xref: /netbsd-src/sys/fs/unionfs/unionfs_vnops.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
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);
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);
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);
136 			vrele(vp);
137 
138 			VOP_UNLOCK(dvp);
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);
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 	struct unionfs_node *unp;
475 	struct unionfs_node_status *unsp;
476 	kauth_cred_t   cred;
477 	struct vnode   *ovp;
478 
479 	UNIONFS_INTERNAL_DEBUG("unionfs_close: enter\n");
480 
481 	KASSERT(VOP_ISLOCKED(ap->a_vp) == LK_EXCLUSIVE);
482 	unp = VTOUNIONFS(ap->a_vp);
483 	cred = ap->a_cred;
484 
485 	unionfs_get_node_status(unp, &unsp);
486 
487 	if (unsp->uns_lower_opencnt <= 0 && unsp->uns_upper_opencnt <= 0) {
488 #ifdef DIAGNOSTIC
489 		printf("unionfs_close: warning: open count is 0\n");
490 #endif
491 		if (unp->un_uppervp != NULLVP)
492 			ovp = unp->un_uppervp;
493 		else
494 			ovp = unp->un_lowervp;
495 	} else if (unsp->uns_upper_opencnt > 0)
496 		ovp = unp->un_uppervp;
497 	else
498 		ovp = unp->un_lowervp;
499 
500 	error = VOP_CLOSE(ovp, ap->a_fflag, cred);
501 
502 	if (error != 0)
503 		goto unionfs_close_abort;
504 
505 	if (ovp == unp->un_uppervp) {
506 		unsp->uns_upper_opencnt--;
507 		if (unsp->uns_upper_opencnt == 0) {
508 			if (unsp->uns_node_flag & UNS_OPENL_4_READDIR) {
509 				VOP_CLOSE(unp->un_lowervp, FREAD, cred);
510 				unsp->uns_node_flag &= ~UNS_OPENL_4_READDIR;
511 				unsp->uns_lower_opencnt--;
512 			}
513 		}
514 	} else
515 		unsp->uns_lower_opencnt--;
516 
517 unionfs_close_abort:
518 	unionfs_tryrem_node_status(unp, unsp);
519 
520 	UNIONFS_INTERNAL_DEBUG("unionfs_close: leave (%d)\n", error);
521 
522 	return (error);
523 }
524 
525 /*
526  * Check the access mode toward shadow file/dir.
527  */
528 static int
529 unionfs_check_corrected_access(u_short mode, struct vattr *va, kauth_cred_t cred)
530 {
531 	int		result;
532 	int		error;
533 	uid_t		uid;	/* upper side vnode's uid */
534 	gid_t		gid;	/* upper side vnode's gid */
535 	u_short		vmode;	/* upper side vnode's mode */
536 	u_short		mask;
537 
538 	mask = 0;
539 	uid = va->va_uid;
540 	gid = va->va_gid;
541 	vmode = va->va_mode;
542 
543 	/* check owner */
544 	if (kauth_cred_getuid(cred) == uid) {
545 		if (mode & VEXEC)
546 			mask |= S_IXUSR;
547 		if (mode & VREAD)
548 			mask |= S_IRUSR;
549 		if (mode & VWRITE)
550 			mask |= S_IWUSR;
551 		return ((vmode & mask) == mask ? 0 : EACCES);
552 	}
553 
554 	/* check group */
555 	error = kauth_cred_ismember_gid(cred, gid, &result);
556 	if (error != 0)
557 		return error;
558 	if (result) {
559 		if (mode & VEXEC)
560 			mask |= S_IXGRP;
561 		if (mode & VREAD)
562 			mask |= S_IRGRP;
563 		if (mode & VWRITE)
564 			mask |= S_IWGRP;
565 		return ((vmode & mask) == mask ? 0 : EACCES);
566 	}
567 
568 	/* check other */
569 	if (mode & VEXEC)
570 		mask |= S_IXOTH;
571 	if (mode & VREAD)
572 		mask |= S_IROTH;
573 	if (mode & VWRITE)
574 		mask |= S_IWOTH;
575 
576 	return ((vmode & mask) == mask ? 0 : EACCES);
577 }
578 
579 static int
580 unionfs_access(void *v)
581 {
582 	struct vop_access_args *ap = v;
583 	struct unionfs_mount *ump;
584 	struct unionfs_node *unp;
585 	struct vnode   *uvp;
586 	struct vnode   *lvp;
587 	struct vattr	va;
588 	int		mode;
589 	int		error;
590 
591 	UNIONFS_INTERNAL_DEBUG("unionfs_access: enter\n");
592 
593 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
594 	unp = VTOUNIONFS(ap->a_vp);
595 	uvp = unp->un_uppervp;
596 	lvp = unp->un_lowervp;
597 	mode = ap->a_mode;
598 	error = EACCES;
599 
600 	if ((mode & VWRITE) &&
601 	    (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) {
602 		switch (ap->a_vp->v_type) {
603 		case VREG:
604 		case VDIR:
605 		case VLNK:
606 			return (EROFS);
607 		default:
608 			break;
609 		}
610 	}
611 
612 	if (uvp != NULLVP) {
613 		error = VOP_ACCESS(uvp, mode, ap->a_cred);
614 
615 		UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
616 
617 		return (error);
618 	}
619 
620 	if (lvp != NULLVP) {
621 		if (mode & VWRITE) {
622 			if (ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY) {
623 				switch (ap->a_vp->v_type) {
624 				case VREG:
625 				case VDIR:
626 				case VLNK:
627 					return (EROFS);
628 				default:
629 					break;
630 				}
631 			} else if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
632 				/* check shadow file/dir */
633 				if (ump->um_copymode != UNIONFS_TRANSPARENT) {
634 					error = unionfs_create_uppervattr(ump,
635 					    lvp, &va, ap->a_cred);
636 					if (error != 0)
637 						return (error);
638 
639 					error = unionfs_check_corrected_access(
640 					    mode, &va, ap->a_cred);
641 					if (error != 0)
642 						return (error);
643 				}
644 			}
645 			mode &= ~VWRITE;
