xref: /netbsd-src/sys/fs/unionfs/unionfs_vnops.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
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: src/sys/fs/unionfs/union_vnops.c,v 1.152 2008/01/13 14:44:06 attilio Exp $
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/fcntl.h>
53 #include <sys/stat.h>
54 #include <sys/dirent.h>
55 #include <sys/proc.h>
56 
57 #include <fs/unionfs/unionfs.h>
58 
59 #if 0
60 #define UNIONFS_INTERNAL_DEBUG(msg, args...)    printf(msg, ## args)
61 #define UNIONFS_IDBG_RENAME
62 #else
63 #define UNIONFS_INTERNAL_DEBUG(msg, args...)
64 #endif
65 
66 static int
67 unionfs_lookup(void *v)
68 {
69 	struct vop_lookup_args *ap = v;
70 	int		iswhiteout;
71 	int		lockflag;
72 	int		error , uerror, lerror;
73 	u_long		nameiop;
74 	u_long		cnflags, cnflagsbk;
75 	struct unionfs_node *dunp;
76 	struct vnode   *dvp, *udvp, *ldvp, *vp, *uvp, *lvp, *dtmpvp;
77 	struct vattr	va;
78 	struct componentname *cnp;
79 
80 	iswhiteout = 0;
81 	lockflag = 0;
82 	error = uerror = lerror = ENOENT;
83 	cnp = ap->a_cnp;
84 	nameiop = cnp->cn_nameiop;
85 	cnflags = cnp->cn_flags;
86 	dvp = ap->a_dvp;
87 	dunp = VTOUNIONFS(dvp);
88 	udvp = dunp->un_uppervp;
89 	ldvp = dunp->un_lowervp;
90 	vp = uvp = lvp = NULLVP;
91 	*(ap->a_vpp) = NULLVP;
92 
93 	UNIONFS_INTERNAL_DEBUG("unionfs_lookup: enter: nameiop=%ld, flags=%lx, path=%s\n", nameiop, cnflags, cnp->cn_nameptr);
94 
95 	if (dvp->v_type != VDIR)
96 		return (ENOTDIR);
97 
98 	/*
99 	 * If read-only and op is not LOOKUP, will return EROFS.
100 	 */
101 	if ((cnflags & ISLASTCN) &&
102 	    (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
103 	    LOOKUP != nameiop)
104 		return (EROFS);
105 
106 	/*
107 	 * lookup dotdot
108 	 */
109 	if (cnflags & ISDOTDOT) {
110 		if (LOOKUP != nameiop && udvp == NULLVP)
111 			return (EROFS);
112 
113 		if (udvp != NULLVP) {
114 			dtmpvp = udvp;
115 			if (ldvp != NULLVP)
116 				VOP_UNLOCK(ldvp, 0);
117 		}
118 		else
119 			dtmpvp = ldvp;
120 
121 		error = VOP_LOOKUP(dtmpvp, &vp, cnp);
122 
123 		if (dtmpvp == udvp && ldvp != NULLVP) {
124 			VOP_UNLOCK(udvp, 0);
125 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
126 		}
127 
128 		if (error == 0) {
129 			/*
130 			 * Exchange lock and reference from vp to
131 			 * dunp->un_dvp. vp is upper/lower vnode, but it
132 			 * will need to return the unionfs vnode.
133 			 */
134 			if (nameiop == DELETE  || nameiop == RENAME)
135 				VOP_UNLOCK(vp, 0);
136 			vrele(vp);
137 
138 			VOP_UNLOCK(dvp, 0);
139 			*(ap->a_vpp) = dunp->un_dvp;
140 			vref(dunp->un_dvp);
141 
142 			vn_lock(dunp->un_dvp, LK_EXCLUSIVE | LK_RETRY);
143 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
144 		} else if (error == ENOENT && (cnflags & MAKEENTRY) &&
145 		    nameiop != CREATE)
146 			cache_enter(dvp, NULLVP, cnp);
147 
148 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
149 
150 		return (error);
151 	}
152 
153 	/*
154 	 * lookup upper layer
155 	 */
156 	if (udvp != NULLVP) {
157 		uerror = VOP_LOOKUP(udvp, &uvp, cnp);
158 
159 		if (uerror == 0) {
160 			if (udvp == uvp) {	/* is dot */
161 				vrele(uvp);
162 				*(ap->a_vpp) = dvp;
163 				vref(dvp);
164 
165 				UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", uerror);
166 
167 				return (uerror);
168 			}
169 		}
170 
171 		/* check whiteout */
172 		if (uerror == ENOENT || uerror == EJUSTRETURN)
173 			if (cnp->cn_flags & ISWHITEOUT)
174 				iswhiteout = 1;	/* don't lookup lower */
175 		if (iswhiteout == 0 && ldvp != NULLVP)
176 			if (VOP_GETATTR(udvp, &va, cnp->cn_cred) == 0 &&
177 			    (va.va_flags & OPAQUE))
178 				iswhiteout = 1;	/* don't lookup lower */
179 #if 0
180 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: debug: whiteout=%d, path=%s\n", iswhiteout, cnp->cn_nameptr);
181 #endif
182 	}
183 
184 	/*
185 	 * lookup lower layer
186 	 */
187 	if (ldvp != NULLVP && !(cnflags & DOWHITEOUT) && iswhiteout == 0) {
188 		/* always op is LOOKUP */
189 		cnp->cn_nameiop = LOOKUP;
190 		cnflagsbk = cnp->cn_flags;
191 		cnp->cn_flags = cnflags;
192 
193 		lerror = VOP_LOOKUP(ldvp, &lvp, cnp);
194 
195 		cnp->cn_nameiop = nameiop;
196 		if (udvp != NULLVP && (uerror == 0 || uerror == EJUSTRETURN))
197 			cnp->cn_flags = cnflagsbk;
198 
199 		if (lerror == 0) {
200 			if (ldvp == lvp) {	/* is dot */
201 				if (uvp != NULLVP)
202 					vrele(uvp);	/* no need? */
203 				vrele(lvp);
204 				*(ap->a_vpp) = dvp;
205 				vref(dvp);
206 
207 				UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", lerror);
208 				if (uvp != NULL)
209 					VOP_UNLOCK(uvp, 0);
210 				return (lerror);
211 			}
212 		}
213 	}
214 
215 	/*
216 	 * check lookup result
217 	 */
218 	if (uvp == NULLVP && lvp == NULLVP) {
219 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n",
220 		    (udvp != NULLVP ? uerror : lerror));
221 		return (udvp != NULLVP ? uerror : lerror);
222 	}
223 
224 	/*
225 	 * check vnode type
226 	 */
227 	if (uvp != NULLVP && lvp != NULLVP && uvp->v_type != lvp->v_type) {
228 		vput(lvp);
229 		lvp = NULLVP;
230 	}
231 
232 	/*
233 	 * check shadow dir
234 	 */
235 	if (uerror != 0 && uerror != EJUSTRETURN && udvp != NULLVP &&
236 	    lerror == 0 && lvp != NULLVP && lvp->v_type == VDIR &&
237 	    !(dvp->v_mount->mnt_flag & MNT_RDONLY) &&
238 	    (1 < cnp->cn_namelen || '.' != *(cnp->cn_nameptr))) {
239 		/* get unionfs vnode in order to create a new shadow dir. */
240 		error = unionfs_nodeget(dvp->v_mount, NULLVP, lvp, dvp, &vp,
241 		    cnp);
242 		if (error != 0)
243 			goto unionfs_lookup_out;
244 		error = unionfs_mkshadowdir(MOUNTTOUNIONFSMOUNT(dvp->v_mount),
245 		    udvp, VTOUNIONFS(vp), cnp);
246 		if (error != 0) {
247 			UNIONFSDEBUG("unionfs_lookup: Unable to create shadow dir.");
248 			vput(vp);
249 			goto unionfs_lookup_out;
250 		}
251 	}
252 	/*
253 	 * get unionfs vnode.
