xref: /titanic_41/usr/src/uts/common/fs/fs_subr.c (revision b02e9a2d4d2071d770e5aa9ae8f83f2bbe1f2ced)
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 2007 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  * Generic vnode operations.
34  */
35 #include <sys/types.h>
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/errno.h>
39 #include <sys/fcntl.h>
40 #include <sys/flock.h>
41 #include <sys/statvfs.h>
42 #include <sys/vfs.h>
43 #include <sys/vnode.h>
44 #include <sys/proc.h>
45 #include <sys/user.h>
46 #include <sys/unistd.h>
47 #include <sys/cred.h>
48 #include <sys/poll.h>
49 #include <sys/debug.h>
50 #include <sys/cmn_err.h>
51 #include <sys/stream.h>
52 #include <fs/fs_subr.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 
61 static callb_cpr_t *frlock_serialize_blocked(flk_cb_when_t, void *);
62 
63 /*
64  * Tunable to limit the number of retry to recover from STALE error.
65  */
66 int fs_estale_retry = 5;
67 
68 /*
69  * The associated operation is not supported by the file system.
70  */
71 int
72 fs_nosys()
73 {
74 	return (ENOSYS);
75 }
76 
77 /*
78  * The associated operation is invalid (on this vnode).
79  */
80 int
81 fs_inval()
82 {
83 	return (EINVAL);
84 }
85 
86 /*
87  * The associated operation is valid only for directories.
88  */
89 int
90 fs_notdir()
91 {
92 	return (ENOTDIR);
93 }
94 
95 /*
96  * Free the file system specific resources. For the file systems that
97  * do not support the forced unmount, it will be a nop function.
98  */
99 
100 /*ARGSUSED*/
101 void
102 fs_freevfs(vfs_t *vfsp)
103 {
104 }
105 
106 /* ARGSUSED */
107 int
108 fs_nosys_map(struct vnode *vp,
109 	offset_t off,
110 	struct as *as,
111 	caddr_t *addrp,
112 	size_t len,
113 	uchar_t prot,
114 	uchar_t maxprot,
115 	uint_t flags,
116 	struct cred *cr,
117 	caller_context_t *ct)
118 {
119 	return (ENOSYS);
120 }
121 
122 /* ARGSUSED */
123 int
124 fs_nosys_addmap(struct vnode *vp,
125 	offset_t off,
126 	struct as *as,
127 	caddr_t addr,
128 	size_t len,
129 	uchar_t prot,
130 	uchar_t maxprot,
131 	uint_t flags,
132 	struct cred *cr,
133 	caller_context_t *ct)
134 {
135 	return (ENOSYS);
136 }
137 
138 /* ARGSUSED */
139 int
140 fs_nosys_poll(vnode_t *vp,
141 	register short events,
142 	int anyyet,
143 	register short *reventsp,
144 	struct pollhead **phpp,
145 	caller_context_t *ct)
146 {
147 	return (ENOSYS);
148 }
149 
150 
151 /*
152  * The file system has nothing to sync to disk.  However, the
153  * VFS_SYNC operation must not fail.
154  */
155 /* ARGSUSED */
156 int
157 fs_sync(struct vfs *vfspp, short flag, cred_t *cr)
158 {
159 	return (0);
160 }
161 
162 /*
163  * Does nothing but VOP_FSYNC must not fail.
164  */
165 /* ARGSUSED */
166 int
167 fs_fsync(vnode_t *vp, int syncflag, cred_t *cr, caller_context_t *ct)
168 {
169 	return (0);
170 }
171 
172 /*
173  * Does nothing but VOP_PUTPAGE must not fail.
174  */
175 /* ARGSUSED */
176 int
177 fs_putpage(vnode_t *vp, offset_t off, size_t len, int flags, cred_t *cr,
178 	caller_context_t *ctp)
179 {
180 	return (0);
181 }
182 
183 /*
184  * Does nothing but VOP_IOCTL must not fail.
185  */
186 /* ARGSUSED */
187 int
188 fs_ioctl(vnode_t *vp, int com, intptr_t data, int flag, cred_t *cred,
189 	int *rvalp)
190 {
191 	return (0);
192 }
193 
194 /*
195  * Read/write lock/unlock.  Does nothing.
196  */
197 /* ARGSUSED */
198 int
199 fs_rwlock(vnode_t *vp, int write_lock, caller_context_t *ctp)
200 {
201 	return (-1);
202 }
203 
204 /* ARGSUSED */
205 void
206 fs_rwunlock(vnode_t *vp, int write_lock, caller_context_t *ctp)
207 {
208 }
209 
210 /*
211  * Compare two vnodes.
