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puffs.c revision 1.72 
      1 /*	$NetBSD: puffs.c,v 1.72 2007/10/29 15:52:45 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 1.72 2007/10/29 15:52:45 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 /*ARGSUSED*/
    106 static void
    107 puffs_defaulterror(struct puffs_usermount *pu, uint8_t type,
    108 	int error, const char *str, void *cookie)
    109 {
    110 
    111 	fprintf(stderr, "%s\n", str);
    112 	abort();
    113 }
    114 
    115 int
    116 puffs_getselectable(struct puffs_usermount *pu)
    117 {
    118 
    119 	return pu->pu_fd;
    120 }
    121 
    122 int
    123 puffs_setblockingmode(struct puffs_usermount *pu, int mode)
    124 {
    125 	int rv, x;
    126 
    127 	if (mode != PUFFSDEV_BLOCK && mode != PUFFSDEV_NONBLOCK) {
    128 		errno = EINVAL;
    129 		return -1;
    130 	}
    131 
    132 	x = mode;
    133 	rv = ioctl(pu->pu_fd, FIONBIO, &x);
    134 
    135 	if (rv == 0) {
    136 		if (mode == PUFFSDEV_BLOCK)
    137 			pu->pu_state &= ~PU_ASYNCFD;
    138 		else
    139 			pu->pu_state |= PU_ASYNCFD;
    140 	}
    141 
    142 	return rv;
    143 }
    144 
    145 int
    146 puffs_getstate(struct puffs_usermount *pu)
    147 {
    148 
    149 	return pu->pu_state & PU_STATEMASK;
    150 }
    151 
    152 void
    153 puffs_setstacksize(struct puffs_usermount *pu, size_t ss)
    154 {
    155 	int stackshift;
    156 
    157 	assert(puffs_getstate(pu) == PUFFS_STATE_BEFOREMOUNT);
    158 	stackshift = -1;
    159 	while (ss) {
    160 		ss >>= 1;
    161 		stackshift++;
    162 	}
    163 	pu->pu_cc_stackshift = stackshift;
    164 	assert(1<<stackshift == ss);
    165 }
    166 
    167 struct puffs_pathobj *
    168 puffs_getrootpathobj(struct puffs_usermount *pu)
    169 {
    170 	struct puffs_node *pnr;
    171 
    172 	pnr = pu->pu_pn_root;
    173 	if (pnr == NULL) {
    174 		errno = ENOENT;
    175 		return NULL;
    176 	}
    177 
    178 	return &pnr->pn_po;
    179 }
    180 
    181 void
    182 puffs_setroot(struct puffs_usermount *pu, struct puffs_node *pn)
    183 {
    184 
    185 	pu->pu_pn_root = pn;
    186 }
    187 
    188 struct puffs_node *
    189 puffs_getroot(struct puffs_usermount *pu)
    190 {
    191 
    192 	return pu->pu_pn_root;
    193 }
    194 
    195 void
    196 puffs_setrootinfo(struct puffs_usermount *pu, enum vtype vt,
    197 	vsize_t vsize, dev_t rdev)
    198 {
    199 	struct puffs_kargs *pargs = pu->pu_kargp;
    200 
    201 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT) {
    202 		warnx("puffs_setrootinfo: call has effect only "
    203 		    "before mount\n");
    204 		return;
    205 	}
    206 
    207 	pargs->pa_root_vtype = vt;
    208 	pargs->pa_root_vsize = vsize;
    209 	pargs->pa_root_rdev = rdev;
    210 }
    211 
    212 void *
    213 puffs_getspecific(struct puffs_usermount *pu)
    214 {
    215 
    216 	return pu->pu_privdata;
    217 }
    218 
    219 size_t
    220 puffs_getmaxreqlen(struct puffs_usermount *pu)
    221 {
    222 
    223 	return pu->pu_maxreqlen;
    224 }
    225 
    226 void
    227 puffs_setmaxreqlen(struct puffs_usermount *pu, size_t reqlen)
    228 {
    229 
    230 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
    231 		warnx("puffs_setmaxreqlen: call has effect only "
    232 		    "before mount\n");
    233 
    234 	pu->pu_kargp->pa_maxmsglen = reqlen;
    235 }
    236 
    237 void
