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: stable/10/sys/kern/vfs_mountroot.c 331276 2018-03-20 22:57:14Z ian $");
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 succeeds.
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
89 static int parse_mount(char **);
90 static 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 */
96 struct vnode *rootvnode;
97
98 /*
99 * Mount of the system's /dev.
100 */
101 struct mount *rootdevmp;
102
103 char *rootdevnames[2] = {NULL, NULL};
104
105 struct mtx root_holds_mtx;
106 MTX_SYSINIT(root_holds, &root_holds_mtx, "root_holds", MTX_DEF);
107
108 struct root_hold_token {
109 const char *who;
110 LIST_ENTRY(root_hold_token) list;
111 };
112
113 static LIST_HEAD(, root_hold_token) root_holds =
114 LIST_HEAD_INITIALIZER(root_holds);
115
116 enum action {
117 A_CONTINUE,
118 A_PANIC,
119 A_REBOOT,
120 A_RETRY
121 };
122
123 static enum action root_mount_onfail = A_CONTINUE;
124
125 static int root_mount_mddev;
126 static int root_mount_complete;
127
128 /* By default wait up to 3 seconds for devices to appear. */
129 static int root_mount_timeout = 3;
130 TUNABLE_INT("vfs.mountroot.timeout", &root_mount_timeout);
131
132 struct root_hold_token *
root_mount_hold(const char * identifier)133 root_mount_hold(const char *identifier)
134 {
135 struct root_hold_token *h;
136
137 if (root_mounted())
138 return (NULL);
139
140 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
141 h->who = identifier;
142 mtx_lock(&root_holds_mtx);
143 LIST_INSERT_HEAD(&root_holds, h, list);
144 mtx_unlock(&root_holds_mtx);
145 return (h);
146 }
147
148 void
root_mount_rel(struct root_hold_token * h)149 root_mount_rel(struct root_hold_token *h)
150 {
151
152 if (h == NULL)
153 return;
154 mtx_lock(&root_holds_mtx);
155 LIST_REMOVE(h, list);
156 wakeup(&root_holds);
157 mtx_unlock(&root_holds_mtx);
158 free(h, M_DEVBUF);
159 }
160
161 int
root_mounted(void)162 root_mounted(void)
163 {
164
165 /* No mutex is acquired here because int stores are atomic. */
166 return (root_mount_complete);
167 }
168
169 void
root_mount_wait(void)170 root_mount_wait(void)
171 {
172
173 /*
174 * Panic on an obvious deadlock - the function can't be called from
175 * a thread which is doing the whole SYSINIT stuff.
176 */
177 KASSERT(curthread->td_proc->p_pid != 0,
178 ("root_mount_wait: cannot be called from the swapper thread"));
179 mtx_lock(&root_holds_mtx);
180 while (!root_mount_complete) {
181 msleep(&root_mount_complete, &root_holds_mtx, PZERO, "rootwait",
182 hz);
183 }
184 mtx_unlock(&root_holds_mtx);
185 }
186
187 static void
set_rootvnode(void)188 set_rootvnode(void)
189 {
190 struct proc *p;
191
192 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
193 panic("Cannot find root vnode");
194
195 VOP_UNLOCK(rootvnode, 0);
196
197 p = curthread->td_proc;
198 FILEDESC_XLOCK(p->p_fd);
199
200 if (p->p_fd->fd_cdir != NULL)
201 vrele(p->p_fd->fd_cdir);
202 p->p_fd->fd_cdir = rootvnode;
203 VREF(rootvnode);
204
205 if (p->p_fd->fd_rdir != NULL)
206 vrele(p->p_fd->fd_rdir);
207 p->p_fd->fd_rdir = rootvnode;
208 VREF(rootvnode);
209
210 FILEDESC_XUNLOCK(p->p_fd);
211 }
212
213 static int
vfs_mountroot_devfs(struct thread * td,struct mount ** mpp)214 vfs_mountroot_devfs(struct thread *td, struct mount **mpp)
215 {
216 struct vfsoptlist *opts;
217 struct vfsconf *vfsp;
218 struct mount *mp;
219 int error;
220
221 *mpp = NULL;
222
223 if (rootdevmp != NULL) {
224 /*
225 * Already have /dev; this happens during rerooting.
