xref: /freebsd/sys/fs/unionfs/union_vnops.c (revision f0a75d274af375d15b97b830966b99a02b7db911)
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_fdidx);
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, -1);
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 			unsp->uns_lower_fdidx = ap->a_fdidx;
497 		}
498 		ap->a_vp->v_object = targetvp->v_object;
499 	}
500 
501 unionfs_open_abort:
502 	if (error != 0)
503 		unionfs_tryrem_node_status(unp, td, unsp);
504 
505 	UNIONFS_INTERNAL_DEBUG("unionfs_open: leave (%d)\n", error);
506 
507 	return (error);
508 }
509 
510 static int
511 unionfs_close(struct vop_close_args *ap)
512 {
513 	int		error;
514 	int		locked;
515 	struct unionfs_node *unp;
516 	struct unionfs_node_status *unsp;
517 	struct ucred   *cred;
518 	struct thread  *td;
519 	struct vnode   *ovp;
520 
521 	UNIONFS_INTERNAL_DEBUG("unionfs_close: enter\n");
522 
523 	locked = 0;
524 	unp = VTOUNIONFS(ap->a_vp);
525 	cred = ap->a_cred;
526 	td = ap->a_td;
527 
528 	if (VOP_ISLOCKED(ap->a_vp, td) != LK_EXCLUSIVE) {
529 		vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, td);
530 		locked = 1;
531 	}
532 	unionfs_get_node_status(unp, td, &unsp);
533 
534 	if (unsp->uns_lower_opencnt <= 0 && unsp->uns_upper_opencnt <= 0) {
535 #ifdef DIAGNOSTIC
536 		printf("unionfs_close: warning: open count is 0\n");
537 #endif
538 		if (unp->un_uppervp != NULLVP)
539 			ovp = unp->un_uppervp;
540 		else
541 			ovp = unp->un_lowervp;
542 	} else if (unsp->uns_upper_opencnt > 0)
543 		ovp = unp->un_uppervp;
544 	else
545 		ovp = unp->un_lowervp;
546 
547 	error = VOP_CLOSE(ovp, ap->a_fflag, cred, td);
548 
549 	if (error != 0)
550 		goto unionfs_close_abort;
551 
552 	ap->a_vp->v_object = ovp->v_object;
553 
554 	if (ovp == unp->un_uppervp) {
555 		unsp->uns_upper_opencnt--;
556 		if (unsp->uns_upper_opencnt == 0) {
557 			if (unsp->uns_node_flag & UNS_OPENL_4_READDIR) {
558 				VOP_CLOSE(unp->un_lowervp, FREAD, cred, td);
559 				unsp->uns_node_flag &= ~UNS_OPENL_4_READDIR;
560 				unsp->uns_lower_opencnt--;
561 			}
562 			if (unsp->uns_lower_opencnt > 0)
563 				ap->a_vp->v_object = unp->un_lowervp->v_object;
564 		}
565 	} else
566 		unsp->uns_lower_opencnt--;
567 
568 unionfs_close_abort:
569 	unionfs_tryrem_node_status(unp, td, unsp);
570 
571 	if (locked != 0)
572 		VOP_UNLOCK(ap->a_vp, 0, td);
573 
574 	UNIONFS_INTERNAL_DEBUG("unionfs_close: leave (%d)\n", error);
575 
576 	return (error);
577 }
578 
579 /*
580  * Check the access mode toward shadow file/dir.
581  */
582 static int
583 unionfs_check_corrected_access(u_short mode,
584 			     struct vattr *va,
585 			     struct ucred *cred)
586 {
587 	int		count;
588 	uid_t		uid;	/* upper side vnode's uid */
589 	gid_t		gid;	/* upper side vnode's gid */
590 	u_short		vmode;	/* upper side vnode's mode */
591 	gid_t          *gp;
592 	u_short		mask;
593 
594 	mask = 0;
595 	uid = va->va_uid;
596 	gid = va->va_gid;
597 	vmode = va->va_mode;
598 
599 	/* check owner */
600 	if (cred->cr_uid == uid) {
601 		if (mode & VEXEC)
602 			mask |= S_IXUSR;
603 		if (mode & VREAD)
604 			mask |= S_IRUSR;
605 		if (mode & VWRITE)
606 			mask |= S_IWUSR;
607 		return ((vmode & mask) == mask ? 0 : EACCES);
608 	}
609 
610 	/* check group */
611 	count = 0;
612 	gp = cred->cr_groups;
613 	for (; count < cred->cr_ngroups; count++, gp++) {
614 		if (gid == *gp) {
615 			if (mode & VEXEC)
616 				mask |= S_IXGRP;
617 			if (mode & VREAD)
618 				mask |= S_IRGRP;
619 			if (mode & VWRITE)
620 				mask |= S_IWGRP;
621 			return ((vmode & mask) == mask ? 0 : EACCES);
622 		}
623 	}
624 
625 	/* check other */
626 	if (mode & VEXEC)
627 		mask |= S_IXOTH;
628 	if (mode & VREAD)
629 		mask |= S_IROTH;
630 	if (mode & VWRITE)
631 		mask |= S_IWOTH;
632 
633 	return ((vmode & mask) == mask ? 0 : EACCES);
634 }
635 
636 static int
637 unionfs_access(struct vop_access_args *ap)
638 {
639 	struct unionfs_mount *ump;
640 	struct unionfs_node *unp;
641 	struct vnode   *uvp;
642 	struct vnode   *lvp;
643 	struct thread  *td;
644 	struct vattr	va;
645 	int		mode;
646 	int		error;
647 
648 	UNIONFS_INTERNAL_DEBUG("unionfs_access: enter\n");
649 
650 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
651 	unp = VTOUNIONFS(ap->a_vp);
652 	uvp = unp->un_uppervp;
653 	lvp = unp->un_lowervp;
654 	td = ap->a_td;
655 	mode = ap->a_mode;
656 	error = EACCES;
657 
658 	if ((mode & VWRITE) &&
659 	    (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) {
660 		switch (ap->a_vp->v_type) {
661 		case VREG:
662 		case VDIR:
663 		case VLNK:
664 			return (EROFS);
665 		default:
666 			break;
667 		}
668 	}
669 
670 	if (uvp != NULLVP) {
671 		error = VOP_ACCESS(uvp, mode, ap->a_cred, td);
672 
673 		UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
674 
675 		return (error);
676 	}
677 
678 	if (lvp != NULLVP) {
679 		if (mode & VWRITE) {
680 			if (ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY) {
681 				switch (ap->a_vp->v_type) {
682 				case VREG:
683 				case VDIR:
684 				case VLNK:
685 					return (EROFS);
686 				default:
687 					break;
688 				}
689 			} else if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
690 				/* check shadow file/dir */
