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puffs.c revision 1.103 
      1 /*	$NetBSD: puffs.c,v 1.103 2010/01/07 22:49:19 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 1.103 2010/01/07 22:49:19 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 	FILLOP(abortop,  ABORTOP);
    103 }
    104 #undef FILLOP
    105 
    106 /*
    107  * Go over all framev entries and write everything we can.  This is
    108  * mostly for the benefit of delivering "unmount" to the kernel.
    109  */
    110 static void
    111 finalpush(struct puffs_usermount *pu)
    112 {
    113 	struct puffs_fctrl_io *fio;
    114 
    115 	LIST_FOREACH(fio, &pu->pu_ios, fio_entries) {
    116 		if (fio->stat & FIO_WRGONE)
    117 			continue;
    118 
    119 		puffs__framev_output(pu, fio->fctrl, fio);
    120 	}
    121 }
    122 
    123 /*ARGSUSED*/
    124 void
    125 puffs_kernerr_abort(struct puffs_usermount *pu, uint8_t type,
    126 	int error, const char *str, puffs_cookie_t cookie)
    127 {
    128 
    129 	fprintf(stderr, "abort: type %d, error %d, cookie %p (%s)\n",
    130 	    type, error, cookie, str);
    131 	abort();
    132 }
    133 
    134 /*ARGSUSED*/
    135 void
    136 puffs_kernerr_log(struct puffs_usermount *pu, uint8_t type,
    137 	int error, const char *str, puffs_cookie_t cookie)
    138 {
    139 
    140 	syslog(LOG_WARNING, "kernel: type %d, error %d, cookie %p (%s)\n",
    141 	    type, error, cookie, str);
    142 }
    143 
    144 int
    145 puffs_getselectable(struct puffs_usermount *pu)
    146 {
    147 
    148 	return pu->pu_fd;
    149 }
    150 
    151 uint64_t
    152 puffs__nextreq(struct puffs_usermount *pu)
    153 {
    154 	uint64_t rv;
    155 
    156 	PU_LOCK();
    157 	rv = pu->pu_nextreq++ | 1ULL<<63;
    158 	PU_UNLOCK();
    159 
    160 	return rv;
    161 }
    162 
    163 int
    164 puffs_setblockingmode(struct puffs_usermount *pu, int mode)
    165 {
    166 	int rv, x;
    167 
    168 	assert(puffs_getstate(pu) == PUFFS_STATE_RUNNING);
    169 
    170 	if (mode != PUFFSDEV_BLOCK && mode != PUFFSDEV_NONBLOCK) {
    171 		errno = EINVAL;
    172 		return -1;
    173 	}
    174 
    175 	x = mode;
    176 	rv = ioctl(pu->pu_fd, FIONBIO, &x);
    177 
    178 	if (rv == 0) {
    179 		if (mode == PUFFSDEV_BLOCK)
    180 			pu->pu_state &= ~PU_ASYNCFD;
    181 		else
    182 			pu->pu_state |= PU_ASYNCFD;
    183 	}
    184 
    185 	return rv;
    186 }
    187 
    188 int
    189 puffs_getstate(struct puffs_usermount *pu)
    190 {
    191 
    192 	return pu->pu_state & PU_STATEMASK;
    193 }
    194 
    195 void
    196 puffs_setstacksize(struct puffs_usermount *pu, size_t ss)
    197 {
    198 	long psize, minsize;
    199 	int stackshift;
    200 	int bonus;
    201 
    202 	assert(puffs_getstate(pu) == PUFFS_STATE_BEFOREMOUNT);
    203 
    204 	psize = sysconf(_SC_PAGESIZE);
    205 	minsize = 4*psize;
    206 	if (ss < (size_t)minsize || ss == PUFFS_STACKSIZE_MIN) {
    207 		if (ss != PUFFS_STACKSIZE_MIN)
    208 			fprintf(stderr, "puffs_setstacksize: adjusting "
    209 			    "stacksize to minimum %ld\n", minsize);
