vfs_mountroot.c revision 228634 
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 228634 2011-12-17 15:26:34Z avg $");
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;
122
123struct root_hold_token *
124root_mount_hold(const char *identifier)
125{
126	struct root_hold_token *h;
127
128	if (root_mounted())
129		return (NULL);
130
131	h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
132	h->who = identifier;
133	mtx_lock(&mountlist_mtx);
134	LIST_INSERT_HEAD(&root_holds, h, list);
135	mtx_unlock(&mountlist_mtx);
136	return (h);
137}
138
139void
140root_mount_rel(struct root_hold_token *h)
141{
142
143	if (h == NULL)
144		return;
145	mtx_lock(&mountlist_mtx);
146	LIST_REMOVE(h, list);
147	wakeup(&root_holds);
148	mtx_unlock(&mountlist_mtx);
149	free(h, M_DEVBUF);
150}
151
152int
153root_mounted(void)
154{
155
156	/* No mutex is acquired here because int stores are atomic. */
157	return (root_mount_complete);
158}
159
160void
161root_mount_wait(void)
162{
163
164	/*
165	 * Panic on an obvious deadlock - the function can't be called from
166	 * a thread which is doing the whole SYSINIT stuff.
167	 */
168	KASSERT(curthread->td_proc->p_pid != 0,
169	    ("root_mount_wait: cannot be called from the swapper thread"));
170	mtx_lock(&mountlist_mtx);
171	while (!root_mount_complete) {
172		msleep(&root_mount_complete, &mountlist_mtx, PZERO, "rootwait",
173		    hz);
174	}
175	mtx_unlock(&mountlist_mtx);
176}
177
178static void
179set_rootvnode(void)
180{
181	struct proc *p;
182
183	if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
184		panic("Cannot find root vnode");
185
186	VOP_UNLOCK(rootvnode, 0);
187
188	p = curthread->td_proc;
189	FILEDESC_XLOCK(p->p_fd);
190
191	if (p->p_fd->fd_cdir != NULL)
192		vrele(p->p_fd->fd_cdir);
193	p->p_fd->fd_cdir = rootvnode;
194	VREF(rootvnode);
195
196	if (p->p_fd->fd_rdir != NULL)
197		vrele(p->p_fd->fd_rdir);
198	p->p_fd->fd_rdir = rootvnode;
199	VREF(rootvnode);
200
201	FILEDESC_XUNLOCK(p->p_fd);
202
203	EVENTHANDLER_INVOKE(mountroot);
204}
205
206static int
207vfs_mountroot_devfs(struct thread *td, struct mount **mpp)
208{
209	struct vfsoptlist *opts;
210	struct vfsconf *vfsp;
211	struct mount *mp;
212	int error;
213
214	*mpp = NULL;
215
216	vfsp = vfs_byname("devfs");
217	KASSERT(vfsp != NULL, ("Could not find devfs by name"));
218	if (vfsp == NULL)
219		return (ENOENT);
220
221	mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
222
223	error = VFS_MOUNT(mp);
224	KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
225	if (error)
226		return (error);
227
228	opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
229	TAILQ_INIT(opts);
230	mp->mnt_opt = opts;
231
232	mtx_lock(&mountlist_mtx);
233	TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
234	mtx_unlock(&mountlist_mtx);
235
236	*mpp = mp;
237	set_rootvnode();
238
239	error = kern_symlink(td, "/", "dev", UIO_SYSSPACE);
240	if (error)
241		printf("kern_symlink /dev -> / returns %d\n", error);
242
243	return (error);
244}
245
246static int
247vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs)
248{
249	struct nameidata nd;
250	struct mount *mporoot, *mpnroot;
251	struct vnode *vp, *vporoot, *vpdevfs;