226 */
227 error = vfs_busy(rootdevmp, 0);
228 if (error != 0)
229 return (error);
230 *mpp = rootdevmp;
231 } else {
232 vfsp = vfs_byname("devfs");
233 KASSERT(vfsp != NULL, ("Could not find devfs by name"));
234 if (vfsp == NULL)
235 return (ENOENT);
236
237 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
238
239 error = VFS_MOUNT(mp);
240 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
241 if (error)
242 return (error);
243
244 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
245 TAILQ_INIT(opts);
246 mp->mnt_opt = opts;
247
248 mtx_lock(&mountlist_mtx);
249 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
250 mtx_unlock(&mountlist_mtx);
251
252 *mpp = mp;
253 rootdevmp = mp;
254 }
255
256 set_rootvnode();
257
258 error = kern_symlink(td, "/", "dev", UIO_SYSSPACE);
259 if (error)
260 printf("kern_symlink /dev -> / returns %d\n", error);
261
262 return (error);
263 }
264
265 static void
vfs_mountroot_shuffle(struct thread * td,struct mount * mpdevfs)266 vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs)
267 {
268 struct nameidata nd;
269 struct mount *mporoot, *mpnroot;
270 struct vnode *vp, *vporoot, *vpdevfs;
271 char *fspath;
272 int error;
273
274 mpnroot = TAILQ_NEXT(mpdevfs, mnt_list);
275
276 /* Shuffle the mountlist. */
277 mtx_lock(&mountlist_mtx);
278 mporoot = TAILQ_FIRST(&mountlist);
279 TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list);
280 if (mporoot != mpdevfs) {
281 TAILQ_REMOVE(&mountlist, mpnroot, mnt_list);
282 TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list);
283 }
284 TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list);
285 mtx_unlock(&mountlist_mtx);
286
287 cache_purgevfs(mporoot);
288 if (mporoot != mpdevfs)
289 cache_purgevfs(mpdevfs);
290
291 VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot);
292
293 VI_LOCK(vporoot);
294 vporoot->v_iflag &= ~VI_MOUNT;
295 VI_UNLOCK(vporoot);
296 vporoot->v_mountedhere = NULL;
297 mporoot->mnt_flag &= ~MNT_ROOTFS;
298 mporoot->mnt_vnodecovered = NULL;
299 vput(vporoot);
300
301 /* Set up the new rootvnode, and purge the cache */
302 mpnroot->mnt_vnodecovered = NULL;
303 set_rootvnode();
304 cache_purgevfs(rootvnode->v_mount);
305
306 if (mporoot != mpdevfs) {
307 /* Remount old root under /.mount or /mnt */
308 fspath = "/.mount";
309 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
310 fspath, td);
311 error = namei(&nd);
312 if (error) {
313 NDFREE(&nd, NDF_ONLY_PNBUF);
314 fspath = "/mnt";
315 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
316 fspath, td);
317 error = namei(&nd);
318 }
319 if (!error) {
320 vp = nd.ni_vp;
321 error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
322 if (!error)
323 error = vinvalbuf(vp, V_SAVE, 0, 0);
324 if (!error) {
325 cache_purge(vp);
326 mporoot->mnt_vnodecovered = vp;
327 vp->v_mountedhere = mporoot;
328 strlcpy(mporoot->mnt_stat.f_mntonname,
329 fspath, MNAMELEN);
330 VOP_UNLOCK(vp, 0);
331 } else
332 vput(vp);
333 }
334 NDFREE(&nd, NDF_ONLY_PNBUF);
335
336 if (error && bootverbose)
337 printf("mountroot: unable to remount previous root "
