xref: /titanic_41/usr/src/uts/common/fs/fs_subr.c (revision 7706a9bf5155da553880e1d88bef039daa6fc46c)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
22 /*	  All Rights Reserved  	*/
23 
24 
25 /*
26  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 /*
31  * Generic vnode operations.
32  */
33 #include <sys/types.h>
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/errno.h>
37 #include <sys/fcntl.h>
38 #include <sys/flock.h>
39 #include <sys/statvfs.h>
40 #include <sys/vfs.h>
41 #include <sys/vnode.h>
42 #include <sys/proc.h>
43 #include <sys/user.h>
44 #include <sys/unistd.h>
45 #include <sys/cred.h>
46 #include <sys/poll.h>
47 #include <sys/debug.h>
48 #include <sys/cmn_err.h>
49 #include <sys/stream.h>
50 #include <fs/fs_subr.h>
51 #include <fs/fs_reparse.h>
52 #include <sys/door.h>
53 #include <sys/acl.h>
54 #include <sys/share.h>
55 #include <sys/file.h>
56 #include <sys/kmem.h>
57 #include <sys/file.h>
58 #include <sys/nbmlock.h>
59 #include <acl/acl_common.h>
60 #include <sys/pathname.h>
61 
62 static callb_cpr_t *frlock_serialize_blocked(flk_cb_when_t, void *);
63 
64 /*
65  * Tunable to limit the number of retry to recover from STALE error.
66  */
67 int fs_estale_retry = 5;
68 
69 /*
70  * supports for reparse point door upcall
71  */
72 static door_handle_t reparsed_door;
73 static kmutex_t reparsed_door_lock;
74 
75 /*
76  * The associated operation is not supported by the file system.
77  */
78 int
79 fs_nosys()
80 {
81 	return (ENOSYS);
82 }
83 
84 /*
85  * The associated operation is invalid (on this vnode).
86  */
87 int
88 fs_inval()
89 {
90 	return (EINVAL);
91 }
92 
93 /*
94  * The associated operation is valid only for directories.
95  */
96 int
97 fs_notdir()
98 {
99 	return (ENOTDIR);
100 }
101 
102 /*
103  * Free the file system specific resources. For the file systems that
104  * do not support the forced unmount, it will be a nop function.
105  */
106 
107 /*ARGSUSED*/
108 void
109 fs_freevfs(vfs_t *vfsp)
110 {
111 }
112 
113 /* ARGSUSED */
114 int
115 fs_nosys_map(struct vnode *vp,
116 	offset_t off,
117 	struct as *as,
118 	caddr_t *addrp,
119 	size_t len,
120 	uchar_t prot,
121 	uchar_t maxprot,
122 	uint_t flags,
123 	struct cred *cr,
124 	caller_context_t *ct)
125 {
126 	return (ENOSYS);
127 }
128 
129 /* ARGSUSED */
130 int
131 fs_nosys_addmap(struct vnode *vp,
132 	offset_t off,
133 	struct as *as,
134 	caddr_t addr,
135 	size_t len,
136 	uchar_t prot,
137 	uchar_t maxprot,
138 	uint_t flags,
139 	struct cred *cr,
140 	caller_context_t *ct)
141 {
142 	return (ENOSYS);
143 }
144 
145 /* ARGSUSED */
146 int
147 fs_nosys_poll(vnode_t *vp,
148 	register short events,
149 	int anyyet,
150 	register short *reventsp,
151 	struct pollhead **phpp,
152 	caller_context_t *ct)
153 {
154 	return (ENOSYS);
155 }
156 
157 
158 /*
159  * The file system has nothing to sync to disk.  However, the
160  * VFS_SYNC operation must not fail.
161  */
162 /* ARGSUSED */
163 int
164 fs_sync(struct vfs *vfspp, short flag, cred_t *cr)
165 {
166 	return (0);
167 }
168 
169 /*
170  * Does nothing but VOP_FSYNC must not fail.
171  */
172 /* ARGSUSED */
173 int
174 fs_fsync(vnode_t *vp, int syncflag, cred_t *cr, caller_context_t *ct)
175 {
176 	return (0);
177 }
178 
179 /*
180  * Does nothing but VOP_PUTPAGE must not fail.