252	char *fspath;
253	int error;
254
255	mpnroot = TAILQ_NEXT(mpdevfs, mnt_list);
256
257	/* Shuffle the mountlist. */
258	mtx_lock(&mountlist_mtx);
259	mporoot = TAILQ_FIRST(&mountlist);
260	TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list);
261	if (mporoot != mpdevfs) {
262		TAILQ_REMOVE(&mountlist, mpnroot, mnt_list);
263		TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list);
264	}
265	TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list);
266	mtx_unlock(&mountlist_mtx);
267
268	cache_purgevfs(mporoot);
269	if (mporoot != mpdevfs)
270		cache_purgevfs(mpdevfs);
271
272	VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot);
273
274	VI_LOCK(vporoot);
275	vporoot->v_iflag &= ~VI_MOUNT;
276	VI_UNLOCK(vporoot);
277	vporoot->v_mountedhere = NULL;
278	mporoot->mnt_flag &= ~MNT_ROOTFS;
279	mporoot->mnt_vnodecovered = NULL;
280	vput(vporoot);
281
282	/* Set up the new rootvnode, and purge the cache */
283	mpnroot->mnt_vnodecovered = NULL;
284	set_rootvnode();
285	cache_purgevfs(rootvnode->v_mount);
286
287	if (mporoot != mpdevfs) {
288		/* Remount old root under /.mount or /mnt */
289		fspath = "/.mount";
290		NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
291		    fspath, td);
292		error = namei(&nd);
293		if (error) {
294			NDFREE(&nd, NDF_ONLY_PNBUF);
295			fspath = "/mnt";
296			NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
297			    fspath, td);
298			error = namei(&nd);
299		}
300		if (!error) {
301			vp = nd.ni_vp;
302			error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
303			if (!error)
304				error = vinvalbuf(vp, V_SAVE, 0, 0);
305			if (!error) {
306				cache_purge(vp);
307				mporoot->mnt_vnodecovered = vp;
308				vp->v_mountedhere = mporoot;
309				strlcpy(mporoot->mnt_stat.f_mntonname,
310				    fspath, MNAMELEN);
311				VOP_UNLOCK(vp, 0);
312			} else
313				vput(vp);
314		}
315		NDFREE(&nd, NDF_ONLY_PNBUF);
316
317		if (error && bootverbose)
318			printf("mountroot: unable to remount previous root "
319			    "under /.mount or /mnt (error %d).\n", error);
320	}
321
322	/* Remount devfs under /dev */
323	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
324	error = namei(&nd);
325	if (!error) {
326		vp = nd.ni_vp;
327		error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
328		if (!error)
329			error = vinvalbuf(vp, V_SAVE, 0, 0);
330		if (!error) {
331			vpdevfs = mpdevfs->mnt_vnodecovered;
332			if (vpdevfs != NULL) {
333				cache_purge(vpdevfs);
334				vpdevfs->v_mountedhere = NULL;
335				vrele(vpdevfs);
336			}
337			mpdevfs->mnt_vnodecovered = vp;
338			vp->v_mountedhere = mpdevfs;
339			VOP_UNLOCK(vp, 0);
340		} else
341			vput(vp);
342	}
343	if (error && bootverbose)
344		printf("mountroot: unable to remount devfs under /dev "
345		    "(error %d).\n", error);
346	NDFREE(&nd, NDF_ONLY_PNBUF);
347
348	if (mporoot == mpdevfs) {
349		vfs_unbusy(mpdevfs);
350		/* Unlink the no longer needed /dev/dev -> / symlink */
351		error = kern_unlink(td, "/dev/dev", UIO_SYSSPACE);
352		if (error && bootverbose)
353			printf("mountroot: unable to unlink /dev/dev "
354			    "(error %d)\n", error);
355	}
356
357	return (0);
358}
359
360/*
361 * Configuration parser.
