xref: /netbsd-src/sys/fs/puffs/puffs_msgif.c (revision 100a3398b8d3c64e571cff36b46c23431b410e09)
1 /*	$NetBSD: puffs_msgif.c,v 1.107 2024/02/09 22:08:37 andvar Exp $	*/
2 
3 /*
4  * Copyright (c) 2005, 2006, 2007  Antti Kantee.  All Rights Reserved.
5  *
6  * Development of this software was supported by the
7  * Google Summer of Code program and the Ulla Tuominen Foundation.
8  * The Google SoC project was mentored by Bill Studenmund.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
20  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: puffs_msgif.c,v 1.107 2024/02/09 22:08:37 andvar Exp $");
34 
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/atomic.h>
38 #include <sys/kmem.h>
39 #include <sys/kthread.h>
40 #include <sys/lock.h>
41 #include <sys/mount.h>
42 #include <sys/namei.h>
43 #include <sys/proc.h>
44 #include <sys/vnode.h>
45 #include <sys/atomic.h>
46 #include <sys/compat_stub.h>
47 
48 #include <uvm/uvm.h>
49 
50 #include <dev/putter/putter_sys.h>
51 
52 #include <fs/puffs/puffs_msgif.h>
53 #include <fs/puffs/puffs_sys.h>
54 
55 /*
56  * waitq data structures
57  */
58 
59 /*
60  * While a request is going to userspace, park the caller within the
61  * kernel.  This is the kernel counterpart of "struct puffs_req".
62  */
63 struct puffs_msgpark {
64 	struct puffs_req	*park_preq;	/* req followed by buf	*/
65 
66 	size_t			park_copylen;	/* userspace copylength	*/
67 	size_t			park_maxlen;	/* max size in comeback */
68 
69 	struct puffs_req	*park_creq;	/* non-compat preq	*/
70 	size_t			park_creqlen;	/* non-compat preq len	*/
71 
72 	parkdone_fn		park_done;	/* "biodone" a'la puffs	*/
73 	void			*park_donearg;
74 
75 	int			park_flags;
76 	int			park_refcount;
77 
78 	kcondvar_t		park_cv;
79 	kmutex_t		park_mtx;
80 
81 	TAILQ_ENTRY(puffs_msgpark) park_entries;
82 };
83 #define PARKFLAG_WAITERGONE	0x01
84 #define PARKFLAG_DONE		0x02
85 #define PARKFLAG_ONQUEUE1	0x04
86 #define PARKFLAG_ONQUEUE2	0x08
87 #define PARKFLAG_CALL		0x10
88 #define PARKFLAG_WANTREPLY	0x20
89 #define	PARKFLAG_HASERROR	0x40
90 
91 static pool_cache_t parkpc;
92 #ifdef PUFFSDEBUG
93 static int totalpark;
94 #endif
95 
96 int puffs_sopreq_expire_timeout = PUFFS_SOPREQ_EXPIRE_TIMEOUT;
97 
98 static int
makepark(void * arg,void * obj,int flags)99 makepark(void *arg, void *obj, int flags)
100 {
101 	struct puffs_msgpark *park = obj;
102 
103 	mutex_init(&park->park_mtx, MUTEX_DEFAULT, IPL_NONE);
104 	cv_init(&park->park_cv, "puffsrpl");
105 
106 	return 0;
107 }
108 
109 static void
nukepark(void * arg,void * obj)110 nukepark(void *arg, void *obj)
111 {
112 	struct puffs_msgpark *park = obj;
113 
114 	cv_destroy(&park->park_cv);
115 	mutex_destroy(&park->park_mtx);
116 }
117 
118 void
puffs_msgif_init(void)119 puffs_msgif_init(void)
120 {
121 
122 	parkpc = pool_cache_init(sizeof(struct puffs_msgpark), 0, 0, 0,
123 	    "puffprkl", NULL, IPL_NONE, makepark, nukepark, NULL);
124 }
125 
126 void
puffs_msgif_destroy(void)127 puffs_msgif_destroy(void)
128 {
129 
130 	pool_cache_destroy(parkpc);
131 }
132 
133 static struct puffs_msgpark *
puffs_msgpark_alloc(int waitok)134 puffs_msgpark_alloc(int waitok)
135 {
136 	struct puffs_msgpark *park;
137 
138 	KASSERT(curlwp != uvm.pagedaemon_lwp || !waitok);
139 
140 	park = pool_cache_get(parkpc, waitok ? PR_WAITOK : PR_NOWAIT);
141 	if (park == NULL)
142 		return park;
143 
144 	park->park_refcount = 1;
145 	park->park_preq = park->park_creq = NULL;
146 	park->park_flags = PARKFLAG_WANTREPLY;
147 
148 #ifdef PUFFSDEBUG
149 	totalpark++;
150 #endif
151 
152 	return park;
153 }
154 
155 static void
puffs_msgpark_reference(struct puffs_msgpark * park)156 puffs_msgpark_reference(struct puffs_msgpark *park)
157 {
158 
159 	KASSERT(mutex_owned(&park->park_mtx));
160 	park->park_refcount++;
161 }
162 
163 /*
164  * Release reference to park structure.
165  */
166 static void
puffs_msgpark_release1(struct puffs_msgpark * park,int howmany)167 puffs_msgpark_release1(struct puffs_msgpark *park, int howmany)
168 {
169 	struct puffs_req *preq = park->park_preq;
170 	struct puffs_req *creq = park->park_creq;
171 	int refcnt;
172 
173 	KASSERT(mutex_owned(&park->park_mtx));
174 	refcnt = park->park_refcount -= howmany;
175 	mutex_exit(&park->park_mtx);
176 
177 	KASSERT(refcnt >= 0);
178 
179 	if (refcnt == 0) {
180 		if (preq)
181 			kmem_free(preq, park->park_maxlen);
182 #if 1
183 		if (creq)
184 			kmem_free(creq, park->park_creqlen);
185 #endif
186 		pool_cache_put(parkpc, park);
187 
188 #ifdef PUFFSDEBUG
189 		totalpark--;
190 #endif
191 	}
192 }
193 #define puffs_msgpark_release(a) puffs_msgpark_release1(a, 1)
194 
195 #ifdef PUFFSDEBUG
196 static void
parkdump(struct puffs_msgpark * park)197 parkdump(struct puffs_msgpark *park)
198 {
199 
200 	DPRINTF(("park %p, preq %p, id %" PRIu64 "\n"
201 	    "\tcopy %zu, max %zu - done: %p/%p\n"
202 	    "\tflags 0x%08x, refcount %d, cv/mtx: %p/%p\n",
203 	    park, park->park_preq, park->park_preq->preq_id,
204 	    park->park_copylen, park->park_maxlen,
205 	    park->park_done, park->park_donearg,
206 	    park->park_flags, park->park_refcount,
207 	    &park->park_cv, &park->park_mtx));
208 }
209 
210 static void
parkqdump(struct puffs_wq * q,int dumpall)211 parkqdump(struct puffs_wq *q, int dumpall)
212 {
213 	struct puffs_msgpark *park;
214 	int total = 0;
215 
216 	TAILQ_FOREACH(park, q, park_entries) {
217 		if (dumpall)
218 			parkdump(park);
219 		total++;
220 	}
221 	DPRINTF(("puffs waitqueue at %p dumped, %d total\n", q, total));
222 
223 }
224 #endif /* PUFFSDEBUG */
225 
226 /*
227  * A word about locking in the park structures: the lock protects the
228  * fields of the *park* structure (not preq) and acts as an interlock
229  * in cv operations.  The lock is always internal to this module and
230  * callers do not need to worry about it.
