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puffs_vfsops.c revision 1.115.2.1
      1 /*	$NetBSD: puffs_vfsops.c,v 1.115.2.1 2015/04/06 15:18:19 skrll Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2005, 2006  Antti Kantee.  All Rights Reserved.
      5  *
      6  * Development of this software was supported by the
      7  * Google Summer of Code program and the Ulla Tuominen Foundation.
      8  * The Google SoC project was mentored by Bill Studenmund.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     20  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     21  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     22  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     25  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: puffs_vfsops.c,v 1.115.2.1 2015/04/06 15:18:19 skrll Exp $");
     34 
     35 #include <sys/param.h>
     36 #include <sys/kernel.h>
     37 #include <sys/mount.h>
     38 #include <sys/extattr.h>
     39 #include <sys/queue.h>
     40 #include <sys/vnode.h>
     41 #include <sys/dirent.h>
     42 #include <sys/kauth.h>
     43 #include <sys/proc.h>
     44 #include <sys/module.h>
     45 #include <sys/kthread.h>
     46 
     47 #include <uvm/uvm.h>
     48 
     49 #include <dev/putter/putter_sys.h>
     50 
     51 #include <miscfs/genfs/genfs.h>
     52 
     53 #include <fs/puffs/puffs_msgif.h>
     54 #include <fs/puffs/puffs_sys.h>
     55 
     56 #include <lib/libkern/libkern.h>
     57 
     58 #include <nfs/nfsproto.h> /* for fh sizes */
     59 
     60 MODULE(MODULE_CLASS_VFS, puffs, "putter");
     61 
     62 VFS_PROTOS(puffs_vfsop);
     63 
     64 static struct putter_ops puffs_putter = {
     65 	.pop_getout	= puffs_msgif_getout,
     66 	.pop_releaseout	= puffs_msgif_releaseout,
     67 	.pop_waitcount	= puffs_msgif_waitcount,
     68 	.pop_dispatch	= puffs_msgif_dispatch,
     69 	.pop_close	= puffs_msgif_close,
     70 };
     71 
     72 static const struct genfs_ops puffs_genfsops = {
     73         .gop_size = puffs_gop_size,
     74 	.gop_write = genfs_gop_write,
     75 	.gop_markupdate = puffs_gop_markupdate,
     76 #if 0
     77 	.gop_alloc, should ask userspace
     78 #endif
     79 };
     80 
     81 /*
     82  * Try to ensure data structures used by the puffs protocol
     83  * do not unexpectedly change.
     84  */
     85 #if defined(__i386__) && defined(__ELF__)
     86 CTASSERT(sizeof(struct puffs_kargs) == 3928);
     87 CTASSERT(sizeof(struct vattr) == 136);
     88 CTASSERT(sizeof(struct puffs_req) == 44);
     89 #endif
     90 
     91 int
     92 puffs_vfsop_mount(struct mount *mp, const char *path, void *data,
     93 	size_t *data_len)
     94 {
     95 	struct puffs_mount *pmp = NULL;
     96 	struct puffs_kargs *args;
     97 	char fstype[_VFS_NAMELEN];
     98 	char *p;
     99 	int error = 0, i;
    100 	pid_t mntpid = curlwp->l_proc->p_pid;
    101 
    102 	if (data == NULL)
    103 		return EINVAL;
    104 	if (*data_len < sizeof *args)
    105 		return EINVAL;
    106 
    107 	if (mp->mnt_flag & MNT_GETARGS) {
    108 		pmp = MPTOPUFFSMP(mp);
    109 		*(struct puffs_kargs *)data = pmp->pmp_args;
    110 		*data_len = sizeof *args;
    111 		return 0;
    112 	}
    113 
    114 	/* update is not supported currently */
    115 	if (mp->mnt_flag & MNT_UPDATE)
    116 		return EOPNOTSUPP;
    117 
    118 	args = (struct puffs_kargs *)data;
    119 
    120 	if (args->pa_vers != PUFFSVERSION) {
    121 		printf("puffs_mount: development version mismatch: "
    122 		    "kernel %d, lib %d\n", PUFFSVERSION, args->pa_vers);
    123 		error = EINVAL;
    124 		goto out;
    125 	}
    126 
    127 	if ((args->pa_flags & ~PUFFS_KFLAG_MASK) != 0) {
    128 		printf("puffs_mount: invalid KFLAGs 0x%x\n", args->pa_flags);
    129 		error = EINVAL;
    130 		goto out;
    131 	}
    132 	if ((args->pa_fhflags & ~PUFFS_FHFLAG_MASK) != 0) {
