xref: /freebsd/sys/fs/unionfs/union_vnops.c (revision b28624fde638caadd4a89f50c9b7e7da0f98c4d2)
1 /*-
2  * Copyright (c) 1992, 1993, 1994, 1995 Jan-Simon Pendry.
3  * Copyright (c) 1992, 1993, 1994, 1995
4  *      The Regents of the University of California.
5  * Copyright (c) 2005, 2006 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
6  * Copyright (c) 2006 Daichi Goto <daichi@freebsd.org>
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * Jan-Simon Pendry.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)union_vnops.c	8.32 (Berkeley) 6/23/95
37  * $FreeBSD$
38  *
39  */
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/conf.h>
44 #include <sys/kernel.h>
45 #include <sys/lock.h>
46 #include <sys/malloc.h>
47 #include <sys/mount.h>
48 #include <sys/mutex.h>
49 #include <sys/namei.h>
50 #include <sys/sysctl.h>
51 #include <sys/vnode.h>
52 #include <sys/kdb.h>
53 #include <sys/fcntl.h>
54 #include <sys/stat.h>
55 #include <sys/dirent.h>
56 #include <sys/proc.h>
57 #include <sys/bio.h>
58 #include <sys/buf.h>
59 
60 #include <fs/unionfs/union.h>
61 
62 #include <vm/vm.h>
63 #include <vm/vm_extern.h>
64 #include <vm/vm_object.h>
65 #include <vm/vnode_pager.h>
66 
67 #if 0
68 #define UNIONFS_INTERNAL_DEBUG(msg, args...)    printf(msg, ## args)
69 #define UNIONFS_IDBG_RENAME
70 #else
71 #define UNIONFS_INTERNAL_DEBUG(msg, args...)
72 #endif
73 
74 /* lockmgr lock <-> reverse table */
75 struct lk_lr_table {
76 	int	lock;
77 	int	revlock;
78 };
79 
80 static struct lk_lr_table un_llt[] = {
81 	{LK_SHARED, LK_RELEASE},
82 	{LK_EXCLUSIVE, LK_RELEASE},
83 	{LK_UPGRADE, LK_DOWNGRADE},
84 	{LK_EXCLUPGRADE, LK_DOWNGRADE},
85 	{LK_DOWNGRADE, LK_UPGRADE},
86 	{0, 0}
87 };
88 
89 
90 static int
91 unionfs_lookup(struct vop_lookup_args *ap)
92 {
93 	int		iswhiteout;
94 	int		lockflag;
95 	int		error , uerror, lerror;
96 	u_long		nameiop;
97 	u_long		cnflags, cnflagsbk;
98 	struct unionfs_node *dunp;
99 	struct vnode   *dvp, *udvp, *ldvp, *vp, *uvp, *lvp, *dtmpvp;
100 	struct vattr	va;
101 	struct componentname *cnp;
102 	struct thread  *td;
103 
104 	iswhiteout = 0;
105 	lockflag = 0;
106 	error = uerror = lerror = ENOENT;
107 	cnp = ap->a_cnp;
108 	nameiop = cnp->cn_nameiop;
109 	cnflags = cnp->cn_flags;
110 	dvp = ap->a_dvp;
111 	dunp = VTOUNIONFS(dvp);
112 	udvp = dunp->un_uppervp;
113 	ldvp = dunp->un_lowervp;
114 	vp = uvp = lvp = NULLVP;
115 	td = curthread;
116 	*(ap->a_vpp) = NULLVP;
117 
118 	UNIONFS_INTERNAL_DEBUG("unionfs_lookup: enter: nameiop=%ld, flags=%lx, path=%s\n", nameiop, cnflags, cnp->cn_nameptr);
119 
120 	if (dvp->v_type != VDIR)
121 		return (ENOTDIR);
122 
123 	/*
124 	 * If read-only and op is not LOOKUP, will return EROFS.
125 	 */
126 	if ((cnflags & ISLASTCN) &&
127 	    (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
128 	    LOOKUP != nameiop)
129 		return (EROFS);
130 
131 	/*
132 	 * lookup dotdot
133 	 */
134 	if (cnflags & ISDOTDOT) {
135 		if (LOOKUP != nameiop && udvp == NULLVP)
136 			return (EROFS);
137 
138 		if (udvp != NULLVP) {
139 			dtmpvp = udvp;
140 			if (ldvp != NULLVP)
141 				VOP_UNLOCK(ldvp, 0, td);
142 		}
143 		else
144 			dtmpvp = ldvp;
145 
146 		error = VOP_LOOKUP(dtmpvp, &vp, cnp);
147 
148 		if (dtmpvp == udvp && ldvp != NULLVP) {
149 			VOP_UNLOCK(udvp, 0, td);
150 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, td);
151 		}
152 
153 		if (error == 0) {
154 			/*
155 			 * Exchange lock and reference from vp to
156 			 * dunp->un_dvp. vp is upper/lower vnode, but it
157 			 * will need to return the unionfs vnode.
158 			 */
159 			if (nameiop == DELETE  || nameiop == RENAME ||
160 			    (cnp->cn_lkflags & LK_TYPE_MASK))
161 				VOP_UNLOCK(vp, 0, td);
162 			vrele(vp);
163 
164 			VOP_UNLOCK(dvp, 0, td);
165 			*(ap->a_vpp) = dunp->un_dvp;
166 			vref(dunp->un_dvp);
167 
168 			if (nameiop == DELETE || nameiop == RENAME)
169 				vn_lock(dunp->un_dvp, LK_EXCLUSIVE | LK_RETRY, td);
170 			else if (cnp->cn_lkflags & LK_TYPE_MASK)
171 				vn_lock(dunp->un_dvp, cnp->cn_lkflags | LK_RETRY, td);
172 
173 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, td);
174 		}
175 
176 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
177 
178 		return (error);
179 	}
180 
181 	/*
182 	 * lookup upper layer
183 	 */
184 	if (udvp != NULLVP) {
185 		uerror = VOP_LOOKUP(udvp, &uvp, cnp);
186 
187 		if (uerror == 0) {
188 			if (udvp == uvp) {	/* is dot */
189 				vrele(uvp);
190 				*(ap->a_vpp) = dvp;
191 				vref(dvp);
192 
193 				UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", uerror);
194 
195 				return (uerror);
196 			}
197 			if (nameiop == DELETE || nameiop == RENAME ||
198 			    (cnp->cn_lkflags & LK_TYPE_MASK))
199 				VOP_UNLOCK(uvp, 0, td);
200 		}
201 
202 		/* check whiteout */
203 		if (uerror == ENOENT || uerror == EJUSTRETURN)
204 			if (cnp->cn_flags & ISWHITEOUT)
205 				iswhiteout = 1;	/* don't lookup lower */
206 		if (iswhiteout == 0 && ldvp != NULLVP)
207 			if (VOP_GETATTR(udvp, &va, cnp->cn_cred, td) == 0 &&
208 			    (va.va_flags & OPAQUE))
209 				iswhiteout = 1;	/* don't lookup lower */
210 #if 0
211 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: debug: whiteout=%d, path=%s\n", iswhiteout, cnp->cn_nameptr);
212 #endif
213 	}
214 
215 	/*
216 	 * lookup lower layer
217 	 */
218 	if (ldvp != NULLVP && !(cnflags & DOWHITEOUT) && iswhiteout == 0) {
219 		/* always op is LOOKUP */
220 		cnp->cn_nameiop = LOOKUP;
221 		cnflagsbk = cnp->cn_flags;
222 		cnp->cn_flags = cnflags;
223 
224 		lerror = VOP_LOOKUP(ldvp, &lvp, cnp);
225 
226 		cnp->cn_nameiop = nameiop;
227 		if (udvp != NULLVP && (uerror == 0 || uerror == EJUSTRETURN))
228 			cnp->cn_flags = cnflagsbk;
229 
230 		if (lerror == 0) {
231 			if (ldvp == lvp) {	/* is dot */
232 				if (uvp != NULLVP)
233 					vrele(uvp);	/* no need? */
234 				vrele(lvp);
235 				*(ap->a_vpp) = dvp;
236 				vref(dvp);
237 
238 				UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", lerror);
239 
240 				return (lerror);
241 			}
242 			if (cnp->cn_lkflags & LK_TYPE_MASK)
243 				VOP_UNLOCK(lvp, 0, td);
244 		}
245 	}
246 
247 	/*
248 	 * check lookup result
249 	 */
250 	if (uvp == NULLVP && lvp == NULLVP) {
251 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n",
252 		    (udvp != NULLVP ? uerror : lerror));
253 		return (udvp != NULLVP ? uerror : lerror);
254 	}
255 
256 	/*
257 	 * check vnode type
258 	 */
259 	if (uvp != NULLVP && lvp != NULLVP && uvp->v_type != lvp->v_type) {
260 		vrele(lvp);
261 		lvp = NULLVP;
262 	}
263 
264 	/*
265 	 * check shadow dir
266 	 */
267 	if (uerror != 0 && uerror != EJUSTRETURN && udvp != NULLVP &&
268 	    lerror == 0 && lvp != NULLVP && lvp->v_type == VDIR &&
269 	    !(dvp->v_mount->mnt_flag & MNT_RDONLY) &&
270 	    (1 < cnp->cn_namelen || '.' != *(cnp->cn_nameptr))) {
271 		/* get unionfs vnode in order to create a new shadow dir. */
272 		error = unionfs_nodeget(dvp->v_mount, NULLVP, lvp, dvp, &vp,
273 		    cnp, td);
274 		if (error != 0)
275 			goto unionfs_lookup_out;
276 
277 		if (LK_SHARED == (cnp->cn_lkflags & LK_TYPE_MASK))
278 			VOP_UNLOCK(vp, 0, td);
279 		if (LK_EXCLUSIVE != VOP_ISLOCKED(vp, td)) {
280 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
281 			lockflag = 1;
282 		}
283 		error = unionfs_mkshadowdir(MOUNTTOUNIONFSMOUNT(dvp->v_mount),
284 		    udvp, VTOUNIONFS(vp), cnp, td);
285 		if (lockflag != 0)
286 			VOP_UNLOCK(vp, 0, td);
287 		if (error != 0) {
288 			UNIONFSDEBUG("unionfs_lookup: Unable to create shadow dir.");
289 			if ((cnp->cn_lkflags & LK_TYPE_MASK) == LK_EXCLUSIVE)
290 				vput(vp);
291 			else
292 				vrele(vp);
293 			goto unionfs_lookup_out;
294 		}
295 		if ((cnp->cn_lkflags & LK_TYPE_MASK) == LK_SHARED)
296 			vn_lock(vp, LK_SHARED | LK_RETRY, td);
297 	}
298 	/*
299 	 * get unionfs vnode.
