xref: /netbsd-src/lib/libpuffs/puffs.c (revision 8ac07aec990b9d2e483062509d0a9fa5b4f57cf2) 
1 /*	$NetBSD: puffs.c,v 1.89 2008/01/28 18:35:50 pooka 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 #if !defined(lint)
34 __RCSID("$NetBSD: puffs.c,v 1.89 2008/01/28 18:35:50 pooka Exp $");
35 #endif /* !lint */
36 
37 #include <sys/param.h>
38 #include <sys/mount.h>
39 
40 #include <assert.h>
41 #include <err.h>
42 #include <errno.h>
43 #include <fcntl.h>
44 #include <mntopts.h>
45 #include <paths.h>
46 #include <puffs.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <syslog.h>
51 #include <unistd.h>
52 
53 #include "puffs_priv.h"
54 
55 /* Most file systems want this for opts, so just give it to them */
56 const struct mntopt puffsmopts[] = {
57 	MOPT_STDOPTS,
58 	PUFFSMOPT_STD,
59 	MOPT_NULL,
60 };
61 
62 #ifdef PUFFS_WITH_THREADS
63 #include <pthread.h>
64 pthread_mutex_t pu_lock = PTHREAD_MUTEX_INITIALIZER;
65 #endif
66 
67 #define FILLOP(lower, upper)						\
68 do {									\
69 	if (pops->puffs_node_##lower)					\
70 		opmask[PUFFS_VN_##upper] = 1;				\
71 } while (/*CONSTCOND*/0)
72 static void
73 fillvnopmask(struct puffs_ops *pops, uint8_t *opmask)
74 {
75 
76 	memset(opmask, 0, PUFFS_VN_MAX);
77 
78 	FILLOP(create,   CREATE);
79 	FILLOP(mknod,    MKNOD);
80 	FILLOP(open,     OPEN);
81 	FILLOP(close,    CLOSE);
82 	FILLOP(access,   ACCESS);
83 	FILLOP(getattr,  GETATTR);
84 	FILLOP(setattr,  SETATTR);
85 	FILLOP(poll,     POLL); /* XXX: not ready in kernel */
86 	FILLOP(mmap,     MMAP);
87 	FILLOP(fsync,    FSYNC);
88 	FILLOP(seek,     SEEK);
89 	FILLOP(remove,   REMOVE);
90 	FILLOP(link,     LINK);
91 	FILLOP(rename,   RENAME);
92 	FILLOP(mkdir,    MKDIR);
93 	FILLOP(rmdir,    RMDIR);
94 	FILLOP(symlink,  SYMLINK);
95 	FILLOP(readdir,  READDIR);
96 	FILLOP(readlink, READLINK);
97 	FILLOP(reclaim,  RECLAIM);
98 	FILLOP(inactive, INACTIVE);
99 	FILLOP(print,    PRINT);
100 	FILLOP(read,     READ);
101 	FILLOP(write,    WRITE);
102 }
103 #undef FILLOP
104 
105 /*
106  * Go over all framev entries and write everything we can.  This is
107  * mostly for the benefit of delivering "unmount" to the kernel.
