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: releng/11.1/sys/kern/vfs_mountroot.c 315540 2017-03-19 10:35:56Z trasz $");
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 static int sysctl_vfs_root_mount_hold(SYSCTL_HANDLER_ARGS);
92 static void vfs_mountroot_wait(void);
93 static int vfs_mountroot_wait_if_neccessary(const char *fs, const char *dev);
94
95 /*
96 * The vnode of the system's root (/ in the filesystem, without chroot
97 * active.)
98 */
99 struct vnode *rootvnode;
100
101 /*
102 * Mount of the system's /dev.
103 */
104 struct mount *rootdevmp;
105
106 char *rootdevnames[2] = {NULL, NULL};
107
108 struct mtx root_holds_mtx;
109 MTX_SYSINIT(root_holds, &root_holds_mtx, "root_holds", MTX_DEF);
110
111 struct root_hold_token {
112 const char *who;
113 LIST_ENTRY(root_hold_token) list;
114 };
115
116 static LIST_HEAD(, root_hold_token) root_holds =
117 LIST_HEAD_INITIALIZER(root_holds);
118
119 enum action {
120 A_CONTINUE,
121 A_PANIC,
122 A_REBOOT,
123 A_RETRY
124 };
125
126 static enum action root_mount_onfail = A_CONTINUE;
127
128 static int root_mount_mddev;
129 static int root_mount_complete;
130
131 /* By default wait up to 3 seconds for devices to appear. */
132 static int root_mount_timeout = 3;
133 TUNABLE_INT("vfs.mountroot.timeout", &root_mount_timeout);
134
135 static int root_mount_always_wait = 0;
136 SYSCTL_INT(_vfs, OID_AUTO, root_mount_always_wait, CTLFLAG_RDTUN,
137 &root_mount_always_wait, 0,
138 "Wait for root mount holds even if the root device already exists");
139
140 SYSCTL_PROC(_vfs, OID_AUTO, root_mount_hold,
141 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
142 NULL, 0, sysctl_vfs_root_mount_hold, "A",
143 "List of root mount hold tokens");
144
145 static int
146 sysctl_vfs_root_mount_hold(SYSCTL_HANDLER_ARGS)
147 {
148 struct sbuf sb;
149 struct root_hold_token *h;
150 int error;
151
152 sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL);
153
154 mtx_lock(&root_holds_mtx);
155 LIST_FOREACH(h, &root_holds, list) {
156 if (h != LIST_FIRST(&root_holds))
157 sbuf_putc(&sb, ' ');
158 sbuf_printf(&sb, "%s", h->who);
159 }
160 mtx_unlock(&root_holds_mtx);
161
162 error = sbuf_finish(&sb);
163 if (error == 0)
164 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
165 sbuf_delete(&sb);
166 return (error);
167 }
168
169 struct root_hold_token *
170 root_mount_hold(const char *identifier)
171 {
172 struct root_hold_token *h;
173
174 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
175 h->who = identifier;
176 mtx_lock(&root_holds_mtx);
177 LIST_INSERT_HEAD(&root_holds, h, list);
178 mtx_unlock(&root_holds_mtx);
179 return (h);
180 }
181
182 void
183 root_mount_rel(struct root_hold_token *h)
184 {
185
186 KASSERT(h != NULL, ("%s: NULL token", __func__));
187
188 mtx_lock(&root_holds_mtx);
189 LIST_REMOVE(h, list);
190 wakeup(&root_holds);
191 mtx_unlock(&root_holds_mtx);
192 free(h, M_DEVBUF);
193 }
194
195 int
196 root_mounted(void)
197 {
198
199 /* No mutex is acquired here because int stores are atomic. */
200 return (root_mount_complete);
201 }
202
203 static void
204 set_rootvnode(void)
205 {
206 struct proc *p;
207
208 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
209 panic("Cannot find root vnode");
210
211 VOP_UNLOCK(rootvnode, 0);
212
213 p = curthread->td_proc;
214 FILEDESC_XLOCK(p->p_fd);
215
216 if (p->p_fd->fd_cdir != NULL)
217 vrele(p->p_fd->fd_cdir);
218 p->p_fd->fd_cdir = rootvnode;
219 VREF(rootvnode);
220
221 if (p->p_fd->fd_rdir != NULL)
222 vrele(p->p_fd->fd_rdir);
223 p->p_fd->fd_rdir = rootvnode;
224 VREF(rootvnode);
225
226 FILEDESC_XUNLOCK(p->p_fd);
227 }
228
229 static int
230 vfs_mountroot_devfs(struct thread *td, struct mount **mpp)
231 {
232 struct vfsoptlist *opts;
233 struct vfsconf *vfsp;
234 struct mount *mp;
235 int error;
236
237 *mpp = NULL;
238
239 if (rootdevmp != NULL) {
240 /*
241 * Already have /dev; this happens during rerooting.