300 	 */
301 	else {
302 		if (uvp != NULLVP)
303 			error = uerror;
304 		else
305 			error = lerror;
306 		if (error != 0)
307 			goto unionfs_lookup_out;
308 		error = unionfs_nodeget(dvp->v_mount, uvp, lvp, dvp, &vp,
309 		    cnp, td);
310 		if (error != 0) {
311 			UNIONFSDEBUG("unionfs_lookup: Unable to create unionfs vnode.");
312 			goto unionfs_lookup_out;
313 		}
314 		if ((nameiop == DELETE || nameiop == RENAME) &&
315 		    (cnp->cn_lkflags & LK_TYPE_MASK) == 0)
316 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
317 	}
318 
319 	*(ap->a_vpp) = vp;
320 
321 unionfs_lookup_out:
322 	if (uvp != NULLVP)
323 		vrele(uvp);
324 	if (lvp != NULLVP)
325 		vrele(lvp);
326 
327 	UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
328 
329 	return (error);
330 }
331 
332 static int
333 unionfs_create(struct vop_create_args *ap)
334 {
335 	struct unionfs_node *dunp;
336 	struct componentname *cnp;
337 	struct thread  *td;
338 	struct vnode   *udvp;
339 	struct vnode   *vp;
340 	int		error;
341 
342 	UNIONFS_INTERNAL_DEBUG("unionfs_create: enter\n");
343 
344 	dunp = VTOUNIONFS(ap->a_dvp);
345 	cnp = ap->a_cnp;
346 	td = curthread;
347 	udvp = dunp->un_uppervp;
348 	error = EROFS;
349 
350 	if (udvp != NULLVP) {
351 		if ((error = VOP_CREATE(udvp, &vp, cnp, ap->a_vap)) == 0) {
352 			VOP_UNLOCK(vp, 0, td);
353 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
354 			    ap->a_dvp, ap->a_vpp, cnp, td);
355 			vrele(vp);
356 		}
357 	}
358 
359 	UNIONFS_INTERNAL_DEBUG("unionfs_create: leave (%d)\n", error);
360 
361 	return (error);
362 }
363 
364 static int
365 unionfs_whiteout(struct vop_whiteout_args *ap)
366 {
367 	struct unionfs_node *dunp;
368 	struct componentname *cnp;
369 	struct vnode   *udvp;
370 	int		error;
371 
372 	UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: enter\n");
373 
374 	dunp = VTOUNIONFS(ap->a_dvp);
375 	cnp = ap->a_cnp;
376 	udvp = dunp->un_uppervp;
377 	error = EOPNOTSUPP;
378 
379 	if (udvp != NULLVP) {
380 		switch (ap->a_flags) {
381 		case CREATE:
382 		case DELETE:
383 		case LOOKUP:
384 			error = VOP_WHITEOUT(udvp, cnp, ap->a_flags);
385 			break;
386 		default:
387 			error = EINVAL;
388 			break;
389 		}
390 	}
391 
392 	UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: leave (%d)\n", error);
393 
394 	return (error);
395 }
396 
397 static int
398 unionfs_mknod(struct vop_mknod_args *ap)
399 {
400 	struct unionfs_node *dunp;
401 	struct componentname *cnp;
402 	struct thread  *td;
403 	struct vnode   *udvp;
404 	struct vnode   *vp;
405 	int		error;
406 
407 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: enter\n");
408 
409 	dunp = VTOUNIONFS(ap->a_dvp);
410 	cnp = ap->a_cnp;
411 	td = curthread;
412 	udvp = dunp->un_uppervp;
413 	error = EROFS;
414 
415 	if (udvp != NULLVP) {
416 		if ((error = VOP_MKNOD(udvp, &vp, cnp, ap->a_vap)) == 0) {
417 			VOP_UNLOCK(vp, 0, td);
418 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
419 			    ap->a_dvp, ap->a_vpp, cnp, td);
420 			vrele(vp);
421 		}
422 	}
423 
424 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: leave (%d)\n", error);
425 
426 	return (error);
427 }
428 
429 static int
430 unionfs_open(struct vop_open_args *ap)
431 {
432 	int		error;
433 	struct unionfs_node *unp;
434 	struct unionfs_node_status *unsp;
435 	struct vnode   *uvp;
436 	struct vnode   *lvp;
437 	struct vnode   *targetvp;
438 	struct ucred   *cred;
439 	struct thread  *td;
440 
441 	UNIONFS_INTERNAL_DEBUG("unionfs_open: enter\n");
442 
443 	error = 0;
444 	unp = VTOUNIONFS(ap->a_vp);
445 	uvp = unp->un_uppervp;
446 	lvp = unp->un_lowervp;
447 	targetvp = NULLVP;
448 	cred = ap->a_cred;
449 	td = ap->a_td;
450 
451 	unionfs_get_node_status(unp, td, &unsp);
452 
453 	if (unsp->uns_lower_opencnt > 0 || unsp->uns_upper_opencnt > 0) {
454 		/* vnode is already opend. */
455 		if (unsp->uns_upper_opencnt > 0)
456 			targetvp = uvp;
457 		else
458 			targetvp = lvp;
459 
460 		if (targetvp == lvp &&
461 		    (ap->a_mode & FWRITE) && lvp->v_type == VREG)
462 			targetvp = NULLVP;
463 	}
464 	if (targetvp == NULLVP) {
465 		if (uvp == NULLVP) {
466 			if ((ap->a_mode & FWRITE) && lvp->v_type == VREG) {
467 				error = unionfs_copyfile(unp,
468 				    !(ap->a_mode & O_TRUNC), cred, td);
469 				if (error != 0)
470 					goto unionfs_open_abort;
471 				targetvp = uvp = unp->un_uppervp;
472 			} else
473 				targetvp = lvp;
474 		} else
475 			targetvp = uvp;
476 	}
477 
478 	error = VOP_OPEN(targetvp, ap->a_mode, cred, td, ap->a_fp);
479 	if (error == 0) {
480 		if (targetvp == uvp) {
481 			if (uvp->v_type == VDIR && lvp != NULLVP &&
482 			    unsp->uns_lower_opencnt <= 0) {
483 				/* open lower for readdir */
484 				error = VOP_OPEN(lvp, FREAD, cred, td, NULL);
485 				if (error != 0) {
486 					VOP_CLOSE(uvp, ap->a_mode, cred, td);
487 					goto unionfs_open_abort;
488 				}
489 				unsp->uns_node_flag |= UNS_OPENL_4_READDIR;
490 				unsp->uns_lower_opencnt++;
491 			}
492 			unsp->uns_upper_opencnt++;
493 		} else {
494 			unsp->uns_lower_opencnt++;
495 			unsp->uns_lower_openmode = ap->a_mode;
496 		}
497 		ap->a_vp->v_object = targetvp->v_object;
498 	}
499 
500 unionfs_open_abort:
501 	if (error != 0)
502 		unionfs_tryrem_node_status(unp, td, unsp);
503 
504 	UNIONFS_INTERNAL_DEBUG("unionfs_open: leave (%d)\n", error);
505 
506 	return (error);
507 }
508 
509 static int
510 unionfs_close(struct vop_close_args *ap)
511 {
512 	int		error;
513 	int		locked;
514 	struct unionfs_node *unp;
515 	struct unionfs_node_status *unsp;
516 	struct ucred   *cred;
517 	struct thread  *td;
518 	struct vnode   *ovp;
519 
520 	UNIONFS_INTERNAL_DEBUG("unionfs_close: enter\n");
521 
522 	locked = 0;
523 	unp = VTOUNIONFS(ap->a_vp);
524 	cred = ap->a_cred;
525 	td = ap->a_td;
526 
527 	if (VOP_ISLOCKED(ap->a_vp, td) != LK_EXCLUSIVE) {
528 		vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, td);
529 		locked = 1;
530 	}
531 	unionfs_get_node_status(unp, td, &unsp);
532 
533 	if (unsp->uns_lower_opencnt <= 0 && unsp->uns_upper_opencnt <= 0) {
534 #ifdef DIAGNOSTIC
535 		printf("unionfs_close: warning: open count is 0\n");
536 #endif
537 		if (unp->un_uppervp != NULLVP)
538 			ovp = unp->un_uppervp;
539 		else
540 			ovp = unp->un_lowervp;
541 	} else if (unsp->uns_upper_opencnt > 0)
542 		ovp = unp->un_uppervp;
543 	else
544 		ovp = unp->un_lowervp;
545 
546 	error = VOP_CLOSE(ovp, ap->a_fflag, cred, td);
547 
548 	if (error != 0)
549 		goto unionfs_close_abort;
550 
551 	ap->a_vp->v_object = ovp->v_object;
552 
553 	if (ovp == unp->un_uppervp) {
554 		unsp->uns_upper_opencnt--;
555 		if (unsp->uns_upper_opencnt == 0) {
556 			if (unsp->uns_node_flag & UNS_OPENL_4_READDIR) {
557 				VOP_CLOSE(unp->un_lowervp, FREAD, cred, td);
558 				unsp->uns_node_flag &= ~UNS_OPENL_4_READDIR;
559 				unsp->uns_lower_opencnt--;
560 			}
561 			if (unsp->uns_lower_opencnt > 0)
562 				ap->a_vp->v_object = unp->un_lowervp->v_object;
563 		}
564 	} else
565 		unsp->uns_lower_opencnt--;
566 
567 unionfs_close_abort:
568 	unionfs_tryrem_node_status(unp, td, unsp);
569 
570 	if (locked != 0)
571 		VOP_UNLOCK(ap->a_vp, 0, td);
572 
573 	UNIONFS_INTERNAL_DEBUG("unionfs_close: leave (%d)\n", error);
574 
575 	return (error);
576 }
577 
578 /*
579  * Check the access mode toward shadow file/dir.