    210 		ss = 4*psize;
    211 	}
    212 
    213 	stackshift = -1;
    214 	bonus = 0;
    215 	while (ss) {
    216 		if (ss & 0x1)
    217 			bonus++;
    218 		ss >>= 1;
    219 		stackshift++;
    220 	}
    221 	if (bonus > 1) {
    222 		stackshift++;
    223 		fprintf(stderr, "puffs_setstacksize: using next power of two: "
    224 		    "%d\n", 1<<stackshift);
    225 	}
    226 
    227 	pu->pu_cc_stackshift = stackshift;
    228 }
    229 
    230 struct puffs_pathobj *
    231 puffs_getrootpathobj(struct puffs_usermount *pu)
    232 {
    233 	struct puffs_node *pnr;
    234 
    235 	pnr = pu->pu_pn_root;
    236 	if (pnr == NULL) {
    237 		errno = ENOENT;
    238 		return NULL;
    239 	}
    240 
    241 	return &pnr->pn_po;
    242 }
    243 
    244 void
    245 puffs_setroot(struct puffs_usermount *pu, struct puffs_node *pn)
    246 {
    247 
    248 	pu->pu_pn_root = pn;
    249 }
    250 
    251 struct puffs_node *
    252 puffs_getroot(struct puffs_usermount *pu)
    253 {
    254 
    255 	return pu->pu_pn_root;
    256 }
    257 
    258 void
    259 puffs_setrootinfo(struct puffs_usermount *pu, enum vtype vt,
    260 	vsize_t vsize, dev_t rdev)
    261 {
    262 	struct puffs_kargs *pargs = pu->pu_kargp;
    263 
    264 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT) {
    265 		warnx("puffs_setrootinfo: call has effect only "
    266 		    "before mount\n");
    267 		return;
    268 	}
    269 
    270 	pargs->pa_root_vtype = vt;
    271 	pargs->pa_root_vsize = vsize;
    272 	pargs->pa_root_rdev = rdev;
    273 }
    274 
    275 void *
    276 puffs_getspecific(struct puffs_usermount *pu)
    277 {
    278 
    279 	return pu->pu_privdata;
    280 }
    281 
    282 void
    283 puffs_setspecific(struct puffs_usermount *pu, void *privdata)
    284 {
    285 
    286 	pu->pu_privdata = privdata;
    287 }
    288 
    289 void
    290 puffs_setmntinfo(struct puffs_usermount *pu,
    291 	const char *mntfromname, const char *puffsname)
    292 {
    293 	struct puffs_kargs *pargs = pu->pu_kargp;
    294 
    295 	(void)strlcpy(pargs->pa_mntfromname, mntfromname,
    296 	    sizeof(pargs->pa_mntfromname));
    297 	(void)strlcpy(pargs->pa_typename, puffsname,
    298 	    sizeof(pargs->pa_typename));
    299 }
    300 
    301 size_t
    302 puffs_getmaxreqlen(struct puffs_usermount *pu)
    303 {
    304 
    305 	return pu->pu_maxreqlen;
    306 }
    307 
    308 void
    309 puffs_setmaxreqlen(struct puffs_usermount *pu, size_t reqlen)
    310 {
    311 
    312 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
    313 		warnx("puffs_setmaxreqlen: call has effect only "
    314 		    "before mount\n");
    315 
    316 	pu->pu_kargp->pa_maxmsglen = reqlen;
    317 }
    318 
    319 void
    320 puffs_setfhsize(struct puffs_usermount *pu, size_t fhsize, int flags)
    321 {
    322 
    323 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
    324 		warnx("puffs_setfhsize: call has effect only before mount\n");
    325 
    326 	pu->pu_kargp->pa_fhsize = fhsize;
    327 	pu->pu_kargp->pa_fhflags = flags;