646 			mode |= VREAD; /* will copy to upper */
647 		}
648 		error = VOP_ACCESS(lvp, mode, ap->a_cred);
649 	}
650 
651 	UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error);
652 
653 	return (error);
654 }
655 
656 static int
657 unionfs_getattr(void *v)
658 {
659 	struct vop_getattr_args *ap = v;
660 	int		error;
661 	struct unionfs_node *unp;
662 	struct unionfs_mount *ump;
663 	struct vnode   *uvp;
664 	struct vnode   *lvp;
665 	struct vattr	va;
666 
667 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: enter\n");
668 
669 	unp = VTOUNIONFS(ap->a_vp);
670 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
671 	uvp = unp->un_uppervp;
672 	lvp = unp->un_lowervp;
673 
674 	if (uvp != NULLVP) {
675 		if ((error = VOP_GETATTR(uvp, ap->a_vap, ap->a_cred)) == 0)
676 			ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid;
677 
678 		UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
679 		    ap->a_vap->va_mode, ap->a_vap->va_uid,
680 		    ap->a_vap->va_gid, error);
681 
682 		return (error);
683 	}
684 
685 	error = VOP_GETATTR(lvp, ap->a_vap, ap->a_cred);
686 
687 	if (error == 0 && !(ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY)) {
688 		/* correct the attr toward shadow file/dir. */
689 		if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) {
690 			unionfs_create_uppervattr_core(ump, ap->a_vap, &va);
691 			ap->a_vap->va_mode = va.va_mode;
692 			ap->a_vap->va_uid = va.va_uid;
693 			ap->a_vap->va_gid = va.va_gid;
694 		}
695 	}
696 
697 	if (error == 0)
698 		ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid;
699 
700 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n",
701 	    ap->a_vap->va_mode, ap->a_vap->va_uid, ap->a_vap->va_gid, error);
702 
703 	return (error);
704 }
705 
706 static int
707 unionfs_setattr(void *v)
708 {
709 	struct vop_setattr_args *ap = v;
710 	int		error;
711 	struct unionfs_node *unp;
712 	struct vnode   *uvp;
713 	struct vnode   *lvp;
714 	struct vattr   *vap;
715 
716 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: enter\n");
717 
718 	error = EROFS;
719 	unp = VTOUNIONFS(ap->a_vp);
720 	uvp = unp->un_uppervp;
721 	lvp = unp->un_lowervp;
722 	vap = ap->a_vap;
723 
724 	if ((ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) &&
725 	    (vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
726 	     vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
727 	     vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL))
728 		return (EROFS);
729 
730 	if (uvp == NULLVP && lvp->v_type == VREG) {
731 		error = unionfs_copyfile(unp, (vap->va_size != 0),
732 		    ap->a_cred);
733 		if (error != 0)
734 			return (error);
735 		uvp = unp->un_uppervp;
736 	}
737 
738 	if (uvp != NULLVP)
739 		error = VOP_SETATTR(uvp, vap, ap->a_cred);
740 
741 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: leave (%d)\n", error);
742 
743 	return (error);
744 }
745 
746 static int
747 unionfs_read(void *v)
748 {
749 	struct vop_read_args *ap = v;
750 	int		error;
751 	struct unionfs_node *unp;
752 	struct vnode   *tvp;
753 
754 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: enter\n"); */
755 
756 	unp = VTOUNIONFS(ap->a_vp);
757 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
758 
759 	error = VOP_READ(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
760 
761 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: leave (%d)\n", error); */
762 
763 	return (error);
764 }
765 
766 static int
767 unionfs_write(void *v)
768 {
769 	struct vop_write_args *ap = v;
770 	int		error;
771 	struct unionfs_node *unp;
772 	struct vnode   *tvp;
773 
774 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: enter\n"); */
775 
776 	unp = VTOUNIONFS(ap->a_vp);
777 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
778 
779 	error = VOP_WRITE(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred);
780 
781 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: leave (%d)\n", error); */
782 
783 	return (error);
784 }
785 
786 static int
787 unionfs_ioctl(void *v)
788 {
789 	struct vop_ioctl_args *ap = v;
790 	int error;
791 	struct unionfs_node *unp;
792 	struct unionfs_node_status *unsp;
793 	struct vnode   *ovp;
794 
795 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: enter\n");
796 
797  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
798 	unp = VTOUNIONFS(ap->a_vp);
799 	unionfs_get_node_status(unp, &unsp);
800 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
801 	unionfs_tryrem_node_status(unp, unsp);
802 	VOP_UNLOCK(ap->a_vp);
803 
804 	if (ovp == NULLVP)
805 		return (EBADF);
806 
807 	error = VOP_IOCTL(ovp, ap->a_command, ap->a_data, ap->a_fflag,
808 	    ap->a_cred);
809 
810 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: lease (%d)\n", error);
811 
812 	return (error);
813 }
814 
815 static int
816 unionfs_poll(void *v)
817 {
