xref: /freebsd/sys/fs/unionfs/union_vnops.c (revision 7e1d3eefd410ca0fbae5a217422821244c3eeee4)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1992, 1993, 1994, 1995 Jan-Simon Pendry.
5  * Copyright (c) 1992, 1993, 1994, 1995
6  *      The Regents of the University of California.
7  * Copyright (c) 2005, 2006, 2012 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
8  * Copyright (c) 2006, 2012 Daichi Goto <daichi@freebsd.org>
9  * All rights reserved.
10  *
11  * This code is derived from software contributed to Berkeley by
12  * Jan-Simon Pendry.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)union_vnops.c	8.32 (Berkeley) 6/23/95
39  * $FreeBSD$
40  *
41  */
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/conf.h>
46 #include <sys/kernel.h>
47 #include <sys/lock.h>
48 #include <sys/malloc.h>
49 #include <sys/mount.h>
50 #include <sys/mutex.h>
51 #include <sys/namei.h>
52 #include <sys/sysctl.h>
53 #include <sys/vnode.h>
54 #include <sys/kdb.h>
55 #include <sys/fcntl.h>
56 #include <sys/stat.h>
57 #include <sys/dirent.h>
58 #include <sys/proc.h>
59 #include <sys/bio.h>
60 #include <sys/buf.h>
61 
62 #include <fs/unionfs/union.h>
63 
64 #include <vm/vm.h>
65 #include <vm/vm_extern.h>
66 #include <vm/vm_object.h>
67 #include <vm/vnode_pager.h>
68 
69 #if 0
70 #define UNIONFS_INTERNAL_DEBUG(msg, args...)    printf(msg, ## args)
71 #define UNIONFS_IDBG_RENAME
72 #else
73 #define UNIONFS_INTERNAL_DEBUG(msg, args...)
74 #endif
75 
76 #define KASSERT_UNIONFS_VNODE(vp) \
77 	KASSERT(((vp)->v_op == &unionfs_vnodeops), \
78 	    ("unionfs: it is not unionfs-vnode"))
79 
80 static int
81 unionfs_lookup(struct vop_cachedlookup_args *ap)
82 {
83 	struct unionfs_node *dunp;
84 	struct vnode   *dvp, *udvp, *ldvp, *vp, *uvp, *lvp, *dtmpvp;
85 	struct vattr	va;
86 	struct componentname *cnp;
87 	struct thread  *td;
88 	u_long		nameiop;
89 	u_long		cnflags, cnflagsbk;
90 	int		iswhiteout;
91 	int		lockflag;
92 	int		error , uerror, lerror;
93 
94 	iswhiteout = 0;
95 	lockflag = 0;
96 	error = uerror = lerror = ENOENT;
97 	cnp = ap->a_cnp;
98 	nameiop = cnp->cn_nameiop;
99 	cnflags = cnp->cn_flags;
100 	dvp = ap->a_dvp;
101 	dunp = VTOUNIONFS(dvp);
102 	udvp = dunp->un_uppervp;
103 	ldvp = dunp->un_lowervp;
104 	vp = uvp = lvp = NULLVP;
105 	td = curthread;
106 	*(ap->a_vpp) = NULLVP;
107 
108 	UNIONFS_INTERNAL_DEBUG(
109 	    "unionfs_lookup: enter: nameiop=%ld, flags=%lx, path=%s\n",
110 	    nameiop, cnflags, cnp->cn_nameptr);
111 
112 	if (dvp->v_type != VDIR)
113 		return (ENOTDIR);
114 
115 	/*
116 	 * If read-only and op is not LOOKUP, will return EROFS.
117 	 */
118 	if ((cnflags & ISLASTCN) &&
119 	    (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
120 	    LOOKUP != nameiop)
121 		return (EROFS);
122 
123 	/*
124 	 * lookup dotdot
125 	 */
126 	if (cnflags & ISDOTDOT) {
127 		if (LOOKUP != nameiop && udvp == NULLVP)
128 			return (EROFS);
129 
130 		if (udvp != NULLVP) {
131 			dtmpvp = udvp;
132 			if (ldvp != NULLVP)
133 				VOP_UNLOCK(ldvp);
134 		}
135 		else
136 			dtmpvp = ldvp;
137 
138 		error = VOP_LOOKUP(dtmpvp, &vp, cnp);
139 
140 		if (dtmpvp == udvp && ldvp != NULLVP) {
141 			VOP_UNLOCK(udvp);
142 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
143 		}
144 
145 		if (error == 0) {
146 			/*
147 			 * Exchange lock and reference from vp to
148 			 * dunp->un_dvp. vp is upper/lower vnode, but it
149 			 * will need to return the unionfs vnode.
150 			 */
151 			if (nameiop == DELETE  || nameiop == RENAME ||
152 			    (cnp->cn_lkflags & LK_TYPE_MASK))
153 				VOP_UNLOCK(vp);
154 			vrele(vp);
155 
156 			VOP_UNLOCK(dvp);
157 			*(ap->a_vpp) = dunp->un_dvp;
158 			vref(dunp->un_dvp);
159 
160 			if (nameiop == DELETE || nameiop == RENAME)
161 				vn_lock(dunp->un_dvp, LK_EXCLUSIVE | LK_RETRY);
162 			else if (cnp->cn_lkflags & LK_TYPE_MASK)
163 				vn_lock(dunp->un_dvp, cnp->cn_lkflags |
164 				    LK_RETRY);
165 
166 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
167 		} else if (error == ENOENT && (cnflags & MAKEENTRY) != 0)
168 			cache_enter(dvp, NULLVP, cnp);
169 
170 		goto unionfs_lookup_return;
171 	}
172 
173 	/*
174 	 * lookup upper layer
175 	 */
176 	if (udvp != NULLVP) {
177 		uerror = VOP_LOOKUP(udvp, &uvp, cnp);
178 
179 		if (uerror == 0) {
180 			if (udvp == uvp) {	/* is dot */
181 				vrele(uvp);
182 				*(ap->a_vpp) = dvp;
183 				vref(dvp);
184 
185 				error = uerror;
186 				goto unionfs_lookup_return;
187 			}
188 			if (nameiop == DELETE || nameiop == RENAME ||
189 			    (cnp->cn_lkflags & LK_TYPE_MASK))
190 				VOP_UNLOCK(uvp);
191 		}
192 
193 		/* check whiteout */
194 		if (uerror == ENOENT || uerror == EJUSTRETURN)
195 			if (cnp->cn_flags & ISWHITEOUT)
196 				iswhiteout = 1;	/* don't lookup lower */
197 		if (iswhiteout == 0 && ldvp != NULLVP)
198 			if (!VOP_GETATTR(udvp, &va, cnp->cn_cred) &&
199 			    (va.va_flags & OPAQUE))
200 				iswhiteout = 1;	/* don't lookup lower */
201 #if 0
202 		UNIONFS_INTERNAL_DEBUG(
203 		    "unionfs_lookup: debug: whiteout=%d, path=%s\n",
204 		    iswhiteout, cnp->cn_nameptr);
205 #endif
206 	}
207 
208 	/*
209 	 * lookup lower layer
210 	 */
211 	if (ldvp != NULLVP && !(cnflags & DOWHITEOUT) && iswhiteout == 0) {
212 		/* always op is LOOKUP */
213 		cnp->cn_nameiop = LOOKUP;
214 		cnflagsbk = cnp->cn_flags;
215 		cnp->cn_flags = cnflags;
216 
217 		lerror = VOP_LOOKUP(ldvp, &lvp, cnp);
218 
219 		cnp->cn_nameiop = nameiop;
220 		if (udvp != NULLVP && (uerror == 0 || uerror == EJUSTRETURN))
221 			cnp->cn_flags = cnflagsbk;
222 
223 		if (lerror == 0) {
224 			if (ldvp == lvp) {	/* is dot */
225 				if (uvp != NULLVP)
226 					vrele(uvp);	/* no need? */
227 				vrele(lvp);
228 				*(ap->a_vpp) = dvp;
229 				vref(dvp);
230 
231 				UNIONFS_INTERNAL_DEBUG(
232 				    "unionfs_lookup: leave (%d)\n", lerror);
233 
234 				return (lerror);
235 			}
236 			if (cnp->cn_lkflags & LK_TYPE_MASK)
237 				VOP_UNLOCK(lvp);
238 		}
239 	}
240 
241 	/*
242 	 * check lookup result
243 	 */
244 	if (uvp == NULLVP && lvp == NULLVP) {
245 		error = (udvp != NULLVP ? uerror : lerror);
246 		goto unionfs_lookup_return;
247 	}
248 
249 	/*
250 	 * check vnode type
251 	 */
252 	if (uvp != NULLVP && lvp != NULLVP && uvp->v_type != lvp->v_type) {
253 		vrele(lvp);
254 		lvp = NULLVP;
255 	}
256 
257 	/*
258 	 * check shadow dir
259 	 */
260 	if (uerror != 0 && uerror != EJUSTRETURN && udvp != NULLVP &&
261 	    lerror == 0 && lvp != NULLVP && lvp->v_type == VDIR &&
262 	    !(dvp->v_mount->mnt_flag & MNT_RDONLY) &&
263 	    (1 < cnp->cn_namelen || '.' != *(cnp->cn_nameptr))) {
264 		/* get unionfs vnode in order to create a new shadow dir. */
265 		error = unionfs_nodeget(dvp->v_mount, NULLVP, lvp, dvp, &vp,
266 		    cnp, td);
267 		if (error != 0)
268 			goto unionfs_lookup_cleanup;
269 
270 		if (LK_SHARED == (cnp->cn_lkflags & LK_TYPE_MASK))
271 			VOP_UNLOCK(vp);
272 		if (LK_EXCLUSIVE != VOP_ISLOCKED(vp)) {
273 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
274 			lockflag = 1;
275 		}
276 		error = unionfs_mkshadowdir(MOUNTTOUNIONFSMOUNT(dvp->v_mount),
277 		    udvp, VTOUNIONFS(vp), cnp, td);
278 		if (lockflag != 0)
279 			VOP_UNLOCK(vp);
280 		if (error != 0) {
281 			UNIONFSDEBUG(
282 			    "unionfs_lookup: Unable to create shadow dir.");
283 			if ((cnp->cn_lkflags & LK_TYPE_MASK) == LK_EXCLUSIVE)
284 				vput(vp);
285 			else
286 				vrele(vp);
287 			goto unionfs_lookup_cleanup;
288 		}
289 		if ((cnp->cn_lkflags & LK_TYPE_MASK) == LK_SHARED)
290 			vn_lock(vp, LK_SHARED | LK_RETRY);
291 	}
292 	/*
293 	 * get unionfs vnode.
294 	 */
295 	else {
296 		if (uvp != NULLVP)
297 			error = uerror;
298 		else
299 			error = lerror;
300 		if (error != 0)
301 			goto unionfs_lookup_cleanup;
302 		/*
303 		 * get socket vnode.
304 		 */
305 		if (uvp != NULLVP && uvp->v_type == VSOCK) {
306 			vp = uvp;
307 			vref(vp);
308 			if (cnp->cn_lkflags & LK_TYPE_MASK)
309 				vn_lock(vp, cnp->cn_lkflags | LK_RETRY);
310 		}
311 		else if (lvp != NULLVP && lvp->v_type == VSOCK) {
312 			vp = lvp;
313 			vref(vp);
314 			if (cnp->cn_lkflags & LK_TYPE_MASK)
315 				vn_lock(vp, cnp->cn_lkflags | LK_RETRY);
316 		}
317 		/*
318 		 * get unionfs vnode.
