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("$FreeBSD$");
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
sysctl_vfs_root_mount_hold(SYSCTL_HANDLER_ARGS)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 *
root_mount_hold(const char * identifier)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
root_mount_rel(struct root_hold_token * h)183 root_mount_rel(struct root_hold_token *h)
184 {
185
186 if (h == NULL)
187 return;
188
189 mtx_lock(&root_holds_mtx);
190 LIST_REMOVE(h, list);
191 wakeup(&root_holds);
192 mtx_unlock(&root_holds_mtx);
193 free(h, M_DEVBUF);
194 }
195
196 int
root_mounted(void)197 root_mounted(void)
198 {
199
200 /* No mutex is acquired here because int stores are atomic. */
201 return (root_mount_complete);
202 }
203
204 static void
set_rootvnode(void)205 set_rootvnode(void)
206 {
207 struct proc *p;
208
209 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
210 panic("Cannot find root vnode");
211
212 VOP_UNLOCK(rootvnode, 0);
213
214 p = curthread->td_proc;
215 FILEDESC_XLOCK(p->p_fd);
216
217 if (p->p_fd->fd_cdir != NULL)
218 vrele(p->p_fd->fd_cdir);
219 p->p_fd->fd_cdir = rootvnode;
220 VREF(rootvnode);
221
222 if (p->p_fd->fd_rdir != NULL)
223 vrele(p->p_fd->fd_rdir);
224 p->p_fd->fd_rdir = rootvnode;
225 VREF(rootvnode);
226
227 FILEDESC_XUNLOCK(p->p_fd);
228 }
229
230 static int
vfs_mountroot_devfs(struct thread * td,struct mount ** mpp)231 vfs_mountroot_devfs(struct thread *td, struct mount **mpp)
232 {
233 struct vfsoptlist *opts;
234 struct vfsconf *vfsp;
235 struct mount *mp;
236 int error;
237
238 *mpp = NULL;
239
240 if (rootdevmp != NULL) {
241 /*
242 * Already have /dev; this happens during rerooting.
243 */
244 error = vfs_busy(rootdevmp, 0);
245 if (error != 0)
246 return (error);
247 *mpp = rootdevmp;
248 } else {
249 vfsp = vfs_byname("devfs");
250 KASSERT(vfsp != NULL, ("Could not find devfs by name"));
251 if (vfsp == NULL)
252 return (ENOENT);
253
254 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
255
256 error = VFS_MOUNT(mp);
257 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
258 if (error)
259 return (error);
260
261 error = VFS_STATFS(mp, &mp->mnt_stat);
262 KASSERT(error == 0, ("VFS_STATFS(devfs) failed %d", error));
263 if (error)
264 return (error);
265
266 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
267 TAILQ_INIT(opts);
268 mp->mnt_opt = opts;
269
270 mtx_lock(&mountlist_mtx);
271 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
272 mtx_unlock(&mountlist_mtx);
273
274 *mpp = mp;
275 rootdevmp = mp;
276 }
277
278 set_rootvnode();
279
280 error = kern_symlinkat(td, "/", AT_FDCWD, "dev", UIO_SYSSPACE);
281 if (error)
282 printf("kern_symlink /dev -> / returns %d\n", error);
283
284 return (error);
285 }
286
287 static void
vfs_mountroot_shuffle(struct thread * td,struct mount * mpdevfs)288 vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs)
289 {
290 struct nameidata nd;
291 struct mount *mporoot, *mpnroot;
292 struct vnode *vp, *vporoot, *vpdevfs;
293 char *fspath;