    133 		printf("puffs_mount: invalid FHFLAGs 0x%x\n", args->pa_fhflags);
    134 		error = EINVAL;
    135 		goto out;
    136 	}
    137 
    138 	for (i = 0; i < __arraycount(args->pa_spare); i++) {
    139 		if (args->pa_spare[i] != 0) {
    140 			printf("puffs_mount: pa_spare[%d] = 0x%x\n",
    141 			    i, args->pa_spare[i]);
    142 			error = EINVAL;
    143 			goto out;
    144 		}
    145 	}
    146 
    147 	/* use dummy value for passthrough */
    148 	if (args->pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH)
    149 		args->pa_fhsize = sizeof(struct fid);
    150 
    151 	/* sanitize file handle length */
    152 	if (PUFFS_TOFHSIZE(args->pa_fhsize) > FHANDLE_SIZE_MAX) {
    153 		printf("puffs_mount: handle size %zu too large\n",
    154 		    args->pa_fhsize);
    155 		error = EINVAL;
    156 		goto out;
    157 	}
    158 	/* sanity check file handle max sizes */
    159 	if (args->pa_fhsize && args->pa_fhflags & PUFFS_FHFLAG_PROTOMASK) {
    160 		size_t kfhsize = PUFFS_TOFHSIZE(args->pa_fhsize);
    161 
    162 		if (args->pa_fhflags & PUFFS_FHFLAG_NFSV2) {
    163 			if (NFSX_FHTOOBIG_P(kfhsize, 0)) {
    164 				printf("puffs_mount: fhsize larger than "
    165 				    "NFSv2 max %d\n",
    166 				    PUFFS_FROMFHSIZE(NFSX_V2FH));
    167 				error = EINVAL;
    168 				goto out;
    169 			}
    170 		}
    171 
    172 		if (args->pa_fhflags & PUFFS_FHFLAG_NFSV3) {
    173 			if (NFSX_FHTOOBIG_P(kfhsize, 1)) {
    174 				printf("puffs_mount: fhsize larger than "
    175 				    "NFSv3 max %d\n",
    176 				    PUFFS_FROMFHSIZE(NFSX_V3FHMAX));
    177 				error = EINVAL;
    178 				goto out;
    179 			}
    180 		}
    181 	}
    182 
    183 	/* don't allow non-printing characters (like my sweet umlauts.. snif) */
    184 	args->pa_typename[sizeof(args->pa_typename)-1] = '\0';
    185 	for (p = args->pa_typename; *p; p++)
    186 		if (*p < ' ' || *p > '~')
    187 			*p = '.';
    188 
    189 	args->pa_mntfromname[sizeof(args->pa_mntfromname)-1] = '\0';
    190 	for (p = args->pa_mntfromname; *p; p++)
    191 		if (*p < ' ' || *p > '~')
    192 			*p = '.';
    193 
    194 	/* build real name */
    195 	(void)strlcpy(fstype, PUFFS_TYPEPREFIX, sizeof(fstype));
    196 	(void)strlcat(fstype, args->pa_typename, sizeof(fstype));
    197 
    198 	/* inform user server if it got the max request size it wanted */
    199 	if (args->pa_maxmsglen == 0 || args->pa_maxmsglen > PUFFS_MSG_MAXSIZE)
    200 		args->pa_maxmsglen = PUFFS_MSG_MAXSIZE;
    201 	else if (args->pa_maxmsglen < 2*PUFFS_MSGSTRUCT_MAX)
    202 		args->pa_maxmsglen = 2*PUFFS_MSGSTRUCT_MAX;
    203 
    204 	(void)strlcpy(args->pa_typename, fstype, sizeof(args->pa_typename));
    205 
    206 	error = set_statvfs_info(path, UIO_USERSPACE, args->pa_mntfromname,
    207 	    UIO_SYSSPACE, fstype, mp, curlwp);
    208 	if (error)
    209 		goto out;
    210 	mp->mnt_stat.f_iosize = DEV_BSIZE;
    211 	mp->mnt_stat.f_namemax = args->pa_svfsb.f_namemax;
    212 
    213 	/*
    214 	 * We can't handle the VFS_STATVFS() mount_domount() does
    215 	 * after VFS_MOUNT() because we'd deadlock, so handle it
    216 	 * here already.
    217 	 */
    218 	copy_statvfs_info(&args->pa_svfsb, mp);
    219 	(void)memcpy(&mp->mnt_stat, &args->pa_svfsb, sizeof(mp->mnt_stat));
    220 
    221 	KASSERT(curlwp != uvm.pagedaemon_lwp);
    222 	pmp = kmem_zalloc(sizeof(struct puffs_mount), KM_SLEEP);
    223 
    224 	mp->mnt_fs_bshift = DEV_BSHIFT;
    225 	mp->mnt_dev_bshift = DEV_BSHIFT;
    226 	mp->mnt_flag &= ~MNT_LOCAL; /* we don't really know, so ... */
    227 	mp->mnt_data = pmp;
    228 
    229 #if 0
    230 	/*
    231 	 * XXX: puffs code is MPSAFE.  However, VFS really isn't.
    232 	 * Currently, there is nothing which protects an inode from
    233 	 * reclaim while there are threads inside the file system.