231  */
232 
233 int
puffs_msgmem_alloc(size_t len,struct puffs_msgpark ** ppark,void ** mem,int cansleep)234 puffs_msgmem_alloc(size_t len, struct puffs_msgpark **ppark, void **mem,
235 	int cansleep)
236 {
237 	struct puffs_msgpark *park;
238 	void *m;
239 
240 	KASSERT(curlwp != uvm.pagedaemon_lwp || !cansleep);
241 	m = kmem_zalloc(len, cansleep ? KM_SLEEP : KM_NOSLEEP);
242 	if (m == NULL) {
243 		KASSERT(cansleep == 0);
244 		return ENOMEM;
245 	}
246 
247 	park = puffs_msgpark_alloc(cansleep);
248 	if (park == NULL) {
249 		KASSERT(cansleep == 0);
250 		kmem_free(m, len);
251 		return ENOMEM;
252 	}
253 
254 	park->park_preq = m;
255 	park->park_maxlen = park->park_copylen = len;
256 
257 	*ppark = park;
258 	*mem = m;
259 
260 	return 0;
261 }
262 
263 void
puffs_msgmem_release(struct puffs_msgpark * park)264 puffs_msgmem_release(struct puffs_msgpark *park)
265 {
266 
267 	if (park == NULL)
268 		return;
269 
270 	mutex_enter(&park->park_mtx);
271 	puffs_msgpark_release(park);
272 }
273 
274 void
puffs_msg_setfaf(struct puffs_msgpark * park)275 puffs_msg_setfaf(struct puffs_msgpark *park)
276 {
277 
278 	KASSERT((park->park_flags & PARKFLAG_CALL) == 0);
279 	park->park_flags &= ~PARKFLAG_WANTREPLY;
280 }
281 
282 void
puffs_msg_setdelta(struct puffs_msgpark * park,size_t delta)283 puffs_msg_setdelta(struct puffs_msgpark *park, size_t delta)
284 {
285 
286 	KASSERT(delta < park->park_maxlen); /* "<=" wouldn't make sense */
287 	park->park_copylen = park->park_maxlen - delta;
288 }
289 
290 void
puffs_msg_setinfo(struct puffs_msgpark * park,int opclass,int type,puffs_cookie_t ck)291 puffs_msg_setinfo(struct puffs_msgpark *park, int opclass, int type,
292 	puffs_cookie_t ck)
293 {
294 
295 	park->park_preq->preq_opclass = PUFFSOP_OPCLASS(opclass);
296 	park->park_preq->preq_optype = type;
297 	park->park_preq->preq_cookie = ck;
298 }
299 
300 void
puffs_msg_setcall(struct puffs_msgpark * park,parkdone_fn donefn,void * donearg)301 puffs_msg_setcall(struct puffs_msgpark *park, parkdone_fn donefn, void *donearg)
302 {
303 
304 	KASSERT(park->park_flags & PARKFLAG_WANTREPLY);
305 	park->park_done = donefn;
306 	park->park_donearg = donearg;
307 	park->park_flags |= PARKFLAG_CALL;
308 }
309 
310 /*
311  * kernel-user-kernel waitqueues
312  */
313 
314 static uint64_t
puffs_getmsgid(struct puffs_mount * pmp)315 puffs_getmsgid(struct puffs_mount *pmp)
316 {
317 	uint64_t rv;
318 
319 	mutex_enter(&pmp->pmp_lock);
320 	rv = pmp->pmp_nextmsgid++;
321 	mutex_exit(&pmp->pmp_lock);
322 
323 	return rv;
324 }
325 
326 /*
327  * A word about reference counting of parks.  A reference must be taken
328  * when accessing a park and additionally when it is on a queue.  So
329  * when taking it off a queue and releasing the access reference, the
330  * reference count is generally decremented by 2.
331  */
332 
333 void
puffs_msg_enqueue(struct puffs_mount * pmp,struct puffs_msgpark * park)334 puffs_msg_enqueue(struct puffs_mount *pmp, struct puffs_msgpark *park)
335 {
336 	struct lwp *l = curlwp;
337 	struct puffs_req *preq, *creq;
338 	ssize_t delta;
339 #if 1
340 	int ret;
341 #endif
342 
343 	/*
344 	 * Some clients reuse a park, so reset some flags.  We might
345 	 * want to provide a caller-side interface for this and add
346 	 * a few more invariant checks here, but this will do for now.
347 	 */
348 	park->park_flags &= ~(PARKFLAG_DONE | PARKFLAG_HASERROR);
349 	KASSERT((park->park_flags & PARKFLAG_WAITERGONE) == 0);
350 
351 	preq = park->park_preq;
352 
353 #if 1
354 	/* check if we do compat adjustments */
355 	if (pmp->pmp_docompat) {
356 		MODULE_HOOK_CALL(puffs_out_50_hook, (preq, &creq, &delta),
357 		    enosys(), ret);
358 		if (ret == 0) {
359 			park->park_creq = park->park_preq;
360 			park->park_creqlen = park->park_maxlen;
361 
362 			park->park_maxlen += delta;
363 			park->park_copylen += delta;
364 			park->park_preq = preq = creq;
365 		}
366 	}
367 #endif
368 
369 	preq->preq_buflen = park->park_maxlen;
370 	KASSERT(preq->preq_id == 0
371 	    || (preq->preq_opclass & PUFFSOPFLAG_ISRESPONSE));
372 
373 	if ((park->park_flags & PARKFLAG_WANTREPLY) == 0)
374 		preq->preq_opclass |= PUFFSOPFLAG_FAF;
375 	else
376 		preq->preq_id = puffs_getmsgid(pmp);
377 
378 	/* fill in caller information */
379 	preq->preq_pid = l->l_proc->p_pid;
380 	preq->preq_lid = l->l_lid;
381 
382 	/*
383 	 * To support cv_sig, yet another movie: check if there are signals
384 	 * pending and we are issuing a non-FAF.  If so, return an error
385 	 * directly UNLESS we are issuing INACTIVE/RECLAIM.  In that case,
386 	 * convert it to a FAF, fire off to the file server and return
387 	 * an error.  Yes, this is bordering disgusting.  Barfbags are on me.