580  */
581 static int
582 unionfs_check_corrected_access(u_short mode,
583 			     struct vattr *va,
584 			     struct ucred *cred)
585 {
586 	int		count;
587 	uid_t		uid;	/* upper side vnode's uid */
588 	gid_t		gid;	/* upper side vnode's gid */
589 	u_short		vmode;	/* upper side vnode's mode */
590 	gid_t          *gp;
591 	u_short		mask;
592 
593 	mask = 0;
594 	uid = va->va_uid;
595 	gid = va->va_gid;
596 	vmode = va->va_mode;
597 
598 	/* check owner */
599 	if (cred->cr_uid == uid) {
600 		if (mode & VEXEC)
601 			mask |= S_IXUSR;
602 		if (mode & VREAD)
603 			mask |= S_IRUSR;
604 		if (mode & VWRITE)
605 			mask |= S_IWUSR;
606 		return ((vmode & mask) == mask ? 0 : EACCES);
607 	}
608 
609 	/* check group */
610 	count = 0;
611 	gp = cred->cr_groups;
612 	for (; count < cred->cr_ngroups; count++, gp++) {
613 		if (gid == *gp) {
614 			if (mode & VEXEC)
615 				mask |= S_IXGRP;
616 			if (mode & VREAD)
617 				mask |= S_IRGRP;
618 			if (mode & VWRITE)
619 				mask |= S_IWGRP;
620 			return ((vmode & mask) == mask ? 0 : EACCES);
621 		}
622 	}
623 
624 	/* check other */
625 	if (mode & VEXEC)
626 		mask |= S_IXOTH;
627 	if (mode & VREAD)
628 		mask |= S_IROTH;
629 	if (mode & VWRITE)
630 		mask |= S_IWOTH;
631 
632 	return ((vmode & mask) == mask ? 0 : EACCES);
633 }
634 
635 static int
636 unionfs_access(struct vop_access_args *ap)
637 {
638 	struct unionfs_mount *ump;
639 	struct unionfs_node *unp;
640 	struct vnode   *uvp;
641 	struct vnode   *lvp;
642 	struct thread  *td;
643 	struct vattr	va;
644 	int		mode;
645 	int		error;
646 
647 	UNIONFS_INTERNAL_DEBUG("unionfs_access: enter\n");
648 
649 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
650 	unp = VTOUNIONFS(ap->a_vp);
651 	uvp = unp->un_uppervp;
652 	lvp = unp->un_lowervp;
653 	td = ap->a_td;
654 	mode = ap->a_mode;
655 	error = EACCES;
656 
657 	if ((mode & VWRITE) &&
658 	    (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) {
659 		switch (ap->a_vp->v_type) {
660 		case VREG:
661 		case VDIR:
662 		case VLNK:
663 			return (EROFS);
664 		default:
665 			break;
666 		}
667 	}
668 
669 	if (uvp != NULLVP) {
670 		error = VOP_ACCESS(uvp, mode, ap->a_cred, td);
671 
672 		UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
673 
674 		return (error);
675 	}
676 
677 	if (lvp != NULLVP) {
678 		if (mode & VWRITE) {
679 			if (ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY) {
680 				switch (ap->a_vp->v_type) {
681 				case VREG:
682 				case VDIR:
683 				case VLNK:
684 					return (EROFS);
685 				default:
686 					break;
687 				}
688 			} else if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
689 				/* check shadow file/dir */
690 				if (ump->um_copymode != UNIONFS_TRANSPARENT) {
691 					error = unionfs_create_uppervattr(ump,
692 					    lvp, &va, ap->a_cred, td);
693 					if (error != 0)
694 						return (error);
695 
696 					error = unionfs_check_corrected_access(
697 					    mode, &va, ap->a_cred);
698 					if (error != 0)
699 						return (error);
700 				}
701 			}
702 			mode &= ~VWRITE;
703 			mode |= VREAD; /* will copy to upper */
704 		}
705 		error = VOP_ACCESS(lvp, mode, ap->a_cred, td);
706 	}
707 
708 	UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
709 
710 	return (error);
711 }
712 
713 static int
714 unionfs_getattr(struct vop_getattr_args *ap)
715 {
716 	int		error;
717 	struct unionfs_node *unp;
718 	struct unionfs_mount *ump;
719 	struct vnode   *uvp;
720 	struct vnode   *lvp;
721 	struct thread  *td;
722 	struct vattr	va;
723 
724 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: enter\n");
725 
726 	unp = VTOUNIONFS(ap->a_vp);
727 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
728 	uvp = unp->un_uppervp;
729 	lvp = unp->un_lowervp;
730 	td = ap->a_td;
731 
732 	if (uvp != NULLVP) {
733 		if ((error = VOP_GETATTR(uvp, ap->a_vap, ap->a_cred, td)) == 0)
734 			ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
735 
736 		UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
737 		    ap->a_vap->va_mode, ap->a_vap->va_uid,
738 		    ap->a_vap->va_gid, error);
739 
740 		return (error);
741 	}
742 
743 	error = VOP_GETATTR(lvp, ap->a_vap, ap->a_cred, td);
744 
745 	if (error == 0 && !(ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY)) {
746 		/* correct the attr toward shadow file/dir. */
747 		if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
748 			unionfs_create_uppervattr_core(ump, ap->a_vap, &va, td);
749 			ap->a_vap->va_mode = va.va_mode;
750 			ap->a_vap->va_uid = va.va_uid;
751 			ap->a_vap->va_gid = va.va_gid;
752 		}
753 	}
754 
755 	if (error == 0)
756 		ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
757 
758 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
759 	    ap->a_vap->va_mode, ap->a_vap->va_uid, ap->a_vap->va_gid, error);
760 
761 	return (error);
762 }
763 
764 static int
765 unionfs_setattr(struct vop_setattr_args *ap)
766 {
767 	int		error;
768 	struct unionfs_node *unp;
769 	struct vnode   *uvp;
770 	struct vnode   *lvp;
771 	struct thread  *td;
772 	struct vattr   *vap;
773 
774 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: enter\n");
775 
776 	error = EROFS;
777 	unp = VTOUNIONFS(ap->a_vp);
778 	uvp = unp->un_uppervp;
779 	lvp = unp->un_lowervp;
780 	td = ap->a_td;
781 	vap = ap->a_vap;
782 
783 	if ((ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) &&
784 	    (vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
785 	     vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
786 	     vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL))
787 		return (EROFS);
788 
789 	if (uvp == NULLVP && lvp->v_type == VREG) {
790 		error = unionfs_copyfile(unp, (vap->va_size != 0),
791 		    ap->a_cred, td);
792 		if (error != 0)
793 			return (error);
794 		uvp = unp->un_uppervp;
795 	}
796 
797 	if (uvp != NULLVP)
798 		error = VOP_SETATTR(uvp, vap, ap->a_cred, td);
799 
800 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: leave (%d)\n", error);
801 
802 	return (error);
803 }
804 
805 static int
806 unionfs_read(struct vop_read_args *ap)
807 {
808 	int		error;
809 	struct unionfs_node *unp;
810 	struct vnode   *tvp;
811 
812 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: enter\n"); */
813 
814 	unp = VTOUNIONFS(ap->a_vp);
815 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
816 
817 	error = VOP_READ(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
818 
819 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: leave (%d)\n", error); */
820 
821 	return (error);
822 }
823 
824 static int
825 unionfs_write(struct vop_write_args *ap)
826 {
827 	int		error;
828 	struct unionfs_node *unp;
829 	struct vnode   *tvp;
830 
831 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: enter\n"); */
832 
833 	unp = VTOUNIONFS(ap->a_vp);
834 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
835 
836 	error = VOP_WRITE(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
837 
838 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: leave (%d)\n", error); */
839 
840 	return (error);
841 }
842 
843 static int
844 unionfs_lease(struct vop_lease_args *ap)
845 {
846 	int error;
847 	struct unionfs_node *unp;
848 	struct vnode   *vp;
849 
850 	UNIONFS_INTERNAL_DEBUG("unionfs_lease: enter\n");
851 
852 	unp = VTOUNIONFS(ap->a_vp);
853 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
854 
855 	error = VOP_LEASE(vp, ap->a_td, ap->a_cred, ap->a_flag);
856 
857 	UNIONFS_INTERNAL_DEBUG("unionfs_lease: lease (%d)\n", error);
858 
859 	return (error);
860 }
861 
862 static int
863 unionfs_ioctl(struct vop_ioctl_args *ap)
864 {
865 	int error;
866 	struct unionfs_node *unp;
867 	struct unionfs_node_status *unsp;
868 	struct vnode   *ovp;
869 
870 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: enter\n");
871 
872  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, ap->a_td);
873 	unp = VTOUNIONFS(ap->a_vp);
874 	unionfs_get_node_status(unp, ap->a_td, &unsp);