    238 puffs_setfhsize(struct puffs_usermount *pu, size_t fhsize, int flags)
    239 {
    240 
    241 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
    242 		warnx("puffs_setfhsize: call has effect only before mount\n");
    243 
    244 	pu->pu_kargp->pa_fhsize = fhsize;
    245 	pu->pu_kargp->pa_fhflags = flags;
    246 }
    247 
    248 void
    249 puffs_setncookiehash(struct puffs_usermount *pu, int nhash)
    250 {
    251 
    252 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
    253 		warnx("puffs_setfhsize: call has effect only before mount\n");
    254 
    255 	pu->pu_kargp->pa_nhashbuckets = nhash;
    256 }
    257 
    258 void
    259 puffs_set_pathbuild(struct puffs_usermount *pu, pu_pathbuild_fn fn)
    260 {
    261 
    262 	pu->pu_pathbuild = fn;
    263 }
    264 
    265 void
    266 puffs_set_pathtransform(struct puffs_usermount *pu, pu_pathtransform_fn fn)
    267 {
    268 
    269 	pu->pu_pathtransform = fn;
    270 }
    271 
    272 void
    273 puffs_set_pathcmp(struct puffs_usermount *pu, pu_pathcmp_fn fn)
    274 {
    275 
    276 	pu->pu_pathcmp = fn;
    277 }
    278 
    279 void
    280 puffs_set_pathfree(struct puffs_usermount *pu, pu_pathfree_fn fn)
    281 {
    282 
    283 	pu->pu_pathfree = fn;
    284 }
    285 
    286 void
    287 puffs_set_namemod(struct puffs_usermount *pu, pu_namemod_fn fn)
    288 {
    289 
    290 	pu->pu_namemod = fn;
    291 }
    292 
    293 void
    294 puffs_set_errnotify(struct puffs_usermount *pu, pu_errnotify_fn fn)
    295 {
    296 
    297 	pu->pu_errnotify = fn;
    298 }
    299 
    300 void
    301 puffs_ml_setloopfn(struct puffs_usermount *pu, puffs_ml_loop_fn lfn)
    302 {
    303 
    304 	pu->pu_ml_lfn = lfn;
    305 }
    306 
    307 void
    308 puffs_ml_settimeout(struct puffs_usermount *pu, struct timespec *ts)
    309 {
    310 
    311 	if (ts == NULL) {
    312 		pu->pu_ml_timep = NULL;
    313 	} else {
    314 		pu->pu_ml_timeout = *ts;
    315 		pu->pu_ml_timep = &pu->pu_ml_timeout;
    316 	}
    317 }
    318 
    319 void
    320 puffs_set_prepost(struct puffs_usermount *pu,
    321 	pu_prepost_fn pre, pu_prepost_fn pst)
    322 {
    323 
    324 	pu->pu_oppre = pre;
    325 	pu->pu_oppost = pst;
    326 }
    327 
    328 void
    329 puffs_setback(struct puffs_cc *pcc, int whatback)
    330 {
    331 	struct puffs_req *preq = pcc->pcc_preq;
    332 
    333 	assert(PUFFSOP_OPCLASS(preq->preq_opclass) == PUFFSOP_VN && (
    334 	    preq->preq_optype == PUFFS_VN_OPEN ||
    335 	    preq->preq_optype == PUFFS_VN_MMAP ||
    336 	    preq->preq_optype == PUFFS_VN_REMOVE ||
    337 	    preq->preq_optype == PUFFS_VN_RMDIR ||
    338 	    preq->preq_optype == PUFFS_VN_INACTIVE));
    339 
    340 	preq->preq_setbacks |= whatback & PUFFS_SETBACK_MASK;
    341 }
    342 
    343 int
    344 puffs_mount(struct puffs_usermount *pu, const char *dir, int mntflags,
    345 	void *cookie)
    346 {
    347 	char rp[MAXPATHLEN];
    348 	int rv;
    349 
    350 #if 1
    351 	/* XXXkludgehere */
    352 	/* kauth doesn't provide this service any longer */
    353 	if (geteuid() != 0)
    354 		mntflags |= MNT_NOSUID | MNT_NODEV;
    355 #endif
    356 
    357 	if (realpath(dir, rp) == NULL)
    358 		return -1;
    359 
    360 	if (strcmp(dir, rp) != 0) {
    361 		warnx("puffs_mount: \"%s\" is a relative path.", dir);
    362 		warnx("puffs_mount: using \"%s\" instead.", rp);
    363 	}
    364 
    365 	pu->pu_kargp->pa_root_cookie = cookie;
