xref: /netbsd-src/sys/ufs/lfs/lfs_rename.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /*	$NetBSD: lfs_rename.c,v 1.7 2014/05/17 07:08:35 dholland Exp $	*/
2 /*  from NetBSD: ufs_rename.c,v 1.6 2013/01/22 09:39:18 dholland Exp  */
3 
4 /*-
5  * Copyright (c) 2012 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Taylor R Campbell.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 /*-
33  * Copyright (c) 1999, 2000, 2001, 2002, 2003 The NetBSD Foundation, Inc.
34  * All rights reserved.
35  *
36  * This code is derived from software contributed to The NetBSD Foundation
37  * by Konrad E. Schroder <perseant@hhhh.org>.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
49  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
50  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
51  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
52  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
53  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
54  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
55  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
56  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
57  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
58  * POSSIBILITY OF SUCH DAMAGE.
59  */
60 /*
61  * Copyright (c) 1986, 1989, 1991, 1993, 1995
62  *	The Regents of the University of California.  All rights reserved.
63  *
64  * Redistribution and use in source and binary forms, with or without
65  * modification, are permitted provided that the following conditions
66  * are met:
67  * 1. Redistributions of source code must retain the above copyright
68  *    notice, this list of conditions and the following disclaimer.
69  * 2. Redistributions in binary form must reproduce the above copyright
70  *    notice, this list of conditions and the following disclaimer in the
71  *    documentation and/or other materials provided with the distribution.
72  * 3. Neither the name of the University nor the names of its contributors
73  *    may be used to endorse or promote products derived from this software
74  *    without specific prior written permission.
75  *
76  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
77  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
78  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
79  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
80  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
81  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
82  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
83  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
84  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
85  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
86  * SUCH DAMAGE.
87  *
88  *	@(#)lfs_vnops.c	8.13 (Berkeley) 6/10/95
89  */
90 
91 #include <sys/cdefs.h>
92 __KERNEL_RCSID(0, "$NetBSD: lfs_rename.c,v 1.7 2014/05/17 07:08:35 dholland Exp $");
93 
94 #include <sys/param.h>
95 #include <sys/systm.h>
96 #include <sys/errno.h>
97 #include <sys/namei.h>
98 #include <sys/resourcevar.h>
99 #include <sys/kernel.h>
100 #include <sys/file.h>
101 #include <sys/stat.h>
102 #include <sys/buf.h>
103 #include <sys/proc.h>
104 #include <sys/mount.h>
105 #include <sys/vnode.h>
106 #include <sys/vnode_if.h>
107 #include <sys/pool.h>
108 #include <sys/signalvar.h>
109 #include <sys/kauth.h>
110 #include <sys/syslog.h>
111 
112 #include <uvm/uvm.h>
113 #include <uvm/uvm_pmap.h>
114 #include <uvm/uvm_stat.h>
115 #include <uvm/uvm_pager.h>
116 
117 #include <miscfs/fifofs/fifo.h>
118 #include <miscfs/genfs/genfs.h>
119 #include <miscfs/specfs/specdev.h>
120 
121 #include <ufs/lfs/ulfs_inode.h>
122 #include <ufs/lfs/ulfsmount.h>
123 #include <ufs/lfs/ulfs_bswap.h>
124 #include <ufs/lfs/ulfs_extern.h>
125 
126 #include <ufs/lfs/lfs.h>
127 #include <ufs/lfs/lfs_extern.h>
128 
129 /*
130  * A virgin directory (no blushing please).
131  *
132  * XXX Copypasta from ulfs_vnops.c.  Kill!
133  */
134 static const struct lfs_dirtemplate mastertemplate = {
135 	0,	12,			LFS_DT_DIR,	1,	".",
136 	0,	LFS_DIRBLKSIZ - 12,	LFS_DT_DIR,	2,	".."
137 };
138 
139 /*
140  * ulfs_gro_directory_empty_p: Return true if the directory vp is
141  * empty.  dvp is its parent.
142  *
143  * vp and dvp must be locked and referenced.
144  */
145 static bool
146 ulfs_gro_directory_empty_p(struct mount *mp, kauth_cred_t cred,
147     struct vnode *vp, struct vnode *dvp)
148 {
149 
150 	(void)mp;
151 	KASSERT(mp != NULL);
152 	KASSERT(vp != NULL);
153 	KASSERT(dvp != NULL);
154 	KASSERT(vp != dvp);
155 	KASSERT(vp->v_mount == mp);
156 	KASSERT(dvp->v_mount == mp);
157 	KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
158 	KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
159 
160 	return ulfs_dirempty(VTOI(vp), VTOI(dvp)->i_number, cred);
161 }
162 
163 /*
164  * ulfs_gro_rename_check_possible: Check whether a rename is possible
165  * independent of credentials.
166  */
167 static int
168 ulfs_gro_rename_check_possible(struct mount *mp,
169     struct vnode *fdvp, struct vnode *fvp,
170     struct vnode *tdvp, struct vnode *tvp)
171 {
172 
173 	(void)mp;
174 	KASSERT(mp != NULL);
175 	KASSERT(fdvp != NULL);
176 	KASSERT(fvp != NULL);
177 	KASSERT(tdvp != NULL);
178 	KASSERT(fdvp != fvp);
179 	KASSERT(fdvp != tvp);
180 	KASSERT(tdvp != fvp);
181 	KASSERT(tdvp != tvp);
182 	KASSERT(fvp != tvp);
183 	KASSERT(fdvp->v_type == VDIR);
184 	KASSERT(tdvp->v_type == VDIR);
185 	KASSERT(fdvp->v_mount == mp);
186 	KASSERT(fvp->v_mount == mp);
187 	KASSERT(tdvp->v_mount == mp);
188 	KASSERT((tvp == NULL) || (tvp->v_mount == mp));
189 	KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE);
190 	KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE);
191 	KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE);
192 	KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE));
193 
194 	return genfs_ufslike_rename_check_possible(
195 	    VTOI(fdvp)->i_flags, VTOI(fvp)->i_flags,
196 	    VTOI(tdvp)->i_flags, (tvp? VTOI(tvp)->i_flags : 0),
197 	    (tvp != NULL),
198 	    IMMUTABLE, APPEND);
199 }
200 
201 /*
202  * ulfs_gro_rename_check_permitted: Check whether a rename is permitted
203  * given our credentials.