388 	 */
389 	if (__predict_false((park->park_flags & PARKFLAG_WANTREPLY)
390 	   && (park->park_flags & PARKFLAG_CALL) == 0
391 	   && (l->l_flag & LW_PENDSIG) != 0 && sigispending(l, 0))) {
392 		sigset_t ss;
393 
394 		/*
395 		 * see the comment about signals in puffs_msg_wait.
396 		 */
397 		sigpending1(l, &ss);
398 		if (sigismember(&ss, SIGINT) ||
399 		    sigismember(&ss, SIGTERM) ||
400 		    sigismember(&ss, SIGKILL) ||
401 		    sigismember(&ss, SIGHUP) ||
402 		    sigismember(&ss, SIGQUIT)) {
403 			park->park_flags |= PARKFLAG_HASERROR;
404 			preq->preq_rv = EINTR;
405 			if (PUFFSOP_OPCLASS(preq->preq_opclass) == PUFFSOP_VN
406 			    && (preq->preq_optype == PUFFS_VN_INACTIVE
407 			     || preq->preq_optype == PUFFS_VN_RECLAIM)) {
408 				park->park_preq->preq_opclass |=
409 				    PUFFSOPFLAG_FAF;
410 				park->park_flags &= ~PARKFLAG_WANTREPLY;
411 				DPRINTF(("puffs_msg_enqueue: "
412 				    "converted to FAF %p\n", park));
413 			} else {
414 				return;
415 			}
416 		}
417 	}
418 
419 	mutex_enter(&pmp->pmp_lock);
420 	if (pmp->pmp_status != PUFFSTAT_RUNNING) {
421 		mutex_exit(&pmp->pmp_lock);
422 		park->park_flags |= PARKFLAG_HASERROR;
423 		preq->preq_rv = ENXIO;
424 		return;
425 	}
426 
427 #ifdef PUFFSDEBUG
428 	parkqdump(&pmp->pmp_msg_touser, puffsdebug > 1);
429 	parkqdump(&pmp->pmp_msg_replywait, puffsdebug > 1);
430 #endif
431 
432 	/*
433 	 * Note: we don't need to lock park since we have the only
434 	 * reference to it at this point.
435 	 */
436 	TAILQ_INSERT_TAIL(&pmp->pmp_msg_touser, park, park_entries);
437 	park->park_flags |= PARKFLAG_ONQUEUE1;
438 	pmp->pmp_msg_touser_count++;
439 	park->park_refcount++;
440 
441 	cv_broadcast(&pmp->pmp_msg_waiter_cv);
442 	mutex_exit(&pmp->pmp_lock);
443 	putter_notify(pmp->pmp_pi);
444 
445 	DPRINTF(("touser: req %" PRIu64 ", preq: %p, park: %p, "
446 	    "c/t: 0x%x/0x%x, f: 0x%x\n", preq->preq_id, preq, park,
447 	    preq->preq_opclass, preq->preq_optype, park->park_flags));
448 }
449 
450 int
puffs_msg_wait(struct puffs_mount * pmp,struct puffs_msgpark * park)451 puffs_msg_wait(struct puffs_mount *pmp, struct puffs_msgpark *park)
452 {
453 	lwp_t *l = curlwp;
454 	proc_t *p = l->l_proc;
455 	struct puffs_req *preq = park->park_preq; /* XXX: hmmm */
456 	sigset_t ss;
457 	sigset_t oss;
458 	int error = 0;
459 	int rv;
460 
461 	/*
462 	 * block unimportant signals.
463 	 *
464 	 * The set of "important" signals here was chosen to be same as
465 	 * nfs interruptible mount.
466 	 */
467 	sigfillset(&ss);
468 	sigdelset(&ss, SIGINT);
469 	sigdelset(&ss, SIGTERM);
470 	sigdelset(&ss, SIGKILL);
471 	sigdelset(&ss, SIGHUP);
472 	sigdelset(&ss, SIGQUIT);
473 	mutex_enter(p->p_lock);
474 	sigprocmask1(l, SIG_BLOCK, &ss, &oss);
475 	mutex_exit(p->p_lock);
476 
477 	mutex_enter(&pmp->pmp_lock);
478 	puffs_mp_reference(pmp);
479 	mutex_exit(&pmp->pmp_lock);
480 
481 	mutex_enter(&park->park_mtx);
482 	/* did the response beat us to the wait? */
483 	if (__predict_false((park->park_flags & PARKFLAG_DONE)
484 	    || (park->park_flags & PARKFLAG_HASERROR))) {
485 		rv = park->park_preq->preq_rv;
486 		mutex_exit(&park->park_mtx);
487 		goto skipwait;
488 	}
489 
490 	if ((park->park_flags & PARKFLAG_WANTREPLY) == 0
491 	    || (park->park_flags & PARKFLAG_CALL)) {
492 		mutex_exit(&park->park_mtx);
493 		rv = 0;
494 		goto skipwait;
495 	}
496 
497 	error = cv_wait_sig(&park->park_cv, &park->park_mtx);
498 	DPRINTF(("puffs_touser: waiter for %p woke up with %d\n",
499 	    park, error));
500 	if (error) {
501 		park->park_flags |= PARKFLAG_WAITERGONE;
502 		if (park->park_flags & PARKFLAG_DONE) {
503 			rv = preq->preq_rv;
504 			mutex_exit(&park->park_mtx);
505 		} else {
506 			/*
507 			 * ok, we marked it as going away, but
508 			 * still need to do queue ops.  take locks
509 			 * in correct order.
510 			 *
511 			 * We don't want to release our reference
512 			 * if it's on replywait queue to avoid error
513 			 * to file server.  putop() code will DTRT.
514 			 */
515 			mutex_exit(&park->park_mtx);
516 			mutex_enter(&pmp->pmp_lock);
517 			mutex_enter(&park->park_mtx);
518 
519 			/*
520 			 * Still on queue1?  We can safely remove it
521 			 * without any consequences since the file
522 			 * server hasn't seen it.  "else" we need to
523 			 * wait for the response and just ignore it
524 			 * to avoid signalling an incorrect error to
525 			 * the file server.
