vfs_mount.c revision 164033
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: head/sys/kern/vfs_mount.c 164033 2006-11-06 13:42:10Z rwatson $");
39
40#include <sys/param.h>
41#include <sys/conf.h>
42#include <sys/clock.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/syscallsubr.h>
55#include <sys/sysproto.h>
56#include <sys/sx.h>
57#include <sys/sysctl.h>
58#include <sys/sysent.h>
59#include <sys/systm.h>
60#include <sys/vnode.h>
61#include <vm/uma.h>
62
63#include <geom/geom.h>
64
65#include <machine/stdarg.h>
66
67#include <security/audit/audit.h>
68#include <security/mac/mac_framework.h>
69
70#include "opt_rootdevname.h"
71#include "opt_ddb.h"
72#include "opt_mac.h"
73
74#ifdef DDB
75#include <ddb/ddb.h>
76#endif
77
78#define	ROOTNAME		"root_device"
79#define	VFS_MOUNTARG_SIZE_MAX	(1024 * 64)
80
81static int	vfs_domount(struct thread *td, const char *fstype,
82		    char *fspath, int fsflags, void *fsdata);
83static struct mount *vfs_mount_alloc(struct vnode *dvp, struct vfsconf *vfsp,
84		    const char *fspath, struct thread *td);
85static int	vfs_mountroot_ask(void);
86static int	vfs_mountroot_try(const char *mountfrom);
87static int	vfs_donmount(struct thread *td, int fsflags,
88		    struct uio *fsoptions);
89static void	free_mntarg(struct mntarg *ma);
90static void	vfs_mount_destroy(struct mount *);
91static int	vfs_getopt_pos(struct vfsoptlist *opts, const char *name);
92
93static int	usermount = 0;
94SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0,
95    "Unprivileged users may mount and unmount file systems");
96
97MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
98MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
99static uma_zone_t mount_zone;
100
101/* List of mounted filesystems. */
102struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist);
103
104/* For any iteration/modification of mountlist */
105struct mtx mountlist_mtx;
106MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF);
107
108TAILQ_HEAD(vfsoptlist, vfsopt);
109struct vfsopt {
110	TAILQ_ENTRY(vfsopt) link;
111	char	*name;
112	void	*value;
113	int	len;
114};
115
116/*
117 * The vnode of the system's root (/ in the filesystem, without chroot
118 * active.)
119 */
120struct vnode	*rootvnode;
121
122/*
123 * The root filesystem is detailed in the kernel environment variable
124 * vfs.root.mountfrom, which is expected to be in the general format
125 *
126 * <vfsname>:[<path>]
127 * vfsname   := the name of a VFS known to the kernel and capable
128 *              of being mounted as root
129 * path      := disk device name or other data used by the filesystem
130 *              to locate its physical store
131 */
132
133/*
134 * Global opts, taken by all filesystems
135 */
136static const char *global_opts[] = {
137	"errmsg",
138	"fstype",
139	"fspath",
140	"rdonly",
141	"ro",
142	"rw",
143	"suid",
144	"exec",
145	"update",
146	NULL
147};
148
149/*
150 * The root specifiers we will try if RB_CDROM is specified.
151 */
152static char *cdrom_rootdevnames[] = {
153	"cd9660:cd0",
154	"cd9660:acd0",
155	NULL
156};
157
158/* legacy find-root code */
159char		*rootdevnames[2] = {NULL, NULL};
160#ifndef ROOTDEVNAME
161#  define ROOTDEVNAME NULL
162#endif
163static const char	*ctrootdevname = ROOTDEVNAME;
164
165/*
166 * ---------------------------------------------------------------------
167 * Functions for building and sanitizing the mount options
168 */
169
170/* Remove one mount option. */
171static void
172vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt)
173{
174
175	TAILQ_REMOVE(opts, opt, link);
176	free(opt->name, M_MOUNT);
177	if (opt->value != NULL)
178		free(opt->value, M_MOUNT);
179#ifdef INVARIANTS
180	else if (opt->len != 0)
181		panic("%s: mount option with NULL value but length != 0",
182		    __func__);
183#endif
184	free(opt, M_MOUNT);
185}
186
187/* Release all resources related to the mount options. */
188static void
189vfs_freeopts(struct vfsoptlist *opts)
190{
191	struct vfsopt *opt;
192
193	while (!TAILQ_EMPTY(opts)) {
194		opt = TAILQ_FIRST(opts);
195		vfs_freeopt(opts, opt);
196	}
197	free(opts, M_MOUNT);
198}
199
200/*
201 * Check if options are equal (with or without the "no" prefix).
202 */
203static int
204vfs_equalopts(const char *opt1, const char *opt2)
205{
206
207	/* "opt" vs. "opt" or "noopt" vs. "noopt" */
208	if (strcmp(opt1, opt2) == 0)
209		return (1);
210	/* "noopt" vs. "opt" */
211	if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
212		return (1);
213	/* "opt" vs. "noopt" */
214	if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
215		return (1);
216	return (0);
217}
218
219/*
220 * If a mount option is specified several times,
221 * (with or without the "no" prefix) only keep
222 * the last occurence of it.
223 */
224static void
225vfs_sanitizeopts(struct vfsoptlist *opts)
226{
227	struct vfsopt *opt, *opt2, *tmp;
228
229	TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) {
230		opt2 = TAILQ_PREV(opt, vfsoptlist, link);
231		while (opt2 != NULL) {
232			if (vfs_equalopts(opt->name, opt2->name)) {
233				tmp = TAILQ_PREV(opt2, vfsoptlist, link);
234				vfs_freeopt(opts, opt2);
235				opt2 = tmp;
236			} else {
237				opt2 = TAILQ_PREV(opt2, vfsoptlist, link);
238			}
239		}
240	}
241}
242
243/*
244 * Build a linked list of mount options from a struct uio.
245 */
246static int
247vfs_buildopts(struct uio *auio, struct vfsoptlist **options)
248{
249	struct vfsoptlist *opts;
250	struct vfsopt *opt;
251	size_t memused;
252	unsigned int i, iovcnt;
253	int error, namelen, optlen;
254
255	opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
256	TAILQ_INIT(opts);
257	memused = 0;
258	iovcnt = auio->uio_iovcnt;
259	for (i = 0; i < iovcnt; i += 2) {
260		opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
261		namelen = auio->uio_iov[i].iov_len;
262		optlen = auio->uio_iov[i + 1].iov_len;
263		opt->name = malloc(namelen, M_MOUNT, M_WAITOK);
264		opt->value = NULL;
265		opt->len = 0;
266
267		/*
268		 * Do this early, so jumps to "bad" will free the current
269		 * option.
270		 */
271		TAILQ_INSERT_TAIL(opts, opt, link);
272		memused += sizeof(struct vfsopt) + optlen + namelen;
273
274		/*
275		 * Avoid consuming too much memory, and attempts to overflow
276		 * memused.
277		 */
278		if (memused > VFS_MOUNTARG_SIZE_MAX ||
279		    optlen > VFS_MOUNTARG_SIZE_MAX ||
280		    namelen > VFS_MOUNTARG_SIZE_MAX) {
281			error = EINVAL;
282			goto bad;
283		}
284
285		if (auio->uio_segflg == UIO_SYSSPACE) {
286			bcopy(auio->uio_iov[i].iov_base, opt->name, namelen);
287		} else {
288			error = copyin(auio->uio_iov[i].iov_base, opt->name,
289			    namelen);
290			if (error)
291				goto bad;
292		}
293		/* Ensure names are null-terminated strings. */
294		if (opt->name[namelen - 1] != '\0') {
295			error = EINVAL;
296			goto bad;
297		}
298		if (optlen != 0) {
299			opt->len = optlen;
300			opt->value = malloc(optlen, M_MOUNT, M_WAITOK);
301			if (auio->uio_segflg == UIO_SYSSPACE) {
302				bcopy(auio->uio_iov[i + 1].iov_base, opt->value,
303				    optlen);
304			} else {
305				error = copyin(auio->uio_iov[i + 1].iov_base,
306				    opt->value, optlen);
307				if (error)
308					goto bad;
309			}
310		}
311	}
312	vfs_sanitizeopts(opts);
313	*options = opts;
314	return (0);
315bad:
316	vfs_freeopts(opts);
317	return (error);
318}
319
320/*
321 * Merge the old mount options with the new ones passed
322 * in the MNT_UPDATE case.
323 */
324static void
325vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts)
326{
327	struct vfsopt *opt, *opt2, *new;
328
329	TAILQ_FOREACH(opt, opts, link) {
330		/*
331		 * Check that this option hasn't been redefined
332		 * nor cancelled with a "no" mount option.