362 */
363
364/* Parser character classes. */
365#define	CC_WHITESPACE		-1
366#define	CC_NONWHITESPACE	-2
367
368/* Parse errors. */
369#define	PE_EOF			-1
370#define	PE_EOL			-2
371
372static __inline int
373parse_peek(char **conf)
374{
375
376	return (**conf);
377}
378
379static __inline void
380parse_poke(char **conf, int c)
381{
382
383	**conf = c;
384}
385
386static __inline void
387parse_advance(char **conf)
388{
389
390	(*conf)++;
391}
392
393static __inline int
394parse_isspace(int c)
395{
396
397	return ((c == ' ' || c == '\t' || c == '\n') ? 1 : 0);
398}
399
400static int
401parse_skipto(char **conf, int mc)
402{
403	int c, match;
404
405	while (1) {
406		c = parse_peek(conf);
407		if (c == 0)
408			return (PE_EOF);
409		switch (mc) {
410		case CC_WHITESPACE:
411			match = (c == ' ' || c == '\t' || c == '\n') ? 1 : 0;
412			break;
413		case CC_NONWHITESPACE:
414			if (c == '\n')
415				return (PE_EOL);
416			match = (c != ' ' && c != '\t') ? 1 : 0;
417			break;
418		default:
419			match = (c == mc) ? 1 : 0;
420			break;
421		}
422		if (match)
423			break;
424		parse_advance(conf);
425	}
426	return (0);
427}
428
429static int
430parse_token(char **conf, char **tok)
431{
432	char *p;
433	size_t len;
434	int error;
435
436	*tok = NULL;
437	error = parse_skipto(conf, CC_NONWHITESPACE);
438	if (error)
439		return (error);
440	p = *conf;
441	error = parse_skipto(conf, CC_WHITESPACE);
442	len = *conf - p;
443	*tok = malloc(len + 1, M_TEMP, M_WAITOK | M_ZERO);
444	bcopy(p, *tok, len);
445	return (0);
446}
447
448static void
449parse_dir_ask_printenv(const char *var)
450{
451	char *val;
452
453	val = getenv(var);
454	if (val != NULL) {
455		printf("  %s=%s\n", var, val);
456		freeenv(val);
457	}
458}
459
460static int
461parse_dir_ask(char **conf)
462{
463	char name[80];
464	char *mnt;
465	int error;
466
467	printf("\nLoader variables:\n");
468	parse_dir_ask_printenv("vfs.root.mountfrom");
469	parse_dir_ask_printenv("vfs.root.mountfrom.options");
470
471	printf("\nManual root filesystem specification:\n");
472	printf("  <fstype>:<device> [options]\n");
473	printf("      Mount <device> using filesystem <fstype>\n");
474	printf("      and with the specified (optional) option list.\n");
475	printf("\n");
476	printf("    eg. ufs:/dev/da0s1a\n");
477	printf("        zfs:tank\n");
478	printf("        cd9660:/dev/acd0 ro\n");
479	printf("          (which is equivalent to: ");
480	printf("mount -t cd9660 -o ro /dev/acd0 /)\n");
481	printf("\n");
482	printf("  ?               List valid disk boot devices\n");
483	printf("  .               Yield 1 second (for background tasks)\n");
484	printf("  <empty line>    Abort manual input\n");
485
486	do {
487		error = EINVAL;
488		printf("\nmountroot> ");
489		cngets(name, sizeof(name), GETS_ECHO);
490		if (name[0] == '\0')
491			break;
492		if (name[0] == '?' && name[1] == '\0') {
493			printf("\nList of GEOM managed disk devices:\n  ");
494			g_dev_print();
495			continue;
496		}
497		if (name[0] == '.' && name[1] == '\0') {
498			pause("rmask", hz);
499			continue;
500		}
501		mnt = name;
502		error = parse_mount(&mnt);
503		if (error == -1)
504			printf("Invalid file system specification.\n");
505	} while (error != 0);
506
507	return (error);
508}
509
510static int
511parse_dir_md(char **conf)
512{
513	struct stat sb;
514	struct thread *td;
515	struct md_ioctl *mdio;
516	char *path, *tok;
517	int error, fd, len;
518
519	td = curthread;
520
521	error = parse_token(conf, &tok);