204  */
205 static int
206 ulfs_gro_rename_check_permitted(struct mount *mp, kauth_cred_t cred,
207     struct vnode *fdvp, struct vnode *fvp,
208     struct vnode *tdvp, struct vnode *tvp)
209 {
210 
211 	(void)mp;
212 	KASSERT(mp != NULL);
213 	KASSERT(fdvp != NULL);
214 	KASSERT(fvp != NULL);
215 	KASSERT(tdvp != NULL);
216 	KASSERT(fdvp != fvp);
217 	KASSERT(fdvp != tvp);
218 	KASSERT(tdvp != fvp);
219 	KASSERT(tdvp != tvp);
220 	KASSERT(fvp != tvp);
221 	KASSERT(fdvp->v_type == VDIR);
222 	KASSERT(tdvp->v_type == VDIR);
223 	KASSERT(fdvp->v_mount == mp);
224 	KASSERT(fvp->v_mount == mp);
225 	KASSERT(tdvp->v_mount == mp);
226 	KASSERT((tvp == NULL) || (tvp->v_mount == mp));
227 	KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE);
228 	KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE);
229 	KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE);
230 	KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE));
231 
232 	return genfs_ufslike_rename_check_permitted(cred,
233 	    fdvp, VTOI(fdvp)->i_mode, VTOI(fdvp)->i_uid,
234 	    fvp, VTOI(fvp)->i_uid,
235 	    tdvp, VTOI(tdvp)->i_mode, VTOI(tdvp)->i_uid,
236 	    tvp, (tvp? VTOI(tvp)->i_uid : 0));
237 }
238 
239 /*
240  * ulfs_gro_remove_check_possible: Check whether a remove is possible
241  * independent of credentials.
242  */
243 static int
244 ulfs_gro_remove_check_possible(struct mount *mp,
245     struct vnode *dvp, struct vnode *vp)
246 {
247 
248 	(void)mp;
249 	KASSERT(mp != NULL);
250 	KASSERT(dvp != NULL);
251 	KASSERT(vp != NULL);
252 	KASSERT(dvp != vp);
253 	KASSERT(dvp->v_type == VDIR);
254 	KASSERT(vp->v_type != VDIR);
255 	KASSERT(dvp->v_mount == mp);
256 	KASSERT(vp->v_mount == mp);
257 	KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
258 	KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
259 
260 	return genfs_ufslike_remove_check_possible(
261 	    VTOI(dvp)->i_flags, VTOI(vp)->i_flags,
262 	    IMMUTABLE, APPEND);
263 }
264 
265 /*
266  * ulfs_gro_remove_check_permitted: Check whether a remove is permitted
267  * given our credentials.
268  */
269 static int
270 ulfs_gro_remove_check_permitted(struct mount *mp, kauth_cred_t cred,
271     struct vnode *dvp, struct vnode *vp)
272 {
273 
274 	(void)mp;
275 	KASSERT(mp != NULL);
276 	KASSERT(dvp != NULL);
277 	KASSERT(vp != NULL);
278 	KASSERT(dvp != vp);
279 	KASSERT(dvp->v_type == VDIR);
280 	KASSERT(vp->v_type != VDIR);
281 	KASSERT(dvp->v_mount == mp);
282 	KASSERT(vp->v_mount == mp);
283 	KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
284 	KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
285 
286 	return genfs_ufslike_remove_check_permitted(cred,
287 	    dvp, VTOI(dvp)->i_mode, VTOI(dvp)->i_uid, vp, VTOI(vp)->i_uid);
288 }
289 
290 /*
291  * ulfs_rename_ulr_overlap_p: True iff tulr overlaps with fulr so that
292  * entering a directory entry at tulr may move fulr.
293  */
294 static bool
295 ulfs_rename_ulr_overlap_p(const struct ulfs_lookup_results *fulr,
296     const struct ulfs_lookup_results *tulr)
297 {
298 	doff_t from_prev_start, from_prev_end, to_start, to_end;
299 
300 	KASSERT(fulr != NULL);
301 	KASSERT(tulr != NULL);
302 	KASSERT(fulr != tulr);
303 
304 	/*
305 	 * fulr is from a DELETE lookup, so fulr->ulr_count is the size
306 	 * of the preceding entry (d_reclen).
307 	 */
308 	from_prev_end = fulr->ulr_offset;
309 	KASSERT(fulr->ulr_count <= from_prev_end);
310 	from_prev_start = (from_prev_end - fulr->ulr_count);
311 
312 	/*
313 	 * tulr is from a RENAME lookup, so tulr->ulr_count is the size
314 	 * of the free space for an entry that we are about to fill.
315 	 */
316 	to_start = tulr->ulr_offset;
317 	KASSERT(tulr->ulr_count < (LFS_MAXDIRSIZE - to_start));
318 	to_end = (to_start + tulr->ulr_count);
319 
320 	return
321 	    (((to_start <= from_prev_start) && (from_prev_start < to_end)) ||
322 		((to_start <= from_prev_end) && (from_prev_end < to_end)));
323 }
324 
325 /*
326  * ulfs_direct_namlen: Return the namlen of the directory entry ep from
327  * the directory vp.