333		 */
334		opt2 = TAILQ_FIRST(toopts);
335		while (opt2 != NULL) {
336			if (strcmp(opt2->name, opt->name) == 0)
337				goto next;
338			if (strncmp(opt2->name, "no", 2) == 0 &&
339			    strcmp(opt2->name + 2, opt->name) == 0) {
340				vfs_freeopt(toopts, opt2);
341				goto next;
342			}
343			opt2 = TAILQ_NEXT(opt2, link);
344		}
345		/* We want this option, duplicate it. */
346		new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
347		new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK);
348		strcpy(new->name, opt->name);
349		if (opt->len != 0) {
350			new->value = malloc(opt->len, M_MOUNT, M_WAITOK);
351			bcopy(opt->value, new->value, opt->len);
352		} else {
353			new->value = NULL;
354		}
355		new->len = opt->len;
356		TAILQ_INSERT_TAIL(toopts, new, link);
357next:
358		continue;
359	}
360}
361
362/*
363 * ---------------------------------------------------------------------
364 * Mount a filesystem
365 */
366int
367nmount(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	struct iovec *iov;
377	unsigned int i;
378	int error;
379	u_int iovcnt;
380
381	AUDIT_ARG(fflags, uap->flags);
382
383	/* Kick out MNT_ROOTFS early as it is legal internally */
384	if (uap->flags & MNT_ROOTFS)
385		return (EINVAL);
386
387	iovcnt = uap->iovcnt;
388	/*
389	 * Check that we have an even number of iovec's
390	 * and that we have at least two options.
391	 */
392	if ((iovcnt & 1) || (iovcnt < 4))
393		return (EINVAL);
394
395	error = copyinuio(uap->iovp, iovcnt, &auio);
396	if (error)
397		return (error);
398	iov = auio->uio_iov;
399	for (i = 0; i < iovcnt; i++) {
400		if (iov->iov_len > MMAXOPTIONLEN) {
401			free(auio, M_IOV);
402			return (EINVAL);
403		}
404		iov++;
405	}
406	error = vfs_donmount(td, uap->flags, auio);
407
408	free(auio, M_IOV);
409	return (error);
410}
411
412/*
413 * ---------------------------------------------------------------------
414 * Various utility functions
415 */
416
417void
418vfs_ref(struct mount *mp)
419{
420
421	MNT_ILOCK(mp);
422	MNT_REF(mp);
423	MNT_IUNLOCK(mp);
424}
425
426void
427vfs_rel(struct mount *mp)
428{
429
430	MNT_ILOCK(mp);
431	MNT_REL(mp);
432	MNT_IUNLOCK(mp);
433}
434
435static int
436mount_init(void *mem, int size, int flags)
437{
438	struct mount *mp;
439
440	mp = (struct mount *)mem;
441	mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
442	lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0);
443	return (0);
444}
445
446static void
447mount_fini(void *mem, int size)
448{
449	struct mount *mp;
450
451	mp = (struct mount *)mem;
452	lockdestroy(&mp->mnt_lock);
453	mtx_destroy(&mp->mnt_mtx);
454}
455
456/*
457 * Allocate and initialize the mount point struct.
458 */
459static struct mount *
460vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp,
461    const char *fspath, struct thread *td)
462{
463	struct mount *mp;
464
465	mp = uma_zalloc(mount_zone, M_WAITOK);
466	bzero(&mp->mnt_startzero,
467	    __rangeof(struct mount, mnt_startzero, mnt_endzero));
468	TAILQ_INIT(&mp->mnt_nvnodelist);
469	mp->mnt_nvnodelistsize = 0;
470	mp->mnt_ref = 0;
471	(void) vfs_busy(mp, LK_NOWAIT, 0, td);
472	mp->mnt_op = vfsp->vfc_vfsops;
473	mp->mnt_vfc = vfsp;
474	vfsp->vfc_refcount++;	/* XXX Unlocked */
475	mp->mnt_stat.f_type = vfsp->vfc_typenum;
476	MNT_ILOCK(mp);
477	mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
478	MNT_IUNLOCK(mp);
479	mp->mnt_gen++;
480	strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
481	mp->mnt_vnodecovered = vp;
482	mp->mnt_cred = crdup(td->td_ucred);
483	mp->mnt_stat.f_owner = td->td_ucred->cr_uid;
484	strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN);
485	mp->mnt_iosize_max = DFLTPHYS;
486#ifdef MAC
487	mac_init_mount(mp);
488	mac_create_mount(td->td_ucred, mp);
489#endif
490	arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0);
491	return (mp);
492}
493
494/*
495 * Destroy the mount struct previously allocated by vfs_mount_alloc().
496 */
497static void
498vfs_mount_destroy(struct mount *mp)
499{
500	int i;
501
502	MNT_ILOCK(mp);
503	for (i = 0; mp->mnt_ref && i < 3; i++)
504		msleep(mp, MNT_MTX(mp), PVFS, "mntref", hz);
505	/*
506	 * This will always cause a 3 second delay in rebooting due to
507	 * refs on the root mountpoint that never go away.  Most of these
508	 * are held by init which never exits.
509	 */
510	if (i == 3 && (!rebooting || bootverbose))
511		printf("Mount point %s had %d dangling refs\n",
512		    mp->mnt_stat.f_mntonname, mp->mnt_ref);
513	if (mp->mnt_holdcnt != 0) {
514		printf("Waiting for mount point to be unheld\n");
515		while (mp->mnt_holdcnt != 0) {
516			mp->mnt_holdcntwaiters++;
517			msleep(&mp->mnt_holdcnt, MNT_MTX(mp),
518			       PZERO, "mntdestroy", 0);
519			mp->mnt_holdcntwaiters--;
520		}
521		printf("mount point unheld\n");
522	}
523	if (mp->mnt_writeopcount > 0) {
524		printf("Waiting for mount point write ops\n");
525		while (mp->mnt_writeopcount > 0) {
526			mp->mnt_kern_flag |= MNTK_SUSPEND;
527			msleep(&mp->mnt_writeopcount,
528			       MNT_MTX(mp),
529			       PZERO, "mntdestroy2", 0);
530		}
531		printf("mount point write ops completed\n");
532	}
533	if (mp->mnt_secondary_writes > 0) {
534		printf("Waiting for mount point secondary write ops\n");
535		while (mp->mnt_secondary_writes > 0) {
536			mp->mnt_kern_flag |= MNTK_SUSPEND;
537			msleep(&mp->mnt_secondary_writes,
538			       MNT_MTX(mp),
539			       PZERO, "mntdestroy3", 0);
540		}
541		printf("mount point secondary write ops completed\n");
542	}
543	MNT_IUNLOCK(mp);
544	mp->mnt_vfc->vfc_refcount--;
545	if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) {
546		struct vnode *vp;
547
548		TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes)
549			vprint("", vp);
550		panic("unmount: dangling vnode");
551	}
552	MNT_ILOCK(mp);
553	if (mp->mnt_kern_flag & MNTK_MWAIT)
554		wakeup(mp);
555	if (mp->mnt_writeopcount != 0)
556		panic("vfs_mount_destroy: nonzero writeopcount");
557	if (mp->mnt_secondary_writes != 0)
558		panic("vfs_mount_destroy: nonzero secondary_writes");
559	if (mp->mnt_nvnodelistsize != 0)
560		panic("vfs_mount_destroy: nonzero nvnodelistsize");
561	mp->mnt_writeopcount = -1000;
562	mp->mnt_nvnodelistsize = -1000;
563	mp->mnt_secondary_writes = -1000;
564	MNT_IUNLOCK(mp);
565#ifdef MAC
566	mac_destroy_mount(mp);
567#endif
568	if (mp->mnt_opt != NULL)
569		vfs_freeopts(mp->mnt_opt);
570	crfree(mp->mnt_cred);
571	uma_zfree(mount_zone, mp);
572}
573
574static int
575vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions)
576{
577	struct vfsoptlist *optlist;
578	struct vfsopt *opt, *noro_opt;
579	char *fstype, *fspath, *errmsg;
580	int error, fstypelen, fspathlen, errmsg_len, errmsg_pos;
581	int has_rw, has_noro;
582
583	errmsg = NULL;
584	errmsg_len = 0;
585	errmsg_pos = -1;
586	has_rw = 0;
587	has_noro = 0;
588
589	error = vfs_buildopts(fsoptions, &optlist);
590	if (error)
591		return (error);
592
593	if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0)
594		errmsg_pos = vfs_getopt_pos(optlist, "errmsg");
595
596	/*
597	 * We need these two options before the others,
598	 * and they are mandatory for any filesystem.
