kernel: Turn the delay before mounting root into a tunable.
[dragonfly.git] / sys / kern / vfs_conf.c
CommitLineData
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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>
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56#include <sys/conf.h>
57#include <sys/cons.h>
335dda38 58#include <sys/device.h>
cd29885a 59#include <sys/disk.h>
21739618 60#include <sys/namecache.h>
1f2de5d4 61#include <sys/paths.h>
e43a034f 62#include <sys/thread2.h>
cd29885a 63#include <sys/nlookup.h>
2c1e28dd 64#include <sys/devfs.h>
b480ee28 65#include <sys/sysctl.h>
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66
67#include "opt_ddb.h"
68#ifdef DDB
69#include <ddb/ddb.h>
70#endif
71
72MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
73
74#define ROOTNAME "root_device"
75
76struct vnode *rootvnode;
28623bf9 77struct nchandle rootnch;
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78
79/*
6fcb48f2 80 * The root specifiers we will try if RB_CDROM is specified. Note that
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81 * with DEVFS we do not use the compatibility slice's whole-disk 'c'
82 * partition. Instead we just use the whole disk, e.g. cd0 or cd0s0.
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83 */
84static char *cdrom_rootdevnames[] = {
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85 "cd9660:cd0", /* SCSI (including AHCI and SILI) */
86 "cd9660:acd0", /* NATA */
87 "cd9660:cd1", /* SCSI (including AHCI and SILI) */
88 "cd9660:acd1", /* NATA */
89 "cd9660:cd8", /* USB */
90 "cd9660:cd9", /* USB */
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91 NULL
92};
93
cd29885a 94int vfs_mountroot_devfs(void);
984263bc 95static void vfs_mountroot(void *junk);
6b98993e 96static int vfs_mountroot_try(const char *mountfrom);
984263bc 97static int vfs_mountroot_ask(void);
cee92776 98static int getline(char *cp, int limit);
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99
100/* legacy find-root code */
101char *rootdevnames[2] = {NULL, NULL};
102static int setrootbyname(char *name);
103
104SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL);
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105
106static int wakedelay = 2; /* delay before mounting root in seconds */
107TUNABLE_INT("vfs.root.wakedelay", &wakedelay);
108
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109/*
110 * Find and mount the root filesystem
111 */
112static void
113vfs_mountroot(void *junk)
114{
b13267a5 115 cdev_t save_rootdev = rootdev;
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116 int i;
117 int dummy;
984263bc 118
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119 /*
120 * Make sure all disk devices created so far have also been probed,
121 * and also make sure that the newly created device nodes for
122 * probed disks are ready, too.
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123 *
124 * Messages can fly around here so get good synchronization
125 * coverage.
a2b57962 126 *
5a82ae89 127 * XXX - Delay some more (default: 2s) to help drivers which pickup
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128 * devices asynchronously and are not caught by CAM's initial
129 * probe.
cd29885a 130 */
2a32d680 131 sync_devs();
5a82ae89 132 tsleep(&dummy, 0, "syncer", hz * wakedelay);
a2b57962 133
cd29885a 134
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135 /*
136 * The root filesystem information is compiled in, and we are
137 * booted with instructions to use it.
138 */
139#ifdef ROOTDEVNAME
140 if ((boothowto & RB_DFLTROOT) &&
141 !vfs_mountroot_try(ROOTDEVNAME))
142 return;
143#endif
144 /*
145 * We are booted with instructions to prompt for the root filesystem,
146 * or to use the compiled-in default when it doesn't exist.
147 */
148 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) {
149 if (!vfs_mountroot_ask())
150 return;
151 }
152
153 /*
154 * We've been given the generic "use CDROM as root" flag. This is
155 * necessary because one media may be used in many different
156 * devices, so we need to search for them.
157 */
158 if (boothowto & RB_CDROM) {
159 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
160 if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
161 return;
162 }
163 }
164
165 /*
166 * Try to use the value read by the loader from /etc/fstab, or
167 * supplied via some other means. This is the preferred
168 * mechanism.
169 */
bc01a404 170 if (!vfs_mountroot_try(kgetenv("vfs.root.mountfrom")))
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171 return;
172
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173 /*
174 * If a vfs set rootdev, try it (XXX VINUM HACK!)
175 */
028066b1 176 if (save_rootdev != NULL) {
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177 rootdev = save_rootdev;
178 if (!vfs_mountroot_try(""))
179 return;
180 }
181
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182 /*
183 * Try values that may have been computed by the machine-dependant
184 * legacy code.
