xref: /freebsd/sys/fs/unionfs/union_vnops.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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_DOWNGRADE, LK_UPGRADE},
85 	{0, 0}
86 };
87 
88 
89 static int
90 unionfs_lookup(struct vop_cachedlookup_args *ap)
91 {
92 	int		iswhiteout;
93 	int		lockflag;
94 	int		error , uerror, lerror;
95 	u_long		nameiop;
96 	u_long		cnflags, cnflagsbk;
97 	struct unionfs_node *dunp;
98 	struct vnode   *dvp, *udvp, *ldvp, *vp, *uvp, *lvp, *dtmpvp;
99 	struct vattr	va;
100 	struct componentname *cnp;
101 	struct thread  *td;
102 
103 	iswhiteout = 0;
104 	lockflag = 0;
105 	error = uerror = lerror = ENOENT;
106 	cnp = ap->a_cnp;
107 	nameiop = cnp->cn_nameiop;
108 	cnflags = cnp->cn_flags;
109 	dvp = ap->a_dvp;
110 	dunp = VTOUNIONFS(dvp);
111 	udvp = dunp->un_uppervp;
112 	ldvp = dunp->un_lowervp;
113 	vp = uvp = lvp = NULLVP;
114 	td = curthread;
115 	*(ap->a_vpp) = NULLVP;
116 
117 	UNIONFS_INTERNAL_DEBUG("unionfs_lookup: enter: nameiop=%ld, flags=%lx, path=%s\n", nameiop, cnflags, cnp->cn_nameptr);
118 
119 	if (dvp->v_type != VDIR)
120 		return (ENOTDIR);
121 
122 	/*
123 	 * If read-only and op is not LOOKUP, will return EROFS.
124 	 */
125 	if ((cnflags & ISLASTCN) &&
126 	    (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
127 	    LOOKUP != nameiop)
128 		return (EROFS);
129 
130 	/*
131 	 * lookup dotdot
132 	 */
133 	if (cnflags & ISDOTDOT) {
134 		if (LOOKUP != nameiop && udvp == NULLVP)
135 			return (EROFS);
136 
137 		if (udvp != NULLVP) {
138 			dtmpvp = udvp;
139 			if (ldvp != NULLVP)
140 				VOP_UNLOCK(ldvp, 0);
141 		}
142 		else
143 			dtmpvp = ldvp;
144 
145 		error = VOP_LOOKUP(dtmpvp, &vp, cnp);
146 
147 		if (dtmpvp == udvp && ldvp != NULLVP) {
148 			VOP_UNLOCK(udvp, 0);
149 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
150 		}
151 
152 		if (error == 0) {
153 			/*
154 			 * Exchange lock and reference from vp to
155 			 * dunp->un_dvp. vp is upper/lower vnode, but it
156 			 * will need to return the unionfs vnode.
157 			 */
158 			if (nameiop == DELETE  || nameiop == RENAME ||
159 			    (cnp->cn_lkflags & LK_TYPE_MASK))
160 				VOP_UNLOCK(vp, 0);
161 			vrele(vp);
162 
163 			VOP_UNLOCK(dvp, 0);
164 			*(ap->a_vpp) = dunp->un_dvp;
165 			vref(dunp->un_dvp);
166 
167 			if (nameiop == DELETE || nameiop == RENAME)
168 				vn_lock(dunp->un_dvp, LK_EXCLUSIVE | LK_RETRY);
169 			else if (cnp->cn_lkflags & LK_TYPE_MASK)
170 				vn_lock(dunp->un_dvp, cnp->cn_lkflags |
171 				    LK_RETRY);
172 
173 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
174 		} else if (error == ENOENT && (cnflags & MAKEENTRY) &&
175 		    nameiop != CREATE)
176 			cache_enter(dvp, NULLVP, cnp);
177 
178 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
179 
180 		return (error);
181 	}
182 
183 	/*
184 	 * lookup upper layer
185 	 */
186 	if (udvp != NULLVP) {
187 		uerror = VOP_LOOKUP(udvp, &uvp, cnp);
188 
189 		if (uerror == 0) {
190 			if (udvp == uvp) {	/* is dot */
191 				vrele(uvp);
192 				*(ap->a_vpp) = dvp;
193 				vref(dvp);
194 
195 				UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", uerror);
196 
197 				return (uerror);
198 			}
199 			if (nameiop == DELETE || nameiop == RENAME ||
200 			    (cnp->cn_lkflags & LK_TYPE_MASK))
201 				VOP_UNLOCK(uvp, 0);
202 		}
203 
204 		/* check whiteout */
205 		if (uerror == ENOENT || uerror == EJUSTRETURN)
206 			if (cnp->cn_flags & ISWHITEOUT)
207 				iswhiteout = 1;	/* don't lookup lower */
208 		if (iswhiteout == 0 && ldvp != NULLVP)
209 			if (VOP_GETATTR(udvp, &va, cnp->cn_cred, td) == 0 &&
210 			    (va.va_flags & OPAQUE))
211 				iswhiteout = 1;	/* don't lookup lower */
212 #if 0
213 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: debug: whiteout=%d, path=%s\n", iswhiteout, cnp->cn_nameptr);
214 #endif
215 	}
216 
217 	/*
218 	 * lookup lower layer
219 	 */
220 	if (ldvp != NULLVP && !(cnflags & DOWHITEOUT) && iswhiteout == 0) {
221 		/* always op is LOOKUP */
222 		cnp->cn_nameiop = LOOKUP;
223 		cnflagsbk = cnp->cn_flags;
224 		cnp->cn_flags = cnflags;
225 
226 		lerror = VOP_LOOKUP(ldvp, &lvp, cnp);
227 
228 		cnp->cn_nameiop = nameiop;
229 		if (udvp != NULLVP && (uerror == 0 || uerror == EJUSTRETURN))
230 			cnp->cn_flags = cnflagsbk;
231 
232 		if (lerror == 0) {
233 			if (ldvp == lvp) {	/* is dot */
234 				if (uvp != NULLVP)
235 					vrele(uvp);	/* no need? */
236 				vrele(lvp);
237 				*(ap->a_vpp) = dvp;
238 				vref(dvp);
239 
240 				UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", lerror);
241 
242 				return (lerror);
243 			}
244 			if (cnp->cn_lkflags & LK_TYPE_MASK)
245 				VOP_UNLOCK(lvp, 0);
246 		}
247 	}
248 
249 	/*
250 	 * check lookup result
251 	 */
252 	if (uvp == NULLVP && lvp == NULLVP) {
253 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n",
254 		    (udvp != NULLVP ? uerror : lerror));
255 		return (udvp != NULLVP ? uerror : lerror);
256 	}
257 
258 	/*
259 	 * check vnode type
260 	 */
261 	if (uvp != NULLVP && lvp != NULLVP && uvp->v_type != lvp->v_type) {
262 		vrele(lvp);
263 		lvp = NULLVP;
264 	}
265 
266 	/*
267 	 * check shadow dir
268 	 */
269 	if (uerror != 0 && uerror != EJUSTRETURN && udvp != NULLVP &&
270 	    lerror == 0 && lvp != NULLVP && lvp->v_type == VDIR &&
271 	    !(dvp->v_mount->mnt_flag & MNT_RDONLY) &&
272 	    (1 < cnp->cn_namelen || '.' != *(cnp->cn_nameptr))) {
273 		/* get unionfs vnode in order to create a new shadow dir. */
274 		error = unionfs_nodeget(dvp->v_mount, NULLVP, lvp, dvp, &vp,
275 		    cnp, td);
276 		if (error != 0)
277 			goto unionfs_lookup_out;
278 
279 		if (LK_SHARED == (cnp->cn_lkflags & LK_TYPE_MASK))
280 			VOP_UNLOCK(vp, 0);
281 		if (LK_EXCLUSIVE != VOP_ISLOCKED(vp)) {
282 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
283 			lockflag = 1;
284 		}
285 		error = unionfs_mkshadowdir(MOUNTTOUNIONFSMOUNT(dvp->v_mount),
286 		    udvp, VTOUNIONFS(vp), cnp, td);
287 		if (lockflag != 0)
288 			VOP_UNLOCK(vp, 0);
289 		if (error != 0) {
290 			UNIONFSDEBUG("unionfs_lookup: Unable to create shadow dir.");
291 			if ((cnp->cn_lkflags & LK_TYPE_MASK) == LK_EXCLUSIVE)
292 				vput(vp);
293 			else
294 				vrele(vp);
295 			goto unionfs_lookup_out;
296 		}
297 		if ((cnp->cn_lkflags & LK_TYPE_MASK) == LK_SHARED)
298 			vn_lock(vp, LK_SHARED | LK_RETRY);
299 	}
300 	/*
301 	 * get unionfs vnode.