181  */
182 /* ARGSUSED */
183 int
184 fs_putpage(vnode_t *vp, offset_t off, size_t len, int flags, cred_t *cr,
185 	caller_context_t *ctp)
186 {
187 	return (0);
188 }
189 
190 /*
191  * Does nothing but VOP_IOCTL must not fail.
192  */
193 /* ARGSUSED */
194 int
195 fs_ioctl(vnode_t *vp, int com, intptr_t data, int flag, cred_t *cred,
196 	int *rvalp)
197 {
198 	return (0);
199 }
200 
201 /*
202  * Read/write lock/unlock.  Does nothing.
203  */
204 /* ARGSUSED */
205 int
206 fs_rwlock(vnode_t *vp, int write_lock, caller_context_t *ctp)
207 {
208 	return (-1);
209 }
210 
211 /* ARGSUSED */
212 void
213 fs_rwunlock(vnode_t *vp, int write_lock, caller_context_t *ctp)
214 {
215 }
216 
217 /*
218  * Compare two vnodes.
219  */
220 /*ARGSUSED2*/
221 int
222 fs_cmp(vnode_t *vp1, vnode_t *vp2, caller_context_t *ct)
223 {
224 	return (vp1 == vp2);
225 }
226 
227 /*
228  * No-op seek operation.
229  */
230 /* ARGSUSED */
231 int
232 fs_seek(vnode_t *vp, offset_t ooff, offset_t *noffp, caller_context_t *ct)
233 {
234 	return ((*noffp < 0 || *noffp > MAXOFFSET_T) ? EINVAL : 0);
235 }
236 
237 /*
238  * File and record locking.
239  */
240 /* ARGSUSED */
241 int
242 fs_frlock(register vnode_t *vp, int cmd, struct flock64 *bfp, int flag,
243 	offset_t offset, flk_callback_t *flk_cbp, cred_t *cr,
244 	caller_context_t *ct)
245 {
246 	int frcmd;
247 	int nlmid;
248 	int error = 0;
249 	flk_callback_t serialize_callback;
250 	int serialize = 0;
251 	v_mode_t mode;
252 
253 	switch (cmd) {
254 
255 	case F_GETLK:
256 	case F_O_GETLK:
257 		if (flag & F_REMOTELOCK) {
258 			frcmd = RCMDLCK;
259 		} else if (flag & F_PXFSLOCK) {
260 			frcmd = PCMDLCK;
261 		} else {
262 			frcmd = 0;
263 			bfp->l_pid = ttoproc(curthread)->p_pid;
264 			bfp->l_sysid = 0;
265 		}
266 		break;
267 
268 	case F_SETLK_NBMAND:
269 		/*
270 		 * Are NBMAND locks allowed on this file?
271 		 */
272 		if (!vp->v_vfsp ||
273 		    !(vp->v_vfsp->vfs_flag & VFS_NBMAND)) {
274 			error = EINVAL;
275 			goto done;
276 		}
277 		if (vp->v_type != VREG) {
278 			error = EINVAL;
279 			goto done;
280 		}
281 		/*FALLTHROUGH*/
282 
283 	case F_SETLK:
284 		if (flag & F_REMOTELOCK) {
285 			frcmd = SETFLCK|RCMDLCK;
286 		} else if (flag & F_PXFSLOCK) {
287 			frcmd = SETFLCK|PCMDLCK;
288 		} else {
289 			frcmd = SETFLCK;
290 			bfp->l_pid = ttoproc(curthread)->p_pid;
291 			bfp->l_sysid = 0;
292 		}
293 		if (cmd == F_SETLK_NBMAND &&
294 		    (bfp->l_type == F_RDLCK || bfp->l_type == F_WRLCK)) {
295 			frcmd |= NBMLCK;
296 		}
297 
298 		if (nbl_need_check(vp)) {
299 			nbl_start_crit(vp, RW_WRITER);
300 			serialize = 1;
301 			if (frcmd & NBMLCK) {
302 				mode = (bfp->l_type == F_RDLCK) ?
