1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2010 Marcel Moolenaar
5 * Copyright (c) 1999-2004 Poul-Henning Kamp
6 * Copyright (c) 1999 Michael Smith
7 * Copyright (c) 1989, 1993
8 * The Regents of the University of California. All rights reserved.
9 * (c) UNIX System Laboratories, Inc.
10 * All or some portions of this file are derived from material licensed
11 * to the University of California by American Telephone and Telegraph
12 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
13 * the permission of UNIX System Laboratories, Inc.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 * 3. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 */
39
40 #include "opt_rootdevname.h"
41
42 #include <sys/cdefs.h>
43 #include <sys/param.h>
44 #include <sys/conf.h>
45 #include <sys/cons.h>
46 #include <sys/eventhandler.h>
47 #include <sys/fcntl.h>
48 #include <sys/jail.h>
49 #include <sys/kernel.h>
50 #include <sys/malloc.h>
51 #include <sys/mdioctl.h>
52 #include <sys/mount.h>
53 #include <sys/mutex.h>
54 #include <sys/namei.h>
55 #include <sys/priv.h>
56 #include <sys/proc.h>
57 #include <sys/filedesc.h>
58 #include <sys/reboot.h>
59 #include <sys/sbuf.h>
60 #include <sys/stat.h>
61 #include <sys/syscallsubr.h>
62 #include <sys/sysproto.h>
63 #include <sys/sx.h>
64 #include <sys/sysctl.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 static TAILQ_HEAD(, root_hold_token) root_holds =
112 TAILQ_HEAD_INITIALIZER(root_holds);
113
114 enum action {
115 A_CONTINUE,
116 A_PANIC,
117 A_REBOOT,
118 A_RETRY
119 };
120
121 enum rh_flags {
122 RH_FREE,
123 RH_ALLOC,
124 RH_ARG,
125 };
126
127 static enum action root_mount_onfail = A_CONTINUE;
128
129 static int root_mount_mddev;
130 static int root_mount_complete;
131
132 /* By default wait up to 3 seconds for devices to appear. */
133 static int root_mount_timeout = 3;
134 TUNABLE_INT("vfs.mountroot.timeout", &root_mount_timeout);
135
136 static int root_mount_always_wait = 0;
137 SYSCTL_INT(_vfs, OID_AUTO, root_mount_always_wait, CTLFLAG_RDTUN,
138 &root_mount_always_wait, 0,
139 "Wait for root mount holds even if the root device already exists");
140
141 SYSCTL_PROC(_vfs, OID_AUTO, root_mount_hold,
142 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
143 NULL, 0, sysctl_vfs_root_mount_hold, "A",
144 "List of root mount hold tokens");
145
146 static int
sysctl_vfs_root_mount_hold(SYSCTL_HANDLER_ARGS)147 sysctl_vfs_root_mount_hold(SYSCTL_HANDLER_ARGS)
148 {
149 struct sbuf sb;
150 struct root_hold_token *h;
151 int error;
152
153 sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL);
154
155 mtx_lock(&root_holds_mtx);
156 TAILQ_FOREACH(h, &root_holds, list) {
157 if (h != TAILQ_FIRST(&root_holds))
158 sbuf_putc(&sb, ' ');
159 sbuf_printf(&sb, "%s", h->who);
160 }
161 mtx_unlock(&root_holds_mtx);
162
163 error = sbuf_finish(&sb);
164 if (error == 0)
165 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
166 sbuf_delete(&sb);
167 return (error);
168 }
169
170 struct root_hold_token *
root_mount_hold(const char * identifier)171 root_mount_hold(const char *identifier)
172 {
173 struct root_hold_token *h;
174
175 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
176 h->flags = RH_ALLOC;
177 h->who = identifier;
178 mtx_lock(&root_holds_mtx);
179 TSHOLD("root mount");
180 TAILQ_INSERT_TAIL(&root_holds, h, list);
181 mtx_unlock(&root_holds_mtx);
182 return (h);
183 }
184
185 void