242 */
243 error = vfs_busy(rootdevmp, 0);
244 if (error != 0)
245 return (error);
246 *mpp = rootdevmp;
247 } else {
248 vfsp = vfs_byname("devfs");
249 KASSERT(vfsp != NULL, ("Could not find devfs by name"));
250 if (vfsp == NULL)
251 return (ENOENT);
252
253 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
254
255 error = VFS_MOUNT(mp);
256 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
257 if (error)
258 return (error);
259
260 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
261 TAILQ_INIT(opts);
262 mp->mnt_opt = opts;
263
264 mtx_lock(&mountlist_mtx);
265 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
266 mtx_unlock(&mountlist_mtx);
267
268 *mpp = mp;
269 rootdevmp = mp;
270 }
271
272 set_rootvnode();
273
274 error = kern_symlinkat(td, "/", AT_FDCWD, "dev", UIO_SYSSPACE);
275 if (error)
276 printf("kern_symlink /dev -> / returns %d\n", error);
277
278 return (error);
279 }
280
281 static void
282 vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs)
283 {
284 struct nameidata nd;
285 struct mount *mporoot, *mpnroot;
286 struct vnode *vp, *vporoot, *vpdevfs;
287 char *fspath;
288 int error;
289
290 mpnroot = TAILQ_NEXT(mpdevfs, mnt_list);
291
292 /* Shuffle the mountlist. */
293 mtx_lock(&mountlist_mtx);
294 mporoot = TAILQ_FIRST(&mountlist);
295 TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list);
296 if (mporoot != mpdevfs) {
297 TAILQ_REMOVE(&mountlist, mpnroot, mnt_list);
298 TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list);
299 }
300 TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list);
301 mtx_unlock(&mountlist_mtx);
302
303 cache_purgevfs(mporoot, true);
304 if (mporoot != mpdevfs)
305 cache_purgevfs(mpdevfs, true);
306
307 VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot);
308
309 VI_LOCK(vporoot);
310 vporoot->v_iflag &= ~VI_MOUNT;
311 VI_UNLOCK(vporoot);
312 vporoot->v_mountedhere = NULL;
313 mporoot->mnt_flag &= ~MNT_ROOTFS;
314 mporoot->mnt_vnodecovered = NULL;
315 vput(vporoot);
316
317 /* Set up the new rootvnode, and purge the cache */
318 mpnroot->mnt_vnodecovered = NULL;
319 set_rootvnode();
320 cache_purgevfs(rootvnode->v_mount, true);
321
322 if (mporoot != mpdevfs) {
323 /* Remount old root under /.mount or /mnt */
324 fspath = "/.mount";
325 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
326 fspath, td);
327 error = namei(&nd);
328 if (error) {
329 NDFREE(&nd, NDF_ONLY_PNBUF);
330 fspath = "/mnt";
331 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
332 fspath, td);
333 error = namei(&nd);
334 }
335 if (!error) {
336 vp = nd.ni_vp;
337 error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
338 if (!error)
339 error = vinvalbuf(vp, V_SAVE, 0, 0);
340 if (!error) {
341 cache_purge(vp);
342 mporoot->mnt_vnodecovered = vp;
343 vp->v_mountedhere = mporoot;
344 strlcpy(mporoot->mnt_stat.f_mntonname,
345 fspath, MNAMELEN);
346 VOP_UNLOCK(vp, 0);
347 } else
348 vput(vp);
349 }
350 NDFREE(&nd, NDF_ONLY_PNBUF);
351
352 if (error)
353 printf("mountroot: unable to remount previous root "