818 	struct vop_poll_args *ap = v;
819 	struct unionfs_node *unp;
820 	struct unionfs_node_status *unsp;
821 	struct vnode   *ovp;
822 
823  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
824 	unp = VTOUNIONFS(ap->a_vp);
825 	unionfs_get_node_status(unp, &unsp);
826 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
827 	unionfs_tryrem_node_status(unp, unsp);
828 	VOP_UNLOCK(ap->a_vp);
829 
830 	if (ovp == NULLVP)
831 		return (EBADF);
832 
833 	return (VOP_POLL(ovp, ap->a_events));
834 }
835 
836 static int
837 unionfs_fsync(void *v)
838 {
839 	struct vop_fsync_args *ap = v;
840 	struct unionfs_node *unp;
841 	struct unionfs_node_status *unsp;
842 	struct vnode   *ovp;
843 
844 	unp = VTOUNIONFS(ap->a_vp);
845 	unionfs_get_node_status(unp, &unsp);
846 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
847 	unionfs_tryrem_node_status(unp, unsp);
848 
849 	if (ovp == NULLVP)
850 		return (EBADF);
851 
852 	return (VOP_FSYNC(ovp, ap->a_cred, ap->a_flags, ap->a_offlo, ap->a_offhi));
853 }
854 
855 static int
856 unionfs_remove(void *v)
857 {
858 	struct vop_remove_args *ap = v;
859 	int		error;
860 	struct unionfs_node *dunp;
861 	struct unionfs_node *unp;
862 	struct unionfs_mount *ump;
863 	struct vnode   *udvp;
864 	struct vnode   *uvp;
865 	struct vnode   *lvp;
866 	struct componentname *cnp;
867 
868 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: enter\n");
869 
870 	error = 0;
871 	dunp = VTOUNIONFS(ap->a_dvp);
872 	unp = VTOUNIONFS(ap->a_vp);
873 	udvp = dunp->un_uppervp;
874 	uvp = unp->un_uppervp;
875 	lvp = unp->un_lowervp;
876 	cnp = ap->a_cnp;
877 
878 	if (udvp == NULLVP)
879 		return (EROFS);
880 
881 	if (uvp != NULLVP) {
882 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
883 		if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP)
884 			cnp->cn_flags |= DOWHITEOUT;
885 		error = VOP_REMOVE(udvp, uvp, cnp);
886 	} else if (lvp != NULLVP)
887 		error = unionfs_mkwhiteout(udvp, cnp, unp->un_path);
888 
889 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: leave (%d)\n", error);
890 
891 	return (error);
892 }
893 
894 static int
895 unionfs_link(void *v)
896 {
897 #if 0
898 	struct vop_link_args *ap = v;
899 	int		error;
900 	int		needrelookup;
901 	struct unionfs_node *dunp;
902 	struct unionfs_node *unp;
903 	struct vnode   *udvp;
904 	struct vnode   *uvp;
905 	struct componentname *cnp;
906 
907 	UNIONFS_INTERNAL_DEBUG("unionfs_link: enter\n");
908 
909 	error = 0;
910 	needrelookup = 0;
911 	dunp = VTOUNIONFS(ap->a_tdvp);
912 	unp = NULL;
913 	udvp = dunp->un_uppervp;
914 	uvp = NULLVP;
915 	cnp = ap->a_cnp;
916 
917 	if (udvp == NULLVP)
918 		return (EROFS);
919 
920 	if (ap->a_vp->v_op != unionfs_vnodeop_p)
921 		uvp = ap->a_vp;
922 	else {
923 		unp = VTOUNIONFS(ap->a_vp);
924 
925 		if (unp->un_uppervp == NULLVP) {
926 			if (ap->a_vp->v_type != VREG)
927 				return (EOPNOTSUPP);
928 
929 			error = unionfs_copyfile(unp, 1, cnp->cn_cred);
930 			if (error != 0)
931 				return (error);
932 			needrelookup = 1;
933 		}
934 		uvp = unp->un_uppervp;
935 	}
936 
937 	if (needrelookup != 0)
938 		error = unionfs_relookup_for_create(ap->a_tdvp, cnp);
939 
940 	if (error == 0)
941 		error = VOP_LINK(udvp, uvp, cnp);
942 
943 	UNIONFS_INTERNAL_DEBUG("unionfs_link: leave (%d)\n", error);
944 
945 	return (error);
946 #else
947 	panic("XXXAD");
948 	return 0;
949 #endif
950 }
951 
952 static int
953 unionfs_rename(void *v)
954 {
955 	struct vop_rename_args *ap = v;
956 	int		error;
957 	struct vnode   *fdvp;
958 	struct vnode   *fvp;
959 	struct componentname *fcnp;
960 	struct vnode   *tdvp;
961 	struct vnode   *tvp;
962 	struct componentname *tcnp;
963 	struct vnode   *ltdvp;
964 	struct vnode   *ltvp;
965 
966 	/* rename target vnodes */
967 	struct vnode   *rfdvp;
968 	struct vnode   *rfvp;
969 	struct vnode   *rtdvp;
970 	struct vnode   *rtvp;
971 
972 	int		needrelookup;
973 	struct unionfs_mount *ump;
974 	struct unionfs_node *unp;
975 
976 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: enter\n");
977 
978 	error = 0;
979 	fdvp = ap->a_fdvp;
980 	fvp = ap->a_fvp;
981 	fcnp = ap->a_fcnp;
982 	tdvp = ap->a_tdvp;
983 	tvp = ap->a_tvp;
984 	tcnp = ap->a_tcnp;
985 	ltdvp = NULLVP;
986 	ltvp = NULLVP;
987 	rfdvp = fdvp;
988 	rfvp = fvp;
989 	rtdvp = tdvp;
990 	rtvp = tvp;
991 	needrelookup = 0;
992 
993 #ifdef DIAGNOSTIC
994 	if (!(fcnp->cn_flags & HASBUF) || !(tcnp->cn_flags & HASBUF))
995 		panic("unionfs_rename: no name");
996 #endif
997 
998 	/* check for cross device rename */
999 	if (fvp->v_mount != tdvp->v_mount ||
1000 	    (tvp != NULLVP && fvp->v_mount != tvp->v_mount)) {
1001 		error = EXDEV;
1002 		goto unionfs_rename_abort;
1003 	}
1004 
1005 	/* Renaming a file to itself has no effect. */
1006 	if (fvp == tvp)
1007 		goto unionfs_rename_abort;
1008 
1009 	/*
1010 	 * from/to vnode is unionfs node.