185 */
6b98993e 186 if (rootdevnames[0] && !vfs_mountroot_try(rootdevnames[0]))
984263bc 187 return;
6b98993e 188 if (rootdevnames[1] && !vfs_mountroot_try(rootdevnames[1]))
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189 return;
190
191 /*
192 * If we have a compiled-in default, and haven't already tried it, try
193 * it now.
194 */
195#ifdef ROOTDEVNAME
196 if (!(boothowto & RB_DFLTROOT))
197 if (!vfs_mountroot_try(ROOTDEVNAME))
198 return;
199#endif
200
201 /*
202 * Everything so far has failed, prompt on the console if we haven't
203 * already tried that.
204 */
205 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask())
206 return;
207 panic("Root mount failed, startup aborted.");
208}
209
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210
211int
212vfs_mountroot_devfs(void)
213{
214 struct vnode *vp;
215 struct nchandle nch;
216 struct nlookupdata nd;
217 struct mount *mp;
218 struct vfsconf *vfsp;
219 int error;
220 struct ucred *cred = proc0.p_ucred;
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221 const char *devfs_path, *init_chroot;
222 char *dev_malloced = NULL;
cd29885a 223
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224 if ((init_chroot = kgetenv("init_chroot")) != NULL) {
225 size_t l;
226
227 l = strlen(init_chroot) + sizeof("/dev");
228 dev_malloced = kmalloc(l, M_MOUNT, M_WAITOK);
229 ksnprintf(dev_malloced, l, "%s/dev", init_chroot);
230 devfs_path = dev_malloced;
231 } else {
232 devfs_path = "/dev";
233 }
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234 /*
235 * Lookup the requested path and extract the nch and vnode.
236 */
237 error = nlookup_init_raw(&nd,
358c69e9 238 devfs_path, UIO_SYSSPACE, NLC_FOLLOW,
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239 cred, &rootnch);
240
241 if (error == 0) {
242 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup_init is ok...\n");
243 if ((error = nlookup(&nd)) == 0) {
244 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup is ok...\n");
245 if (nd.nl_nch.ncp->nc_vp == NULL) {
246 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup: simply not found\n");
247 error = ENOENT;
248 }
249 }
250 }
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251 if (dev_malloced != NULL)
252 kfree(dev_malloced, M_MOUNT), dev_malloced = NULL;
253 devfs_path = NULL;
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254 if (error) {
255 nlookup_done(&nd);
256 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup failed, error: %d\n", error);
257 return (error);
258 }
259
260 /*
261 * Extract the locked+refd ncp and cleanup the nd structure
262 */
263 nch = nd.nl_nch;
264 cache_zero(&nd.nl_nch);
265 nlookup_done(&nd);
266
267 /*
268 * now we have the locked ref'd nch and unreferenced vnode.
269 */
270 vp = nch.ncp->nc_vp;
271 if ((error = vget(vp, LK_EXCLUSIVE)) != 0) {
272 cache_put(&nch);
273 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vget failed\n");
274 return (error);
275 }
276 cache_unlock(&nch);
277
278 if ((error = vinvalbuf(vp, V_SAVE, 0, 0)) != 0) {
279 cache_drop(&nch);
280 vput(vp);
281 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vinvalbuf failed\n");
282 return (error);
283 }
284 if (vp->v_type != VDIR) {
285 cache_drop(&nch);
286 vput(vp);
287 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vp is not VDIR\n");
288 return (ENOTDIR);
289 }
290
291 vfsp = vfsconf_find_by_name("devfs");
2247fe02 292 vsetflags(vp, VMOUNT);
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293
294 /*
295 * Allocate and initialize the filesystem.
296 */
297 mp = kmalloc(sizeof(struct mount), M_MOUNT, M_ZERO|M_WAITOK);
aac0aabd 298 mount_init(mp);
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299 vfs_busy(mp, LK_NOWAIT);
300 mp->mnt_op = vfsp->vfc_vfsops;
301 mp->mnt_vfc = vfsp;
302 vfsp->vfc_refcount++;
303 mp->mnt_stat.f_type = vfsp->vfc_typenum;
304 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
305 strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
306 mp->mnt_stat.f_owner = cred->cr_uid;
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307 vn_unlock(vp);
308
309 /*
310 * Mount the filesystem.
311 */
312 error = VFS_MOUNT(mp, "/dev", NULL, cred);
313
314 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
315
316 /*
317 * Put the new filesystem on the mount list after root. The mount
318 * point gets its own mnt_ncmountpt (unless the VFS already set one
319 * up) which represents the root of the mount. The lookup code
320 * detects the mount point going forward and checks the root of
321 * the mount going backwards.
