vfs_mountroot.c revision 259892 
1/*-
2 * Copyright (c) 2010 Marcel Moolenaar
3 * Copyright (c) 1999-2004 Poul-Henning Kamp
4 * Copyright (c) 1999 Michael Smith
5 * Copyright (c) 1989, 1993
6 *      The Regents of the University of California.  All rights reserved.
7 * (c) UNIX System Laboratories, Inc.
8 * All or some portions of this file are derived from material licensed
9 * to the University of California by American Telephone and Telegraph
10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
11 * the permission of UNIX System Laboratories, Inc.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 *    notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 *    notice, this list of conditions and the following disclaimer in the
20 *    documentation and/or other materials provided with the distribution.
21 * 4. Neither the name of the University nor the names of its contributors
22 *    may be used to endorse or promote products derived from this software
23 *    without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 */
37
38#include "opt_rootdevname.h"
39
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD: head/sys/kern/vfs_mountroot.c 259892 2013-12-25 22:14:42Z dim $");
42
43#include <sys/param.h>
44#include <sys/conf.h>
45#include <sys/cons.h>
46#include <sys/fcntl.h>
47#include <sys/jail.h>
48#include <sys/kernel.h>
49#include <sys/malloc.h>
50#include <sys/mdioctl.h>
51#include <sys/mount.h>
52#include <sys/mutex.h>
53#include <sys/namei.h>
54#include <sys/priv.h>
55#include <sys/proc.h>
56#include <sys/filedesc.h>
57#include <sys/reboot.h>
58#include <sys/sbuf.h>
59#include <sys/stat.h>
60#include <sys/syscallsubr.h>
61#include <sys/sysproto.h>
62#include <sys/sx.h>
63#include <sys/sysctl.h>
64#include <sys/sysent.h>
65#include <sys/systm.h>
66#include <sys/vnode.h>
67
68#include <geom/geom.h>
69
70/*
71 * The root filesystem is detailed in the kernel environment variable
72 * vfs.root.mountfrom, which is expected to be in the general format
73 *
74 * <vfsname>:[<path>][	<vfsname>:[<path>] ...]
75 * vfsname   := the name of a VFS known to the kernel and capable
76 *              of being mounted as root
77 * path      := disk device name or other data used by the filesystem
78 *              to locate its physical store
79 *
80 * If the environment variable vfs.root.mountfrom is a space separated list,
81 * each list element is tried in turn and the root filesystem will be mounted
82 * from the first one that suceeds.
83 *
84 * The environment variable vfs.root.mountfrom.options is a comma delimited
85 * set of string mount options.  These mount options must be parseable
86 * by nmount() in the kernel.
87 */
88
89static int parse_mount(char **);
90static struct mntarg *parse_mountroot_options(struct mntarg *, const char *);
91
92/*
93 * The vnode of the system's root (/ in the filesystem, without chroot
94 * active.)
95 */
96struct vnode *rootvnode;
97
98char *rootdevnames[2] = {NULL, NULL};
99
100struct root_hold_token {
101	const char			*who;
102	LIST_ENTRY(root_hold_token)	list;
103};
104
105static LIST_HEAD(, root_hold_token)	root_holds =
106    LIST_HEAD_INITIALIZER(root_holds);
107
108enum action {
109	A_CONTINUE,
110	A_PANIC,
111	A_REBOOT,
112	A_RETRY
113};
114
115static enum action root_mount_onfail = A_CONTINUE;
116
117static int root_mount_mddev;
118static int root_mount_complete;
119
120/* By default wait up to 3 seconds for devices to appear. */
121static int root_mount_timeout = 3;
122TUNABLE_INT("vfs.mountroot.timeout", &root_mount_timeout);
123
124struct root_hold_token *
125root_mount_hold(const char *identifier)
126{
127	struct root_hold_token *h;
128
129	if (root_mounted())
130		return (NULL);
131
132	h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
133	h->who = identifier;
134	mtx_lock(&mountlist_mtx);
135	LIST_INSERT_HEAD(&root_holds, h, list);
136	mtx_unlock(&mountlist_mtx);
137	return (h);
138}
139
140void
141root_mount_rel(struct root_hold_token *h)
142{
143
144	if (h == NULL)
145		return;
146	mtx_lock(&mountlist_mtx);
147	LIST_REMOVE(h, list);
148	wakeup(&root_holds);
149	mtx_unlock(&mountlist_mtx);
150	free(h, M_DEVBUF);
151}
152
153int
154root_mounted(void)
155{
156
157	/* No mutex is acquired here because int stores are atomic. */
158	return (root_mount_complete);
159}
160
161void
162root_mount_wait(void)
163{
164
165	/*
166	 * Panic on an obvious deadlock - the function can't be called from
167	 * a thread which is doing the whole SYSINIT stuff.