328  */
329 static int			/* XXX int?  uint8_t?  */
330 ulfs_direct_namlen(const struct lfs_direct *ep, const struct vnode *vp)
331 {
332 	bool swap;
333 
334 	KASSERT(ep != NULL);
335 	KASSERT(vp != NULL);
336 	KASSERT(VTOI(vp) != NULL);
337 	KASSERT(VTOI(vp)->i_ump != NULL);
338 
339 #if (BYTE_ORDER == LITTLE_ENDIAN)
340 	swap = (ULFS_IPNEEDSWAP(VTOI(vp)) == 0);
341 #else
342 	swap = (ULFS_IPNEEDSWAP(VTOI(vp)) != 0);
343 #endif
344 
345 	return ((FSFMT(vp) && swap)? ep->d_type : ep->d_namlen);
346 }
347 
348 /*
349  * ulfs_rename_recalculate_fulr: If we have just entered a directory into
350  * dvp at tulr, and we were about to remove one at fulr for an entry
351  * named fcnp, fulr may be invalid.  So, if necessary, recalculate it.
352  */
353 static int
354 ulfs_rename_recalculate_fulr(struct vnode *dvp,
355     struct ulfs_lookup_results *fulr, const struct ulfs_lookup_results *tulr,
356     const struct componentname *fcnp)
357 {
358 	struct mount *mp;
359 	struct lfs *fs;
360 	struct ulfsmount *ump;
361 	int needswap;
362 	/* XXX int is a silly type for this; blame ulfsmount::um_dirblksiz.  */
363 	int dirblksiz;
364 	doff_t search_start, search_end;
365 	doff_t offset;		/* Offset of entry we're examining.  */
366 	struct buf *bp;		/* I/O block we're examining.  */
367 	char *dirbuf;		/* Pointer into directory at search_start.  */
368 	struct lfs_direct *ep;	/* Pointer to the entry we're examining.  */
369 	/* XXX direct::d_reclen is 16-bit;
370 	 * ulfs_lookup_results::ulr_reclen is 32-bit.  Blah.  */
371 	uint32_t reclen;	/* Length of the entry we're examining.  */
372 	uint32_t prev_reclen;	/* Length of the preceding entry.  */
373 	int error;
374 
375 	KASSERT(dvp != NULL);
376 	KASSERT(dvp->v_mount != NULL);
377 	KASSERT(VTOI(dvp) != NULL);
378 	KASSERT(fulr != NULL);
379 	KASSERT(tulr != NULL);
380 	KASSERT(fulr != tulr);
381 	KASSERT(ulfs_rename_ulr_overlap_p(fulr, tulr));
382 
383 	mp = dvp->v_mount;
384 	ump = VFSTOULFS(mp);
385 	fs = ump->um_lfs;
386 	KASSERT(ump != NULL);
387 	KASSERT(ump == VTOI(dvp)->i_ump);
388 	KASSERT(fs == VTOI(dvp)->i_lfs);
389 
390 	needswap = ULFS_MPNEEDSWAP(fs);
391 
392 	dirblksiz = fs->um_dirblksiz;
393 	KASSERT(0 < dirblksiz);
394 	KASSERT((dirblksiz & (dirblksiz - 1)) == 0);
395 
396 	/* A directory block may not span across multiple I/O blocks.  */
397 	KASSERT(dirblksiz <= mp->mnt_stat.f_iosize);
398 
399 	/* Find the bounds of the search.  */
400 	search_start = tulr->ulr_offset;
401 	KASSERT(fulr->ulr_reclen < (LFS_MAXDIRSIZE - fulr->ulr_offset));
402 	search_end = (fulr->ulr_offset + fulr->ulr_reclen);
403 
404 	/* Compaction must happen only within a directory block. (*)  */
405 	KASSERT(search_start <= search_end);
406 	KASSERT((search_end - (search_start &~ (dirblksiz - 1))) <= dirblksiz);
407 
408 	dirbuf = NULL;
409 	bp = NULL;
410 	error = ulfs_blkatoff(dvp, (off_t)search_start, &dirbuf, &bp, false);
411 	if (error)
412 		return error;
413 	KASSERT(dirbuf != NULL);
414 	KASSERT(bp != NULL);
415 
416 	/*
417 	 * Guarantee we sha'n't go past the end of the buffer we got.
418 	 * dirbuf is bp->b_data + (search_start & (iosize - 1)), and
419 	 * the valid range is [bp->b_data, bp->b_data + bp->b_bcount).
420 	 */
421 	KASSERT((search_end - search_start) <=
422 	    (bp->b_bcount - (search_start & (mp->mnt_stat.f_iosize - 1))));
423 
424 	prev_reclen = fulr->ulr_count;
425 	offset = search_start;
426 
427 	/*
428 	 * Search from search_start to search_end for the entry matching
429 	 * fcnp, which must be there because we found it before and it
430 	 * should only at most have moved earlier.
431 	 */
432 	for (;;) {
433 		KASSERT(search_start <= offset);
434 		KASSERT(offset < search_end);
435 
436 		/*
437 		 * Examine the directory entry at offset.
438 		 */
439 		ep = (struct lfs_direct *)(dirbuf + (offset - search_start));
440 		reclen = ulfs_rw16(ep->d_reclen, needswap);
441 
442 		if (ep->d_ino == 0)
443 			goto next;	/* Entry is unused.  */
444 
445 		if (ulfs_rw32(ep->d_ino, needswap) == ULFS_WINO)
446 			goto next;	/* Entry is whiteout.  */
447 
448 		if (fcnp->cn_namelen != ulfs_direct_namlen(ep, dvp))
449 			goto next;	/* Wrong name length.  */
450 
451 		if (memcmp(ep->d_name, fcnp->cn_nameptr, fcnp->cn_namelen))
452 			goto next;	/* Wrong name.  */
453 
454 		/* Got it!  */
455 		break;
456 
457 next:
458 		if (! ((reclen < search_end) &&
459 			(offset < (search_end - reclen)))) {
460 			brelse(bp, 0);
461 			return EIO;	/* XXX Panic?  What?  */
462 		}
463 
464 		/* We may not move past the search end.  */
465 		KASSERT(reclen < search_end);
466 		KASSERT(offset < (search_end - reclen));
467 
468 		/*
469 		 * We may not move across a directory block boundary;
470 		 * see (*) above.