302 	 */
303 	else {
304 		if (uvp != NULLVP)
305 			error = uerror;
306 		else
307 			error = lerror;
308 		if (error != 0)
309 			goto unionfs_lookup_out;
310 		error = unionfs_nodeget(dvp->v_mount, uvp, lvp, dvp, &vp,
311 		    cnp, td);
312 		if (error != 0) {
313 			UNIONFSDEBUG("unionfs_lookup: Unable to create unionfs vnode.");
314 			goto unionfs_lookup_out;
315 		}
316 		if ((nameiop == DELETE || nameiop == RENAME) &&
317 		    (cnp->cn_lkflags & LK_TYPE_MASK) == 0)
318 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
319 	}
320 
321 	*(ap->a_vpp) = vp;
322 
323 	if (cnflags & MAKEENTRY)
324 		cache_enter(dvp, vp, cnp);
325 
326 unionfs_lookup_out:
327 	if (uvp != NULLVP)
328 		vrele(uvp);
329 	if (lvp != NULLVP)
330 		vrele(lvp);
331 
332 	if (error == ENOENT && (cnflags & MAKEENTRY) && nameiop != CREATE)
333 		cache_enter(dvp, NULLVP, cnp);
334 
335 	UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
336 
337 	return (error);
338 }
339 
340 static int
341 unionfs_create(struct vop_create_args *ap)
342 {
343 	struct unionfs_node *dunp;
344 	struct componentname *cnp;
345 	struct vnode   *udvp;
346 	struct vnode   *vp;
347 	int		error;
348 
349 	UNIONFS_INTERNAL_DEBUG("unionfs_create: enter\n");
350 
351 	dunp = VTOUNIONFS(ap->a_dvp);
352 	cnp = ap->a_cnp;
353 	udvp = dunp->un_uppervp;
354 	error = EROFS;
355 
356 	if (udvp != NULLVP) {
357 		if ((error = VOP_CREATE(udvp, &vp, cnp, ap->a_vap)) == 0) {
358 			VOP_UNLOCK(vp, 0);
359 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
360 			    ap->a_dvp, ap->a_vpp, cnp, curthread);
361 			vrele(vp);
362 		}
363 	}
364 
365 	UNIONFS_INTERNAL_DEBUG("unionfs_create: leave (%d)\n", error);
366 
367 	return (error);
368 }
369 
370 static int
371 unionfs_whiteout(struct vop_whiteout_args *ap)
372 {
373 	struct unionfs_node *dunp;
374 	struct componentname *cnp;
375 	struct vnode   *udvp;
376 	int		error;
377 
378 	UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: enter\n");
379 
380 	dunp = VTOUNIONFS(ap->a_dvp);
381 	cnp = ap->a_cnp;
382 	udvp = dunp->un_uppervp;
383 	error = EOPNOTSUPP;
384 
385 	if (udvp != NULLVP) {
386 		switch (ap->a_flags) {
387 		case CREATE:
388 		case DELETE:
389 		case LOOKUP:
390 			error = VOP_WHITEOUT(udvp, cnp, ap->a_flags);
391 			break;
392 		default:
393 			error = EINVAL;
394 			break;
395 		}
396 	}
397 
398 	UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: leave (%d)\n", error);
399 
400 	return (error);
401 }
402 
403 static int
404 unionfs_mknod(struct vop_mknod_args *ap)
405 {
406 	struct unionfs_node *dunp;
407 	struct componentname *cnp;
408 	struct vnode   *udvp;
409 	struct vnode   *vp;
410 	int		error;
411 
412 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: enter\n");
413 
414 	dunp = VTOUNIONFS(ap->a_dvp);
415 	cnp = ap->a_cnp;
416 	udvp = dunp->un_uppervp;
417 	error = EROFS;
418 
419 	if (udvp != NULLVP) {
420 		if ((error = VOP_MKNOD(udvp, &vp, cnp, ap->a_vap)) == 0) {
421 			VOP_UNLOCK(vp, 0);
422 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
423 			    ap->a_dvp, ap->a_vpp, cnp, curthread);
424 			vrele(vp);
425 		}
426 	}
427 
428 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: leave (%d)\n", error);
429 
430 	return (error);
431 }
432 
433 static int
434 unionfs_open(struct vop_open_args *ap)
435 {
436 	int		error;
437 	struct unionfs_node *unp;
438 	struct unionfs_node_status *unsp;
439 	struct vnode   *uvp;
440 	struct vnode   *lvp;
441 	struct vnode   *targetvp;
442 	struct ucred   *cred;
443 	struct thread  *td;
444 
445 	UNIONFS_INTERNAL_DEBUG("unionfs_open: enter\n");
446 
447 	error = 0;
448 	unp = VTOUNIONFS(ap->a_vp);
449 	uvp = unp->un_uppervp;
450 	lvp = unp->un_lowervp;
451 	targetvp = NULLVP;
452 	cred = ap->a_cred;
453 	td = ap->a_td;
454 
455 	unionfs_get_node_status(unp, td, &unsp);
456 
457 	if (unsp->uns_lower_opencnt > 0 || unsp->uns_upper_opencnt > 0) {
458 		/* vnode is already opend. */
459 		if (unsp->uns_upper_opencnt > 0)
460 			targetvp = uvp;
461 		else
462 			targetvp = lvp;
463 
464 		if (targetvp == lvp &&
465 		    (ap->a_mode & FWRITE) && lvp->v_type == VREG)
466 			targetvp = NULLVP;
467 	}
468 	if (targetvp == NULLVP) {
469 		if (uvp == NULLVP) {
470 			if ((ap->a_mode & FWRITE) && lvp->v_type == VREG) {
471 				error = unionfs_copyfile(unp,
472 				    !(ap->a_mode & O_TRUNC), cred, td);
473 				if (error != 0)
474 					goto unionfs_open_abort;
475 				targetvp = uvp = unp->un_uppervp;
476 			} else
477 				targetvp = lvp;
478 		} else
479 			targetvp = uvp;
480 	}
481 
482 	error = VOP_OPEN(targetvp, ap->a_mode, cred, td, ap->a_fp);
483 	if (error == 0) {
484 		if (targetvp == uvp) {
485 			if (uvp->v_type == VDIR && lvp != NULLVP &&
486 			    unsp->uns_lower_opencnt <= 0) {
487 				/* open lower for readdir */
488 				error = VOP_OPEN(lvp, FREAD, cred, td, NULL);
489 				if (error != 0) {
490 					VOP_CLOSE(uvp, ap->a_mode, cred, td);
491 					goto unionfs_open_abort;
492 				}
493 				unsp->uns_node_flag |= UNS_OPENL_4_READDIR;
494 				unsp->uns_lower_opencnt++;
495 			}
496 			unsp->uns_upper_opencnt++;
497 		} else {
498 			unsp->uns_lower_opencnt++;
499 			unsp->uns_lower_openmode = ap->a_mode;
500 		}
501 		ap->a_vp->v_object = targetvp->v_object;
502 	}
503 
504 unionfs_open_abort:
505 	if (error != 0)
506 		unionfs_tryrem_node_status(unp, td, unsp);
507 
508 	UNIONFS_INTERNAL_DEBUG("unionfs_open: leave (%d)\n", error);
509 
510 	return (error);
511 }
512 
513 static int
514 unionfs_close(struct vop_close_args *ap)
515 {
516 	int		error;
517 	int		locked;
518 	struct unionfs_node *unp;
519 	struct unionfs_node_status *unsp;
520 	struct ucred   *cred;
521 	struct thread  *td;
522 	struct vnode   *ovp;
523 
524 	UNIONFS_INTERNAL_DEBUG("unionfs_close: enter\n");
525 
526 	locked = 0;
527 	unp = VTOUNIONFS(ap->a_vp);
528 	cred = ap->a_cred;
529 	td = ap->a_td;
530 
531 	if (VOP_ISLOCKED(ap->a_vp) != LK_EXCLUSIVE) {
532 		vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
533 		locked = 1;
534 	}
535 	unionfs_get_node_status(unp, td, &unsp);
536 
537 	if (unsp->uns_lower_opencnt <= 0 && unsp->uns_upper_opencnt <= 0) {
538 #ifdef DIAGNOSTIC
539 		printf("unionfs_close: warning: open count is 0\n");
540 #endif
541 		if (unp->un_uppervp != NULLVP)
542 			ovp = unp->un_uppervp;
543 		else
544 			ovp = unp->un_lowervp;
545 	} else if (unsp->uns_upper_opencnt > 0)
546 		ovp = unp->un_uppervp;
547 	else
548 		ovp = unp->un_lowervp;
549 
550 	error = VOP_CLOSE(ovp, ap->a_fflag, cred, td);
551 
552 	if (error != 0)
553 		goto unionfs_close_abort;
554 
555 	ap->a_vp->v_object = ovp->v_object;
556 
557 	if (ovp == unp->un_uppervp) {
558 		unsp->uns_upper_opencnt--;
559 		if (unsp->uns_upper_opencnt == 0) {
560 			if (unsp->uns_node_flag & UNS_OPENL_4_READDIR) {
561 				VOP_CLOSE(unp->un_lowervp, FREAD, cred, td);
562 				unsp->uns_node_flag &= ~UNS_OPENL_4_READDIR;
563 				unsp->uns_lower_opencnt--;
564 			}
565 			if (unsp->uns_lower_opencnt > 0)
566 				ap->a_vp->v_object = unp->un_lowervp->v_object;
567 		}
568 	} else
569 		unsp->uns_lower_opencnt--;
570 
571 unionfs_close_abort:
572 	unionfs_tryrem_node_status(unp, td, unsp);
573 
574 	if (locked != 0)
575 		VOP_UNLOCK(ap->a_vp, 0);
576 
577 	UNIONFS_INTERNAL_DEBUG("unionfs_close: leave (%d)\n", error);
578 
579 	return (error);
580 }
581 
582 /*
583  * Check the access mode toward shadow file/dir.