    234 	 * This means that in the event of a server crash, an MPSAFE
    235 	 * mount is likely to end up accessing invalid memory.  For the
    236 	 * non-mpsafe case, the kernel lock, general structure of
    237 	 * puffs and pmp_refcount protect the threads during escape.
    238 	 *
    239 	 * Fixing this will require:
    240 	 *  a) fixing vfs
    241 	 * OR
    242 	 *  b) adding a small sleep to puffs_msgif_close() between
    243 	 *     userdead() and dounmount().
    244 	 *     (well, this isn't really a fix, but would solve
    245 	 *     99.999% of the race conditions).
    246 	 *
    247 	 * Also, in the event of "b", unmount -f should be used,
    248 	 * like with any other file system, sparingly and only when
    249 	 * it is "known" to be safe.
    250 	 */
    251 	mp->mnt_iflags |= IMNT_MPSAFE;
    252 #endif
    253 
    254 	pmp->pmp_status = PUFFSTAT_MOUNTING;
    255 	pmp->pmp_mp = mp;
    256 	pmp->pmp_msg_maxsize = args->pa_maxmsglen;
    257 	pmp->pmp_args = *args;
    258 
    259 	/*
    260 	 * Inform the fileops processing code that we have a mountpoint.
    261 	 * If it doesn't know about anyone with our pid/fd having the
    262 	 * device open, punt
    263 	 */
    264 	if ((pmp->pmp_pi
    265 	    = putter_attach(mntpid, args->pa_fd, pmp, &puffs_putter)) == NULL) {
    266 		error = ENOENT;
    267 		goto out;
    268 	}
    269 
    270 	/* XXX: check parameters */
    271 	pmp->pmp_root_cookie = args->pa_root_cookie;
    272 	pmp->pmp_root_vtype = args->pa_root_vtype;
    273 	pmp->pmp_root_vsize = args->pa_root_vsize;
    274 	pmp->pmp_root_rdev = args->pa_root_rdev;
    275 	pmp->pmp_docompat = args->pa_time32;
    276 
    277 	mutex_init(&pmp->pmp_lock, MUTEX_DEFAULT, IPL_NONE);
    278 	mutex_init(&pmp->pmp_sopmtx, MUTEX_DEFAULT, IPL_NONE);
    279 	cv_init(&pmp->pmp_msg_waiter_cv, "puffsget");
    280 	cv_init(&pmp->pmp_refcount_cv, "puffsref");
    281 	cv_init(&pmp->pmp_unmounting_cv, "puffsum");
    282 	cv_init(&pmp->pmp_sopcv, "puffsop");
    283 	TAILQ_INIT(&pmp->pmp_msg_touser);
    284 	TAILQ_INIT(&pmp->pmp_msg_replywait);
    285 	TAILQ_INIT(&pmp->pmp_sopfastreqs);
    286 	TAILQ_INIT(&pmp->pmp_sopnodereqs);
    287 
    288 	if ((error = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
    289 	    puffs_sop_thread, pmp, NULL, "puffsop")) != 0)
    290 		goto out;
    291 	pmp->pmp_sopthrcount = 1;
    292 
    293 	DPRINTF(("puffs_mount: mount point at %p, puffs specific at %p\n",
    294 	    mp, MPTOPUFFSMP(mp)));
    295 
    296 	vfs_getnewfsid(mp);
    297 
    298  out:
    299 	if (error && pmp && pmp->pmp_pi)
    300 		putter_detach(pmp->pmp_pi);
    301 	if (error && pmp)
    302 		kmem_free(pmp, sizeof(struct puffs_mount));
    303 	return error;
    304 }
    305 
    306 int
    307 puffs_vfsop_start(struct mount *mp, int flags)
    308 {
    309 	struct puffs_mount *pmp = MPTOPUFFSMP(mp);
    310 
    311 	KASSERT(pmp->pmp_status == PUFFSTAT_MOUNTING);
    312 	pmp->pmp_status = PUFFSTAT_RUNNING;
    313 
    314 	return 0;
    315 }
    316 
    317 int
    318 puffs_vfsop_unmount(struct mount *mp, int mntflags)
    319 {
    320 	PUFFS_MSG_VARS(vfs, unmount);
    321 	struct puffs_mount *pmp;
    322 	int error, force;
    323 
    324 	error = 0;
    325 	force = mntflags & MNT_FORCE;
    326 	pmp = MPTOPUFFSMP(mp);
    327 
    328 	DPRINTF(("puffs_unmount: detach filesystem from vfs, current "
    329 	    "status 0x%x\n", pmp->pmp_status));
    330 
    331 	/*
    332 	 * flush all the vnodes.  VOP_RECLAIM() takes care that the
    333 	 * root vnode does not get flushed until unmount.  The
    334 	 * userspace root node cookie is stored in the mount
    335 	 * structure, so we can always re-instantiate a root vnode,
    336 	 * should userspace unmount decide it doesn't want to
    337 	 * cooperate.