471 		 */
472 		KASSERT((offset &~ (dirblksiz - 1)) ==
473 		    ((offset + reclen) &~ (dirblksiz - 1)));
474 
475 		prev_reclen = reclen;
476 		offset += reclen;
477 	}
478 
479 	/*
480 	 * Found the entry.  Record where.
481 	 */
482 	fulr->ulr_offset = offset;
483 	fulr->ulr_reclen = reclen;
484 
485 	/*
486 	 * Record the preceding record length, but not if we're at the
487 	 * start of a directory block.
488 	 */
489 	fulr->ulr_count = ((offset & (dirblksiz - 1))? prev_reclen : 0);
490 
491 	brelse(bp, 0);
492 	return 0;
493 }
494 
495 /*
496  * ulfs_gro_remove: Rename an object over another link to itself,
497  * effectively removing just the original link.
498  */
499 static int
500 ulfs_gro_remove(struct mount *mp, kauth_cred_t cred,
501     struct vnode *dvp, struct componentname *cnp, void *de, struct vnode *vp)
502 {
503 	struct ulfs_lookup_results *ulr = de;
504 	int error;
505 
506 	KASSERT(mp != NULL);
507 	KASSERT(dvp != NULL);
508 	KASSERT(cnp != NULL);
509 	KASSERT(ulr != NULL);
510 	KASSERT(vp != NULL);
511 	KASSERT(dvp != vp);
512 	KASSERT(dvp->v_mount == mp);
513 	KASSERT(vp->v_mount == mp);
514 	KASSERT(dvp->v_type == VDIR);
515 	KASSERT(vp->v_type != VDIR);
516 	KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
517 	KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
518 	KASSERT(cnp->cn_nameiop == DELETE);
519 
520 	/* XXX ulfs_dirremove decrements vp's link count for us.  */
521 	error = ulfs_dirremove(dvp, ulr, VTOI(vp), cnp->cn_flags, 0);
522 	if (error)
523 		goto out1;
524 
525 	VN_KNOTE(dvp, NOTE_WRITE);
526 	VN_KNOTE(vp, (VTOI(vp)->i_nlink? NOTE_LINK : NOTE_DELETE));
527 
528 out1:
529 	return error;
530 }
531 
532 /*
533  * ulfs_gro_lookup: Look up and save the lookup results.
534  */
535 static int
536 ulfs_gro_lookup(struct mount *mp, struct vnode *dvp,
537     struct componentname *cnp, void *de_ret, struct vnode **vp_ret)
538 {
539 	struct ulfs_lookup_results *ulr_ret = de_ret;
540 	struct vnode *vp = NULL;
541 	int error;
542 
543 	(void)mp;
544 	KASSERT(mp != NULL);
545 	KASSERT(dvp != NULL);
546 	KASSERT(cnp != NULL);
547 	KASSERT(ulr_ret != NULL);
548 	KASSERT(vp_ret != NULL);
549 	KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
550 
551 	/* Kludge cargo-culted from dholland's ulfs_rename.  */
552 	cnp->cn_flags &=~ MODMASK;
553 	cnp->cn_flags |= (LOCKPARENT | LOCKLEAF);
554 
555 	error = relookup(dvp, &vp, cnp, 0 /* dummy */);
556 	if ((error == 0) && (vp == NULL)) {
557 		error = ENOENT;
558 		goto out;
559 	} else if (error) {
560 		return error;
561 	}
562 
563 	/*
564 	 * Thanks to VFS insanity, relookup locks vp, which screws us
565 	 * in various ways.
566 	 */
567 	KASSERT(vp != NULL);
568 	VOP_UNLOCK(vp);
569 
570 out:	*ulr_ret = VTOI(dvp)->i_crap;
571 	*vp_ret = vp;
572 	return error;
573 }
574 
575 /*
576  * ulfs_rmdired_p: Check whether the directory vp has been rmdired.
577  *
578  * vp must be locked and referenced.
579  */
580 static bool
581 ulfs_rmdired_p(struct vnode *vp)
582 {
583 
584 	KASSERT(vp != NULL);
585 	KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
586 	KASSERT(vp->v_type == VDIR);
587 
588 	/* XXX Is this correct?  */
589 	return (VTOI(vp)->i_size == 0);
590 }
591 
592 /*
593  * ulfs_dirbuf_dotdot_namlen: Return the namlen of the directory buffer
594  * dirbuf that came from the directory vp.  Swap byte order if
595  * necessary.
596  */
597 static int			/* XXX int?  uint8_t?  */
598 ulfs_dirbuf_dotdot_namlen(const struct lfs_dirtemplate *dirbuf,
599     const struct vnode *vp)
600 {
601 	bool swap;
602 
603 	KASSERT(dirbuf != NULL);
604 	KASSERT(vp != NULL);
605 	KASSERT(VTOI(vp) != NULL);
606 	KASSERT(VTOI(vp)->i_ump != NULL);
607 
608 #if (BYTE_ORDER == LITTLE_ENDIAN)
609 	swap = (ULFS_IPNEEDSWAP(VTOI(vp)) == 0);
610 #else
611 	swap = (ULFS_IPNEEDSWAP(VTOI(vp)) != 0);
612 #endif
613 
614 	return ((FSFMT(vp) && swap)?
615 	    dirbuf->dotdot_type : dirbuf->dotdot_namlen);
616 }
617 
618 /*
619  * ulfs_read_dotdot: Store in *ino_ret the inode number of the parent
620  * of the directory vp.
