xref: /freebsd/sys/fs/unionfs/union_vnops.c (revision ce74223a366b59bb7ea8febef9e4db1fc700136a)
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 	int		count;
635 	uid_t		uid;	/* upper side vnode's uid */
636 	gid_t		gid;	/* upper side vnode's gid */
637 	u_short		vmode;	/* upper side vnode's mode */
638 	u_short		mask;
639 
640 	mask = 0;
641 	uid = va->va_uid;
642 	gid = va->va_gid;
643 	vmode = va->va_mode;
644 
645 	/* check owner */
646 	if (cred->cr_uid == uid) {
647 		if (accmode & VEXEC)
648 			mask |= S_IXUSR;
649 		if (accmode & VREAD)
650 			mask |= S_IRUSR;
651 		if (accmode & VWRITE)
652 			mask |= S_IWUSR;
653 		return ((vmode & mask) == mask ? 0 : EACCES);
654 	}
655 
656 	/* check group */
657 	count = 0;
658 	if (groupmember(gid, cred)) {
659 		if (accmode & VEXEC)
660 			mask |= S_IXGRP;
661 		if (accmode & VREAD)
662 			mask |= S_IRGRP;
663 		if (accmode & VWRITE)
664 			mask |= S_IWGRP;
665 		return ((vmode & mask) == mask ? 0 : EACCES);
666 	}
667 
668 	/* check other */
669 	if (accmode & VEXEC)
670 		mask |= S_IXOTH;
671 	if (accmode & VREAD)
672 		mask |= S_IROTH;
673 	if (accmode & VWRITE)
674 		mask |= S_IWOTH;
675 
676 	return ((vmode & mask) == mask ? 0 : EACCES);
677 }
678 
679 static int
680 unionfs_access(struct vop_access_args *ap)
681 {
682 	struct unionfs_mount *ump;
683 	struct unionfs_node *unp;
684 	struct vnode   *uvp;
685 	struct vnode   *lvp;
686 	struct thread  *td;
687 	struct vattr	va;
688 	accmode_t	accmode;
689 	int		error;
690 
691 	UNIONFS_INTERNAL_DEBUG("unionfs_access: enter\n");
692 
693 	KASSERT_UNIONFS_VNODE(ap->a_vp);
694 
695 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
696 	unp = VTOUNIONFS(ap->a_vp);
697 	uvp = unp->un_uppervp;
698 	lvp = unp->un_lowervp;
699 	td = ap->a_td;
700 	accmode = ap->a_accmode;
701 	error = EACCES;
702 
703 	if ((accmode & VWRITE) &&
704 	    (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) {
705 		switch (ap->a_vp->v_type) {
706 		case VREG:
707 		case VDIR:
708 		case VLNK:
709 			return (EROFS);
710 		default:
711 			break;
712 		}
713 	}
714 
715 	if (uvp != NULLVP) {
716 		error = VOP_ACCESS(uvp, accmode, ap->a_cred, td);
717 
718 		UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
719 
720 		return (error);
721 	}
722 
723 	if (lvp != NULLVP) {
724 		if (accmode & VWRITE) {
725 			if (ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY) {
726 				switch (ap->a_vp->v_type) {
727 				case VREG:
728 				case VDIR:
729 				case VLNK:
730 					return (EROFS);
731 				default:
732 					break;
733 				}
734 			} else if (ap->a_vp->v_type == VREG ||
735 			    ap->a_vp->v_type == VDIR) {
736 				/* check shadow file/dir */
737 				if (ump->um_copymode != UNIONFS_TRANSPARENT) {
738 					error = unionfs_create_uppervattr(ump,
739 					    lvp, &va, ap->a_cred, td);
740 					if (error != 0)
741 						return (error);
742 
743 					error = unionfs_check_corrected_access(
744 					    accmode, &va, ap->a_cred);
745 					if (error != 0)
746 						return (error);
747 				}
748 			}
749 			accmode &= ~(VWRITE | VAPPEND);
750 			accmode |= VREAD; /* will copy to upper */
751 		}
752 		error = VOP_ACCESS(lvp, accmode, ap->a_cred, td);
753 	}
754 
755 	UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
756 
757 	return (error);
758 }
759 
760 static int
761 unionfs_getattr(struct vop_getattr_args *ap)
762 {
763 	struct unionfs_node *unp;
764 	struct unionfs_mount *ump;
765 	struct vnode   *uvp;
766 	struct vnode   *lvp;
767 	struct thread  *td;
768 	struct vattr	va;
769 	int		error;
770 
771 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: enter\n");
772 
773 	KASSERT_UNIONFS_VNODE(ap->a_vp);
774 
775 	unp = VTOUNIONFS(ap->a_vp);
776 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
777 	uvp = unp->un_uppervp;
778 	lvp = unp->un_lowervp;
779 	td = curthread;
780 
781 	if (uvp != NULLVP) {
782 		if ((error = VOP_GETATTR(uvp, ap->a_vap, ap->a_cred)) == 0)
783 			ap->a_vap->va_fsid =
784 			    ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
785 
786 		UNIONFS_INTERNAL_DEBUG(
787 		    "unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
788 		    ap->a_vap->va_mode, ap->a_vap->va_uid,
789 		    ap->a_vap->va_gid, error);
790 
791 		return (error);
792 	}
793 
794 	error = VOP_GETATTR(lvp, ap->a_vap, ap->a_cred);
795 
796 	if (error == 0 && !(ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY)) {
797 		/* correct the attr toward shadow file/dir. */
798 		if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
799 			unionfs_create_uppervattr_core(ump, ap->a_vap, &va, td);
800 			ap->a_vap->va_mode = va.va_mode;
801 			ap->a_vap->va_uid = va.va_uid;
802 			ap->a_vap->va_gid = va.va_gid;
803 		}
804 	}
805 
806 	if (error == 0)
807 		ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
808 
809 	UNIONFS_INTERNAL_DEBUG(
810 	    "unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
811 	    ap->a_vap->va_mode, ap->a_vap->va_uid, ap->a_vap->va_gid, error);
812 
813 	return (error);
814 }
815 
816 static int
817 unionfs_setattr(struct vop_setattr_args *ap)
818 {
819 	struct unionfs_node *unp;
820 	struct vnode   *uvp;
821 	struct vnode   *lvp;
822 	struct thread  *td;
823 	struct vattr   *vap;
824 	int		error;
825 
826 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: enter\n");
827 
828 	KASSERT_UNIONFS_VNODE(ap->a_vp);
829 
830 	error = EROFS;
831 	unp = VTOUNIONFS(ap->a_vp);
832 	uvp = unp->un_uppervp;
833 	lvp = unp->un_lowervp;
834 	td = curthread;
835 	vap = ap->a_vap;
836 
837 	if ((ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) &&
838 	    (vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
839 	     vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
840 	     vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL))
841 		return (EROFS);
842 
843 	if (uvp == NULLVP && lvp->v_type == VREG) {
844 		error = unionfs_copyfile(unp, (vap->va_size != 0),
845 		    ap->a_cred, td);
846 		if (error != 0)
847 			return (error);
848 		uvp = unp->un_uppervp;
849 	}
850 
851 	if (uvp != NULLVP)
852 		error = VOP_SETATTR(uvp, vap, ap->a_cred);
853 
854 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: leave (%d)\n", error);
855 
856 	return (error);
857 }
858 
859 static int
860 unionfs_read(struct vop_read_args *ap)
861 {
862 	struct unionfs_node *unp;
863 	struct vnode   *tvp;
864 	int		error;
865 
866 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: enter\n"); */
867 
868 	KASSERT_UNIONFS_VNODE(ap->a_vp);
869 
870 	unp = VTOUNIONFS(ap->a_vp);
871 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
872 
873 	error = VOP_READ(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
874 
875 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: leave (%d)\n", error); */
876 
877 	return (error);
878 }
879 
880 static int
881 unionfs_write(struct vop_write_args *ap)
882 {
883 	struct unionfs_node *unp;
884 	struct vnode   *tvp;
885 	int		error;
886 
887 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: enter\n"); */
888 
889 	KASSERT_UNIONFS_VNODE(ap->a_vp);
890 
891 	unp = VTOUNIONFS(ap->a_vp);
892 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
893 
894 	error = VOP_WRITE(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
895 
896 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: leave (%d)\n", error); */
897 
898 	return (error);
899 }
900 
901 static int
902 unionfs_ioctl(struct vop_ioctl_args *ap)
