1 /*-
2 * Copyright (c) 1999 Michael Smith
3 * All rights reserved.
4 * Copyright (c) 1999 Poul-Henning Kamp
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD: src/sys/kern/vfs_conf.c,v 1.49.2.5 2003/01/07 11:56:53 joerg Exp $
29 */
30
31 /*
32 * Locate and mount the root filesystem.
33 *
34 * The root filesystem is detailed in the kernel environment variable
35 * vfs.root.mountfrom, which is expected to be in the general format
36 *
37 * <vfsname>:[<path>]
38 * vfsname := the name of a VFS known to the kernel and capable
39 * of being mounted as root
40 * path := disk device name or other data used by the filesystem
41 * to locate its physical store
42 *
43 */
44
45 #include "opt_rootdevname.h"
46
47 #include <sys/param.h>
48 #include <sys/kernel.h>
49 #include <sys/systm.h>
50 #include <sys/proc.h>
51 #include <sys/vnode.h>
52 #include <sys/mount.h>
53 #include <sys/malloc.h>
54 #include <sys/reboot.h>
55 #include <sys/diskslice.h>
56 #include <sys/conf.h>
57 #include <sys/cons.h>
58 #include <sys/kbio.h>
59 #include <sys/device.h>
60 #include <sys/disk.h>
61 #include <sys/namecache.h>
62 #include <sys/paths.h>
63 #include <sys/thread2.h>
64 #include <sys/nlookup.h>
65 #include <sys/devfs.h>
66 #include <sys/sysctl.h>
67
68 #include "opt_ddb.h"
69 #ifdef DDB
70 #include <ddb/ddb.h>
71 #endif
72
73 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
74
75 #define ROOTNAME "root_device"
76
77 struct vnode *rootvnode;
78 struct nchandle rootnch;
79
80 /*
81 * The root specifiers we will try if RB_CDROM is specified. Note that
82 * with DEVFS we do not use the compatibility slice's whole-disk 'c'
83 * partition. Instead we just use the whole disk, e.g. cd0 or cd0s0.
84 */
85 static char *cdrom_rootdevnames[] = {
86 "cd9660:cd0", /* SCSI (including AHCI and SILI) */
87 "cd9660:acd0", /* NATA */
88 "cd9660:cd1", /* SCSI (including AHCI and SILI) */
89 "cd9660:acd1", /* NATA */
90 "cd9660:cd8", /* USB */
91 "cd9660:cd9", /* USB */
92 NULL
93 };
94
95 int vfs_mountroot_devfs(void);
96 static void vfs_mountroot(void *junk);
97 static int vfs_mountroot_try(const char *mountfrom);
98 static int vfs_mountroot_ask(void);
99 static int get_line(char *cp, int limit);
100
101 /* legacy find-root code */
102 char *rootdevnames[2] = {NULL, NULL};
103 static int setrootbyname(char *name);
104
105 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL);
106
107 static int wakedelay = 2; /* delay before mounting root in seconds */
108 TUNABLE_INT("vfs.root.wakedelay", &wakedelay);
109
110 /*
111 * Find and mount the root filesystem
112 */
113 static void
vfs_mountroot(void * junk)114 vfs_mountroot(void *junk)
115 {
116 cdev_t save_rootdev = rootdev;
117 int i;
118 int dummy;
119
120 /*
121 * Make sure all disk devices created so far have also been probed,
122 * and also make sure that the newly created device nodes for
123 * probed disks are ready, too.
124 *
125 * Messages can fly around here so get good synchronization
126 * coverage.
127 *
128 * XXX - Delay some more (default: 2s) to help drivers which pickup
129 * devices asynchronously and are not caught by CAM's initial
130 * probe.
131 */
132 sync_devs();
133 tsleep(&dummy, 0, "syncer", hz * wakedelay);
134
135
136 /*
137 * The root filesystem information is compiled in, and we are
138 * booted with instructions to use it.