621  */
622 static int
623 ulfs_read_dotdot(struct vnode *vp, kauth_cred_t cred, ino_t *ino_ret)
624 {
625 	struct lfs_dirtemplate dirbuf;
626 	int error;
627 
628 	KASSERT(vp != NULL);
629 	KASSERT(ino_ret != NULL);
630 	KASSERT(vp->v_type == VDIR);
631 
632 	error = vn_rdwr(UIO_READ, vp, &dirbuf, sizeof dirbuf, (off_t)0,
633 	    UIO_SYSSPACE, IO_NODELOCKED, cred, NULL, NULL);
634 	if (error)
635 		return error;
636 
637 	if (ulfs_dirbuf_dotdot_namlen(&dirbuf, vp) != 2 ||
638 	    dirbuf.dotdot_name[0] != '.' ||
639 	    dirbuf.dotdot_name[1] != '.')
640 		/* XXX Panic?  Print warning?  */
641 		return ENOTDIR;
642 
643 	*ino_ret = ulfs_rw32(dirbuf.dotdot_ino,
644 	    ULFS_IPNEEDSWAP(VTOI(vp)));
645 	return 0;
646 }
647 
648 /*
649  * ulfs_gro_lock_directory: Lock the directory vp, but fail if it has
650  * been rmdir'd.
651  */
652 static int
653 ulfs_gro_lock_directory(struct mount *mp, struct vnode *vp)
654 {
655 
656 	(void)mp;
657 	KASSERT(mp != NULL);
658 	KASSERT(vp != NULL);
659 	KASSERT(vp->v_mount == mp);
660 
661 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
662 
663 	if (ulfs_rmdired_p(vp)) {
664 		VOP_UNLOCK(vp);
665 		return ENOENT;
666 	}
667 
668 	return 0;
669 }
670 
671 /*
672  * ulfs_gro_genealogy: Analyze the genealogy of the source and target
673  * directories.
674  */
675 static int
676 ulfs_gro_genealogy(struct mount *mp, kauth_cred_t cred,
677     struct vnode *fdvp, struct vnode *tdvp,
678     struct vnode **intermediate_node_ret)
679 {
680 	struct vnode *vp, *dvp;
681 	ino_t dotdot_ino = -1;	/* XXX  gcc 4.8: maybe-uninitialized */
682 	int error;
683 
684 	KASSERT(mp != NULL);
685 	KASSERT(fdvp != NULL);
686 	KASSERT(tdvp != NULL);
687 	KASSERT(fdvp != tdvp);
688 	KASSERT(intermediate_node_ret != NULL);
689 	KASSERT(fdvp->v_mount == mp);
690 	KASSERT(tdvp->v_mount == mp);
691 	KASSERT(fdvp->v_type == VDIR);
692 	KASSERT(tdvp->v_type == VDIR);
693 
694 	/*
695 	 * We need to provisionally lock tdvp to keep rmdir from
696 	 * deleting it -- or any ancestor -- at an inopportune moment.
697 	 */
698 	error = ulfs_gro_lock_directory(mp, tdvp);
699 	if (error)
700 		return error;
701 
702 	vp = tdvp;
703 	vref(vp);
704 
705 	for (;;) {
706 		KASSERT(vp != NULL);
707 		KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
708 		KASSERT(vp->v_mount == mp);
709 		KASSERT(vp->v_type == VDIR);
710 		KASSERT(!ulfs_rmdired_p(vp));
711 
712 		/* Did we hit the root without finding fdvp?  */
713 		if (VTOI(vp)->i_number == ULFS_ROOTINO) {
714 			vput(vp);
715 			*intermediate_node_ret = NULL;
716 			return 0;
717 		}
718 
719 		error = ulfs_read_dotdot(vp, cred, &dotdot_ino);
720 		if (error) {
721 			vput(vp);
722 			return error;
723 		}
724 
725 		/* Did we find that fdvp is an ancestor of tdvp?  */
726 		if (VTOI(fdvp)->i_number == dotdot_ino) {
727 			/* Unlock vp, but keep it referenced.  */
728 			VOP_UNLOCK(vp);
729 			*intermediate_node_ret = vp;
730 			return 0;
731 		}
732 
733 		/* Neither -- keep ascending the family tree.  */
734 
735 		/*
736 		 * Unlock vp so that we can lock the parent, but keep
737 		 * vp referenced until after we have found the parent,
738 		 * so that dotdot_ino will not be recycled.
739 		 *
740 		 * XXX This guarantees that vp's inode number will not
741 		 * be recycled, but why can't dotdot_ino be recycled?
742 		 */
743 		VOP_UNLOCK(vp);
744 		error = VFS_VGET(mp, dotdot_ino, &dvp);
745 		vrele(vp);
746 		if (error)
747 			return error;
748 
749 		KASSERT(dvp != NULL);
750 		KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
751 		vp = dvp;
752 
753 		if (vp->v_type != VDIR) {
754 			/*
755 			 * XXX Panic?  Print a warning?  Can this
756 			 * happen if we lose the race I suspect to
757 			 * exist above, and the `..' inode number has
758 			 * been recycled?
759 			 */
760 			vput(vp);
761 			return ENOTDIR;
762 		}
763 
764 		if (ulfs_rmdired_p(vp)) {
765 			vput(vp);
766 			return ENOENT;
767 		}
768 	}
769 }
770 
771 /*
772  * ulfs_gro_rename: Actually perform the rename operation.