303 				    V_READ : V_RDANDWR;
304 				if (vn_is_mapped(vp, mode)) {
305 					error = EAGAIN;
306 					goto done;
307 				}
308 			}
309 		}
310 		break;
311 
312 	case F_SETLKW:
313 		if (flag & F_REMOTELOCK) {
314 			frcmd = SETFLCK|SLPFLCK|RCMDLCK;
315 		} else if (flag & F_PXFSLOCK) {
316 			frcmd = SETFLCK|SLPFLCK|PCMDLCK;
317 		} else {
318 			frcmd = SETFLCK|SLPFLCK;
319 			bfp->l_pid = ttoproc(curthread)->p_pid;
320 			bfp->l_sysid = 0;
321 		}
322 
323 		if (nbl_need_check(vp)) {
324 			nbl_start_crit(vp, RW_WRITER);
325 			serialize = 1;
326 		}
327 		break;
328 
329 	case F_HASREMOTELOCKS:
330 		nlmid = GETNLMID(bfp->l_sysid);
331 		if (nlmid != 0) {	/* booted as a cluster */
332 			l_has_rmt(bfp) =
333 			    cl_flk_has_remote_locks_for_nlmid(vp, nlmid);
334 		} else {		/* not booted as a cluster */
335 			l_has_rmt(bfp) = flk_has_remote_locks(vp);
336 		}
337 
338 		goto done;
339 
340 	default:
341 		error = EINVAL;
342 		goto done;
343 	}
344 
345 	/*
346 	 * If this is a blocking lock request and we're serializing lock
347 	 * requests, modify the callback list to leave the critical region
348 	 * while we're waiting for the lock.
349 	 */
350 
351 	if (serialize && (frcmd & SLPFLCK) != 0) {
352 		flk_add_callback(&serialize_callback,
353 		    frlock_serialize_blocked, vp, flk_cbp);
354 		flk_cbp = &serialize_callback;
355 	}
356 
357 	error = reclock(vp, bfp, frcmd, flag, offset, flk_cbp);
358 
359 done:
360 	if (serialize)
361 		nbl_end_crit(vp);
362 
363 	return (error);
364 }
365 
366 /*
367  * Callback when a lock request blocks and we are serializing requests.  If
368  * before sleeping, leave the critical region.  If after wakeup, reenter
369  * the critical region.
370  */
371 
372 static callb_cpr_t *
373 frlock_serialize_blocked(flk_cb_when_t when, void *infop)
374 {
375 	vnode_t *vp = (vnode_t *)infop;
376 
377 	if (when == FLK_BEFORE_SLEEP)
378 		nbl_end_crit(vp);
379 	else {
380 		nbl_start_crit(vp, RW_WRITER);
381 	}
382 
383 	return (NULL);
384 }
385 
386 /*
387  * Allow any flags.
388  */
389 /* ARGSUSED */
390 int
391 fs_setfl(
392 	vnode_t *vp,
393 	int oflags,
394 	int nflags,
395 	cred_t *cr,
396 	caller_context_t *ct)
397 {
398 	return (0);
399 }
400 
401 /*
402  * Return the answer requested to poll() for non-device files.
403  * Only POLLIN, POLLRDNORM, and POLLOUT are recognized.
404  */
405 struct pollhead fs_pollhd;
406 
407 /* ARGSUSED */
408 int
409 fs_poll(vnode_t *vp,
410 	register short events,
411 	int anyyet,
412 	register short *reventsp,
413 	struct pollhead **phpp,
414 	caller_context_t *ct)
415 {
416 	*reventsp = 0;
417 	if (events & POLLIN)
418 		*reventsp |= POLLIN;
419 	if (events & POLLRDNORM)
420 		*reventsp |= POLLRDNORM;
421 	if (events & POLLRDBAND)
422 		*reventsp |= POLLRDBAND;
423 	if (events & POLLOUT)
424 		*reventsp |= POLLOUT;
425 	if (events & POLLWRBAND)
426 		*reventsp |= POLLWRBAND;
427 	*phpp = !anyyet && !*reventsp ? &fs_pollhd : (struct pollhead *)NULL;
428 	return (0);
429 }
430 
431 /*
432  * POSIX pathconf() support.
