xref: /illumos-gate/usr/src/uts/common/fs/nfs/nfs_client.c (revision 7f7322febbcfe774b7270abc3b191c094bfcc517)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  *
26  *  	Copyright (c) 1983,1984,1985,1986,1987,1988,1989  AT&T.
27  *	All rights reserved.
28  */
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include <sys/param.h>
33 #include <sys/types.h>
34 #include <sys/systm.h>
35 #include <sys/thread.h>
36 #include <sys/t_lock.h>
37 #include <sys/time.h>
38 #include <sys/vnode.h>
39 #include <sys/vfs.h>
40 #include <sys/errno.h>
41 #include <sys/buf.h>
42 #include <sys/stat.h>
43 #include <sys/cred.h>
44 #include <sys/kmem.h>
45 #include <sys/debug.h>
46 #include <sys/dnlc.h>
47 #include <sys/vmsystm.h>
48 #include <sys/flock.h>
49 #include <sys/share.h>
50 #include <sys/cmn_err.h>
51 #include <sys/tiuser.h>
52 #include <sys/sysmacros.h>
53 #include <sys/callb.h>
54 #include <sys/acl.h>
55 #include <sys/kstat.h>
56 #include <sys/signal.h>
57 #include <sys/list.h>
58 #include <sys/zone.h>
59 
60 #include <rpc/types.h>
61 #include <rpc/xdr.h>
62 #include <rpc/auth.h>
63 #include <rpc/clnt.h>
64 
65 #include <nfs/nfs.h>
66 #include <nfs/nfs_clnt.h>
67 
68 #include <nfs/rnode.h>
69 #include <nfs/nfs_acl.h>
70 #include <nfs/lm.h>
71 
72 #include <vm/hat.h>
73 #include <vm/as.h>
74 #include <vm/page.h>
75 #include <vm/pvn.h>
76 #include <vm/seg.h>
77 #include <vm/seg_map.h>
78 #include <vm/seg_vn.h>
79 
80 static void	nfs3_attr_cache(vnode_t *, vattr_t *, vattr_t *, hrtime_t,
81 			cred_t *);
82 static int	nfs_getattr_cache(vnode_t *, struct vattr *);
83 static int	nfs_remove_locking_id(vnode_t *, int, char *, char *, int *);
84 
85 struct mi_globals {
86 	kmutex_t	mig_lock;  /* lock protecting mig_list */
87 	list_t		mig_list;  /* list of NFS v2 or v3 mounts in zone */
88 	boolean_t	mig_destructor_called;
89 };
90 
91 static zone_key_t mi_list_key;
92 
93 /* Debugging flag for PC file shares. */
94 extern int	share_debug;
95 
96 /*
97  * Attributes caching:
98  *
99  * Attributes are cached in the rnode in struct vattr form.
100  * There is a time associated with the cached attributes (r_attrtime)
101  * which tells whether the attributes are valid. The time is initialized
102  * to the difference between current time and the modify time of the vnode
103  * when new attributes are cached. This allows the attributes for
104  * files that have changed recently to be timed out sooner than for files
105  * that have not changed for a long time. There are minimum and maximum
106  * timeout values that can be set per mount point.
107  */
108 
109 int
110 nfs_waitfor_purge_complete(vnode_t *vp)
111 {
112 	rnode_t *rp;
113 	k_sigset_t smask;
114 
115 	rp = VTOR(vp);
116 	if (rp->r_serial != NULL && rp->r_serial != curthread) {
117 		mutex_enter(&rp->r_statelock);
118 		sigintr(&smask, VTOMI(vp)->mi_flags & MI_INT);
119 		while (rp->r_serial != NULL) {
120 			if (!cv_wait_sig(&rp->r_cv, &rp->r_statelock)) {
121 				sigunintr(&smask);
122 				mutex_exit(&rp->r_statelock);
123 				return (EINTR);
124 			}
125 		}
126 		sigunintr(&smask);
127 		mutex_exit(&rp->r_statelock);
128 	}
129 	return (0);
130 }
131 
132 /*
133  * Validate caches by checking cached attributes. If the cached
134  * attributes have timed out, then get new attributes from the server.
135  * As a side affect, this will do cache invalidation if the attributes
136  * have changed.
137  *
138  * If the attributes have not timed out and if there is a cache
139  * invalidation being done by some other thread, then wait until that
140  * thread has completed the cache invalidation.
141  */
142 int
143 nfs_validate_caches(vnode_t *vp, cred_t *cr)
144 {
145 	int error;
146 	struct vattr va;
147 
148 	if (ATTRCACHE_VALID(vp)) {
149 		error = nfs_waitfor_purge_complete(vp);
150 		if (error)
151 			return (error);
152 		return (0);
153 	}
154 
155 	va.va_mask = AT_ALL;
156 	return (nfs_getattr_otw(vp, &va, cr));
157 }
158 
159 /*
160  * Validate caches by checking cached attributes. If the cached
161  * attributes have timed out, then get new attributes from the server.
162  * As a side affect, this will do cache invalidation if the attributes
163  * have changed.
164  *
165  * If the attributes have not timed out and if there is a cache
166  * invalidation being done by some other thread, then wait until that
167  * thread has completed the cache invalidation.
168  */
169 int
170 nfs3_validate_caches(vnode_t *vp, cred_t *cr)
171 {
172 	int error;
173 	struct vattr va;
174 
175 	if (ATTRCACHE_VALID(vp)) {
176 		error = nfs_waitfor_purge_complete(vp);
177 		if (error)
178 			return (error);
179 		return (0);
180 	}
181 
182 	va.va_mask = AT_ALL;
183 	return (nfs3_getattr_otw(vp, &va, cr));
184 }
185 
186 /*
187  * Purge all of the various NFS `data' caches.
188  */
189 void
190 nfs_purge_caches(vnode_t *vp, int purge_dnlc, cred_t *cr)
191 {
192 	rnode_t *rp;
193 	char *contents;
194 	int size;
195 	int error;
196 
197 	/*
198 	 * Purge the DNLC for any entries which refer to this file.
199 	 * Avoid recursive entry into dnlc_purge_vp() in case of a directory.
200 	 */
201 	rp = VTOR(vp);
202 	mutex_enter(&rp->r_statelock);
203 	if (vp->v_count > 1 &&
204 	    (vp->v_type == VDIR || purge_dnlc == NFS_PURGE_DNLC) &&
205 	    !(rp->r_flags & RINDNLCPURGE)) {
206 		/*
207 		 * Set the RINDNLCPURGE flag to prevent recursive entry
208 		 * into dnlc_purge_vp()
209 		 */
210 		if (vp->v_type == VDIR)
211 			rp->r_flags |= RINDNLCPURGE;
212 		mutex_exit(&rp->r_statelock);
213 		dnlc_purge_vp(vp);
214 		mutex_enter(&rp->r_statelock);
215 		if (rp->r_flags & RINDNLCPURGE)
216 			rp->r_flags &= ~RINDNLCPURGE;
217 	}
218 
219 	/*
220 	 * Clear any readdir state bits and purge the readlink response cache.
221 	 */
222 	contents = rp->r_symlink.contents;
223 	size = rp->r_symlink.size;
224 	rp->r_symlink.contents = NULL;
225 	mutex_exit(&rp->r_statelock);
226 
227 	if (contents != NULL) {
228 
229 		kmem_free((void *)contents, size);
230 	}
231 
232 	/*
233 	 * Flush the page cache.
234 	 */
235 	if (vn_has_cached_data(vp)) {
236 		error = VOP_PUTPAGE(vp, (u_offset_t)0, 0, B_INVAL, cr);
237 		if (error && (error == ENOSPC || error == EDQUOT)) {
238 			mutex_enter(&rp->r_statelock);
239 			if (!rp->r_error)
240 				rp->r_error = error;
241 			mutex_exit(&rp->r_statelock);
242 		}
243 	}
244 
245 	/*
246 	 * Flush the readdir response cache.
247 	 */
248 	if (HAVE_RDDIR_CACHE(rp))
249 		nfs_purge_rddir_cache(vp);
250 }
251 
252 /*
253  * Purge the readdir cache of all entries
254  */
255 void
256 nfs_purge_rddir_cache(vnode_t *vp)
257 {
258 	rnode_t *rp;
259 	rddir_cache *rdc;
260 	rddir_cache *nrdc;
261 
262 	rp = VTOR(vp);
263 top:
264 	mutex_enter(&rp->r_statelock);
265 	rp->r_direof = NULL;
266 	rp->r_flags &= ~RLOOKUP;
267 	rp->r_flags |= RREADDIRPLUS;
268 	rdc = avl_first(&rp->r_dir);
269 	while (rdc != NULL) {
270 		nrdc = AVL_NEXT(&rp->r_dir, rdc);
271 		avl_remove(&rp->r_dir, rdc);
272 		rddir_cache_rele(rdc);
273 		rdc = nrdc;
274 	}
275 	mutex_exit(&rp->r_statelock);
276 }
277 
278 /*
279  * Do a cache check based on the post-operation attributes.
280  * Then make them the new cached attributes.  If no attributes
281  * were returned, then mark the attributes as timed out.
282  */
283 void
284 nfs3_cache_post_op_attr(vnode_t *vp, post_op_attr *poap, hrtime_t t, cred_t *cr)
285 {
286 	vattr_t attr;
287 
288 	if (!poap->attributes) {
289 		PURGE_ATTRCACHE(vp);
290 		return;
291 	}
292 	(void) nfs3_cache_fattr3(vp, &poap->attr, &attr, t, cr);
293 }
294 
295 /*
296  * Same as above, but using a vattr
297  */
298 void
299 nfs3_cache_post_op_vattr(vnode_t *vp, post_op_vattr *poap, hrtime_t t,
300     cred_t *cr)
301 {
302 	if (!poap->attributes) {
303 		PURGE_ATTRCACHE(vp);
304 		return;
305 	}
306 	nfs_attr_cache(vp, poap->fres.vap, t, cr);
307 }
308 
309 /*
310  * Do a cache check based on the weak cache consistency attributes.
311  * These consist of a small set of pre-operation attributes and the
312  * full set of post-operation attributes.
313  *
314  * If we are given the pre-operation attributes, then use them to
315  * check the validity of the various caches.  Then, if we got the
316  * post-operation attributes, make them the new cached attributes.
317  * If we didn't get the post-operation attributes, then mark the
318  * attribute cache as timed out so that the next reference will
319  * cause a GETATTR to the server to refresh with the current
320  * attributes.
321  *
322  * Otherwise, if we didn't get the pre-operation attributes, but
323  * we did get the post-operation attributes, then use these
324  * attributes to check the validity of the various caches.  This
325  * will probably cause a flush of the caches because if the
326  * operation succeeded, the attributes of the object were changed
327  * in some way from the old post-operation attributes.  This
328  * should be okay because it is the safe thing to do.  After
329  * checking the data caches, then we make these the new cached
330  * attributes.
331  *
332  * Otherwise, we didn't get either the pre- or post-operation
333  * attributes.  Simply mark the attribute cache as timed out so
334  * the next reference will cause a GETATTR to the server to
335  * refresh with the current attributes.
336  *
337  * If an error occurred trying to convert the over the wire
338  * attributes to a vattr, then simply mark the attribute cache as
339  * timed out.
340  */
341 void
342 nfs3_cache_wcc_data(vnode_t *vp, wcc_data *wccp, hrtime_t t, cred_t *cr)
343 {
344 	vattr_t bva;
345 	vattr_t ava;
346 
347 	if (wccp->after.attributes) {
348 		if (fattr3_to_vattr(vp, &wccp->after.attr, &ava)) {
349 			PURGE_ATTRCACHE(vp);
350 			return;
351 		}
352 		if (wccp->before.attributes) {
353 			bva.va_ctime.tv_sec = wccp->before.attr.ctime.seconds;
354 			bva.va_ctime.tv_nsec = wccp->before.attr.ctime.nseconds;
355 			bva.va_mtime.tv_sec = wccp->before.attr.mtime.seconds;
356 			bva.va_mtime.tv_nsec = wccp->before.attr.mtime.nseconds;
357 			bva.va_size = wccp->before.attr.size;
358 			nfs3_attr_cache(vp, &bva, &ava, t, cr);
359 		} else
360 			nfs_attr_cache(vp, &ava, t, cr);
361 	} else {
362 		PURGE_ATTRCACHE(vp);
363 	}
364 }
365 
366 /*
367  * Set attributes cache for given vnode using nfsattr.
368  *
369  * This routine does not do cache validation with the attributes.
370  *
371  * If an error occurred trying to convert the over the wire
372  * attributes to a vattr, then simply mark the attribute cache as
373  * timed out.
374  */
375 void
376 nfs_attrcache(vnode_t *vp, struct nfsfattr *na, hrtime_t t)
377 {
378 	rnode_t *rp;
379 	struct vattr va;
380 
381 	if (!nattr_to_vattr(vp, na, &va)) {
382 		rp = VTOR(vp);
383 		mutex_enter(&rp->r_statelock);
384 		if (rp->r_mtime <= t)
385 			nfs_attrcache_va(vp, &va);
386 		mutex_exit(&rp->r_statelock);
387 	} else {
388 		PURGE_ATTRCACHE(vp);
389 	}
390 }
391 
392 /*
393  * Set attributes cache for given vnode using fattr3.
394  *
395  * This routine does not do cache validation with the attributes.
396  *
397  * If an error occurred trying to convert the over the wire
398  * attributes to a vattr, then simply mark the attribute cache as
399  * timed out.
400  */
401 void
402 nfs3_attrcache(vnode_t *vp, fattr3 *na, hrtime_t t)
403 {
404 	rnode_t *rp;
405 	struct vattr va;
406 
407 	if (!fattr3_to_vattr(vp, na, &va)) {
408 		rp = VTOR(vp);
409 		mutex_enter(&rp->r_statelock);
410 		if (rp->r_mtime <= t)
411 			nfs_attrcache_va(vp, &va);
412 		mutex_exit(&rp->r_statelock);
413 	} else {
414 		PURGE_ATTRCACHE(vp);
415 	}
416 }
417 
418 /*
419  * Do a cache check based on attributes returned over the wire.  The
420  * new attributes are cached.
421  *
422  * If an error occurred trying to convert the over the wire attributes
423  * to a vattr, then just return that error.
424  *
425  * As a side affect, the vattr argument is filled in with the converted
426  * attributes.
427  */
428 int
429 nfs_cache_fattr(vnode_t *vp, struct nfsfattr *na, vattr_t *vap, hrtime_t t,
430     cred_t *cr)
431 {
432 	int error;
433 
434 	error = nattr_to_vattr(vp, na, vap);
435 	if (error)
436 		return (error);
437 	nfs_attr_cache(vp, vap, t, cr);
438 	return (0);
439 }
440 
441 /*
442  * Do a cache check based on attributes returned over the wire.  The
443  * new attributes are cached.
444  *
445  * If an error occurred trying to convert the over the wire attributes
446  * to a vattr, then just return that error.
447  *
448  * As a side affect, the vattr argument is filled in with the converted
449  * attributes.
450  */
451 int
452 nfs3_cache_fattr3(vnode_t *vp, fattr3 *na, vattr_t *vap, hrtime_t t, cred_t *cr)
453 {
454 	int error;
455 
456 	error = fattr3_to_vattr(vp, na, vap);
457 	if (error)
458 		return (error);
459 	nfs_attr_cache(vp, vap, t, cr);
460 	return (0);
461 }
462 
463 /*
464  * Use the passed in virtual attributes to check to see whether the
465  * data and metadata caches are valid, cache the new attributes, and
466  * then do the cache invalidation if required.
467  *
468  * The cache validation and caching of the new attributes is done
469  * atomically via the use of the mutex, r_statelock.  If required,
470  * the cache invalidation is done atomically w.r.t. the cache
471  * validation and caching of the attributes via the pseudo lock,
472  * r_serial.
473  *
474  * This routine is used to do cache validation and attributes caching
475  * for operations with a single set of post operation attributes.