875 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
876 	VOP_UNLOCK(ap->a_vp, 0, ap->a_td);
877 
878 	if (ovp == NULLVP)
879 		return (EBADF);
880 
881 	error = VOP_IOCTL(ovp, ap->a_command, ap->a_data, ap->a_fflag,
882 	    ap->a_cred, ap->a_td);
883 
884 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: lease (%d)\n", error);
885 
886 	return (error);
887 }
888 
889 static int
890 unionfs_poll(struct vop_poll_args *ap)
891 {
892 	struct unionfs_node *unp;
893 	struct unionfs_node_status *unsp;
894 	struct vnode   *ovp;
895 
896  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, ap->a_td);
897 	unp = VTOUNIONFS(ap->a_vp);
898 	unionfs_get_node_status(unp, ap->a_td, &unsp);
899 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
900 	VOP_UNLOCK(ap->a_vp, 0, ap->a_td);
901 
902 	if (ovp == NULLVP)
903 		return (EBADF);
904 
905 	return (VOP_POLL(ovp, ap->a_events, ap->a_cred, ap->a_td));
906 }
907 
908 static int
909 unionfs_fsync(struct vop_fsync_args *ap)
910 {
911 	struct unionfs_node *unp;
912 	struct unionfs_node_status *unsp;
913 	struct vnode   *ovp;
914 
915 	unp = VTOUNIONFS(ap->a_vp);
916 	unionfs_get_node_status(unp, ap->a_td, &unsp);
917 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
918 
919 	if (ovp == NULLVP)
920 		return (EBADF);
921 
922 	return (VOP_FSYNC(ovp, ap->a_waitfor, ap->a_td));
923 }
924 
925 static int
926 unionfs_remove(struct vop_remove_args *ap)
927 {
928 	int		error;
929 	struct unionfs_node *dunp;
930 	struct unionfs_node *unp;
931 	struct vnode   *udvp;
932 	struct vnode   *uvp;
933 	struct vnode   *lvp;
934 	struct componentname *cnp;
935 	struct thread  *td;
936 
937 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: enter\n");
938 
939 	error = 0;
940 	dunp = VTOUNIONFS(ap->a_dvp);
941 	unp = VTOUNIONFS(ap->a_vp);
942 	udvp = dunp->un_uppervp;
943 	uvp = unp->un_uppervp;
944 	lvp = unp->un_lowervp;
945 	cnp = ap->a_cnp;
946 	td = curthread;
947 
948 	if (udvp == NULLVP)
949 		return (EROFS);
950 
951 	if (uvp != NULLVP) {
952 		cnp->cn_flags |= DOWHITEOUT;
953 		error = VOP_REMOVE(udvp, uvp, cnp);
954 	} else if (lvp != NULLVP)
955 		error = unionfs_mkwhiteout(udvp, cnp, td, unp->un_path);
956 
957 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: leave (%d)\n", error);
958 
959 	return (error);
960 }
961 
962 static int
963 unionfs_link(struct vop_link_args *ap)
964 {
965 	int		error;
966 	int		needrelookup;
967 	struct unionfs_node *dunp;
968 	struct unionfs_node *unp;
969 	struct vnode   *udvp;
970 	struct vnode   *uvp;
971 	struct componentname *cnp;
972 	struct thread  *td;
973 
974 	UNIONFS_INTERNAL_DEBUG("unionfs_link: enter\n");
975 
976 	error = 0;
977 	needrelookup = 0;
978 	dunp = VTOUNIONFS(ap->a_tdvp);
979 	unp = NULL;
980 	udvp = dunp->un_uppervp;
981 	uvp = NULLVP;
982 	cnp = ap->a_cnp;
983 	td = curthread;
984 
985 	if (udvp == NULLVP)
986 		return (EROFS);
987 
988 	if (ap->a_vp->v_op != &unionfs_vnodeops)
989 		uvp = ap->a_vp;
990 	else {
991 		unp = VTOUNIONFS(ap->a_vp);
992 
993 		if (unp->un_uppervp == NULLVP) {
994 			if (ap->a_vp->v_type != VREG)
995 				return (EOPNOTSUPP);
996 
997 			error = unionfs_copyfile(unp, 1, cnp->cn_cred, td);
998 			if (error != 0)
999 				return (error);
1000 			needrelookup = 1;
1001 		}
1002 		uvp = unp->un_uppervp;
1003 	}
1004 
1005 	if (needrelookup != 0)
1006 		error = unionfs_relookup_for_create(ap->a_tdvp, cnp, td);
1007 
1008 	if (error == 0)
1009 		error = VOP_LINK(udvp, uvp, cnp);
1010 
1011 	UNIONFS_INTERNAL_DEBUG("unionfs_link: leave (%d)\n", error);
1012 
1013 	return (error);
1014 }
1015 
1016 static int
1017 unionfs_rename(struct vop_rename_args *ap)
1018 {
1019 	int		error;
1020 	struct vnode   *fdvp;
1021 	struct vnode   *fvp;
1022 	struct componentname *fcnp;
1023 	struct vnode   *tdvp;
1024 	struct vnode   *tvp;
1025 	struct componentname *tcnp;
1026 	struct vnode   *ltdvp;
1027 	struct vnode   *ltvp;
1028 	struct thread  *td;
1029 
1030 	/* rename target vnodes */
1031 	struct vnode   *rfdvp;
1032 	struct vnode   *rfvp;
1033 	struct vnode   *rtdvp;
1034 	struct vnode   *rtvp;
1035 
1036 	int		needrelookup;
1037 	struct unionfs_mount *ump;
1038 	struct unionfs_node *unp;
1039 
1040 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: enter\n");
1041 
1042 	error = 0;
1043 	fdvp = ap->a_fdvp;
1044 	fvp = ap->a_fvp;
1045 	fcnp = ap->a_fcnp;
1046 	tdvp = ap->a_tdvp;
1047 	tvp = ap->a_tvp;
1048 	tcnp = ap->a_tcnp;
1049 	ltdvp = NULLVP;
1050 	ltvp = NULLVP;
1051 	td = curthread;
1052 	rfdvp = fdvp;
1053 	rfvp = fvp;
1054 	rtdvp = tdvp;
1055 	rtvp = tvp;
1056 	needrelookup = 0;
1057 
1058 #ifdef DIAGNOSTIC
1059 	if (!(fcnp->cn_flags & HASBUF) || !(tcnp->cn_flags & HASBUF))
1060 		panic("unionfs_rename: no name");
1061 #endif
1062 
1063 	/* check for cross device rename */
1064 	if (fvp->v_mount != tdvp->v_mount ||
1065 	    (tvp != NULLVP && fvp->v_mount != tvp->v_mount)) {
1066 		error = EXDEV;
1067 		goto unionfs_rename_abort;
1068 	}
1069 
1070 	/* Renaming a file to itself has no effect. */
1071 	if (fvp == tvp)
1072 		goto unionfs_rename_abort;
1073 
1074 	/*
1075 	 * from/to vnode is unionfs node.
1076 	 */
1077 
1078 	unp = VTOUNIONFS(fdvp);
1079 #ifdef UNIONFS_IDBG_RENAME
1080 	UNIONFS_INTERNAL_DEBUG("fdvp=%p, ufdvp=%p, lfdvp=%p\n", fdvp, unp->un_uppervp, unp->un_lowervp);
1081 #endif
1082 	if (unp->un_uppervp == NULLVP) {
1083 		error = ENODEV;
1084 		goto unionfs_rename_abort;
1085 	}
1086 	rfdvp = unp->un_uppervp;
1087 	vref(rfdvp);
1088 
1089 	unp = VTOUNIONFS(fvp);
1090 #ifdef UNIONFS_IDBG_RENAME
1091 	UNIONFS_INTERNAL_DEBUG("fvp=%p, ufvp=%p, lfvp=%p\n", fvp, unp->un_uppervp, unp->un_lowervp);
1092 #endif
1093 	ump = MOUNTTOUNIONFSMOUNT(fvp->v_mount);
1094 	if (unp->un_uppervp == NULLVP) {
1095 		switch (fvp->v_type) {
1096 		case VREG:
1097 			if ((error = vn_lock(fvp, LK_EXCLUSIVE, td)) != 0)
1098 				goto unionfs_rename_abort;
1099 			error = unionfs_copyfile(unp, 1, fcnp->cn_cred, td);
1100 			VOP_UNLOCK(fvp, 0, td);
1101 			if (error != 0)
1102 				goto unionfs_rename_abort;
1103 			break;
1104 		case VDIR:
1105 			if ((error = vn_lock(fvp, LK_EXCLUSIVE, td)) != 0)
1106 				goto unionfs_rename_abort;
1107 			error = unionfs_mkshadowdir(ump, rfdvp, unp, fcnp, td);
1108 			VOP_UNLOCK(fvp, 0, td);
1109 			if (error != 0)
1110 				goto unionfs_rename_abort;
1111 			break;
1112 		default:
1113 			error = ENODEV;
1114 			goto unionfs_rename_abort;
1115 		}
1116 
1117 		needrelookup = 1;
1118 	}
1119 
1120 	if (unp->un_lowervp != NULLVP)
1121 		fcnp->cn_flags |= DOWHITEOUT;
1122 	rfvp = unp->un_uppervp;
1123 	vref(rfvp);
1124 
1125 	unp = VTOUNIONFS(tdvp);
1126 #ifdef UNIONFS_IDBG_RENAME
1127 	UNIONFS_INTERNAL_DEBUG("tdvp=%p, utdvp=%p, ltdvp=%p\n", tdvp, unp->un_uppervp, unp->un_lowervp);
1128 #endif
1129 	if (unp->un_uppervp == NULLVP) {
1130 		error = ENODEV;
1131 		goto unionfs_rename_abort;
1132 	}
1133 	rtdvp = unp->un_uppervp;
1134 	ltdvp = unp->un_lowervp;
1135 	vref(rtdvp);
1136 
1137 	if (tdvp == tvp) {
1138 		rtvp = rtdvp;
1139 		vref(rtvp);
1140 	} else if (tvp != NULLVP) {
1141 		unp = VTOUNIONFS(tvp);
1142 #ifdef UNIONFS_IDBG_RENAME
1143 		UNIONFS_INTERNAL_DEBUG("tvp=%p, utvp=%p, ltvp=%p\n", tvp, unp->un_uppervp, unp->un_lowervp);
1144 #endif
1145 		if (unp->un_uppervp == NULLVP)
1146 			rtvp = NULLVP;
1147 		else {
1148 			if (tvp->v_type == VDIR) {
1149 				error = EINVAL;
1150 				goto unionfs_rename_abort;
1151 			}
1152 			rtvp = unp->un_uppervp;
1153 			ltvp = unp->un_lowervp;
1154 			vref(rtvp);
1155 		}
1156 	}
1157 
1158 	if (needrelookup != 0) {
1159 		if ((error = vn_lock(fdvp, LK_EXCLUSIVE, td)) != 0)
1160 			goto unionfs_rename_abort;
1161 		error = unionfs_relookup_for_delete(fdvp, fcnp, td);
1162 		VOP_UNLOCK(fdvp, 0, td);
1163 		if (error != 0)
1164 			goto unionfs_rename_abort;
1165 
1166 		/* Locke of tvp is canceled in order to avoid recursive lock. */