903 {
904 	struct unionfs_node *unp;
905 	struct unionfs_node_status *unsp;
906 	struct vnode   *ovp;
907 	int error;
908 
909 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: enter\n");
910 
911 	KASSERT_UNIONFS_VNODE(ap->a_vp);
912 
913  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
914 	unp = VTOUNIONFS(ap->a_vp);
915 	unionfs_get_node_status(unp, ap->a_td, &unsp);
916 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
917 	unionfs_tryrem_node_status(unp, unsp);
918 	VOP_UNLOCK(ap->a_vp);
919 
920 	if (ovp == NULLVP)
921 		return (EBADF);
922 
923 	error = VOP_IOCTL(ovp, ap->a_command, ap->a_data, ap->a_fflag,
924 	    ap->a_cred, ap->a_td);
925 
926 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: leave (%d)\n", error);
927 
928 	return (error);
929 }
930 
931 static int
932 unionfs_poll(struct vop_poll_args *ap)
933 {
934 	struct unionfs_node *unp;
935 	struct unionfs_node_status *unsp;
936 	struct vnode *ovp;
937 
938 	KASSERT_UNIONFS_VNODE(ap->a_vp);
939 
940  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
941 	unp = VTOUNIONFS(ap->a_vp);
942 	unionfs_get_node_status(unp, ap->a_td, &unsp);
943 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
944 	unionfs_tryrem_node_status(unp, unsp);
945 	VOP_UNLOCK(ap->a_vp);
946 
947 	if (ovp == NULLVP)
948 		return (EBADF);
949 
950 	return (VOP_POLL(ovp, ap->a_events, ap->a_cred, ap->a_td));
951 }
952 
953 static int
954 unionfs_fsync(struct vop_fsync_args *ap)
955 {
956 	struct unionfs_node *unp;
957 	struct unionfs_node_status *unsp;
958 	struct vnode *ovp;
959 
960 	KASSERT_UNIONFS_VNODE(ap->a_vp);
961 
962 	unp = VTOUNIONFS(ap->a_vp);
963 	unionfs_get_node_status(unp, ap->a_td, &unsp);
964 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
965 	unionfs_tryrem_node_status(unp, unsp);
966 
967 	if (ovp == NULLVP)
968 		return (EBADF);
969 
970 	return (VOP_FSYNC(ovp, ap->a_waitfor, ap->a_td));
971 }
972 
973 static int
974 unionfs_remove(struct vop_remove_args *ap)
975 {
976 	char	       *path;
977 	struct unionfs_node *dunp;
978 	struct unionfs_node *unp;
979 	struct unionfs_mount *ump;
980 	struct vnode   *udvp;
981 	struct vnode   *uvp;
982 	struct vnode   *lvp;
983 	struct vnode   *vp;
984 	struct componentname *cnp;
985 	struct componentname cn;
986 	struct thread  *td;
987 	int		error;
988 	int		pathlen;
989 
990 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: enter\n");
991 
992 	KASSERT_UNIONFS_VNODE(ap->a_dvp);
993 
994 	error = 0;
995 	dunp = VTOUNIONFS(ap->a_dvp);
996 	udvp = dunp->un_uppervp;
997 	cnp = ap->a_cnp;
998 	td = curthread;
999 
1000 	if (ap->a_vp->v_op != &unionfs_vnodeops) {
1001 		if (ap->a_vp->v_type != VSOCK)
1002 			return (EINVAL);
1003 		ump = NULL;
1004 		vp = uvp = lvp = NULLVP;
1005 		/* search vnode */
1006 		VOP_UNLOCK(ap->a_vp);
1007 		error = unionfs_relookup(udvp, &vp, cnp, &cn, td,
1008 		    cnp->cn_nameptr, cnp->cn_namelen, DELETE);
1009 		if (error != 0 && error != ENOENT) {
1010 			vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
1011 			return (error);
1012 		}
1013 
1014 		if (error == 0 && vp == ap->a_vp) {
1015 			/* target vnode in upper */
1016 			uvp = vp;
1017 			vrele(vp);
1018 		} else {
1019 			/* target vnode in lower */
1020 			if (vp != NULLVP) {
1021 				if (udvp == vp)
1022 					vrele(vp);
1023 				else
1024 					vput(vp);
1025 			}
1026 			vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
1027 			lvp = ap->a_vp;
1028 		}
1029 		path = cnp->cn_nameptr;
1030 		pathlen = cnp->cn_namelen;
1031 	} else {
1032 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
1033 		unp = VTOUNIONFS(ap->a_vp);
1034 		uvp = unp->un_uppervp;
1035 		lvp = unp->un_lowervp;
1036 		path = unp->un_path;
1037 		pathlen = unp->un_pathlen;
1038 	}
1039 
1040 	if (udvp == NULLVP)
1041 		return (EROFS);
1042 
1043 	if (uvp != NULLVP) {
1044 		/*
1045 		 * XXX: if the vnode type is VSOCK, it will create whiteout
1046 		 *      after remove.
1047 		 */
1048 		if (ump == NULL || ump->um_whitemode == UNIONFS_WHITE_ALWAYS ||
1049 		    lvp != NULLVP)
1050 			cnp->cn_flags |= DOWHITEOUT;
1051 		error = VOP_REMOVE(udvp, uvp, cnp);
1052 	} else if (lvp != NULLVP)
1053 		error = unionfs_mkwhiteout(udvp, cnp, td, path, pathlen);
1054 
1055 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: leave (%d)\n", error);
1056 
1057 	return (error);
1058 }
1059 
1060 static int
1061 unionfs_link(struct vop_link_args *ap)
1062 {
1063 	struct unionfs_node *dunp;
1064 	struct unionfs_node *unp;
1065 	struct vnode   *udvp;
1066 	struct vnode   *uvp;
1067 	struct componentname *cnp;
1068 	struct thread  *td;
1069 	int		error;
1070 	int		needrelookup;
1071 
1072 	UNIONFS_INTERNAL_DEBUG("unionfs_link: enter\n");
1073 
1074 	KASSERT_UNIONFS_VNODE(ap->a_tdvp);
1075 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1076 
1077 	error = 0;
1078 	needrelookup = 0;
1079 	dunp = VTOUNIONFS(ap->a_tdvp);
1080 	unp = NULL;
1081 	udvp = dunp->un_uppervp;
1082 	uvp = NULLVP;
1083 	cnp = ap->a_cnp;
1084 	td = curthread;
1085 
1086 	if (udvp == NULLVP)
1087 		return (EROFS);
1088 
1089 	if (ap->a_vp->v_op != &unionfs_vnodeops)
1090 		uvp = ap->a_vp;
1091 	else {
1092 		unp = VTOUNIONFS(ap->a_vp);
1093 
1094 		if (unp->un_uppervp == NULLVP) {
1095 			if (ap->a_vp->v_type != VREG)
1096 				return (EOPNOTSUPP);
1097 
1098 			error = unionfs_copyfile(unp, 1, cnp->cn_cred, td);
1099 			if (error != 0)
1100 				return (error);
1101 			needrelookup = 1;
1102 		}
1103 		uvp = unp->un_uppervp;
1104 	}
1105 
1106 	if (needrelookup != 0)
1107 		error = unionfs_relookup_for_create(ap->a_tdvp, cnp, td);
1108 
1109 	if (error == 0)
1110 		error = VOP_LINK(udvp, uvp, cnp);
1111 
1112 	UNIONFS_INTERNAL_DEBUG("unionfs_link: leave (%d)\n", error);
1113 
1114 	return (error);
1115 }
1116 
1117 static int
1118 unionfs_rename(struct vop_rename_args *ap)
1119 {
1120 	struct vnode   *fdvp;
1121 	struct vnode   *fvp;
1122 	struct componentname *fcnp;
1123 	struct vnode   *tdvp;
1124 	struct vnode   *tvp;
1125 	struct componentname *tcnp;
1126 	struct vnode   *ltdvp;
1127 	struct vnode   *ltvp;
1128 	struct thread  *td;
1129 
1130 	/* rename target vnodes */
1131 	struct vnode   *rfdvp;
1132 	struct vnode   *rfvp;
1133 	struct vnode   *rtdvp;
1134 	struct vnode   *rtvp;
1135 
1136 	struct unionfs_mount *ump;
1137 	struct unionfs_node *unp;
1138 	int		error;
1139 	int		needrelookup;
1140 
1141 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: enter\n");
1142 
1143 	error = 0;
1144 	fdvp = ap->a_fdvp;
1145 	fvp = ap->a_fvp;
1146 	fcnp = ap->a_fcnp;
1147 	tdvp = ap->a_tdvp;
1148 	tvp = ap->a_tvp;
1149 	tcnp = ap->a_tcnp;
1150 	ltdvp = NULLVP;
1151 	ltvp = NULLVP;
1152 	td = curthread;
1153 	rfdvp = fdvp;
1154 	rfvp = fvp;
1155 	rtdvp = tdvp;
1156 	rtvp = tvp;
1157 	needrelookup = 0;
1158 
1159 #ifdef DIAGNOSTIC
1160 	if (!(fcnp->cn_flags & HASBUF) || !(tcnp->cn_flags & HASBUF))
1161 		panic("unionfs_rename: no name");
1162 #endif
1163 
1164 	/* check for cross device rename */
1165 	if (fvp->v_mount != tdvp->v_mount ||
1166 	    (tvp != NULLVP && fvp->v_mount != tvp->v_mount)) {
1167 		if (fvp->v_op != &unionfs_vnodeops)
1168 			error = ENODEV;
1169 		else
1170 			error = EXDEV;
1171 		goto unionfs_rename_abort;
1172 	}
1173 
1174 	/* Renaming a file to itself has no effect. */
1175 	if (fvp == tvp)
1176 		goto unionfs_rename_abort;
1177 
1178 	/*
1179 	 * from/to vnode is unionfs node.