691 				if (ump->um_copymode != UNIONFS_TRANSPARENT) {
692 					error = unionfs_create_uppervattr(ump,
693 					    lvp, &va, ap->a_cred, td);
694 					if (error != 0)
695 						return (error);
696 
697 					error = unionfs_check_corrected_access(
698 					    mode, &va, ap->a_cred);
699 					if (error != 0)
700 						return (error);
701 				}
702 			}
703 			mode &= ~VWRITE;
704 			mode |= VREAD; /* will copy to upper */
705 		}
706 		error = VOP_ACCESS(lvp, mode, ap->a_cred, td);
707 	}
708 
709 	UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
710 
711 	return (error);
712 }
713 
714 static int
715 unionfs_getattr(struct vop_getattr_args *ap)
716 {
717 	int		error;
718 	struct unionfs_node *unp;
719 	struct unionfs_mount *ump;
720 	struct vnode   *uvp;
721 	struct vnode   *lvp;
722 	struct thread  *td;
723 	struct vattr	va;
724 
725 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: enter\n");
726 
727 	unp = VTOUNIONFS(ap->a_vp);
728 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
729 	uvp = unp->un_uppervp;
730 	lvp = unp->un_lowervp;
731 	td = ap->a_td;
732 
733 	if (uvp != NULLVP) {
734 		if ((error = VOP_GETATTR(uvp, ap->a_vap, ap->a_cred, td)) == 0)
735 			ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
736 
737 		UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
738 		    ap->a_vap->va_mode, ap->a_vap->va_uid,
739 		    ap->a_vap->va_gid, error);
740 
741 		return (error);
742 	}
743 
744 	error = VOP_GETATTR(lvp, ap->a_vap, ap->a_cred, td);
745 
746 	if (error == 0 && !(ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY)) {
747 		/* correct the attr toward shadow file/dir. */
748 		if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
749 			unionfs_create_uppervattr_core(ump, ap->a_vap, &va, td);
750 			ap->a_vap->va_mode = va.va_mode;
751 			ap->a_vap->va_uid = va.va_uid;
752 			ap->a_vap->va_gid = va.va_gid;
753 		}
754 	}
755 
756 	if (error == 0)
757 		ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
758 
759 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
760 	    ap->a_vap->va_mode, ap->a_vap->va_uid, ap->a_vap->va_gid, error);
761 
762 	return (error);
763 }
764 
765 static int
766 unionfs_setattr(struct vop_setattr_args *ap)
767 {
768 	int		error;
769 	struct unionfs_node *unp;
770 	struct vnode   *uvp;
771 	struct vnode   *lvp;
772 	struct thread  *td;
773 	struct vattr   *vap;
774 
775 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: enter\n");
776 
777 	error = EROFS;
778 	unp = VTOUNIONFS(ap->a_vp);
779 	uvp = unp->un_uppervp;
780 	lvp = unp->un_lowervp;
781 	td = ap->a_td;
782 	vap = ap->a_vap;
783 
784 	if ((ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) &&
785 	    (vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
786 	     vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
787 	     vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL))
788 		return (EROFS);
789 
790 	if (uvp == NULLVP && lvp->v_type == VREG) {
791 		error = unionfs_copyfile(unp, (vap->va_size != 0),
792 		    ap->a_cred, td);
793 		if (error != 0)
794 			return (error);
795 		uvp = unp->un_uppervp;
796 	}
797 
798 	if (uvp != NULLVP)
799 		error = VOP_SETATTR(uvp, vap, ap->a_cred, td);
800 
801 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: leave (%d)\n", error);
802 
803 	return (error);
804 }
805 
806 static int
807 unionfs_read(struct vop_read_args *ap)
808 {
809 	int		error;
810 	struct unionfs_node *unp;
811 	struct vnode   *tvp;
812 
813 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: enter\n"); */
814 
815 	unp = VTOUNIONFS(ap->a_vp);
816 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
817 
818 	error = VOP_READ(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
819 
820 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: leave (%d)\n", error); */
821 
822 	return (error);
823 }
824 
825 static int
826 unionfs_write(struct vop_write_args *ap)
827 {
828 	int		error;
829 	struct unionfs_node *unp;
830 	struct vnode   *tvp;
831 
832 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: enter\n"); */
833 
834 	unp = VTOUNIONFS(ap->a_vp);
835 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
836 
837 	error = VOP_WRITE(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
838 
839 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: leave (%d)\n", error); */
840 
841 	return (error);
842 }
843 
844 static int
845 unionfs_lease(struct vop_lease_args *ap)
846 {
847 	int error;
848 	struct unionfs_node *unp;
849 	struct vnode   *vp;
850 
851 	UNIONFS_INTERNAL_DEBUG("unionfs_lease: enter\n");
852 
853 	unp = VTOUNIONFS(ap->a_vp);
854 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
855 
856 	error = VOP_LEASE(vp, ap->a_td, ap->a_cred, ap->a_flag);
857 
858 	UNIONFS_INTERNAL_DEBUG("unionfs_lease: lease (%d)\n", error);
859 
860 	return (error);
861 }
862 
863 static int
864 unionfs_ioctl(struct vop_ioctl_args *ap)
865 {
866 	int error;
867 	struct unionfs_node *unp;
868 	struct unionfs_node_status *unsp;
869 	struct vnode   *ovp;
870 
871 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: enter\n");
872 
873  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, ap->a_td);
874 	unp = VTOUNIONFS(ap->a_vp);