1167 		if (tvp != NULLVP && tvp != tdvp)
1168 			VOP_UNLOCK(tvp, 0, td);
1169 		error = unionfs_relookup_for_rename(tdvp, tcnp, td);
1170 		if (tvp != NULLVP && tvp != tdvp)
1171 			vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY, td);
1172 		if (error != 0)
1173 			goto unionfs_rename_abort;
1174 	}
1175 
1176 	error = VOP_RENAME(rfdvp, rfvp, fcnp, rtdvp, rtvp, tcnp);
1177 
1178 	if (fdvp != rfdvp)
1179 		vrele(fdvp);
1180 	if (fvp != rfvp)
1181 		vrele(fvp);
1182 	if (tdvp != rtdvp)
1183 		vrele(tdvp);
1184 	if (tvp != rtvp && tvp != NULLVP) {
1185 		if (rtvp == NULLVP)
1186 			vput(tvp);
1187 		else
1188 			vrele(tvp);
1189 	}
1190 	if (ltdvp != NULLVP)
1191 		VOP_UNLOCK(ltdvp, 0, td);
1192 	if (ltvp != NULLVP)
1193 		VOP_UNLOCK(ltvp, 0, td);
1194 
1195 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1196 
1197 	return (error);
1198 
1199 unionfs_rename_abort:
1200 	if (fdvp != rfdvp)
1201 		vrele(rfdvp);
1202 	if (fvp != rfvp)
1203 		vrele(rfvp);
1204 	if (tdvp != rtdvp)
1205 		vrele(rtdvp);
1206 	vput(tdvp);
1207 	if (tvp != rtvp && rtvp != NULLVP)
1208 		vrele(rtvp);
1209 	if (tvp != NULLVP) {
1210 		if (tdvp != tvp)
1211 			vput(tvp);
1212 		else
1213 			vrele(tvp);
1214 	}
1215 	vrele(fdvp);
1216 	vrele(fvp);
1217 
1218 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1219 
1220 	return (error);
1221 }
1222 
1223 static int
1224 unionfs_mkdir(struct vop_mkdir_args *ap)
1225 {
1226 	int		error;
1227 	int		lkflags;
1228 	struct unionfs_node *dunp;
1229 	struct componentname *cnp;
1230 	struct thread  *td;
1231 	struct vnode   *udvp;
1232 	struct vnode   *uvp;
1233 	struct vattr	va;
1234 
1235 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: enter\n");
1236 
1237 	error = EROFS;
1238 	dunp = VTOUNIONFS(ap->a_dvp);
1239 	cnp = ap->a_cnp;
1240 	lkflags = cnp->cn_lkflags;
1241 	td = curthread;
1242 	udvp = dunp->un_uppervp;
1243 
1244 	if (udvp != NULLVP) {
1245 		/* check opaque */
1246 		if (!(cnp->cn_flags & ISWHITEOUT)) {
1247 			error = VOP_GETATTR(udvp, &va, cnp->cn_cred, td);
1248 			if (error != 0)
1249 				return (error);
1250 			if (va.va_flags & OPAQUE)
1251 				cnp->cn_flags |= ISWHITEOUT;
1252 		}
1253 
1254 		if ((error = VOP_MKDIR(udvp, &uvp, cnp, ap->a_vap)) == 0) {
1255 			VOP_UNLOCK(uvp, 0, td);
1256 			cnp->cn_lkflags = LK_EXCLUSIVE;
1257 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1258 			    ap->a_dvp, ap->a_vpp, cnp, td);
1259 			cnp->cn_lkflags = lkflags;
1260 			vrele(uvp);
1261 		}
1262 	}
1263 
1264 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: leave (%d)\n", error);
1265 
1266 	return (error);
1267 }
1268 
1269 static int
1270 unionfs_rmdir(struct vop_rmdir_args *ap)
1271 {
1272 	int		error;
1273 	struct unionfs_node *dunp;
1274 	struct unionfs_node *unp;
1275 	struct componentname *cnp;
1276 	struct thread  *td;
1277 	struct vnode   *udvp;
1278 	struct vnode   *uvp;
1279 	struct vnode   *lvp;
1280 
1281 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: enter\n");
1282 
1283 	error = 0;
1284 	dunp = VTOUNIONFS(ap->a_dvp);
1285 	unp = VTOUNIONFS(ap->a_vp);
1286 	cnp = ap->a_cnp;
1287 	td = curthread;
1288 	udvp = dunp->un_uppervp;
1289 	uvp = unp->un_uppervp;
1290 	lvp = unp->un_lowervp;
1291 
1292 	if (udvp == NULLVP)
1293 		return (EROFS);
1294 
1295 	if (udvp == uvp)
1296 		return (EOPNOTSUPP);
1297 
1298 	if (uvp != NULLVP) {
1299 		if (lvp != NULLVP) {
1300 			error = unionfs_check_rmdir(ap->a_vp, cnp->cn_cred, td);
1301 			if (error != 0)
1302 				return (error);
1303 		}
1304 		cnp->cn_flags |= DOWHITEOUT;
1305 		error = VOP_RMDIR(udvp, uvp, cnp);
1306 	}
1307 	else if (lvp != NULLVP)
1308 		error = unionfs_mkwhiteout(udvp, cnp, td, unp->un_path);
1309 
1310 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: leave (%d)\n", error);
1311 
1312 	return (error);
1313 }
1314 
1315 static int
1316 unionfs_symlink(struct vop_symlink_args *ap)
1317 {
1318 	int		error;
1319 	int		lkflags;
1320 	struct unionfs_node *dunp;
1321 	struct componentname *cnp;
1322 	struct thread  *td;
1323 	struct vnode   *udvp;
1324 	struct vnode   *uvp;
1325 
1326 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: enter\n");
1327 
1328 	error = EROFS;
1329 	dunp = VTOUNIONFS(ap->a_dvp);
1330 	cnp = ap->a_cnp;
1331 	lkflags = cnp->cn_lkflags;
1332 	td = curthread;
1333 	udvp = dunp->un_uppervp;
1334 
1335 	if (udvp != NULLVP) {
1336 		error = VOP_SYMLINK(udvp, &uvp, cnp, ap->a_vap, ap->a_target);
1337 		if (error == 0) {
1338 			VOP_UNLOCK(uvp, 0, td);
1339 			cnp->cn_lkflags = LK_EXCLUSIVE;
1340 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1341 			    ap->a_dvp, ap->a_vpp, cnp, td);
1342 			cnp->cn_lkflags = lkflags;
1343 			vrele(uvp);
1344 		}
1345 	}
1346 
1347 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: leave (%d)\n", error);
1348 
1349 	return (error);
1350 }
1351 
1352 static int
1353 unionfs_readdir(struct vop_readdir_args *ap)
1354 {
1355 	int		error;
1356 	int		eofflag;
1357 	int		locked;
1358 	struct unionfs_node *unp;
1359 	struct unionfs_node_status *unsp;
1360 	struct uio     *uio;
1361 	struct vnode   *uvp;
1362 	struct vnode   *lvp;
1363 	struct thread  *td;
1364 	struct vattr    va;
1365 
1366 	int		ncookies_bk;
1367 	u_long         *cookies_bk;
1368 
1369 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: enter\n");
1370 
1371 	error = 0;
1372 	eofflag = 0;
1373 	locked = 0;
1374 	unp = VTOUNIONFS(ap->a_vp);
1375 	uio = ap->a_uio;
1376 	uvp = unp->un_uppervp;
1377 	lvp = unp->un_lowervp;
1378 	td = uio->uio_td;
1379 	ncookies_bk = 0;
1380 	cookies_bk = NULL;
1381 
1382 	if (ap->a_vp->v_type != VDIR)
1383 		return (ENOTDIR);
1384 
1385 	/* check opaque */
1386 	if (uvp != NULLVP && lvp != NULLVP) {
1387 		if ((error = VOP_GETATTR(uvp, &va, ap->a_cred, td)) != 0)
1388 			return (error);
1389 		if (va.va_flags & OPAQUE)
1390 			lvp = NULLVP;
1391 	}
1392 
1393 	if (VOP_ISLOCKED(ap->a_vp, td) != LK_EXCLUSIVE) {
1394 		vn_lock(ap->a_vp, LK_UPGRADE | LK_RETRY, td);
1395 		locked = 1;
1396 	}
1397 	unionfs_get_node_status(unp, curthread, &unsp);
1398 	if (locked == 1)
1399 		vn_lock(ap->a_vp, LK_DOWNGRADE | LK_RETRY, td);
1400 
1401 	/* upper only */
1402 	if (uvp != NULLVP && lvp == NULLVP) {
1403 		if (unsp->uns_upper_opencnt <= 0)
1404 			error = EBADF;
1405 		else {
1406 			error = VOP_READDIR(uvp, uio, ap->a_cred, ap->a_eofflag,
1407 			    ap->a_ncookies, ap->a_cookies);
1408 			unsp->uns_readdir_status = 0;
1409 		}
1410 
1411 		goto unionfs_readdir_exit;
1412 	}
1413 
1414 	/* lower only */
1415 	if (uvp == NULLVP && lvp != NULLVP) {
1416 		if (unsp->uns_lower_opencnt <= 0)
1417 			error = EBADF;
1418 		else {
1419 			error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1420 			    ap->a_ncookies, ap->a_cookies);
1421 			unsp->uns_readdir_status = 2;
1422 		}
1423 
1424 		goto unionfs_readdir_exit;
1425 	}
1426 
1427 	/*
1428 	 * readdir upper and lower
1429 	 */
1430 	if (unsp->uns_lower_opencnt <= 0 || unsp->uns_upper_opencnt <= 0) {
1431 		error = EBADF;
1432 		goto unionfs_readdir_exit;
1433 	}
1434 
1435 	if (uio->uio_offset == 0)
1436 		unsp->uns_readdir_status = 0;
1437 
1438 	if (unsp->uns_readdir_status == 0) {
1439 		/* read upper */
1440 		error = VOP_READDIR(uvp, uio, ap->a_cred, &eofflag,
1441 				    ap->a_ncookies, ap->a_cookies);
1442 
1443 		if (error != 0 || eofflag == 0) {
1444 			UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1445 			return (error);
1446 		}
1447 		unsp->uns_readdir_status = 1;
1448 
1449 		/*
1450 		 * ufs(and other fs) needs size of uio_resid larger than
1451 		 * DIRBLKSIZ.
1452 		 * size of DIRBLKSIZ equals DEV_BSIZE.
1453 		 * (see: ufs/ufs/ufs_vnops.c ufs_readdir func , ufs/ufs/dir.h)
1454 		 */
1455 		if (uio->uio_resid <= (uio->uio_resid & (DEV_BSIZE -1))) {
1456 			UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1457 			return (0);
1458 		}
1459 
1460 		/*
1461 		 * backup cookies
1462 		 * It prepares to readdir in lower.