    366 	if ((rv = mount(MOUNT_PUFFS, rp, mntflags,
    367 	    pu->pu_kargp, sizeof(struct puffs_kargs))) == -1)
    368 		goto out;
    369 #if 0
    370 	if ((rv = ioctl(pu->pu_fd, PUFFSREQSIZEOP, &pu->pu_maxreqlen)) == -1)
    371 		goto out;
    372 #endif
    373 	PU_SETSTATE(pu, PUFFS_STATE_RUNNING);
    374 
    375  out:
    376 	free(pu->pu_kargp);
    377 	pu->pu_kargp = NULL;
    378 
    379 	return rv;
    380 }
    381 
    382 struct puffs_usermount *
    383 _puffs_init(int develv, struct puffs_ops *pops, const char *mntfromname,
    384 	const char *puffsname, void *priv, uint32_t pflags)
    385 {
    386 	struct puffs_usermount *pu;
    387 	struct puffs_kargs *pargs;
    388 	int sverrno, fd;
    389 
    390 	if (develv != PUFFS_DEVEL_LIBVERSION) {
    391 		warnx("puffs_init: mounting with lib version %d, need %d",
    392 		    develv, PUFFS_DEVEL_LIBVERSION);
    393 		errno = EINVAL;
    394 		return NULL;
    395 	}
    396 
    397 	fd = open(_PATH_PUFFS, O_RDONLY);
    398 	if (fd == -1) {
    399 		warnx("puffs_init: cannot open %s", _PATH_PUFFS);
    400 		return NULL;
    401 	}
    402 	if (fd <= 2)
    403 		warnx("puffs_init: device fd %d (<= 2), sure this is "
    404 		    "what you want?", fd);
    405 
    406 	pu = malloc(sizeof(struct puffs_usermount));
    407 	if (pu == NULL)
    408 		goto failfree;
    409 	memset(pu, 0, sizeof(struct puffs_usermount));
    410 
    411 	pargs = pu->pu_kargp = malloc(sizeof(struct puffs_kargs));
    412 	if (pargs == NULL)
    413 		goto failfree;
    414 	memset(pargs, 0, sizeof(struct puffs_kargs));
    415 
    416 	pargs->pa_vers = PUFFSDEVELVERS | PUFFSVERSION;
    417 	pargs->pa_flags = PUFFS_FLAG_KERN(pflags);
    418 	pargs->pa_fd = pu->pu_fd = fd;
    419 	fillvnopmask(pops, pargs->pa_vnopmask);
    420 	(void)strlcpy(pargs->pa_typename, puffsname,
    421 	    sizeof(pargs->pa_typename));
    422 	(void)strlcpy(pargs->pa_mntfromname, mntfromname,
    423 	    sizeof(pargs->pa_mntfromname));
    424 
    425 	puffs_zerostatvfs(&pargs->pa_svfsb);
    426 	pargs->pa_root_cookie = NULL;
    427 	pargs->pa_root_vtype = VDIR;
    428 	pargs->pa_root_vsize = 0;
    429 	pargs->pa_root_rdev = 0;
    430 	pargs->pa_maxmsglen = 0;
    431 
    432 	pu->pu_flags = pflags;
    433 	pu->pu_ops = *pops;
    434 	free(pops); /* XXX */
    435 
    436 	pu->pu_privdata = priv;
    437 	pu->pu_cc_stackshift = PUFFS_CC_STACKSHIFT_DEFAULT;
    438 	LIST_INIT(&pu->pu_pnodelst);
    439 	LIST_INIT(&pu->pu_framectrl.fb_ios);
    440 	LIST_INIT(&pu->pu_ccnukelst);
    441 	TAILQ_INIT(&pu->pu_sched);
    442 	TAILQ_INIT(&pu->pu_exq);
    443 
    444 	/* defaults for some user-settable translation functions */
    445 	pu->pu_cmap = NULL; /* identity translation */
    446 
    447 	pu->pu_pathbuild = puffs_stdpath_buildpath;
    448 	pu->pu_pathfree = puffs_stdpath_freepath;
    449 	pu->pu_pathcmp = puffs_stdpath_cmppath;
    450 	pu->pu_pathtransform = NULL;
    451 	pu->pu_namemod = NULL;
    452 
    453 	pu->pu_errnotify = puffs_defaulterror;
    454 
    455 	PU_SETSTATE(pu, PUFFS_STATE_BEFOREMOUNT);
    456 
    457 	return pu;
    458 
    459  failfree:
    460 	/* can't unmount() from here for obvious reasons */
    461 	sverrno = errno;
    462 	close(fd);
    463 	free(pu);
    464 	errno = sverrno;
    465 	return NULL;
    466 }
    467 
    468 /*
    469  * XXX: there's currently no clean way to request unmount from
    470  * within the user server, so be very brutal about it.