1011 	 */
1012 
1013 	unp = VTOUNIONFS(fdvp);
1014 #ifdef UNIONFS_IDBG_RENAME
1015 	UNIONFS_INTERNAL_DEBUG("fdvp=%p, ufdvp=%p, lfdvp=%p\n", fdvp, unp->un_uppervp, unp->un_lowervp);
1016 #endif
1017 	if (unp->un_uppervp == NULLVP) {
1018 		error = ENODEV;
1019 		goto unionfs_rename_abort;
1020 	}
1021 	rfdvp = unp->un_uppervp;
1022 	vref(rfdvp);
1023 
1024 	unp = VTOUNIONFS(fvp);
1025 #ifdef UNIONFS_IDBG_RENAME
1026 	UNIONFS_INTERNAL_DEBUG("fvp=%p, ufvp=%p, lfvp=%p\n", fvp, unp->un_uppervp, unp->un_lowervp);
1027 #endif
1028 	ump = MOUNTTOUNIONFSMOUNT(fvp->v_mount);
1029 	if (unp->un_uppervp == NULLVP) {
1030 		switch (fvp->v_type) {
1031 		case VREG:
1032 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1033 				goto unionfs_rename_abort;
1034 			error = unionfs_copyfile(unp, 1, fcnp->cn_cred);
1035 			VOP_UNLOCK(fvp);
1036 			if (error != 0)
1037 				goto unionfs_rename_abort;
1038 			break;
1039 		case VDIR:
1040 			if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
1041 				goto unionfs_rename_abort;
1042 			error = unionfs_mkshadowdir(ump, rfdvp, unp, fcnp);
1043 			VOP_UNLOCK(fvp);
1044 			if (error != 0)
1045 				goto unionfs_rename_abort;
1046 			break;
1047 		default:
1048 			error = ENODEV;
1049 			goto unionfs_rename_abort;
1050 		}
1051 
1052 		needrelookup = 1;
1053 	}
1054 
1055 	if (unp->un_lowervp != NULLVP)
1056 		fcnp->cn_flags |= DOWHITEOUT;
1057 	rfvp = unp->un_uppervp;
1058 	vref(rfvp);
1059 
1060 	unp = VTOUNIONFS(tdvp);
1061 #ifdef UNIONFS_IDBG_RENAME
1062 	UNIONFS_INTERNAL_DEBUG("tdvp=%p, utdvp=%p, ltdvp=%p\n", tdvp, unp->un_uppervp, unp->un_lowervp);
1063 #endif
1064 	if (unp->un_uppervp == NULLVP) {
1065 		error = ENODEV;
1066 		goto unionfs_rename_abort;
1067 	}
1068 	rtdvp = unp->un_uppervp;
1069 	ltdvp = unp->un_lowervp;
1070 	vref(rtdvp);
1071 
1072 	if (tdvp == tvp) {
1073 		rtvp = rtdvp;
1074 		vref(rtvp);
1075 	} else if (tvp != NULLVP) {
1076 		unp = VTOUNIONFS(tvp);
1077 #ifdef UNIONFS_IDBG_RENAME
1078 		UNIONFS_INTERNAL_DEBUG("tvp=%p, utvp=%p, ltvp=%p\n", tvp, unp->un_uppervp, unp->un_lowervp);
1079 #endif
1080 		if (unp->un_uppervp == NULLVP)
1081 			rtvp = NULLVP;
1082 		else {
1083 			if (tvp->v_type == VDIR) {
1084 				error = EINVAL;
1085 				goto unionfs_rename_abort;
1086 			}
1087 			rtvp = unp->un_uppervp;
1088 			ltvp = unp->un_lowervp;
1089 			vref(rtvp);
1090 		}
1091 	}
1092 
1093 	if (needrelookup != 0) {
1094 		if ((error = vn_lock(fdvp, LK_EXCLUSIVE)) != 0)
1095 			goto unionfs_rename_abort;
1096 		error = unionfs_relookup_for_delete(fdvp, fcnp);
1097 		VOP_UNLOCK(fdvp);
1098 		if (error != 0)
1099 			goto unionfs_rename_abort;
1100 
1101 		/* Locke of tvp is canceled in order to avoid recursive lock. */
1102 		if (tvp != NULLVP && tvp != tdvp)
1103 			VOP_UNLOCK(tvp);
1104 		error = unionfs_relookup_for_rename(tdvp, tcnp);
1105 		if (tvp != NULLVP && tvp != tdvp)
1106 			vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
1107 		if (error != 0)
1108 			goto unionfs_rename_abort;
1109 	}
1110 
1111 	error = VOP_RENAME(rfdvp, rfvp, fcnp, rtdvp, rtvp, tcnp);
1112 
1113 	if (error == 0) {
1114 		if (rtvp != NULLVP && rtvp->v_type == VDIR)
1115 			cache_purge(tdvp);
1116 		if (fvp->v_type == VDIR && fdvp != tdvp)
1117 			cache_purge(fdvp);
1118 	}
1119 
1120 	if (fdvp != rfdvp)
1121 		vrele(fdvp);
1122 	if (fvp != rfvp)
1123 		vrele(fvp);
1124 	if (ltdvp != NULLVP)
1125 		VOP_UNLOCK(ltdvp);
1126 	if (tdvp != rtdvp)
1127 		vrele(tdvp);
1128 	if (ltvp != NULLVP)
1129 		VOP_UNLOCK(ltvp);
1130 	if (tvp != rtvp && tvp != NULLVP) {
1131 		if (rtvp == NULLVP)
1132 			vput(tvp);
1133 		else
1134 			vrele(tvp);
1135 	}
1136 
1137 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1138 
1139 	return (error);
1140 
1141 unionfs_rename_abort:
1142 	if (fdvp != rfdvp)
1143 		vrele(rfdvp);
1144 	if (fvp != rfvp)
1145 		vrele(rfvp);
1146 	if (tdvp != rtdvp)
1147 		vrele(rtdvp);
1148 	vput(tdvp);
1149 	if (tvp != rtvp && rtvp != NULLVP)
1150 		vrele(rtvp);
1151 	if (tvp != NULLVP) {
1152 		if (tdvp != tvp)
1153 			vput(tvp);
1154 		else
1155 			vrele(tvp);
1156 	}
1157 	vrele(fdvp);
1158 	vrele(fvp);
1159 
1160 	UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error);
1161 
1162 	return (error);
1163 }
1164 
1165 static int
1166 unionfs_mkdir(void *v)
1167 {
1168 	struct vop_mkdir_args *ap = v;
1169 	int		error;
1170 	struct unionfs_node *dunp;
1171 	struct componentname *cnp;
1172 	struct vnode   *udvp;
1173 	struct vnode   *uvp;
1174 	struct vattr	va;
1175 
1176 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: enter\n");
1177 
1178 	error = EROFS;
1179 	dunp = VTOUNIONFS(ap->a_dvp);
1180 	cnp = ap->a_cnp;
1181 	udvp = dunp->un_uppervp;
1182 
1183 	if (udvp != NULLVP) {
1184 		/* check opaque */
1185 		if (!(cnp->cn_flags & ISWHITEOUT)) {
1186 			error = VOP_GETATTR(udvp, &va, cnp->cn_cred);
1187 			if (error != 0)
1188 				return (error);
1189 			if (va.va_flags & OPAQUE)
1190 				cnp->cn_flags |= ISWHITEOUT;
1191 		}
1192 
1193 		if ((error = VOP_MKDIR(udvp, &uvp, cnp, ap->a_vap)) == 0) {
1194 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1195 			    ap->a_dvp, ap->a_vpp, cnp);