139 */
140 #ifdef ROOTDEVNAME
141 if ((boothowto & RB_DFLTROOT) &&
142 !vfs_mountroot_try(ROOTDEVNAME))
143 return;
144 #endif
145 /*
146 * We are booted with instructions to prompt for the root filesystem,
147 * or to use the compiled-in default when it doesn't exist.
148 */
149 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) {
150 if (!vfs_mountroot_ask())
151 return;
152 }
153
154 /*
155 * We've been given the generic "use CDROM as root" flag. This is
156 * necessary because one media may be used in many different
157 * devices, so we need to search for them.
158 */
159 if (boothowto & RB_CDROM) {
160 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
161 if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
162 return;
163 }
164 }
165
166 /*
167 * Try to use the value read by the loader from /etc/fstab, or
168 * supplied via some other means. This is the preferred
169 * mechanism.
170 */
171 if (!vfs_mountroot_try(kgetenv("vfs.root.mountfrom")))
172 return;
173
174 /*
175 * If a vfs set rootdev, try it (XXX VINUM HACK!)
176 */
177 if (save_rootdev != NULL) {
178 rootdev = save_rootdev;
179 if (!vfs_mountroot_try(""))
180 return;
181 }
182
183 /*
184 * Try values that may have been computed by the machine-dependant
185 * legacy code.
186 */
187 if (rootdevnames[0] && !vfs_mountroot_try(rootdevnames[0]))
188 return;
189 if (rootdevnames[1] && !vfs_mountroot_try(rootdevnames[1]))
190 return;
191
192 /*
193 * If we have a compiled-in default, and haven't already tried it, try
194 * it now.
195 */
196 #ifdef ROOTDEVNAME
197 if (!(boothowto & RB_DFLTROOT))
198 if (!vfs_mountroot_try(ROOTDEVNAME))
199 return;
200 #endif
201
202 /*
203 * Everything so far has failed, prompt on the console if we haven't
204 * already tried that.
205 */
206 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask())
207 return;
208 panic("Root mount failed, startup aborted.");
209 }
210
211
212 int
vfs_mountroot_devfs(void)213 vfs_mountroot_devfs(void)
214 {
215 struct vnode *vp;
216 struct nchandle nch;
217 struct nlookupdata nd;
218 struct mount *mp;
219 struct vfsconf *vfsp;
220 int error;
221 struct ucred *cred = proc0.p_ucred;
222 const char *devfs_path, *init_chroot;
223 char *dev_malloced = NULL;
224
225 if ((init_chroot = kgetenv("init_chroot")) != NULL) {
226 size_t l;
227
228 l = strlen(init_chroot) + sizeof("/dev");
229 dev_malloced = kmalloc(l, M_MOUNT, M_WAITOK);
230 ksnprintf(dev_malloced, l, "%s/dev", init_chroot);
231 devfs_path = dev_malloced;
232 } else {
233 devfs_path = "/dev";
234 }
235 /*
236 * Lookup the requested path and extract the nch and vnode.
237 */
238 error = nlookup_init_raw(&nd, devfs_path, UIO_SYSSPACE,
239 NLC_FOLLOW, cred, &rootnch);
240
241 if (error == 0) {
242 devfs_debug(DEVFS_DEBUG_DEBUG,
243 "vfs_mountroot_devfs: nlookup_init is ok...\n");
244 if ((error = nlookup(&nd)) == 0) {
245 devfs_debug(DEVFS_DEBUG_DEBUG,
246 "vfs_mountroot_devfs: nlookup is ok...\n");
247 if (nd.nl_nch.ncp->nc_vp == NULL) {
248 devfs_debug(DEVFS_DEBUG_SHOW,
249 "vfs_mountroot_devfs: nlookup: "
250 "simply not found\n");
251 error = ENOENT;
252 }
253 }
254 }
255 if (dev_malloced != NULL)
256 kfree(dev_malloced, M_MOUNT), dev_malloced = NULL;
257 devfs_path = NULL;
258 if (error) {
259 nlookup_done(&nd);
260 devfs_debug(DEVFS_DEBUG_SHOW,
261 "vfs_mountroot_devfs: nlookup failed, error: %d\n",
262 error);
263 return (error);
264 }
265
266 /*
267 * Extract the locked+refd ncp and cleanup the nd structure
268 */
269 nch = nd.nl_nch;
270 cache_zero(&nd.nl_nch);
271 nlookup_done(&nd);
272
273 /*
274 * now we have the locked ref'd nch and unreferenced vnode.