294 int error;
295
296 mpnroot = TAILQ_NEXT(mpdevfs, mnt_list);
297
298 /* Shuffle the mountlist. */
299 mtx_lock(&mountlist_mtx);
300 mporoot = TAILQ_FIRST(&mountlist);
301 TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list);
302 if (mporoot != mpdevfs) {
303 TAILQ_REMOVE(&mountlist, mpnroot, mnt_list);
304 TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list);
305 }
306 TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list);
307 mtx_unlock(&mountlist_mtx);
308
309 cache_purgevfs(mporoot, true);
310 if (mporoot != mpdevfs)
311 cache_purgevfs(mpdevfs, true);
312
313 VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot);
314
315 VI_LOCK(vporoot);
316 vporoot->v_iflag &= ~VI_MOUNT;
317 VI_UNLOCK(vporoot);
318 vporoot->v_mountedhere = NULL;
319 mporoot->mnt_flag &= ~MNT_ROOTFS;
320 mporoot->mnt_vnodecovered = NULL;
321 vput(vporoot);
322
323 /* Set up the new rootvnode, and purge the cache */
324 mpnroot->mnt_vnodecovered = NULL;
325 set_rootvnode();
326 cache_purgevfs(rootvnode->v_mount, true);
327
328 if (mporoot != mpdevfs) {
329 /* Remount old root under /.mount or /mnt */
330 fspath = "/.mount";
331 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
332 fspath, td);
333 error = namei(&nd);
334 if (error) {
335 NDFREE(&nd, NDF_ONLY_PNBUF);
336 fspath = "/mnt";
337 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
338 fspath, td);
339 error = namei(&nd);
340 }
341 if (!error) {
342 vp = nd.ni_vp;
343 error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
344 if (!error)
345 error = vinvalbuf(vp, V_SAVE, 0, 0);
346 if (!error) {
347 cache_purge(vp);
348 mporoot->mnt_vnodecovered = vp;
349 vp->v_mountedhere = mporoot;
350 strlcpy(mporoot->mnt_stat.f_mntonname,
351 fspath, MNAMELEN);
352 VOP_UNLOCK(vp, 0);
353 } else
354 vput(vp);
355 }
356 NDFREE(&nd, NDF_ONLY_PNBUF);
357
358 if (error)
359 printf("mountroot: unable to remount previous root "
360 "under /.mount or /mnt (error %d)\n", error);
361 }
362
363 /* Remount devfs under /dev */
364 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
365 error = namei(&nd);
366 if (!error) {
367 vp = nd.ni_vp;
368 error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
369 if (!error)
370 error = vinvalbuf(vp, V_SAVE, 0, 0);
371 if (!error) {
372 vpdevfs = mpdevfs->mnt_vnodecovered;
373 if (vpdevfs != NULL) {
374 cache_purge(vpdevfs);
375 vpdevfs->v_mountedhere = NULL;
376 vrele(vpdevfs);
377 }
378 mpdevfs->mnt_vnodecovered = vp;
379 vp->v_mountedhere = mpdevfs;
380 VOP_UNLOCK(vp, 0);
381 } else
382 vput(vp);
383 }
384 if (error)
385 printf("mountroot: unable to remount devfs under /dev "
386 "(error %d)\n", error);
387 NDFREE(&nd, NDF_ONLY_PNBUF);
388
389 if (mporoot == mpdevfs) {
390 vfs_unbusy(mpdevfs);
391 /* Unlink the no longer needed /dev/dev -> / symlink */
392 error = kern_unlinkat(td, AT_FDCWD, "/dev/dev",
393 UIO_SYSSPACE, 0);
394 if (error)
395 printf("mountroot: unable to unlink /dev/dev "
396 "(error %d)\n", error);
397 }
398 }
399
400 /*
401 * Configuration parser.