    338 	 */
    339 	error = vflush(mp, NULLVP, force ? FORCECLOSE : 0);
    340 	if (error)
    341 		goto out;
    342 
    343 	/*
    344 	 * If we are not DYING, we should ask userspace's opinion
    345 	 * about the situation
    346 	 */
    347 	mutex_enter(&pmp->pmp_lock);
    348 	if (pmp->pmp_status != PUFFSTAT_DYING) {
    349 		pmp->pmp_unmounting = 1;
    350 		mutex_exit(&pmp->pmp_lock);
    351 
    352 		PUFFS_MSG_ALLOC(vfs, unmount);
    353 		puffs_msg_setinfo(park_unmount,
    354 		    PUFFSOP_VFS, PUFFS_VFS_UNMOUNT, NULL);
    355 		unmount_msg->pvfsr_flags = mntflags;
    356 
    357 		PUFFS_MSG_ENQUEUEWAIT(pmp, park_unmount, error);
    358 		PUFFS_MSG_RELEASE(unmount);
    359 
    360 		error = checkerr(pmp, error, __func__);
    361 		DPRINTF(("puffs_unmount: error %d force %d\n", error, force));
    362 
    363 		mutex_enter(&pmp->pmp_lock);
    364 		pmp->pmp_unmounting = 0;
    365 		cv_broadcast(&pmp->pmp_unmounting_cv);
    366 	}
    367 
    368 	/*
    369 	 * if userspace cooperated or we really need to die,
    370 	 * screw what userland thinks and just die.
    371 	 */
    372 	if (error == 0 || force) {
    373 		struct puffs_sopreq *psopr;
    374 
    375 		/* tell waiters & other resources to go unwait themselves */
    376 		puffs_userdead(pmp);
    377 		putter_detach(pmp->pmp_pi);
    378 
    379 		/*
    380 		 * Wait until there are no more users for the mount resource.
    381 		 * Notice that this is hooked against transport_close
    382 		 * and return from touser.  In an ideal world, it would
    383 		 * be hooked against final return from all operations.
    384 		 * But currently it works well enough, since nobody
    385 		 * does weird blocking voodoo after return from touser().
    386 		 */
    387 		while (pmp->pmp_refcount != 0)
    388 			cv_wait(&pmp->pmp_refcount_cv, &pmp->pmp_lock);
    389 		mutex_exit(&pmp->pmp_lock);
    390 
    391 		/*
    392 		 * Release kernel thread now that there is nothing
    393 		 * it would be wanting to lock.
    394 		 */
    395 		KASSERT(curlwp != uvm.pagedaemon_lwp);
    396 		psopr = kmem_alloc(sizeof(*psopr), KM_SLEEP);
    397 		psopr->psopr_sopreq = PUFFS_SOPREQSYS_EXIT;
    398 		mutex_enter(&pmp->pmp_sopmtx);
    399 		if (pmp->pmp_sopthrcount == 0) {
    400 			mutex_exit(&pmp->pmp_sopmtx);
    401 			kmem_free(psopr, sizeof(*psopr));
    402 			mutex_enter(&pmp->pmp_sopmtx);
    403 			KASSERT(pmp->pmp_sopthrcount == 0);
    404 		} else {
    405 			TAILQ_INSERT_TAIL(&pmp->pmp_sopfastreqs,
    406 			    psopr, psopr_entries);
    407 			cv_signal(&pmp->pmp_sopcv);
    408 		}
    409 		while (pmp->pmp_sopthrcount > 0)
    410 			cv_wait(&pmp->pmp_sopcv, &pmp->pmp_sopmtx);
    411 		mutex_exit(&pmp->pmp_sopmtx);
    412 
    413 		/* free resources now that we hopefully have no waiters left */
    414 		cv_destroy(&pmp->pmp_unmounting_cv);
    415 		cv_destroy(&pmp->pmp_refcount_cv);
    416 		cv_destroy(&pmp->pmp_msg_waiter_cv);
    417 		cv_destroy(&pmp->pmp_sopcv);
    418 		mutex_destroy(&pmp->pmp_lock);
    419 		mutex_destroy(&pmp->pmp_sopmtx);
    420 
    421 		kmem_free(pmp, sizeof(struct puffs_mount));
    422 		error = 0;
    423 	} else {
    424 		mutex_exit(&pmp->pmp_lock);
    425 	}
    426 
    427  out:
    428 	DPRINTF(("puffs_unmount: return %d\n", error));
    429 	return error;
    430 }
    431 
    432 /*
    433  * This doesn't need to travel to userspace
    434  */
    435 int
    436 puffs_vfsop_root(struct mount *mp, struct vnode **vpp)
    437 {
    438 	struct puffs_mount *pmp = MPTOPUFFSMP(mp);
    439 	int rv;
    440 
    441 	rv = puffs_cookie2vnode(pmp, pmp->pmp_root_cookie, vpp);
    442 	KASSERT(rv != PUFFS_NOSUCHCOOKIE);
    443 	if (rv != 0)
    444 		return rv;
    445 	rv = vn_lock(*vpp, LK_EXCLUSIVE);
    446 	if (rv != 0) {
    447 		vrele(*vpp);
    448 		*vpp = NULL;
    449 		return rv;
    450 	}
    451 	return 0;
    452 }
    453 
    454 int
    455 puffs_vfsop_statvfs(struct mount *mp, struct statvfs *sbp)
    456 {
    457 	PUFFS_MSG_VARS(vfs, statvfs);
    458 	struct puffs_mount *pmp;
    459 	int error = 0;
    460 
    461 	pmp = MPTOPUFFSMP(mp);
    462 
    463 	/*
    464 	 * If we are mounting, it means that the userspace counterpart
    465 	 * is calling mount(2), but mount(2) also calls statvfs.  So
    466 	 * requesting statvfs from userspace would mean a deadlock.