1463 		 */
1464 		if (ap->a_ncookies != NULL) {
1465 			ncookies_bk = *(ap->a_ncookies);
1466 			*(ap->a_ncookies) = 0;
1467 		}
1468 		if (ap->a_cookies != NULL) {
1469 			cookies_bk = *(ap->a_cookies);
1470 			*(ap->a_cookies) = NULL;
1471 		}
1472 	}
1473 
1474 	/* initialize for readdir in lower */
1475 	if (unsp->uns_readdir_status == 1) {
1476 		unsp->uns_readdir_status = 2;
1477 		uio->uio_offset = 0;
1478 	}
1479 
1480 	if (lvp == NULLVP) {
1481 		error = EBADF;
1482 		goto unionfs_readdir_exit;
1483 	}
1484 	/* read lower */
1485 	error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1486 			    ap->a_ncookies, ap->a_cookies);
1487 
1488 	if (cookies_bk != NULL) {
1489 		/* merge cookies */
1490 		int		size;
1491 		u_long         *newcookies, *pos;
1492 
1493 		size = *(ap->a_ncookies) + ncookies_bk;
1494 		newcookies = (u_long *) malloc(size * sizeof(u_long),
1495 		    M_TEMP, M_WAITOK);
1496 		pos = newcookies;
1497 
1498 		memcpy(pos, cookies_bk, ncookies_bk * sizeof(u_long));
1499 		pos += ncookies_bk * sizeof(u_long);
1500 		memcpy(pos, *(ap->a_cookies), *(ap->a_ncookies) * sizeof(u_long));
1501 		free(cookies_bk, M_TEMP);
1502 		free(*(ap->a_cookies), M_TEMP);
1503 		*(ap->a_ncookies) = size;
1504 		*(ap->a_cookies) = newcookies;
1505 	}
1506 
1507 unionfs_readdir_exit:
1508 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1509 
1510 	return (error);
1511 }
1512 
1513 static int
1514 unionfs_readlink(struct vop_readlink_args *ap)
1515 {
1516 	int error;
1517 	struct unionfs_node *unp;
1518 	struct vnode   *vp;
1519 
1520 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: enter\n");
1521 
1522 	unp = VTOUNIONFS(ap->a_vp);
1523 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1524 
1525 	error = VOP_READLINK(vp, ap->a_uio, ap->a_cred);
1526 
1527 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: leave (%d)\n", error);
1528 
1529 	return (error);
1530 }
1531 
1532 static int
1533 unionfs_getwritemount(struct vop_getwritemount_args *ap)
1534 {
1535 	int		error;
1536 	struct vnode   *uvp;
1537 	struct vnode   *vp;
1538 
1539 	UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: enter\n");
1540 
1541 	error = 0;
1542 	vp = ap->a_vp;
1543 
1544 	if (vp == NULLVP || (vp->v_mount->mnt_flag & MNT_RDONLY))
1545 		return (EACCES);
1546 
1547 	uvp = UNIONFSVPTOUPPERVP(vp);
1548 	if (uvp == NULLVP && VREG == vp->v_type)
1549 		uvp = UNIONFSVPTOUPPERVP(VTOUNIONFS(vp)->un_dvp);
1550 
1551 	if (uvp != NULLVP)
1552 		error = VOP_GETWRITEMOUNT(uvp, ap->a_mpp);
1553 	else {
1554 		VI_LOCK(vp);
1555 		if (vp->v_iflag & VI_FREE)
1556 			error = EOPNOTSUPP;
1557 		else
1558 			error = EACCES;
1559 		VI_UNLOCK(vp);
1560 	}
1561 
1562 	UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: leave (%d)\n", error);
1563 
1564 	return (error);
1565 }
1566 
1567 static int
1568 unionfs_inactive(struct vop_inactive_args *ap)
1569 {
1570 	struct unionfs_node *unp;
1571 
1572 	unp = VTOUNIONFS(ap->a_vp);
1573 
1574 	if (unp == NULL || !(unp->un_flag & UNIONFS_CACHED))
1575 		vgone(ap->a_vp);
1576 
1577 	return (0);
1578 }
1579 
1580 static int
1581 unionfs_reclaim(struct vop_reclaim_args *ap)
1582 {
1583 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: enter\n"); */
1584 
1585 	unionfs_hashrem(ap->a_vp, ap->a_td);
1586 
1587 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: leave\n"); */
1588 
1589 	return (0);
1590 }
1591 
1592 static int
1593 unionfs_print(struct vop_print_args *ap)
1594 {
1595 	struct unionfs_node *unp;
1596 	/* struct unionfs_node_status *unsp; */
1597 
1598 	unp = VTOUNIONFS(ap->a_vp);
1599 	/* unionfs_get_node_status(unp, curthread, &unsp); */
1600 
1601 	printf("unionfs_vp=%p, uppervp=%p, lowervp=%p\n",
1602 	    ap->a_vp, unp->un_uppervp, unp->un_lowervp);
1603 	/*
1604 	printf("unionfs opencnt: uppervp=%d, lowervp=%d\n",
1605 	    unsp->uns_upper_opencnt, unsp->uns_lower_opencnt);
1606 	*/
1607 
1608 	if (unp->un_uppervp != NULLVP)
1609 		vprint("unionfs: upper", unp->un_uppervp);
1610 	if (unp->un_lowervp != NULLVP)
1611 		vprint("unionfs: lower", unp->un_lowervp);
1612 
1613 	return (0);
1614 }
1615 
1616 static int
1617 unionfs_get_llt_revlock(int flags)
1618 {
1619 	int count;
1620 
1621 	flags &= LK_TYPE_MASK;
1622 	for (count = 0; un_llt[count].lock != 0; count++) {
1623 		if (flags == un_llt[count].lock) {
1624 			return un_llt[count].revlock;
1625 		}
1626 	}
1627 
1628 	return 0;
1629 }
1630 
1631 static int
1632 unionfs_lock(struct vop_lock1_args *ap)
1633 {
1634 	int		error;
1635 	int		flags;
1636 	int		revlock;
1637 	int		uhold;
1638 	struct unionfs_mount *ump;
1639 	struct unionfs_node *unp;
1640 	struct vnode   *vp;
1641 	struct vnode   *uvp;
1642 	struct vnode   *lvp;
1643 	struct thread  *td;
1644 
1645 	error = 0;
1646 	uhold = 0;
1647 	flags = ap->a_flags;
1648 	vp = ap->a_vp;
1649 	td = ap->a_td;
1650 
1651 	if (LK_RELEASE == (flags & LK_TYPE_MASK) || !(flags & LK_TYPE_MASK))
1652 		return (VOP_UNLOCK(vp, flags, td));
1653 
1654 	if ((revlock = unionfs_get_llt_revlock(flags)) == 0)
1655 		panic("unknown lock type: 0x%x", flags & LK_TYPE_MASK);
1656 
1657 	if (!(flags & LK_INTERLOCK))
1658 		VI_LOCK(vp);
1659 
1660 	ump = MOUNTTOUNIONFSMOUNT(vp->v_mount);
1661 	unp = VTOUNIONFS(vp);
1662 	if (NULL == unp)
1663 		goto unionfs_lock_null_vnode;
1664 	lvp = unp->un_lowervp;
1665 	uvp = unp->un_uppervp;
1666 
1667 	/*
1668 	 * Sometimes, lower or upper is already exclusive locked.
1669 	 * (ex. vfs_domount: mounted vnode is already locked.)
1670 	 */
1671 	if ((flags & LK_TYPE_MASK) == LK_EXCLUSIVE &&
1672 	    vp == ump->um_rootvp)
1673 		flags |= LK_CANRECURSE;
1674 
1675 	if (lvp != NULLVP) {
1676 		VI_LOCK_FLAGS(lvp, MTX_DUPOK);
1677 		flags |= LK_INTERLOCK;
1678 		vholdl(lvp);
1679 
1680 		VI_UNLOCK(vp);
1681 		ap->a_flags &= ~LK_INTERLOCK;
1682 
1683 		error = VOP_LOCK(lvp, flags, td);
1684 
1685 		VI_LOCK(vp);
1686 		unp = VTOUNIONFS(vp);
1687 		if (unp == NULL) {
1688 			if (error == 0)
1689 				VOP_UNLOCK(lvp, 0, td);
1690 			VI_UNLOCK(vp);
1691 			vdrop(lvp);
1692 			return (vop_stdlock(ap));
1693 		}
1694 	}
1695 
1696 	if (error == 0 && uvp != NULLVP) {
1697 		VI_LOCK_FLAGS(uvp, MTX_DUPOK);
1698 		flags |= LK_INTERLOCK;
1699 		vholdl(uvp);
1700 		uhold = 1;
1701 
1702 		VI_UNLOCK(vp);
1703 		ap->a_flags &= ~LK_INTERLOCK;
1704 
1705 		error = VOP_LOCK(uvp, flags, td);
1706 
1707 		VI_LOCK(vp);
1708 		unp = VTOUNIONFS(vp);
1709 		if (unp == NULL) {
1710 			if (error == 0) {
1711 				VOP_UNLOCK(uvp, 0, td);
1712 				if (lvp != NULLVP)
1713 					VOP_UNLOCK(lvp, 0, td);
1714 			}
1715 			VI_UNLOCK(vp);
1716 			if (lvp != NULLVP)
1717 				vdrop(lvp);
1718 			vdrop(uvp);
1719 			return (vop_stdlock(ap));
1720 		}
1721 
1722 		if (error != 0 && lvp != NULLVP)
1723 			vn_lock(lvp, revlock | LK_RETRY, td);
1724 	}
1725 
1726 	VI_UNLOCK(vp);
1727 	if (lvp != NULLVP)
1728 		vdrop(lvp);
1729 	if (uhold != 0)
1730 		vdrop(uvp);
1731 
1732 	return (error);
1733 
1734 unionfs_lock_null_vnode:
1735 	ap->a_flags |= LK_INTERLOCK;
1736 	return (vop_stdlock(ap));
1737 }
1738 
1739 static int
1740 unionfs_unlock(struct vop_unlock_args *ap)
1741 {
1742 	int		error;
1743 	int		flags;
1744 	int		mtxlkflag;
1745 	int		uhold;
1746 	struct vnode   *vp;
1747 	struct vnode   *lvp;
1748 	struct vnode   *uvp;
1749 	struct unionfs_node *unp;
1750 
1751 	error = 0;