319 		 */
320 		else
321 			error = unionfs_nodeget(dvp->v_mount, uvp, lvp,
322 			    dvp, &vp, cnp, td);
323 		if (error != 0) {
324 			UNIONFSDEBUG(
325 			    "unionfs_lookup: Unable to create unionfs vnode.");
326 			goto unionfs_lookup_cleanup;
327 		}
328 		if ((nameiop == DELETE || nameiop == RENAME) &&
329 		    (cnp->cn_lkflags & LK_TYPE_MASK) == 0)
330 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
331 	}
332 
333 	*(ap->a_vpp) = vp;
334 
335 	if ((cnflags & MAKEENTRY) && vp->v_type != VSOCK)
336 		cache_enter(dvp, vp, cnp);
337 
338 unionfs_lookup_cleanup:
339 	if (uvp != NULLVP)
340 		vrele(uvp);
341 	if (lvp != NULLVP)
342 		vrele(lvp);
343 
344 	if (error == ENOENT && (cnflags & MAKEENTRY) != 0)
345 		cache_enter(dvp, NULLVP, cnp);
346 
347 unionfs_lookup_return:
348 
349 	/* Ensure subsequent vnops will get a valid pathname buffer. */
350 	if (nameiop != LOOKUP && (error == 0 || error == EJUSTRETURN))
351 		cnp->cn_flags |= SAVENAME;
352 
353 	UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
354 
355 	return (error);
356 }
357 
358 static int
359 unionfs_create(struct vop_create_args *ap)
360 {
361 	struct unionfs_node *dunp;
362 	struct componentname *cnp;
363 	struct vnode   *udvp;
364 	struct vnode   *vp;
365 	int		error;
366 
367 	UNIONFS_INTERNAL_DEBUG("unionfs_create: enter\n");
368 
369 	KASSERT_UNIONFS_VNODE(ap->a_dvp);
370 
371 	dunp = VTOUNIONFS(ap->a_dvp);
372 	cnp = ap->a_cnp;
373 	udvp = dunp->un_uppervp;
374 	error = EROFS;
375 
376 	if (udvp != NULLVP) {
377 		error = VOP_CREATE(udvp, &vp, cnp, ap->a_vap);
378 		if (error != 0)
379 			goto unionfs_create_abort;
380 
381 		if (vp->v_type == VSOCK)
382 			*(ap->a_vpp) = vp;
383 		else {
384 			VOP_UNLOCK(vp);
385 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
386 			    ap->a_dvp, ap->a_vpp, cnp, curthread);
387 			vrele(vp);
388 		}
389 	}
390 
391 unionfs_create_abort:
392 	UNIONFS_INTERNAL_DEBUG("unionfs_create: leave (%d)\n", error);
393 
394 	return (error);
395 }
396 
397 static int
398 unionfs_whiteout(struct vop_whiteout_args *ap)
399 {
400 	struct unionfs_node *dunp;
401 	struct componentname *cnp;
402 	struct vnode   *udvp;
403 	int		error;
404 
405 	UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: enter\n");
406 
407 	KASSERT_UNIONFS_VNODE(ap->a_dvp);
408 
409 	dunp = VTOUNIONFS(ap->a_dvp);
410 	cnp = ap->a_cnp;
411 	udvp = dunp->un_uppervp;
412 	error = EOPNOTSUPP;
413 
414 	if (udvp != NULLVP) {
415 		switch (ap->a_flags) {
416 		case CREATE:
417 		case DELETE:
418 		case LOOKUP:
419 			error = VOP_WHITEOUT(udvp, cnp, ap->a_flags);
420 			break;
421 		default:
422 			error = EINVAL;
423 			break;
424 		}
425 	}
426 
427 	UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: leave (%d)\n", error);
428 
429 	return (error);
430 }
431 
432 static int
433 unionfs_mknod(struct vop_mknod_args *ap)
434 {
435 	struct unionfs_node *dunp;
436 	struct componentname *cnp;
437 	struct vnode   *udvp;
438 	struct vnode   *vp;
439 	int		error;
440 
441 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: enter\n");
442 
443 	KASSERT_UNIONFS_VNODE(ap->a_dvp);
444 
445 	dunp = VTOUNIONFS(ap->a_dvp);
446 	cnp = ap->a_cnp;
447 	udvp = dunp->un_uppervp;
448 	error = EROFS;
449 
450 	if (udvp != NULLVP) {
451 		error = VOP_MKNOD(udvp, &vp, cnp, ap->a_vap);
452 		if (error != 0)
453 			goto unionfs_mknod_abort;
454 
455 		if (vp->v_type == VSOCK)
456 			*(ap->a_vpp) = vp;
457 		else {
458 			VOP_UNLOCK(vp);
459 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
460 			    ap->a_dvp, ap->a_vpp, cnp, curthread);
461 			vrele(vp);
462 		}
463 	}
464 
465 unionfs_mknod_abort:
466 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: leave (%d)\n", error);
467 
468 	return (error);
469 }
470 
471 static int
472 unionfs_open(struct vop_open_args *ap)
473 {
474 	struct unionfs_node *unp;
475 	struct unionfs_node_status *unsp;
476 	struct vnode   *uvp;
477 	struct vnode   *lvp;
478 	struct vnode   *targetvp;
479 	struct ucred   *cred;
480 	struct thread  *td;
481 	int		error;
482 
483 	UNIONFS_INTERNAL_DEBUG("unionfs_open: enter\n");
484 
485 	KASSERT_UNIONFS_VNODE(ap->a_vp);
486 
487 	error = 0;
488 	unp = VTOUNIONFS(ap->a_vp);
489 	uvp = unp->un_uppervp;
490 	lvp = unp->un_lowervp;
491 	targetvp = NULLVP;
492 	cred = ap->a_cred;
493 	td = ap->a_td;
494 
495 	unionfs_get_node_status(unp, td, &unsp);
496 
497 	if (unsp->uns_lower_opencnt > 0 || unsp->uns_upper_opencnt > 0) {
498 		/* vnode is already opend. */
499 		if (unsp->uns_upper_opencnt > 0)
500 			targetvp = uvp;
501 		else
502 			targetvp = lvp;
503 
504 		if (targetvp == lvp &&
505 		    (ap->a_mode & FWRITE) && lvp->v_type == VREG)
506 			targetvp = NULLVP;
507 	}
508 	if (targetvp == NULLVP) {
509 		if (uvp == NULLVP) {
510 			if ((ap->a_mode & FWRITE) && lvp->v_type == VREG) {
511 				error = unionfs_copyfile(unp,
512 				    !(ap->a_mode & O_TRUNC), cred, td);
513 				if (error != 0)
514 					goto unionfs_open_abort;
515 				targetvp = uvp = unp->un_uppervp;
516 			} else
517 				targetvp = lvp;
518 		} else
519 			targetvp = uvp;
520 	}
521 
522 	error = VOP_OPEN(targetvp, ap->a_mode, cred, td, ap->a_fp);
523 	if (error == 0) {
524 		if (targetvp == uvp) {
525 			if (uvp->v_type == VDIR && lvp != NULLVP &&
526 			    unsp->uns_lower_opencnt <= 0) {
527 				/* open lower for readdir */
528 				error = VOP_OPEN(lvp, FREAD, cred, td, NULL);
529 				if (error != 0) {
530 					VOP_CLOSE(uvp, ap->a_mode, cred, td);
531 					goto unionfs_open_abort;
532 				}
533 				unsp->uns_node_flag |= UNS_OPENL_4_READDIR;
534 				unsp->uns_lower_opencnt++;
535 			}
536 			unsp->uns_upper_opencnt++;
537 		} else {
538 			unsp->uns_lower_opencnt++;
539 			unsp->uns_lower_openmode = ap->a_mode;
540 		}
541 		ap->a_vp->v_object = targetvp->v_object;
542 	}
543 
544 unionfs_open_abort:
545 	if (error != 0)
546 		unionfs_tryrem_node_status(unp, unsp);
547 
548 	UNIONFS_INTERNAL_DEBUG("unionfs_open: leave (%d)\n", error);
549 
550 	return (error);
551 }
552 
553 static int
554 unionfs_close(struct vop_close_args *ap)
555 {
556 	struct unionfs_node *unp;
557 	struct unionfs_node_status *unsp;
558 	struct ucred   *cred;
559 	struct thread  *td;
560 	struct vnode   *vp;
561 	struct vnode   *ovp;
562 	int		error;
563 	int		locked;
564 
565 	UNIONFS_INTERNAL_DEBUG("unionfs_close: enter\n");
566 
567 	KASSERT_UNIONFS_VNODE(ap->a_vp);
568 
569 	locked = 0;
570 	vp = ap->a_vp;
571 	unp = VTOUNIONFS(vp);
572 	cred = ap->a_cred;
573 	td = ap->a_td;
574 
575 	if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
576 		if (vn_lock(vp, LK_UPGRADE) != 0)
577 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
578 		locked = 1;
579 	}
580 	unionfs_get_node_status(unp, td, &unsp);
581 
582 	if (unsp->uns_lower_opencnt <= 0 && unsp->uns_upper_opencnt <= 0) {
583 #ifdef DIAGNOSTIC
584 		printf("unionfs_close: warning: open count is 0\n");
585 #endif
586 		if (unp->un_uppervp != NULLVP)
587 			ovp = unp->un_uppervp;
588 		else
589 			ovp = unp->un_lowervp;
590 	} else if (unsp->uns_upper_opencnt > 0)
591 		ovp = unp->un_uppervp;
592 	else
593 		ovp = unp->un_lowervp;
594 
595 	error = VOP_CLOSE(ovp, ap->a_fflag, cred, td);
596 
597 	if (error != 0)
598 		goto unionfs_close_abort;
599 
600 	vp->v_object = ovp->v_object;
601 
602 	if (ovp == unp->un_uppervp) {
603 		unsp->uns_upper_opencnt--;
604 		if (unsp->uns_upper_opencnt == 0) {
605 			if (unsp->uns_node_flag & UNS_OPENL_4_READDIR) {
606 				VOP_CLOSE(unp->un_lowervp, FREAD, cred, td);
607 				unsp->uns_node_flag &= ~UNS_OPENL_4_READDIR;
608 				unsp->uns_lower_opencnt--;
609 			}
610 			if (unsp->uns_lower_opencnt > 0)
611 				vp->v_object = unp->un_lowervp->v_object;
612 		}
613 	} else
614 		unsp->uns_lower_opencnt--;
615 
616 unionfs_close_abort:
617 	unionfs_tryrem_node_status(unp, unsp);
618 
619 	if (locked != 0)
620 		vn_lock(vp, LK_DOWNGRADE | LK_RETRY);
621 
622 	UNIONFS_INTERNAL_DEBUG("unionfs_close: leave (%d)\n", error);
623 
624 	return (error);
625 }
626 
627 /*
628  * Check the access mode toward shadow file/dir.