1196 			if (error) {
1197 				vput(uvp);
1198 			} else {
1199 				vrele(uvp);
1200 			}
1201 		}
1202 	}
1203 
1204 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: leave (%d)\n", error);
1205 
1206 	return (error);
1207 }
1208 
1209 static int
1210 unionfs_rmdir(void *v)
1211 {
1212 	struct vop_rmdir_args *ap = v;
1213 	int		error;
1214 	struct unionfs_node *dunp;
1215 	struct unionfs_node *unp;
1216 	struct unionfs_mount *ump;
1217 	struct componentname *cnp;
1218 	struct vnode   *udvp;
1219 	struct vnode   *uvp;
1220 	struct vnode   *lvp;
1221 
1222 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: enter\n");
1223 
1224 	error = 0;
1225 	dunp = VTOUNIONFS(ap->a_dvp);
1226 	unp = VTOUNIONFS(ap->a_vp);
1227 	cnp = ap->a_cnp;
1228 	udvp = dunp->un_uppervp;
1229 	uvp = unp->un_uppervp;
1230 	lvp = unp->un_lowervp;
1231 
1232 	if (udvp == NULLVP)
1233 		return (EROFS);
1234 
1235 	if (udvp == uvp)
1236 		return (EOPNOTSUPP);
1237 
1238 	if (uvp != NULLVP) {
1239 		if (lvp != NULLVP) {
1240 			error = unionfs_check_rmdir(ap->a_vp, cnp->cn_cred);
1241 			if (error != 0)
1242 				return (error);
1243 		}
1244 		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
1245 		if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP)
1246 			cnp->cn_flags |= DOWHITEOUT;
1247 		error = VOP_RMDIR(udvp, uvp, cnp);
1248 	}
1249 	else if (lvp != NULLVP)
1250 		error = unionfs_mkwhiteout(udvp, cnp, unp->un_path);
1251 
1252 	if (error == 0) {
1253 		cache_purge(ap->a_dvp);
1254 		cache_purge(ap->a_vp);
1255 	}
1256 
1257 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: leave (%d)\n", error);
1258 
1259 	return (error);
1260 }
1261 
1262 static int
1263 unionfs_symlink(void *v)
1264 {
1265 	struct vop_symlink_args *ap = v;
1266 	int		error;
1267 	struct unionfs_node *dunp;
1268 	struct componentname *cnp;
1269 	struct vnode   *udvp;
1270 	struct vnode   *uvp;
1271 
1272 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: enter\n");
1273 
1274 	error = EROFS;
1275 	dunp = VTOUNIONFS(ap->a_dvp);
1276 	cnp = ap->a_cnp;
1277 	udvp = dunp->un_uppervp;
1278 
1279 	if (udvp != NULLVP) {
1280 		error = VOP_SYMLINK(udvp, &uvp, cnp, ap->a_vap, ap->a_target);
1281 		if (error == 0) {
1282 			error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP,
1283 			    ap->a_dvp, ap->a_vpp, cnp);
1284 			if (error) {
1285 				vput(uvp);
1286 			} else {
1287 				vrele(uvp);
1288 			}
1289 		}
1290 	}
1291 
1292 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: leave (%d)\n", error);
1293 
1294 	return (error);
1295 }
1296 
1297 static int
1298 unionfs_readdir(void *v)
1299 {
1300 	struct vop_readdir_args *ap = v;
1301 	int		error;
1302 	int		eofflag;
1303 	int		locked;
1304 	struct unionfs_node *unp;
1305 	struct unionfs_node_status *unsp;
1306 	struct uio     *uio;
1307 	struct vnode   *uvp;
1308 	struct vnode   *lvp;
1309 	struct vattr    va;
1310 
1311 	int		ncookies_bk;
1312 	off_t          *cookies_bk;
1313 
1314 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: enter\n");
1315 
1316 	error = 0;
1317 	eofflag = 0;
1318 	locked = 0;
1319 	unp = VTOUNIONFS(ap->a_vp);
1320 	uio = ap->a_uio;
1321 	uvp = unp->un_uppervp;
1322 	lvp = unp->un_lowervp;
1323 	ncookies_bk = 0;
1324 	cookies_bk = NULL;
1325 
1326 	if (ap->a_vp->v_type != VDIR)
1327 		return (ENOTDIR);
1328 
1329 	/* check opaque */
1330 	if (uvp != NULLVP && lvp != NULLVP) {
1331 		if ((error = VOP_GETATTR(uvp, &va, ap->a_cred)) != 0)
1332 			goto unionfs_readdir_exit;
1333 		if (va.va_flags & OPAQUE)
1334 			lvp = NULLVP;
1335 	}
1336 
1337 	/* check the open count. unionfs needs to open before readdir. */
1338 	VOP_UNLOCK(ap->a_vp);
1339 	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
1340 	unionfs_get_node_status(unp, &unsp);
1341 	if ((uvp != NULLVP && unsp->uns_upper_opencnt <= 0) ||
1342 	    (lvp != NULLVP && unsp->uns_lower_opencnt <= 0)) {
1343 		unionfs_tryrem_node_status(unp, unsp);
1344 		error = EBADF;
1345 	}
1346 	if (error != 0)
1347 		goto unionfs_readdir_exit;
1348 
1349 	/* upper only */
1350 	if (uvp != NULLVP && lvp == NULLVP) {
1351 		error = VOP_READDIR(uvp, uio, ap->a_cred, ap->a_eofflag,
1352 		    ap->a_cookies, ap->a_ncookies);
1353 		unsp->uns_readdir_status = 0;
1354 
1355 		goto unionfs_readdir_exit;
1356 	}
1357 
1358 	/* lower only */
1359 	if (uvp == NULLVP && lvp != NULLVP) {
1360 		error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1361 		    ap->a_cookies, ap->a_ncookies);
1362 		unsp->uns_readdir_status = 2;
1363 
1364 		goto unionfs_readdir_exit;
1365 	}
1366 
1367 	/*
1368 	 * readdir upper and lower
1369 	 */
1370 	KASSERT(uvp != NULLVP);
1371 	KASSERT(lvp != NULLVP);
1372 	if (uio->uio_offset == 0)
1373 		unsp->uns_readdir_status = 0;
1374 
1375 	if (unsp->uns_readdir_status == 0) {
1376 		/* read upper */
1377 		error = VOP_READDIR(uvp, uio, ap->a_cred, &eofflag,
1378 				    ap->a_cookies, ap->a_ncookies);
1379 
1380 		if (error != 0 || eofflag == 0)
1381 			goto unionfs_readdir_exit;
1382 		unsp->uns_readdir_status = 1;
1383 
1384 		/*
1385 		 * ufs(and other fs) needs size of uio_resid larger than
1386 		 * DIRBLKSIZ.