168	 */
169	KASSERT(curthread->td_proc->p_pid != 0,
170	    ("root_mount_wait: cannot be called from the swapper thread"));
171	mtx_lock(&mountlist_mtx);
172	while (!root_mount_complete) {
173		msleep(&root_mount_complete, &mountlist_mtx, PZERO, "rootwait",
174		    hz);
175	}
176	mtx_unlock(&mountlist_mtx);
177}
178
179static void
180set_rootvnode(void)
181{
182	struct proc *p;
183
184	if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
185		panic("Cannot find root vnode");
186
187	VOP_UNLOCK(rootvnode, 0);
188
189	p = curthread->td_proc;
190	FILEDESC_XLOCK(p->p_fd);
191
192	if (p->p_fd->fd_cdir != NULL)
193		vrele(p->p_fd->fd_cdir);
194	p->p_fd->fd_cdir = rootvnode;
195	VREF(rootvnode);
196
197	if (p->p_fd->fd_rdir != NULL)
198		vrele(p->p_fd->fd_rdir);
199	p->p_fd->fd_rdir = rootvnode;
200	VREF(rootvnode);
201
202	FILEDESC_XUNLOCK(p->p_fd);
203}
204
205static int
206vfs_mountroot_devfs(struct thread *td, struct mount **mpp)
207{
208	struct vfsoptlist *opts;
209	struct vfsconf *vfsp;
210	struct mount *mp;
211	int error;
212
213	*mpp = NULL;
214
215	vfsp = vfs_byname("devfs");
216	KASSERT(vfsp != NULL, ("Could not find devfs by name"));
217	if (vfsp == NULL)
218		return (ENOENT);
219
220	mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
221
222	error = VFS_MOUNT(mp);
223	KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
224	if (error)
225		return (error);
226
227	opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
228	TAILQ_INIT(opts);
229	mp->mnt_opt = opts;
230
231	mtx_lock(&mountlist_mtx);
232	TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
233	mtx_unlock(&mountlist_mtx);
234
235	*mpp = mp;
236	set_rootvnode();
237
238	error = kern_symlink(td, "/", "dev", UIO_SYSSPACE);
239	if (error)
240		printf("kern_symlink /dev -> / returns %d\n", error);
241
242	return (error);
243}
244
245static int
246vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs)
247{
248	struct nameidata nd;
249	struct mount *mporoot, *mpnroot;
250	struct vnode *vp, *vporoot, *vpdevfs;
251	char *fspath;
252	int error;
253
254	mpnroot = TAILQ_NEXT(mpdevfs, mnt_list);
255
256	/* Shuffle the mountlist. */
257	mtx_lock(&mountlist_mtx);
258	mporoot = TAILQ_FIRST(&mountlist);
259	TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list);
260	if (mporoot != mpdevfs) {
261		TAILQ_REMOVE(&mountlist, mpnroot, mnt_list);
262		TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list);
263	}
264	TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list);
265	mtx_unlock(&mountlist_mtx);
266
267	cache_purgevfs(mporoot);
268	if (mporoot != mpdevfs)
269		cache_purgevfs(mpdevfs);
