2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)vfs_lookup.c 8.4 (Berkeley) 2/16/94
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
42 #include "opt_capsicum.h"
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/capsicum.h>
49 #include <sys/fcntl.h>
52 #include <sys/mutex.h>
53 #include <sys/namei.h>
54 #include <sys/vnode.h>
55 #include <sys/mount.h>
56 #include <sys/filedesc.h>
59 #include <sys/syscallsubr.h>
60 #include <sys/sysctl.h>
62 #include <sys/ktrace.h>
65 #include <machine/_inttypes.h>
68 #include <security/audit/audit.h>
69 #include <security/mac/mac_framework.h>
73 #define NAMEI_DIAGNOSTIC 1
74 #undef NAMEI_DIAGNOSTIC
76 SDT_PROVIDER_DEFINE(vfs);
77 SDT_PROBE_DEFINE4(vfs, namei, lookup, entry, "struct vnode *", "char *",
78 "unsigned long", "bool");
79 SDT_PROBE_DEFINE3(vfs, namei, lookup, return, "int", "struct vnode *", "bool");
81 /* Allocation zone for namei. */
82 uma_zone_t namei_zone;
84 /* Placeholder vnode for mp traversal. */
85 static struct vnode *vp_crossmp;
88 crossmp_vop_islocked(struct vop_islocked_args *ap)
95 crossmp_vop_lock1(struct vop_lock1_args *ap)
98 struct lock *lk __unused;
99 const char *file __unused;
100 int flags, line __unused;
108 if ((flags & LK_SHARED) == 0)
109 panic("invalid lock request for crossmp");
111 WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER, file, line,
112 flags & LK_INTERLOCK ? &VI_MTX(vp)->lock_object : NULL);
113 WITNESS_LOCK(&lk->lock_object, 0, file, line);
114 if ((flags & LK_INTERLOCK) != 0)
116 LOCK_LOG_LOCK("SLOCK", &lk->lock_object, 0, 0, ap->a_file, line);
121 crossmp_vop_unlock(struct vop_unlock_args *ap)
124 struct lock *lk __unused;
129 WITNESS_UNLOCK(&lk->lock_object, 0, LOCK_FILE, LOCK_LINE);
130 LOCK_LOG_LOCK("SUNLOCK", &lk->lock_object, 0, 0, LOCK_FILE,
135 static struct vop_vector crossmp_vnodeops = {
136 .vop_default = &default_vnodeops,
137 .vop_islocked = crossmp_vop_islocked,
138 .vop_lock1 = crossmp_vop_lock1,
139 .vop_unlock = crossmp_vop_unlock,
142 * VFS_VOP_VECTOR_REGISTER(crossmp_vnodeops) is not used here since the vnode
143 * gets allocated early. See nameiinit for the direct call below.
146 struct nameicap_tracker {
148 TAILQ_ENTRY(nameicap_tracker) nm_link;
151 /* Zone for cap mode tracker elements used for dotdot capability checks. */
152 static uma_zone_t nt_zone;
155 nameiinit(void *dummy __unused)
158 namei_zone = uma_zcreate("NAMEI", MAXPATHLEN, NULL, NULL, NULL, NULL,
160 nt_zone = uma_zcreate("rentr", sizeof(struct nameicap_tracker),
161 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
162 vfs_vector_op_register(&crossmp_vnodeops);
163 getnewvnode("crossmp", NULL, &crossmp_vnodeops, &vp_crossmp);
165 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_SECOND, nameiinit, NULL);
167 static int lookup_cap_dotdot = 1;
168 SYSCTL_INT(_vfs, OID_AUTO, lookup_cap_dotdot, CTLFLAG_RWTUN,
169 &lookup_cap_dotdot, 0,
170 "enables \"..\" components in path lookup in capability mode");
171 static int lookup_cap_dotdot_nonlocal = 1;
172 SYSCTL_INT(_vfs, OID_AUTO, lookup_cap_dotdot_nonlocal, CTLFLAG_RWTUN,
173 &lookup_cap_dotdot_nonlocal, 0,
174 "enables \"..\" components in path lookup in capability mode "
175 "on non-local mount");
178 nameicap_tracker_add(struct nameidata *ndp, struct vnode *dp)
180 struct nameicap_tracker *nt;
182 if ((ndp->ni_lcf & NI_LCF_CAP_DOTDOT) == 0 || dp->v_type != VDIR)
184 if ((ndp->ni_lcf & (NI_LCF_BENEATH_ABS | NI_LCF_BENEATH_LATCHED)) ==
185 NI_LCF_BENEATH_ABS) {
186 MPASS((ndp->ni_lcf & NI_LCF_LATCH) != 0);
187 if (dp != ndp->ni_beneath_latch)
189 ndp->ni_lcf |= NI_LCF_BENEATH_LATCHED;
191 nt = uma_zalloc(nt_zone, M_WAITOK);
194 TAILQ_INSERT_TAIL(&ndp->ni_cap_tracker, nt, nm_link);
198 nameicap_cleanup(struct nameidata *ndp, bool clean_latch)
200 struct nameicap_tracker *nt, *nt1;
202 KASSERT(TAILQ_EMPTY(&ndp->ni_cap_tracker) ||
203 (ndp->ni_lcf & NI_LCF_CAP_DOTDOT) != 0, ("not strictrelative"));
204 TAILQ_FOREACH_SAFE(nt, &ndp->ni_cap_tracker, nm_link, nt1) {
205 TAILQ_REMOVE(&ndp->ni_cap_tracker, nt, nm_link);
207 uma_zfree(nt_zone, nt);
209 if (clean_latch && (ndp->ni_lcf & NI_LCF_LATCH) != 0) {
210 ndp->ni_lcf &= ~NI_LCF_LATCH;
211 vrele(ndp->ni_beneath_latch);
216 * For dotdot lookups in capability mode, only allow the component
217 * lookup to succeed if the resulting directory was already traversed
218 * during the operation. This catches situations where already
219 * traversed directory is moved to different parent, and then we walk
220 * over it with dotdots.