254 	 */
255 	else {
256 		if (uvp != NULLVP)
257 			error = uerror;
258 		else
259 			error = lerror;
260 		if (error != 0)
261 			goto unionfs_lookup_out;
262 		error = unionfs_nodeget(dvp->v_mount, uvp, lvp, dvp, &vp, cnp);
263 		if (error != 0) {
264 			UNIONFSDEBUG("unionfs_lookup: Unable to create unionfs vnode.");
265 			goto unionfs_lookup_out;
266 		}
267 	}
268 
269 	*(ap->a_vpp) = vp;
270 
271 	if (cnflags & MAKEENTRY)
272 		cache_enter(dvp, vp, cnp);
273 
274 	/* XXXAD lock status on error */
275 unionfs_lookup_out:
276 	if (uvp != NULLVP)
277 		vrele(uvp);
278 	if (lvp != NULLVP)
279 		vrele(lvp);
280 
281 	if (error == ENOENT && (cnflags & MAKEENTRY) && nameiop != CREATE)
282 		cache_enter(dvp, NULLVP, cnp);
283 
284 	UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
285 
286 	return (error);
287 }
288 
289 static int
290 unionfs_create(void *v)
291 {
292 	struct vop_create_args *ap = v;
293 	struct unionfs_node *dunp;
294 	struct componentname *cnp;
295 	struct vnode   *udvp;
296 	struct vnode   *vp;
297 	int		error;
298 
299 	UNIONFS_INTERNAL_DEBUG("unionfs_create: enter\n");
300 
301 	dunp = VTOUNIONFS(ap->a_dvp);
302 	cnp = ap->a_cnp;
303 	udvp = dunp->un_uppervp;
304 	error = EROFS;
305 
306 	if (udvp != NULLVP) {
307 		if ((error = VOP_CREATE(udvp, &vp, cnp, ap->a_vap)) == 0) {
308 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
309 			    ap->a_dvp, ap->a_vpp, cnp);
310 			if (error) {
311 				vput(vp);
312 			} else {
313 				vrele(vp);
314 			}
315 		}
316 	}
317 
318 	UNIONFS_INTERNAL_DEBUG("unionfs_create: leave (%d)\n", error);
319 
320 	return (error);
321 }
322 
323 static int
324 unionfs_whiteout(void *v)
325 {
326 	struct vop_whiteout_args *ap = v;
327 	struct unionfs_node *dunp;
328 	struct componentname *cnp;
329 	struct vnode   *udvp;
330 	int		error;
331 
332 	UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: enter\n");
333 
334 	dunp = VTOUNIONFS(ap->a_dvp);
335 	cnp = ap->a_cnp;
336 	udvp = dunp->un_uppervp;
337 	error = EOPNOTSUPP;
338 
339 	if (udvp != NULLVP) {
340 		switch (ap->a_flags) {
341 		case CREATE:
342 		case DELETE:
343 		case LOOKUP:
344 			error = VOP_WHITEOUT(udvp, cnp, ap->a_flags);
345 			break;
346 		default:
347 			error = EINVAL;
348 			break;
349 		}
350 	}
351 
352 	UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: leave (%d)\n", error);
353 
354 	return (error);
355 }
356 
357 static int
358 unionfs_mknod(void *v)
359 {
360 	struct vop_mknod_args *ap = v;
361 	struct unionfs_node *dunp;
362 	struct componentname *cnp;
363 	struct vnode   *udvp;
364 	struct vnode   *vp;
365 	int		error;
366 
367 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: enter\n");
368 
369 	dunp = VTOUNIONFS(ap->a_dvp);
370 	cnp = ap->a_cnp;
371 	udvp = dunp->un_uppervp;
372 	error = EROFS;
373 
374 	if (udvp != NULLVP) {
375 		if ((error = VOP_MKNOD(udvp, &vp, cnp, ap->a_vap)) == 0) {
376 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
377 			    ap->a_dvp, ap->a_vpp, cnp);
378 			if (error) {
379 				vput(vp);
380 			} else {
381 				vrele(vp);
382 			}
383 		}
384 	}
385 
386 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: leave (%d)\n", error);
387 
388 	return (error);
389 }
390 
391 static int
392 unionfs_open(void *v)
393 {
394 	struct vop_open_args *ap = v;
395 	int		error;
396 	struct unionfs_node *unp;
397 	struct unionfs_node_status *unsp;
398 	struct vnode   *uvp;
399 	struct vnode   *lvp;
400 	struct vnode   *targetvp;
401 	kauth_cred_t   cred;
402 
403 	UNIONFS_INTERNAL_DEBUG("unionfs_open: enter\n");
404 
405 	error = 0;
406 	unp = VTOUNIONFS(ap->a_vp);
407 	uvp = unp->un_uppervp;
408 	lvp = unp->un_lowervp;
409 	targetvp = NULLVP;
410 	cred = ap->a_cred;
411 
412 	unionfs_get_node_status(unp, &unsp);
413 
414 	if (unsp->uns_lower_opencnt > 0 || unsp->uns_upper_opencnt > 0) {
415 		/* vnode is already opend. */
416 		if (unsp->uns_upper_opencnt > 0)
417 			targetvp = uvp;
418 		else
419 			targetvp = lvp;
420 
421 		if (targetvp == lvp &&
422 		    (ap->a_mode & FWRITE) && lvp->v_type == VREG)
423 			targetvp = NULLVP;
424 	}
425 	if (targetvp == NULLVP) {
426 		if (uvp == NULLVP) {
427 			if ((ap->a_mode & FWRITE) && lvp->v_type == VREG) {
428 				error = unionfs_copyfile(unp,
429 				    !(ap->a_mode & O_TRUNC), cred);
430 				if (error != 0)
431 					goto unionfs_open_abort;
432 				targetvp = uvp = unp->un_uppervp;
433 			} else
434 				targetvp = lvp;
435 		} else
436 			targetvp = uvp;
437 	}
438 
439 	error = VOP_OPEN(targetvp, ap->a_mode, cred);
440 	if (error == 0) {
441 		if (targetvp == uvp) {
442 			if (uvp->v_type == VDIR && lvp != NULLVP &&
443 			    unsp->uns_lower_opencnt <= 0) {
444 				/* open lower for readdir */
445 				error = VOP_OPEN(lvp, FREAD, cred);
446 				if (error != 0) {
447 					VOP_CLOSE(uvp, ap->a_mode, cred);
448 					goto unionfs_open_abort;
449 				}
450 				unsp->uns_node_flag |= UNS_OPENL_4_READDIR;
451 				unsp->uns_lower_opencnt++;
452 			}
453 			unsp->uns_upper_opencnt++;
454 		} else {
455 			unsp->uns_lower_opencnt++;
456 			unsp->uns_lower_openmode = ap->a_mode;
457 		}
458 	}
459 
460 unionfs_open_abort:
461 	if (error != 0)
462 		unionfs_tryrem_node_status(unp, unsp);
463 
464 	UNIONFS_INTERNAL_DEBUG("unionfs_open: leave (%d)\n", error);
465 
466 	return (error);
467 }
468 
469 static int
470 unionfs_close(void *v)
471 {
472 	struct vop_close_args *ap = v;
473 	int		error;
474 	int		locked;
475 	struct unionfs_node *unp;
476 	struct unionfs_node_status *unsp;
477 	kauth_cred_t   cred;
478 	struct vnode   *ovp;
479 
480 	UNIONFS_INTERNAL_DEBUG("unionfs_close: enter\n");
481 
482 	locked = 0;
483 	unp = VTOUNIONFS(ap->a_vp);
484 	cred = ap->a_cred;
485 
486 	if (VOP_ISLOCKED(ap->a_vp) != LK_EXCLUSIVE) {
487 		vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
488 		locked = 1;
489 	}
490 	unionfs_get_node_status(unp, &unsp);
491 
492 	if (unsp->uns_lower_opencnt <= 0 && unsp->uns_upper_opencnt <= 0) {
493 #ifdef DIAGNOSTIC
494 		printf("unionfs_close: warning: open count is 0\n");
495 #endif
496 		if (unp->un_uppervp != NULLVP)
497 			ovp = unp->un_uppervp;
498 		else
499 			ovp = unp->un_lowervp;
500 	} else if (unsp->uns_upper_opencnt > 0)
501 		ovp = unp->un_uppervp;
502 	else
503 		ovp = unp->un_lowervp;
504 
505 	error = VOP_CLOSE(ovp, ap->a_fflag, cred);
506 
507 	if (error != 0)
508 		goto unionfs_close_abort;
509 
510 	if (ovp == unp->un_uppervp) {
511 		unsp->uns_upper_opencnt--;
512 		if (unsp->uns_upper_opencnt == 0) {
513 			if (unsp->uns_node_flag & UNS_OPENL_4_READDIR) {
514 				VOP_CLOSE(unp->un_lowervp, FREAD, cred);
515 				unsp->uns_node_flag &= ~UNS_OPENL_4_READDIR;
516 				unsp->uns_lower_opencnt--;
517 			}
518 		}
519 	} else
520 		unsp->uns_lower_opencnt--;
521 
522 unionfs_close_abort:
523 	unionfs_tryrem_node_status(unp, unsp);
524 
525 	if (locked != 0)
526 		VOP_UNLOCK(ap->a_vp, 0);
527 
528 	UNIONFS_INTERNAL_DEBUG("unionfs_close: leave (%d)\n", error);
529 
530 	return (error);
531 }
532 
533 /*
534  * Check the access mode toward shadow file/dir.