773  */
774 static int
775 ulfs_gro_rename(struct mount *mp, kauth_cred_t cred,
776     struct vnode *fdvp, struct componentname *fcnp,
777     void *fde, struct vnode *fvp,
778     struct vnode *tdvp, struct componentname *tcnp,
779     void *tde, struct vnode *tvp)
780 {
781 	struct ulfs_lookup_results *fulr = fde;
782 	struct ulfs_lookup_results *tulr = tde;
783 	bool directory_p, reparent_p;
784 	struct lfs_direct *newdir;
785 	int error;
786 
787 	KASSERT(mp != NULL);
788 	KASSERT(fdvp != NULL);
789 	KASSERT(fcnp != NULL);
790 	KASSERT(fulr != NULL);
791 	KASSERT(fvp != NULL);
792 	KASSERT(tdvp != NULL);
793 	KASSERT(tcnp != NULL);
794 	KASSERT(tulr != NULL);
795 	KASSERT(fulr != tulr);
796 	KASSERT(fdvp != fvp);
797 	KASSERT(fdvp != tvp);
798 	KASSERT(tdvp != fvp);
799 	KASSERT(tdvp != tvp);
800 	KASSERT(fvp != tvp);
801 	KASSERT(fdvp->v_mount == mp);
802 	KASSERT(fvp->v_mount == mp);
803 	KASSERT(tdvp->v_mount == mp);
804 	KASSERT((tvp == NULL) || (tvp->v_mount == mp));
805 	KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE);
806 	KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE);
807 	KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE);
808 	KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE));
809 
810 	/*
811 	 * We shall need to temporarily bump the link count, so make
812 	 * sure there is room to do so.
813 	 */
814 	if ((nlink_t)VTOI(fvp)->i_nlink >= LINK_MAX)
815 		return EMLINK;
816 
817 	directory_p = (fvp->v_type == VDIR);
818 	KASSERT(directory_p == ((VTOI(fvp)->i_mode & LFS_IFMT) == LFS_IFDIR));
819 	KASSERT((tvp == NULL) || (directory_p == (tvp->v_type == VDIR)));
820 	KASSERT((tvp == NULL) || (directory_p ==
821 		((VTOI(tvp)->i_mode & LFS_IFMT) == LFS_IFDIR)));
822 
823 	reparent_p = (fdvp != tdvp);
824 	KASSERT(reparent_p == (VTOI(fdvp)->i_number != VTOI(tdvp)->i_number));
825 
826 	/*
827 	 * Commence hacking of the data on disk.
828 	 */
829 
830 	error = 0;
831 
832 	/*
833 	 * 1) Bump link count while we're moving stuff
834 	 *    around.  If we crash somewhere before
835 	 *    completing our work, the link count
836 	 *    may be wrong, but correctable.
837 	 */
838 
839 	KASSERT((nlink_t)VTOI(fvp)->i_nlink < LINK_MAX);
840 	VTOI(fvp)->i_nlink++;
841 	DIP_ASSIGN(VTOI(fvp), nlink, VTOI(fvp)->i_nlink);
842 	VTOI(fvp)->i_flag |= IN_CHANGE;
843 	error = lfs_update(fvp, NULL, NULL, UPDATE_DIROP);
844 	if (error)
845 		goto whymustithurtsomuch;
846 
847 	/*
848 	 * 2) If target doesn't exist, link the target
849 	 *    to the source and unlink the source.
850 	 *    Otherwise, rewrite the target directory
851 	 *    entry to reference the source inode and
852 	 *    expunge the original entry's existence.
853 	 */
854 
855 	if (tvp == NULL) {
856 		/*
857 		 * Account for ".." in new directory.
858 		 * When source and destination have the same
859 		 * parent we don't fool with the link count.
860 		 */
861 		if (directory_p && reparent_p) {
862 			if ((nlink_t)VTOI(tdvp)->i_nlink >= LINK_MAX) {
863 				error = EMLINK;
864 				goto whymustithurtsomuch;
865 			}
866 			KASSERT((nlink_t)VTOI(tdvp)->i_nlink < LINK_MAX);
867 			VTOI(tdvp)->i_nlink++;
868 			DIP_ASSIGN(VTOI(tdvp), nlink, VTOI(tdvp)->i_nlink);
869 			VTOI(tdvp)->i_flag |= IN_CHANGE;
870 			error = lfs_update(tdvp, NULL, NULL, UPDATE_DIROP);
871 			if (error) {
872 				/*
873 				 * Link count update didn't take --
874 				 * back out the in-memory link count.
875 				 */
876 				KASSERT(0 < VTOI(tdvp)->i_nlink);
877 				VTOI(tdvp)->i_nlink--;
878 				DIP_ASSIGN(VTOI(tdvp), nlink,
879 				    VTOI(tdvp)->i_nlink);
880 				VTOI(tdvp)->i_flag |= IN_CHANGE;
881 				goto whymustithurtsomuch;
882 			}
883 		}
884 
885 		newdir = pool_cache_get(ulfs_direct_cache, PR_WAITOK);
886 		ulfs_makedirentry(VTOI(fvp), tcnp, newdir);
887 		error = ulfs_direnter(tdvp, tulr, NULL, newdir, tcnp, NULL);
888 		pool_cache_put(ulfs_direct_cache, newdir);
889 		if (error) {
890 			if (directory_p && reparent_p) {
891 				/*
892 				 * Directory update didn't take, but
893 				 * the link count update did -- back
894 				 * out the in-memory link count and the
895 				 * on-disk link count.
896 				 */
897 				KASSERT(0 < VTOI(tdvp)->i_nlink);
898 				VTOI(tdvp)->i_nlink--;
899 				DIP_ASSIGN(VTOI(tdvp), nlink,
900 				    VTOI(tdvp)->i_nlink);
901 				VTOI(tdvp)->i_flag |= IN_CHANGE;
902 				(void)lfs_update(tdvp, NULL, NULL,
903 				    UPDATE_WAIT | UPDATE_DIROP);
904 			}
905 			goto whymustithurtsomuch;
906 		}
907 	} else {
908 		if (directory_p)
909 			/* XXX WTF?  Why purge here?  Why not purge others?  */
910 			cache_purge(tdvp);
911 
912 		/*
913 		 * Make the target directory's entry for tcnp point at
914 		 * the source node.