222 * Also allow to force failure of dotdot lookups for non-local
223 * filesystems, where external agents might assist local lookups to
224 * escape the compartment.
227 nameicap_check_dotdot(struct nameidata *ndp, struct vnode *dp)
229 struct nameicap_tracker *nt;
232 if ((ndp->ni_lcf & NI_LCF_CAP_DOTDOT) == 0 || dp == NULL ||
236 if (lookup_cap_dotdot_nonlocal == 0 && mp != NULL &&
237 (mp->mnt_flag & MNT_LOCAL) == 0)
238 return (ENOTCAPABLE);
239 TAILQ_FOREACH_REVERSE(nt, &ndp->ni_cap_tracker, nameicap_tracker_head,
241 if ((ndp->ni_lcf & NI_LCF_LATCH) != 0 &&
242 ndp->ni_beneath_latch == nt->dp) {
243 ndp->ni_lcf &= ~NI_LCF_BENEATH_LATCHED;
244 nameicap_cleanup(ndp, false);
250 return (ENOTCAPABLE);
254 namei_cleanup_cnp(struct componentname *cnp)
257 uma_zfree(namei_zone, cnp->cn_pnbuf);
259 cnp->cn_pnbuf = NULL;
260 cnp->cn_nameptr = NULL;
265 namei_handle_root(struct nameidata *ndp, struct vnode **dpp)
267 struct componentname *cnp;
270 if ((ndp->ni_lcf & NI_LCF_STRICTRELATIVE) != 0) {
272 if (KTRPOINT(curthread, KTR_CAPFAIL))
273 ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL);
275 return (ENOTCAPABLE);
277 if ((cnp->cn_flags & BENEATH) != 0) {
278 ndp->ni_lcf |= NI_LCF_BENEATH_ABS;
279 ndp->ni_lcf &= ~NI_LCF_BENEATH_LATCHED;
280 nameicap_cleanup(ndp, false);
282 while (*(cnp->cn_nameptr) == '/') {
286 *dpp = ndp->ni_rootdir;
292 namei_setup(struct nameidata *ndp, struct vnode **dpp, struct pwd **pwdp)
294 struct componentname *cnp;
299 struct filecaps dirfd_caps;
306 startdir_used = false;
310 #ifdef CAPABILITY_MODE
312 * In capability mode, lookups must be restricted to happen in
313 * the subtree with the root specified by the file descriptor:
314 * - The root must be real file descriptor, not the pseudo-descriptor
316 * - The passed path must be relative and not absolute.
317 * - If lookup_cap_dotdot is disabled, path must not contain the
319 * - If lookup_cap_dotdot is enabled, we verify that all '..'
320 * components lookups result in the directories which were
321 * previously walked by us, which prevents an escape from
324 if (IN_CAPABILITY_MODE(td) && (cnp->cn_flags & NOCAPCHECK) == 0) {
325 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE;
326 ndp->ni_resflags |= NIRES_STRICTREL;
327 if (ndp->ni_dirfd == AT_FDCWD) {
329 if (KTRPOINT(td, KTR_CAPFAIL))
330 ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL);
339 * Get starting point for the translation.
343 * The reference on ni_rootdir is acquired in the block below to avoid
344 * back-to-back atomics for absolute lookups.
346 ndp->ni_rootdir = pwd->pwd_rdir;
347 ndp->ni_topdir = pwd->pwd_jdir;
349 if (cnp->cn_pnbuf[0] == '/') {
350 ndp->ni_resflags |= NIRES_ABS;
351 error = namei_handle_root(ndp, dpp);
353 if (ndp->ni_startdir != NULL) {
354 *dpp = ndp->ni_startdir;
355 startdir_used = true;
356 } else if (ndp->ni_dirfd == AT_FDCWD) {
357 *dpp = pwd->pwd_cdir;
360 rights = *ndp->ni_rightsneeded;
361 cap_rights_set_one(&rights, CAP_LOOKUP);
363 if (cnp->cn_flags & AUDITVNODE1)
364 AUDIT_ARG_ATFD1(ndp->ni_dirfd);
365 if (cnp->cn_flags & AUDITVNODE2)
366 AUDIT_ARG_ATFD2(ndp->ni_dirfd);
368 * Effectively inlined fgetvp_rights, because we need to
369 * inspect the file as well as grabbing the vnode.
371 error = fget_cap(td, ndp->ni_dirfd, &rights,
372 &dfp, &ndp->ni_filecaps);
375 * Preserve the error; it should either be EBADF
376 * or capability-related, both of which can be
377 * safely returned to the caller.
380 if (dfp->f_ops == &badfileops) {
382 } else if (dfp->f_vnode == NULL) {
388 if ((dfp->f_flag & FSEARCH) != 0)
389 cnp->cn_flags |= NOEXECCHECK;
395 * If file descriptor doesn't have all rights,
396 * all lookups relative to it must also be
400 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights,
402 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL ||
403 ndp->ni_filecaps.fc_nioctls != -1) {
404 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE;
405 ndp->ni_resflags |= NIRES_STRICTREL;
409 if (error == 0 && (*dpp)->v_type != VDIR)
412 if (error == 0 && (cnp->cn_flags & BENEATH) != 0) {
413 if (ndp->ni_dirfd == AT_FDCWD) {
414 ndp->ni_beneath_latch = pwd->pwd_cdir;
415 vrefact(ndp->ni_beneath_latch);
417 rights = *ndp->ni_rightsneeded;
418 cap_rights_set_one(&rights, CAP_LOOKUP);
419 error = fgetvp_rights(td, ndp->ni_dirfd, &rights,
420 &dirfd_caps, &ndp->ni_beneath_latch);
421 if (error == 0 && (*dpp)->v_type != VDIR) {
422 vrele(ndp->ni_beneath_latch);
427 ndp->ni_lcf |= NI_LCF_LATCH;
430 * If we are auditing the kernel pathname, save the user pathname.