402 */
403
404 /* Parser character classes. */
405 #define CC_WHITESPACE -1
406 #define CC_NONWHITESPACE -2
407
408 /* Parse errors. */
409 #define PE_EOF -1
410 #define PE_EOL -2
411
412 static __inline int
parse_peek(char ** conf)413 parse_peek(char **conf)
414 {
415
416 return (**conf);
417 }
418
419 static __inline void
parse_poke(char ** conf,int c)420 parse_poke(char **conf, int c)
421 {
422
423 **conf = c;
424 }
425
426 static __inline void
parse_advance(char ** conf)427 parse_advance(char **conf)
428 {
429
430 (*conf)++;
431 }
432
433 static int
parse_skipto(char ** conf,int mc)434 parse_skipto(char **conf, int mc)
435 {
436 int c, match;
437
438 while (1) {
439 c = parse_peek(conf);
440 if (c == 0)
441 return (PE_EOF);
442 switch (mc) {
443 case CC_WHITESPACE:
444 match = (c == ' ' || c == '\t' || c == '\n') ? 1 : 0;
445 break;
446 case CC_NONWHITESPACE:
447 if (c == '\n')
448 return (PE_EOL);
449 match = (c != ' ' && c != '\t') ? 1 : 0;
450 break;
451 default:
452 match = (c == mc) ? 1 : 0;
453 break;
454 }
455 if (match)
456 break;
457 parse_advance(conf);
458 }
459 return (0);
460 }
461
462 static int
parse_token(char ** conf,char ** tok)463 parse_token(char **conf, char **tok)
464 {
465 char *p;
466 size_t len;
467 int error;
468
469 *tok = NULL;
470 error = parse_skipto(conf, CC_NONWHITESPACE);
471 if (error)
472 return (error);
473 p = *conf;
474 error = parse_skipto(conf, CC_WHITESPACE);
475 len = *conf - p;
476 *tok = malloc(len + 1, M_TEMP, M_WAITOK | M_ZERO);
477 bcopy(p, *tok, len);
478 return (0);
479 }
480
481 static void
parse_dir_ask_printenv(const char * var)482 parse_dir_ask_printenv(const char *var)
483 {
484 char *val;
485
486 val = kern_getenv(var);
487 if (val != NULL) {
488 printf(" %s=%s\n", var, val);
489 freeenv(val);
490 }
491 }
492
493 static int
parse_dir_ask(char ** conf)494 parse_dir_ask(char **conf)
495 {
496 char name[80];
497 char *mnt;
498 int error;
499
500 vfs_mountroot_wait();
501
502 printf("\nLoader variables:\n");
503 parse_dir_ask_printenv("vfs.root.mountfrom");
504 parse_dir_ask_printenv("vfs.root.mountfrom.options");
505
506 printf("\nManual root filesystem specification:\n");
507 printf(" <fstype>:<device> [options]\n");
508 printf(" Mount <device> using filesystem <fstype>\n");
509 printf(" and with the specified (optional) option list.\n");
510 printf("\n");
511 printf(" eg. ufs:/dev/da0s1a\n");
512 printf(" zfs:tank\n");
513 printf(" cd9660:/dev/cd0 ro\n");
514 printf(" (which is equivalent to: ");
515 printf("mount -t cd9660 -o ro /dev/cd0 /)\n");
516 printf("\n");
517 printf(" ? List valid disk boot devices\n");
518 printf(" . Yield 1 second (for background tasks)\n");
519 printf(" <empty line> Abort manual input\n");
520
521 do {
522 error = EINVAL;
523 printf("\nmountroot> ");
524 cngets(name, sizeof(name), GETS_ECHO);
525 if (name[0] == '\0')
526 break;
527 if (name[0] == '?' && name[1] == '\0') {
528 printf("\nList of GEOM managed disk devices:\n ");
529 g_dev_print();
530 continue;
531 }
532 if (name[0] == '.' && name[1] == '\0') {