root_mount_hold_token(const char * identifier,struct root_hold_token * h)186 root_mount_hold_token(const char *identifier, struct root_hold_token *h)
187 {
188 #ifdef INVARIANTS
189 struct root_hold_token *t;
190 #endif
191
192 h->flags = RH_ARG;
193 h->who = identifier;
194 mtx_lock(&root_holds_mtx);
195 #ifdef INVARIANTS
196 TAILQ_FOREACH(t, &root_holds, list) {
197 if (t == h) {
198 panic("Duplicate mount hold by '%s' on %p",
199 identifier, h);
200 }
201 }
202 #endif
203 TSHOLD("root mount");
204 TAILQ_INSERT_TAIL(&root_holds, h, list);
205 mtx_unlock(&root_holds_mtx);
206 }
207
208 void
root_mount_rel(struct root_hold_token * h)209 root_mount_rel(struct root_hold_token *h)
210 {
211
212 if (h == NULL || h->flags == RH_FREE)
213 return;
214
215 mtx_lock(&root_holds_mtx);
216 TAILQ_REMOVE(&root_holds, h, list);
217 TSRELEASE("root mount");
218 wakeup(&root_holds);
219 mtx_unlock(&root_holds_mtx);
220 if (h->flags == RH_ALLOC) {
221 free(h, M_DEVBUF);
222 } else
223 h->flags = RH_FREE;
224 }
225
226 int
root_mounted(void)227 root_mounted(void)
228 {
229
230 /* No mutex is acquired here because int stores are atomic. */
231 return (root_mount_complete);
232 }
233
234 static void
set_rootvnode(void)235 set_rootvnode(void)
236 {
237
238 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
239 panic("set_rootvnode: Cannot find root vnode");
240
241 VOP_UNLOCK(rootvnode);
242
243 pwd_set_rootvnode();
244 }
245
246 static int
vfs_mountroot_devfs(struct thread * td,struct mount ** mpp)247 vfs_mountroot_devfs(struct thread *td, struct mount **mpp)
248 {
249 struct vfsoptlist *opts;
250 struct vfsconf *vfsp;
251 struct mount *mp;
252 int error;
253
254 *mpp = NULL;
255
256 if (rootdevmp != NULL) {
257 /*
258 * Already have /dev; this happens during rerooting.
259 */
260 error = vfs_busy(rootdevmp, 0);
261 if (error != 0)
262 return (error);
263 *mpp = rootdevmp;
264 } else {
265 vfsp = vfs_byname("devfs");
266 KASSERT(vfsp != NULL, ("Could not find devfs by name"));
267 if (vfsp == NULL)
268 return (ENOENT);
269
270 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
271
272 error = VFS_MOUNT(mp);
273 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
274 if (error)
275 return (error);
276
277 error = VFS_STATFS(mp, &mp->mnt_stat);
278 KASSERT(error == 0, ("VFS_STATFS(devfs) failed %d", error));
279 if (error)
280 return (error);
281
282 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
283 TAILQ_INIT(opts);
284 mp->mnt_opt = opts;
285
286 mtx_lock(&mountlist_mtx);
287 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
288 mtx_unlock(&mountlist_mtx);
289
290 *mpp = mp;
291 rootdevmp = mp;
292 vfs_op_exit(mp);
293 }
294
295 set_rootvnode();
296
297 error = kern_symlinkat(td, "/", AT_FDCWD, "dev", UIO_SYSSPACE);
298 if (error)
299 printf("kern_symlink /dev -> / returns %d\n", error);
300
301 return (error);
302 }
303
304 static void
vfs_mountroot_shuffle(struct thread * td,struct mount * mpdevfs)305 vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs)
306 {
307 struct nameidata nd;
308 struct mount *mporoot, *mpnroot;
309 struct vnode *vp, *vporoot, *vpdevfs;
310 char *fspath;
311 int error;
312
313 mpnroot = TAILQ_NEXT(mpdevfs, mnt_list);
314
315 /* Shuffle the mountlist. */
316 mtx_lock(&mountlist_mtx);
317 mporoot = TAILQ_FIRST(&mountlist);
318 TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list);
319 if (mporoot != mpdevfs) {
320 TAILQ_REMOVE(&mountlist, mpnroot, mnt_list);
321 TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list);