526 			 */
527 			if (park->park_flags & PARKFLAG_ONQUEUE1) {
528 				TAILQ_REMOVE(&pmp->pmp_msg_touser,
529 				    park, park_entries);
530 				puffs_msgpark_release(park);
531 				pmp->pmp_msg_touser_count--;
532 				park->park_flags &= ~PARKFLAG_ONQUEUE1;
533 			} else {
534 				mutex_exit(&park->park_mtx);
535 			}
536 			mutex_exit(&pmp->pmp_lock);
537 
538 			rv = EINTR;
539 		}
540 	} else {
541 		rv = preq->preq_rv;
542 		mutex_exit(&park->park_mtx);
543 	}
544 
545  skipwait:
546 	mutex_enter(&pmp->pmp_lock);
547 	puffs_mp_release(pmp);
548 	mutex_exit(&pmp->pmp_lock);
549 
550 	mutex_enter(p->p_lock);
551 	sigprocmask1(l, SIG_SETMASK, &oss, NULL);
552 	mutex_exit(p->p_lock);
553 
554 	return rv;
555 }
556 
557 /*
558  * XXX: this suuuucks.  Hopefully I'll get rid of this lossage once
559  * the whole setback-nonsense gets fixed.
560  */
561 int
puffs_msg_wait2(struct puffs_mount * pmp,struct puffs_msgpark * park,struct puffs_node * pn1,struct puffs_node * pn2)562 puffs_msg_wait2(struct puffs_mount *pmp, struct puffs_msgpark *park,
563 	struct puffs_node *pn1, struct puffs_node *pn2)
564 {
565 	struct puffs_req *preq;
566 	int rv;
567 
568 	rv = puffs_msg_wait(pmp, park);
569 
570 	preq = park->park_preq;
571 	if (pn1 && preq->preq_setbacks & PUFFS_SETBACK_INACT_N1)
572 		pn1->pn_stat |= PNODE_DOINACT;
573 	if (pn2 && preq->preq_setbacks & PUFFS_SETBACK_INACT_N2)
574 		pn2->pn_stat |= PNODE_DOINACT;
575 
576 	if (pn1 && preq->preq_setbacks & PUFFS_SETBACK_NOREF_N1)
577 		pn1->pn_stat |= PNODE_NOREFS;
578 	if (pn2 && preq->preq_setbacks & PUFFS_SETBACK_NOREF_N2)
579 		pn2->pn_stat |= PNODE_NOREFS;
580 
581 	return rv;
582 
583 }
584 
585 /*
586  * XXX: lazy bum.  please, for the love of foie gras, fix me.
587  * This should *NOT* depend on setfaf.  Also "memcpy" could
588  * be done more nicely.
589  */
590 void
puffs_msg_sendresp(struct puffs_mount * pmp,struct puffs_req * origpreq,int rv)591 puffs_msg_sendresp(struct puffs_mount *pmp, struct puffs_req *origpreq, int rv)
592 {
593 	struct puffs_msgpark *park;
594 	struct puffs_req *preq;
595 
596 	puffs_msgmem_alloc(sizeof(struct puffs_req), &park, (void *)&preq, 1);
597 	puffs_msg_setfaf(park); /* XXXXXX: avoids reqid override */
598 
599 	memcpy(preq, origpreq, sizeof(struct puffs_req));
600 	preq->preq_rv = rv;
601 	preq->preq_opclass |= PUFFSOPFLAG_ISRESPONSE;
602 
603 	puffs_msg_enqueue(pmp, park);
604 	puffs_msgmem_release(park);
605 }
606 
607 /*
608  * Get next request in the outgoing queue.  "maxsize" controls the
609  * size the caller can accommodate and "nonblock" signals if this
610  * should block while waiting for input.  Handles all locking internally.
611  */
612 int
puffs_msgif_getout(void * ctx,size_t maxsize,int nonblock,uint8_t ** data,size_t * dlen,void ** parkptr)613 puffs_msgif_getout(void *ctx, size_t maxsize, int nonblock,
614 	uint8_t **data, size_t *dlen, void **parkptr)
615 {
616 	struct puffs_mount *pmp = ctx;
617 	struct puffs_msgpark *park = NULL;
618 	struct puffs_req *preq = NULL;
619 	int error;
620 
621 	error = 0;
622 	mutex_enter(&pmp->pmp_lock);
623 	puffs_mp_reference(pmp);
624 	for (;;) {
625 		/* RIP? */
626 		if (pmp->pmp_status != PUFFSTAT_RUNNING) {
627 			error = ENXIO;
628 			break;
629 		}
630 
631 		/* need platinum yendorian express card? */
632 		if (TAILQ_EMPTY(&pmp->pmp_msg_touser)) {
633 			DPRINTF(("puffs_getout: no outgoing op, "));
634 			if (nonblock) {
635 				DPRINTF(("returning EWOULDBLOCK\n"));
636 				error = EWOULDBLOCK;
637 				break;
638 			}
639 			DPRINTF(("waiting ...\n"));
640 
641 			error = cv_wait_sig(&pmp->pmp_msg_waiter_cv,
642 			    &pmp->pmp_lock);
643 			if (error)
644 				break;
645 			else
646 				continue;
647 		}
648 
649 		park = TAILQ_FIRST(&pmp->pmp_msg_touser);
650 		if (park == NULL)
651 			continue;
652 
653 		mutex_enter(&park->park_mtx);
654 		puffs_msgpark_reference(park);
655 
656 		DPRINTF(("puffs_getout: found park at %p, ", park));
657 
658 		/* If it's a goner, don't process any furher */
659 		if (park->park_flags & PARKFLAG_WAITERGONE) {
660 			DPRINTF(("waitergone!\n"));
661 			puffs_msgpark_release(park);
662 			continue;
663 		}
664 		preq = park->park_preq;
665 
666 #if 0
667 		/* check size */
668 		/*
669 		 * XXX: this check is not valid for now, we don't know
670 		 * the size of the caller's input buffer.  i.e. this
671 		 * will most likely go away
672 		 */
673 		if (maxsize < preq->preq_frhdr.pfr_len) {
674 			DPRINTF(("buffer too small\n"));
675 			puffs_msgpark_release(park);
676 			error = E2BIG;
677 			break;
678 		}
679 #endif
680 
681 		DPRINTF(("returning\n"));
682 
683 		/*
684 		 * Ok, we found what we came for.  Release it from the
685 		 * outgoing queue but do not unlock.  We will unlock
686 		 * only after we "releaseout" it to avoid complications:
687 		 * otherwise it is (theoretically) possible for userland
688 		 * to race us into "put" before we have a change to put
689 		 * this baby on the receiving queue.