522	if (error)
523		return (error);
524
525	len = strlen(tok);
526	mdio = malloc(sizeof(*mdio) + len + 1, M_TEMP, M_WAITOK | M_ZERO);
527	path = (void *)(mdio + 1);
528	bcopy(tok, path, len);
529	free(tok, M_TEMP);
530
531	/* Get file status. */
532	error = kern_stat(td, path, UIO_SYSSPACE, &sb);
533	if (error)
534		goto out;
535
536	/* Open /dev/mdctl so that we can attach/detach. */
537	error = kern_open(td, "/dev/" MDCTL_NAME, UIO_SYSSPACE, O_RDWR, 0);
538	if (error)
539		goto out;
540
541	fd = td->td_retval[0];
542	mdio->md_version = MDIOVERSION;
543	mdio->md_type = MD_VNODE;
544
545	if (root_mount_mddev != -1) {
546		mdio->md_unit = root_mount_mddev;
547		DROP_GIANT();
548		error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
549		PICKUP_GIANT();
550		/* Ignore errors. We don't care. */
551		root_mount_mddev = -1;
552	}
553
554	mdio->md_file = (void *)(mdio + 1);
555	mdio->md_options = MD_AUTOUNIT | MD_READONLY;
556	mdio->md_mediasize = sb.st_size;
557	mdio->md_unit = 0;
558	DROP_GIANT();
559	error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio);
560	PICKUP_GIANT();
561	if (error)
562		goto out;
563
564	if (mdio->md_unit > 9) {
565		printf("rootmount: too many md units\n");
566		mdio->md_file = NULL;
567		mdio->md_options = 0;
568		mdio->md_mediasize = 0;
569		DROP_GIANT();
570		error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
571		PICKUP_GIANT();
572		/* Ignore errors. We don't care. */
573		error = ERANGE;
574		goto out;
575	}
576
577	root_mount_mddev = mdio->md_unit;
578	printf(MD_NAME "%u attached to %s\n", root_mount_mddev, mdio->md_file);
579
580	error = kern_close(td, fd);
581
582 out:
583	free(mdio, M_TEMP);
584	return (error);
585}
586
587static int
588parse_dir_onfail(char **conf)
589{
590	char *action;
591	int error;
592
593	error = parse_token(conf, &action);
594	if (error)
595		return (error);
596
597	if (!strcmp(action, "continue"))
598		root_mount_onfail = A_CONTINUE;
599	else if (!strcmp(action, "panic"))
600		root_mount_onfail = A_PANIC;
601	else if (!strcmp(action, "reboot"))
602		root_mount_onfail = A_REBOOT;
603	else if (!strcmp(action, "retry"))
604		root_mount_onfail = A_RETRY;
605	else {
606		printf("rootmount: %s: unknown action\n", action);
607		error = EINVAL;
608	}
609
610	free(action, M_TEMP);
611	return (0);
612}
613
614static int
615parse_dir_timeout(char **conf)
616{
617	char *tok, *endtok;
618	long secs;
619	int error;
620
621	error = parse_token(conf, &tok);
622	if (error)
623		return (error);
624
625	secs = strtol(tok, &endtok, 0);
626	error = (secs < 0 || *endtok != '\0') ? EINVAL : 0;
627	if (!error)
628		root_mount_timeout = secs;
629	free(tok, M_TEMP);
630	return (error);
631}
632
633static int
634parse_directive(char **conf)
635{
636	char *dir;
637	int error;
638
639	error = parse_token(conf, &dir);
640	if (error)
641		return (error);
642
643	if (strcmp(dir, ".ask") == 0)
644		error = parse_dir_ask(conf);
645	else if (strcmp(dir, ".md") == 0)
646		error = parse_dir_md(conf);
647	else if (strcmp(dir, ".onfail") == 0)
648		error = parse_dir_onfail(conf);
649	else if (strcmp(dir, ".timeout") == 0)
650		error = parse_dir_timeout(conf);
651	else {
652		printf("mountroot: invalid directive `%s'\n", dir);
653		/* Ignore the rest of the line. */
654		(void)parse_skipto(conf, '\n');
655		error = EINVAL;
656	}
657	free(dir, M_TEMP);
658	return (error);
659}
660
661static int
662parse_mount_dev_present(const char *dev)
663{
664	struct nameidata nd;
