xref: /freebsd/sys/kern/vfs_mount.c (revision a0e793cbf1951d07fc47a0d9ea389d7dacba5213)
1 /*-
2  * Copyright (c) 1999-2004 Poul-Henning Kamp
3  * Copyright (c) 1999 Michael Smith
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * (c) UNIX System Laboratories, Inc.
7  * All or some portions of this file are derived from material licensed
8  * to the University of California by American Telephone and Telegraph
9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10  * the permission of UNIX System Laboratories, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/param.h>
41 #include <sys/conf.h>
42 #include <sys/fcntl.h>
43 #include <sys/jail.h>
44 #include <sys/kernel.h>
45 #include <sys/libkern.h>
46 #include <sys/malloc.h>
47 #include <sys/mount.h>
48 #include <sys/mutex.h>
49 #include <sys/namei.h>
50 #include <sys/priv.h>
51 #include <sys/proc.h>
52 #include <sys/filedesc.h>
53 #include <sys/reboot.h>
54 #include <sys/sbuf.h>
55 #include <sys/syscallsubr.h>
56 #include <sys/sysproto.h>
57 #include <sys/sx.h>
58 #include <sys/sysctl.h>
59 #include <sys/sysent.h>
60 #include <sys/systm.h>
61 #include <sys/vnode.h>
62 #include <vm/uma.h>
63 
64 #include <geom/geom.h>
65 
66 #include <machine/stdarg.h>
67 
68 #include <security/audit/audit.h>
69 #include <security/mac/mac_framework.h>
70 
71 #define	VFS_MOUNTARG_SIZE_MAX	(1024 * 64)
72 
73 static int	vfs_domount(struct thread *td, const char *fstype, char *fspath,
74 		    uint64_t fsflags, struct vfsoptlist **optlist);
75 static void	free_mntarg(struct mntarg *ma);
76 
77 static int	usermount = 0;
78 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0,
79     "Unprivileged users may mount and unmount file systems");
80 
81 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
82 static uma_zone_t mount_zone;
83 
84 /* List of mounted filesystems. */
85 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist);
86 
87 /* For any iteration/modification of mountlist */
88 struct mtx mountlist_mtx;
89 MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF);
90 
91 /*
92  * Global opts, taken by all filesystems
93  */
94 static const char *global_opts[] = {
95 	"errmsg",
96 	"fstype",
97 	"fspath",
98 	"ro",
99 	"rw",
100 	"nosuid",
101 	"noexec",
102 	NULL
103 };
104 
105 static int
106 mount_init(void *mem, int size, int flags)
107 {
108 	struct mount *mp;
109 
110 	mp = (struct mount *)mem;
111 	mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
112 	lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0);
113 	return (0);
114 }
115 
116 static void
117 mount_fini(void *mem, int size)
118 {
119 	struct mount *mp;
120 
121 	mp = (struct mount *)mem;
122 	lockdestroy(&mp->mnt_explock);
123 	mtx_destroy(&mp->mnt_mtx);
124 }
125 
126 static void
127 vfs_mount_init(void *dummy __unused)
128 {
129 
130 	mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), NULL,
131 	    NULL, mount_init, mount_fini, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
132 }
133 SYSINIT(vfs_mount, SI_SUB_VFS, SI_ORDER_ANY, vfs_mount_init, NULL);
134 
135 /*
136  * ---------------------------------------------------------------------
137  * Functions for building and sanitizing the mount options
138  */
139 
140 /* Remove one mount option. */
141 static void
142 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt)
143 {
144 
145 	TAILQ_REMOVE(opts, opt, link);
146 	free(opt->name, M_MOUNT);
147 	if (opt->value != NULL)
148 		free(opt->value, M_MOUNT);
149 	free(opt, M_MOUNT);
150 }
151 
152 /* Release all resources related to the mount options. */
153 void
154 vfs_freeopts(struct vfsoptlist *opts)
155 {
156 	struct vfsopt *opt;
157 
158 	while (!TAILQ_EMPTY(opts)) {
159 		opt = TAILQ_FIRST(opts);
160 		vfs_freeopt(opts, opt);
161 	}
162 	free(opts, M_MOUNT);
163 }
164 
165 void
166 vfs_deleteopt(struct vfsoptlist *opts, const char *name)
167 {
168 	struct vfsopt *opt, *temp;
169 
170 	if (opts == NULL)
171 		return;
172 	TAILQ_FOREACH_SAFE(opt, opts, link, temp)  {
173 		if (strcmp(opt->name, name) == 0)
174 			vfs_freeopt(opts, opt);
175 	}
176 }
177 
178 static int
179 vfs_isopt_ro(const char *opt)
180 {
181 
182 	if (strcmp(opt, "ro") == 0 || strcmp(opt, "rdonly") == 0 ||
183 	    strcmp(opt, "norw") == 0)
184 		return (1);
185 	return (0);
186 }
187 
188 static int
189 vfs_isopt_rw(const char *opt)
190 {
191 
192 	if (strcmp(opt, "rw") == 0 || strcmp(opt, "noro") == 0)
193 		return (1);
194 	return (0);
195 }
196 
197 /*
198  * Check if options are equal (with or without the "no" prefix).
199  */
200 static int
201 vfs_equalopts(const char *opt1, const char *opt2)
202 {
203 	char *p;
204 
205 	/* "opt" vs. "opt" or "noopt" vs. "noopt" */
206 	if (strcmp(opt1, opt2) == 0)
207 		return (1);
208 	/* "noopt" vs. "opt" */
209 	if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
210 		return (1);
211 	/* "opt" vs. "noopt" */
212 	if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
213 		return (1);
214 	while ((p = strchr(opt1, '.')) != NULL &&
215 	    !strncmp(opt1, opt2, ++p - opt1)) {
216 		opt2 += p - opt1;
217 		opt1 = p;
218 		/* "foo.noopt" vs. "foo.opt" */
219 		if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
220 			return (1);
221 		/* "foo.opt" vs. "foo.noopt" */
222 		if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
223 			return (1);
224 	}
225 	/* "ro" / "rdonly" / "norw" / "rw" / "noro" */
226 	if ((vfs_isopt_ro(opt1) || vfs_isopt_rw(opt1)) &&
227 	    (vfs_isopt_ro(opt2) || vfs_isopt_rw(opt2)))
228 		return (1);
229 	return (0);
230 }
231 
232 /*
233  * If a mount option is specified several times,
234  * (with or without the "no" prefix) only keep
235  * the last occurrence of it.
236  */
237 static void
238 vfs_sanitizeopts(struct vfsoptlist *opts)
239 {
240 	struct vfsopt *opt, *opt2, *tmp;
241 
242 	TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) {
243 		opt2 = TAILQ_PREV(opt, vfsoptlist, link);
244 		while (opt2 != NULL) {
245 			if (vfs_equalopts(opt->name, opt2->name)) {
246 				tmp = TAILQ_PREV(opt2, vfsoptlist, link);
247 				vfs_freeopt(opts, opt2);
248 				opt2 = tmp;
249 			} else {
250 				opt2 = TAILQ_PREV(opt2, vfsoptlist, link);
251 			}
252 		}
253 	}
254 }
255 
256 /*
257  * Build a linked list of mount options from a struct uio.
258  */
259 int
260 vfs_buildopts(struct uio *auio, struct vfsoptlist **options)
261 {
262 	struct vfsoptlist *opts;
263 	struct vfsopt *opt;
264 	size_t memused, namelen, optlen;
265 	unsigned int i, iovcnt;
266 	int error;
267 
268 	opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
269 	TAILQ_INIT(opts);
270 	memused = 0;
271 	iovcnt = auio->uio_iovcnt;
272 	for (i = 0; i < iovcnt; i += 2) {
273 		namelen = auio->uio_iov[i].iov_len;
274 		optlen = auio->uio_iov[i + 1].iov_len;
275 		memused += sizeof(struct vfsopt) + optlen + namelen;
276 		/*
277 		 * Avoid consuming too much memory, and attempts to overflow
278 		 * memused.
279 		 */
280 		if (memused > VFS_MOUNTARG_SIZE_MAX ||
281 		    optlen > VFS_MOUNTARG_SIZE_MAX ||
282 		    namelen > VFS_MOUNTARG_SIZE_MAX) {
283 			error = EINVAL;
284 			goto bad;
285 		}
286 
287 		opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
288 		opt->name = malloc(namelen, M_MOUNT, M_WAITOK);
289 		opt->value = NULL;
290 		opt->len = 0;
291 		opt->pos = i / 2;
292 		opt->seen = 0;
293 
294 		/*
295 		 * Do this early, so jumps to "bad" will free the current
296 		 * option.