1180 	 */
1181 
1182 	KASSERT_UNIONFS_VNODE(fdvp);
1183 	KASSERT_UNIONFS_VNODE(fvp);
1184 	KASSERT_UNIONFS_VNODE(tdvp);
1185 	if (tvp != NULLVP)
1186 		KASSERT_UNIONFS_VNODE(tvp);
1187 
1188 	unp = VTOUNIONFS(fdvp);
1189 #ifdef UNIONFS_IDBG_RENAME
1190 	UNIONFS_INTERNAL_DEBUG("fdvp=%p, ufdvp=%p, lfdvp=%p\n",
1191 	    fdvp, unp->un_uppervp, unp->un_lowervp);
1192 #endif
1193 	if (unp->un_uppervp == NULLVP) {
1194 		error = ENODEV;
1195 		goto unionfs_rename_abort;
1196 	}
1197 	rfdvp = unp->un_uppervp;
1198 	vref(rfdvp);
1199 
1200 	unp = VTOUNIONFS(fvp);
1201 #ifdef UNIONFS_IDBG_RENAME
1202 	UNIONFS_INTERNAL_DEBUG("fvp=%p, ufvp=%p, lfvp=%p\n",
1203 	    fvp, unp->un_uppervp, unp->un_lowervp);
1204 #endif
1205 	ump = MOUNTTOUNIONFSMOUNT(fvp->v_mount);
1206 	if (unp->un_uppervp == NULLVP) {
1207 		switch (fvp->v_type) {
1208 		case VREG:
1209 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1210 				goto unionfs_rename_abort;
1211 			error = unionfs_copyfile(unp, 1, fcnp->cn_cred, td);
1212 			VOP_UNLOCK(fvp);
1213 			if (error != 0)
1214 				goto unionfs_rename_abort;
1215 			break;
1216 		case VDIR:
1217 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1218 				goto unionfs_rename_abort;
1219 			error = unionfs_mkshadowdir(ump, rfdvp, unp, fcnp, td);
1220 			VOP_UNLOCK(fvp);
1221 			if (error != 0)
1222 				goto unionfs_rename_abort;
1223 			break;
1224 		default:
1225 			error = ENODEV;
1226 			goto unionfs_rename_abort;
1227 		}
1228 
1229 		needrelookup = 1;
1230 	}
1231 
1232 	if (unp->un_lowervp != NULLVP)
1233 		fcnp->cn_flags |= DOWHITEOUT;
1234 	rfvp = unp->un_uppervp;
1235 	vref(rfvp);
1236 
1237 	unp = VTOUNIONFS(tdvp);
1238 #ifdef UNIONFS_IDBG_RENAME
1239 	UNIONFS_INTERNAL_DEBUG("tdvp=%p, utdvp=%p, ltdvp=%p\n",
1240 	    tdvp, unp->un_uppervp, unp->un_lowervp);
1241 #endif
1242 	if (unp->un_uppervp == NULLVP) {
1243 		error = ENODEV;
1244 		goto unionfs_rename_abort;
1245 	}
1246 	rtdvp = unp->un_uppervp;
1247 	ltdvp = unp->un_lowervp;
1248 	vref(rtdvp);
1249 
1250 	if (tdvp == tvp) {
1251 		rtvp = rtdvp;
1252 		vref(rtvp);
1253 	} else if (tvp != NULLVP) {
1254 		unp = VTOUNIONFS(tvp);
1255 #ifdef UNIONFS_IDBG_RENAME
1256 		UNIONFS_INTERNAL_DEBUG("tvp=%p, utvp=%p, ltvp=%p\n",
1257 		    tvp, unp->un_uppervp, unp->un_lowervp);
1258 #endif
1259 		if (unp->un_uppervp == NULLVP)
1260 			rtvp = NULLVP;
1261 		else {
1262 			if (tvp->v_type == VDIR) {
1263 				error = EINVAL;
1264 				goto unionfs_rename_abort;
1265 			}
1266 			rtvp = unp->un_uppervp;
1267 			ltvp = unp->un_lowervp;
1268 			vref(rtvp);
1269 		}
1270 	}
1271 
1272 	if (rfvp == rtvp)
1273 		goto unionfs_rename_abort;
1274 
1275 	if (needrelookup != 0) {
1276 		if ((error = vn_lock(fdvp, LK_EXCLUSIVE)) != 0)
1277 			goto unionfs_rename_abort;
1278 		error = unionfs_relookup_for_delete(fdvp, fcnp, td);
1279 		VOP_UNLOCK(fdvp);
1280 		if (error != 0)
1281 			goto unionfs_rename_abort;
1282 
1283 		/* Lock of tvp is canceled in order to avoid recursive lock. */
1284 		if (tvp != NULLVP && tvp != tdvp)
1285 			VOP_UNLOCK(tvp);
1286 		error = unionfs_relookup_for_rename(tdvp, tcnp, td);
1287 		if (tvp != NULLVP && tvp != tdvp)
1288 			vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
1289 		if (error != 0)
1290 			goto unionfs_rename_abort;
1291 	}
1292 
1293 	error = VOP_RENAME(rfdvp, rfvp, fcnp, rtdvp, rtvp, tcnp);
1294 
1295 	if (error == 0) {
1296 		if (rtvp != NULLVP && rtvp->v_type == VDIR)
1297 			cache_purge(tdvp);
1298 		if (fvp->v_type == VDIR && fdvp != tdvp)
1299 			cache_purge(fdvp);
1300 	}
1301 
1302 	if (ltdvp != NULLVP)
1303 		VOP_UNLOCK(ltdvp);
1304 	if (tdvp != rtdvp)
1305 		vrele(tdvp);
1306 	if (ltvp != NULLVP)
1307 		VOP_UNLOCK(ltvp);
1308 	if (tvp != rtvp && tvp != NULLVP) {
1309 		if (rtvp == NULLVP)
1310 			vput(tvp);
1311 		else
1312 			vrele(tvp);
1313 	}
1314 	if (fdvp != rfdvp)
1315 		vrele(fdvp);
1316 	if (fvp != rfvp)
1317 		vrele(fvp);
1318 
1319 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1320 
1321 	return (error);
1322 
1323 unionfs_rename_abort:
1324 	vput(tdvp);
1325 	if (tdvp != rtdvp)
1326 		vrele(rtdvp);
1327 	if (tvp != NULLVP) {
1328 		if (tdvp != tvp)
1329 			vput(tvp);
1330 		else
1331 			vrele(tvp);
1332 	}
1333 	if (tvp != rtvp && rtvp != NULLVP)
1334 		vrele(rtvp);
1335 	if (fdvp != rfdvp)
1336 		vrele(rfdvp);
1337 	if (fvp != rfvp)
1338 		vrele(rfvp);
1339 	vrele(fdvp);
1340 	vrele(fvp);
1341 
1342 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1343 
1344 	return (error);
1345 }
1346 
1347 static int
1348 unionfs_mkdir(struct vop_mkdir_args *ap)
1349 {
1350 	struct unionfs_node *dunp;
1351 	struct componentname *cnp;
1352 	struct thread  *td;
1353 	struct vnode   *udvp;
1354 	struct vnode   *uvp;
1355 	struct vattr	va;
1356 	int		error;
1357 	int		lkflags;
1358 
1359 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: enter\n");
1360 
1361 	KASSERT_UNIONFS_VNODE(ap->a_dvp);
1362 
1363 	error = EROFS;
1364 	dunp = VTOUNIONFS(ap->a_dvp);
1365 	cnp = ap->a_cnp;
1366 	lkflags = cnp->cn_lkflags;
1367 	td = curthread;
1368 	udvp = dunp->un_uppervp;
1369 
1370 	if (udvp != NULLVP) {
1371 		/* check opaque */
1372 		if (!(cnp->cn_flags & ISWHITEOUT)) {
1373 			error = VOP_GETATTR(udvp, &va, cnp->cn_cred);
1374 			if (error != 0)
1375 				return (error);
1376 			if ((va.va_flags & OPAQUE) != 0)
1377 				cnp->cn_flags |= ISWHITEOUT;
1378 		}
1379 
1380 		if ((error = VOP_MKDIR(udvp, &uvp, cnp, ap->a_vap)) == 0) {
1381 			VOP_UNLOCK(uvp);
1382 			cnp->cn_lkflags = LK_EXCLUSIVE;
1383 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1384 			    ap->a_dvp, ap->a_vpp, cnp, td);
1385 			cnp->cn_lkflags = lkflags;
1386 			vrele(uvp);
1387 		}
1388 	}
1389 
1390 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: leave (%d)\n", error);
1391 
1392 	return (error);
1393 }
1394 
1395 static int
1396 unionfs_rmdir(struct vop_rmdir_args *ap)
1397 {
1398 	struct unionfs_node *dunp;
1399 	struct unionfs_node *unp;
1400 	struct unionfs_mount *ump;
1401 	struct componentname *cnp;
1402 	struct thread  *td;
1403 	struct vnode   *udvp;
1404 	struct vnode   *uvp;
1405 	struct vnode   *lvp;
1406 	int		error;
1407 
1408 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: enter\n");
1409 
1410 	KASSERT_UNIONFS_VNODE(ap->a_dvp);
1411 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1412 
1413 	error = 0;
1414 	dunp = VTOUNIONFS(ap->a_dvp);
1415 	unp = VTOUNIONFS(ap->a_vp);
1416 	cnp = ap->a_cnp;
1417 	td = curthread;
1418 	udvp = dunp->un_uppervp;
1419 	uvp = unp->un_uppervp;
1420 	lvp = unp->un_lowervp;
1421 
1422 	if (udvp == NULLVP)
1423 		return (EROFS);
1424 
1425 	if (udvp == uvp)
1426 		return (EOPNOTSUPP);
1427 
1428 	if (uvp != NULLVP) {
1429 		if (lvp != NULLVP) {
1430 			error = unionfs_check_rmdir(ap->a_vp, cnp->cn_cred, td);
1431 			if (error != 0)
1432 				return (error);
1433 		}
1434 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
1435 		if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP)
1436 			cnp->cn_flags |= DOWHITEOUT;
1437 		/*
1438 		 * The relookup path will need to relock the parent dvp and
1439 		 * possibly the vp as well.  Locking is expected to be done
1440 		 * in parent->child order; drop the lock on vp to avoid LOR
1441 		 * and potential recursion on vp's lock.
