xref: /netbsd/sys/fs/unionfs/unionfs_vnops.c (revision 6550d01e)
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/buf.h>
53 #include <sys/fcntl.h>
54 #include <sys/stat.h>
55 #include <sys/dirent.h>
56 #include <sys/proc.h>
57 
58 #include <fs/unionfs/unionfs.h>
59 
60 #if 0
61 #define UNIONFS_INTERNAL_DEBUG(msg, args...)    printf(msg, ## args)
62 #define UNIONFS_IDBG_RENAME
63 #else
64 #define UNIONFS_INTERNAL_DEBUG(msg, args...)
65 #endif
66 
67 static int
68 unionfs_lookup(void *v)
69 {
70 	struct vop_lookup_args *ap = v;
71 	int		iswhiteout;
72 	int		lockflag;
73 	int		error , uerror, lerror;
74 	u_long		nameiop;
75 	u_long		cnflags, cnflagsbk;
76 	struct unionfs_node *dunp;
77 	struct vnode   *dvp, *udvp, *ldvp, *vp, *uvp, *lvp, *dtmpvp;
78 	struct vattr	va;
79 	struct componentname *cnp;
80 
81 	iswhiteout = 0;
82 	lockflag = 0;
83 	error = uerror = lerror = ENOENT;
84 	cnp = ap->a_cnp;
85 	nameiop = cnp->cn_nameiop;
86 	cnflags = cnp->cn_flags;
87 	dvp = ap->a_dvp;
88 	dunp = VTOUNIONFS(dvp);
89 	udvp = dunp->un_uppervp;
90 	ldvp = dunp->un_lowervp;
91 	vp = uvp = lvp = NULLVP;
92 	*(ap->a_vpp) = NULLVP;
93 
94 	UNIONFS_INTERNAL_DEBUG("unionfs_lookup: enter: nameiop=%ld, flags=%lx, path=%s\n", nameiop, cnflags, cnp->cn_nameptr);
95 
96 	if (dvp->v_type != VDIR)
97 		return (ENOTDIR);
98 
99 	/*
100 	 * If read-only and op is not LOOKUP, will return EROFS.
101 	 */
102 	if ((cnflags & ISLASTCN) &&
103 	    (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
104 	    LOOKUP != nameiop)
105 		return (EROFS);
106 
107 	/*
108 	 * lookup dotdot
109 	 */
110 	if (cnflags & ISDOTDOT) {
111 		if (LOOKUP != nameiop && udvp == NULLVP)
112 			return (EROFS);
113 
114 		if (udvp != NULLVP) {
115 			dtmpvp = udvp;
116 			if (ldvp != NULLVP)
117 				VOP_UNLOCK(ldvp);
118 		}
119 		else
120 			dtmpvp = ldvp;
121 
122 		error = VOP_LOOKUP(dtmpvp, &vp, cnp);
123 
124 		if (dtmpvp == udvp && ldvp != NULLVP) {
125 			VOP_UNLOCK(udvp);
126 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
127 		}
128 
129 		if (error == 0) {
130 			/*
131 			 * Exchange lock and reference from vp to
132 			 * dunp->un_dvp. vp is upper/lower vnode, but it
133 			 * will need to return the unionfs vnode.
134 			 */
135 			if (nameiop == DELETE  || nameiop == RENAME)
136 				VOP_UNLOCK(vp);
137 			vrele(vp);
138 
139 			VOP_UNLOCK(dvp);
140 			*(ap->a_vpp) = dunp->un_dvp;
141 			vref(dunp->un_dvp);
142 
143 			vn_lock(dunp->un_dvp, LK_EXCLUSIVE | LK_RETRY);
144 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
145 		} else if (error == ENOENT && (cnflags & MAKEENTRY) &&
146 		    nameiop != CREATE)
147 			cache_enter(dvp, NULLVP, cnp);
148 
149 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
150 
151 		return (error);
152 	}
153 
154 	/*
155 	 * lookup upper layer
156 	 */
157 	if (udvp != NULLVP) {
158 		uerror = VOP_LOOKUP(udvp, &uvp, cnp);
159 
160 		if (uerror == 0) {
161 			if (udvp == uvp) {	/* is dot */
162 				vrele(uvp);
163 				*(ap->a_vpp) = dvp;
164 				vref(dvp);
165 
166 				UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", uerror);
167 
168 				return (uerror);
169 			}
170 		}
171 
172 		/* check whiteout */
173 		if (uerror == ENOENT || uerror == EJUSTRETURN)
174 			if (cnp->cn_flags & ISWHITEOUT)
175 				iswhiteout = 1;	/* don't lookup lower */
176 		if (iswhiteout == 0 && ldvp != NULLVP)
177 			if (VOP_GETATTR(udvp, &va, cnp->cn_cred) == 0 &&
178 			    (va.va_flags & OPAQUE))
179 				iswhiteout = 1;	/* don't lookup lower */
180 #if 0
181 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: debug: whiteout=%d, path=%s\n", iswhiteout, cnp->cn_nameptr);
182 #endif
183 	}
184 
185 	/*
186 	 * lookup lower layer
187 	 */
188 	if (ldvp != NULLVP && !(cnflags & DOWHITEOUT) && iswhiteout == 0) {
189 		/* always op is LOOKUP */
190 		cnp->cn_nameiop = LOOKUP;
191 		cnflagsbk = cnp->cn_flags;
192 		cnp->cn_flags = cnflags;
193 
194 		lerror = VOP_LOOKUP(ldvp, &lvp, cnp);
195 
196 		cnp->cn_nameiop = nameiop;
197 		if (udvp != NULLVP && (uerror == 0 || uerror == EJUSTRETURN))
198 			cnp->cn_flags = cnflagsbk;
199 
200 		if (lerror == 0) {
201 			if (ldvp == lvp) {	/* is dot */
202 				if (uvp != NULLVP)
203 					vrele(uvp);	/* no need? */
204 				vrele(lvp);
205 				*(ap->a_vpp) = dvp;
206 				vref(dvp);
207 
208 				UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", lerror);
209 				if (uvp != NULL)
210 					VOP_UNLOCK(uvp);
211 				return (lerror);
212 			}
213 		}
214 	}
215 
216 	/*
217 	 * check lookup result
218 	 */
219 	if (uvp == NULLVP && lvp == NULLVP) {
220 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n",
221 		    (udvp != NULLVP ? uerror : lerror));
222 		return (udvp != NULLVP ? uerror : lerror);
223 	}
224 
225 	/*
226 	 * check vnode type
227 	 */
228 	if (uvp != NULLVP && lvp != NULLVP && uvp->v_type != lvp->v_type) {
229 		vput(lvp);
230 		lvp = NULLVP;
231 	}
232 
233 	/*
234 	 * check shadow dir
235 	 */
236 	if (uerror != 0 && uerror != EJUSTRETURN && udvp != NULLVP &&
237 	    lerror == 0 && lvp != NULLVP && lvp->v_type == VDIR &&
238 	    !(dvp->v_mount->mnt_flag & MNT_RDONLY) &&
239 	    (1 < cnp->cn_namelen || '.' != *(cnp->cn_nameptr))) {
240 		/* get unionfs vnode in order to create a new shadow dir. */
241 		error = unionfs_nodeget(dvp->v_mount, NULLVP, lvp, dvp, &vp,
242 		    cnp);
243 		if (error != 0)
244 			goto unionfs_lookup_out;
245 		error = unionfs_mkshadowdir(MOUNTTOUNIONFSMOUNT(dvp->v_mount),
246 		    udvp, VTOUNIONFS(vp), cnp);
247 		if (error != 0) {
248 			UNIONFSDEBUG("unionfs_lookup: Unable to create shadow dir.");
249 			vput(vp);
250 			goto unionfs_lookup_out;
251 		}
252 	}
253 	/*
254 	 * get unionfs vnode.