    328 }
    329 
    330 void
    331 puffs_setncookiehash(struct puffs_usermount *pu, int nhash)
    332 {
    333 
    334 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
    335 		warnx("puffs_setfhsize: call has effect only before mount\n");
    336 
    337 	pu->pu_kargp->pa_nhashbuckets = nhash;
    338 }
    339 
    340 void
    341 puffs_set_pathbuild(struct puffs_usermount *pu, pu_pathbuild_fn fn)
    342 {
    343 
    344 	pu->pu_pathbuild = fn;
    345 }
    346 
    347 void
    348 puffs_set_pathtransform(struct puffs_usermount *pu, pu_pathtransform_fn fn)
    349 {
    350 
    351 	pu->pu_pathtransform = fn;
    352 }
    353 
    354 void
    355 puffs_set_pathcmp(struct puffs_usermount *pu, pu_pathcmp_fn fn)
    356 {
    357 
    358 	pu->pu_pathcmp = fn;
    359 }
    360 
    361 void
    362 puffs_set_pathfree(struct puffs_usermount *pu, pu_pathfree_fn fn)
    363 {
    364 
    365 	pu->pu_pathfree = fn;
    366 }
    367 
    368 void
    369 puffs_set_namemod(struct puffs_usermount *pu, pu_namemod_fn fn)
    370 {
    371 
    372 	pu->pu_namemod = fn;
    373 }
    374 
    375 void
    376 puffs_set_errnotify(struct puffs_usermount *pu, pu_errnotify_fn fn)
    377 {
    378 
    379 	pu->pu_errnotify = fn;
    380 }
    381 
    382 void
    383 puffs_set_cmap(struct puffs_usermount *pu, pu_cmap_fn fn)
    384 {
    385 
    386 	pu->pu_cmap = fn;
    387 }
    388 
    389 void
    390 puffs_ml_setloopfn(struct puffs_usermount *pu, puffs_ml_loop_fn lfn)
    391 {
    392 
    393 	pu->pu_ml_lfn = lfn;
    394 }
    395 
    396 void
    397 puffs_ml_settimeout(struct puffs_usermount *pu, struct timespec *ts)
    398 {
    399 
    400 	if (ts == NULL) {
    401 		pu->pu_ml_timep = NULL;
    402 	} else {
    403 		pu->pu_ml_timeout = *ts;
    404 		pu->pu_ml_timep = &pu->pu_ml_timeout;
    405 	}
    406 }
    407 
    408 void
    409 puffs_set_prepost(struct puffs_usermount *pu,
    410 	pu_prepost_fn pre, pu_prepost_fn pst)
    411 {
    412 
    413 	pu->pu_oppre = pre;
    414 	pu->pu_oppost = pst;
    415 }
    416 
    417 void
    418 puffs_setback(struct puffs_cc *pcc, int whatback)
    419 {
    420 	struct puffs_req *preq = puffs__framebuf_getdataptr(pcc->pcc_pb);
    421 
    422 	assert(PUFFSOP_OPCLASS(preq->preq_opclass) == PUFFSOP_VN && (
    423 	    preq->preq_optype == PUFFS_VN_OPEN ||
    424 	    preq->preq_optype == PUFFS_VN_MMAP ||
    425 	    preq->preq_optype == PUFFS_VN_REMOVE ||
    426 	    preq->preq_optype == PUFFS_VN_RMDIR ||
    427 	    preq->preq_optype == PUFFS_VN_INACTIVE));
    428 
    429 	preq->preq_setbacks |= whatback & PUFFS_SETBACK_MASK;
    430 }
    431 
    432 int
    433 puffs_daemon(struct puffs_usermount *pu, int nochdir, int noclose)
    434 {
    435 	long int n;
    436 	int parent, value, fd;
    437 
    438 	if (pipe(pu->pu_dpipe) == -1)
    439 		return -1;
    440 
    441 	switch (fork()) {
    442 	case -1:
    443 		return -1;
    444 	case 0:
    445 		parent = 0;
    446 		break;
    447 	default:
    448 		parent = 1;
    449 		break;
    450 	}