270
271	VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot);
272
273	VI_LOCK(vporoot);
274	vporoot->v_iflag &= ~VI_MOUNT;
275	VI_UNLOCK(vporoot);
276	vporoot->v_mountedhere = NULL;
277	mporoot->mnt_flag &= ~MNT_ROOTFS;
278	mporoot->mnt_vnodecovered = NULL;
279	vput(vporoot);
280
281	/* Set up the new rootvnode, and purge the cache */
282	mpnroot->mnt_vnodecovered = NULL;
283	set_rootvnode();
284	cache_purgevfs(rootvnode->v_mount);
285
286	if (mporoot != mpdevfs) {
287		/* Remount old root under /.mount or /mnt */
288		fspath = "/.mount";
289		NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
290		    fspath, td);
291		error = namei(&nd);
292		if (error) {
293			NDFREE(&nd, NDF_ONLY_PNBUF);
294			fspath = "/mnt";
295			NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
296			    fspath, td);
297			error = namei(&nd);
298		}
299		if (!error) {
300			vp = nd.ni_vp;
301			error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
302			if (!error)
303				error = vinvalbuf(vp, V_SAVE, 0, 0);
304			if (!error) {
305				cache_purge(vp);
306				mporoot->mnt_vnodecovered = vp;
307				vp->v_mountedhere = mporoot;
308				strlcpy(mporoot->mnt_stat.f_mntonname,
309				    fspath, MNAMELEN);
310				VOP_UNLOCK(vp, 0);
311			} else
312				vput(vp);
313		}
314		NDFREE(&nd, NDF_ONLY_PNBUF);
315
316		if (error && bootverbose)
317			printf("mountroot: unable to remount previous root "
318			    "under /.mount or /mnt (error %d).\n", error);
319	}
320
321	/* Remount devfs under /dev */
322	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
323	error = namei(&nd);
324	if (!error) {
325		vp = nd.ni_vp;
326		error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
327		if (!error)
328			error = vinvalbuf(vp, V_SAVE, 0, 0);
329		if (!error) {
330			vpdevfs = mpdevfs->mnt_vnodecovered;
331			if (vpdevfs != NULL) {
332				cache_purge(vpdevfs);
333				vpdevfs->v_mountedhere = NULL;
334				vrele(vpdevfs);
335			}
336			mpdevfs->mnt_vnodecovered = vp;
337			vp->v_mountedhere = mpdevfs;
338			VOP_UNLOCK(vp, 0);
339		} else
340			vput(vp);
341	}
342	if (error && bootverbose)
343		printf("mountroot: unable to remount devfs under /dev "
344		    "(error %d).\n", error);
345	NDFREE(&nd, NDF_ONLY_PNBUF);
346
347	if (mporoot == mpdevfs) {
348		vfs_unbusy(mpdevfs);
349		/* Unlink the no longer needed /dev/dev -> / symlink */
350		error = kern_unlink(td, "/dev/dev", UIO_SYSSPACE);
351		if (error && bootverbose)
352			printf("mountroot: unable to unlink /dev/dev "
353			    "(error %d)\n", error);
354	}
355
356	return (0);
357}
358
359/*
360 * Configuration parser.