275 */
276 vp = nch.ncp->nc_vp;
277 if ((error = vget(vp, LK_EXCLUSIVE)) != 0) {
278 cache_put(&nch);
279 devfs_debug(DEVFS_DEBUG_SHOW,
280 "vfs_mountroot_devfs: vget failed\n");
281 return (error);
282 }
283 cache_unlock(&nch);
284
285 if ((error = vinvalbuf(vp, V_SAVE, 0, 0)) != 0) {
286 cache_drop(&nch);
287 vput(vp);
288 devfs_debug(DEVFS_DEBUG_SHOW,
289 "vfs_mountroot_devfs: vinvalbuf failed\n");
290 return (error);
291 }
292 if (vp->v_type != VDIR) {
293 cache_drop(&nch);
294 vput(vp);
295 devfs_debug(DEVFS_DEBUG_SHOW,
296 "vfs_mountroot_devfs: vp is not VDIR\n");
297 return (ENOTDIR);
298 }
299
300 vfsp = vfsconf_find_by_name("devfs");
301
302 /*
303 * Allocate and initialize the filesystem.
304 */
305 mp = kmalloc(sizeof(struct mount), M_MOUNT, M_ZERO|M_WAITOK);
306 mount_init(mp, vfsp->vfc_vfsops);
307 vfs_busy(mp, LK_NOWAIT);
308 mp->mnt_vfc = vfsp;
309 mp->mnt_pbuf_count = nswbuf_kva / NSWBUF_SPLIT;
310 vfsp->vfc_refcount++;
311 mp->mnt_stat.f_type = vfsp->vfc_typenum;
312 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
313 if (vfsp->vfc_flags & VFCF_MPSAFE)
314 mp->mnt_kern_flag |= MNTK_ALL_MPSAFE;
315 strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
316 mp->mnt_stat.f_owner = cred->cr_uid;
317 mp->mnt_ncmounton = nch;
318 vn_unlock(vp);
319
320 /*
321 * Mount the filesystem.
322 */
323 error = VFS_MOUNT(mp, "/dev", NULL, cred);
324 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
325
326 /*
327 * Put the new filesystem on the mount list after root. The mount
328 * point gets its own mnt_ncmountpt (unless the VFS already set one
329 * up) which represents the root of the mount. The lookup code
330 * detects the mount point going forward and checks the root of
331 * the mount going backwards.
332 *
333 * It is not necessary to invalidate or purge the vnode underneath
334 * because elements under the mount will be given their own glue
335 * namecache record.
336 */
337 if (!error) {
338 if (mp->mnt_ncmountpt.ncp == NULL) {
339 /*
340 * allocate, then unlock, but leave the ref intact
341 */
342 cache_allocroot(&mp->mnt_ncmountpt, mp, NULL);
343 cache_unlock(&mp->mnt_ncmountpt);
344 }
345 vn_unlock(vp);
346 cache_lock(&nch);
347 nch.ncp->nc_flag |= NCF_ISMOUNTPT;
348 cache_unlock(&nch);
349 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
350
351 /*
352 * XXX get the root of the fs and
353 * cache_setvp(mnt_ncmountpt...)