1442 		 * vp is expected to remain referenced during VOP_RMDIR(),
1443 		 * so vref/vrele should not be necessary here.
1444 		 */
1445 		VOP_UNLOCK(ap->a_vp);
1446 		VNPASS(vrefcnt(ap->a_vp) > 0, ap->a_vp);
1447 		error = unionfs_relookup_for_delete(ap->a_dvp, cnp, td);
1448 		vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
1449 		if (error == 0 && VN_IS_DOOMED(uvp))
1450 			error = ENOENT;
1451 		if (error == 0)
1452 			error = VOP_RMDIR(udvp, uvp, cnp);
1453 	} else if (lvp != NULLVP)
1454 		error = unionfs_mkwhiteout(udvp, cnp, td,
1455 		    unp->un_path, unp->un_pathlen);
1456 
1457 	if (error == 0) {
1458 		cache_purge(ap->a_dvp);
1459 		cache_purge(ap->a_vp);
1460 	}
1461 
1462 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: leave (%d)\n", error);
1463 
1464 	return (error);
1465 }
1466 
1467 static int
1468 unionfs_symlink(struct vop_symlink_args *ap)
1469 {
1470 	struct unionfs_node *dunp;
1471 	struct componentname *cnp;
1472 	struct thread  *td;
1473 	struct vnode   *udvp;
1474 	struct vnode   *uvp;
1475 	int		error;
1476 	int		lkflags;
1477 
1478 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: enter\n");
1479 
1480 	KASSERT_UNIONFS_VNODE(ap->a_dvp);
1481 
1482 	error = EROFS;
1483 	dunp = VTOUNIONFS(ap->a_dvp);
1484 	cnp = ap->a_cnp;
1485 	lkflags = cnp->cn_lkflags;
1486 	td = curthread;
1487 	udvp = dunp->un_uppervp;
1488 
1489 	if (udvp != NULLVP) {
1490 		error = VOP_SYMLINK(udvp, &uvp, cnp, ap->a_vap, ap->a_target);
1491 		if (error == 0) {
1492 			VOP_UNLOCK(uvp);
1493 			cnp->cn_lkflags = LK_EXCLUSIVE;
1494 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1495 			    ap->a_dvp, ap->a_vpp, cnp, td);
1496 			cnp->cn_lkflags = lkflags;
1497 			vrele(uvp);
1498 		}
1499 	}
1500 
1501 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: leave (%d)\n", error);
1502 
1503 	return (error);
1504 }
1505 
1506 static int
1507 unionfs_readdir(struct vop_readdir_args *ap)
1508 {
1509 	struct unionfs_node *unp;
1510 	struct unionfs_node_status *unsp;
1511 	struct uio     *uio;
1512 	struct vnode   *vp;
1513 	struct vnode   *uvp;
1514 	struct vnode   *lvp;
1515 	struct thread  *td;
1516 	struct vattr    va;
1517 
1518 	u_long         *cookies_bk;
1519 	int		error;
1520 	int		eofflag;
1521 	int		locked;
1522 	int		ncookies_bk;
1523 	int		uio_offset_bk;
1524 
1525 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: enter\n");
1526 
1527 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1528 
1529 	error = 0;
1530 	eofflag = 0;
1531 	locked = 0;
1532 	uio_offset_bk = 0;
1533 	uio = ap->a_uio;
1534 	uvp = NULLVP;
1535 	lvp = NULLVP;
1536 	td = uio->uio_td;
1537 	ncookies_bk = 0;
1538 	cookies_bk = NULL;
1539 
1540 	vp = ap->a_vp;
1541 	if (vp->v_type != VDIR)
1542 		return (ENOTDIR);
1543 
1544 	/* check the open count. unionfs needs to open before readdir. */
1545 	if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
1546 		if (vn_lock(vp, LK_UPGRADE) != 0)
1547 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1548 		locked = 1;
1549 	}
1550 	unp = VTOUNIONFS(vp);
1551 	if (unp == NULL)
1552 		error = EBADF;
1553 	else {
1554 		uvp = unp->un_uppervp;
1555 		lvp = unp->un_lowervp;
1556 		unionfs_get_node_status(unp, td, &unsp);
1557 		if ((uvp != NULLVP && unsp->uns_upper_opencnt <= 0) ||
1558 			(lvp != NULLVP && unsp->uns_lower_opencnt <= 0)) {
1559 			unionfs_tryrem_node_status(unp, unsp);
1560 			error = EBADF;
1561 		}
1562 	}
1563 	if (locked)
1564 		vn_lock(vp, LK_DOWNGRADE | LK_RETRY);
1565 	if (error != 0)
1566 		goto unionfs_readdir_exit;
1567 
1568 	/* check opaque */
1569 	if (uvp != NULLVP && lvp != NULLVP) {
1570 		if ((error = VOP_GETATTR(uvp, &va, ap->a_cred)) != 0)
1571 			goto unionfs_readdir_exit;
1572 		if (va.va_flags & OPAQUE)
1573 			lvp = NULLVP;
1574 	}
1575 
1576 	/* upper only */
1577 	if (uvp != NULLVP && lvp == NULLVP) {
1578 		error = VOP_READDIR(uvp, uio, ap->a_cred, ap->a_eofflag,
1579 		    ap->a_ncookies, ap->a_cookies);
1580 		unsp->uns_readdir_status = 0;
1581 
1582 		goto unionfs_readdir_exit;
1583 	}
1584 
1585 	/* lower only */
1586 	if (uvp == NULLVP && lvp != NULLVP) {
1587 		error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1588 		    ap->a_ncookies, ap->a_cookies);
1589 		unsp->uns_readdir_status = 2;
1590 
1591 		goto unionfs_readdir_exit;
1592 	}
1593 
1594 	/*
1595 	 * readdir upper and lower
1596 	 */
1597 	KASSERT(uvp != NULLVP, ("unionfs_readdir: null upper vp"));
1598 	KASSERT(lvp != NULLVP, ("unionfs_readdir: null lower vp"));
1599 	if (uio->uio_offset == 0)
1600 		unsp->uns_readdir_status = 0;
1601 
1602 	if (unsp->uns_readdir_status == 0) {
1603 		/* read upper */
1604 		error = VOP_READDIR(uvp, uio, ap->a_cred, &eofflag,
1605 				    ap->a_ncookies, ap->a_cookies);
1606 
1607 		if (error != 0 || eofflag == 0)
1608 			goto unionfs_readdir_exit;
1609 		unsp->uns_readdir_status = 1;
1610 
1611 		/*
1612 		 * UFS(and other FS) needs size of uio_resid larger than
1613 		 * DIRBLKSIZ.
1614 		 * size of DIRBLKSIZ equals DEV_BSIZE.
1615 		 * (see: ufs/ufs/ufs_vnops.c ufs_readdir func , ufs/ufs/dir.h)
1616 		 */
1617 		if (uio->uio_resid <= (uio->uio_resid & (DEV_BSIZE -1)))
1618 			goto unionfs_readdir_exit;
1619 
1620 		/*
1621 		 * Backup cookies.
1622 		 * It prepares to readdir in lower.
1623 		 */
1624 		if (ap->a_ncookies != NULL) {
1625 			ncookies_bk = *(ap->a_ncookies);
1626 			*(ap->a_ncookies) = 0;
1627 		}
1628 		if (ap->a_cookies != NULL) {
1629 			cookies_bk = *(ap->a_cookies);
1630 			*(ap->a_cookies) = NULL;
1631 		}
1632 	}
1633 
1634 	/* initialize for readdir in lower */
1635 	if (unsp->uns_readdir_status == 1) {
1636 		unsp->uns_readdir_status = 2;
1637 		/*
1638 		 * Backup uio_offset. See the comment after the
1639 		 * VOP_READDIR call on the lower layer.