584  */
585 static int
586 unionfs_check_corrected_access(u_short mode,
587 			     struct vattr *va,
588 			     struct ucred *cred)
589 {
590 	int		count;
591 	uid_t		uid;	/* upper side vnode's uid */
592 	gid_t		gid;	/* upper side vnode's gid */
593 	u_short		vmode;	/* upper side vnode's mode */
594 	gid_t          *gp;
595 	u_short		mask;
596 
597 	mask = 0;
598 	uid = va->va_uid;
599 	gid = va->va_gid;
600 	vmode = va->va_mode;
601 
602 	/* check owner */
603 	if (cred->cr_uid == uid) {
604 		if (mode & VEXEC)
605 			mask |= S_IXUSR;
606 		if (mode & VREAD)
607 			mask |= S_IRUSR;
608 		if (mode & VWRITE)
609 			mask |= S_IWUSR;
610 		return ((vmode & mask) == mask ? 0 : EACCES);
611 	}
612 
613 	/* check group */
614 	count = 0;
615 	gp = cred->cr_groups;
616 	for (; count < cred->cr_ngroups; count++, gp++) {
617 		if (gid == *gp) {
618 			if (mode & VEXEC)
619 				mask |= S_IXGRP;
620 			if (mode & VREAD)
621 				mask |= S_IRGRP;
622 			if (mode & VWRITE)
623 				mask |= S_IWGRP;
624 			return ((vmode & mask) == mask ? 0 : EACCES);
625 		}
626 	}
627 
628 	/* check other */
629 	if (mode & VEXEC)
630 		mask |= S_IXOTH;
631 	if (mode & VREAD)
632 		mask |= S_IROTH;
633 	if (mode & VWRITE)
634 		mask |= S_IWOTH;
635 
636 	return ((vmode & mask) == mask ? 0 : EACCES);
637 }
638 
639 static int
640 unionfs_access(struct vop_access_args *ap)
641 {
642 	struct unionfs_mount *ump;
643 	struct unionfs_node *unp;
644 	struct vnode   *uvp;
645 	struct vnode   *lvp;
646 	struct thread  *td;
647 	struct vattr	va;
648 	int		mode;
649 	int		error;
650 
651 	UNIONFS_INTERNAL_DEBUG("unionfs_access: enter\n");
652 
653 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
654 	unp = VTOUNIONFS(ap->a_vp);
655 	uvp = unp->un_uppervp;
656 	lvp = unp->un_lowervp;
657 	td = ap->a_td;
658 	mode = ap->a_mode;
659 	error = EACCES;
660 
661 	if ((mode & VWRITE) &&
662 	    (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) {
663 		switch (ap->a_vp->v_type) {
664 		case VREG:
665 		case VDIR:
666 		case VLNK:
667 			return (EROFS);
668 		default:
669 			break;
670 		}
671 	}
672 
673 	if (uvp != NULLVP) {
674 		error = VOP_ACCESS(uvp, mode, ap->a_cred, td);
675 
676 		UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
677 
678 		return (error);
679 	}
680 
681 	if (lvp != NULLVP) {
682 		if (mode & VWRITE) {
683 			if (ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY) {
684 				switch (ap->a_vp->v_type) {
685 				case VREG:
686 				case VDIR:
687 				case VLNK:
688 					return (EROFS);
689 				default:
690 					break;
691 				}
692 			} else if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
693 				/* check shadow file/dir */
694 				if (ump->um_copymode != UNIONFS_TRANSPARENT) {
695 					error = unionfs_create_uppervattr(ump,
696 					    lvp, &va, ap->a_cred, td);
697 					if (error != 0)
698 						return (error);
699 
700 					error = unionfs_check_corrected_access(
701 					    mode, &va, ap->a_cred);
702 					if (error != 0)
703 						return (error);
704 				}
705 			}
706 			mode &= ~VWRITE;
707 			mode |= VREAD; /* will copy to upper */
708 		}
709 		error = VOP_ACCESS(lvp, mode, ap->a_cred, td);
710 	}
711 
712 	UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
713 
714 	return (error);
715 }
716 
717 static int
718 unionfs_getattr(struct vop_getattr_args *ap)
719 {
720 	int		error;
721 	struct unionfs_node *unp;
722 	struct unionfs_mount *ump;
723 	struct vnode   *uvp;
724 	struct vnode   *lvp;
725 	struct thread  *td;
726 	struct vattr	va;
727 
728 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: enter\n");
729 
730 	unp = VTOUNIONFS(ap->a_vp);
731 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
732 	uvp = unp->un_uppervp;
733 	lvp = unp->un_lowervp;
734 	td = ap->a_td;
735 
736 	if (uvp != NULLVP) {
737 		if ((error = VOP_GETATTR(uvp, ap->a_vap, ap->a_cred, td)) == 0)
738 			ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
739 
740 		UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
741 		    ap->a_vap->va_mode, ap->a_vap->va_uid,
742 		    ap->a_vap->va_gid, error);
743 
744 		return (error);
745 	}
746 
747 	error = VOP_GETATTR(lvp, ap->a_vap, ap->a_cred, td);
748 
749 	if (error == 0 && !(ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY)) {
750 		/* correct the attr toward shadow file/dir. */
751 		if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
752 			unionfs_create_uppervattr_core(ump, ap->a_vap, &va, td);
753 			ap->a_vap->va_mode = va.va_mode;
754 			ap->a_vap->va_uid = va.va_uid;
755 			ap->a_vap->va_gid = va.va_gid;
756 		}
757 	}
758 
759 	if (error == 0)
760 		ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
761 
762 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
763 	    ap->a_vap->va_mode, ap->a_vap->va_uid, ap->a_vap->va_gid, error);
764 
765 	return (error);
766 }
767 
768 static int
769 unionfs_setattr(struct vop_setattr_args *ap)
770 {
771 	int		error;
772 	struct unionfs_node *unp;
773 	struct vnode   *uvp;
774 	struct vnode   *lvp;
775 	struct thread  *td;
776 	struct vattr   *vap;
777 
778 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: enter\n");
779 
780 	error = EROFS;
781 	unp = VTOUNIONFS(ap->a_vp);
782 	uvp = unp->un_uppervp;
783 	lvp = unp->un_lowervp;
784 	td = ap->a_td;
785 	vap = ap->a_vap;
786 
787 	if ((ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) &&
788 	    (vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
789 	     vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
790 	     vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL))
791 		return (EROFS);
792 
793 	if (uvp == NULLVP && lvp->v_type == VREG) {
794 		error = unionfs_copyfile(unp, (vap->va_size != 0),
795 		    ap->a_cred, td);
796 		if (error != 0)
797 			return (error);
798 		uvp = unp->un_uppervp;
799 	}
800 
801 	if (uvp != NULLVP)
802 		error = VOP_SETATTR(uvp, vap, ap->a_cred, td);
803 
804 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: leave (%d)\n", error);
805 
806 	return (error);
807 }
808 
809 static int
810 unionfs_read(struct vop_read_args *ap)
811 {
812 	int		error;
813 	struct unionfs_node *unp;
814 	struct vnode   *tvp;
815 
816 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: enter\n"); */
817 
818 	unp = VTOUNIONFS(ap->a_vp);
819 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
820 
821 	error = VOP_READ(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
822 
823 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: leave (%d)\n", error); */
824 
825 	return (error);
826 }
827 
828 static int
829 unionfs_write(struct vop_write_args *ap)
830 {
831 	int		error;
832 	struct unionfs_node *unp;
833 	struct vnode   *tvp;
834 
835 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: enter\n"); */
836 
837 	unp = VTOUNIONFS(ap->a_vp);
838 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
839 
840 	error = VOP_WRITE(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
841 
842 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: leave (%d)\n", error); */
843 
844 	return (error);
845 }
846 
847 static int
848 unionfs_lease(struct vop_lease_args *ap)
849 {
850 	int error;
851 	struct unionfs_node *unp;
852 	struct vnode   *vp;
853 
854 	UNIONFS_INTERNAL_DEBUG("unionfs_lease: enter\n");
855 
856 	unp = VTOUNIONFS(ap->a_vp);
857 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
858 
859 	error = VOP_LEASE(vp, ap->a_td, ap->a_cred, ap->a_flag);
860 
861 	UNIONFS_INTERNAL_DEBUG("unionfs_lease: lease (%d)\n", error);
862 
863 	return (error);
864 }
865 
866 static int
867 unionfs_ioctl(struct vop_ioctl_args *ap)
868 {
869 	int error;
870 	struct unionfs_node *unp;
871 	struct unionfs_node_status *unsp;
872 	struct vnode   *ovp;
873 
874 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: enter\n");
875 
876  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
877 	unp = VTOUNIONFS(ap->a_vp);
878 	unionfs_get_node_status(unp, ap->a_td, &unsp);
879 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
880 	unionfs_tryrem_node_status(unp, ap->a_td, unsp);
881 	VOP_UNLOCK(ap->a_vp, 0);
882 
883 	if (ovp == NULLVP)
884 		return (EBADF);
885 