665	int error;
666
667	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, dev, curthread);
668	error = namei(&nd);
669	if (!error)
670		vput(nd.ni_vp);
671	NDFREE(&nd, NDF_ONLY_PNBUF);
672	return (error != 0) ? 0 : 1;
673}
674
675static int
676parse_mount(char **conf)
677{
678	char errmsg[255];
679	struct mntarg *ma;
680	char *dev, *fs, *opts, *tok;
681	int delay, error, timeout;
682
683	error = parse_token(conf, &tok);
684	if (error)
685		return (error);
686	fs = tok;
687	error = parse_skipto(&tok, ':');
688	if (error) {
689		free(fs, M_TEMP);
690		return (error);
691	}
692	parse_poke(&tok, '\0');
693	parse_advance(&tok);
694	dev = tok;
695
696	if (root_mount_mddev != -1) {
697		/* Handle substitution for the md unit number. */
698		tok = strstr(dev, "md#");
699		if (tok != NULL)
700			tok[2] = '0' + root_mount_mddev;
701	}
702
703	/* Parse options. */
704	error = parse_token(conf, &tok);
705	opts = (error == 0) ? tok : NULL;
706
707	printf("Trying to mount root from %s:%s [%s]...\n", fs, dev,
708	    (opts != NULL) ? opts : "");
709
710	bzero(errmsg, sizeof(errmsg));
711
712	if (vfs_byname(fs) == NULL) {
713		strlcpy(errmsg, "unknown file system", sizeof(errmsg));
714		error = ENOENT;
715		goto out;
716	}
717
718	if (strcmp(fs, "zfs") != 0 && dev[0] != '\0' &&
719	    !parse_mount_dev_present(dev)) {
720		printf("mountroot: waiting for device %s ...\n", dev);
721		delay = hz / 10;
722		timeout = root_mount_timeout * hz;
723		do {
724			pause("rmdev", delay);
725			timeout -= delay;
726		} while (timeout > 0 && !parse_mount_dev_present(dev));
727		if (timeout <= 0) {
728			error = ENODEV;
729			goto out;
730		}
731	}
732
733	ma = NULL;
734	ma = mount_arg(ma, "fstype", fs, -1);
735	ma = mount_arg(ma, "fspath", "/", -1);
736	ma = mount_arg(ma, "from", dev, -1);
737	ma = mount_arg(ma, "errmsg", errmsg, sizeof(errmsg));
738	ma = mount_arg(ma, "ro", NULL, 0);
739	ma = parse_mountroot_options(ma, opts);
740	error = kernel_mount(ma, MNT_ROOTFS);
741
742 out:
743	if (error) {
744		printf("Mounting from %s:%s failed with error %d",
745		    fs, dev, error);
746		if (errmsg[0] != '\0')
747			printf(": %s", errmsg);
748		printf(".\n");
749	}
750	free(fs, M_TEMP);
751	if (opts != NULL)
752		free(opts, M_TEMP);
753	/* kernel_mount can return -1 on error. */
754	return ((error < 0) ? EDOOFUS : error);
755}
756
757static int
758vfs_mountroot_parse(struct sbuf *sb, struct mount *mpdevfs)
759{
760	struct mount *mp;
761	char *conf;
762	int error;
763
764	root_mount_mddev = -1;
765
766retry:
767	conf = sbuf_data(sb);
768	mp = TAILQ_NEXT(mpdevfs, mnt_list);
769	error = (mp == NULL) ? 0 : EDOOFUS;
770	root_mount_onfail = A_CONTINUE;
771	while (mp == NULL) {
772		error = parse_skipto(&conf, CC_NONWHITESPACE);
773		if (error == PE_EOL) {
774			parse_advance(&conf);
775			continue;
776		}
777		if (error < 0)
778			break;
779		switch (parse_peek(&conf)) {
780		case '#':
781			error = parse_skipto(&conf, '\n');
782			break;
783		case '.':
784			error = parse_directive(&conf);
785			break;
786		default:
787			error = parse_mount(&conf);
788			break;
789		}
790		if (error < 0)
791			break;
792		/* Ignore any trailing garbage on the line. */
793		if (parse_peek(&conf) != '\n') {
794			printf("mountroot: advancing to next directive...\n");
795			(void)parse_skipto(&conf, '\n');
796		}
797		mp = TAILQ_NEXT(mpdevfs, mnt_list);
798	}
799	if (mp != NULL)
800		return (0);
801
802	/*
803	 * We failed to mount (a new) root.