322 }
323 TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list);
324 mtx_unlock(&mountlist_mtx);
325
326 cache_purgevfs(mporoot);
327 if (mporoot != mpdevfs)
328 cache_purgevfs(mpdevfs);
329
330 if (VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot))
331 panic("vfs_mountroot_shuffle: Cannot find root vnode");
332
333 VI_LOCK(vporoot);
334 vporoot->v_iflag &= ~VI_MOUNT;
335 vn_irflag_unset_locked(vporoot, VIRF_MOUNTPOINT);
336 vporoot->v_mountedhere = NULL;
337 VI_UNLOCK(vporoot);
338 mporoot->mnt_flag &= ~MNT_ROOTFS;
339 mporoot->mnt_vnodecovered = NULL;
340 vput(vporoot);
341
342 /* Set up the new rootvnode, and purge the cache */
343 mpnroot->mnt_vnodecovered = NULL;
344 set_rootvnode();
345 cache_purgevfs(rootvnode->v_mount);
346
347 if (mporoot != mpdevfs) {
348 /* Remount old root under /.mount or /mnt */
349 fspath = "/.mount";
350 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspath);
351 error = namei(&nd);
352 if (error) {
353 fspath = "/mnt";
354 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
355 fspath);
356 error = namei(&nd);
357 }
358 if (!error) {
359 NDFREE_PNBUF(&nd);
360 vp = nd.ni_vp;
361 error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
362 if (!error)
363 error = vinvalbuf(vp, V_SAVE, 0, 0);
364 if (!error) {
365 cache_purge(vp);
366 VI_LOCK(vp);
367 mporoot->mnt_vnodecovered = vp;
368 vn_irflag_set_locked(vp, VIRF_MOUNTPOINT);
369 vp->v_mountedhere = mporoot;
370 strlcpy(mporoot->mnt_stat.f_mntonname,
371 fspath, MNAMELEN);
372 VI_UNLOCK(vp);
373 VOP_UNLOCK(vp);
374 } else
375 vput(vp);
376 }
377
378 if (error)
379 printf("mountroot: unable to remount previous root "
380 "under /.mount or /mnt (error %d)\n", error);
381 }
382
383 /* Remount devfs under /dev */
384 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev");
385 error = namei(&nd);
386 if (!error) {
387 NDFREE_PNBUF(&nd);
388 vp = nd.ni_vp;
389 error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
390 if (!error)
391 error = vinvalbuf(vp, V_SAVE, 0, 0);
392 if (!error) {
393 vpdevfs = mpdevfs->mnt_vnodecovered;
394 if (vpdevfs != NULL) {
395 cache_purge(vpdevfs);
396 VI_LOCK(vpdevfs);
397 vn_irflag_unset_locked(vpdevfs, VIRF_MOUNTPOINT);
398 vpdevfs->v_mountedhere = NULL;
399 VI_UNLOCK(vpdevfs);
400 vrele(vpdevfs);
401 }
402 VI_LOCK(vp);
403 mpdevfs->mnt_vnodecovered = vp;
404 vn_irflag_set_locked(vp, VIRF_MOUNTPOINT);
405 vp->v_mountedhere = mpdevfs;
406 VI_UNLOCK(vp);
407 VOP_UNLOCK(vp);
408 } else
409 vput(vp);
410 }
411 if (error)
412 printf("mountroot: unable to remount devfs under /dev "
413 "(error %d)\n", error);
414
415 if (mporoot == mpdevfs) {
416 vfs_unbusy(mpdevfs);
417 /* Unlink the no longer needed /dev/dev -> / symlink */
418 error = kern_funlinkat(td, AT_FDCWD, "/dev/dev", FD_NONE,
419 UIO_SYSSPACE, 0, 0);
420 if (error)
421 printf("mountroot: unable to unlink /dev/dev "
422 "(error %d)\n", error);
423 }
424 }
425
426 /*
427 * Configuration parser.
428 */
429
430 /* Parser character classes. */
431 #define CC_WHITESPACE -1
432 #define CC_NONWHITESPACE -2
433
434 /* Parse errors. */
435 #define PE_EOF -1
436 #define PE_EOL -2
437
438 static __inline int
parse_peek(char ** conf)439 parse_peek(char **conf)
440 {
441
442 return (**conf);
443 }
444
445 static __inline void
parse_poke(char ** conf,int c)446 parse_poke(char **conf, int c)
447 {
448
449 **conf = c;
450 }
451
452 static __inline void
parse_advance(char ** conf)453 parse_advance(char **conf)