1387 		 * size of DIRBLKSIZ equals DEV_BSIZE.
1388 		 * (see: ufs/ufs/ufs_vnops.c ufs_readdir func , ufs/ufs/dir.h)
1389 		 */
1390 		if (uio->uio_resid <= (uio->uio_resid & (DEV_BSIZE -1)))
1391 			goto unionfs_readdir_exit;
1392 
1393 		/*
1394 		 * backup cookies
1395 		 * It prepares to readdir in lower.
1396 		 */
1397 		if (ap->a_ncookies != NULL) {
1398 			ncookies_bk = *(ap->a_ncookies);
1399 			*(ap->a_ncookies) = 0;
1400 		}
1401 		if (ap->a_cookies != NULL) {
1402 			cookies_bk = *(ap->a_cookies);
1403 			*(ap->a_cookies) = NULL;
1404 		}
1405 	}
1406 
1407 	/* initialize for readdir in lower */
1408 	if (unsp->uns_readdir_status == 1) {
1409 		unsp->uns_readdir_status = 2;
1410 		uio->uio_offset = 0;
1411 	}
1412 
1413 	if (lvp == NULLVP) {
1414 		error = EBADF;
1415 		goto unionfs_readdir_exit;
1416 	}
1417 	/* read lower */
1418 	error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
1419 			    ap->a_cookies, ap->a_ncookies);
1420 
1421 	if (cookies_bk != NULL) {
1422 		/* merge cookies */
1423 		int		size;
1424 		off_t         *newcookies, *pos;
1425 
1426 		size = *(ap->a_ncookies) + ncookies_bk;
1427 		newcookies = (off_t *) malloc(size * sizeof(off_t),
1428 		    M_TEMP, M_WAITOK);
1429 		pos = newcookies;
1430 
1431 		memcpy(pos, cookies_bk, ncookies_bk * sizeof(off_t));
1432 		pos += ncookies_bk * sizeof(off_t);
1433 		memcpy(pos, *(ap->a_cookies), *(ap->a_ncookies) * sizeof(off_t));
1434 		free(cookies_bk, M_TEMP);
1435 		free(*(ap->a_cookies), M_TEMP);
1436 		*(ap->a_ncookies) = size;
1437 		*(ap->a_cookies) = newcookies;
1438 	}
1439 
1440 unionfs_readdir_exit:
1441 	if (error != 0 && ap->a_eofflag != NULL)
1442 		*(ap->a_eofflag) = 1;
1443 
1444 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
1445 
1446 	return (error);
1447 }
1448 
1449 static int
1450 unionfs_readlink(void *v)
1451 {
1452 	struct vop_readlink_args *ap = v;
1453 	int error;
1454 	struct unionfs_node *unp;
1455 	struct vnode   *vp;
1456 
1457 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: enter\n");
1458 
1459 	unp = VTOUNIONFS(ap->a_vp);
1460 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1461 
1462 	error = VOP_READLINK(vp, ap->a_uio, ap->a_cred);
1463 
1464 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: leave (%d)\n", error);
1465 
1466 	return (error);
1467 }
1468 
1469 static int
1470 unionfs_inactive(void *v)
1471 {
1472 	struct vop_inactive_args *ap = v;
1473 	*ap->a_recycle = true;
1474 	VOP_UNLOCK(ap->a_vp);
1475 	return (0);
1476 }
1477 
1478 static int
1479 unionfs_reclaim(void *v)
1480 {
1481 	struct vop_reclaim_args *ap = v;
1482 
1483 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: enter\n"); */
1484 
1485 	unionfs_noderem(ap->a_vp);
1486 
1487 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: leave\n"); */
1488 
1489 	return (0);
1490 }
1491 
1492 static int
1493 unionfs_print(void *v)
1494 {
1495 	struct vop_print_args *ap = v;
1496 	struct unionfs_node *unp;
1497 	/* struct unionfs_node_status *unsp; */
1498 
1499 	unp = VTOUNIONFS(ap->a_vp);
1500 	/* unionfs_get_node_status(unp, &unsp); */
1501 
1502 	printf("unionfs_vp=%p, uppervp=%p, lowervp=%p\n",
1503 	    ap->a_vp, unp->un_uppervp, unp->un_lowervp);
1504 	/*
1505 	printf("unionfs opencnt: uppervp=%d, lowervp=%d\n",
1506 	    unsp->uns_upper_opencnt, unsp->uns_lower_opencnt);
1507 	*/
1508 
1509 	if (unp->un_uppervp != NULLVP)
1510 		vprint("unionfs: upper", unp->un_uppervp);
1511 	if (unp->un_lowervp != NULLVP)
1512 		vprint("unionfs: lower", unp->un_lowervp);
1513 
1514 	return (0);
1515 }
1516 
1517 static int
1518 unionfs_lock(void *v)
1519 {
1520 	struct vop_lock_args *ap = v;
1521 	int		error;
1522 	int		flags;
1523 	struct vnode   *lvp;
1524 	struct vnode   *uvp;
1525 	struct unionfs_node *unp;
1526 
1527 	unp = VTOUNIONFS(ap->a_vp);
1528 	lvp = unp->un_lowervp;
1529 	uvp = unp->un_uppervp;
1530 	flags = ap->a_flags;
1531 	error = 0;
1532 
1533 	if (lvp != NULLVP) {
1534 		error = VOP_LOCK(lvp, flags);
1535 	}
1536 	if (error == 0 && uvp != NULLVP) {
1537 		error = VOP_LOCK(uvp, flags);
1538 		if (error != 0) {
1539 			VOP_UNLOCK(lvp);
1540 		}
1541 	}
1542 
1543 	return error;
1544 }
1545 
1546 static int