476  */
477 void
478 nfs_attr_cache(vnode_t *vp, vattr_t *vap, hrtime_t t, cred_t *cr)
479 {
480 	rnode_t *rp;
481 	int mtime_changed;
482 	int ctime_changed;
483 	vsecattr_t *vsp;
484 	int was_serial;
485 
486 	rp = VTOR(vp);
487 
488 	mutex_enter(&rp->r_statelock);
489 
490 	if (rp->r_serial != curthread) {
491 		klwp_t *lwp = ttolwp(curthread);
492 
493 		was_serial = 0;
494 		if (lwp != NULL)
495 			lwp->lwp_nostop++;
496 		while (rp->r_serial != NULL) {
497 			if (!cv_wait_sig(&rp->r_cv, &rp->r_statelock)) {
498 				mutex_exit(&rp->r_statelock);
499 				if (lwp != NULL)
500 					lwp->lwp_nostop--;
501 				return;
502 			}
503 		}
504 		if (lwp != NULL)
505 			lwp->lwp_nostop--;
506 	} else
507 		was_serial = 1;
508 
509 	if (rp->r_mtime > t) {
510 		mutex_exit(&rp->r_statelock);
511 		return;
512 	}
513 
514 	if (!(rp->r_flags & RWRITEATTR)) {
515 		if (!CACHE_VALID(rp, vap->va_mtime, vap->va_size))
516 			mtime_changed = 1;
517 		else
518 			mtime_changed = 0;
519 		if (rp->r_attr.va_ctime.tv_sec != vap->va_ctime.tv_sec ||
520 		    rp->r_attr.va_ctime.tv_nsec != vap->va_ctime.tv_nsec)
521 			ctime_changed = 1;
522 		else
523 			ctime_changed = 0;
524 	} else if (rp->r_size != vap->va_size &&
525 		    (!vn_has_cached_data(vp) ||
526 		    (!(rp->r_flags & RDIRTY) && rp->r_count == 0))) {
527 		mtime_changed = 1;
528 		ctime_changed = 0;
529 	} else {
530 		mtime_changed = 0;
531 		ctime_changed = 0;
532 	}
533 
534 	nfs_attrcache_va(vp, vap);
535 
536 	if (!mtime_changed && !ctime_changed) {
537 		mutex_exit(&rp->r_statelock);
538 		return;
539 	}
540 
541 	rp->r_serial = curthread;
542 
543 	mutex_exit(&rp->r_statelock);
544 
545 	if (mtime_changed)
546 		nfs_purge_caches(vp, NFS_NOPURGE_DNLC, cr);
547 
548 	if (ctime_changed) {
549 		(void) nfs_access_purge_rp(rp);
550 		if (rp->r_secattr != NULL) {
551 			mutex_enter(&rp->r_statelock);
552 			vsp = rp->r_secattr;
553 			rp->r_secattr = NULL;
554 			mutex_exit(&rp->r_statelock);
555 			if (vsp != NULL)
556 				nfs_acl_free(vsp);
557 		}
558 	}
559 
560 	if (!was_serial) {
561 		mutex_enter(&rp->r_statelock);
562 		rp->r_serial = NULL;
563 		cv_broadcast(&rp->r_cv);
564 		mutex_exit(&rp->r_statelock);
565 	}
566 }
567 
568 /*
569  * Use the passed in "before" virtual attributes to check to see
570  * whether the data and metadata caches are valid, cache the "after"
571  * new attributes, and then do the cache invalidation if required.
572  *
573  * The cache validation and caching of the new attributes is done
574  * atomically via the use of the mutex, r_statelock.  If required,
575  * the cache invalidation is done atomically w.r.t. the cache
576  * validation and caching of the attributes via the pseudo lock,
577  * r_serial.
578  *
579  * This routine is used to do cache validation and attributes caching
580  * for operations with both pre operation attributes and post operation
581  * attributes.
582  */
583 static void
584 nfs3_attr_cache(vnode_t *vp, vattr_t *bvap, vattr_t *avap, hrtime_t t,
585     cred_t *cr)
586 {
587 	rnode_t *rp;
588 	int mtime_changed;
589 	int ctime_changed;
590 	vsecattr_t *vsp;
591 	int was_serial;
592 
593 	rp = VTOR(vp);
594 
595 	mutex_enter(&rp->r_statelock);
596 
597 	if (rp->r_serial != curthread) {
598 		klwp_t *lwp = ttolwp(curthread);
599 
600 		was_serial = 0;
601 		if (lwp != NULL)
602 			lwp->lwp_nostop++;
603 		while (rp->r_serial != NULL) {
604 			if (!cv_wait_sig(&rp->r_cv, &rp->r_statelock)) {
605 				mutex_exit(&rp->r_statelock);
606 				if (lwp != NULL)
607 					lwp->lwp_nostop--;
608 				return;
609 			}
610 		}
611 		if (lwp != NULL)
612 			lwp->lwp_nostop--;
613 	} else
614 		was_serial = 1;
615 
616 	if (rp->r_mtime > t) {
617 		mutex_exit(&rp->r_statelock);
618 		return;
619 	}
620 
621 	if (!(rp->r_flags & RWRITEATTR)) {
622 		if (!CACHE_VALID(rp, bvap->va_mtime, bvap->va_size))
623 			mtime_changed = 1;
624 		else
625 			mtime_changed = 0;
626 		if (rp->r_attr.va_ctime.tv_sec != bvap->va_ctime.tv_sec ||
627 		    rp->r_attr.va_ctime.tv_nsec != bvap->va_ctime.tv_nsec)
628 			ctime_changed = 1;
629 		else
630 			ctime_changed = 0;
631 	} else {
632 		mtime_changed = 0;
633 		ctime_changed = 0;
634 	}
635 
636 	nfs_attrcache_va(vp, avap);
637 
638 	if (!mtime_changed && !ctime_changed) {
639 		mutex_exit(&rp->r_statelock);
640 		return;
641 	}
642 
643 	rp->r_serial = curthread;
644 
645 	mutex_exit(&rp->r_statelock);
646 
647 	if (mtime_changed)
648 		nfs_purge_caches(vp, NFS_NOPURGE_DNLC, cr);
649 
650 	if (ctime_changed) {
651 		(void) nfs_access_purge_rp(rp);
652 		if (rp->r_secattr != NULL) {
653 			mutex_enter(&rp->r_statelock);
654 			vsp = rp->r_secattr;
655 			rp->r_secattr = NULL;
656 			mutex_exit(&rp->r_statelock);
657 			if (vsp != NULL)
658 				nfs_acl_free(vsp);
659 		}
660 	}
661 
662 	if (!was_serial) {
663 		mutex_enter(&rp->r_statelock);
664 		rp->r_serial = NULL;
665 		cv_broadcast(&rp->r_cv);
666 		mutex_exit(&rp->r_statelock);
667 	}
668 }
669 
670 /*
671  * Set attributes cache for given vnode using virtual attributes.
672  *
673  * Set the timeout value on the attribute cache and fill it
674  * with the passed in attributes.
675  *
676  * The caller must be holding r_statelock.
677  */
678 void
679 nfs_attrcache_va(vnode_t *vp, struct vattr *va)
680 {
681 	rnode_t *rp;
682 	mntinfo_t *mi;
683 	hrtime_t delta;
684 	hrtime_t now;
685 
686 	rp = VTOR(vp);
687 
688 	ASSERT(MUTEX_HELD(&rp->r_statelock));
689 
690 	now = gethrtime();
691 
692 	mi = VTOMI(vp);
693 
694 	/*
695 	 * Delta is the number of nanoseconds that we will
696 	 * cache the attributes of the file.  It is based on
697 	 * the number of nanoseconds since the last time that
698 	 * we detected a change.  The assumption is that files
699 	 * that changed recently are likely to change again.
700 	 * There is a minimum and a maximum for regular files
701 	 * and for directories which is enforced though.
702 	 *
703 	 * Using the time since last change was detected
704 	 * eliminates direct comparison or calculation
705 	 * using mixed client and server times.  NFS does
706 	 * not make any assumptions regarding the client
707 	 * and server clocks being synchronized.
708 	 */
709 	if (va->va_mtime.tv_sec != rp->r_attr.va_mtime.tv_sec ||
710 	    va->va_mtime.tv_nsec != rp->r_attr.va_mtime.tv_nsec ||
711 	    va->va_size != rp->r_attr.va_size)
712 		rp->r_mtime = now;
713 
714 	if ((mi->mi_flags & MI_NOAC) || (vp->v_flag & VNOCACHE))
715 		delta = 0;
716 	else {
717 		delta = now - rp->r_mtime;
718 		if (vp->v_type == VDIR) {
719 			if (delta < mi->mi_acdirmin)
720 				delta = mi->mi_acdirmin;
721 			else if (delta > mi->mi_acdirmax)
722 				delta = mi->mi_acdirmax;
723 		} else {
724 			if (delta < mi->mi_acregmin)
725 				delta = mi->mi_acregmin;
726 			else if (delta > mi->mi_acregmax)
727 				delta = mi->mi_acregmax;
728 		}
729 	}
730 	rp->r_attrtime = now + delta;
731 	rp->r_attr = *va;
732 	/*
733 	 * Update the size of the file if there is no cached data or if
734 	 * the cached data is clean and there is no data being written
735 	 * out.
736 	 */
737 	if (rp->r_size != va->va_size &&
738 	    (!vn_has_cached_data(vp) ||
739 	    (!(rp->r_flags & RDIRTY) && rp->r_count == 0)))
740 		rp->r_size = va->va_size;
741 	nfs_setswaplike(vp, va);
742 	rp->r_flags &= ~RWRITEATTR;
743 }
744 
745 /*
746  * Fill in attribute from the cache.
747  * If valid, then return 0 to indicate that no error occurred,
748  * otherwise return 1 to indicate that an error occurred.
749  */
750 static int
751 nfs_getattr_cache(vnode_t *vp, struct vattr *vap)
752 {
753 	rnode_t *rp;
754 
755 	rp = VTOR(vp);
756 	mutex_enter(&rp->r_statelock);
757 	if (ATTRCACHE_VALID(vp)) {
758 		/*
759 		 * Cached attributes are valid
760 		 */
761 		*vap = rp->r_attr;
762 		mutex_exit(&rp->r_statelock);
763 		return (0);
764 	}
765 	mutex_exit(&rp->r_statelock);
766 	return (1);
767 }
768 
769 /*
770  * Get attributes over-the-wire and update attributes cache
771  * if no error occurred in the over-the-wire operation.
772  * Return 0 if successful, otherwise error.
773  */
774 int
775 nfs_getattr_otw(vnode_t *vp, struct vattr *vap, cred_t *cr)
776 {
777 	int error;
778 	struct nfsattrstat ns;
779 	int douprintf;
780 	mntinfo_t *mi;
781 	failinfo_t fi;
782 	hrtime_t t;
783 
784 	mi = VTOMI(vp);
785 	fi.vp = vp;
786 	fi.fhp = NULL;		/* no need to update, filehandle not copied */
787 	fi.copyproc = nfscopyfh;
788 	fi.lookupproc = nfslookup;
789 	fi.xattrdirproc = acl_getxattrdir2;
790 
791 	if (mi->mi_flags & MI_ACL) {
792 		error = acl_getattr2_otw(vp, vap, cr);
793 		if (mi->mi_flags & MI_ACL)
794 			return (error);
795 	}
796 
797 	douprintf = 1;
798 
799 	t = gethrtime();
800 
801 	error = rfs2call(mi, RFS_GETATTR,
802 			xdr_fhandle, (caddr_t)VTOFH(vp),
803 			xdr_attrstat, (caddr_t)&ns, cr,
804 			&douprintf, &ns.ns_status, 0, &fi);
805 
806 	if (!error) {
807 		error = geterrno(ns.ns_status);
808 		if (!error)
809 			error = nfs_cache_fattr(vp, &ns.ns_attr, vap, t, cr);
810 		else {
811 			PURGE_STALE_FH(error, vp, cr);
812 		}
813 	}
814 
815 	return (error);
816 }
817 
818 /*
819  * Return either cached ot remote attributes. If get remote attr
820  * use them to check and invalidate caches, then cache the new attributes.
821  */
822 int
823 nfsgetattr(vnode_t *vp, struct vattr *vap, cred_t *cr)
824 {
825 	int error;
826 	rnode_t *rp;
827 
828 	/*
829 	 * If we've got cached attributes, we're done, otherwise go
830 	 * to the server to get attributes, which will update the cache
831 	 * in the process.
832 	 */
833 	error = nfs_getattr_cache(vp, vap);
834 	if (error)
835 		error = nfs_getattr_otw(vp, vap, cr);
836 
837 	/* Return the client's view of file size */
838 	rp = VTOR(vp);
839 	mutex_enter(&rp->r_statelock);
840 	vap->va_size = rp->r_size;
841 	mutex_exit(&rp->r_statelock);
842 
843 	return (error);
844 }
845 
846 /*
847  * Get attributes over-the-wire and update attributes cache
848  * if no error occurred in the over-the-wire operation.
849  * Return 0 if successful, otherwise error.
850  */
851 int
852 nfs3_getattr_otw(vnode_t *vp, struct vattr *vap, cred_t *cr)
853 {
854 	int error;
855 	GETATTR3args args;
856 	GETATTR3vres res;
857 	int douprintf;
858 	failinfo_t fi;
859 	hrtime_t t;
860 
861 	args.object = *VTOFH3(vp);
862 	fi.vp = vp;
863 	fi.fhp = (caddr_t)&args.object;
864 	fi.copyproc = nfs3copyfh;
865 	fi.lookupproc = nfs3lookup;
866 	fi.xattrdirproc = acl_getxattrdir3;
867 	res.fres.vp = vp;
868 	res.fres.vap = vap;
869 
870 	douprintf = 1;
871 
872 	t = gethrtime();
873 
874 	error = rfs3call(VTOMI(vp), NFSPROC3_GETATTR,
875 	    xdr_nfs_fh3, (caddr_t)&args,
876 	    xdr_GETATTR3vres, (caddr_t)&res, cr,
877 	    &douprintf, &res.status, 0, &fi);
878 
879 	if (error)
880 		return (error);
881 
882 	error = geterrno3(res.status);
883 	if (error) {
884 		PURGE_STALE_FH(error, vp, cr);
885 		return (error);
886 	}
887 
888 	/*
889 	 * Catch status codes that indicate fattr3 to vattr translation failure
890 	 */
891 	if (res.fres.status)
892 		return (res.fres.status);
893 
894 	nfs_attr_cache(vp, vap, t, cr);
895 	return (0);
896 }
897 
898 /*
899  * Return either cached or remote attributes. If get remote attr
900  * use them to check and invalidate caches, then cache the new attributes.
901  */
902 int
903 nfs3getattr(vnode_t *vp, struct vattr *vap, cred_t *cr)
904 {
905 	int error;
906 	rnode_t *rp;
907 
908 	/*
909 	 * If we've got cached attributes, we're done, otherwise go
910 	 * to the server to get attributes, which will update the cache
911 	 * in the process.
912 	 */
913 	error = nfs_getattr_cache(vp, vap);
914 	if (error)
915 		error = nfs3_getattr_otw(vp, vap, cr);
916 
917 	/* Return the client's view of file size */
918 	rp = VTOR(vp);
919 	mutex_enter(&rp->r_statelock);
920 	vap->va_size = rp->r_size;
921 	mutex_exit(&rp->r_statelock);
922 
923 	return (error);
924 }
925 
926 vtype_t nf_to_vt[] = {
927 	VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK
928 };
929 /*
930  * Convert NFS Version 2 over the network attributes to the local
931  * virtual attributes.  The mapping between the UID_NOBODY/GID_NOBODY
932  * network representation and the local representation is done here.
933  * Returns 0 for success, error if failed due to overflow.
