/* * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * The contents of this file constitute Original Code as defined in and * are subject to the Apple Public Source License Version 1.1 (the * "License"). You may not use this file except in compliance with the * License. Please obtain a copy of the License at * http://www.apple.com/publicsource and read it before using this file. * * This Original Code and all software distributed under the License are * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the * License for the specific language governing rights and limitations * under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */ /* * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * 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. * * @(#)vfs_lookup.c 8.10 (Berkeley) 5/27/95 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* For _PC_NAME_MAX */ #include #include #include #if KTRACE #include #endif static void kdebug_lookup(struct vnode *dp, struct componentname *cnp); /* * Convert a pathname into a pointer to a locked inode. * * The FOLLOW flag is set when symbolic links are to be followed * when they occur at the end of the name translation process. * Symbolic links are always followed for all other pathname * components other than the last. * * The segflg defines whether the name is to be copied from user * space or kernel space. * * Overall outline of namei: * * copy in name * get starting directory * while (!done && !error) { * call lookup to search path. * if symbolic link, massage name in buffer and continue * } */ int namei(ndp) register struct nameidata *ndp; { register struct filedesc *fdp; /* pointer to file descriptor state */ register char *cp; /* pointer into pathname argument */ register struct vnode *dp; /* the directory we are searching */ uio_t auio; int error; struct componentname *cnp = &ndp->ni_cnd; vfs_context_t ctx = cnp->cn_context; struct proc *p = vfs_context_proc(ctx); char *tmppn; char uio_buf[ UIO_SIZEOF(1) ]; #if DIAGNOSTIC if (!vfs_context_ucred(ctx) || !p) panic ("namei: bad cred/proc"); if (cnp->cn_nameiop & (~OPMASK)) panic ("namei: nameiop contaminated with flags"); if (cnp->cn_flags & OPMASK) panic ("namei: flags contaminated with nameiops"); #endif fdp = p->p_fd; /* * Get a buffer for the name to be translated, and copy the * name into the buffer. */ if ((cnp->cn_flags & HASBUF) == 0) { cnp->cn_pnbuf = &ndp->ni_pathbuf; cnp->cn_pnlen = PATHBUFLEN; } #if LP64_DEBUG if (IS_VALID_UIO_SEGFLG(ndp->ni_segflg) == 0) { panic("%s :%d - invalid ni_segflg\n", __FILE__, __LINE__); } #endif /* LP64_DEBUG */ retry_copy: if (UIO_SEG_IS_USER_SPACE(ndp->ni_segflg)) error = copyinstr(ndp->ni_dirp, cnp->cn_pnbuf, cnp->cn_pnlen, (size_t *)&ndp->ni_pathlen); else error = copystr(CAST_DOWN(void *, ndp->ni_dirp), cnp->cn_pnbuf, cnp->cn_pnlen, (size_t *)&ndp->ni_pathlen); if (error == ENAMETOOLONG && !(cnp->cn_flags & HASBUF)) { MALLOC_ZONE(cnp->cn_pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK); cnp->cn_flags |= HASBUF; cnp->cn_pnlen = MAXPATHLEN; goto retry_copy; } if (error) goto error_out; /* If we are auditing the kernel pathname, save the user pathname */ if (cnp->cn_flags & AUDITVNPATH1) AUDIT_ARG(upath, p, cnp->cn_pnbuf, ARG_UPATH1); if (cnp->cn_flags & AUDITVNPATH2) AUDIT_ARG(upath, p, cnp->cn_pnbuf, ARG_UPATH2); /* * Do not allow empty pathnames */ if (*cnp->cn_pnbuf == '\0') { error = ENOENT; goto error_out; } ndp->ni_loopcnt = 0; #if KTRACE if (KTRPOINT(p, KTR_NAMEI)) ktrnamei(p->p_tracep, cnp->cn_pnbuf); #endif /* * determine the starting point for the translation. */ if ((ndp->ni_rootdir = fdp->fd_rdir) == NULLVP) { if ( !