915 		 *
916 		 * XXX ulfs_dirrewrite decrements tvp's link count, but
917 		 * doesn't touch the link count of the new inode.  Go
918 		 * figure.
919 		 */
920 		error = ulfs_dirrewrite(VTOI(tdvp), tulr->ulr_offset,
921 		    VTOI(tvp), VTOI(fvp)->i_number, LFS_IFTODT(VTOI(fvp)->i_mode),
922 		    ((directory_p && reparent_p) ? reparent_p : directory_p),
923 		    IN_CHANGE | IN_UPDATE);
924 		if (error)
925 			goto whymustithurtsomuch;
926 
927 		/*
928 		 * If the source and target are directories, and the
929 		 * target is in the same directory as the source,
930 		 * decrement the link count of the common parent
931 		 * directory, since we are removing the target from
932 		 * that directory.
933 		 */
934 		if (directory_p && !reparent_p) {
935 			KASSERT(fdvp == tdvp);
936 			/* XXX check, don't kassert */
937 			KASSERT(0 < VTOI(tdvp)->i_nlink);
938 			VTOI(tdvp)->i_nlink--;
939 			DIP_ASSIGN(VTOI(tdvp), nlink, VTOI(tdvp)->i_nlink);
940 			VTOI(tdvp)->i_flag |= IN_CHANGE;
941 		}
942 
943 		if (directory_p) {
944 			/*
945 			 * XXX I don't understand the following comment
946 			 * from ulfs_rename -- in particular, the part
947 			 * about `there may be other hard links'.
948 			 *
949 			 * Truncate inode. The only stuff left in the directory
950 			 * is "." and "..". The "." reference is inconsequential
951 			 * since we are quashing it. We have removed the "."
952 			 * reference and the reference in the parent directory,
953 			 * but there may be other hard links.
954 			 *
955 			 * XXX The ulfs_dirempty call earlier does
956 			 * not guarantee anything about nlink.
957 			 */
958 			if (VTOI(tvp)->i_nlink != 1)
959 				ulfs_dirbad(VTOI(tvp), (doff_t)0,
960 				    "hard-linked directory");
961 			VTOI(tvp)->i_nlink = 0;
962 			DIP_ASSIGN(VTOI(tvp), nlink, 0);
963 			error = lfs_truncate(tvp, (off_t)0, IO_SYNC, cred);
964 			if (error)
965 				goto whymustithurtsomuch;
966 		}
967 	}
968 
969 	/*
970 	 * If the source is a directory with a new parent, the link
971 	 * count of the old parent directory must be decremented and
972 	 * ".." set to point to the new parent.
973 	 *
974 	 * XXX ulfs_dirrewrite updates the link count of fdvp, but not
975 	 * the link count of fvp or the link count of tdvp.  Go figure.
976 	 */
977 	if (directory_p && reparent_p) {
978 		error = ulfs_dirrewrite(VTOI(fvp), mastertemplate.dot_reclen,
979 		    VTOI(fdvp), VTOI(tdvp)->i_number, LFS_DT_DIR, 0, IN_CHANGE);
980 #if 0		/* XXX This branch was not in ulfs_rename! */
981 		if (error)
982 			goto whymustithurtsomuch;
983 #endif
984 
985 		/* XXX WTF?  Why purge here?  Why not purge others?  */
986 		cache_purge(fdvp);
987 	}
988 
989 	/*
990 	 * 3) Unlink the source.
991 	 */
992 
993 	/*
994 	 * ulfs_direnter may compact the directory in the process of
995 	 * inserting a new entry.  That may invalidate fulr, which we
996 	 * need in order to remove the old entry.  In that case, we
997 	 * need to recalculate what fulr should be.
998 	 */
999 	if (!reparent_p && (tvp == NULL) &&
1000 	    ulfs_rename_ulr_overlap_p(fulr, tulr)) {
1001 		error = ulfs_rename_recalculate_fulr(fdvp, fulr, tulr, fcnp);
1002 #if 0				/* XXX */
1003 		if (error)	/* XXX Try to back out changes?  */
1004 			goto whymustithurtsomuch;
1005 #endif
1006 	}
1007 
1008 	/*
1009 	 * XXX 0 means !isrmdir.  But can't this be an rmdir?
1010 	 * XXX Well, turns out that argument to ulfs_dirremove is ignored...
1011 	 * XXX And it turns out ulfs_dirremove updates the link count of fvp.
1012 	 * XXX But it doesn't update the link count of fdvp.  Go figure.
1013 	 * XXX fdvp's link count is updated in ulfs_dirrewrite instead.
1014 	 * XXX Actually, sometimes it doesn't update fvp's link count.
1015 	 * XXX I hate the world.
1016 	 */
1017 	error = ulfs_dirremove(fdvp, fulr, VTOI(fvp), fcnp->cn_flags, 0);
1018 	if (error)
1019 #if 0				/* XXX */
1020 		goto whymustithurtsomuch;
1021 #endif
1022 		goto arghmybrainhurts;
1023 
1024 	/*
1025 	 * XXX Perhaps this should go at the top, in case the file
1026 	 * system is modified but incompletely so because of an
1027 	 * intermediate error.
1028 	 */
1029 	genfs_rename_knote(fdvp, fvp, tdvp, tvp,
1030 	    ((tvp != NULL) && (VTOI(tvp)->i_nlink == 0)));
1031 #if 0				/* XXX */
1032 	genfs_rename_cache_purge(fdvp, fvp, tdvp, tvp);
1033 #endif
1034 	goto arghmybrainhurts;
1035 
1036 whymustithurtsomuch:
1037 	KASSERT(0 < VTOI(fvp)->i_nlink);
1038 	VTOI(fvp)->i_nlink--;
1039 	DIP_ASSIGN(VTOI(fvp), nlink, VTOI(fvp)->i_nlink);
1040 	VTOI(fvp)->i_flag |= IN_CHANGE;
1041 
1042 arghmybrainhurts:
1043 /*ihateyou:*/
1044 	return error;
1045 }
1046 
1047 /*
1048  * lfs_gro_rename: Actually perform the rename operation.  Do a little
1049  * LFS bookkeeping and then defer to ulfs_gro_rename.