934  */
935 int
936 nattr_to_vattr(vnode_t *vp, struct nfsfattr *na, struct vattr *vap)
937 {
938 	/* overflow in time attributes? */
939 #ifndef _LP64
940 	if (!NFS2_FATTR_TIME_OK(na))
941 		return (EOVERFLOW);
942 #endif
943 
944 	if (na->na_type < NFNON || na->na_type > NFSOC)
945 		vap->va_type = VBAD;
946 	else
947 		vap->va_type = nf_to_vt[na->na_type];
948 	vap->va_mode = na->na_mode;
949 	vap->va_uid = (na->na_uid == NFS_UID_NOBODY) ? UID_NOBODY : na->na_uid;
950 	vap->va_gid = (na->na_gid == NFS_GID_NOBODY) ? GID_NOBODY : na->na_gid;
951 	vap->va_fsid = vp->v_vfsp->vfs_dev;
952 	vap->va_nodeid = na->na_nodeid;
953 	vap->va_nlink = na->na_nlink;
954 	vap->va_size = na->na_size;	/* keep for cache validation */
955 	/*
956 	 * nfs protocol defines times as unsigned so don't extend sign,
957 	 * unless sysadmin set nfs_allow_preepoch_time.
958 	 */
959 	NFS_TIME_T_CONVERT(vap->va_atime.tv_sec, na->na_atime.tv_sec);
960 	vap->va_atime.tv_nsec = (uint32_t)(na->na_atime.tv_usec * 1000);
961 	NFS_TIME_T_CONVERT(vap->va_mtime.tv_sec, na->na_mtime.tv_sec);
962 	vap->va_mtime.tv_nsec = (uint32_t)(na->na_mtime.tv_usec * 1000);
963 	NFS_TIME_T_CONVERT(vap->va_ctime.tv_sec, na->na_ctime.tv_sec);
964 	vap->va_ctime.tv_nsec = (uint32_t)(na->na_ctime.tv_usec * 1000);
965 	/*
966 	 * Shannon's law - uncompress the received dev_t
967 	 * if the top half of is zero indicating a response
968 	 * from an `older style' OS. Except for when it is a
969 	 * `new style' OS sending the maj device of zero,
970 	 * in which case the algorithm still works because the
971 	 * fact that it is a new style server
972 	 * is hidden by the minor device not being greater
973 	 * than 255 (a requirement in this case).
974 	 */
975 	if ((na->na_rdev & 0xffff0000) == 0)
976 		vap->va_rdev = nfsv2_expdev(na->na_rdev);
977 	else
978 		vap->va_rdev = expldev(na->na_rdev);
979 
980 	vap->va_nblocks = na->na_blocks;
981 	switch (na->na_type) {
982 	case NFBLK:
983 		vap->va_blksize = DEV_BSIZE;
984 		break;
985 
986 	case NFCHR:
987 		vap->va_blksize = MAXBSIZE;
988 		break;
989 
990 	case NFSOC:
991 	default:
992 		vap->va_blksize = na->na_blocksize;
993 		break;
994 	}
995 	/*
996 	 * This bit of ugliness is a hack to preserve the
997 	 * over-the-wire protocols for named-pipe vnodes.
998 	 * It remaps the special over-the-wire type to the
999 	 * VFIFO type. (see note in nfs.h)
1000 	 */
1001 	if (NA_ISFIFO(na)) {
1002 		vap->va_type = VFIFO;
1003 		vap->va_mode = (vap->va_mode & ~S_IFMT) | S_IFIFO;
1004 		vap->va_rdev = 0;
1005 		vap->va_blksize = na->na_blocksize;
1006 	}
1007 	vap->va_seq = 0;
1008 	return (0);
1009 }
1010 
1011 /*
1012  * Convert NFS Version 3 over the network attributes to the local
1013  * virtual attributes.  The mapping between the UID_NOBODY/GID_NOBODY
1014  * network representation and the local representation is done here.
1015  */
1016 vtype_t nf3_to_vt[] = {
1017 	VBAD, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK, VFIFO
1018 };
1019 
1020 int
1021 fattr3_to_vattr(vnode_t *vp, fattr3 *na, struct vattr *vap)
1022 {
1023 
1024 #ifndef _LP64
1025 	/* overflow in time attributes? */
1026 	if (!NFS3_FATTR_TIME_OK(na))
1027 		return (EOVERFLOW);
1028 #endif
1029 	if (!NFS3_SIZE_OK(na->size))
1030 		/* file too big */
1031 		return (EFBIG);
1032 
1033 	vap->va_mask = AT_ALL;
1034 
1035 	if (na->type < NF3REG || na->type > NF3FIFO)
1036 		vap->va_type = VBAD;
1037 	else
1038 		vap->va_type = nf3_to_vt[na->type];
1039 	vap->va_mode = na->mode;
1040 	vap->va_uid = (na->uid == NFS_UID_NOBODY) ? UID_NOBODY : (uid_t)na->uid;
1041 	vap->va_gid = (na->gid == NFS_GID_NOBODY) ? GID_NOBODY : (gid_t)na->gid;
1042 	vap->va_fsid = vp->v_vfsp->vfs_dev;
1043 	vap->va_nodeid = na->fileid;
1044 	vap->va_nlink = na->nlink;
1045 	vap->va_size = na->size;
1046 
1047 	/*
1048 	 * nfs protocol defines times as unsigned so don't extend sign,
1049 	 * unless sysadmin set nfs_allow_preepoch_time.
1050 	 */
1051 	NFS_TIME_T_CONVERT(vap->va_atime.tv_sec, na->atime.seconds);
1052 	vap->va_atime.tv_nsec = (uint32_t)na->atime.nseconds;
1053 	NFS_TIME_T_CONVERT(vap->va_mtime.tv_sec, na->mtime.seconds);
1054 	vap->va_mtime.tv_nsec = (uint32_t)na->mtime.nseconds;
1055 	NFS_TIME_T_CONVERT(vap->va_ctime.tv_sec, na->ctime.seconds);
1056 	vap->va_ctime.tv_nsec = (uint32_t)na->ctime.nseconds;
1057 
1058 	switch (na->type) {
1059 	case NF3BLK:
1060 		vap->va_rdev = makedevice(na->rdev.specdata1,
1061 					na->rdev.specdata2);
1062 		vap->va_blksize = DEV_BSIZE;
1063 		vap->va_nblocks = 0;
1064 		break;
1065 	case NF3CHR:
1066 		vap->va_rdev = makedevice(na->rdev.specdata1,
1067 					na->rdev.specdata2);
1068 		vap->va_blksize = MAXBSIZE;
1069 		vap->va_nblocks = 0;
1070 		break;
1071 	case NF3REG:
1072 	case NF3DIR:
1073 	case NF3LNK:
1074 		vap->va_rdev = 0;
1075 		vap->va_blksize = MAXBSIZE;
1076 		vap->va_nblocks = (u_longlong_t)
1077 		    ((na->used + (size3)DEV_BSIZE - (size3)1) /
1078 		    (size3)DEV_BSIZE);
1079 		break;
1080 	case NF3SOCK:
1081 	case NF3FIFO:
1082 	default:
1083 		vap->va_rdev = 0;
1084 		vap->va_blksize = MAXBSIZE;
1085 		vap->va_nblocks = 0;
1086 		break;
1087 	}
1088 	vap->va_seq = 0;
1089 	return (0);
1090 }
1091 
1092 /*
1093  * Asynchronous I/O parameters.  nfs_async_threads is the high-water mark
1094  * for the demand-based allocation of async threads per-mount.  The
1095  * nfs_async_timeout is the amount of time a thread will live after it
1096  * becomes idle, unless new I/O requests are received before the thread
1097  * dies.  See nfs_async_putpage and nfs_async_start.
1098  */
1099 
1100 int nfs_async_timeout = -1;	/* uninitialized */
1101 
1102 static void	nfs_async_start(struct vfs *);
1103 
1104 static void
1105 free_async_args(struct nfs_async_reqs *args)
1106 {
1107 	rnode_t *rp;
1108 
1109 	if (args->a_io != NFS_INACTIVE) {
1110 		rp = VTOR(args->a_vp);
1111 		mutex_enter(&rp->r_statelock);
1112 		rp->r_count--;
1113 		if (args->a_io == NFS_PUTAPAGE ||
1114 		    args->a_io == NFS_PAGEIO)
1115 			rp->r_awcount--;
1116 		cv_broadcast(&rp->r_cv);
1117 		mutex_exit(&rp->r_statelock);
1118 		VN_RELE(args->a_vp);
1119 	}
1120 	crfree(args->a_cred);
1121 	kmem_free(args, sizeof (*args));
1122 }
1123 
1124 /*
1125  * Cross-zone thread creation and NFS access is disallowed, yet fsflush() and
1126  * pageout(), running in the global zone, have legitimate reasons to do
1127  * VOP_PUTPAGE(B_ASYNC) on other zones' NFS mounts.  We avoid the problem by
1128  * use of a a per-mount "asynchronous requests manager thread" which is
1129  * signaled by the various asynchronous work routines when there is
1130  * asynchronous work to be done.  It is responsible for creating new
1131  * worker threads if necessary, and notifying existing worker threads
1132  * that there is work to be done.
1133  *
1134  * In other words, it will "take the specifications from the customers and
1135  * give them to the engineers."
1136  *
1137  * Worker threads die off of their own accord if they are no longer
1138  * needed.
1139  *
1140  * This thread is killed when the zone is going away or the filesystem
1141  * is being unmounted.
1142  */
1143 void
1144 nfs_async_manager(vfs_t *vfsp)
1145 {
1146 	callb_cpr_t cprinfo;
1147 	mntinfo_t *mi;
1148 	uint_t max_threads;
1149 
1150 	mi = VFTOMI(vfsp);
1151 
1152 	CALLB_CPR_INIT(&cprinfo, &mi->mi_async_lock, callb_generic_cpr,
1153 		    "nfs_async_manager");
1154 
1155 	mutex_enter(&mi->mi_async_lock);
1156 	/*
1157 	 * We want to stash the max number of threads that this mount was
1158 	 * allowed so we can use it later when the variable is set to zero as
1159 	 * part of the zone/mount going away.
1160 	 *
1161 	 * We want to be able to create at least one thread to handle
1162 	 * asyncrhonous inactive calls.
1163 	 */
1164 	max_threads = MAX(mi->mi_max_threads, 1);
1165 	mutex_enter(&mi->mi_lock);
1166 	/*
1167 	 * We don't want to wait for mi_max_threads to go to zero, since that
1168 	 * happens as part of a failed unmount, but this thread should only
1169 	 * exit when the mount/zone is really going away.
1170 	 *
1171 	 * Once MI_ASYNC_MGR_STOP is set, no more async operations will be
1172 	 * attempted: the various _async_*() functions know to do things
1173 	 * inline if mi_max_threads == 0.  Henceforth we just drain out the
1174 	 * outstanding requests.
1175 	 *
1176 	 * Note that we still create zthreads even if we notice the zone is
1177 	 * shutting down (MI_ASYNC_MGR_STOP is set); this may cause the zone
1178 	 * shutdown sequence to take slightly longer in some cases, but
1179 	 * doesn't violate the protocol, as all threads will exit as soon as
1180 	 * they're done processing the remaining requests.
1181 	 */
1182 	while (!(mi->mi_flags & MI_ASYNC_MGR_STOP) ||
1183 	    mi->mi_async_req_count > 0) {
1184 		mutex_exit(&mi->mi_lock);
1185 		CALLB_CPR_SAFE_BEGIN(&cprinfo);
1186 		cv_wait(&mi->mi_async_reqs_cv, &mi->mi_async_lock);
1187 		CALLB_CPR_SAFE_END(&cprinfo, &mi->mi_async_lock);
1188 		while (mi->mi_async_req_count > 0) {
1189 			/*
1190 			 * Paranoia: If the mount started out having
1191 			 * (mi->mi_max_threads == 0), and the value was
1192 			 * later changed (via a debugger or somesuch),
1193 			 * we could be confused since we will think we
1194 			 * can't create any threads, and the calling
1195 			 * code (which looks at the current value of
1196 			 * mi->mi_max_threads, now non-zero) thinks we
1197 			 * can.
1198 			 *
1199 			 * So, because we're paranoid, we create threads
1200 			 * up to the maximum of the original and the
1201 			 * current value. This means that future
1202 			 * (debugger-induced) lowerings of
1203 			 * mi->mi_max_threads are ignored for our
1204 			 * purposes, but who told them they could change
1205 			 * random values on a live kernel anyhow?
1206 			 */
1207 			if (mi->mi_threads <
1208 			    MAX(mi->mi_max_threads, max_threads)) {
1209 				mi->mi_threads++;
1210 				mutex_exit(&mi->mi_async_lock);
1211 				VFS_HOLD(vfsp);	/* hold for new thread */
1212 				(void) zthread_create(NULL, 0, nfs_async_start,
1213 				    vfsp, 0, minclsyspri);
1214 				mutex_enter(&mi->mi_async_lock);
1215 			}
1216 			cv_signal(&mi->mi_async_work_cv);
1217 			ASSERT(mi->mi_async_req_count != 0);
1218 			mi->mi_async_req_count--;
1219 		}
1220 		mutex_enter(&mi->mi_lock);
1221 	}
1222 	mutex_exit(&mi->mi_lock);
1223 	/*
1224 	 * Let everyone know we're done.
1225 	 */
1226 	mi->mi_manager_thread = NULL;
1227 	cv_broadcast(&mi->mi_async_cv);
1228 
1229 	/*
1230 	 * There is no explicit call to mutex_exit(&mi->mi_async_lock)
1231 	 * since CALLB_CPR_EXIT is actually responsible for releasing
1232 	 * 'mi_async_lock'.
1233 	 */
1234 	CALLB_CPR_EXIT(&cprinfo);
1235 	VFS_RELE(vfsp);	/* release thread's hold */
1236 	zthread_exit();
1237 }
1238 
1239 /*
1240  * Signal (and wait for) the async manager thread to clean up and go away.
1241  */
1242 void
1243 nfs_async_manager_stop(vfs_t *vfsp)
1244 {
1245 	mntinfo_t *mi = VFTOMI(vfsp);
1246 
1247 	mutex_enter(&mi->mi_async_lock);
1248 	mutex_enter(&mi->mi_lock);
1249 	mi->mi_flags |= MI_ASYNC_MGR_STOP;
1250 	mutex_exit(&mi->mi_lock);
1251 	cv_broadcast(&mi->mi_async_reqs_cv);
1252 	while (mi->mi_manager_thread != NULL)
1253 		cv_wait(&mi->mi_async_cv, &mi->mi_async_lock);
1254 	mutex_exit(&mi->mi_async_lock);
1255 }
1256 
1257 int
1258 nfs_async_readahead(vnode_t *vp, u_offset_t blkoff, caddr_t addr,
1259 	struct seg *seg, cred_t *cr, void (*readahead)(vnode_t *,
1260 	u_offset_t, caddr_t, struct seg *, cred_t *))
1261 {
1262 	rnode_t *rp;
1263 	mntinfo_t *mi;
1264 	struct nfs_async_reqs *args;
1265 
1266 	rp = VTOR(vp);
1267 	ASSERT(rp->r_freef == NULL);
1268 
1269 	mi = VTOMI(vp);
1270 
1271 	/*
1272 	 * If addr falls in a different segment, don't bother doing readahead.
1273 	 */
1274 	if (addr >= seg->s_base + seg->s_size)
1275 		return (-1);
1276 
1277 	/*
1278 	 * If we can't allocate a request structure, punt on the readahead.
1279 	 */
1280 	if ((args = kmem_alloc(sizeof (*args), KM_NOSLEEP)) == NULL)
1281 		return (-1);
1282 
1283 	/*
1284 	 * If a lock operation is pending, don't initiate any new
1285 	 * readaheads.  Otherwise, bump r_count to indicate the new
1286 	 * asynchronous I/O.