    451 	pu->pu_state |= PU_PUFFSDAEMON;
    452 
    453 	if (parent) {
    454 		close(pu->pu_dpipe[1]);
    455 		n = read(pu->pu_dpipe[0], &value, sizeof(int));
    456 		if (n == -1)
    457 			err(1, "puffs_daemon");
    458 		if (n != sizeof(value))
    459 			errx(1, "puffs_daemon got %ld bytes", n);
    460 		if (value) {
    461 			errno = value;
    462 			err(1, "puffs_daemon");
    463 		}
    464 		exit(0);
    465 	} else {
    466 		if (setsid() == -1)
    467 			goto fail;
    468 
    469 		if (!nochdir)
    470 			chdir("/");
    471 
    472 		if (!noclose) {
    473 			fd = open(_PATH_DEVNULL, O_RDWR, 0);
    474 			if (fd == -1)
    475 				goto fail;
    476 			dup2(fd, STDIN_FILENO);
    477 			dup2(fd, STDOUT_FILENO);
    478 			dup2(fd, STDERR_FILENO);
    479 			if (fd > STDERR_FILENO)
    480 				close(fd);
    481 		}
    482 		return 0;
    483 	}
    484 
    485  fail:
    486 	n = write(pu->pu_dpipe[1], &errno, sizeof(int));
    487 	assert(n == 4);
    488 	return -1;
    489 }
    490 
    491 static void
    492 shutdaemon(struct puffs_usermount *pu, int error)
    493 {
    494 	ssize_t n;
    495 
    496 	n = write(pu->pu_dpipe[1], &error, sizeof(int));
    497 	assert(n == 4);
    498 	close(pu->pu_dpipe[0]);
    499 	close(pu->pu_dpipe[1]);
    500 	pu->pu_state &= ~PU_PUFFSDAEMON;
    501 }
    502 
    503 int
    504 puffs_mount(struct puffs_usermount *pu, const char *dir, int mntflags,
    505 	puffs_cookie_t cookie)
    506 {
    507 	char rp[MAXPATHLEN];
    508 	int rv, fd, sverrno;
    509 	char *comfd;
    510 
    511 	pu->pu_kargp->pa_root_cookie = cookie;
    512 
    513 	/* XXXkludgehere */
    514 	/* kauth doesn't provide this service any longer */
    515 	if (geteuid() != 0)
    516 		mntflags |= MNT_NOSUID | MNT_NODEV;
    517 
    518 	if (realpath(dir, rp) == NULL) {
    519 		rv = -1;
    520 		goto out;
    521 	}
    522 
    523 	if (strcmp(dir, rp) != 0) {
    524 		warnx("puffs_mount: \"%s\" is a relative path.", dir);
    525 		warnx("puffs_mount: using \"%s\" instead.", rp);
    526 	}
    527 
    528 	/*
    529 	 * Undocumented...  Well, documented only here.
    530 	 *
    531 	 * This is used for imaginative purposes.  If the env variable is
    532 	 * set, puffs_mount() doesn't do the regular mount procedure.
    533 	 * Rather, it crams the mount data down the comfd and sets comfd as
    534 	 * the puffs descriptor.
    535 	 *
    536 	 * This shouldn't be used unless you can read my mind ( ... or write
    537 	 * it, not to mention execute it, but that's starting to get silly).
    538 	 */
    539 	if ((comfd = getenv("PUFFS_COMFD")) != NULL) {
    540 		size_t len;
    541 
    542 		if (sscanf(comfd, "%d", &pu->pu_fd) != 1) {
    543 			errno = EINVAL;
    544 			rv = -1;
    545 			goto out;
    546 		}
    547 		/* check that what we got at least resembles an fd */
    548 		if (fcntl(pu->pu_fd, F_GETFL) == -1) {
    549 			rv = -1;
    550 			goto out;
    551 		}
    552 
    553 		len = strlen(dir)+1;
    554 
    555 #define allwrite(buf, len)						\
    556 do {									\