(fdp->fd_flags & FD_CHROOT)) ndp->ni_rootdir = rootvnode; } cnp->cn_nameptr = cnp->cn_pnbuf; ndp->ni_usedvp = NULLVP; if (*(cnp->cn_nameptr) == '/') { while (*(cnp->cn_nameptr) == '/') { cnp->cn_nameptr++; ndp->ni_pathlen--; } dp = ndp->ni_rootdir; } else if (cnp->cn_flags & USEDVP) { dp = ndp->ni_dvp; ndp->ni_usedvp = dp; } else dp = fdp->fd_cdir; if (dp == NULLVP) { error = ENOENT; goto error_out; } ndp->ni_dvp = NULLVP; ndp->ni_vp = NULLVP; for (;;) { int need_newpathbuf; int linklen; ndp->ni_startdir = dp; if ( (error = lookup(ndp)) ) { goto error_out; } /* * Check for symbolic link */ if ((cnp->cn_flags & ISSYMLINK) == 0) { return (0); } if ((cnp->cn_flags & FSNODELOCKHELD)) { cnp->cn_flags &= ~FSNODELOCKHELD; unlock_fsnode(ndp->ni_dvp, NULL); } if (ndp->ni_loopcnt++ >= MAXSYMLINKS) { error = ELOOP; break; } if (ndp->ni_pathlen > 1 || !(cnp->cn_flags & HASBUF)) need_newpathbuf = 1; else need_newpathbuf = 0; if (need_newpathbuf) { MALLOC_ZONE(cp, char *, MAXPATHLEN, M_NAMEI, M_WAITOK); } else { cp = cnp->cn_pnbuf; } auio = uio_createwithbuffer(1, 0, UIO_SYSSPACE, UIO_READ, &uio_buf[0], sizeof(uio_buf)); uio_addiov(auio, CAST_USER_ADDR_T(cp), MAXPATHLEN); error = VNOP_READLINK(ndp->ni_vp, auio, ctx); if (error) { if (need_newpathbuf) FREE_ZONE(cp, MAXPATHLEN, M_NAMEI); break; } // LP64todo - fix this linklen = MAXPATHLEN - uio_resid(auio); if (linklen + ndp->ni_pathlen > MAXPATHLEN) { if (need_newpathbuf) FREE_ZONE(cp, MAXPATHLEN, M_NAMEI); error = ENAMETOOLONG; break; } if (need_newpathbuf) { long len = cnp->cn_pnlen; tmppn = cnp->cn_pnbuf; bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen); cnp->cn_pnbuf = cp; cnp->cn_pnlen = MAXPATHLEN; if ( (cnp->cn_flags & HASBUF) ) FREE_ZONE(tmppn, len, M_NAMEI); else cnp->cn_flags |= HASBUF; } else cnp->cn_pnbuf[linklen] = '\0'; ndp->ni_pathlen += linklen; cnp->cn_nameptr = cnp->cn_pnbuf; /* * starting point for 'relative' * symbolic link path */ dp = ndp->ni_dvp; /* * get rid of references returned via 'lookup' */ vnode_put(ndp->ni_vp); vnode_put(ndp->ni_dvp); ndp->ni_vp = NULLVP; ndp->ni_dvp = NULLVP; /* * Check if symbolic link restarts us at the root */ if (*(cnp->cn_nameptr) == '/') { while (*(cnp->cn_nameptr) == '/') { cnp->cn_nameptr++; ndp->ni_pathlen--; } if ((dp = ndp->ni_rootdir) == NULLVP) { error = ENOENT; goto error_out; } } } /* * only come here if we fail to handle a SYMLINK... * if either ni_dvp or ni_vp is non-NULL, then * we need to drop the iocount that was picked * up in the lookup routine */ if (ndp->ni_dvp) vnode_put(ndp->ni_dvp); if (ndp->ni_vp) vnode_put(ndp->ni_vp); error_out: if ( (cnp->cn_flags & HASBUF) ) { cnp->cn_flags &= ~HASBUF; FREE_ZONE(cnp->cn_pnbuf, cnp->cn_pnlen, M_NAMEI); } cnp->cn_pnbuf = NULL; ndp->ni_vp = NULLVP; return (error); } /* * Search a pathname. * This is a very central and rather complicated routine. * * The pathname is pointed to by ni_ptr and is of length ni_pathlen. * The starting directory is taken from ni_startdir. The pathname is * descended until done, or a symbolic link is encountered. The variable * ni_more is clear if the path is completed; it is set to one if a * symbolic link needing interpretation is encountered. * * The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on * whether the name is to be looked up, created, renamed, or deleted. * When CREATE, RENAME, or DELETE is specified, information