338 "under /.mount or /mnt (error %d).\n", error);
339 }
340
341 /* Remount devfs under /dev */
342 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
343 error = namei(&nd);
344 if (!error) {
345 vp = nd.ni_vp;
346 error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
347 if (!error)
348 error = vinvalbuf(vp, V_SAVE, 0, 0);
349 if (!error) {
350 vpdevfs = mpdevfs->mnt_vnodecovered;
351 if (vpdevfs != NULL) {
352 cache_purge(vpdevfs);
353 vpdevfs->v_mountedhere = NULL;
354 vrele(vpdevfs);
355 }
356 mpdevfs->mnt_vnodecovered = vp;
357 vp->v_mountedhere = mpdevfs;
358 VOP_UNLOCK(vp, 0);
359 } else
360 vput(vp);
361 }
362 if (error && bootverbose)
363 printf("mountroot: unable to remount devfs under /dev "
364 "(error %d).\n", error);
365 NDFREE(&nd, NDF_ONLY_PNBUF);
366
367 if (mporoot == mpdevfs) {
368 vfs_unbusy(mpdevfs);
369 /* Unlink the no longer needed /dev/dev -> / symlink */
370 error = kern_unlink(td, "/dev/dev", UIO_SYSSPACE);
371 if (error && bootverbose)
372 printf("mountroot: unable to unlink /dev/dev "
373 "(error %d)\n", error);
374 }
375 }
376
377 /*
378 * Configuration parser.
379 */
380
381 /* Parser character classes. */
382 #define CC_WHITESPACE -1
383 #define CC_NONWHITESPACE -2
384
385 /* Parse errors. */
386 #define PE_EOF -1
387 #define PE_EOL -2
388
389 static __inline int
parse_peek(char ** conf)390 parse_peek(char **conf)
391 {
392
393 return (**conf);
394 }
395
396 static __inline void
parse_poke(char ** conf,int c)397 parse_poke(char **conf, int c)
398 {
399
400 **conf = c;
401 }
402
403 static __inline void
parse_advance(char ** conf)404 parse_advance(char **conf)
405 {
406
407 (*conf)++;
408 }
409
410 static int
parse_skipto(char ** conf,int mc)411 parse_skipto(char **conf, int mc)
412 {
413 int c, match;
414
415 while (1) {
416 c = parse_peek(conf);
417 if (c == 0)
418 return (PE_EOF);
419 switch (mc) {
420 case CC_WHITESPACE:
421 match = (c == ' ' || c == '\t' || c == '\n') ? 1 : 0;
422 break;
423 case CC_NONWHITESPACE:
424 if (c == '\n')
425 return (PE_EOL);
426 match = (c != ' ' && c != '\t') ? 1 : 0;
427 break;
428 default:
429 match = (c == mc) ? 1 : 0;
430 break;
431 }
432 if (match)
433 break;
434 parse_advance(conf);
435 }
436 return (0);
437 }
438
439 static int
parse_token(char ** conf,char ** tok)440 parse_token(char **conf, char **tok)
441 {
442 char *p;
443 size_t len;
444 int error;
445
446 *tok = NULL;
447 error = parse_skipto(conf, CC_NONWHITESPACE);
448 if (error)
449 return (error);
450 p = *conf;
451 error = parse_skipto(conf, CC_WHITESPACE);
452 len = *conf - p;
453 *tok = malloc(len + 1, M_TEMP, M_WAITOK | M_ZERO);
454 bcopy(p, *tok, len);
455 return (0);
456 }
457
458 static void
parse_dir_ask_printenv(const char * var)459 parse_dir_ask_printenv(const char *var)
460 {
461 char *val;
462
463 val = getenv(var);
464 if (val != NULL) {
465 printf(" %s=%s\n", var, val);
466 freeenv(val);
467 }
468 }
469
470 static int
parse_dir_ask(char ** conf)471 parse_dir_ask(char **conf)
472 {
473 char name[80];
474 char *mnt;