1640 		 */
1641 		uio_offset_bk = uio->uio_offset;
1642 		uio->uio_offset = 0;
1643 	}
1644 
1645 	if (lvp == NULLVP) {
1646 		error = EBADF;
1647 		goto unionfs_readdir_exit;
1648 	}
1649 	/* read lower */
1650 	error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1651 			    ap->a_ncookies, ap->a_cookies);
1652 
1653 	/*
1654 	 * We can't return an uio_offset of 0: this would trigger an
1655 	 * infinite loop, because the next call to unionfs_readdir would
1656 	 * always restart with the upper layer (uio_offset == 0) and
1657 	 * always return some data.
1658 	 *
1659 	 * This happens when the lower layer root directory is removed.
1660 	 * (A root directory deleting of unionfs should not be permitted.
1661 	 *  But current VFS can not do it.)
1662 	 */
1663 	if (uio->uio_offset == 0)
1664 		uio->uio_offset = uio_offset_bk;
1665 
1666 	if (cookies_bk != NULL) {
1667 		/* merge cookies */
1668 		int		size;
1669 		u_long         *newcookies, *pos;
1670 
1671 		size = *(ap->a_ncookies) + ncookies_bk;
1672 		newcookies = (u_long *) malloc(size * sizeof(u_long),
1673 		    M_TEMP, M_WAITOK);
1674 		pos = newcookies;
1675 
1676 		memcpy(pos, cookies_bk, ncookies_bk * sizeof(u_long));
1677 		pos += ncookies_bk;
1678 		memcpy(pos, *(ap->a_cookies),
1679 		    *(ap->a_ncookies) * sizeof(u_long));
1680 		free(cookies_bk, M_TEMP);
1681 		free(*(ap->a_cookies), M_TEMP);
1682 		*(ap->a_ncookies) = size;
1683 		*(ap->a_cookies) = newcookies;
1684 	}
1685 
1686 unionfs_readdir_exit:
1687 	if (error != 0 && ap->a_eofflag != NULL)
1688 		*(ap->a_eofflag) = 1;
1689 
1690 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1691 
1692 	return (error);
1693 }
1694 
1695 static int
1696 unionfs_readlink(struct vop_readlink_args *ap)
1697 {
1698 	struct unionfs_node *unp;
1699 	struct vnode   *vp;
1700 	int error;
1701 
1702 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: enter\n");
1703 
1704 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1705 
1706 	unp = VTOUNIONFS(ap->a_vp);
1707 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1708 
1709 	error = VOP_READLINK(vp, ap->a_uio, ap->a_cred);
1710 
1711 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: leave (%d)\n", error);
1712 
1713 	return (error);
1714 }
1715 
1716 static int
1717 unionfs_getwritemount(struct vop_getwritemount_args *ap)
1718 {
1719 	struct vnode   *uvp;
1720 	struct vnode   *vp;
1721 	int		error;
1722 
1723 	UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: enter\n");
1724 
1725 	error = 0;
1726 	vp = ap->a_vp;
1727 
1728 	if (vp == NULLVP || (vp->v_mount->mnt_flag & MNT_RDONLY))
1729 		return (EACCES);
1730 
1731 	KASSERT_UNIONFS_VNODE(vp);
1732 
1733 	uvp = UNIONFSVPTOUPPERVP(vp);
1734 	if (uvp == NULLVP && VREG == vp->v_type)
1735 		uvp = UNIONFSVPTOUPPERVP(VTOUNIONFS(vp)->un_dvp);
1736 
1737 	if (uvp != NULLVP)
1738 		error = VOP_GETWRITEMOUNT(uvp, ap->a_mpp);
1739 	else {
1740 		VI_LOCK(vp);
1741 		if (vp->v_holdcnt == 0)
1742 			error = EOPNOTSUPP;
1743 		else
1744 			error = EACCES;
1745 		VI_UNLOCK(vp);
1746 	}
1747 
1748 	UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: leave (%d)\n", error);
1749 
1750 	return (error);
1751 }
1752 
1753 static int
1754 unionfs_inactive(struct vop_inactive_args *ap)
1755 {
1756 	ap->a_vp->v_object = NULL;
1757 	vrecycle(ap->a_vp);
1758 	return (0);
1759 }
1760 
1761 static int
1762 unionfs_reclaim(struct vop_reclaim_args *ap)
1763 {
1764 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: enter\n"); */
1765 
1766 	unionfs_noderem(ap->a_vp, curthread);
1767 
1768 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: leave\n"); */
1769 
1770 	return (0);
1771 }
1772 
1773 static int
1774 unionfs_print(struct vop_print_args *ap)
1775 {
1776 	struct unionfs_node *unp;
1777 	/* struct unionfs_node_status *unsp; */
1778 
1779 	unp = VTOUNIONFS(ap->a_vp);
1780 	/* unionfs_get_node_status(unp, curthread, &unsp); */
1781 
1782 	printf("unionfs_vp=%p, uppervp=%p, lowervp=%p\n",
1783 	    ap->a_vp, unp->un_uppervp, unp->un_lowervp);
1784 	/*
1785 	printf("unionfs opencnt: uppervp=%d, lowervp=%d\n",
1786 	    unsp->uns_upper_opencnt, unsp->uns_lower_opencnt);
1787 	*/
1788 
1789 	if (unp->un_uppervp != NULLVP)
1790 		vn_printf(unp->un_uppervp, "unionfs: upper ");
1791 	if (unp->un_lowervp != NULLVP)
1792 		vn_printf(unp->un_lowervp, "unionfs: lower ");
1793 
1794 	return (0);
1795 }
1796 
1797 static int
1798 unionfs_islocked(struct vop_islocked_args *ap)
1799 {
1800 	struct unionfs_node *unp;
1801 
1802 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1803 
1804 	unp = VTOUNIONFS(ap->a_vp);
1805 	if (unp == NULL)
1806 		return (vop_stdislocked(ap));
1807 
1808 	if (unp->un_uppervp != NULLVP)
1809 		return (VOP_ISLOCKED(unp->un_uppervp));
1810 	if (unp->un_lowervp != NULLVP)
1811 		return (VOP_ISLOCKED(unp->un_lowervp));
1812 	return (vop_stdislocked(ap));
1813 }
1814 
1815 static int
1816 unionfs_get_llt_revlock(struct vnode *vp, int flags)
1817 {
1818 	int revlock;
1819 
1820 	revlock = 0;
1821 
1822 	switch (flags & LK_TYPE_MASK) {
1823 	case LK_SHARED:
1824 		if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
1825 			revlock = LK_UPGRADE;
1826 		else
1827 			revlock = LK_RELEASE;
1828 		break;
1829 	case LK_EXCLUSIVE:
1830 	case LK_UPGRADE:
1831 		revlock = LK_RELEASE;
1832 		break;
1833 	case LK_DOWNGRADE:
1834 		revlock = LK_UPGRADE;
1835 		break;
1836 	default:
1837 		break;
1838 	}
1839 
1840 	return (revlock);
1841 }
1842 
1843 /*
1844  * The state of an acquired lock is adjusted similarly to
1845  * the time of error generating.
1846  * flags: LK_RELEASE or LK_UPGRADE
1847  */
1848 static void
1849 unionfs_revlock(struct vnode *vp, int flags)
1850 {
1851 	if (flags & LK_RELEASE)
1852 		VOP_UNLOCK_FLAGS(vp, flags);
1853 	else {
1854 		/* UPGRADE */
1855 		if (vn_lock(vp, flags) != 0)
1856 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1857 	}
1858 }
1859 
1860 static int
1861 unionfs_lock(struct vop_lock1_args *ap)
1862 {
1863 	struct mount   *mp;
1864 	struct unionfs_mount *ump;
1865 	struct unionfs_node *unp;
1866 	struct vnode   *vp;
1867 	struct vnode   *uvp;
1868 	struct vnode   *lvp;
1869 	int		error;
1870 	int		flags;
1871 	int		revlock;
1872 	int		interlock;
1873 	int		uhold;
1874 
1875 	KASSERT_UNIONFS_VNODE(ap->a_vp);
1876 
1877 	error = 0;
1878 	interlock = 1;
1879 	uhold = 0;
1880 	flags = ap->a_flags;
1881 	vp = ap->a_vp;
1882 
1883 	if (LK_RELEASE == (flags & LK_TYPE_MASK) || !(flags & LK_TYPE_MASK))
1884 		return (VOP_UNLOCK_FLAGS(vp, flags | LK_RELEASE));
1885 
1886 	if ((flags & LK_INTERLOCK) == 0)
1887 		VI_LOCK(vp);
1888 
1889 	mp = vp->v_mount;
1890 	if (mp == NULL)
1891 		goto unionfs_lock_null_vnode;
1892 
1893 	ump = MOUNTTOUNIONFSMOUNT(mp);
1894 	unp = VTOUNIONFS(vp);
1895 	if (ump == NULL || unp == NULL)
1896 		goto unionfs_lock_null_vnode;
1897 	lvp = unp->un_lowervp;
1898 	uvp = unp->un_uppervp;
1899 
1900 	if ((revlock = unionfs_get_llt_revlock(vp, flags)) == 0)
1901 		panic("unknown lock type: 0x%x", flags & LK_TYPE_MASK);
1902 
1903 	if ((vp->v_iflag & VI_OWEINACT) != 0)
1904 		flags |= LK_NOWAIT;
1905 
1906 	/*
1907 	 * Sometimes, lower or upper is already exclusive locked.
