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puffs.c revision 1.94 
      1 /*	$NetBSD: puffs.c,v 1.94 2008/12/12 19:45:16 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 1.94 2008/12/12 19:45:16 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, puffs_cookie_t 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 void
    272 puffs_setspecific(struct puffs_usermount *pu, void *privdata)
    273 {
    274 
    275 	pu->pu_privdata = privdata;
    276 }
    277 
    278 size_t
    279 puffs_getmaxreqlen(struct puffs_usermount *pu)
    280 {
    281 
    282 	return pu->pu_maxreqlen;
    283 }
    284 
    285 void
    286 puffs_setmaxreqlen(struct puffs_usermount *pu, size_t reqlen)
    287 {
    288 
    289 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
    290 		warnx("puffs_setmaxreqlen: call has effect only "
    291 		    "before mount\n");
    292 
    293 	pu->pu_kargp->pa_maxmsglen = reqlen;
    294 }
    295 
    296 void
    297 puffs_setfhsize(struct puffs_usermount *pu, size_t fhsize, int flags)
    298 {
    299 
    300 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
    301 		warnx("puffs_setfhsize: call has effect only before mount\n");
    302 
    303 	pu->pu_kargp->pa_fhsize = fhsize;
    304 	pu->pu_kargp->pa_fhflags = flags;
    305 }
    306 
    307 void
    308 puffs_setncookiehash(struct puffs_usermount *pu, int nhash)
    309 {
    310 
    311 	if (puffs_getstate(pu) != PUFFS_STATE_BEFOREMOUNT)
    312 		warnx("puffs_setfhsize: call has effect only before mount\n");
    313 
    314 	pu->pu_kargp->pa_nhashbuckets = nhash;
    315 }
    316 
    317 void
    318 puffs_set_pathbuild(struct puffs_usermount *pu, pu_pathbuild_fn fn)
    319 {
    320 
    321 	pu->pu_pathbuild = fn;
    322 }
    323 
    324 void
    325 puffs_set_pathtransform(struct puffs_usermount *pu, pu_pathtransform_fn fn)
    326 {
    327 
    328 	pu->pu_pathtransform = fn;
    329 }
    330 
    331 void
    332 puffs_set_pathcmp(struct puffs_usermount *pu, pu_pathcmp_fn fn)
    333 {
    334 
    335 	pu->pu_pathcmp = fn;
    336 }
    337 
    338 void
    339 puffs_set_pathfree(struct puffs_usermount *pu, pu_pathfree_fn fn)
    340 {
    341 
    342 	pu->pu_pathfree = fn;
    343 }
    344 
    345 void
    346 puffs_set_namemod(struct puffs_usermount *pu, pu_namemod_fn fn)
    347 {
    348 
    349 	pu->pu_namemod = fn;
    350 }
    351 
    352 void
    353 puffs_set_errnotify(struct puffs_usermount *pu, pu_errnotify_fn fn)
    354 {
    355 
    356 	pu->pu_errnotify = fn;
    357 }
    358 
    359 void
    360 puffs_set_cmap(struct puffs_usermount *pu, pu_cmap_fn fn)
    361 {
    362 
    363 	pu->pu_cmap = fn;
    364 }
    365 
    366 void
    367 puffs_ml_setloopfn(struct puffs_usermount *pu, puffs_ml_loop_fn lfn)
    368 {
    369 
    370 	pu->pu_ml_lfn = lfn;
    371 }
    372 
    373 void
    374 puffs_ml_settimeout(struct puffs_usermount *pu, struct timespec *ts)
    375 {
    376 
    377 	if (ts == NULL) {
    378 		pu->pu_ml_timep = NULL;
    379 	} else {
    380 		pu->pu_ml_timeout = *ts;
    381 		pu->pu_ml_timep = &pu->pu_ml_timeout;
    382 	}
    383 }
    384 
    385 void
    386 puffs_set_prepost(struct puffs_usermount *pu,
    387 	pu_prepost_fn pre, pu_prepost_fn pst)
    388 {
    389 
    390 	pu->pu_oppre = pre;
    391 	pu->pu_oppost = pst;
    392 }
    393 
    394 void
    395 puffs_setback(struct puffs_cc *pcc, int whatback)