1287 	 */
1288 	if (!nfs_rw_tryenter(&rp->r_lkserlock, RW_READER)) {
1289 		kmem_free(args, sizeof (*args));
1290 		return (-1);
1291 	}
1292 	mutex_enter(&rp->r_statelock);
1293 	rp->r_count++;
1294 	mutex_exit(&rp->r_statelock);
1295 	nfs_rw_exit(&rp->r_lkserlock);
1296 
1297 	args->a_next = NULL;
1298 #ifdef DEBUG
1299 	args->a_queuer = curthread;
1300 #endif
1301 	VN_HOLD(vp);
1302 	args->a_vp = vp;
1303 	ASSERT(cr != NULL);
1304 	crhold(cr);
1305 	args->a_cred = cr;
1306 	args->a_io = NFS_READ_AHEAD;
1307 	args->a_nfs_readahead = readahead;
1308 	args->a_nfs_blkoff = blkoff;
1309 	args->a_nfs_seg = seg;
1310 	args->a_nfs_addr = addr;
1311 
1312 	mutex_enter(&mi->mi_async_lock);
1313 
1314 	/*
1315 	 * If asyncio has been disabled, don't bother readahead.
1316 	 */
1317 	if (mi->mi_max_threads == 0) {
1318 		mutex_exit(&mi->mi_async_lock);
1319 		goto noasync;
1320 	}
1321 
1322 	/*
1323 	 * Link request structure into the async list and
1324 	 * wakeup async thread to do the i/o.
1325 	 */
1326 	if (mi->mi_async_reqs[NFS_READ_AHEAD] == NULL) {
1327 		mi->mi_async_reqs[NFS_READ_AHEAD] = args;
1328 		mi->mi_async_tail[NFS_READ_AHEAD] = args;
1329 	} else {
1330 		mi->mi_async_tail[NFS_READ_AHEAD]->a_next = args;
1331 		mi->mi_async_tail[NFS_READ_AHEAD] = args;
1332 	}
1333 
1334 	if (mi->mi_io_kstats) {
1335 		mutex_enter(&mi->mi_lock);
1336 		kstat_waitq_enter(KSTAT_IO_PTR(mi->mi_io_kstats));
1337 		mutex_exit(&mi->mi_lock);
1338 	}
1339 
1340 	mi->mi_async_req_count++;
1341 	ASSERT(mi->mi_async_req_count != 0);
1342 	cv_signal(&mi->mi_async_reqs_cv);
1343 	mutex_exit(&mi->mi_async_lock);
1344 	return (0);
1345 
1346 noasync:
1347 	mutex_enter(&rp->r_statelock);
1348 	rp->r_count--;
1349 	cv_broadcast(&rp->r_cv);
1350 	mutex_exit(&rp->r_statelock);
1351 	VN_RELE(vp);
1352 	crfree(cr);
1353 	kmem_free(args, sizeof (*args));
1354 	return (-1);
1355 }
1356 
1357 int
1358 nfs_async_putapage(vnode_t *vp, page_t *pp, u_offset_t off, size_t len,
1359 	int flags, cred_t *cr, int (*putapage)(vnode_t *, page_t *,
1360 	u_offset_t, size_t, int, cred_t *))
1361 {
1362 	rnode_t *rp;
1363 	mntinfo_t *mi;
1364 	struct nfs_async_reqs *args;
1365 
1366 	ASSERT(flags & B_ASYNC);
1367 	ASSERT(vp->v_vfsp != NULL);
1368 
1369 	rp = VTOR(vp);
1370 	ASSERT(rp->r_count > 0);
1371 
1372 	mi = VTOMI(vp);
1373 
1374 	/*
1375 	 * If we can't allocate a request structure, do the putpage
1376 	 * operation synchronously in this thread's context.
1377 	 */
1378 	if ((args = kmem_alloc(sizeof (*args), KM_NOSLEEP)) == NULL)
1379 		goto noasync;
1380 
1381 	args->a_next = NULL;
1382 #ifdef DEBUG
1383 	args->a_queuer = curthread;
1384 #endif
1385 	VN_HOLD(vp);
1386 	args->a_vp = vp;
1387 	ASSERT(cr != NULL);
1388 	crhold(cr);
1389 	args->a_cred = cr;
1390 	args->a_io = NFS_PUTAPAGE;
1391 	args->a_nfs_putapage = putapage;
1392 	args->a_nfs_pp = pp;
1393 	args->a_nfs_off = off;
1394 	args->a_nfs_len = (uint_t)len;
1395 	args->a_nfs_flags = flags;
1396 
1397 	mutex_enter(&mi->mi_async_lock);
1398 
1399 	/*
1400 	 * If asyncio has been disabled, then make a synchronous request.
1401 	 * This check is done a second time in case async io was diabled
1402 	 * while this thread was blocked waiting for memory pressure to
1403 	 * reduce or for the queue to drain.
1404 	 */
1405 	if (mi->mi_max_threads == 0) {
1406 		mutex_exit(&mi->mi_async_lock);
1407 		goto noasync;
1408 	}
1409 
1410 	/*
1411 	 * Link request structure into the async list and
1412 	 * wakeup async thread to do the i/o.
1413 	 */
1414 	if (mi->mi_async_reqs[NFS_PUTAPAGE] == NULL) {
1415 		mi->mi_async_reqs[NFS_PUTAPAGE] = args;
1416 		mi->mi_async_tail[NFS_PUTAPAGE] = args;
1417 	} else {
1418 		mi->mi_async_tail[NFS_PUTAPAGE]->a_next = args;
1419 		mi->mi_async_tail[NFS_PUTAPAGE] = args;
1420 	}
1421 
1422 	mutex_enter(&rp->r_statelock);
1423 	rp->r_count++;
1424 	rp->r_awcount++;
1425 	mutex_exit(&rp->r_statelock);
1426 
1427 	if (mi->mi_io_kstats) {
1428 		mutex_enter(&mi->mi_lock);
1429 		kstat_waitq_enter(KSTAT_IO_PTR(mi->mi_io_kstats));
1430 		mutex_exit(&mi->mi_lock);
1431 	}
1432 
1433 	mi->mi_async_req_count++;
1434 	ASSERT(mi->mi_async_req_count != 0);
1435 	cv_signal(&mi->mi_async_reqs_cv);
1436 	mutex_exit(&mi->mi_async_lock);
1437 	return (0);
1438 
1439 noasync:
1440 	if (args != NULL) {
1441 		VN_RELE(vp);
1442 		crfree(cr);
1443 		kmem_free(args, sizeof (*args));
1444 	}
1445 
1446 	if (curproc == proc_pageout || curproc == proc_fsflush) {
1447 		/*
1448 		 * If we get here in the context of the pageout/fsflush,
1449 		 * we refuse to do a sync write, because this may hang
1450 		 * pageout (and the machine). In this case, we just
1451 		 * re-mark the page as dirty and punt on the page.
1452 		 *
1453 		 * Make sure B_FORCE isn't set.  We can re-mark the
1454 		 * pages as dirty and unlock the pages in one swoop by
1455 		 * passing in B_ERROR to pvn_write_done().  However,
1456 		 * we should make sure B_FORCE isn't set - we don't
1457 		 * want the page tossed before it gets written out.
1458 		 */
1459 		if (flags & B_FORCE)
1460 			flags &= ~(B_INVAL | B_FORCE);
1461 		pvn_write_done(pp, flags | B_ERROR);
1462 		return (0);
1463 	}
1464 	if (nfs_zone() != mi->mi_zone) {
1465 		/*
1466 		 * So this was a cross-zone sync putpage.  We pass in B_ERROR
1467 		 * to pvn_write_done() to re-mark the pages as dirty and unlock
1468 		 * them.
1469 		 *
1470 		 * We don't want to clear B_FORCE here as the caller presumably
1471 		 * knows what they're doing if they set it.
1472 		 */
1473 		pvn_write_done(pp, flags | B_ERROR);
1474 		return (EPERM);
1475 	}
1476 	return ((*putapage)(vp, pp, off, len, flags, cr));
1477 }
1478 
1479 int
1480 nfs_async_pageio(vnode_t *vp, page_t *pp, u_offset_t io_off, size_t io_len,
1481 	int flags, cred_t *cr, int (*pageio)(vnode_t *, page_t *, u_offset_t,
1482 	size_t, int, cred_t *))
1483 {
1484 	rnode_t *rp;
1485 	mntinfo_t *mi;
1486 	struct nfs_async_reqs *args;
1487 
1488 	ASSERT(flags & B_ASYNC);
1489 	ASSERT(vp->v_vfsp != NULL);
1490 
1491 	rp = VTOR(vp);
1492 	ASSERT(rp->r_count > 0);
1493 
1494 	mi = VTOMI(vp);
1495 
1496 	/*
1497 	 * If we can't allocate a request structure, do the pageio
1498 	 * request synchronously in this thread's context.
1499 	 */
1500 	if ((args = kmem_alloc(sizeof (*args), KM_NOSLEEP)) == NULL)
1501 		goto noasync;
1502 
1503 	args->a_next = NULL;
1504 #ifdef DEBUG
1505 	args->a_queuer = curthread;
1506 #endif
1507 	VN_HOLD(vp);
1508 	args->a_vp = vp;
1509 	ASSERT(cr != NULL);
1510 	crhold(cr);
1511 	args->a_cred = cr;
1512 	args->a_io = NFS_PAGEIO;
1513 	args->a_nfs_pageio = pageio;
1514 	args->a_nfs_pp = pp;
1515 	args->a_nfs_off = io_off;
1516 	args->a_nfs_len = (uint_t)io_len;
1517 	args->a_nfs_flags = flags;
1518 
1519 	mutex_enter(&mi->mi_async_lock);
1520 
1521 	/*
1522 	 * If asyncio has been disabled, then make a synchronous request.
1523 	 * This check is done a second time in case async io was diabled
1524 	 * while this thread was blocked waiting for memory pressure to
1525 	 * reduce or for the queue to drain.
1526 	 */
1527 	if (mi->mi_max_threads == 0) {
1528 		mutex_exit(&mi->mi_async_lock);
1529 		goto noasync;
1530 	}
1531 
1532 	/*
1533 	 * Link request structure into the async list and
1534 	 * wakeup async thread to do the i/o.
1535 	 */
1536 	if (mi->mi_async_reqs[NFS_PAGEIO] == NULL) {
1537 		mi->mi_async_reqs[NFS_PAGEIO] = args;
1538 		mi->mi_async_tail[NFS_PAGEIO] = args;
1539 	} else {
1540 		mi->mi_async_tail[NFS_PAGEIO]->a_next = args;
1541 		mi->mi_async_tail[NFS_PAGEIO] = args;
1542 	}
1543 
1544 	mutex_enter(&rp->r_statelock);
1545 	rp->r_count++;
1546 	rp->r_awcount++;
1547 	mutex_exit(&rp->r_statelock);
1548 
1549 	if (mi->mi_io_kstats) {
1550 		mutex_enter(&mi->mi_lock);
1551 		kstat_waitq_enter(KSTAT_IO_PTR(mi->mi_io_kstats));
1552 		mutex_exit(&mi->mi_lock);
1553 	}
1554 
1555 	mi->mi_async_req_count++;
1556 	ASSERT(mi->mi_async_req_count != 0);
1557 	cv_signal(&mi->mi_async_reqs_cv);
1558 	mutex_exit(&mi->mi_async_lock);
1559 	return (0);
1560 
1561 noasync:
1562 	if (args != NULL) {
1563 		VN_RELE(vp);
1564 		crfree(cr);
1565 		kmem_free(args, sizeof (*args));
1566 	}
1567 
1568 	/*
1569 	 * If we can't do it ASYNC, for reads we do nothing (but cleanup
1570 	 * the page list), for writes we do it synchronously, except for
1571 	 * proc_pageout/proc_fsflush as described below.
1572 	 */
1573 	if (flags & B_READ) {
1574 		pvn_read_done(pp, flags | B_ERROR);
1575 		return (0);
1576 	}
1577 
1578 	if (curproc == proc_pageout || curproc == proc_fsflush) {
1579 		/*
1580 		 * If we get here in the context of the pageout/fsflush,
1581 		 * we refuse to do a sync write, because this may hang
1582 		 * pageout/fsflush (and the machine). In this case, we just
1583 		 * re-mark the page as dirty and punt on the page.
1584 		 *
1585 		 * Make sure B_FORCE isn't set.  We can re-mark the
1586 		 * pages as dirty and unlock the pages in one swoop by
1587 		 * passing in B_ERROR to pvn_write_done().  However,
1588 		 * we should make sure B_FORCE isn't set - we don't
1589 		 * want the page tossed before it gets written out.
1590 		 */
1591 		if (flags & B_FORCE)
1592 			flags &= ~(B_INVAL | B_FORCE);
1593 		pvn_write_done(pp, flags | B_ERROR);
1594 		return (0);
1595 	}
1596 
1597 	if (nfs_zone() != mi->mi_zone) {
1598 		/*
1599 		 * So this was a cross-zone sync pageio.  We pass in B_ERROR
1600 		 * to pvn_write_done() to re-mark the pages as dirty and unlock
1601 		 * them.
1602 		 *
1603 		 * We don't want to clear B_FORCE here as the caller presumably
1604 		 * knows what they're doing if they set it.
1605 		 */
1606 		pvn_write_done(pp, flags | B_ERROR);
1607 		return (EPERM);
1608 	}
1609 	return ((*pageio)(vp, pp, io_off, io_len, flags, cr));
1610 }
1611 
1612 void
1613 nfs_async_readdir(vnode_t *vp, rddir_cache *rdc, cred_t *cr,
1614 	int (*readdir)(vnode_t *, rddir_cache *, cred_t *))
1615 {
1616 	rnode_t *rp;
1617 	mntinfo_t *mi;
1618 	struct nfs_async_reqs *args;
1619 
1620 	rp = VTOR(vp);
1621 	ASSERT(rp->r_freef == NULL);
1622 
1623 	mi = VTOMI(vp);
1624 
1625 	/*
1626 	 * If we can't allocate a request structure, do the readdir
1627 	 * operation synchronously in this thread's context.
1628 	 */
1629 	if ((args = kmem_alloc(sizeof (*args), KM_NOSLEEP)) == NULL)
1630 		goto noasync;
1631 
1632 	args->a_next = NULL;
1633 #ifdef DEBUG
1634 	args->a_queuer = curthread;
1635 #endif
1636 	VN_HOLD(vp);
1637 	args->a_vp = vp;
1638 	ASSERT(cr != NULL);
1639 	crhold(cr);
1640 	args->a_cred = cr;
1641 	args->a_io = NFS_READDIR;
1642 	args->a_nfs_readdir = readdir;
1643 	args->a_nfs_rdc = rdc;
1644 
1645 	mutex_enter(&mi->mi_async_lock);
1646 
1647 	/*
1648 	 * If asyncio has been disabled, then make a synchronous request.
1649 	 */
1650 	if (mi->mi_max_threads == 0) {
1651 		mutex_exit(&mi->mi_async_lock);
1652 		goto noasync;
1653 	}
1654 
1655 	/*
1656 	 * Link request structure into the async list and
1657 	 * wakeup async thread to do the i/o.
1658 	 */
1659 	if (mi->mi_async_reqs[NFS_READDIR] == NULL) {
1660 		mi->mi_async_reqs[NFS_READDIR] = args;
1661 		mi->mi_async_tail[NFS_READDIR] = args;
1662 	} else {
1663 		mi->mi_async_tail[NFS_READDIR]->a_next = args;
1664 		mi->mi_async_tail[NFS_READDIR] = args;
1665 	}
1666 
1667 	mutex_enter(&rp->r_statelock);
1668 	rp->r_count++;
1669 	mutex_exit(&rp->r_statelock);
1670 
1671 	if (mi->mi_io_kstats) {
1672 		mutex_enter(&mi->mi_lock);
1673 		kstat_waitq_enter(KSTAT_IO_PTR(mi->mi_io_kstats));
1674 		mutex_exit(&mi->mi_lock);
1675 	}
1676 
1677 	mi->mi_async_req_count++;
1678 	ASSERT(mi->mi_async_req_count != 0);
1679 	cv_signal(&mi->mi_async_reqs_cv);
1680 	mutex_exit(&mi->mi_async_lock);
1681 	return;
1682 
1683 noasync:
1684 	if (args != NULL) {
1685 		VN_RELE(vp);
1686 		crfree(cr);
1687 		kmem_free(args, sizeof (*args));
1688 	}
1689 
1690 	rdc->entries = NULL;
1691 	mutex_enter(&rp->r_statelock);
1692 	ASSERT(rdc->flags & RDDIR);
1693 	rdc->flags &= ~RDDIR;
1694 	rdc->flags |= RDDIRREQ;
1695 	/*
1696 	 * Check the flag to see if RDDIRWAIT is set. If RDDIRWAIT
1697 	 * is set, wakeup the thread sleeping in cv_wait_sig().