629  */
630 static int
631 unionfs_check_corrected_access(accmode_t accmode, struct vattr *va,
632     struct ucred *cred)
633 {
634 	uid_t		uid;	/* upper side vnode's uid */
635 	gid_t		gid;	/* upper side vnode's gid */
636 	u_short		vmode;	/* upper side vnode's mode */
637 	u_short		mask;
638 
639 	mask = 0;
640 	uid = va->va_uid;
641 	gid = va->va_gid;
642 	vmode = va->va_mode;
643 
644 	/* check owner */
645 	if (cred->cr_uid == uid) {
646 		if (accmode & VEXEC)
647 			mask |= S_IXUSR;
648 		if (accmode & VREAD)
649 			mask |= S_IRUSR;
650 		if (accmode & VWRITE)
651 			mask |= S_IWUSR;
652 		return ((vmode & mask) == mask ? 0 : EACCES);
653 	}
654 
655 	/* check group */
656 	if (groupmember(gid, cred)) {
657 		if (accmode & VEXEC)
658 			mask |= S_IXGRP;
659 		if (accmode & VREAD)
660 			mask |= S_IRGRP;
661 		if (accmode & VWRITE)
662 			mask |= S_IWGRP;
663 		return ((vmode & mask) == mask ? 0 : EACCES);
664 	}
665 
666 	/* check other */
667 	if (accmode & VEXEC)
668 		mask |= S_IXOTH;
669 	if (accmode & VREAD)
670 		mask |= S_IROTH;
671 	if (accmode & VWRITE)
672 		mask |= S_IWOTH;
673 
674 	return ((vmode & mask) == mask ? 0 : EACCES);
675 }
676 
677 static int
678 unionfs_access(struct vop_access_args *ap)
679 {
680 	struct unionfs_mount *ump;
681 	struct unionfs_node *unp;
682 	struct vnode   *uvp;
683 	struct vnode   *lvp;
684 	struct thread  *td;
685 	struct vattr	va;
686 	accmode_t	accmode;
687 	int		error;
688 
689 	UNIONFS_INTERNAL_DEBUG("unionfs_access: enter\n");
690 
691 	KASSERT_UNIONFS_VNODE(ap->a_vp);
692 
693 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
694 	unp = VTOUNIONFS(ap->a_vp);
695 	uvp = unp->un_uppervp;
696 	lvp = unp->un_lowervp;
697 	td = ap->a_td;
698 	accmode = ap->a_accmode;
699 	error = EACCES;
700 
701 	if ((accmode & VWRITE) &&
702 	    (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) {
703 		switch (ap->a_vp->v_type) {
704 		case VREG:
705 		case VDIR:
706 		case VLNK:
707 			return (EROFS);
708 		default:
709 			break;
710 		}
711 	}
712 
713 	if (uvp != NULLVP) {
714 		error = VOP_ACCESS(uvp, accmode, ap->a_cred, td);
715 
716 		UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
717 
718 		return (error);
719 	}
720 
721 	if (lvp != NULLVP) {
722 		if (accmode & VWRITE) {
723 			if (ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY) {
724 				switch (ap->a_vp->v_type) {
725 				case VREG:
726 				case VDIR:
727 				case VLNK:
728 					return (EROFS);
729 				default:
730 					break;
731 				}
732 			} else if (ap->a_vp->v_type == VREG ||
733 			    ap->a_vp->v_type == VDIR) {
734 				/* check shadow file/dir */
735 				if (ump->um_copymode != UNIONFS_TRANSPARENT) {
736 					error = unionfs_create_uppervattr(ump,
737 					    lvp, &va, ap->a_cred, td);
738 					if (error != 0)
739 						return (error);
740 
741 					error = unionfs_check_corrected_access(
742 					    accmode, &va, ap->a_cred);
743 					if (error != 0)
744 						return (error);
745 				}
746 			}
747 			accmode &= ~(VWRITE | VAPPEND);
748 			accmode |= VREAD; /* will copy to upper */
749 		}
750 		error = VOP_ACCESS(lvp, accmode, ap->a_cred, td);
751 	}
752 
753 	UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
754 
755 	return (error);
756 }
757 
758 static int
759 unionfs_getattr(struct vop_getattr_args *ap)
760 {
761 	struct unionfs_node *unp;
762 	struct unionfs_mount *ump;
763 	struct vnode   *uvp;
764 	struct vnode   *lvp;
765 	struct thread  *td;
766 	struct vattr	va;
767 	int		error;
768 
769 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: enter\n");
770 
771 	KASSERT_UNIONFS_VNODE(ap->a_vp);
772 
773 	unp = VTOUNIONFS(ap->a_vp);
774 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
775 	uvp = unp->un_uppervp;
776 	lvp = unp->un_lowervp;
777 	td = curthread;
778 
779 	if (uvp != NULLVP) {
780 		if ((error = VOP_GETATTR(uvp, ap->a_vap, ap->a_cred)) == 0)
781 			ap->a_vap->va_fsid =
782 			    ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
783 
784 		UNIONFS_INTERNAL_DEBUG(
785 		    "unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
786 		    ap->a_vap->va_mode, ap->a_vap->va_uid,
787 		    ap->a_vap->va_gid, error);
788 
789 		return (error);
790 	}
791 
792 	error = VOP_GETATTR(lvp, ap->a_vap, ap->a_cred);
793 
794 	if (error == 0 && !(ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY)) {
795 		/* correct the attr toward shadow file/dir. */
796 		if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
797 			unionfs_create_uppervattr_core(ump, ap->a_vap, &va, td);
798 			ap->a_vap->va_mode = va.va_mode;
799 			ap->a_vap->va_uid = va.va_uid;
800 			ap->a_vap->va_gid = va.va_gid;
801 		}
802 	}
803 
804 	if (error == 0)
805 		ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
806 
807 	UNIONFS_INTERNAL_DEBUG(
808 	    "unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
809 	    ap->a_vap->va_mode, ap->a_vap->va_uid, ap->a_vap->va_gid, error);
810 
811 	return (error);
812 }
813 
814 static int
815 unionfs_setattr(struct vop_setattr_args *ap)
816 {
817 	struct unionfs_node *unp;
818 	struct vnode   *uvp;
819 	struct vnode   *lvp;
820 	struct thread  *td;
821 	struct vattr   *vap;
822 	int		error;
823 
824 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: enter\n");
825 
826 	KASSERT_UNIONFS_VNODE(ap->a_vp);
827 
828 	error = EROFS;
829 	unp = VTOUNIONFS(ap->a_vp);
830 	uvp = unp->un_uppervp;
831 	lvp = unp->un_lowervp;
832 	td = curthread;
833 	vap = ap->a_vap;
834 
835 	if ((ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) &&
836 	    (vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
837 	     vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
838 	     vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL))
839 		return (EROFS);
840 
841 	if (uvp == NULLVP && lvp->v_type == VREG) {
842 		error = unionfs_copyfile(unp, (vap->va_size != 0),
843 		    ap->a_cred, td);
844 		if (error != 0)
845 			return (error);
846 		uvp = unp->un_uppervp;
847 	}
848 
849 	if (uvp != NULLVP)
850 		error = VOP_SETATTR(uvp, vap, ap->a_cred);
851 
852 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: leave (%d)\n", error);
853 
854 	return (error);
855 }
856 
857 static int
858 unionfs_read(struct vop_read_args *ap)
859 {
860 	struct unionfs_node *unp;
861 	struct vnode   *tvp;
862 	int		error;
863 
864 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: enter\n"); */
865 
866 	KASSERT_UNIONFS_VNODE(ap->a_vp);
867 
868 	unp = VTOUNIONFS(ap->a_vp);
869 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
870 
871 	error = VOP_READ(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
872 
873 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: leave (%d)\n", error); */
874 
875 	return (error);
876 }
877 
878 static int
879 unionfs_write(struct vop_write_args *ap)
880 {
881 	struct unionfs_node *unp;
882 	struct vnode   *tvp;
883 	int		error;
884 
885 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: enter\n"); */
886 
887 	KASSERT_UNIONFS_VNODE(ap->a_vp);
888 
889 	unp = VTOUNIONFS(ap->a_vp);
890 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
891 
892 	error = VOP_WRITE(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
893 
894 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: leave (%d)\n", error); */
895 
896 	return (error);
897 }
898 
899 static int
900 unionfs_ioctl(struct vop_ioctl_args *ap)
901 {
902 	struct unionfs_node *unp;
903 	struct unionfs_node_status *unsp;
904 	struct vnode   *ovp;
905 	int error;
906 
907 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: enter\n");
908 
909 	KASSERT_UNIONFS_VNODE(ap->a_vp);
910 
911  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
912 	unp = VTOUNIONFS(ap->a_vp);
913 	unionfs_get_node_status(unp, ap->a_td, &unsp);
914 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
915 	unionfs_tryrem_node_status(unp, unsp);
916 	VOP_UNLOCK(ap->a_vp);
917 
918 	if (ovp == NULLVP)
919 		return (EBADF);
920 
921 	error = VOP_IOCTL(ovp, ap->a_command, ap->a_data, ap->a_fflag,
922 	    ap->a_cred, ap->a_td);
923 
924 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: leave (%d)\n", error);
925 
926 	return (error);
927 }
928 
929 static int
930 unionfs_poll(struct vop_poll_args *ap)
931 {
932 	struct unionfs_node *unp;
933 	struct unionfs_node_status *unsp;
934 	struct vnode *ovp;
935 
936 	KASSERT_UNIONFS_VNODE(ap->a_vp);
937 
938  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
939 	unp = VTOUNIONFS(ap->a_vp);
940 	unionfs_get_node_status(unp, ap->a_td, &unsp);
941 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
942 	unionfs_tryrem_node_status(unp, unsp);
943 	VOP_UNLOCK(ap->a_vp);
944 
945 	if (ovp == NULLVP)
946 		return (EBADF);
947 
948 	return (VOP_POLL(ovp, ap->a_events, ap->a_cred, ap->a_td));
949 }
950 
951 static int
952 unionfs_fsync(struct vop_fsync_args *ap)
953 {
954 	struct unionfs_node *unp;
955 	struct unionfs_node_status *unsp;
956 	struct vnode *ovp;
957 
958 	KASSERT_UNIONFS_VNODE(ap->a_vp);
959 
960 	unp = VTOUNIONFS(ap->a_vp);
961 	unionfs_get_node_status(unp, ap->a_td, &unsp);
962 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
963 	unionfs_tryrem_node_status(unp, unsp);
964 
965 	if (ovp == NULLVP)
966 		return (EBADF);
967 
968 	return (VOP_FSYNC(ovp, ap->a_waitfor, ap->a_td));
969 }
970 
971 static int
972 unionfs_remove(struct vop_remove_args *ap)
973 {
974 	char	       *path;
975 	struct unionfs_node *dunp;
976 	struct unionfs_node *unp;
977 	struct unionfs_mount *ump;
978 	struct vnode   *udvp;
979 	struct vnode   *uvp;
980 	struct vnode   *lvp;
981 	struct vnode   *vp;
982 	struct componentname *cnp;
983 	struct componentname cn;
984 	struct thread  *td;
985 	int		error;
986 	int		pathlen;
987 
988 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: enter\n");
989 
990 	KASSERT_UNIONFS_VNODE(ap->a_dvp);
991 
992 	error = 0;
993 	dunp = VTOUNIONFS(ap->a_dvp);
994 	udvp = dunp->un_uppervp;
995 	cnp = ap->a_cnp;
996 	td = curthread;
997 
998 	if (ap->a_vp->v_op != &unionfs_vnodeops) {
999 		if (ap->a_vp->v_type != VSOCK)
1000 			return (EINVAL);
1001 		ump = NULL;
1002 		vp = uvp = lvp = NULLVP;
1003 		/* search vnode */
1004 		VOP_UNLOCK(ap->a_vp);
1005 		error = unionfs_relookup(udvp, &vp, cnp, &cn, td,
1006 		    cnp->cn_nameptr, cnp->cn_namelen, DELETE);
1007 		if (error != 0 && error != ENOENT) {
1008 			vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
1009 			return (error);
1010 		}
1011 
1012 		if (error == 0 && vp == ap->a_vp) {
1013 			/* target vnode in upper */
1014 			uvp = vp;
1015 			vrele(vp);
1016 		} else {
1017 			/* target vnode in lower */
1018 			if (vp != NULLVP) {
1019 				if (udvp == vp)
1020 					vrele(vp);
1021 				else
1022 					vput(vp);
1023 			}
1024 			vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
1025 			lvp = ap->a_vp;
1026 		}
1027 		path = cnp->cn_nameptr;
1028 		pathlen = cnp->cn_namelen;
1029 	} else {
1030 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
1031 		unp = VTOUNIONFS(ap->a_vp);
1032 		uvp = unp->un_uppervp;
1033 		lvp = unp->un_lowervp;
1034 		path = unp->un_path;
1035 		pathlen = unp->un_pathlen;
1036 	}
1037 
1038 	if (udvp == NULLVP)
1039 		return (EROFS);
1040 
1041 	if (uvp != NULLVP) {
1042 		/*
1043 		 * XXX: if the vnode type is VSOCK, it will create whiteout
1044 		 *      after remove.