804	 */
805	switch (root_mount_onfail) {
806	case A_CONTINUE:
807		break;
808	case A_PANIC:
809		panic("mountroot: unable to (re-)mount root.");
810		/* NOTREACHED */
811	case A_RETRY:
812		goto retry;
813	case A_REBOOT:
814		kern_reboot(RB_NOSYNC);
815		/* NOTREACHED */
816	}
817
818	return (error);
819}
820
821static void
822vfs_mountroot_conf0(struct sbuf *sb)
823{
824	char *s, *tok, *mnt, *opt;
825	int error;
826
827	sbuf_printf(sb, ".onfail panic\n");
828	sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
829	if (boothowto & RB_ASKNAME)
830		sbuf_printf(sb, ".ask\n");
831#ifdef ROOTDEVNAME
832	if (boothowto & RB_DFLTROOT)
833		sbuf_printf(sb, "%s\n", ROOTDEVNAME);
834#endif
835	if (boothowto & RB_CDROM) {
836		sbuf_printf(sb, "cd9660:/dev/cd0 ro\n");
837		sbuf_printf(sb, ".timeout 0\n");
838		sbuf_printf(sb, "cd9660:/dev/acd0 ro\n");
839		sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
840	}
841	s = getenv("vfs.root.mountfrom");
842	if (s != NULL) {
843		opt = getenv("vfs.root.mountfrom.options");
844		tok = s;
845		error = parse_token(&tok, &mnt);
846		while (!error) {
847			sbuf_printf(sb, "%s %s\n", mnt,
848			    (opt != NULL) ? opt : "");
849			free(mnt, M_TEMP);
850			error = parse_token(&tok, &mnt);
851		}
852		if (opt != NULL)
853			freeenv(opt);
854		freeenv(s);
855	}
856	if (rootdevnames[0] != NULL)
857		sbuf_printf(sb, "%s\n", rootdevnames[0]);
858	if (rootdevnames[1] != NULL)
859		sbuf_printf(sb, "%s\n", rootdevnames[1]);
860#ifdef ROOTDEVNAME
861	if (!(boothowto & RB_DFLTROOT))
862		sbuf_printf(sb, "%s\n", ROOTDEVNAME);
863#endif
864	if (!(boothowto & RB_ASKNAME))
865		sbuf_printf(sb, ".ask\n");
866}
867
868static int
869vfs_mountroot_readconf(struct thread *td, struct sbuf *sb)
870{
871	static char buf[128];
872	struct nameidata nd;
873	off_t ofs;
874	int error, flags;
875	int len, resid;
876	int vfslocked;
877
878	NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE,
879	    "/.mount.conf", td);
880	flags = FREAD;
881	error = vn_open(&nd, &flags, 0, NULL);
882	if (error)
883		return (error);
884
885	vfslocked = NDHASGIANT(&nd);
886	NDFREE(&nd, NDF_ONLY_PNBUF);
887	ofs = 0;
888	len = sizeof(buf) - 1;
889	while (1) {
890		error = vn_rdwr(UIO_READ, nd.ni_vp, buf, len, ofs,
891		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
892		    NOCRED, &resid, td);
893		if (error)
894			break;
895		if (resid == len)
896			break;
897		buf[len - resid] = 0;
898		sbuf_printf(sb, "%s", buf);
899		ofs += len - resid;
900	}
901
902	VOP_UNLOCK(nd.ni_vp, 0);
903	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
904	VFS_UNLOCK_GIANT(vfslocked);
905	return (error);
906}
907
908static void
909vfs_mountroot_wait(void)
910{
911	struct root_hold_token *h;
912	struct timeval lastfail;
913	int curfail;
914
915	curfail = 0;
916	while (1) {
917		DROP_GIANT();
918		g_waitidle();
919		PICKUP_GIANT();
920		mtx_lock(&mountlist_mtx);
921		if (LIST_EMPTY(&root_holds)) {