433  */
434 /* ARGSUSED */
435 int
436 fs_pathconf(
437 	vnode_t *vp,
438 	int cmd,
439 	ulong_t *valp,
440 	cred_t *cr,
441 	caller_context_t *ct)
442 {
443 	register ulong_t val;
444 	register int error = 0;
445 	struct statvfs64 vfsbuf;
446 
447 	switch (cmd) {
448 
449 	case _PC_LINK_MAX:
450 		val = MAXLINK;
451 		break;
452 
453 	case _PC_MAX_CANON:
454 		val = MAX_CANON;
455 		break;
456 
457 	case _PC_MAX_INPUT:
458 		val = MAX_INPUT;
459 		break;
460 
461 	case _PC_NAME_MAX:
462 		bzero(&vfsbuf, sizeof (vfsbuf));
463 		if (error = VFS_STATVFS(vp->v_vfsp, &vfsbuf))
464 			break;
465 		val = vfsbuf.f_namemax;
466 		break;
467 
468 	case _PC_PATH_MAX:
469 	case _PC_SYMLINK_MAX:
470 		val = MAXPATHLEN;
471 		break;
472 
473 	case _PC_PIPE_BUF:
474 		val = PIPE_BUF;
475 		break;
476 
477 	case _PC_NO_TRUNC:
478 		if (vp->v_vfsp->vfs_flag & VFS_NOTRUNC)
479 			val = 1;	/* NOTRUNC is enabled for vp */
480 		else
481 			val = (ulong_t)-1;
482 		break;
483 
484 	case _PC_VDISABLE:
485 		val = _POSIX_VDISABLE;
486 		break;
487 
488 	case _PC_CHOWN_RESTRICTED:
489 		if (rstchown)
490 			val = rstchown; /* chown restricted enabled */
491 		else
492 			val = (ulong_t)-1;
493 		break;
494 
495 	case _PC_FILESIZEBITS:
496 
497 		/*
498 		 * If ever we come here it means that underlying file system
499 		 * does not recognise the command and therefore this
500 		 * configurable limit cannot be determined. We return -1
501 		 * and don't change errno.
502 		 */
503 
504 		val = (ulong_t)-1;    /* large file support */
505 		break;
506 
507 	case _PC_ACL_ENABLED:
508 		val = 0;
509 		break;
510 
511 	case _PC_CASE_BEHAVIOR:
512 		val = _CASE_SENSITIVE;
513 		if (vfs_has_feature(vp->v_vfsp, VFSFT_CASEINSENSITIVE) == 1)
514 			val |= _CASE_INSENSITIVE;
515 		if (vfs_has_feature(vp->v_vfsp, VFSFT_NOCASESENSITIVE) == 1)
516 			val &= ~_CASE_SENSITIVE;
517 		break;
518 
519 	case _PC_SATTR_ENABLED:
520 	case _PC_SATTR_EXISTS:
521 		val = 0;
522 		break;
523 
524 	case _PC_ACCESS_FILTERING:
525 		val = 0;
526 		break;
527 
528 	default:
529 		error = EINVAL;
530 		break;
531 	}
532 
533 	if (error == 0)
534 		*valp = val;
535 	return (error);
536 }
537 
538 /*
539  * Dispose of a page.
540  */
541 /* ARGSUSED */
542 void
543 fs_dispose(
544 	struct vnode *vp,
545 	page_t *pp,
546 	int fl,
547 	int dn,
548 	struct cred *cr,
549 	caller_context_t *ct)
550 {
551 
552 	ASSERT(fl == B_FREE || fl == B_INVAL);
553 
554 	if (fl == B_FREE)
555 		page_free(pp, dn);
556 	else
557 		page_destroy(pp, dn);
558 }
559 
560 /* ARGSUSED */
561 void
562 fs_nodispose(
563 	struct vnode *vp,
564 	page_t *pp,
565 	int fl,
566 	int dn,
567 	struct cred *cr,
568 	caller_context_t *ct)
569 {
570 	cmn_err(CE_PANIC, "fs_nodispose invoked");
571 }
572 
573 /*
574  * fabricate acls for file systems that do not support acls.