    557 	ssize_t al_rv;							\
    558 	al_rv = write(pu->pu_fd, buf, len);				\
    559 	if ((size_t)al_rv != len) {					\
    560 		if (al_rv != -1)					\
    561 			errno = EIO;					\
    562 		rv = -1;						\
    563 		abort();\
    564 		goto out;						\
    565 	}								\
    566 } while (/*CONSTCOND*/0)
    567 		allwrite(&len, sizeof(len));
    568 		allwrite(dir, len);
    569 		len = strlen(pu->pu_kargp->pa_mntfromname)+1;
    570 		allwrite(&len, sizeof(len));
    571 		allwrite(pu->pu_kargp->pa_mntfromname, len);
    572 		allwrite(&mntflags, sizeof(mntflags));
    573 		allwrite(pu->pu_kargp, sizeof(*pu->pu_kargp));
    574 		allwrite(&pu->pu_flags, sizeof(pu->pu_flags));
    575 #undef allwrite
    576 
    577 		rv = 0;
    578 	} else {
    579 		fd = open(_PATH_PUFFS, O_RDWR);
    580 		if (fd == -1) {
    581 			warnx("puffs_mount: cannot open %s", _PATH_PUFFS);
    582 			rv = -1;
    583 			goto out;
    584 		}
    585 		if (fd <= 2)
    586 			warnx("puffs_mount: device fd %d (<= 2), sure this is "
    587 			    "what you want?", fd);
    588 
    589 		pu->pu_kargp->pa_fd = pu->pu_fd = fd;
    590 		if ((rv = mount(MOUNT_PUFFS, rp, mntflags,
    591 		    pu->pu_kargp, sizeof(struct puffs_kargs))) == -1)
    592 			goto out;
    593 	}
    594 
    595 	PU_SETSTATE(pu, PUFFS_STATE_RUNNING);
    596 
    597  out:
    598 	if (rv != 0)
    599 		sverrno = errno;
    600 	else
    601 		sverrno = 0;
    602 	free(pu->pu_kargp);
    603 	pu->pu_kargp = NULL;
    604 
    605 	if (pu->pu_state & PU_PUFFSDAEMON)
    606 		shutdaemon(pu, sverrno);
    607 
    608 	errno = sverrno;
    609 	return rv;
    610 }
    611 
    612 /*ARGSUSED*/
    613 struct puffs_usermount *
    614 _puffs_init(int dummy, struct puffs_ops *pops, const char *mntfromname,
    615 	const char *puffsname, void *priv, uint32_t pflags)
    616 {
    617 	struct puffs_usermount *pu;
    618 	struct puffs_kargs *pargs;
    619 	int sverrno;
    620 
    621 	if (puffsname == PUFFS_DEFER)
    622 		puffsname = "n/a";
    623 	if (mntfromname == PUFFS_DEFER)
    624 		mntfromname = "n/a";
    625 	if (priv == PUFFS_DEFER)
    626 		priv = NULL;
    627 
    628 	pu = malloc(sizeof(struct puffs_usermount));
    629 	if (pu == NULL)
    630 		goto failfree;
    631 	memset(pu, 0, sizeof(struct puffs_usermount));
    632 
    633 	pargs = pu->pu_kargp = malloc(sizeof(struct puffs_kargs));
    634 	if (pargs == NULL)
    635 		goto failfree;
    636 	memset(pargs, 0, sizeof(struct puffs_kargs));
    637 
    638 	pargs->pa_vers = PUFFSDEVELVERS | PUFFSVERSION;
    639 	pargs->pa_flags = PUFFS_FLAG_KERN(pflags);
    640 	fillvnopmask(pops, pargs->pa_vnopmask);
    641 	puffs_setmntinfo(pu, mntfromname, puffsname);
    642 
    643 	puffs_zerostatvfs(&pargs->pa_svfsb);
    644 	pargs->pa_root_cookie = NULL;
    645 	pargs->pa_root_vtype = VDIR;
    646 	pargs->pa_root_vsize = 0;
    647 	pargs->pa_root_rdev = 0;
    648 	pargs->pa_maxmsglen = 0;
    649 
    650 	pu->pu_flags = pflags;
    651 	pu->pu_ops = *pops;
    652 	free(pops); /* XXX */
    653 
    654 	pu->pu_privdata = priv;