212  */
213 /*ARGSUSED2*/
214 int
215 fs_cmp(vnode_t *vp1, vnode_t *vp2, caller_context_t *ct)
216 {
217 	return (vp1 == vp2);
218 }
219 
220 /*
221  * No-op seek operation.
222  */
223 /* ARGSUSED */
224 int
225 fs_seek(vnode_t *vp, offset_t ooff, offset_t *noffp, caller_context_t *ct)
226 {
227 	return ((*noffp < 0 || *noffp > MAXOFFSET_T) ? EINVAL : 0);
228 }
229 
230 /*
231  * File and record locking.
232  */
233 /* ARGSUSED */
234 int
235 fs_frlock(register vnode_t *vp, int cmd, struct flock64 *bfp, int flag,
236 	offset_t offset, flk_callback_t *flk_cbp, cred_t *cr,
237 	caller_context_t *ct)
238 {
239 	int frcmd;
240 	int nlmid;
241 	int error = 0;
242 	flk_callback_t serialize_callback;
243 	int serialize = 0;
244 	v_mode_t mode;
245 
246 	switch (cmd) {
247 
248 	case F_GETLK:
249 	case F_O_GETLK:
250 		if (flag & F_REMOTELOCK) {
251 			frcmd = RCMDLCK;
252 		} else if (flag & F_PXFSLOCK) {
253 			frcmd = PCMDLCK;
254 		} else {
255 			frcmd = 0;
256 			bfp->l_pid = ttoproc(curthread)->p_pid;
257 			bfp->l_sysid = 0;
258 		}
259 		break;
260 
261 	case F_SETLK_NBMAND:
262 		/*
263 		 * Are NBMAND locks allowed on this file?
264 		 */
265 		if (!vp->v_vfsp ||
266 		    !(vp->v_vfsp->vfs_flag & VFS_NBMAND)) {
267 			error = EINVAL;
268 			goto done;
269 		}
270 		if (vp->v_type != VREG) {
271 			error = EINVAL;
272 			goto done;
273 		}
274 		/*FALLTHROUGH*/
275 
276 	case F_SETLK:
277 		if (flag & F_REMOTELOCK) {
278 			frcmd = SETFLCK|RCMDLCK;
279 		} else if (flag & F_PXFSLOCK) {
280 			frcmd = SETFLCK|PCMDLCK;
281 		} else {
282 			frcmd = SETFLCK;
283 			bfp->l_pid = ttoproc(curthread)->p_pid;
284 			bfp->l_sysid = 0;
285 		}
286 		if (cmd == F_SETLK_NBMAND &&
287 		    (bfp->l_type == F_RDLCK || bfp->l_type == F_WRLCK)) {
288 			frcmd |= NBMLCK;
289 		}
290 		/*
291 		 * Check whether there is an NBMAND share reservation that
292 		 * conflicts with the lock request.
293 		 */
294 		if (nbl_need_check(vp)) {
295 			nbl_start_crit(vp, RW_WRITER);
296 			serialize = 1;
297 			if (frcmd & NBMLCK) {
298 				mode = (bfp->l_type == F_RDLCK) ?
299 				    V_READ : V_RDANDWR;
300 				if (vn_is_mapped(vp, mode)) {
301 					error = EAGAIN;
302 					goto done;
303 				}
304 			}
305 			if (share_blocks_lock(vp, bfp)) {
306 				error = EAGAIN;
307 				goto done;
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 there is an NBMAND share reservation that conflicts
324 		 * with the lock request, block until the conflicting share
325 		 * reservation goes away.
326 		 */
327 		if (nbl_need_check(vp)) {
328 			nbl_start_crit(vp, RW_WRITER);
329 			serialize = 1;
330 			if (share_blocks_lock(vp, bfp)) {
331 				error = wait_for_share(vp, bfp);
332 				if (error != 0)
333 					goto done;
334 			}
335 		}
336 		break;
337 
338 	case F_HASREMOTELOCKS:
339 		nlmid = GETNLMID(bfp->l_sysid);
340 		if (nlmid != 0) {	/* booted as a cluster */
341 			l_has_rmt(bfp) =
342 			    cl_flk_has_remote_locks_for_nlmid(vp, nlmid);
343 		} else {		/* not booted as a cluster */
344 			l_has_rmt(bfp) = flk_has_remote_locks(vp);
345 		}
346 
347 		goto done;
348 
349 	default:
350 		error = EINVAL;
351 		goto done;
352 	}
353 
354 	/*
355 	 * If this is a blocking lock request and we're serializing lock
356 	 * requests, modify the callback list to leave the critical region
357 	 * while we're waiting for the lock.