475 int error;
476
477 printf("\nLoader variables:\n");
478 parse_dir_ask_printenv("vfs.root.mountfrom");
479 parse_dir_ask_printenv("vfs.root.mountfrom.options");
480
481 printf("\nManual root filesystem specification:\n");
482 printf(" <fstype>:<device> [options]\n");
483 printf(" Mount <device> using filesystem <fstype>\n");
484 printf(" and with the specified (optional) option list.\n");
485 printf("\n");
486 printf(" eg. ufs:/dev/da0s1a\n");
487 printf(" zfs:tank\n");
488 printf(" cd9660:/dev/acd0 ro\n");
489 printf(" (which is equivalent to: ");
490 printf("mount -t cd9660 -o ro /dev/acd0 /)\n");
491 printf("\n");
492 printf(" ? List valid disk boot devices\n");
493 printf(" . Yield 1 second (for background tasks)\n");
494 printf(" <empty line> Abort manual input\n");
495
496 do {
497 error = EINVAL;
498 printf("\nmountroot> ");
499 cngets(name, sizeof(name), GETS_ECHO);
500 if (name[0] == '\0')
501 break;
502 if (name[0] == '?' && name[1] == '\0') {
503 printf("\nList of GEOM managed disk devices:\n ");
504 g_dev_print();
505 continue;
506 }
507 if (name[0] == '.' && name[1] == '\0') {
508 pause("rmask", hz);
509 continue;
510 }
511 mnt = name;
512 error = parse_mount(&mnt);
513 if (error == -1)
514 printf("Invalid file system specification.\n");
515 } while (error != 0);
516
517 return (error);
518 }
519
520 static int
parse_dir_md(char ** conf)521 parse_dir_md(char **conf)
522 {
523 struct stat sb;
524 struct thread *td;
525 struct md_ioctl *mdio;
526 char *path, *tok;
527 int error, fd, len;
528
529 td = curthread;
530
531 error = parse_token(conf, &tok);
532 if (error)
533 return (error);
534
535 len = strlen(tok);
536 mdio = malloc(sizeof(*mdio) + len + 1, M_TEMP, M_WAITOK | M_ZERO);
537 path = (void *)(mdio + 1);
538 bcopy(tok, path, len);
539 free(tok, M_TEMP);
540
541 /* Get file status. */
542 error = kern_stat(td, path, UIO_SYSSPACE, &sb);
543 if (error)
544 goto out;
545
546 /* Open /dev/mdctl so that we can attach/detach. */
547 error = kern_open(td, "/dev/" MDCTL_NAME, UIO_SYSSPACE, O_RDWR, 0);
548 if (error)
549 goto out;
550
551 fd = td->td_retval[0];
552 mdio->md_version = MDIOVERSION;
553 mdio->md_type = MD_VNODE;
554
555 if (root_mount_mddev != -1) {
556 mdio->md_unit = root_mount_mddev;
557 DROP_GIANT();
558 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
559 PICKUP_GIANT();
560 /* Ignore errors. We don't care. */
561 root_mount_mddev = -1;
562 }
563
564 mdio->md_file = (void *)(mdio + 1);
565 mdio->md_options = MD_AUTOUNIT | MD_READONLY;
566 mdio->md_mediasize = sb.st_size;
567 mdio->md_unit = 0;
568 DROP_GIANT();
569 error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio);
570 PICKUP_GIANT();
571 if (error)
572 goto out;
573
574 if (mdio->md_unit > 9) {
575 printf("rootmount: too many md units\n");
576 mdio->md_file = NULL;
577 mdio->md_options = 0;
578 mdio->md_mediasize = 0;
579 DROP_GIANT();
580 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
581 PICKUP_GIANT();
582 /* Ignore errors. We don't care. */
583 error = ERANGE;
584 goto out;
585 }
586