1908 	 * (ex. vfs_domount: mounted vnode is already locked.)
1909 	 */
1910 	if ((flags & LK_TYPE_MASK) == LK_EXCLUSIVE &&
1911 	    vp == ump->um_rootvp)
1912 		flags |= LK_CANRECURSE;
1913 
1914 	if (lvp != NULLVP) {
1915 		if (uvp != NULLVP && flags & LK_UPGRADE) {
1916 			/*
1917 			 * Share Lock is once released and a deadlock is
1918 			 * avoided.
1919 			 */
1920 			vholdnz(uvp);
1921 			uhold = 1;
1922 			VOP_UNLOCK(uvp);
1923 			unp = VTOUNIONFS(vp);
1924 			if (unp == NULL) {
1925 				/* vnode is released. */
1926 				VI_UNLOCK(vp);
1927 				VOP_UNLOCK(lvp);
1928 				vdrop(uvp);
1929 				return (EBUSY);
1930 			}
1931 		}
1932 		VI_LOCK_FLAGS(lvp, MTX_DUPOK);
1933 		flags |= LK_INTERLOCK;
1934 		vholdl(lvp);
1935 
1936 		VI_UNLOCK(vp);
1937 		ap->a_flags &= ~LK_INTERLOCK;
1938 
1939 		error = VOP_LOCK(lvp, flags);
1940 
1941 		VI_LOCK(vp);
1942 		unp = VTOUNIONFS(vp);
1943 		if (unp == NULL) {
1944 			/* vnode is released. */
1945 			VI_UNLOCK(vp);
1946 			if (error == 0)
1947 				VOP_UNLOCK(lvp);
1948 			vdrop(lvp);
1949 			if (uhold != 0)
1950 				vdrop(uvp);
1951 			return (vop_stdlock(ap));
1952 		}
1953 	}
1954 
1955 	if (error == 0 && uvp != NULLVP) {
1956 		if (uhold && flags & LK_UPGRADE) {
1957 			flags &= ~LK_TYPE_MASK;
1958 			flags |= LK_EXCLUSIVE;
1959 		}
1960 		VI_LOCK_FLAGS(uvp, MTX_DUPOK);
1961 		flags |= LK_INTERLOCK;
1962 		if (uhold == 0) {
1963 			vholdl(uvp);
1964 			uhold = 1;
1965 		}
1966 
1967 		VI_UNLOCK(vp);
1968 		ap->a_flags &= ~LK_INTERLOCK;
1969 
1970 		error = VOP_LOCK(uvp, flags);
1971 
1972 		VI_LOCK(vp);
1973 		unp = VTOUNIONFS(vp);
1974 		if (unp == NULL) {
1975 			/* vnode is released. */
1976 			VI_UNLOCK(vp);
1977 			if (error == 0)
1978 				VOP_UNLOCK(uvp);
1979 			vdrop(uvp);
1980 			if (lvp != NULLVP) {
1981 				VOP_UNLOCK(lvp);
1982 				vdrop(lvp);
1983 			}
1984 			return (vop_stdlock(ap));
1985 		}
1986 		if (error != 0 && lvp != NULLVP) {
1987 			/* rollback */
1988 			VI_UNLOCK(vp);
1989 			unionfs_revlock(lvp, revlock);
1990 			interlock = 0;
1991 		}
1992 	}
1993 
1994 	if (interlock)
1995 		VI_UNLOCK(vp);
1996 	if (lvp != NULLVP)
1997 		vdrop(lvp);
1998 	if (uhold != 0)
1999 		vdrop(uvp);
2000 
2001 	return (error);
2002 
2003 unionfs_lock_null_vnode:
2004 	ap->a_flags |= LK_INTERLOCK;
2005 	return (vop_stdlock(ap));
2006 }
2007 
2008 static int
2009 unionfs_unlock(struct vop_unlock_args *ap)
2010 {
2011 	struct vnode   *vp;
2012 	struct vnode   *lvp;
2013 	struct vnode   *uvp;
2014 	struct unionfs_node *unp;
2015 	int		error;
2016 	int		uhold;
2017 
2018 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2019 
2020 	error = 0;
2021 	uhold = 0;
2022 	vp = ap->a_vp;
2023 
2024 	unp = VTOUNIONFS(vp);
2025 	if (unp == NULL)
2026 		goto unionfs_unlock_null_vnode;
2027 	lvp = unp->un_lowervp;
2028 	uvp = unp->un_uppervp;
2029 
2030 	if (lvp != NULLVP) {
2031 		vholdnz(lvp);
2032 		error = VOP_UNLOCK(lvp);
2033 	}
2034 
2035 	if (error == 0 && uvp != NULLVP) {
2036 		vholdnz(uvp);
2037 		uhold = 1;
2038 		error = VOP_UNLOCK(uvp);
2039 	}
2040 
2041 	if (lvp != NULLVP)
2042 		vdrop(lvp);
2043 	if (uhold != 0)
2044 		vdrop(uvp);
2045 
2046 	return error;
2047 
2048 unionfs_unlock_null_vnode:
2049 	return (vop_stdunlock(ap));
2050 }
2051 
2052 static int
2053 unionfs_pathconf(struct vop_pathconf_args *ap)
2054 {
2055 	struct unionfs_node *unp;
2056 	struct vnode   *vp;
2057 
2058 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2059 
2060 	unp = VTOUNIONFS(ap->a_vp);
2061 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
2062 
2063 	return (VOP_PATHCONF(vp, ap->a_name, ap->a_retval));
2064 }
2065 
2066 static int
2067 unionfs_advlock(struct vop_advlock_args *ap)
2068 {
2069 	struct unionfs_node *unp;
2070 	struct unionfs_node_status *unsp;
2071 	struct vnode   *vp;
2072 	struct vnode   *uvp;
2073 	struct thread  *td;
2074 	int error;
2075 
2076 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: enter\n");
2077 
2078 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2079 
2080 	vp = ap->a_vp;
2081 	td = curthread;
2082 
2083 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2084 
2085 	unp = VTOUNIONFS(ap->a_vp);
2086 	uvp = unp->un_uppervp;
2087 
2088 	if (uvp == NULLVP) {
2089 		error = unionfs_copyfile(unp, 1, td->td_ucred, td);
2090 		if (error != 0)
2091 			goto unionfs_advlock_abort;
2092 		uvp = unp->un_uppervp;
2093 
2094 		unionfs_get_node_status(unp, td, &unsp);
2095 		if (unsp->uns_lower_opencnt > 0) {
2096 			/* try reopen the vnode */
2097 			error = VOP_OPEN(uvp, unsp->uns_lower_openmode,
2098 				td->td_ucred, td, NULL);
2099 			if (error)
2100 				goto unionfs_advlock_abort;
2101 			unsp->uns_upper_opencnt++;
2102 			VOP_CLOSE(unp->un_lowervp, unsp->uns_lower_openmode,
2103 			    td->td_ucred, td);
2104 			unsp->uns_lower_opencnt--;
2105 		} else
2106 			unionfs_tryrem_node_status(unp, unsp);
2107 	}
2108 
2109 	VOP_UNLOCK(vp);
2110 
2111 	error = VOP_ADVLOCK(uvp, ap->a_id, ap->a_op, ap->a_fl, ap->a_flags);
2112 
2113 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
2114 
2115 	return error;
2116 
2117 unionfs_advlock_abort:
2118 	VOP_UNLOCK(vp);
2119 
2120 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
2121 
2122 	return error;
2123 }
2124 
2125 static int
2126 unionfs_strategy(struct vop_strategy_args *ap)
2127 {
2128 	struct unionfs_node *unp;
2129 	struct vnode   *vp;
2130 
2131 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2132 
2133 	unp = VTOUNIONFS(ap->a_vp);
2134 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
2135 
2136 #ifdef DIAGNOSTIC
2137 	if (vp == NULLVP)
2138 		panic("unionfs_strategy: nullvp");
2139 
2140 	if (ap->a_bp->b_iocmd == BIO_WRITE && vp == unp->un_lowervp)
2141 		panic("unionfs_strategy: writing to lowervp");
2142 #endif
2143 
2144 	return (VOP_STRATEGY(vp, ap->a_bp));
2145 }
2146 
2147 static int
2148 unionfs_getacl(struct vop_getacl_args *ap)
2149 {
2150 	struct unionfs_node *unp;
2151 	struct vnode   *vp;
2152 	int		error;
2153 
2154 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2155 
2156 	unp = VTOUNIONFS(ap->a_vp);
2157 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
2158 
2159 	UNIONFS_INTERNAL_DEBUG("unionfs_getacl: enter\n");
2160 
2161 	error = VOP_GETACL(vp, ap->a_type, ap->a_aclp, ap->a_cred, ap->a_td);
2162 