354 "under /.mount or /mnt (error %d)\n", error);
355 }
356
357 /* Remount devfs under /dev */
358 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
359 error = namei(&nd);
360 if (!error) {
361 vp = nd.ni_vp;
362 error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
363 if (!error)
364 error = vinvalbuf(vp, V_SAVE, 0, 0);
365 if (!error) {
366 vpdevfs = mpdevfs->mnt_vnodecovered;
367 if (vpdevfs != NULL) {
368 cache_purge(vpdevfs);
369 vpdevfs->v_mountedhere = NULL;
370 vrele(vpdevfs);
371 }
372 mpdevfs->mnt_vnodecovered = vp;
373 vp->v_mountedhere = mpdevfs;
374 VOP_UNLOCK(vp, 0);
375 } else
376 vput(vp);
377 }
378 if (error)
379 printf("mountroot: unable to remount devfs under /dev "
380 "(error %d)\n", error);
381 NDFREE(&nd, NDF_ONLY_PNBUF);
382
383 if (mporoot == mpdevfs) {
384 vfs_unbusy(mpdevfs);
385 /* Unlink the no longer needed /dev/dev -> / symlink */
386 error = kern_unlinkat(td, AT_FDCWD, "/dev/dev",
387 UIO_SYSSPACE, 0);
388 if (error)
389 printf("mountroot: unable to unlink /dev/dev "
390 "(error %d)\n", error);
391 }
392 }
393
394 /*
395 * Configuration parser.
396 */
397
398 /* Parser character classes. */
399 #define CC_WHITESPACE -1
400 #define CC_NONWHITESPACE -2
401
402 /* Parse errors. */
403 #define PE_EOF -1
404 #define PE_EOL -2
405
406 static __inline int
407 parse_peek(char **conf)
408 {
409
410 return (**conf);
411 }
412
413 static __inline void
414 parse_poke(char **conf, int c)
415 {
416
417 **conf = c;
418 }
419
420 static __inline void
421 parse_advance(char **conf)
422 {
423
424 (*conf)++;
425 }
426
427 static int
428 parse_skipto(char **conf, int mc)
429 {
430 int c, match;
431
432 while (1) {
433 c = parse_peek(conf);
434 if (c == 0)
435 return (PE_EOF);
436 switch (mc) {
437 case CC_WHITESPACE:
438 match = (c == ' ' || c == '\t' || c == '\n') ? 1 : 0;
439 break;
440 case CC_NONWHITESPACE:
441 if (c == '\n')
442 return (PE_EOL);
443 match = (c != ' ' && c != '\t') ? 1 : 0;
444 break;
445 default:
446 match = (c == mc) ? 1 : 0;
447 break;
448 }
449 if (match)
450 break;
451 parse_advance(conf);
452 }
453 return (0);
454 }
455
456 static int
457 parse_token(char **conf, char **tok)
458 {
459 char *p;
460 size_t len;
461 int error;
462
463 *tok = NULL;
464 error = parse_skipto(conf, CC_NONWHITESPACE);
465 if (error)
466 return (error);
467 p = *conf;
468 error = parse_skipto(conf, CC_WHITESPACE);
469 len = *conf - p;
470 *tok = malloc(len + 1, M_TEMP, M_WAITOK | M_ZERO);
471 bcopy(p, *tok, len);
472 return (0);
473 }
474
475 static void
476 parse_dir_ask_printenv(const char *var)
477 {
478 char *val;
479
480 val = kern_getenv(var);
481 if (val != NULL) {
482 printf(" %s=%s\n", var, val);
483 freeenv(val);
484 }
485 }
486
487 static int
488 parse_dir_ask(char **conf)
489 {
490 char name[80];
491 char *mnt;
492 int error;
493
494 vfs_mountroot_wait();
495
496 printf("\nLoader variables:\n");
497 parse_dir_ask_printenv("vfs.root.mountfrom");
498 parse_dir_ask_printenv("vfs.root.mountfrom.options");
499
500 printf("\nManual root filesystem specification:\n");