    396 {
    397 	struct puffs_req *preq = puffs__framebuf_getdataptr(pcc->pcc_pb);
    398 
    399 	assert(PUFFSOP_OPCLASS(preq->preq_opclass) == PUFFSOP_VN && (
    400 	    preq->preq_optype == PUFFS_VN_OPEN ||
    401 	    preq->preq_optype == PUFFS_VN_MMAP ||
    402 	    preq->preq_optype == PUFFS_VN_REMOVE ||
    403 	    preq->preq_optype == PUFFS_VN_RMDIR ||
    404 	    preq->preq_optype == PUFFS_VN_INACTIVE));
    405 
    406 	preq->preq_setbacks |= whatback & PUFFS_SETBACK_MASK;
    407 }
    408 
    409 int
    410 puffs_daemon(struct puffs_usermount *pu, int nochdir, int noclose)
    411 {
    412 	ssize_t n;
    413 	int parent, value, fd;
    414 
    415 	if (pipe(pu->pu_dpipe) == -1)
    416 		return -1;
    417 
    418 	switch (fork()) {
    419 	case -1:
    420 		return -1;
    421 	case 0:
    422 		parent = 0;
    423 		break;
    424 	default:
    425 		parent = 1;
    426 		break;
    427 	}
    428 	pu->pu_state |= PU_PUFFSDAEMON;
    429 
    430 	if (parent) {
    431 		n = read(pu->pu_dpipe[0], &value, sizeof(int));
    432 		if (n == -1)
    433 			err(1, "puffs_daemon");
    434 		assert(n == sizeof(value));
    435 		if (value) {
    436 			errno = value;
    437 			err(1, "puffs_daemon");
    438 		}
    439 		exit(0);
    440 	} else {
    441 		if (setsid() == -1)
    442 			goto fail;
    443 
    444 		if (!nochdir)
    445 			chdir("/");
    446 
    447 		if (!noclose) {
    448 			fd = open(_PATH_DEVNULL, O_RDWR, 0);
    449 			if (fd == -1)
    450 				goto fail;
    451 			dup2(fd, STDIN_FILENO);
    452 			dup2(fd, STDOUT_FILENO);
    453 			dup2(fd, STDERR_FILENO);
    454 			if (fd > STDERR_FILENO)
    455 				close(fd);
    456 		}
    457 		return 0;
    458 	}
    459 
    460  fail:
    461 	n = write(pu->pu_dpipe[1], &errno, sizeof(int));
    462 	assert(n == 4);
    463 	return -1;
    464 }
    465 
    466 static void
    467 shutdaemon(struct puffs_usermount *pu, int error)
    468 {
    469 	ssize_t n;
    470 
    471 	n = write(pu->pu_dpipe[1], &error, sizeof(int));
    472 	assert(n == 4);
    473 	close(pu->pu_dpipe[0]);
    474 	close(pu->pu_dpipe[1]);
    475 	pu->pu_state &= ~PU_PUFFSDAEMON;
    476 }
    477 
    478 int
    479 puffs_mount(struct puffs_usermount *pu, const char *dir, int mntflags,
    480 	puffs_cookie_t cookie)
    481 {
    482 	char rp[MAXPATHLEN];
    483 	int rv, fd, sverrno;
    484 	char *comfd;
    485 
    486 	pu->pu_kargp->pa_root_cookie = cookie;
    487 
    488 	/* XXXkludgehere */
    489 	/* kauth doesn't provide this service any longer */
    490 	if (geteuid() != 0)
    491 		mntflags |= MNT_NOSUID | MNT_NODEV;
    492 
    493 	if (realpath(dir, rp) == NULL) {
    494 		rv = -1;
    495 		goto out;
    496 	}
    497 
    498 	if (strcmp(dir, rp) != 0) {
    499 		warnx("puffs_mount: \"%s\" is a relative path.", dir);
    500 		warnx("puffs_mount: using \"%s\" instead.", rp);
    501 	}
    502 
    503 	/*
    504 	 * Undocumented...  Well, documented only here.
    505 	 *
    506 	 * This is used for imaginative purposes.  If the env variable is
    507 	 * set, puffs_mount() doesn't do the regular mount procedure.
    508 	 * Rather, it crams the mount data down the comfd and sets comfd as
    509 	 * the puffs descriptor.
    510 	 *
    511 	 * This shouldn't be used unless you can read my mind ( ... or write
    512 	 * it, not to mention execute it, but that's starting to get silly).