535  */
536 static int
537 unionfs_check_corrected_access(u_short mode, struct vattr *va, kauth_cred_t cred)
538 {
539 	int		result;
540 	int		error;
541 	uid_t		uid;	/* upper side vnode's uid */
542 	gid_t		gid;	/* upper side vnode's gid */
543 	u_short		vmode;	/* upper side vnode's mode */
544 	u_short		mask;
545 
546 	mask = 0;
547 	uid = va->va_uid;
548 	gid = va->va_gid;
549 	vmode = va->va_mode;
550 
551 	/* check owner */
552 	if (kauth_cred_getuid(cred) == uid) {
553 		if (mode & VEXEC)
554 			mask |= S_IXUSR;
555 		if (mode & VREAD)
556 			mask |= S_IRUSR;
557 		if (mode & VWRITE)
558 			mask |= S_IWUSR;
559 		return ((vmode & mask) == mask ? 0 : EACCES);
560 	}
561 
562 	/* check group */
563 	error = kauth_cred_ismember_gid(cred, gid, &result);
564 	if (error != 0)
565 		return error;
566 	if (result) {
567 		if (mode & VEXEC)
568 			mask |= S_IXGRP;
569 		if (mode & VREAD)
570 			mask |= S_IRGRP;
571 		if (mode & VWRITE)
572 			mask |= S_IWGRP;
573 		return ((vmode & mask) == mask ? 0 : EACCES);
574 	}
575 
576 	/* check other */
577 	if (mode & VEXEC)
578 		mask |= S_IXOTH;
579 	if (mode & VREAD)
580 		mask |= S_IROTH;
581 	if (mode & VWRITE)
582 		mask |= S_IWOTH;
583 
584 	return ((vmode & mask) == mask ? 0 : EACCES);
585 }
586 
587 static int
588 unionfs_access(void *v)
589 {
590 	struct vop_access_args *ap = v;
591 	struct unionfs_mount *ump;
592 	struct unionfs_node *unp;
593 	struct vnode   *uvp;
594 	struct vnode   *lvp;
595 	struct vattr	va;
596 	int		mode;
597 	int		error;
598 
599 	UNIONFS_INTERNAL_DEBUG("unionfs_access: enter\n");
600 
601 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
602 	unp = VTOUNIONFS(ap->a_vp);
603 	uvp = unp->un_uppervp;
604 	lvp = unp->un_lowervp;
605 	mode = ap->a_mode;
606 	error = EACCES;
607 
608 	if ((mode & VWRITE) &&
609 	    (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) {
610 		switch (ap->a_vp->v_type) {
611 		case VREG:
612 		case VDIR:
613 		case VLNK:
614 			return (EROFS);
615 		default:
616 			break;
617 		}
618 	}
619 
620 	if (uvp != NULLVP) {
621 		error = VOP_ACCESS(uvp, mode, ap->a_cred);
622 
623 		UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
624 
625 		return (error);
626 	}
627 
628 	if (lvp != NULLVP) {
629 		if (mode & VWRITE) {
630 			if (ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY) {
631 				switch (ap->a_vp->v_type) {
632 				case VREG:
633 				case VDIR:
634 				case VLNK:
635 					return (EROFS);
636 				default:
637 					break;
638 				}
639 			} else if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
640 				/* check shadow file/dir */
641 				if (ump->um_copymode != UNIONFS_TRANSPARENT) {
642 					error = unionfs_create_uppervattr(ump,
643 					    lvp, &va, ap->a_cred);
644 					if (error != 0)
645 						return (error);
646 
647 					error = unionfs_check_corrected_access(
648 					    mode, &va, ap->a_cred);
649 					if (error != 0)
650 						return (error);
651 				}
652 			}
653 			mode &= ~VWRITE;
654 			mode |= VREAD; /* will copy to upper */
655 		}
656 		error = VOP_ACCESS(lvp, mode, ap->a_cred);
657 	}
658 
659 	UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
660 
661 	return (error);
662 }
663 
664 static int
665 unionfs_getattr(void *v)
666 {
667 	struct vop_getattr_args *ap = v;
668 	int		error;
669 	struct unionfs_node *unp;
670 	struct unionfs_mount *ump;
671 	struct vnode   *uvp;
672 	struct vnode   *lvp;
673 	struct vattr	va;
674 
675 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: enter\n");
676 
677 	unp = VTOUNIONFS(ap->a_vp);
678 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
679 	uvp = unp->un_uppervp;
680 	lvp = unp->un_lowervp;
681 
682 	if (uvp != NULLVP) {
683 		if ((error = VOP_GETATTR(uvp, ap->a_vap, ap->a_cred)) == 0)
684 			ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid;
685 
686 		UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
687 		    ap->a_vap->va_mode, ap->a_vap->va_uid,
688 		    ap->a_vap->va_gid, error);
689 
690 		return (error);
691 	}
692 
693 	error = VOP_GETATTR(lvp, ap->a_vap, ap->a_cred);
694 
695 	if (error == 0 && !(ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY)) {
696 		/* correct the attr toward shadow file/dir. */
697 		if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
698 			unionfs_create_uppervattr_core(ump, ap->a_vap, &va);
699 			ap->a_vap->va_mode = va.va_mode;
700 			ap->a_vap->va_uid = va.va_uid;
701 			ap->a_vap->va_gid = va.va_gid;
702 		}
703 	}
704 
705 	if (error == 0)
706 		ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid;
707 
708 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
709 	    ap->a_vap->va_mode, ap->a_vap->va_uid, ap->a_vap->va_gid, error);
710 
711 	return (error);
712 }
713 
714 static int
715 unionfs_setattr(void *v)
716 {
717 	struct vop_setattr_args *ap = v;
718 	int		error;
719 	struct unionfs_node *unp;
720 	struct vnode   *uvp;
721 	struct vnode   *lvp;
722 	struct vattr   *vap;
723 
724 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: enter\n");
725 
726 	error = EROFS;
727 	unp = VTOUNIONFS(ap->a_vp);
728 	uvp = unp->un_uppervp;
729 	lvp = unp->un_lowervp;
730 	vap = ap->a_vap;
731 
732 	if ((ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) &&
733 	    (vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
734 	     vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
735 	     vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL))
736 		return (EROFS);
737 
738 	if (uvp == NULLVP && lvp->v_type == VREG) {
739 		error = unionfs_copyfile(unp, (vap->va_size != 0),
740 		    ap->a_cred);
741 		if (error != 0)
742 			return (error);
743 		uvp = unp->un_uppervp;
744 	}
745 
746 	if (uvp != NULLVP)
747 		error = VOP_SETATTR(uvp, vap, ap->a_cred);
748 
749 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: leave (%d)\n", error);
750 
751 	return (error);
752 }
753 
754 static int
755 unionfs_read(void *v)
756 {
757 	struct vop_read_args *ap = v;
758 	int		error;
759 	struct unionfs_node *unp;
760 	struct vnode   *tvp;
761 
762 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: enter\n"); */
763 
764 	unp = VTOUNIONFS(ap->a_vp);
765 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
766 
767 	error = VOP_READ(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
768 
769 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: leave (%d)\n", error); */