875 	unionfs_get_node_status(unp, ap->a_td, &unsp);
876 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
877 	VOP_UNLOCK(ap->a_vp, 0, ap->a_td);
878 
879 	if (ovp == NULLVP)
880 		return (EBADF);
881 
882 	error = VOP_IOCTL(ovp, ap->a_command, ap->a_data, ap->a_fflag,
883 	    ap->a_cred, ap->a_td);
884 
885 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: lease (%d)\n", error);
886 
887 	return (error);
888 }
889 
890 static int
891 unionfs_poll(struct vop_poll_args *ap)
892 {
893 	struct unionfs_node *unp;
894 	struct unionfs_node_status *unsp;
895 	struct vnode   *ovp;
896 
897  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, ap->a_td);
898 	unp = VTOUNIONFS(ap->a_vp);
899 	unionfs_get_node_status(unp, ap->a_td, &unsp);
900 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
901 	VOP_UNLOCK(ap->a_vp, 0, ap->a_td);
902 
903 	if (ovp == NULLVP)
904 		return (EBADF);
905 
906 	return (VOP_POLL(ovp, ap->a_events, ap->a_cred, ap->a_td));
907 }
908 
909 static int
910 unionfs_fsync(struct vop_fsync_args *ap)
911 {
912 	struct unionfs_node *unp;
913 	struct unionfs_node_status *unsp;
914 	struct vnode   *ovp;
915 
916 	unp = VTOUNIONFS(ap->a_vp);
917 	unionfs_get_node_status(unp, ap->a_td, &unsp);
918 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
919 
920 	if (ovp == NULLVP)
921 		return (EBADF);
922 
923 	return (VOP_FSYNC(ovp, ap->a_waitfor, ap->a_td));
924 }
925 
926 static int
927 unionfs_remove(struct vop_remove_args *ap)
928 {
929 	int		error;
930 	struct unionfs_node *dunp;
931 	struct unionfs_node *unp;
932 	struct vnode   *udvp;
933 	struct vnode   *uvp;
934 	struct vnode   *lvp;
935 	struct componentname *cnp;
936 	struct thread  *td;
937 
938 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: enter\n");
939 
940 	error = 0;
941 	dunp = VTOUNIONFS(ap->a_dvp);
942 	unp = VTOUNIONFS(ap->a_vp);
943 	udvp = dunp->un_uppervp;
944 	uvp = unp->un_uppervp;
945 	lvp = unp->un_lowervp;
946 	cnp = ap->a_cnp;
947 	td = curthread;
948 
949 	if (udvp == NULLVP)
950 		return (EROFS);
951 
952 	if (uvp != NULLVP) {
953 		cnp->cn_flags |= DOWHITEOUT;
954 		error = VOP_REMOVE(udvp, uvp, cnp);
955 	} else if (lvp != NULLVP)
956 		error = unionfs_mkwhiteout(udvp, cnp, td, unp->un_path);
957 
958 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: leave (%d)\n", error);
959 
960 	return (error);
961 }
962 
963 static int
964 unionfs_link(struct vop_link_args *ap)
965 {
966 	int		error;
967 	int		needrelookup;
968 	struct unionfs_node *dunp;
969 	struct unionfs_node *unp;
970 	struct vnode   *udvp;
971 	struct vnode   *uvp;
972 	struct componentname *cnp;
973 	struct thread  *td;
974 
975 	UNIONFS_INTERNAL_DEBUG("unionfs_link: enter\n");
976 
977 	error = 0;
978 	needrelookup = 0;
979 	dunp = VTOUNIONFS(ap->a_tdvp);
980 	unp = NULL;
981 	udvp = dunp->un_uppervp;
982 	uvp = NULLVP;
983 	cnp = ap->a_cnp;
984 	td = curthread;
985 
986 	if (udvp == NULLVP)
987 		return (EROFS);
988 
989 	if (ap->a_vp->v_op != &unionfs_vnodeops)
990 		uvp = ap->a_vp;
991 	else {
992 		unp = VTOUNIONFS(ap->a_vp);
993 
994 		if (unp->un_uppervp == NULLVP) {
995 			if (ap->a_vp->v_type != VREG)
996 				return (EOPNOTSUPP);
997 
998 			error = unionfs_copyfile(unp, 1, cnp->cn_cred, td);
999 			if (error != 0)
1000 				return (error);
1001 			needrelookup = 1;
1002 		}
1003 		uvp = unp->un_uppervp;
1004 	}
1005 
1006 	if (needrelookup != 0)
1007 		error = unionfs_relookup_for_create(ap->a_tdvp, cnp, td);
1008 
1009 	if (error == 0)
1010 		error = VOP_LINK(udvp, uvp, cnp);
1011 
1012 	UNIONFS_INTERNAL_DEBUG("unionfs_link: leave (%d)\n", error);
1013 
1014 	return (error);
1015 }
1016 
1017 static int
1018 unionfs_rename(struct vop_rename_args *ap)
1019 {
1020 	int		error;
1021 	struct vnode   *fdvp;
1022 	struct vnode   *fvp;
1023 	struct componentname *fcnp;
1024 	struct vnode   *tdvp;
1025 	struct vnode   *tvp;
1026 	struct componentname *tcnp;
1027 	struct vnode   *ltdvp;
1028 	struct vnode   *ltvp;
1029 	struct thread  *td;
1030 
1031 	/* rename target vnodes */
1032 	struct vnode   *rfdvp;
1033 	struct vnode   *rfvp;
1034 	struct vnode   *rtdvp;
1035 	struct vnode   *rtvp;
1036 
1037 	int		needrelookup;
1038 	struct unionfs_mount *ump;
1039 	struct unionfs_node *unp;
1040 
1041 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: enter\n");
1042 
1043 	error = 0;
1044 	fdvp = ap->a_fdvp;
1045 	fvp = ap->a_fvp;
1046 	fcnp = ap->a_fcnp;
1047 	tdvp = ap->a_tdvp;
1048 	tvp = ap->a_tvp;
1049 	tcnp = ap->a_tcnp;
1050 	ltdvp = NULLVP;
1051 	ltvp = NULLVP;
1052 	td = curthread;
1053 	rfdvp = fdvp;
1054 	rfvp = fvp;
1055 	rtdvp = tdvp;
1056 	rtvp = tvp;
1057 	needrelookup = 0;
1058 
1059 #ifdef DIAGNOSTIC
1060 	if (!(fcnp->cn_flags & HASBUF) || !(tcnp->cn_flags & HASBUF))
1061 		panic("unionfs_rename: no name");
1062 #endif
1063 
1064 	/* check for cross device rename */
1065 	if (fvp->v_mount != tdvp->v_mount ||
1066 	    (tvp != NULLVP && fvp->v_mount != tvp->v_mount)) {
1067 		error = EXDEV;
1068 		goto unionfs_rename_abort;
1069 	}
1070 
1071 	/* Renaming a file to itself has no effect. */
1072 	if (fvp == tvp)
1073 		goto unionfs_rename_abort;
1074 
1075 	/*
1076 	 * from/to vnode is unionfs node.