108  */
109 static void
110 finalpush(struct puffs_usermount *pu)
111 {
112 	struct puffs_fctrl_io *fio;
113 
114 	LIST_FOREACH(fio, &pu->pu_ios, fio_entries) {
115 		if (fio->stat & FIO_WRGONE)
116 			continue;
117 
118 		puffs__framev_output(pu, fio->fctrl, fio);
119 	}
120 }
121 
122 /*ARGSUSED*/
123 static void
124 puffs_defaulterror(struct puffs_usermount *pu, uint8_t type,
125 	int error, const char *str, void *cookie)
126 {
127 
128 	fprintf(stderr, "abort: type %d, error %d, cookie %p (%s)\n",
129 	    type, error, cookie, str);
130 	abort();
131 }
132 
133 int
134 puffs_getselectable(struct puffs_usermount *pu)
135 {
136 
137 	return pu->pu_fd;
138 }
139 
140 uint64_t
141 puffs__nextreq(struct puffs_usermount *pu)
142 {
143 	uint64_t rv;
144 
145 	PU_LOCK();
146 	rv = pu->pu_nextreq++;
147 	PU_UNLOCK();
148 
149 	return rv;
150 }
151 
152 int
153 puffs_setblockingmode(struct puffs_usermount *pu, int mode)
154 {
155 	int rv, x;
156 
157 	assert(puffs_getstate(pu) == PUFFS_STATE_RUNNING);
158 
159 	if (mode != PUFFSDEV_BLOCK && mode != PUFFSDEV_NONBLOCK) {
160 		errno = EINVAL;
161 		return -1;
162 	}
163 
164 	x = mode;
165 	rv = ioctl(pu->pu_fd, FIONBIO, &x);
166 
167 	if (rv == 0) {
168 		if (mode == PUFFSDEV_BLOCK)
169 			pu->pu_state &= ~PU_ASYNCFD;
170 		else
171 			pu->pu_state |= PU_ASYNCFD;
172 	}
173 
174 	return rv;
175 }
176 
177 int
178 puffs_getstate(struct puffs_usermount *pu)
179 {
180 
181 	return pu->pu_state & PU_STATEMASK;
182 }
183 
184 void
185 puffs_setstacksize(struct puffs_usermount *pu, size_t ss)
186 {
187 	long psize, minsize;
188 	int stackshift;
189 	int bonus;
190 
191 	assert(puffs_getstate(pu) == PUFFS_STATE_BEFOREMOUNT);
192 
193 	psize = sysconf(_SC_PAGESIZE);
194 	minsize = 4*psize;
195 	if (ss < minsize || ss == PUFFS_STACKSIZE_MIN) {
196 		if (ss != PUFFS_STACKSIZE_MIN)
197 			fprintf(stderr, "puffs_setstacksize: adjusting "
198 			    "stacksize to minimum %ld\n", minsize);
199 		ss = 4*psize;
200 	}
201 
202 	stackshift = -1;
203 	bonus = 0;
204 	while (ss) {
205 		if (ss & 0x1)
206 			bonus++;
207 		ss >>= 1;
208 		stackshift++;
209 	}
210 	if (bonus > 1) {
211 		stackshift++;
212 		fprintf(stderr, "puffs_setstacksize: using next power of two: "
213 		    "%d\n", 1<<stackshift);
214 	}
215 
216 	pu->pu_cc_stackshift = stackshift;
217 }
218 
219 struct puffs_pathobj *
220 puffs_getrootpathobj(struct puffs_usermount *pu)
221 {
222 	struct puffs_node *pnr;
223 
224 	pnr = pu->pu_pn_root;
225 	if (pnr == NULL) {
226 		errno = ENOENT;
227 		return NULL;
228 	}
229 
230 	return &pnr->pn_po;
231 }
232 
233 void
234 puffs_setroot(struct puffs_usermount *pu, struct puffs_node *pn)
235 {
236 
237 	pu->pu_pn_root = pn;
238 }
239 
240 struct puffs_node *
241 puffs_getroot(struct puffs_usermount *pu)
242 {
243 
244 	return pu->pu_pn_root;
245 }
246 
247 void