354 */
355 mountlist_insert(mp, MNTINS_LAST);
356 vn_unlock(vp);
357 //checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
358 error = vfs_allocate_syncvnode(mp);
359 if (error) {
360 devfs_debug(DEVFS_DEBUG_SHOW,
361 "vfs_mountroot_devfs: "
362 "vfs_allocate_syncvnode failed\n");
363 }
364 vfs_unbusy(mp);
365 error = VFS_START(mp, 0);
366 vrele(vp);
367 } else {
368 bzero(&mp->mnt_ncmounton, sizeof(mp->mnt_ncmounton));
369 vn_syncer_thr_stop(mp);
370 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
371 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
372 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
373 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
374 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
375 mp->mnt_vfc->vfc_refcount--;
376 vfs_unbusy(mp);
377 kfree(mp, M_MOUNT);
378 cache_drop(&nch);
379 vput(vp);
380 devfs_debug(DEVFS_DEBUG_SHOW,
381 "vfs_mountroot_devfs: mount failed\n");
382 }
383
384 devfs_debug(DEVFS_DEBUG_DEBUG,
385 "rootmount_devfs done with error: %d\n", error);
386 return (error);
387 }
388
389
390 /*
391 * Mount (mountfrom) as the root filesystem.
392 */
393 static int
vfs_mountroot_try(const char * mountfrom)394 vfs_mountroot_try(const char *mountfrom)
395 {
396 struct mount *mp;
397 char *vfsname, *devname;
398 int error;
399 char patt[32];
400 const char *cp, *ep;
401 char *mf;
402 struct proc *p;
403 struct vnode *vp;
404
405 vfsname = NULL;
406 devname = NULL;
407 mp = NULL;
408 error = EINVAL;
409
410 if (mountfrom == NULL)
411 return(error); /* don't complain */
412
413 crit_enter();
414 kprintf("Mounting root from %s\n", mountfrom);
415 crit_exit();
416
417 cp = mountfrom;
418 /* parse vfs name and devname */
419 vfsname = kmalloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
420 devname = kmalloc(MNAMELEN, M_MOUNT, M_WAITOK);
421 mf = kmalloc(MFSNAMELEN+MNAMELEN, M_MOUNT, M_WAITOK);
422 for(;;) {
423 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
424 bzero(vfsname, MFSNAMELEN);
425 bzero(devname, MNAMELEN);
426 bzero(mf, MFSNAMELEN+MNAMELEN);
427 strncpy(mf, cp, MFSNAMELEN+MNAMELEN);
428
429 vfsname[0] = devname[0] = 0;
430 ksprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
431 if (ksscanf(mf, patt, vfsname, devname) < 1)
432 goto end;
433
434 /* allocate a root mount */
435 error = vfs_rootmountalloc(vfsname,
436 devname[0] != 0 ? devname : ROOTNAME, &mp);
437 if (error != 0) {
438 kprintf("Can't allocate root mount for filesystem '%s': %d\n",
439 vfsname, error);
440 goto end;
441 }
442 mp->mnt_flag |= MNT_ROOTFS;
443
444 /* do our best to set rootdev (really just for UFS) */
445 if (strcmp(vfsname, "hammer") != 0 &&
446 strcmp(vfsname, "hammer2") != 0 &&
447 (devname[0] != 0) && setrootbyname(devname)) {
448 kprintf("setrootbyname failed\n");
449 }
450
451 /* If the root device is a type "memory disk", mount RW */
452 if (rootdev != NULL && dev_is_good(rootdev) &&
453 (dev_dflags(rootdev) & D_MEMDISK)) {
454 mp->mnt_flag &= ~MNT_RDONLY;
455 }
456