255 	 */
256 	else {
257 		if (uvp != NULLVP)
258 			error = uerror;
259 		else
260 			error = lerror;
261 		if (error != 0)
262 			goto unionfs_lookup_out;
263 		error = unionfs_nodeget(dvp->v_mount, uvp, lvp, dvp, &vp, cnp);
264 		if (error != 0) {
265 			UNIONFSDEBUG("unionfs_lookup: Unable to create unionfs vnode.");
266 			goto unionfs_lookup_out;
267 		}
268 	}
269 
270 	*(ap->a_vpp) = vp;
271 
272 	if (cnflags & MAKEENTRY)
273 		cache_enter(dvp, vp, cnp);
274 
275 	/* XXXAD lock status on error */
276 unionfs_lookup_out:
277 	if (uvp != NULLVP)
278 		vrele(uvp);
279 	if (lvp != NULLVP)
280 		vrele(lvp);
281 
282 	if (error == ENOENT && (cnflags & MAKEENTRY) && nameiop != CREATE)
283 		cache_enter(dvp, NULLVP, cnp);
284 
285 	UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
286 
287 	return (error);
288 }
289 
290 static int
291 unionfs_create(void *v)
292 {
293 	struct vop_create_args *ap = v;
294 	struct unionfs_node *dunp;
295 	struct componentname *cnp;
296 	struct vnode   *udvp;
297 	struct vnode   *vp;
298 	int		error;
299 
300 	UNIONFS_INTERNAL_DEBUG("unionfs_create: enter\n");
301 
302 	dunp = VTOUNIONFS(ap->a_dvp);
303 	cnp = ap->a_cnp;
304 	udvp = dunp->un_uppervp;
305 	error = EROFS;
306 
307 	if (udvp != NULLVP) {
308 		if ((error = VOP_CREATE(udvp, &vp, cnp, ap->a_vap)) == 0) {
309 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
310 			    ap->a_dvp, ap->a_vpp, cnp);
311 			if (error) {
312 				vput(vp);
313 			} else {
314 				vrele(vp);
315 			}
316 		}
317 	}
318 
319 	UNIONFS_INTERNAL_DEBUG("unionfs_create: leave (%d)\n", error);
320 
321 	return (error);
322 }
323 
324 static int
325 unionfs_whiteout(void *v)
326 {
327 	struct vop_whiteout_args *ap = v;
328 	struct unionfs_node *dunp;
329 	struct componentname *cnp;
330 	struct vnode   *udvp;
331 	int		error;
332 
333 	UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: enter\n");
334 
335 	dunp = VTOUNIONFS(ap->a_dvp);
336 	cnp = ap->a_cnp;
337 	udvp = dunp->un_uppervp;
338 	error = EOPNOTSUPP;
339 
340 	if (udvp != NULLVP) {
341 		switch (ap->a_flags) {
342 		case CREATE:
343 		case DELETE:
344 		case LOOKUP:
345 			error = VOP_WHITEOUT(udvp, cnp, ap->a_flags);
346 			break;
347 		default:
348 			error = EINVAL;
349 			break;
350 		}
351 	}
352 
353 	UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: leave (%d)\n", error);
354 
355 	return (error);
356 }
357 
358 static int
359 unionfs_mknod(void *v)
360 {
361 	struct vop_mknod_args *ap = v;
362 	struct unionfs_node *dunp;
363 	struct componentname *cnp;
364 	struct vnode   *udvp;
365 	struct vnode   *vp;
366 	int		error;
367 
368 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: enter\n");
369 
370 	dunp = VTOUNIONFS(ap->a_dvp);
371 	cnp = ap->a_cnp;
372 	udvp = dunp->un_uppervp;
373 	error = EROFS;
374 
375 	if (udvp != NULLVP) {
376 		if ((error = VOP_MKNOD(udvp, &vp, cnp, ap->a_vap)) == 0) {
377 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
378 			    ap->a_dvp, ap->a_vpp, cnp);
379 			if (error) {
380 				vput(vp);
381 			} else {
382 				vrele(vp);
383 			}
384 		}
385 	}
386 
387 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: leave (%d)\n", error);
388 
389 	return (error);
390 }
391 
392 static int
393 unionfs_open(void *v)
394 {
395 	struct vop_open_args *ap = v;
396 	int		error;
397 	struct unionfs_node *unp;
398 	struct unionfs_node_status *unsp;
399 	struct vnode   *uvp;
400 	struct vnode   *lvp;
401 	struct vnode   *targetvp;
402 	kauth_cred_t   cred;
403 
404 	UNIONFS_INTERNAL_DEBUG("unionfs_open: enter\n");
405 
406 	error = 0;
407 	unp = VTOUNIONFS(ap->a_vp);
408 	uvp = unp->un_uppervp;
409 	lvp = unp->un_lowervp;
410 	targetvp = NULLVP;
411 	cred = ap->a_cred;
412 
413 	unionfs_get_node_status(unp, &unsp);
414 
415 	if (unsp->uns_lower_opencnt > 0 || unsp->uns_upper_opencnt > 0) {
416 		/* vnode is already opend. */
417 		if (unsp->uns_upper_opencnt > 0)
418 			targetvp = uvp;
419 		else
420 			targetvp = lvp;
421 
422 		if (targetvp == lvp &&
423 		    (ap->a_mode & FWRITE) && lvp->v_type == VREG)
424 			targetvp = NULLVP;
425 	}
426 	if (targetvp == NULLVP) {
427 		if (uvp == NULLVP) {
428 			if ((ap->a_mode & FWRITE) && lvp->v_type == VREG) {
429 				error = unionfs_copyfile(unp,
430 				    !(ap->a_mode & O_TRUNC), cred);
431 				if (error != 0)
432 					goto unionfs_open_abort;
433 				targetvp = uvp = unp->un_uppervp;
434 			} else
435 				targetvp = lvp;
436 		} else
437 			targetvp = uvp;
438 	}
439 
440 	error = VOP_OPEN(targetvp, ap->a_mode, cred);
441 	if (error == 0) {
442 		if (targetvp == uvp) {
443 			if (uvp->v_type == VDIR && lvp != NULLVP &&
444 			    unsp->uns_lower_opencnt <= 0) {
445 				/* open lower for readdir */
446 				error = VOP_OPEN(lvp, FREAD, cred);
447 				if (error != 0) {
448 					VOP_CLOSE(uvp, ap->a_mode, cred);
449 					goto unionfs_open_abort;
450 				}
451 				unsp->uns_node_flag |= UNS_OPENL_4_READDIR;
452 				unsp->uns_lower_opencnt++;
453 			}
454 			unsp->uns_upper_opencnt++;
455 		} else {
456 			unsp->uns_lower_opencnt++;
457 			unsp->uns_lower_openmode = ap->a_mode;
458 		}
459 	}
460 
461 unionfs_open_abort:
462 	if (error != 0)
463 		unionfs_tryrem_node_status(unp, unsp);
464 
465 	UNIONFS_INTERNAL_DEBUG("unionfs_open: leave (%d)\n", error);
466 
467 	return (error);
468 }
469 
470 static int
471 unionfs_close(void *v)
472 {
473 	struct vop_close_args *ap = v;
474 	int		error;
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 	KASSERT(VOP_ISLOCKED(ap->a_vp) == LK_EXCLUSIVE);
483 	unp = VTOUNIONFS(ap->a_vp);
484 	cred = ap->a_cred;
485 
486 	unionfs_get_node_status(unp, &unsp);
487 
488 	if (unsp->uns_lower_opencnt <= 0 && unsp->uns_upper_opencnt <= 0) {
489 #ifdef DIAGNOSTIC
490 		printf("unionfs_close: warning: open count is 0\n");
491 #endif
492 		if (unp->un_uppervp != NULLVP)
493 			ovp = unp->un_uppervp;
494 		else
495 			ovp = unp->un_lowervp;
496 	} else if (unsp->uns_upper_opencnt > 0)
497 		ovp = unp->un_uppervp;
498 	else
499 		ovp = unp->un_lowervp;
500 
501 	error = VOP_CLOSE(ovp, ap->a_fflag, cred);
502 
503 	if (error != 0)
504 		goto unionfs_close_abort;
505 
506 	if (ovp == unp->un_uppervp) {
507 		unsp->uns_upper_opencnt--;
508 		if (unsp->uns_upper_opencnt == 0) {
509 			if (unsp->uns_node_flag & UNS_OPENL_4_READDIR) {
510 				VOP_CLOSE(unp->un_lowervp, FREAD, cred);
511 				unsp->uns_node_flag &= ~UNS_OPENL_4_READDIR;
512 				unsp->uns_lower_opencnt--;
513 			}
514 		}
515 	} else
516 		unsp->uns_lower_opencnt--;
517 
518 unionfs_close_abort:
519 	unionfs_tryrem_node_status(unp, unsp);
520 
521 	UNIONFS_INTERNAL_DEBUG("unionfs_close: leave (%d)\n", error);
522 
523 	return (error);
524 }
525 
526 /*
527  * Check the access mode toward shadow file/dir.