690 		 */
691 		TAILQ_REMOVE(&pmp->pmp_msg_touser, park, park_entries);
692 		KASSERT(park->park_flags & PARKFLAG_ONQUEUE1);
693 		park->park_flags &= ~PARKFLAG_ONQUEUE1;
694 		mutex_exit(&park->park_mtx);
695 
696 		pmp->pmp_msg_touser_count--;
697 		KASSERT(pmp->pmp_msg_touser_count >= 0);
698 
699 		break;
700 	}
701 	puffs_mp_release(pmp);
702 	mutex_exit(&pmp->pmp_lock);
703 
704 	if (error == 0) {
705 		*data = (uint8_t *)preq;
706 		preq->preq_pth.pth_framelen = park->park_copylen;
707 		*dlen = preq->preq_pth.pth_framelen;
708 		*parkptr = park;
709 	}
710 
711 	return error;
712 }
713 
714 /*
715  * Release outgoing structure.  Now, depending on the success of the
716  * outgoing send, it is either going onto the result waiting queue
717  * or the death chamber.
718  */
719 void
puffs_msgif_releaseout(void * ctx,void * parkptr,int status)720 puffs_msgif_releaseout(void *ctx, void *parkptr, int status)
721 {
722 	struct puffs_mount *pmp = ctx;
723 	struct puffs_msgpark *park = parkptr;
724 
725 	DPRINTF(("puffs_releaseout: returning park %p, errno %d: " ,
726 	    park, status));
727 	mutex_enter(&pmp->pmp_lock);
728 	mutex_enter(&park->park_mtx);
729 	if (park->park_flags & PARKFLAG_WANTREPLY) {
730 		if (status == 0) {
731 			DPRINTF(("enqueue replywait\n"));
732 			TAILQ_INSERT_TAIL(&pmp->pmp_msg_replywait, park,
733 			    park_entries);
734 			park->park_flags |= PARKFLAG_ONQUEUE2;
735 		} else {
736 			DPRINTF(("error path!\n"));
737 			park->park_preq->preq_rv = status;
738 			park->park_flags |= PARKFLAG_DONE;
739 			cv_signal(&park->park_cv);
740 		}
741 		puffs_msgpark_release(park);
742 	} else {
743 		DPRINTF(("release\n"));
744 		puffs_msgpark_release1(park, 2);
745 	}
746 	mutex_exit(&pmp->pmp_lock);
747 }
748 
749 size_t
puffs_msgif_waitcount(void * ctx)750 puffs_msgif_waitcount(void *ctx)
751 {
752 	struct puffs_mount *pmp = ctx;
753 	size_t rv;
754 
755 	mutex_enter(&pmp->pmp_lock);
756 	rv = pmp->pmp_msg_touser_count;
757 	mutex_exit(&pmp->pmp_lock);
758 
759 	return rv;
760 }
761 
762 /*
763  * XXX: locking with this one?
764  */
765 static void
puffsop_msg(void * ctx,struct puffs_req * preq)766 puffsop_msg(void *ctx, struct puffs_req *preq)
767 {
768 	struct puffs_mount *pmp = ctx;
769 	struct putter_hdr *pth = &preq->preq_pth;
770 	struct puffs_msgpark *park;
771 	int wgone;
772 
773 	mutex_enter(&pmp->pmp_lock);
774 
775 	/* Locate waiter */
776 	TAILQ_FOREACH(park, &pmp->pmp_msg_replywait, park_entries) {
777 		if (park->park_preq->preq_id == preq->preq_id)
778 			break;
779 	}
780 	if (park == NULL) {
781 		DPRINTF(("puffsop_msg: no request: %" PRIu64 "\n",
782 		    preq->preq_id));
783 		mutex_exit(&pmp->pmp_lock);
784 		return; /* XXX send error */
785 	}
786 
787 	mutex_enter(&park->park_mtx);
788 	puffs_msgpark_reference(park);
789 	if (pth->pth_framelen > park->park_maxlen) {
790 		DPRINTF(("puffsop_msg: invalid buffer length: "
791 		    "%" PRIu64 " (req %" PRIu64 ", \n", pth->pth_framelen,
792 		    preq->preq_id));
793 		park->park_preq->preq_rv = EPROTO;
794 		cv_signal(&park->park_cv);
795 		puffs_msgpark_release1(park, 2);
796 		mutex_exit(&pmp->pmp_lock);
797 		return; /* XXX: error */
798 	}
799 	wgone = park->park_flags & PARKFLAG_WAITERGONE;
800 
801 	KASSERT(park->park_flags & PARKFLAG_ONQUEUE2);
802 	TAILQ_REMOVE(&pmp->pmp_msg_replywait, park, park_entries);
803 	park->park_flags &= ~PARKFLAG_ONQUEUE2;
804 	mutex_exit(&pmp->pmp_lock);
805 
806 	if (wgone) {
807 		DPRINTF(("puffsop_msg: bad service - waiter gone for "
808 		    "park %p\n", park));
809 	} else {
810 #if 1
811 		if (park->park_creq) {
812 			struct puffs_req *creq;
813 			size_t csize;
814 
815 			KASSERT(pmp->pmp_docompat);
816 			MODULE_HOOK_CALL_VOID(puffs_in_50_hook,
817 			     (preq, park->park_creq), __nothing);
818 			creq = park->park_creq;
819 			csize = park->park_creqlen;
820 			park->park_creq = park->park_preq;
821 			park->park_creqlen = park->park_maxlen;
822 
823 			park->park_preq = creq;
824 			park->park_maxlen = csize;
825 
826 			memcpy(park->park_creq, preq, pth->pth_framelen);
827 		} else {
828 #endif
829 			memcpy(park->park_preq, preq, pth->pth_framelen);
830 		}
831 
832 		if (park->park_flags & PARKFLAG_CALL) {
833 			DPRINTF(("puffsop_msg: call for %p, arg %p\n",
834 			    park->park_preq, park->park_donearg));
835 			park->park_done(pmp, preq, park->park_donearg);
836 		}
837 	}
838 
839 	if (!wgone) {
840 		DPRINTF(("puffs_putop: flagging done for "
841 		    "park %p\n", park));
842 		cv_signal(&park->park_cv);
843 	}
844 
845 	park->park_flags |= PARKFLAG_DONE;
846 	puffs_msgpark_release1(park, 2);
847 }
848 
849 /*
850  * Node expiry. We come here after an inactive on an unexpired node.