    513 	 */
    514 	if ((comfd = getenv("PUFFS_COMFD")) != NULL) {
    515 		size_t len;
    516 
    517 		if (sscanf(comfd, "%d", &pu->pu_fd) != 1) {
    518 			errno = EINVAL;
    519 			rv = -1;
    520 			goto out;
    521 		}
    522 		/* check that what we got at least resembles an fd */
    523 		if (fcntl(pu->pu_fd, F_GETFL) == -1) {
    524 			rv = -1;
    525 			goto out;
    526 		}
    527 
    528 		len = strlen(dir)+1;
    529 
    530 #define allwrite(buf, len)						\
    531 do {									\
    532 	ssize_t al_rv;							\
    533 	al_rv = write(pu->pu_fd, buf, len);				\
    534 	if (al_rv != len) {						\
    535 		if (al_rv != -1)					\
    536 			errno = EIO;					\
    537 		rv = -1;						\
    538 		abort();\
    539 		goto out;						\
    540 	}								\
    541 } while (/*CONSTCOND*/0)
    542 		allwrite(&len, sizeof(len));
    543 		allwrite(dir, len);
    544 		len = strlen(pu->pu_kargp->pa_mntfromname)+1;
    545 		allwrite(&len, sizeof(len));
    546 		allwrite(pu->pu_kargp->pa_mntfromname, len);
    547 		allwrite(&mntflags, sizeof(mntflags));
    548 		allwrite(pu->pu_kargp, sizeof(*pu->pu_kargp));
    549 		allwrite(&pu->pu_flags, sizeof(pu->pu_flags));
    550 #undef allwrite
    551 
    552 		rv = 0;
    553 	} else {
    554 		fd = open(_PATH_PUFFS, O_RDWR);
    555 		if (fd == -1) {
    556 			warnx("puffs_mount: cannot open %s", _PATH_PUFFS);
    557 			rv = -1;
    558 			goto out;
    559 		}
    560 		if (fd <= 2)
    561 			warnx("puffs_mount: device fd %d (<= 2), sure this is "
    562 			    "what you want?", fd);
    563 
    564 		pu->pu_kargp->pa_fd = pu->pu_fd = fd;
    565 		if ((rv = mount(MOUNT_PUFFS, rp, mntflags,
    566 		    pu->pu_kargp, sizeof(struct puffs_kargs))) == -1)
    567 			goto out;
    568 	}
    569 
    570 	PU_SETSTATE(pu, PUFFS_STATE_RUNNING);
    571 
    572  out:
    573 	if (rv != 0)
    574 		sverrno = errno;
    575 	else
    576 		sverrno = 0;
    577 	free(pu->pu_kargp);
    578 	pu->pu_kargp = NULL;
    579 
    580 	if (pu->pu_state & PU_PUFFSDAEMON)
    581 		shutdaemon(pu, sverrno);
    582 
    583 	errno = sverrno;
    584 	return rv;
    585 }
    586 
    587 struct puffs_usermount *
    588 _puffs_init(int develv, struct puffs_ops *pops, const char *mntfromname,
    589 	const char *puffsname, void *priv, uint32_t pflags)
    590 {
    591 	struct puffs_usermount *pu;
    592 	struct puffs_kargs *pargs;
    593 	int sverrno;
    594 
    595 	if (develv != PUFFS_DEVEL_LIBVERSION) {
    596 		warnx("puffs_init: mounting with lib version %d, need %d",
    597 		    develv, PUFFS_DEVEL_LIBVERSION);
    598 		errno = EINVAL;
    599 		return NULL;
    600 	}
    601 
    602 	pu = malloc(sizeof(struct puffs_usermount));
    603 	if (pu == NULL)
    604 		goto failfree;
    605 	memset(pu, 0, sizeof(struct puffs_usermount));
    606 
    607 	pargs = pu->pu_kargp = malloc(sizeof(struct puffs_kargs));
    608 	if (pargs == NULL)
    609 		goto failfree;
    610 	memset(pargs, 0, sizeof(struct puffs_kargs));
    611 
    612 	pargs->pa_vers = PUFFSDEVELVERS | PUFFSVERSION;
    613 	pargs->pa_flags = PUFFS_FLAG_KERN(pflags);
    614 	fillvnopmask(pops, pargs->pa_vnopmask);
    615 	(void)strlcpy(pargs->pa_typename, puffsname,
    616 	    sizeof(pargs->pa_typename));
    617 	(void)strlcpy(pargs->pa_mntfromname, mntfromname,
    618 	    sizeof(pargs->pa_mntfromname));
