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Diffstat (limited to 'sys/sys/namei.h')
| -rw-r--r-- | sys/sys/namei.h | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/sys/sys/namei.h b/sys/sys/namei.h new file mode 100644 index 0000000..bb8f0a9 --- /dev/null +++ b/sys/sys/namei.h @@ -0,0 +1,189 @@ +/* + * Copyright (c) 1985, 1989, 1991, 1993 + * The 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 8.2 (Berkeley) 1/4/94 + * $Id$ + */ + +#ifndef _SYS_NAMEI_H_ +#define _SYS_NAMEI_H_ + +/* + * Encapsulation of namei parameters. + */ +struct nameidata { + /* + * Arguments to namei/lookup. + */ + caddr_t ni_dirp; /* pathname pointer */ + enum uio_seg ni_segflg; /* location of pathname */ + /* u_long ni_nameiop; namei operation */ + /* u_long ni_flags; flags to namei */ + /* struct proc *ni_proc; process requesting lookup */ + /* + * Arguments to lookup. + */ + /* struct ucred *ni_cred; credentials */ + struct vnode *ni_startdir; /* starting directory */ + struct vnode *ni_rootdir; /* logical root directory */ + /* + * Results: returned from/manipulated by lookup + */ + struct vnode *ni_vp; /* vnode of result */ + struct vnode *ni_dvp; /* vnode of intermediate directory */ + /* + * Shared between namei and lookup/commit routines. + */ + long ni_pathlen; /* remaining chars in path */ + char *ni_next; /* next location in pathname */ + u_long ni_loopcnt; /* count of symlinks encountered */ + /* + * Lookup parameters: this structure describes the subset of + * information from the nameidata structure that is passed + * through the VOP interface. + */ + struct componentname { + /* + * Arguments to lookup. + */ + u_long cn_nameiop; /* namei operation */ + u_long cn_flags; /* flags to namei */ + struct proc *cn_proc; /* process requesting lookup */ + struct ucred *cn_cred; /* credentials */ + /* + * Shared between lookup and commit routines. + */ + char *cn_pnbuf; /* pathname buffer */ + char *cn_nameptr; /* pointer to looked up name */ + long cn_namelen; /* length of looked up component */ + u_long cn_hash; /* hash value of looked up name */ + long cn_consume; /* chars to consume in lookup() */ + } ni_cnd; +}; + +#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 modifier flags, stored in ni_cnd.flags + */ +#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 0x00100 /* do not cross mount points */ +#define RDONLY 0x00200 /* lookup with read-only semantics */ +#define HASBUF 0x00400 /* has allocated pathname buffer */ +#define SAVENAME 0x00800 /* save pathanme buffer */ +#define SAVESTART 0x01000 /* save starting directory */ +#define ISDOTDOT 0x02000 /* current component name is .. */ +#define MAKEENTRY 0x04000 /* entry is to be added to name cache */ +#define ISLASTCN 0x08000 /* this is last component of pathname */ +#define ISSYMLINK 0x10000 /* symlink needs interpretation */ +#define PARAMASK 0xfff00 /* mask of parameter descriptors */ +/* + * Initialization of an nameidata structure. + */ +#define NDINIT(ndp, op, flags, segflg, namep, p) { \ + (ndp)->ni_cnd.cn_nameiop = op; \ + (ndp)->ni_cnd.cn_flags = flags; \ + (ndp)->ni_segflg = segflg; \ + (ndp)->ni_dirp = namep; \ + (ndp)->ni_cnd.cn_proc = p; \ +} +#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 */ + struct namecache **nc_back; /* hash chain */ + 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)); +int lookup __P((struct nameidata *ndp)); +#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 /* !_SYS_NAMEI_H_ */ |