454 {
455
456 (*conf)++;
457 }
458
459 static int
parse_skipto(char ** conf,int mc)460 parse_skipto(char **conf, int mc)
461 {
462 int c, match;
463
464 while (1) {
465 c = parse_peek(conf);
466 if (c == 0)
467 return (PE_EOF);
468 switch (mc) {
469 case CC_WHITESPACE:
470 match = (c == ' ' || c == '\t' || c == '\n') ? 1 : 0;
471 break;
472 case CC_NONWHITESPACE:
473 if (c == '\n')
474 return (PE_EOL);
475 match = (c != ' ' && c != '\t') ? 1 : 0;
476 break;
477 default:
478 match = (c == mc) ? 1 : 0;
479 break;
480 }
481 if (match)
482 break;
483 parse_advance(conf);
484 }
485 return (0);
486 }
487
488 static int
parse_token(char ** conf,char ** tok)489 parse_token(char **conf, char **tok)
490 {
491 char *p;
492 size_t len;
493 int error;
494
495 *tok = NULL;
496 error = parse_skipto(conf, CC_NONWHITESPACE);
497 if (error)
498 return (error);
499 p = *conf;
500 error = parse_skipto(conf, CC_WHITESPACE);
501 len = *conf - p;
502 *tok = malloc(len + 1, M_TEMP, M_WAITOK | M_ZERO);
503 bcopy(p, *tok, len);
504 return (0);
505 }
506
507 static void
parse_dir_ask_printenv(const char * var)508 parse_dir_ask_printenv(const char *var)
509 {
510 char *val;
511
512 val = kern_getenv(var);
513 if (val != NULL) {
514 printf(" %s=%s\n", var, val);
515 freeenv(val);
516 }
517 }
518
519 static int
parse_dir_ask(char ** conf)520 parse_dir_ask(char **conf)
521 {
522 char name[80];
523 char *mnt;
524 int error;
525
526 vfs_mountroot_wait();
527
528 printf("\nLoader variables:\n");
529 parse_dir_ask_printenv("vfs.root.mountfrom");
530 parse_dir_ask_printenv("vfs.root.mountfrom.options");
531
532 printf("\nManual root filesystem specification:\n");
533 printf(" <fstype>:<device> [options]\n");
534 printf(" Mount <device> using filesystem <fstype>\n");
535 printf(" and with the specified (optional) option list.\n");
536 printf("\n");
537 printf(" eg. ufs:/dev/da0s1a\n");
538 printf(" zfs:zroot/ROOT/default\n");
539 printf(" cd9660:/dev/cd0 ro\n");
540 printf(" (which is equivalent to: ");
541 printf("mount -t cd9660 -o ro /dev/cd0 /)\n");
542 printf("\n");
543 printf(" ? List valid disk boot devices\n");
544 printf(" . Yield 1 second (for background tasks)\n");
545 printf(" <empty line> Abort manual input\n");
546
547 do {
548 error = EINVAL;
549 printf("\nmountroot> ");
550 cngets(name, sizeof(name), GETS_ECHO);
551 if (name[0] == '\0')
552 break;
553 if (name[0] == '?' && name[1] == '\0') {
554 printf("\nList of GEOM managed disk devices:\n ");
555 g_dev_print();
556 continue;
557 }
558 if (name[0] == '.' && name[1] == '\0') {
559 pause("rmask", hz);
560 continue;
561 }
562 mnt = name;
563 error = parse_mount(&mnt);
564 if (error == -1)
565 printf("Invalid file system specification.\n");
566 } while (error != 0);
567
568 return (error);
569 }
570
571 static int
parse_dir_md(char ** conf)572 parse_dir_md(char **conf)
573 {
574 struct stat sb;
575 struct thread *td;
576 struct md_ioctl *mdio;
577 char *path, *tok;
578 int error, fd, len;
579
580 td = curthread;
581 fd = -1;
582
583 error = parse_token(conf, &tok);
584 if (error)
585 return (error);
586
587 len = strlen(tok);
588 mdio = malloc(sizeof(*mdio) + len + 1, M_TEMP, M_WAITOK | M_ZERO);
589 path = (void *)(mdio + 1);
590 bcopy(tok, path, len);
591 free(tok, M_TEMP);
592
593 /* Get file status. */
594 error = kern_statat(td, 0, AT_FDCWD, path, UIO_SYSSPACE, &sb);
595 if (error)
596 goto out;
597
598 /* Open /dev/mdctl so that we can attach/detach. */
