMASK 0x00fc /* mask of operational modifiers */
104	/*
105	* Namei parameter descriptors.
106	*
107	* SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
108	* If the caller of namei sets the flag (for example execve wants to
109	* know the name of the program that is being executed), then it must
110	* free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
111	* be freed by either the commit routine or the VOP_ABORT routine.
112	* SAVESTART is set only by the callers of namei. It implies SAVENAME
113	* plus the addition of saving the parent directory that contains the
114	* name in ni_startdir. It allows repeated calls to lookup for the
115	* name being sought. The caller is responsible for releasing the
116	* buffer and for vrele'ing ni_startdir.
117	*/
118	#define NOCROSSMOUNT 0x0100 /* do not cross mount points */
119	#define REMOTE 0x0200 /* lookup for remote filesystem servers */
120	#define HASBUF 0x0400 /* has allocated pathname buffer */
121	#define SAVENAME 0x0800 /* save pathanme buffer */
122	#define SAVESTART 0x1000 /* save starting directory */
123	#define PARAMASK 0xff00 /* mask of parameter descriptors */
124	#endif
125
126	/*
127	* This structure describes the elements in the cache of recent
128	* names looked up by namei. NCHNAMLEN is sized to make structure
129	* size a power of two to optimize malloc's. Minimum reasonable
130	* size is 15.
131	*/
132
133	#define NCHNAMLEN 31 /* maximum name segment length we bother with */
134
135	struct namecache {
136	struct namecache nc_forw; / hash chain, MUST BE FIRST */
137	struct namecache nc_back; / hash chain, MUST BE FIRST */
138	struct namecache nc_nxt; / LRU chain */
139	struct namecache *nc_prev; / LRU chain */
140	struct vnode nc_dvp; / vnode of parent of name */
141	u_long nc_dvpid; /* capability number of nc_dvp */
142	struct vnode nc_vp; / vnode the name refers to */
143	u_long nc_vpid; /* capability number of nc_vp */
144	char nc_nlen; /* length of name */
145	char nc_name[NCHNAMLEN]; /* segment name */
146	};
147
148	#ifdef KERNEL
149	u_long nextvnodeid;
150	int namei __P((struct nameidata ndp, struct proc p));
151	int lookup __P((struct nameidata ndp, struct proc p));
152	#endif
153
154	/*
155	* Stats on usefulness of namei caches.
156	*/
157	struct nchstats {
158	long ncs_goodhits; /* hits that we can really use */
159	long ncs_neghits; /* negative hits that we can use */
160	long ncs_badhits; /* hits we must drop */
161	long ncs_falsehits; /* hits with id mismatch */
162	long ncs_miss; /* misses */
163	long ncs_long; /* long names that ignore cache */
164	long ncs_pass2; /* names found with passes == 2 */
165	long ncs_2passes; /* number of times we attempt it */
166	};
167	#endif /* !_NAMEI_H_ */