587 root_mount_mddev = mdio->md_unit;
588 printf(MD_NAME "%u attached to %s\n", root_mount_mddev, mdio->md_file);
589
590 error = kern_close(td, fd);
591
592 out:
593 free(mdio, M_TEMP);
594 return (error);
595 }
596
597 static int
parse_dir_onfail(char ** conf)598 parse_dir_onfail(char **conf)
599 {
600 char *action;
601 int error;
602
603 error = parse_token(conf, &action);
604 if (error)
605 return (error);
606
607 if (!strcmp(action, "continue"))
608 root_mount_onfail = A_CONTINUE;
609 else if (!strcmp(action, "panic"))
610 root_mount_onfail = A_PANIC;
611 else if (!strcmp(action, "reboot"))
612 root_mount_onfail = A_REBOOT;
613 else if (!strcmp(action, "retry"))
614 root_mount_onfail = A_RETRY;
615 else {
616 printf("rootmount: %s: unknown action\n", action);
617 error = EINVAL;
618 }
619
620 free(action, M_TEMP);
621 return (0);
622 }
623
624 static int
parse_dir_timeout(char ** conf)625 parse_dir_timeout(char **conf)
626 {
627 char *tok, *endtok;
628 long secs;
629 int error;
630
631 error = parse_token(conf, &tok);
632 if (error)
633 return (error);
634
635 secs = strtol(tok, &endtok, 0);
636 error = (secs < 0 || *endtok != '\0') ? EINVAL : 0;
637 if (!error)
638 root_mount_timeout = secs;
639 free(tok, M_TEMP);
640 return (error);
641 }
642
643 static int
parse_directive(char ** conf)644 parse_directive(char **conf)
645 {
646 char *dir;
647 int error;
648
649 error = parse_token(conf, &dir);
650 if (error)
651 return (error);
652
653 if (strcmp(dir, ".ask") == 0)
654 error = parse_dir_ask(conf);
655 else if (strcmp(dir, ".md") == 0)
656 error = parse_dir_md(conf);
657 else if (strcmp(dir, ".onfail") == 0)
658 error = parse_dir_onfail(conf);
659 else if (strcmp(dir, ".timeout") == 0)
660 error = parse_dir_timeout(conf);
661 else {
662 printf("mountroot: invalid directive `%s'\n", dir);
663 /* Ignore the rest of the line. */
664 (void)parse_skipto(conf, '\n');
665 error = EINVAL;
666 }
667 free(dir, M_TEMP);
668 return (error);
669 }
670
671 static int
parse_mount_dev_present(const char * dev)672 parse_mount_dev_present(const char *dev)
673 {
674 struct nameidata nd;
675 int error;
676
677 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, dev, curthread);
678 error = namei(&nd);
679 if (!error)
680 vput(nd.ni_vp);
681 NDFREE(&nd, NDF_ONLY_PNBUF);
682 return (error != 0) ? 0 : 1;
683 }
684
685 #define ERRMSGL 255
686 static int
parse_mount(char ** conf)687 parse_mount(char **conf)
688 {
689 char *errmsg;
690 struct mntarg *ma;
691 char *dev, *fs, *opts, *tok;
692 int delay, error, timeout;
693
694 error = parse_token(conf, &tok);
695 if (error)
696 return (error);
697 fs = tok;
698 error = parse_skipto(&tok, ':');
699 if (error) {
700 free(fs, M_TEMP);
701 return (error);
702 }
703 parse_poke(&tok, '\0');
704 parse_advance(&tok);
705 dev = tok;
706
707 if (root_mount_mddev != -1) {
708 /* Handle substitution for the md unit number. */
709 tok = strstr(dev, "md#");
710 if (tok != NULL)
711 tok[2] = '0' + root_mount_mddev;
712 }
713
714 /* Parse options. */
715 error = parse_token(conf, &tok);