501 printf(" <fstype>:<device> [options]\n");
502 printf(" Mount <device> using filesystem <fstype>\n");
503 printf(" and with the specified (optional) option list.\n");
504 printf("\n");
505 printf(" eg. ufs:/dev/da0s1a\n");
506 printf(" zfs:tank\n");
507 printf(" cd9660:/dev/cd0 ro\n");
508 printf(" (which is equivalent to: ");
509 printf("mount -t cd9660 -o ro /dev/cd0 /)\n");
510 printf("\n");
511 printf(" ? List valid disk boot devices\n");
512 printf(" . Yield 1 second (for background tasks)\n");
513 printf(" <empty line> Abort manual input\n");
514
515 do {
516 error = EINVAL;
517 printf("\nmountroot> ");
518 cngets(name, sizeof(name), GETS_ECHO);
519 if (name[0] == '\0')
520 break;
521 if (name[0] == '?' && name[1] == '\0') {
522 printf("\nList of GEOM managed disk devices:\n ");
523 g_dev_print();
524 continue;
525 }
526 if (name[0] == '.' && name[1] == '\0') {
527 pause("rmask", hz);
528 continue;
529 }
530 mnt = name;
531 error = parse_mount(&mnt);
532 if (error == -1)
533 printf("Invalid file system specification.\n");
534 } while (error != 0);
535
536 return (error);
537 }
538
539 static int
540 parse_dir_md(char **conf)
541 {
542 struct stat sb;
543 struct thread *td;
544 struct md_ioctl *mdio;
545 char *path, *tok;
546 int error, fd, len;
547
548 td = curthread;
549
550 error = parse_token(conf, &tok);
551 if (error)
552 return (error);
553
554 len = strlen(tok);
555 mdio = malloc(sizeof(*mdio) + len + 1, M_TEMP, M_WAITOK | M_ZERO);
556 path = (void *)(mdio + 1);
557 bcopy(tok, path, len);
558 free(tok, M_TEMP);
559
560 /* Get file status. */
561 error = kern_statat(td, 0, AT_FDCWD, path, UIO_SYSSPACE, &sb, NULL);
562 if (error)
563 goto out;
564
565 /* Open /dev/mdctl so that we can attach/detach. */
566 error = kern_openat(td, AT_FDCWD, "/dev/" MDCTL_NAME, UIO_SYSSPACE,
567 O_RDWR, 0);
568 if (error)
569 goto out;
570
571 fd = td->td_retval[0];
572 mdio->md_version = MDIOVERSION;
573 mdio->md_type = MD_VNODE;
574
575 if (root_mount_mddev != -1) {
576 mdio->md_unit = root_mount_mddev;
577 DROP_GIANT();
578 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
579 PICKUP_GIANT();
580 /* Ignore errors. We don't care. */
581 root_mount_mddev = -1;
582 }
583
584 mdio->md_file = (void *)(mdio + 1);
585 mdio->md_options = MD_AUTOUNIT | MD_READONLY;
586 mdio->md_mediasize = sb.st_size;
587 mdio->md_unit = 0;
588 DROP_GIANT();
589 error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio);
590 PICKUP_GIANT();
591 if (error)
592 goto out;
593
594 if (mdio->md_unit > 9) {
595 printf("rootmount: too many md units\n");
596 mdio->md_file = NULL;
597 mdio->md_options = 0;
598 mdio->md_mediasize = 0;
599 DROP_GIANT();
600 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
601 PICKUP_GIANT();
602 /* Ignore errors. We don't care. */
603 error = ERANGE;
604 goto out;
605 }
606
607 root_mount_mddev = mdio->md_unit;
608 printf(MD_NAME "%u attached to %s\n", root_mount_mddev, mdio->md_file);
609
610 error = kern_close(td, fd);
611
612 out:
613 free(mdio, M_TEMP);
614 return (error);
615 }
616
617 static int
618 parse_dir_onfail(char **conf)
619 {
620 char *action;
621 int error;
622
623 error = parse_token(conf, &action);
624 if (error)
625 return (error);
626
627 if (!strcmp(action, "continue"))
628 root_mount_onfail = A_CONTINUE;
629 else if (!strcmp(action, "panic"))
630 root_mount_onfail = A_PANIC;
631 else if (!strcmp(action, "reboot"))
632 root_mount_onfail = A_REBOOT;
633 else if (!strcmp(action, "retry"))
634 root_mount_onfail = A_RETRY;
635 else {
636 printf("rootmount: %s: unknown action\n", action);
637 error = EINVAL;
638 }
639
640 free(action, M_TEMP);
641 return (0);
642 }
643
644 static int
645 parse_dir_timeout(char **conf)
646 {
647 char *tok, *endtok;
648 long secs;
649 int error;
650
651 error = parse_token(conf, &tok);
652 if (error)
653 return (error);
654
655 secs = strtol(tok, &endtok, 0);
656 error = (secs < 0 || *endtok != '\0') ? EINVAL : 0;
657 if (!error)
658 root_mount_timeout = secs;
659 free(tok, M_TEMP);
660 return (error);
661 }
662
663 static int
664 parse_directive(char **conf)
665 {
666 char *dir;
667 int error;
668
669 error = parse_token(conf, &dir);
670 if (error)
671 return (error);
672
673 if (strcmp(dir, ".ask") == 0)
674 error = parse_dir_ask(conf);
675 else if (strcmp(dir, ".md") == 0)
676 error = parse_dir_md(conf);
677 else if (strcmp(dir, ".onfail") == 0)
678 error = parse_dir_onfail(conf);
679 else if (strcmp(dir, ".timeout") == 0)
680 error = parse_dir_timeout(conf);
681 else {
682 printf("mountroot: invalid directive `%s'\n", dir);
683 /* Ignore the rest of the line. */
684 (void)parse_skipto(conf, '\n');
685 error = EINVAL;
686 }
687 free(dir, M_TEMP);
688 return (error);
689 }
690
691 static int
692 parse_mount_dev_present(const char *dev)
693 {
694 struct nameidata nd;
695 int error;
696
697 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, dev, curthread);
698 error = namei(&nd);
699 if (!error)
700 vput(nd.ni_vp);
701 NDFREE(&nd, NDF_ONLY_PNBUF);
702 return (error != 0) ? 0 : 1;
703 }
704
705 #define ERRMSGL 255
706 static int
707 parse_mount(char **conf)
708 {
709 char *errmsg;
710 struct mntarg *ma;
711 char *dev, *fs, *opts, *tok;
712 int error;
713
714 error = parse_token(conf, &tok);
715 if (error)
716 return (error);
717 fs = tok;
718 error = parse_skipto(&tok, ':');
719 if (error) {
720 free(fs, M_TEMP);
721 return (error);
722 }
723 parse_poke(&tok, '\0');
724 parse_advance(&tok);
725 dev = tok;
726
727 if (root_mount_mddev != -1) {
728 /* Handle substitution for the md unit number. */
729 tok = strstr(dev, "md#");
730 if (tok != NULL)
731 tok[2] = '' + root_mount_mddev;
732 }
733
734 /* Parse options. */
735 error = parse_token(conf, &tok);
736 opts = (error == 0) ? tok : NULL;
737
738 printf("Trying to mount root from %s:%s [%s]...\n", fs, dev,
739 (opts != NULL) ? opts : "");
740
741 errmsg = malloc(ERRMSGL, M_TEMP, M_WAITOK | M_ZERO);
742
743 if (vfs_byname(fs) == NULL) {
744 strlcpy(errmsg, "unknown file system", ERRMSGL);
745 error = ENOENT;