1752 	mtxlkflag = 0;
1753 	uhold = 0;
1754 	flags = ap->a_flags | LK_RELEASE;
1755 	vp = ap->a_vp;
1756 
1757 	if (flags & LK_INTERLOCK)
1758 		mtxlkflag = 1;
1759 	else if (mtx_owned(VI_MTX(vp)) == 0) {
1760 		VI_LOCK(vp);
1761 		mtxlkflag = 2;
1762 	}
1763 
1764 	unp = VTOUNIONFS(vp);
1765 	if (unp == NULL)
1766 		goto unionfs_unlock_null_vnode;
1767 	lvp = unp->un_lowervp;
1768 	uvp = unp->un_uppervp;
1769 
1770 	if (lvp != NULLVP) {
1771 		VI_LOCK_FLAGS(lvp, MTX_DUPOK);
1772 		flags |= LK_INTERLOCK;
1773 		vholdl(lvp);
1774 
1775 		VI_UNLOCK(vp);
1776 		ap->a_flags &= ~LK_INTERLOCK;
1777 
1778 		error = VOP_UNLOCK(lvp, flags, ap->a_td);
1779 
1780 		VI_LOCK(vp);
1781 	}
1782 
1783 	if (error == 0 && uvp != NULLVP) {
1784 		VI_LOCK_FLAGS(uvp, MTX_DUPOK);
1785 		flags |= LK_INTERLOCK;
1786 		vholdl(uvp);
1787 		uhold = 1;
1788 
1789 		VI_UNLOCK(vp);
1790 		ap->a_flags &= ~LK_INTERLOCK;
1791 
1792 		error = VOP_UNLOCK(uvp, flags, ap->a_td);
1793 
1794 		VI_LOCK(vp);
1795 	}
1796 
1797 	VI_UNLOCK(vp);
1798 	if (lvp != NULLVP)
1799 		vdrop(lvp);
1800 	if (uhold != 0)
1801 		vdrop(uvp);
1802 	if (mtxlkflag == 0)
1803 		VI_LOCK(vp);
1804 
1805 	return error;
1806 
1807 unionfs_unlock_null_vnode:
1808 	if (mtxlkflag == 2)
1809 		VI_UNLOCK(vp);
1810 	return (vop_stdunlock(ap));
1811 }
1812 
1813 static int
1814 unionfs_pathconf(struct vop_pathconf_args *ap)
1815 {
1816 	struct unionfs_node *unp;
1817 	struct vnode   *vp;
1818 
1819 	unp = VTOUNIONFS(ap->a_vp);
1820 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1821 
1822 	return (VOP_PATHCONF(vp, ap->a_name, ap->a_retval));
1823 }
1824 
1825 static int
1826 unionfs_advlock(struct vop_advlock_args *ap)
1827 {
1828 	int error;
1829 	struct unionfs_node *unp;
1830 	struct unionfs_node_status *unsp;
1831 	struct vnode   *vp;
1832 	struct vnode   *uvp;
1833 	struct thread  *td;
1834 
1835 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: enter\n");
1836 
1837 	vp = ap->a_vp;
1838 	td = curthread;
1839 
1840 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1841 
1842 	unp = VTOUNIONFS(ap->a_vp);
1843 	uvp = unp->un_uppervp;
1844 
1845 	if (uvp == NULLVP) {
1846 		error = unionfs_copyfile(unp, 1, td->td_ucred, td);
1847 		if (error != 0)
1848 			goto unionfs_advlock_abort;
1849 		uvp = unp->un_uppervp;
1850 
1851 		unionfs_get_node_status(unp, td, &unsp);
1852 		if (unsp->uns_lower_opencnt > 0) {
1853 			/* try reopen the vnode */
1854 			error = VOP_OPEN(uvp, unsp->uns_lower_openmode,
1855 				td->td_ucred, td, NULL);
1856 			if (error)
1857 				goto unionfs_advlock_abort;
1858 			unsp->uns_upper_opencnt++;
1859 			VOP_CLOSE(unp->un_lowervp, unsp->uns_lower_openmode, td->td_ucred, td);
1860 			unsp->uns_lower_opencnt--;
1861 		}
1862 	}
1863 
1864 	VOP_UNLOCK(vp, 0, td);
1865 
1866 	error = VOP_ADVLOCK(uvp, ap->a_id, ap->a_op, ap->a_fl, ap->a_flags);
1867 
1868 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
1869 
1870 	return error;
1871 
1872 unionfs_advlock_abort:
1873 	VOP_UNLOCK(vp, 0, td);
1874 
1875 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
1876 
1877 	return error;
1878 }
1879 
1880 static int
1881 unionfs_strategy(struct vop_strategy_args *ap)
1882 {
1883 	struct unionfs_node *unp;
1884 	struct vnode   *vp;
1885 
1886 	unp = VTOUNIONFS(ap->a_vp);
1887 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1888 
1889 #ifdef DIAGNOSTIC
1890 	if (vp == NULLVP)
1891 		panic("unionfs_strategy: nullvp");
1892 
1893 	if (ap->a_bp->b_iocmd == BIO_WRITE && vp == unp->un_lowervp)
1894 		panic("unionfs_strategy: writing to lowervp");
1895 #endif
1896 
1897 	return (VOP_STRATEGY(vp, ap->a_bp));
1898 }
1899 
1900 static int
1901 unionfs_getacl(struct vop_getacl_args *ap)
1902 {
1903 	int		error;
1904 	struct unionfs_node *unp;
1905 	struct vnode   *vp;
1906 
1907 	unp = VTOUNIONFS(ap->a_vp);
1908 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1909 
1910 	UNIONFS_INTERNAL_DEBUG("unionfs_getacl: enter\n");
1911 
1912 	error = VOP_GETACL(vp, ap->a_type, ap->a_aclp, ap->a_cred, ap->a_td);
1913 
1914 	UNIONFS_INTERNAL_DEBUG("unionfs_getacl: leave (%d)\n", error);
1915 
1916 	return (error);
1917 }
1918 
1919 static int
1920 unionfs_setacl(struct vop_setacl_args *ap)
1921 {
1922 	int		error;
1923 	struct unionfs_node *unp;
1924 	struct vnode   *uvp;
1925 	struct vnode   *lvp;
1926 	struct thread  *td;
1927 
1928 	UNIONFS_INTERNAL_DEBUG("unionfs_setacl: enter\n");
1929 
1930 	error = EROFS;
1931 	unp = VTOUNIONFS(ap->a_vp);
1932 	uvp = unp->un_uppervp;
1933 	lvp = unp->un_lowervp;
1934 	td = ap->a_td;
1935 
1936 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
1937 		return (EROFS);
1938 
1939 	if (uvp == NULLVP && lvp->v_type == VREG) {
1940 		if ((error = unionfs_copyfile(unp, 1, ap->a_cred, td)) != 0)
1941 			return (error);
1942 		uvp = unp->un_uppervp;
1943 	}
1944 
1945 	if (uvp != NULLVP)
1946 		error = VOP_SETACL(uvp, ap->a_type, ap->a_aclp, ap->a_cred, td);
1947 
1948 	UNIONFS_INTERNAL_DEBUG("unionfs_setacl: leave (%d)\n", error);
1949 
1950 	return (error);
1951 }
1952 
1953 static int
1954 unionfs_aclcheck(struct vop_aclcheck_args *ap)
1955 {
1956 	int		error;
1957 	struct unionfs_node *unp;
1958 	struct vnode   *vp;
1959 
1960 	UNIONFS_INTERNAL_DEBUG("unionfs_aclcheck: enter\n");
1961 
1962 	unp = VTOUNIONFS(ap->a_vp);
1963 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1964 
1965 	error = VOP_ACLCHECK(vp, ap->a_type, ap->a_aclp, ap->a_cred, ap->a_td);
1966 
1967 	UNIONFS_INTERNAL_DEBUG("unionfs_aclcheck: leave (%d)\n", error);
1968 
1969 	return (error);
1970 }
1971 
1972 static int
1973 unionfs_openextattr(struct vop_openextattr_args *ap)
1974 {
1975 	int		error;
1976 	struct unionfs_node *unp;
1977 	struct vnode   *vp;
1978 
1979 	unp = VTOUNIONFS(ap->a_vp);
1980 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1981 
1982 	if ((vp == unp->un_uppervp && (unp->un_flag & UNIONFS_OPENEXTU)) ||
1983 	    (vp == unp->un_lowervp && (unp->un_flag & UNIONFS_OPENEXTL)))
1984 		return (EBUSY);
1985 
1986 	error = VOP_OPENEXTATTR(vp, ap->a_cred, ap->a_td);
1987 
1988 	if (error == 0) {
1989 		if (vp == unp->un_uppervp)
1990 			unp->un_flag |= UNIONFS_OPENEXTU;
1991 		else
1992 			unp->un_flag |= UNIONFS_OPENEXTL;
1993 	}
1994 
1995 	return (error);
1996 }
1997 
1998 static int
1999 unionfs_closeextattr(struct vop_closeextattr_args *ap)
2000 {
2001 	int		error;
2002 	struct unionfs_node *unp;
2003 	struct vnode   *vp;
2004 
2005 	unp = VTOUNIONFS(ap->a_vp);
2006 	vp = NULLVP;
2007 
2008 	if (unp->un_flag & UNIONFS_OPENEXTU)
2009 		vp = unp->un_uppervp;
2010 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2011 		vp = unp->un_lowervp;
2012 
2013 	if (vp == NULLVP)
2014 		return (EOPNOTSUPP);
2015 
2016 	error = VOP_CLOSEEXTATTR(vp, ap->a_commit, ap->a_cred, ap->a_td);
2017 
2018 	if (error == 0) {
2019 		if (vp == unp->un_uppervp)
2020 			unp->un_flag &= ~UNIONFS_OPENEXTU;
2021 		else
2022 			unp->un_flag &= ~UNIONFS_OPENEXTL;
2023 	}
2024 
2025 	return (error);
2026 }
2027 
2028 static int
2029 unionfs_getextattr(struct vop_getextattr_args *ap)
2030 {
2031 	struct unionfs_node *unp;
2032 	struct vnode   *vp;
2033 
2034 	unp = VTOUNIONFS(ap->a_vp);
2035 	vp = NULLVP;
2036 
2037 	if (unp->un_flag & UNIONFS_OPENEXTU)
2038 		vp = unp->un_uppervp;
2039 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2040 		vp = unp->un_lowervp;