1077 	 */
1078 
1079 	unp = VTOUNIONFS(fdvp);
1080 #ifdef UNIONFS_IDBG_RENAME
1081 	UNIONFS_INTERNAL_DEBUG("fdvp=%p, ufdvp=%p, lfdvp=%p\n", fdvp, unp->un_uppervp, unp->un_lowervp);
1082 #endif
1083 	if (unp->un_uppervp == NULLVP) {
1084 		error = ENODEV;
1085 		goto unionfs_rename_abort;
1086 	}
1087 	rfdvp = unp->un_uppervp;
1088 	vref(rfdvp);
1089 
1090 	unp = VTOUNIONFS(fvp);
1091 #ifdef UNIONFS_IDBG_RENAME
1092 	UNIONFS_INTERNAL_DEBUG("fvp=%p, ufvp=%p, lfvp=%p\n", fvp, unp->un_uppervp, unp->un_lowervp);
1093 #endif
1094 	ump = MOUNTTOUNIONFSMOUNT(fvp->v_mount);
1095 	if (unp->un_uppervp == NULLVP) {
1096 		switch (fvp->v_type) {
1097 		case VREG:
1098 			if ((error = vn_lock(fvp, LK_EXCLUSIVE, td)) != 0)
1099 				goto unionfs_rename_abort;
1100 			error = unionfs_copyfile(unp, 1, fcnp->cn_cred, td);
1101 			VOP_UNLOCK(fvp, 0, td);
1102 			if (error != 0)
1103 				goto unionfs_rename_abort;
1104 			break;
1105 		case VDIR:
1106 			if ((error = vn_lock(fvp, LK_EXCLUSIVE, td)) != 0)
1107 				goto unionfs_rename_abort;
1108 			error = unionfs_mkshadowdir(ump, rfdvp, unp, fcnp, td);
1109 			VOP_UNLOCK(fvp, 0, td);
1110 			if (error != 0)
1111 				goto unionfs_rename_abort;
1112 			break;
1113 		default:
1114 			error = ENODEV;
1115 			goto unionfs_rename_abort;
1116 		}
1117 
1118 		needrelookup = 1;
1119 	}
1120 
1121 	if (unp->un_lowervp != NULLVP)
1122 		fcnp->cn_flags |= DOWHITEOUT;
1123 	rfvp = unp->un_uppervp;
1124 	vref(rfvp);
1125 
1126 	unp = VTOUNIONFS(tdvp);
1127 #ifdef UNIONFS_IDBG_RENAME
1128 	UNIONFS_INTERNAL_DEBUG("tdvp=%p, utdvp=%p, ltdvp=%p\n", tdvp, unp->un_uppervp, unp->un_lowervp);
1129 #endif
1130 	if (unp->un_uppervp == NULLVP) {
1131 		error = ENODEV;
1132 		goto unionfs_rename_abort;
1133 	}
1134 	rtdvp = unp->un_uppervp;
1135 	ltdvp = unp->un_lowervp;
1136 	vref(rtdvp);
1137 
1138 	if (tdvp == tvp) {
1139 		rtvp = rtdvp;
1140 		vref(rtvp);
1141 	} else if (tvp != NULLVP) {
1142 		unp = VTOUNIONFS(tvp);
1143 #ifdef UNIONFS_IDBG_RENAME
1144 		UNIONFS_INTERNAL_DEBUG("tvp=%p, utvp=%p, ltvp=%p\n", tvp, unp->un_uppervp, unp->un_lowervp);
1145 #endif
1146 		if (unp->un_uppervp == NULLVP)
1147 			rtvp = NULLVP;
1148 		else {
1149 			if (tvp->v_type == VDIR) {
1150 				error = EINVAL;
1151 				goto unionfs_rename_abort;
1152 			}
1153 			rtvp = unp->un_uppervp;
1154 			ltvp = unp->un_lowervp;
1155 			vref(rtvp);
1156 		}
1157 	}
1158 
1159 	if (needrelookup != 0) {
1160 		if ((error = vn_lock(fdvp, LK_EXCLUSIVE, td)) != 0)
1161 			goto unionfs_rename_abort;
1162 		error = unionfs_relookup_for_delete(fdvp, fcnp, td);
1163 		VOP_UNLOCK(fdvp, 0, td);
1164 		if (error != 0)
1165 			goto unionfs_rename_abort;
1166 
1167 		/* Locke of tvp is canceled in order to avoid recursive lock. */
1168 		if (tvp != NULLVP && tvp != tdvp)
1169 			VOP_UNLOCK(tvp, 0, td);
1170 		error = unionfs_relookup_for_rename(tdvp, tcnp, td);
1171 		if (tvp != NULLVP && tvp != tdvp)
1172 			vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY, td);
1173 		if (error != 0)
1174 			goto unionfs_rename_abort;
1175 	}
1176 
1177 	error = VOP_RENAME(rfdvp, rfvp, fcnp, rtdvp, rtvp, tcnp);
1178 
1179 	if (fdvp != rfdvp)
1180 		vrele(fdvp);
1181 	if (fvp != rfvp)
1182 		vrele(fvp);
1183 	if (tdvp != rtdvp)
1184 		vrele(tdvp);
1185 	if (tvp != rtvp && tvp != NULLVP) {
1186 		if (rtvp == NULLVP)
1187 			vput(tvp);
1188 		else
1189 			vrele(tvp);
1190 	}
1191 	if (ltdvp != NULLVP)
1192 		VOP_UNLOCK(ltdvp, 0, td);
1193 	if (ltvp != NULLVP)
1194 		VOP_UNLOCK(ltvp, 0, td);
1195 
1196 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1197 
1198 	return (error);
1199 
1200 unionfs_rename_abort:
1201 	if (fdvp != rfdvp)
1202 		vrele(rfdvp);
1203 	if (fvp != rfvp)
1204 		vrele(rfvp);
1205 	if (tdvp != rtdvp)
1206 		vrele(rtdvp);
1207 	vput(tdvp);
1208 	if (tvp != rtvp && rtvp != NULLVP)
1209 		vrele(rtvp);
1210 	if (tvp != NULLVP) {
1211 		if (tdvp != tvp)
1212 			vput(tvp);
1213 		else
1214 			vrele(tvp);
1215 	}
1216 	vrele(fdvp);
1217 	vrele(fvp);
1218 
1219 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1220 