    655 	pu->pu_cc_stackshift = PUFFS_CC_STACKSHIFT_DEFAULT;
    656 	LIST_INIT(&pu->pu_pnodelst);
    657 	LIST_INIT(&pu->pu_ios);
    658 	LIST_INIT(&pu->pu_ios_rmlist);
    659 	LIST_INIT(&pu->pu_ccmagazin);
    660 	TAILQ_INIT(&pu->pu_sched);
    661 
    662 	pu->pu_framectrl[PU_FRAMECTRL_FS].rfb = puffs__fsframe_read;
    663 	pu->pu_framectrl[PU_FRAMECTRL_FS].wfb = puffs__fsframe_write;
    664 	pu->pu_framectrl[PU_FRAMECTRL_FS].cmpfb = puffs__fsframe_cmp;
    665 	pu->pu_framectrl[PU_FRAMECTRL_FS].gotfb = puffs__fsframe_gotframe;
    666 	pu->pu_framectrl[PU_FRAMECTRL_FS].fdnotfn = puffs_framev_unmountonclose;
    667 
    668 	/* defaults for some user-settable translation functions */
    669 	pu->pu_cmap = NULL; /* identity translation */
    670 
    671 	pu->pu_pathbuild = puffs_stdpath_buildpath;
    672 	pu->pu_pathfree = puffs_stdpath_freepath;
    673 	pu->pu_pathcmp = puffs_stdpath_cmppath;
    674 	pu->pu_pathtransform = NULL;
    675 	pu->pu_namemod = NULL;
    676 
    677 	pu->pu_errnotify = puffs_kernerr_log;
    678 
    679 	PU_SETSTATE(pu, PUFFS_STATE_BEFOREMOUNT);
    680 
    681 	return pu;
    682 
    683  failfree:
    684 	/* can't unmount() from here for obvious reasons */
    685 	sverrno = errno;
    686 	free(pu);
    687 	errno = sverrno;
    688 	return NULL;
    689 }
    690 
    691 void
    692 puffs_cancel(struct puffs_usermount *pu, int error)
    693 {
    694 
    695 	assert(puffs_getstate(pu) < PUFFS_STATE_RUNNING);
    696 	shutdaemon(pu, error);
    697 	free(pu);
    698 }
    699 
    700 /*ARGSUSED1*/
    701 int
    702 puffs_exit(struct puffs_usermount *pu, int unused /* strict compat */)
    703 {
    704 	struct puffs_framebuf *pb;
    705 	struct puffs_req *preq;
    706 	void *winp;
    707 	size_t winlen;
    708 	int sverrno;
    709 
    710 	pb = puffs_framebuf_make();
    711 	if (pb == NULL) {
    712 		errno = ENOMEM;
    713 		return -1;
    714 	}
    715 
    716 	winlen = sizeof(struct puffs_req);
    717 	if (puffs_framebuf_getwindow(pb, 0, &winp, &winlen) == -1) {
    718 		sverrno = errno;
    719 		puffs_framebuf_destroy(pb);
    720 		errno = sverrno;
    721 		return -1;
    722 	}
    723 	preq = winp;
    724 
    725 	preq->preq_buflen = sizeof(struct puffs_req);
    726 	preq->preq_opclass = PUFFSOP_UNMOUNT;
    727 	preq->preq_id = puffs__nextreq(pu);
    728 
    729 	puffs_framev_enqueue_justsend(pu, puffs_getselectable(pu), pb, 1, 0);
    730 
    731 	return 0;
    732 }
    733 
    734 /*
    735  * Actual mainloop.  This is called from a context which can block.
    736  * It is called either from puffs_mainloop (indirectly, via
    737  * puffs_cc_continue() or from puffs_cc_yield()).
    738  */
    739 void
    740 puffs__theloop(struct puffs_cc *pcc)
    741 {
    742 	struct puffs_usermount *pu = pcc->pcc_pu;
    743 	struct puffs_framectrl *pfctrl;
    744 	struct puffs_fctrl_io *fio;
    745 	struct kevent *curev;
    746 	size_t nchanges;
    747 	int ndone;
    748 
    749 	while (puffs_getstate(pu) != PUFFS_STATE_UNMOUNTED) {
    750 		/*
    751 		 * Schedule existing requests.