575  */
576 /* ARGSUSED */
577 int
578 fs_fab_acl(
579 	vnode_t *vp,
580 	vsecattr_t *vsecattr,
581 	int flag,
582 	cred_t *cr,
583 	caller_context_t *ct)
584 {
585 	aclent_t	*aclentp;
586 	ace_t		*acep;
587 	struct vattr	vattr;
588 	int		error;
589 	size_t		aclsize;
590 
591 	vsecattr->vsa_aclcnt	= 0;
592 	vsecattr->vsa_aclentsz	= 0;
593 	vsecattr->vsa_aclentp	= NULL;
594 	vsecattr->vsa_dfaclcnt	= 0;	/* Default ACLs are not fabricated */
595 	vsecattr->vsa_dfaclentp	= NULL;
596 
597 	vattr.va_mask = AT_MODE | AT_UID | AT_GID;
598 	if (error = VOP_GETATTR(vp, &vattr, 0, cr, ct))
599 		return (error);
600 
601 	if (vsecattr->vsa_mask & (VSA_ACLCNT | VSA_ACL)) {
602 		aclsize = 4 * sizeof (aclent_t);
603 		vsecattr->vsa_aclcnt	= 4; /* USER, GROUP, OTHER, and CLASS */
604 		vsecattr->vsa_aclentp = kmem_zalloc(aclsize, KM_SLEEP);
605 		aclentp = vsecattr->vsa_aclentp;
606 
607 		aclentp->a_type = USER_OBJ;	/* Owner */
608 		aclentp->a_perm = ((ushort_t)(vattr.va_mode & 0700)) >> 6;
609 		aclentp->a_id = vattr.va_uid;   /* Really undefined */
610 		aclentp++;
611 
612 		aclentp->a_type = GROUP_OBJ;    /* Group */
613 		aclentp->a_perm = ((ushort_t)(vattr.va_mode & 0070)) >> 3;
614 		aclentp->a_id = vattr.va_gid;   /* Really undefined */
615 		aclentp++;
616 
617 		aclentp->a_type = OTHER_OBJ;    /* Other */
618 		aclentp->a_perm = vattr.va_mode & 0007;
619 		aclentp->a_id = (gid_t)-1;	/* Really undefined */
620 		aclentp++;
621 
622 		aclentp->a_type = CLASS_OBJ;    /* Class */
623 		aclentp->a_perm = (ushort_t)(0007);
624 		aclentp->a_id = (gid_t)-1;	/* Really undefined */
625 	} else if (vsecattr->vsa_mask & (VSA_ACECNT | VSA_ACE)) {
626 		aclsize = 6 * sizeof (ace_t);
627 		vsecattr->vsa_aclcnt	= 6;
628 		vsecattr->vsa_aclentp = kmem_zalloc(aclsize, KM_SLEEP);
629 		vsecattr->vsa_aclentsz = aclsize;
630 		acep = vsecattr->vsa_aclentp;
631 		(void) memcpy(acep, trivial_acl, sizeof (ace_t) * 6);
632 		adjust_ace_pair(acep, (vattr.va_mode & 0700) >> 6);
633 		adjust_ace_pair(acep + 2, (vattr.va_mode & 0070) >> 3);
634 		adjust_ace_pair(acep + 4, vattr.va_mode & 0007);
635 	}
636 
637 	return (0);
638 }
639 
640 /*
641  * Common code for implementing DOS share reservations
642  */
643 /* ARGSUSED4 */
644 int
645 fs_shrlock(
646 	struct vnode *vp,
647 	int cmd,
648 	struct shrlock *shr,
649 	int flag,
650 	cred_t *cr,
651 	caller_context_t *ct)
652 {
653 	int error;
654 
655 	/*
656 	 * Make sure that the file was opened with permissions appropriate
657 	 * for the request, and make sure the caller isn't trying to sneak
658 	 * in an NBMAND request.
659 	 */
660 	if (cmd == F_SHARE) {
661 		if (((shr->s_access & F_RDACC) && (flag & FREAD) == 0) ||
662 		    ((shr->s_access & F_WRACC) && (flag & FWRITE) == 0))
663 			return (EBADF);
664 		if (shr->s_access & (F_RMACC | F_MDACC))
665 			return (EINVAL);
666 		if (shr->s_deny & (F_MANDDNY | F_RMDNY))
667 			return (EINVAL);
668 	}
669 	if (cmd == F_SHARE_NBMAND) {
670 		/* make sure nbmand is allowed on the file */
671 		if (!vp->v_vfsp ||
672 		    !(vp->v_vfsp->vfs_flag & VFS_NBMAND)) {
673 			return (EINVAL);
674 		}
675 		if (vp->v_type != VREG) {
676 			return (EINVAL);
677 		}
678 	}
679 
680 	nbl_start_crit(vp, RW_WRITER);
681 
682 	switch (cmd) {
683 
684 	case F_SHARE_NBMAND:
685 		shr->s_deny |= F_MANDDNY;
686 		/*FALLTHROUGH*/
687 	case F_SHARE:
688 		error = add_share(vp, shr);
689 		break;
690 
691 	case F_UNSHARE:
692 		error = del_share(vp, shr);
693 		break;
694 
695 	case F_HASREMOTELOCKS:
696 		/*
697 		 * We are overloading this command to refer to remote
698 		 * shares as well as remote locks, despite its name.