528  */
529 static int
530 unionfs_check_corrected_access(u_short mode, struct vattr *va, kauth_cred_t cred)
531 {
532 	int		result;
533 	int		error;
534 	uid_t		uid;	/* upper side vnode's uid */
535 	gid_t		gid;	/* upper side vnode's gid */
536 	u_short		vmode;	/* upper side vnode's mode */
537 	u_short		mask;
538 
539 	mask = 0;
540 	uid = va->va_uid;
541 	gid = va->va_gid;
542 	vmode = va->va_mode;
543 
544 	/* check owner */
545 	if (kauth_cred_getuid(cred) == uid) {
546 		if (mode & VEXEC)
547 			mask |= S_IXUSR;
548 		if (mode & VREAD)
549 			mask |= S_IRUSR;
550 		if (mode & VWRITE)
551 			mask |= S_IWUSR;
552 		return ((vmode & mask) == mask ? 0 : EACCES);
553 	}
554 
555 	/* check group */
556 	error = kauth_cred_ismember_gid(cred, gid, &result);
557 	if (error != 0)
558 		return error;
559 	if (result) {
560 		if (mode & VEXEC)
561 			mask |= S_IXGRP;
562 		if (mode & VREAD)
563 			mask |= S_IRGRP;
564 		if (mode & VWRITE)
565 			mask |= S_IWGRP;
566 		return ((vmode & mask) == mask ? 0 : EACCES);
567 	}
568 
569 	/* check other */
570 	if (mode & VEXEC)
571 		mask |= S_IXOTH;
572 	if (mode & VREAD)
573 		mask |= S_IROTH;
574 	if (mode & VWRITE)
575 		mask |= S_IWOTH;
576 
577 	return ((vmode & mask) == mask ? 0 : EACCES);
578 }
579 
580 static int
581 unionfs_access(void *v)
582 {
583 	struct vop_access_args *ap = v;
584 	struct unionfs_mount *ump;
585 	struct unionfs_node *unp;
586 	struct vnode   *uvp;
587 	struct vnode   *lvp;
588 	struct vattr	va;
589 	int		mode;
590 	int		error;
591 
592 	UNIONFS_INTERNAL_DEBUG("unionfs_access: enter\n");
593 
594 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
595 	unp = VTOUNIONFS(ap->a_vp);
596 	uvp = unp->un_uppervp;
597 	lvp = unp->un_lowervp;
598 	mode = ap->a_mode;
599 	error = EACCES;
600 
601 	if ((mode & VWRITE) &&
602 	    (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) {
603 		switch (ap->a_vp->v_type) {
604 		case VREG:
605 		case VDIR:
606 		case VLNK:
607 			return (EROFS);
608 		default:
609 			break;
610 		}
611 	}
612 
613 	if (uvp != NULLVP) {
614 		error = VOP_ACCESS(uvp, mode, ap->a_cred);
615 
616 		UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
617 
618 		return (error);
619 	}
620 
621 	if (lvp != NULLVP) {
622 		if (mode & VWRITE) {
623 			if (ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY) {
624 				switch (ap->a_vp->v_type) {
625 				case VREG:
626 				case VDIR:
627 				case VLNK:
628 					return (EROFS);
629 				default:
630 					break;
631 				}
632 			} else if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
633 				/* check shadow file/dir */
634 				if (ump->um_copymode != UNIONFS_TRANSPARENT) {
635 					error = unionfs_create_uppervattr(ump,
636 					    lvp, &va, ap->a_cred);
637 					if (error != 0)
638 						return (error);
639 
640 					error = unionfs_check_corrected_access(
641 					    mode, &va, ap->a_cred);
642 					if (error != 0)
643 						return (error);
644 				}
645 			}
646 			mode &= ~VWRITE;
647 			mode |= VREAD; /* will copy to upper */
648 		}
649 		error = VOP_ACCESS(lvp, mode, ap->a_cred);
650 	}
651 
652 	UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
653 
654 	return (error);
655 }
656 
657 static int
658 unionfs_getattr(void *v)
659 {
660 	struct vop_getattr_args *ap = v;
661 	int		error;
662 	struct unionfs_node *unp;
663 	struct unionfs_mount *ump;
664 	struct vnode   *uvp;
665 	struct vnode   *lvp;
666 	struct vattr	va;
667 
668 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: enter\n");
669 
670 	unp = VTOUNIONFS(ap->a_vp);
671 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
672 	uvp = unp->un_uppervp;
673 	lvp = unp->un_lowervp;
674 
675 	if (uvp != NULLVP) {
676 		if ((error = VOP_GETATTR(uvp, ap->a_vap, ap->a_cred)) == 0)
677 			ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid;
678 
679 		UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
680 		    ap->a_vap->va_mode, ap->a_vap->va_uid,
681 		    ap->a_vap->va_gid, error);
682 
683 		return (error);
684 	}
685 
686 	error = VOP_GETATTR(lvp, ap->a_vap, ap->a_cred);
687 
688 	if (error == 0 && !(ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY)) {
689 		/* correct the attr toward shadow file/dir. */
690 		if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
691 			unionfs_create_uppervattr_core(ump, ap->a_vap, &va);
692 			ap->a_vap->va_mode = va.va_mode;
693 			ap->a_vap->va_uid = va.va_uid;
694 			ap->a_vap->va_gid = va.va_gid;
695 		}
696 	}
697 
698 	if (error == 0)
699 		ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid;
700 
701 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
702 	    ap->a_vap->va_mode, ap->a_vap->va_uid, ap->a_vap->va_gid, error);
703 
704 	return (error);
705 }
706 
707 static int
708 unionfs_setattr(void *v)
709 {
710 	struct vop_setattr_args *ap = v;
711 	int		error;
712 	struct unionfs_node *unp;
713 	struct vnode   *uvp;
714 	struct vnode   *lvp;
715 	struct vattr   *vap;
716 
717 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: enter\n");
718 
719 	error = EROFS;
720 	unp = VTOUNIONFS(ap->a_vp);
721 	uvp = unp->un_uppervp;
722 	lvp = unp->un_lowervp;
723 	vap = ap->a_vap;
724 
725 	if ((ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) &&
726 	    (vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
727 	     vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
728 	     vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL))
729 		return (EROFS);
730 
731 	if (uvp == NULLVP && lvp->v_type == VREG) {
732 		error = unionfs_copyfile(unp, (vap->va_size != 0),
733 		    ap->a_cred);
734 		if (error != 0)
735 			return (error);
736 		uvp = unp->un_uppervp;
737 	}
738 
739 	if (uvp != NULLVP)
740 		error = VOP_SETATTR(uvp, vap, ap->a_cred);
741 
742 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: leave (%d)\n", error);
743 
744 	return (error);
745 }
746 
747 static int
748 unionfs_read(void *v)
749 {
750 	struct vop_read_args *ap = v;
751 	int		error;
752 	struct unionfs_node *unp;
753 	struct vnode   *tvp;
754 
755 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: enter\n"); */
756 
757 	unp = VTOUNIONFS(ap->a_vp);
758 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
759 
760 	error = VOP_READ(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