533 pause("rmask", hz);
534 continue;
535 }
536 mnt = name;
537 error = parse_mount(&mnt);
538 if (error == -1)
539 printf("Invalid file system specification.\n");
540 } while (error != 0);
541
542 return (error);
543 }
544
545 static int
parse_dir_md(char ** conf)546 parse_dir_md(char **conf)
547 {
548 struct stat sb;
549 struct thread *td;
550 struct md_ioctl *mdio;
551 char *path, *tok;
552 int error, fd, len;
553
554 td = curthread;
555
556 error = parse_token(conf, &tok);
557 if (error)
558 return (error);
559
560 len = strlen(tok);
561 mdio = malloc(sizeof(*mdio) + len + 1, M_TEMP, M_WAITOK | M_ZERO);
562 path = (void *)(mdio + 1);
563 bcopy(tok, path, len);
564 free(tok, M_TEMP);
565
566 /* Get file status. */
567 error = kern_statat(td, 0, AT_FDCWD, path, UIO_SYSSPACE, &sb, NULL);
568 if (error)
569 goto out;
570
571 /* Open /dev/mdctl so that we can attach/detach. */
572 error = kern_openat(td, AT_FDCWD, "/dev/" MDCTL_NAME, UIO_SYSSPACE,
573 O_RDWR, 0);
574 if (error)
575 goto out;
576
577 fd = td->td_retval[0];
578 mdio->md_version = MDIOVERSION;
579 mdio->md_type = MD_VNODE;
580
581 if (root_mount_mddev != -1) {
582 mdio->md_unit = root_mount_mddev;
583 DROP_GIANT();
584 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
585 PICKUP_GIANT();
586 /* Ignore errors. We don't care. */
587 root_mount_mddev = -1;
588 }
589
590 mdio->md_file = (void *)(mdio + 1);
591 mdio->md_options = MD_AUTOUNIT | MD_READONLY;
592 mdio->md_mediasize = sb.st_size;
593 mdio->md_unit = 0;
594 DROP_GIANT();
595 error = kern_ioctl(td, fd, MDIOCATTACH, (void *)mdio);
596 PICKUP_GIANT();
597 if (error)
598 goto out;
599
600 if (mdio->md_unit > 9) {
601 printf("rootmount: too many md units\n");
602 mdio->md_file = NULL;
603 mdio->md_options = 0;
604 mdio->md_mediasize = 0;
605 DROP_GIANT();
606 error = kern_ioctl(td, fd, MDIOCDETACH, (void *)mdio);
607 PICKUP_GIANT();
608 /* Ignore errors. We don't care. */
609 error = ERANGE;
610 goto out;
611 }
612
613 root_mount_mddev = mdio->md_unit;
614 printf(MD_NAME "%u attached to %s\n", root_mount_mddev, mdio->md_file);
615
616 error = kern_close(td, fd);
617
618 out:
619 free(mdio, M_TEMP);
620 return (error);
621 }
622
623 static int
parse_dir_onfail(char ** conf)624 parse_dir_onfail(char **conf)
625 {
626 char *action;
627 int error;
628
629 error = parse_token(conf, &action);
630 if (error)
631 return (error);
632
633 if (!strcmp(action, "continue"))
634 root_mount_onfail = A_CONTINUE;
635 else if (!strcmp(action, "panic"))
636 root_mount_onfail = A_PANIC;
637 else if (!strcmp(action, "reboot"))
638 root_mount_onfail = A_REBOOT;
639 else if (!strcmp(action, "retry"))
640 root_mount_onfail = A_RETRY;
641 else {
642 printf("rootmount: %s: unknown action\n", action);
643 error = EINVAL;
644 }
645
646 free(action, M_TEMP);
647 return (0);
648 }
649
650 static int
parse_dir_timeout(char ** conf)651 parse_dir_timeout(char **conf)
652 {
653 char *tok, *endtok;
654 long secs;
655 int error;
656
657 error = parse_token(conf, &tok);