1045 		 */
1046 		if (ump == NULL || ump->um_whitemode == UNIONFS_WHITE_ALWAYS ||
1047 		    lvp != NULLVP)
1048 			cnp->cn_flags |= DOWHITEOUT;
1049 		error = VOP_REMOVE(udvp, uvp, cnp);
1050 	} else if (lvp != NULLVP)
1051 		error = unionfs_mkwhiteout(udvp, cnp, td, path, pathlen);
1052 
1053 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: leave (%d)\n", error);
1054 
1055 	return (error);
1056 }
1057 
1058 static int
1059 unionfs_link(struct vop_link_args *ap)
1060 {
1061 	struct unionfs_node *dunp;
1062 	struct unionfs_node *unp;
1063 	struct vnode   *udvp;
1064 	struct vnode   *uvp;
1065 	struct componentname *cnp;
1066 	struct thread  *td;
1067 	int		error;
1068 	int		needrelookup;
1069 
1070 	UNIONFS_INTERNAL_DEBUG("unionfs_link: enter\n");
1071 
1072 	KASSERT_UNIONFS_VNODE(ap->a_tdvp);
1073 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1074 
1075 	error = 0;
1076 	needrelookup = 0;
1077 	dunp = VTOUNIONFS(ap->a_tdvp);
1078 	unp = NULL;
1079 	udvp = dunp->un_uppervp;
1080 	uvp = NULLVP;
1081 	cnp = ap->a_cnp;
1082 	td = curthread;
1083 
1084 	if (udvp == NULLVP)
1085 		return (EROFS);
1086 
1087 	if (ap->a_vp->v_op != &unionfs_vnodeops)
1088 		uvp = ap->a_vp;
1089 	else {
1090 		unp = VTOUNIONFS(ap->a_vp);
1091 
1092 		if (unp->un_uppervp == NULLVP) {
1093 			if (ap->a_vp->v_type != VREG)
1094 				return (EOPNOTSUPP);
1095 
1096 			error = unionfs_copyfile(unp, 1, cnp->cn_cred, td);
1097 			if (error != 0)
1098 				return (error);
1099 			needrelookup = 1;
1100 		}
1101 		uvp = unp->un_uppervp;
1102 	}
1103 
1104 	if (needrelookup != 0)
1105 		error = unionfs_relookup_for_create(ap->a_tdvp, cnp, td);
1106 
1107 	if (error == 0)
1108 		error = VOP_LINK(udvp, uvp, cnp);
1109 
1110 	UNIONFS_INTERNAL_DEBUG("unionfs_link: leave (%d)\n", error);
1111 
1112 	return (error);
1113 }
1114 
1115 static int
1116 unionfs_rename(struct vop_rename_args *ap)
1117 {
1118 	struct vnode   *fdvp;
1119 	struct vnode   *fvp;
1120 	struct componentname *fcnp;
1121 	struct vnode   *tdvp;
1122 	struct vnode   *tvp;
1123 	struct componentname *tcnp;
1124 	struct vnode   *ltdvp;
1125 	struct vnode   *ltvp;
1126 	struct thread  *td;
1127 
1128 	/* rename target vnodes */
1129 	struct vnode   *rfdvp;
1130 	struct vnode   *rfvp;
1131 	struct vnode   *rtdvp;
1132 	struct vnode   *rtvp;
1133 
1134 	struct unionfs_mount *ump;
1135 	struct unionfs_node *unp;
1136 	int		error;
1137 	int		needrelookup;
1138 
1139 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: enter\n");
1140 
1141 	error = 0;
1142 	fdvp = ap->a_fdvp;
1143 	fvp = ap->a_fvp;
1144 	fcnp = ap->a_fcnp;
1145 	tdvp = ap->a_tdvp;
1146 	tvp = ap->a_tvp;
1147 	tcnp = ap->a_tcnp;
1148 	ltdvp = NULLVP;
1149 	ltvp = NULLVP;
1150 	td = curthread;
1151 	rfdvp = fdvp;
1152 	rfvp = fvp;
1153 	rtdvp = tdvp;
1154 	rtvp = tvp;
1155 	needrelookup = 0;
1156 
1157 #ifdef DIAGNOSTIC
1158 	if (!(fcnp->cn_flags & HASBUF) || !(tcnp->cn_flags & HASBUF))
1159 		panic("unionfs_rename: no name");
1160 #endif
1161 
1162 	/* check for cross device rename */
1163 	if (fvp->v_mount != tdvp->v_mount ||
1164 	    (tvp != NULLVP && fvp->v_mount != tvp->v_mount)) {
1165 		if (fvp->v_op != &unionfs_vnodeops)
1166 			error = ENODEV;
1167 		else
1168 			error = EXDEV;
1169 		goto unionfs_rename_abort;
1170 	}
1171 
1172 	/* Renaming a file to itself has no effect. */
1173 	if (fvp == tvp)
1174 		goto unionfs_rename_abort;
1175 
1176 	/*
1177 	 * from/to vnode is unionfs node.
1178 	 */
1179 
1180 	KASSERT_UNIONFS_VNODE(fdvp);
1181 	KASSERT_UNIONFS_VNODE(fvp);
1182 	KASSERT_UNIONFS_VNODE(tdvp);
1183 	if (tvp != NULLVP)
1184 		KASSERT_UNIONFS_VNODE(tvp);
1185 
1186 	unp = VTOUNIONFS(fdvp);
1187 #ifdef UNIONFS_IDBG_RENAME
1188 	UNIONFS_INTERNAL_DEBUG("fdvp=%p, ufdvp=%p, lfdvp=%p\n",
1189 	    fdvp, unp->un_uppervp, unp->un_lowervp);
1190 #endif
1191 	if (unp->un_uppervp == NULLVP) {
1192 		error = ENODEV;
1193 		goto unionfs_rename_abort;
1194 	}
1195 	rfdvp = unp->un_uppervp;
1196 	vref(rfdvp);
1197 
1198 	unp = VTOUNIONFS(fvp);
1199 #ifdef UNIONFS_IDBG_RENAME
1200 	UNIONFS_INTERNAL_DEBUG("fvp=%p, ufvp=%p, lfvp=%p\n",
1201 	    fvp, unp->un_uppervp, unp->un_lowervp);
1202 #endif
1203 	ump = MOUNTTOUNIONFSMOUNT(fvp->v_mount);
1204 	if (unp->un_uppervp == NULLVP) {
1205 		switch (fvp->v_type) {
1206 		case VREG:
1207 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1208 				goto unionfs_rename_abort;
1209 			error = unionfs_copyfile(unp, 1, fcnp->cn_cred, td);
1210 			VOP_UNLOCK(fvp);
1211 			if (error != 0)
1212 				goto unionfs_rename_abort;
1213 			break;
1214 		case VDIR:
1215 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1216 				goto unionfs_rename_abort;
1217 			error = unionfs_mkshadowdir(ump, rfdvp, unp, fcnp, td);
1218 			VOP_UNLOCK(fvp);
1219 			if (error != 0)
1220 				goto unionfs_rename_abort;
1221 			break;
1222 		default:
1223 			error = ENODEV;
1224 			goto unionfs_rename_abort;
1225 		}
1226 
1227 		needrelookup = 1;
1228 	}
1229 
1230 	if (unp->un_lowervp != NULLVP)
1231 		fcnp->cn_flags |= DOWHITEOUT;
1232 	rfvp = unp->un_uppervp;
1233 	vref(rfvp);
1234 
1235 	unp = VTOUNIONFS(tdvp);
1236 #ifdef UNIONFS_IDBG_RENAME
1237 	UNIONFS_INTERNAL_DEBUG("tdvp=%p, utdvp=%p, ltdvp=%p\n",
1238 	    tdvp, unp->un_uppervp, unp->un_lowervp);
1239 #endif
1240 	if (unp->un_uppervp == NULLVP) {
1241 		error = ENODEV;
1242 		goto unionfs_rename_abort;
1243 	}
1244 	rtdvp = unp->un_uppervp;
1245 	ltdvp = unp->un_lowervp;
1246 	vref(rtdvp);
1247 
1248 	if (tdvp == tvp) {
1249 		rtvp = rtdvp;
1250 		vref(rtvp);
1251 	} else if (tvp != NULLVP) {
1252 		unp = VTOUNIONFS(tvp);
1253 #ifdef UNIONFS_IDBG_RENAME
1254 		UNIONFS_INTERNAL_DEBUG("tvp=%p, utvp=%p, ltvp=%p\n",
1255 		    tvp, unp->un_uppervp, unp->un_lowervp);
1256 #endif
1257 		if (unp->un_uppervp == NULLVP)
1258 			rtvp = NULLVP;
1259 		else {
1260 			if (tvp->v_type == VDIR) {
1261 				error = EINVAL;
1262 				goto unionfs_rename_abort;
1263 			}
1264 			rtvp = unp->un_uppervp;
1265 			ltvp = unp->un_lowervp;
1266 			vref(rtvp);
1267 		}
1268 	}
1269 
1270 	if (rfvp == rtvp)
1271 		goto unionfs_rename_abort;
1272 
1273 	if (needrelookup != 0) {
1274 		if ((error = vn_lock(fdvp, LK_EXCLUSIVE)) != 0)
1275 			goto unionfs_rename_abort;
1276 		error = unionfs_relookup_for_delete(fdvp, fcnp, td);
1277 		VOP_UNLOCK(fdvp);
1278 		if (error != 0)
1279 			goto unionfs_rename_abort;
1280 
1281 		/* Lock of tvp is canceled in order to avoid recursive lock. */
1282 		if (tvp != NULLVP && tvp != tdvp)
1283 			VOP_UNLOCK(tvp);
1284 		error = unionfs_relookup_for_rename(tdvp, tcnp, td);
1285 		if (tvp != NULLVP && tvp != tdvp)
1286 			vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
1287 		if (error != 0)
1288 			goto unionfs_rename_abort;
1289 	}
1290 
1291 	error = VOP_RENAME(rfdvp, rfvp, fcnp, rtdvp, rtvp, tcnp);
1292 
1293 	if (error == 0) {
1294 		if (rtvp != NULLVP && rtvp->v_type == VDIR)
1295 			cache_purge(tdvp);
1296 		if (fvp->v_type == VDIR && fdvp != tdvp)
1297 			cache_purge(fdvp);
1298 	}
1299 
1300 	if (ltdvp != NULLVP)
1301 		VOP_UNLOCK(ltdvp);
1302 	if (tdvp != rtdvp)
1303 		vrele(tdvp);
1304 	if (ltvp != NULLVP)
1305 		VOP_UNLOCK(ltvp);
1306 	if (tvp != rtvp && tvp != NULLVP) {
1307 		if (rtvp == NULLVP)
1308 			vput(tvp);
1309 		else
1310 			vrele(tvp);
1311 	}
1312 	if (fdvp != rfdvp)
1313 		vrele(fdvp);
1314 	if (fvp != rfvp)
1315 		vrele(fvp);
1316 
1317 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1318 
1319 	return (error);
1320 
1321 unionfs_rename_abort:
1322 	vput(tdvp);
1323 	if (tdvp != rtdvp)
1324 		vrele(rtdvp);
1325 	if (tvp != NULLVP) {
1326 		if (tdvp != tvp)
1327 			vput(tvp);
1328 		else
1329 			vrele(tvp);
1330 	}
1331 	if (tvp != rtvp && rtvp != NULLVP)
1332 		vrele(rtvp);
1333 	if (fdvp != rfdvp)
1334 		vrele(rfdvp);
1335 	if (fvp != rfvp)
1336 		vrele(rfvp);
1337 	vrele(fdvp);
1338 	vrele(fvp);
1339 
1340 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1341 
1342 	return (error);
1343 }
1344 
1345 static int
1346 unionfs_mkdir(struct vop_mkdir_args *ap)
1347 {
1348 	struct unionfs_node *dunp;
1349 	struct componentname *cnp;
1350 	struct thread  *td;
1351 	struct vnode   *udvp;
1352 	struct vnode   *uvp;
1353 	struct vattr	va;
1354 	int		error;
1355 	int		lkflags;
1356 