599 error = kern_openat(td, AT_FDCWD, "/dev/" MDCTL_NAME, UIO_SYSSPACE,
600 O_RDWR, 0);
601 if (error)
602 goto out;
603
604 fd = td->td_retval[0];
605 mdio->md_version = MDIOVERSION;
606 mdio->md_type = MD_VNODE;
607
608 if (root_mount_mddev != -1) {
609 mdio->md_unit = root_mount_mddev;
610 (void)kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
611 /* Ignore errors. We don't care. */
612 root_mount_mddev = -1;
613 }
614
615 mdio->md_file = (void *)(mdio + 1);
616 mdio->md_options = MD_AUTOUNIT | MD_READONLY;
617 mdio->md_mediasize = sb.st_size;
618 mdio->md_unit = 0;
619 error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio);
620 if (error)
621 goto out;
622
623 if (mdio->md_unit > 9) {
624 printf("rootmount: too many md units\n");
625 mdio->md_file = NULL;
626 mdio->md_options = 0;
627 mdio->md_mediasize = 0;
628 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
629 /* Ignore errors. We don't care. */
630 error = ERANGE;
631 goto out;
632 }
633
634 root_mount_mddev = mdio->md_unit;
635 printf(MD_NAME "%u attached to %s\n", root_mount_mddev, mdio->md_file);
636
637 out:
638 if (fd >= 0)
639 (void)kern_close(td, fd);
640 free(mdio, M_TEMP);
641 return (error);
642 }
643
644 static int
parse_dir_onfail(char ** conf)645 parse_dir_onfail(char **conf)
646 {
647 char *action;
648 int error;
649
650 error = parse_token(conf, &action);
651 if (error)
652 return (error);
653
654 if (!strcmp(action, "continue"))
655 root_mount_onfail = A_CONTINUE;
656 else if (!strcmp(action, "panic"))
657 root_mount_onfail = A_PANIC;
658 else if (!strcmp(action, "reboot"))
659 root_mount_onfail = A_REBOOT;
660 else if (!strcmp(action, "retry"))
661 root_mount_onfail = A_RETRY;
662 else {
663 printf("rootmount: %s: unknown action\n", action);
664 error = EINVAL;
665 }
666
667 free(action, M_TEMP);
668 return (0);
669 }
670
671 static int
parse_dir_timeout(char ** conf)672 parse_dir_timeout(char **conf)
673 {
674 char *tok, *endtok;
675 long secs;
676 int error;
677
678 error = parse_token(conf, &tok);
679 if (error)
680 return (error);
681
682 secs = strtol(tok, &endtok, 0);
683 error = (secs < 0 || *endtok != '\0') ? EINVAL : 0;
684 if (!error)
685 root_mount_timeout = secs;
686 free(tok, M_TEMP);
687 return (error);
688 }
689
690 static int
parse_directive(char ** conf)691 parse_directive(char **conf)
692 {
693 char *dir;
694 int error;
695
696 error = parse_token(conf, &dir);
697 if (error)
698 return (error);
699
700 if (strcmp(dir, ".ask") == 0)
701 error = parse_dir_ask(conf);
702 else if (strcmp(dir, ".md") == 0)
703 error = parse_dir_md(conf);
704 else if (strcmp(dir, ".onfail") == 0)
705 error = parse_dir_onfail(conf);
706 else if (strcmp(dir, ".timeout") == 0)
707 error = parse_dir_timeout(conf);
708 else {
709 printf("mountroot: invalid directive `%s'\n", dir);
710 /* Ignore the rest of the line. */
711 (void)parse_skipto(conf, '\n');
712 error = EINVAL;
713 }
714 free(dir, M_TEMP);
715 return (error);
716 }
717
718 static bool
parse_mount_dev_present(const char * dev)719 parse_mount_dev_present(const char *dev)
720 {
721 struct nameidata nd;
722 int error;
723
724 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, dev);
725 error = namei(&nd);
726 if (error != 0)
727 return (false);
728 vrele(nd.ni_vp);
729 NDFREE_PNBUF(&nd);
730 return (true);
731 }
732
733 #define ERRMSGL 255
734 static int
parse_mount(char ** conf)735 parse_mount(char **conf)
736 {
737 char *errmsg;