297 		 */
298 		TAILQ_INSERT_TAIL(opts, opt, link);
299 
300 		if (auio->uio_segflg == UIO_SYSSPACE) {
301 			bcopy(auio->uio_iov[i].iov_base, opt->name, namelen);
302 		} else {
303 			error = copyin(auio->uio_iov[i].iov_base, opt->name,
304 			    namelen);
305 			if (error)
306 				goto bad;
307 		}
308 		/* Ensure names are null-terminated strings. */
309 		if (namelen == 0 || opt->name[namelen - 1] != '\0') {
310 			error = EINVAL;
311 			goto bad;
312 		}
313 		if (optlen != 0) {
314 			opt->len = optlen;
315 			opt->value = malloc(optlen, M_MOUNT, M_WAITOK);
316 			if (auio->uio_segflg == UIO_SYSSPACE) {
317 				bcopy(auio->uio_iov[i + 1].iov_base, opt->value,
318 				    optlen);
319 			} else {
320 				error = copyin(auio->uio_iov[i + 1].iov_base,
321 				    opt->value, optlen);
322 				if (error)
323 					goto bad;
324 			}
325 		}
326 	}
327 	vfs_sanitizeopts(opts);
328 	*options = opts;
329 	return (0);
330 bad:
331 	vfs_freeopts(opts);
332 	return (error);
333 }
334 
335 /*
336  * Merge the old mount options with the new ones passed
337  * in the MNT_UPDATE case.
338  *
339  * XXX: This function will keep a "nofoo" option in the new
340  * options.  E.g, if the option's canonical name is "foo",
341  * "nofoo" ends up in the mount point's active options.
342  */
343 static void
344 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *oldopts)
345 {
346 	struct vfsopt *opt, *new;
347 
348 	TAILQ_FOREACH(opt, oldopts, link) {
349 		new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
350 		new->name = strdup(opt->name, M_MOUNT);
351 		if (opt->len != 0) {
352 			new->value = malloc(opt->len, M_MOUNT, M_WAITOK);
353 			bcopy(opt->value, new->value, opt->len);
354 		} else
355 			new->value = NULL;
356 		new->len = opt->len;
357 		new->seen = opt->seen;
358 		TAILQ_INSERT_HEAD(toopts, new, link);
359 	}
360 	vfs_sanitizeopts(toopts);
361 }
362 
363 /*
364  * Mount a filesystem.
365  */
366 int
367 sys_nmount(td, uap)
368 	struct thread *td;
369 	struct nmount_args /* {
370 		struct iovec *iovp;
371 		unsigned int iovcnt;
372 		int flags;
373 	} */ *uap;
374 {
375 	struct uio *auio;
376 	int error;
377 	u_int iovcnt;
378 	uint64_t flags;
379 
380 	/*
381 	 * Mount flags are now 64-bits. On 32-bit archtectures only
382 	 * 32-bits are passed in, but from here on everything handles
383 	 * 64-bit flags correctly.
384 	 */
385 	flags = uap->flags;
386 
387 	AUDIT_ARG_FFLAGS(flags);
388 	CTR4(KTR_VFS, "%s: iovp %p with iovcnt %d and flags %d", __func__,
389 	    uap->iovp, uap->iovcnt, flags);
390 
391 	/*
392 	 * Filter out MNT_ROOTFS.  We do not want clients of nmount() in
393 	 * userspace to set this flag, but we must filter it out if we want
394 	 * MNT_UPDATE on the root file system to work.
395 	 * MNT_ROOTFS should only be set by the kernel when mounting its
396 	 * root file system.
397 	 */
398 	flags &= ~MNT_ROOTFS;
399 
400 	iovcnt = uap->iovcnt;
401 	/*
402 	 * Check that we have an even number of iovec's
403 	 * and that we have at least two options.
404 	 */
405 	if ((iovcnt & 1) || (iovcnt < 4)) {
406 		CTR2(KTR_VFS, "%s: failed for invalid iovcnt %d", __func__,
407 		    uap->iovcnt);
408 		return (EINVAL);
409 	}
410 
411 	error = copyinuio(uap->iovp, iovcnt, &auio);
412 	if (error) {
413 		CTR2(KTR_VFS, "%s: failed for invalid uio op with %d errno",
414 		    __func__, error);
415 		return (error);
416 	}
417 	error = vfs_donmount(td, flags, auio);
418 
419 	free(auio, M_IOV);
420 	return (error);
421 }
422 
423 /*
424  * ---------------------------------------------------------------------
425  * Various utility functions
426  */
427 
428 void
429 vfs_ref(struct mount *mp)
430 {
431 
432 	CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
433 	MNT_ILOCK(mp);
434 	MNT_REF(mp);
435 	MNT_IUNLOCK(mp);
436 }
437 
438 void
439 vfs_rel(struct mount *mp)
440 {
441 
442 	CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
443 	MNT_ILOCK(mp);
444 	MNT_REL(mp);
445 	MNT_IUNLOCK(mp);
446 }
447 
448 /*
449  * Allocate and initialize the mount point struct.
450  */
451 struct mount *
452 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath,
453     struct ucred *cred)
454 {
455 	struct mount *mp;
456 
457 	mp = uma_zalloc(mount_zone, M_WAITOK);
458 	bzero(&mp->mnt_startzero,
459 	    __rangeof(struct mount, mnt_startzero, mnt_endzero));
460 	TAILQ_INIT(&mp->mnt_nvnodelist);
461 	mp->mnt_nvnodelistsize = 0;
462 	TAILQ_INIT(&mp->mnt_activevnodelist);
463 	mp->mnt_activevnodelistsize = 0;
464 	mp->mnt_ref = 0;
465 	(void) vfs_busy(mp, MBF_NOWAIT);
466 	atomic_add_acq_int(&vfsp->vfc_refcount, 1);
467 	mp->mnt_op = vfsp->vfc_vfsops;
468 	mp->mnt_vfc = vfsp;
469 	mp->mnt_stat.f_type = vfsp->vfc_typenum;
470 	mp->mnt_gen++;
471 	strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
472 	mp->mnt_vnodecovered = vp;
473 	mp->mnt_cred = crdup(cred);
474 	mp->mnt_stat.f_owner = cred->cr_uid;
475 	strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN);
476 	mp->mnt_iosize_max = DFLTPHYS;
477 #ifdef MAC
478 	mac_mount_init(mp);
479 	mac_mount_create(cred, mp);
480 #endif
481 	arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0);
482 	TAILQ_INIT(&mp->mnt_uppers);
483 	return (mp);
484 }
485 
486 /*
487  * Destroy the mount struct previously allocated by vfs_mount_alloc().
488  */
489 void
490 vfs_mount_destroy(struct mount *mp)
491 {
492 
493 	MNT_ILOCK(mp);
494 	mp->mnt_kern_flag |= MNTK_REFEXPIRE;
495 	if (mp->mnt_kern_flag & MNTK_MWAIT) {
496 		mp->mnt_kern_flag &= ~MNTK_MWAIT;
497 		wakeup(mp);
498 	}
499 	while (mp->mnt_ref)
500 		msleep(mp, MNT_MTX(mp), PVFS, "mntref", 0);
501 	KASSERT(mp->mnt_ref == 0,
502 	    ("%s: invalid refcount in the drain path @ %s:%d", __func__,
503 	    __FILE__, __LINE__));
504 	if (mp->mnt_writeopcount != 0)
505 		panic("vfs_mount_destroy: nonzero writeopcount");
506 	if (mp->mnt_secondary_writes != 0)
507 		panic("vfs_mount_destroy: nonzero secondary_writes");
508 	atomic_subtract_rel_int(&mp->mnt_vfc->vfc_refcount, 1);
509 	if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) {
510 		struct vnode *vp;
511 
512 		TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes)
513 			vprint("", vp);
514 		panic("unmount: dangling vnode");
515 	}
516 	KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers"));
517 	if (mp->mnt_nvnodelistsize != 0)
518 		panic("vfs_mount_destroy: nonzero nvnodelistsize");
519 	if (mp->mnt_activevnodelistsize != 0)
520 		panic("vfs_mount_destroy: nonzero activevnodelistsize");
521 	if (mp->mnt_lockref != 0)
522 		panic("vfs_mount_destroy: nonzero lock refcount");
523 	MNT_IUNLOCK(mp);
524 #ifdef MAC
525 	mac_mount_destroy(mp);
526 #endif
527 	if (mp->mnt_opt != NULL)
528 		vfs_freeopts(mp->mnt_opt);
529 	crfree(mp->mnt_cred);
530 	uma_zfree(mount_zone, mp);
531 }
532 
533 int
534 vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions)
535 {
536 	struct vfsoptlist *optlist;
537 	struct vfsopt *opt, *tmp_opt;
538 	char *fstype, *fspath, *errmsg;
539 	int error, fstypelen, fspathlen, errmsg_len, errmsg_pos;
540 
541 	errmsg = fspath = NULL;
542 	errmsg_len = fspathlen = 0;
543 	errmsg_pos = -1;
544 
545 	error = vfs_buildopts(fsoptions, &optlist);
546 	if (error)
547 		return (error);
548 
549 	if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0)
550 		errmsg_pos = vfs_getopt_pos(optlist, "errmsg");
551 
552 	/*
553 	 * We need these two options before the others,
554 	 * and they are mandatory for any filesystem.