361 */
362
363/* Parser character classes. */
364#define	CC_WHITESPACE		-1
365#define	CC_NONWHITESPACE	-2
366
367/* Parse errors. */
368#define	PE_EOF			-1
369#define	PE_EOL			-2
370
371static __inline int
372parse_peek(char **conf)
373{
374
375	return (**conf);
376}
377
378static __inline void
379parse_poke(char **conf, int c)
380{
381
382	**conf = c;
383}
384
385static __inline void
386parse_advance(char **conf)
387{
388
389	(*conf)++;
390}
391
392static int
393parse_skipto(char **conf, int mc)
394{
395	int c, match;
396
397	while (1) {
398		c = parse_peek(conf);
399		if (c == 0)
400			return (PE_EOF);
401		switch (mc) {
402		case CC_WHITESPACE:
403			match = (c == ' ' || c == '\t' || c == '\n') ? 1 : 0;
404			break;
405		case CC_NONWHITESPACE:
406			if (c == '\n')
407				return (PE_EOL);
408			match = (c != ' ' && c != '\t') ? 1 : 0;
409			break;
410		default:
411			match = (c == mc) ? 1 : 0;
412			break;
413		}
414		if (match)
415			break;
416		parse_advance(conf);
417	}
418	return (0);
419}
420
421static int
422parse_token(char **conf, char **tok)
423{
424	char *p;
425	size_t len;
426	int error;
427
428	*tok = NULL;
429	error = parse_skipto(conf, CC_NONWHITESPACE);
430	if (error)
431		return (error);
432	p = *conf;
433	error = parse_skipto(conf, CC_WHITESPACE);
434	len = *conf - p;
435	*tok = malloc(len + 1, M_TEMP, M_WAITOK | M_ZERO);
436	bcopy(p, *tok, len);
437	return (0);
438}
439
440static void
441parse_dir_ask_printenv(const char *var)
442{
443	char *val;
444
445	val = getenv(var);
446	if (val != NULL) {
447		printf("  %s=%s\n", var, val);
448		freeenv(val);
449	}
450}
451
452static int
453parse_dir_ask(char **conf)
454{
455	char name[80];
456	char *mnt;
457	int error;
458
459	printf("\nLoader variables:\n");
460	parse_dir_ask_printenv("vfs.root.mountfrom");
461	parse_dir_ask_printenv("vfs.root.mountfrom.options");
462
463	printf("\nManual root filesystem specification:\n");
464	printf("  <fstype>:<device> [options]\n");
465	printf("      Mount <device> using filesystem <fstype>\n");
466	printf("      and with the specified (optional) option list.\n");
467	printf("\n");
468	printf("    eg. ufs:/dev/da0s1a\n");
469	printf("        zfs:tank\n");
470	printf("        cd9660:/dev/acd0 ro\n");
471	printf("          (which is equivalent to: ");
472	printf("mount -t cd9660 -o ro /dev/acd0 /)\n");
473	printf("\n");
474	printf("  ?               List valid disk boot devices\n");
475	printf("  .               Yield 1 second (for background tasks)\n");
476	printf("  <empty line>    Abort manual input\n");
477
478	do {
479		error = EINVAL;
480		printf("\nmountroot> ");
481		cngets(name, sizeof(name), GETS_ECHO);
482		if (name[0] == '\0')
483			break;
484		if (name[0] == '?' && name[1] == '\0') {
485			printf("\nList of GEOM managed disk devices:\n  ");
486			g_dev_print();
487			continue;
488		}
489		if (name[0] == '.' && name[1] == '\0') {
490			pause("rmask", hz);
491			continue;
492		}
493		mnt = name;
494		error = parse_mount(&mnt);
495		if (error == -1)
496			printf("Invalid file system specification.\n");
497	} while (error != 0);
498
499	return (error);
500}
501
502static int
503parse_dir_md(char **conf)
504{
505	struct stat sb;
506	struct thread *td;
507	struct md_ioctl *mdio;
508	char *path, *tok;
509	int error, fd, len;
510
511	td = curthread;
512
513	error = parse_token(conf, &tok);
514	if (error)
515		return (error);
516
517	len = strlen(tok);
518	mdio = malloc(sizeof(*mdio) + len + 1, M_TEMP, M_WAITOK | M_ZERO);