    619 
    620 	puffs_zerostatvfs(&pargs->pa_svfsb);
    621 	pargs->pa_root_cookie = NULL;
    622 	pargs->pa_root_vtype = VDIR;
    623 	pargs->pa_root_vsize = 0;
    624 	pargs->pa_root_rdev = 0;
    625 	pargs->pa_maxmsglen = 0;
    626 
    627 	pu->pu_flags = pflags;
    628 	pu->pu_ops = *pops;
    629 	free(pops); /* XXX */
    630 
    631 	pu->pu_privdata = priv;
    632 	pu->pu_cc_stackshift = PUFFS_CC_STACKSHIFT_DEFAULT;
    633 	LIST_INIT(&pu->pu_pnodelst);
    634 	LIST_INIT(&pu->pu_ios);
    635 	LIST_INIT(&pu->pu_ios_rmlist);
    636 	LIST_INIT(&pu->pu_ccmagazin);
    637 	TAILQ_INIT(&pu->pu_sched);
    638 
    639 	pu->pu_framectrl[PU_FRAMECTRL_FS].rfb = puffs__fsframe_read;
    640 	pu->pu_framectrl[PU_FRAMECTRL_FS].wfb = puffs__fsframe_write;
    641 	pu->pu_framectrl[PU_FRAMECTRL_FS].cmpfb = puffs__fsframe_cmp;
    642 	pu->pu_framectrl[PU_FRAMECTRL_FS].gotfb = puffs__fsframe_gotframe;
    643 	pu->pu_framectrl[PU_FRAMECTRL_FS].fdnotfn = puffs_framev_unmountonclose;
    644 
    645 	/* defaults for some user-settable translation functions */
    646 	pu->pu_cmap = NULL; /* identity translation */
    647 
    648 	pu->pu_pathbuild = puffs_stdpath_buildpath;
    649 	pu->pu_pathfree = puffs_stdpath_freepath;
    650 	pu->pu_pathcmp = puffs_stdpath_cmppath;
    651 	pu->pu_pathtransform = NULL;
    652 	pu->pu_namemod = NULL;
    653 
    654 	pu->pu_errnotify = puffs_defaulterror;
    655 
    656 	PU_SETSTATE(pu, PUFFS_STATE_BEFOREMOUNT);
    657 
    658 	return pu;
    659 
    660  failfree:
    661 	/* can't unmount() from here for obvious reasons */
    662 	sverrno = errno;
    663 	free(pu);
    664 	errno = sverrno;
    665 	return NULL;
    666 }
    667 
    668 void
    669 puffs_cancel(struct puffs_usermount *pu, int error)
    670 {
    671 
    672 	assert(puffs_getstate(pu) < PUFFS_STATE_RUNNING);
    673 	shutdaemon(pu, error);
    674 	free(pu);
    675 }
    676 
    677 /*
    678  * XXX: there's currently no clean way to request unmount from
    679  * within the user server, so be very brutal about it.
    680  */
    681 /*ARGSUSED1*/
    682 int
    683 puffs_exit(struct puffs_usermount *pu, int force)
    684 {
    685 	struct puffs_node *pn;
    686 
    687 	force = 1; /* currently */
    688 	assert((pu->pu_state & PU_PUFFSDAEMON) == 0);
    689 
    690 	if (pu->pu_fd)
    691 		close(pu->pu_fd);
    692 
    693 	while ((pn = LIST_FIRST(&pu->pu_pnodelst)) != NULL)
    694 		puffs_pn_put(pn);
    695 
    696 	finalpush(pu);
    697 	puffs__framev_exit(pu);
    698 	puffs__cc_exit(pu);
    699 	if (pu->pu_state & PU_HASKQ)
    700 		close(pu->pu_kq);
    701 	free(pu);
    702 
    703 	return 0; /* always succesful for now, WILL CHANGE */
    704 }
    705 
    706 /*
    707  * Actual mainloop.  This is called from a context which can block.
    708  * It is called either from puffs_mainloop (indirectly, via
    709  * puffs_cc_continue() or from puffs_cc_yield()).
    710  */
    711 void
    712 puffs__theloop(struct puffs_cc *pcc)
    713 {
    714 	struct puffs_usermount *pu = pcc->pcc_pu;
    715 	struct puffs_framectrl *pfctrl;
    716 	struct puffs_fctrl_io *fio;
    717 	struct kevent *curev;
    718 	size_t nchanges;
    719 	int ndone;
    720 
    721 	while (puffs_getstate(pu) != PUFFS_STATE_UNMOUNTED) {
    722 		/*
    723 		 * Schedule existing requests.