770 
771 	return (error);
772 }
773 
774 static int
775 unionfs_write(void *v)
776 {
777 	struct vop_write_args *ap = v;
778 	int		error;
779 	struct unionfs_node *unp;
780 	struct vnode   *tvp;
781 
782 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: enter\n"); */
783 
784 	unp = VTOUNIONFS(ap->a_vp);
785 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
786 
787 	error = VOP_WRITE(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
788 
789 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: leave (%d)\n", error); */
790 
791 	return (error);
792 }
793 
794 static int
795 unionfs_ioctl(void *v)
796 {
797 	struct vop_ioctl_args *ap = v;
798 	int error;
799 	struct unionfs_node *unp;
800 	struct unionfs_node_status *unsp;
801 	struct vnode   *ovp;
802 
803 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: enter\n");
804 
805  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
806 	unp = VTOUNIONFS(ap->a_vp);
807 	unionfs_get_node_status(unp, &unsp);
808 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
809 	unionfs_tryrem_node_status(unp, unsp);
810 	VOP_UNLOCK(ap->a_vp, 0);
811 
812 	if (ovp == NULLVP)
813 		return (EBADF);
814 
815 	error = VOP_IOCTL(ovp, ap->a_command, ap->a_data, ap->a_fflag,
816 	    ap->a_cred);
817 
818 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: lease (%d)\n", error);
819 
820 	return (error);
821 }
822 
823 static int
824 unionfs_poll(void *v)
825 {
826 	struct vop_poll_args *ap = v;
827 	struct unionfs_node *unp;
828 	struct unionfs_node_status *unsp;
829 	struct vnode   *ovp;
830 
831  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
832 	unp = VTOUNIONFS(ap->a_vp);
833 	unionfs_get_node_status(unp, &unsp);
834 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
835 	unionfs_tryrem_node_status(unp, unsp);
836 	VOP_UNLOCK(ap->a_vp, 0);
837 
838 	if (ovp == NULLVP)
839 		return (EBADF);
840 
841 	return (VOP_POLL(ovp, ap->a_events));
842 }
843 
844 static int
845 unionfs_fsync(void *v)
846 {
847 	struct vop_fsync_args *ap = v;
848 	struct unionfs_node *unp;
849 	struct unionfs_node_status *unsp;
850 	struct vnode   *ovp;
851 
852 	unp = VTOUNIONFS(ap->a_vp);
853 	unionfs_get_node_status(unp, &unsp);
854 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
855 	unionfs_tryrem_node_status(unp, unsp);
856 
857 	if (ovp == NULLVP)
858 		return (EBADF);
859 
860 	return (VOP_FSYNC(ovp, ap->a_cred, ap->a_flags, ap->a_offlo, ap->a_offhi));
861 }
862 
863 static int
864 unionfs_remove(void *v)
865 {
866 	struct vop_remove_args *ap = v;
867 	int		error;
868 	struct unionfs_node *dunp;
869 	struct unionfs_node *unp;
870 	struct unionfs_mount *ump;
871 	struct vnode   *udvp;
872 	struct vnode   *uvp;
873 	struct vnode   *lvp;
874 	struct componentname *cnp;
875 
876 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: enter\n");
877 
878 	error = 0;
879 	dunp = VTOUNIONFS(ap->a_dvp);
880 	unp = VTOUNIONFS(ap->a_vp);
881 	udvp = dunp->un_uppervp;
882 	uvp = unp->un_uppervp;
883 	lvp = unp->un_lowervp;
884 	cnp = ap->a_cnp;
885 
886 	if (udvp == NULLVP)
887 		return (EROFS);
888 
889 	if (uvp != NULLVP) {
890 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
891 		if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP)
892 			cnp->cn_flags |= DOWHITEOUT;
893 		error = VOP_REMOVE(udvp, uvp, cnp);
894 	} else if (lvp != NULLVP)
895 		error = unionfs_mkwhiteout(udvp, cnp, unp->un_path);
896 
897 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: leave (%d)\n", error);
898 
899 	return (error);
900 }
901 
902 static int
903 unionfs_link(void *v)
904 {
905 #if 0
906 	struct vop_link_args *ap = v;
907 	int		error;
908 	int		needrelookup;
909 	struct unionfs_node *dunp;
910 	struct unionfs_node *unp;
911 	struct vnode   *udvp;
912 	struct vnode   *uvp;
913 	struct componentname *cnp;
914 
915 	UNIONFS_INTERNAL_DEBUG("unionfs_link: enter\n");
916 
917 	error = 0;
918 	needrelookup = 0;
919 	dunp = VTOUNIONFS(ap->a_tdvp);
920 	unp = NULL;
921 	udvp = dunp->un_uppervp;
922 	uvp = NULLVP;
923 	cnp = ap->a_cnp;
924 
925 	if (udvp == NULLVP)
926 		return (EROFS);
927 
928 	if (ap->a_vp->v_op != unionfs_vnodeop_p)
929 		uvp = ap->a_vp;
930 	else {
931 		unp = VTOUNIONFS(ap->a_vp);
932 
933 		if (unp->un_uppervp == NULLVP) {
934 			if (ap->a_vp->v_type != VREG)
935 				return (EOPNOTSUPP);
936 
937 			error = unionfs_copyfile(unp, 1, cnp->cn_cred);
938 			if (error != 0)
939 				return (error);
940 			needrelookup = 1;
941 		}
942 		uvp = unp->un_uppervp;
943 	}
944 
945 	if (needrelookup != 0)
946 		error = unionfs_relookup_for_create(ap->a_tdvp, cnp);
947 
948 	if (error == 0)
949 		error = VOP_LINK(udvp, uvp, cnp);
950 
951 	UNIONFS_INTERNAL_DEBUG("unionfs_link: leave (%d)\n", error);
952 
953 	return (error);
954 #else
955 	panic("XXXAD");
956 	return 0;
957 #endif
958 }
959 
960 static int
961 unionfs_rename(void *v)
962 {
963 	struct vop_rename_args *ap = v;
964 	int		error;
965 	struct vnode   *fdvp;
966 	struct vnode   *fvp;
967 	struct componentname *fcnp;
968 	struct vnode   *tdvp;
969 	struct vnode   *tvp;
970 	struct componentname *tcnp;
971 	struct vnode   *ltdvp;
972 	struct vnode   *ltvp;
973 
974 	/* rename target vnodes */
975 	struct vnode   *rfdvp;
976 	struct vnode   *rfvp;
977 	struct vnode   *rtdvp;
978 	struct vnode   *rtvp;
979 
980 	int		needrelookup;
981 	struct unionfs_mount *ump;
982 	struct unionfs_node *unp;
983 
984 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: enter\n");
985 
986 	error = 0;
987 	fdvp = ap->a_fdvp;
988 	fvp = ap->a_fvp;
989 	fcnp = ap->a_fcnp;
990 	tdvp = ap->a_tdvp;
991 	tvp = ap->a_tvp;
992 	tcnp = ap->a_tcnp;
993 	ltdvp = NULLVP;
994 	ltvp = NULLVP;
995 	rfdvp = fdvp;
996 	rfvp = fvp;
997 	rtdvp = tdvp;
998 	rtvp = tvp;
999 	needrelookup = 0;
1000 
1001 #ifdef DIAGNOSTIC
1002 	if (!(fcnp->cn_flags & HASBUF) || !(tcnp->cn_flags & HASBUF))
1003 		panic("unionfs_rename: no name");
1004 #endif
1005 
1006 	/* check for cross device rename */
1007 	if (fvp->v_mount != tdvp->v_mount ||
1008 	    (tvp != NULLVP && fvp->v_mount != tvp->v_mount)) {
1009 		error = EXDEV;
1010 		goto unionfs_rename_abort;
1011 	}
1012 
1013 	/* Renaming a file to itself has no effect. */
1014 	if (fvp == tvp)
1015 		goto unionfs_rename_abort;
1016 
1017 	/*
1018 	 * from/to vnode is unionfs node.