555 	 * Ensure they are NUL terminated as well.
556 	 */
557 	fstypelen = 0;
558 	error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen);
559 	if (error || fstype[fstypelen - 1] != '\0') {
560 		error = EINVAL;
561 		if (errmsg != NULL)
562 			strncpy(errmsg, "Invalid fstype", errmsg_len);
563 		goto bail;
564 	}
565 	fspathlen = 0;
566 	error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen);
567 	if (error || fspath[fspathlen - 1] != '\0') {
568 		error = EINVAL;
569 		if (errmsg != NULL)
570 			strncpy(errmsg, "Invalid fspath", errmsg_len);
571 		goto bail;
572 	}
573 
574 	/*
575 	 * We need to see if we have the "update" option
576 	 * before we call vfs_domount(), since vfs_domount() has special
577 	 * logic based on MNT_UPDATE.  This is very important
578 	 * when we want to update the root filesystem.
579 	 */
580 	TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) {
581 		if (strcmp(opt->name, "update") == 0) {
582 			fsflags |= MNT_UPDATE;
583 			vfs_freeopt(optlist, opt);
584 		}
585 		else if (strcmp(opt->name, "async") == 0)
586 			fsflags |= MNT_ASYNC;
587 		else if (strcmp(opt->name, "force") == 0) {
588 			fsflags |= MNT_FORCE;
589 			vfs_freeopt(optlist, opt);
590 		}
591 		else if (strcmp(opt->name, "reload") == 0) {
592 			fsflags |= MNT_RELOAD;
593 			vfs_freeopt(optlist, opt);
594 		}
595 		else if (strcmp(opt->name, "multilabel") == 0)
596 			fsflags |= MNT_MULTILABEL;
597 		else if (strcmp(opt->name, "noasync") == 0)
598 			fsflags &= ~MNT_ASYNC;
599 		else if (strcmp(opt->name, "noatime") == 0)
600 			fsflags |= MNT_NOATIME;
601 		else if (strcmp(opt->name, "atime") == 0) {
602 			free(opt->name, M_MOUNT);
603 			opt->name = strdup("nonoatime", M_MOUNT);
604 		}
605 		else if (strcmp(opt->name, "noclusterr") == 0)
606 			fsflags |= MNT_NOCLUSTERR;
607 		else if (strcmp(opt->name, "clusterr") == 0) {
608 			free(opt->name, M_MOUNT);
609 			opt->name = strdup("nonoclusterr", M_MOUNT);
610 		}
611 		else if (strcmp(opt->name, "noclusterw") == 0)
612 			fsflags |= MNT_NOCLUSTERW;
613 		else if (strcmp(opt->name, "clusterw") == 0) {
614 			free(opt->name, M_MOUNT);
615 			opt->name = strdup("nonoclusterw", M_MOUNT);
616 		}
617 		else if (strcmp(opt->name, "noexec") == 0)
618 			fsflags |= MNT_NOEXEC;
619 		else if (strcmp(opt->name, "exec") == 0) {
620 			free(opt->name, M_MOUNT);
621 			opt->name = strdup("nonoexec", M_MOUNT);
622 		}
623 		else if (strcmp(opt->name, "nosuid") == 0)
624 			fsflags |= MNT_NOSUID;
625 		else if (strcmp(opt->name, "suid") == 0) {
626 			free(opt->name, M_MOUNT);
627 			opt->name = strdup("nonosuid", M_MOUNT);
628 		}
629 		else if (strcmp(opt->name, "nosymfollow") == 0)
630 			fsflags |= MNT_NOSYMFOLLOW;
631 		else if (strcmp(opt->name, "symfollow") == 0) {
632 			free(opt->name, M_MOUNT);
633 			opt->name = strdup("nonosymfollow", M_MOUNT);
634 		}
635 		else if (strcmp(opt->name, "noro") == 0)
636 			fsflags &= ~MNT_RDONLY;
637 		else if (strcmp(opt->name, "rw") == 0)
638 			fsflags &= ~MNT_RDONLY;
639 		else if (strcmp(opt->name, "ro") == 0)
640 			fsflags |= MNT_RDONLY;
641 		else if (strcmp(opt->name, "rdonly") == 0) {
642 			free(opt->name, M_MOUNT);
643 			opt->name = strdup("ro", M_MOUNT);
644 			fsflags |= MNT_RDONLY;
645 		}
646 		else if (strcmp(opt->name, "suiddir") == 0)
647 			fsflags |= MNT_SUIDDIR;
648 		else if (strcmp(opt->name, "sync") == 0)
649 			fsflags |= MNT_SYNCHRONOUS;
650 		else if (strcmp(opt->name, "union") == 0)
651 			fsflags |= MNT_UNION;
652 	}
653 
654 	/*
655 	 * Be ultra-paranoid about making sure the type and fspath
656 	 * variables will fit in our mp buffers, including the
657 	 * terminating NUL.
658 	 */
659 	if (fstypelen > MFSNAMELEN || fspathlen > MNAMELEN) {
660 		error = ENAMETOOLONG;
661 		goto bail;
662 	}
663 
664 	error = vfs_domount(td, fstype, fspath, fsflags, &optlist);
665 bail:
666 	/* copyout the errmsg */
667 	if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt)
668 	    && errmsg_len > 0 && errmsg != NULL) {
669 		if (fsoptions->uio_segflg == UIO_SYSSPACE) {
670 			bcopy(errmsg,
671 			    fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
672 			    fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
673 		} else {
674 			copyout(errmsg,
675 			    fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
676 			    fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
677 		}
678 	}
679 
680 	if (optlist != NULL)
681 		vfs_freeopts(optlist);
682 	return (error);
683 }
684 
685 /*
686  * Old mount API.
687  */
688 #ifndef _SYS_SYSPROTO_H_
689 struct mount_args {
690 	char	*type;
691 	char	*path;
692 	int	flags;
693 	caddr_t	data;
694 };
695 #endif
696 /* ARGSUSED */
697 int
698 sys_mount(td, uap)
699 	struct thread *td;
700 	struct mount_args /* {
701 		char *type;
702 		char *path;
703 		int flags;
704 		caddr_t data;
705 	} */ *uap;
706 {
707 	char *fstype;
708 	struct vfsconf *vfsp = NULL;
709 	struct mntarg *ma = NULL;
710 	uint64_t flags;
711 	int error;
712 
713 	/*
714 	 * Mount flags are now 64-bits. On 32-bit architectures only
715 	 * 32-bits are passed in, but from here on everything handles
716 	 * 64-bit flags correctly.
717 	 */
718 	flags = uap->flags;
719 
720 	AUDIT_ARG_FFLAGS(flags);
721 
722 	/*
723 	 * Filter out MNT_ROOTFS.  We do not want clients of mount() in
724 	 * userspace to set this flag, but we must filter it out if we want
725 	 * MNT_UPDATE on the root file system to work.
726 	 * MNT_ROOTFS should only be set by the kernel when mounting its
727 	 * root file system.