    752 		 */
    753 		while ((pcc = TAILQ_FIRST(&pu->pu_sched)) != NULL) {
    754 			TAILQ_REMOVE(&pu->pu_sched, pcc, pcc_schedent);
    755 			puffs__goto(pcc);
    756 		}
    757 
    758 		if (pu->pu_ml_lfn)
    759 			pu->pu_ml_lfn(pu);
    760 
    761 		/* XXX: can we still do these optimizations? */
    762 #if 0
    763 		/*
    764 		 * Do this here, because:
    765 		 *  a) loopfunc might generate some results
    766 		 *  b) it's still "after" event handling (except for round 1)
    767 		 */
    768 		if (puffs_req_putput(ppr) == -1)
    769 			goto out;
    770 		puffs_req_resetput(ppr);
    771 
    772 		/* micro optimization: skip kevent syscall if possible */
    773 		if (pu->pu_nfds == 1 && pu->pu_ml_timep == NULL
    774 		    && (pu->pu_state & PU_ASYNCFD) == 0) {
    775 			pfctrl = XXX->fctrl;
    776 			puffs_framev_input(pu, pfctrl, XXX);
    777 			continue;
    778 		}
    779 #endif
    780 
    781 		/* else: do full processing */
    782 		/* Don't bother worrying about O(n) for now */
    783 		LIST_FOREACH(fio, &pu->pu_ios, fio_entries) {
    784 			if (fio->stat & FIO_WRGONE)
    785 				continue;
    786 
    787 			pfctrl = fio->fctrl;
    788 
    789 			/*
    790 			 * Try to write out everything to avoid the
    791 			 * need for enabling EVFILT_WRITE.  The likely
    792 			 * case is that we can fit everything into the
    793 			 * socket buffer.
    794 			 */
    795 			puffs__framev_output(pu, pfctrl, fio);
    796 		}
    797 
    798 		/*
    799 		 * Build list of which to enable/disable in writecheck.
    800 		 */
    801 		nchanges = 0;
    802 		LIST_FOREACH(fio, &pu->pu_ios, fio_entries) {
    803 			if (fio->stat & FIO_WRGONE)
    804 				continue;
    805 
    806 			/* en/disable write checks for kqueue as needed */
    807 			assert((FIO_EN_WRITE(fio) && FIO_RM_WRITE(fio)) == 0);
    808 			if (FIO_EN_WRITE(fio)) {
    809 				EV_SET(&pu->pu_evs[nchanges], fio->io_fd,
    810 				    EVFILT_WRITE, EV_ENABLE, 0, 0,
    811 				    (uintptr_t)fio);
    812 				fio->stat |= FIO_WR;
    813 				nchanges++;
    814 			}
    815 			if (FIO_RM_WRITE(fio)) {
    816 				EV_SET(&pu->pu_evs[nchanges], fio->io_fd,
    817 				    EVFILT_WRITE, EV_DISABLE, 0, 0,
    818 				    (uintptr_t)fio);
    819 				fio->stat &= ~FIO_WR;
    820 				nchanges++;
    821 			}
    822 			assert(nchanges <= pu->pu_nfds);
    823 		}
    824 
    825 		ndone = kevent(pu->pu_kq, pu->pu_evs, nchanges,
    826 		    pu->pu_evs, 2*pu->pu_nfds, pu->pu_ml_timep);
    827 
    828 		if (ndone == -1) {
    829 			if (errno != EINTR)
    830 				break;
    831 			else
    832 				continue;
    833 		}
    834 
    835 		/* uoptimize */
    836 		if (ndone == 0)
    837 			continue;
    838 
    839 		/* iterate over the results */
    840 		for (curev = pu->pu_evs; ndone--; curev++) {
    841 			int what;
    842 
    843 #if 0
    844 			/* get & possibly dispatch events from kernel */
    845 			if (curev->ident == puffsfd) {
    846 				if (puffs_req_handle(pgr, ppr, 0) == -1)
    847 					goto out;
    848 				continue;
    849 			}
    850 #endif
    851 
    852 			fio = (void *)curev->udata;
    853 			pfctrl = fio->fctrl;
    854 			if (curev->flags & EV_ERROR) {
    855 				assert(curev->filter == EVFILT_WRITE);
    856 				fio->stat &= ~FIO_WR;
    857 
    858 				/* XXX: how to know if it's a transient error */
    859 				puffs__framev_writeclose(pu, fio,
    860 				    (int)curev->data);
    861 				puffs__framev_notify(fio, PUFFS_FBIO_ERROR);
    862 				continue;
    863 			}
    864 
    865 			what = 0;
    866 			if (curev->filter == EVFILT_READ) {
    867 				puffs__framev_input(pu, pfctrl, fio);
    868 				what |= PUFFS_FBIO_READ;
    869 			}
    870 
    871 			else if (curev->filter == EVFILT_WRITE) {
    872 				puffs__framev_output(pu, pfctrl, fio);
    873 				what |= PUFFS_FBIO_WRITE;
    874 			}
    875 			if (what)
    876 				puffs__framev_notify(fio, what);
    877 		}
    878 
    879 		/*
    880 		 * Really free fd's now that we don't have references
    881 		 * to them.