699 		 */
700 		shr->s_access = shr_has_remote_shares(vp, shr->s_sysid);
701 		error = 0;
702 		break;
703 
704 	default:
705 		error = EINVAL;
706 		break;
707 	}
708 
709 	nbl_end_crit(vp);
710 	return (error);
711 }
712 
713 /*ARGSUSED1*/
714 int
715 fs_vnevent_nosupport(vnode_t *vp, vnevent_t e, vnode_t *dvp, char *fnm,
716     caller_context_t *ct)
717 {
718 	ASSERT(vp != NULL);
719 	return (ENOTSUP);
720 }
721 
722 /*ARGSUSED1*/
723 int
724 fs_vnevent_support(vnode_t *vp, vnevent_t e, vnode_t *dvp, char *fnm,
725     caller_context_t *ct)
726 {
727 	ASSERT(vp != NULL);
728 	return (0);
729 }
730 
731 /*
732  * return 1 for non-trivial ACL.
733  *
734  * NB: It is not necessary for the caller to VOP_RWLOCK since
735  *	we only issue VOP_GETSECATTR.
736  *
737  * Returns 0 == trivial
738  *         1 == NOT Trivial
739  *	   <0 could not determine.
740  */
741 int
742 fs_acl_nontrivial(vnode_t *vp, cred_t *cr)
743 {
744 	ulong_t		acl_styles;
745 	ulong_t		acl_flavor;
746 	vsecattr_t 	vsecattr;
747 	int 		error;
748 	int		isnontrivial;
749 
750 	/* determine the forms of ACLs maintained */
751 	error = VOP_PATHCONF(vp, _PC_ACL_ENABLED, &acl_styles, cr, NULL);
752 
753 	/* clear bits we don't understand and establish default acl_style */
754 	acl_styles &= (_ACL_ACLENT_ENABLED | _ACL_ACE_ENABLED);
755 	if (error || (acl_styles == 0))
756 		acl_styles = _ACL_ACLENT_ENABLED;
757 
758 	vsecattr.vsa_aclentp = NULL;
759 	vsecattr.vsa_dfaclentp = NULL;
760 	vsecattr.vsa_aclcnt = 0;
761 	vsecattr.vsa_dfaclcnt = 0;
762 
763 	while (acl_styles) {
764 		/* select one of the styles as current flavor */
765 		acl_flavor = 0;
766 		if (acl_styles & _ACL_ACLENT_ENABLED) {
767 			acl_flavor = _ACL_ACLENT_ENABLED;
768 			vsecattr.vsa_mask = VSA_ACLCNT | VSA_DFACLCNT;
769 		} else if (acl_styles & _ACL_ACE_ENABLED) {
770 			acl_flavor = _ACL_ACE_ENABLED;
771 			vsecattr.vsa_mask = VSA_ACECNT | VSA_ACE;
772 		}
773 
774 		ASSERT(vsecattr.vsa_mask && acl_flavor);
775 		error = VOP_GETSECATTR(vp, &vsecattr, 0, cr, NULL);
776 		if (error == 0)
777 			break;
778 
779 		/* that flavor failed */
780 		acl_styles &= ~acl_flavor;
781 	}
782 
783 	/* if all styles fail then assume trivial */
784 	if (acl_styles == 0)
785 		return (0);
786 
787 	/* process the flavor that worked */
788 	isnontrivial = 0;
789 	if (acl_flavor & _ACL_ACLENT_ENABLED) {
790 		if (vsecattr.vsa_aclcnt > MIN_ACL_ENTRIES)
791 			isnontrivial = 1;
792 		if (vsecattr.vsa_aclcnt && vsecattr.vsa_aclentp != NULL)
793 			kmem_free(vsecattr.vsa_aclentp,
794 			    vsecattr.vsa_aclcnt * sizeof (aclent_t));
795 		if (vsecattr.vsa_dfaclcnt && vsecattr.vsa_dfaclentp != NULL)
796 			kmem_free(vsecattr.vsa_dfaclentp,
797 			    vsecattr.vsa_dfaclcnt * sizeof (aclent_t));
798 	}
799 	if (acl_flavor & _ACL_ACE_ENABLED) {
800 
801 		isnontrivial = ace_trivial(vsecattr.vsa_aclentp,
802 		    vsecattr.vsa_aclcnt);
803 
804 		if (vsecattr.vsa_aclcnt && vsecattr.vsa_aclentp != NULL)
805 			kmem_free(vsecattr.vsa_aclentp,
806 			    vsecattr.vsa_aclcnt * sizeof (ace_t));
807 		/* ACE has no vsecattr.vsa_dfaclcnt */
808 	}
809 	return (isnontrivial);
810 }
811 
812 /*
813  * Check whether we need a retry to recover from STALE error.