1019 	 */
1020 
1021 	unp = VTOUNIONFS(fdvp);
1022 #ifdef UNIONFS_IDBG_RENAME
1023 	UNIONFS_INTERNAL_DEBUG("fdvp=%p, ufdvp=%p, lfdvp=%p\n", fdvp, unp->un_uppervp, unp->un_lowervp);
1024 #endif
1025 	if (unp->un_uppervp == NULLVP) {
1026 		error = ENODEV;
1027 		goto unionfs_rename_abort;
1028 	}
1029 	rfdvp = unp->un_uppervp;
1030 	vref(rfdvp);
1031 
1032 	unp = VTOUNIONFS(fvp);
1033 #ifdef UNIONFS_IDBG_RENAME
1034 	UNIONFS_INTERNAL_DEBUG("fvp=%p, ufvp=%p, lfvp=%p\n", fvp, unp->un_uppervp, unp->un_lowervp);
1035 #endif
1036 	ump = MOUNTTOUNIONFSMOUNT(fvp->v_mount);
1037 	if (unp->un_uppervp == NULLVP) {
1038 		switch (fvp->v_type) {
1039 		case VREG:
1040 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1041 				goto unionfs_rename_abort;
1042 			error = unionfs_copyfile(unp, 1, fcnp->cn_cred);
1043 			VOP_UNLOCK(fvp, 0);
1044 			if (error != 0)
1045 				goto unionfs_rename_abort;
1046 			break;
1047 		case VDIR:
1048 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1049 				goto unionfs_rename_abort;
1050 			error = unionfs_mkshadowdir(ump, rfdvp, unp, fcnp);
1051 			VOP_UNLOCK(fvp, 0);
1052 			if (error != 0)
1053 				goto unionfs_rename_abort;
1054 			break;
1055 		default:
1056 			error = ENODEV;
1057 			goto unionfs_rename_abort;
1058 		}
1059 
1060 		needrelookup = 1;
1061 	}
1062 
1063 	if (unp->un_lowervp != NULLVP)
1064 		fcnp->cn_flags |= DOWHITEOUT;
1065 	rfvp = unp->un_uppervp;
1066 	vref(rfvp);
1067 
1068 	unp = VTOUNIONFS(tdvp);
1069 #ifdef UNIONFS_IDBG_RENAME
1070 	UNIONFS_INTERNAL_DEBUG("tdvp=%p, utdvp=%p, ltdvp=%p\n", tdvp, unp->un_uppervp, unp->un_lowervp);
1071 #endif
1072 	if (unp->un_uppervp == NULLVP) {
1073 		error = ENODEV;
1074 		goto unionfs_rename_abort;
1075 	}
1076 	rtdvp = unp->un_uppervp;
1077 	ltdvp = unp->un_lowervp;
1078 	vref(rtdvp);
1079 
1080 	if (tdvp == tvp) {
1081 		rtvp = rtdvp;
1082 		vref(rtvp);
1083 	} else if (tvp != NULLVP) {
1084 		unp = VTOUNIONFS(tvp);
1085 #ifdef UNIONFS_IDBG_RENAME
1086 		UNIONFS_INTERNAL_DEBUG("tvp=%p, utvp=%p, ltvp=%p\n", tvp, unp->un_uppervp, unp->un_lowervp);
1087 #endif
1088 		if (unp->un_uppervp == NULLVP)
1089 			rtvp = NULLVP;
1090 		else {
1091 			if (tvp->v_type == VDIR) {
1092 				error = EINVAL;
1093 				goto unionfs_rename_abort;
1094 			}
1095 			rtvp = unp->un_uppervp;
1096 			ltvp = unp->un_lowervp;
1097 			vref(rtvp);
1098 		}
1099 	}
1100 
1101 	if (needrelookup != 0) {
1102 		if ((error = vn_lock(fdvp, LK_EXCLUSIVE)) != 0)
1103 			goto unionfs_rename_abort;
1104 		error = unionfs_relookup_for_delete(fdvp, fcnp);
1105 		VOP_UNLOCK(fdvp, 0);
1106 		if (error != 0)
1107 			goto unionfs_rename_abort;
1108 
1109 		/* Locke of tvp is canceled in order to avoid recursive lock. */
1110 		if (tvp != NULLVP && tvp != tdvp)
1111 			VOP_UNLOCK(tvp, 0);
1112 		error = unionfs_relookup_for_rename(tdvp, tcnp);
1113 		if (tvp != NULLVP && tvp != tdvp)
1114 			vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
1115 		if (error != 0)
1116 			goto unionfs_rename_abort;
1117 	}
1118 
1119 	error = VOP_RENAME(rfdvp, rfvp, fcnp, rtdvp, rtvp, tcnp);
1120 
1121 	if (error == 0) {
1122 		if (rtvp != NULLVP && rtvp->v_type == VDIR)
1123 			cache_purge(tdvp);
1124 		if (fvp->v_type == VDIR && fdvp != tdvp)
1125 			cache_purge(fdvp);
1126 	}
1127 
1128 	if (fdvp != rfdvp)
1129 		vrele(fdvp);
1130 	if (fvp != rfvp)
1131 		vrele(fvp);
1132 	if (ltdvp != NULLVP)
1133 		VOP_UNLOCK(ltdvp, 0);
1134 	if (tdvp != rtdvp)
1135 		vrele(tdvp);
1136 	if (ltvp != NULLVP)
1137 		VOP_UNLOCK(ltvp, 0);
1138 	if (tvp != rtvp && tvp != NULLVP) {
1139 		if (rtvp == NULLVP)
1140 			vput(tvp);
1141 		else
1142 			vrele(tvp);
1143 	}
1144 
1145 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1146 
1147 	return (error);
1148 
1149 unionfs_rename_abort:
1150 	if (fdvp != rfdvp)
1151 		vrele(rfdvp);
1152 	if (fvp != rfvp)
1153 		vrele(rfvp);
1154 	if (tdvp != rtdvp)
1155 		vrele(rtdvp);
1156 	vput(tdvp);
1157 	if (tvp != rtvp && rtvp != NULLVP)
1158 		vrele(rtvp);
1159 	if (tvp != NULLVP) {
1160 		if (tdvp != tvp)
1161 			vput(tvp);
1162 		else
1163 			vrele(tvp);
1164 	}
1165 	vrele(fdvp);
1166 	vrele(fvp);
1167 
1168 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1169 
1170 	return (error);
1171 }
1172 
1173 static int
1174 unionfs_mkdir(void *v)
1175 {
1176 	struct vop_mkdir_args *ap = v;
1177 	int		error;
1178 	struct unionfs_node *dunp;
1179 	struct componentname *cnp;
1180 	struct vnode   *udvp;
1181 	struct vnode   *uvp;
1182 	struct vattr	va;
1183 
1184 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: enter\n");
1185 
1186 	error = EROFS;
1187 	dunp = VTOUNIONFS(ap->a_dvp);
1188 	cnp = ap->a_cnp;
1189 	udvp = dunp->un_uppervp;
1190 
1191 	if (udvp != NULLVP) {
1192 		/* check opaque */
1193 		if (!(cnp->cn_flags & ISWHITEOUT)) {
1194 			error = VOP_GETATTR(udvp, &va, cnp->cn_cred);
1195 			if (error != 0)
1196 				return (error);
1197 			if (va.va_flags & OPAQUE)
1198 				cnp->cn_flags |= ISWHITEOUT;
1199 		}
1200 
1201 		if ((error = VOP_MKDIR(udvp, &uvp, cnp, ap->a_vap)) == 0) {
1202 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1203 			    ap->a_dvp, ap->a_vpp, cnp);
1204 			if (error) {
1205 				vput(uvp);
1206 			} else {
1207 				vrele(uvp);
1208 			}
1209 		}
1210 	}
1211 