658 if (error)
659 return (error);
660
661 secs = strtol(tok, &endtok, 0);
662 error = (secs < 0 || *endtok != '\0') ? EINVAL : 0;
663 if (!error)
664 root_mount_timeout = secs;
665 free(tok, M_TEMP);
666 return (error);
667 }
668
669 static int
parse_directive(char ** conf)670 parse_directive(char **conf)
671 {
672 char *dir;
673 int error;
674
675 error = parse_token(conf, &dir);
676 if (error)
677 return (error);
678
679 if (strcmp(dir, ".ask") == 0)
680 error = parse_dir_ask(conf);
681 else if (strcmp(dir, ".md") == 0)
682 error = parse_dir_md(conf);
683 else if (strcmp(dir, ".onfail") == 0)
684 error = parse_dir_onfail(conf);
685 else if (strcmp(dir, ".timeout") == 0)
686 error = parse_dir_timeout(conf);
687 else {
688 printf("mountroot: invalid directive `%s'\n", dir);
689 /* Ignore the rest of the line. */
690 (void)parse_skipto(conf, '\n');
691 error = EINVAL;
692 }
693 free(dir, M_TEMP);
694 return (error);
695 }
696
697 static int
parse_mount_dev_present(const char * dev)698 parse_mount_dev_present(const char *dev)
699 {
700 struct nameidata nd;
701 int error;
702
703 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, dev, curthread);
704 error = namei(&nd);
705 if (!error)
706 vput(nd.ni_vp);
707 NDFREE(&nd, NDF_ONLY_PNBUF);
708 return (error != 0) ? 0 : 1;
709 }
710
711 #define ERRMSGL 255
712 static int
parse_mount(char ** conf)713 parse_mount(char **conf)
714 {
715 char *errmsg;
716 struct mntarg *ma;
717 char *dev, *fs, *opts, *tok;
718 int delay, error, timeout;
719
720 error = parse_token(conf, &tok);
721 if (error)
722 return (error);
723 fs = tok;
724 error = parse_skipto(&tok, ':');
725 if (error) {
726 free(fs, M_TEMP);
727 return (error);
728 }
729 parse_poke(&tok, '\0');
730 parse_advance(&tok);
731 dev = tok;
732
733 if (root_mount_mddev != -1) {
734 /* Handle substitution for the md unit number. */
735 tok = strstr(dev, "md#");
736 if (tok != NULL)
737 tok[2] = '0' + root_mount_mddev;
738 }
739
740 /* Parse options. */
741 error = parse_token(conf, &tok);
742 opts = (error == 0) ? tok : NULL;
743
744 printf("Trying to mount root from %s:%s [%s]...\n", fs, dev,
745 (opts != NULL) ? opts : "");
746
747 errmsg = malloc(ERRMSGL, M_TEMP, M_WAITOK | M_ZERO);
748
749 if (vfs_byname(fs) == NULL) {
750 strlcpy(errmsg, "unknown file system", ERRMSGL);
751 error = ENOENT;
752 goto out;
753 }
754
755 error = vfs_mountroot_wait_if_neccessary(fs, dev);
756 if (error != 0)
757 goto out;
758
759 delay = hz / 10;
760 timeout = root_mount_timeout * hz;
761
762 for (;;) {
763 ma = NULL;
764 ma = mount_arg(ma, "fstype", fs, -1);
765 ma = mount_arg(ma, "fspath", "/", -1);
766 ma = mount_arg(ma, "from", dev, -1);
767 ma = mount_arg(ma, "errmsg", errmsg, ERRMSGL);
768 ma = mount_arg(ma, "ro", NULL, 0);
769 ma = parse_mountroot_options(ma, opts);
770
771 error = kernel_mount(ma, MNT_ROOTFS);
772 if (error == 0 || timeout <= 0)
773 break;
774
775 if (root_mount_timeout * hz == timeout ||
776 (bootverbose && timeout % hz == 0)) {
777 printf("Mounting from %s:%s failed with error %d; "