2163 	UNIONFS_INTERNAL_DEBUG("unionfs_getacl: leave (%d)\n", error);
2164 
2165 	return (error);
2166 }
2167 
2168 static int
2169 unionfs_setacl(struct vop_setacl_args *ap)
2170 {
2171 	struct unionfs_node *unp;
2172 	struct vnode   *uvp;
2173 	struct vnode   *lvp;
2174 	struct thread  *td;
2175 	int		error;
2176 
2177 	UNIONFS_INTERNAL_DEBUG("unionfs_setacl: enter\n");
2178 
2179 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2180 
2181 	error = EROFS;
2182 	unp = VTOUNIONFS(ap->a_vp);
2183 	uvp = unp->un_uppervp;
2184 	lvp = unp->un_lowervp;
2185 	td = ap->a_td;
2186 
2187 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2188 		return (EROFS);
2189 
2190 	if (uvp == NULLVP && lvp->v_type == VREG) {
2191 		if ((error = unionfs_copyfile(unp, 1, ap->a_cred, td)) != 0)
2192 			return (error);
2193 		uvp = unp->un_uppervp;
2194 	}
2195 
2196 	if (uvp != NULLVP)
2197 		error = VOP_SETACL(uvp, ap->a_type, ap->a_aclp, ap->a_cred, td);
2198 
2199 	UNIONFS_INTERNAL_DEBUG("unionfs_setacl: leave (%d)\n", error);
2200 
2201 	return (error);
2202 }
2203 
2204 static int
2205 unionfs_aclcheck(struct vop_aclcheck_args *ap)
2206 {
2207 	struct unionfs_node *unp;
2208 	struct vnode   *vp;
2209 	int		error;
2210 
2211 	UNIONFS_INTERNAL_DEBUG("unionfs_aclcheck: enter\n");
2212 
2213 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2214 
2215 	unp = VTOUNIONFS(ap->a_vp);
2216 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
2217 
2218 	error = VOP_ACLCHECK(vp, ap->a_type, ap->a_aclp, ap->a_cred, ap->a_td);
2219 
2220 	UNIONFS_INTERNAL_DEBUG("unionfs_aclcheck: leave (%d)\n", error);
2221 
2222 	return (error);
2223 }
2224 
2225 static int
2226 unionfs_openextattr(struct vop_openextattr_args *ap)
2227 {
2228 	struct unionfs_node *unp;
2229 	struct vnode   *vp;
2230 	struct vnode   *tvp;
2231 	int		error;
2232 
2233 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2234 
2235 	vp = ap->a_vp;
2236 	unp = VTOUNIONFS(vp);
2237 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
2238 
2239 	if ((tvp == unp->un_uppervp && (unp->un_flag & UNIONFS_OPENEXTU)) ||
2240 	    (tvp == unp->un_lowervp && (unp->un_flag & UNIONFS_OPENEXTL)))
2241 		return (EBUSY);
2242 
2243 	error = VOP_OPENEXTATTR(tvp, ap->a_cred, ap->a_td);
2244 
2245 	if (error == 0) {
2246 		if (vn_lock(vp, LK_UPGRADE) != 0)
2247 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2248 		if (tvp == unp->un_uppervp)
2249 			unp->un_flag |= UNIONFS_OPENEXTU;
2250 		else
2251 			unp->un_flag |= UNIONFS_OPENEXTL;
2252 		vn_lock(vp, LK_DOWNGRADE | LK_RETRY);
2253 	}
2254 
2255 	return (error);
2256 }
2257 
2258 static int
2259 unionfs_closeextattr(struct vop_closeextattr_args *ap)
2260 {
2261 	struct unionfs_node *unp;
2262 	struct vnode   *vp;
2263 	struct vnode   *tvp;
2264 	int		error;
2265 
2266 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2267 
2268 	vp = ap->a_vp;
2269 	unp = VTOUNIONFS(vp);
2270 	tvp = NULLVP;
2271 
2272 	if (unp->un_flag & UNIONFS_OPENEXTU)
2273 		tvp = unp->un_uppervp;
2274 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2275 		tvp = unp->un_lowervp;
2276 
2277 	if (tvp == NULLVP)
2278 		return (EOPNOTSUPP);
2279 
2280 	error = VOP_CLOSEEXTATTR(tvp, ap->a_commit, ap->a_cred, ap->a_td);
2281 
2282 	if (error == 0) {
2283 		if (vn_lock(vp, LK_UPGRADE) != 0)
2284 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2285 		if (tvp == unp->un_uppervp)
2286 			unp->un_flag &= ~UNIONFS_OPENEXTU;
2287 		else
2288 			unp->un_flag &= ~UNIONFS_OPENEXTL;
2289 		vn_lock(vp, LK_DOWNGRADE | LK_RETRY);
2290 	}
2291 
2292 	return (error);
2293 }
2294 
2295 static int
2296 unionfs_getextattr(struct vop_getextattr_args *ap)
2297 {
2298 	struct unionfs_node *unp;
2299 	struct vnode   *vp;
2300 
2301 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2302 
2303 	unp = VTOUNIONFS(ap->a_vp);
2304 	vp = NULLVP;
2305 
2306 	if (unp->un_flag & UNIONFS_OPENEXTU)
2307 		vp = unp->un_uppervp;
2308 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2309 		vp = unp->un_lowervp;
2310 
2311 	if (vp == NULLVP)
2312 		return (EOPNOTSUPP);
2313 
2314 	return (VOP_GETEXTATTR(vp, ap->a_attrnamespace, ap->a_name,
2315 	    ap->a_uio, ap->a_size, ap->a_cred, ap->a_td));
2316 }
2317 
2318 static int
2319 unionfs_setextattr(struct vop_setextattr_args *ap)
2320 {
2321 	struct unionfs_node *unp;
2322 	struct vnode   *uvp;
2323 	struct vnode   *lvp;
2324 	struct vnode   *ovp;
2325 	struct ucred   *cred;
2326 	struct thread  *td;
2327 	int		error;
2328 
2329 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2330 
2331 	error = EROFS;
2332 	unp = VTOUNIONFS(ap->a_vp);
2333 	uvp = unp->un_uppervp;
2334 	lvp = unp->un_lowervp;
2335 	ovp = NULLVP;
2336 	cred = ap->a_cred;
2337 	td = ap->a_td;
2338 
2339 	UNIONFS_INTERNAL_DEBUG("unionfs_setextattr: enter (un_flag=%x)\n",
2340 	    unp->un_flag);
2341 
2342 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2343 		return (EROFS);
2344 
2345 	if (unp->un_flag & UNIONFS_OPENEXTU)
2346 		ovp = unp->un_uppervp;
2347 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2348 		ovp = unp->un_lowervp;
2349 
2350 	if (ovp == NULLVP)
2351 		return (EOPNOTSUPP);
2352 
2353 	if (ovp == lvp && lvp->v_type == VREG) {
2354 		VOP_CLOSEEXTATTR(lvp, 0, cred, td);
2355 		if (uvp == NULLVP &&
2356 		    (error = unionfs_copyfile(unp, 1, cred, td)) != 0) {
2357 unionfs_setextattr_reopen:
2358 			if ((unp->un_flag & UNIONFS_OPENEXTL) &&
2359 			    VOP_OPENEXTATTR(lvp, cred, td)) {
2360 #ifdef DIAGNOSTIC
2361 				panic("unionfs: VOP_OPENEXTATTR failed");
2362 #endif
2363 				unp->un_flag &= ~UNIONFS_OPENEXTL;
2364 			}
2365 			goto unionfs_setextattr_abort;
2366 		}
2367 		uvp = unp->un_uppervp;
2368 		if ((error = VOP_OPENEXTATTR(uvp, cred, td)) != 0)
2369 			goto unionfs_setextattr_reopen;
2370 		unp->un_flag &= ~UNIONFS_OPENEXTL;
2371 		unp->un_flag |= UNIONFS_OPENEXTU;
2372 		ovp = uvp;
2373 	}
2374 
2375 	if (ovp == uvp)
2376 		error = VOP_SETEXTATTR(ovp, ap->a_attrnamespace, ap->a_name,
2377 		    ap->a_uio, cred, td);
2378 
2379 unionfs_setextattr_abort:
2380 	UNIONFS_INTERNAL_DEBUG("unionfs_setextattr: leave (%d)\n", error);
2381 
2382 	return (error);
2383 }
2384 
2385 static int
2386 unionfs_listextattr(struct vop_listextattr_args *ap)
2387 {
2388 	struct unionfs_node *unp;
2389 	struct vnode *vp;
2390 