1547 unionfs_unlock(void *v)
1548 {
1549 	struct vop_unlock_args *ap = v;
1550 	int		error;
1551 	struct vnode   *lvp;
1552 	struct vnode   *uvp;
1553 	struct unionfs_node *unp;
1554 
1555 	unp = VTOUNIONFS(ap->a_vp);
1556 	lvp = unp->un_lowervp;
1557 	uvp = unp->un_uppervp;
1558 	error = 0;
1559 
1560 	if (lvp != NULLVP) {
1561 		error = VOP_UNLOCK(lvp);
1562 	}
1563 	if (error == 0 && uvp != NULLVP) {
1564 		error = VOP_UNLOCK(uvp);
1565 	}
1566 
1567 	return error;
1568 }
1569 
1570 static int
1571 unionfs_pathconf(void *v)
1572 {
1573 	struct vop_pathconf_args *ap = v;
1574 	struct unionfs_node *unp;
1575 	struct vnode   *vp;
1576 
1577 	unp = VTOUNIONFS(ap->a_vp);
1578 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1579 
1580 	return (VOP_PATHCONF(vp, ap->a_name, ap->a_retval));
1581 }
1582 
1583 static int
1584 unionfs_advlock(void *v)
1585 {
1586 	struct vop_advlock_args *ap = v;
1587 	int error;
1588 	struct unionfs_node *unp;
1589 	struct unionfs_node_status *unsp;
1590 	struct vnode   *vp;
1591 	struct vnode   *uvp;
1592 	kauth_cred_t	cred;
1593 
1594 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: enter\n");
1595 
1596 	vp = ap->a_vp;
1597 	cred = kauth_cred_get();
1598 
1599 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1600 
1601 	unp = VTOUNIONFS(ap->a_vp);
1602 	uvp = unp->un_uppervp;
1603 
1604 	if (uvp == NULLVP) {
1605 		error = unionfs_copyfile(unp, 1, cred);
1606 		if (error != 0)
1607 			goto unionfs_advlock_abort;
1608 		uvp = unp->un_uppervp;
1609 
1610 		unionfs_get_node_status(unp, &unsp);
1611 		if (unsp->uns_lower_opencnt > 0) {
1612 			/* try reopen the vnode */
1613 			error = VOP_OPEN(uvp, unsp->uns_lower_openmode, cred);
1614 			if (error)
1615 				goto unionfs_advlock_abort;
1616 			unsp->uns_upper_opencnt++;
1617 			VOP_CLOSE(unp->un_lowervp, unsp->uns_lower_openmode, cred);
1618 			unsp->uns_lower_opencnt--;
1619 		} else
1620 			unionfs_tryrem_node_status(unp, unsp);
1621 	}
1622 
1623 	VOP_UNLOCK(vp);
1624 
1625 	error = VOP_ADVLOCK(uvp, ap->a_id, ap->a_op, ap->a_fl, ap->a_flags);
1626 
1627 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
1628 
1629 	return error;
1630 
1631 unionfs_advlock_abort:
1632 	VOP_UNLOCK(vp);
1633 
1634 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error);
1635 
1636 	return error;
1637 }
1638 
1639 static int
1640 unionfs_strategy(void *v)
1641 {
1642 	struct vop_strategy_args *ap = v;
1643 	struct unionfs_node *unp;
1644 	struct vnode   *vp;
1645 
1646 	unp = VTOUNIONFS(ap->a_vp);
1647 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1648 
1649 #ifdef DIAGNOSTIC
1650 	if (vp == NULLVP)
1651 		panic("unionfs_strategy: nullvp");
1652 	if ((ap->a_bp->b_flags & B_READ) == 0 && vp == unp->un_lowervp)
1653 		panic("unionfs_strategy: writing to lowervp");
1654 #endif
1655 
1656 	return (VOP_STRATEGY(vp, ap->a_bp));
1657 }
1658 
1659 static int
1660 unionfs_kqfilter(void *v)
1661 {
1662 	struct vop_kqfilter_args *ap = v;
1663 	struct unionfs_node *unp;
1664 	struct vnode   *tvp;
1665 
1666 	unp = VTOUNIONFS(ap->a_vp);
1667 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1668 
1669 	return VOP_KQFILTER(tvp, ap->a_kn);
1670 }
1671 
1672 static int
1673 unionfs_bmap(void *v)
1674 {
1675 	struct vop_bmap_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_BMAP(tvp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp);
1683 }
1684 
1685 static int
1686 unionfs_mmap(void *v)
1687 {
1688 	struct vop_mmap_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_MMAP(tvp, ap->a_prot, ap->a_cred);
1696 }
1697 
1698 static int
1699 unionfs_abortop(void *v)
1700 {
1701 	struct vop_abortop_args *ap = v;
1702 	struct unionfs_node *unp;
1703 	struct vnode   *tvp;
1704 
1705 	unp = VTOUNIONFS(ap->a_dvp);
1706 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1707 
1708 	return VOP_ABORTOP(tvp, ap->a_cnp);
1709 }
1710 
1711 static int
1712 unionfs_islocked(void *v)
1713 {
1714 	struct vop_islocked_args *ap = v;
1715 	struct unionfs_node *unp;
1716 	struct vnode   *tvp;
1717 
1718 	unp = VTOUNIONFS(ap->a_vp);
1719 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1720 
1721 	return VOP_ISLOCKED(tvp);
1722 }
1723 
1724 static int
1725 unionfs_seek(void *v)