1357 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: enter\n");
1358 
1359 	KASSERT_UNIONFS_VNODE(ap->a_dvp);
1360 
1361 	error = EROFS;
1362 	dunp = VTOUNIONFS(ap->a_dvp);
1363 	cnp = ap->a_cnp;
1364 	lkflags = cnp->cn_lkflags;
1365 	td = curthread;
1366 	udvp = dunp->un_uppervp;
1367 
1368 	if (udvp != NULLVP) {
1369 		/* check opaque */
1370 		if (!(cnp->cn_flags & ISWHITEOUT)) {
1371 			error = VOP_GETATTR(udvp, &va, cnp->cn_cred);
1372 			if (error != 0)
1373 				return (error);
1374 			if ((va.va_flags & OPAQUE) != 0)
1375 				cnp->cn_flags |= ISWHITEOUT;
1376 		}
1377 
1378 		if ((error = VOP_MKDIR(udvp, &uvp, cnp, ap->a_vap)) == 0) {
1379 			VOP_UNLOCK(uvp);
1380 			cnp->cn_lkflags = LK_EXCLUSIVE;
1381 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1382 			    ap->a_dvp, ap->a_vpp, cnp, td);
1383 			cnp->cn_lkflags = lkflags;
1384 			vrele(uvp);
1385 		}
1386 	}
1387 
1388 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: leave (%d)\n", error);
1389 
1390 	return (error);
1391 }
1392 
1393 static int
1394 unionfs_rmdir(struct vop_rmdir_args *ap)
1395 {
1396 	struct unionfs_node *dunp;
1397 	struct unionfs_node *unp;
1398 	struct unionfs_mount *ump;
1399 	struct componentname *cnp;
1400 	struct thread  *td;
1401 	struct vnode   *udvp;
1402 	struct vnode   *uvp;
1403 	struct vnode   *lvp;
1404 	int		error;
1405 
1406 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: enter\n");
1407 
1408 	KASSERT_UNIONFS_VNODE(ap->a_dvp);
1409 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1410 
1411 	error = 0;
1412 	dunp = VTOUNIONFS(ap->a_dvp);
1413 	unp = VTOUNIONFS(ap->a_vp);
1414 	cnp = ap->a_cnp;
1415 	td = curthread;
1416 	udvp = dunp->un_uppervp;
1417 	uvp = unp->un_uppervp;
1418 	lvp = unp->un_lowervp;
1419 
1420 	if (udvp == NULLVP)
1421 		return (EROFS);
1422 
1423 	if (udvp == uvp)
1424 		return (EOPNOTSUPP);
1425 
1426 	if (uvp != NULLVP) {
1427 		if (lvp != NULLVP) {
1428 			error = unionfs_check_rmdir(ap->a_vp, cnp->cn_cred, td);
1429 			if (error != 0)
1430 				return (error);
1431 		}
1432 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
1433 		if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP)
1434 			cnp->cn_flags |= DOWHITEOUT;
1435 		/*
1436 		 * The relookup path will need to relock the parent dvp and
1437 		 * possibly the vp as well.  Locking is expected to be done
1438 		 * in parent->child order; drop the lock on vp to avoid LOR
1439 		 * and potential recursion on vp's lock.
1440 		 * vp is expected to remain referenced during VOP_RMDIR(),
1441 		 * so vref/vrele should not be necessary here.
1442 		 */
1443 		VOP_UNLOCK(ap->a_vp);
1444 		VNPASS(vrefcnt(ap->a_vp) > 0, ap->a_vp);
1445 		error = unionfs_relookup_for_delete(ap->a_dvp, cnp, td);
1446 		vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
1447 		if (error == 0 && VN_IS_DOOMED(uvp))
1448 			error = ENOENT;
1449 		if (error == 0)
1450 			error = VOP_RMDIR(udvp, uvp, cnp);
1451 	} else if (lvp != NULLVP)
1452 		error = unionfs_mkwhiteout(udvp, cnp, td,
1453 		    unp->un_path, unp->un_pathlen);
1454 
1455 	if (error == 0) {
1456 		cache_purge(ap->a_dvp);
1457 		cache_purge(ap->a_vp);
1458 	}
1459 
1460 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: leave (%d)\n", error);
1461 
1462 	return (error);
1463 }
1464 
1465 static int
1466 unionfs_symlink(struct vop_symlink_args *ap)
1467 {
1468 	struct unionfs_node *dunp;
1469 	struct componentname *cnp;
1470 	struct thread  *td;
1471 	struct vnode   *udvp;
1472 	struct vnode   *uvp;
1473 	int		error;
1474 	int		lkflags;
1475 
1476 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: enter\n");
1477 
1478 	KASSERT_UNIONFS_VNODE(ap->a_dvp);
1479 
1480 	error = EROFS;
1481 	dunp = VTOUNIONFS(ap->a_dvp);
1482 	cnp = ap->a_cnp;
1483 	lkflags = cnp->cn_lkflags;
1484 	td = curthread;
1485 	udvp = dunp->un_uppervp;
1486 
1487 	if (udvp != NULLVP) {
1488 		error = VOP_SYMLINK(udvp, &uvp, cnp, ap->a_vap, ap->a_target);
1489 		if (error == 0) {
1490 			VOP_UNLOCK(uvp);
1491 			cnp->cn_lkflags = LK_EXCLUSIVE;
1492 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1493 			    ap->a_dvp, ap->a_vpp, cnp, td);
1494 			cnp->cn_lkflags = lkflags;
1495 			vrele(uvp);
1496 		}
1497 	}
1498 
1499 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: leave (%d)\n", error);
1500 
1501 	return (error);
1502 }
1503 
1504 static int
1505 unionfs_readdir(struct vop_readdir_args *ap)
1506 {
1507 	struct unionfs_node *unp;
1508 	struct unionfs_node_status *unsp;
1509 	struct uio     *uio;
1510 	struct vnode   *vp;
1511 	struct vnode   *uvp;
1512 	struct vnode   *lvp;
1513 	struct thread  *td;
1514 	struct vattr    va;
1515 
1516 	u_long         *cookies_bk;
1517 	int		error;
1518 	int		eofflag;
1519 	int		locked;
1520 	int		ncookies_bk;
1521 	int		uio_offset_bk;
1522 
1523 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: enter\n");
1524 
1525 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1526 
1527 	error = 0;
1528 	eofflag = 0;
1529 	locked = 0;
1530 	uio_offset_bk = 0;
1531 	uio = ap->a_uio;
1532 	uvp = NULLVP;
1533 	lvp = NULLVP;
1534 	td = uio->uio_td;
1535 	ncookies_bk = 0;
1536 	cookies_bk = NULL;
1537 
1538 	vp = ap->a_vp;
1539 	if (vp->v_type != VDIR)
1540 		return (ENOTDIR);
1541 
1542 	/* check the open count. unionfs needs to open before readdir. */
1543 	if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
1544 		if (vn_lock(vp, LK_UPGRADE) != 0)
1545 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1546 		locked = 1;
1547 	}
1548 	unp = VTOUNIONFS(vp);
1549 	if (unp == NULL)
1550 		error = EBADF;
1551 	else {
1552 		uvp = unp->un_uppervp;
1553 		lvp = unp->un_lowervp;
1554 		unionfs_get_node_status(unp, td, &unsp);
1555 		if ((uvp != NULLVP && unsp->uns_upper_opencnt <= 0) ||
1556 			(lvp != NULLVP && unsp->uns_lower_opencnt <= 0)) {
1557 			unionfs_tryrem_node_status(unp, unsp);
1558 			error = EBADF;
1559 		}
1560 	}
1561 	if (locked)
1562 		vn_lock(vp, LK_DOWNGRADE | LK_RETRY);
1563 	if (error != 0)
1564 		goto unionfs_readdir_exit;
1565 
1566 	/* check opaque */
1567 	if (uvp != NULLVP && lvp != NULLVP) {
1568 		if ((error = VOP_GETATTR(uvp, &va, ap->a_cred)) != 0)
1569 			goto unionfs_readdir_exit;
1570 		if (va.va_flags & OPAQUE)
1571 			lvp = NULLVP;
1572 	}
1573 
1574 	/* upper only */
1575 	if (uvp != NULLVP && lvp == NULLVP) {
1576 		error = VOP_READDIR(uvp, uio, ap->a_cred, ap->a_eofflag,
1577 		    ap->a_ncookies, ap->a_cookies);
1578 		unsp->uns_readdir_status = 0;
1579 
1580 		goto unionfs_readdir_exit;
1581 	}
1582 
1583 	/* lower only */
1584 	if (uvp == NULLVP && lvp != NULLVP) {
1585 		error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1586 		    ap->a_ncookies, ap->a_cookies);
1587 		unsp->uns_readdir_status = 2;
1588 
1589 		goto unionfs_readdir_exit;
1590 	}
1591 
1592 	/*
1593 	 * readdir upper and lower
1594 	 */
1595 	KASSERT(uvp != NULLVP, ("unionfs_readdir: null upper vp"));
1596 	KASSERT(lvp != NULLVP, ("unionfs_readdir: null lower vp"));
1597 	if (uio->uio_offset == 0)
1598 		unsp->uns_readdir_status = 0;
1599 
1600 	if (unsp->uns_readdir_status == 0) {
1601 		/* read upper */
1602 		error = VOP_READDIR(uvp, uio, ap->a_cred, &eofflag,
1603 				    ap->a_ncookies, ap->a_cookies);
1604 
1605 		if (error != 0 || eofflag == 0)
1606 			goto unionfs_readdir_exit;
1607 		unsp->uns_readdir_status = 1;
1608 
1609 		/*
1610 		 * UFS(and other FS) needs size of uio_resid larger than
1611 		 * DIRBLKSIZ.
1612 		 * size of DIRBLKSIZ equals DEV_BSIZE.
1613 		 * (see: ufs/ufs/ufs_vnops.c ufs_readdir func , ufs/ufs/dir.h)
1614 		 */
1615 		if (uio->uio_resid <= (uio->uio_resid & (DEV_BSIZE -1)))
1616 			goto unionfs_readdir_exit;
1617 
1618 		/*
1619 		 * Backup cookies.
1620 		 * It prepares to readdir in lower.
1621 		 */
1622 		if (ap->a_ncookies != NULL) {
1623 			ncookies_bk = *(ap->a_ncookies);
1624 			*(ap->a_ncookies) = 0;
1625 		}
1626 		if (ap->a_cookies != NULL) {
1627 			cookies_bk = *(ap->a_cookies);
1628 			*(ap->a_cookies) = NULL;
1629 		}
1630 	}
1631 
1632 	/* initialize for readdir in lower */
1633 	if (unsp->uns_readdir_status == 1) {
1634 		unsp->uns_readdir_status = 2;
1635 		/*
1636 		 * Backup uio_offset. See the comment after the
1637 		 * VOP_READDIR call on the lower layer.