599	 * Ensure they are NUL terminated as well.
600	 */
601	fstypelen = 0;
602	error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen);
603	if (error || fstype[fstypelen - 1] != '\0') {
604		error = EINVAL;
605		if (errmsg != NULL)
606			strncpy(errmsg, "Invalid fstype", errmsg_len);
607		goto bail;
608	}
609	fspathlen = 0;
610	error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen);
611	if (error || fspath[fspathlen - 1] != '\0') {
612		error = EINVAL;
613		if (errmsg != NULL)
614			strncpy(errmsg, "Invalid fspath", errmsg_len);
615		goto bail;
616	}
617
618	/*
619	 * We need to see if we have the "update" option
620	 * before we call vfs_domount(), since vfs_domount() has special
621	 * logic based on MNT_UPDATE.  This is very important
622	 * when we want to update the root filesystem.
623	 */
624	TAILQ_FOREACH(opt, optlist, link) {
625		if (strcmp(opt->name, "update") == 0)
626			fsflags |= MNT_UPDATE;
627		else if (strcmp(opt->name, "async") == 0)
628			fsflags |= MNT_ASYNC;
629		else if (strcmp(opt->name, "force") == 0)
630			fsflags |= MNT_FORCE;
631		else if (strcmp(opt->name, "multilabel") == 0)
632			fsflags |= MNT_MULTILABEL;
633		else if (strcmp(opt->name, "noasync") == 0)
634			fsflags &= ~MNT_ASYNC;
635		else if (strcmp(opt->name, "noatime") == 0)
636			fsflags |= MNT_NOATIME;
637		else if (strcmp(opt->name, "noclusterr") == 0)
638			fsflags |= MNT_NOCLUSTERR;
639		else if (strcmp(opt->name, "noclusterw") == 0)
640			fsflags |= MNT_NOCLUSTERW;
641		else if (strcmp(opt->name, "noexec") == 0)
642			fsflags |= MNT_NOEXEC;
643		else if (strcmp(opt->name, "nosuid") == 0)
644			fsflags |= MNT_NOSUID;
645		else if (strcmp(opt->name, "nosymfollow") == 0)
646			fsflags |= MNT_NOSYMFOLLOW;
647		else if (strcmp(opt->name, "noro") == 0) {
648			fsflags &= ~MNT_RDONLY;
649			has_noro = 1;
650		}
651		else if (strcmp(opt->name, "rw") == 0) {
652			fsflags &= ~MNT_RDONLY;
653			has_rw = 1;
654		}
655		else if (strcmp(opt->name, "ro") == 0 ||
656		    strcmp(opt->name, "rdonly") == 0)
657			fsflags |= MNT_RDONLY;
658		else if (strcmp(opt->name, "snapshot") == 0)
659			fsflags |= MNT_SNAPSHOT;
660		else if (strcmp(opt->name, "suiddir") == 0)
661			fsflags |= MNT_SUIDDIR;
662		else if (strcmp(opt->name, "sync") == 0)
663			fsflags |= MNT_SYNCHRONOUS;
664		else if (strcmp(opt->name, "union") == 0)
665			fsflags |= MNT_UNION;
666	}
667
668	/*
669	 * If "rw" was specified as a mount option, and we
670	 * are trying to update a mount-point from "ro" to "rw",
671	 * we need a mount option "noro", since in vfs_mergeopts(),
672	 * "noro" will cancel "ro", but "rw" will not do anything.
673	 */
674	if (has_rw && !has_noro) {
675		noro_opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
676		noro_opt->name = strdup("noro", M_MOUNT);
677		noro_opt->value = NULL;
678		noro_opt->len = 0;
679		TAILQ_INSERT_TAIL(optlist, noro_opt, link);
680	}
681
682	/*
683	 * Be ultra-paranoid about making sure the type and fspath
684	 * variables will fit in our mp buffers, including the
685	 * terminating NUL.
686	 */
687	if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) {
688		error = ENAMETOOLONG;
689		goto bail;
690	}
691
692	mtx_lock(&Giant);
693	error = vfs_domount(td, fstype, fspath, fsflags, optlist);
694	mtx_unlock(&Giant);
695bail:
696	/* copyout the errmsg */
697	if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt)
698	    && errmsg_len > 0 && errmsg != NULL) {
699		if (fsoptions->uio_segflg == UIO_SYSSPACE) {
700			bcopy(errmsg,
701			    fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
702			    fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
703		} else {
704			copyout(errmsg,
705			    fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
706			    fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
707		}
708	}
709
710	if (error != 0)
711		vfs_freeopts(optlist);
712	return (error);
713}
714
715/*
716 * ---------------------------------------------------------------------
717 * Old mount API.
718 */
719#ifndef _SYS_SYSPROTO_H_
720struct mount_args {
721	char	*type;
722	char	*path;
723	int	flags;
724	caddr_t	data;
725};
726#endif
727/* ARGSUSED */
728int
729mount(td, uap)
730	struct thread *td;
731	struct mount_args /* {
732		char *type;
733		char *path;
734		int flags;
735		caddr_t data;
736	} */ *uap;
737{
738	char *fstype;
739	struct vfsconf *vfsp = NULL;
740	struct mntarg *ma = NULL;
741	int error;
742
743	AUDIT_ARG(fflags, uap->flags);
744
745	/* Kick out MNT_ROOTFS early as it is legal internally */
746	uap->flags &= ~MNT_ROOTFS;
747
748	fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK);
749	error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL);
750	if (error) {
751		free(fstype, M_TEMP);
752		return (error);
753	}
754
755	AUDIT_ARG(text, fstype);
756	mtx_lock(&Giant);
757	vfsp = vfs_byname_kld(fstype, td, &error);
758	free(fstype, M_TEMP);
759	if (vfsp == NULL) {
760		mtx_unlock(&Giant);
761		return (ENOENT);
762	}
763	if (vfsp->vfc_vfsops->vfs_cmount == NULL) {
764		mtx_unlock(&Giant);
765		return (EOPNOTSUPP);
766	}
767
768	ma = mount_argsu(ma, "fstype", uap->type, MNAMELEN);
769	ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN);
770	ma = mount_argb(ma, uap->flags & MNT_RDONLY, "noro");
771	ma = mount_argb(ma, !(uap->flags & MNT_NOSUID), "nosuid");
772	ma = mount_argb(ma, !(uap->flags & MNT_NOEXEC), "noexec");
773
774	error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, uap->flags, td);
775	mtx_unlock(&Giant);
776	return (error);
777}
778
779
780/*
781 * vfs_domount(): actually attempt a filesystem mount.
782 */
783static int
784vfs_domount(
785	struct thread *td,	/* Calling thread. */
786	const char *fstype,	/* Filesystem type. */
787	char *fspath,		/* Mount path. */
788	int fsflags,		/* Flags common to all filesystems. */
789	void *fsdata		/* Options local to the filesystem. */
790	)
791{
792	struct vnode *vp;
793	struct mount *mp;
794	struct vfsconf *vfsp;
795	struct export_args export;
796	int error, flag = 0;
797	struct vattr va;
798	struct nameidata nd;
799
800	mtx_assert(&Giant, MA_OWNED);
801	/*
802	 * Be ultra-paranoid about making sure the type and fspath
803	 * variables will fit in our mp buffers, including the
804	 * terminating NUL.
805	 */
806	if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN)
807		return (ENAMETOOLONG);
808
809	if (jailed(td->td_ucred))
810		return (EPERM);
811	if (usermount == 0) {
812		if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0)
813			return (error);
814	}
815
816	/*
817	 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users.
818	 */
819	if (fsflags & MNT_EXPORTED) {
820		error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED);
821		if (error)
822			return (error);
823	}
824	if (fsflags & MNT_SUIDDIR) {
825		error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR);
826		if (error)
827			return (error);
828
829	}
830	/*
831	 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users.