358 	 */
359 
360 	if (serialize && (frcmd & SLPFLCK) != 0) {
361 		flk_add_callback(&serialize_callback,
362 		    frlock_serialize_blocked, vp, flk_cbp);
363 		flk_cbp = &serialize_callback;
364 	}
365 
366 	error = reclock(vp, bfp, frcmd, flag, offset, flk_cbp);
367 
368 done:
369 	if (serialize)
370 		nbl_end_crit(vp);
371 
372 	return (error);
373 }
374 
375 /*
376  * Callback when a lock request blocks and we are serializing requests.  If
377  * before sleeping, leave the critical region.  If after wakeup, reenter
378  * the critical region.
379  */
380 
381 static callb_cpr_t *
382 frlock_serialize_blocked(flk_cb_when_t when, void *infop)
383 {
384 	vnode_t *vp = (vnode_t *)infop;
385 
386 	if (when == FLK_BEFORE_SLEEP)
387 		nbl_end_crit(vp);
388 	else {
389 		nbl_start_crit(vp, RW_WRITER);
390 	}
391 
392 	return (NULL);
393 }
394 
395 /*
396  * Allow any flags.
397  */
398 /* ARGSUSED */
399 int
400 fs_setfl(
401 	vnode_t *vp,
402 	int oflags,
403 	int nflags,
404 	cred_t *cr,
405 	caller_context_t *ct)
406 {
407 	return (0);
408 }
409 
410 /*
411  * Return the answer requested to poll() for non-device files.
412  * Only POLLIN, POLLRDNORM, and POLLOUT are recognized.
413  */
414 struct pollhead fs_pollhd;
415 
416 /* ARGSUSED */
417 int
418 fs_poll(vnode_t *vp,
419 	register short events,
420 	int anyyet,
421 	register short *reventsp,
422 	struct pollhead **phpp,
423 	caller_context_t *ct)
424 {
425 	*reventsp = 0;
426 	if (events & POLLIN)
427 		*reventsp |= POLLIN;
428 	if (events & POLLRDNORM)
429 		*reventsp |= POLLRDNORM;
430 	if (events & POLLRDBAND)
431 		*reventsp |= POLLRDBAND;
432 	if (events & POLLOUT)
433 		*reventsp |= POLLOUT;
434 	if (events & POLLWRBAND)
435 		*reventsp |= POLLWRBAND;
436 	*phpp = !anyyet && !*reventsp ? &fs_pollhd : (struct pollhead *)NULL;
437 	return (0);
438 }
439 
440 /*
441  * POSIX pathconf() support.
442  */
443 /* ARGSUSED */
444 int
445 fs_pathconf(
446 	vnode_t *vp,
447 	int cmd,
448 	ulong_t *valp,
449 	cred_t *cr,
450 	caller_context_t *ct)
451 {
452 	register ulong_t val;
453 	register int error = 0;
454 	struct statvfs64 vfsbuf;
455 
456 	switch (cmd) {
457 
458 	case _PC_LINK_MAX:
459 		val = MAXLINK;
460 		break;
461 
462 	case _PC_MAX_CANON:
463 		val = MAX_CANON;
464 		break;
465 
466 	case _PC_MAX_INPUT:
467 		val = MAX_INPUT;
468 		break;
469 
470 	case _PC_NAME_MAX:
471 		bzero(&vfsbuf, sizeof (vfsbuf));
472 		if (error = VFS_STATVFS(vp->v_vfsp, &vfsbuf))
473 			break;
474 		val = vfsbuf.f_namemax;
475 		break;
476 
477 	case _PC_PATH_MAX:
478 	case _PC_SYMLINK_MAX:
479 		val = MAXPATHLEN;
480 		break;
481 
482 	case _PC_PIPE_BUF:
483 		val = PIPE_BUF;
484 		break;
485 
486 	case _PC_NO_TRUNC:
487 		if (vp->v_vfsp->vfs_flag & VFS_NOTRUNC)
488 			val = 1;	/* NOTRUNC is enabled for vp */
489 		else
490 			val = (ulong_t)-1;
491 		break;
492 
493 	case _PC_VDISABLE:
494 		val = _POSIX_VDISABLE;
495 		break;
496 
497 	case _PC_CHOWN_RESTRICTED:
498 		if (rstchown)
499 			val = rstchown; /* chown restricted enabled */
500 		else
501 			val = (ulong_t)-1;
502 		break;
503 
504 	case _PC_FILESIZEBITS:
505 
506 		/*
507 		 * If ever we come here it means that underlying file system
508 		 * does not recognise the command and therefore this
509 		 * configurable limit cannot be determined. We return -1
510 		 * and don't change errno.