1638 		 */
1639 		uio_offset_bk = uio->uio_offset;
1640 		uio->uio_offset = 0;
1641 	}
1642 
1643 	if (lvp == NULLVP) {
1644 		error = EBADF;
1645 		goto unionfs_readdir_exit;
1646 	}
1647 	/* read lower */
1648 	error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1649 			    ap->a_ncookies, ap->a_cookies);
1650 
1651 	/*
1652 	 * We can't return an uio_offset of 0: this would trigger an
1653 	 * infinite loop, because the next call to unionfs_readdir would
1654 	 * always restart with the upper layer (uio_offset == 0) and
1655 	 * always return some data.
1656 	 *
1657 	 * This happens when the lower layer root directory is removed.
1658 	 * (A root directory deleting of unionfs should not be permitted.
1659 	 *  But current VFS can not do it.)
1660 	 */
1661 	if (uio->uio_offset == 0)
1662 		uio->uio_offset = uio_offset_bk;
1663 
1664 	if (cookies_bk != NULL) {
1665 		/* merge cookies */
1666 		int		size;
1667 		u_long         *newcookies, *pos;
1668 
1669 		size = *(ap->a_ncookies) + ncookies_bk;
1670 		newcookies = (u_long *) malloc(size * sizeof(u_long),
1671 		    M_TEMP, M_WAITOK);
1672 		pos = newcookies;
1673 
1674 		memcpy(pos, cookies_bk, ncookies_bk * sizeof(u_long));
1675 		pos += ncookies_bk;
1676 		memcpy(pos, *(ap->a_cookies),
1677 		    *(ap->a_ncookies) * sizeof(u_long));
1678 		free(cookies_bk, M_TEMP);
1679 		free(*(ap->a_cookies), M_TEMP);
1680 		*(ap->a_ncookies) = size;
1681 		*(ap->a_cookies) = newcookies;
1682 	}
1683 
1684 unionfs_readdir_exit:
1685 	if (error != 0 && ap->a_eofflag != NULL)
1686 		*(ap->a_eofflag) = 1;
1687 
1688 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1689 
1690 	return (error);
1691 }
1692 
1693 static int
1694 unionfs_readlink(struct vop_readlink_args *ap)
1695 {
1696 	struct unionfs_node *unp;
1697 	struct vnode   *vp;
1698 	int error;
1699 
1700 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: enter\n");
1701 
1702 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1703 
1704 	unp = VTOUNIONFS(ap->a_vp);
1705 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1706 
1707 	error = VOP_READLINK(vp, ap->a_uio, ap->a_cred);
1708 
1709 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: leave (%d)\n", error);
1710 
1711 	return (error);
1712 }
1713 
1714 static int
1715 unionfs_getwritemount(struct vop_getwritemount_args *ap)
1716 {
1717 	struct vnode   *uvp;
1718 	struct vnode   *vp;
1719 	int		error;
1720 
1721 	UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: enter\n");
1722 
1723 	error = 0;
1724 	vp = ap->a_vp;
1725 
1726 	if (vp == NULLVP || (vp->v_mount->mnt_flag & MNT_RDONLY))
1727 		return (EACCES);
1728 
1729 	KASSERT_UNIONFS_VNODE(vp);
1730 
1731 	uvp = UNIONFSVPTOUPPERVP(vp);
1732 	if (uvp == NULLVP && VREG == vp->v_type)
1733 		uvp = UNIONFSVPTOUPPERVP(VTOUNIONFS(vp)->un_dvp);
1734 
1735 	if (uvp != NULLVP)
1736 		error = VOP_GETWRITEMOUNT(uvp, ap->a_mpp);
1737 	else {
1738 		VI_LOCK(vp);
1739 		if (vp->v_holdcnt == 0)
1740 			error = EOPNOTSUPP;
1741 		else
1742 			error = EACCES;
1743 		VI_UNLOCK(vp);
1744 	}
1745 
1746 	UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: leave (%d)\n", error);
1747 
1748 	return (error);
1749 }
1750 
1751 static int
1752 unionfs_inactive(struct vop_inactive_args *ap)
1753 {
1754 	ap->a_vp->v_object = NULL;
1755 	vrecycle(ap->a_vp);
1756 	return (0);
1757 }
1758 
1759 static int
1760 unionfs_reclaim(struct vop_reclaim_args *ap)
1761 {
1762 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: enter\n"); */
1763 
1764 	unionfs_noderem(ap->a_vp, curthread);
1765 
1766 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: leave\n"); */
1767 
1768 	return (0);
1769 }
1770 
1771 static int
1772 unionfs_print(struct vop_print_args *ap)
1773 {
1774 	struct unionfs_node *unp;
1775 	/* struct unionfs_node_status *unsp; */
1776 
1777 	unp = VTOUNIONFS(ap->a_vp);
1778 	/* unionfs_get_node_status(unp, curthread, &unsp); */
1779 
1780 	printf("unionfs_vp=%p, uppervp=%p, lowervp=%p\n",
1781 	    ap->a_vp, unp->un_uppervp, unp->un_lowervp);
1782 	/*
1783 	printf("unionfs opencnt: uppervp=%d, lowervp=%d\n",
1784 	    unsp->uns_upper_opencnt, unsp->uns_lower_opencnt);
1785 	*/
1786 
1787 	if (unp->un_uppervp != NULLVP)
1788 		vn_printf(unp->un_uppervp, "unionfs: upper ");
1789 	if (unp->un_lowervp != NULLVP)
1790 		vn_printf(unp->un_lowervp, "unionfs: lower ");
1791 
1792 	return (0);
1793 }
1794 
1795 static int
1796 unionfs_islocked(struct vop_islocked_args *ap)
1797 {
1798 	struct unionfs_node *unp;
1799 
1800 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1801 
1802 	unp = VTOUNIONFS(ap->a_vp);
1803 	if (unp == NULL)
1804 		return (vop_stdislocked(ap));
1805 
1806 	if (unp->un_uppervp != NULLVP)
1807 		return (VOP_ISLOCKED(unp->un_uppervp));
1808 	if (unp->un_lowervp != NULLVP)
1809 		return (VOP_ISLOCKED(unp->un_lowervp));
1810 	return (vop_stdislocked(ap));
1811 }
1812 
1813 static int
1814 unionfs_get_llt_revlock(struct vnode *vp, int flags)
1815 {
1816 	int revlock;
1817 
1818 	revlock = 0;
1819 
1820 	switch (flags & LK_TYPE_MASK) {
1821 	case LK_SHARED:
1822 		if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
1823 			revlock = LK_UPGRADE;
1824 		else
1825 			revlock = LK_RELEASE;
1826 		break;
1827 	case LK_EXCLUSIVE:
1828 	case LK_UPGRADE:
1829 		revlock = LK_RELEASE;
1830 		break;
1831 	case LK_DOWNGRADE:
1832 		revlock = LK_UPGRADE;
1833 		break;
1834 	default:
1835 		break;
1836 	}
1837 
1838 	return (revlock);
1839 }
1840 
1841 /*
1842  * The state of an acquired lock is adjusted similarly to
1843  * the time of error generating.
1844  * flags: LK_RELEASE or LK_UPGRADE
1845  */
1846 static void
1847 unionfs_revlock(struct vnode *vp, int flags)
1848 {
1849 	if (flags & LK_RELEASE)
1850 		VOP_UNLOCK_FLAGS(vp, flags);
1851 	else {
1852 		/* UPGRADE */
1853 		if (vn_lock(vp, flags) != 0)
1854 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1855 	}
1856 }
1857 
1858 static int
1859 unionfs_lock(struct vop_lock1_args *ap)
1860 {
1861 	struct mount   *mp;
1862 	struct unionfs_mount *ump;
1863 	struct unionfs_node *unp;
1864 	struct vnode   *vp;
1865 	struct vnode   *uvp;
1866 	struct vnode   *lvp;
1867 	int		error;
1868 	int		flags;
1869 	int		revlock;
1870 	int		interlock;
1871 	int		uhold;
1872 
1873 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1874 
1875 	error = 0;
1876 	interlock = 1;
1877 	uhold = 0;
1878 	flags = ap->a_flags;
1879 	vp = ap->a_vp;
1880 
1881 	if (LK_RELEASE == (flags & LK_TYPE_MASK) || !(flags & LK_TYPE_MASK))
1882 		return (VOP_UNLOCK_FLAGS(vp, flags | LK_RELEASE));
1883 
1884 	if ((flags & LK_INTERLOCK) == 0)
1885 		VI_LOCK(vp);
1886 
1887 	mp = vp->v_mount;
1888 	if (mp == NULL)
1889 		goto unionfs_lock_null_vnode;
1890 
1891 	ump = MOUNTTOUNIONFSMOUNT(mp);
1892 	unp = VTOUNIONFS(vp);
1893 	if (ump == NULL || unp == NULL)
1894 		goto unionfs_lock_null_vnode;
1895 	lvp = unp->un_lowervp;
1896 	uvp = unp->un_uppervp;
1897 
1898 	if ((revlock = unionfs_get_llt_revlock(vp, flags)) == 0)
1899 		panic("unknown lock type: 0x%x", flags & LK_TYPE_MASK);
1900 
1901 	if ((vp->v_iflag & VI_OWEINACT) != 0)
1902 		flags |= LK_NOWAIT;
1903 
1904 	/*
1905 	 * Sometimes, lower or upper is already exclusive locked.
1906 	 * (ex. vfs_domount: mounted vnode is already locked.)
1907 	 */
1908 	if ((flags & LK_TYPE_MASK) == LK_EXCLUSIVE &&
1909 	    vp == ump->um_rootvp)
1910 		flags |= LK_CANRECURSE;
1911 
1912 	if (lvp != NULLVP) {
1913 		if (uvp != NULLVP && flags & LK_UPGRADE) {
1914 			/*
1915 			 * Share Lock is once released and a deadlock is
1916 			 * avoided.