519	path = (void *)(mdio + 1);
520	bcopy(tok, path, len);
521	free(tok, M_TEMP);
522
523	/* Get file status. */
524	error = kern_stat(td, path, UIO_SYSSPACE, &sb);
525	if (error)
526		goto out;
527
528	/* Open /dev/mdctl so that we can attach/detach. */
529	error = kern_open(td, "/dev/" MDCTL_NAME, UIO_SYSSPACE, O_RDWR, 0);
530	if (error)
531		goto out;
532
533	fd = td->td_retval[0];
534	mdio->md_version = MDIOVERSION;
535	mdio->md_type = MD_VNODE;
536
537	if (root_mount_mddev != -1) {
538		mdio->md_unit = root_mount_mddev;
539		DROP_GIANT();
540		error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
541		PICKUP_GIANT();
542		/* Ignore errors. We don't care. */
543		root_mount_mddev = -1;
544	}
545
546	mdio->md_file = (void *)(mdio + 1);
547	mdio->md_options = MD_AUTOUNIT | MD_READONLY;
548	mdio->md_mediasize = sb.st_size;
549	mdio->md_unit = 0;
550	DROP_GIANT();
551	error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio);
552	PICKUP_GIANT();
553	if (error)
554		goto out;
555
556	if (mdio->md_unit > 9) {
557		printf("rootmount: too many md units\n");
558		mdio->md_file = NULL;
559		mdio->md_options = 0;
560		mdio->md_mediasize = 0;
561		DROP_GIANT();
562		error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
563		PICKUP_GIANT();
564		/* Ignore errors. We don't care. */
565		error = ERANGE;
566		goto out;
567	}
568
569	root_mount_mddev = mdio->md_unit;
570	printf(MD_NAME "%u attached to %s\n", root_mount_mddev, mdio->md_file);
571
572	error = kern_close(td, fd);
573
574 out:
575	free(mdio, M_TEMP);
576	return (error);
577}
578
579static int
580parse_dir_onfail(char **conf)
581{
582	char *action;
583	int error;
584
585	error = parse_token(conf, &action);
586	if (error)
587		return (error);
588
589	if (!strcmp(action, "continue"))
590		root_mount_onfail = A_CONTINUE;
591	else if (!strcmp(action, "panic"))
592		root_mount_onfail = A_PANIC;
593	else if (!strcmp(action, "reboot"))
594		root_mount_onfail = A_REBOOT;
595	else if (!strcmp(action, "retry"))
596		root_mount_onfail = A_RETRY;
597	else {
598		printf("rootmount: %s: unknown action\n", action);
599		error = EINVAL;
600	}
601
602	free(action, M_TEMP);
603	return (0);
604}
605
606static int
607parse_dir_timeout(char **conf)
608{
609	char *tok, *endtok;
610	long secs;
611	int error;
612
613	error = parse_token(conf, &tok);
614	if (error)
615		return (error);
616
617	secs = strtol(tok, &endtok, 0);
618	error = (secs < 0 || *endtok != '\0') ? EINVAL : 0;
619	if (!error)
620		root_mount_timeout = secs;
621	free(tok, M_TEMP);
622	return (error);
623}
624
625static int
626parse_directive(char **conf)
627{
628	char *dir;
629	int error;
630
631	error = parse_token(conf, &dir);
632	if (error)
633		return (error);
634
635	if (strcmp(dir, ".ask") == 0)
636		error = parse_dir_ask(conf);
637	else if (strcmp(dir, ".md") == 0)
638		error = parse_dir_md(conf);
639	else if (strcmp(dir, ".onfail") == 0)
640		error = parse_dir_onfail(conf);
641	else if (strcmp(dir, ".timeout") == 0)
642		error = parse_dir_timeout(conf);
643	else {
644		printf("mountroot: invalid directive `%s'\n", dir);
645		/* Ignore the rest of the line. */
646		(void)parse_skipto(conf, '\n');
647		error = EINVAL;
648	}
649	free(dir, M_TEMP);
650	return (error);
651}
652
653static int
654parse_mount_dev_present(const char *dev)
655{
656	struct nameidata nd;
657	int error;
658
659	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, dev, curthread);