2391 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2392 
2393 	unp = VTOUNIONFS(ap->a_vp);
2394 	vp = NULLVP;
2395 
2396 	if (unp->un_flag & UNIONFS_OPENEXTU)
2397 		vp = unp->un_uppervp;
2398 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2399 		vp = unp->un_lowervp;
2400 
2401 	if (vp == NULLVP)
2402 		return (EOPNOTSUPP);
2403 
2404 	return (VOP_LISTEXTATTR(vp, ap->a_attrnamespace, ap->a_uio,
2405 	    ap->a_size, ap->a_cred, ap->a_td));
2406 }
2407 
2408 static int
2409 unionfs_deleteextattr(struct vop_deleteextattr_args *ap)
2410 {
2411 	struct unionfs_node *unp;
2412 	struct vnode   *uvp;
2413 	struct vnode   *lvp;
2414 	struct vnode   *ovp;
2415 	struct ucred   *cred;
2416 	struct thread  *td;
2417 	int		error;
2418 
2419 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2420 
2421 	error = EROFS;
2422 	unp = VTOUNIONFS(ap->a_vp);
2423 	uvp = unp->un_uppervp;
2424 	lvp = unp->un_lowervp;
2425 	ovp = NULLVP;
2426 	cred = ap->a_cred;
2427 	td = ap->a_td;
2428 
2429 	UNIONFS_INTERNAL_DEBUG("unionfs_deleteextattr: enter (un_flag=%x)\n",
2430 	    unp->un_flag);
2431 
2432 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2433 		return (EROFS);
2434 
2435 	if (unp->un_flag & UNIONFS_OPENEXTU)
2436 		ovp = unp->un_uppervp;
2437 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2438 		ovp = unp->un_lowervp;
2439 
2440 	if (ovp == NULLVP)
2441 		return (EOPNOTSUPP);
2442 
2443 	if (ovp == lvp && lvp->v_type == VREG) {
2444 		VOP_CLOSEEXTATTR(lvp, 0, cred, td);
2445 		if (uvp == NULLVP &&
2446 		    (error = unionfs_copyfile(unp, 1, cred, td)) != 0) {
2447 unionfs_deleteextattr_reopen:
2448 			if ((unp->un_flag & UNIONFS_OPENEXTL) &&
2449 			    VOP_OPENEXTATTR(lvp, cred, td)) {
2450 #ifdef DIAGNOSTIC
2451 				panic("unionfs: VOP_OPENEXTATTR failed");
2452 #endif
2453 				unp->un_flag &= ~UNIONFS_OPENEXTL;
2454 			}
2455 			goto unionfs_deleteextattr_abort;
2456 		}
2457 		uvp = unp->un_uppervp;
2458 		if ((error = VOP_OPENEXTATTR(uvp, cred, td)) != 0)
2459 			goto unionfs_deleteextattr_reopen;
2460 		unp->un_flag &= ~UNIONFS_OPENEXTL;
2461 		unp->un_flag |= UNIONFS_OPENEXTU;
2462 		ovp = uvp;
2463 	}
2464 
2465 	if (ovp == uvp)
2466 		error = VOP_DELETEEXTATTR(ovp, ap->a_attrnamespace, ap->a_name,
2467 		    ap->a_cred, ap->a_td);
2468 
2469 unionfs_deleteextattr_abort:
2470 	UNIONFS_INTERNAL_DEBUG("unionfs_deleteextattr: leave (%d)\n", error);
2471 
2472 	return (error);
2473 }
2474 
2475 static int
2476 unionfs_setlabel(struct vop_setlabel_args *ap)
2477 {
2478 	struct unionfs_node *unp;
2479 	struct vnode   *uvp;
2480 	struct vnode   *lvp;
2481 	struct thread  *td;
2482 	int		error;
2483 
2484 	UNIONFS_INTERNAL_DEBUG("unionfs_setlabel: enter\n");
2485 
2486 	KASSERT_UNIONFS_VNODE(ap->a_vp);
2487 
2488 	error = EROFS;
2489 	unp = VTOUNIONFS(ap->a_vp);
2490 	uvp = unp->un_uppervp;
2491 	lvp = unp->un_lowervp;
2492 	td = ap->a_td;
2493 
2494 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2495 		return (EROFS);
2496 
2497 	if (uvp == NULLVP && lvp->v_type == VREG) {
2498 		if ((error = unionfs_copyfile(unp, 1, ap->a_cred, td)) != 0)
2499 			return (error);
2500 		uvp = unp->un_uppervp;
2501 	}
2502 
2503 	if (uvp != NULLVP)
2504 		error = VOP_SETLABEL(uvp, ap->a_label, ap->a_cred, td);
2505 
2506 	UNIONFS_INTERNAL_DEBUG("unionfs_setlabel: leave (%d)\n", error);
2507 
2508 	return (error);
2509 }
2510 
2511 static int
2512 unionfs_vptofh(struct vop_vptofh_args *ap)
2513 {
2514 	return (EOPNOTSUPP);
2515 }
2516 
2517 static int
2518 unionfs_add_writecount(struct vop_add_writecount_args *ap)
2519 {
2520 	struct vnode *tvp, *vp;
2521 	struct unionfs_node *unp;
2522 	int error;
2523 
2524 	vp = ap->a_vp;
2525 	unp = VTOUNIONFS(vp);
2526 	tvp = unp->un_uppervp != NULL ? unp->un_uppervp : unp->un_lowervp;
2527 	VI_LOCK(vp);
2528 	/* text refs are bypassed to lowervp */
2529 	VNASSERT(vp->v_writecount >= 0, vp, ("wrong null writecount"));
2530 	VNASSERT(vp->v_writecount + ap->a_inc >= 0, vp,
2531 	    ("wrong writecount inc %d", ap->a_inc));
2532 	if (tvp != NULL)
2533 		error = VOP_ADD_WRITECOUNT(tvp, ap->a_inc);
2534 	else if (vp->v_writecount < 0)
2535 		error = ETXTBSY;
2536 	else
2537 		error = 0;
2538 	if (error == 0)
2539 		vp->v_writecount += ap->a_inc;
2540 	VI_UNLOCK(vp);
2541 	return (error);
2542 }
2543 
2544 struct vop_vector unionfs_vnodeops = {
2545 	.vop_default =		&default_vnodeops,
2546 
2547 	.vop_access =		unionfs_access,
2548 	.vop_aclcheck =		unionfs_aclcheck,
2549 	.vop_advlock =		unionfs_advlock,
2550 	.vop_bmap =		VOP_EOPNOTSUPP,
2551 	.vop_cachedlookup =	unionfs_lookup,
2552 	.vop_close =		unionfs_close,
2553 	.vop_closeextattr =	unionfs_closeextattr,
2554 	.vop_create =		unionfs_create,
2555 	.vop_deleteextattr =	unionfs_deleteextattr,
2556 	.vop_fsync =		unionfs_fsync,
2557 	.vop_getacl =		unionfs_getacl,
2558 	.vop_getattr =		unionfs_getattr,
2559 	.vop_getextattr =	unionfs_getextattr,
2560 	.vop_getwritemount =	unionfs_getwritemount,
2561 	.vop_inactive =		unionfs_inactive,
2562 	.vop_need_inactive =	vop_stdneed_inactive,
2563 	.vop_islocked =		unionfs_islocked,
2564 	.vop_ioctl =		unionfs_ioctl,
2565 	.vop_link =		unionfs_link,
2566 	.vop_listextattr =	unionfs_listextattr,
2567 	.vop_lock1 =		unionfs_lock,
2568 	.vop_lookup =		vfs_cache_lookup,
2569 	.vop_mkdir =		unionfs_mkdir,
2570 	.vop_mknod =		unionfs_mknod,
2571 	.vop_open =		unionfs_open,
2572 	.vop_openextattr =	unionfs_openextattr,
2573 	.vop_pathconf =		unionfs_pathconf,
2574 	.vop_poll =		unionfs_poll,
2575 	.vop_print =		unionfs_print,
2576 	.vop_read =		unionfs_read,
2577 	.vop_readdir =		unionfs_readdir,
2578 	.vop_readlink =		unionfs_readlink,
2579 	.vop_reclaim =		unionfs_reclaim,
2580 	.vop_remove =		unionfs_remove,
2581 	.vop_rename =		unionfs_rename,
2582 	.vop_rmdir =		unionfs_rmdir,
2583 	.vop_setacl =		unionfs_setacl,
2584 	.vop_setattr =		unionfs_setattr,
2585 	.vop_setextattr =	unionfs_setextattr,
2586 	.vop_setlabel =		unionfs_setlabel,
2587 	.vop_strategy =		unionfs_strategy,
2588 	.vop_symlink =		unionfs_symlink,
2589 	.vop_unlock =		unionfs_unlock,
2590 	.vop_whiteout =		unionfs_whiteout,
2591 	.vop_write =		unionfs_write,
2592 	.vop_vptofh =		unionfs_vptofh,
2593 	.vop_add_writecount =	unionfs_add_writecount,
2594 };
2595 VFS_VOP_VECTOR_REGISTER(unionfs_vnodeops);
2596