761 
762 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: leave (%d)\n", error); */
763 
764 	return (error);
765 }
766 
767 static int
768 unionfs_write(void *v)
769 {
770 	struct vop_write_args *ap = v;
771 	int		error;
772 	struct unionfs_node *unp;
773 	struct vnode   *tvp;
774 
775 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: enter\n"); */
776 
777 	unp = VTOUNIONFS(ap->a_vp);
778 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
779 
780 	error = VOP_WRITE(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
781 
782 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: leave (%d)\n", error); */
783 
784 	return (error);
785 }
786 
787 static int
788 unionfs_ioctl(void *v)
789 {
790 	struct vop_ioctl_args *ap = v;
791 	int error;
792 	struct unionfs_node *unp;
793 	struct unionfs_node_status *unsp;
794 	struct vnode   *ovp;
795 
796 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: enter\n");
797 
798  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
799 	unp = VTOUNIONFS(ap->a_vp);
800 	unionfs_get_node_status(unp, &unsp);
801 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
802 	unionfs_tryrem_node_status(unp, unsp);
803 	VOP_UNLOCK(ap->a_vp);
804 
805 	if (ovp == NULLVP)
806 		return (EBADF);
807 
808 	error = VOP_IOCTL(ovp, ap->a_command, ap->a_data, ap->a_fflag,
809 	    ap->a_cred);
810 
811 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: lease (%d)\n", error);
812 
813 	return (error);
814 }
815 
816 static int
817 unionfs_poll(void *v)
818 {
819 	struct vop_poll_args *ap = v;
820 	struct unionfs_node *unp;
821 	struct unionfs_node_status *unsp;
822 	struct vnode   *ovp;
823 
824  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
825 	unp = VTOUNIONFS(ap->a_vp);
826 	unionfs_get_node_status(unp, &unsp);
827 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
828 	unionfs_tryrem_node_status(unp, unsp);
829 	VOP_UNLOCK(ap->a_vp);
830 
831 	if (ovp == NULLVP)
832 		return (EBADF);
833 
834 	return (VOP_POLL(ovp, ap->a_events));
835 }
836 
837 static int
838 unionfs_fsync(void *v)
839 {
840 	struct vop_fsync_args *ap = v;
841 	struct unionfs_node *unp;
842 	struct unionfs_node_status *unsp;
843 	struct vnode   *ovp;
844 
845 	unp = VTOUNIONFS(ap->a_vp);
846 	unionfs_get_node_status(unp, &unsp);
847 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
848 	unionfs_tryrem_node_status(unp, unsp);
849 
850 	if (ovp == NULLVP)
851 		return (EBADF);
852 
853 	return (VOP_FSYNC(ovp, ap->a_cred, ap->a_flags, ap->a_offlo, ap->a_offhi));
854 }
855 
856 static int
857 unionfs_remove(void *v)
858 {
859 	struct vop_remove_args *ap = v;
860 	int		error;
861 	struct unionfs_node *dunp;
862 	struct unionfs_node *unp;
863 	struct unionfs_mount *ump;
864 	struct vnode   *udvp;
865 	struct vnode   *uvp;
866 	struct vnode   *lvp;
867 	struct componentname *cnp;
868 
869 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: enter\n");
870 
871 	error = 0;
872 	dunp = VTOUNIONFS(ap->a_dvp);
873 	unp = VTOUNIONFS(ap->a_vp);
874 	udvp = dunp->un_uppervp;
875 	uvp = unp->un_uppervp;
876 	lvp = unp->un_lowervp;
877 	cnp = ap->a_cnp;
878 
879 	if (udvp == NULLVP)
880 		return (EROFS);
881 
882 	if (uvp != NULLVP) {
883 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
884 		if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP)
885 			cnp->cn_flags |= DOWHITEOUT;
886 		error = VOP_REMOVE(udvp, uvp, cnp);
887 	} else if (lvp != NULLVP)
888 		error = unionfs_mkwhiteout(udvp, cnp, unp->un_path);
889 
890 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: leave (%d)\n", error);
891 
892 	return (error);
893 }
894 
895 static int
896 unionfs_link(void *v)
897 {
898 #if 0
899 	struct vop_link_args *ap = v;
900 	int		error;
901 	int		needrelookup;
902 	struct unionfs_node *dunp;
903 	struct unionfs_node *unp;
904 	struct vnode   *udvp;
905 	struct vnode   *uvp;
906 	struct componentname *cnp;
907 
908 	UNIONFS_INTERNAL_DEBUG("unionfs_link: enter\n");
909 
910 	error = 0;
911 	needrelookup = 0;
912 	dunp = VTOUNIONFS(ap->a_tdvp);
913 	unp = NULL;
914 	udvp = dunp->un_uppervp;
915 	uvp = NULLVP;
916 	cnp = ap->a_cnp;
917 
918 	if (udvp == NULLVP)
919 		return (EROFS);
920 
921 	if (ap->a_vp->v_op != unionfs_vnodeop_p)
922 		uvp = ap->a_vp;
923 	else {
924 		unp = VTOUNIONFS(ap->a_vp);
925 
926 		if (unp->un_uppervp == NULLVP) {
927 			if (ap->a_vp->v_type != VREG)
928 				return (EOPNOTSUPP);
929 
930 			error = unionfs_copyfile(unp, 1, cnp->cn_cred);
931 			if (error != 0)
932 				return (error);
933 			needrelookup = 1;
934 		}
935 		uvp = unp->un_uppervp;
936 	}
937 
938 	if (needrelookup != 0)
939 		error = unionfs_relookup_for_create(ap->a_tdvp, cnp);
940 
941 	if (error == 0)
942 		error = VOP_LINK(udvp, uvp, cnp);
943 
944 	UNIONFS_INTERNAL_DEBUG("unionfs_link: leave (%d)\n", error);
945 
946 	return (error);
947 #else
948 	panic("XXXAD");
949 	return 0;
950 #endif
951 }
952 
953 static int
954 unionfs_rename(void *v)
955 {
956 	struct vop_rename_args *ap = v;
957 	int		error;
958 	struct vnode   *fdvp;
959 	struct vnode   *fvp;
960 	struct componentname *fcnp;
961 	struct vnode   *tdvp;
962 	struct vnode   *tvp;
963 	struct componentname *tcnp;
964 	struct vnode   *ltdvp;
965 	struct vnode   *ltvp;
966 
967 	/* rename target vnodes */
968 	struct vnode   *rfdvp;
969 	struct vnode   *rfvp;
970 	struct vnode   *rtdvp;
971 	struct vnode   *rtvp;
972 
973 	int		needrelookup;
974 	struct unionfs_mount *ump;
975 	struct unionfs_node *unp;
976 
977 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: enter\n");
978 
979 	error = 0;
980 	fdvp = ap->a_fdvp;
981 	fvp = ap->a_fvp;
982 	fcnp = ap->a_fcnp;
983 	tdvp = ap->a_tdvp;
984 	tvp = ap->a_tvp;
985 	tcnp = ap->a_tcnp;
986 	ltdvp = NULLVP;
987 	ltvp = NULLVP;
988 	rfdvp = fdvp;
989 	rfvp = fvp;
990 	rtdvp = tdvp;
991 	rtvp = tvp;
992 	needrelookup = 0;
993 
994 	/* check for cross device rename */
995 	if (fvp->v_mount != tdvp->v_mount ||
996 	    (tvp != NULLVP && fvp->v_mount != tvp->v_mount)) {
997 		error = EXDEV;
998 		goto unionfs_rename_abort;
999 	}
1000 
1001 	/* Renaming a file to itself has no effect. */
1002 	if (fvp == tvp)
1003 		goto unionfs_rename_abort;
1004 
1005 	/*
1006 	 * from/to vnode is unionfs node.