886 	error = VOP_IOCTL(ovp, ap->a_command, ap->a_data, ap->a_fflag,
887 	    ap->a_cred, ap->a_td);
888 
889 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: lease (%d)\n", error);
890 
891 	return (error);
892 }
893 
894 static int
895 unionfs_poll(struct vop_poll_args *ap)
896 {
897 	struct unionfs_node *unp;
898 	struct unionfs_node_status *unsp;
899 	struct vnode   *ovp;
900 
901  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
902 	unp = VTOUNIONFS(ap->a_vp);
903 	unionfs_get_node_status(unp, ap->a_td, &unsp);
904 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
905 	unionfs_tryrem_node_status(unp, ap->a_td, unsp);
906 	VOP_UNLOCK(ap->a_vp, 0);
907 
908 	if (ovp == NULLVP)
909 		return (EBADF);
910 
911 	return (VOP_POLL(ovp, ap->a_events, ap->a_cred, ap->a_td));
912 }
913 
914 static int
915 unionfs_fsync(struct vop_fsync_args *ap)
916 {
917 	struct unionfs_node *unp;
918 	struct unionfs_node_status *unsp;
919 	struct vnode   *ovp;
920 
921 	unp = VTOUNIONFS(ap->a_vp);
922 	unionfs_get_node_status(unp, ap->a_td, &unsp);
923 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
924 	unionfs_tryrem_node_status(unp, ap->a_td, unsp);
925 
926 	if (ovp == NULLVP)
927 		return (EBADF);
928 
929 	return (VOP_FSYNC(ovp, ap->a_waitfor, ap->a_td));
930 }
931 
932 static int
933 unionfs_remove(struct vop_remove_args *ap)
934 {
935 	int		error;
936 	struct unionfs_node *dunp;
937 	struct unionfs_node *unp;
938 	struct unionfs_mount *ump;
939 	struct vnode   *udvp;
940 	struct vnode   *uvp;
941 	struct vnode   *lvp;
942 	struct componentname *cnp;
943 	struct thread  *td;
944 
945 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: enter\n");
946 
947 	error = 0;
948 	dunp = VTOUNIONFS(ap->a_dvp);
949 	unp = VTOUNIONFS(ap->a_vp);
950 	udvp = dunp->un_uppervp;
951 	uvp = unp->un_uppervp;
952 	lvp = unp->un_lowervp;
953 	cnp = ap->a_cnp;
954 	td = curthread;
955 
956 	if (udvp == NULLVP)
957 		return (EROFS);
958 
959 	if (uvp != NULLVP) {
960 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
961 		if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP)
962 			cnp->cn_flags |= DOWHITEOUT;
963 		error = VOP_REMOVE(udvp, uvp, cnp);
964 	} else if (lvp != NULLVP)
965 		error = unionfs_mkwhiteout(udvp, cnp, td, unp->un_path);
966 
967 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: leave (%d)\n", error);
968 
969 	return (error);
970 }
971 
972 static int
973 unionfs_link(struct vop_link_args *ap)
974 {
975 	int		error;
976 	int		needrelookup;
977 	struct unionfs_node *dunp;
978 	struct unionfs_node *unp;
979 	struct vnode   *udvp;
980 	struct vnode   *uvp;
981 	struct componentname *cnp;
982 	struct thread  *td;
983 
984 	UNIONFS_INTERNAL_DEBUG("unionfs_link: enter\n");
985 
986 	error = 0;
987 	needrelookup = 0;
988 	dunp = VTOUNIONFS(ap->a_tdvp);
989 	unp = NULL;
990 	udvp = dunp->un_uppervp;
991 	uvp = NULLVP;
992 	cnp = ap->a_cnp;
993 	td = curthread;
994 
995 	if (udvp == NULLVP)
996 		return (EROFS);
997 
998 	if (ap->a_vp->v_op != &unionfs_vnodeops)
999 		uvp = ap->a_vp;
1000 	else {
1001 		unp = VTOUNIONFS(ap->a_vp);
1002 
1003 		if (unp->un_uppervp == NULLVP) {
1004 			if (ap->a_vp->v_type != VREG)
1005 				return (EOPNOTSUPP);
1006 
1007 			error = unionfs_copyfile(unp, 1, cnp->cn_cred, td);
1008 			if (error != 0)
1009 				return (error);
1010 			needrelookup = 1;
1011 		}
1012 		uvp = unp->un_uppervp;
1013 	}
1014 
1015 	if (needrelookup != 0)
1016 		error = unionfs_relookup_for_create(ap->a_tdvp, cnp, td);
1017 
1018 	if (error == 0)
1019 		error = VOP_LINK(udvp, uvp, cnp);
1020 
1021 	UNIONFS_INTERNAL_DEBUG("unionfs_link: leave (%d)\n", error);
1022 
1023 	return (error);
1024 }
1025 
1026 static int
1027 unionfs_rename(struct vop_rename_args *ap)
1028 {
1029 	int		error;
1030 	struct vnode   *fdvp;
1031 	struct vnode   *fvp;
1032 	struct componentname *fcnp;
1033 	struct vnode   *tdvp;
1034 	struct vnode   *tvp;
1035 	struct componentname *tcnp;
1036 	struct vnode   *ltdvp;
1037 	struct vnode   *ltvp;
1038 	struct thread  *td;
1039 
1040 	/* rename target vnodes */
1041 	struct vnode   *rfdvp;
1042 	struct vnode   *rfvp;
1043 	struct vnode   *rtdvp;
1044 	struct vnode   *rtvp;
1045 
1046 	int		needrelookup;
1047 	struct unionfs_mount *ump;
1048 	struct unionfs_node *unp;
1049 
1050 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: enter\n");
1051 
1052 	error = 0;
1053 	fdvp = ap->a_fdvp;
1054 	fvp = ap->a_fvp;
1055 	fcnp = ap->a_fcnp;
1056 	tdvp = ap->a_tdvp;
1057 	tvp = ap->a_tvp;
1058 	tcnp = ap->a_tcnp;
1059 	ltdvp = NULLVP;
1060 	ltvp = NULLVP;
1061 	td = curthread;
1062 	rfdvp = fdvp;
1063 	rfvp = fvp;
1064 	rtdvp = tdvp;
1065 	rtvp = tvp;
1066 	needrelookup = 0;
1067 
1068 #ifdef DIAGNOSTIC
1069 	if (!(fcnp->cn_flags & HASBUF) || !(tcnp->cn_flags & HASBUF))
1070 		panic("unionfs_rename: no name");
1071 #endif
1072 
1073 	/* check for cross device rename */
1074 	if (fvp->v_mount != tdvp->v_mount ||
1075 	    (tvp != NULLVP && fvp->v_mount != tvp->v_mount)) {
1076 		error = EXDEV;
1077 		goto unionfs_rename_abort;
1078 	}
1079 
1080 	/* Renaming a file to itself has no effect. */
1081 	if (fvp == tvp)
1082 		goto unionfs_rename_abort;
1083 
1084 	/*
1085 	 * from/to vnode is unionfs node.
1086 	 */
1087 
1088 	unp = VTOUNIONFS(fdvp);
1089 #ifdef UNIONFS_IDBG_RENAME
1090 	UNIONFS_INTERNAL_DEBUG("fdvp=%p, ufdvp=%p, lfdvp=%p\n", fdvp, unp->un_uppervp, unp->un_lowervp);
1091 #endif
1092 	if (unp->un_uppervp == NULLVP) {
1093 		error = ENODEV;
1094 		goto unionfs_rename_abort;
1095 	}
1096 	rfdvp = unp->un_uppervp;
1097 	vref(rfdvp);
1098 
1099 	unp = VTOUNIONFS(fvp);
1100 #ifdef UNIONFS_IDBG_RENAME
1101 	UNIONFS_INTERNAL_DEBUG("fvp=%p, ufvp=%p, lfvp=%p\n", fvp, unp->un_uppervp, unp->un_lowervp);
1102 #endif
1103 	ump = MOUNTTOUNIONFSMOUNT(fvp->v_mount);
1104 	if (unp->un_uppervp == NULLVP) {
1105 		switch (fvp->v_type) {
1106 		case VREG:
1107 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1108 				goto unionfs_rename_abort;
1109 			error = unionfs_copyfile(unp, 1, fcnp->cn_cred, td);
1110 			VOP_UNLOCK(fvp, 0);
1111 			if (error != 0)
1112 				goto unionfs_rename_abort;
1113 			break;
1114 		case VDIR:
1115 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1116 				goto unionfs_rename_abort;
1117 			error = unionfs_mkshadowdir(ump, rfdvp, unp, fcnp, td);
1118 			VOP_UNLOCK(fvp, 0);
1119 			if (error != 0)
1120 				goto unionfs_rename_abort;
1121 			break;
1122 		default:
1123 			error = ENODEV;
1124 			goto unionfs_rename_abort;
1125 		}
1126 
1127 		needrelookup = 1;
1128 	}
1129 
1130 	if (unp->un_lowervp != NULLVP)
1131 		fcnp->cn_flags |= DOWHITEOUT;
1132 	rfvp = unp->un_uppervp;
1133 	vref(rfvp);
1134 
1135 	unp = VTOUNIONFS(tdvp);
1136 #ifdef UNIONFS_IDBG_RENAME
1137 	UNIONFS_INTERNAL_DEBUG("tdvp=%p, utdvp=%p, ltdvp=%p\n", tdvp, unp->un_uppervp, unp->un_lowervp);
1138 #endif
1139 	if (unp->un_uppervp == NULLVP) {
1140 		error = ENODEV;
1141 		goto unionfs_rename_abort;
1142 	}
1143 	rtdvp = unp->un_uppervp;
1144 	ltdvp = unp->un_lowervp;
1145 	vref(rtdvp);
1146 
1147 	if (tdvp == tvp) {
1148 		rtvp = rtdvp;
1149 		vref(rtvp);
1150 	} else if (tvp != NULLVP) {
1151 		unp = VTOUNIONFS(tvp);
1152 #ifdef UNIONFS_IDBG_RENAME
1153 		UNIONFS_INTERNAL_DEBUG("tvp=%p, utvp=%p, ltvp=%p\n", tvp, unp->un_uppervp, unp->un_lowervp);
1154 #endif
1155 		if (unp->un_uppervp == NULLVP)
1156 			rtvp = NULLVP;
1157 		else {
1158 			if (tvp->v_type == VDIR) {
1159 				error = EINVAL;
1160 				goto unionfs_rename_abort;
1161 			}
1162 			rtvp = unp->un_uppervp;
1163 			ltvp = unp->un_lowervp;
1164 			vref(rtvp);
1165 		}
1166 	}
1167 
1168 	if (needrelookup != 0) {
1169 		if ((error = vn_lock(fdvp, LK_EXCLUSIVE)) != 0)
1170 			goto unionfs_rename_abort;
1171 		error = unionfs_relookup_for_delete(fdvp, fcnp, td);
1172 		VOP_UNLOCK(fdvp, 0);
1173 		if (error != 0)
1174 			goto unionfs_rename_abort;
1175 
1176 		/* Locke of tvp is canceled in order to avoid recursive lock. */
1177 		if (tvp != NULLVP && tvp != tdvp)
1178 			VOP_UNLOCK(tvp, 0);
1179 		error = unionfs_relookup_for_rename(tdvp, tcnp, td);
1180 		if (tvp != NULLVP && tvp != tdvp)
1181 			vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