832	 */
833	if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) {
834		if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0)
835			fsflags |= MNT_NOSUID | MNT_USER;
836	}
837
838	/* Load KLDs before we lock the covered vnode to avoid reversals. */
839	vfsp = NULL;
840	if ((fsflags & MNT_UPDATE) == 0) {
841		/* Don't try to load KLDs if we're mounting the root. */
842		if (fsflags & MNT_ROOTFS)
843			vfsp = vfs_byname(fstype);
844		else
845			vfsp = vfs_byname_kld(fstype, td, &error);
846		if (vfsp == NULL)
847			return (ENODEV);
848	}
849	/*
850	 * Get vnode to be covered
851	 */
852	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_SYSSPACE,
853	    fspath, td);
854	if ((error = namei(&nd)) != 0)
855		return (error);
856	NDFREE(&nd, NDF_ONLY_PNBUF);
857	vp = nd.ni_vp;
858	if (fsflags & MNT_UPDATE) {
859		if ((vp->v_vflag & VV_ROOT) == 0) {
860			vput(vp);
861			return (EINVAL);
862		}
863		mp = vp->v_mount;
864		MNT_ILOCK(mp);
865		flag = mp->mnt_flag;
866		/*
867		 * We only allow the filesystem to be reloaded if it
868		 * is currently mounted read-only.
869		 */
870		if ((fsflags & MNT_RELOAD) &&
871		    ((mp->mnt_flag & MNT_RDONLY) == 0)) {
872			MNT_IUNLOCK(mp);
873			vput(vp);
874			return (EOPNOTSUPP);	/* Needs translation */
875		}
876		MNT_IUNLOCK(mp);
877		/*
878		 * Only privileged root, or (if MNT_USER is set) the user that
879		 * did the original mount is permitted to update it.
880		 */
881		error = vfs_suser(mp, td);
882		if (error) {
883			vput(vp);
884			return (error);
885		}
886		if (vfs_busy(mp, LK_NOWAIT, 0, td)) {
887			vput(vp);
888			return (EBUSY);
889		}
890		VI_LOCK(vp);
891		if ((vp->v_iflag & VI_MOUNT) != 0 ||
892		    vp->v_mountedhere != NULL) {
893			VI_UNLOCK(vp);
894			vfs_unbusy(mp, td);
895			vput(vp);
896			return (EBUSY);
897		}
898		vp->v_iflag |= VI_MOUNT;
899		VI_UNLOCK(vp);
900		MNT_ILOCK(mp);
901		mp->mnt_flag |= fsflags &
902		    (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT | MNT_ROOTFS);
903		MNT_IUNLOCK(mp);
904		VOP_UNLOCK(vp, 0, td);
905		mp->mnt_optnew = fsdata;
906		vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt);
907	} else {
908		/*
909		 * If the user is not root, ensure that they own the directory
910		 * onto which we are attempting to mount.
911		 */
912		error = VOP_GETATTR(vp, &va, td->td_ucred, td);
913		if (error) {
914			vput(vp);
915			return (error);
916		}
917		if (va.va_uid != td->td_ucred->cr_uid) {
918			error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN,
919			    SUSER_ALLOWJAIL);
920			if (error) {
921				vput(vp);
922				return (error);
923			}
924		}
925		error = vinvalbuf(vp, V_SAVE, td, 0, 0);
926		if (error != 0) {
927			vput(vp);
928			return (error);
929		}
930		if (vp->v_type != VDIR) {
931			vput(vp);
932			return (ENOTDIR);
933		}
934		VI_LOCK(vp);
935		if ((vp->v_iflag & VI_MOUNT) != 0 ||
936		    vp->v_mountedhere != NULL) {
937			VI_UNLOCK(vp);
938			vput(vp);
939			return (EBUSY);
940		}
941		vp->v_iflag |= VI_MOUNT;
942		VI_UNLOCK(vp);
943
944		/*
945		 * Allocate and initialize the filesystem.
946		 */
947		mp = vfs_mount_alloc(vp, vfsp, fspath, td);
948		VOP_UNLOCK(vp, 0, td);
949
950		/* XXXMAC: pass to vfs_mount_alloc? */
951		mp->mnt_optnew = fsdata;
952	}
953
954	/*
955	 * Set the mount level flags.
956	 */
957	MNT_ILOCK(mp);
958	mp->mnt_flag = (mp->mnt_flag & ~MNT_UPDATEMASK) |
959		(fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS |
960			    MNT_RDONLY));
961	if ((mp->mnt_flag & MNT_ASYNC) == 0)
962		mp->mnt_kern_flag &= ~MNTK_ASYNC;
963	MNT_IUNLOCK(mp);
964	/*
965	 * Mount the filesystem.
966	 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
967	 * get.  No freeing of cn_pnbuf.
968	 */
969        error = VFS_MOUNT(mp, td);
970
971	/*
972	 * Process the export option only if we are
973	 * updating mount options.
974	 */
975	if (!error && (fsflags & MNT_UPDATE)) {
976		if (vfs_copyopt(mp->mnt_optnew, "export", &export,
977		    sizeof(export)) == 0)
978			error = vfs_export(mp, &export);
979	}
980
981	if (!error) {
982		if (mp->mnt_opt != NULL)
983			vfs_freeopts(mp->mnt_opt);
984		mp->mnt_opt = mp->mnt_optnew;
985		(void)VFS_STATFS(mp, &mp->mnt_stat, td);
986	}
987	/*
988	 * Prevent external consumers of mount options from reading
989	 * mnt_optnew.
990	*/
991	mp->mnt_optnew = NULL;
992	if (mp->mnt_flag & MNT_UPDATE) {
993		MNT_ILOCK(mp);
994		if (error)
995			mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) |
996				(flag & ~MNT_QUOTA);
997		else
998			mp->mnt_flag &=	~(MNT_UPDATE | MNT_RELOAD |
999					  MNT_FORCE | MNT_SNAPSHOT);
1000		if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0)
1001			mp->mnt_kern_flag |= MNTK_ASYNC;
1002		else
1003			mp->mnt_kern_flag &= ~MNTK_ASYNC;
1004		MNT_IUNLOCK(mp);
1005		if ((mp->mnt_flag & MNT_RDONLY) == 0) {
1006			if (mp->mnt_syncer == NULL)
1007				error = vfs_allocate_syncvnode(mp);
1008		} else {
1009			if (mp->mnt_syncer != NULL)
1010				vrele(mp->mnt_syncer);
1011			mp->mnt_syncer = NULL;
1012		}
1013		vfs_unbusy(mp, td);
1014		VI_LOCK(vp);
1015		vp->v_iflag &= ~VI_MOUNT;
1016		VI_UNLOCK(vp);
1017		vrele(vp);
1018		return (error);
1019	}
1020	MNT_ILOCK(mp);
1021	if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0)
1022		mp->mnt_kern_flag |= MNTK_ASYNC;
1023	else
1024		mp->mnt_kern_flag &= ~MNTK_ASYNC;
1025	MNT_IUNLOCK(mp);
1026	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1027	/*
1028	 * Put the new filesystem on the mount list after root.
1029	 */
1030	cache_purge(vp);
1031	if (!error) {
1032		struct vnode *newdp;
1033
1034		VI_LOCK(vp);
1035		vp->v_iflag &= ~VI_MOUNT;
1036		VI_UNLOCK(vp);
1037		vp->v_mountedhere = mp;
1038		mtx_lock(&mountlist_mtx);
1039		TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
1040		mtx_unlock(&mountlist_mtx);
1041		vfs_event_signal(NULL, VQ_MOUNT, 0);
1042		if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp, td))
1043			panic("mount: lost mount");
1044		mountcheckdirs(vp, newdp);
1045		vput(newdp);
1046		VOP_UNLOCK(vp, 0, td);
1047		if ((mp->mnt_flag & MNT_RDONLY) == 0)
1048			error = vfs_allocate_syncvnode(mp);
1049		vfs_unbusy(mp, td);
1050		if (error)
1051			vrele(vp);
1052	} else {
1053		VI_LOCK(vp);
1054		vp->v_iflag &= ~VI_MOUNT;
1055		VI_UNLOCK(vp);
1056		vfs_unbusy(mp, td);
1057		vfs_mount_destroy(mp);
1058		vput(vp);
1059	}
1060	return (error);
1061}
1062
1063/*
1064 * ---------------------------------------------------------------------
1065 * Unmount a filesystem.
1066 *
1067 * Note: unmount takes a path to the vnode mounted on as argument,
1068 * not special file (as before).