738 struct mntarg *ma;
739 char *dev, *fs, *opts, *tok;
740 int delay, error, timeout;
741
742 error = parse_token(conf, &tok);
743 if (error)
744 return (error);
745 fs = tok;
746 error = parse_skipto(&tok, ':');
747 if (error) {
748 free(fs, M_TEMP);
749 return (error);
750 }
751 parse_poke(&tok, '\0');
752 parse_advance(&tok);
753 dev = tok;
754
755 if (root_mount_mddev != -1) {
756 /* Handle substitution for the md unit number. */
757 tok = strstr(dev, "md#");
758 if (tok != NULL)
759 tok[2] = '0' + root_mount_mddev;
760 }
761
762 /* Parse options. */
763 error = parse_token(conf, &tok);
764 opts = (error == 0) ? tok : NULL;
765
766 printf("Trying to mount root from %s:%s [%s]...\n", fs, dev,
767 (opts != NULL) ? opts : "");
768
769 errmsg = malloc(ERRMSGL, M_TEMP, M_WAITOK | M_ZERO);
770
771 if (vfs_byname(fs) == NULL) {
772 strlcpy(errmsg, "unknown file system", ERRMSGL);
773 error = ENOENT;
774 goto out;
775 }
776
777 error = vfs_mountroot_wait_if_neccessary(fs, dev);
778 if (error != 0)
779 goto out;
780
781 delay = hz / 10;
782 timeout = root_mount_timeout * hz;
783
784 for (;;) {
785 ma = NULL;
786 ma = mount_arg(ma, "fstype", fs, -1);
787 ma = mount_arg(ma, "fspath", "/", -1);
788 ma = mount_arg(ma, "from", dev, -1);
789 ma = mount_arg(ma, "errmsg", errmsg, ERRMSGL);
790 ma = mount_arg(ma, "ro", NULL, 0);
791 ma = parse_mountroot_options(ma, opts);
792
793 error = kernel_mount(ma, MNT_ROOTFS);
794 if (error == 0 || error == EILSEQ || timeout <= 0)
795 break;
796
797 if (root_mount_timeout * hz == timeout ||
798 (bootverbose && timeout % hz == 0)) {
799 printf("Mounting from %s:%s failed with error %d; "
800 "retrying for %d more second%s\n", fs, dev, error,
801 timeout / hz, (timeout / hz > 1) ? "s" : "");
802 }
803 pause("rmretry", delay);
804 timeout -= delay;
805 }
806 out:
807 if (error) {
808 printf("Mounting from %s:%s failed with error %d",
809 fs, dev, error);
810 if (errmsg[0] != '\0')
811 printf(": %s", errmsg);
812 printf(".\n");
813 }
814 free(fs, M_TEMP);
815 free(errmsg, M_TEMP);
816 if (opts != NULL)
817 free(opts, M_TEMP);
818 /* kernel_mount can return -1 on error. */
819 return ((error < 0) ? EDOOFUS : error);
820 }
821 #undef ERRMSGL
822
823 static int
vfs_mountroot_parse(struct sbuf * sb,struct mount * mpdevfs)824 vfs_mountroot_parse(struct sbuf *sb, struct mount *mpdevfs)
825 {
826 struct mount *mp;
827 char *conf;
828 int error;
829
830 root_mount_mddev = -1;
831
832 retry:
833 conf = sbuf_data(sb);
834 mp = TAILQ_NEXT(mpdevfs, mnt_list);
835 error = (mp == NULL) ? 0 : EDOOFUS;
836 root_mount_onfail = A_CONTINUE;
837 while (mp == NULL) {
838 error = parse_skipto(&conf, CC_NONWHITESPACE);
839 if (error == PE_EOL) {
840 parse_advance(&conf);
841 continue;
842 }
843 if (error < 0)
844 break;
845 switch (parse_peek(&conf)) {
846 case '#':
847 error = parse_skipto(&conf, '\n');
848 break;
849 case '.':
850 error = parse_directive(&conf);
851 break;
852 default:
853 error = parse_mount(&conf);
854 if (error == -1) {
855 printf("mountroot: invalid file system "
856 "specification.\n");
857 error = 0;
858 }
859 break;
860 }
861 if (error < 0)
862 break;
863 /* Ignore any trailing garbage on the line. */
864 if (parse_peek(&conf) != '\n') {
865 printf("mountroot: advancing to next directive...\n");
866 (void)parse_skipto(&conf, '\n');
867 }
868 mp = TAILQ_NEXT(mpdevfs, mnt_list);
869 }
870 if (mp != NULL)
871 return (0);
872
873 /*
874 * We failed to mount (a new) root.