322 *
323 * It is not necessary to invalidate or purge the vnode underneath
324 * because elements under the mount will be given their own glue
325 * namecache record.
326 */
327 if (!error) {
328 if (mp->mnt_ncmountpt.ncp == NULL) {
329 /*
330 * allocate, then unlock, but leave the ref intact
331 */
332 cache_allocroot(&mp->mnt_ncmountpt, mp, NULL);
333 cache_unlock(&mp->mnt_ncmountpt);
334 }
335 mp->mnt_ncmounton = nch; /* inherits ref */
336 nch.ncp->nc_flag |= NCF_ISMOUNTPT;
337
338 /* XXX get the root of the fs and cache_setvp(mnt_ncmountpt...) */
2247fe02 339 vclrflags(vp, VMOUNT);
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340 mountlist_insert(mp, MNTINS_LAST);
341 vn_unlock(vp);
342 //checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
343 error = vfs_allocate_syncvnode(mp);
344 if (error) {
345 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vfs_allocate_syncvnode failed\n");
346 }
347 vfs_unbusy(mp);
348 error = VFS_START(mp, 0);
349 vrele(vp);
350 } else {
351 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
352 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
353 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
354 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
355 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
2247fe02 356 vclrflags(vp, VMOUNT);
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357 mp->mnt_vfc->vfc_refcount--;
358 vfs_unbusy(mp);
359 kfree(mp, M_MOUNT);
360 cache_drop(&nch);
361 vput(vp);
362 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: mount failed\n");
363 }
364
365 devfs_debug(DEVFS_DEBUG_DEBUG, "rootmount_devfs done with error: %d\n", error);
366 return (error);
367}
368
369
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370/*
371 * Mount (mountfrom) as the root filesystem.
372 */
373static int
6b98993e 374vfs_mountroot_try(const char *mountfrom)
984263bc 375{
da4f706e 376 struct mount *mp;
6b98993e 377 char *vfsname, *devname;
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MD
378 int error;
379 char patt[32];
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SW
380 const char *cp, *ep;
381 char *mf;
69f27b85
FT
382 struct proc *p;
383 struct vnode *vp;
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MD
384
385 vfsname = NULL;
6b98993e 386 devname = NULL;
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387 mp = NULL;
388 error = EINVAL;
389
390 if (mountfrom == NULL)
391 return(error); /* don't complain */
392
e43a034f 393 crit_enter();
6ea70f76 394 kprintf("Mounting root from %s\n", mountfrom);
e43a034f 395 crit_exit();
984263bc 396
6b08c773 397 cp = mountfrom;
6b98993e 398 /* parse vfs name and devname */
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MD
399 vfsname = kmalloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
400 devname = kmalloc(MNAMELEN, M_MOUNT, M_WAITOK);
1f1d24d2
AP
401 mf = kmalloc(MFSNAMELEN+MNAMELEN, M_MOUNT, M_WAITOK);
402 for(;;) {
403 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
1f1d24d2
AP
404 bzero(vfsname, MFSNAMELEN);
405 bzero(devname, MNAMELEN);
406 bzero(mf, MFSNAMELEN+MNAMELEN);
407 strncpy(mf, cp, MFSNAMELEN+MNAMELEN);
408
409 vfsname[0] = devname[0] = 0;
410 ksprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
411 if (ksscanf(mf, patt, vfsname, devname) < 1)
412 goto end;
413
414 /* allocate a root mount */
415 error = vfs_rootmountalloc(vfsname,
416 devname[0] != 0 ? devname : ROOTNAME, &mp);
417 if (error != 0) {
418 kprintf("Can't allocate root mount for filesystem '%s': %d\n",
419 vfsname, error);
420 goto end;
421 }
422 mp->mnt_flag |= MNT_ROOTFS;
984263bc 423
1f1d24d2 424 /* do our best to set rootdev */
104cb849
MN
425 if ((strcmp(vfsname, "hammer") != 0) && (devname[0] != 0) &&
426 setrootbyname(devname))
1f1d24d2 427 kprintf("setrootbyname failed\n");
984263bc 428
1f1d24d2
AP
429 /* If the root device is a type "memory disk", mount RW */
430 if (rootdev != NULL && dev_is_good(rootdev) &&