922			mtx_unlock(&mountlist_mtx);
923			break;
924		}
925		if (ppsratecheck(&lastfail, &curfail, 1)) {
926			printf("Root mount waiting for:");
927			LIST_FOREACH(h, &root_holds, list)
928				printf(" %s", h->who);
929			printf("\n");
930		}
931		msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold",
932		    hz);
933	}
934}
935
936void
937vfs_mountroot(void)
938{
939	struct mount *mp;
940	struct sbuf *sb;
941	struct thread *td;
942	time_t timebase;
943	int error;
944
945	td = curthread;
946
947	vfs_mountroot_wait();
948
949	sb = sbuf_new_auto();
950	vfs_mountroot_conf0(sb);
951	sbuf_finish(sb);
952
953	error = vfs_mountroot_devfs(td, &mp);
954	while (!error) {
955		error = vfs_mountroot_parse(sb, mp);
956		if (!error) {
957			error = vfs_mountroot_shuffle(td, mp);
958			if (!error) {
959				sbuf_clear(sb);
960				error = vfs_mountroot_readconf(td, sb);
961				sbuf_finish(sb);
962			}
963		}
964	}
965
966	sbuf_delete(sb);
967
968	/*
969	 * Iterate over all currently mounted file systems and use
970	 * the time stamp found to check and/or initialize the RTC.
971	 * Call inittodr() only once and pass it the largest of the
972	 * timestamps we encounter.
973	 */
974	timebase = 0;
975	mtx_lock(&mountlist_mtx);
976	mp = TAILQ_FIRST(&mountlist);
977	while (mp != NULL) {
978		if (mp->mnt_time > timebase)
979			timebase = mp->mnt_time;
980		mp = TAILQ_NEXT(mp, mnt_list);
981	}
982	mtx_unlock(&mountlist_mtx);
983	inittodr(timebase);
984
985	/* Keep prison0's root in sync with the global rootvnode. */
986	mtx_lock(&prison0.pr_mtx);
987	prison0.pr_root = rootvnode;
988	vref(prison0.pr_root);
989	mtx_unlock(&prison0.pr_mtx);
990
991	mtx_lock(&mountlist_mtx);
992	atomic_store_rel_int(&root_mount_complete, 1);
993	wakeup(&root_mount_complete);
994	mtx_unlock(&mountlist_mtx);
995}
996
997static struct mntarg *
998parse_mountroot_options(struct mntarg *ma, const char *options)
999{
1000	char *p;
1001	char *name, *name_arg;
1002	char *val, *val_arg;
1003	char *opts;
1004
1005	if (options == NULL || options[0] == '\0')
1006		return (ma);
1007
1008	p = opts = strdup(options, M_MOUNT);
1009	if (opts == NULL) {
1010		return (ma);
1011	}
1012
1013	while((name = strsep(&p, ",")) != NULL) {
1014		if (name[0] == '\0')
1015			break;
1016
1017		val = strchr(name, '=');
1018		if (val != NULL) {
1019			*val = '\0';
1020			++val;
1021		}
1022		if( strcmp(name, "rw") == 0 ||
1023		    strcmp(name, "noro") == 0) {
1024			/*
1025			 * The first time we mount the root file system,
1026			 * we need to mount 'ro', so We need to ignore
1027			 * 'rw' and 'noro' mount options.
1028			 */
1029			continue;
1030		}
1031		name_arg = strdup(name, M_MOUNT);
1032		val_arg = NULL;
1033		if (val != NULL)
1034			val_arg = strdup(val, M_MOUNT);
1035
1036		ma = mount_arg(ma, name_arg, val_arg,
1037		    (val_arg != NULL ? -1 : 0));
1038	}
1039	free(opts, M_MOUNT);
1040	return (ma);
1041}
1042