1698 	 * The woken up thread will reset the flag to RDDIR and will
1699 	 * continue with the readdir opeartion.
1700 	 */
1701 	if (rdc->flags & RDDIRWAIT) {
1702 		rdc->flags &= ~RDDIRWAIT;
1703 		cv_broadcast(&rdc->cv);
1704 	}
1705 	mutex_exit(&rp->r_statelock);
1706 	rddir_cache_rele(rdc);
1707 }
1708 
1709 void
1710 nfs_async_commit(vnode_t *vp, page_t *plist, offset3 offset, count3 count,
1711 	cred_t *cr, void (*commit)(vnode_t *, page_t *, offset3, count3,
1712 	cred_t *))
1713 {
1714 	rnode_t *rp;
1715 	mntinfo_t *mi;
1716 	struct nfs_async_reqs *args;
1717 	page_t *pp;
1718 
1719 	rp = VTOR(vp);
1720 	mi = VTOMI(vp);
1721 
1722 	/*
1723 	 * If we can't allocate a request structure, do the commit
1724 	 * operation synchronously in this thread's context.
1725 	 */
1726 	if ((args = kmem_alloc(sizeof (*args), KM_NOSLEEP)) == NULL)
1727 		goto noasync;
1728 
1729 	args->a_next = NULL;
1730 #ifdef DEBUG
1731 	args->a_queuer = curthread;
1732 #endif
1733 	VN_HOLD(vp);
1734 	args->a_vp = vp;
1735 	ASSERT(cr != NULL);
1736 	crhold(cr);
1737 	args->a_cred = cr;
1738 	args->a_io = NFS_COMMIT;
1739 	args->a_nfs_commit = commit;
1740 	args->a_nfs_plist = plist;
1741 	args->a_nfs_offset = offset;
1742 	args->a_nfs_count = count;
1743 
1744 	mutex_enter(&mi->mi_async_lock);
1745 
1746 	/*
1747 	 * If asyncio has been disabled, then make a synchronous request.
1748 	 * This check is done a second time in case async io was diabled
1749 	 * while this thread was blocked waiting for memory pressure to
1750 	 * reduce or for the queue to drain.
1751 	 */
1752 	if (mi->mi_max_threads == 0) {
1753 		mutex_exit(&mi->mi_async_lock);
1754 		goto noasync;
1755 	}
1756 
1757 	/*
1758 	 * Link request structure into the async list and
1759 	 * wakeup async thread to do the i/o.
1760 	 */
1761 	if (mi->mi_async_reqs[NFS_COMMIT] == NULL) {
1762 		mi->mi_async_reqs[NFS_COMMIT] = args;
1763 		mi->mi_async_tail[NFS_COMMIT] = args;
1764 	} else {
1765 		mi->mi_async_tail[NFS_COMMIT]->a_next = args;
1766 		mi->mi_async_tail[NFS_COMMIT] = args;
1767 	}
1768 
1769 	mutex_enter(&rp->r_statelock);
1770 	rp->r_count++;
1771 	mutex_exit(&rp->r_statelock);
1772 
1773 	if (mi->mi_io_kstats) {
1774 		mutex_enter(&mi->mi_lock);
1775 		kstat_waitq_enter(KSTAT_IO_PTR(mi->mi_io_kstats));
1776 		mutex_exit(&mi->mi_lock);
1777 	}
1778 
1779 	mi->mi_async_req_count++;
1780 	ASSERT(mi->mi_async_req_count != 0);
1781 	cv_signal(&mi->mi_async_reqs_cv);
1782 	mutex_exit(&mi->mi_async_lock);
1783 	return;
1784 
1785 noasync:
1786 	if (args != NULL) {
1787 		VN_RELE(vp);
1788 		crfree(cr);
1789 		kmem_free(args, sizeof (*args));
1790 	}
1791 
1792 	if (curproc == proc_pageout || curproc == proc_fsflush ||
1793 	    nfs_zone() != mi->mi_zone) {
1794 		while (plist != NULL) {
1795 			pp = plist;
1796 			page_sub(&plist, pp);
1797 			pp->p_fsdata = C_COMMIT;
1798 			page_unlock(pp);
1799 		}
1800 		return;
1801 	}
1802 	(*commit)(vp, plist, offset, count, cr);
1803 }
1804 
1805 void
1806 nfs_async_inactive(vnode_t *vp, cred_t *cr,
1807     void (*inactive)(vnode_t *, cred_t *))
1808 {
1809 	mntinfo_t *mi;
1810 	struct nfs_async_reqs *args;
1811 
1812 	mi = VTOMI(vp);
1813 
1814 	args = kmem_alloc(sizeof (*args), KM_SLEEP);
1815 	args->a_next = NULL;
1816 #ifdef DEBUG
1817 	args->a_queuer = curthread;
1818 #endif
1819 	args->a_vp = vp;
1820 	ASSERT(cr != NULL);
1821 	crhold(cr);
1822 	args->a_cred = cr;
1823 	args->a_io = NFS_INACTIVE;
1824 	args->a_nfs_inactive = inactive;
1825 
1826 	/*
1827 	 * Note that we don't check mi->mi_max_threads here, since we
1828 	 * *need* to get rid of this vnode regardless of whether someone
1829 	 * set nfs3_max_threads/nfs_max_threads to zero in /etc/system.
1830 	 *
1831 	 * The manager thread knows about this and is willing to create
1832 	 * at least one thread to accomodate us.
1833 	 */
1834 	mutex_enter(&mi->mi_async_lock);
1835 	if (mi->mi_manager_thread == NULL) {
1836 		rnode_t *rp = VTOR(vp);
1837 
1838 		mutex_exit(&mi->mi_async_lock);
1839 		crfree(cr);	/* drop our reference */
1840 		kmem_free(args, sizeof (*args));
1841 		/*
1842 		 * We can't do an over-the-wire call since we're in the wrong
1843 		 * zone, so we need to clean up state as best we can and then
1844 		 * throw away the vnode.
1845 		 */
1846 		mutex_enter(&rp->r_statelock);
1847 		if (rp->r_unldvp != NULL) {
1848 			vnode_t *unldvp;
1849 			char *unlname;
1850 			cred_t *unlcred;
1851 
1852 			unldvp = rp->r_unldvp;
1853 			rp->r_unldvp = NULL;
1854 			unlname = rp->r_unlname;
1855 			rp->r_unlname = NULL;
1856 			unlcred = rp->r_unlcred;
1857 			rp->r_unlcred = NULL;
1858 			mutex_exit(&rp->r_statelock);
1859 
1860 			VN_RELE(unldvp);
1861 			kmem_free(unlname, MAXNAMELEN);
1862 			crfree(unlcred);
1863 		} else {
1864 			mutex_exit(&rp->r_statelock);
1865 		}
1866 		/*
1867 		 * No need to explicitly throw away any cached pages.  The
1868 		 * eventual rinactive() will attempt a synchronous
1869 		 * VOP_PUTPAGE() which will immediately fail since the request
1870 		 * is coming from the wrong zone, and then will proceed to call
1871 		 * nfs_invalidate_pages() which will clean things up for us.
1872 		 */
1873 		rp_addfree(VTOR(vp), cr);
1874 		return;
1875 	}
1876 
1877 	if (mi->mi_async_reqs[NFS_INACTIVE] == NULL) {
1878 		mi->mi_async_reqs[NFS_INACTIVE] = args;
1879 	} else {
1880 		mi->mi_async_tail[NFS_INACTIVE]->a_next = args;
1881 	}
1882 	mi->mi_async_tail[NFS_INACTIVE] = args;
1883 	/*
1884 	 * Don't increment r_count, since we're trying to get rid of the vnode.
1885 	 */
1886 
1887 	mi->mi_async_req_count++;
1888 	ASSERT(mi->mi_async_req_count != 0);
1889 	cv_signal(&mi->mi_async_reqs_cv);
1890 	mutex_exit(&mi->mi_async_lock);
1891 }
1892 
1893 /*
1894  * The async queues for each mounted file system are arranged as a
1895  * set of queues, one for each async i/o type.  Requests are taken
1896  * from the queues in a round-robin fashion.  A number of consecutive
1897  * requests are taken from each queue before moving on to the next
1898  * queue.  This functionality may allow the NFS Version 2 server to do
1899  * write clustering, even if the client is mixing writes and reads
1900  * because it will take multiple write requests from the queue
1901  * before processing any of the other async i/o types.
1902  *
1903  * XXX The nfs_async_start thread is unsafe in the light of the present
1904  * model defined by cpr to suspend the system. Specifically over the
1905  * wire calls are cpr-unsafe. The thread should be reevaluated in
1906  * case of future updates to the cpr model.
1907  */
1908 static void
1909 nfs_async_start(struct vfs *vfsp)
1910 {
1911 	struct nfs_async_reqs *args;
1912 	mntinfo_t *mi = VFTOMI(vfsp);
1913 	clock_t time_left = 1;
1914 	callb_cpr_t cprinfo;
1915 	int i;
1916 
1917 	/*
1918 	 * Dynamic initialization of nfs_async_timeout to allow nfs to be
1919 	 * built in an implementation independent manner.
1920 	 */
1921 	if (nfs_async_timeout == -1)
1922 		nfs_async_timeout = NFS_ASYNC_TIMEOUT;
1923 
1924 	CALLB_CPR_INIT(&cprinfo, &mi->mi_async_lock, callb_generic_cpr, "nas");
1925 
1926 	mutex_enter(&mi->mi_async_lock);
1927 	for (;;) {
1928 		/*
1929 		 * Find the next queue containing an entry.  We start
1930 		 * at the current queue pointer and then round robin
1931 		 * through all of them until we either find a non-empty
1932 		 * queue or have looked through all of them.
1933 		 */
1934 		for (i = 0; i < NFS_ASYNC_TYPES; i++) {
1935 			args = *mi->mi_async_curr;
1936 			if (args != NULL)
1937 				break;
1938 			mi->mi_async_curr++;
1939 			if (mi->mi_async_curr ==
1940 			    &mi->mi_async_reqs[NFS_ASYNC_TYPES])
1941 				mi->mi_async_curr = &mi->mi_async_reqs[0];
1942 		}
1943 		/*
1944 		 * If we didn't find a entry, then block until woken up
1945 		 * again and then look through the queues again.
1946 		 */
1947 		if (args == NULL) {
1948 			/*
1949 			 * Exiting is considered to be safe for CPR as well
1950 			 */
1951 			CALLB_CPR_SAFE_BEGIN(&cprinfo);
1952 
1953 			/*
1954 			 * Wakeup thread waiting to unmount the file
1955 			 * system only if all async threads are inactive.
1956 			 *
1957 			 * If we've timed-out and there's nothing to do,
1958 			 * then get rid of this thread.
1959 			 */
1960 			if (mi->mi_max_threads == 0 || time_left <= 0) {
1961 				if (--mi->mi_threads == 0)
1962 					cv_signal(&mi->mi_async_cv);
1963 				CALLB_CPR_EXIT(&cprinfo);
1964 				VFS_RELE(vfsp);	/* release thread's hold */
1965 				zthread_exit();
1966 				/* NOTREACHED */
1967 			}
1968 			time_left = cv_timedwait(&mi->mi_async_work_cv,
1969 			    &mi->mi_async_lock, nfs_async_timeout + lbolt);
1970 
1971 			CALLB_CPR_SAFE_END(&cprinfo, &mi->mi_async_lock);
1972 
1973 			continue;
1974 		}
1975 		time_left = 1;
1976 
1977 		/*
1978 		 * Remove the request from the async queue and then
1979 		 * update the current async request queue pointer.  If
1980 		 * the current queue is empty or we have removed enough
1981 		 * consecutive entries from it, then reset the counter
1982 		 * for this queue and then move the current pointer to
1983 		 * the next queue.
1984 		 */
1985 		*mi->mi_async_curr = args->a_next;
1986 		if (*mi->mi_async_curr == NULL ||
1987 		    --mi->mi_async_clusters[args->a_io] == 0) {
1988 			mi->mi_async_clusters[args->a_io] =
1989 						mi->mi_async_init_clusters;
1990 			mi->mi_async_curr++;
1991 			if (mi->mi_async_curr ==
1992 			    &mi->mi_async_reqs[NFS_ASYNC_TYPES])
1993 				mi->mi_async_curr = &mi->mi_async_reqs[0];
1994 		}
1995 
1996 		if (args->a_io != NFS_INACTIVE && mi->mi_io_kstats) {
1997 			mutex_enter(&mi->mi_lock);
1998 			kstat_waitq_exit(KSTAT_IO_PTR(mi->mi_io_kstats));
1999 			mutex_exit(&mi->mi_lock);
2000 		}
2001 
2002 		mutex_exit(&mi->mi_async_lock);
2003 
2004 		/*
2005 		 * Obtain arguments from the async request structure.
2006 		 */
2007 		if (args->a_io == NFS_READ_AHEAD && mi->mi_max_threads > 0) {
2008 			(*args->a_nfs_readahead)(args->a_vp, args->a_nfs_blkoff,
2009 					args->a_nfs_addr, args->a_nfs_seg,
2010 					args->a_cred);
2011 		} else if (args->a_io == NFS_PUTAPAGE) {
2012 			(void) (*args->a_nfs_putapage)(args->a_vp,
2013 					args->a_nfs_pp, args->a_nfs_off,
2014 					args->a_nfs_len, args->a_nfs_flags,
2015 					args->a_cred);
2016 		} else if (args->a_io == NFS_PAGEIO) {
2017 			(void) (*args->a_nfs_pageio)(args->a_vp,
2018 					args->a_nfs_pp, args->a_nfs_off,
2019 					args->a_nfs_len, args->a_nfs_flags,
2020 					args->a_cred);
2021 		} else if (args->a_io == NFS_READDIR) {
2022 			(void) ((*args->a_nfs_readdir)(args->a_vp,
2023 					args->a_nfs_rdc, args->a_cred));
2024 		} else if (args->a_io == NFS_COMMIT) {
2025 			(*args->a_nfs_commit)(args->a_vp, args->a_nfs_plist,
2026 					args->a_nfs_offset, args->a_nfs_count,
2027 					args->a_cred);
2028 		} else if (args->a_io == NFS_INACTIVE) {
2029 			(*args->a_nfs_inactive)(args->a_vp, args->a_cred);
2030 		}
2031 
2032 		/*
2033 		 * Now, release the vnode and free the credentials
2034 		 * structure.
2035 		 */
2036 		free_async_args(args);
2037 		/*
2038 		 * Reacquire the mutex because it will be needed above.
2039 		 */
2040 		mutex_enter(&mi->mi_async_lock);
2041 	}
2042 }
2043 
2044 void
2045 nfs_async_stop(struct vfs *vfsp)
2046 {
2047 	mntinfo_t *mi = VFTOMI(vfsp);
2048 
2049 	/*
2050 	 * Wait for all outstanding async operations to complete and for the
2051 	 * worker threads to exit.
2052 	 */
2053 	mutex_enter(&mi->mi_async_lock);
2054 	mi->mi_max_threads = 0;
2055 	cv_broadcast(&mi->mi_async_work_cv);
2056 	while (mi->mi_threads != 0)
2057 		cv_wait(&mi->mi_async_cv, &mi->mi_async_lock);
2058 	mutex_exit(&mi->mi_async_lock);
2059 }
2060 
2061 /*
2062  * nfs_async_stop_sig:
2063  * Wait for all outstanding putpage operation to complete. If a signal
2064  * is deliver we will abort and return non-zero. If we can put all the
2065  * pages we will return 0. This routine is called from nfs_unmount and
2066  * nfs3_unmount to make these operations interruptable.