    467 	 * Compensate.
    468 	 */
    469 	if (__predict_false(pmp->pmp_status == PUFFSTAT_MOUNTING))
    470 		return EINPROGRESS;
    471 
    472 	PUFFS_MSG_ALLOC(vfs, statvfs);
    473 	puffs_msg_setinfo(park_statvfs, PUFFSOP_VFS, PUFFS_VFS_STATVFS, NULL);
    474 
    475 	PUFFS_MSG_ENQUEUEWAIT(pmp, park_statvfs, error);
    476 	error = checkerr(pmp, error, __func__);
    477 	statvfs_msg->pvfsr_sb.f_iosize = DEV_BSIZE;
    478 
    479 	/*
    480 	 * Try to produce a sensible result even in the event
    481 	 * of userspace error.
    482 	 *
    483 	 * XXX: cache the copy in non-error case
    484 	 */
    485 	if (!error) {
    486 		copy_statvfs_info(&statvfs_msg->pvfsr_sb, mp);
    487 		(void)memcpy(sbp, &statvfs_msg->pvfsr_sb,
    488 		    sizeof(struct statvfs));
    489 	} else {
    490 		copy_statvfs_info(sbp, mp);
    491 	}
    492 
    493 	PUFFS_MSG_RELEASE(statvfs);
    494 	return error;
    495 }
    496 
    497 static bool
    498 pageflush_selector(void *cl, struct vnode *vp)
    499 {
    500 	return vp->v_type == VREG &&
    501 	    !(LIST_EMPTY(&vp->v_dirtyblkhd) && UVM_OBJ_IS_CLEAN(&vp->v_uobj));
    502 }
    503 
    504 static int
    505 pageflush(struct mount *mp, kauth_cred_t cred, int waitfor)
    506 {
    507 	struct puffs_node *pn;
    508 	struct vnode *vp;
    509 	struct vnode_iterator *marker;
    510 	int error, rv, fsyncwait;
    511 
    512 	error = 0;
    513 	fsyncwait = (waitfor == MNT_WAIT) ? FSYNC_WAIT : 0;
    514 
    515 	/*
    516 	 * Sync all cached data from regular vnodes (which are not
    517 	 * currently locked, see below).  After this we call VFS_SYNC
    518 	 * for the fs server, which should handle data and metadata for
    519 	 * all the nodes it knows to exist.
    520 	 */
    521 	vfs_vnode_iterator_init(mp, &marker);
    522 	while ((vp = vfs_vnode_iterator_next(marker, pageflush_selector,
    523 	    NULL)))
    524 	{
    525 		/*
    526 		 * Here we try to get a reference to the vnode and to
    527 		 * lock it.  This is mostly cargo-culted, but I will
    528 		 * offer an explanation to why I believe this might
    529 		 * actually do the right thing.
    530 		 *
    531 		 * If the vnode is a goner, we quite obviously don't need
    532 		 * to sync it.
    533 		 *
    534 		 * If the vnode was busy, we don't need to sync it because
    535 		 * this is never called with MNT_WAIT except from
    536 		 * dounmount(), when we are wait-flushing all the dirty
    537 		 * vnodes through other routes in any case.  So there,
    538 		 * sync() doesn't actually sync.  Happy now?