851  * The expiry has been queued and is done in sop thread.
852  */
853 static void
puffsop_expire(struct puffs_mount * pmp,puffs_cookie_t cookie)854 puffsop_expire(struct puffs_mount *pmp, puffs_cookie_t cookie)
855 {
856 	struct vnode *vp;
857 
858 	KASSERT(PUFFS_USE_FS_TTL(pmp));
859 
860 	/*
861 	 * If it still exists and has no reference,
862 	 * vrele should cause it to be reclaimed.
863 	 * Otherwise, we have nothing to do.
864 	 */
865 	if (puffs_cookie2vnode(pmp, cookie, &vp) == 0) {
866 		VPTOPP(vp)->pn_stat &= ~PNODE_SOPEXP;
867 		vrele(vp);
868 	}
869 
870 	return;
871 }
872 
873 static void
puffsop_flush(struct puffs_mount * pmp,struct puffs_flush * pf)874 puffsop_flush(struct puffs_mount *pmp, struct puffs_flush *pf)
875 {
876 	struct vnode *vp;
877 	voff_t offlo, offhi;
878 	int rv, flags = 0;
879 
880 	KASSERT(pf->pf_req.preq_pth.pth_framelen == sizeof(struct puffs_flush));
881 
882 	/* XXX: slurry */
883 	if (pf->pf_op == PUFFS_INVAL_NAMECACHE_ALL) {
884 		cache_purgevfs(PMPTOMP(pmp));
885 		rv = 0;
886 		goto out;
887 	}
888 
889 	/*
890 	 * Get vnode, don't lock it.  Namecache is protected by its own lock
891 	 * and we have a reference to protect against premature harvesting.
892 	 *
893 	 * The node we want here might be locked and the op is in
894 	 * userspace waiting for us to complete ==> deadlock.  Another
895 	 * reason we need to eventually bump locking to userspace, as we
896 	 * will need to lock the node if we wish to do flushes.
897 	 */
898 	rv = puffs_cookie2vnode(pmp, pf->pf_cookie, &vp);
899 	if (rv) {
900 		if (rv == PUFFS_NOSUCHCOOKIE)
901 			rv = ENOENT;
902 		goto out;
903 	}
904 
905 	switch (pf->pf_op) {
906 #if 0
907 	/* not quite ready, yet */
908 	case PUFFS_INVAL_NAMECACHE_NODE:
909 	struct componentname *pf_cn;
910 	char *name;
911 		/* get comfortab^Wcomponentname */
912 		pf_cn = kmem_alloc(componentname);
913 		memset(pf_cn, 0, sizeof(struct componentname));
914 		break;
915 
916 #endif
917 	case PUFFS_INVAL_NAMECACHE_DIR:
918 		if (vp->v_type != VDIR) {
919 			rv = EINVAL;
920 			break;
921 		}
922 		cache_purge1(vp, NULL, 0, PURGE_CHILDREN);
923 		break;
924 
925 	case PUFFS_INVAL_PAGECACHE_NODE_RANGE:
926 		flags = PGO_FREE;
927 		/*FALLTHROUGH*/
928 	case PUFFS_FLUSH_PAGECACHE_NODE_RANGE:
929 		if (flags == 0)
930 			flags = PGO_CLEANIT;
931 
932 		if (pf->pf_end > vp->v_size || vp->v_type != VREG) {
933 			rv = EINVAL;
934 			break;
935 		}
936 
937 		offlo = trunc_page(pf->pf_start);
938 		offhi = round_page(pf->pf_end);
939 		if (offhi != 0 && offlo >= offhi) {
940 			rv = EINVAL;
941 			break;
942 		}
943 
944 		rw_enter(vp->v_uobj.vmobjlock, RW_WRITER);
945 		rv = VOP_PUTPAGES(vp, offlo, offhi, flags);
946 		break;
947 
948 	default:
949 		rv = EINVAL;
950 	}
951 
952 	vrele(vp);
953 
954  out:
955 	puffs_msg_sendresp(pmp, &pf->pf_req, rv);
956 }
957 
958 int
puffs_msgif_dispatch(void * ctx,struct putter_hdr * pth)959 puffs_msgif_dispatch(void *ctx, struct putter_hdr *pth)
960 {
961 	struct puffs_mount *pmp = ctx;
962 	struct puffs_req *preq = (struct puffs_req *)pth;
963 	struct puffs_sopreq *psopr;
964 
965 	if (pth->pth_framelen < sizeof(struct puffs_req)) {
966 		puffs_msg_sendresp(pmp, preq, EINVAL); /* E2SMALL */
967 		return 0;
968 	}
969 
970 	switch (PUFFSOP_OPCLASS(preq->preq_opclass)) {
971 	case PUFFSOP_VN:
972 	case PUFFSOP_VFS:
973 		DPRINTF(("dispatch: vn/vfs message 0x%x\n", preq->preq_optype));
974 		puffsop_msg(pmp, preq);
975 		break;
976 
977 	case PUFFSOP_FLUSH: /* process in sop thread */
978 	{
979 		struct puffs_flush *pf;
980 
981 		DPRINTF(("dispatch: flush 0x%x\n", preq->preq_optype));
982 
983 		if (preq->preq_pth.pth_framelen != sizeof(struct puffs_flush)) {
984 			puffs_msg_sendresp(pmp, preq, EINVAL); /* E2SMALL */
985 			break;
986 		}
987 		pf = (struct puffs_flush *)preq;
988 
989 		KASSERT(curlwp != uvm.pagedaemon_lwp);
990 		psopr = kmem_alloc(sizeof(*psopr), KM_SLEEP);
991 		memcpy(&psopr->psopr_pf, pf, sizeof(*pf));
992 		psopr->psopr_sopreq = PUFFS_SOPREQ_FLUSH;
993 
994 		mutex_enter(&pmp->pmp_sopmtx);
995 		if (pmp->pmp_sopthrcount == 0) {
996 			mutex_exit(&pmp->pmp_sopmtx);
997 			kmem_free(psopr, sizeof(*psopr));
998 			puffs_msg_sendresp(pmp, preq, ENXIO);
999 		} else {
1000 			TAILQ_INSERT_TAIL(&pmp->pmp_sopfastreqs,
1001 			    psopr, psopr_entries);
1002 			cv_signal(&pmp->pmp_sopcv);
1003 			mutex_exit(&pmp->pmp_sopmtx);
1004 		}
1005 		break;
1006 	}
1007 
1008 	case PUFFSOP_UNMOUNT: /* process in sop thread */
1009 	{
1010 