2067  */
2068 int
2069 nfs_async_stop_sig(struct vfs *vfsp)
2070 {
2071 	mntinfo_t *mi = VFTOMI(vfsp);
2072 	ushort_t omax;
2073 	int rval;
2074 
2075 	/*
2076 	 * Wait for all outstanding async operations to complete and for the
2077 	 * worker threads to exit.
2078 	 */
2079 	mutex_enter(&mi->mi_async_lock);
2080 	omax = mi->mi_max_threads;
2081 	mi->mi_max_threads = 0;
2082 	/*
2083 	 * Tell all the worker threads to exit.
2084 	 */
2085 	cv_broadcast(&mi->mi_async_work_cv);
2086 	while (mi->mi_threads != 0) {
2087 		if (!cv_wait_sig(&mi->mi_async_cv, &mi->mi_async_lock))
2088 			break;
2089 	}
2090 	rval = (mi->mi_threads != 0);	/* Interrupted */
2091 	if (rval)
2092 		mi->mi_max_threads = omax;
2093 	mutex_exit(&mi->mi_async_lock);
2094 
2095 	return (rval);
2096 }
2097 
2098 int
2099 writerp(rnode_t *rp, caddr_t base, int tcount, struct uio *uio, int pgcreated)
2100 {
2101 	int pagecreate;
2102 	int n;
2103 	int saved_n;
2104 	caddr_t saved_base;
2105 	u_offset_t offset;
2106 	int error;
2107 	int sm_error;
2108 
2109 	ASSERT(tcount <= MAXBSIZE && tcount <= uio->uio_resid);
2110 	ASSERT(((uintptr_t)base & MAXBOFFSET) + tcount <= MAXBSIZE);
2111 	ASSERT(nfs_rw_lock_held(&rp->r_rwlock, RW_WRITER));
2112 
2113 	/*
2114 	 * Move bytes in at most PAGESIZE chunks. We must avoid
2115 	 * spanning pages in uiomove() because page faults may cause
2116 	 * the cache to be invalidated out from under us. The r_size is not
2117 	 * updated until after the uiomove. If we push the last page of a
2118 	 * file before r_size is correct, we will lose the data written past
2119 	 * the current (and invalid) r_size.
2120 	 */
2121 	do {
2122 		offset = uio->uio_loffset;
2123 		pagecreate = 0;
2124 
2125 		/*
2126 		 * n is the number of bytes required to satisfy the request
2127 		 *   or the number of bytes to fill out the page.
2128 		 */
2129 		n = (int)MIN((PAGESIZE - ((uintptr_t)base & PAGEOFFSET)),
2130 		    tcount);
2131 
2132 		/*
2133 		 * Check to see if we can skip reading in the page
2134 		 * and just allocate the memory.  We can do this
2135 		 * if we are going to rewrite the entire mapping
2136 		 * or if we are going to write to or beyond the current
2137 		 * end of file from the beginning of the mapping.
2138 		 *
2139 		 * The read of r_size is now protected by r_statelock.
2140 		 */
2141 		mutex_enter(&rp->r_statelock);
2142 		/*
2143 		 * When pgcreated is nonzero the caller has already done
2144 		 * a segmap_getmapflt with forcefault 0 and S_WRITE. With
2145 		 * segkpm this means we already have at least one page
2146 		 * created and mapped at base.
2147 		 */
2148 		pagecreate = pgcreated ||
2149 			(((uintptr_t)base & PAGEOFFSET) == 0 &&
2150 			(n == PAGESIZE || ((offset + n) >= rp->r_size)));
2151 
2152 		mutex_exit(&rp->r_statelock);
2153 		if (pagecreate) {
2154 			/*
2155 			 * The last argument tells segmap_pagecreate() to
2156 			 * always lock the page, as opposed to sometimes
2157 			 * returning with the page locked. This way we avoid a
2158 			 * fault on the ensuing uiomove(), but also
2159 			 * more importantly (to fix bug 1094402) we can
2160 			 * call segmap_fault() to unlock the page in all
2161 			 * cases. An alternative would be to modify
2162 			 * segmap_pagecreate() to tell us when it is
2163 			 * locking a page, but that's a fairly major
2164 			 * interface change.
2165 			 */
2166 			if (pgcreated == 0)
2167 				(void) segmap_pagecreate(segkmap, base,
2168 							(uint_t)n, 1);
2169 			saved_base = base;
2170 			saved_n = n;
2171 		}
2172 
2173 		/*
2174 		 * The number of bytes of data in the last page can not
2175 		 * be accurately be determined while page is being
2176 		 * uiomove'd to and the size of the file being updated.
2177 		 * Thus, inform threads which need to know accurately
2178 		 * how much data is in the last page of the file.  They
2179 		 * will not do the i/o immediately, but will arrange for
2180 		 * the i/o to happen later when this modify operation
2181 		 * will have finished.
2182 		 */
2183 		ASSERT(!(rp->r_flags & RMODINPROGRESS));
2184 		mutex_enter(&rp->r_statelock);
2185 		rp->r_flags |= RMODINPROGRESS;
2186 		rp->r_modaddr = (offset & MAXBMASK);
2187 		mutex_exit(&rp->r_statelock);
2188 
2189 		error = uiomove(base, n, UIO_WRITE, uio);
2190 
2191 		/*
2192 		 * r_size is the maximum number of
2193 		 * bytes known to be in the file.
2194 		 * Make sure it is at least as high as the
2195 		 * first unwritten byte pointed to by uio_loffset.
2196 		 */
2197 		mutex_enter(&rp->r_statelock);
2198 		if (rp->r_size < uio->uio_loffset)
2199 			rp->r_size = uio->uio_loffset;
2200 		rp->r_flags &= ~RMODINPROGRESS;
2201 		rp->r_flags |= RDIRTY;
2202 		mutex_exit(&rp->r_statelock);
2203 
2204 		/* n = # of bytes written */
2205 		n = (int)(uio->uio_loffset - offset);
2206 		base += n;
2207 		tcount -= n;
2208 		/*
2209 		 * If we created pages w/o initializing them completely,
2210 		 * we need to zero the part that wasn't set up.
2211 		 * This happens on a most EOF write cases and if
2212 		 * we had some sort of error during the uiomove.
2213 		 */
2214 		if (pagecreate) {
2215 			if ((uio->uio_loffset & PAGEOFFSET) || n == 0)
2216 				(void) kzero(base, PAGESIZE - n);
2217 
2218 			if (pgcreated) {
2219 				/*
2220 				 * Caller is responsible for this page,
2221 				 * it was not created in this loop.
2222 				 */
2223 				pgcreated = 0;
2224 			} else {
2225 				/*
2226 				 * For bug 1094402: segmap_pagecreate locks
2227 				 * page. Unlock it. This also unlocks the
2228 				 * pages allocated by page_create_va() in
2229 				 * segmap_pagecreate().
2230 				 */
2231 				sm_error = segmap_fault(kas.a_hat, segkmap,
2232 						saved_base, saved_n,
2233 						F_SOFTUNLOCK, S_WRITE);
2234 				if (error == 0)
2235 					error = sm_error;
2236 			}
2237 		}
2238 	} while (tcount > 0 && error == 0);
2239 
2240 	return (error);
2241 }
2242 
2243 int
2244 nfs_putpages(vnode_t *vp, u_offset_t off, size_t len, int flags, cred_t *cr)
2245 {
2246 	rnode_t *rp;
2247 	page_t *pp;
2248 	u_offset_t eoff;
2249 	u_offset_t io_off;
2250 	size_t io_len;
2251 	int error;
2252 	int rdirty;
2253 	int err;
2254 
2255 	rp = VTOR(vp);
2256 	ASSERT(rp->r_count > 0);
2257 
2258 	if (!vn_has_cached_data(vp))
2259 		return (0);
2260 
2261 	ASSERT(vp->v_type != VCHR);
2262 
2263 	/*
2264 	 * If ROUTOFSPACE is set, then all writes turn into B_INVAL
2265 	 * writes.  B_FORCE is set to force the VM system to actually
2266 	 * invalidate the pages, even if the i/o failed.  The pages
2267 	 * need to get invalidated because they can't be written out
2268 	 * because there isn't any space left on either the server's
2269 	 * file system or in the user's disk quota.  The B_FREE bit
2270 	 * is cleared to avoid confusion as to whether this is a
2271 	 * request to place the page on the freelist or to destroy
2272 	 * it.
2273 	 */
2274 	if ((rp->r_flags & ROUTOFSPACE) ||
2275 	    (vp->v_vfsp->vfs_flag & VFS_UNMOUNTED))
2276 		flags = (flags & ~B_FREE) | B_INVAL | B_FORCE;
2277 
2278 	if (len == 0) {
2279 		/*
2280 		 * If doing a full file synchronous operation, then clear
2281 		 * the RDIRTY bit.  If a page gets dirtied while the flush
2282 		 * is happening, then RDIRTY will get set again.  The
2283 		 * RDIRTY bit must get cleared before the flush so that
2284 		 * we don't lose this information.
2285 		 */
2286 		if (off == (u_offset_t)0 &&
2287 		    !(flags & B_ASYNC) &&
2288 		    (rp->r_flags & RDIRTY)) {
2289 			mutex_enter(&rp->r_statelock);
2290 			rdirty = (rp->r_flags & RDIRTY);
2291 			rp->r_flags &= ~RDIRTY;
2292 			mutex_exit(&rp->r_statelock);
2293 		} else
2294 			rdirty = 0;
2295 
2296 		/*
2297 		 * Search the entire vp list for pages >= off, and flush
2298 		 * the dirty pages.
2299 		 */
2300 		error = pvn_vplist_dirty(vp, off, rp->r_putapage,
2301 					flags, cr);
2302 
2303 		/*
2304 		 * If an error occured and the file was marked as dirty
2305 		 * before and we aren't forcibly invalidating pages, then
2306 		 * reset the RDIRTY flag.
2307 		 */
2308 		if (error && rdirty &&
2309 		    (flags & (B_INVAL | B_FORCE)) != (B_INVAL | B_FORCE)) {
2310 			mutex_enter(&rp->r_statelock);
2311 			rp->r_flags |= RDIRTY;
2312 			mutex_exit(&rp->r_statelock);
2313 		}
2314 	} else {
2315 		/*
2316 		 * Do a range from [off...off + len) looking for pages
2317 		 * to deal with.
2318 		 */
2319 		error = 0;
2320 #ifdef lint
2321 		io_len = 0;
2322 #endif
2323 		eoff = off + len;
2324 		mutex_enter(&rp->r_statelock);
2325 		for (io_off = off; io_off < eoff && io_off < rp->r_size;
2326 		    io_off += io_len) {
2327 			mutex_exit(&rp->r_statelock);
2328 			/*
2329 			 * If we are not invalidating, synchronously
2330 			 * freeing or writing pages use the routine
2331 			 * page_lookup_nowait() to prevent reclaiming
2332 			 * them from the free list.
2333 			 */
2334 			if ((flags & B_INVAL) || !(flags & B_ASYNC)) {
2335 				pp = page_lookup(vp, io_off,
2336 				    (flags & (B_INVAL | B_FREE)) ?
2337 				    SE_EXCL : SE_SHARED);
2338 			} else {
2339 				pp = page_lookup_nowait(vp, io_off,
2340 				    (flags & B_FREE) ? SE_EXCL : SE_SHARED);
2341 			}
2342 
2343 			if (pp == NULL || !pvn_getdirty(pp, flags))
2344 				io_len = PAGESIZE;
2345 			else {
2346 				err = (*rp->r_putapage)(vp, pp, &io_off,
2347 				    &io_len, flags, cr);
2348 				if (!error)
2349 					error = err;
2350 				/*
2351 				 * "io_off" and "io_len" are returned as
2352 				 * the range of pages we actually wrote.
2353 				 * This allows us to skip ahead more quickly
2354 				 * since several pages may've been dealt
2355 				 * with by this iteration of the loop.
2356 				 */
2357 			}
2358 			mutex_enter(&rp->r_statelock);
2359 		}
2360 		mutex_exit(&rp->r_statelock);
2361 	}
2362 
2363 	return (error);
2364 }
2365 
2366 void
2367 nfs_invalidate_pages(vnode_t *vp, u_offset_t off, cred_t *cr)
2368 {
2369 	rnode_t *rp;
2370 
2371 	rp = VTOR(vp);
2372 	mutex_enter(&rp->r_statelock);
2373 	while (rp->r_flags & RTRUNCATE)
2374 		cv_wait(&rp->r_cv, &rp->r_statelock);
2375 	rp->r_flags |= RTRUNCATE;
2376 	if (off == (u_offset_t)0) {
2377 		rp->r_flags &= ~RDIRTY;
2378 		if (!(rp->r_flags & RSTALE))
2379 			rp->r_error = 0;
2380 	}
2381 	rp->r_truncaddr = off;
2382 	mutex_exit(&rp->r_statelock);
2383 	(void) pvn_vplist_dirty(vp, off, rp->r_putapage,
2384 		B_INVAL | B_TRUNC, cr);
2385 	mutex_enter(&rp->r_statelock);
2386 	rp->r_flags &= ~RTRUNCATE;
2387 	cv_broadcast(&rp->r_cv);
2388 	mutex_exit(&rp->r_statelock);
2389 }
2390 
2391 static int nfs_write_error_to_cons_only = 0;
2392 #define	MSG(x)	(nfs_write_error_to_cons_only ? (x) : (x) + 1)
2393 
2394 /*
2395  * Print a file handle
2396  */
2397 void
2398 nfs_printfhandle(nfs_fhandle *fhp)
2399 {
2400 	int *ip;
2401 	char *buf;
2402 	size_t bufsize;
2403 	char *cp;
2404 
2405 	/*
2406 	 * 13 == "(file handle:"
2407 	 * maximum of NFS_FHANDLE / sizeof (*ip) elements in fh_buf times
2408 	 *	1 == ' '
2409 	 *	8 == maximum strlen of "%x"
2410 	 * 3 == ")\n\0"
2411 	 */
2412 	bufsize = 13 + ((NFS_FHANDLE_LEN / sizeof (*ip)) * (1 + 8)) + 3;
2413 	buf = kmem_alloc(bufsize, KM_NOSLEEP);
2414 	if (buf == NULL)
2415 		return;
2416 
2417 	cp = buf;
2418 	(void) strcpy(cp, "(file handle:");
2419 	while (*cp != '\0')
2420 		cp++;
2421 	for (ip = (int *)fhp->fh_buf;
2422 	    ip < (int *)&fhp->fh_buf[fhp->fh_len];
2423 	    ip++) {
2424 		(void) sprintf(cp, " %x", *ip);
2425 		while (*cp != '\0')
2426 			cp++;
2427 	}
2428 	(void) strcpy(cp, ")\n");
2429 
2430 	zcmn_err(getzoneid(), CE_CONT, MSG("^%s"), buf);
2431 
2432 	kmem_free(buf, bufsize);
2433 }
2434 
2435 /*
2436  * Notify the system administrator that an NFS write error has
2437  * occurred.
2438  */
2439 
2440 /* seconds between ENOSPC/EDQUOT messages */
2441 clock_t nfs_write_error_interval = 5;
2442 
2443 void
2444 nfs_write_error(vnode_t *vp, int error, cred_t *cr)
2445 {
2446 	mntinfo_t *mi;
2447 
2448 	mi = VTOMI(vp);
2449 	/*
2450 	 * In case of forced unmount or zone shutdown, do not print any
2451 	 * messages since it can flood the console with error messages.
2452 	 */
2453 	if (FS_OR_ZONE_GONE(mi->mi_vfsp))
2454 		return;
2455 
2456 	/*
2457 	 * No use in flooding the console with ENOSPC
2458 	 * messages from the same file system.