728 	 */
729 	flags &= ~MNT_ROOTFS;
730 
731 	fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK);
732 	error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL);
733 	if (error) {
734 		free(fstype, M_TEMP);
735 		return (error);
736 	}
737 
738 	AUDIT_ARG_TEXT(fstype);
739 	vfsp = vfs_byname_kld(fstype, td, &error);
740 	free(fstype, M_TEMP);
741 	if (vfsp == NULL)
742 		return (ENOENT);
743 	if (vfsp->vfc_vfsops->vfs_cmount == NULL)
744 		return (EOPNOTSUPP);
745 
746 	ma = mount_argsu(ma, "fstype", uap->type, MFSNAMELEN);
747 	ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN);
748 	ma = mount_argb(ma, flags & MNT_RDONLY, "noro");
749 	ma = mount_argb(ma, !(flags & MNT_NOSUID), "nosuid");
750 	ma = mount_argb(ma, !(flags & MNT_NOEXEC), "noexec");
751 
752 	error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, flags);
753 	return (error);
754 }
755 
756 /*
757  * vfs_domount_first(): first file system mount (not update)
758  */
759 static int
760 vfs_domount_first(
761 	struct thread *td,		/* Calling thread. */
762 	struct vfsconf *vfsp,		/* File system type. */
763 	char *fspath,			/* Mount path. */
764 	struct vnode *vp,		/* Vnode to be covered. */
765 	uint64_t fsflags,		/* Flags common to all filesystems. */
766 	struct vfsoptlist **optlist	/* Options local to the filesystem. */
767 	)
768 {
769 	struct vattr va;
770 	struct mount *mp;
771 	struct vnode *newdp;
772 	int error;
773 
774 	ASSERT_VOP_ELOCKED(vp, __func__);
775 	KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here"));
776 
777 	/*
778 	 * If the user is not root, ensure that they own the directory
779 	 * onto which we are attempting to mount.
780 	 */
781 	error = VOP_GETATTR(vp, &va, td->td_ucred);
782 	if (error == 0 && va.va_uid != td->td_ucred->cr_uid)
783 		error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN, 0);
784 	if (error == 0)
785 		error = vinvalbuf(vp, V_SAVE, 0, 0);
786 	if (error == 0 && vp->v_type != VDIR)
787 		error = ENOTDIR;
788 	if (error == 0) {
789 		VI_LOCK(vp);
790 		if ((vp->v_iflag & VI_MOUNT) == 0 && vp->v_mountedhere == NULL)
791 			vp->v_iflag |= VI_MOUNT;
792 		else
793 			error = EBUSY;
794 		VI_UNLOCK(vp);
795 	}
796 	if (error != 0) {
797 		vput(vp);
798 		return (error);
799 	}
800 	VOP_UNLOCK(vp, 0);
801 
802 	/* Allocate and initialize the filesystem. */
803 	mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred);
804 	/* XXXMAC: pass to vfs_mount_alloc? */
805 	mp->mnt_optnew = *optlist;
806 	/* Set the mount level flags. */
807 	mp->mnt_flag = (fsflags & (MNT_UPDATEMASK | MNT_ROOTFS | MNT_RDONLY));
808 
809 	/*
810 	 * Mount the filesystem.
811 	 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
812 	 * get.  No freeing of cn_pnbuf.
813 	 */
814 	error = VFS_MOUNT(mp);
815 	if (error != 0) {
816 		vfs_unbusy(mp);
817 		vfs_mount_destroy(mp);
818 		VI_LOCK(vp);
819 		vp->v_iflag &= ~VI_MOUNT;
820 		VI_UNLOCK(vp);
821 		vrele(vp);
822 		return (error);
823 	}
824 
825 	if (mp->mnt_opt != NULL)
826 		vfs_freeopts(mp->mnt_opt);
827 	mp->mnt_opt = mp->mnt_optnew;
828 	*optlist = NULL;
829 	(void)VFS_STATFS(mp, &mp->mnt_stat);
830 
831 	/*
832 	 * Prevent external consumers of mount options from reading mnt_optnew.
833 	 */
834 	mp->mnt_optnew = NULL;
835 
836 	MNT_ILOCK(mp);
837 	if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
838 	    (mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
839 		mp->mnt_kern_flag |= MNTK_ASYNC;
840 	else
841 		mp->mnt_kern_flag &= ~MNTK_ASYNC;
842 	MNT_IUNLOCK(mp);
843 
844 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
845 	cache_purge(vp);
846 	VI_LOCK(vp);
847 	vp->v_iflag &= ~VI_MOUNT;
848 	VI_UNLOCK(vp);
849 	vp->v_mountedhere = mp;
850 	/* Place the new filesystem at the end of the mount list. */
851 	mtx_lock(&mountlist_mtx);
852 	TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
853 	mtx_unlock(&mountlist_mtx);
854 	vfs_event_signal(NULL, VQ_MOUNT, 0);
855 	if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp))
856 		panic("mount: lost mount");
857 	VOP_UNLOCK(vp, 0);
858 	EVENTHANDLER_INVOKE(vfs_mounted, mp, newdp, td);
859 	VOP_UNLOCK(newdp, 0);
860 	mountcheckdirs(vp, newdp);
861 	vrele(newdp);
862 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
863 		vfs_allocate_syncvnode(mp);
864 	vfs_unbusy(mp);
865 	return (0);
866 }
867 
868 /*
869  * vfs_domount_update(): update of mounted file system
870  */
871 static int
872 vfs_domount_update(
873 	struct thread *td,		/* Calling thread. */
874 	struct vnode *vp,		/* Mount point vnode. */
875 	uint64_t fsflags,		/* Flags common to all filesystems. */
876 	struct vfsoptlist **optlist	/* Options local to the filesystem. */
877 	)
878 {
879 	struct oexport_args oexport;
880 	struct export_args export;
881 	struct mount *mp;
882 	int error, export_error;
883 	uint64_t flag;
884 
885 	ASSERT_VOP_ELOCKED(vp, __func__);
886 	KASSERT((fsflags & MNT_UPDATE) != 0, ("MNT_UPDATE should be here"));
887 
888 	if ((vp->v_vflag & VV_ROOT) == 0) {
889 		vput(vp);
890 		return (EINVAL);
891 	}
892 	mp = vp->v_mount;
893 	/*
894 	 * We only allow the filesystem to be reloaded if it
895 	 * is currently mounted read-only.
896 	 */
897 	flag = mp->mnt_flag;
898 	if ((fsflags & MNT_RELOAD) != 0 && (flag & MNT_RDONLY) == 0) {
899 		vput(vp);
900 		return (EOPNOTSUPP);	/* Needs translation */
901 	}
902 	/*
903 	 * Only privileged root, or (if MNT_USER is set) the user that
904 	 * did the original mount is permitted to update it.
905 	 */
906 	error = vfs_suser(mp, td);
907 	if (error != 0) {
908 		vput(vp);
909 		return (error);
910 	}
911 	if (vfs_busy(mp, MBF_NOWAIT)) {
912 		vput(vp);
913 		return (EBUSY);
914 	}
915 	VI_LOCK(vp);
916 	if ((vp->v_iflag & VI_MOUNT) != 0 || vp->v_mountedhere != NULL) {
917 		VI_UNLOCK(vp);
918 		vfs_unbusy(mp);
919 		vput(vp);
920 		return (EBUSY);
921 	}
922 	vp->v_iflag |= VI_MOUNT;
923 	VI_UNLOCK(vp);
924 	VOP_UNLOCK(vp, 0);
925 
926 	MNT_ILOCK(mp);
927 	mp->mnt_flag &= ~MNT_UPDATEMASK;
928 	mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE |
929 	    MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY);
930 	if ((mp->mnt_flag & MNT_ASYNC) == 0)
931 		mp->mnt_kern_flag &= ~MNTK_ASYNC;
932 	MNT_IUNLOCK(mp);
933 	mp->mnt_optnew = *optlist;
934 	vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt);
935 
936 	/*
937 	 * Mount the filesystem.
938 	 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
939 	 * get.  No freeing of cn_pnbuf.