1182 		if (error != 0)
1183 			goto unionfs_rename_abort;
1184 	}
1185 
1186 	error = VOP_RENAME(rfdvp, rfvp, fcnp, rtdvp, rtvp, tcnp);
1187 
1188 	if (error == 0) {
1189 		if (rtvp != NULLVP && rtvp->v_type == VDIR)
1190 			cache_purge(tdvp);
1191 		if (fvp->v_type == VDIR && fdvp != tdvp)
1192 			cache_purge(fdvp);
1193 	}
1194 
1195 	if (fdvp != rfdvp)
1196 		vrele(fdvp);
1197 	if (fvp != rfvp)
1198 		vrele(fvp);
1199 	if (ltdvp != NULLVP)
1200 		VOP_UNLOCK(ltdvp, 0);
1201 	if (tdvp != rtdvp)
1202 		vrele(tdvp);
1203 	if (ltvp != NULLVP)
1204 		VOP_UNLOCK(ltvp, 0);
1205 	if (tvp != rtvp && tvp != NULLVP) {
1206 		if (rtvp == NULLVP)
1207 			vput(tvp);
1208 		else
1209 			vrele(tvp);
1210 	}
1211 
1212 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1213 
1214 	return (error);
1215 
1216 unionfs_rename_abort:
1217 	if (fdvp != rfdvp)
1218 		vrele(rfdvp);
1219 	if (fvp != rfvp)
1220 		vrele(rfvp);
1221 	if (tdvp != rtdvp)
1222 		vrele(rtdvp);
1223 	vput(tdvp);
1224 	if (tvp != rtvp && rtvp != NULLVP)
1225 		vrele(rtvp);
1226 	if (tvp != NULLVP) {
1227 		if (tdvp != tvp)
1228 			vput(tvp);
1229 		else
1230 			vrele(tvp);
1231 	}
1232 	vrele(fdvp);
1233 	vrele(fvp);
1234 
1235 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1236 
1237 	return (error);
1238 }
1239 
1240 static int
1241 unionfs_mkdir(struct vop_mkdir_args *ap)
1242 {
1243 	int		error;
1244 	int		lkflags;
1245 	struct unionfs_node *dunp;
1246 	struct componentname *cnp;
1247 	struct thread  *td;
1248 	struct vnode   *udvp;
1249 	struct vnode   *uvp;
1250 	struct vattr	va;
1251 
1252 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: enter\n");
1253 
1254 	error = EROFS;
1255 	dunp = VTOUNIONFS(ap->a_dvp);
1256 	cnp = ap->a_cnp;
1257 	lkflags = cnp->cn_lkflags;
1258 	td = curthread;
1259 	udvp = dunp->un_uppervp;
1260 
1261 	if (udvp != NULLVP) {
1262 		/* check opaque */
1263 		if (!(cnp->cn_flags & ISWHITEOUT)) {
1264 			error = VOP_GETATTR(udvp, &va, cnp->cn_cred, td);
1265 			if (error != 0)
1266 				return (error);
1267 			if (va.va_flags & OPAQUE)
1268 				cnp->cn_flags |= ISWHITEOUT;
1269 		}
1270 
1271 		if ((error = VOP_MKDIR(udvp, &uvp, cnp, ap->a_vap)) == 0) {
1272 			VOP_UNLOCK(uvp, 0);
1273 			cnp->cn_lkflags = LK_EXCLUSIVE;
1274 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1275 			    ap->a_dvp, ap->a_vpp, cnp, td);
1276 			cnp->cn_lkflags = lkflags;
1277 			vrele(uvp);
1278 		}
1279 	}
1280 
1281 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: leave (%d)\n", error);
1282 
1283 	return (error);
1284 }
1285 
1286 static int
1287 unionfs_rmdir(struct vop_rmdir_args *ap)
1288 {
1289 	int		error;
1290 	struct unionfs_node *dunp;
1291 	struct unionfs_node *unp;
1292 	struct unionfs_mount *ump;
1293 	struct componentname *cnp;
1294 	struct thread  *td;
1295 	struct vnode   *udvp;
1296 	struct vnode   *uvp;
1297 	struct vnode   *lvp;
1298 
1299 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: enter\n");
1300 
1301 	error = 0;
1302 	dunp = VTOUNIONFS(ap->a_dvp);
1303 	unp = VTOUNIONFS(ap->a_vp);
1304 	cnp = ap->a_cnp;
1305 	td = curthread;
1306 	udvp = dunp->un_uppervp;
1307 	uvp = unp->un_uppervp;
1308 	lvp = unp->un_lowervp;
1309 
1310 	if (udvp == NULLVP)
1311 		return (EROFS);
1312 
1313 	if (udvp == uvp)
1314 		return (EOPNOTSUPP);
1315 
1316 	if (uvp != NULLVP) {
1317 		if (lvp != NULLVP) {
1318 			error = unionfs_check_rmdir(ap->a_vp, cnp->cn_cred, td);
1319 			if (error != 0)
1320 				return (error);
1321 		}
1322 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
1323 		if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP)
1324 			cnp->cn_flags |= DOWHITEOUT;
1325 		error = VOP_RMDIR(udvp, uvp, cnp);
1326 	}
1327 	else if (lvp != NULLVP)
1328 		error = unionfs_mkwhiteout(udvp, cnp, td, unp->un_path);
1329 
1330 	if (error == 0) {
1331 		cache_purge(ap->a_dvp);
1332 		cache_purge(ap->a_vp);
1333 	}
1334 
1335 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: leave (%d)\n", error);
1336 
1337 	return (error);
1338 }
1339 
1340 static int
1341 unionfs_symlink(struct vop_symlink_args *ap)
1342 {
1343 	int		error;
1344 	int		lkflags;
1345 	struct unionfs_node *dunp;
1346 	struct componentname *cnp;
1347 	struct thread  *td;
1348 	struct vnode   *udvp;
1349 	struct vnode   *uvp;
1350 
1351 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: enter\n");
1352 
1353 	error = EROFS;
1354 	dunp = VTOUNIONFS(ap->a_dvp);
1355 	cnp = ap->a_cnp;
1356 	lkflags = cnp->cn_lkflags;
1357 	td = curthread;
1358 	udvp = dunp->un_uppervp;
1359 
1360 	if (udvp != NULLVP) {
1361 		error = VOP_SYMLINK(udvp, &uvp, cnp, ap->a_vap, ap->a_target);
1362 		if (error == 0) {
1363 			VOP_UNLOCK(uvp, 0);
1364 			cnp->cn_lkflags = LK_EXCLUSIVE;
1365 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1366 			    ap->a_dvp, ap->a_vpp, cnp, td);
1367 			cnp->cn_lkflags = lkflags;
1368 			vrele(uvp);
1369 		}
1370 	}
1371 
1372 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: leave (%d)\n", error);
1373 
1374 	return (error);
1375 }
1376 
1377 static int
1378 unionfs_readdir(struct vop_readdir_args *ap)
1379 {
1380 	int		error;
1381 	int		eofflag;
1382 	int		locked;
1383 	struct unionfs_node *unp;
1384 	struct unionfs_node_status *unsp;
1385 	struct uio     *uio;
1386 	struct vnode   *uvp;
1387 	struct vnode   *lvp;
1388 	struct thread  *td;
1389 	struct vattr    va;
1390 
1391 	int		ncookies_bk;
1392 	u_long         *cookies_bk;
1393 
1394 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: enter\n");
1395 
1396 	error = 0;
1397 	eofflag = 0;
1398 	locked = 0;
1399 	unp = VTOUNIONFS(ap->a_vp);
1400 	uio = ap->a_uio;
1401 	uvp = unp->un_uppervp;
1402 	lvp = unp->un_lowervp;
1403 	td = uio->uio_td;
1404 	ncookies_bk = 0;
1405 	cookies_bk = NULL;
1406 
1407 	if (ap->a_vp->v_type != VDIR)
1408 		return (ENOTDIR);
1409 
1410 	/* check opaque */
1411 	if (uvp != NULLVP && lvp != NULLVP) {
1412 		if ((error = VOP_GETATTR(uvp, &va, ap->a_cred, td)) != 0)
1413 			goto unionfs_readdir_exit;
1414 		if (va.va_flags & OPAQUE)
1415 			lvp = NULLVP;
1416 	}
1417 
1418 	/* check the open count. unionfs needs to open before readdir. */
1419 	if (VOP_ISLOCKED(ap->a_vp) != LK_EXCLUSIVE) {
1420 		vn_lock(ap->a_vp, LK_UPGRADE | LK_RETRY);
1421 		locked = 1;
1422 	}
1423 	unionfs_get_node_status(unp, td, &unsp);
1424 	if ((uvp != NULLVP && unsp->uns_upper_opencnt <= 0) ||
1425 	    (lvp != NULLVP && unsp->uns_lower_opencnt <= 0)) {
1426 		unionfs_tryrem_node_status(unp, td, unsp);
1427 		error = EBADF;
1428 	}
1429 	if (locked == 1)
1430 		vn_lock(ap->a_vp, LK_DOWNGRADE | LK_RETRY);
1431 	if (error != 0)
1432 		goto unionfs_readdir_exit;
1433 
1434 	/* upper only */
1435 	if (uvp != NULLVP && lvp == NULLVP) {
1436 		error = VOP_READDIR(uvp, uio, ap->a_cred, ap->a_eofflag,
1437 		    ap->a_ncookies, ap->a_cookies);
1438 		unsp->uns_readdir_status = 0;
1439 
1440 		goto unionfs_readdir_exit;
1441 	}
1442 
1443 	/* lower only */
1444 	if (uvp == NULLVP && lvp != NULLVP) {
1445 		error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1446 		    ap->a_ncookies, ap->a_cookies);
1447 		unsp->uns_readdir_status = 2;
1448 
1449 		goto unionfs_readdir_exit;
1450 	}
1451 
1452 	/*
1453 	 * readdir upper and lower
1454 	 */
1455 	KASSERT(uvp != NULLVP, ("unionfs_readdir: null upper vp"));
1456 	KASSERT(lvp != NULLVP, ("unionfs_readdir: null lower vp"));
1457 	if (uio->uio_offset == 0)
1458 		unsp->uns_readdir_status = 0;
1459 
1460 	if (unsp->uns_readdir_status == 0) {
1461 		/* read upper */
1462 		error = VOP_READDIR(uvp, uio, ap->a_cred, &eofflag,
1463 				    ap->a_ncookies, ap->a_cookies);
1464 
1465 		if (error != 0 || eofflag == 0)
1466 			goto unionfs_readdir_exit;
1467 		unsp->uns_readdir_status = 1;
1468 
1469 		/*
1470 		 * ufs(and other fs) needs size of uio_resid larger than
1471 		 * DIRBLKSIZ.
1472 		 * size of DIRBLKSIZ equals DEV_BSIZE.
1473 		 * (see: ufs/ufs/ufs_vnops.c ufs_readdir func , ufs/ufs/dir.h)
1474 		 */
1475 		if (uio->uio_resid <= (uio->uio_resid & (DEV_BSIZE -1)))
1476 			goto unionfs_readdir_exit;
1477 
1478 		/*
1479 		 * backup cookies
1480 		 * It prepares to readdir in lower.