746 goto out;
747 }
748
749 error = vfs_mountroot_wait_if_neccessary(fs, dev);
750 if (error != 0)
751 goto out;
752
753 ma = NULL;
754 ma = mount_arg(ma, "fstype", fs, -1);
755 ma = mount_arg(ma, "fspath", "/", -1);
756 ma = mount_arg(ma, "from", dev, -1);
757 ma = mount_arg(ma, "errmsg", errmsg, ERRMSGL);
758 ma = mount_arg(ma, "ro", NULL, 0);
759 ma = parse_mountroot_options(ma, opts);
760 error = kernel_mount(ma, MNT_ROOTFS);
761
762 out:
763 if (error) {
764 printf("Mounting from %s:%s failed with error %d",
765 fs, dev, error);
766 if (errmsg[0] != '\0')
767 printf(": %s", errmsg);
768 printf(".\n");
769 }
770 free(fs, M_TEMP);
771 free(errmsg, M_TEMP);
772 if (opts != NULL)
773 free(opts, M_TEMP);
774 /* kernel_mount can return -1 on error. */
775 return ((error < 0) ? EDOOFUS : error);
776 }
777 #undef ERRMSGL
778
779 static int
780 vfs_mountroot_parse(struct sbuf *sb, struct mount *mpdevfs)
781 {
782 struct mount *mp;
783 char *conf;
784 int error;
785
786 root_mount_mddev = -1;
787
788 retry:
789 conf = sbuf_data(sb);
790 mp = TAILQ_NEXT(mpdevfs, mnt_list);
791 error = (mp == NULL) ? 0 : EDOOFUS;
792 root_mount_onfail = A_CONTINUE;
793 while (mp == NULL) {
794 error = parse_skipto(&conf, CC_NONWHITESPACE);
795 if (error == PE_EOL) {
796 parse_advance(&conf);
797 continue;
798 }
799 if (error < 0)
800 break;
801 switch (parse_peek(&conf)) {
802 case '#':
803 error = parse_skipto(&conf, '\n');
804 break;
805 case '.':
806 error = parse_directive(&conf);
807 break;
808 default:
809 error = parse_mount(&conf);
810 if (error == -1) {
811 printf("mountroot: invalid file system "
812 "specification.\n");
813 error = 0;
814 }
815 break;
816 }
817 if (error < 0)
818 break;
819 /* Ignore any trailing garbage on the line. */
820 if (parse_peek(&conf) != '\n') {
821 printf("mountroot: advancing to next directive...\n");
822 (void)parse_skipto(&conf, '\n');
823 }
824 mp = TAILQ_NEXT(mpdevfs, mnt_list);
825 }
826 if (mp != NULL)
827 return (0);
828
829 /*
830 * We failed to mount (a new) root.
831 */
832 switch (root_mount_onfail) {
833 case A_CONTINUE:
834 break;
835 case A_PANIC:
836 panic("mountroot: unable to (re-)mount root.");
837 /* NOTREACHED */
838 case A_RETRY:
839 goto retry;
840 case A_REBOOT:
841 kern_reboot(RB_NOSYNC);
842 /* NOTREACHED */
843 }
844
845 return (error);
846 }
847
848 static void
849 vfs_mountroot_conf0(struct sbuf *sb)
850 {
851 char *s, *tok, *mnt, *opt;
852 int error;
853
854 sbuf_printf(sb, ".onfail panic\n");
855 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
856 if (boothowto & RB_ASKNAME)
857 sbuf_printf(sb, ".ask\n");
858 #ifdef ROOTDEVNAME
859 if (boothowto & RB_DFLTROOT)
860 sbuf_printf(sb, "%s\n", ROOTDEVNAME);
861 #endif
862 if (boothowto & RB_CDROM) {
863 sbuf_printf(sb, "cd9660:/dev/cd0 ro\n");
864 sbuf_printf(sb, ".timeout 0\n");
865 sbuf_printf(sb, "cd9660:/dev/cd1 ro\n");
866 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
867 }
868 s = kern_getenv("vfs.root.mountfrom");
869 if (s != NULL) {
870 opt = kern_getenv("vfs.root.mountfrom.options");