716 opts = (error == 0) ? tok : NULL;
717
718 printf("Trying to mount root from %s:%s [%s]...\n", fs, dev,
719 (opts != NULL) ? opts : "");
720
721 errmsg = malloc(ERRMSGL, M_TEMP, M_WAITOK | M_ZERO);
722
723 if (vfs_byname(fs) == NULL) {
724 strlcpy(errmsg, "unknown file system", ERRMSGL);
725 error = ENOENT;
726 goto out;
727 }
728
729 if (strcmp(fs, "zfs") != 0 && strstr(fs, "nfs") == NULL &&
730 dev[0] != '\0' && !parse_mount_dev_present(dev)) {
731 printf("mountroot: waiting for device %s ...\n", dev);
732 delay = hz / 10;
733 timeout = root_mount_timeout * hz;
734 do {
735 pause("rmdev", delay);
736 timeout -= delay;
737 } while (timeout > 0 && !parse_mount_dev_present(dev));
738 if (timeout <= 0) {
739 error = ENODEV;
740 goto out;
741 }
742 }
743
744 delay = hz / 10;
745 timeout = root_mount_timeout * hz;
746
747 for (;;) {
748 ma = NULL;
749 ma = mount_arg(ma, "fstype", fs, -1);
750 ma = mount_arg(ma, "fspath", "/", -1);
751 ma = mount_arg(ma, "from", dev, -1);
752 ma = mount_arg(ma, "errmsg", errmsg, ERRMSGL);
753 ma = mount_arg(ma, "ro", NULL, 0);
754 ma = parse_mountroot_options(ma, opts);
755
756 error = kernel_mount(ma, MNT_ROOTFS);
757 if (error == 0 || timeout <= 0)
758 break;
759
760 if (root_mount_timeout * hz == timeout ||
761 (bootverbose && timeout % hz == 0)) {
762 printf("Mounting from %s:%s failed with error %d; "
763 "retrying for %d more second%s\n", fs, dev, error,
764 timeout / hz, (timeout / hz > 1) ? "s" : "");
765 }
766 pause("rmretry", delay);
767 timeout -= delay;
768 }
769 out:
770 if (error) {
771 printf("Mounting from %s:%s failed with error %d",
772 fs, dev, error);
773 if (errmsg[0] != '\0')
774 printf(": %s", errmsg);
775 printf(".\n");
776 }
777 free(fs, M_TEMP);
778 free(errmsg, M_TEMP);
779 if (opts != NULL)
780 free(opts, M_TEMP);
781 /* kernel_mount can return -1 on error. */
782 return ((error < 0) ? EDOOFUS : error);
783 }
784 #undef ERRMSGL
785
786 static int
vfs_mountroot_parse(struct sbuf * sb,struct mount * mpdevfs)787 vfs_mountroot_parse(struct sbuf *sb, struct mount *mpdevfs)
788 {
789 struct mount *mp;
790 char *conf;
791 int error;
792
793 root_mount_mddev = -1;
794
795 retry:
796 conf = sbuf_data(sb);
797 mp = TAILQ_NEXT(mpdevfs, mnt_list);
798 error = (mp == NULL) ? 0 : EDOOFUS;
799 root_mount_onfail = A_CONTINUE;
800 while (mp == NULL) {
801 error = parse_skipto(&conf, CC_NONWHITESPACE);
802 if (error == PE_EOL) {
803 parse_advance(&conf);
804 continue;
805 }
806 if (error < 0)
807 break;
808 switch (parse_peek(&conf)) {
809 case '#':
810 error = parse_skipto(&conf, '\n');
811 break;
812 case '.':
813 error = parse_directive(&conf);
814 break;
815 default:
816 error = parse_mount(&conf);
817 break;
818 }
819 if (error < 0)
820 break;
821 /* Ignore any trailing garbage on the line. */
822 if (parse_peek(&conf) != '\n') {
823 printf("mountroot: advancing to next directive...\n");
824 (void)parse_skipto(&conf, '\n');
825 }
826 mp = TAILQ_NEXT(mpdevfs, mnt_list);
827 }
828 if (mp != NULL)
829 return (0);
830
831 /*
832 * We failed to mount (a new) root.