1917 			 */
1918 			vholdnz(uvp);
1919 			uhold = 1;
1920 			VOP_UNLOCK(uvp);
1921 			unp = VTOUNIONFS(vp);
1922 			if (unp == NULL) {
1923 				/* vnode is released. */
1924 				VI_UNLOCK(vp);
1925 				VOP_UNLOCK(lvp);
1926 				vdrop(uvp);
1927 				return (EBUSY);
1928 			}
1929 		}
1930 		VI_LOCK_FLAGS(lvp, MTX_DUPOK);
1931 		flags |= LK_INTERLOCK;
1932 		vholdl(lvp);
1933 
1934 		VI_UNLOCK(vp);
1935 		ap->a_flags &= ~LK_INTERLOCK;
1936 
1937 		error = VOP_LOCK(lvp, flags);
1938 
1939 		VI_LOCK(vp);
1940 		unp = VTOUNIONFS(vp);
1941 		if (unp == NULL) {
1942 			/* vnode is released. */
1943 			VI_UNLOCK(vp);
1944 			if (error == 0)
1945 				VOP_UNLOCK(lvp);
1946 			vdrop(lvp);
1947 			if (uhold != 0)
1948 				vdrop(uvp);
1949 			return (vop_stdlock(ap));
1950 		}
1951 	}
1952 
1953 	if (error == 0 && uvp != NULLVP) {
1954 		if (uhold && flags & LK_UPGRADE) {
1955 			flags &= ~LK_TYPE_MASK;
1956 			flags |= LK_EXCLUSIVE;
1957 		}
1958 		VI_LOCK_FLAGS(uvp, MTX_DUPOK);
1959 		flags |= LK_INTERLOCK;
1960 		if (uhold == 0) {
1961 			vholdl(uvp);
1962 			uhold = 1;
1963 		}
1964 
1965 		VI_UNLOCK(vp);
1966 		ap->a_flags &= ~LK_INTERLOCK;
1967 
1968 		error = VOP_LOCK(uvp, flags);
1969 
1970 		VI_LOCK(vp);
1971 		unp = VTOUNIONFS(vp);
1972 		if (unp == NULL) {
1973 			/* vnode is released. */
1974 			VI_UNLOCK(vp);
1975 			if (error == 0)
1976 				VOP_UNLOCK(uvp);
1977 			vdrop(uvp);
1978 			if (lvp != NULLVP) {
1979 				VOP_UNLOCK(lvp);
1980 				vdrop(lvp);
1981 			}
1982 			return (vop_stdlock(ap));
1983 		}
1984 		if (error != 0 && lvp != NULLVP) {
1985 			/* rollback */
1986 			VI_UNLOCK(vp);
1987 			unionfs_revlock(lvp, revlock);
1988 			interlock = 0;
1989 		}
1990 	}
1991 
1992 	if (interlock)
1993 		VI_UNLOCK(vp);
1994 	if (lvp != NULLVP)
1995 		vdrop(lvp);
1996 	if (uhold != 0)
1997 		vdrop(uvp);
1998 
1999 	return (error);
2000 
2001 unionfs_lock_null_vnode:
2002 	ap->a_flags |= LK_INTERLOCK;
2003 	return (vop_stdlock(ap));
2004 }
2005 
2006 static int
2007 unionfs_unlock(struct vop_unlock_args *ap)
2008 {
2009 	struct vnode   *vp;
2010 	struct vnode   *lvp;
2011 	struct vnode   *uvp;
2012 	struct unionfs_node *unp;
2013 	int		error;
2014 	int		uhold;
2015 
2016 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2017 
2018 	error = 0;
2019 	uhold = 0;
2020 	vp = ap->a_vp;
2021 
2022 	unp = VTOUNIONFS(vp);
2023 	if (unp == NULL)
2024 		goto unionfs_unlock_null_vnode;
2025 	lvp = unp->un_lowervp;
2026 	uvp = unp->un_uppervp;
2027 
2028 	if (lvp != NULLVP) {
2029 		vholdnz(lvp);
2030 		error = VOP_UNLOCK(lvp);
2031 	}
2032 
2033 	if (error == 0 && uvp != NULLVP) {
2034 		vholdnz(uvp);
2035 		uhold = 1;
2036 		error = VOP_UNLOCK(uvp);
2037 	}
2038 
2039 	if (lvp != NULLVP)
2040 		vdrop(lvp);
2041 	if (uhold != 0)
2042 		vdrop(uvp);
2043 
2044 	return error;
2045 
2046 unionfs_unlock_null_vnode:
2047 	return (vop_stdunlock(ap));
2048 }
2049 
2050 static int
2051 unionfs_pathconf(struct vop_pathconf_args *ap)
2052 {
2053 	struct unionfs_node *unp;
2054 	struct vnode   *vp;
2055 
2056 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2057 
2058 	unp = VTOUNIONFS(ap->a_vp);
2059 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
2060 
2061 	return (VOP_PATHCONF(vp, ap->a_name, ap->a_retval));
2062 }
2063 
2064 static int
2065 unionfs_advlock(struct vop_advlock_args *ap)
2066 {
2067 	struct unionfs_node *unp;
2068 	struct unionfs_node_status *unsp;
2069 	struct vnode   *vp;
2070 	struct vnode   *uvp;
2071 	struct thread  *td;
2072 	int error;
2073 
2074 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: enter\n");
2075 
2076 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2077 
2078 	vp = ap->a_vp;
2079 	td = curthread;
2080 
2081 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2082 
2083 	unp = VTOUNIONFS(ap->a_vp);
2084 	uvp = unp->un_uppervp;
2085 
2086 	if (uvp == NULLVP) {
2087 		error = unionfs_copyfile(unp, 1, td->td_ucred, td);
2088 		if (error != 0)
2089 			goto unionfs_advlock_abort;
2090 		uvp = unp->un_uppervp;
2091 
2092 		unionfs_get_node_status(unp, td, &unsp);
2093 		if (unsp->uns_lower_opencnt > 0) {
2094 			/* try reopen the vnode */
2095 			error = VOP_OPEN(uvp, unsp->uns_lower_openmode,
2096 				td->td_ucred, td, NULL);
2097 			if (error)
2098 				goto unionfs_advlock_abort;
2099 			unsp->uns_upper_opencnt++;
2100 			VOP_CLOSE(unp->un_lowervp, unsp->uns_lower_openmode,
2101 			    td->td_ucred, td);
2102 			unsp->uns_lower_opencnt--;
2103 		} else
2104 			unionfs_tryrem_node_status(unp, unsp);
2105 	}
2106 
2107 	VOP_UNLOCK(vp);
2108 
2109 	error = VOP_ADVLOCK(uvp, ap->a_id, ap->a_op, ap->a_fl, ap->a_flags);
2110 
2111 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
2112 
2113 	return error;
2114 
2115 unionfs_advlock_abort:
2116 	VOP_UNLOCK(vp);
2117 
2118 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
2119 
2120 	return error;
2121 }
2122 
2123 static int
2124 unionfs_strategy(struct vop_strategy_args *ap)
2125 {
2126 	struct unionfs_node *unp;
2127 	struct vnode   *vp;
2128 
2129 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2130 
2131 	unp = VTOUNIONFS(ap->a_vp);
2132 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
2133 
2134 #ifdef DIAGNOSTIC
2135 	if (vp == NULLVP)
2136 		panic("unionfs_strategy: nullvp");
2137 
2138 	if (ap->a_bp->b_iocmd == BIO_WRITE && vp == unp->un_lowervp)
2139 		panic("unionfs_strategy: writing to lowervp");
2140 #endif
2141 
2142 	return (VOP_STRATEGY(vp, ap->a_bp));
2143 }
2144 
2145 static int
2146 unionfs_getacl(struct vop_getacl_args *ap)
2147 {
2148 	struct unionfs_node *unp;
2149 	struct vnode   *vp;
2150 	int		error;
2151 
2152 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2153 
2154 	unp = VTOUNIONFS(ap->a_vp);
2155 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
2156 
2157 	UNIONFS_INTERNAL_DEBUG("unionfs_getacl: enter\n");
2158 
2159 	error = VOP_GETACL(vp, ap->a_type, ap->a_aclp, ap->a_cred, ap->a_td);
2160 
2161 	UNIONFS_INTERNAL_DEBUG("unionfs_getacl: leave (%d)\n", error);
2162 
2163 	return (error);
2164 }
2165 
2166 static int
2167 unionfs_setacl(struct vop_setacl_args *ap)
2168 {
2169 	struct unionfs_node *unp;
2170 	struct vnode   *uvp;
2171 	struct vnode   *lvp;
2172 	struct thread  *td;
2173 	int		error;
2174 
2175 	UNIONFS_INTERNAL_DEBUG("unionfs_setacl: enter\n");
2176 
2177 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2178 
2179 	error = EROFS;
2180 	unp = VTOUNIONFS(ap->a_vp);
2181 	uvp = unp->un_uppervp;
2182 	lvp = unp->un_lowervp;
2183 	td = ap->a_td;
2184 
2185 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2186 		return (EROFS);
2187 
2188 	if (uvp == NULLVP && lvp->v_type == VREG) {
2189 		if ((error = unionfs_copyfile(unp, 1, ap->a_cred, td)) != 0)
2190 			return (error);
2191 		uvp = unp->un_uppervp;
2192 	}
2193 
2194 	if (uvp != NULLVP)
2195 		error = VOP_SETACL(uvp, ap->a_type, ap->a_aclp, ap->a_cred, td);
2196 
2197 	UNIONFS_INTERNAL_DEBUG("unionfs_setacl: leave (%d)\n", error);
2198 
2199 	return (error);
2200 }
2201 
2202 static int
2203 unionfs_aclcheck(struct vop_aclcheck_args *ap)
2204 {
2205 	struct unionfs_node *unp;
2206 	struct vnode   *vp;
2207 	int		error;
2208 
2209 	UNIONFS_INTERNAL_DEBUG("unionfs_aclcheck: enter\n");
2210 
2211 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2212 
2213 	unp = VTOUNIONFS(ap->a_vp);
2214 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
2215 
2216 	error = VOP_ACLCHECK(vp, ap->a_type, ap->a_aclp, ap->a_cred, ap->a_td);
2217 
2218 	UNIONFS_INTERNAL_DEBUG("unionfs_aclcheck: leave (%d)\n", error);
2219 
2220 	return (error);
2221 }
2222 
2223 static int
2224 unionfs_openextattr(struct vop_openextattr_args *ap)
2225 {
2226 	struct unionfs_node *unp;
2227 	struct vnode   *vp;
2228 	struct vnode   *tvp;
2229 	int		error;
2230 
2231 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2232 
2233 	vp = ap->a_vp;
2234 	unp = VTOUNIONFS(vp);
2235 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
2236 
2237 	if ((tvp == unp->un_uppervp && (unp->un_flag & UNIONFS_OPENEXTU)) ||
2238 	    (tvp == unp->un_lowervp && (unp->un_flag & UNIONFS_OPENEXTL)))
2239 		return (EBUSY);
2240 
2241 	error = VOP_OPENEXTATTR(tvp, ap->a_cred, ap->a_td);
2242 
2243 	if (error == 0) {
2244 		if (vn_lock(vp, LK_UPGRADE) != 0)
2245 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2246 		if (tvp == unp->un_uppervp)
2247 			unp->un_flag |= UNIONFS_OPENEXTU;
2248 		else
2249 			unp->un_flag |= UNIONFS_OPENEXTL;
2250 		vn_lock(vp, LK_DOWNGRADE | LK_RETRY);
2251 	}
2252 
2253 	return (error);
2254 }
2255 
2256 static int
2257 unionfs_closeextattr(struct vop_closeextattr_args *ap)
2258 {
2259 	struct unionfs_node *unp;
2260 	struct vnode   *vp;
2261 	struct vnode   *tvp;
2262 	int		error;
2263 
2264 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2265 
2266 	vp = ap->a_vp;
2267 	unp = VTOUNIONFS(vp);
2268 	tvp = NULLVP;
2269 
2270 	if (unp->un_flag & UNIONFS_OPENEXTU)
2271 		tvp = unp->un_uppervp;
2272 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2273 		tvp = unp->un_lowervp;
2274 
2275 	if (tvp == NULLVP)
2276 		return (EOPNOTSUPP);
2277 
2278 	error = VOP_CLOSEEXTATTR(tvp, ap->a_commit, ap->a_cred, ap->a_td);
2279 
2280 	if (error == 0) {
2281 		if (vn_lock(vp, LK_UPGRADE) != 0)