1011 		DPRINTF(("dispatch: unmount 0x%x\n", preq->preq_optype));
1012 
1013 		KASSERT(curlwp != uvm.pagedaemon_lwp);
1014 		psopr = kmem_alloc(sizeof(*psopr), KM_SLEEP);
1015 		psopr->psopr_preq = *preq;
1016 		psopr->psopr_sopreq = PUFFS_SOPREQ_UNMOUNT;
1017 
1018 		mutex_enter(&pmp->pmp_sopmtx);
1019 		if (pmp->pmp_sopthrcount == 0) {
1020 			mutex_exit(&pmp->pmp_sopmtx);
1021 			kmem_free(psopr, sizeof(*psopr));
1022 			puffs_msg_sendresp(pmp, preq, ENXIO);
1023 		} else {
1024 			TAILQ_INSERT_TAIL(&pmp->pmp_sopfastreqs,
1025 			    psopr, psopr_entries);
1026 			cv_signal(&pmp->pmp_sopcv);
1027 			mutex_exit(&pmp->pmp_sopmtx);
1028 		}
1029 		break;
1030 	}
1031 
1032 	default:
1033 		DPRINTF(("dispatch: invalid opclass 0x%x\n", preq->preq_opclass));
1034 		puffs_msg_sendresp(pmp, preq, EOPNOTSUPP);
1035 		break;
1036 	}
1037 
1038 	return 0;
1039 }
1040 
1041 /*
1042  * Work loop for thread processing all ops from server which
1043  * cannot safely be handled in caller context.  This includes
1044  * everything which might need a lock currently "held" by the file
1045  * server, i.e. a long-term kernel lock which will be released only
1046  * once the file server acknowledges a request
1047  */
1048 #define TIMED_OUT(expire) \
1049     ((int)((unsigned int)getticks() - (unsigned int)expire) > 0)
1050 void
puffs_sop_thread(void * arg)1051 puffs_sop_thread(void *arg)
1052 {
1053 	struct puffs_mount *pmp = arg;
1054 	struct mount *mp = PMPTOMP(pmp);
1055 	struct puffs_sopreq *psopr;
1056 	bool keeprunning;
1057 	bool unmountme = false;
1058 	int timeo;
1059 
1060 	timeo = PUFFS_USE_FS_TTL(pmp) ? puffs_sopreq_expire_timeout : 0;
1061 
1062 	mutex_enter(&pmp->pmp_sopmtx);
1063 	for (keeprunning = true; keeprunning; ) {
1064 		/*
1065 		 * We have a fast queue for flush and umount, and a node
1066 		 * queue for delayes node reclaims. Requests on node queue 			 * are not honoured before clock reaches psopr_at. This
1067 		 * code assumes that requests are ordered by psopr_at.
1068 		 */
1069 		do {
1070 			psopr = TAILQ_FIRST(&pmp->pmp_sopfastreqs);
1071 			if (psopr != NULL) {
1072 				TAILQ_REMOVE(&pmp->pmp_sopfastreqs,
1073 					     psopr, psopr_entries);
1074 				break;
1075 			}
1076 
1077 			psopr = TAILQ_FIRST(&pmp->pmp_sopnodereqs);
1078 			if ((psopr != NULL) && TIMED_OUT(psopr->psopr_at)) {
1079 				TAILQ_REMOVE(&pmp->pmp_sopnodereqs,
1080 					     psopr, psopr_entries);
1081 				break;
1082 			}
1083 
1084 			cv_timedwait(&pmp->pmp_sopcv, &pmp->pmp_sopmtx, timeo);
1085 		} while (1 /* CONSTCOND */);
1086 
1087 		mutex_exit(&pmp->pmp_sopmtx);
1088 
1089 		switch (psopr->psopr_sopreq) {
1090 		case PUFFS_SOPREQSYS_EXIT:
1091 			keeprunning = false;
1092 			break;
1093 		case PUFFS_SOPREQ_FLUSH:
1094 			puffsop_flush(pmp, &psopr->psopr_pf);
1095 			break;
1096 		case PUFFS_SOPREQ_EXPIRE:
1097 			puffsop_expire(pmp, psopr->psopr_ck);
1098 			break;
1099 		case PUFFS_SOPREQ_UNMOUNT:
1100 			puffs_msg_sendresp(pmp, &psopr->psopr_preq, 0);
1101 
1102 			unmountme = true;
1103 			keeprunning = false;
1104 
1105 			/*
1106 			 * We know the mountpoint is still alive because
1107 			 * the thread that is us (poetic?) is still alive.
1108 			 */
1109 			vfs_ref(mp);
1110 			break;
1111 		}
1112 
1113 		kmem_free(psopr, sizeof(*psopr));
1114 		mutex_enter(&pmp->pmp_sopmtx);
1115 	}
1116 
1117 	/*
1118 	 * Purge remaining ops.
1119 	 */
1120 	while ((psopr = TAILQ_FIRST(&pmp->pmp_sopfastreqs)) != NULL) {
1121 		TAILQ_REMOVE(&pmp->pmp_sopfastreqs, psopr, psopr_entries);
1122 		mutex_exit(&pmp->pmp_sopmtx);
1123 		puffs_msg_sendresp(pmp, &psopr->psopr_preq, ENXIO);
1124 		kmem_free(psopr, sizeof(*psopr));
1125 		mutex_enter(&pmp->pmp_sopmtx);
1126 	}
1127 
1128 	while ((psopr = TAILQ_FIRST(&pmp->pmp_sopnodereqs)) != NULL) {
1129 		TAILQ_REMOVE(&pmp->pmp_sopnodereqs, psopr, psopr_entries);
1130 		mutex_exit(&pmp->pmp_sopmtx);
1131 		KASSERT(psopr->psopr_sopreq == PUFFS_SOPREQ_EXPIRE);
1132 		kmem_free(psopr, sizeof(*psopr));
1133 		mutex_enter(&pmp->pmp_sopmtx);
1134 	}
1135 
1136 	pmp->pmp_sopthrcount--;
1137 	cv_broadcast(&pmp->pmp_sopcv);
1138 	mutex_exit(&pmp->pmp_sopmtx); /* not allowed to access fs after this */
1139 
1140 	/*
1141 	 * If unmount was requested, we can now safely do it here, since
1142 	 * our context is dead from the point-of-view of puffs_unmount()
1143 	 * and we are just another thread.  dounmount() makes internally
1144 	 * sure that VFS_UNMOUNT() isn't called reentrantly and that it
1145 	 * is eventually completed.