    724 		 */
    725 		while ((pcc = TAILQ_FIRST(&pu->pu_sched)) != NULL) {
    726 			TAILQ_REMOVE(&pu->pu_sched, pcc, pcc_schedent);
    727 			puffs__goto(pcc);
    728 		}
    729 
    730 		if (pu->pu_ml_lfn)
    731 			pu->pu_ml_lfn(pu);
    732 
    733 		/* XXX: can we still do these optimizations? */
    734 #if 0
    735 		/*
    736 		 * Do this here, because:
    737 		 *  a) loopfunc might generate some results
    738 		 *  b) it's still "after" event handling (except for round 1)
    739 		 */
    740 		if (puffs_req_putput(ppr) == -1)
    741 			goto out;
    742 		puffs_req_resetput(ppr);
    743 
    744 		/* micro optimization: skip kevent syscall if possible */
    745 		if (pu->pu_nfds == 1 && pu->pu_ml_timep == NULL
    746 		    && (pu->pu_state & PU_ASYNCFD) == 0) {
    747 			pfctrl = XXX->fctrl;
    748 			puffs_framev_input(pu, pfctrl, XXX);
    749 			continue;
    750 		}
    751 #endif
    752 
    753 		/* else: do full processing */
    754 		/* Don't bother worrying about O(n) for now */
    755 		LIST_FOREACH(fio, &pu->pu_ios, fio_entries) {
    756 			if (fio->stat & FIO_WRGONE)
    757 				continue;
    758 
    759 			pfctrl = fio->fctrl;
    760 
    761 			/*
    762 			 * Try to write out everything to avoid the
    763 			 * need for enabling EVFILT_WRITE.  The likely
    764 			 * case is that we can fit everything into the
    765 			 * socket buffer.
    766 			 */
    767 			puffs__framev_output(pu, pfctrl, fio);
    768 		}
    769 
    770 		/*
    771 		 * Build list of which to enable/disable in writecheck.
    772 		 */
    773 		nchanges = 0;
    774 		LIST_FOREACH(fio, &pu->pu_ios, fio_entries) {
    775 			if (fio->stat & FIO_WRGONE)
    776 				continue;
    777 
    778 			/* en/disable write checks for kqueue as needed */
    779 			assert((FIO_EN_WRITE(fio) && FIO_RM_WRITE(fio)) == 0);
    780 			if (FIO_EN_WRITE(fio)) {
    781 				EV_SET(&pu->pu_evs[nchanges], fio->io_fd,
    782 				    EVFILT_WRITE, EV_ENABLE, 0, 0,
    783 				    (uintptr_t)fio);
    784 				fio->stat |= FIO_WR;
    785 				nchanges++;
    786 			}
    787 			if (FIO_RM_WRITE(fio)) {
    788 				EV_SET(&pu->pu_evs[nchanges], fio->io_fd,
    789 				    EVFILT_WRITE, EV_DISABLE, 0, 0,
    790 				    (uintptr_t)fio);
    791 				fio->stat &= ~FIO_WR;
    792 				nchanges++;
    793 			}
    794 			assert(nchanges <= pu->pu_nfds);
    795 		}
    796 
    797 		ndone = kevent(pu->pu_kq, pu->pu_evs, nchanges,
    798 		    pu->pu_evs, 2*pu->pu_nfds, pu->pu_ml_timep);
    799 
    800 		if (ndone == -1) {
    801 			if (errno != EINTR)
    802 				break;
    803 			else
    804 				continue;
    805 		}
    806 
    807 		/* uoptimize */
    808 		if (ndone == 0)
    809 			continue;
    810 
    811 		/* iterate over the results */
    812 		for (curev = pu->pu_evs; ndone--; curev++) {
    813 			int what;
    814 
    815 #if 0
    816 			/* get & possibly dispatch events from kernel */
    817 			if (curev->ident == puffsfd) {
    818 				if (puffs_req_handle(pgr, ppr, 0) == -1)
    819 					goto out;
    820 				continue;
    821 			}
    822 #endif
    823 
    824 			fio = (void *)curev->udata;
    825 			pfctrl = fio->fctrl;
    826 			if (curev->flags & EV_ERROR) {
    827 				assert(curev->filter == EVFILT_WRITE);
    828 				fio->stat &= ~FIO_WR;
    829 
    830 				/* XXX: how to know if it's a transient error */
    831 				puffs__framev_writeclose(pu, fio,
    832 				    (int)curev->data);
    833 				puffs__framev_notify(fio, PUFFS_FBIO_ERROR);
    834 				continue;
    835 			}
    836 
    837 			what = 0;
    838 			if (curev->filter == EVFILT_READ) {
    839 				puffs__framev_input(pu, pfctrl, fio);
    840 				what |= PUFFS_FBIO_READ;
    841 			}
    842 
    843 			else if (curev->filter == EVFILT_WRITE) {
    844 				puffs__framev_output(pu, pfctrl, fio);
    845 				what |= PUFFS_FBIO_WRITE;
    846 			}
    847 			if (what)
    848 				puffs__framev_notify(fio, what);
    849 		}
    850 
    851 		/*
    852 		 * Really free fd's now that we don't have references
    853 		 * to them.