2282 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2283 		if (tvp == unp->un_uppervp)
2284 			unp->un_flag &= ~UNIONFS_OPENEXTU;
2285 		else
2286 			unp->un_flag &= ~UNIONFS_OPENEXTL;
2287 		vn_lock(vp, LK_DOWNGRADE | LK_RETRY);
2288 	}
2289 
2290 	return (error);
2291 }
2292 
2293 static int
2294 unionfs_getextattr(struct vop_getextattr_args *ap)
2295 {
2296 	struct unionfs_node *unp;
2297 	struct vnode   *vp;
2298 
2299 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2300 
2301 	unp = VTOUNIONFS(ap->a_vp);
2302 	vp = NULLVP;
2303 
2304 	if (unp->un_flag & UNIONFS_OPENEXTU)
2305 		vp = unp->un_uppervp;
2306 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2307 		vp = unp->un_lowervp;
2308 
2309 	if (vp == NULLVP)
2310 		return (EOPNOTSUPP);
2311 
2312 	return (VOP_GETEXTATTR(vp, ap->a_attrnamespace, ap->a_name,
2313 	    ap->a_uio, ap->a_size, ap->a_cred, ap->a_td));
2314 }
2315 
2316 static int
2317 unionfs_setextattr(struct vop_setextattr_args *ap)
2318 {
2319 	struct unionfs_node *unp;
2320 	struct vnode   *uvp;
2321 	struct vnode   *lvp;
2322 	struct vnode   *ovp;
2323 	struct ucred   *cred;
2324 	struct thread  *td;
2325 	int		error;
2326 
2327 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2328 
2329 	error = EROFS;
2330 	unp = VTOUNIONFS(ap->a_vp);
2331 	uvp = unp->un_uppervp;
2332 	lvp = unp->un_lowervp;
2333 	ovp = NULLVP;
2334 	cred = ap->a_cred;
2335 	td = ap->a_td;
2336 
2337 	UNIONFS_INTERNAL_DEBUG("unionfs_setextattr: enter (un_flag=%x)\n",
2338 	    unp->un_flag);
2339 
2340 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2341 		return (EROFS);
2342 
2343 	if (unp->un_flag & UNIONFS_OPENEXTU)
2344 		ovp = unp->un_uppervp;
2345 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2346 		ovp = unp->un_lowervp;
2347 
2348 	if (ovp == NULLVP)
2349 		return (EOPNOTSUPP);
2350 
2351 	if (ovp == lvp && lvp->v_type == VREG) {
2352 		VOP_CLOSEEXTATTR(lvp, 0, cred, td);
2353 		if (uvp == NULLVP &&
2354 		    (error = unionfs_copyfile(unp, 1, cred, td)) != 0) {
2355 unionfs_setextattr_reopen:
2356 			if ((unp->un_flag & UNIONFS_OPENEXTL) &&
2357 			    VOP_OPENEXTATTR(lvp, cred, td)) {
2358 #ifdef DIAGNOSTIC
2359 				panic("unionfs: VOP_OPENEXTATTR failed");
2360 #endif
2361 				unp->un_flag &= ~UNIONFS_OPENEXTL;
2362 			}
2363 			goto unionfs_setextattr_abort;
2364 		}
2365 		uvp = unp->un_uppervp;
2366 		if ((error = VOP_OPENEXTATTR(uvp, cred, td)) != 0)
2367 			goto unionfs_setextattr_reopen;
2368 		unp->un_flag &= ~UNIONFS_OPENEXTL;
2369 		unp->un_flag |= UNIONFS_OPENEXTU;
2370 		ovp = uvp;
2371 	}
2372 
2373 	if (ovp == uvp)
2374 		error = VOP_SETEXTATTR(ovp, ap->a_attrnamespace, ap->a_name,
2375 		    ap->a_uio, cred, td);
2376 
2377 unionfs_setextattr_abort:
2378 	UNIONFS_INTERNAL_DEBUG("unionfs_setextattr: leave (%d)\n", error);
2379 
2380 	return (error);
2381 }
2382 
2383 static int
2384 unionfs_listextattr(struct vop_listextattr_args *ap)
2385 {
2386 	struct unionfs_node *unp;
2387 	struct vnode *vp;
2388 
2389 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2390 
2391 	unp = VTOUNIONFS(ap->a_vp);
2392 	vp = NULLVP;
2393 
2394 	if (unp->un_flag & UNIONFS_OPENEXTU)
2395 		vp = unp->un_uppervp;
2396 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2397 		vp = unp->un_lowervp;
2398 
2399 	if (vp == NULLVP)
2400 		return (EOPNOTSUPP);
2401 
2402 	return (VOP_LISTEXTATTR(vp, ap->a_attrnamespace, ap->a_uio,
2403 	    ap->a_size, ap->a_cred, ap->a_td));
2404 }
2405 
2406 static int
2407 unionfs_deleteextattr(struct vop_deleteextattr_args *ap)
2408 {
2409 	struct unionfs_node *unp;
2410 	struct vnode   *uvp;
2411 	struct vnode   *lvp;
2412 	struct vnode   *ovp;
2413 	struct ucred   *cred;
2414 	struct thread  *td;
2415 	int		error;
2416 
2417 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2418 
2419 	error = EROFS;
2420 	unp = VTOUNIONFS(ap->a_vp);
2421 	uvp = unp->un_uppervp;
2422 	lvp = unp->un_lowervp;
2423 	ovp = NULLVP;
2424 	cred = ap->a_cred;
2425 	td = ap->a_td;
2426 
2427 	UNIONFS_INTERNAL_DEBUG("unionfs_deleteextattr: enter (un_flag=%x)\n",
2428 	    unp->un_flag);
2429 
2430 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2431 		return (EROFS);
2432 
2433 	if (unp->un_flag & UNIONFS_OPENEXTU)
2434 		ovp = unp->un_uppervp;
2435 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2436 		ovp = unp->un_lowervp;
2437 
2438 	if (ovp == NULLVP)
2439 		return (EOPNOTSUPP);
2440 
2441 	if (ovp == lvp && lvp->v_type == VREG) {
2442 		VOP_CLOSEEXTATTR(lvp, 0, cred, td);
2443 		if (uvp == NULLVP &&
2444 		    (error = unionfs_copyfile(unp, 1, cred, td)) != 0) {
2445 unionfs_deleteextattr_reopen:
2446 			if ((unp->un_flag & UNIONFS_OPENEXTL) &&
2447 			    VOP_OPENEXTATTR(lvp, cred, td)) {
2448 #ifdef DIAGNOSTIC
2449 				panic("unionfs: VOP_OPENEXTATTR failed");
2450 #endif
2451 				unp->un_flag &= ~UNIONFS_OPENEXTL;
2452 			}
2453 			goto unionfs_deleteextattr_abort;
2454 		}
2455 		uvp = unp->un_uppervp;
2456 		if ((error = VOP_OPENEXTATTR(uvp, cred, td)) != 0)
2457 			goto unionfs_deleteextattr_reopen;
2458 		unp->un_flag &= ~UNIONFS_OPENEXTL;
2459 		unp->un_flag |= UNIONFS_OPENEXTU;
2460 		ovp = uvp;
2461 	}
2462 
2463 	if (ovp == uvp)
2464 		error = VOP_DELETEEXTATTR(ovp, ap->a_attrnamespace, ap->a_name,
2465 		    ap->a_cred, ap->a_td);
2466 
2467 unionfs_deleteextattr_abort:
2468 	UNIONFS_INTERNAL_DEBUG("unionfs_deleteextattr: leave (%d)\n", error);
2469 
2470 	return (error);
2471 }
2472 
2473 static int
2474 unionfs_setlabel(struct vop_setlabel_args *ap)
2475 {
2476 	struct unionfs_node *unp;
2477 	struct vnode   *uvp;
2478 	struct vnode   *lvp;
2479 	struct thread  *td;
2480 	int		error;
2481 
2482 	UNIONFS_INTERNAL_DEBUG("unionfs_setlabel: enter\n");
2483 
2484 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2485 
2486 	error = EROFS;
2487 	unp = VTOUNIONFS(ap->a_vp);
2488 	uvp = unp->un_uppervp;
2489 	lvp = unp->un_lowervp;
2490 	td = ap->a_td;
2491 
2492 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2493 		return (EROFS);
2494 
2495 	if (uvp == NULLVP && lvp->v_type == VREG) {
2496 		if ((error = unionfs_copyfile(unp, 1, ap->a_cred, td)) != 0)
2497 			return (error);
2498 		uvp = unp->un_uppervp;
2499 	}
2500 
2501 	if (uvp != NULLVP)
2502 		error = VOP_SETLABEL(uvp, ap->a_label, ap->a_cred, td);
2503 
2504 	UNIONFS_INTERNAL_DEBUG("unionfs_setlabel: leave (%d)\n", error);
2505 
2506 	return (error);
2507 }
2508 
2509 static int
2510 unionfs_vptofh(struct vop_vptofh_args *ap)
2511 {
2512 	return (EOPNOTSUPP);
2513 }
2514 
2515 static int
2516 unionfs_add_writecount(struct vop_add_writecount_args *ap)
2517 {
2518 	struct vnode *tvp, *vp;
2519 	struct unionfs_node *unp;
2520 	int error;
2521 
2522 	vp = ap->a_vp;
2523 	unp = VTOUNIONFS(vp);
2524 	tvp = unp->un_uppervp != NULL ? unp->un_uppervp : unp->un_lowervp;
2525 	VI_LOCK(vp);
2526 	/* text refs are bypassed to lowervp */
2527 	VNASSERT(vp->v_writecount >= 0, vp, ("wrong null writecount"));
2528 	VNASSERT(vp->v_writecount + ap->a_inc >= 0, vp,
2529 	    ("wrong writecount inc %d", ap->a_inc));
2530 	if (tvp != NULL)
2531 		error = VOP_ADD_WRITECOUNT(tvp, ap->a_inc);
2532 	else if (vp->v_writecount < 0)
2533 		error = ETXTBSY;
2534 	else
2535 		error = 0;
2536 	if (error == 0)
2537 		vp->v_writecount += ap->a_inc;
2538 	VI_UNLOCK(vp);
2539 	return (error);
2540 }
2541 
2542 struct vop_vector unionfs_vnodeops = {
2543 	.vop_default =		&default_vnodeops,
2544 
2545 	.vop_access =		unionfs_access,
2546 	.vop_aclcheck =		unionfs_aclcheck,
2547 	.vop_advlock =		unionfs_advlock,
2548 	.vop_bmap =		VOP_EOPNOTSUPP,
2549 	.vop_cachedlookup =	unionfs_lookup,
2550 	.vop_close =		unionfs_close,
2551 	.vop_closeextattr =	unionfs_closeextattr,
2552 	.vop_create =		unionfs_create,
2553 	.vop_deleteextattr =	unionfs_deleteextattr,
2554 	.vop_fsync =		unionfs_fsync,
2555 	.vop_getacl =		unionfs_getacl,
2556 	.vop_getattr =		unionfs_getattr,
2557 	.vop_getextattr =	unionfs_getextattr,
2558 	.vop_getwritemount =	unionfs_getwritemount,
2559 	.vop_inactive =		unionfs_inactive,
2560 	.vop_need_inactive =	vop_stdneed_inactive,
2561 	.vop_islocked =		unionfs_islocked,
2562 	.vop_ioctl =		unionfs_ioctl,
2563 	.vop_link =		unionfs_link,
2564 	.vop_listextattr =	unionfs_listextattr,
2565 	.vop_lock1 =		unionfs_lock,
2566 	.vop_lookup =		vfs_cache_lookup,
2567 	.vop_mkdir =		unionfs_mkdir,
2568 	.vop_mknod =		unionfs_mknod,
2569 	.vop_open =		unionfs_open,
2570 	.vop_openextattr =	unionfs_openextattr,
2571 	.vop_pathconf =		unionfs_pathconf,
2572 	.vop_poll =		unionfs_poll,
2573 	.vop_print =		unionfs_print,
2574 	.vop_read =		unionfs_read,
2575 	.vop_readdir =		unionfs_readdir,
2576 	.vop_readlink =		unionfs_readlink,
2577 	.vop_reclaim =		unionfs_reclaim,
2578 	.vop_remove =		unionfs_remove,
2579 	.vop_rename =		unionfs_rename,
2580 	.vop_rmdir =		unionfs_rmdir,
2581 	.vop_setacl =		unionfs_setacl,
2582 	.vop_setattr =		unionfs_setattr,
2583 	.vop_setextattr =	unionfs_setextattr,
2584 	.vop_setlabel =		unionfs_setlabel,
2585 	.vop_strategy =		unionfs_strategy,
2586 	.vop_symlink =		unionfs_symlink,
2587 	.vop_unlock =		unionfs_unlock,
2588 	.vop_whiteout =		unionfs_whiteout,
2589 	.vop_write =		unionfs_write,
2590 	.vop_vptofh =		unionfs_vptofh,
2591 	.vop_add_writecount =	unionfs_add_writecount,
2592 };
2593 VFS_VOP_VECTOR_REGISTER(unionfs_vnodeops);
2594