1007 	 */
1008 
1009 	unp = VTOUNIONFS(fdvp);
1010 #ifdef UNIONFS_IDBG_RENAME
1011 	UNIONFS_INTERNAL_DEBUG("fdvp=%p, ufdvp=%p, lfdvp=%p\n", fdvp, unp->un_uppervp, unp->un_lowervp);
1012 #endif
1013 	if (unp->un_uppervp == NULLVP) {
1014 		error = ENODEV;
1015 		goto unionfs_rename_abort;
1016 	}
1017 	rfdvp = unp->un_uppervp;
1018 	vref(rfdvp);
1019 
1020 	unp = VTOUNIONFS(fvp);
1021 #ifdef UNIONFS_IDBG_RENAME
1022 	UNIONFS_INTERNAL_DEBUG("fvp=%p, ufvp=%p, lfvp=%p\n", fvp, unp->un_uppervp, unp->un_lowervp);
1023 #endif
1024 	ump = MOUNTTOUNIONFSMOUNT(fvp->v_mount);
1025 	if (unp->un_uppervp == NULLVP) {
1026 		switch (fvp->v_type) {
1027 		case VREG:
1028 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1029 				goto unionfs_rename_abort;
1030 			error = unionfs_copyfile(unp, 1, fcnp->cn_cred);
1031 			VOP_UNLOCK(fvp);
1032 			if (error != 0)
1033 				goto unionfs_rename_abort;
1034 			break;
1035 		case VDIR:
1036 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1037 				goto unionfs_rename_abort;
1038 			error = unionfs_mkshadowdir(ump, rfdvp, unp, fcnp);
1039 			VOP_UNLOCK(fvp);
1040 			if (error != 0)
1041 				goto unionfs_rename_abort;
1042 			break;
1043 		default:
1044 			error = ENODEV;
1045 			goto unionfs_rename_abort;
1046 		}
1047 
1048 		needrelookup = 1;
1049 	}
1050 
1051 	if (unp->un_lowervp != NULLVP)
1052 		fcnp->cn_flags |= DOWHITEOUT;
1053 	rfvp = unp->un_uppervp;
1054 	vref(rfvp);
1055 
1056 	unp = VTOUNIONFS(tdvp);
1057 #ifdef UNIONFS_IDBG_RENAME
1058 	UNIONFS_INTERNAL_DEBUG("tdvp=%p, utdvp=%p, ltdvp=%p\n", tdvp, unp->un_uppervp, unp->un_lowervp);
1059 #endif
1060 	if (unp->un_uppervp == NULLVP) {
1061 		error = ENODEV;
1062 		goto unionfs_rename_abort;
1063 	}
1064 	rtdvp = unp->un_uppervp;
1065 	ltdvp = unp->un_lowervp;
1066 	vref(rtdvp);
1067 
1068 	if (tdvp == tvp) {
1069 		rtvp = rtdvp;
1070 		vref(rtvp);
1071 	} else if (tvp != NULLVP) {
1072 		unp = VTOUNIONFS(tvp);
1073 #ifdef UNIONFS_IDBG_RENAME
1074 		UNIONFS_INTERNAL_DEBUG("tvp=%p, utvp=%p, ltvp=%p\n", tvp, unp->un_uppervp, unp->un_lowervp);
1075 #endif
1076 		if (unp->un_uppervp == NULLVP)
1077 			rtvp = NULLVP;
1078 		else {
1079 			if (tvp->v_type == VDIR) {
1080 				error = EINVAL;
1081 				goto unionfs_rename_abort;
1082 			}
1083 			rtvp = unp->un_uppervp;
1084 			ltvp = unp->un_lowervp;
1085 			vref(rtvp);
1086 		}
1087 	}
1088 
1089 	if (needrelookup != 0) {
1090 		if ((error = vn_lock(fdvp, LK_EXCLUSIVE)) != 0)
1091 			goto unionfs_rename_abort;
1092 		error = unionfs_relookup_for_delete(fdvp, fcnp);
1093 		VOP_UNLOCK(fdvp);
1094 		if (error != 0)
1095 			goto unionfs_rename_abort;
1096 
1097 		/* Locke of tvp is canceled in order to avoid recursive lock. */
1098 		if (tvp != NULLVP && tvp != tdvp)
1099 			VOP_UNLOCK(tvp);
1100 		error = unionfs_relookup_for_rename(tdvp, tcnp);
1101 		if (tvp != NULLVP && tvp != tdvp)
1102 			vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
1103 		if (error != 0)
1104 			goto unionfs_rename_abort;
1105 	}
1106 
1107 	error = VOP_RENAME(rfdvp, rfvp, fcnp, rtdvp, rtvp, tcnp);
1108 
1109 	if (error == 0) {
1110 		if (rtvp != NULLVP && rtvp->v_type == VDIR)
1111 			cache_purge(tdvp);
1112 		if (fvp->v_type == VDIR && fdvp != tdvp)
1113 			cache_purge(fdvp);
1114 	}
1115 
1116 	if (fdvp != rfdvp)
1117 		vrele(fdvp);
1118 	if (fvp != rfvp)
1119 		vrele(fvp);
1120 	if (ltdvp != NULLVP)
1121 		VOP_UNLOCK(ltdvp);
1122 	if (tdvp != rtdvp)
1123 		vrele(tdvp);
1124 	if (ltvp != NULLVP)
1125 		VOP_UNLOCK(ltvp);
1126 	if (tvp != rtvp && tvp != NULLVP) {
1127 		if (rtvp == NULLVP)
1128 			vput(tvp);
1129 		else
1130 			vrele(tvp);
1131 	}
1132 
1133 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1134 
1135 	return (error);
1136 
1137 unionfs_rename_abort:
1138 	if (fdvp != rfdvp)
1139 		vrele(rfdvp);
1140 	if (fvp != rfvp)
1141 		vrele(rfvp);
1142 	if (tdvp != rtdvp)
1143 		vrele(rtdvp);
1144 	vput(tdvp);
1145 	if (tvp != rtvp && rtvp != NULLVP)
1146 		vrele(rtvp);
1147 	if (tvp != NULLVP) {
1148 		if (tdvp != tvp)
1149 			vput(tvp);
1150 		else
1151 			vrele(tvp);
1152 	}
1153 	vrele(fdvp);
1154 	vrele(fvp);
1155 
1156 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1157 
1158 	return (error);
1159 }
1160 
1161 static int
1162 unionfs_mkdir(void *v)
1163 {
1164 	struct vop_mkdir_args *ap = v;
1165 	int		error;
1166 	struct unionfs_node *dunp;
1167 	struct componentname *cnp;
1168 	struct vnode   *udvp;
1169 	struct vnode   *uvp;
1170 	struct vattr	va;
1171 
1172 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: enter\n");
1173 
1174 	error = EROFS;
1175 	dunp = VTOUNIONFS(ap->a_dvp);
1176 	cnp = ap->a_cnp;
1177 	udvp = dunp->un_uppervp;
1178 
1179 	if (udvp != NULLVP) {
1180 		/* check opaque */
1181 		if (!(cnp->cn_flags & ISWHITEOUT)) {
1182 			error = VOP_GETATTR(udvp, &va, cnp->cn_cred);
1183 			if (error != 0)
1184 				return (error);
1185 			if (va.va_flags & OPAQUE)
1186 				cnp->cn_flags |= ISWHITEOUT;
1187 		}
1188 
1189 		if ((error = VOP_MKDIR(udvp, &uvp, cnp, ap->a_vap)) == 0) {
1190 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1191 			    ap->a_dvp, ap->a_vpp, cnp);
1192 			if (error) {
1193 				vput(uvp);
1194 			} else {
1195 				vrele(uvp);
1196 			}
1197 		}
1198 	}
1199 