2459 	 */
2460 	if ((error != ENOSPC && error != EDQUOT) ||
2461 	    lbolt - mi->mi_printftime > 0) {
2462 		zoneid_t zoneid = mi->mi_zone->zone_id;
2463 
2464 #ifdef DEBUG
2465 		nfs_perror(error, "NFS%ld write error on host %s: %m.\n",
2466 		    mi->mi_vers, VTOR(vp)->r_server->sv_hostname, NULL);
2467 #else
2468 		nfs_perror(error, "NFS write error on host %s: %m.\n",
2469 		    VTOR(vp)->r_server->sv_hostname, NULL);
2470 #endif
2471 		if (error == ENOSPC || error == EDQUOT) {
2472 			zcmn_err(zoneid, CE_CONT,
2473 			    MSG("^File: userid=%d, groupid=%d\n"),
2474 			    crgetuid(cr), crgetgid(cr));
2475 			if (crgetuid(CRED()) != crgetuid(cr) ||
2476 			    crgetgid(CRED()) != crgetgid(cr)) {
2477 				zcmn_err(zoneid, CE_CONT,
2478 				    MSG("^User: userid=%d, groupid=%d\n"),
2479 				    crgetuid(CRED()), crgetgid(CRED()));
2480 			}
2481 			mi->mi_printftime = lbolt +
2482 			    nfs_write_error_interval * hz;
2483 		}
2484 		nfs_printfhandle(&VTOR(vp)->r_fh);
2485 #ifdef DEBUG
2486 		if (error == EACCES) {
2487 			zcmn_err(zoneid, CE_CONT,
2488 			    MSG("^nfs_bio: cred is%s kcred\n"),
2489 			    cr == kcred ? "" : " not");
2490 		}
2491 #endif
2492 	}
2493 }
2494 
2495 /* ARGSUSED */
2496 static void *
2497 nfs_mi_init(zoneid_t zoneid)
2498 {
2499 	struct mi_globals *mig;
2500 
2501 	mig = kmem_alloc(sizeof (*mig), KM_SLEEP);
2502 	mutex_init(&mig->mig_lock, NULL, MUTEX_DEFAULT, NULL);
2503 	list_create(&mig->mig_list, sizeof (mntinfo_t),
2504 	    offsetof(mntinfo_t, mi_zone_node));
2505 	mig->mig_destructor_called = B_FALSE;
2506 	return (mig);
2507 }
2508 
2509 /*
2510  * Callback routine to tell all NFS mounts in the zone to stop creating new
2511  * threads.  Existing threads should exit.
2512  */
2513 /* ARGSUSED */
2514 static void
2515 nfs_mi_shutdown(zoneid_t zoneid, void *data)
2516 {
2517 	struct mi_globals *mig = data;
2518 	mntinfo_t *mi;
2519 
2520 	ASSERT(mig != NULL);
2521 again:
2522 	mutex_enter(&mig->mig_lock);
2523 	for (mi = list_head(&mig->mig_list); mi != NULL;
2524 	    mi = list_next(&mig->mig_list, mi)) {
2525 
2526 		/*
2527 		 * If we've done the shutdown work for this FS, skip.
2528 		 * Once we go off the end of the list, we're done.
2529 		 */
2530 		if (mi->mi_flags & MI_DEAD)
2531 			continue;
2532 
2533 		/*
2534 		 * We will do work, so not done.  Get a hold on the FS.
2535 		 */
2536 		VFS_HOLD(mi->mi_vfsp);
2537 
2538 		/*
2539 		 * purge the DNLC for this filesystem
2540 		 */
2541 		(void) dnlc_purge_vfsp(mi->mi_vfsp, 0);
2542 
2543 		mutex_enter(&mi->mi_async_lock);
2544 		/*
2545 		 * Tell existing async worker threads to exit.
2546 		 */
2547 		mi->mi_max_threads = 0;
2548 		cv_broadcast(&mi->mi_async_work_cv);
2549 		/*
2550 		 * Set MI_ASYNC_MGR_STOP so the async manager thread starts
2551 		 * getting ready to exit when it's done with its current work.
2552 		 * Also set MI_DEAD to note we've acted on this FS.
2553 		 */
2554 		mutex_enter(&mi->mi_lock);
2555 		mi->mi_flags |= (MI_ASYNC_MGR_STOP|MI_DEAD);
2556 		mutex_exit(&mi->mi_lock);
2557 		/*
2558 		 * Wake up the async manager thread.
2559 		 */
2560 		cv_broadcast(&mi->mi_async_reqs_cv);
2561 		mutex_exit(&mi->mi_async_lock);
2562 
2563 		/*
2564 		 * Drop lock and release FS, which may change list, then repeat.
2565 		 * We're done when every mi has been done or the list is empty.
2566 		 */
2567 		mutex_exit(&mig->mig_lock);
2568 		VFS_RELE(mi->mi_vfsp);
2569 		goto again;
2570 	}
2571 	mutex_exit(&mig->mig_lock);
2572 }
2573 
2574 static void
2575 nfs_mi_free_globals(struct mi_globals *mig)
2576 {
2577 	list_destroy(&mig->mig_list);	/* makes sure the list is empty */
2578 	mutex_destroy(&mig->mig_lock);
2579 	kmem_free(mig, sizeof (*mig));
2580 
2581 }
2582 
2583 /* ARGSUSED */
2584 static void
2585 nfs_mi_destroy(zoneid_t zoneid, void *data)
2586 {
2587 	struct mi_globals *mig = data;
2588 
2589 	ASSERT(mig != NULL);
2590 	mutex_enter(&mig->mig_lock);
2591 	if (list_head(&mig->mig_list) != NULL) {
2592 		/* Still waiting for VFS_FREEVFS() */
2593 		mig->mig_destructor_called = B_TRUE;
2594 		mutex_exit(&mig->mig_lock);
2595 		return;
2596 	}
2597 	nfs_mi_free_globals(mig);
2598 }
2599 
2600 /*
2601  * Add an NFS mount to the per-zone list of NFS mounts.
2602  */
2603 void
2604 nfs_mi_zonelist_add(mntinfo_t *mi)
2605 {
2606 	struct mi_globals *mig;
2607 
2608 	mig = zone_getspecific(mi_list_key, mi->mi_zone);
2609 	mutex_enter(&mig->mig_lock);
2610 	list_insert_head(&mig->mig_list, mi);
2611 	mutex_exit(&mig->mig_lock);
2612 }
2613 
2614 /*
2615  * Remove an NFS mount from the per-zone list of NFS mounts.
2616  */
2617 static void
2618 nfs_mi_zonelist_remove(mntinfo_t *mi)
2619 {
2620 	struct mi_globals *mig;
2621 
2622 	mig = zone_getspecific(mi_list_key, mi->mi_zone);
2623 	mutex_enter(&mig->mig_lock);
2624 	list_remove(&mig->mig_list, mi);
2625 	/*
2626 	 * We can be called asynchronously by VFS_FREEVFS() after the zone
2627 	 * shutdown/destroy callbacks have executed; if so, clean up the zone's
2628 	 * mi globals.
2629 	 */
2630 	if (list_head(&mig->mig_list) == NULL &&
2631 	    mig->mig_destructor_called == B_TRUE) {
2632 		nfs_mi_free_globals(mig);
2633 		return;
2634 	}
2635 	mutex_exit(&mig->mig_lock);
2636 }
2637 
2638 /*
2639  * NFS Client initialization routine.  This routine should only be called
2640  * once.  It performs the following tasks:
2641  *	- Initalize all global locks
2642  * 	- Call sub-initialization routines (localize access to variables)
2643  */
2644 int
2645 nfs_clntinit(void)
2646 {
2647 #ifdef DEBUG
2648 	static boolean_t nfs_clntup = B_FALSE;
2649 #endif
2650 	int error;
2651 
2652 #ifdef DEBUG
2653 	ASSERT(nfs_clntup == B_FALSE);
2654 #endif
2655 
2656 	error = nfs_subrinit();
2657 	if (error)
2658 		return (error);
2659 
2660 	error = nfs_vfsinit();
2661 	if (error) {
2662 		/*
2663 		 * Cleanup nfs_subrinit() work
2664 		 */
2665 		nfs_subrfini();
2666 		return (error);
2667 	}
2668 	zone_key_create(&mi_list_key, nfs_mi_init, nfs_mi_shutdown,
2669 	    nfs_mi_destroy);
2670 
2671 	nfs4_clnt_init();
2672 
2673 #ifdef DEBUG
2674 	nfs_clntup = B_TRUE;
2675 #endif
2676 
2677 	return (0);
2678 }
2679 
2680 /*
2681  * This routine is only called if the NFS Client has been initialized but
2682  * the module failed to be installed. This routine will cleanup the previously
2683  * allocated/initialized work.
2684  */
2685 void
2686 nfs_clntfini(void)
2687 {
2688 	(void) zone_key_delete(mi_list_key);
2689 	nfs_subrfini();
2690 	nfs_vfsfini();
2691 	nfs4_clnt_fini();
2692 }
2693 
2694 /*
2695  * nfs_lockrelease:
2696  *
2697  * Release any locks on the given vnode that are held by the current
2698  * process.
2699  */
2700 void
2701 nfs_lockrelease(vnode_t *vp, int flag, offset_t offset, cred_t *cr)
2702 {
2703 	flock64_t ld;
2704 	struct shrlock shr;
2705 	char *buf;
2706 	int remote_lock_possible;
2707 	int ret;
2708 
2709 	ASSERT((uintptr_t)vp > KERNELBASE);
2710 
2711 	/*
2712 	 * Generate an explicit unlock operation for the entire file.  As a
2713 	 * partial optimization, only generate the unlock if there is a
2714 	 * lock registered for the file.  We could check whether this
2715 	 * particular process has any locks on the file, but that would
2716 	 * require the local locking code to provide yet another query
2717 	 * routine.  Note that no explicit synchronization is needed here.
2718 	 * At worst, flk_has_remote_locks() will return a false positive,
2719 	 * in which case the unlock call wastes time but doesn't harm
2720 	 * correctness.
2721 	 *
2722 	 * In addition, an unlock request is generated if the process
2723 	 * is listed as possibly having a lock on the file because the
2724 	 * server and client lock managers may have gotten out of sync.
2725 	 * N.B. It is important to make sure nfs_remove_locking_id() is
2726 	 * called here even if flk_has_remote_locks(vp) reports true.
2727 	 * If it is not called and there is an entry on the process id
2728 	 * list, that entry will never get removed.
2729 	 */
2730 	remote_lock_possible = nfs_remove_locking_id(vp, RLMPL_PID,
2731 	    (char *)&(ttoproc(curthread)->p_pid), NULL, NULL);
2732 	if (remote_lock_possible || flk_has_remote_locks(vp)) {
2733 		ld.l_type = F_UNLCK;	/* set to unlock entire file */
2734 		ld.l_whence = 0;	/* unlock from start of file */
2735 		ld.l_start = 0;
2736 		ld.l_len = 0;		/* do entire file */
2737 		ret = VOP_FRLOCK(vp, F_SETLK, &ld, flag, offset, NULL, cr);
2738 
2739 		if (ret != 0) {
2740 			/*
2741 			 * If VOP_FRLOCK fails, make sure we unregister
2742 			 * local locks before we continue.
2743 			 */
2744 			ld.l_pid = ttoproc(curthread)->p_pid;
2745 			lm_register_lock_locally(vp, NULL, &ld, flag, offset);
2746 #ifdef DEBUG
2747 			nfs_perror(ret,
2748 			    "NFS lock release error on vp %p: %m.\n",
2749 			    (void *)vp, NULL);
2750 #endif
2751 		}
2752 
2753 		/*
2754 		 * The call to VOP_FRLOCK may put the pid back on the
2755 		 * list.  We need to remove it.
2756 		 */
2757 		(void) nfs_remove_locking_id(vp, RLMPL_PID,
2758 		    (char *)&(ttoproc(curthread)->p_pid), NULL, NULL);
2759 	}
2760 
2761 	/*
2762 	 * As long as the vp has a share matching our pid,
2763 	 * pluck it off and unshare it.  There are circumstances in
2764 	 * which the call to nfs_remove_locking_id() may put the
2765 	 * owner back on the list, in which case we simply do a
2766 	 * redundant and harmless unshare.
2767 	 */
2768 	buf = kmem_alloc(MAX_SHR_OWNER_LEN, KM_SLEEP);
2769 	while (nfs_remove_locking_id(vp, RLMPL_OWNER,
2770 	    (char *)NULL, buf, &shr.s_own_len)) {
2771 		shr.s_owner = buf;
2772 		shr.s_access = 0;
2773 		shr.s_deny = 0;
2774 		shr.s_sysid = 0;
2775 		shr.s_pid = curproc->p_pid;
2776 
2777 		ret = VOP_SHRLOCK(vp, F_UNSHARE, &shr, flag, cr);
2778 #ifdef DEBUG
2779 		if (ret != 0) {
2780 			nfs_perror(ret,
2781 			    "NFS share release error on vp %p: %m.\n",
2782 			    (void *)vp, NULL);
2783 		}
2784 #endif
2785 	}
2786 	kmem_free(buf, MAX_SHR_OWNER_LEN);
2787 }
2788 
2789 /*
2790  * nfs_lockcompletion:
2791  *
2792  * If the vnode has a lock that makes it unsafe to cache the file, mark it
2793  * as non cachable (set VNOCACHE bit).
2794  */
2795 
2796 void
2797 nfs_lockcompletion(vnode_t *vp, int cmd)
2798 {
2799 #ifdef DEBUG
2800 	rnode_t *rp = VTOR(vp);
2801 
2802 	ASSERT(nfs_rw_lock_held(&rp->r_lkserlock, RW_WRITER));
2803 #endif
2804 
2805 	if (cmd == F_SETLK || cmd == F_SETLKW) {
2806 		if (!lm_safemap(vp)) {
2807 			mutex_enter(&vp->v_lock);
2808 			vp->v_flag |= VNOCACHE;
2809 			mutex_exit(&vp->v_lock);
2810 		} else {
2811 			mutex_enter(&vp->v_lock);
2812 			vp->v_flag &= ~VNOCACHE;
2813 			mutex_exit(&vp->v_lock);
2814 		}
2815 	}
2816 	/*
2817 	 * The cached attributes of the file are stale after acquiring
2818 	 * the lock on the file. They were updated when the file was
2819 	 * opened, but not updated when the lock was acquired. Therefore the
2820 	 * cached attributes are invalidated after the lock is obtained.
2821 	 */
2822 	PURGE_ATTRCACHE(vp);
2823 }
2824 
2825 /*
2826  * The lock manager holds state making it possible for the client
2827  * and server to be out of sync.  For example, if the response from
2828  * the server granting a lock request is lost, the server will think
2829  * the lock is granted and the client will think the lock is lost.
2830  * The client can tell when it is not positive if it is in sync with
2831  * the server.
2832  *
2833  * To deal with this, a list of processes for which the client is
2834  * not sure if the server holds a lock is attached to the rnode.
2835  * When such a process closes the rnode, an unlock request is sent
2836  * to the server to unlock the entire file.
2837  *
2838  * The list is kept as a singularly linked NULL terminated list.
2839  * Because it is only added to under extreme error conditions, the
2840  * list shouldn't get very big.  DEBUG kernels print a message if
2841  * the list gets bigger than nfs_lmpl_high_water.  This is arbitrarily
2842  * choosen to be 8, but can be tuned at runtime.
2843  */
2844 #ifdef DEBUG
2845 /* int nfs_lmpl_high_water = 8; */
2846 int nfs_lmpl_high_water = 128;
2847 int nfs_cnt_add_locking_id = 0;
2848 int nfs_len_add_locking_id = 0;
2849 #endif /* DEBUG */
2850 
2851 /*
2852  * Record that the nfs lock manager server may be holding a lock on
2853  * a vnode for a process.