457 error = VFS_MOUNT(mp, NULL, NULL, proc0.p_ucred);
458
459 if (!error)
460 break;
461 end:
462 if(*ep == 0)
463 break;
464 cp = ep + 1;
465 }
466
467 if (vfsname != NULL)
468 kfree(vfsname, M_MOUNT);
469 if (devname != NULL)
470 kfree(devname, M_MOUNT);
471 if (mf != NULL)
472 kfree(mf, M_MOUNT);
473 if (error == 0) {
474 /* register with list of mounted filesystems */
475 mountlist_insert(mp, MNTINS_FIRST);
476
477 /* sanity check system clock against root fs timestamp */
478 inittodr(mp->mnt_time);
479
480 /* Get the vnode for '/'. Set p->p_fd->fd_cdir to reference it. */
481 mp = mountlist_boot_getfirst();
482 if (VFS_ROOT(mp, &vp))
483 panic("cannot find root vnode");
484 if (mp->mnt_ncmountpt.ncp == NULL) {
485 cache_allocroot(&mp->mnt_ncmountpt, mp, vp);
486 cache_unlock(&mp->mnt_ncmountpt); /* leave ref intact */
487 }
488 p = curproc;
489 p->p_fd->fd_cdir = vp;
490 vref(p->p_fd->fd_cdir);
491 p->p_fd->fd_rdir = vp;
492 vref(p->p_fd->fd_rdir);
493 vfs_cache_setroot(vp, cache_hold(&mp->mnt_ncmountpt));
494 vn_unlock(vp); /* leave ref intact */
495 cache_copy(&mp->mnt_ncmountpt, &p->p_fd->fd_ncdir);
496 cache_copy(&mp->mnt_ncmountpt, &p->p_fd->fd_nrdir);
497
498 vfs_unbusy(mp);
499 if (mp->mnt_syncer == NULL) {
500 error = vfs_allocate_syncvnode(mp);
501 if (error)
502 kprintf("Warning: no syncer vp for root!\n");
503 error = 0;
504 }
505 VFS_START( mp, 0 );
506 } else {
507 if (mp != NULL) {
508 vn_syncer_thr_stop(mp);
509 vfs_unbusy(mp);
510 kfree(mp, M_MOUNT);
511 }
512 kprintf("Root mount failed: %d\n", error);
513 }
514 return(error);
515 }
516
517
518 static void
vfs_mountroot_ask_callback(char * name,cdev_t dev,bool is_alias,void * arg __unused)519 vfs_mountroot_ask_callback(char *name, cdev_t dev, bool is_alias,
520 void *arg __unused)
521 {
522 if (!is_alias && dev_is_good(dev) && (dev_dflags(dev) & D_DISK))
523 kprintf(" \"%s\" ", name);
524 }
525
526
527 /*
528 * Spin prompting on the console for a suitable root filesystem
529 */
530 static int
vfs_mountroot_ask(void)531 vfs_mountroot_ask(void)
532 {
533 char name[128];
534 int llimit = 100;
535
536 kprintf("\nManual root filesystem specification:\n");
537 kprintf(" <fstype>:<device> Specify root (e.g. ufs:da0s1a)\n");
538 kprintf(" ? List valid disk boot devices\n");
539 kprintf(" panic Just panic\n");
540 kprintf(" abort Abort manual input\n");
541 while (llimit--) {
542 kprintf("\nmountroot> ");
543
544 if (get_line(name, 128) < 0)
545 break;
546 if (name[0] == 0) {
547 ;
548 } else if (name[0] == '?') {
549 kprintf("Possibly valid devices for root FS:\n");
550 //enumerate all disk devices
551 devfs_scan_callback(vfs_mountroot_ask_callback, NULL);
552 kprintf("\n");
553 continue;
554 } else if (strcmp(name, "panic") == 0) {
555 panic("panic from console");
556 } else if (strcmp(name, "abort") == 0) {
557 break;
558 } else if (vfs_mountroot_try(name) == 0) {
559 return(0);
560 }
561 }
562 return(1);
563 }
564
565
566 static int
get_line(char * cp,int limit)567 get_line(char *cp, int limit)