    882 		 */
    883 		while ((fio = LIST_FIRST(&pu->pu_ios_rmlist)) != NULL) {
    884 			LIST_REMOVE(fio, fio_entries);
    885 			free(fio);
    886 		}
    887 	}
    888 
    889 	if (puffs__cc_restoremain(pu) == -1)
    890 		warn("cannot restore main context.  impending doom");
    891 }
    892 
    893 int
    894 puffs_mainloop(struct puffs_usermount *pu)
    895 {
    896 	struct puffs_fctrl_io *fio;
    897 	struct puffs_cc *pcc;
    898 	struct kevent *curev;
    899 	int sverrno;
    900 
    901 	assert(puffs_getstate(pu) >= PUFFS_STATE_RUNNING);
    902 
    903 	pu->pu_kq = kqueue();
    904 	if (pu->pu_kq == -1)
    905 		goto out;
    906 	pu->pu_state |= PU_HASKQ;
    907 
    908 	puffs_setblockingmode(pu, PUFFSDEV_NONBLOCK);
    909 	if (puffs__framev_addfd_ctrl(pu, puffs_getselectable(pu),
    910 	    PUFFS_FBIO_READ | PUFFS_FBIO_WRITE,
    911 	    &pu->pu_framectrl[PU_FRAMECTRL_FS]) == -1)
    912 		goto out;
    913 
    914 	curev = realloc(pu->pu_evs, (2*pu->pu_nfds)*sizeof(struct kevent));
    915 	if (curev == NULL)
    916 		goto out;
    917 	pu->pu_evs = curev;
    918 
    919 	LIST_FOREACH(fio, &pu->pu_ios, fio_entries) {
    920 		EV_SET(curev, fio->io_fd, EVFILT_READ, EV_ADD,
    921 		    0, 0, (uintptr_t)fio);
    922 		curev++;
    923 		EV_SET(curev, fio->io_fd, EVFILT_WRITE, EV_ADD | EV_DISABLE,
    924 		    0, 0, (uintptr_t)fio);
    925 		curev++;
    926 	}
    927 	if (kevent(pu->pu_kq, pu->pu_evs, 2*pu->pu_nfds, NULL, 0, NULL) == -1)
    928 		goto out;
    929 
    930 	pu->pu_state |= PU_INLOOP;
    931 
    932 	/*
    933 	 * Create alternate execution context and jump to it.  Note
    934 	 * that we come "out" of savemain twice.  Where we come out
    935 	 * of it depends on the architecture.  If the return address is
    936 	 * stored on the stack, we jump out from puffs_cc_continue(),
    937 	 * for a register return address from puffs__cc_savemain().
    938 	 * PU_MAINRESTORE makes sure we DTRT in both cases.
    939 	 */
    940 	if (puffs__cc_create(pu, puffs__theloop, &pcc) == -1) {
    941 		goto out;
    942 	}
    943 	if (puffs__cc_savemain(pu) == -1) {
    944 		goto out;
    945 	}
    946 	if ((pu->pu_state & PU_MAINRESTORE) == 0)
    947 		puffs_cc_continue(pcc);
    948 
    949 	finalpush(pu);
    950 	errno = 0;
    951 
    952  out:
    953 	/* store the real error for a while */
    954 	sverrno = errno;
    955 
    956 	errno = sverrno;
    957 	if (errno)
    958 		return -1;
    959 	else
    960 		return 0;
    961 }
    962