511 		 */
512 
513 		val = (ulong_t)-1;    /* large file support */
514 		break;
515 
516 	case _PC_ACL_ENABLED:
517 		val = 0;
518 		break;
519 
520 	case _PC_CASE_BEHAVIOR:
521 		val = _CASE_SENSITIVE;
522 		if (vfs_has_feature(vp->v_vfsp, VFSFT_CASEINSENSITIVE) == 1)
523 			val |= _CASE_INSENSITIVE;
524 		if (vfs_has_feature(vp->v_vfsp, VFSFT_NOCASESENSITIVE) == 1)
525 			val &= ~_CASE_SENSITIVE;
526 		break;
527 
528 	case _PC_SATTR_ENABLED:
529 	case _PC_SATTR_EXISTS:
530 		val = 0;
531 		break;
532 
533 	default:
534 		error = EINVAL;
535 		break;
536 	}
537 
538 	if (error == 0)
539 		*valp = val;
540 	return (error);
541 }
542 
543 /*
544  * Dispose of a page.
545  */
546 /* ARGSUSED */
547 void
548 fs_dispose(
549 	struct vnode *vp,
550 	page_t *pp,
551 	int fl,
552 	int dn,
553 	struct cred *cr,
554 	caller_context_t *ct)
555 {
556 
557 	ASSERT(fl == B_FREE || fl == B_INVAL);
558 
559 	if (fl == B_FREE)
560 		page_free(pp, dn);
561 	else
562 		page_destroy(pp, dn);
563 }
564 
565 /* ARGSUSED */
566 void
567 fs_nodispose(
568 	struct vnode *vp,
569 	page_t *pp,
570 	int fl,
571 	int dn,
572 	struct cred *cr,
573 	caller_context_t *ct)
574 {
575 	cmn_err(CE_PANIC, "fs_nodispose invoked");
576 }
577 
578 /*
579  * fabricate acls for file systems that do not support acls.
580  */
581 /* ARGSUSED */
582 int
583 fs_fab_acl(
584 	vnode_t *vp,
585 	vsecattr_t *vsecattr,
586 	int flag,
587 	cred_t *cr,
588 	caller_context_t *ct)
589 {
590 	aclent_t	*aclentp;
591 	ace_t		*acep;
592 	struct vattr	vattr;
593 	int		error;
594 	size_t		aclsize;
595 
596 	vsecattr->vsa_aclcnt	= 0;
597 	vsecattr->vsa_aclentsz	= 0;
598 	vsecattr->vsa_aclentp	= NULL;
599 	vsecattr->vsa_dfaclcnt	= 0;	/* Default ACLs are not fabricated */
600 	vsecattr->vsa_dfaclentp	= NULL;
601 
602 	vattr.va_mask = AT_MODE | AT_UID | AT_GID;
603 	if (error = VOP_GETATTR(vp, &vattr, 0, cr, ct))
604 		return (error);
605 
606 	if (vsecattr->vsa_mask & (VSA_ACLCNT | VSA_ACL)) {
607 		aclsize = 4 * sizeof (aclent_t);
608 		vsecattr->vsa_aclcnt	= 4; /* USER, GROUP, OTHER, and CLASS */
609 		vsecattr->vsa_aclentp = kmem_zalloc(aclsize, KM_SLEEP);
610 		aclentp = vsecattr->vsa_aclentp;
611 
612 		aclentp->a_type = USER_OBJ;	/* Owner */
613 		aclentp->a_perm = ((ushort_t)(vattr.va_mode & 0700)) >> 6;
614 		aclentp->a_id = vattr.va_uid;   /* Really undefined */
615 		aclentp++;
616 
617 		aclentp->a_type = GROUP_OBJ;    /* Group */
618 		aclentp->a_perm = ((ushort_t)(vattr.va_mode & 0070)) >> 3;
619 		aclentp->a_id = vattr.va_gid;   /* Really undefined */
620 		aclentp++;
621 
622 		aclentp->a_type = OTHER_OBJ;    /* Other */
623 		aclentp->a_perm = vattr.va_mode & 0007;
624 		aclentp->a_id = (gid_t)-1;	/* Really undefined */
625 		aclentp++;
626 
627 		aclentp->a_type = CLASS_OBJ;    /* Class */
628 		aclentp->a_perm = (ushort_t)(0007);
629 		aclentp->a_id = (gid_t)-1;	/* Really undefined */