1200 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: leave (%d)\n", error);
1201 
1202 	return (error);
1203 }
1204 
1205 static int
1206 unionfs_rmdir(void *v)
1207 {
1208 	struct vop_rmdir_args *ap = v;
1209 	int		error;
1210 	struct unionfs_node *dunp;
1211 	struct unionfs_node *unp;
1212 	struct unionfs_mount *ump;
1213 	struct componentname *cnp;
1214 	struct vnode   *udvp;
1215 	struct vnode   *uvp;
1216 	struct vnode   *lvp;
1217 
1218 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: enter\n");
1219 
1220 	error = 0;
1221 	dunp = VTOUNIONFS(ap->a_dvp);
1222 	unp = VTOUNIONFS(ap->a_vp);
1223 	cnp = ap->a_cnp;
1224 	udvp = dunp->un_uppervp;
1225 	uvp = unp->un_uppervp;
1226 	lvp = unp->un_lowervp;
1227 
1228 	if (udvp == NULLVP)
1229 		return (EROFS);
1230 
1231 	if (udvp == uvp)
1232 		return (EOPNOTSUPP);
1233 
1234 	if (uvp != NULLVP) {
1235 		if (lvp != NULLVP) {
1236 			error = unionfs_check_rmdir(ap->a_vp, cnp->cn_cred);
1237 			if (error != 0)
1238 				return (error);
1239 		}
1240 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
1241 		if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP)
1242 			cnp->cn_flags |= DOWHITEOUT;
1243 		error = VOP_RMDIR(udvp, uvp, cnp);
1244 	}
1245 	else if (lvp != NULLVP)
1246 		error = unionfs_mkwhiteout(udvp, cnp, unp->un_path);
1247 
1248 	if (error == 0) {
1249 		cache_purge(ap->a_dvp);
1250 		cache_purge(ap->a_vp);
1251 	}
1252 
1253 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: leave (%d)\n", error);
1254 
1255 	return (error);
1256 }
1257 
1258 static int
1259 unionfs_symlink(void *v)
1260 {
1261 	struct vop_symlink_args *ap = v;
1262 	int		error;
1263 	struct unionfs_node *dunp;
1264 	struct componentname *cnp;
1265 	struct vnode   *udvp;
1266 	struct vnode   *uvp;
1267 
1268 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: enter\n");
1269 
1270 	error = EROFS;
1271 	dunp = VTOUNIONFS(ap->a_dvp);
1272 	cnp = ap->a_cnp;
1273 	udvp = dunp->un_uppervp;
1274 
1275 	if (udvp != NULLVP) {
1276 		error = VOP_SYMLINK(udvp, &uvp, cnp, ap->a_vap, ap->a_target);
1277 		if (error == 0) {
1278 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1279 			    ap->a_dvp, ap->a_vpp, cnp);
1280 			if (error) {
1281 				vput(uvp);
1282 			} else {
1283 				vrele(uvp);
1284 			}
1285 		}
1286 	}
1287 
1288 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: leave (%d)\n", error);
1289 
1290 	return (error);
1291 }
1292 
1293 static int
1294 unionfs_readdir(void *v)
1295 {
1296 	struct vop_readdir_args *ap = v;
1297 	int		error;
1298 	int		eofflag;
1299 	int		locked;
1300 	struct unionfs_node *unp;
1301 	struct unionfs_node_status *unsp;
1302 	struct uio     *uio;
1303 	struct vnode   *uvp;
1304 	struct vnode   *lvp;
1305 	struct vattr    va;
1306 
1307 	int		ncookies_bk;
1308 	off_t          *cookies_bk;
1309 
1310 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: enter\n");
1311 
1312 	error = 0;
1313 	eofflag = 0;
1314 	locked = 0;
1315 	unp = VTOUNIONFS(ap->a_vp);
1316 	uio = ap->a_uio;
1317 	uvp = unp->un_uppervp;
1318 	lvp = unp->un_lowervp;
1319 	ncookies_bk = 0;
1320 	cookies_bk = NULL;
1321 
1322 	if (ap->a_vp->v_type != VDIR)
1323 		return (ENOTDIR);
1324 
1325 	/* check opaque */
1326 	if (uvp != NULLVP && lvp != NULLVP) {
1327 		if ((error = VOP_GETATTR(uvp, &va, ap->a_cred)) != 0)
1328 			goto unionfs_readdir_exit;
1329 		if (va.va_flags & OPAQUE)
1330 			lvp = NULLVP;
1331 	}
1332 
1333 	/* check the open count. unionfs needs to open before readdir. */
1334 	VOP_UNLOCK(ap->a_vp);
1335 	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
1336 	unionfs_get_node_status(unp, &unsp);
1337 	if ((uvp != NULLVP && unsp->uns_upper_opencnt <= 0) ||
1338 	    (lvp != NULLVP && unsp->uns_lower_opencnt <= 0)) {
1339 		unionfs_tryrem_node_status(unp, unsp);
1340 		error = EBADF;
1341 	}
1342 	if (error != 0)
1343 		goto unionfs_readdir_exit;
1344 
1345 	/* upper only */
1346 	if (uvp != NULLVP && lvp == NULLVP) {
1347 		error = VOP_READDIR(uvp, uio, ap->a_cred, ap->a_eofflag,
1348 		    ap->a_cookies, ap->a_ncookies);
1349 		unsp->uns_readdir_status = 0;
1350 
1351 		goto unionfs_readdir_exit;
1352 	}
1353 
1354 	/* lower only */
1355 	if (uvp == NULLVP && lvp != NULLVP) {
1356 		error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1357 		    ap->a_cookies, ap->a_ncookies);
1358 		unsp->uns_readdir_status = 2;
1359 
1360 		goto unionfs_readdir_exit;
1361 	}
1362 
1363 	/*
1364 	 * readdir upper and lower
1365 	 */
1366 	KASSERT(uvp != NULLVP);
1367 	KASSERT(lvp != NULLVP);
1368 	if (uio->uio_offset == 0)
1369 		unsp->uns_readdir_status = 0;
1370 
1371 	if (unsp->uns_readdir_status == 0) {
1372 		/* read upper */
1373 		error = VOP_READDIR(uvp, uio, ap->a_cred, &eofflag,
1374 				    ap->a_cookies, ap->a_ncookies);
1375 
1376 		if (error != 0 || eofflag == 0)
1377 			goto unionfs_readdir_exit;
1378 		unsp->uns_readdir_status = 1;
1379 
1380 		/*
1381 		 * ufs(and other fs) needs size of uio_resid larger than
1382 		 * DIRBLKSIZ.
1383 		 * size of DIRBLKSIZ equals DEV_BSIZE.
1384 		 * (see: ufs/ufs/ufs_vnops.c ufs_readdir func , ufs/ufs/dir.h)
1385 		 */
1386 		if (uio->uio_resid <= (uio->uio_resid & (DEV_BSIZE -1)))
1387 			goto unionfs_readdir_exit;
1388 
1389 		/*
1390 		 * backup cookies
1391 		 * It prepares to readdir in lower.