432 if (cnp->cn_flags & AUDITVNODE1)
433 AUDIT_ARG_UPATH1_VP(td, ndp->ni_rootdir, *dpp, cnp->cn_pnbuf);
434 if (cnp->cn_flags & AUDITVNODE2)
435 AUDIT_ARG_UPATH2_VP(td, ndp->ni_rootdir, *dpp, cnp->cn_pnbuf);
436 if (ndp->ni_startdir != NULL && !startdir_used)
437 vrele(ndp->ni_startdir);
444 MPASS((ndp->ni_lcf & (NI_LCF_BENEATH_ABS | NI_LCF_LATCH)) !=
446 if (((ndp->ni_lcf & NI_LCF_STRICTRELATIVE) != 0 &&
447 lookup_cap_dotdot != 0) ||
448 ((ndp->ni_lcf & NI_LCF_STRICTRELATIVE) == 0 &&
449 (cnp->cn_flags & BENEATH) != 0))
450 ndp->ni_lcf |= NI_LCF_CAP_DOTDOT;
451 SDT_PROBE4(vfs, namei, lookup, entry, *dpp, cnp->cn_pnbuf,
452 cnp->cn_flags, false);
458 * Convert a pathname into a pointer to a locked vnode.
460 * The FOLLOW flag is set when symbolic links are to be followed
461 * when they occur at the end of the name translation process.
462 * Symbolic links are always followed for all other pathname
463 * components other than the last.
465 * The segflg defines whether the name is to be copied from user
466 * space or kernel space.
468 * Overall outline of namei:
471 * get starting directory
472 * while (!done && !error) {
473 * call lookup to search path.
474 * if symbolic link, massage name in buffer and continue
478 namei(struct nameidata *ndp)
480 char *cp; /* pointer into pathname argument */
481 struct vnode *dp; /* the directory we are searching */
482 struct iovec aiov; /* uio for reading symbolic links */
483 struct componentname *cnp;
488 enum cache_fpl_status status;
496 * While NDINIT may seem like a more natural place to do it, there are
497 * callers which directly modify flags past invoking init.
499 cnp->cn_origflags = cnp->cn_flags;
501 ndp->ni_cnd.cn_cred = ndp->ni_cnd.cn_thread->td_ucred;
502 KASSERT(cnp->cn_cred && td->td_proc, ("namei: bad cred/proc"));
503 KASSERT((cnp->cn_flags & NAMEI_INTERNAL_FLAGS) == 0,
504 ("namei: unexpected flags: %" PRIx64 "\n",
505 cnp->cn_flags & NAMEI_INTERNAL_FLAGS));
506 if (cnp->cn_flags & NOCACHE)
507 KASSERT(cnp->cn_nameiop != LOOKUP,
508 ("%s: NOCACHE passed with LOOKUP", __func__));
509 MPASS(ndp->ni_startdir == NULL || ndp->ni_startdir->v_type == VDIR ||
510 ndp->ni_startdir->v_type == VBAD);
516 * Get a buffer for the name to be translated, and copy the
517 * name into the buffer.
519 cnp->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK);
520 if (ndp->ni_segflg == UIO_SYSSPACE)
521 error = copystr(ndp->ni_dirp, cnp->cn_pnbuf, MAXPATHLEN,
524 error = copyinstr(ndp->ni_dirp, cnp->cn_pnbuf, MAXPATHLEN,
527 if (__predict_false(error != 0)) {
528 namei_cleanup_cnp(cnp);
533 * Don't allow empty pathnames.
535 if (__predict_false(*cnp->cn_pnbuf == '\0')) {
536 namei_cleanup_cnp(cnp);
541 if (KTRPOINT(td, KTR_NAMEI)) {
542 KASSERT(cnp->cn_thread == curthread,
543 ("namei not using curthread"));
544 ktrnamei(cnp->cn_pnbuf);
548 cnp->cn_nameptr = cnp->cn_pnbuf;
551 * First try looking up the target without locking any vnodes.
553 * We may need to start from scratch or pick up where it left off.
555 error = cache_fplookup(ndp, &status, &pwd);
557 case CACHE_FPL_STATUS_UNSET:
558 __assert_unreachable();
560 case CACHE_FPL_STATUS_HANDLED:
564 case CACHE_FPL_STATUS_PARTIAL:
565 TAILQ_INIT(&ndp->ni_cap_tracker);
566 dp = ndp->ni_startdir;
568 case CACHE_FPL_STATUS_ABORTED:
569 TAILQ_INIT(&ndp->ni_cap_tracker);
570 error = namei_setup(ndp, &dp, &pwd);
572 namei_cleanup_cnp(cnp);
584 ndp->ni_startdir = dp;
589 * If not a symbolic link, we're done.