630 	} else if (vsecattr->vsa_mask & (VSA_ACECNT | VSA_ACE)) {
631 		aclsize = 6 * sizeof (ace_t);
632 		vsecattr->vsa_aclcnt	= 6;
633 		vsecattr->vsa_aclentp = kmem_zalloc(aclsize, KM_SLEEP);
634 		vsecattr->vsa_aclentsz = aclsize;
635 		acep = vsecattr->vsa_aclentp;
636 		(void) memcpy(acep, trivial_acl, sizeof (ace_t) * 6);
637 		adjust_ace_pair(acep, (vattr.va_mode & 0700) >> 6);
638 		adjust_ace_pair(acep + 2, (vattr.va_mode & 0070) >> 3);
639 		adjust_ace_pair(acep + 4, vattr.va_mode & 0007);
640 	}
641 
642 	return (0);
643 }
644 
645 /*
646  * Common code for implementing DOS share reservations
647  */
648 /* ARGSUSED4 */
649 int
650 fs_shrlock(
651 	struct vnode *vp,
652 	int cmd,
653 	struct shrlock *shr,
654 	int flag,
655 	cred_t *cr,
656 	caller_context_t *ct)
657 {
658 	int error;
659 
660 	/*
661 	 * Make sure that the file was opened with permissions appropriate
662 	 * for the request, and make sure the caller isn't trying to sneak
663 	 * in an NBMAND request.
664 	 */
665 	if (cmd == F_SHARE) {
666 		if (((shr->s_access & F_RDACC) && (flag & FREAD) == 0) ||
667 		    ((shr->s_access & F_WRACC) && (flag & FWRITE) == 0))
668 			return (EBADF);
669 		if (shr->s_access & (F_RMACC | F_MDACC))
670 			return (EINVAL);
671 		if (shr->s_deny & (F_MANDDNY | F_RMDNY))
672 			return (EINVAL);
673 	}
674 	if (cmd == F_SHARE_NBMAND) {
675 		/* make sure nbmand is allowed on the file */
676 		if (!vp->v_vfsp ||
677 		    !(vp->v_vfsp->vfs_flag & VFS_NBMAND)) {
678 			return (EINVAL);
679 		}
680 		if (vp->v_type != VREG) {
681 			return (EINVAL);
682 		}
683 	}
684 
685 	nbl_start_crit(vp, RW_WRITER);
686 
687 	switch (cmd) {
688 
689 	case F_SHARE_NBMAND:
690 		shr->s_deny |= F_MANDDNY;
691 		/*FALLTHROUGH*/
692 	case F_SHARE:
693 		error = add_share(vp, shr);
694 		break;
695 
696 	case F_UNSHARE:
697 		error = del_share(vp, shr);
698 		break;
699 
700 	case F_HASREMOTELOCKS:
701 		/*
702 		 * We are overloading this command to refer to remote
703 		 * shares as well as remote locks, despite its name.
704 		 */
705 		shr->s_access = shr_has_remote_shares(vp, shr->s_sysid);
706 		error = 0;
707 		break;
708 
709 	default:
710 		error = EINVAL;
711 		break;
712 	}
713 
714 	nbl_end_crit(vp);
715 	return (error);
716 }
717 
718 /*ARGSUSED1*/
719 int
720 fs_vnevent_nosupport(vnode_t *vp, vnevent_t e, vnode_t *dvp, char *fnm,
721     caller_context_t *ct)
722 {
723 	ASSERT(vp != NULL);
724 	return (ENOTSUP);
725 }
726 
727 /*ARGSUSED1*/
728 int
729 fs_vnevent_support(vnode_t *vp, vnevent_t e, vnode_t *dvp, char *fnm,
730     caller_context_t *ct)
731 {
732 	ASSERT(vp != NULL);
733 	return (0);
734 }
735 
736 /*
737  * return 1 for non-trivial ACL.
738  *
739  * NB: It is not necessary for the caller to VOP_RWLOCK since
740  *	we only issue VOP_GETSECATTR.
741  *
742  * Returns 0 == trivial
743  *         1 == NOT Trivial
744  *	   <0 could not determine.