660	error = namei(&nd);
661	if (!error)
662		vput(nd.ni_vp);
663	NDFREE(&nd, NDF_ONLY_PNBUF);
664	return (error != 0) ? 0 : 1;
665}
666
667#define	ERRMSGL	255
668static int
669parse_mount(char **conf)
670{
671	char *errmsg;
672	struct mntarg *ma;
673	char *dev, *fs, *opts, *tok;
674	int delay, error, timeout;
675
676	error = parse_token(conf, &tok);
677	if (error)
678		return (error);
679	fs = tok;
680	error = parse_skipto(&tok, ':');
681	if (error) {
682		free(fs, M_TEMP);
683		return (error);
684	}
685	parse_poke(&tok, '\0');
686	parse_advance(&tok);
687	dev = tok;
688
689	if (root_mount_mddev != -1) {
690		/* Handle substitution for the md unit number. */
691		tok = strstr(dev, "md#");
692		if (tok != NULL)
693			tok[2] = '0' + root_mount_mddev;
694	}
695
696	/* Parse options. */
697	error = parse_token(conf, &tok);
698	opts = (error == 0) ? tok : NULL;
699
700	printf("Trying to mount root from %s:%s [%s]...\n", fs, dev,
701	    (opts != NULL) ? opts : "");
702
703	errmsg = malloc(ERRMSGL, M_TEMP, M_WAITOK | M_ZERO);
704
705	if (vfs_byname(fs) == NULL) {
706		strlcpy(errmsg, "unknown file system", ERRMSGL);
707		error = ENOENT;
708		goto out;
709	}
710
711	if (strcmp(fs, "zfs") != 0 && strstr(fs, "nfs") == NULL &&
712	    dev[0] != '\0' && !parse_mount_dev_present(dev)) {
713		printf("mountroot: waiting for device %s ...\n", dev);
714		delay = hz / 10;
715		timeout = root_mount_timeout * hz;
716		do {
717			pause("rmdev", delay);
718			timeout -= delay;
719		} while (timeout > 0 && !parse_mount_dev_present(dev));
720		if (timeout <= 0) {
721			error = ENODEV;
722			goto out;
723		}
724	}
725
726	ma = NULL;
727	ma = mount_arg(ma, "fstype", fs, -1);
728	ma = mount_arg(ma, "fspath", "/", -1);
729	ma = mount_arg(ma, "from", dev, -1);
730	ma = mount_arg(ma, "errmsg", errmsg, ERRMSGL);
731	ma = mount_arg(ma, "ro", NULL, 0);
732	ma = parse_mountroot_options(ma, opts);
733	error = kernel_mount(ma, MNT_ROOTFS);
734
735 out:
736	if (error) {
737		printf("Mounting from %s:%s failed with error %d",
738		    fs, dev, error);
739		if (errmsg[0] != '\0')
740			printf(": %s", errmsg);
741		printf(".\n");
742	}
743	free(fs, M_TEMP);
744	free(errmsg, M_TEMP);
745	if (opts != NULL)
746		free(opts, M_TEMP);
747	/* kernel_mount can return -1 on error. */
748	return ((error < 0) ? EDOOFUS : error);
749}
750#undef ERRMSGL
751
752static int
753vfs_mountroot_parse(struct sbuf *sb, struct mount *mpdevfs)
754{
755	struct mount *mp;
756	char *conf;
757	int error;
758
759	root_mount_mddev = -1;
760
761retry:
762	conf = sbuf_data(sb);
763	mp = TAILQ_NEXT(mpdevfs, mnt_list);
764	error = (mp == NULL) ? 0 : EDOOFUS;
765	root_mount_onfail = A_CONTINUE;
766	while (mp == NULL) {
767		error = parse_skipto(&conf, CC_NONWHITESPACE);
768		if (error == PE_EOL) {
769			parse_advance(&conf);
770			continue;
771		}
772		if (error < 0)
773			break;
774		switch (parse_peek(&conf)) {
775		case '#':
776			error = parse_skipto(&conf, '\n');
777			break;
778		case '.':
779			error = parse_directive(&conf);
780			break;
781		default:
782			error = parse_mount(&conf);
783			break;
784		}
785		if (error < 0)
786			break;
787		/* Ignore any trailing garbage on the line. */
788		if (parse_peek(&conf) != '\n') {
789			printf("mountroot: advancing to next directive...\n");
790			(void)parse_skipto(&conf, '\n');
791		}
792		mp = TAILQ_NEXT(mpdevfs, mnt_list);
793	}
794	if (mp != NULL)
795		return (0);
796
797	/*
798	 * We failed to mount (a new) root.