248 puffs_setrootinfo(struct puffs_usermount *pu, enum vtype vt,
249 	vsize_t vsize, dev_t rdev)
250 {
251 	struct puffs_kargs *pargs = pu->pu_kargp;
252 
253 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT) {
254 		warnx("puffs_setrootinfo: call has effect only "
255 		    "before mount\n");
256 		return;
257 	}
258 
259 	pargs->pa_root_vtype = vt;
260 	pargs->pa_root_vsize = vsize;
261 	pargs->pa_root_rdev = rdev;
262 }
263 
264 void *
265 puffs_getspecific(struct puffs_usermount *pu)
266 {
267 
268 	return pu->pu_privdata;
269 }
270 
271 size_t
272 puffs_getmaxreqlen(struct puffs_usermount *pu)
273 {
274 
275 	return pu->pu_maxreqlen;
276 }
277 
278 void
279 puffs_setmaxreqlen(struct puffs_usermount *pu, size_t reqlen)
280 {
281 
282 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
283 		warnx("puffs_setmaxreqlen: call has effect only "
284 		    "before mount\n");
285 
286 	pu->pu_kargp->pa_maxmsglen = reqlen;
287 }
288 
289 void
290 puffs_setfhsize(struct puffs_usermount *pu, size_t fhsize, int flags)
291 {
292 
293 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
294 		warnx("puffs_setfhsize: call has effect only before mount\n");
295 
296 	pu->pu_kargp->pa_fhsize = fhsize;
297 	pu->pu_kargp->pa_fhflags = flags;
298 }
299 
300 void
301 puffs_setncookiehash(struct puffs_usermount *pu, int nhash)
302 {
303 
304 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
305 		warnx("puffs_setfhsize: call has effect only before mount\n");
306 
307 	pu->pu_kargp->pa_nhashbuckets = nhash;
308 }
309 
310 void
311 puffs_set_pathbuild(struct puffs_usermount *pu, pu_pathbuild_fn fn)
312 {
313 
314 	pu->pu_pathbuild = fn;
315 }
316 
317 void
318 puffs_set_pathtransform(struct puffs_usermount *pu, pu_pathtransform_fn fn)
319 {
320 
321 	pu->pu_pathtransform = fn;
322 }
323 
324 void
325 puffs_set_pathcmp(struct puffs_usermount *pu, pu_pathcmp_fn fn)
326 {
327 
328 	pu->pu_pathcmp = fn;
329 }
330 
331 void
332 puffs_set_pathfree(struct puffs_usermount *pu, pu_pathfree_fn fn)
333 {
334 
335 	pu->pu_pathfree = fn;
336 }
337 
338 void
339 puffs_set_namemod(struct puffs_usermount *pu, pu_namemod_fn fn)
340 {
341 
342 	pu->pu_namemod = fn;
343 }
344 
345 void
346 puffs_set_errnotify(struct puffs_usermount *pu, pu_errnotify_fn fn)
347 {
348 
349 	pu->pu_errnotify = fn;
350 }
351 
352 void
353 puffs_set_cmap(struct puffs_usermount *pu, pu_cmap_fn fn)
354 {
355 
356 	pu->pu_cmap = fn;
357 }
358 
359 void
360 puffs_ml_setloopfn(struct puffs_usermount *pu, puffs_ml_loop_fn lfn)
361 {
362 
363 	pu->pu_ml_lfn = lfn;
364 }
365 
366 void
367 puffs_ml_settimeout(struct puffs_usermount *pu, struct timespec *ts)
368 {
369 
370 	if (ts == NULL) {
371 		pu->pu_ml_timep = NULL;
372 	} else {
373 		pu->pu_ml_timeout = *ts;
374 		pu->pu_ml_timep = &pu->pu_ml_timeout;
375 	}
376 }
377 
378 void
379 puffs_set_prepost(struct puffs_usermount *pu,
380 	pu_prepost_fn pre, pu_prepost_fn pst)