1050  */
1051 static int
1052 lfs_gro_rename(struct mount *mp, kauth_cred_t cred,
1053     struct vnode *fdvp, struct componentname *fcnp,
1054     void *fde, struct vnode *fvp,
1055     struct vnode *tdvp, struct componentname *tcnp,
1056     void *tde, struct vnode *tvp)
1057 {
1058 	int error;
1059 
1060 	KASSERT(mp != NULL);
1061 	KASSERT(fdvp != NULL);
1062 	KASSERT(fcnp != NULL);
1063 	KASSERT(fde != NULL);
1064 	KASSERT(fvp != NULL);
1065 	KASSERT(tdvp != NULL);
1066 	KASSERT(tcnp != NULL);
1067 	KASSERT(tde != NULL);
1068 	KASSERT(fdvp != fvp);
1069 	KASSERT(fdvp != tvp);
1070 	KASSERT(tdvp != fvp);
1071 	KASSERT(tdvp != tvp);
1072 	KASSERT(fvp != tvp);
1073 	KASSERT(fdvp->v_mount == mp);
1074 	KASSERT(fvp->v_mount == mp);
1075 	KASSERT(tdvp->v_mount == mp);
1076 	KASSERT((tvp == NULL) || (tvp->v_mount == mp));
1077 	KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE);
1078 	KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE);
1079 	KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE);
1080 	KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE));
1081 
1082 	error = lfs_set_dirop(tdvp, tvp);
1083 	if (error != 0)
1084 		return error;
1085 
1086 	MARK_VNODE(fdvp);
1087 	MARK_VNODE(fvp);
1088 
1089 	error = ulfs_gro_rename(mp, cred,
1090 	    fdvp, fcnp, fde, fvp,
1091 	    tdvp, tcnp, tde, tvp);
1092 
1093 	UNMARK_VNODE(fdvp);
1094 	UNMARK_VNODE(fvp);
1095 	UNMARK_VNODE(tdvp);
1096 	if (tvp) {
1097 		UNMARK_VNODE(tvp);
1098 	}
1099 	lfs_unset_dirop(VFSTOULFS(mp)->um_lfs, tdvp, "rename");
1100 	vrele(tdvp);
1101 	if (tvp) {
1102 		vrele(tvp);
1103 	}
1104 
1105 	return error;
1106 }
1107 
1108 static const struct genfs_rename_ops lfs_genfs_rename_ops = {
1109 	.gro_directory_empty_p		= ulfs_gro_directory_empty_p,
1110 	.gro_rename_check_possible	= ulfs_gro_rename_check_possible,
1111 	.gro_rename_check_permitted	= ulfs_gro_rename_check_permitted,
1112 	.gro_remove_check_possible	= ulfs_gro_remove_check_possible,
1113 	.gro_remove_check_permitted	= ulfs_gro_remove_check_permitted,
1114 	.gro_rename			= lfs_gro_rename,
1115 	.gro_remove			= ulfs_gro_remove,
1116 	.gro_lookup			= ulfs_gro_lookup,
1117 	.gro_genealogy			= ulfs_gro_genealogy,
1118 	.gro_lock_directory		= ulfs_gro_lock_directory,
1119 };
1120 
1121 /*
1122  * lfs_sane_rename: The hairiest vop, with the saner API.
1123  *
1124  * Arguments:
1125  *
1126  * . fdvp (from directory vnode),
1127  * . fcnp (from component name),
1128  * . tdvp (to directory vnode),
1129  * . tcnp (to component name),
1130  * . cred (credentials structure), and
1131  * . posixly_correct (flag for behaviour if target & source link same file).
1132  *
1133  * fdvp and tdvp may be the same, and must be referenced and unlocked.
1134  */
1135 static int
1136 lfs_sane_rename(
1137     struct vnode *fdvp, struct componentname *fcnp,
1138     struct vnode *tdvp, struct componentname *tcnp,
1139     kauth_cred_t cred, bool posixly_correct)
1140 {
1141 	struct ulfs_lookup_results fulr, tulr;
1142 
1143 	/*
1144 	 * XXX Provisional kludge -- ulfs_lookup does not reject rename
1145 	 * of . or .. (from or to), so we hack it here.  This is not
1146 	 * the right place: it should be caller's responsibility to
1147 	 * reject this case.
1148 	 */
1149 	KASSERT(fcnp != NULL);
1150 	KASSERT(tcnp != NULL);
1151 	KASSERT(fcnp != tcnp);
1152 	KASSERT(fcnp->cn_nameptr != NULL);
1153 	KASSERT(tcnp->cn_nameptr != NULL);
1154 
1155 	if ((fcnp->cn_flags | tcnp->cn_flags) & ISDOTDOT)
1156 		return EINVAL;	/* XXX EISDIR?  */
1157 	if ((fcnp->cn_namelen == 1) && (fcnp->cn_nameptr[0] == '.'))
1158 		return EINVAL;
1159 	if ((tcnp->cn_namelen == 1) && (tcnp->cn_nameptr[0] == '.'))
1160 		return EINVAL;
1161 
1162 	return genfs_sane_rename(&lfs_genfs_rename_ops,
1163 	    fdvp, fcnp, &fulr, tdvp, tcnp, &tulr,
1164 	    cred, posixly_correct);
1165 }
1166 
1167 /*
1168  * lfs_rename: The hairiest vop, with the insanest API.  Defer to
1169  * genfs_insane_rename immediately.
1170  */
1171 int
1172 lfs_rename(void *v)
1173 {
1174 
1175 	return genfs_insane_rename(v, &lfs_sane_rename);
1176 }
1177