778 "retrying for %d more second%s\n", fs, dev, error,
779 timeout / hz, (timeout / hz > 1) ? "s" : "");
780 }
781 pause("rmretry", delay);
782 timeout -= delay;
783 }
784 out:
785 if (error) {
786 printf("Mounting from %s:%s failed with error %d",
787 fs, dev, error);
788 if (errmsg[0] != '\0')
789 printf(": %s", errmsg);
790 printf(".\n");
791 }
792 free(fs, M_TEMP);
793 free(errmsg, M_TEMP);
794 if (opts != NULL)
795 free(opts, M_TEMP);
796 /* kernel_mount can return -1 on error. */
797 return ((error < 0) ? EDOOFUS : error);
798 }
799 #undef ERRMSGL
800
801 static int
vfs_mountroot_parse(struct sbuf * sb,struct mount * mpdevfs)802 vfs_mountroot_parse(struct sbuf *sb, struct mount *mpdevfs)
803 {
804 struct mount *mp;
805 char *conf;
806 int error;
807
808 root_mount_mddev = -1;
809
810 retry:
811 conf = sbuf_data(sb);
812 mp = TAILQ_NEXT(mpdevfs, mnt_list);
813 error = (mp == NULL) ? 0 : EDOOFUS;
814 root_mount_onfail = A_CONTINUE;
815 while (mp == NULL) {
816 error = parse_skipto(&conf, CC_NONWHITESPACE);
817 if (error == PE_EOL) {
818 parse_advance(&conf);
819 continue;
820 }
821 if (error < 0)
822 break;
823 switch (parse_peek(&conf)) {
824 case '#':
825 error = parse_skipto(&conf, '\n');
826 break;
827 case '.':
828 error = parse_directive(&conf);
829 break;
830 default:
831 error = parse_mount(&conf);
832 if (error == -1) {
833 printf("mountroot: invalid file system "
834 "specification.\n");
835 error = 0;
836 }
837 break;
838 }
839 if (error < 0)
840 break;
841 /* Ignore any trailing garbage on the line. */
842 if (parse_peek(&conf) != '\n') {
843 printf("mountroot: advancing to next directive...\n");
844 (void)parse_skipto(&conf, '\n');
845 }
846 mp = TAILQ_NEXT(mpdevfs, mnt_list);
847 }
848 if (mp != NULL)
849 return (0);
850
851 /*
852 * We failed to mount (a new) root.
853 */
854 switch (root_mount_onfail) {
855 case A_CONTINUE:
856 break;
857 case A_PANIC:
858 panic("mountroot: unable to (re-)mount root.");
859 /* NOTREACHED */
860 case A_RETRY:
861 goto retry;
862 case A_REBOOT:
863 kern_reboot(RB_NOSYNC);
864 /* NOTREACHED */
865 }
866
867 return (error);
868 }
869
870 static void
vfs_mountroot_conf0(struct sbuf * sb)871 vfs_mountroot_conf0(struct sbuf *sb)
872 {
873 char *s, *tok, *mnt, *opt;
874 int error;
875
876 sbuf_printf(sb, ".onfail panic\n");
877 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
878 if (boothowto & RB_ASKNAME)
879 sbuf_printf(sb, ".ask\n");
880 #ifdef ROOTDEVNAME
881 if (boothowto & RB_DFLTROOT)
882 sbuf_printf(sb, "%s\n", ROOTDEVNAME);
883 #endif
884 if (boothowto & RB_CDROM) {
885 sbuf_printf(sb, "cd9660:/dev/cd0 ro\n");
886 sbuf_printf(sb, ".timeout 0\n");
887 sbuf_printf(sb, "cd9660:/dev/cd1 ro\n");
888 sbuf_printf(sb, ".timeout %d\n", root_mount_timeout);
889 }
890 s = kern_getenv("vfs.root.mountfrom");
891 if (s != NULL) {
892 opt = kern_getenv("vfs.root.mountfrom.options");
893 tok = s;
894 error = parse_token(&tok, &mnt);
895 while (!error) {
896 sbuf_printf(sb, "%s %s\n", mnt,
897 (opt != NULL) ? opt : "");