usable in * creating, renaming, or deleting a directory entry may be calculated. * If flag has LOCKPARENT or'ed into it, the parent directory is returned * locked. If flag has WANTPARENT or'ed into it, the parent directory is * returned unlocked. Otherwise the parent directory is not returned. If * the target of the pathname exists and LOCKLEAF is or'ed into the flag * the target is returned locked, otherwise it is returned unlocked. * When creating or renaming and LOCKPARENT is specified, the target may not * be ".". When deleting and LOCKPARENT is specified, the target may be ".". * * Overall outline of lookup: * * dirloop: * identify next component of name at ndp->ni_ptr * handle degenerate case where name is null string * if .. and crossing mount points and on mounted filesys, find parent * call VNOP_LOOKUP routine for next component name * directory vnode returned in ni_dvp, unlocked unless LOCKPARENT set * component vnode returned in ni_vp (if it exists), locked. * if result vnode is mounted on and crossing mount points, * find mounted on vnode * if more components of name, do next level at dirloop * return the answer in ni_vp, locked if LOCKLEAF set * if LOCKPARENT set, return locked parent in ni_dvp * if WANTPARENT set, return unlocked parent in ni_dvp */ int lookup(ndp) register struct nameidata *ndp; { register char *cp; /* pointer into pathname argument */ vnode_t tdp; /* saved dp */ vnode_t dp; /* the directory we are searching */ mount_t mp; /* mount table entry */ int docache = 1; /* == 0 do not cache last component */ int wantparent; /* 1 => wantparent or lockparent flag */ int rdonly; /* lookup read-only flag bit */ int trailing_slash = 0; int dp_authorized = 0; int error = 0; struct componentname *cnp = &ndp->ni_cnd; vfs_context_t ctx = cnp->cn_context; /* * Setup: break out flag bits into variables. */ if (cnp->cn_flags & (NOCACHE | DOWHITEOUT)) { if ((cnp->cn_flags & NOCACHE) || (cnp->cn_nameiop == DELETE)) docache = 0; } wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT); rdonly = cnp->cn_flags & RDONLY; cnp->cn_flags &= ~ISSYMLINK; cnp->cn_consume = 0; dp = ndp->ni_startdir; ndp->ni_startdir = NULLVP; cp = cnp->cn_nameptr; if (*cp == '\0') { if ( (vnode_getwithref(dp)) ) { dp = NULLVP; error = ENOENT; goto bad; } goto emptyname; } dirloop: ndp->ni_vp = NULLVP; if ( (error = cache_lookup_path(ndp, cnp, dp, ctx, &trailing_slash, &dp_authorized)) ) { dp = NULLVP; goto bad; } if ((cnp->cn_flags & ISLASTCN)) { if (docache) cnp->cn_flags |= MAKEENTRY; } else cnp->cn_flags |= MAKEENTRY; dp = ndp->ni_dvp; if (ndp->ni_vp != NULLVP) { /* * cache_lookup_path returned a non-NULL ni_vp then, * we're guaranteed that the dp is a VDIR, it's * been authorized, and vp is not ".." */ goto returned_from_lookup_path; } /* * Handle "..": two special cases. * 1. If at root directory (e.g. after chroot) * or at absolute root directory * then ignore it so can't get out. * 2. If this vnode is the root of a mounted * filesystem, then replace it with the * vnode which was mounted on so we take the * .. in the other file system. */ if ( (cnp->cn_flags & ISDOTDOT) ) { for (;;) { if (dp == ndp->ni_rootdir || dp == rootvnode) { ndp->ni_dvp = dp; ndp->ni_vp = dp; /* * we're pinned at the root * we've already got one reference on 'dp' * courtesy of cache_lookup_path... take * another one for the ".." * if we fail to get the new reference, we'll * drop our original down in 'bad' */ if ( (vnode_get(dp)) ) { error = ENOENT; goto bad; } goto nextname; } if ((dp->v_flag & VROOT) == 0 || (cnp->cn_flags & NOCROSSMOUNT)) break; if (dp->v_mount == NULL) { /* forced umount */ error = EBADF; goto bad; } tdp = dp; dp = tdp->v_mount->mnt_vnodecovered; vnode_put(tdp); if ( (vnode_getwithref(dp)) ) { dp = NULLVP; error = ENOENT; goto bad; } ndp->ni_dvp = dp; dp_authorized = 0; } } /* * We now have a segment name to search for, and a directory to search. */ unionlookup: ndp->ni_vp = NULLVP; if (dp->v_type != VDIR) { error = ENOTDIR; goto lookup_error; } if ( !