2041 
2042 	if (vp == NULLVP)
2043 		return (EOPNOTSUPP);
2044 
2045 	return (VOP_GETEXTATTR(vp, ap->a_attrnamespace, ap->a_name,
2046 	    ap->a_uio, ap->a_size, ap->a_cred, ap->a_td));
2047 }
2048 
2049 static int
2050 unionfs_setextattr(struct vop_setextattr_args *ap)
2051 {
2052 	int		error;
2053 	struct unionfs_node *unp;
2054 	struct vnode   *uvp;
2055 	struct vnode   *lvp;
2056 	struct vnode   *ovp;
2057 	struct ucred   *cred;
2058 	struct thread  *td;
2059 
2060 	error = EROFS;
2061 	unp = VTOUNIONFS(ap->a_vp);
2062 	uvp = unp->un_uppervp;
2063 	lvp = unp->un_lowervp;
2064 	ovp = NULLVP;
2065 	cred = ap->a_cred;
2066 	td = ap->a_td;
2067 
2068 	UNIONFS_INTERNAL_DEBUG("unionfs_setextattr: enter (un_flag=%x)\n", unp->un_flag);
2069 
2070 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2071 		return (EROFS);
2072 
2073 	if (unp->un_flag & UNIONFS_OPENEXTU)
2074 		ovp = unp->un_uppervp;
2075 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2076 		ovp = unp->un_lowervp;
2077 
2078 	if (ovp == NULLVP)
2079 		return (EOPNOTSUPP);
2080 
2081 	if (ovp == lvp && lvp->v_type == VREG) {
2082 		VOP_CLOSEEXTATTR(lvp, 0, cred, td);
2083 		if (uvp == NULLVP &&
2084 		    (error = unionfs_copyfile(unp, 1, cred, td)) != 0) {
2085 unionfs_setextattr_reopen:
2086 			if ((unp->un_flag & UNIONFS_OPENEXTL) &&
2087 			    VOP_OPENEXTATTR(lvp, cred, td)) {
2088 #ifdef DIAGNOSTIC
2089 				panic("unionfs: VOP_OPENEXTATTR failed");
2090 #endif
2091 				unp->un_flag &= ~UNIONFS_OPENEXTL;
2092 			}
2093 			goto unionfs_setextattr_abort;
2094 		}
2095 		uvp = unp->un_uppervp;
2096 		if ((error = VOP_OPENEXTATTR(uvp, cred, td)) != 0)
2097 			goto unionfs_setextattr_reopen;
2098 		unp->un_flag &= ~UNIONFS_OPENEXTL;
2099 		unp->un_flag |= UNIONFS_OPENEXTU;
2100 		ovp = uvp;
2101 	}
2102 
2103 	if (ovp == uvp)
2104 		error = VOP_SETEXTATTR(ovp, ap->a_attrnamespace, ap->a_name,
2105 		    ap->a_uio, cred, td);
2106 
2107 unionfs_setextattr_abort:
2108 	UNIONFS_INTERNAL_DEBUG("unionfs_setextattr: leave (%d)\n", error);
2109 
2110 	return (error);
2111 }
2112 
2113 static int
2114 unionfs_listextattr(struct vop_listextattr_args *ap)
2115 {
2116 	struct unionfs_node *unp;
2117 	struct vnode   *vp;
2118 
2119 	unp = VTOUNIONFS(ap->a_vp);
2120 	vp = NULLVP;
2121 
2122 	if (unp->un_flag & UNIONFS_OPENEXTU)
2123 		vp = unp->un_uppervp;
2124 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2125 		vp = unp->un_lowervp;
2126 
2127 	if (vp == NULLVP)
2128 		return (EOPNOTSUPP);
2129 
2130 	return (VOP_LISTEXTATTR(vp, ap->a_attrnamespace, ap->a_uio,
2131 	    ap->a_size, ap->a_cred, ap->a_td));
2132 }
2133 
2134 static int
2135 unionfs_deleteextattr(struct vop_deleteextattr_args *ap)
2136 {
2137 	int		error;
2138 	struct unionfs_node *unp;
2139 	struct vnode   *uvp;
2140 	struct vnode   *lvp;
2141 	struct vnode   *ovp;
2142 	struct ucred   *cred;
2143 	struct thread  *td;
2144 
2145 	error = EROFS;
2146 	unp = VTOUNIONFS(ap->a_vp);
2147 	uvp = unp->un_uppervp;
2148 	lvp = unp->un_lowervp;
2149 	ovp = NULLVP;
2150 	cred = ap->a_cred;
2151 	td = ap->a_td;
2152 
2153 	UNIONFS_INTERNAL_DEBUG("unionfs_deleteextattr: enter (un_flag=%x)\n", unp->un_flag);
2154 
2155 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2156 		return (EROFS);
2157 
2158 	if (unp->un_flag & UNIONFS_OPENEXTU)
2159 		ovp = unp->un_uppervp;
2160 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2161 		ovp = unp->un_lowervp;
2162 
2163 	if (ovp == NULLVP)
2164 		return (EOPNOTSUPP);
2165 
2166 	if (ovp == lvp && lvp->v_type == VREG) {
2167 		VOP_CLOSEEXTATTR(lvp, 0, cred, td);
2168 		if (uvp == NULLVP &&
2169 		    (error = unionfs_copyfile(unp, 1, cred, td)) != 0) {
2170 unionfs_deleteextattr_reopen:
2171 			if ((unp->un_flag & UNIONFS_OPENEXTL) &&
2172 			    VOP_OPENEXTATTR(lvp, cred, td)) {
2173 #ifdef DIAGNOSTIC
2174 				panic("unionfs: VOP_OPENEXTATTR failed");
2175 #endif
2176 				unp->un_flag &= ~UNIONFS_OPENEXTL;
2177 			}
2178 			goto unionfs_deleteextattr_abort;
2179 		}
2180 		uvp = unp->un_uppervp;
2181 		if ((error = VOP_OPENEXTATTR(uvp, cred, td)) != 0)
2182 			goto unionfs_deleteextattr_reopen;
2183 		unp->un_flag &= ~UNIONFS_OPENEXTL;
2184 		unp->un_flag |= UNIONFS_OPENEXTU;
2185 		ovp = uvp;
2186 	}
2187 
2188 	if (ovp == uvp)
2189 		error = VOP_DELETEEXTATTR(ovp, ap->a_attrnamespace, ap->a_name,
2190 		    ap->a_cred, ap->a_td);
2191 
2192 unionfs_deleteextattr_abort:
2193 	UNIONFS_INTERNAL_DEBUG("unionfs_deleteextattr: leave (%d)\n", error);
2194 
2195 	return (error);
2196 }
2197 
2198 static int
2199 unionfs_setlabel(struct vop_setlabel_args *ap)
2200 {
2201 	int		error;
2202 	struct unionfs_node *unp;
2203 	struct vnode   *uvp;
2204 	struct vnode   *lvp;
2205 	struct thread  *td;
2206 
2207 	UNIONFS_INTERNAL_DEBUG("unionfs_setlabel: enter\n");
2208 
2209 	error = EROFS;
2210 	unp = VTOUNIONFS(ap->a_vp);
2211 	uvp = unp->un_uppervp;
2212 	lvp = unp->un_lowervp;
2213 	td = ap->a_td;
2214 
2215 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2216 		return (EROFS);
2217 
2218 	if (uvp == NULLVP && lvp->v_type == VREG) {
2219 		if ((error = unionfs_copyfile(unp, 1, ap->a_cred, td)) != 0)
2220 			return (error);
2221 		uvp = unp->un_uppervp;
2222 	}
2223 
2224 	if (uvp != NULLVP)
2225 		error = VOP_SETLABEL(uvp, ap->a_label, ap->a_cred, td);
2226 
2227 	UNIONFS_INTERNAL_DEBUG("unionfs_setlabel: leave (%d)\n", error);
2228 
2229 	return (error);
2230 }
2231 
2232 static int
2233 unionfs_vptofh(struct vop_vptofh_args *ap)
2234 {
2235 	return (EOPNOTSUPP);
2236 }
2237 
2238 struct vop_vector unionfs_vnodeops = {
2239 	.vop_default =		&default_vnodeops,
2240 
2241 	.vop_access =		unionfs_access,
2242 	.vop_aclcheck =		unionfs_aclcheck,
2243 	.vop_advlock =		unionfs_advlock,
2244 	.vop_bmap =		VOP_EOPNOTSUPP,
2245 	.vop_close =		unionfs_close,
2246 	.vop_closeextattr =	unionfs_closeextattr,
2247 	.vop_create =		unionfs_create,
2248 	.vop_deleteextattr =	unionfs_deleteextattr,
2249 	.vop_fsync =		unionfs_fsync,
2250 	.vop_getacl =		unionfs_getacl,
2251 	.vop_getattr =		unionfs_getattr,
2252 	.vop_getextattr =	unionfs_getextattr,
2253 	.vop_getwritemount =	unionfs_getwritemount,
2254 	.vop_inactive =		unionfs_inactive,
2255 	.vop_ioctl =		unionfs_ioctl,
2256 	.vop_lease =		unionfs_lease,
2257 	.vop_link =		unionfs_link,
2258 	.vop_listextattr =	unionfs_listextattr,
2259 	.vop_lock1 =		unionfs_lock,
2260 	.vop_lookup =		unionfs_lookup,
2261 	.vop_mkdir =		unionfs_mkdir,
2262 	.vop_mknod =		unionfs_mknod,
2263 	.vop_open =		unionfs_open,
2264 	.vop_openextattr =	unionfs_openextattr,
2265 	.vop_pathconf =		unionfs_pathconf,
2266 	.vop_poll =		unionfs_poll,
2267 	.vop_print =		unionfs_print,
2268 	.vop_read =		unionfs_read,
2269 	.vop_readdir =		unionfs_readdir,
2270 	.vop_readlink =		unionfs_readlink,
2271 	.vop_reclaim =		unionfs_reclaim,
2272 	.vop_remove =		unionfs_remove,
2273 	.vop_rename =		unionfs_rename,
2274 	.vop_rmdir =		unionfs_rmdir,
2275 	.vop_setacl =		unionfs_setacl,
2276 	.vop_setattr =		unionfs_setattr,
2277 	.vop_setextattr =	unionfs_setextattr,
2278 	.vop_setlabel =		unionfs_setlabel,
2279 	.vop_strategy =		unionfs_strategy,
2280 	.vop_symlink =		unionfs_symlink,
2281 	.vop_unlock =		unionfs_unlock,
2282 	.vop_whiteout =		unionfs_whiteout,
2283 	.vop_write =		unionfs_write,
2284 	.vop_vptofh =		unionfs_vptofh,
2285 };
2286