898 free(mnt, M_TEMP);
899 error = parse_token(&tok, &mnt);
900 }
901 if (opt != NULL)
902 freeenv(opt);
903 freeenv(s);
904 }
905 if (rootdevnames[0] != NULL)
906 sbuf_printf(sb, "%s\n", rootdevnames[0]);
907 if (rootdevnames[1] != NULL)
908 sbuf_printf(sb, "%s\n", rootdevnames[1]);
909 #ifdef ROOTDEVNAME
910 if (!(boothowto & RB_DFLTROOT))
911 sbuf_printf(sb, "%s\n", ROOTDEVNAME);
912 #endif
913 if (!(boothowto & RB_ASKNAME))
914 sbuf_printf(sb, ".ask\n");
915 }
916
917 static int
vfs_mountroot_readconf(struct thread * td,struct sbuf * sb)918 vfs_mountroot_readconf(struct thread *td, struct sbuf *sb)
919 {
920 static char buf[128];
921 struct nameidata nd;
922 off_t ofs;
923 ssize_t resid;
924 int error, flags, len;
925
926 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/.mount.conf", td);
927 flags = FREAD;
928 error = vn_open(&nd, &flags, 0, NULL);
929 if (error)
930 return (error);
931
932 NDFREE(&nd, NDF_ONLY_PNBUF);
933 ofs = 0;
934 len = sizeof(buf) - 1;
935 while (1) {
936 error = vn_rdwr(UIO_READ, nd.ni_vp, buf, len, ofs,
937 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
938 NOCRED, &resid, td);
939 if (error)
940 break;
941 if (resid == len)
942 break;
943 buf[len - resid] = 0;
944 sbuf_printf(sb, "%s", buf);
945 ofs += len - resid;
946 }
947
948 VOP_UNLOCK(nd.ni_vp, 0);
949 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
950 return (error);
951 }
952
953 static void
vfs_mountroot_wait(void)954 vfs_mountroot_wait(void)
955 {
956 struct root_hold_token *h;
957 struct timeval lastfail;
958 int curfail;
959
960 curfail = 0;
961 while (1) {
962 DROP_GIANT();
963 g_waitidle();
964 PICKUP_GIANT();
965 mtx_lock(&root_holds_mtx);
966 if (LIST_EMPTY(&root_holds)) {
967 mtx_unlock(&root_holds_mtx);
968 break;
969 }
970 if (ppsratecheck(&lastfail, &curfail, 1)) {
971 printf("Root mount waiting for:");
972 LIST_FOREACH(h, &root_holds, list)
973 printf(" %s", h->who);
974 printf("\n");
975 }
976 msleep(&root_holds, &root_holds_mtx, PZERO | PDROP, "roothold",
977 hz);
978 }
979 }
980
981 static int
vfs_mountroot_wait_if_neccessary(const char * fs,const char * dev)982 vfs_mountroot_wait_if_neccessary(const char *fs, const char *dev)
983 {
984 int delay, timeout;
985
986 /*
987 * In case of ZFS and NFS we don't have a way to wait for
988 * specific device. Also do the wait if the user forced that
989 * behaviour by setting vfs.root_mount_always_wait=1.
990 */
991 if (strcmp(fs, "zfs") == 0 || strstr(fs, "nfs") != NULL ||
992 dev[0] == '\0' || root_mount_always_wait != 0) {
993 vfs_mountroot_wait();
994 return (0);
995 }
996
997 /*
998 * Otherwise, no point in waiting if the device is already there.
999 * Note that we must wait for GEOM to finish reconfiguring itself,
1000 * eg for geom_part(4) to finish tasting.
1001 */
1002 DROP_GIANT();
1003 g_waitidle();
1004 PICKUP_GIANT();
1005 if (parse_mount_dev_present(dev))
1006 return (0);
1007
1008 /*
1009 * No luck. Let's wait. This code looks weird, but it's that way
1010 * to behave exactly as it used to work before.