(dp_authorized || (cnp->cn_flags & DONOTAUTH)) ) { if ( (error = vnode_authorize(dp, NULL, KAUTH_VNODE_SEARCH, ctx)) ) goto lookup_error; } if ( (error = VNOP_LOOKUP(dp, &ndp->ni_vp, cnp, ctx)) ) { lookup_error: if ((error == ENOENT) && (dp->v_flag & VROOT) && (dp->v_mount != NULL) && (dp->v_mount->mnt_flag & MNT_UNION)) { if ((cnp->cn_flags & FSNODELOCKHELD)) { cnp->cn_flags &= ~FSNODELOCKHELD; unlock_fsnode(dp, NULL); } tdp = dp; dp = tdp->v_mount->mnt_vnodecovered; vnode_put(tdp); if ( (vnode_getwithref(dp)) ) { dp = NULLVP; error = ENOENT; goto bad; } ndp->ni_dvp = dp; dp_authorized = 0; goto unionlookup; } if (error != EJUSTRETURN) goto bad; if (ndp->ni_vp != NULLVP) panic("leaf should be empty"); /* * If creating and at end of pathname, then can consider * allowing file to be created. */ if (rdonly) { error = EROFS; goto bad; } if ((cnp->cn_flags & ISLASTCN) && trailing_slash && !(cnp->cn_flags & WILLBEDIR)) { error = ENOENT; goto bad; } /* * We return with ni_vp NULL to indicate that the entry * doesn't currently exist, leaving a pointer to the * referenced directory vnode in ndp->ni_dvp. */ if (cnp->cn_flags & SAVESTART) { if ( (vnode_get(ndp->ni_dvp)) ) { error = ENOENT; goto bad; } ndp->ni_startdir = ndp->ni_dvp; } if (!wantparent) vnode_put(ndp->ni_dvp); if (kdebug_enable) kdebug_lookup(ndp->ni_dvp, cnp); return (0); } returned_from_lookup_path: dp = ndp->ni_vp; /* * Take into account any additional components consumed by * the underlying filesystem. */ if (cnp->cn_consume > 0) { cnp->cn_nameptr += cnp->cn_consume; ndp->ni_next += cnp->cn_consume; ndp->ni_pathlen -= cnp->cn_consume; cnp->cn_consume = 0; } else { if (dp->v_name == NULL || dp->v_parent == NULLVP) { int isdot_or_dotdot; int update_flags = 0; isdot_or_dotdot = (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') || (cnp->cn_flags & ISDOTDOT); if (isdot_or_dotdot == 0) { if (dp->v_name == NULL) update_flags |= VNODE_UPDATE_NAME; if (ndp->ni_dvp != NULLVP && dp->v_parent == NULLVP) update_flags |= VNODE_UPDATE_PARENT; if (update_flags) vnode_update_identity(dp, ndp->ni_dvp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_hash, update_flags); } } if ( (cnp->cn_flags & MAKEENTRY) && (dp->v_flag & VNCACHEABLE) && LIST_FIRST(&dp->v_nclinks) == NULL) { /* * missing from name cache, but should * be in it... this can happen if volfs * causes the vnode to be created or the * name cache entry got recycled but the * vnode didn't... * check to make sure that ni_dvp is valid * cache_lookup_path may return a NULL */ if (ndp->ni_dvp != NULL) cache_enter(ndp->ni_dvp, dp, cnp); } } /* * Check to see if the vnode has been mounted on... * if so find the root of the mounted file system. */ check_mounted_on: if ((dp->v_type == VDIR) && dp->v_mountedhere && ((cnp->cn_flags & NOCROSSMOUNT) == 0)) { vnode_lock(dp); if ((dp->v_type == VDIR) && (mp = dp->v_mountedhere)) { mp->mnt_crossref++; vnode_unlock(dp); if (vfs_busy(mp, 0)) { mount_dropcrossref(mp, dp, 0); goto check_mounted_on; } error = VFS_ROOT(mp, &tdp, ctx); /* * mount_dropcrossref does a vnode_put * on dp if the 3rd arg is non-zero */ mount_dropcrossref(mp, dp, 1); dp = NULL; vfs_unbusy(mp); if (error) { goto bad2; } ndp->ni_vp = dp = tdp; goto check_mounted_on; } vnode_unlock(dp); } /* * Check for symbolic link */ if ((dp->v_type == VLNK) && ((cnp->cn_flags & FOLLOW) || trailing_slash || *ndp->ni_next == '/')) { cnp->cn_flags |= ISSYMLINK; return (0); } /* * Check for bogus trailing slashes. */ if (trailing_slash) { if (dp->v_type != VDIR) { error = ENOTDIR; goto bad2; } trailing_slash = 0; } nextname: /* * Not a symbolic link. If more pathname, * continue at next component, else return. */ if (*ndp->ni_next == '/') { cnp->cn_nameptr = ndp->ni_next + 1; ndp->ni_pathlen--; while (*cnp->cn_nameptr == '/') { cnp->cn_nameptr++; ndp->ni_pathlen--; } vnode_put(ndp->ni_dvp); cp = cnp->cn_nameptr; if (*cp == '\0') goto emptyname; vnode_put(dp); goto dirloop; } /* * Disallow directory write attempts on read-only file systems. */ if (rdonly && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { error = EROFS; goto bad2; } if (cnp->cn_flags & SAVESTART) { /* * note that we already hold a reference * on both dp and ni_dvp, but for some reason * can't get another one... in this case we * need to do vnode_put on dp in 'bad2' */ if ( (vnode_get(ndp->ni_dvp)) ) { error = ENOENT; goto bad2; } ndp->ni_startdir = ndp->ni_dvp; } if (!wantparent && ndp->ni_dvp) vnode_put(ndp->ni_dvp); if (cnp->cn_flags & AUDITVNPATH1) AUDIT_ARG(vnpath, dp, ARG_VNODE1); else if (cnp->cn_flags & AUDITVNPATH2) AUDIT_ARG(vnpath, dp, ARG_VNODE2); if (kdebug_enable) kdebug_lookup(dp, cnp); return (0); emptyname: cnp->cn_namelen = 0; /* * A degenerate name (e.g. / or "") which is a way of * talking about a directory, e.g. like "/." or ".". */ if (dp->v_type != VDIR) { error = ENOTDIR; goto bad; } if (cnp->cn_nameiop != LOOKUP) { error = EISDIR; goto bad; } if (wantparent) { /* * note that we already hold a reference * on dp, but for some reason can't * get another one... in this case we * need to do vnode_put on dp in 'bad' */ if ( (vnode_get(dp)) ) { error = ENOENT; goto bad; } ndp->ni_dvp = dp; } cnp->cn_flags &= ~ISDOTDOT; cnp->cn_flags |= ISLASTCN; ndp->ni_next = cp; ndp->ni_vp = dp; if (cnp->cn_flags & AUDITVNPATH1) AUDIT_ARG(vnpath, dp, ARG_VNODE1); else if (cnp->cn_flags & AUDITVNPATH2) AUDIT_ARG(vnpath, dp, ARG_VNODE2); if (cnp->cn_flags & SAVESTART) panic("lookup: SAVESTART"); return (0); bad2: if ((cnp->cn_flags & FSNODELOCKHELD)) { cnp->cn_flags &= ~FSNODELOCKHELD; unlock_fsnode(ndp->ni_dvp, NULL); } if (ndp->ni_dvp) vnode_put(ndp->ni_dvp); if (dp) vnode_put(dp); ndp->ni_vp = NULLVP; if (kdebug_enable) kdebug_lookup(dp, cnp); return (error); bad: if ((cnp->cn_flags & FSNODELOCKHELD)) { cnp->cn_flags &= ~FSNODELOCKHELD; unlock_fsnode(ndp->ni_dvp, NULL); } if (dp) vnode_put(dp); ndp->ni_vp = NULLVP; if (kdebug_enable) kdebug_lookup(dp, cnp); return (error); } /* * relookup - lookup a path name component * Used by lookup to re-aquire things. */ int relookup(dvp, vpp, cnp) struct vnode *dvp, **vpp; struct componentname *cnp; { struct vnode *dp = 0; /* the directory we are searching */ int wantparent; /* 1 => wantparent or lockparent flag */ int rdonly; /* lookup read-only flag bit */ int error = 0; #ifdef NAMEI_DIAGNOSTIC int i, newhash; /* DEBUG: check name hash */ char *cp; /* DEBUG: check name ptr/len */ #endif vfs_context_t ctx = cnp->cn_context;; /* * Setup: break out flag bits into variables. */ wantparent = cnp->cn_flags & (LOCKPARENT|WANTPARENT); rdonly = cnp->cn_flags & RDONLY; cnp->cn_flags &= ~ISSYMLINK; if (cnp->cn_flags & NOCACHE) cnp->cn_flags &= ~MAKEENTRY; else cnp->cn_flags |= MAKEENTRY; dp = dvp; /* * Check for degenerate name (e.g. / or "") * which is a way of talking about a directory, * e.g. like "/." or ".". */ if (cnp->cn_nameptr[0] == '\0') { if (cnp->cn_nameiop != LOOKUP || wantparent) { error = EISDIR; goto bad; } if (dp->v_type != VDIR) { error = ENOTDIR; goto bad; } if ( (vnode_get(dp)) ) { error = ENOENT; goto bad; } *vpp = dp; if (cnp->cn_flags & SAVESTART) panic("lookup: SAVESTART"); return (0); } /* * We now have a segment name to search for, and a directory to search. */ if ( (error = VNOP_LOOKUP(dp, vpp, cnp, ctx)) ) { if (error != EJUSTRETURN) goto bad; #if DIAGNOSTIC if (*vpp != NULL) panic("leaf should be empty"); #endif /* * If creating and at end of pathname, then can consider * allowing file to be created. */ if (rdonly) { error = EROFS; goto bad; } /* * We return with ni_vp NULL to indicate that the entry * doesn't currently exist, leaving a pointer to the * (possibly locked) directory inode in ndp->ni_dvp. */ return (0); } dp = *vpp; #if DIAGNOSTIC /* * Check for symbolic link */ if (dp->v_type == VLNK && (cnp->cn_flags & FOLLOW)) panic ("relookup: symlink found.\n"); #endif /* * Disallow directory write attempts on read-only file systems. */ if (rdonly && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { error = EROFS; goto bad2; } /* ASSERT(dvp == ndp->ni_startdir) */ return (0); bad2: vnode_put(dp); bad: *vpp = NULL; return (error); } /* * Free pathname buffer */ void nameidone(struct nameidata *ndp) { if ((ndp->ni_cnd.cn_flags & FSNODELOCKHELD)) { ndp->ni_cnd.cn_flags &= ~FSNODELOCKHELD; unlock_fsnode(ndp->ni_dvp, NULL); } if (ndp->ni_cnd.cn_flags & HASBUF) { char *tmp = ndp->ni_cnd.cn_pnbuf; ndp->ni_cnd.cn_pnbuf = NULL; ndp->ni_cnd.cn_flags &= ~HASBUF; FREE_ZONE(tmp, ndp->ni_cnd.cn_pnlen, M_NAMEI); } } #define NUMPARMS 23 static void kdebug_lookup(dp, cnp) struct vnode *dp; struct componentname *cnp; { register unsigned int i, n; register int dbg_namelen; register int save_dbg_namelen; register char *dbg_nameptr; long dbg_parms[NUMPARMS]; char dbg_buf[4]; static char *dbg_filler = ">>>>"; /* Collect the pathname for tracing */ dbg_namelen = (cnp->cn_nameptr - cnp->cn_pnbuf) + cnp->cn_namelen; dbg_nameptr = cnp->cn_nameptr + cnp->cn_namelen; if (dbg_namelen > sizeof(dbg_parms)) dbg_namelen = sizeof(dbg_parms); dbg_nameptr -= dbg_namelen; save_dbg_namelen = dbg_namelen; i = 0; while (dbg_namelen > 0) { if (dbg_namelen >= 4) { dbg_parms[i++] = *(long *)dbg_nameptr; dbg_nameptr += sizeof(long); dbg_namelen -= sizeof(long); } else { for (n = 0; n < dbg_namelen; n++) dbg_buf[n] = *dbg_nameptr++; while (n <= 3) { if (*dbg_nameptr) dbg_buf[n++] = '>'; else dbg_buf[n++] = 0; } dbg_parms[i++] = *(long *)&dbg_buf[0]; break; } } while (i < NUMPARMS) { if (*dbg_nameptr) dbg_parms[i++] = *(long *)dbg_filler; else dbg_parms[i++] = 0; } /* In the event that we collect multiple, consecutive pathname entries, we must mark the start of the path's string. */ KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW,36)) | DBG_FUNC_START, (unsigned int)dp, dbg_parms[0], dbg_parms[1], dbg_parms[2], 0); for (dbg_namelen = save_dbg_namelen-12, i=3; dbg_namelen > 0; dbg_namelen -=(4 * sizeof(long)), i+= 4) { KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW,36)) | DBG_FUNC_NONE, dbg_parms[i], dbg_parms[i+1], dbg_parms[i+2], dbg_parms[i+3], 0); } }