1481 		 */
1482 		if (ap->a_ncookies != NULL) {
1483 			ncookies_bk = *(ap->a_ncookies);
1484 			*(ap->a_ncookies) = 0;
1485 		}
1486 		if (ap->a_cookies != NULL) {
1487 			cookies_bk = *(ap->a_cookies);
1488 			*(ap->a_cookies) = NULL;
1489 		}
1490 	}
1491 
1492 	/* initialize for readdir in lower */
1493 	if (unsp->uns_readdir_status == 1) {
1494 		unsp->uns_readdir_status = 2;
1495 		uio->uio_offset = 0;
1496 	}
1497 
1498 	if (lvp == NULLVP) {
1499 		error = EBADF;
1500 		goto unionfs_readdir_exit;
1501 	}
1502 	/* read lower */
1503 	error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1504 			    ap->a_ncookies, ap->a_cookies);
1505 
1506 	if (cookies_bk != NULL) {
1507 		/* merge cookies */
1508 		int		size;
1509 		u_long         *newcookies, *pos;
1510 
1511 		size = *(ap->a_ncookies) + ncookies_bk;
1512 		newcookies = (u_long *) malloc(size * sizeof(u_long),
1513 		    M_TEMP, M_WAITOK);
1514 		pos = newcookies;
1515 
1516 		memcpy(pos, cookies_bk, ncookies_bk * sizeof(u_long));
1517 		pos += ncookies_bk * sizeof(u_long);
1518 		memcpy(pos, *(ap->a_cookies), *(ap->a_ncookies) * sizeof(u_long));
1519 		free(cookies_bk, M_TEMP);
1520 		free(*(ap->a_cookies), M_TEMP);
1521 		*(ap->a_ncookies) = size;
1522 		*(ap->a_cookies) = newcookies;
1523 	}
1524 
1525 unionfs_readdir_exit:
1526 	if (error != 0 && ap->a_eofflag != NULL)
1527 		*(ap->a_eofflag) = 1;
1528 
1529 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1530 
1531 	return (error);
1532 }
1533 
1534 static int
1535 unionfs_readlink(struct vop_readlink_args *ap)
1536 {
1537 	int error;
1538 	struct unionfs_node *unp;
1539 	struct vnode   *vp;
1540 
1541 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: enter\n");
1542 
1543 	unp = VTOUNIONFS(ap->a_vp);
1544 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1545 
1546 	error = VOP_READLINK(vp, ap->a_uio, ap->a_cred);
1547 
1548 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: leave (%d)\n", error);
1549 
1550 	return (error);
1551 }
1552 
1553 static int
1554 unionfs_getwritemount(struct vop_getwritemount_args *ap)
1555 {
1556 	int		error;
1557 	struct vnode   *uvp;
1558 	struct vnode   *vp;
1559 
1560 	UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: enter\n");
1561 
1562 	error = 0;
1563 	vp = ap->a_vp;
1564 
1565 	if (vp == NULLVP || (vp->v_mount->mnt_flag & MNT_RDONLY))
1566 		return (EACCES);
1567 
1568 	uvp = UNIONFSVPTOUPPERVP(vp);
1569 	if (uvp == NULLVP && VREG == vp->v_type)
1570 		uvp = UNIONFSVPTOUPPERVP(VTOUNIONFS(vp)->un_dvp);
1571 
1572 	if (uvp != NULLVP)
1573 		error = VOP_GETWRITEMOUNT(uvp, ap->a_mpp);
1574 	else {
1575 		VI_LOCK(vp);
1576 		if (vp->v_iflag & VI_FREE)
1577 			error = EOPNOTSUPP;
1578 		else
1579 			error = EACCES;
1580 		VI_UNLOCK(vp);
1581 	}
1582 
1583 	UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: leave (%d)\n", error);
1584 
1585 	return (error);
1586 }
1587 
1588 static int
1589 unionfs_inactive(struct vop_inactive_args *ap)
1590 {
1591 	ap->a_vp->v_object = NULL;
1592 	vrecycle(ap->a_vp, ap->a_td);
1593 	return (0);
1594 }
1595 
1596 static int
1597 unionfs_reclaim(struct vop_reclaim_args *ap)
1598 {
1599 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: enter\n"); */
1600 
1601 	unionfs_noderem(ap->a_vp, ap->a_td);
1602 
1603 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: leave\n"); */
1604 
1605 	return (0);
1606 }
1607 
1608 static int
1609 unionfs_print(struct vop_print_args *ap)
1610 {
1611 	struct unionfs_node *unp;
1612 	/* struct unionfs_node_status *unsp; */
1613 
1614 	unp = VTOUNIONFS(ap->a_vp);
1615 	/* unionfs_get_node_status(unp, curthread, &unsp); */
1616 
1617 	printf("unionfs_vp=%p, uppervp=%p, lowervp=%p\n",
1618 	    ap->a_vp, unp->un_uppervp, unp->un_lowervp);
1619 	/*
1620 	printf("unionfs opencnt: uppervp=%d, lowervp=%d\n",
1621 	    unsp->uns_upper_opencnt, unsp->uns_lower_opencnt);
1622 	*/
1623 
1624 	if (unp->un_uppervp != NULLVP)
1625 		vprint("unionfs: upper", unp->un_uppervp);
1626 	if (unp->un_lowervp != NULLVP)
1627 		vprint("unionfs: lower", unp->un_lowervp);
1628 
1629 	return (0);
1630 }
1631 
1632 static int
1633 unionfs_get_llt_revlock(int flags)
1634 {
1635 	int count;
1636 
1637 	flags &= LK_TYPE_MASK;
1638 	for (count = 0; un_llt[count].lock != 0; count++) {
1639 		if (flags == un_llt[count].lock) {
1640 			return un_llt[count].revlock;
1641 		}
1642 	}
1643 
1644 	return 0;
1645 }
1646 
1647 static int
1648 unionfs_lock(struct vop_lock1_args *ap)
1649 {
1650 	int		error;
1651 	int		flags;
1652 	int		revlock;
1653 	int		uhold;
1654 	struct mount   *mp;
1655 	struct unionfs_mount *ump;
1656 	struct unionfs_node *unp;
1657 	struct vnode   *vp;
1658 	struct vnode   *uvp;
1659 	struct vnode   *lvp;
1660 
1661 	error = 0;
1662 	uhold = 0;
1663 	flags = ap->a_flags;
1664 	vp = ap->a_vp;
1665 
1666 	if (LK_RELEASE == (flags & LK_TYPE_MASK) || !(flags & LK_TYPE_MASK))
1667 		return (VOP_UNLOCK(vp, flags));
1668 
1669 	if ((revlock = unionfs_get_llt_revlock(flags)) == 0)
1670 		panic("unknown lock type: 0x%x", flags & LK_TYPE_MASK);
1671 
1672 	if ((flags & LK_INTERLOCK) == 0)
1673 		VI_LOCK(vp);
1674 
1675 	mp = vp->v_mount;
1676 	if (mp == NULL)
1677 		goto unionfs_lock_null_vnode;
1678 
1679 	ump = MOUNTTOUNIONFSMOUNT(mp);
1680 	unp = VTOUNIONFS(vp);
1681 	if (ump == NULL || unp == NULL)
1682 		goto unionfs_lock_null_vnode;
1683 	lvp = unp->un_lowervp;
1684 	uvp = unp->un_uppervp;
1685 
1686 	if ((mp->mnt_kern_flag & MNTK_MPSAFE) != 0 &&
1687 	    (vp->v_iflag & VI_OWEINACT) != 0)
1688 		flags |= LK_NOWAIT;
1689 
1690 	/*
1691 	 * Sometimes, lower or upper is already exclusive locked.
1692 	 * (ex. vfs_domount: mounted vnode is already locked.)
1693 	 */
1694 	if ((flags & LK_TYPE_MASK) == LK_EXCLUSIVE &&
1695 	    vp == ump->um_rootvp)
1696 		flags |= LK_CANRECURSE;
1697 
1698 	if (lvp != NULLVP) {
1699 		VI_LOCK_FLAGS(lvp, MTX_DUPOK);
1700 		flags |= LK_INTERLOCK;
1701 		vholdl(lvp);
1702 
1703 		VI_UNLOCK(vp);
1704 		ap->a_flags &= ~LK_INTERLOCK;
1705 
1706 		error = VOP_LOCK(lvp, flags);
1707 
1708 		VI_LOCK(vp);
1709 		unp = VTOUNIONFS(vp);
1710 		if (unp == NULL) {
1711 			VI_UNLOCK(vp);
1712 			if (error == 0)
1713 				VOP_UNLOCK(lvp, 0);
1714 			vdrop(lvp);
1715 			return (vop_stdlock(ap));
1716 		}
1717 	}
1718 
1719 	if (error == 0 && uvp != NULLVP) {
1720 		VI_LOCK_FLAGS(uvp, MTX_DUPOK);
1721 		flags |= LK_INTERLOCK;
1722 		vholdl(uvp);
1723 		uhold = 1;
1724 
1725 		VI_UNLOCK(vp);
1726 		ap->a_flags &= ~LK_INTERLOCK;
1727 
1728 		error = VOP_LOCK(uvp, flags);
1729 
1730 		VI_LOCK(vp);
1731 		unp = VTOUNIONFS(vp);
1732 		if (unp == NULL) {
1733 			VI_UNLOCK(vp);
1734 			if (error == 0) {
1735 				VOP_UNLOCK(uvp, 0);
1736 				if (lvp != NULLVP)
1737 					VOP_UNLOCK(lvp, 0);
1738 			}
1739 			if (lvp != NULLVP)
1740 				vdrop(lvp);
1741 			vdrop(uvp);
1742 			return (vop_stdlock(ap));
1743 		}
1744 
1745 		if (error != 0 && lvp != NULLVP) {
1746 			VI_UNLOCK(vp);
1747 			if ((revlock & LK_TYPE_MASK) == LK_RELEASE)
1748 				VOP_UNLOCK(lvp, revlock);
1749 			else
1750 				vn_lock(lvp, revlock | LK_RETRY);
1751 			goto unionfs_lock_abort;
1752 		}
1753 	}
1754 
1755 	VI_UNLOCK(vp);
1756 unionfs_lock_abort:
1757 	if (lvp != NULLVP)
1758 		vdrop(lvp);
1759 	if (uhold != 0)
1760 		vdrop(uvp);
1761 
1762 	return (error);
1763 
1764 unionfs_lock_null_vnode:
1765 	ap->a_flags |= LK_INTERLOCK;
1766 	return (vop_stdlock(ap));
1767 }
1768 
1769 static int
1770 unionfs_unlock(struct vop_unlock_args *ap)
1771 {
1772 	int		error;
1773 	int		flags;
1774 	int		mtxlkflag;
1775 	int		uhold;
1776 	struct vnode   *vp;