591 if ((cnp->cn_flags & ISSYMLINK) == 0) {
592 if ((cnp->cn_flags & (SAVENAME | SAVESTART)) == 0) {
593 namei_cleanup_cnp(cnp);
595 cnp->cn_flags |= HASBUF;
596 if ((ndp->ni_lcf & (NI_LCF_BENEATH_ABS |
597 NI_LCF_BENEATH_LATCHED)) == NI_LCF_BENEATH_ABS) {
601 nameicap_cleanup(ndp, true);
602 SDT_PROBE3(vfs, namei, lookup, return, error,
603 (error == 0 ? ndp->ni_vp : NULL), false);
609 if (ndp->ni_loopcnt++ >= MAXSYMLINKS) {
614 if ((cnp->cn_flags & NOMACCHECK) == 0) {
615 error = mac_vnode_check_readlink(td->td_ucred,
621 if (ndp->ni_pathlen > 1)
622 cp = uma_zalloc(namei_zone, M_WAITOK);
626 aiov.iov_len = MAXPATHLEN;
627 auio.uio_iov = &aiov;
630 auio.uio_rw = UIO_READ;
631 auio.uio_segflg = UIO_SYSSPACE;
633 auio.uio_resid = MAXPATHLEN;
634 error = VOP_READLINK(ndp->ni_vp, &auio, cnp->cn_cred);
636 if (ndp->ni_pathlen > 1)
637 uma_zfree(namei_zone, cp);
640 linklen = MAXPATHLEN - auio.uio_resid;
642 if (ndp->ni_pathlen > 1)
643 uma_zfree(namei_zone, cp);
647 if (linklen + ndp->ni_pathlen > MAXPATHLEN) {
648 if (ndp->ni_pathlen > 1)
649 uma_zfree(namei_zone, cp);
650 error = ENAMETOOLONG;
653 if (ndp->ni_pathlen > 1) {
654 bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen);
655 uma_zfree(namei_zone, cnp->cn_pnbuf);
658 cnp->cn_pnbuf[linklen] = '\0';
659 ndp->ni_pathlen += linklen;
663 * Check if root directory should replace current directory.
665 cnp->cn_nameptr = cnp->cn_pnbuf;
666 if (*(cnp->cn_nameptr) == '/') {
668 error = namei_handle_root(ndp, &dp);
678 namei_cleanup_cnp(cnp);
679 nameicap_cleanup(ndp, true);
680 SDT_PROBE3(vfs, namei, lookup, return, error, NULL, false);
686 compute_cn_lkflags(struct mount *mp, int lkflags, int cnflags)
689 if (mp == NULL || ((lkflags & LK_SHARED) &&
690 (!(mp->mnt_kern_flag & MNTK_LOOKUP_SHARED) ||
691 ((cnflags & ISDOTDOT) &&
692 (mp->mnt_kern_flag & MNTK_LOOKUP_EXCL_DOTDOT))))) {
693 lkflags &= ~LK_SHARED;
694 lkflags |= LK_EXCLUSIVE;
696 lkflags |= LK_NODDLKTREAT;
701 needs_exclusive_leaf(struct mount *mp, int flags)
705 * Intermediate nodes can use shared locks, we only need to
706 * force an exclusive lock for leaf nodes.
708 if ((flags & (ISLASTCN | LOCKLEAF)) != (ISLASTCN | LOCKLEAF))
711 /* Always use exclusive locks if LOCKSHARED isn't set. */
712 if (!(flags & LOCKSHARED))
716 * For lookups during open(), if the mount point supports
717 * extended shared operations, then use a shared lock for the
718 * leaf node, otherwise use an exclusive lock.
720 if ((flags & ISOPEN) != 0)
721 return (!MNT_EXTENDED_SHARED(mp));
724 * Lookup requests outside of open() that specify LOCKSHARED
725 * only need a shared lock on the leaf vnode.
732 * This is a very central and rather complicated routine.
734 * The pathname is pointed to by ni_ptr and is of length ni_pathlen.
735 * The starting directory is taken from ni_startdir. The pathname is
736 * descended until done, or a symbolic link is encountered. The variable
737 * ni_more is clear if the path is completed; it is set to one if a
738 * symbolic link needing interpretation is encountered.
740 * The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on
741 * whether the name is to be looked up, created, renamed, or deleted.
742 * When CREATE, RENAME, or DELETE is specified, information usable in
743 * creating, renaming, or deleting a directory entry may be calculated.
744 * If flag has LOCKPARENT or'ed into it, the parent directory is returned
745 * locked. If flag has WANTPARENT or'ed into it, the parent directory is
746 * returned unlocked. Otherwise the parent directory is not returned. If
747 * the target of the pathname exists and LOCKLEAF is or'ed into the flag
748 * the target is returned locked, otherwise it is returned unlocked.
749 * When creating or renaming and LOCKPARENT is specified, the target may not
750 * be ".". When deleting and LOCKPARENT is specified, the target may be ".".
752 * Overall outline of lookup:
755 * identify next component of name at ndp->ni_ptr
756 * handle degenerate case where name is null string
757 * if .. and crossing mount points and on mounted filesys, find parent
758 * call VOP_LOOKUP routine for next component name
759 * directory vnode returned in ni_dvp, unlocked unless LOCKPARENT set
760 * component vnode returned in ni_vp (if it exists), locked.
761 * if result vnode is mounted on and crossing mount points,
762 * find mounted on vnode
763 * if more components of name, do next level at dirloop
764 * return the answer in ni_vp, locked if LOCKLEAF set
765 * if LOCKPARENT set, return locked parent in ni_dvp
766 * if WANTPARENT set, return unlocked parent in ni_dvp
769 lookup(struct nameidata *ndp)
771 char *cp; /* pointer into pathname argument */
772 char *prev_ni_next; /* saved ndp->ni_next */
773 struct vnode *dp = NULL; /* the directory we are searching */
774 struct vnode *tdp; /* saved dp */
775 struct mount *mp; /* mount table entry */
777 size_t prev_ni_pathlen; /* saved ndp->ni_pathlen */
778 int docache; /* == 0 do not cache last component */
779 int wantparent; /* 1 => wantparent or lockparent flag */
780 int rdonly; /* lookup read-only flag bit */
782 int dpunlocked = 0; /* dp has already been unlocked */
783 int relookup = 0; /* do not consume the path component */
784 struct componentname *cnp = &ndp->ni_cnd;
789 * Setup: break out flag bits into variables.