1221 	return (error);
1222 }
1223 
1224 static int
1225 unionfs_mkdir(struct vop_mkdir_args *ap)
1226 {
1227 	int		error;
1228 	int		lkflags;
1229 	struct unionfs_node *dunp;
1230 	struct componentname *cnp;
1231 	struct thread  *td;
1232 	struct vnode   *udvp;
1233 	struct vnode   *uvp;
1234 	struct vattr	va;
1235 
1236 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: enter\n");
1237 
1238 	error = EROFS;
1239 	dunp = VTOUNIONFS(ap->a_dvp);
1240 	cnp = ap->a_cnp;
1241 	lkflags = cnp->cn_lkflags;
1242 	td = curthread;
1243 	udvp = dunp->un_uppervp;
1244 
1245 	if (udvp != NULLVP) {
1246 		/* check opaque */
1247 		if (!(cnp->cn_flags & ISWHITEOUT)) {
1248 			error = VOP_GETATTR(udvp, &va, cnp->cn_cred, td);
1249 			if (error != 0)
1250 				return (error);
1251 			if (va.va_flags & OPAQUE)
1252 				cnp->cn_flags |= ISWHITEOUT;
1253 		}
1254 
1255 		if ((error = VOP_MKDIR(udvp, &uvp, cnp, ap->a_vap)) == 0) {
1256 			VOP_UNLOCK(uvp, 0, td);
1257 			cnp->cn_lkflags = LK_EXCLUSIVE;
1258 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1259 			    ap->a_dvp, ap->a_vpp, cnp, td);
1260 			cnp->cn_lkflags = lkflags;
1261 			vrele(uvp);
1262 		}
1263 	}
1264 
1265 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: leave (%d)\n", error);
1266 
1267 	return (error);
1268 }
1269 
1270 static int
1271 unionfs_rmdir(struct vop_rmdir_args *ap)
1272 {
1273 	int		error;
1274 	struct unionfs_node *dunp;
1275 	struct unionfs_node *unp;
1276 	struct componentname *cnp;
1277 	struct thread  *td;
1278 	struct vnode   *udvp;
1279 	struct vnode   *uvp;
1280 	struct vnode   *lvp;
1281 
1282 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: enter\n");
1283 
1284 	error = 0;
1285 	dunp = VTOUNIONFS(ap->a_dvp);
1286 	unp = VTOUNIONFS(ap->a_vp);
1287 	cnp = ap->a_cnp;
1288 	td = curthread;
1289 	udvp = dunp->un_uppervp;
1290 	uvp = unp->un_uppervp;
1291 	lvp = unp->un_lowervp;
1292 
1293 	if (udvp == NULLVP)
1294 		return (EROFS);
1295 
1296 	if (udvp == uvp)
1297 		return (EOPNOTSUPP);
1298 
1299 	if (uvp != NULLVP) {
1300 		if (lvp != NULLVP) {
1301 			error = unionfs_check_rmdir(ap->a_vp, cnp->cn_cred, td);
1302 			if (error != 0)
1303 				return (error);
1304 		}
1305 		cnp->cn_flags |= DOWHITEOUT;
1306 		error = VOP_RMDIR(udvp, uvp, cnp);
1307 	}
1308 	else if (lvp != NULLVP)
1309 		error = unionfs_mkwhiteout(udvp, cnp, td, unp->un_path);
1310 
1311 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: leave (%d)\n", error);
1312 
1313 	return (error);
1314 }
1315 
1316 static int
1317 unionfs_symlink(struct vop_symlink_args *ap)
1318 {
1319 	int		error;
1320 	int		lkflags;
1321 	struct unionfs_node *dunp;
1322 	struct componentname *cnp;
1323 	struct thread  *td;
1324 	struct vnode   *udvp;
1325 	struct vnode   *uvp;
1326 
1327 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: enter\n");
1328 
1329 	error = EROFS;
1330 	dunp = VTOUNIONFS(ap->a_dvp);
1331 	cnp = ap->a_cnp;
1332 	lkflags = cnp->cn_lkflags;
1333 	td = curthread;
1334 	udvp = dunp->un_uppervp;
1335 
1336 	if (udvp != NULLVP) {
1337 		error = VOP_SYMLINK(udvp, &uvp, cnp, ap->a_vap, ap->a_target);
1338 		if (error == 0) {
1339 			VOP_UNLOCK(uvp, 0, td);
1340 			cnp->cn_lkflags = LK_EXCLUSIVE;
1341 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1342 			    ap->a_dvp, ap->a_vpp, cnp, td);
1343 			cnp->cn_lkflags = lkflags;
1344 			vrele(uvp);
1345 		}
1346 	}
1347 
1348 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: leave (%d)\n", error);
1349 
1350 	return (error);
1351 }
1352 
1353 static int
1354 unionfs_readdir(struct vop_readdir_args *ap)
1355 {
1356 	int		error;
1357 	int		eofflag;
1358 	int		locked;
1359 	struct unionfs_node *unp;
1360 	struct unionfs_node_status *unsp;
1361 	struct uio     *uio;
1362 	struct vnode   *uvp;
1363 	struct vnode   *lvp;
1364 	struct thread  *td;
1365 	struct vattr    va;
1366 
1367 	int		ncookies_bk;
1368 	u_long         *cookies_bk;
1369 
1370 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: enter\n");
1371 
1372 	error = 0;