814  */
815 int
816 fs_need_estale_retry(int retry_count)
817 {
818 	if (retry_count < fs_estale_retry)
819 		return (1);
820 	else
821 		return (0);
822 }
823 
824 
825 static int (*fs_av_scan)(vnode_t *, cred_t *, int) = NULL;
826 
827 /*
828  * Routine for anti-virus scanner to call to register its scanning routine.
829  */
830 void
831 fs_vscan_register(int (*av_scan)(vnode_t *, cred_t *, int))
832 {
833 	fs_av_scan = av_scan;
834 }
835 
836 /*
837  * Routine for file systems to call to initiate anti-virus scanning.
838  * Scanning will only be done on REGular files (currently).
839  */
840 int
841 fs_vscan(vnode_t *vp, cred_t *cr, int async)
842 {
843 	int ret = 0;
844 
845 	if (fs_av_scan && vp->v_type == VREG)
846 		ret = (*fs_av_scan)(vp, cr, async);
847 
848 	return (ret);
849 }
850 
851 /*
852  * support functions for reparse point
853  */
854 /*
855  * reparse_vnode_parse
856  *
857  * Read the symlink data of a reparse point specified by the vnode
858  * and return the reparse data as name-value pair in the nvlist.
859  */
860 int
861 reparse_vnode_parse(vnode_t *vp, nvlist_t *nvl)
862 {
863 	int err;
864 	char *lkdata;
865 	struct uio uio;
866 	struct iovec iov;
867 
868 	if (vp == NULL || nvl == NULL)
869 		return (EINVAL);
870 
871 	lkdata = kmem_alloc(MAXREPARSELEN, KM_SLEEP);
872 
873 	/*
874 	 * Set up io vector to read sym link data
875 	 */
876 	iov.iov_base = lkdata;
877 	iov.iov_len = MAXREPARSELEN;
878 	uio.uio_iov = &iov;
879 	uio.uio_iovcnt = 1;
880 	uio.uio_segflg = UIO_SYSSPACE;
881 	uio.uio_extflg = UIO_COPY_CACHED;
882 	uio.uio_loffset = (offset_t)0;
883 	uio.uio_resid = MAXREPARSELEN;
884 
885 	if ((err = VOP_READLINK(vp, &uio, kcred, NULL)) == 0) {
886 		*(lkdata + MAXREPARSELEN - uio.uio_resid) = '\0';
887 		err = reparse_parse(lkdata, nvl);
888 	}
889 	kmem_free(lkdata, MAXREPARSELEN);	/* done with lkdata */
890 
891 	return (err);
892 }
893 
894 void
895 reparse_point_init()
896 {
897 	mutex_init(&reparsed_door_lock, NULL, MUTEX_DEFAULT, NULL);
898 }
899 
900 static door_handle_t
901 reparse_door_get_handle()
902 {
903 	door_handle_t dh;
904 
905 	mutex_enter(&reparsed_door_lock);
906 	if ((dh = reparsed_door) == NULL) {
907 		if (door_ki_open(REPARSED_DOOR, &reparsed_door) != 0) {
908 			reparsed_door = NULL;
909 			dh = NULL;
910 		} else
911 			dh = reparsed_door;
912 	}
913 	mutex_exit(&reparsed_door_lock);
914 	return (dh);
915 }
916 
917 static void
918 reparse_door_reset_handle()
919 {
920 	mutex_enter(&reparsed_door_lock);
921 	reparsed_door = NULL;
922 	mutex_exit(&reparsed_door_lock);
923 }
924 
925 /*
926  * reparse_kderef
927  *
928  * Accepts the service-specific item from the reparse point and returns
929  * the service-specific data requested.  The caller specifies the size of
930  * the buffer provided via *bufsz; the routine will fail with EOVERFLOW
931  * if the results will not fit in the buffer, in which case, *bufsz will
932  * contain the number of bytes needed to hold the results.