1146 	 */
1147 	if (unmountme) {
1148 		(void)dounmount(mp, MNT_FORCE, curlwp);
1149 		vfs_rele(mp);
1150 	}
1151 
1152 	kthread_exit(0);
1153 }
1154 
1155 int
puffs_msgif_close(void * ctx)1156 puffs_msgif_close(void *ctx)
1157 {
1158 	struct puffs_mount *pmp = ctx;
1159 	struct mount *mp = PMPTOMP(pmp);
1160 
1161 	mutex_enter(&pmp->pmp_lock);
1162 	puffs_mp_reference(pmp);
1163 
1164 	/*
1165 	 * Free the waiting callers before proceeding any further.
1166 	 * The syncer might be jogging around in this file system
1167 	 * currently.  If we allow it to go to the userspace of no
1168 	 * return while trying to get the syncer lock, well ...
1169 	 */
1170 	puffs_userdead(pmp);
1171 
1172 	/*
1173 	 * Make sure someone from puffs_unmount() isn't currently in
1174 	 * userspace.  If we don't take this precautionary step,
1175 	 * they might notice that the mountpoint has disappeared
1176 	 * from under them once they return.  Especially note that we
1177 	 * cannot simply test for an unmounter before calling
1178 	 * dounmount(), since it might be possible that that particular
1179 	 * invocation of unmount was called without MNT_FORCE.  Here we
1180 	 * *must* make sure unmount succeeds.  Also, restart is necessary
1181 	 * since pmp isn't locked.  We might end up with PUTTER_DEAD after
1182 	 * restart and exit from there.
1183 	 */
1184 	if (pmp->pmp_unmounting) {
1185 		cv_wait(&pmp->pmp_unmounting_cv, &pmp->pmp_lock);
1186 		puffs_mp_release(pmp);
1187 		mutex_exit(&pmp->pmp_lock);
1188 		DPRINTF(("puffs_fop_close: unmount was in progress for pmp %p, "
1189 		    "restart\n", pmp));
1190 		return ERESTART;
1191 	}
1192 
1193 	/* Won't access pmp from here anymore */
1194 	vfs_ref(mp);
1195 	puffs_mp_release(pmp);
1196 	mutex_exit(&pmp->pmp_lock);
1197 
1198 	/* Detach from VFS. */
1199 	(void)dounmount(mp, MNT_FORCE, curlwp);
1200 	vfs_rele(mp);
1201 
1202 	return 0;
1203 }
1204 
1205 /*
1206  * We're dead, kaput, RIP, slightly more than merely pining for the
1207  * fjords, belly-up, fallen, lifeless, finished, expired, gone to meet
1208  * our maker, ceased to be, etcetc.  YASD.  It's a dead FS!
1209  *
1210  * Caller must hold puffs mutex.
1211  */
1212 void
puffs_userdead(struct puffs_mount * pmp)1213 puffs_userdead(struct puffs_mount *pmp)
1214 {
1215 	struct puffs_msgpark *park, *park_next;
1216 
1217 	/*
1218 	 * Mark filesystem status as dying so that operations don't
1219 	 * attempt to march to userspace any longer.
1220 	 */
1221 	pmp->pmp_status = PUFFSTAT_DYING;
1222 
1223 	/* signal waiters on REQUEST TO file server queue */
1224 	for (park = TAILQ_FIRST(&pmp->pmp_msg_touser); park; park = park_next) {
1225 
1226 		mutex_enter(&park->park_mtx);
1227 		puffs_msgpark_reference(park);
1228 		park_next = TAILQ_NEXT(park, park_entries);
1229 
1230 		KASSERT(park->park_flags & PARKFLAG_ONQUEUE1);
1231 		TAILQ_REMOVE(&pmp->pmp_msg_touser, park, park_entries);
1232 		park->park_flags &= ~PARKFLAG_ONQUEUE1;
1233 		pmp->pmp_msg_touser_count--;
1234 
1235 		/*
1236 		 * Even though waiters on QUEUE1 are removed in touser()
1237 		 * in case of WAITERGONE, it is still possible for us to
1238 		 * get raced here due to having to retake locks in said
1239 		 * touser().  In the race case simply "ignore" the item
1240 		 * on the queue and move on to the next one.
1241 		 */
1242 		if (park->park_flags & PARKFLAG_WAITERGONE) {
1243 			KASSERT((park->park_flags & PARKFLAG_CALL) == 0);
1244 			KASSERT(park->park_flags & PARKFLAG_WANTREPLY);
1245 			puffs_msgpark_release(park);
1246 
1247 		} else {
1248 			park->park_preq->preq_rv = ENXIO;
1249 
1250 			if (park->park_flags & PARKFLAG_CALL) {
1251 				park->park_done(pmp, park->park_preq,
1252 				    park->park_donearg);
1253 				puffs_msgpark_release1(park, 2);
1254 			} else if ((park->park_flags & PARKFLAG_WANTREPLY)==0) {
1255 				puffs_msgpark_release1(park, 2);
1256 			} else {
1257 				park->park_preq->preq_rv = ENXIO;
1258 				cv_signal(&park->park_cv);
1259 				puffs_msgpark_release(park);
1260 			}
1261 		}
1262 	}
1263 
1264 	/* signal waiters on RESPONSE FROM file server queue */
1265 	for (park=TAILQ_FIRST(&pmp->pmp_msg_replywait); park; park=park_next) {
1266 		mutex_enter(&park->park_mtx);
1267 		puffs_msgpark_reference(park);
1268 		park_next = TAILQ_NEXT(park, park_entries);
1269 
1270 		KASSERT(park->park_flags & PARKFLAG_ONQUEUE2);
1271 		KASSERT(park->park_flags & PARKFLAG_WANTREPLY);
1272 
1273 		TAILQ_REMOVE(&pmp->pmp_msg_replywait, park, park_entries);
1274 		park->park_flags &= ~PARKFLAG_ONQUEUE2;
1275 
1276 		if (park->park_flags & PARKFLAG_WAITERGONE) {
1277 			KASSERT((park->park_flags & PARKFLAG_CALL) == 0);
1278 			puffs_msgpark_release(park);
1279 		} else {
1280 			park->park_preq->preq_rv = ENXIO;
1281 			if (park->park_flags & PARKFLAG_CALL) {
1282 				park->park_done(pmp, park->park_preq,
1283 				    park->park_donearg);
1284 				puffs_msgpark_release1(park, 2);
1285 			} else {
1286 				cv_signal(&park->park_cv);
1287 				puffs_msgpark_release(park);
1288 			}
1289 		}
1290 	}
1291 
1292 	cv_broadcast(&pmp->pmp_msg_waiter_cv);
1293 }
1294