1777 	struct vnode   *lvp;
1778 	struct vnode   *uvp;
1779 	struct unionfs_node *unp;
1780 
1781 	error = 0;
1782 	mtxlkflag = 0;
1783 	uhold = 0;
1784 	flags = ap->a_flags | LK_RELEASE;
1785 	vp = ap->a_vp;
1786 
1787 	if ((flags & LK_INTERLOCK) != 0)
1788 		mtxlkflag = 1;
1789 	else if (mtx_owned(VI_MTX(vp)) == 0) {
1790 		VI_LOCK(vp);
1791 		mtxlkflag = 2;
1792 	}
1793 
1794 	unp = VTOUNIONFS(vp);
1795 	if (unp == NULL)
1796 		goto unionfs_unlock_null_vnode;
1797 	lvp = unp->un_lowervp;
1798 	uvp = unp->un_uppervp;
1799 
1800 	if (lvp != NULLVP) {
1801 		VI_LOCK_FLAGS(lvp, MTX_DUPOK);
1802 		flags |= LK_INTERLOCK;
1803 		vholdl(lvp);
1804 
1805 		VI_UNLOCK(vp);
1806 		ap->a_flags &= ~LK_INTERLOCK;
1807 
1808 		error = VOP_UNLOCK(lvp, flags);
1809 
1810 		VI_LOCK(vp);
1811 	}
1812 
1813 	if (error == 0 && uvp != NULLVP) {
1814 		VI_LOCK_FLAGS(uvp, MTX_DUPOK);
1815 		flags |= LK_INTERLOCK;
1816 		vholdl(uvp);
1817 		uhold = 1;
1818 
1819 		VI_UNLOCK(vp);
1820 		ap->a_flags &= ~LK_INTERLOCK;
1821 
1822 		error = VOP_UNLOCK(uvp, flags);
1823 
1824 		VI_LOCK(vp);
1825 	}
1826 
1827 	VI_UNLOCK(vp);
1828 	if (lvp != NULLVP)
1829 		vdrop(lvp);
1830 	if (uhold != 0)
1831 		vdrop(uvp);
1832 	if (mtxlkflag == 0)
1833 		VI_LOCK(vp);
1834 
1835 	return error;
1836 
1837 unionfs_unlock_null_vnode:
1838 	if (mtxlkflag == 2)
1839 		VI_UNLOCK(vp);
1840 	return (vop_stdunlock(ap));
1841 }
1842 
1843 static int
1844 unionfs_pathconf(struct vop_pathconf_args *ap)
1845 {
1846 	struct unionfs_node *unp;
1847 	struct vnode   *vp;
1848 
1849 	unp = VTOUNIONFS(ap->a_vp);
1850 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1851 
1852 	return (VOP_PATHCONF(vp, ap->a_name, ap->a_retval));
1853 }
1854 
1855 static int
1856 unionfs_advlock(struct vop_advlock_args *ap)
1857 {
1858 	int error;
1859 	struct unionfs_node *unp;
1860 	struct unionfs_node_status *unsp;
1861 	struct vnode   *vp;
1862 	struct vnode   *uvp;
1863 	struct thread  *td;
1864 
1865 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: enter\n");
1866 
1867 	vp = ap->a_vp;
1868 	td = curthread;
1869 
1870 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1871 
1872 	unp = VTOUNIONFS(ap->a_vp);
1873 	uvp = unp->un_uppervp;
1874 
1875 	if (uvp == NULLVP) {
1876 		error = unionfs_copyfile(unp, 1, td->td_ucred, td);
1877 		if (error != 0)
1878 			goto unionfs_advlock_abort;
1879 		uvp = unp->un_uppervp;
1880 
1881 		unionfs_get_node_status(unp, td, &unsp);
1882 		if (unsp->uns_lower_opencnt > 0) {
1883 			/* try reopen the vnode */
1884 			error = VOP_OPEN(uvp, unsp->uns_lower_openmode,
1885 				td->td_ucred, td, NULL);
1886 			if (error)
1887 				goto unionfs_advlock_abort;
1888 			unsp->uns_upper_opencnt++;
1889 			VOP_CLOSE(unp->un_lowervp, unsp->uns_lower_openmode, td->td_ucred, td);
1890 			unsp->uns_lower_opencnt--;
1891 		} else
1892 			unionfs_tryrem_node_status(unp, td, unsp);
1893 	}
1894 
1895 	VOP_UNLOCK(vp, 0);
1896 
1897 	error = VOP_ADVLOCK(uvp, ap->a_id, ap->a_op, ap->a_fl, ap->a_flags);
1898 
1899 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
1900 
1901 	return error;
1902 
1903 unionfs_advlock_abort:
1904 	VOP_UNLOCK(vp, 0);
1905 
1906 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
1907 
1908 	return error;
1909 }
1910 
1911 static int
1912 unionfs_strategy(struct vop_strategy_args *ap)
1913 {
1914 	struct unionfs_node *unp;
1915 	struct vnode   *vp;
1916 
1917 	unp = VTOUNIONFS(ap->a_vp);
1918 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1919 
1920 #ifdef DIAGNOSTIC
1921 	if (vp == NULLVP)
1922 		panic("unionfs_strategy: nullvp");
1923 
1924 	if (ap->a_bp->b_iocmd == BIO_WRITE && vp == unp->un_lowervp)
1925 		panic("unionfs_strategy: writing to lowervp");
1926 #endif
1927 
1928 	return (VOP_STRATEGY(vp, ap->a_bp));
1929 }
1930 
1931 static int
1932 unionfs_getacl(struct vop_getacl_args *ap)
1933 {
1934 	int		error;
1935 	struct unionfs_node *unp;
1936 	struct vnode   *vp;
1937 
1938 	unp = VTOUNIONFS(ap->a_vp);
1939 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1940 
1941 	UNIONFS_INTERNAL_DEBUG("unionfs_getacl: enter\n");
1942 
1943 	error = VOP_GETACL(vp, ap->a_type, ap->a_aclp, ap->a_cred, ap->a_td);
1944 
1945 	UNIONFS_INTERNAL_DEBUG("unionfs_getacl: leave (%d)\n", error);
1946 
1947 	return (error);
1948 }
1949 
1950 static int
1951 unionfs_setacl(struct vop_setacl_args *ap)
1952 {
1953 	int		error;
1954 	struct unionfs_node *unp;
1955 	struct vnode   *uvp;
1956 	struct vnode   *lvp;
1957 	struct thread  *td;
1958 
1959 	UNIONFS_INTERNAL_DEBUG("unionfs_setacl: enter\n");
1960 
1961 	error = EROFS;
1962 	unp = VTOUNIONFS(ap->a_vp);
1963 	uvp = unp->un_uppervp;
1964 	lvp = unp->un_lowervp;
1965 	td = ap->a_td;
1966 
1967 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
1968 		return (EROFS);
1969 
1970 	if (uvp == NULLVP && lvp->v_type == VREG) {
1971 		if ((error = unionfs_copyfile(unp, 1, ap->a_cred, td)) != 0)
1972 			return (error);
1973 		uvp = unp->un_uppervp;
1974 	}
1975 
1976 	if (uvp != NULLVP)
1977 		error = VOP_SETACL(uvp, ap->a_type, ap->a_aclp, ap->a_cred, td);
1978 
1979 	UNIONFS_INTERNAL_DEBUG("unionfs_setacl: leave (%d)\n", error);
1980 
1981 	return (error);
1982 }
1983 
1984 static int
1985 unionfs_aclcheck(struct vop_aclcheck_args *ap)
1986 {
1987 	int		error;
1988 	struct unionfs_node *unp;
1989 	struct vnode   *vp;
1990 
1991 	UNIONFS_INTERNAL_DEBUG("unionfs_aclcheck: enter\n");
1992 
1993 	unp = VTOUNIONFS(ap->a_vp);
1994 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1995 
1996 	error = VOP_ACLCHECK(vp, ap->a_type, ap->a_aclp, ap->a_cred, ap->a_td);
1997 
1998 	UNIONFS_INTERNAL_DEBUG("unionfs_aclcheck: leave (%d)\n", error);
1999 
2000 	return (error);
2001 }
2002 
2003 static int
2004 unionfs_openextattr(struct vop_openextattr_args *ap)
2005 {
2006 	int		error;
2007 	struct unionfs_node *unp;
2008 	struct vnode   *vp;
2009 	struct vnode   *tvp;
2010 
2011 	vp = ap->a_vp;
2012 	unp = VTOUNIONFS(vp);
2013 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
2014 
2015 	if ((tvp == unp->un_uppervp && (unp->un_flag & UNIONFS_OPENEXTU)) ||
2016 	    (tvp == unp->un_lowervp && (unp->un_flag & UNIONFS_OPENEXTL)))
2017 		return (EBUSY);
2018 
2019 	error = VOP_OPENEXTATTR(tvp, ap->a_cred, ap->a_td);
2020 
2021 	if (error == 0) {
2022 		vn_lock(vp, LK_UPGRADE | LK_RETRY);
2023 		if (tvp == unp->un_uppervp)
2024 			unp->un_flag |= UNIONFS_OPENEXTU;
2025 		else
2026 			unp->un_flag |= UNIONFS_OPENEXTL;
2027 		vn_lock(vp, LK_DOWNGRADE | LK_RETRY);
2028 	}
2029 
2030 	return (error);
2031 }
2032 
2033 static int
2034 unionfs_closeextattr(struct vop_closeextattr_args *ap)
2035 {
2036 	int		error;
2037 	struct unionfs_node *unp;
2038 	struct vnode   *vp;
2039 	struct vnode   *tvp;
2040 
2041 	vp = ap->a_vp;
2042 	unp = VTOUNIONFS(vp);
2043 	tvp = NULLVP;
2044 
2045 	if (unp->un_flag & UNIONFS_OPENEXTU)
2046 		tvp = unp->un_uppervp;
2047 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2048 		tvp = unp->un_lowervp;
2049 
2050 	if (tvp == NULLVP)
2051 		return (EOPNOTSUPP);
2052 
2053 	error = VOP_CLOSEEXTATTR(tvp, ap->a_commit, ap->a_cred, ap->a_td);
2054 
2055 	if (error == 0) {
2056 		vn_lock(vp, LK_UPGRADE | LK_RETRY);
2057 		if (tvp == unp->un_uppervp)
2058 			unp->un_flag &= ~UNIONFS_OPENEXTU;
2059 		else
2060 			unp->un_flag &= ~UNIONFS_OPENEXTL;
2061 		vn_lock(vp, LK_DOWNGRADE | LK_RETRY);
2062 	}
2063 
2064 	return (error);
2065 }
2066 
2067 static int
2068 unionfs_getextattr(struct vop_getextattr_args *ap)
2069 {
2070 	struct unionfs_node *unp;
2071 	struct vnode   *vp;
2072 