833 */
834 switch (root_mount_onfail) {
835 case A_CONTINUE:
836 break;
837 case A_PANIC:
838 panic("mountroot: unable to (re-)mount root.");
839 /* NOTREACHED */
840 case A_RETRY:
841 goto retry;
842 case A_REBOOT:
843 kern_reboot(RB_NOSYNC);
844 /* NOTREACHED */
845 }
846
847 return (error);
848 }
849
850 static void
vfs_mountroot_conf0(struct sbuf * sb)851 vfs_mountroot_conf0(struct sbuf *sb)
852 {
853 char *s, *tok, *mnt, *opt;
854 int error;
855
856 sbuf_printf(sb, ".onfail panic\n");
857 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
858 if (boothowto & RB_ASKNAME)
859 sbuf_printf(sb, ".ask\n");
860 #ifdef ROOTDEVNAME
861 if (boothowto & RB_DFLTROOT)
862 sbuf_printf(sb, "%s\n", ROOTDEVNAME);
863 #endif
864 if (boothowto & RB_CDROM) {
865 sbuf_printf(sb, "cd9660:/dev/cd0 ro\n");
866 sbuf_printf(sb, ".timeout 0\n");
867 sbuf_printf(sb, "cd9660:/dev/acd0 ro\n");
868 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
869 }
870 s = getenv("vfs.root.mountfrom");
871 if (s != NULL) {
872 opt = getenv("vfs.root.mountfrom.options");
873 tok = s;
874 error = parse_token(&tok, &mnt);
875 while (!error) {
876 sbuf_printf(sb, "%s %s\n", mnt,
877 (opt != NULL) ? opt : "");
878 free(mnt, M_TEMP);
879 error = parse_token(&tok, &mnt);
880 }
881 if (opt != NULL)
882 freeenv(opt);
883 freeenv(s);
884 }
885 if (rootdevnames[0] != NULL)
886 sbuf_printf(sb, "%s\n", rootdevnames[0]);
887 if (rootdevnames[1] != NULL)
888 sbuf_printf(sb, "%s\n", rootdevnames[1]);
889 #ifdef ROOTDEVNAME
890 if (!(boothowto & RB_DFLTROOT))
891 sbuf_printf(sb, "%s\n", ROOTDEVNAME);
892 #endif
893 if (!(boothowto & RB_ASKNAME))
894 sbuf_printf(sb, ".ask\n");
895 }
896
897 static int
vfs_mountroot_readconf(struct thread * td,struct sbuf * sb)898 vfs_mountroot_readconf(struct thread *td, struct sbuf *sb)
899 {
900 static char buf[128];
901 struct nameidata nd;
902 off_t ofs;
903 ssize_t resid;
904 int error, flags, len;
905
906 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/.mount.conf", td);
907 flags = FREAD;
908 error = vn_open(&nd, &flags, 0, NULL);
909 if (error)
910 return (error);
911
912 NDFREE(&nd, NDF_ONLY_PNBUF);
913 ofs = 0;
914 len = sizeof(buf) - 1;
915 while (1) {
916 error = vn_rdwr(UIO_READ, nd.ni_vp, buf, len, ofs,
917 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
918 NOCRED, &resid, td);
919 if (error)
920 break;
921 if (resid == len)
922 break;
923 buf[len - resid] = 0;
924 sbuf_printf(sb, "%s", buf);
925 ofs += len - resid;
926 }
927
928 VOP_UNLOCK(nd.ni_vp, 0);
929 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
930 return (error);
931 }
932
933 static void
vfs_mountroot_wait(void)934 vfs_mountroot_wait(void)
935 {
936 struct root_hold_token *h;
937 struct timeval lastfail;
938 int curfail;
939
940 curfail = 0;
941 while (1) {
942 DROP_GIANT();
943 g_waitidle();
944 PICKUP_GIANT();
945 mtx_lock(&root_holds_mtx);
946 if (LIST_EMPTY(&root_holds)) {