792 wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT);
793 KASSERT(cnp->cn_nameiop == LOOKUP || wantparent,
794 ("CREATE, DELETE, RENAME require LOCKPARENT or WANTPARENT."));
796 * When set to zero, docache causes the last component of the
797 * pathname to be deleted from the cache and the full lookup
798 * of the name to be done (via VOP_CACHEDLOOKUP()). Often
799 * filesystems need some pre-computed values that are made
800 * during the full lookup, for instance UFS sets dp->i_offset.
802 * The docache variable is set to zero when requested by the
803 * NOCACHE flag and for all modifying operations except CREATE.
805 docache = (cnp->cn_flags & NOCACHE) ^ NOCACHE;
806 if (cnp->cn_nameiop == DELETE ||
807 (wantparent && cnp->cn_nameiop != CREATE &&
808 cnp->cn_nameiop != LOOKUP))
810 rdonly = cnp->cn_flags & RDONLY;
811 cnp->cn_flags &= ~ISSYMLINK;
814 * We use shared locks until we hit the parent of the last cn then
815 * we adjust based on the requesting flags.
817 cnp->cn_lkflags = LK_SHARED;
818 dp = ndp->ni_startdir;
819 ndp->ni_startdir = NULLVP;
821 compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | LK_RETRY,
826 * Search a new directory.
828 * The last component of the filename is left accessible via
829 * cnp->cn_nameptr for callers that need the name. Callers needing
830 * the name set the SAVENAME flag. When done, they assume
831 * responsibility for freeing the pathname buffer.
833 for (cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++)
835 cnp->cn_namelen = cp - cnp->cn_nameptr;
836 if (cnp->cn_namelen > NAME_MAX) {
837 error = ENAMETOOLONG;
840 #ifdef NAMEI_DIAGNOSTIC
843 printf("{%s}: ", cnp->cn_nameptr);
846 prev_ni_pathlen = ndp->ni_pathlen;
847 ndp->ni_pathlen -= cnp->cn_namelen;
848 KASSERT(ndp->ni_pathlen <= PATH_MAX,
849 ("%s: ni_pathlen underflow to %zd\n", __func__, ndp->ni_pathlen));
850 prev_ni_next = ndp->ni_next;
854 * Replace multiple slashes by a single slash and trailing slashes
855 * by a null. This must be done before VOP_LOOKUP() because some
856 * fs's don't know about trailing slashes. Remember if there were
857 * trailing slashes to handle symlinks, existing non-directories
858 * and non-existing files that won't be directories specially later.
860 while (*cp == '/' && (cp[1] == '/' || cp[1] == '\0')) {
864 *ndp->ni_next = '\0';
865 cnp->cn_flags |= TRAILINGSLASH;
870 cnp->cn_flags |= MAKEENTRY;
871 if (*cp == '\0' && docache == 0)
872 cnp->cn_flags &= ~MAKEENTRY;
873 if (cnp->cn_namelen == 2 &&
874 cnp->cn_nameptr[1] == '.' && cnp->cn_nameptr[0] == '.')
875 cnp->cn_flags |= ISDOTDOT;
877 cnp->cn_flags &= ~ISDOTDOT;
878 if (*ndp->ni_next == 0)
879 cnp->cn_flags |= ISLASTCN;
881 cnp->cn_flags &= ~ISLASTCN;
883 if ((cnp->cn_flags & ISLASTCN) != 0 &&
884 cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.' &&
885 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
890 nameicap_tracker_add(ndp, dp);
893 * Check for degenerate name (e.g. / or "")
894 * which is a way of talking about a directory,
895 * e.g. like "/." or ".".
897 if (cnp->cn_nameptr[0] == '\0') {
898 if (dp->v_type != VDIR) {
902 if (cnp->cn_nameiop != LOOKUP) {
912 if (cnp->cn_flags & AUDITVNODE1)
913 AUDIT_ARG_VNODE1(dp);
914 else if (cnp->cn_flags & AUDITVNODE2)
915 AUDIT_ARG_VNODE2(dp);
917 if (!(cnp->cn_flags & (LOCKPARENT | LOCKLEAF)))
919 /* XXX This should probably move to the top of function. */
920 if (cnp->cn_flags & SAVESTART)
921 panic("lookup: SAVESTART");
926 * Handle "..": five special cases.
927 * 0. If doing a capability lookup and lookup_cap_dotdot is
928 * disabled, return ENOTCAPABLE.
929 * 1. Return an error if this is the last component of
930 * the name and the operation is DELETE or RENAME.
931 * 2. If at root directory (e.g. after chroot)
932 * or at absolute root directory
933 * then ignore it so can't get out.
934 * 3. If this vnode is the root of a mounted
935 * filesystem, then replace it with the
936 * vnode which was mounted on so we take the
937 * .. in the other filesystem.
938 * 4. If the vnode is the top directory of
939 * the jail or chroot, don't let them out.
940 * 5. If doing a capability lookup and lookup_cap_dotdot is
941 * enabled, return ENOTCAPABLE if the lookup would escape
942 * from the initial file descriptor directory. Checks are
943 * done by ensuring that namei() already traversed the
944 * result of dotdot lookup.
946 if (cnp->cn_flags & ISDOTDOT) {
947 if ((ndp->ni_lcf & (NI_LCF_STRICTRELATIVE | NI_LCF_CAP_DOTDOT))
948 == NI_LCF_STRICTRELATIVE) {
950 if (KTRPOINT(curthread, KTR_CAPFAIL))
951 ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL);
956 if ((cnp->cn_flags & ISLASTCN) != 0 &&
957 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
962 for (pr = cnp->cn_cred->cr_prison; pr != NULL;
964 if (dp == pr->pr_root)
966 if (dp == ndp->ni_rootdir ||
967 dp == ndp->ni_topdir ||
970 ((dp->v_vflag & VV_ROOT) != 0 &&
971 (cnp->cn_flags & NOCROSSMOUNT) != 0)) {
977 if ((dp->v_vflag & VV_ROOT) == 0)
979 if (VN_IS_DOOMED(dp)) { /* forced unmount */
984 dp = dp->v_mount->mnt_vnodecovered;
988 compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags |
989 LK_RETRY, ISDOTDOT));
990 error = nameicap_check_dotdot(ndp, dp);
993 if (KTRPOINT(curthread, KTR_CAPFAIL))
994 ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL);
1002 * We now have a segment name to search for, and a directory to search.