745  */
746 int
747 fs_acl_nontrivial(vnode_t *vp, cred_t *cr)
748 {
749 	ulong_t		acl_styles;
750 	ulong_t		acl_flavor;
751 	vsecattr_t 	vsecattr;
752 	int 		error;
753 	int		isnontrivial;
754 
755 	/* determine the forms of ACLs maintained */
756 	error = VOP_PATHCONF(vp, _PC_ACL_ENABLED, &acl_styles, cr, NULL);
757 
758 	/* clear bits we don't understand and establish default acl_style */
759 	acl_styles &= (_ACL_ACLENT_ENABLED | _ACL_ACE_ENABLED);
760 	if (error || (acl_styles == 0))
761 		acl_styles = _ACL_ACLENT_ENABLED;
762 
763 	vsecattr.vsa_aclentp = NULL;
764 	vsecattr.vsa_dfaclentp = NULL;
765 	vsecattr.vsa_aclcnt = 0;
766 	vsecattr.vsa_dfaclcnt = 0;
767 
768 	while (acl_styles) {
769 		/* select one of the styles as current flavor */
770 		acl_flavor = 0;
771 		if (acl_styles & _ACL_ACLENT_ENABLED) {
772 			acl_flavor = _ACL_ACLENT_ENABLED;
773 			vsecattr.vsa_mask = VSA_ACLCNT | VSA_DFACLCNT;
774 		} else if (acl_styles & _ACL_ACE_ENABLED) {
775 			acl_flavor = _ACL_ACE_ENABLED;
776 			vsecattr.vsa_mask = VSA_ACECNT | VSA_ACE;
777 		}
778 
779 		ASSERT(vsecattr.vsa_mask && acl_flavor);
780 		error = VOP_GETSECATTR(vp, &vsecattr, 0, cr, NULL);
781 		if (error == 0)
782 			break;
783 
784 		/* that flavor failed */
785 		acl_styles &= ~acl_flavor;
786 	}
787 
788 	/* if all styles fail then assume trivial */
789 	if (acl_styles == 0)
790 		return (0);
791 
792 	/* process the flavor that worked */
793 	isnontrivial = 0;
794 	if (acl_flavor & _ACL_ACLENT_ENABLED) {
795 		if (vsecattr.vsa_aclcnt > MIN_ACL_ENTRIES)
796 			isnontrivial = 1;
797 		if (vsecattr.vsa_aclcnt && vsecattr.vsa_aclentp != NULL)
798 			kmem_free(vsecattr.vsa_aclentp,
799 			    vsecattr.vsa_aclcnt * sizeof (aclent_t));
800 		if (vsecattr.vsa_dfaclcnt && vsecattr.vsa_dfaclentp != NULL)
801 			kmem_free(vsecattr.vsa_dfaclentp,
802 			    vsecattr.vsa_dfaclcnt * sizeof (aclent_t));
803 	}
804 	if (acl_flavor & _ACL_ACE_ENABLED) {
805 
806 		isnontrivial = ace_trivial(vsecattr.vsa_aclentp,
807 		    vsecattr.vsa_aclcnt);
808 
809 		if (vsecattr.vsa_aclcnt && vsecattr.vsa_aclentp != NULL)
810 			kmem_free(vsecattr.vsa_aclentp,
811 			    vsecattr.vsa_aclcnt * sizeof (ace_t));
812 		/* ACE has no vsecattr.vsa_dfaclcnt */
813 	}
814 	return (isnontrivial);
815 }
816 
817 /*
818  * Check whether we need a retry to recover from STALE error.
819  */
820 int
821 fs_need_estale_retry(int retry_count)
822 {
823 	if (retry_count < fs_estale_retry)
824 		return (1);
825 	else
826 		return (0);
827 }
828 
829 
830 static int (*fs_av_scan)(vnode_t *, cred_t *, int) = NULL;
831 
832 /*
833  * Routine for anti-virus scanner to call to register its scanning routine.
834  */
835 void
836 fs_vscan_register(int (*av_scan)(vnode_t *, cred_t *, int))
837 {
838 	fs_av_scan = av_scan;
839 }
840 
841 /*
842  * Routine for file systems to call to initiate anti-virus scanning.
843  * Scanning will only be done on REGular files (currently).
844  */
845 int
846 fs_vscan(vnode_t *vp, cred_t *cr, int async)
847 {
848 	int ret = 0;
849 
850 	if (fs_av_scan && vp->v_type == VREG)
851 		ret = (*fs_av_scan)(vp, cr, async);
852 
853 	return (ret);
854 }
855