799	 */
800	switch (root_mount_onfail) {
801	case A_CONTINUE:
802		break;
803	case A_PANIC:
804		panic("mountroot: unable to (re-)mount root.");
805		/* NOTREACHED */
806	case A_RETRY:
807		goto retry;
808	case A_REBOOT:
809		kern_reboot(RB_NOSYNC);
810		/* NOTREACHED */
811	}
812
813	return (error);
814}
815
816static void
817vfs_mountroot_conf0(struct sbuf *sb)
818{
819	char *s, *tok, *mnt, *opt;
820	int error;
821
822	sbuf_printf(sb, ".onfail panic\n");
823	sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
824	if (boothowto & RB_ASKNAME)
825		sbuf_printf(sb, ".ask\n");
826#ifdef ROOTDEVNAME
827	if (boothowto & RB_DFLTROOT)
828		sbuf_printf(sb, "%s\n", ROOTDEVNAME);
829#endif
830	if (boothowto & RB_CDROM) {
831		sbuf_printf(sb, "cd9660:/dev/cd0 ro\n");
832		sbuf_printf(sb, ".timeout 0\n");
833		sbuf_printf(sb, "cd9660:/dev/acd0 ro\n");
834		sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
835	}
836	s = getenv("vfs.root.mountfrom");
837	if (s != NULL) {
838		opt = getenv("vfs.root.mountfrom.options");
839		tok = s;
840		error = parse_token(&tok, &mnt);
841		while (!error) {
842			sbuf_printf(sb, "%s %s\n", mnt,
843			    (opt != NULL) ? opt : "");
844			free(mnt, M_TEMP);
845			error = parse_token(&tok, &mnt);
846		}
847		if (opt != NULL)
848			freeenv(opt);
849		freeenv(s);
850	}
851	if (rootdevnames[0] != NULL)
852		sbuf_printf(sb, "%s\n", rootdevnames[0]);
853	if (rootdevnames[1] != NULL)
854		sbuf_printf(sb, "%s\n", rootdevnames[1]);
855#ifdef ROOTDEVNAME
856	if (!(boothowto & RB_DFLTROOT))
857		sbuf_printf(sb, "%s\n", ROOTDEVNAME);
858#endif
859	if (!(boothowto & RB_ASKNAME))
860		sbuf_printf(sb, ".ask\n");
861}
862
863static int
864vfs_mountroot_readconf(struct thread *td, struct sbuf *sb)
865{
866	static char buf[128];
867	struct nameidata nd;
868	off_t ofs;
869	ssize_t resid;
870	int error, flags, len;
871
872	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/.mount.conf", td);
873	flags = FREAD;
874	error = vn_open(&nd, &flags, 0, NULL);
875	if (error)
876		return (error);
877
878	NDFREE(&nd, NDF_ONLY_PNBUF);
879	ofs = 0;
880	len = sizeof(buf) - 1;
881	while (1) {
882		error = vn_rdwr(UIO_READ, nd.ni_vp, buf, len, ofs,
883		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
884		    NOCRED, &resid, td);
885		if (error)
886			break;
887		if (resid == len)
888			break;
889		buf[len - resid] = 0;
890		sbuf_printf(sb, "%s", buf);
891		ofs += len - resid;
892	}
893
894	VOP_UNLOCK(nd.ni_vp, 0);
895	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
896	return (error);
897}
898
899static void
900vfs_mountroot_wait(void)
901{
902	struct root_hold_token *h;
903	struct timeval lastfail;
904	int curfail;
905
906	curfail = 0;
907	while (1) {
908		DROP_GIANT();
909		g_waitidle();
910		PICKUP_GIANT();
911		mtx_lock(&mountlist_mtx);
912		if (LIST_EMPTY(&root_holds)) {
913			mtx_unlock(&mountlist_mtx);
914			break;