1006 error = mac_vnode_check_lookup(cnp->cn_thread->td_ucred, dp, cnp);
1012 ASSERT_VOP_LOCKED(dp, "lookup");
1014 * If we have a shared lock we may need to upgrade the lock for the
1017 if ((cnp->cn_flags & LOCKPARENT) && (cnp->cn_flags & ISLASTCN) &&
1018 dp != vp_crossmp && VOP_ISLOCKED(dp) == LK_SHARED)
1019 vn_lock(dp, LK_UPGRADE|LK_RETRY);
1020 if (VN_IS_DOOMED(dp)) {
1025 * If we're looking up the last component and we need an exclusive
1026 * lock, adjust our lkflags.
1028 if (needs_exclusive_leaf(dp->v_mount, cnp->cn_flags))
1029 cnp->cn_lkflags = LK_EXCLUSIVE;
1030 #ifdef NAMEI_DIAGNOSTIC
1031 vn_printf(dp, "lookup in ");
1033 lkflags_save = cnp->cn_lkflags;
1034 cnp->cn_lkflags = compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags,
1036 error = VOP_LOOKUP(dp, &ndp->ni_vp, cnp);
1037 cnp->cn_lkflags = lkflags_save;
1039 KASSERT(ndp->ni_vp == NULL, ("leaf should be empty"));
1040 #ifdef NAMEI_DIAGNOSTIC
1041 printf("not found\n");
1043 if ((error == ENOENT) &&
1044 (dp->v_vflag & VV_ROOT) && (dp->v_mount != NULL) &&
1045 (dp->v_mount->mnt_flag & MNT_UNION)) {
1047 dp = dp->v_mount->mnt_vnodecovered;
1051 compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags |
1052 LK_RETRY, cnp->cn_flags));
1053 nameicap_tracker_add(ndp, dp);
1057 if (error == ERELOOKUP) {
1065 if (error != EJUSTRETURN)
1068 * At this point, we know we're at the end of the
1069 * pathname. If creating / renaming, we can consider
1070 * allowing the file or directory to be created / renamed,
1071 * provided we're not on a read-only filesystem.
1077 /* trailing slash only allowed for directories */
1078 if ((cnp->cn_flags & TRAILINGSLASH) &&
1079 !(cnp->cn_flags & WILLBEDIR)) {
1083 if ((cnp->cn_flags & LOCKPARENT) == 0)
1086 * We return with ni_vp NULL to indicate that the entry
1087 * doesn't currently exist, leaving a pointer to the
1088 * (possibly locked) directory vnode in ndp->ni_dvp.
1090 if (cnp->cn_flags & SAVESTART) {
1091 ndp->ni_startdir = ndp->ni_dvp;
1092 VREF(ndp->ni_startdir);
1098 #ifdef NAMEI_DIAGNOSTIC
1104 * Check to see if the vnode has been mounted on;
1105 * if so find the root of the mounted filesystem.
1107 while (dp->v_type == VDIR && (mp = dp->v_mountedhere) &&
1108 (cnp->cn_flags & NOCROSSMOUNT) == 0) {
1109 if (vfs_busy(mp, 0))
1112 if (dp != ndp->ni_dvp)
1116 vrefact(vp_crossmp);
1117 ndp->ni_dvp = vp_crossmp;
1118 error = VFS_ROOT(mp, compute_cn_lkflags(mp, cnp->cn_lkflags,
1119 cnp->cn_flags), &tdp);
1121 if (vn_lock(vp_crossmp, LK_SHARED | LK_NOWAIT))
1122 panic("vp_crossmp exclusively locked or reclaimed");
1127 ndp->ni_vp = dp = tdp;
1131 * Check for symbolic link
1133 if ((dp->v_type == VLNK) &&
1134 ((cnp->cn_flags & FOLLOW) || (cnp->cn_flags & TRAILINGSLASH) ||
1135 *ndp->ni_next == '/')) {
1136 cnp->cn_flags |= ISSYMLINK;
1137 if (VN_IS_DOOMED(dp)) {
1139 * We can't know whether the directory was mounted with
1140 * NOSYMFOLLOW, so we can't follow safely.
1145 if (dp->v_mount->mnt_flag & MNT_NOSYMFOLLOW) {
1150 * Symlink code always expects an unlocked dvp.
1152 if (ndp->ni_dvp != ndp->ni_vp) {
1153 VOP_UNLOCK(ndp->ni_dvp);
1154 ni_dvp_unlocked = 1;
1161 * Not a symbolic link that we will follow. Continue with the
1162 * next component if there is any; otherwise, we're done.
1164 KASSERT((cnp->cn_flags & ISLASTCN) || *ndp->ni_next == '/',
1165 ("lookup: invalid path state."));
1168 ndp->ni_pathlen = prev_ni_pathlen;
1169 ndp->ni_next = prev_ni_next;
1170 if (ndp->ni_dvp != dp)
1176 if (cnp->cn_flags & ISDOTDOT) {
1177 error = nameicap_check_dotdot(ndp, ndp->ni_vp);
1180 if (KTRPOINT(curthread, KTR_CAPFAIL))
1181 ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL);
1186 if (*ndp->ni_next == '/') {
1187 cnp->cn_nameptr = ndp->ni_next;
1188 while (*cnp->cn_nameptr == '/') {
1192 if (ndp->ni_dvp != dp)
1199 * If we're processing a path with a trailing slash,
1200 * check that the end result is a directory.