940 	 */
941 	error = VFS_MOUNT(mp);
942 
943 	export_error = 0;
944 	if (error == 0) {
945 		/* Process the export option. */
946 		if (vfs_copyopt(mp->mnt_optnew, "export", &export,
947 		    sizeof(export)) == 0) {
948 			export_error = vfs_export(mp, &export);
949 		} else if (vfs_copyopt(mp->mnt_optnew, "export", &oexport,
950 		    sizeof(oexport)) == 0) {
951 			export.ex_flags = oexport.ex_flags;
952 			export.ex_root = oexport.ex_root;
953 			export.ex_anon = oexport.ex_anon;
954 			export.ex_addr = oexport.ex_addr;
955 			export.ex_addrlen = oexport.ex_addrlen;
956 			export.ex_mask = oexport.ex_mask;
957 			export.ex_masklen = oexport.ex_masklen;
958 			export.ex_indexfile = oexport.ex_indexfile;
959 			export.ex_numsecflavors = 0;
960 			export_error = vfs_export(mp, &export);
961 		}
962 	}
963 
964 	MNT_ILOCK(mp);
965 	if (error == 0) {
966 		mp->mnt_flag &=	~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE |
967 		    MNT_SNAPSHOT);
968 	} else {
969 		/*
970 		 * If we fail, restore old mount flags. MNT_QUOTA is special,
971 		 * because it is not part of MNT_UPDATEMASK, but it could have
972 		 * changed in the meantime if quotactl(2) was called.
973 		 * All in all we want current value of MNT_QUOTA, not the old
974 		 * one.
975 		 */
976 		mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA);
977 	}
978 	if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
979 	    (mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
980 		mp->mnt_kern_flag |= MNTK_ASYNC;
981 	else
982 		mp->mnt_kern_flag &= ~MNTK_ASYNC;
983 	MNT_IUNLOCK(mp);
984 
985 	if (error != 0)
986 		goto end;
987 
988 	if (mp->mnt_opt != NULL)
989 		vfs_freeopts(mp->mnt_opt);
990 	mp->mnt_opt = mp->mnt_optnew;
991 	*optlist = NULL;
992 	(void)VFS_STATFS(mp, &mp->mnt_stat);
993 	/*
994 	 * Prevent external consumers of mount options from reading
995 	 * mnt_optnew.
996 	 */
997 	mp->mnt_optnew = NULL;
998 
999 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
1000 		vfs_allocate_syncvnode(mp);
1001 	else
1002 		vfs_deallocate_syncvnode(mp);
1003 end:
1004 	vfs_unbusy(mp);
1005 	VI_LOCK(vp);
1006 	vp->v_iflag &= ~VI_MOUNT;
1007 	VI_UNLOCK(vp);
1008 	vrele(vp);
1009 	return (error != 0 ? error : export_error);
1010 }
1011 
1012 /*
1013  * vfs_domount(): actually attempt a filesystem mount.
1014  */
1015 static int
1016 vfs_domount(
1017 	struct thread *td,		/* Calling thread. */
1018 	const char *fstype,		/* Filesystem type. */
1019 	char *fspath,			/* Mount path. */
1020 	uint64_t fsflags,		/* Flags common to all filesystems. */
1021 	struct vfsoptlist **optlist	/* Options local to the filesystem. */
1022 	)
1023 {
1024 	struct vfsconf *vfsp;
1025 	struct nameidata nd;
1026 	struct vnode *vp;
1027 	char *pathbuf;
1028 	int error;
1029 
1030 	/*
1031 	 * Be ultra-paranoid about making sure the type and fspath
1032 	 * variables will fit in our mp buffers, including the
1033 	 * terminating NUL.
1034 	 */
1035 	if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN)
1036 		return (ENAMETOOLONG);
1037 
1038 	if (jailed(td->td_ucred) || usermount == 0) {
1039 		if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0)
1040 			return (error);
1041 	}
1042 
1043 	/*
1044 	 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users.
1045 	 */
1046 	if (fsflags & MNT_EXPORTED) {
1047 		error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED);
1048 		if (error)
1049 			return (error);
1050 	}
1051 	if (fsflags & MNT_SUIDDIR) {
1052 		error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR);
1053 		if (error)
1054 			return (error);
1055 	}
1056 	/*
1057 	 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users.
1058 	 */
1059 	if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) {
1060 		if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0)
1061 			fsflags |= MNT_NOSUID | MNT_USER;
1062 	}
1063 
1064 	/* Load KLDs before we lock the covered vnode to avoid reversals. */
1065 	vfsp = NULL;
1066 	if ((fsflags & MNT_UPDATE) == 0) {
1067 		/* Don't try to load KLDs if we're mounting the root. */
1068 		if (fsflags & MNT_ROOTFS)
1069 			vfsp = vfs_byname(fstype);
1070 		else
1071 			vfsp = vfs_byname_kld(fstype, td, &error);
1072 		if (vfsp == NULL)
1073 			return (ENODEV);
1074 		if (jailed(td->td_ucred) && !(vfsp->vfc_flags & VFCF_JAIL))
1075 			return (EPERM);
1076 	}
1077 
1078 	/*
1079 	 * Get vnode to be covered or mount point's vnode in case of MNT_UPDATE.
1080 	 */
1081 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1,
1082 	    UIO_SYSSPACE, fspath, td);
1083 	error = namei(&nd);
1084 	if (error != 0)
1085 		return (error);
1086 	NDFREE(&nd, NDF_ONLY_PNBUF);
1087 	vp = nd.ni_vp;
1088 	if ((fsflags & MNT_UPDATE) == 0) {
1089 		pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
1090 		strcpy(pathbuf, fspath);
1091 		error = vn_path_to_global_path(td, vp, pathbuf, MNAMELEN);
1092 		/* debug.disablefullpath == 1 results in ENODEV */
1093 		if (error == 0 || error == ENODEV) {
1094 			error = vfs_domount_first(td, vfsp, pathbuf, vp,
1095 			    fsflags, optlist);
1096 		}
1097 		free(pathbuf, M_TEMP);
1098 	} else
1099 		error = vfs_domount_update(td, vp, fsflags, optlist);
1100 
1101 	ASSERT_VI_UNLOCKED(vp, __func__);
1102 	ASSERT_VOP_UNLOCKED(vp, __func__);
1103 
1104 	return (error);
1105 }
1106 
1107 /*
1108  * Unmount a filesystem.
1109  *
1110  * Note: unmount takes a path to the vnode mounted on as argument, not
1111  * special file (as before).
1112  */
1113 #ifndef _SYS_SYSPROTO_H_
1114 struct unmount_args {
1115 	char	*path;
1116 	int	flags;
1117 };
1118 #endif
1119 /* ARGSUSED */
1120 int
1121 sys_unmount(td, uap)
1122 	struct thread *td;
1123 	register struct unmount_args /* {
1124 		char *path;
1125 		int flags;
1126 	} */ *uap;
1127 {
1128 	struct nameidata nd;
1129 	struct mount *mp;
1130 	char *pathbuf;
1131 	int error, id0, id1;
1132 
1133 	AUDIT_ARG_VALUE(uap->flags);
1134 	if (jailed(td->td_ucred) || usermount == 0) {
1135 		error = priv_check(td, PRIV_VFS_UNMOUNT);
1136 		if (error)
1137 			return (error);
1138 	}
1139 
1140 	pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
1141 	error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL);
1142 	if (error) {
1143 		free(pathbuf, M_TEMP);
1144 		return (error);
1145 	}
1146 	if (uap->flags & MNT_BYFSID) {
1147 		AUDIT_ARG_TEXT(pathbuf);
1148 		/* Decode the filesystem ID. */
1149 		if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) {
1150 			free(pathbuf, M_TEMP);
1151 			return (EINVAL);
1152 		}
1153 
1154 		mtx_lock(&mountlist_mtx);
1155 		TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
1156 			if (mp->mnt_stat.f_fsid.val[0] == id0 &&
1157 			    mp->mnt_stat.f_fsid.val[1] == id1)
1158 				break;
1159 		}
1160 		mtx_unlock(&mountlist_mtx);
1161 	} else {
1162 		/*
1163 		 * Try to find global path for path argument.
1164 		 */
1165 		NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1,
1166 		    UIO_SYSSPACE, pathbuf, td);
1167 		if (namei(&nd) == 0) {
1168 			NDFREE(&nd, NDF_ONLY_PNBUF);
1169 			error = vn_path_to_global_path(td, nd.ni_vp, pathbuf,
1170 			    MNAMELEN);
1171 			if (error == 0 || error == ENODEV)
1172 				vput(nd.ni_vp);
1173 		}
1174 		mtx_lock(&mountlist_mtx);
1175 		TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
1176 			if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0)
1177 				break;
1178 		}
1179 		mtx_unlock(&mountlist_mtx);
1180 	}
1181 	free(pathbuf, M_TEMP);
1182 	if (mp == NULL) {
1183 		/*
1184 		 * Previously we returned ENOENT for a nonexistent path and
1185 		 * EINVAL for a non-mountpoint.  We cannot tell these apart
1186 		 * now, so in the !MNT_BYFSID case return the more likely
1187 		 * EINVAL for compatibility.