1069 */
1070#ifndef _SYS_SYSPROTO_H_
1071struct unmount_args {
1072	char	*path;
1073	int	flags;
1074};
1075#endif
1076/* ARGSUSED */
1077int
1078unmount(td, uap)
1079	struct thread *td;
1080	register struct unmount_args /* {
1081		char *path;
1082		int flags;
1083	} */ *uap;
1084{
1085	struct mount *mp;
1086	char *pathbuf;
1087	int error, id0, id1;
1088
1089	if (jailed(td->td_ucred))
1090		return (EPERM);
1091	if (usermount == 0) {
1092		error = priv_check(td, PRIV_VFS_UNMOUNT);
1093		if (error)
1094			return (error);
1095	}
1096
1097	pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
1098	error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL);
1099	if (error) {
1100		free(pathbuf, M_TEMP);
1101		return (error);
1102	}
1103	AUDIT_ARG(upath, td, pathbuf, ARG_UPATH1);
1104	mtx_lock(&Giant);
1105	if (uap->flags & MNT_BYFSID) {
1106		/* Decode the filesystem ID. */
1107		if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) {
1108			mtx_unlock(&Giant);
1109			free(pathbuf, M_TEMP);
1110			return (EINVAL);
1111		}
1112
1113		mtx_lock(&mountlist_mtx);
1114		TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
1115			if (mp->mnt_stat.f_fsid.val[0] == id0 &&
1116			    mp->mnt_stat.f_fsid.val[1] == id1)
1117				break;
1118		}
1119		mtx_unlock(&mountlist_mtx);
1120	} else {
1121		mtx_lock(&mountlist_mtx);
1122		TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
1123			if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0)
1124				break;
1125		}
1126		mtx_unlock(&mountlist_mtx);
1127	}
1128	free(pathbuf, M_TEMP);
1129	if (mp == NULL) {
1130		/*
1131		 * Previously we returned ENOENT for a nonexistent path and
1132		 * EINVAL for a non-mountpoint.  We cannot tell these apart
1133		 * now, so in the !MNT_BYFSID case return the more likely
1134		 * EINVAL for compatibility.
1135		 */
1136		mtx_unlock(&Giant);
1137		return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL);
1138	}
1139
1140	/*
1141	 * Don't allow unmounting the root filesystem.
1142	 */
1143	if (mp->mnt_flag & MNT_ROOTFS) {
1144		mtx_unlock(&Giant);
1145		return (EINVAL);
1146	}
1147	error = dounmount(mp, uap->flags, td);
1148	mtx_unlock(&Giant);
1149	return (error);
1150}
1151
1152/*
1153 * Do the actual filesystem unmount.
1154 */
1155int
1156dounmount(mp, flags, td)
1157	struct mount *mp;
1158	int flags;
1159	struct thread *td;
1160{
1161	struct vnode *coveredvp, *fsrootvp;
1162	int error;
1163	int async_flag;
1164	int mnt_gen_r;
1165
1166	mtx_assert(&Giant, MA_OWNED);
1167
1168	if ((coveredvp = mp->mnt_vnodecovered) != NULL) {
1169		mnt_gen_r = mp->mnt_gen;
1170		VI_LOCK(coveredvp);
1171		vholdl(coveredvp);
1172		error = vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK, td);
1173		vdrop(coveredvp);
1174		/*
1175		 * Check for mp being unmounted while waiting for the
1176		 * covered vnode lock.
1177		 */
1178		if (error)
1179			return (error);
1180		if (coveredvp->v_mountedhere != mp ||
1181		    coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) {
1182			VOP_UNLOCK(coveredvp, 0, td);
1183			return (EBUSY);
1184		}
1185	}
1186	/*
1187	 * Only privileged root, or (if MNT_USER is set) the user that did the
1188	 * original mount is permitted to unmount this filesystem.
1189	 */
1190	error = vfs_suser(mp, td);
1191	if (error) {
1192		if (coveredvp)
1193			VOP_UNLOCK(coveredvp, 0, td);
1194		return (error);
1195	}
1196
1197	MNT_ILOCK(mp);
1198	if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
1199		MNT_IUNLOCK(mp);
1200		if (coveredvp)
1201			VOP_UNLOCK(coveredvp, 0, td);
1202		return (EBUSY);
1203	}
1204	mp->mnt_kern_flag |= MNTK_UNMOUNT;
1205	/* Allow filesystems to detect that a forced unmount is in progress. */
1206	if (flags & MNT_FORCE)
1207		mp->mnt_kern_flag |= MNTK_UNMOUNTF;
1208	error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK |
1209	    ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), MNT_MTX(mp), td);
1210	if (error) {
1211		MNT_ILOCK(mp);
1212		mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
1213		if (mp->mnt_kern_flag & MNTK_MWAIT)
1214			wakeup(mp);
1215		MNT_IUNLOCK(mp);
1216		if (coveredvp)
1217			VOP_UNLOCK(coveredvp, 0, td);
1218		return (error);
1219	}
1220	vn_start_write(NULL, &mp, V_WAIT);
1221
1222	if (mp->mnt_flag & MNT_EXPUBLIC)
1223		vfs_setpublicfs(NULL, NULL, NULL);
1224
1225	vfs_msync(mp, MNT_WAIT);
1226	MNT_ILOCK(mp);
1227	async_flag = mp->mnt_flag & MNT_ASYNC;
1228	mp->mnt_flag &= ~MNT_ASYNC;
1229	mp->mnt_kern_flag &= ~MNTK_ASYNC;
1230	MNT_IUNLOCK(mp);
1231	cache_purgevfs(mp);	/* remove cache entries for this file sys */
1232	if (mp->mnt_syncer != NULL)
1233		vrele(mp->mnt_syncer);
1234	/*
1235	 * For forced unmounts, move process cdir/rdir refs on the fs root
1236	 * vnode to the covered vnode.  For non-forced unmounts we want
1237	 * such references to cause an EBUSY error.
1238	 */
1239	if ((flags & MNT_FORCE) &&
1240	    VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) {
1241		if (mp->mnt_vnodecovered != NULL)
1242			mountcheckdirs(fsrootvp, mp->mnt_vnodecovered);
1243		if (fsrootvp == rootvnode) {
1244			vrele(rootvnode);
1245			rootvnode = NULL;
1246		}
1247		vput(fsrootvp);
1248	}
1249	if (((mp->mnt_flag & MNT_RDONLY) ||
1250	     (error = VFS_SYNC(mp, MNT_WAIT, td)) == 0) ||
1251	    (flags & MNT_FORCE)) {
1252		error = VFS_UNMOUNT(mp, flags, td);
1253	}
1254	vn_finished_write(mp);
1255	if (error) {
1256		/* Undo cdir/rdir and rootvnode changes made above. */
1257		if ((flags & MNT_FORCE) &&
1258		    VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) {
1259			if (mp->mnt_vnodecovered != NULL)
1260				mountcheckdirs(mp->mnt_vnodecovered, fsrootvp);
1261			if (rootvnode == NULL) {
1262				rootvnode = fsrootvp;
1263				vref(rootvnode);
1264			}
1265			vput(fsrootvp);
1266		}
1267		if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL)
1268			(void) vfs_allocate_syncvnode(mp);
1269		MNT_ILOCK(mp);
1270		mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
1271		mp->mnt_flag |= async_flag;
1272		if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0)
1273			mp->mnt_kern_flag |= MNTK_ASYNC;
1274		lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td);
1275		if (mp->mnt_kern_flag & MNTK_MWAIT)
1276			wakeup(mp);
1277		MNT_IUNLOCK(mp);
1278		if (coveredvp)
1279			VOP_UNLOCK(coveredvp, 0, td);
1280		return (error);
1281	}
1282	mtx_lock(&mountlist_mtx);
1283	TAILQ_REMOVE(&mountlist, mp, mnt_list);
1284	mtx_unlock(&mountlist_mtx);
1285	if (coveredvp != NULL) {
1286		coveredvp->v_mountedhere = NULL;
1287		vput(coveredvp);
1288	}
1289	vfs_event_signal(NULL, VQ_UNMOUNT, 0);
1290	lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td);
1291	vfs_mount_destroy(mp);
1292	return (0);
1293}
1294
1295/*
1296 * ---------------------------------------------------------------------
1297 * Mounting of root filesystem
1298 *
1299 */
1300
1301struct root_hold_token {
1302	const char 			*who;
1303	LIST_ENTRY(root_hold_token)	list;
1304};
1305
1306static LIST_HEAD(, root_hold_token)	root_holds =
1307    LIST_HEAD_INITIALIZER(&root_holds);
1308
1309struct root_hold_token *
1310root_mount_hold(const char *identifier)
1311{
1312	struct root_hold_token *h;
1313
1314	h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
1315	h->who = identifier;
1316	mtx_lock(&mountlist_mtx);
1317	LIST_INSERT_HEAD(&root_holds, h, list);
1318	mtx_unlock(&mountlist_mtx);
1319	return (h);
1320}
1321
1322void
1323root_mount_rel(struct root_hold_token *h)
1324{
1325
1326	mtx_lock(&mountlist_mtx);
1327	LIST_REMOVE(h, list);
1328	wakeup(&root_holds);
1329	mtx_unlock(&mountlist_mtx);
1330	free(h, M_DEVBUF);
1331}
1332
1333static void
1334root_mount_wait(void)
1335{
1336	struct root_hold_token *h;
1337
1338	for (;;) {
1339		DROP_GIANT();
1340		g_waitidle();
1341		PICKUP_GIANT();
1342		mtx_lock(&mountlist_mtx);
1343		if (LIST_EMPTY(&root_holds)) {
1344			mtx_unlock(&mountlist_mtx);
1345			break;
1346		}
1347		printf("Root mount waiting for:");
1348		LIST_FOREACH(h, &root_holds, list)
1349			printf(" %s", h->who);
1350		printf("\n");
1351		msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold",
1352		    hz);
1353	}
1354}
1355
1356static void
1357set_rootvnode(struct thread *td)
1358{
1359	struct proc *p;
1360
1361	if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode, td))
1362		panic("Cannot find root vnode");
1363
1364	p = td->td_proc;
1365	FILEDESC_LOCK(p->p_fd);
1366
1367	if (p->p_fd->fd_cdir != NULL)
1368		vrele(p->p_fd->fd_cdir);
1369	p->p_fd->fd_cdir = rootvnode;
1370	VREF(rootvnode);
1371
1372	if (p->p_fd->fd_rdir != NULL)
1373		vrele(p->p_fd->fd_rdir);
1374	p->p_fd->fd_rdir = rootvnode;
1375	VREF(rootvnode);
1376
1377	FILEDESC_UNLOCK(p->p_fd);
1378
1379	VOP_UNLOCK(rootvnode, 0, td);
1380}
1381
1382/*
1383 * Mount /devfs as our root filesystem, but do not put it on the mountlist
1384 * yet.  Create a /dev -> / symlink so that absolute pathnames will lookup.