1392 		 */
1393 		if (ap->a_ncookies != NULL) {
1394 			ncookies_bk = *(ap->a_ncookies);
1395 			*(ap->a_ncookies) = 0;
1396 		}
1397 		if (ap->a_cookies != NULL) {
1398 			cookies_bk = *(ap->a_cookies);
1399 			*(ap->a_cookies) = NULL;
1400 		}
1401 	}
1402 
1403 	/* initialize for readdir in lower */
1404 	if (unsp->uns_readdir_status == 1) {
1405 		unsp->uns_readdir_status = 2;
1406 		uio->uio_offset = 0;
1407 	}
1408 
1409 	if (lvp == NULLVP) {
1410 		error = EBADF;
1411 		goto unionfs_readdir_exit;
1412 	}
1413 	/* read lower */
1414 	error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1415 			    ap->a_cookies, ap->a_ncookies);
1416 
1417 	if (cookies_bk != NULL) {
1418 		/* merge cookies */
1419 		int		size;
1420 		off_t         *newcookies, *pos;
1421 
1422 		size = *(ap->a_ncookies) + ncookies_bk;
1423 		newcookies = (off_t *) malloc(size * sizeof(off_t),
1424 		    M_TEMP, M_WAITOK);
1425 		pos = newcookies;
1426 
1427 		memcpy(pos, cookies_bk, ncookies_bk * sizeof(off_t));
1428 		pos += ncookies_bk * sizeof(off_t);
1429 		memcpy(pos, *(ap->a_cookies), *(ap->a_ncookies) * sizeof(off_t));
1430 		free(cookies_bk, M_TEMP);
1431 		free(*(ap->a_cookies), M_TEMP);
1432 		*(ap->a_ncookies) = size;
1433 		*(ap->a_cookies) = newcookies;
1434 	}
1435 
1436 unionfs_readdir_exit:
1437 	if (error != 0 && ap->a_eofflag != NULL)
1438 		*(ap->a_eofflag) = 1;
1439 
1440 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1441 
1442 	return (error);
1443 }
1444 
1445 static int
1446 unionfs_readlink(void *v)
1447 {
1448 	struct vop_readlink_args *ap = v;
1449 	int error;
1450 	struct unionfs_node *unp;
1451 	struct vnode   *vp;
1452 
1453 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: enter\n");
1454 
1455 	unp = VTOUNIONFS(ap->a_vp);
1456 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1457 
1458 	error = VOP_READLINK(vp, ap->a_uio, ap->a_cred);
1459 
1460 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: leave (%d)\n", error);
1461 
1462 	return (error);
1463 }
1464 
1465 static int
1466 unionfs_inactive(void *v)
1467 {
1468 	struct vop_inactive_args *ap = v;
1469 	*ap->a_recycle = true;
1470 	VOP_UNLOCK(ap->a_vp);
1471 	return (0);
1472 }
1473 
1474 static int
1475 unionfs_reclaim(void *v)
1476 {
1477 	struct vop_reclaim_args *ap = v;
1478 
1479 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: enter\n"); */
1480 
1481 	unionfs_noderem(ap->a_vp);
1482 
1483 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: leave\n"); */
1484 
1485 	return (0);
1486 }
1487 
1488 static int
1489 unionfs_print(void *v)
1490 {
1491 	struct vop_print_args *ap = v;
1492 	struct unionfs_node *unp;
1493 	/* struct unionfs_node_status *unsp; */
1494 
1495 	unp = VTOUNIONFS(ap->a_vp);
1496 	/* unionfs_get_node_status(unp, &unsp); */
1497 
1498 	printf("unionfs_vp=%p, uppervp=%p, lowervp=%p\n",
1499 	    ap->a_vp, unp->un_uppervp, unp->un_lowervp);
1500 	/*
1501 	printf("unionfs opencnt: uppervp=%d, lowervp=%d\n",
1502 	    unsp->uns_upper_opencnt, unsp->uns_lower_opencnt);
1503 	*/
1504 
1505 	if (unp->un_uppervp != NULLVP)
1506 		vprint("unionfs: upper", unp->un_uppervp);
1507 	if (unp->un_lowervp != NULLVP)
1508 		vprint("unionfs: lower", unp->un_lowervp);
1509 
1510 	return (0);
1511 }
1512 
1513 static int
1514 unionfs_lock(void *v)
1515 {
1516 	struct vop_lock_args *ap = v;
1517 	int		error;
1518 	int		flags;
1519 	struct vnode   *lvp;
1520 	struct vnode   *uvp;
1521 	struct unionfs_node *unp;
1522 
1523 	unp = VTOUNIONFS(ap->a_vp);
1524 	lvp = unp->un_lowervp;
1525 	uvp = unp->un_uppervp;
1526 	flags = ap->a_flags;
1527 	error = 0;
1528 
1529 	if (lvp != NULLVP) {
1530 		error = VOP_LOCK(lvp, flags);
1531 	}
1532 	if (error == 0 && uvp != NULLVP) {
1533 		error = VOP_LOCK(uvp, flags);
1534 		if (error != 0) {
1535 			VOP_UNLOCK(lvp);
1536 		}
1537 	}
1538 
1539 	return error;
1540 }
1541 
1542 static int
1543 unionfs_unlock(void *v)
1544 {
1545 	struct vop_unlock_args *ap = v;
1546 	int		error;
1547 	struct vnode   *lvp;
1548 	struct vnode   *uvp;
1549 	struct unionfs_node *unp;
1550 
1551 	unp = VTOUNIONFS(ap->a_vp);
1552 	lvp = unp->un_lowervp;
1553 	uvp = unp->un_uppervp;
1554 	error = 0;
1555 
1556 	if (lvp != NULLVP) {
1557 		error = VOP_UNLOCK(lvp);
1558 	}
1559 	if (error == 0 && uvp != NULLVP) {
1560 		error = VOP_UNLOCK(uvp);
1561 	}
1562 
1563 	return error;
1564 }
1565 
1566 static int
1567 unionfs_pathconf(void *v)
1568 {
1569 	struct vop_pathconf_args *ap = v;
1570 	struct unionfs_node *unp;
1571 	struct vnode   *vp;
1572 
1573 	unp = VTOUNIONFS(ap->a_vp);
1574 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1575 
1576 	return (VOP_PATHCONF(vp, ap->a_name, ap->a_retval));
1577 }
1578 
1579 static int
1580 unionfs_advlock(void *v)
1581 {
1582 	struct vop_advlock_args *ap = v;
1583 	int error;
1584 	struct unionfs_node *unp;
1585 	struct unionfs_node_status *unsp;
1586 	struct vnode   *vp;
1587 	struct vnode   *uvp;
1588 	kauth_cred_t	cred;
1589 
1590 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: enter\n");
1591 
1592 	vp = ap->a_vp;
1593 	cred = kauth_cred_get();
1594 
1595 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1596 
1597 	unp = VTOUNIONFS(ap->a_vp);
1598 	uvp = unp->un_uppervp;
1599 
1600 	if (uvp == NULLVP) {
1601 		error = unionfs_copyfile(unp, 1, cred);
1602 		if (error != 0)
1603 			goto unionfs_advlock_abort;
1604 		uvp = unp->un_uppervp;
1605 
1606 		unionfs_get_node_status(unp, &unsp);
1607 		if (unsp->uns_lower_opencnt > 0) {
1608 			/* try reopen the vnode */
1609 			error = VOP_OPEN(uvp, unsp->uns_lower_openmode, cred);
1610 			if (error)
1611 				goto unionfs_advlock_abort;
1612 			unsp->uns_upper_opencnt++;
1613 			VOP_CLOSE(unp->un_lowervp, unsp->uns_lower_openmode, cred);
1614 			unsp->uns_lower_opencnt--;
1615 		} else
1616 			unionfs_tryrem_node_status(unp, unsp);
1617 	}
1618 
1619 	VOP_UNLOCK(vp);
1620 
1621 	error = VOP_ADVLOCK(uvp, ap->a_id, ap->a_op, ap->a_fl, ap->a_flags);
1622 
1623 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
1624 
1625 	return error;
1626 
1627 unionfs_advlock_abort:
1628 	VOP_UNLOCK(vp);
1629 
1630 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
1631 
1632 	return error;
1633 }
1634 
1635 static int
1636 unionfs_strategy(void *v)
1637 {
1638 	struct vop_strategy_args *ap = v;
1639 	struct unionfs_node *unp;
1640 	struct vnode   *vp;
1641 
1642 	unp = VTOUNIONFS(ap->a_vp);