1188 		 */
1189 		return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL);
1190 	}
1191 
1192 	/*
1193 	 * Don't allow unmounting the root filesystem.
1194 	 */
1195 	if (mp->mnt_flag & MNT_ROOTFS)
1196 		return (EINVAL);
1197 	error = dounmount(mp, uap->flags, td);
1198 	return (error);
1199 }
1200 
1201 /*
1202  * Do the actual filesystem unmount.
1203  */
1204 int
1205 dounmount(mp, flags, td)
1206 	struct mount *mp;
1207 	int flags;
1208 	struct thread *td;
1209 {
1210 	struct vnode *coveredvp, *fsrootvp;
1211 	int error;
1212 	uint64_t async_flag;
1213 	int mnt_gen_r;
1214 
1215 	if ((coveredvp = mp->mnt_vnodecovered) != NULL) {
1216 		mnt_gen_r = mp->mnt_gen;
1217 		VI_LOCK(coveredvp);
1218 		vholdl(coveredvp);
1219 		vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
1220 		vdrop(coveredvp);
1221 		/*
1222 		 * Check for mp being unmounted while waiting for the
1223 		 * covered vnode lock.
1224 		 */
1225 		if (coveredvp->v_mountedhere != mp ||
1226 		    coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) {
1227 			VOP_UNLOCK(coveredvp, 0);
1228 			return (EBUSY);
1229 		}
1230 	}
1231 	/*
1232 	 * Only privileged root, or (if MNT_USER is set) the user that did the
1233 	 * original mount is permitted to unmount this filesystem.
1234 	 */
1235 	error = vfs_suser(mp, td);
1236 	if (error) {
1237 		if (coveredvp)
1238 			VOP_UNLOCK(coveredvp, 0);
1239 		return (error);
1240 	}
1241 
1242 	vn_start_write(NULL, &mp, V_WAIT);
1243 	MNT_ILOCK(mp);
1244 	if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 ||
1245 	    !TAILQ_EMPTY(&mp->mnt_uppers)) {
1246 		MNT_IUNLOCK(mp);
1247 		if (coveredvp)
1248 			VOP_UNLOCK(coveredvp, 0);
1249 		vn_finished_write(mp);
1250 		return (EBUSY);
1251 	}
1252 	mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_NOINSMNTQ;
1253 	/* Allow filesystems to detect that a forced unmount is in progress. */
1254 	if (flags & MNT_FORCE) {
1255 		mp->mnt_kern_flag |= MNTK_UNMOUNTF;
1256 		MNT_IUNLOCK(mp);
1257 		/*
1258 		 * Must be done after setting MNTK_UNMOUNTF and before
1259 		 * waiting for mnt_lockref to become 0.
1260 		 */
1261 		VFS_PURGE(mp);
1262 		MNT_ILOCK(mp);
1263 	}
1264 	error = 0;
1265 	if (mp->mnt_lockref) {
1266 		mp->mnt_kern_flag |= MNTK_DRAINING;
1267 		error = msleep(&mp->mnt_lockref, MNT_MTX(mp), PVFS,
1268 		    "mount drain", 0);
1269 	}
1270 	MNT_IUNLOCK(mp);
1271 	KASSERT(mp->mnt_lockref == 0,
1272 	    ("%s: invalid lock refcount in the drain path @ %s:%d",
1273 	    __func__, __FILE__, __LINE__));
1274 	KASSERT(error == 0,
1275 	    ("%s: invalid return value for msleep in the drain path @ %s:%d",
1276 	    __func__, __FILE__, __LINE__));
1277 
1278 	if (mp->mnt_flag & MNT_EXPUBLIC)
1279 		vfs_setpublicfs(NULL, NULL, NULL);
1280 
1281 	vfs_msync(mp, MNT_WAIT);
1282 	MNT_ILOCK(mp);
1283 	async_flag = mp->mnt_flag & MNT_ASYNC;
1284 	mp->mnt_flag &= ~MNT_ASYNC;
1285 	mp->mnt_kern_flag &= ~MNTK_ASYNC;
1286 	MNT_IUNLOCK(mp);
1287 	cache_purgevfs(mp);	/* remove cache entries for this file sys */
1288 	vfs_deallocate_syncvnode(mp);
1289 	/*
1290 	 * For forced unmounts, move process cdir/rdir refs on the fs root
1291 	 * vnode to the covered vnode.  For non-forced unmounts we want
1292 	 * such references to cause an EBUSY error.
1293 	 */
1294 	if ((flags & MNT_FORCE) &&
1295 	    VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
1296 		if (mp->mnt_vnodecovered != NULL)
1297 			mountcheckdirs(fsrootvp, mp->mnt_vnodecovered);
1298 		if (fsrootvp == rootvnode) {
1299 			vrele(rootvnode);
1300 			rootvnode = NULL;
1301 		}
1302 		vput(fsrootvp);
1303 	}
1304 	if (((mp->mnt_flag & MNT_RDONLY) ||
1305 	     (error = VFS_SYNC(mp, MNT_WAIT)) == 0) || (flags & MNT_FORCE) != 0)
1306 		error = VFS_UNMOUNT(mp, flags);
1307 	vn_finished_write(mp);
1308 	/*
1309 	 * If we failed to flush the dirty blocks for this mount point,
1310 	 * undo all the cdir/rdir and rootvnode changes we made above.
1311 	 * Unless we failed to do so because the device is reporting that
1312 	 * it doesn't exist anymore.
1313 	 */
1314 	if (error && error != ENXIO) {
1315 		if ((flags & MNT_FORCE) &&
1316 		    VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
1317 			if (mp->mnt_vnodecovered != NULL)
1318 				mountcheckdirs(mp->mnt_vnodecovered, fsrootvp);
1319 			if (rootvnode == NULL) {
1320 				rootvnode = fsrootvp;
1321 				vref(rootvnode);
1322 			}
1323 			vput(fsrootvp);
1324 		}
1325 		MNT_ILOCK(mp);
1326 		mp->mnt_kern_flag &= ~MNTK_NOINSMNTQ;
1327 		if ((mp->mnt_flag & MNT_RDONLY) == 0) {
1328 			MNT_IUNLOCK(mp);
1329 			vfs_allocate_syncvnode(mp);
1330 			MNT_ILOCK(mp);
1331 		}
1332 		mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
1333 		mp->mnt_flag |= async_flag;
1334 		if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
1335 		    (mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
1336 			mp->mnt_kern_flag |= MNTK_ASYNC;
1337 		if (mp->mnt_kern_flag & MNTK_MWAIT) {
1338 			mp->mnt_kern_flag &= ~MNTK_MWAIT;
1339 			wakeup(mp);
1340 		}
1341 		MNT_IUNLOCK(mp);
1342 		if (coveredvp)
1343 			VOP_UNLOCK(coveredvp, 0);
1344 		return (error);
1345 	}
1346 	mtx_lock(&mountlist_mtx);
1347 	TAILQ_REMOVE(&mountlist, mp, mnt_list);
1348 	mtx_unlock(&mountlist_mtx);
1349 	EVENTHANDLER_INVOKE(vfs_unmounted, mp, td);
1350 	if (coveredvp != NULL) {
1351 		coveredvp->v_mountedhere = NULL;
1352 		vput(coveredvp);
1353 	}
1354 	vfs_event_signal(NULL, VQ_UNMOUNT, 0);
1355 	vfs_mount_destroy(mp);
1356 	return (0);
1357 }
1358 
1359 /*
1360  * Report errors during filesystem mounting.
1361  */
1362 void
1363 vfs_mount_error(struct mount *mp, const char *fmt, ...)
1364 {
1365 	struct vfsoptlist *moptlist = mp->mnt_optnew;
1366 	va_list ap;
1367 	int error, len;
1368 	char *errmsg;
1369 
1370 	error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len);
1371 	if (error || errmsg == NULL || len <= 0)
1372 		return;
1373 
1374 	va_start(ap, fmt);
1375 	vsnprintf(errmsg, (size_t)len, fmt, ap);
1376 	va_end(ap);
1377 }
1378 
1379 void
1380 vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...)