    539 		 */
    540 		error = vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT);
    541 		if (error) {
    542 			vrele(vp);
    543 			continue;
    544 		}
    545 		pn = VPTOPP(vp);
    546 		/* hmm.. is the FAF thing entirely sensible? */
    547 		if (waitfor == MNT_LAZY) {
    548 			mutex_enter(vp->v_interlock);
    549 			pn->pn_stat |= PNODE_FAF;
    550 			mutex_exit(vp->v_interlock);
    551 		}
    552 		rv = VOP_FSYNC(vp, cred, fsyncwait, 0, 0);
    553 		if (waitfor == MNT_LAZY) {
    554 			mutex_enter(vp->v_interlock);
    555 			pn->pn_stat &= ~PNODE_FAF;
    556 			mutex_exit(vp->v_interlock);
    557 		}
    558 		if (rv)
    559 			error = rv;
    560 		vput(vp);
    561 	}
    562 	vfs_vnode_iterator_destroy(marker);
    563 
    564 	return error;
    565 }
    566 
    567 int
    568 puffs_vfsop_sync(struct mount *mp, int waitfor, struct kauth_cred *cred)
    569 {
    570 	PUFFS_MSG_VARS(vfs, sync);
    571 	struct puffs_mount *pmp = MPTOPUFFSMP(mp);
    572 	int error, rv;
    573 
    574 	error = pageflush(mp, cred, waitfor);
    575 
    576 	/* sync fs */
    577 	PUFFS_MSG_ALLOC(vfs, sync);
    578 	sync_msg->pvfsr_waitfor = waitfor;
    579 	puffs_credcvt(&sync_msg->pvfsr_cred, cred);
    580 	puffs_msg_setinfo(park_sync, PUFFSOP_VFS, PUFFS_VFS_SYNC, NULL);
    581 
    582 	PUFFS_MSG_ENQUEUEWAIT(pmp, park_sync, rv);
    583 	rv = checkerr(pmp, rv, __func__);
    584 	if (rv)
    585 		error = rv;
    586 
    587 	PUFFS_MSG_RELEASE(sync);
    588 	return error;
    589 }
    590 
    591 int
    592 puffs_vfsop_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
    593 {
    594 	PUFFS_MSG_VARS(vfs, fhtonode);
    595 	struct puffs_mount *pmp = MPTOPUFFSMP(mp);
    596 	struct vnode *vp;
    597 	void *fhdata;
    598 	size_t argsize, fhlen;
    599 	int error;
    600 
    601 	if (pmp->pmp_args.pa_fhsize == 0)
    602 		return EOPNOTSUPP;
    603 
    604 	if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH) {
    605 		fhlen = fhp->fid_len;
    606 		fhdata = fhp;
    607 	} else {
    608 		fhlen = PUFFS_FROMFHSIZE(fhp->fid_len);
    609 		fhdata = fhp->fid_data;
    610 
    611 		if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_DYNAMIC) {
    612 			if (pmp->pmp_args.pa_fhsize < fhlen)
    613 				return EINVAL;
    614 		} else {
    615 			if (pmp->pmp_args.pa_fhsize != fhlen)
    616 				return EINVAL;
    617 		}
    618 	}
    619 
    620 	argsize = sizeof(struct puffs_vfsmsg_fhtonode) + fhlen;
    621 	puffs_msgmem_alloc(argsize, &park_fhtonode, (void *)&fhtonode_msg, 1);
    622 	fhtonode_msg->pvfsr_dsize = fhlen;
    623 	memcpy(fhtonode_msg->pvfsr_data, fhdata, fhlen);
    624 	puffs_msg_setinfo(park_fhtonode, PUFFSOP_VFS, PUFFS_VFS_FHTOVP, NULL);
    625 
    626 	PUFFS_MSG_ENQUEUEWAIT(pmp, park_fhtonode, error);
    627 	error = checkerr(pmp, error, __func__);
    628 	if (error)
    629 		goto out;
    630 
    631 	error = puffs_getvnode(mp, fhtonode_msg->pvfsr_fhcookie,
    632 	    fhtonode_msg->pvfsr_vtype, fhtonode_msg->pvfsr_size,
    633 	    fhtonode_msg->pvfsr_rdev, &vp);
    634 	if (error)
    635 		goto out;
    636 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    637 
    638 	*vpp = vp;
    639  out:
    640 	puffs_msgmem_release(park_fhtonode);
    641 	return error;
    642 }
    643 
    644 int
    645 puffs_vfsop_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
    646 {
    647 	PUFFS_MSG_VARS(vfs, nodetofh);
    648 	struct puffs_mount *pmp = MPTOPUFFSMP(vp->v_mount);
    649 	size_t argsize, fhlen;
    650 	int error;
    651 
    652 	if (pmp->pmp_args.pa_fhsize == 0)
    653 		return EOPNOTSUPP;
    654 
    655 	/* if file handles are static len, we can test len immediately */