1202 if ((cnp->cn_flags & TRAILINGSLASH) && dp->v_type != VDIR) {
1207 * Disallow directory write attempts on read-only filesystems.
1210 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
1214 if (cnp->cn_flags & SAVESTART) {
1215 ndp->ni_startdir = ndp->ni_dvp;
1216 VREF(ndp->ni_startdir);
1219 ni_dvp_unlocked = 2;
1220 if (ndp->ni_dvp != dp)
1224 } else if ((cnp->cn_flags & LOCKPARENT) == 0 && ndp->ni_dvp != dp) {
1225 VOP_UNLOCK(ndp->ni_dvp);
1226 ni_dvp_unlocked = 1;
1229 if (cnp->cn_flags & AUDITVNODE1)
1230 AUDIT_ARG_VNODE1(dp);
1231 else if (cnp->cn_flags & AUDITVNODE2)
1232 AUDIT_ARG_VNODE2(dp);
1234 if ((cnp->cn_flags & LOCKLEAF) == 0)
1238 * FIXME: for lookups which only cross a mount point to fetch the
1239 * root vnode, ni_dvp will be set to vp_crossmp. This can be a problem
1240 * if either WANTPARENT or LOCKPARENT is set.
1243 * Because of shared lookup we may have the vnode shared locked, but
1244 * the caller may want it to be exclusively locked.
1246 if (needs_exclusive_leaf(dp->v_mount, cnp->cn_flags) &&
1247 VOP_ISLOCKED(dp) != LK_EXCLUSIVE) {
1248 vn_lock(dp, LK_UPGRADE | LK_RETRY);
1249 if (VN_IS_DOOMED(dp)) {
1254 if (ndp->ni_vp != NULL && ndp->ni_vp->v_type == VDIR)
1255 nameicap_tracker_add(ndp, ndp->ni_vp);
1259 if (ni_dvp_unlocked != 2) {
1260 if (dp != ndp->ni_dvp && !ni_dvp_unlocked)
1273 * relookup - lookup a path name component
1274 * Used by lookup to re-acquire things.
1277 relookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp)
1279 struct vnode *dp = NULL; /* the directory we are searching */
1280 int wantparent; /* 1 => wantparent or lockparent flag */
1281 int rdonly; /* lookup read-only flag bit */
1284 KASSERT(cnp->cn_flags & ISLASTCN,
1285 ("relookup: Not given last component."));
1287 * Setup: break out flag bits into variables.
1289 wantparent = cnp->cn_flags & (LOCKPARENT|WANTPARENT);
1290 KASSERT(wantparent, ("relookup: parent not wanted."));
1291 rdonly = cnp->cn_flags & RDONLY;
1292 cnp->cn_flags &= ~ISSYMLINK;
1294 cnp->cn_lkflags = LK_EXCLUSIVE;
1295 vn_lock(dp, LK_EXCLUSIVE | LK_RETRY);
1298 * Search a new directory.
1300 * The last component of the filename is left accessible via
1301 * cnp->cn_nameptr for callers that need the name. Callers needing
1302 * the name set the SAVENAME flag. When done, they assume
1303 * responsibility for freeing the pathname buffer.
1305 #ifdef NAMEI_DIAGNOSTIC
1306 printf("{%s}: ", cnp->cn_nameptr);
1310 * Check for "" which represents the root directory after slash
1313 if (cnp->cn_nameptr[0] == '\0') {
1315 * Support only LOOKUP for "/" because lookup()
1316 * can't succeed for CREATE, DELETE and RENAME.
1318 KASSERT(cnp->cn_nameiop == LOOKUP, ("nameiop must be LOOKUP"));
1319 KASSERT(dp->v_type == VDIR, ("dp is not a directory"));
1321 if (!(cnp->cn_flags & LOCKLEAF))
1324 /* XXX This should probably move to the top of function. */
1325 if (cnp->cn_flags & SAVESTART)
1326 panic("lookup: SAVESTART");
1330 if (cnp->cn_flags & ISDOTDOT)
1331 panic ("relookup: lookup on dot-dot");
1334 * We now have a segment name to search for, and a directory to search.
1336 #ifdef NAMEI_DIAGNOSTIC
1337 vn_printf(dp, "search in ");
1339 if ((error = VOP_LOOKUP(dp, vpp, cnp)) != 0) {
1340 KASSERT(*vpp == NULL, ("leaf should be empty"));
1341 if (error != EJUSTRETURN)
1344 * If creating and at end of pathname, then can consider
1345 * allowing file to be created.
1351 /* ASSERT(dvp == ndp->ni_startdir) */
1352 if (cnp->cn_flags & SAVESTART)
1354 if ((cnp->cn_flags & LOCKPARENT) == 0)
1357 * We return with ni_vp NULL to indicate that the entry
1358 * doesn't currently exist, leaving a pointer to the
1359 * (possibly locked) directory vnode in ndp->ni_dvp.
1367 * Disallow directory write attempts on read-only filesystems.
1370 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
1379 * Set the parent lock/ref state to the requested state.
1381 if ((cnp->cn_flags & LOCKPARENT) == 0 && dvp != dp) {
1386 } else if (!wantparent)
1389 * Check for symbolic link
1391 KASSERT(dp->v_type != VLNK || !(cnp->cn_flags & FOLLOW),
1392 ("relookup: symlink found.\n"));
1394 /* ASSERT(dvp == ndp->ni_startdir) */
1395 if (cnp->cn_flags & SAVESTART)
1398 if ((cnp->cn_flags & LOCKLEAF) == 0)
1408 * Free data allocated by namei(); see namei(9) for details.