875 */
876 switch (root_mount_onfail) {
877 case A_CONTINUE:
878 break;
879 case A_PANIC:
880 panic("mountroot: unable to (re-)mount root.");
881 /* NOTREACHED */
882 case A_RETRY:
883 goto retry;
884 case A_REBOOT:
885 kern_reboot(RB_NOSYNC);
886 /* NOTREACHED */
887 }
888
889 return (error);
890 }
891
892 static void
vfs_mountroot_conf0(struct sbuf * sb)893 vfs_mountroot_conf0(struct sbuf *sb)
894 {
895 char *s, *tok, *mnt, *opt;
896 int error;
897
898 sbuf_printf(sb, ".onfail panic\n");
899 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
900 if (boothowto & RB_ASKNAME)
901 sbuf_printf(sb, ".ask\n");
902 #ifdef ROOTDEVNAME
903 if (boothowto & RB_DFLTROOT)
904 sbuf_printf(sb, "%s\n", ROOTDEVNAME);
905 #endif
906 if (boothowto & RB_CDROM) {
907 sbuf_printf(sb, "cd9660:/dev/cd0 ro\n");
908 sbuf_printf(sb, ".timeout 0\n");
909 sbuf_printf(sb, "cd9660:/dev/cd1 ro\n");
910 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
911 }
912 s = kern_getenv("vfs.root.mountfrom");
913 if (s != NULL) {
914 opt = kern_getenv("vfs.root.mountfrom.options");
915 tok = s;
916 error = parse_token(&tok, &mnt);
917 while (!error) {
918 sbuf_printf(sb, "%s %s\n", mnt,
919 (opt != NULL) ? opt : "");
920 free(mnt, M_TEMP);
921 error = parse_token(&tok, &mnt);
922 }
923 if (opt != NULL)
924 freeenv(opt);
925 freeenv(s);
926 }
927 if (rootdevnames[0] != NULL)
928 sbuf_printf(sb, "%s\n", rootdevnames[0]);
929 if (rootdevnames[1] != NULL)
930 sbuf_printf(sb, "%s\n", rootdevnames[1]);
931 #ifdef ROOTDEVNAME
932 if (!(boothowto & RB_DFLTROOT))
933 sbuf_printf(sb, "%s\n", ROOTDEVNAME);
934 #endif
935 if (!(boothowto & RB_ASKNAME))
936 sbuf_printf(sb, ".ask\n");
937 }
938
939 static int
vfs_mountroot_readconf(struct thread * td,struct sbuf * sb)940 vfs_mountroot_readconf(struct thread *td, struct sbuf *sb)
941 {
942 static char buf[128];
943 struct nameidata nd;
944 off_t ofs;
945 ssize_t resid;
946 int error, flags, len;
947
948 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/.mount.conf");
949 flags = FREAD;
950 error = vn_open(&nd, &flags, 0, NULL);
951 if (error)
952 return (error);
953
954 NDFREE_PNBUF(&nd);
955 ofs = 0;
956 len = sizeof(buf) - 1;
957 while (1) {
958 error = vn_rdwr(UIO_READ, nd.ni_vp, buf, len, ofs,
959 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
960 NOCRED, &resid, td);
961 if (error)
962 break;
963 if (resid == len)
964 break;
965 buf[len - resid] = 0;
966 sbuf_printf(sb, "%s", buf);
967 ofs += len - resid;
968 }
969
970 VOP_UNLOCK(nd.ni_vp);
971 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
972 return (error);
973 }
974
975 static void
vfs_mountroot_wait(void)976 vfs_mountroot_wait(void)
977 {
978 struct root_hold_token *h;
979 struct thread *td;
980 struct timeval lastfail;
981 int curfail;
982
983 TSENTER();
984
985 curfail = 0;
986 lastfail.tv_sec = 0;
987 eventratecheck(&lastfail, &curfail, 1);
988 td = curthread;
989 while (1) {
990 g_waitidle(td);
991 mtx_lock(&root_holds_mtx);
992 if (TAILQ_EMPTY(&root_holds)) {
993 mtx_unlock(&root_holds_mtx);
994 break;
995 }
996 if (eventratecheck(&lastfail, &curfail, 1)) {
997 printf("Root mount waiting for:");
998 TAILQ_FOREACH(h, &root_holds, list)
999 printf(" %s", h->who);
1000 printf("\n");
1001 }
1002 TSWAIT("root mount");
1003 msleep(&root_holds, &root_holds_mtx, PZERO | PDROP, "roothold",
1004 hz);
1005 TSUNWAIT("root mount");
1006 }
1007 g_waitidle(td);
1008
1009 TSEXIT();
1010 }
1011
1012 static int
vfs_mountroot_wait_if_neccessary(const char * fs,const char * dev)1013 vfs_mountroot_wait_if_neccessary(const char *fs, const char *dev)
1014 {
1015 int delay, timeout;
1016
1017 /*
1018 * In case of ZFS and NFS we don't have a way to wait for
1019 * specific device. Also do the wait if the user forced that
1020 * behaviour by setting vfs.root_mount_always_wait=1.
1021 */
1022 if (strcmp(fs, "zfs") == 0 || strstr(fs, "nfs") != NULL ||
1023 dev[0] == '\0' || root_mount_always_wait != 0) {
1024 vfs_mountroot_wait();
1025 return (0);
1026 }
1027
1028 /*
1029 * Otherwise, no point in waiting if the device is already there.
1030 * Note that we must wait for GEOM to finish reconfiguring itself,
1031 * eg for geom_part(4) to finish tasting.