2073 	unp = VTOUNIONFS(ap->a_vp);
2074 	vp = NULLVP;
2075 
2076 	if (unp->un_flag & UNIONFS_OPENEXTU)
2077 		vp = unp->un_uppervp;
2078 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2079 		vp = unp->un_lowervp;
2080 
2081 	if (vp == NULLVP)
2082 		return (EOPNOTSUPP);
2083 
2084 	return (VOP_GETEXTATTR(vp, ap->a_attrnamespace, ap->a_name,
2085 	    ap->a_uio, ap->a_size, ap->a_cred, ap->a_td));
2086 }
2087 
2088 static int
2089 unionfs_setextattr(struct vop_setextattr_args *ap)
2090 {
2091 	int		error;
2092 	struct unionfs_node *unp;
2093 	struct vnode   *uvp;
2094 	struct vnode   *lvp;
2095 	struct vnode   *ovp;
2096 	struct ucred   *cred;
2097 	struct thread  *td;
2098 
2099 	error = EROFS;
2100 	unp = VTOUNIONFS(ap->a_vp);
2101 	uvp = unp->un_uppervp;
2102 	lvp = unp->un_lowervp;
2103 	ovp = NULLVP;
2104 	cred = ap->a_cred;
2105 	td = ap->a_td;
2106 
2107 	UNIONFS_INTERNAL_DEBUG("unionfs_setextattr: enter (un_flag=%x)\n", unp->un_flag);
2108 
2109 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2110 		return (EROFS);
2111 
2112 	if (unp->un_flag & UNIONFS_OPENEXTU)
2113 		ovp = unp->un_uppervp;
2114 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2115 		ovp = unp->un_lowervp;
2116 
2117 	if (ovp == NULLVP)
2118 		return (EOPNOTSUPP);
2119 
2120 	if (ovp == lvp && lvp->v_type == VREG) {
2121 		VOP_CLOSEEXTATTR(lvp, 0, cred, td);
2122 		if (uvp == NULLVP &&
2123 		    (error = unionfs_copyfile(unp, 1, cred, td)) != 0) {
2124 unionfs_setextattr_reopen:
2125 			if ((unp->un_flag & UNIONFS_OPENEXTL) &&
2126 			    VOP_OPENEXTATTR(lvp, cred, td)) {
2127 #ifdef DIAGNOSTIC
2128 				panic("unionfs: VOP_OPENEXTATTR failed");
2129 #endif
2130 				unp->un_flag &= ~UNIONFS_OPENEXTL;
2131 			}
2132 			goto unionfs_setextattr_abort;
2133 		}
2134 		uvp = unp->un_uppervp;
2135 		if ((error = VOP_OPENEXTATTR(uvp, cred, td)) != 0)
2136 			goto unionfs_setextattr_reopen;
2137 		unp->un_flag &= ~UNIONFS_OPENEXTL;
2138 		unp->un_flag |= UNIONFS_OPENEXTU;
2139 		ovp = uvp;
2140 	}
2141 
2142 	if (ovp == uvp)
2143 		error = VOP_SETEXTATTR(ovp, ap->a_attrnamespace, ap->a_name,
2144 		    ap->a_uio, cred, td);
2145 
2146 unionfs_setextattr_abort:
2147 	UNIONFS_INTERNAL_DEBUG("unionfs_setextattr: leave (%d)\n", error);
2148 
2149 	return (error);
2150 }
2151 
2152 static int
2153 unionfs_listextattr(struct vop_listextattr_args *ap)
2154 {
2155 	struct unionfs_node *unp;
2156 	struct vnode   *vp;
2157 
2158 	unp = VTOUNIONFS(ap->a_vp);
2159 	vp = NULLVP;
2160 
2161 	if (unp->un_flag & UNIONFS_OPENEXTU)
2162 		vp = unp->un_uppervp;
2163 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2164 		vp = unp->un_lowervp;
2165 
2166 	if (vp == NULLVP)
2167 		return (EOPNOTSUPP);
2168 
2169 	return (VOP_LISTEXTATTR(vp, ap->a_attrnamespace, ap->a_uio,
2170 	    ap->a_size, ap->a_cred, ap->a_td));
2171 }
2172 
2173 static int
2174 unionfs_deleteextattr(struct vop_deleteextattr_args *ap)
2175 {
2176 	int		error;
2177 	struct unionfs_node *unp;
2178 	struct vnode   *uvp;
2179 	struct vnode   *lvp;
2180 	struct vnode   *ovp;
2181 	struct ucred   *cred;
2182 	struct thread  *td;
2183 
2184 	error = EROFS;
2185 	unp = VTOUNIONFS(ap->a_vp);
2186 	uvp = unp->un_uppervp;
2187 	lvp = unp->un_lowervp;
2188 	ovp = NULLVP;
2189 	cred = ap->a_cred;
2190 	td = ap->a_td;
2191 
2192 	UNIONFS_INTERNAL_DEBUG("unionfs_deleteextattr: enter (un_flag=%x)\n", unp->un_flag);
2193 
2194 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2195 		return (EROFS);
2196 
2197 	if (unp->un_flag & UNIONFS_OPENEXTU)
2198 		ovp = unp->un_uppervp;
2199 	else if (unp->un_flag & UNIONFS_OPENEXTL)
2200 		ovp = unp->un_lowervp;
2201 
2202 	if (ovp == NULLVP)
2203 		return (EOPNOTSUPP);
2204 
2205 	if (ovp == lvp && lvp->v_type == VREG) {
2206 		VOP_CLOSEEXTATTR(lvp, 0, cred, td);
2207 		if (uvp == NULLVP &&
2208 		    (error = unionfs_copyfile(unp, 1, cred, td)) != 0) {
2209 unionfs_deleteextattr_reopen:
2210 			if ((unp->un_flag & UNIONFS_OPENEXTL) &&
2211 			    VOP_OPENEXTATTR(lvp, cred, td)) {
2212 #ifdef DIAGNOSTIC
2213 				panic("unionfs: VOP_OPENEXTATTR failed");
2214 #endif
2215 				unp->un_flag &= ~UNIONFS_OPENEXTL;
2216 			}
2217 			goto unionfs_deleteextattr_abort;
2218 		}
2219 		uvp = unp->un_uppervp;
2220 		if ((error = VOP_OPENEXTATTR(uvp, cred, td)) != 0)
2221 			goto unionfs_deleteextattr_reopen;
2222 		unp->un_flag &= ~UNIONFS_OPENEXTL;
2223 		unp->un_flag |= UNIONFS_OPENEXTU;
2224 		ovp = uvp;
2225 	}
2226 
2227 	if (ovp == uvp)
2228 		error = VOP_DELETEEXTATTR(ovp, ap->a_attrnamespace, ap->a_name,
2229 		    ap->a_cred, ap->a_td);
2230 
2231 unionfs_deleteextattr_abort:
2232 	UNIONFS_INTERNAL_DEBUG("unionfs_deleteextattr: leave (%d)\n", error);
2233 
2234 	return (error);
2235 }
2236 
2237 static int
2238 unionfs_setlabel(struct vop_setlabel_args *ap)
2239 {
2240 	int		error;
2241 	struct unionfs_node *unp;
2242 	struct vnode   *uvp;
2243 	struct vnode   *lvp;
2244 	struct thread  *td;
2245 
2246 	UNIONFS_INTERNAL_DEBUG("unionfs_setlabel: enter\n");
2247 
2248 	error = EROFS;
2249 	unp = VTOUNIONFS(ap->a_vp);
2250 	uvp = unp->un_uppervp;
2251 	lvp = unp->un_lowervp;
2252 	td = ap->a_td;
2253 
2254 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2255 		return (EROFS);
2256 
2257 	if (uvp == NULLVP && lvp->v_type == VREG) {
2258 		if ((error = unionfs_copyfile(unp, 1, ap->a_cred, td)) != 0)
2259 			return (error);
2260 		uvp = unp->un_uppervp;
2261 	}
2262 
2263 	if (uvp != NULLVP)
2264 		error = VOP_SETLABEL(uvp, ap->a_label, ap->a_cred, td);
2265 
2266 	UNIONFS_INTERNAL_DEBUG("unionfs_setlabel: leave (%d)\n", error);
2267 
2268 	return (error);
2269 }
2270 
2271 static int
2272 unionfs_vptofh(struct vop_vptofh_args *ap)
2273 {
2274 	return (EOPNOTSUPP);
2275 }
2276 
2277 struct vop_vector unionfs_vnodeops = {
2278 	.vop_default =		&default_vnodeops,
2279 
2280 	.vop_access =		unionfs_access,
2281 	.vop_aclcheck =		unionfs_aclcheck,
2282 	.vop_advlock =		unionfs_advlock,
2283 	.vop_bmap =		VOP_EOPNOTSUPP,
2284 	.vop_cachedlookup =	unionfs_lookup,
2285 	.vop_close =		unionfs_close,
2286 	.vop_closeextattr =	unionfs_closeextattr,
2287 	.vop_create =		unionfs_create,
2288 	.vop_deleteextattr =	unionfs_deleteextattr,
2289 	.vop_fsync =		unionfs_fsync,
2290 	.vop_getacl =		unionfs_getacl,
2291 	.vop_getattr =		unionfs_getattr,
2292 	.vop_getextattr =	unionfs_getextattr,
2293 	.vop_getwritemount =	unionfs_getwritemount,
2294 	.vop_inactive =		unionfs_inactive,
2295 	.vop_ioctl =		unionfs_ioctl,
2296 	.vop_lease =		unionfs_lease,
2297 	.vop_link =		unionfs_link,
2298 	.vop_listextattr =	unionfs_listextattr,
2299 	.vop_lock1 =		unionfs_lock,
2300 	.vop_lookup =		vfs_cache_lookup,
2301 	.vop_mkdir =		unionfs_mkdir,
2302 	.vop_mknod =		unionfs_mknod,
2303 	.vop_open =		unionfs_open,
2304 	.vop_openextattr =	unionfs_openextattr,
2305 	.vop_pathconf =		unionfs_pathconf,
2306 	.vop_poll =		unionfs_poll,
2307 	.vop_print =		unionfs_print,
2308 	.vop_read =		unionfs_read,
2309 	.vop_readdir =		unionfs_readdir,
2310 	.vop_readlink =		unionfs_readlink,
2311 	.vop_reclaim =		unionfs_reclaim,
2312 	.vop_remove =		unionfs_remove,
2313 	.vop_rename =		unionfs_rename,
2314 	.vop_rmdir =		unionfs_rmdir,
2315 	.vop_setacl =		unionfs_setacl,
2316 	.vop_setattr =		unionfs_setattr,
2317 	.vop_setextattr =	unionfs_setextattr,
2318 	.vop_setlabel =		unionfs_setlabel,
2319 	.vop_strategy =		unionfs_strategy,
2320 	.vop_symlink =		unionfs_symlink,
2321 	.vop_unlock =		unionfs_unlock,
2322 	.vop_whiteout =		unionfs_whiteout,
2323 	.vop_write =		unionfs_write,
2324 	.vop_vptofh =		unionfs_vptofh,
2325 };
2326