947 mtx_unlock(&root_holds_mtx);
948 break;
949 }
950 if (ppsratecheck(&lastfail, &curfail, 1)) {
951 printf("Root mount waiting for:");
952 LIST_FOREACH(h, &root_holds, list)
953 printf(" %s", h->who);
954 printf("\n");
955 }
956 msleep(&root_holds, &root_holds_mtx, PZERO | PDROP, "roothold",
957 hz);
958 }
959 }
960
961 void
vfs_mountroot(void)962 vfs_mountroot(void)
963 {
964 struct mount *mp;
965 struct sbuf *sb;
966 struct thread *td;
967 time_t timebase;
968 int error;
969
970 td = curthread;
971
972 vfs_mountroot_wait();
973
974 sb = sbuf_new_auto();
975 vfs_mountroot_conf0(sb);
976 sbuf_finish(sb);
977
978 error = vfs_mountroot_devfs(td, &mp);
979 while (!error) {
980 error = vfs_mountroot_parse(sb, mp);
981 if (!error) {
982 vfs_mountroot_shuffle(td, mp);
983 sbuf_clear(sb);
984 error = vfs_mountroot_readconf(td, sb);
985 sbuf_finish(sb);
986 }
987 }
988
989 sbuf_delete(sb);
990
991 /*
992 * Iterate over all currently mounted file systems and use
993 * the time stamp found to check and/or initialize the RTC.
994 * Call inittodr() only once and pass it the largest of the
995 * timestamps we encounter.
996 */
997 timebase = 0;
998 mtx_lock(&mountlist_mtx);
999 mp = TAILQ_FIRST(&mountlist);
1000 while (mp != NULL) {
1001 if (mp->mnt_time > timebase)
1002 timebase = mp->mnt_time;
1003 mp = TAILQ_NEXT(mp, mnt_list);
1004 }
1005 mtx_unlock(&mountlist_mtx);
1006 inittodr(timebase);
1007
1008 /* Keep prison0's root in sync with the global rootvnode. */
1009 mtx_lock(&prison0.pr_mtx);
1010 prison0.pr_root = rootvnode;
1011 vref(prison0.pr_root);
1012 mtx_unlock(&prison0.pr_mtx);
1013
1014 mtx_lock(&root_holds_mtx);
1015 atomic_store_rel_int(&root_mount_complete, 1);
1016 wakeup(&root_mount_complete);
1017 mtx_unlock(&root_holds_mtx);
1018
1019 EVENTHANDLER_INVOKE(mountroot);
1020 }
1021
1022 static struct mntarg *
parse_mountroot_options(struct mntarg * ma,const char * options)1023 parse_mountroot_options(struct mntarg *ma, const char *options)
1024 {
1025 char *p;
1026 char *name, *name_arg;
1027 char *val, *val_arg;
1028 char *opts;
1029
1030 if (options == NULL || options[0] == '\0')
1031 return (ma);
1032
1033 p = opts = strdup(options, M_MOUNT);
1034 if (opts == NULL) {
1035 return (ma);
1036 }
1037
1038 while((name = strsep(&p, ",")) != NULL) {
1039 if (name[0] == '\0')
1040 break;
1041
1042 val = strchr(name, '=');
1043 if (val != NULL) {
1044 *val = '\0';
1045 ++val;
1046 }
1047 if( strcmp(name, "rw") == 0 ||
1048 strcmp(name, "noro") == 0) {
1049 /*
1050 * The first time we mount the root file system,
1051 * we need to mount 'ro', so We need to ignore
1052 * 'rw' and 'noro' mount options.
1053 */
1054 continue;
1055 }
1056 name_arg = strdup(name, M_MOUNT);
1057 val_arg = NULL;
1058 if (val != NULL)
1059 val_arg = strdup(val, M_MOUNT);
1060
1061 ma = mount_arg(ma, name_arg, val_arg,
1062 (val_arg != NULL ? -1 : 0));
1063 }
1064 free(opts, M_MOUNT);
1065 return (ma);
1066 }
1067