    471  */
    472 /*ARGSUSED1*/
    473 int
    474 puffs_exit(struct puffs_usermount *pu, int force)
    475 {
    476 	struct puffs_node *pn;
    477 
    478 	force = 1; /* currently */
    479 
    480 	if (pu->pu_fd)
    481 		close(pu->pu_fd);
    482 
    483 	while ((pn = LIST_FIRST(&pu->pu_pnodelst)) != NULL)
    484 		puffs_pn_put(pn);
    485 
    486 	puffs_framev_exit(pu);
    487 	if (pu->pu_state & PU_HASKQ)
    488 		close(pu->pu_kq);
    489 	free(pu);
    490 
    491 	return 0; /* always succesful for now, WILL CHANGE */
    492 }
    493 
    494 int
    495 puffs_mainloop(struct puffs_usermount *pu, int flags)
    496 {
    497 	struct puffs_getreq *pgr = NULL;
    498 	struct puffs_putreq *ppr = NULL;
    499 	struct puffs_framectrl *pfctrl = &pu->pu_framectrl;
    500 	struct puffs_fctrl_io *fio;
    501 	struct puffs_cc *pcc;
    502 	struct kevent *curev, *newevs;
    503 	size_t nchanges;
    504 	int puffsfd, sverrno;
    505 	int ndone;
    506 
    507 	assert(puffs_getstate(pu) >= PUFFS_STATE_RUNNING);
    508 
    509 	pgr = puffs_req_makeget(pu, puffs_getmaxreqlen(pu), 0);
    510 	if (pgr == NULL)
    511 		goto out;
    512 
    513 	ppr = puffs_req_makeput(pu);
    514 	if (ppr == NULL)
    515 		goto out;
    516 
    517 	newevs = realloc(pfctrl->evs, (2*pfctrl->nfds+1)*sizeof(struct kevent));
    518 	if (newevs == NULL)
    519 		goto out;
    520 	pfctrl->evs = newevs;
    521 
    522 	if ((flags & PUFFSLOOP_NODAEMON) == 0)
    523 		if (daemon(1, 0) == -1)
    524 			goto out;
    525 	pu->pu_state |= PU_INLOOP;
    526 
    527 	pu->pu_kq = kqueue();
    528 	if (pu->pu_kq == -1)
    529 		goto out;
    530 	pu->pu_state |= PU_HASKQ;
    531 
    532 	curev = pfctrl->evs;
    533 	LIST_FOREACH(fio, &pfctrl->fb_ios, fio_entries) {
    534 		EV_SET(curev, fio->io_fd, EVFILT_READ, EV_ADD,
    535 		    0, 0, (uintptr_t)fio);
    536 		curev++;
    537 		EV_SET(curev, fio->io_fd, EVFILT_WRITE, EV_ADD | EV_DISABLE,
    538 		    0, 0, (uintptr_t)fio);
    539 		curev++;
    540 	}
    541 	puffsfd = puffs_getselectable(pu);
    542 	EV_SET(curev, puffsfd, EVFILT_READ, EV_ADD, 0, 0, 0);
    543 	if (kevent(pu->pu_kq, pfctrl->evs, 2*pfctrl->nfds+1,
    544 	    NULL, 0, NULL) == -1)
    545 		goto out;
    546 
    547 	while (puffs_getstate(pu) != PUFFS_STATE_UNMOUNTED) {
    548 		if (pu->pu_ml_lfn)
    549 			pu->pu_ml_lfn(pu);
    550 
    551 		/*
    552 		 * Do this here, because:
    553 		 *  a) loopfunc might generate some results
    554 		 *  b) it's still "after" event handling (except for round 1)
    555 		 */
    556 		if (puffs_req_putput(ppr) == -1)
    557 			goto out;
    558 		puffs_req_resetput(ppr);
    559 
    560 		/* micro optimization: skip kevent syscall if possible */
    561 		if (pfctrl->nfds == 0 && pu->pu_ml_timep == NULL
    562 		    && (pu->pu_state & PU_ASYNCFD) == 0) {
    563 			if (puffs_req_handle(pgr, ppr, 0) == -1)
    564 				goto out;
    565 			continue;
    566 		}
    567 
    568 		/* else: do full processing */
    569 
    570 		/*
    571 		 * Build list of which to enable/disable in writecheck.
    572 		 * Don't bother worrying about O(n) for now.
    573 		 */
    574 		nchanges = 0;
    575 		LIST_FOREACH(fio, &pfctrl->fb_ios, fio_entries) {
    576 			if (fio->stat & FIO_WRGONE)
    577 				continue;
    578 
    579 			/*
    580 			 * Try to write out everything to avoid the
    581 			 * need for enabling EVFILT_WRITE.  The likely
    582 			 * case is that we can fit everything into the
    583 			 * socket buffer.