2854  *
2855  * Because the nfs lock manager server holds state, it is possible
2856  * for the server to get out of sync with the client.  This routine is called
2857  * from the client when it is no longer sure if the server is in sync
2858  * with the client.  nfs_lockrelease() will then notice this and send
2859  * an unlock request when the file is closed
2860  */
2861 void
2862 nfs_add_locking_id(vnode_t *vp, pid_t pid, int type, char *id, int len)
2863 {
2864 	rnode_t *rp;
2865 	lmpl_t *new;
2866 	lmpl_t *cur;
2867 	lmpl_t **lmplp;
2868 #ifdef DEBUG
2869 	int list_len = 1;
2870 #endif /* DEBUG */
2871 
2872 #ifdef DEBUG
2873 	++nfs_cnt_add_locking_id;
2874 #endif /* DEBUG */
2875 	/*
2876 	 * allocate new lmpl_t now so we don't sleep
2877 	 * later after grabbing mutexes
2878 	 */
2879 	ASSERT(len < MAX_SHR_OWNER_LEN);
2880 	new = kmem_alloc(sizeof (*new), KM_SLEEP);
2881 	new->lmpl_type = type;
2882 	new->lmpl_pid = pid;
2883 	new->lmpl_owner = kmem_alloc(len, KM_SLEEP);
2884 	bcopy(id, new->lmpl_owner, len);
2885 	new->lmpl_own_len = len;
2886 	new->lmpl_next = (lmpl_t *)NULL;
2887 #ifdef DEBUG
2888 	if (type == RLMPL_PID) {
2889 		ASSERT(len == sizeof (pid_t));
2890 		ASSERT(pid == *(pid_t *)new->lmpl_owner);
2891 	} else {
2892 		ASSERT(type == RLMPL_OWNER);
2893 	}
2894 #endif
2895 
2896 	rp = VTOR(vp);
2897 	mutex_enter(&rp->r_statelock);
2898 
2899 	/*
2900 	 * Add this id to the list for this rnode only if the
2901 	 * rnode is active and the id is not already there.
2902 	 */
2903 	ASSERT(rp->r_flags & RHASHED);
2904 	lmplp = &(rp->r_lmpl);
2905 	for (cur = rp->r_lmpl; cur != (lmpl_t *)NULL; cur = cur->lmpl_next) {
2906 		if (cur->lmpl_pid == pid &&
2907 		    cur->lmpl_type == type &&
2908 		    cur->lmpl_own_len == len &&
2909 		    bcmp(cur->lmpl_owner, new->lmpl_owner, len) == 0) {
2910 			kmem_free(new->lmpl_owner, len);
2911 			kmem_free(new, sizeof (*new));
2912 			break;
2913 		}
2914 		lmplp = &cur->lmpl_next;
2915 #ifdef DEBUG
2916 		++list_len;
2917 #endif /* DEBUG */
2918 	}
2919 	if (cur == (lmpl_t *)NULL) {
2920 		*lmplp = new;
2921 #ifdef DEBUG
2922 		if (list_len > nfs_len_add_locking_id) {
2923 			nfs_len_add_locking_id = list_len;
2924 		}
2925 		if (list_len > nfs_lmpl_high_water) {
2926 			cmn_err(CE_WARN, "nfs_add_locking_id: long list "
2927 			    "vp=%p is %d", (void *)vp, list_len);
2928 		}
2929 #endif /* DEBUG */
2930 	}
2931 
2932 #ifdef DEBUG
2933 	if (share_debug) {
2934 		int nitems = 0;
2935 		int npids = 0;
2936 		int nowners = 0;
2937 
2938 		/*
2939 		 * Count the number of things left on r_lmpl after the remove.
2940 		 */
2941 		for (cur = rp->r_lmpl; cur != (lmpl_t *)NULL;
2942 		    cur = cur->lmpl_next) {
2943 			nitems++;
2944 			if (cur->lmpl_type == RLMPL_PID) {
2945 				npids++;
2946 			} else if (cur->lmpl_type == RLMPL_OWNER) {
2947 				nowners++;
2948 			} else {
2949 				cmn_err(CE_PANIC, "nfs_add_locking_id: "
2950 				    "unrecognised lmpl_type %d",
2951 				    cur->lmpl_type);
2952 			}
2953 		}
2954 
2955 		cmn_err(CE_CONT, "nfs_add_locking_id(%s): %d PIDs + %d "
2956 		    "OWNs = %d items left on r_lmpl\n",
2957 		    (type == RLMPL_PID) ? "P" : "O", npids, nowners, nitems);
2958 	}
2959 #endif
2960 
2961 	mutex_exit(&rp->r_statelock);
2962 }
2963 
2964 /*
2965  * Remove an id from the lock manager id list.
2966  *
2967  * If the id is not in the list return 0.  If it was found and
2968  * removed, return 1.
2969  */
2970 static int
2971 nfs_remove_locking_id(vnode_t *vp, int type, char *id, char *rid, int *rlen)
2972 {
2973 	lmpl_t *cur;
2974 	lmpl_t **lmplp;
2975 	rnode_t *rp;
2976 	int rv = 0;
2977 
2978 	ASSERT(type == RLMPL_PID || type == RLMPL_OWNER);
2979 
2980 	rp = VTOR(vp);
2981 
2982 	mutex_enter(&rp->r_statelock);
2983 	ASSERT(rp->r_flags & RHASHED);
2984 	lmplp = &(rp->r_lmpl);
2985 
2986 	/*
2987 	 * Search through the list and remove the entry for this id
2988 	 * if it is there.  The special case id == NULL allows removal
2989 	 * of the first share on the r_lmpl list belonging to the
2990 	 * current process (if any), without regard to further details
2991 	 * of its identity.
2992 	 */
2993 	for (cur = rp->r_lmpl; cur != (lmpl_t *)NULL; cur = cur->lmpl_next) {
2994 		if (cur->lmpl_type == type &&
2995 		    cur->lmpl_pid == curproc->p_pid &&
2996 		    (id == (char *)NULL ||
2997 		    bcmp(cur->lmpl_owner, id, cur->lmpl_own_len) == 0)) {
2998 			*lmplp = cur->lmpl_next;
2999 			ASSERT(cur->lmpl_own_len < MAX_SHR_OWNER_LEN);
3000 			if (rid != NULL) {
3001 				bcopy(cur->lmpl_owner, rid, cur->lmpl_own_len);
3002 				*rlen = cur->lmpl_own_len;
3003 			}
3004 			kmem_free(cur->lmpl_owner, cur->lmpl_own_len);
3005 			kmem_free(cur, sizeof (*cur));
3006 			rv = 1;
3007 			break;
3008 		}
3009 		lmplp = &cur->lmpl_next;
3010 	}
3011 
3012 #ifdef DEBUG
3013 	if (share_debug) {
3014 		int nitems = 0;
3015 		int npids = 0;
3016 		int nowners = 0;
3017 
3018 		/*
3019 		 * Count the number of things left on r_lmpl after the remove.
3020 		 */
3021 		for (cur = rp->r_lmpl; cur != (lmpl_t *)NULL;
3022 				cur = cur->lmpl_next) {
3023 			nitems++;
3024 			if (cur->lmpl_type == RLMPL_PID) {
3025 				npids++;
3026 			} else if (cur->lmpl_type == RLMPL_OWNER) {
3027 				nowners++;
3028 			} else {
3029 				cmn_err(CE_PANIC,
3030 					"nrli: unrecognised lmpl_type %d",
3031 					cur->lmpl_type);
3032 			}
3033 		}
3034 
3035 		cmn_err(CE_CONT,
3036 		"nrli(%s): %d PIDs + %d OWNs = %d items left on r_lmpl\n",
3037 			(type == RLMPL_PID) ? "P" : "O",
3038 			npids,
3039 			nowners,
3040 			nitems);
3041 	}
3042 #endif
3043 
3044 	mutex_exit(&rp->r_statelock);
3045 	return (rv);
3046 }
3047 
3048 void
3049 nfs_free_mi(mntinfo_t *mi)
3050 {
3051 	ASSERT(mi->mi_flags & MI_ASYNC_MGR_STOP);
3052 	ASSERT(mi->mi_manager_thread == NULL);
3053 	ASSERT(mi->mi_threads == 0);
3054 
3055 	/*
3056 	 * Remove the node from the global list before we start tearing it down.
3057 	 */
3058 	nfs_mi_zonelist_remove(mi);
3059 	if (mi->mi_klmconfig) {
3060 		lm_free_config(mi->mi_klmconfig);
3061 		kmem_free(mi->mi_klmconfig, sizeof (struct knetconfig));
3062 	}
3063 	mutex_destroy(&mi->mi_lock);
3064 	mutex_destroy(&mi->mi_remap_lock);
3065 	mutex_destroy(&mi->mi_async_lock);
3066 	cv_destroy(&mi->mi_failover_cv);
3067 	cv_destroy(&mi->mi_async_work_cv);
3068 	cv_destroy(&mi->mi_async_reqs_cv);
3069 	cv_destroy(&mi->mi_async_cv);
3070 	zone_rele(mi->mi_zone);
3071 	kmem_free(mi, sizeof (*mi));
3072 }
3073 
3074 static int
3075 mnt_kstat_update(kstat_t *ksp, int rw)
3076 {
3077 	mntinfo_t *mi;
3078 	struct mntinfo_kstat *mik;
3079 	vfs_t *vfsp;
3080 	int i;
3081 
3082 	/* this is a read-only kstat. Bail out on a write */
3083 	if (rw == KSTAT_WRITE)
3084 		return (EACCES);
3085 
3086 	/*
3087 	 * We don't want to wait here as kstat_chain_lock could be held by
3088 	 * dounmount(). dounmount() takes vfs_reflock before the chain lock
3089 	 * and thus could lead to a deadlock.
3090 	 */
3091 	vfsp = (struct vfs *)ksp->ks_private;
3092 
3093 
3094 	mi = VFTOMI(vfsp);
3095 
3096 	mik = (struct mntinfo_kstat *)ksp->ks_data;
3097 
3098 	(void) strcpy(mik->mik_proto, mi->mi_curr_serv->sv_knconf->knc_proto);
3099 	mik->mik_vers = (uint32_t)mi->mi_vers;
3100 	mik->mik_flags = mi->mi_flags;
3101 	mik->mik_secmod = mi->mi_curr_serv->sv_secdata->secmod;
3102 	mik->mik_curread = (uint32_t)mi->mi_curread;
3103 	mik->mik_curwrite = (uint32_t)mi->mi_curwrite;
3104 	mik->mik_retrans = mi->mi_retrans;
3105 	mik->mik_timeo = mi->mi_timeo;
3106 	mik->mik_acregmin = HR2SEC(mi->mi_acregmin);
3107 	mik->mik_acregmax = HR2SEC(mi->mi_acregmax);
3108 	mik->mik_acdirmin = HR2SEC(mi->mi_acdirmin);
3109 	mik->mik_acdirmax = HR2SEC(mi->mi_acdirmax);
3110 	for (i = 0; i < NFS_CALLTYPES + 1; i++) {
3111 		mik->mik_timers[i].srtt = (uint32_t)mi->mi_timers[i].rt_srtt;
3112 		mik->mik_timers[i].deviate =
3113 		    (uint32_t)mi->mi_timers[i].rt_deviate;
3114 		mik->mik_timers[i].rtxcur =
3115 		    (uint32_t)mi->mi_timers[i].rt_rtxcur;
3116 	}
3117 	mik->mik_noresponse = (uint32_t)mi->mi_noresponse;
3118 	mik->mik_failover = (uint32_t)mi->mi_failover;
3119 	mik->mik_remap = (uint32_t)mi->mi_remap;
3120 	(void) strcpy(mik->mik_curserver, mi->mi_curr_serv->sv_hostname);
3121 
3122 	return (0);
3123 }
3124 
3125 void
3126 nfs_mnt_kstat_init(struct vfs *vfsp)
3127 {
3128 	mntinfo_t *mi = VFTOMI(vfsp);
3129 
3130 	/*
3131 	 * Create the version specific kstats.
3132 	 *
3133 	 * PSARC 2001/697 Contract Private Interface
3134 	 * All nfs kstats are under SunMC contract
3135 	 * Please refer to the PSARC listed above and contact
3136 	 * SunMC before making any changes!
3137 	 *
3138 	 * Changes must be reviewed by Solaris File Sharing
3139 	 * Changes must be communicated to contract-2001-697@sun.com
3140 	 *
3141 	 */
3142 
3143 	mi->mi_io_kstats = kstat_create_zone("nfs", getminor(vfsp->vfs_dev),
3144 	    NULL, "nfs", KSTAT_TYPE_IO, 1, 0, mi->mi_zone->zone_id);
3145 	if (mi->mi_io_kstats) {
3146 		if (mi->mi_zone->zone_id != GLOBAL_ZONEID)
3147 			kstat_zone_add(mi->mi_io_kstats, GLOBAL_ZONEID);
3148 		mi->mi_io_kstats->ks_lock = &mi->mi_lock;
3149 		kstat_install(mi->mi_io_kstats);
3150 	}
3151 
3152 	if ((mi->mi_ro_kstats = kstat_create_zone("nfs",
3153 	    getminor(vfsp->vfs_dev), "mntinfo", "misc", KSTAT_TYPE_RAW,
3154 	    sizeof (struct mntinfo_kstat), 0, mi->mi_zone->zone_id)) != NULL) {
3155 		if (mi->mi_zone->zone_id != GLOBAL_ZONEID)
3156 			kstat_zone_add(mi->mi_ro_kstats, GLOBAL_ZONEID);
3157 		mi->mi_ro_kstats->ks_update = mnt_kstat_update;
3158 		mi->mi_ro_kstats->ks_private = (void *)vfsp;
3159 		kstat_install(mi->mi_ro_kstats);
3160 	}
3161 }
3162 
3163 nfs_delmapcall_t *
3164 nfs_init_delmapcall()
3165 {
3166 	nfs_delmapcall_t	*delmap_call;
3167 
3168 	delmap_call = kmem_alloc(sizeof (nfs_delmapcall_t), KM_SLEEP);
3169 	delmap_call->call_id = curthread;
3170 	delmap_call->error = 0;
3171 
3172 	return (delmap_call);
3173 }
3174 
3175 void
3176 nfs_free_delmapcall(nfs_delmapcall_t *delmap_call)
3177 {
3178 	kmem_free(delmap_call, sizeof (nfs_delmapcall_t));
3179 }
3180 
3181 /*
3182  * Searches for the current delmap caller (based on curthread) in the list of
3183  * callers.  If it is found, we remove it and free the delmap caller.
3184  * Returns:
3185  *	0 if the caller wasn't found
3186  *	1 if the caller was found, removed and freed.  *errp is set to what
3187  * 	the result of the delmap was.
3188  */
3189 int
3190 nfs_find_and_delete_delmapcall(rnode_t *rp, int *errp)
3191 {
3192 	nfs_delmapcall_t	*delmap_call;
3193 
3194 	/*
3195 	 * If the list doesn't exist yet, we create it and return
3196 	 * that the caller wasn't found.  No list = no callers.
3197 	 */
3198 	mutex_enter(&rp->r_statelock);
3199 	if (!(rp->r_flags & RDELMAPLIST)) {
3200 		/* The list does not exist */
3201 		list_create(&rp->r_indelmap, sizeof (nfs_delmapcall_t),
3202 		    offsetof(nfs_delmapcall_t, call_node));
3203 		rp->r_flags |= RDELMAPLIST;
3204 		mutex_exit(&rp->r_statelock);
3205 		return (0);
3206 	} else {
3207 		/* The list exists so search it */
3208 		for (delmap_call = list_head(&rp->r_indelmap);
3209 		    delmap_call != NULL;
3210 		    delmap_call = list_next(&rp->r_indelmap, delmap_call)) {
3211 			if (delmap_call->call_id == curthread) {
3212 				/* current caller is in the list */
3213 				*errp = delmap_call->error;
3214 				list_remove(&rp->r_indelmap, delmap_call);
3215 				mutex_exit(&rp->r_statelock);
3216 				nfs_free_delmapcall(delmap_call);
3217 				return (1);
3218 			}
3219 		}
3220 	}
3221 	mutex_exit(&rp->r_statelock);
3222 	return (0);
3223 }
3224