1212 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: leave (%d)\n", error);
1213 
1214 	return (error);
1215 }
1216 
1217 static int
1218 unionfs_rmdir(void *v)
1219 {
1220 	struct vop_rmdir_args *ap = v;
1221 	int		error;
1222 	struct unionfs_node *dunp;
1223 	struct unionfs_node *unp;
1224 	struct unionfs_mount *ump;
1225 	struct componentname *cnp;
1226 	struct vnode   *udvp;
1227 	struct vnode   *uvp;
1228 	struct vnode   *lvp;
1229 
1230 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: enter\n");
1231 
1232 	error = 0;
1233 	dunp = VTOUNIONFS(ap->a_dvp);
1234 	unp = VTOUNIONFS(ap->a_vp);
1235 	cnp = ap->a_cnp;
1236 	udvp = dunp->un_uppervp;
1237 	uvp = unp->un_uppervp;
1238 	lvp = unp->un_lowervp;
1239 
1240 	if (udvp == NULLVP)
1241 		return (EROFS);
1242 
1243 	if (udvp == uvp)
1244 		return (EOPNOTSUPP);
1245 
1246 	if (uvp != NULLVP) {
1247 		if (lvp != NULLVP) {
1248 			error = unionfs_check_rmdir(ap->a_vp, cnp->cn_cred);
1249 			if (error != 0)
1250 				return (error);
1251 		}
1252 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
1253 		if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP)
1254 			cnp->cn_flags |= DOWHITEOUT;
1255 		error = VOP_RMDIR(udvp, uvp, cnp);
1256 	}
1257 	else if (lvp != NULLVP)
1258 		error = unionfs_mkwhiteout(udvp, cnp, unp->un_path);
1259 
1260 	if (error == 0) {
1261 		cache_purge(ap->a_dvp);
1262 		cache_purge(ap->a_vp);
1263 	}
1264 
1265 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: leave (%d)\n", error);
1266 
1267 	return (error);
1268 }
1269 
1270 static int
1271 unionfs_symlink(void *v)
1272 {
1273 	struct vop_symlink_args *ap = v;
1274 	int		error;
1275 	struct unionfs_node *dunp;
1276 	struct componentname *cnp;
1277 	struct vnode   *udvp;
1278 	struct vnode   *uvp;
1279 
1280 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: enter\n");
1281 
1282 	error = EROFS;
1283 	dunp = VTOUNIONFS(ap->a_dvp);
1284 	cnp = ap->a_cnp;
1285 	udvp = dunp->un_uppervp;
1286 
1287 	if (udvp != NULLVP) {
1288 		error = VOP_SYMLINK(udvp, &uvp, cnp, ap->a_vap, ap->a_target);
1289 		if (error == 0) {
1290 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1291 			    ap->a_dvp, ap->a_vpp, cnp);
1292 			if (error) {
1293 				vput(uvp);
1294 			} else {
1295 				vrele(uvp);
1296 			}
1297 		}
1298 	}
1299 
1300 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: leave (%d)\n", error);
1301 
1302 	return (error);
1303 }
1304 
1305 static int
1306 unionfs_readdir(void *v)
1307 {
1308 	struct vop_readdir_args *ap = v;
1309 	int		error;
1310 	int		eofflag;
1311 	int		locked;
1312 	struct unionfs_node *unp;
1313 	struct unionfs_node_status *unsp;
1314 	struct uio     *uio;
1315 	struct vnode   *uvp;
1316 	struct vnode   *lvp;
1317 	struct vattr    va;
1318 
1319 	int		ncookies_bk;
1320 	off_t          *cookies_bk;
1321 
1322 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: enter\n");
1323 
1324 	error = 0;
1325 	eofflag = 0;
1326 	locked = 0;
1327 	unp = VTOUNIONFS(ap->a_vp);
1328 	uio = ap->a_uio;
1329 	uvp = unp->un_uppervp;
1330 	lvp = unp->un_lowervp;
1331 	ncookies_bk = 0;
1332 	cookies_bk = NULL;
1333 
1334 	if (ap->a_vp->v_type != VDIR)
1335 		return (ENOTDIR);
1336 
1337 	/* check opaque */
1338 	if (uvp != NULLVP && lvp != NULLVP) {
1339 		if ((error = VOP_GETATTR(uvp, &va, ap->a_cred)) != 0)
1340 			goto unionfs_readdir_exit;
1341 		if (va.va_flags & OPAQUE)
1342 			lvp = NULLVP;
1343 	}
1344 
1345 	/* check the open count. unionfs needs to open before readdir. */
1346 	VOP_UNLOCK(ap->a_vp, 0);
1347 	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
1348 	unionfs_get_node_status(unp, &unsp);
1349 	if ((uvp != NULLVP && unsp->uns_upper_opencnt <= 0) ||
1350 	    (lvp != NULLVP && unsp->uns_lower_opencnt <= 0)) {
1351 		unionfs_tryrem_node_status(unp, unsp);
1352 		error = EBADF;
1353 	}
1354 	if (error != 0)
1355 		goto unionfs_readdir_exit;
1356 
1357 	/* upper only */
1358 	if (uvp != NULLVP && lvp == NULLVP) {
1359 		error = VOP_READDIR(uvp, uio, ap->a_cred, ap->a_eofflag,
1360 		    ap->a_cookies, ap->a_ncookies);
1361 		unsp->uns_readdir_status = 0;
1362 
1363 		goto unionfs_readdir_exit;
1364 	}
1365 
1366 	/* lower only */
1367 	if (uvp == NULLVP && lvp != NULLVP) {
1368 		error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1369 		    ap->a_cookies, ap->a_ncookies);
1370 		unsp->uns_readdir_status = 2;
1371 
1372 		goto unionfs_readdir_exit;
1373 	}
1374 
1375 	/*
1376 	 * readdir upper and lower
1377 	 */
1378 	KASSERT(uvp != NULLVP);
1379 	KASSERT(lvp != NULLVP);
1380 	if (uio->uio_offset == 0)
1381 		unsp->uns_readdir_status = 0;
1382 
1383 	if (unsp->uns_readdir_status == 0) {
1384 		/* read upper */
1385 		error = VOP_READDIR(uvp, uio, ap->a_cred, &eofflag,
1386 				    ap->a_cookies, ap->a_ncookies);
1387 
1388 		if (error != 0 || eofflag == 0)
1389 			goto unionfs_readdir_exit;
1390 		unsp->uns_readdir_status = 1;
1391 
1392 		/*
1393 		 * ufs(and other fs) needs size of uio_resid larger than
1394 		 * DIRBLKSIZ.
1395 		 * size of DIRBLKSIZ equals DEV_BSIZE.
1396 		 * (see: ufs/ufs/ufs_vnops.c ufs_readdir func , ufs/ufs/dir.h)
1397 		 */
1398 		if (uio->uio_resid <= (uio->uio_resid & (DEV_BSIZE -1)))
1399 			goto unionfs_readdir_exit;
1400 
1401 		/*
1402 		 * backup cookies
1403 		 * It prepares to readdir in lower.