    584 			 */
    585 			if (puffs_framev_output(pu, pfctrl, fio, ppr)) {
    586 				/* need kernel notify? (error condition) */
    587 				if (puffs_req_putput(ppr) == -1)
    588 					goto out;
    589 				puffs_req_resetput(ppr);
    590 			}
    591 
    592 			/* en/disable write checks for kqueue as needed */
    593 			assert((FIO_EN_WRITE(fio) && FIO_RM_WRITE(fio)) == 0);
    594 			if (FIO_EN_WRITE(fio)) {
    595 				EV_SET(&pfctrl->evs[nchanges], fio->io_fd,
    596 				    EVFILT_WRITE, EV_ENABLE, 0, 0,
    597 				    (uintptr_t)fio);
    598 				fio->stat |= FIO_WR;
    599 				nchanges++;
    600 			}
    601 			if (FIO_RM_WRITE(fio)) {
    602 				EV_SET(&pfctrl->evs[nchanges], fio->io_fd,
    603 				    EVFILT_WRITE, EV_DISABLE, 0, 0,
    604 				    (uintptr_t)fio);
    605 				fio->stat &= ~FIO_WR;
    606 				nchanges++;
    607 			}
    608 			assert(nchanges <= pfctrl->nfds);
    609 		}
    610 
    611 		ndone = kevent(pu->pu_kq, pfctrl->evs, nchanges,
    612 		    pfctrl->evs, pfctrl->nfds+1, pu->pu_ml_timep);
    613 
    614 		if (ndone == -1) {
    615 			if (errno != EINTR)
    616 				goto out;
    617 			else
    618 				continue;
    619 		}
    620 
    621 		/* uoptimize */
    622 		if (ndone == 0)
    623 			continue;
    624 
    625 		/* iterate over the results */
    626 		for (curev = pfctrl->evs; ndone--; curev++) {
    627 			int what;
    628 
    629 			/* get & possibly dispatch events from kernel */
    630 			if (curev->ident == puffsfd) {
    631 				if (puffs_req_handle(pgr, ppr, 0) == -1)
    632 					goto out;
    633 				continue;
    634 			}
    635 
    636 			fio = (void *)curev->udata;
    637 			if (curev->flags & EV_ERROR) {
    638 				assert(curev->filter == EVFILT_WRITE);
    639 				fio->stat &= ~FIO_WR;
    640 
    641 				/* XXX: how to know if it's a transient error */
    642 				puffs_framev_writeclose(pu, fio,
    643 				    (int)curev->data);
    644 				puffs_framev_notify(fio, PUFFS_FBIO_ERROR);
    645 				continue;
    646 			}
    647 
    648 			what = 0;
    649 			if (curev->filter == EVFILT_READ) {
    650 				puffs_framev_input(pu, pfctrl, fio, ppr);
    651 				what |= PUFFS_FBIO_READ;
    652 			}
    653 
    654 			else if (curev->filter == EVFILT_WRITE) {
    655 				puffs_framev_output(pu, pfctrl, fio, ppr);
    656 				what |= PUFFS_FBIO_WRITE;
    657 			}
    658 			if (what)
    659 				puffs_framev_notify(fio, what);
    660 		}
    661 
    662 		/*
    663 		 * Schedule continuations.
    664 		 */
    665 		while ((pcc = TAILQ_FIRST(&pu->pu_sched)) != NULL) {
    666 			TAILQ_REMOVE(&pu->pu_sched, pcc, entries);
    667 			puffs_goto(pcc);
    668 		}
    669 
    670 		/*
    671 		 * Really free fd's now that we don't have references
    672 		 * to them.
    673 		 */
    674 		while ((fio = LIST_FIRST(&pfctrl->fb_ios_rmlist)) != NULL) {
    675 			LIST_REMOVE(fio, fio_entries);
    676 			free(fio);
    677 		}
    678 	}
    679 	errno = 0;
    680 	puffs_req_putput(ppr);
    681 
    682  out:
    683 	/* store the real error for a while */
    684 	sverrno = errno;
    685 
    686 	if (ppr)
    687 		puffs_req_destroyput(ppr);
    688 	if (pgr)
    689 		puffs_req_destroyget(pgr);
    690 
    691 	errno = sverrno;
    692 	if (errno)
    693 		return -1;
    694 	else
    695 		return 0;
    696 }
    697