    656 	if (((pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_DYNAMIC) == 0)
    657 	    && ((pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH) == 0)
    658 	    && (PUFFS_FROMFHSIZE(*fh_size) < pmp->pmp_args.pa_fhsize)) {
    659 		*fh_size = PUFFS_TOFHSIZE(pmp->pmp_args.pa_fhsize);
    660 		return E2BIG;
    661 	}
    662 
    663 	if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH)
    664 		fhlen = *fh_size;
    665 	else
    666 		fhlen = PUFFS_FROMFHSIZE(*fh_size);
    667 
    668 	argsize = sizeof(struct puffs_vfsmsg_nodetofh) + fhlen;
    669 	puffs_msgmem_alloc(argsize, &park_nodetofh, (void *)&nodetofh_msg, 1);
    670 	nodetofh_msg->pvfsr_fhcookie = VPTOPNC(vp);
    671 	nodetofh_msg->pvfsr_dsize = fhlen;
    672 	puffs_msg_setinfo(park_nodetofh, PUFFSOP_VFS, PUFFS_VFS_VPTOFH, NULL);
    673 
    674 	PUFFS_MSG_ENQUEUEWAIT(pmp, park_nodetofh, error);
    675 	error = checkerr(pmp, error, __func__);
    676 
    677 	if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH)
    678 		fhlen = nodetofh_msg->pvfsr_dsize;
    679 	else if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_DYNAMIC)
    680 		fhlen = PUFFS_TOFHSIZE(nodetofh_msg->pvfsr_dsize);
    681 	else
    682 		fhlen = PUFFS_TOFHSIZE(pmp->pmp_args.pa_fhsize);
    683 
    684 	if (error) {
    685 		if (error == E2BIG)
    686 			*fh_size = fhlen;
    687 		goto out;
    688 	}
    689 
    690 	if (fhlen > FHANDLE_SIZE_MAX) {
    691 		puffs_senderr(pmp, PUFFS_ERR_VPTOFH, E2BIG,
    692 		    "file handle too big", VPTOPNC(vp));
    693 		error = EPROTO;
    694 		goto out;
    695 	}
    696 
    697 	if (*fh_size < fhlen) {
    698 		*fh_size = fhlen;
    699 		error = E2BIG;
    700 		goto out;
    701 	}
    702 	*fh_size = fhlen;
    703 
    704 	if (fhp) {
    705 		if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH) {
    706 			memcpy(fhp, nodetofh_msg->pvfsr_data, fhlen);
    707 		} else {
    708 			fhp->fid_len = *fh_size;
    709 			memcpy(fhp->fid_data, nodetofh_msg->pvfsr_data,
    710 			    nodetofh_msg->pvfsr_dsize);
    711 		}
    712 	}
    713 
    714  out:
    715 	puffs_msgmem_release(park_nodetofh);
    716 	return error;
    717 }
    718 
    719 int
    720 puffs_vfsop_loadvnode(struct mount *mp, struct vnode *vp,
    721     const void *key, size_t key_len, const void **new_key)
    722 {
    723 	struct puffs_mount *pmp;
    724 	struct puffs_node *pnode;
    725 
    726 	KASSERT(key_len == sizeof(puffs_cookie_t));
    727 
    728 	pmp = MPTOPUFFSMP(mp);
    729 
    730 	/* Allocate and initialize the pnode. */
    731 	pnode = pool_get(&puffs_pnpool, PR_WAITOK);
    732 	memset(pnode, 0, sizeof(struct puffs_node));
    733 
    734 	pnode->pn_vp = vp;
    735 	memcpy(&pnode->pn_cookie, key, key_len);
    736 	pnode->pn_refcount = 1;
    737 	mutex_init(&pnode->pn_mtx, MUTEX_DEFAULT, IPL_NONE);
    738 	mutex_init(&pnode->pn_sizemtx, MUTEX_DEFAULT, IPL_NONE);
    739 	selinit(&pnode->pn_sel);
    740 	vp->v_tag = VT_PUFFS;
    741 	vp->v_type = VNON;
    742 	vp->v_op = puffs_vnodeop_p;
    743 	if (pnode->pn_cookie == pmp->pmp_root_cookie)
    744 		vp->v_vflag |= VV_ROOT;
    745 	vp->v_data = pnode;
    746 
    747 	genfs_node_init(vp, &puffs_genfsops);
    748 	uvm_vnp_setsize(vp, 0);
    749 
    750 	*new_key = &pnode->pn_cookie;
    751 	return 0;
    752 }
    753 
    754 void
    755 puffs_vfsop_init(void)
    756 {
    757 
    758 	/* some checks depend on this */
    759 	KASSERT(VNOVAL == VSIZENOTSET);
    760 
    761 	pool_init(&puffs_pnpool, sizeof(struct puffs_node), 0, 0, 0,
    762 	    "puffpnpl", &pool_allocator_nointr, IPL_NONE);
    763 	pool_init(&puffs_vapool, sizeof(struct vattr), 0, 0, 0,