1373 	eofflag = 0;
1374 	locked = 0;
1375 	unp = VTOUNIONFS(ap->a_vp);
1376 	uio = ap->a_uio;
1377 	uvp = unp->un_uppervp;
1378 	lvp = unp->un_lowervp;
1379 	td = uio->uio_td;
1380 	ncookies_bk = 0;
1381 	cookies_bk = NULL;
1382 
1383 	if (ap->a_vp->v_type != VDIR)
1384 		return (ENOTDIR);
1385 
1386 	/* check opaque */
1387 	if (uvp != NULLVP && lvp != NULLVP) {
1388 		if ((error = VOP_GETATTR(uvp, &va, ap->a_cred, td)) != 0)
1389 			return (error);
1390 		if (va.va_flags & OPAQUE)
1391 			lvp = NULLVP;
1392 	}
1393 
1394 	if (VOP_ISLOCKED(ap->a_vp, td) != LK_EXCLUSIVE) {
1395 		vn_lock(ap->a_vp, LK_UPGRADE | LK_RETRY, td);
1396 		locked = 1;
1397 	}
1398 	unionfs_get_node_status(unp, curthread, &unsp);
1399 	if (locked == 1)
1400 		vn_lock(ap->a_vp, LK_DOWNGRADE | LK_RETRY, td);
1401 
1402 	/* upper only */
1403 	if (uvp != NULLVP && lvp == NULLVP) {
1404 		if (unsp->uns_upper_opencnt <= 0)
1405 			error = EBADF;
1406 		else {
1407 			error = VOP_READDIR(uvp, uio, ap->a_cred, ap->a_eofflag,
1408 			    ap->a_ncookies, ap->a_cookies);
1409 			unsp->uns_readdir_status = 0;
1410 		}
1411 
1412 		goto unionfs_readdir_exit;
1413 	}
1414 
1415 	/* lower only */
1416 	if (uvp == NULLVP && lvp != NULLVP) {
1417 		if (unsp->uns_lower_opencnt <= 0)
1418 			error = EBADF;
1419 		else {
1420 			error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1421 			    ap->a_ncookies, ap->a_cookies);
1422 			unsp->uns_readdir_status = 2;
1423 		}
1424 
1425 		goto unionfs_readdir_exit;
1426 	}
1427 
1428 	/*
1429 	 * readdir upper and lower
1430 	 */
1431 	if (unsp->uns_lower_opencnt <= 0 || unsp->uns_upper_opencnt <= 0) {
1432 		error = EBADF;
1433 		goto unionfs_readdir_exit;
1434 	}
1435 
1436 	if (uio->uio_offset == 0)
1437 		unsp->uns_readdir_status = 0;
1438 
1439 	if (unsp->uns_readdir_status == 0) {
1440 		/* read upper */
1441 		error = VOP_READDIR(uvp, uio, ap->a_cred, &eofflag,
1442 				    ap->a_ncookies, ap->a_cookies);
1443 
1444 		if (error != 0 || eofflag == 0) {
1445 			UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1446 			return (error);
1447 		}
1448 		unsp->uns_readdir_status = 1;
1449 
1450 		/*
1451 		 * ufs(and other fs) needs size of uio_resid larger than
1452 		 * DIRBLKSIZ.
1453 		 * size of DIRBLKSIZ equals DEV_BSIZE.
1454 		 * (see: ufs/ufs/ufs_vnops.c ufs_readdir func , ufs/ufs/dir.h)
1455 		 */
1456 		if (uio->uio_resid <= (uio->uio_resid & (DEV_BSIZE -1))) {
1457 			UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1458 			return (0);
1459 		}
1460 
1461 		/*
1462 		 * backup cookies
1463 		 * It prepares to readdir in lower.
1464 		 */
1465 		if (ap->a_ncookies != NULL) {
1466 			ncookies_bk = *(ap->a_ncookies);
1467 			*(ap->a_ncookies) = 0;
1468 		}
1469 		if (ap->a_cookies != NULL) {
1470 			cookies_bk = *(ap->a_cookies);
1471 			*(ap->a_cookies) = NULL;
1472 		}
1473 	}
1474 
1475 	/* initialize for readdir in lower */
1476 	if (unsp->uns_readdir_status == 1) {
1477 		unsp->uns_readdir_status = 2;
1478 		uio->uio_offset = 0;
1479 	}
1480 
1481 	if (lvp == NULLVP) {
1482 		error = EBADF;
1483 		goto unionfs_readdir_exit;
1484 	}
1485 	/* read lower */
1486 	error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1487 			    ap->a_ncookies, ap->a_cookies);
1488 
1489 	if (cookies_bk != NULL) {
1490 		/* merge cookies */
1491 		int		size;
1492 		u_long         *newcookies, *pos;
1493 
1494 		size = *(ap->a_ncookies) + ncookies_bk;
1495 		newcookies = (u_long *) malloc(size * sizeof(u_long),
1496 		    M_TEMP, M_WAITOK);
1497 		pos = newcookies;
1498 
1499 		memcpy(pos, cookies_bk, ncookies_bk * sizeof(u_long));
1500 		pos += ncookies_bk * sizeof(u_long);
1501 		memcpy(pos, *(ap->a_cookies), *(ap->a_ncookies) * sizeof(u_long));
1502 		free(cookies_bk, M_TEMP);
1503 		free(*(ap->a_cookies), M_TEMP);
1504 		*(ap->a_ncookies) = size;
1505 		*(ap->a_cookies) = newcookies;
1506 	}
1507 
1508 unionfs_readdir_exit:
1509 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1510 
1511 	return (error);
1512 }
1513 
1514 static int
1515 unionfs_readlink(struct vop_readlink_args *ap)