871 tok = s;
872 error = parse_token(&tok, &mnt);
873 while (!error) {
874 sbuf_printf(sb, "%s %s\n", mnt,
875 (opt != NULL) ? opt : "");
876 free(mnt, M_TEMP);
877 error = parse_token(&tok, &mnt);
878 }
879 if (opt != NULL)
880 freeenv(opt);
881 freeenv(s);
882 }
883 if (rootdevnames[0] != NULL)
884 sbuf_printf(sb, "%s\n", rootdevnames[0]);
885 if (rootdevnames[1] != NULL)
886 sbuf_printf(sb, "%s\n", rootdevnames[1]);
887 #ifdef ROOTDEVNAME
888 if (!(boothowto & RB_DFLTROOT))
889 sbuf_printf(sb, "%s\n", ROOTDEVNAME);
890 #endif
891 if (!(boothowto & RB_ASKNAME))
892 sbuf_printf(sb, ".ask\n");
893 }
894
895 static int
896 vfs_mountroot_readconf(struct thread *td, struct sbuf *sb)
897 {
898 static char buf[128];
899 struct nameidata nd;
900 off_t ofs;
901 ssize_t resid;
902 int error, flags, len;
903
904 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/.mount.conf", td);
905 flags = FREAD;
906 error = vn_open(&nd, &flags, 0, NULL);
907 if (error)
908 return (error);
909
910 NDFREE(&nd, NDF_ONLY_PNBUF);
911 ofs = 0;
912 len = sizeof(buf) - 1;
913 while (1) {
914 error = vn_rdwr(UIO_READ, nd.ni_vp, buf, len, ofs,
915 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
916 NOCRED, &resid, td);
917 if (error)
918 break;
919 if (resid == len)
920 break;
921 buf[len - resid] = 0;
922 sbuf_printf(sb, "%s", buf);
923 ofs += len - resid;
924 }
925
926 VOP_UNLOCK(nd.ni_vp, 0);
927 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
928 return (error);
929 }
930
931 static void
932 vfs_mountroot_wait(void)
933 {
934 struct root_hold_token *h;
935 struct timeval lastfail;
936 int curfail;
937
938 curfail = 0;
939 while (1) {
940 DROP_GIANT();
941 g_waitidle();
942 PICKUP_GIANT();
943 mtx_lock(&root_holds_mtx);
944 if (LIST_EMPTY(&root_holds)) {
945 mtx_unlock(&root_holds_mtx);
946 break;
947 }
948 if (ppsratecheck(&lastfail, &curfail, 1)) {
949 printf("Root mount waiting for:");
950 LIST_FOREACH(h, &root_holds, list)
951 printf(" %s", h->who);
952 printf("\n");
953 }
954 msleep(&root_holds, &root_holds_mtx, PZERO | PDROP, "roothold",
955 hz);
956 }
957 }
958
959 static int
960 vfs_mountroot_wait_if_neccessary(const char *fs, const char *dev)
961 {
962 int delay, timeout;
963
964 /*
965 * In case of ZFS and NFS we don't have a way to wait for
966 * specific device. Also do the wait if the user forced that
967 * behaviour by setting vfs.root_mount_always_wait=1.
968 */
969 if (strcmp(fs, "zfs") == 0 || strstr(fs, "nfs") != NULL ||
970 dev[0] == '\0' || root_mount_always_wait != 0) {
971 vfs_mountroot_wait();
972 return (0);
973 }
974
975 /*
976 * Otherwise, no point in waiting if the device is already there.
977 * Note that we must wait for GEOM to finish reconfiguring itself,
978 * eg for geom_part(4) to finish tasting.
979 */
980 DROP_GIANT();
981 g_waitidle();
982 PICKUP_GIANT();
983 if (parse_mount_dev_present(dev))
984 return (0);
985
986 /*
987 * No luck. Let's wait. This code looks weird, but it's that way
988 * to behave exactly as it used to work before.