1381 {
1382 	va_list ap;
1383 	int error, len;
1384 	char *errmsg;
1385 
1386 	error = vfs_getopt(opts, "errmsg", (void **)&errmsg, &len);
1387 	if (error || errmsg == NULL || len <= 0)
1388 		return;
1389 
1390 	va_start(ap, fmt);
1391 	vsnprintf(errmsg, (size_t)len, fmt, ap);
1392 	va_end(ap);
1393 }
1394 
1395 /*
1396  * ---------------------------------------------------------------------
1397  * Functions for querying mount options/arguments from filesystems.
1398  */
1399 
1400 /*
1401  * Check that no unknown options are given
1402  */
1403 int
1404 vfs_filteropt(struct vfsoptlist *opts, const char **legal)
1405 {
1406 	struct vfsopt *opt;
1407 	char errmsg[255];
1408 	const char **t, *p, *q;
1409 	int ret = 0;
1410 
1411 	TAILQ_FOREACH(opt, opts, link) {
1412 		p = opt->name;
1413 		q = NULL;
1414 		if (p[0] == 'n' && p[1] == 'o')
1415 			q = p + 2;
1416 		for(t = global_opts; *t != NULL; t++) {
1417 			if (strcmp(*t, p) == 0)
1418 				break;
1419 			if (q != NULL) {
1420 				if (strcmp(*t, q) == 0)
1421 					break;
1422 			}
1423 		}
1424 		if (*t != NULL)
1425 			continue;
1426 		for(t = legal; *t != NULL; t++) {
1427 			if (strcmp(*t, p) == 0)
1428 				break;
1429 			if (q != NULL) {
1430 				if (strcmp(*t, q) == 0)
1431 					break;
1432 			}
1433 		}
1434 		if (*t != NULL)
1435 			continue;
1436 		snprintf(errmsg, sizeof(errmsg),
1437 		    "mount option <%s> is unknown", p);
1438 		ret = EINVAL;
1439 	}
1440 	if (ret != 0) {
1441 		TAILQ_FOREACH(opt, opts, link) {
1442 			if (strcmp(opt->name, "errmsg") == 0) {
1443 				strncpy((char *)opt->value, errmsg, opt->len);
1444 				break;
1445 			}
1446 		}
1447 		if (opt == NULL)
1448 			printf("%s\n", errmsg);
1449 	}
1450 	return (ret);
1451 }
1452 
1453 /*
1454  * Get a mount option by its name.
1455  *
1456  * Return 0 if the option was found, ENOENT otherwise.
1457  * If len is non-NULL it will be filled with the length
1458  * of the option. If buf is non-NULL, it will be filled
1459  * with the address of the option.
1460  */
1461 int
1462 vfs_getopt(opts, name, buf, len)
1463 	struct vfsoptlist *opts;
1464 	const char *name;
1465 	void **buf;
1466 	int *len;
1467 {
1468 	struct vfsopt *opt;
1469 
1470 	KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
1471 
1472 	TAILQ_FOREACH(opt, opts, link) {
1473 		if (strcmp(name, opt->name) == 0) {
1474 			opt->seen = 1;
1475 			if (len != NULL)
1476 				*len = opt->len;
1477 			if (buf != NULL)
1478 				*buf = opt->value;
1479 			return (0);
1480 		}
1481 	}
1482 	return (ENOENT);
1483 }
1484 
1485 int
1486 vfs_getopt_pos(struct vfsoptlist *opts, const char *name)
1487 {
1488 	struct vfsopt *opt;
1489 
1490 	if (opts == NULL)
1491 		return (-1);
1492 
1493 	TAILQ_FOREACH(opt, opts, link) {
1494 		if (strcmp(name, opt->name) == 0) {
1495 			opt->seen = 1;
1496 			return (opt->pos);
1497 		}
1498 	}
1499 	return (-1);
1500 }
1501 
1502 int
1503 vfs_getopt_size(struct vfsoptlist *opts, const char *name, off_t *value)
1504 {
1505 	char *opt_value, *vtp;
1506 	quad_t iv;
1507 	int error, opt_len;
1508 
1509 	error = vfs_getopt(opts, name, (void **)&opt_value, &opt_len);
1510 	if (error != 0)
1511 		return (error);
1512 	if (opt_len == 0 || opt_value == NULL)
1513 		return (EINVAL);
1514 	if (opt_value[0] == '\0' || opt_value[opt_len - 1] != '\0')
1515 		return (EINVAL);
1516 	iv = strtoq(opt_value, &vtp, 0);
1517 	if (vtp == opt_value || (vtp[0] != '\0' && vtp[1] != '\0'))
1518 		return (EINVAL);
1519 	if (iv < 0)
1520 		return (EINVAL);
1521 	switch (vtp[0]) {
1522 	case 't':
1523 	case 'T':
1524 		iv *= 1024;
1525 	case 'g':
1526 	case 'G':
1527 		iv *= 1024;
1528 	case 'm':
1529 	case 'M':
1530 		iv *= 1024;
1531 	case 'k':
1532 	case 'K':
1533 		iv *= 1024;
1534 	case '\0':
1535 		break;
1536 	default:
1537 		return (EINVAL);
1538 	}
1539 	*value = iv;
1540 
1541 	return (0);
1542 }
1543 
1544 char *
1545 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error)
1546 {
1547 	struct vfsopt *opt;
1548 
1549 	*error = 0;
1550 	TAILQ_FOREACH(opt, opts, link) {
1551 		if (strcmp(name, opt->name) != 0)
1552 			continue;
1553 		opt->seen = 1;
1554 		if (opt->len == 0 ||
1555 		    ((char *)opt->value)[opt->len - 1] != '\0') {
1556 			*error = EINVAL;
1557 			return (NULL);
1558 		}
1559 		return (opt->value);
1560 	}
1561 	*error = ENOENT;
1562 	return (NULL);
1563 }
1564 
1565 int
1566 vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w,
1567 	uint64_t val)
1568 {
1569 	struct vfsopt *opt;
1570 
1571 	TAILQ_FOREACH(opt, opts, link) {
1572 		if (strcmp(name, opt->name) == 0) {
1573 			opt->seen = 1;
1574 			if (w != NULL)
1575 				*w |= val;
1576 			return (1);
1577 		}
1578 	}
1579 	if (w != NULL)
1580 		*w &= ~val;
1581 	return (0);
1582 }
1583 
1584 int
1585 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...)
1586 {
1587 	va_list ap;
1588 	struct vfsopt *opt;
1589 	int ret;
1590 
1591 	KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
1592 
1593 	TAILQ_FOREACH(opt, opts, link) {
1594 		if (strcmp(name, opt->name) != 0)
1595 			continue;
1596 		opt->seen = 1;
1597 		if (opt->len == 0 || opt->value == NULL)
1598 			return (0);
1599 		if (((char *)opt->value)[opt->len - 1] != '\0')
1600 			return (0);
1601 		va_start(ap, fmt);
1602 		ret = vsscanf(opt->value, fmt, ap);
1603 		va_end(ap);
1604 		return (ret);
1605 	}
1606 	return (0);
1607 }
1608 
1609 int
1610 vfs_setopt(struct vfsoptlist *opts, const char *name, void *value, int len)
1611 {
1612 	struct vfsopt *opt;
1613 
1614 	TAILQ_FOREACH(opt, opts, link) {
1615 		if (strcmp(name, opt->name) != 0)
1616 			continue;
1617 		opt->seen = 1;
1618 		if (opt->value == NULL)
1619 			opt->len = len;
1620 		else {
1621 			if (opt->len != len)
1622 				return (EINVAL);
1623 			bcopy(value, opt->value, len);
1624 		}
1625 		return (0);
1626 	}
1627 	return (ENOENT);
1628 }
1629 
1630 int
1631 vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value, int len)
1632 {
1633 	struct vfsopt *opt;
1634 
1635 	TAILQ_FOREACH(opt, opts, link) {
1636 		if (strcmp(name, opt->name) != 0)
1637 			continue;
1638 		opt->seen = 1;
1639 		if (opt->value == NULL)
1640 			opt->len = len;
1641 		else {
1642 			if (opt->len < len)
1643 				return (EINVAL);
1644 			opt->len = len;
1645 			bcopy(value, opt->value, len);
1646 		}
1647 		return (0);
1648 	}
1649 	return (ENOENT);
1650 }
1651 
1652 int
1653 vfs_setopts(struct vfsoptlist *opts, const char *name, const char *value)
1654 {
1655 	struct vfsopt *opt;
1656 
1657 	TAILQ_FOREACH(opt, opts, link) {
1658 		if (strcmp(name, opt->name) != 0)
1659 			continue;
1660 		opt->seen = 1;
1661 		if (opt->value == NULL)
1662 			opt->len = strlen(value) + 1;
1663 		else if (strlcpy(opt->value, value, opt->len) >= opt->len)
1664 			return (EINVAL);
1665 		return (0);
1666 	}
1667 	return (ENOENT);
1668 }
1669 
1670 /*
1671  * Find and copy a mount option.