1726 {
1727 	struct vop_seek_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_SEEK(tvp, ap->a_oldoff, ap->a_newoff, ap->a_cred);
1735 }
1736 
1737 static int
1738 unionfs_putpages(void *v)
1739 {
1740 	struct vop_putpages_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 	mutex_exit(&ap->a_vp->v_interlock);
1748 	if (ap->a_flags & PGO_RECLAIM) {
1749 		return 0;
1750 	}
1751 	mutex_enter(&tvp->v_interlock);
1752 
1753 	return VOP_PUTPAGES(tvp, ap->a_offlo, ap->a_offhi, ap->a_flags);
1754 }
1755 
1756 static int
1757 unionfs_getpages(void *v)
1758 {
1759 	struct vop_getpages_args *ap = v;
1760 	struct unionfs_node *unp;
1761 	struct vnode   *tvp;
1762 
1763 	unp = VTOUNIONFS(ap->a_vp);
1764 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1765 
1766 	if (ap->a_flags & PGO_LOCKED) {
1767 		return EBUSY;
1768 	}
1769 	mutex_exit(&ap->a_vp->v_interlock);
1770 	mutex_enter(&tvp->v_interlock);
1771 
1772 	return VOP_GETPAGES(tvp, ap->a_offset, ap->a_m, ap->a_count,
1773 	    ap->a_centeridx, ap->a_access_type, ap->a_advice, ap->a_flags);
1774 }
1775 
1776 static int
1777 unionfs_revoke(void *v)
1778 {
1779 	struct vop_revoke_args *ap = v;
1780 	struct unionfs_node *unp;
1781 	struct vnode   *tvp;
1782 	int error;
1783 
1784 	unp = VTOUNIONFS(ap->a_vp);
1785 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
1786 
1787 	error = VOP_REVOKE(tvp, ap->a_flags);
1788 	if (error == 0) {
1789 		vgone(ap->a_vp);	/* ??? */
1790 	}
1791 	return error;
1792 }
1793 
1794 /*
1795  * Global vfs data structures
1796  */
1797 int (**unionfs_vnodeop_p)(void *);
1798 const struct vnodeopv_entry_desc unionfs_vnodeop_entries[] = {
1799 	{ &vop_default_desc, vn_default_error },
1800 	{ &vop_lookup_desc, unionfs_lookup },		/* lookup */
1801 	{ &vop_create_desc, unionfs_create },		/* create */
1802 	{ &vop_whiteout_desc, unionfs_whiteout },	/* whiteout */
1803 	{ &vop_mknod_desc, unionfs_mknod },		/* mknod */
1804 	{ &vop_open_desc, unionfs_open },		/* open */
1805 	{ &vop_close_desc, unionfs_close },		/* close */
1806 	{ &vop_access_desc, unionfs_access },		/* access */
1807 	{ &vop_getattr_desc, unionfs_getattr },		/* getattr */
1808 	{ &vop_setattr_desc, unionfs_setattr },		/* setattr */
1809 	{ &vop_read_desc, unionfs_read },		/* read */
1810 	{ &vop_write_desc, unionfs_write },		/* write */
1811 	{ &vop_ioctl_desc, unionfs_ioctl },		/* ioctl */
1812 	{ &vop_poll_desc, unionfs_poll },		/* select */
1813 	{ &vop_revoke_desc, unionfs_revoke },		/* revoke */
1814 	{ &vop_mmap_desc, unionfs_mmap },		/* mmap */
1815 	{ &vop_fsync_desc, unionfs_fsync },		/* fsync */
1816 	{ &vop_seek_desc, unionfs_seek },		/* seek */
1817 	{ &vop_remove_desc, unionfs_remove },		/* remove */
1818 	{ &vop_link_desc, unionfs_link },		/* link */
1819 	{ &vop_rename_desc, unionfs_rename },		/* rename */
1820 	{ &vop_mkdir_desc, unionfs_mkdir },		/* mkdir */
1821 	{ &vop_rmdir_desc, unionfs_rmdir },		/* rmdir */
1822 	{ &vop_symlink_desc, unionfs_symlink },		/* symlink */
1823 	{ &vop_readdir_desc, unionfs_readdir },		/* readdir */
1824 	{ &vop_readlink_desc, unionfs_readlink },	/* readlink */
1825 	{ &vop_abortop_desc, unionfs_abortop },		/* abortop */
1826 	{ &vop_inactive_desc, unionfs_inactive },	/* inactive */
1827 	{ &vop_reclaim_desc, unionfs_reclaim },		/* reclaim */
1828 	{ &vop_lock_desc, unionfs_lock },		/* lock */
1829 	{ &vop_unlock_desc, unionfs_unlock },		/* unlock */
1830 	{ &vop_bmap_desc, unionfs_bmap },		/* bmap */
1831 	{ &vop_strategy_desc, unionfs_strategy },	/* strategy */
1832 	{ &vop_print_desc, unionfs_print },		/* print */
1833 	{ &vop_islocked_desc, unionfs_islocked },	/* islocked */
1834 	{ &vop_pathconf_desc, unionfs_pathconf },	/* pathconf */
1835 	{ &vop_advlock_desc, unionfs_advlock },		/* advlock */
1836 	{ &vop_getpages_desc, unionfs_getpages },	/* getpages */
1837 	{ &vop_putpages_desc, unionfs_putpages },	/* putpages */
1838 	{ &vop_kqfilter_desc, unionfs_kqfilter },	/* kqfilter */
1839 #ifdef notdef
1840 	{ &vop_bwrite_desc, unionfs_bwrite },		/* bwrite */
1841 #endif
1842 	{ NULL, NULL }
1843 };
1844 const struct vnodeopv_desc unionfs_vnodeop_opv_desc =
1845 	{ &unionfs_vnodeop_p, unionfs_vnodeop_entries };
1846