381 {
382 
383 	pu->pu_oppre = pre;
384 	pu->pu_oppost = pst;
385 }
386 
387 void
388 puffs_setback(struct puffs_cc *pcc, int whatback)
389 {
390 	struct puffs_req *preq = puffs__framebuf_getdataptr(pcc->pcc_pb);
391 
392 	assert(PUFFSOP_OPCLASS(preq->preq_opclass) == PUFFSOP_VN && (
393 	    preq->preq_optype == PUFFS_VN_OPEN ||
394 	    preq->preq_optype == PUFFS_VN_MMAP ||
395 	    preq->preq_optype == PUFFS_VN_REMOVE ||
396 	    preq->preq_optype == PUFFS_VN_RMDIR ||
397 	    preq->preq_optype == PUFFS_VN_INACTIVE));
398 
399 	preq->preq_setbacks |= whatback & PUFFS_SETBACK_MASK;
400 }
401 
402 int
403 puffs_daemon(struct puffs_usermount *pu, int nochdir, int noclose)
404 {
405 	ssize_t n;
406 	int parent, value, fd;
407 
408 	if (pipe(pu->pu_dpipe) == -1)
409 		return -1;
410 
411 	switch (fork()) {
412 	case -1:
413 		return -1;
414 	case 0:
415 		parent = 0;
416 		break;
417 	default:
418 		parent = 1;
419 		break;
420 	}
421 	pu->pu_state |= PU_PUFFSDAEMON;
422 
423 	if (parent) {
424 		n = read(pu->pu_dpipe[0], &value, sizeof(int));
425 		if (n == -1)
426 			err(1, "puffs_daemon");
427 		assert(n == sizeof(value));
428 		if (value) {
429 			errno = value;
430 			err(1, "puffs_daemon");
431 		}
432 		exit(0);
433 	} else {
434 		if (setsid() == -1)
435 			goto fail;
436 
437 		if (!nochdir)
438 			chdir("/");
439 
440 		if (!noclose) {
441 			fd = open(_PATH_DEVNULL, O_RDWR, 0);
442 			if (fd == -1)
443 				goto fail;
444 			dup2(fd, STDIN_FILENO);
445 			dup2(fd, STDOUT_FILENO);
446 			dup2(fd, STDERR_FILENO);
447 			if (fd > STDERR_FILENO)
448 				close(fd);
449 		}
450 		return 0;
451 	}
452 
453  fail:
454 	n = write(pu->pu_dpipe[1], &errno, sizeof(int));
455 	assert(n == 4);
456 	return -1;
457 }
458 
459 int
460 puffs_mount(struct puffs_usermount *pu, const char *dir, int mntflags,
461 	void *cookie)
462 {
463 	char rp[MAXPATHLEN];
464 	ssize_t n;
465 	int rv, fd, sverrno;
466 	char *comfd;
467 
468 	pu->pu_kargp->pa_root_cookie = cookie;
469 
470 	/* XXXkludgehere */
471 	/* kauth doesn't provide this service any longer */
472 	if (geteuid() != 0)
473 		mntflags |= MNT_NOSUID | MNT_NODEV;
474 
475 	if (realpath(dir, rp) == NULL) {
476 		rv = -1;
477 		goto out;
478 	}
479 
480 	if (strcmp(dir, rp) != 0) {
481 		warnx("puffs_mount: \"%s\" is a relative path.", dir);
482 		warnx("puffs_mount: using \"%s\" instead.", rp);
483 	}
484 
485 	/*
486 	 * Undocumented...  Well, documented only here.
487 	 *
488 	 * This is used for imaginative purposes.  If the env variable is
489 	 * set, puffs_mount() doesn't do the regular mount procedure.
490 	 * Rather, it crams the mount data down the comfd and sets comfd as
491 	 * the puffs descriptor.
492 	 *
493 	 * This shouldn't be used unless you can read my mind ( ... or write
494 	 * it, not to mention execute it, but that's starting to get silly).