    854 		 */
    855 		while ((fio = LIST_FIRST(&pu->pu_ios_rmlist)) != NULL) {
    856 			LIST_REMOVE(fio, fio_entries);
    857 			free(fio);
    858 		}
    859 	}
    860 
    861 	if (puffs__cc_restoremain(pu) == -1)
    862 		warn("cannot restore main context.  impending doom");
    863 }
    864 
    865 int
    866 puffs_mainloop(struct puffs_usermount *pu)
    867 {
    868 	struct puffs_fctrl_io *fio;
    869 	struct puffs_cc *pcc;
    870 	struct kevent *curev;
    871 	int sverrno;
    872 
    873 	assert(puffs_getstate(pu) >= PUFFS_STATE_RUNNING);
    874 
    875 	pu->pu_kq = kqueue();
    876 	if (pu->pu_kq == -1)
    877 		goto out;
    878 	pu->pu_state |= PU_HASKQ;
    879 
    880 	puffs_setblockingmode(pu, PUFFSDEV_NONBLOCK);
    881 	if (puffs__framev_addfd_ctrl(pu, puffs_getselectable(pu),
    882 	    PUFFS_FBIO_READ | PUFFS_FBIO_WRITE,
    883 	    &pu->pu_framectrl[PU_FRAMECTRL_FS]) == -1)
    884 		goto out;
    885 
    886 	curev = realloc(pu->pu_evs, (2*pu->pu_nfds)*sizeof(struct kevent));
    887 	if (curev == NULL)
    888 		goto out;
    889 	pu->pu_evs = curev;
    890 
    891 	LIST_FOREACH(fio, &pu->pu_ios, fio_entries) {
    892 		EV_SET(curev, fio->io_fd, EVFILT_READ, EV_ADD,
    893 		    0, 0, (uintptr_t)fio);
    894 		curev++;
    895 		EV_SET(curev, fio->io_fd, EVFILT_WRITE, EV_ADD | EV_DISABLE,
    896 		    0, 0, (uintptr_t)fio);
    897 		curev++;
    898 	}
    899 	if (kevent(pu->pu_kq, pu->pu_evs, 2*pu->pu_nfds, NULL, 0, NULL) == -1)
    900 		goto out;
    901 
    902 	pu->pu_state |= PU_INLOOP;
    903 
    904 	/*
    905 	 * Create alternate execution context and jump to it.  Note
    906 	 * that we come "out" of savemain twice.  Where we come out
    907 	 * of it depends on the architecture.  If the return address is
    908 	 * stored on the stack, we jump out from puffs_cc_continue(),
    909 	 * for a register return address from puffs__cc_savemain().
    910 	 * PU_MAINRESTORE makes sure we DTRT in both cases.
    911 	 */
    912 	if (puffs__cc_create(pu, puffs__theloop, &pcc) == -1) {
    913 		goto out;
    914 	}
    915 	if (puffs__cc_savemain(pu) == -1) {
    916 		goto out;
    917 	}
    918 	if ((pu->pu_state & PU_MAINRESTORE) == 0)
    919 		puffs_cc_continue(pcc);
    920 
    921 	finalpush(pu);
    922 	errno = 0;
    923 
    924  out:
    925 	/* store the real error for a while */
    926 	sverrno = errno;
    927 
    928 	errno = sverrno;
    929 	if (errno)
    930 		return -1;
    931 	else
    932 		return 0;
    933 }
    934