1411 NDFREE_PNBUF(struct nameidata *ndp)
1414 if ((ndp->ni_cnd.cn_flags & HASBUF) != 0) {
1415 MPASS((ndp->ni_cnd.cn_flags & (SAVENAME | SAVESTART)) != 0);
1416 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf);
1417 ndp->ni_cnd.cn_flags &= ~HASBUF;
1422 (NDFREE)(struct nameidata *ndp, const u_int flags)
1430 if (!(flags & NDF_NO_FREE_PNBUF)) {
1433 if (!(flags & NDF_NO_VP_UNLOCK) &&
1434 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp)
1436 if (!(flags & NDF_NO_DVP_UNLOCK) &&
1437 (ndp->ni_cnd.cn_flags & LOCKPARENT) &&
1438 ndp->ni_dvp != ndp->ni_vp)
1440 if (!(flags & NDF_NO_VP_RELE) && ndp->ni_vp) {
1449 VOP_UNLOCK(ndp->ni_vp);
1450 if (!(flags & NDF_NO_DVP_RELE) &&
1451 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) {
1460 VOP_UNLOCK(ndp->ni_dvp);
1461 if (!(flags & NDF_NO_STARTDIR_RELE) &&
1462 (ndp->ni_cnd.cn_flags & SAVESTART)) {
1463 vrele(ndp->ni_startdir);
1464 ndp->ni_startdir = NULL;
1470 * Validate the final state of ndp after the lookup.
1472 * Historically filesystems were allowed to modify cn_flags. Most notably they
1473 * can add SAVENAME to the request, resulting in HASBUF and pushing subsequent
1474 * clean up to the consumer. In practice this seems to only concern != LOOKUP
1477 * As a step towards stricter API contract this routine validates the state to
1478 * clean up. Note validation is a work in progress with the intent of becoming
1479 * stricter over time.
1481 #define NDMODIFYINGFLAGS (LOCKLEAF | LOCKPARENT | WANTPARENT | SAVENAME | SAVESTART | HASBUF)
1483 NDVALIDATE(struct nameidata *ndp)
1485 struct componentname *cnp;
1486 u_int64_t used, orig;
1489 orig = cnp->cn_origflags;
1490 used = cnp->cn_flags;
1491 switch (cnp->cn_nameiop) {
1494 * For plain lookup we require strict conformance -- nothing
1495 * to clean up if it was not requested by the caller.
1497 orig &= NDMODIFYINGFLAGS;
1498 used &= NDMODIFYINGFLAGS;
1499 if ((orig & (SAVENAME | SAVESTART)) != 0)
1509 * Some filesystems set SAVENAME to provoke HASBUF, accomodate
1510 * for it until it gets fixed.
1512 orig &= NDMODIFYINGFLAGS;
1513 orig |= (SAVENAME | HASBUF);
1514 used &= NDMODIFYINGFLAGS;
1515 used |= (SAVENAME | HASBUF);
1523 panic("%s: mismatched flags for op %d: added %" PRIx64 ", "
1524 "removed %" PRIx64" (%" PRIx64" != %" PRIx64"; stored %" PRIx64" != %" PRIx64")",
1525 __func__, cnp->cn_nameiop, used & ~orig, orig &~ used,
1526 orig, used, cnp->cn_origflags, cnp->cn_flags);
1531 * Determine if there is a suitable alternate filename under the specified
1532 * prefix for the specified path. If the create flag is set, then the
1533 * alternate prefix will be used so long as the parent directory exists.
1534 * This is used by the various compatibility ABIs so that Linux binaries prefer
1535 * files under /compat/linux for example. The chosen path (whether under
1536 * the prefix or under /) is returned in a kernel malloc'd buffer pointed
1537 * to by pathbuf. The caller is responsible for free'ing the buffer from
1538 * the M_TEMP bucket if one is returned.
1541 kern_alternate_path(struct thread *td, const char *prefix, const char *path,
1542 enum uio_seg pathseg, char **pathbuf, int create, int dirfd)
1544 struct nameidata nd, ndroot;
1545 char *ptr, *buf, *cp;
1549 buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1552 /* Copy the prefix into the new pathname as a starting point. */
1553 len = strlcpy(buf, prefix, MAXPATHLEN);
1554 if (len >= MAXPATHLEN) {
1559 sz = MAXPATHLEN - len;
1562 /* Append the filename to the prefix. */
1563 if (pathseg == UIO_SYSSPACE)
1564 error = copystr(path, ptr, sz, &len);
1566 error = copyinstr(path, ptr, sz, &len);
1574 /* Only use a prefix with absolute pathnames. */
1580 if (dirfd != AT_FDCWD) {
1582 * We want the original because the "prefix" is
1583 * included in the already opened dirfd.
1585 bcopy(ptr, buf, len);
1590 * We know that there is a / somewhere in this pathname.
1591 * Search backwards for it, to find the file's parent dir
1592 * to see if it exists in the alternate tree. If it does,
1593 * and we want to create a file (cflag is set). We don't
1594 * need to worry about the root comparison in this case.
1598 for (cp = &ptr[len] - 1; *cp != '/'; cp--);
1601 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, buf, td);
1607 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, buf, td);
1614 * We now compare the vnode of the prefix to the one
1615 * vnode asked. If they resolve to be the same, then we
1616 * ignore the match so that the real root gets used.
1617 * This avoids the problem of traversing "../.." to find the
1618 * root directory and never finding it, because "/" resolves
1619 * to the emulation root directory. This is expensive :-(
1621 NDINIT(&ndroot, LOOKUP, FOLLOW, UIO_SYSSPACE, prefix,
1624 /* We shouldn't ever get an error from this namei(). */
1625 error = namei(&ndroot);
1627 if (nd.ni_vp == ndroot.ni_vp)
1630 NDFREE(&ndroot, NDF_ONLY_PNBUF);
1631 vrele(ndroot.ni_vp);
1635 NDFREE(&nd, NDF_ONLY_PNBUF);
1639 /* If there was an error, use the original path name. */
1641 bcopy(ptr, buf, len);