568 {
569 char *lp;
570 int dummy;
571 int c;
572
573 lp = cp;
574 cnpoll(TRUE);
575 for (;;) {
576 c = cncheckc();
577
578 switch (c) {
579 case NOKEY:
580 tsleep(&dummy, 0, "cnpoll", hz / 25);
581 break;
582 case -1:
583 goto done;
584 case '\n':
585 case '\r':
586 kprintf("\n");
587 *lp++ = '\0';
588 c = 0;
589 goto done;
590 case '\b':
591 case '\177':
592 if (lp > cp) {
593 kprintf("\b \b");
594 lp--;
595 } else {
596 kprintf("%c", 7);
597 }
598 continue;
599 case '#':
600 kprintf("#");
601 lp--;
602 if (lp < cp)
603 lp = cp;
604 continue;
605 case 'u' & 037:
606 /* NOTE: '@' no longer processed here, used for H2 */
607 lp = cp;
608 kprintf("%c", '\n');
609 continue;
610 default:
611 if (lp - cp >= limit - 1) {
612 kprintf("%c", 7);
613 } else {
614 kprintf("%c", c);
615 *lp++ = c;
616 }
617 continue;
618 }
619 }
620 done:
621 cnpoll(FALSE);
622 return c;
623 }
624
625 /*
626 * Convert a given name to the cdev_t of the disk-like device
627 * it refers to.
628 */
629 cdev_t
kgetdiskbyname(const char * name)630 kgetdiskbyname(const char *name)
631 {
632 cdev_t rdev;
633
634 /*
635 * Get the base name of the device
636 */
637 if (strncmp(name, __SYS_PATH_DEV, sizeof(__SYS_PATH_DEV) - 1) == 0)
638 name += sizeof(__SYS_PATH_DEV) - 1;
639
640 /*
641 * Locate the device
642 */
643 rdev = devfs_find_device_by_name("%s", name);
644 if (rdev == NULL) {
645 kprintf("no disk named '%s'\n", name);
646 }
647 /*
648 * FOUND DEVICE
649 */
650 return(rdev);
651 }
652
653 /*
654 * Set rootdev to match (name), given that we expect it to
655 * refer to a disk-like device.
656 */
657 static int
setrootbyname(char * name)658 setrootbyname(char *name)
659 {
660 cdev_t diskdev;
661
662 diskdev = kgetdiskbyname(name);
663 if (diskdev != NULL) {
664 rootdev = diskdev;
665 return (0);
666 }
667 /* set to NULL if kgetdiskbyname() fails so that if the first rootdev is
668 * found by fails to mount and the second one isn't found, mountroot_try
669 * doesn't try again with the first one
670 */
671 rootdev = NULL;
672 return (1);
673 }
674
675 #ifdef DDB
DB_SHOW_COMMAND(disk,db_getdiskbyname)676 DB_SHOW_COMMAND(disk, db_getdiskbyname)
677 {
678 cdev_t dev;
679
680 if (modif[0] == '\0') {
681 db_error("usage: show disk/devicename");
682 return;
683 }
684 dev = kgetdiskbyname(modif);
685 if (dev != NULL)
686 db_printf("cdev_t = %p\n", dev);
687 else
688 db_printf("No disk device matched.\n");
689 }
690 #endif
691
692 static int
vfs_sysctl_real_root(SYSCTL_HANDLER_ARGS)693 vfs_sysctl_real_root(SYSCTL_HANDLER_ARGS)
694 {
695 char *real_root;
696 size_t len;
697 int error;
698
699 real_root = kgetenv("vfs.root.realroot");
700
701 if (real_root == NULL)
702 real_root = "";
703
704 len = strlen(real_root) + 1;
705
706 error = sysctl_handle_string(oidp, real_root, len, req);
707
708 return error;
709 }
710
711 SYSCTL_PROC(_vfs, OID_AUTO, real_root,
712 CTLTYPE_STRING | CTLFLAG_RD, 0, 0, vfs_sysctl_real_root,
713 "A", "Real root mount string");
714