1011 */
1012 vfs_mountroot_wait();
1013 printf("mountroot: waiting for device %s...\n", dev);
1014 delay = hz / 10;
1015 timeout = root_mount_timeout * hz;
1016 do {
1017 pause("rmdev", delay);
1018 timeout -= delay;
1019 } while (timeout > 0 && !parse_mount_dev_present(dev));
1020
1021 if (timeout <= 0)
1022 return (ENODEV);
1023
1024 return (0);
1025 }
1026
1027 void
vfs_mountroot(void)1028 vfs_mountroot(void)
1029 {
1030 struct mount *mp;
1031 struct sbuf *sb;
1032 struct thread *td;
1033 time_t timebase;
1034 int error;
1035
1036 td = curthread;
1037
1038 sb = sbuf_new_auto();
1039 vfs_mountroot_conf0(sb);
1040 sbuf_finish(sb);
1041
1042 error = vfs_mountroot_devfs(td, &mp);
1043 while (!error) {
1044 error = vfs_mountroot_parse(sb, mp);
1045 if (!error) {
1046 vfs_mountroot_shuffle(td, mp);
1047 sbuf_clear(sb);
1048 error = vfs_mountroot_readconf(td, sb);
1049 sbuf_finish(sb);
1050 }
1051 }
1052
1053 sbuf_delete(sb);
1054
1055 /*
1056 * Iterate over all currently mounted file systems and use
1057 * the time stamp found to check and/or initialize the RTC.
1058 * Call inittodr() only once and pass it the largest of the
1059 * timestamps we encounter.
1060 */
1061 timebase = 0;
1062 mtx_lock(&mountlist_mtx);
1063 mp = TAILQ_FIRST(&mountlist);
1064 while (mp != NULL) {
1065 if (mp->mnt_time > timebase)
1066 timebase = mp->mnt_time;
1067 mp = TAILQ_NEXT(mp, mnt_list);
1068 }
1069 mtx_unlock(&mountlist_mtx);
1070 inittodr(timebase);
1071
1072 /* Keep prison0's root in sync with the global rootvnode. */
1073 mtx_lock(&prison0.pr_mtx);
1074 prison0.pr_root = rootvnode;
1075 vref(prison0.pr_root);
1076 mtx_unlock(&prison0.pr_mtx);
1077
1078 mtx_lock(&root_holds_mtx);
1079 atomic_store_rel_int(&root_mount_complete, 1);
1080 wakeup(&root_mount_complete);
1081 mtx_unlock(&root_holds_mtx);
1082
1083 EVENTHANDLER_INVOKE(mountroot);
1084 }
1085
1086 static struct mntarg *
parse_mountroot_options(struct mntarg * ma,const char * options)1087 parse_mountroot_options(struct mntarg *ma, const char *options)
1088 {
1089 char *p;
1090 char *name, *name_arg;
1091 char *val, *val_arg;
1092 char *opts;
1093
1094 if (options == NULL || options[0] == '\0')
1095 return (ma);
1096
1097 p = opts = strdup(options, M_MOUNT);
1098 if (opts == NULL) {
1099 return (ma);
1100 }
1101
1102 while((name = strsep(&p, ",")) != NULL) {
1103 if (name[0] == '\0')
1104 break;
1105
1106 val = strchr(name, '=');
1107 if (val != NULL) {
1108 *val = '\0';
1109 ++val;
1110 }
1111 if( strcmp(name, "rw") == 0 ||
1112 strcmp(name, "noro") == 0) {
1113 /*
1114 * The first time we mount the root file system,
1115 * we need to mount 'ro', so We need to ignore
1116 * 'rw' and 'noro' mount options.
1117 */
1118 continue;
1119 }
1120 name_arg = strdup(name, M_MOUNT);
1121 val_arg = NULL;
1122 if (val != NULL)
1123 val_arg = strdup(val, M_MOUNT);
1124
1125 ma = mount_arg(ma, name_arg, val_arg,
1126 (val_arg != NULL ? -1 : 0));
1127 }
1128 free(opts, M_MOUNT);
1129 return (ma);
1130 }
1131