495 	 */
496 	if ((comfd = getenv("PUFFS_COMFD")) != NULL) {
497 		size_t len;
498 
499 		if (sscanf(comfd, "%d", &pu->pu_fd) != 1) {
500 			errno = EINVAL;
501 			rv = -1;
502 			goto out;
503 		}
504 		/* check that what we got at least resembles an fd */
505 		if (fcntl(pu->pu_fd, F_GETFL) == -1) {
506 			rv = -1;
507 			goto out;
508 		}
509 
510 		len = strlen(dir)+1;
511 
512 #define allwrite(buf, len)						\
513 do {									\
514 	ssize_t al_rv;							\
515 	al_rv = write(pu->pu_fd, buf, len);				\
516 	if (al_rv != len) {						\
517 		if (al_rv != -1)					\
518 			errno = EIO;					\
519 		rv = -1;						\
520 		abort();\
521 		goto out;						\
522 	}								\
523 } while (/*CONSTCOND*/0)
524 		allwrite(&len, sizeof(len));
525 		allwrite(dir, len);
526 		len = strlen(pu->pu_kargp->pa_mntfromname)+1;
527 		allwrite(&len, sizeof(len));
528 		allwrite(pu->pu_kargp->pa_mntfromname, len);
529 		allwrite(&mntflags, sizeof(mntflags));
530 		allwrite(pu->pu_kargp, sizeof(*pu->pu_kargp));
531 		allwrite(&pu->pu_flags, sizeof(pu->pu_flags));
532 #undef allwrite
533 
534 		rv = 0;
535 	} else {
536 		fd = open(_PATH_PUFFS, O_RDWR);
537 		if (fd == -1) {
538 			warnx("puffs_mount: cannot open %s", _PATH_PUFFS);
539 			rv = -1;
540 			goto out;
541 		}
542 		if (fd <= 2)
543 			warnx("puffs_mount: device fd %d (<= 2), sure this is "
544 			    "what you want?", fd);
545 
546 		pu->pu_kargp->pa_fd = pu->pu_fd = fd;
547 		if ((rv = mount(MOUNT_PUFFS, rp, mntflags,
548 		    pu->pu_kargp, sizeof(struct puffs_kargs))) == -1)
549 			goto out;
550 	}
551 
552 	PU_SETSTATE(pu, PUFFS_STATE_RUNNING);
553 
554  out:
555 	if (rv != 0)
556 		sverrno = errno;
557 	else
558 		sverrno = 0;
559 	free(pu->pu_kargp);
560 	pu->pu_kargp = NULL;
561 
562 	if (pu->pu_state & PU_PUFFSDAEMON) {
563 		n = write(pu->pu_dpipe[1], &sverrno, sizeof(int));
564 		assert(n == 4);
565 		close(pu->pu_dpipe[0]);
566 		close(pu->pu_dpipe[1]);
567 	}
568 
569 	errno = sverrno;
570 	return rv;
571 }
572 
573 struct puffs_usermount *
574 _puffs_init(int develv, struct puffs_ops *pops, const char *mntfromname,
575 	const char *puffsname, void *priv, uint32_t pflags)
576 {
577 	struct puffs_usermount *pu;
578 	struct puffs_kargs *pargs;
579 	int sverrno;
580 
581 	if (develv != PUFFS_DEVEL_LIBVERSION) {
582 		warnx("puffs_init: mounting with lib version %d, need %d",
583 		    develv, PUFFS_DEVEL_LIBVERSION);
584 		errno = EINVAL;
585 		return NULL;
586 	}
587 
588 	pu = malloc(sizeof(struct puffs_usermount));
589 	if (pu == NULL)
590 		goto failfree;
591 	memset(pu, 0, sizeof(struct puffs_usermount));
592 
593 	pargs = pu->pu_kargp = malloc(sizeof(struct puffs_kargs));
594 	if (pargs == NULL)
595 		goto failfree;