1385 */
1386
1387static void
1388devfs_first(void)
1389{
1390	struct thread *td = curthread;
1391	struct vfsoptlist *opts;
1392	struct vfsconf *vfsp;
1393	struct mount *mp = NULL;
1394	int error;
1395
1396	vfsp = vfs_byname("devfs");
1397	KASSERT(vfsp != NULL, ("Could not find devfs by name"));
1398	if (vfsp == NULL)
1399		return;
1400
1401	mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td);
1402
1403	error = VFS_MOUNT(mp, td);
1404	KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
1405	if (error)
1406		return;
1407
1408	opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
1409	TAILQ_INIT(opts);
1410	mp->mnt_opt = opts;
1411
1412	mtx_lock(&mountlist_mtx);
1413	TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
1414	mtx_unlock(&mountlist_mtx);
1415
1416	set_rootvnode(td);
1417
1418	error = kern_symlink(td, "/", "dev", UIO_SYSSPACE);
1419	if (error)
1420		printf("kern_symlink /dev -> / returns %d\n", error);
1421}
1422
1423/*
1424 * Surgically move our devfs to be mounted on /dev.
1425 */
1426
1427static void
1428devfs_fixup(struct thread *td)
1429{
1430	struct nameidata nd;
1431	int error;
1432	struct vnode *vp, *dvp;
1433	struct mount *mp;
1434
1435	/* Remove our devfs mount from the mountlist and purge the cache */
1436	mtx_lock(&mountlist_mtx);
1437	mp = TAILQ_FIRST(&mountlist);
1438	TAILQ_REMOVE(&mountlist, mp, mnt_list);
1439	mtx_unlock(&mountlist_mtx);
1440	cache_purgevfs(mp);
1441
1442	VFS_ROOT(mp, LK_EXCLUSIVE, &dvp, td);
1443	VI_LOCK(dvp);
1444	dvp->v_iflag &= ~VI_MOUNT;
1445	dvp->v_mountedhere = NULL;
1446	VI_UNLOCK(dvp);
1447
1448	/* Set up the real rootvnode, and purge the cache */
1449	TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL;
1450	set_rootvnode(td);
1451	cache_purgevfs(rootvnode->v_mount);
1452
1453	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
1454	error = namei(&nd);
1455	if (error) {
1456		printf("Lookup of /dev for devfs, error: %d\n", error);
1457		return;
1458	}
1459	NDFREE(&nd, NDF_ONLY_PNBUF);
1460	vp = nd.ni_vp;
1461	if (vp->v_type != VDIR) {
1462		vput(vp);
1463	}
1464	error = vinvalbuf(vp, V_SAVE, td, 0, 0);
1465	if (error) {
1466		vput(vp);
1467	}
1468	cache_purge(vp);
1469	mp->mnt_vnodecovered = vp;
1470	vp->v_mountedhere = mp;
1471	mtx_lock(&mountlist_mtx);
1472	TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
1473	mtx_unlock(&mountlist_mtx);
1474	VOP_UNLOCK(vp, 0, td);
1475	vput(dvp);
1476	vfs_unbusy(mp, td);
1477
1478	/* Unlink the no longer needed /dev/dev -> / symlink */
1479	kern_unlink(td, "/dev/dev", UIO_SYSSPACE);
1480}
1481
1482/*
1483 * Report errors during filesystem mounting.
1484 */
1485void
1486vfs_mount_error(struct mount *mp, const char *fmt, ...)
1487{
1488	struct vfsoptlist *moptlist = mp->mnt_optnew;
1489	va_list ap;
1490	int error, len;
1491	char *errmsg;
1492
1493	error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len);
1494	if (error || errmsg == NULL || len <= 0)
1495		return;
1496
1497	va_start(ap, fmt);
1498	vsnprintf(errmsg, (size_t)len, fmt, ap);
1499	va_end(ap);
1500}
1501
1502/*
1503 * Find and mount the root filesystem
1504 */
1505void
1506vfs_mountroot(void)
1507{
1508	char *cp;
1509	int error, i, asked = 0;
1510
1511	root_mount_wait();
1512
1513	mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount),
1514	    NULL, NULL, mount_init, mount_fini,
1515	    UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
1516	devfs_first();
1517
1518	/*
1519	 * We are booted with instructions to prompt for the root filesystem.
1520	 */
1521	if (boothowto & RB_ASKNAME) {
1522		if (!vfs_mountroot_ask())
1523			return;
1524		asked = 1;
1525	}
1526
1527	/*
1528	 * The root filesystem information is compiled in, and we are
1529	 * booted with instructions to use it.
1530	 */
1531	if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) {
1532		if (!vfs_mountroot_try(ctrootdevname))
1533			return;
1534		ctrootdevname = NULL;
1535	}
1536
1537	/*
1538	 * We've been given the generic "use CDROM as root" flag.  This is
1539	 * necessary because one media may be used in many different
1540	 * devices, so we need to search for them.
1541	 */
1542	if (boothowto & RB_CDROM) {
1543		for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
1544			if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
1545				return;
1546		}
1547	}
1548
1549	/*
1550	 * Try to use the value read by the loader from /etc/fstab, or
1551	 * supplied via some other means.  This is the preferred
1552	 * mechanism.
1553	 */
1554	cp = getenv("vfs.root.mountfrom");
1555	if (cp != NULL) {
1556		error = vfs_mountroot_try(cp);
1557		freeenv(cp);
1558		if (!error)
1559			return;
1560	}
1561
1562	/*
1563	 * Try values that may have been computed by code during boot
1564	 */
1565	if (!vfs_mountroot_try(rootdevnames[0]))
1566		return;
1567	if (!vfs_mountroot_try(rootdevnames[1]))
1568		return;
1569
1570	/*
1571	 * If we (still) have a compiled-in default, try it.
1572	 */
1573	if (ctrootdevname != NULL)
1574		if (!vfs_mountroot_try(ctrootdevname))
1575			return;
1576	/*
1577	 * Everything so far has failed, prompt on the console if we haven't
1578	 * already tried that.
1579	 */
1580	if (!asked)
1581		if (!vfs_mountroot_ask())
1582			return;
1583
1584	panic("Root mount failed, startup aborted.");
1585}
1586
1587/*
1588 * Mount (mountfrom) as the root filesystem.