1516 {
1517 	int error;
1518 	struct unionfs_node *unp;
1519 	struct vnode   *vp;
1520 
1521 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: enter\n");
1522 
1523 	unp = VTOUNIONFS(ap->a_vp);
1524 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1525 
1526 	error = VOP_READLINK(vp, ap->a_uio, ap->a_cred);
1527 
1528 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: leave (%d)\n", error);
1529 
1530 	return (error);
1531 }
1532 
1533 static int
1534 unionfs_getwritemount(struct vop_getwritemount_args *ap)
1535 {
1536 	int		error;
1537 	struct vnode   *uvp;
1538 	struct vnode   *vp;
1539 
1540 	UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: enter\n");
1541 
1542 	error = 0;
1543 	vp = ap->a_vp;
1544 
1545 	if (vp == NULLVP || (vp->v_mount->mnt_flag & MNT_RDONLY))
1546 		return (EACCES);
1547 
1548 	uvp = UNIONFSVPTOUPPERVP(vp);
1549 	if (uvp == NULLVP && VREG == vp->v_type)
1550 		uvp = UNIONFSVPTOUPPERVP(VTOUNIONFS(vp)->un_dvp);
1551 
1552 	if (uvp != NULLVP)
1553 		error = VOP_GETWRITEMOUNT(uvp, ap->a_mpp);
1554 	else {
1555 		VI_LOCK(vp);
1556 		if (vp->v_iflag & VI_FREE)
1557 			error = EOPNOTSUPP;
1558 		else
1559 			error = EACCES;
1560 		VI_UNLOCK(vp);
1561 	}
1562 
1563 	UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: leave (%d)\n", error);
1564 
1565 	return (error);
1566 }
1567 
1568 static int
1569 unionfs_inactive(struct vop_inactive_args *ap)
1570 {
1571 	struct unionfs_node *unp;
1572 
1573 	unp = VTOUNIONFS(ap->a_vp);
1574 
1575 	if (unp == NULL || !(unp->un_flag & UNIONFS_CACHED))
1576 		vgone(ap->a_vp);
1577 
1578 	return (0);
1579 }
1580 
1581 static int
1582 unionfs_reclaim(struct vop_reclaim_args *ap)
1583 {
1584 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: enter\n"); */
1585 
1586 	unionfs_hashrem(ap->a_vp, ap->a_td);
1587 
1588 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: leave\n"); */
1589 
1590 	return (0);
1591 }
1592 
1593 static int
1594 unionfs_print(struct vop_print_args *ap)
1595 {
1596 	struct unionfs_node *unp;
1597 	/* struct unionfs_node_status *unsp; */
1598 
1599 	unp = VTOUNIONFS(ap->a_vp);
1600 	/* unionfs_get_node_status(unp, curthread, &unsp); */
1601 
1602 	printf("unionfs_vp=%p, uppervp=%p, lowervp=%p\n",
1603 	    ap->a_vp, unp->un_uppervp, unp->un_lowervp);
1604 	/*
1605 	printf("unionfs opencnt: uppervp=%d, lowervp=%d\n",
1606 	    unsp->uns_upper_opencnt, unsp->uns_lower_opencnt);
1607 	*/
1608 
1609 	if (unp->un_uppervp != NULLVP)
1610 		vprint("unionfs: upper", unp->un_uppervp);
1611 	if (unp->un_lowervp != NULLVP)
1612 		vprint("unionfs: lower", unp->un_lowervp);
1613 
1614 	return (0);
1615 }
1616 
1617 static int
1618 unionfs_get_llt_revlock(int flags)
1619 {
1620 	int count;
1621 
1622 	flags &= LK_TYPE_MASK;
1623 	for (count = 0; un_llt[count].lock != 0; count++) {
1624 		if (flags == un_llt[count].lock) {
1625 			return un_llt[count].revlock;
1626 		}
1627 	}
1628 
1629 	return 0;
1630 }
1631 
1632 static int
1633 unionfs_lock(struct _vop_lock_args *ap)
1634 {
1635 	int		error;
1636 	int		flags;
1637 	int		revlock;
1638 	int		uhold;
1639 	struct unionfs_mount *ump;
1640 	struct unionfs_node *unp;
1641 	struct vnode   *vp;
1642 	struct vnode   *uvp;
1643 	struct vnode   *lvp;
1644 	struct thread  *td;
1645 
1646 	error = 0;
1647 	uhold = 0;
1648 	flags = ap->a_flags;
1649 	vp = ap->a_vp;
1650 	td = ap->a_td;
1651 
1652 	if (LK_RELEASE == (flags & LK_TYPE_MASK) || !(flags & LK_TYPE_MASK))
1653 		return (VOP_UNLOCK(vp, flags, td));
1654 
1655 	if ((revlock = unionfs_get_llt_revlock(flags)) == 0)
1656 		panic("unknown lock type: 0x%x", flags & LK_TYPE_MASK);
1657 
1658 	if (!(flags & LK_INTERLOCK))
1659 		VI_LOCK(vp);
1660 
1661 	ump = MOUNTTOUNIONFSMOUNT(vp->v_mount);
1662 	unp = VTOUNIONFS(vp);
1663 	if (NULL == unp)
1664 		goto unionfs_lock_null_vnode;
1665 	lvp = unp->un_lowervp;
1666 	uvp = unp->un_uppervp;
1667 
1668 	/*
1669 	 * Sometimes, lower or upper is already exclusive locked.
1670 	 * (ex. vfs_domount: mounted vnode is already locked.)