596 	memset(pargs, 0, sizeof(struct puffs_kargs));
597 
598 	pargs->pa_vers = PUFFSDEVELVERS | PUFFSVERSION;
599 	pargs->pa_flags = PUFFS_FLAG_KERN(pflags);
600 	fillvnopmask(pops, pargs->pa_vnopmask);
601 	(void)strlcpy(pargs->pa_typename, puffsname,
602 	    sizeof(pargs->pa_typename));
603 	(void)strlcpy(pargs->pa_mntfromname, mntfromname,
604 	    sizeof(pargs->pa_mntfromname));
605 
606 	puffs_zerostatvfs(&pargs->pa_svfsb);
607 	pargs->pa_root_cookie = NULL;
608 	pargs->pa_root_vtype = VDIR;
609 	pargs->pa_root_vsize = 0;
610 	pargs->pa_root_rdev = 0;
611 	pargs->pa_maxmsglen = 0;
612 
613 	pu->pu_flags = pflags;
614 	pu->pu_ops = *pops;
615 	free(pops); /* XXX */
616 
617 	pu->pu_privdata = priv;
618 	pu->pu_cc_stackshift = PUFFS_CC_STACKSHIFT_DEFAULT;
619 	LIST_INIT(&pu->pu_pnodelst);
620 	LIST_INIT(&pu->pu_ios);
621 	LIST_INIT(&pu->pu_ios_rmlist);
622 	LIST_INIT(&pu->pu_ccmagazin);
623 	TAILQ_INIT(&pu->pu_sched);
624 
625 	pu->pu_framectrl[PU_FRAMECTRL_FS].rfb = puffs__fsframe_read;
626 	pu->pu_framectrl[PU_FRAMECTRL_FS].wfb = puffs__fsframe_write;
627 	pu->pu_framectrl[PU_FRAMECTRL_FS].cmpfb = puffs__fsframe_cmp;
628 	pu->pu_framectrl[PU_FRAMECTRL_FS].gotfb = puffs__fsframe_gotframe;
629 	pu->pu_framectrl[PU_FRAMECTRL_FS].fdnotfn = puffs_framev_unmountonclose;
630 
631 	/* defaults for some user-settable translation functions */
632 	pu->pu_cmap = NULL; /* identity translation */
633 
634 	pu->pu_pathbuild = puffs_stdpath_buildpath;
635 	pu->pu_pathfree = puffs_stdpath_freepath;
636 	pu->pu_pathcmp = puffs_stdpath_cmppath;
637 	pu->pu_pathtransform = NULL;
638 	pu->pu_namemod = NULL;
639 
640 	pu->pu_errnotify = puffs_defaulterror;
641 
642 	PU_SETSTATE(pu, PUFFS_STATE_BEFOREMOUNT);
643 
644 	return pu;
645 
646  failfree:
647 	/* can't unmount() from here for obvious reasons */
648 	sverrno = errno;
649 	free(pu);
650 	errno = sverrno;
651 	return NULL;
652 }
653 
654 /*
655  * XXX: there's currently no clean way to request unmount from
656  * within the user server, so be very brutal about it.
657  */
658 /*ARGSUSED1*/
659 int
660 puffs_exit(struct puffs_usermount *pu, int force)
661 {
662 	struct puffs_node *pn;
663 
664 	force = 1; /* currently */
665 
666 	if (pu->pu_fd)
667 		close(pu->pu_fd);
668 
669 	while ((pn = LIST_FIRST(&pu->pu_pnodelst)) != NULL)
670 		puffs_pn_put(pn);
671 
672 	finalpush(pu);
673 	puffs__framev_exit(pu);
674 	if (pu->pu_state & PU_HASKQ)
675 		close(pu->pu_kq);
676 	free(pu);
677 
678 	return 0; /* always succesful for now, WILL CHANGE */
679 }
680 
681 /*
682  * Actual mainloop.  This is called from a context which can block.
683  * It is called either from puffs_mainloop (indirectly, via
684  * puffs_cc_continue() or from puffs_cc_yield()).