1404 		 */
1405 		if (ap->a_ncookies != NULL) {
1406 			ncookies_bk = *(ap->a_ncookies);
1407 			*(ap->a_ncookies) = 0;
1408 		}
1409 		if (ap->a_cookies != NULL) {
1410 			cookies_bk = *(ap->a_cookies);
1411 			*(ap->a_cookies) = NULL;
1412 		}
1413 	}
1414 
1415 	/* initialize for readdir in lower */
1416 	if (unsp->uns_readdir_status == 1) {
1417 		unsp->uns_readdir_status = 2;
1418 		uio->uio_offset = 0;
1419 	}
1420 
1421 	if (lvp == NULLVP) {
1422 		error = EBADF;
1423 		goto unionfs_readdir_exit;
1424 	}
1425 	/* read lower */
1426 	error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1427 			    ap->a_cookies, ap->a_ncookies);
1428 
1429 	if (cookies_bk != NULL) {
1430 		/* merge cookies */
1431 		int		size;
1432 		off_t         *newcookies, *pos;
1433 
1434 		size = *(ap->a_ncookies) + ncookies_bk;
1435 		newcookies = (off_t *) malloc(size * sizeof(off_t),
1436 		    M_TEMP, M_WAITOK);
1437 		pos = newcookies;
1438 
1439 		memcpy(pos, cookies_bk, ncookies_bk * sizeof(off_t));
1440 		pos += ncookies_bk * sizeof(off_t);
1441 		memcpy(pos, *(ap->a_cookies), *(ap->a_ncookies) * sizeof(off_t));
1442 		free(cookies_bk, M_TEMP);
1443 		free(*(ap->a_cookies), M_TEMP);
1444 		*(ap->a_ncookies) = size;
1445 		*(ap->a_cookies) = newcookies;
1446 	}
1447 
1448 unionfs_readdir_exit:
1449 	if (error != 0 && ap->a_eofflag != NULL)
1450 		*(ap->a_eofflag) = 1;
1451 
1452 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1453 
1454 	return (error);
1455 }
1456 
1457 static int
1458 unionfs_readlink(void *v)
1459 {
1460 	struct vop_readlink_args *ap = v;
1461 	int error;
1462 	struct unionfs_node *unp;
1463 	struct vnode   *vp;
1464 
1465 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: enter\n");
1466 
1467 	unp = VTOUNIONFS(ap->a_vp);
1468 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1469 
1470 	error = VOP_READLINK(vp, ap->a_uio, ap->a_cred);
1471 
1472 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: leave (%d)\n", error);
1473 
1474 	return (error);
1475 }
1476 
1477 static int
1478 unionfs_inactive(void *v)
1479 {
1480 	struct vop_inactive_args *ap = v;
1481 	*ap->a_recycle = true;
1482 	VOP_UNLOCK(ap->a_vp, 0);
1483 	return (0);
1484 }
1485 
1486 static int
1487 unionfs_reclaim(void *v)
1488 {
1489 	struct vop_reclaim_args *ap = v;
1490 
1491 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: enter\n"); */
1492 
1493 	unionfs_noderem(ap->a_vp);
1494 
1495 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: leave\n"); */
1496 
1497 	return (0);
1498 }
1499 
1500 static int
1501 unionfs_print(void *v)
1502 {
1503 	struct vop_print_args *ap = v;
1504 	struct unionfs_node *unp;
1505 	/* struct unionfs_node_status *unsp; */
1506 
1507 	unp = VTOUNIONFS(ap->a_vp);
1508 	/* unionfs_get_node_status(unp, &unsp); */
1509 
1510 	printf("unionfs_vp=%p, uppervp=%p, lowervp=%p\n",
1511 	    ap->a_vp, unp->un_uppervp, unp->un_lowervp);
1512 	/*
1513 	printf("unionfs opencnt: uppervp=%d, lowervp=%d\n",
1514 	    unsp->uns_upper_opencnt, unsp->uns_lower_opencnt);
1515 	*/
1516 
1517 	if (unp->un_uppervp != NULLVP)
1518 		vprint("unionfs: upper", unp->un_uppervp);
1519 	if (unp->un_lowervp != NULLVP)
1520 		vprint("unionfs: lower", unp->un_lowervp);
1521 
1522 	return (0);
1523 }
1524 
1525 static int
1526 unionfs_lock(void *v)
1527 {
1528 	struct vop_lock_args *ap = v;
1529 	int		error;
1530 	int		flags;
1531 	struct vnode   *lvp;
1532 	struct vnode   *uvp;
1533 	struct unionfs_node *unp;
1534 
1535 	unp = VTOUNIONFS(ap->a_vp);
1536 	lvp = unp->un_lowervp;
1537 	uvp = unp->un_uppervp;
1538 	flags = ap->a_flags;
1539 	error = 0;
1540 
1541 	if ((flags & LK_INTERLOCK) != 0) {
1542 		mutex_exit(&ap->a_vp->v_interlock);
1543 		flags &= ~LK_INTERLOCK;
1544 	}
1545 
1546 	if (lvp != NULLVP) {
1547 		error = VOP_LOCK(lvp, flags);
1548 	}
1549 	if (error == 0 && uvp != NULLVP) {
1550 		error = VOP_LOCK(uvp, flags);
1551 		if (error != 0) {
1552 			VOP_UNLOCK(lvp, 0);
1553 		}
1554 	}
1555 
1556 	return error;
1557 }
1558 
1559 static int
1560 unionfs_unlock(void *v)
1561 {
1562 	struct vop_unlock_args *ap = v;
1563 	int		error;
1564 	struct vnode   *lvp;
1565 	struct vnode   *uvp;
1566 	struct unionfs_node *unp;
1567 
1568 	unp = VTOUNIONFS(ap->a_vp);
1569 	lvp = unp->un_lowervp;
1570 	uvp = unp->un_uppervp;
1571 	error = 0;
1572 
1573 	if (lvp != NULLVP) {
1574 		error = VOP_UNLOCK(lvp, ap->a_flags);
1575 	}
1576 	if (error == 0 && uvp != NULLVP) {
1577 		error = VOP_UNLOCK(uvp, ap->a_flags);
1578 	}
1579 
1580 	return error;
1581 }
1582 
1583 static int
1584 unionfs_pathconf(void *v)
1585 {
1586 	struct vop_pathconf_args *ap = v;
1587 	struct unionfs_node *unp;
1588 	struct vnode   *vp;
1589 
1590 	unp = VTOUNIONFS(ap->a_vp);
1591 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1592 
1593 	return (VOP_PATHCONF(vp, ap->a_name, ap->a_retval));
1594 }
1595 
1596 static int
1597 unionfs_advlock(void *v)
1598 {
1599 	struct vop_advlock_args *ap = v;
1600 	int error;
1601 	struct unionfs_node *unp;
1602 	struct unionfs_node_status *unsp;
1603 	struct vnode   *vp;
1604 	struct vnode   *uvp;
1605 	kauth_cred_t	cred;
1606 
1607 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: enter\n");
1608 
1609 	vp = ap->a_vp;
1610 	cred = kauth_cred_get();
1611 
1612 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1613 
1614 	unp = VTOUNIONFS(ap->a_vp);
1615 	uvp = unp->un_uppervp;
1616 
1617 	if (uvp == NULLVP) {
1618 		error = unionfs_copyfile(unp, 1, cred);
1619 		if (error != 0)
1620 			goto unionfs_advlock_abort;
1621 		uvp = unp->un_uppervp;
1622 
1623 		unionfs_get_node_status(unp, &unsp);
1624 		if (unsp->uns_lower_opencnt > 0) {
1625 			/* try reopen the vnode */
1626 			error = VOP_OPEN(uvp, unsp->uns_lower_openmode, cred);
1627 			if (error)
1628 				goto unionfs_advlock_abort;
1629 			unsp->uns_upper_opencnt++;
1630 			VOP_CLOSE(unp->un_lowervp, unsp->uns_lower_openmode, cred);
1631 			unsp->uns_lower_opencnt--;
1632 		} else
1633 			unionfs_tryrem_node_status(unp, unsp);
1634 	}
1635 
1636 	VOP_UNLOCK(vp, 0);
1637 
1638 	error = VOP_ADVLOCK(uvp, ap->a_id, ap->a_op, ap->a_fl, ap->a_flags);
1639 
1640 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
1641 
1642 	return error;
1643 
1644 unionfs_advlock_abort:
1645 	VOP_UNLOCK(vp, 0);
1646 
1647 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
1648 
1649 	return error;
1650 }
1651 
1652 static int
1653 unionfs_strategy(void *v)
1654 {
1655 	struct vop_strategy_args *ap = v;
1656 	struct unionfs_node *unp;