1032 */
1033 g_waitidle(curthread);
1034 if (parse_mount_dev_present(dev))
1035 return (0);
1036
1037 /*
1038 * No luck. Let's wait. This code looks weird, but it's that way
1039 * to behave exactly as it used to work before.
1040 */
1041 vfs_mountroot_wait();
1042 if (parse_mount_dev_present(dev))
1043 return (0);
1044 printf("mountroot: waiting for device %s...\n", dev);
1045 delay = hz / 10;
1046 timeout = root_mount_timeout * hz;
1047 do {
1048 pause("rmdev", delay);
1049 timeout -= delay;
1050 } while (timeout > 0 && !parse_mount_dev_present(dev));
1051
1052 if (timeout <= 0)
1053 return (ENODEV);
1054
1055 return (0);
1056 }
1057
1058 void
vfs_mountroot(void)1059 vfs_mountroot(void)
1060 {
1061 struct mount *mp;
1062 struct sbuf *sb;
1063 struct thread *td;
1064 time_t timebase;
1065 int error;
1066
1067 mtx_assert(&Giant, MA_NOTOWNED);
1068
1069 TSENTER();
1070
1071 td = curthread;
1072
1073 sb = sbuf_new_auto();
1074 vfs_mountroot_conf0(sb);
1075 sbuf_finish(sb);
1076
1077 error = vfs_mountroot_devfs(td, &mp);
1078 while (!error) {
1079 error = vfs_mountroot_parse(sb, mp);
1080 if (!error) {
1081 vfs_mountroot_shuffle(td, mp);
1082 sbuf_clear(sb);
1083 error = vfs_mountroot_readconf(td, sb);
1084 sbuf_finish(sb);
1085 }
1086 }
1087
1088 sbuf_delete(sb);
1089
1090 /*
1091 * Iterate over all currently mounted file systems and use
1092 * the time stamp found to check and/or initialize the RTC.
1093 * Call inittodr() only once and pass it the largest of the
1094 * timestamps we encounter.
1095 */
1096 timebase = 0;
1097 mtx_lock(&mountlist_mtx);
1098 mp = TAILQ_FIRST(&mountlist);
1099 while (mp != NULL) {
1100 if (mp->mnt_time > timebase)
1101 timebase = mp->mnt_time;
1102 mp = TAILQ_NEXT(mp, mnt_list);
1103 }
1104 mtx_unlock(&mountlist_mtx);
1105 inittodr(timebase);
1106
1107 /* Keep prison0's root in sync with the global rootvnode. */
1108 mtx_lock(&prison0.pr_mtx);
1109 prison0.pr_root = rootvnode;
1110 vref(prison0.pr_root);
1111 mtx_unlock(&prison0.pr_mtx);
1112
1113 mtx_lock(&root_holds_mtx);
1114 atomic_store_rel_int(&root_mount_complete, 1);
1115 wakeup(&root_mount_complete);
1116 mtx_unlock(&root_holds_mtx);
1117
1118 EVENTHANDLER_INVOKE(mountroot);
1119
1120 TSEXIT();
1121 }
1122
1123 static struct mntarg *
parse_mountroot_options(struct mntarg * ma,const char * options)1124 parse_mountroot_options(struct mntarg *ma, const char *options)
1125 {
1126 char *p;
1127 char *name, *name_arg;
1128 char *val, *val_arg;
1129 char *opts;
1130
1131 if (options == NULL || options[0] == '\0')
1132 return (ma);
1133
1134 p = opts = strdup(options, M_MOUNT);
1135 if (opts == NULL) {
1136 return (ma);
1137 }
1138
1139 while((name = strsep(&p, ",")) != NULL) {
1140 if (name[0] == '\0')
1141 break;
1142
1143 val = strchr(name, '=');
1144 if (val != NULL) {
1145 *val = '\0';
1146 ++val;
1147 }
1148 if (strcmp(name, "rw") == 0 || strcmp(name, "noro") == 0) {
1149 /*
1150 * The first time we mount the root file system,
1151 * we need to mount 'ro', so We need to ignore
1152 * 'rw' and 'noro' mount options.
1153 */
1154 continue;
1155 }
1156 name_arg = strdup(name, M_MOUNT);
1157 val_arg = NULL;
1158 if (val != NULL)
1159 val_arg = strdup(val, M_MOUNT);
1160
1161 ma = mount_arg(ma, name_arg, val_arg,
1162 (val_arg != NULL ? -1 : 0));
1163 }
1164 free(opts, M_MOUNT);
1165 return (ma);
1166 }
1167