1589 */
1590static int
1591vfs_mountroot_try(const char *mountfrom)
1592{
1593	struct mount	*mp;
1594	char		*vfsname, *path;
1595	time_t		timebase;
1596	int		error;
1597	char		patt[32];
1598
1599	vfsname = NULL;
1600	path    = NULL;
1601	mp      = NULL;
1602	error   = EINVAL;
1603
1604	if (mountfrom == NULL)
1605		return (error);		/* don't complain */
1606	printf("Trying to mount root from %s\n", mountfrom);
1607
1608	/* parse vfs name and path */
1609	vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
1610	path = malloc(MNAMELEN, M_MOUNT, M_WAITOK);
1611	vfsname[0] = path[0] = 0;
1612	sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
1613	if (sscanf(mountfrom, patt, vfsname, path) < 1)
1614		goto out;
1615
1616	if (path[0] == '\0')
1617		strcpy(path, ROOTNAME);
1618
1619	error = kernel_vmount(
1620	    MNT_RDONLY | MNT_ROOTFS,
1621	    "fstype", vfsname,
1622	    "fspath", "/",
1623	    "from", path,
1624	    NULL);
1625	if (error == 0) {
1626		/*
1627		 * We mount devfs prior to mounting the / FS, so the first
1628		 * entry will typically be devfs.
1629		 */
1630		mp = TAILQ_FIRST(&mountlist);
1631		KASSERT(mp != NULL, ("%s: mountlist is empty", __func__));
1632
1633		/*
1634		 * Iterate over all currently mounted file systems and use
1635		 * the time stamp found to check and/or initialize the RTC.
1636		 * Typically devfs has no time stamp and the only other FS
1637		 * is the actual / FS.
1638		 * Call inittodr() only once and pass it the largest of the
1639		 * timestamps we encounter.
1640		 */
1641		timebase = 0;
1642		do {
1643			if (mp->mnt_time > timebase)
1644				timebase = mp->mnt_time;
1645			mp = TAILQ_NEXT(mp, mnt_list);
1646		} while (mp != NULL);
1647		inittodr(timebase);
1648
1649		devfs_fixup(curthread);
1650	}
1651out:
1652	free(path, M_MOUNT);
1653	free(vfsname, M_MOUNT);
1654	return (error);
1655}
1656
1657/*
1658 * ---------------------------------------------------------------------
1659 * Interactive root filesystem selection code.
1660 */
1661
1662static int
1663vfs_mountroot_ask(void)
1664{
1665	char name[128];
1666
1667	for(;;) {
1668		printf("\nManual root filesystem specification:\n");
1669		printf("  <fstype>:<device>  Mount <device> using filesystem <fstype>\n");
1670#if defined(__amd64__) || defined(__i386__) || defined(__ia64__)
1671		printf("                       eg. ufs:da0s1a\n");
1672#else
1673		printf("                       eg. ufs:/dev/da0a\n");
1674#endif
1675		printf("  ?                  List valid disk boot devices\n");
1676		printf("  <empty line>       Abort manual input\n");
1677		printf("\nmountroot> ");
1678		gets(name, sizeof(name), 1);
1679		if (name[0] == '\0')
1680			return (1);
1681		if (name[0] == '?') {
1682			printf("\nList of GEOM managed disk devices:\n  ");
1683			g_dev_print();
1684			continue;
1685		}
1686		if (!vfs_mountroot_try(name))
1687			return (0);
1688	}
1689}
1690
1691/*
1692 * ---------------------------------------------------------------------
1693 * Functions for querying mount options/arguments from filesystems.
1694 */
1695
1696/*
1697 * Check that no unknown options are given
1698 */
1699int
1700vfs_filteropt(struct vfsoptlist *opts, const char **legal)
1701{
1702	struct vfsopt *opt;
1703	const char **t, *p;
1704
1705
1706	TAILQ_FOREACH(opt, opts, link) {
1707		p = opt->name;
1708		if (p[0] == 'n' && p[1] == 'o')
1709			p += 2;
1710		for(t = global_opts; *t != NULL; t++)
1711			if (!strcmp(*t, p))
1712				break;
1713		if (*t != NULL)
1714			continue;
1715		for(t = legal; *t != NULL; t++)
1716			if (!strcmp(*t, p))
1717				break;
1718		if (*t != NULL)
1719			continue;
1720		printf("mount option <%s> is unknown\n", p);
1721		return (EINVAL);
1722	}
1723	return (0);
1724}
1725
1726/*
1727 * Get a mount option by its name.
1728 *
1729 * Return 0 if the option was found, ENOENT otherwise.
1730 * If len is non-NULL it will be filled with the length
1731 * of the option. If buf is non-NULL, it will be filled
1732 * with the address of the option.
1733 */
1734int
1735vfs_getopt(opts, name, buf, len)
1736	struct vfsoptlist *opts;
1737	const char *name;
1738	void **buf;
1739	int *len;
1740{
1741	struct vfsopt *opt;
1742
1743	KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
1744
1745	TAILQ_FOREACH(opt, opts, link) {
1746		if (strcmp(name, opt->name) == 0) {
1747			if (len != NULL)
1748				*len = opt->len;
1749			if (buf != NULL)
1750				*buf = opt->value;
1751			return (0);
1752		}
1753	}
1754	return (ENOENT);
1755}
1756
1757static int
1758vfs_getopt_pos(struct vfsoptlist *opts, const char *name)
1759{
1760	struct vfsopt *opt;
1761	int i;
1762
1763	if (opts == NULL)
1764		return (-1);
1765
1766	i = 0;
1767	TAILQ_FOREACH(opt, opts, link) {
1768		if (strcmp(name, opt->name) == 0)
1769			return (i);
1770		++i;
1771	}
1772	return (-1);
1773}
1774
1775char *
1776vfs_getopts(struct vfsoptlist *opts, const char *name, int *error)
1777{
1778	struct vfsopt *opt;
1779
1780	*error = 0;
1781	TAILQ_FOREACH(opt, opts, link) {
1782		if (strcmp(name, opt->name) != 0)
1783			continue;
1784		if (((char *)opt->value)[opt->len - 1] != '\0') {
1785			*error = EINVAL;
1786			return (NULL);
1787		}
1788		return (opt->value);
1789	}
1790	return (NULL);
1791}
1792
1793int
1794vfs_flagopt(struct vfsoptlist *opts, const char *name, u_int *w, u_int val)
1795{
1796	struct vfsopt *opt;
1797
1798	TAILQ_FOREACH(opt, opts, link) {
1799		if (strcmp(name, opt->name) == 0) {
1800			if (w != NULL)
1801				*w |= val;
1802			return (1);
1803		}
1804	}
1805	if (w != NULL)
1806		*w &= ~val;
1807	return (0);
1808}
1809
1810int
1811vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...)
1812{
1813	va_list ap;
1814	struct vfsopt *opt;
1815	int ret;
1816
1817	KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
1818
1819	TAILQ_FOREACH(opt, opts, link) {
1820		if (strcmp(name, opt->name) != 0)
1821			continue;
1822		if (((char *)opt->value)[opt->len - 1] != '\0')
1823			return (0);
1824		va_start(ap, fmt);
1825		ret = vsscanf(opt->value, fmt, ap);
1826		va_end(ap);
1827		return (ret);
1828	}
1829	return (0);
1830}
1831
1832/*
1833 * Find and copy a mount option.
1834 *
1835 * The size of the buffer has to be specified
1836 * in len, if it is not the same length as the
1837 * mount option, EINVAL is returned.
1838 * Returns ENOENT if the option is not found.