915		}
916		if (ppsratecheck(&lastfail, &curfail, 1)) {
917			printf("Root mount waiting for:");
918			LIST_FOREACH(h, &root_holds, list)
919				printf(" %s", h->who);
920			printf("\n");
921		}
922		msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold",
923		    hz);
924	}
925}
926
927void
928vfs_mountroot(void)
929{
930	struct mount *mp;
931	struct sbuf *sb;
932	struct thread *td;
933	time_t timebase;
934	int error;
935
936	td = curthread;
937
938	vfs_mountroot_wait();
939
940	sb = sbuf_new_auto();
941	vfs_mountroot_conf0(sb);
942	sbuf_finish(sb);
943
944	error = vfs_mountroot_devfs(td, &mp);
945	while (!error) {
946		error = vfs_mountroot_parse(sb, mp);
947		if (!error) {
948			error = vfs_mountroot_shuffle(td, mp);
949			if (!error) {
950				sbuf_clear(sb);
951				error = vfs_mountroot_readconf(td, sb);
952				sbuf_finish(sb);
953			}
954		}
955	}
956
957	sbuf_delete(sb);
958
959	/*
960	 * Iterate over all currently mounted file systems and use
961	 * the time stamp found to check and/or initialize the RTC.
962	 * Call inittodr() only once and pass it the largest of the
963	 * timestamps we encounter.
964	 */
965	timebase = 0;
966	mtx_lock(&mountlist_mtx);
967	mp = TAILQ_FIRST(&mountlist);
968	while (mp != NULL) {
969		if (mp->mnt_time > timebase)
970			timebase = mp->mnt_time;
971		mp = TAILQ_NEXT(mp, mnt_list);
972	}
973	mtx_unlock(&mountlist_mtx);
974	inittodr(timebase);
975
976	/* Keep prison0's root in sync with the global rootvnode. */
977	mtx_lock(&prison0.pr_mtx);
978	prison0.pr_root = rootvnode;
979	vref(prison0.pr_root);
980	mtx_unlock(&prison0.pr_mtx);
981
982	mtx_lock(&mountlist_mtx);
983	atomic_store_rel_int(&root_mount_complete, 1);
984	wakeup(&root_mount_complete);
985	mtx_unlock(&mountlist_mtx);
986
987	EVENTHANDLER_INVOKE(mountroot);
988}
989
990static struct mntarg *
991parse_mountroot_options(struct mntarg *ma, const char *options)
992{
993	char *p;
994	char *name, *name_arg;
995	char *val, *val_arg;
996	char *opts;
997
998	if (options == NULL || options[0] == '\0')
999		return (ma);
1000
1001	p = opts = strdup(options, M_MOUNT);
1002	if (opts == NULL) {
1003		return (ma);
1004	}
1005
1006	while((name = strsep(&p, ",")) != NULL) {
1007		if (name[0] == '\0')
1008			break;
1009
1010		val = strchr(name, '=');
1011		if (val != NULL) {
1012			*val = '\0';
1013			++val;
1014		}
1015		if( strcmp(name, "rw") == 0 ||
1016		    strcmp(name, "noro") == 0) {
1017			/*
1018			 * The first time we mount the root file system,
1019			 * we need to mount 'ro', so We need to ignore
1020			 * 'rw' and 'noro' mount options.
1021			 */
1022			continue;
1023		}
1024		name_arg = strdup(name, M_MOUNT);
1025		val_arg = NULL;
1026		if (val != NULL)
1027			val_arg = strdup(val, M_MOUNT);
1028
1029		ma = mount_arg(ma, name_arg, val_arg,
1030		    (val_arg != NULL ? -1 : 0));
1031	}
1032	free(opts, M_MOUNT);
1033	return (ma);
1034}
1035