933  *
934  * if ok return 0 and update *bufsize with length of actual result
935  * else return error code.
936  */
937 int
938 reparse_kderef(const char *svc_type, const char *svc_data, char *buf,
939     size_t *bufsize)
940 {
941 	int err, retries, need_free, retried_doorhd;
942 	size_t dlen, res_len;
943 	char *darg;
944 	door_arg_t door_args;
945 	reparsed_door_res_t *resp;
946 	door_handle_t rp_door;
947 
948 	if (svc_type == NULL || svc_data == NULL || buf == NULL ||
949 	    bufsize == NULL)
950 		return (EINVAL);
951 
952 	/* get reparsed's door handle */
953 	if ((rp_door = reparse_door_get_handle()) == NULL)
954 		return (EBADF);
955 
956 	/* setup buffer for door_call args and results */
957 	dlen = strlen(svc_type) + strlen(svc_data) + 2;
958 	if (*bufsize < dlen) {
959 		darg = kmem_alloc(dlen, KM_SLEEP);
960 		need_free = 1;
961 	} else {
962 		darg = buf;	/* use same buffer for door's args & results */
963 		need_free = 0;
964 	}
965 
966 	/* build argument string of door call */
967 	(void) snprintf(darg, dlen, "%s:%s", svc_type, svc_data);
968 
969 	/* setup args for door call */
970 	door_args.data_ptr = darg;
971 	door_args.data_size = dlen;
972 	door_args.desc_ptr = NULL;
973 	door_args.desc_num = 0;
974 	door_args.rbuf = buf;
975 	door_args.rsize = *bufsize;
976 
977 	/* do the door_call */
978 	retried_doorhd = 0;
979 	retries = 0;
980 	door_ki_hold(rp_door);
981 	while ((err = door_ki_upcall_limited(rp_door, &door_args,
982 	    NULL, SIZE_MAX, 0)) != 0) {
983 		if (err == EAGAIN || err == EINTR) {
984 			if (++retries < REPARSED_DOORCALL_MAX_RETRY) {
985 				delay(SEC_TO_TICK(1));
986 				continue;
987 			}
988 		} else if (err == EBADF) {
989 			/* door server goes away... */
990 			reparse_door_reset_handle();
991 
992 			if (retried_doorhd == 0) {
993 				door_ki_rele(rp_door);
994 				retried_doorhd++;
995 				rp_door = reparse_door_get_handle();
996 				if (rp_door != NULL) {
997 					door_ki_hold(rp_door);
998 					continue;
999 				}
1000 			}
1001 		}
1002 		break;
1003 	}
1004 
1005 	if (rp_door)
1006 		door_ki_rele(rp_door);
1007 
1008 	if (need_free)
1009 		kmem_free(darg, dlen);		/* done with args buffer */
1010 
1011 	if (err != 0)
1012 		return (err);
1013 
1014 	resp = (reparsed_door_res_t *)door_args.rbuf;
1015 	if ((err = resp->res_status) == 0) {
1016 		/*
1017 		 * have to save the length of the results before the
1018 		 * bcopy below since it's can be an overlap copy that
1019 		 * overwrites the reparsed_door_res_t structure at
1020 		 * the beginning of the buffer.
1021 		 */
1022 		res_len = (size_t)resp->res_len;
1023 
1024 		/* deref call is ok */
1025 		if (res_len > *bufsize)
1026 			err = EOVERFLOW;
1027 		else
1028 			bcopy(resp->res_data, buf, res_len);
1029 		*bufsize = res_len;
1030 	}
1031 	if (door_args.rbuf != buf)
1032 		kmem_free(door_args.rbuf, door_args.rsize);
1033 
1034 	return (err);
1035 }
1036