1671 	 */
1672 	if ((flags & LK_TYPE_MASK) == LK_EXCLUSIVE &&
1673 	    vp == ump->um_rootvp)
1674 		flags |= LK_CANRECURSE;
1675 
1676 	if (lvp != NULLVP) {
1677 		VI_LOCK_FLAGS(lvp, MTX_DUPOK);
1678 		flags |= LK_INTERLOCK;
1679 		vholdl(lvp);
1680 
1681 		VI_UNLOCK(vp);
1682 		ap->a_flags &= ~LK_INTERLOCK;
1683 
1684 		error = VOP_LOCK(lvp, flags, td);
1685 
1686 		VI_LOCK(vp);
1687 		unp = VTOUNIONFS(vp);
1688 		if (unp == NULL) {
1689 			if (error == 0)
1690 				VOP_UNLOCK(lvp, 0, td);
1691 			VI_UNLOCK(vp);
1692 			vdrop(lvp);
1693 			return (vop_stdlock(ap));
1694 		}
1695 	}
1696 
1697 	if (error == 0 && uvp != NULLVP) {
1698 		VI_LOCK_FLAGS(uvp, MTX_DUPOK);
1699 		flags |= LK_INTERLOCK;
1700 		vholdl(uvp);
1701 		uhold = 1;
1702 
1703 		VI_UNLOCK(vp);
1704 		ap->a_flags &= ~LK_INTERLOCK;
1705 
1706 		error = VOP_LOCK(uvp, flags, td);
1707 
1708 		VI_LOCK(vp);
1709 		unp = VTOUNIONFS(vp);
1710 		if (unp == NULL) {
1711 			if (error == 0) {
1712 				VOP_UNLOCK(uvp, 0, td);
1713 				if (lvp != NULLVP)
1714 					VOP_UNLOCK(lvp, 0, td);
1715 			}
1716 			VI_UNLOCK(vp);
1717 			if (lvp != NULLVP)
1718 				vdrop(lvp);
1719 			vdrop(uvp);
1720 			return (vop_stdlock(ap));
1721 		}
1722 
1723 		if (error != 0 && lvp != NULLVP)
1724 			vn_lock(lvp, revlock | LK_RETRY, td);
1725 	}
1726 
1727 	VI_UNLOCK(vp);
1728 	if (lvp != NULLVP)
1729 		vdrop(lvp);
1730 	if (uhold != 0)
1731 		vdrop(uvp);
1732 
1733 	return (error);
1734 
1735 unionfs_lock_null_vnode:
1736 	ap->a_flags |= LK_INTERLOCK;
1737 	return (vop_stdlock(ap));
1738 }
1739 
1740 static int
1741 unionfs_unlock(struct vop_unlock_args *ap)
1742 {
1743 	int		error;
1744 	int		flags;
1745 	int		mtxlkflag;
1746 	int		uhold;
1747 	struct vnode   *vp;
1748 	struct vnode   *lvp;
1749 	struct vnode   *uvp;
1750 	struct unionfs_node *unp;
1751 
1752 	error = 0;
1753 	mtxlkflag = 0;
1754 	uhold = 0;
1755 	flags = ap->a_flags | LK_RELEASE;
1756 	vp = ap->a_vp;
1757 
1758 	if (flags & LK_INTERLOCK)
1759 		mtxlkflag = 1;
1760 	else if (mtx_owned(VI_MTX(vp)) == 0) {
1761 		VI_LOCK(vp);
1762 		mtxlkflag = 2;
1763 	}
1764 
1765 	unp = VTOUNIONFS(vp);
1766 	if (unp == NULL)
1767 		goto unionfs_unlock_null_vnode;
1768 	lvp = unp->un_lowervp;
1769 	uvp = unp->un_uppervp;
1770 
1771 	if (lvp != NULLVP) {
1772 		VI_LOCK_FLAGS(lvp, MTX_DUPOK);
1773 		flags |= LK_INTERLOCK;
1774 		vholdl(lvp);
1775 
1776 		VI_UNLOCK(vp);
1777 		ap->a_flags &= ~LK_INTERLOCK;
1778 
1779 		error = VOP_UNLOCK(lvp, flags, ap->a_td);
1780 
1781 		VI_LOCK(vp);
1782 	}
1783 
1784 	if (error == 0 && uvp != NULLVP) {
1785 		VI_LOCK_FLAGS(uvp, MTX_DUPOK);
1786 		flags |= LK_INTERLOCK;
1787 		vholdl(uvp);
1788 		uhold = 1;
1789 
1790 		VI_UNLOCK(vp);
1791 		ap->a_flags &= ~LK_INTERLOCK;
1792 
1793 		error = VOP_UNLOCK(uvp, flags, ap->a_td);
1794 
1795 		VI_LOCK(vp);
1796 	}
1797 
1798 	VI_UNLOCK(vp);
1799 	if (lvp != NULLVP)
1800 		vdrop(lvp);
1801 	if (uhold != 0)
1802 		vdrop(uvp);
1803 	if (mtxlkflag == 0)
1804 		VI_LOCK(vp);
1805 
1806 	return error;
1807 
1808 unionfs_unlock_null_vnode:
1809 	if (mtxlkflag == 2)
1810 		VI_UNLOCK(vp);
1811 	return (vop_stdunlock(ap));
1812 }
1813 
1814 static int
1815 unionfs_pathconf(struct vop_pathconf_args *ap)
1816 {
1817 	struct unionfs_node *unp;
1818 	struct vnode   *vp;
1819 
1820 	unp = VTOUNIONFS(ap->a_vp);
1821 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1822 
1823 	return (VOP_PATHCONF(vp, ap->a_name, ap->a_retval));
1824 }
1825 
1826 static int
1827 unionfs_advlock(struct vop_advlock_args *ap)
1828 {
1829 	int error;
1830 	struct unionfs_node *unp;
1831 	struct unionfs_node_status *unsp;
1832 	struct vnode   *vp;
1833 	struct vnode   *uvp;
1834 	struct thread  *td;
1835 
1836 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: enter\n");
1837 
1838 	vp = ap->a_vp;
1839 	td = curthread;
1840 
1841 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1842 
1843 	unp = VTOUNIONFS(ap->a_vp);
1844 	uvp = unp->un_uppervp;
1845 
1846 	if (uvp == NULLVP) {
1847 		error = unionfs_copyfile(unp, 1, td->td_ucred, td);
1848 		if (error != 0)
1849 			goto unionfs_advlock_abort;
1850 		uvp = unp->un_uppervp;
1851 
1852 		unionfs_get_node_status(unp, td, &unsp);
1853 		if (unsp->uns_lower_opencnt > 0) {
1854 			/* try reopen the vnode */
1855 			error = VOP_OPEN(uvp, unsp->uns_lower_openmode, td->td_ucred, td, unsp->uns_lower_fdidx);
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_lock =		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