1839 */
1840int
1841vfs_copyopt(opts, name, dest, len)
1842	struct vfsoptlist *opts;
1843	const char *name;
1844	void *dest;
1845	int len;
1846{
1847	struct vfsopt *opt;
1848
1849	KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL"));
1850
1851	TAILQ_FOREACH(opt, opts, link) {
1852		if (strcmp(name, opt->name) == 0) {
1853			if (len != opt->len)
1854				return (EINVAL);
1855			bcopy(opt->value, dest, opt->len);
1856			return (0);
1857		}
1858	}
1859	return (ENOENT);
1860}
1861
1862/*
1863 * This is a helper function for filesystems to traverse their
1864 * vnodes.  See MNT_VNODE_FOREACH() in sys/mount.h
1865 */
1866
1867struct vnode *
1868__mnt_vnode_next(struct vnode **mvp, struct mount *mp)
1869{
1870	struct vnode *vp;
1871
1872	mtx_assert(MNT_MTX(mp), MA_OWNED);
1873
1874	KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
1875	vp = TAILQ_NEXT(*mvp, v_nmntvnodes);
1876	while (vp != NULL && vp->v_type == VMARKER)
1877		vp = TAILQ_NEXT(vp, v_nmntvnodes);
1878
1879	/* Check if we are done */
1880	if (vp == NULL) {
1881		__mnt_vnode_markerfree(mvp, mp);
1882		return (NULL);
1883	}
1884	TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
1885	TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
1886	return (vp);
1887}
1888
1889struct vnode *
1890__mnt_vnode_first(struct vnode **mvp, struct mount *mp)
1891{
1892	struct vnode *vp;
1893
1894	mtx_assert(MNT_MTX(mp), MA_OWNED);
1895
1896	vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
1897	while (vp != NULL && vp->v_type == VMARKER)
1898		vp = TAILQ_NEXT(vp, v_nmntvnodes);
1899
1900	/* Check if we are done */
1901	if (vp == NULL) {
1902		*mvp = NULL;
1903		return (NULL);
1904	}
1905	mp->mnt_holdcnt++;
1906	MNT_IUNLOCK(mp);
1907	*mvp = (struct vnode *) malloc(sizeof(struct vnode),
1908				       M_VNODE_MARKER,
1909				       M_WAITOK | M_ZERO);
1910	MNT_ILOCK(mp);
1911	(*mvp)->v_type = VMARKER;
1912
1913	vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
1914	while (vp != NULL && vp->v_type == VMARKER)
1915		vp = TAILQ_NEXT(vp, v_nmntvnodes);
1916
1917	/* Check if we are done */
1918	if (vp == NULL) {
1919		MNT_IUNLOCK(mp);
1920		free(*mvp, M_VNODE_MARKER);
1921		MNT_ILOCK(mp);
1922		*mvp = NULL;
1923		mp->mnt_holdcnt--;
1924		if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0)
1925			wakeup(&mp->mnt_holdcnt);
1926		return (NULL);
1927	}
1928	mp->mnt_markercnt++;
1929	(*mvp)->v_mount = mp;
1930	TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
1931	return (vp);
1932}
1933
1934
1935void
1936__mnt_vnode_markerfree(struct vnode **mvp, struct mount *mp)
1937{
1938
1939	if (*mvp == NULL)
1940		return;
1941
1942	mtx_assert(MNT_MTX(mp), MA_OWNED);
1943
1944	KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
1945	TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
1946	MNT_IUNLOCK(mp);
1947	free(*mvp, M_VNODE_MARKER);
1948	MNT_ILOCK(mp);
1949	*mvp = NULL;
1950
1951	mp->mnt_markercnt--;
1952	mp->mnt_holdcnt--;
1953	if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0)
1954		wakeup(&mp->mnt_holdcnt);
1955}
1956
1957
1958int
1959__vfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
1960{
1961	int error;
1962
1963	error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat, td);
1964	if (sbp != &mp->mnt_stat)
1965		*sbp = mp->mnt_stat;
1966	return (error);
1967}
1968
1969void
1970vfs_mountedfrom(struct mount *mp, const char *from)
1971{
1972
1973	bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname);
1974	strlcpy(mp->mnt_stat.f_mntfromname, from,
1975	    sizeof mp->mnt_stat.f_mntfromname);
1976}
1977
1978/*
1979 * ---------------------------------------------------------------------
1980 * This is the api for building mount args and mounting filesystems from
1981 * inside the kernel.
1982 *
1983 * The API works by accumulation of individual args.  First error is
1984 * latched.
1985 *
1986 * XXX: should be documented in new manpage kernel_mount(9)
1987 */
1988
1989/* A memory allocation which must be freed when we are done */
1990struct mntaarg {
1991	SLIST_ENTRY(mntaarg)	next;
1992};
1993
1994/* The header for the mount arguments */
1995struct mntarg {
1996	struct iovec *v;
1997	int len;
1998	int error;
1999	SLIST_HEAD(, mntaarg)	list;
2000};
2001
2002/*
2003 * Add a boolean argument.
2004 *
2005 * flag is the boolean value.
2006 * name must start with "no".
2007 */
2008struct mntarg *
2009mount_argb(struct mntarg *ma, int flag, const char *name)
2010{
2011
2012	KASSERT(name[0] == 'n' && name[1] == 'o',
2013	    ("mount_argb(...,%s): name must start with 'no'", name));
2014
2015	return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0));
2016}
2017
2018/*
2019 * Add an argument printf style
2020 */
2021struct mntarg *
2022mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...)
2023{
2024	va_list ap;
2025	struct mntaarg *maa;
2026	struct sbuf *sb;
2027	int len;
2028
2029	if (ma == NULL) {
2030		ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
2031		SLIST_INIT(&ma->list);
2032	}
2033	if (ma->error)
2034		return (ma);
2035
2036	ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
2037	    M_MOUNT, M_WAITOK);
2038	ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
2039	ma->v[ma->len].iov_len = strlen(name) + 1;
2040	ma->len++;
2041
2042	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
2043	va_start(ap, fmt);
2044	sbuf_vprintf(sb, fmt, ap);
2045	va_end(ap);
2046	sbuf_finish(sb);
2047	len = sbuf_len(sb) + 1;
2048	maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
2049	SLIST_INSERT_HEAD(&ma->list, maa, next);
2050	bcopy(sbuf_data(sb), maa + 1, len);
2051	sbuf_delete(sb);
2052
2053	ma->v[ma->len].iov_base = maa + 1;
2054	ma->v[ma->len].iov_len = len;
2055	ma->len++;
2056
2057	return (ma);
2058}
2059
2060/*
2061 * Add an argument which is a userland string.
2062 */
2063struct mntarg *
2064mount_argsu(struct mntarg *ma, const char *name, const void *val, int len)
2065{
2066	struct mntaarg *maa;
2067	char *tbuf;
2068
2069	if (val == NULL)
2070		return (ma);
2071	if (ma == NULL) {
2072		ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
2073		SLIST_INIT(&ma->list);
2074	}
2075	if (ma->error)
2076		return (ma);
2077	maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
2078	SLIST_INSERT_HEAD(&ma->list, maa, next);
2079	tbuf = (void *)(maa + 1);
2080	ma->error = copyinstr(val, tbuf, len, NULL);
2081	return (mount_arg(ma, name, tbuf, -1));
2082}
2083
2084/*
2085 * Plain argument.
2086 *
2087 * If length is -1, use printf.
2088 */
2089struct mntarg *
2090mount_arg(struct mntarg *ma, const char *name, const void *val, int len)
2091{
2092
2093	if (ma == NULL) {
2094		ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
2095		SLIST_INIT(&ma->list);
2096	}
2097	if (ma->error)
2098		return (ma);
2099
2100	ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
2101	    M_MOUNT, M_WAITOK);
2102	ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
2103	ma->v[ma->len].iov_len = strlen(name) + 1;
2104	ma->len++;
2105
2106	ma->v[ma->len].iov_base = (void *)(uintptr_t)val;
2107	if (len < 0)
2108		ma->v[ma->len].iov_len = strlen(val) + 1;
2109	else
2110		ma->v[ma->len].iov_len = len;
2111	ma->len++;
2112	return (ma);
2113}
2114
2115/*
2116 * Free a mntarg structure
2117 */
2118static void
2119free_mntarg(struct mntarg *ma)
2120{
2121	struct mntaarg *maa;
2122
2123	while (!SLIST_EMPTY(&ma->list)) {
2124		maa = SLIST_FIRST(&ma->list);
2125		SLIST_REMOVE_HEAD(&ma->list, next);
2126		free(maa, M_MOUNT);
2127	}
2128	free(ma->v, M_MOUNT);
2129	free(ma, M_MOUNT);
2130}
2131
2132/*
2133 * Mount a filesystem
2134 */
2135int
2136kernel_mount(struct mntarg *ma, int flags)
2137{
2138	struct uio auio;
2139	int error;
2140
2141	KASSERT(ma != NULL, ("kernel_mount NULL ma"));
2142	KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v"));
2143	KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len));
2144
2145	auio.uio_iov = ma->v;
2146	auio.uio_iovcnt = ma->len;
2147	auio.uio_segflg = UIO_SYSSPACE;
2148
2149	error = ma->error;
2150	if (!error)
2151		error = vfs_donmount(curthread, flags, &auio);
2152	free_mntarg(ma);
2153	return (error);
2154}
2155
2156/*
2157 * A printflike function to mount a filesystem.
2158 */
2159int
2160kernel_vmount(int flags, ...)
2161{
2162	struct mntarg *ma = NULL;
2163	va_list ap;
2164	const char *cp;
2165	const void *vp;
2166	int error;
2167
2168	va_start(ap, flags);
2169	for (;;) {
2170		cp = va_arg(ap, const char *);
2171		if (cp == NULL)
2172			break;
2173		vp = va_arg(ap, const void *);
2174		ma = mount_arg(ma, cp, vp, -1);
2175	}
2176	va_end(ap);
2177
2178	error = kernel_mount(ma, flags);
2179	return (error);
2180}
2181