1643 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1644 
1645 #ifdef DIAGNOSTIC
1646 	if (vp == NULLVP)
1647 		panic("unionfs_strategy: nullvp");
1648 	if ((ap->a_bp->b_flags & B_READ) == 0 && vp == unp->un_lowervp)
1649 		panic("unionfs_strategy: writing to lowervp");
1650 #endif
1651 
1652 	return (VOP_STRATEGY(vp, ap->a_bp));
1653 }
1654 
1655 static int
1656 unionfs_kqfilter(void *v)
1657 {
1658 	struct vop_kqfilter_args *ap = v;
1659 	struct unionfs_node *unp;
1660 	struct vnode   *tvp;
1661 
1662 	unp = VTOUNIONFS(ap->a_vp);
1663 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1664 
1665 	return VOP_KQFILTER(tvp, ap->a_kn);
1666 }
1667 
1668 static int
1669 unionfs_bmap(void *v)
1670 {
1671 	struct vop_bmap_args *ap = v;
1672 	struct unionfs_node *unp;
1673 	struct vnode   *tvp;
1674 
1675 	unp = VTOUNIONFS(ap->a_vp);
1676 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1677 
1678 	return VOP_BMAP(tvp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp);
1679 }
1680 
1681 static int
1682 unionfs_mmap(void *v)
1683 {
1684 	struct vop_mmap_args *ap = v;
1685 	struct unionfs_node *unp;
1686 	struct vnode   *tvp;
1687 
1688 	unp = VTOUNIONFS(ap->a_vp);
1689 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1690 
1691 	return VOP_MMAP(tvp, ap->a_prot, ap->a_cred);
1692 }
1693 
1694 static int
1695 unionfs_abortop(void *v)
1696 {
1697 	struct vop_abortop_args *ap = v;
1698 	struct unionfs_node *unp;
1699 	struct vnode   *tvp;
1700 
1701 	unp = VTOUNIONFS(ap->a_dvp);
1702 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1703 
1704 	return VOP_ABORTOP(tvp, ap->a_cnp);
1705 }
1706 
1707 static int
1708 unionfs_islocked(void *v)
1709 {
1710 	struct vop_islocked_args *ap = v;
1711 	struct unionfs_node *unp;
1712 	struct vnode   *tvp;
1713 
1714 	unp = VTOUNIONFS(ap->a_vp);
1715 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1716 
1717 	return VOP_ISLOCKED(tvp);
1718 }
1719 
1720 static int
1721 unionfs_seek(void *v)
1722 {
1723 	struct vop_seek_args *ap = v;
1724 	struct unionfs_node *unp;
1725 	struct vnode   *tvp;
1726 
1727 	unp = VTOUNIONFS(ap->a_vp);
1728 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1729 
1730 	return VOP_SEEK(tvp, ap->a_oldoff, ap->a_newoff, ap->a_cred);
1731 }
1732 
1733 static int
1734 unionfs_putpages(void *v)
1735 {
1736 	struct vop_putpages_args *ap = v;
1737 	struct unionfs_node *unp;
1738 	struct vnode   *tvp;
1739 
1740 	unp = VTOUNIONFS(ap->a_vp);
1741 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1742 
1743 	mutex_exit(&ap->a_vp->v_interlock);
1744 	if (ap->a_flags & PGO_RECLAIM) {
1745 		return 0;
1746 	}
1747 	mutex_enter(&tvp->v_interlock);
1748 
1749 	return VOP_PUTPAGES(tvp, ap->a_offlo, ap->a_offhi, ap->a_flags);
1750 }
1751 
1752 static int
1753 unionfs_getpages(void *v)
1754 {
1755 	struct vop_getpages_args *ap = v;
1756 	struct unionfs_node *unp;
1757 	struct vnode   *tvp;
1758 
1759 	unp = VTOUNIONFS(ap->a_vp);
1760 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1761 
1762 	if (ap->a_flags & PGO_LOCKED) {
1763 		return EBUSY;
1764 	}
1765 	mutex_exit(&ap->a_vp->v_interlock);
1766 	mutex_enter(&tvp->v_interlock);
1767 
1768 	return VOP_GETPAGES(tvp, ap->a_offset, ap->a_m, ap->a_count,
1769 	    ap->a_centeridx, ap->a_access_type, ap->a_advice, ap->a_flags);
1770 }
1771 
1772 static int
1773 unionfs_revoke(void *v)
1774 {
1775 	struct vop_revoke_args *ap = v;
1776 	struct unionfs_node *unp;
1777 	struct vnode   *tvp;
1778 	int error;
1779 
1780 	unp = VTOUNIONFS(ap->a_vp);
1781 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1782 
1783 	error = VOP_REVOKE(tvp, ap->a_flags);
1784 	if (error == 0) {
1785 		vgone(ap->a_vp);	/* ??? */
1786 	}
1787 	return error;
1788 }
1789 
1790 /*
1791  * Global vfs data structures
1792  */
1793 int (**unionfs_vnodeop_p)(void *);
1794 const struct vnodeopv_entry_desc unionfs_vnodeop_entries[] = {
1795 	{ &vop_default_desc, vn_default_error },
1796 	{ &vop_lookup_desc, unionfs_lookup },		/* lookup */
1797 	{ &vop_create_desc, unionfs_create },		/* create */
1798 	{ &vop_whiteout_desc, unionfs_whiteout },	/* whiteout */
1799 	{ &vop_mknod_desc, unionfs_mknod },		/* mknod */
1800 	{ &vop_open_desc, unionfs_open },		/* open */
1801 	{ &vop_close_desc, unionfs_close },		/* close */
1802 	{ &vop_access_desc, unionfs_access },		/* access */
1803 	{ &vop_getattr_desc, unionfs_getattr },		/* getattr */
1804 	{ &vop_setattr_desc, unionfs_setattr },		/* setattr */
1805 	{ &vop_read_desc, unionfs_read },		/* read */
1806 	{ &vop_write_desc, unionfs_write },		/* write */
1807 	{ &vop_ioctl_desc, unionfs_ioctl },		/* ioctl */
1808 	{ &vop_poll_desc, unionfs_poll },		/* select */
1809 	{ &vop_revoke_desc, unionfs_revoke },		/* revoke */
1810 	{ &vop_mmap_desc, unionfs_mmap },		/* mmap */
1811 	{ &vop_fsync_desc, unionfs_fsync },		/* fsync */
1812 	{ &vop_seek_desc, unionfs_seek },		/* seek */
1813 	{ &vop_remove_desc, unionfs_remove },		/* remove */
1814 	{ &vop_link_desc, unionfs_link },		/* link */
1815 	{ &vop_rename_desc, unionfs_rename },		/* rename */
1816 	{ &vop_mkdir_desc, unionfs_mkdir },		/* mkdir */
1817 	{ &vop_rmdir_desc, unionfs_rmdir },		/* rmdir */
1818 	{ &vop_symlink_desc, unionfs_symlink },		/* symlink */
1819 	{ &vop_readdir_desc, unionfs_readdir },		/* readdir */
1820 	{ &vop_readlink_desc, unionfs_readlink },	/* readlink */
1821 	{ &vop_abortop_desc, unionfs_abortop },		/* abortop */
1822 	{ &vop_inactive_desc, unionfs_inactive },	/* inactive */
1823 	{ &vop_reclaim_desc, unionfs_reclaim },		/* reclaim */
1824 	{ &vop_lock_desc, unionfs_lock },		/* lock */
1825 	{ &vop_unlock_desc, unionfs_unlock },		/* unlock */
1826 	{ &vop_bmap_desc, unionfs_bmap },		/* bmap */
1827 	{ &vop_strategy_desc, unionfs_strategy },	/* strategy */
1828 	{ &vop_print_desc, unionfs_print },		/* print */
1829 	{ &vop_islocked_desc, unionfs_islocked },	/* islocked */
1830 	{ &vop_pathconf_desc, unionfs_pathconf },	/* pathconf */
1831 	{ &vop_advlock_desc, unionfs_advlock },		/* advlock */
1832 	{ &vop_getpages_desc, unionfs_getpages },	/* getpages */
1833 	{ &vop_putpages_desc, unionfs_putpages },	/* putpages */
1834 	{ &vop_kqfilter_desc, unionfs_kqfilter },	/* kqfilter */
1835 #ifdef notdef
1836 	{ &vop_bwrite_desc, unionfs_bwrite },		/* bwrite */
1837 #endif
1838 	{ NULL, NULL }
1839 };
1840 const struct vnodeopv_desc unionfs_vnodeop_opv_desc =
1841 	{ &unionfs_vnodeop_p, unionfs_vnodeop_entries };
1842