685  */
686 void
687 puffs__theloop(struct puffs_cc *pcc)
688 {
689 	struct puffs_usermount *pu = pcc->pcc_pu;
690 	struct puffs_framectrl *pfctrl;
691 	struct puffs_fctrl_io *fio;
692 	struct kevent *curev;
693 	size_t nchanges;
694 	int ndone;
695 
696 	while (puffs_getstate(pu) != PUFFS_STATE_UNMOUNTED) {
697 		/*
698 		 * Schedule existing requests.
699 		 */
700 		while ((pcc = TAILQ_FIRST(&pu->pu_sched)) != NULL) {
701 			TAILQ_REMOVE(&pu->pu_sched, pcc, pcc_schedent);
702 			puffs__goto(pcc);
703 		}
704 
705 		if (pu->pu_ml_lfn)
706 			pu->pu_ml_lfn(pu);
707 
708 		/* XXX: can we still do these optimizations? */
709 #if 0
710 		/*
711 		 * Do this here, because:
712 		 *  a) loopfunc might generate some results
713 		 *  b) it's still "after" event handling (except for round 1)
714 		 */
715 		if (puffs_req_putput(ppr) == -1)
716 			goto out;
717 		puffs_req_resetput(ppr);
718 
719 		/* micro optimization: skip kevent syscall if possible */
720 		if (pu->pu_nfds == 1 && pu->pu_ml_timep == NULL
721 		    && (pu->pu_state & PU_ASYNCFD) == 0) {
722 			pfctrl = XXX->fctrl;
723 			puffs_framev_input(pu, pfctrl, XXX);
724 			continue;
725 		}
726 #endif
727 
728 		/* else: do full processing */
729 		/* Don't bother worrying about O(n) for now */
730 		LIST_FOREACH(fio, &pu->pu_ios, fio_entries) {
731 			if (fio->stat & FIO_WRGONE)
732 				continue;
733 
734 			pfctrl = fio->fctrl;
735 
736 			/*
737 			 * Try to write out everything to avoid the
738 			 * need for enabling EVFILT_WRITE.  The likely
739 			 * case is that we can fit everything into the
740 			 * socket buffer.
741 			 */
742 			puffs__framev_output(pu, pfctrl, fio);
743 		}
744 
745 		/*
746 		 * Build list of which to enable/disable in writecheck.
747 		 */
748 		nchanges = 0;
749 		LIST_FOREACH(fio, &pu->pu_ios, fio_entries) {
750 			if (fio->stat & FIO_WRGONE)
751 				continue;
752 
753 			/* en/disable write checks for kqueue as needed */
754 			assert((FIO_EN_WRITE(fio) && FIO_RM_WRITE(fio)) == 0);
755 			if (FIO_EN_WRITE(fio)) {
756 				EV_SET(&pu->pu_evs[nchanges], fio->io_fd,
757 				    EVFILT_WRITE, EV_ENABLE, 0, 0,
758 				    (uintptr_t)fio);
759 				fio->stat |= FIO_WR;
760 				nchanges++;
761 			}
762 			if (FIO_RM_WRITE(fio)) {
763 				EV_SET(&pu->pu_evs[nchanges], fio->io_fd,
764 				    EVFILT_WRITE, EV_DISABLE, 0, 0,
765 				    (uintptr_t)fio);
766 				fio->stat &= ~FIO_WR;
767 				nchanges++;
768 			}
769 			assert(nchanges <= pu->pu_nfds);
770 		}
771 
772 		ndone = kevent(pu->pu_kq, pu->pu_evs, nchanges,
773 		    pu->pu_evs, 2*pu->pu_nfds, pu->pu_ml_timep);
774 
775 		if (ndone == -1) {
776 			if (errno != EINTR)
777 				break;
778 			else
779 				continue;
780 		}
781 
782 		/* uoptimize */
783 		if (ndone == 0)
784 			continue;
785 
786 		/* iterate over the results */