    764 	    "puffvapl", &pool_allocator_nointr, IPL_NONE);
    765 	puffs_msgif_init();
    766 }
    767 
    768 void
    769 puffs_vfsop_done(void)
    770 {
    771 
    772 	puffs_msgif_destroy();
    773 	pool_destroy(&puffs_pnpool);
    774 	pool_destroy(&puffs_vapool);
    775 }
    776 
    777 int
    778 puffs_vfsop_snapshot(struct mount *mp, struct vnode *vp, struct timespec *ts)
    779 {
    780 
    781 	return EOPNOTSUPP;
    782 }
    783 
    784 int
    785 puffs_vfsop_extattrctl(struct mount *mp, int cmd, struct vnode *vp,
    786 	int attrnamespace, const char *attrname)
    787 {
    788 	PUFFS_MSG_VARS(vfs, extattrctl);
    789 	struct puffs_mount *pmp = MPTOPUFFSMP(mp);
    790 	struct puffs_node *pnp;
    791 	puffs_cookie_t pnc;
    792 	int error, flags;
    793 
    794 	if (vp) {
    795 		/* doesn't make sense for puffs servers */
    796 		if (vp->v_mount != mp)
    797 			return EXDEV;
    798 		pnp = vp->v_data;
    799 		pnc = pnp->pn_cookie;
    800 		flags = PUFFS_EXTATTRCTL_HASNODE;
    801 	} else {
    802 		pnp = pnc = NULL;
    803 		flags = 0;
    804 	}
    805 
    806 	PUFFS_MSG_ALLOC(vfs, extattrctl);
    807 	extattrctl_msg->pvfsr_cmd = cmd;
    808 	extattrctl_msg->pvfsr_attrnamespace = attrnamespace;
    809 	extattrctl_msg->pvfsr_flags = flags;
    810 	if (attrname) {
    811 		strlcpy(extattrctl_msg->pvfsr_attrname, attrname,
    812 		    sizeof(extattrctl_msg->pvfsr_attrname));
    813 		extattrctl_msg->pvfsr_flags |= PUFFS_EXTATTRCTL_HASATTRNAME;
    814 	}
    815 	puffs_msg_setinfo(park_extattrctl,
    816 	    PUFFSOP_VFS, PUFFS_VFS_EXTATTRCTL, pnc);
    817 
    818 	puffs_msg_enqueue(pmp, park_extattrctl);
    819 	if (vp) {
    820 		mutex_enter(&pnp->pn_mtx);
    821 		puffs_referencenode(pnp);
    822 		mutex_exit(&pnp->pn_mtx);
    823 		VOP_UNLOCK(vp);
    824 	}
    825 	error = puffs_msg_wait2(pmp, park_extattrctl, pnp, NULL);
    826 	PUFFS_MSG_RELEASE(extattrctl);
    827 	if (vp) {
    828 		puffs_releasenode(pnp);
    829 	}
    830 
    831 	return checkerr(pmp, error, __func__);
    832 }
    833 
    834 const struct vnodeopv_desc * const puffs_vnodeopv_descs[] = {
    835 	&puffs_vnodeop_opv_desc,
    836 	&puffs_specop_opv_desc,
    837 	&puffs_fifoop_opv_desc,
    838 	&puffs_msgop_opv_desc,
    839 	NULL,
    840 };
    841 
    842 struct vfsops puffs_vfsops = {
    843 	.vfs_name = MOUNT_PUFFS,
    844 	.vfs_min_mount_data = sizeof (struct puffs_kargs),
    845 	.vfs_mount = puffs_vfsop_mount,
    846 	.vfs_start = puffs_vfsop_start,
    847 	.vfs_unmount = puffs_vfsop_unmount,
    848 	.vfs_root = puffs_vfsop_root,
    849 	.vfs_quotactl = (void *)eopnotsupp,
    850 	.vfs_statvfs = puffs_vfsop_statvfs,
    851 	.vfs_sync = puffs_vfsop_sync,
    852 	.vfs_vget = (void *)eopnotsupp,
    853 	.vfs_loadvnode = puffs_vfsop_loadvnode,
    854 	.vfs_fhtovp = puffs_vfsop_fhtovp,
    855 	.vfs_vptofh = puffs_vfsop_vptofh,
    856 	.vfs_init = puffs_vfsop_init,
    857 	.vfs_done = puffs_vfsop_done,
    858 	.vfs_snapshot = puffs_vfsop_snapshot,
    859 	.vfs_extattrctl = puffs_vfsop_extattrctl,
    860 	.vfs_suspendctl = (void *)eopnotsupp,
    861 	.vfs_renamelock_enter = genfs_renamelock_enter,
    862 	.vfs_renamelock_exit = genfs_renamelock_exit,
    863 	.vfs_fsync = (void *)eopnotsupp,
    864 	.vfs_opv_descs = puffs_vnodeopv_descs
    865 };
    866 
    867 static int
    868 puffs_modcmd(modcmd_t cmd, void *arg)
    869 {
    870 
    871 	switch (cmd) {
    872 	case MODULE_CMD_INIT:
    873 		return vfs_attach(&puffs_vfsops);
    874 	case MODULE_CMD_FINI:
    875 		return vfs_detach(&puffs_vfsops);
    876 	default:
    877 		return ENOTTY;
    878 	}
    879 }
    880