1672  *
1673  * The size of the buffer has to be specified
1674  * in len, if it is not the same length as the
1675  * mount option, EINVAL is returned.
1676  * Returns ENOENT if the option is not found.
1677  */
1678 int
1679 vfs_copyopt(opts, name, dest, len)
1680 	struct vfsoptlist *opts;
1681 	const char *name;
1682 	void *dest;
1683 	int len;
1684 {
1685 	struct vfsopt *opt;
1686 
1687 	KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL"));
1688 
1689 	TAILQ_FOREACH(opt, opts, link) {
1690 		if (strcmp(name, opt->name) == 0) {
1691 			opt->seen = 1;
1692 			if (len != opt->len)
1693 				return (EINVAL);
1694 			bcopy(opt->value, dest, opt->len);
1695 			return (0);
1696 		}
1697 	}
1698 	return (ENOENT);
1699 }
1700 
1701 int
1702 __vfs_statfs(struct mount *mp, struct statfs *sbp)
1703 {
1704 	int error;
1705 
1706 	error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat);
1707 	if (sbp != &mp->mnt_stat)
1708 		*sbp = mp->mnt_stat;
1709 	return (error);
1710 }
1711 
1712 void
1713 vfs_mountedfrom(struct mount *mp, const char *from)
1714 {
1715 
1716 	bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname);
1717 	strlcpy(mp->mnt_stat.f_mntfromname, from,
1718 	    sizeof mp->mnt_stat.f_mntfromname);
1719 }
1720 
1721 /*
1722  * ---------------------------------------------------------------------
1723  * This is the api for building mount args and mounting filesystems from
1724  * inside the kernel.
1725  *
1726  * The API works by accumulation of individual args.  First error is
1727  * latched.
1728  *
1729  * XXX: should be documented in new manpage kernel_mount(9)
1730  */
1731 
1732 /* A memory allocation which must be freed when we are done */
1733 struct mntaarg {
1734 	SLIST_ENTRY(mntaarg)	next;
1735 };
1736 
1737 /* The header for the mount arguments */
1738 struct mntarg {
1739 	struct iovec *v;
1740 	int len;
1741 	int error;
1742 	SLIST_HEAD(, mntaarg)	list;
1743 };
1744 
1745 /*
1746  * Add a boolean argument.
1747  *
1748  * flag is the boolean value.
1749  * name must start with "no".
1750  */
1751 struct mntarg *
1752 mount_argb(struct mntarg *ma, int flag, const char *name)
1753 {
1754 
1755 	KASSERT(name[0] == 'n' && name[1] == 'o',
1756 	    ("mount_argb(...,%s): name must start with 'no'", name));
1757 
1758 	return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0));
1759 }
1760 
1761 /*
1762  * Add an argument printf style
1763  */
1764 struct mntarg *
1765 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...)
1766 {
1767 	va_list ap;
1768 	struct mntaarg *maa;
1769 	struct sbuf *sb;
1770 	int len;
1771 
1772 	if (ma == NULL) {
1773 		ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
1774 		SLIST_INIT(&ma->list);
1775 	}
1776 	if (ma->error)
1777 		return (ma);
1778 
1779 	ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
1780 	    M_MOUNT, M_WAITOK);
1781 	ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
1782 	ma->v[ma->len].iov_len = strlen(name) + 1;
1783 	ma->len++;
1784 
1785 	sb = sbuf_new_auto();
1786 	va_start(ap, fmt);
1787 	sbuf_vprintf(sb, fmt, ap);
1788 	va_end(ap);
1789 	sbuf_finish(sb);
1790 	len = sbuf_len(sb) + 1;
1791 	maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
1792 	SLIST_INSERT_HEAD(&ma->list, maa, next);
1793 	bcopy(sbuf_data(sb), maa + 1, len);
1794 	sbuf_delete(sb);
1795 
1796 	ma->v[ma->len].iov_base = maa + 1;
1797 	ma->v[ma->len].iov_len = len;
1798 	ma->len++;
1799 
1800 	return (ma);
1801 }
1802 
1803 /*
1804  * Add an argument which is a userland string.
1805  */
1806 struct mntarg *
1807 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len)
1808 {
1809 	struct mntaarg *maa;
1810 	char *tbuf;
1811 
1812 	if (val == NULL)
1813 		return (ma);
1814 	if (ma == NULL) {
1815 		ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
1816 		SLIST_INIT(&ma->list);
1817 	}
1818 	if (ma->error)
1819 		return (ma);
1820 	maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
1821 	SLIST_INSERT_HEAD(&ma->list, maa, next);
1822 	tbuf = (void *)(maa + 1);
1823 	ma->error = copyinstr(val, tbuf, len, NULL);
1824 	return (mount_arg(ma, name, tbuf, -1));
1825 }
1826 
1827 /*
1828  * Plain argument.
1829  *
1830  * If length is -1, treat value as a C string.
1831  */
1832 struct mntarg *
1833 mount_arg(struct mntarg *ma, const char *name, const void *val, int len)
1834 {
1835 
1836 	if (ma == NULL) {
1837 		ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
1838 		SLIST_INIT(&ma->list);
1839 	}
1840 	if (ma->error)
1841 		return (ma);
1842 
1843 	ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
1844 	    M_MOUNT, M_WAITOK);
1845 	ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
1846 	ma->v[ma->len].iov_len = strlen(name) + 1;
1847 	ma->len++;
1848 
1849 	ma->v[ma->len].iov_base = (void *)(uintptr_t)val;
1850 	if (len < 0)
1851 		ma->v[ma->len].iov_len = strlen(val) + 1;
1852 	else
1853 		ma->v[ma->len].iov_len = len;
1854 	ma->len++;
1855 	return (ma);
1856 }
1857 
1858 /*
1859  * Free a mntarg structure
1860  */
1861 static void
1862 free_mntarg(struct mntarg *ma)
1863 {
1864 	struct mntaarg *maa;
1865 
1866 	while (!SLIST_EMPTY(&ma->list)) {
1867 		maa = SLIST_FIRST(&ma->list);
1868 		SLIST_REMOVE_HEAD(&ma->list, next);
1869 		free(maa, M_MOUNT);
1870 	}
1871 	free(ma->v, M_MOUNT);
1872 	free(ma, M_MOUNT);
1873 }
1874 
1875 /*
1876  * Mount a filesystem
1877  */
1878 int
1879 kernel_mount(struct mntarg *ma, uint64_t flags)
1880 {
1881 	struct uio auio;
1882 	int error;
1883 
1884 	KASSERT(ma != NULL, ("kernel_mount NULL ma"));
1885 	KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v"));
1886 	KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len));
1887 
1888 	auio.uio_iov = ma->v;
1889 	auio.uio_iovcnt = ma->len;
1890 	auio.uio_segflg = UIO_SYSSPACE;
1891 
1892 	error = ma->error;
1893 	if (!error)
1894 		error = vfs_donmount(curthread, flags, &auio);
1895 	free_mntarg(ma);
1896 	return (error);
1897 }
1898 
1899 /*
1900  * A printflike function to mount a filesystem.
1901  */
1902 int
1903 kernel_vmount(int flags, ...)
1904 {
1905 	struct mntarg *ma = NULL;
1906 	va_list ap;
1907 	const char *cp;
1908 	const void *vp;
1909 	int error;
1910 
1911 	va_start(ap, flags);
1912 	for (;;) {
1913 		cp = va_arg(ap, const char *);
1914 		if (cp == NULL)
1915 			break;
1916 		vp = va_arg(ap, const void *);
1917 		ma = mount_arg(ma, cp, vp, (vp != NULL ? -1 : 0));
1918 	}
1919 	va_end(ap);
1920 
1921 	error = kernel_mount(ma, flags);
1922 	return (error);
1923 }
1924 
1925 void
1926 vfs_oexport_conv(const struct oexport_args *oexp, struct export_args *exp)
1927 {
1928 
1929 	bcopy(oexp, exp, sizeof(*oexp));
1930 	exp->ex_numsecflavors = 0;
1931 }
1932