787 		for (curev = pu->pu_evs; ndone--; curev++) {
788 			int what;
789 
790 #if 0
791 			/* get & possibly dispatch events from kernel */
792 			if (curev->ident == puffsfd) {
793 				if (puffs_req_handle(pgr, ppr, 0) == -1)
794 					goto out;
795 				continue;
796 			}
797 #endif
798 
799 			fio = (void *)curev->udata;
800 			pfctrl = fio->fctrl;
801 			if (curev->flags & EV_ERROR) {
802 				assert(curev->filter == EVFILT_WRITE);
803 				fio->stat &= ~FIO_WR;
804 
805 				/* XXX: how to know if it's a transient error */
806 				puffs__framev_writeclose(pu, fio,
807 				    (int)curev->data);
808 				puffs__framev_notify(fio, PUFFS_FBIO_ERROR);
809 				continue;
810 			}
811 
812 			what = 0;
813 			if (curev->filter == EVFILT_READ) {
814 				puffs__framev_input(pu, pfctrl, fio);
815 				what |= PUFFS_FBIO_READ;
816 			}
817 
818 			else if (curev->filter == EVFILT_WRITE) {
819 				puffs__framev_output(pu, pfctrl, fio);
820 				what |= PUFFS_FBIO_WRITE;
821 			}
822 			if (what)
823 				puffs__framev_notify(fio, what);
824 		}
825 
826 		/*
827 		 * Really free fd's now that we don't have references
828 		 * to them.
829 		 */
830 		while ((fio = LIST_FIRST(&pu->pu_ios_rmlist)) != NULL) {
831 			LIST_REMOVE(fio, fio_entries);
832 			free(fio);
833 		}
834 	}
835 }
836 
837 int
838 puffs_mainloop(struct puffs_usermount *pu)
839 {
840 	struct puffs_fctrl_io *fio;
841 	struct puffs_cc *pcc;
842 	struct kevent *curev;
843 	int sverrno, rv;
844 
845 	assert(puffs_getstate(pu) >= PUFFS_STATE_RUNNING);
846 
847 	pu->pu_kq = kqueue();
848 	if (pu->pu_kq == -1)
849 		goto out;
850 	pu->pu_state |= PU_HASKQ;
851 
852 	puffs_setblockingmode(pu, PUFFSDEV_NONBLOCK);
853 	if (puffs__framev_addfd_ctrl(pu, puffs_getselectable(pu),
854 	    PUFFS_FBIO_READ | PUFFS_FBIO_WRITE,
855 	    &pu->pu_framectrl[PU_FRAMECTRL_FS]) == -1)
856 		goto out;
857 
858 	curev = realloc(pu->pu_evs, (2*pu->pu_nfds)*sizeof(struct kevent));
859 	if (curev == NULL)
860 		goto out;
861 	pu->pu_evs = curev;
862 
863 	LIST_FOREACH(fio, &pu->pu_ios, fio_entries) {
864 		EV_SET(curev, fio->io_fd, EVFILT_READ, EV_ADD,
865 		    0, 0, (uintptr_t)fio);
866 		curev++;
867 		EV_SET(curev, fio->io_fd, EVFILT_WRITE, EV_ADD | EV_DISABLE,
868 		    0, 0, (uintptr_t)fio);
869 		curev++;
870 	}
871 	if (kevent(pu->pu_kq, pu->pu_evs, 2*pu->pu_nfds, NULL, 0, NULL) == -1)
872 		goto out;
873 
874 	pu->pu_state |= PU_INLOOP;
875 
876 	/* Create alternate execution context and jump to it */
877 	rv = puffs__cc_create(pu, puffs__theloop, &pcc);
878 	if (rv)
879 		goto out;
880 	puffs_cc_continue(pcc);
881 
882 	finalpush(pu);
883 	errno = 0;
884 
885  out:
886 	/* store the real error for a while */
887 	sverrno = errno;
888 
889 	errno = sverrno;
890 	if (errno)
891 		return -1;
892 	else
893 		return 0;
894 }
895