1657 	struct vnode   *vp;
1658 
1659 	unp = VTOUNIONFS(ap->a_vp);
1660 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1661 
1662 #ifdef DIAGNOSTIC
1663 	if (vp == NULLVP)
1664 		panic("unionfs_strategy: nullvp");
1665 	if ((ap->a_bp->b_flags & B_READ) == 0 && vp == unp->un_lowervp)
1666 		panic("unionfs_strategy: writing to lowervp");
1667 #endif
1668 
1669 	return (VOP_STRATEGY(vp, ap->a_bp));
1670 }
1671 
1672 static int
1673 unionfs_kqfilter(void *v)
1674 {
1675 	struct vop_kqfilter_args *ap = v;
1676 	struct unionfs_node *unp;
1677 	struct vnode   *tvp;
1678 
1679 	unp = VTOUNIONFS(ap->a_vp);
1680 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1681 
1682 	return VOP_KQFILTER(tvp, ap->a_kn);
1683 }
1684 
1685 static int
1686 unionfs_bmap(void *v)
1687 {
1688 	struct vop_bmap_args *ap = v;
1689 	struct unionfs_node *unp;
1690 	struct vnode   *tvp;
1691 
1692 	unp = VTOUNIONFS(ap->a_vp);
1693 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1694 
1695 	return VOP_BMAP(tvp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp);
1696 }
1697 
1698 static int
1699 unionfs_mmap(void *v)
1700 {
1701 	struct vop_mmap_args *ap = v;
1702 	struct unionfs_node *unp;
1703 	struct vnode   *tvp;
1704 
1705 	unp = VTOUNIONFS(ap->a_vp);
1706 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1707 
1708 	return VOP_MMAP(tvp, ap->a_prot, ap->a_cred);
1709 }
1710 
1711 static int
1712 unionfs_abortop(void *v)
1713 {
1714 	struct vop_abortop_args *ap = v;
1715 	struct unionfs_node *unp;
1716 	struct vnode   *tvp;
1717 
1718 	unp = VTOUNIONFS(ap->a_dvp);
1719 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1720 
1721 	return VOP_ABORTOP(tvp, ap->a_cnp);
1722 }
1723 
1724 static int
1725 unionfs_islocked(void *v)
1726 {
1727 	struct vop_islocked_args *ap = v;
1728 	struct unionfs_node *unp;
1729 	struct vnode   *tvp;
1730 
1731 	unp = VTOUNIONFS(ap->a_vp);
1732 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1733 
1734 	return VOP_ISLOCKED(tvp);
1735 }
1736 
1737 static int
1738 unionfs_seek(void *v)
1739 {
1740 	struct vop_seek_args *ap = v;
1741 	struct unionfs_node *unp;
1742 	struct vnode   *tvp;
1743 
1744 	unp = VTOUNIONFS(ap->a_vp);
1745 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1746 
1747 	return VOP_SEEK(tvp, ap->a_oldoff, ap->a_newoff, ap->a_cred);
1748 }
1749 
1750 static int
1751 unionfs_putpages(void *v)
1752 {
1753 	struct vop_putpages_args *ap = v;
1754 	struct unionfs_node *unp;
1755 	struct vnode   *tvp;
1756 
1757 	unp = VTOUNIONFS(ap->a_vp);
1758 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1759 
1760 	mutex_exit(&ap->a_vp->v_interlock);
1761 	if (ap->a_flags & PGO_RECLAIM) {
1762 		return 0;
1763 	}
1764 	mutex_enter(&tvp->v_interlock);
1765 
1766 	return VOP_PUTPAGES(tvp, ap->a_offlo, ap->a_offhi, ap->a_flags);
1767 }
1768 
1769 static int
1770 unionfs_getpages(void *v)
1771 {
1772 	struct vop_getpages_args *ap = v;
1773 	struct unionfs_node *unp;
1774 	struct vnode   *tvp;
1775 
1776 	unp = VTOUNIONFS(ap->a_vp);
1777 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1778 
1779 	if (ap->a_flags & PGO_LOCKED) {
1780 		return EBUSY;
1781 	}
1782 	mutex_exit(&ap->a_vp->v_interlock);
1783 	mutex_enter(&tvp->v_interlock);
1784 
1785 	return VOP_GETPAGES(tvp, ap->a_offset, ap->a_m, ap->a_count,
1786 	    ap->a_centeridx, ap->a_access_type, ap->a_advice, ap->a_flags);
1787 }
1788 
1789 static int
1790 unionfs_revoke(void *v)
1791 {
1792 	struct vop_revoke_args *ap = v;
1793 	struct unionfs_node *unp;
1794 	struct vnode   *tvp;
1795 	int error;
1796 
1797 	unp = VTOUNIONFS(ap->a_vp);
1798 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1799 
1800 	error = VOP_REVOKE(tvp, ap->a_flags);
1801 	if (error == 0) {
1802 		vgone(ap->a_vp);	/* ??? */
1803 	}
1804 	return error;
1805 }
1806 
1807 /*
1808  * Global vfs data structures
1809  */
1810 int (**unionfs_vnodeop_p)(void *);
1811 const struct vnodeopv_entry_desc unionfs_vnodeop_entries[] = {
1812 	{ &vop_default_desc, vn_default_error },
1813 	{ &vop_lookup_desc, unionfs_lookup },		/* lookup */
1814 	{ &vop_create_desc, unionfs_create },		/* create */
1815 	{ &vop_whiteout_desc, unionfs_whiteout },	/* whiteout */
1816 	{ &vop_mknod_desc, unionfs_mknod },		/* mknod */
1817 	{ &vop_open_desc, unionfs_open },		/* open */
1818 	{ &vop_close_desc, unionfs_close },		/* close */
1819 	{ &vop_access_desc, unionfs_access },		/* access */
1820 	{ &vop_getattr_desc, unionfs_getattr },		/* getattr */
1821 	{ &vop_setattr_desc, unionfs_setattr },		/* setattr */
1822 	{ &vop_read_desc, unionfs_read },		/* read */
1823 	{ &vop_write_desc, unionfs_write },		/* write */
1824 	{ &vop_ioctl_desc, unionfs_ioctl },		/* ioctl */
1825 	{ &vop_poll_desc, unionfs_poll },		/* select */
1826 	{ &vop_revoke_desc, unionfs_revoke },		/* revoke */
1827 	{ &vop_mmap_desc, unionfs_mmap },		/* mmap */
1828 	{ &vop_fsync_desc, unionfs_fsync },		/* fsync */
1829 	{ &vop_seek_desc, unionfs_seek },		/* seek */
1830 	{ &vop_remove_desc, unionfs_remove },		/* remove */
1831 	{ &vop_link_desc, unionfs_link },		/* link */
1832 	{ &vop_rename_desc, unionfs_rename },		/* rename */
1833 	{ &vop_mkdir_desc, unionfs_mkdir },		/* mkdir */
1834 	{ &vop_rmdir_desc, unionfs_rmdir },		/* rmdir */
1835 	{ &vop_symlink_desc, unionfs_symlink },		/* symlink */
1836 	{ &vop_readdir_desc, unionfs_readdir },		/* readdir */
1837 	{ &vop_readlink_desc, unionfs_readlink },	/* readlink */
1838 	{ &vop_abortop_desc, unionfs_abortop },		/* abortop */
1839 	{ &vop_inactive_desc, unionfs_inactive },	/* inactive */
1840 	{ &vop_reclaim_desc, unionfs_reclaim },		/* reclaim */
1841 	{ &vop_lock_desc, unionfs_lock },		/* lock */
1842 	{ &vop_unlock_desc, unionfs_unlock },		/* unlock */
1843 	{ &vop_bmap_desc, unionfs_bmap },		/* bmap */
1844 	{ &vop_strategy_desc, unionfs_strategy },	/* strategy */
1845 	{ &vop_print_desc, unionfs_print },		/* print */
1846 	{ &vop_islocked_desc, unionfs_islocked },	/* islocked */
1847 	{ &vop_pathconf_desc, unionfs_pathconf },	/* pathconf */
1848 	{ &vop_advlock_desc, unionfs_advlock },		/* advlock */
1849 	{ &vop_getpages_desc, unionfs_getpages },	/* getpages */
1850 	{ &vop_putpages_desc, unionfs_putpages },	/* putpages */
1851 	{ &vop_kqfilter_desc, unionfs_kqfilter },	/* kqfilter */
1852 #ifdef notdef
1853 	{ &vop_bwrite_desc, unionfs_bwrite },		/* bwrite */
1854 #endif
1855 	{ NULL, NULL }
1856 };
1857 const struct vnodeopv_desc unionfs_vnodeop_opv_desc =
1858 	{ &unionfs_vnodeop_p, unionfs_vnodeop_entries };
1859