989 */
990 vfs_mountroot_wait();
991 printf("mountroot: waiting for device %s...\n", dev);
992 delay = hz / 10;
993 timeout = root_mount_timeout * hz;
994 do {
995 pause("rmdev", delay);
996 timeout -= delay;
997 } while (timeout > 0 && !parse_mount_dev_present(dev));
998
999 if (timeout <= 0)
1000 return (ENODEV);
1001
1002 return (0);
1003 }
1004
1005 void
1006 vfs_mountroot(void)
1007 {
1008 struct mount *mp;
1009 struct sbuf *sb;
1010 struct thread *td;
1011 time_t timebase;
1012 int error;
1013
1014 td = curthread;
1015
1016 sb = sbuf_new_auto();
1017 vfs_mountroot_conf0(sb);
1018 sbuf_finish(sb);
1019
1020 error = vfs_mountroot_devfs(td, &mp);
1021 while (!error) {
1022 error = vfs_mountroot_parse(sb, mp);
1023 if (!error) {
1024 vfs_mountroot_shuffle(td, mp);
1025 sbuf_clear(sb);
1026 error = vfs_mountroot_readconf(td, sb);
1027 sbuf_finish(sb);
1028 }
1029 }
1030
1031 sbuf_delete(sb);
1032
1033 /*
1034 * Iterate over all currently mounted file systems and use
1035 * the time stamp found to check and/or initialize the RTC.
1036 * Call inittodr() only once and pass it the largest of the
1037 * timestamps we encounter.
1038 */
1039 timebase = 0;
1040 mtx_lock(&mountlist_mtx);
1041 mp = TAILQ_FIRST(&mountlist);
1042 while (mp != NULL) {
1043 if (mp->mnt_time > timebase)
1044 timebase = mp->mnt_time;
1045 mp = TAILQ_NEXT(mp, mnt_list);
1046 }
1047 mtx_unlock(&mountlist_mtx);
1048 inittodr(timebase);
1049
1050 /* Keep prison0's root in sync with the global rootvnode. */
1051 mtx_lock(&prison0.pr_mtx);
1052 prison0.pr_root = rootvnode;
1053 vref(prison0.pr_root);
1054 mtx_unlock(&prison0.pr_mtx);
1055
1056 mtx_lock(&root_holds_mtx);
1057 atomic_store_rel_int(&root_mount_complete, 1);
1058 wakeup(&root_mount_complete);
1059 mtx_unlock(&root_holds_mtx);
1060
1061 EVENTHANDLER_INVOKE(mountroot);
1062 }
1063
1064 static struct mntarg *
1065 parse_mountroot_options(struct mntarg *ma, const char *options)
1066 {
1067 char *p;
1068 char *name, *name_arg;
1069 char *val, *val_arg;
1070 char *opts;
1071
1072 if (options == NULL || options[0] == '\0')
1073 return (ma);
1074
1075 p = opts = strdup(options, M_MOUNT);
1076 if (opts == NULL) {
1077 return (ma);
1078 }
1079
1080 while((name = strsep(&p, ",")) != NULL) {
1081 if (name[0] == '\0')
1082 break;
1083
1084 val = strchr(name, '=');
1085 if (val != NULL) {
1086 *val = '\0';
1087 ++val;
1088 }
1089 if( strcmp(name, "rw") == 0 ||
1090 strcmp(name, "noro") == 0) {
1091 /*
1092 * The first time we mount the root file system,
1093 * we need to mount 'ro', so We need to ignore
1094 * 'rw' and 'noro' mount options.
1095 */
1096 continue;
1097 }
1098 name_arg = strdup(name, M_MOUNT);
1099 val_arg = NULL;
1100 if (val != NULL)
1101 val_arg = strdup(val, M_MOUNT);
1102
1103 ma = mount_arg(ma, name_arg, val_arg,
1104 (val_arg != NULL ? -1 : 0));
1105 }
1106 free(opts, M_MOUNT);
1107 return (ma);
1108 }
Cache object: 798f0c8e390a83ba68e6359e48464ce7
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