431 (dev_dflags(rootdev) & D_MEMDISK)) {
432 mp->mnt_flag &= ~MNT_RDONLY;
433 }
984263bc 434
1f1d24d2 435 error = VFS_MOUNT(mp, NULL, NULL, proc0.p_ucred);
984263bc 436
1f1d24d2
AP
437 if (!error)
438 break;
439end:
440 if(*ep == 0)
441 break;
442 cp = ep + 1;
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MD
443 }
444
984263bc 445 if (vfsname != NULL)
efda3bd0 446 kfree(vfsname, M_MOUNT);
6b98993e 447 if (devname != NULL)
efda3bd0 448 kfree(devname, M_MOUNT);
1f1d24d2
AP
449 if (mf != NULL)
450 kfree(mf, M_MOUNT);
f2365172 451 if (error == 0) {
984263bc 452 /* register with list of mounted filesystems */
861905fb 453 mountlist_insert(mp, MNTINS_FIRST);
984263bc 454
8a8d5d85 455 /* sanity check system clock against root fs timestamp */
984263bc 456 inittodr(mp->mnt_time);
69f27b85
FT
457
458 /* Get the vnode for '/'. Set p->p_fd->fd_cdir to reference it. */
459 mp = mountlist_boot_getfirst();
460 if (VFS_ROOT(mp, &vp))
461 panic("cannot find root vnode");
462 if (mp->mnt_ncmountpt.ncp == NULL) {
463 cache_allocroot(&mp->mnt_ncmountpt, mp, vp);
464 cache_unlock(&mp->mnt_ncmountpt); /* leave ref intact */
465 }
466 p = curproc;
467 p->p_fd->fd_cdir = vp;
468 vref(p->p_fd->fd_cdir);
469 p->p_fd->fd_rdir = vp;
470 vref(p->p_fd->fd_rdir);
471 vfs_cache_setroot(vp, cache_hold(&mp->mnt_ncmountpt));
472 vn_unlock(vp); /* leave ref intact */
473 cache_copy(&mp->mnt_ncmountpt, &p->p_fd->fd_ncdir);
474 cache_copy(&mp->mnt_ncmountpt, &p->p_fd->fd_nrdir);
475
f9642f56 476 vfs_unbusy(mp);
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MD
477 if (mp->mnt_syncer == NULL) {
478 error = vfs_allocate_syncvnode(mp);
479 if (error)
480 kprintf("Warning: no syncer vp for root!\n");
481 error = 0;
482 }
69f27b85 483 VFS_START( mp, 0 );
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MD
484 } else {
485 if (mp != NULL) {
486 vfs_unbusy(mp);
487 kfree(mp, M_MOUNT);
488 }
489 kprintf("Root mount failed: %d\n", error);
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490 }
491 return(error);
492}
493
cd29885a 494
3a3826b3 495static void
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496vfs_mountroot_ask_callback(char *name, cdev_t dev, bool is_alias,
497 void *arg __unused)
3a3826b3 498{
b28e21ef
SW
499 if (!is_alias && dev_is_good(dev) && (dev_dflags(dev) & D_DISK))
500 kprintf(" \"%s\" ", name);
3a3826b3
AH
501}
502
cd29885a 503
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504/*
505 * Spin prompting on the console for a suitable root filesystem
506 */
507static int
508vfs_mountroot_ask(void)
509{
510 char name[128];
cee92776 511 int llimit = 100;
984263bc 512
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513 kprintf("\nManual root filesystem specification:\n");
514 kprintf(" <fstype>:<device> Specify root (e.g. ufs:da0s1a)\n");
515 kprintf(" ? List valid disk boot devices\n");
516 kprintf(" panic Just panic\n");
517 kprintf(" abort Abort manual input\n");
518 while (llimit--) {
6ea70f76 519 kprintf("\nmountroot> ");
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MD
520
521 if (getline(name, 128) < 0)
522 break;
523 if (name[0] == 0) {
524 ;
525 } else if (name[0] == '?') {
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526 kprintf("Possibly valid devices for root FS:\n");
527 //enumerate all disk devices
3a3826b3 528 devfs_scan_callback(vfs_mountroot_ask_callback, NULL);
6ea70f76 529 kprintf("\n");
984263bc 530 continue;
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MD
531 } else if (strcmp(name, "panic") == 0) {
532 panic("panic from console");
533 } else if (strcmp(name, "abort") == 0) {
534 break;
535 } else if (vfs_mountroot_try(name) == 0) {
984263bc 536 return(0);
cee92776 537 }
984263bc 538 }
cee92776 539 return(1);
0e9b9130
MD
540}
541
cd29885a 542
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MD
543static int
544getline(char *cp, int limit)
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MD
545{
546 char *lp;
547 int c;
548
549 lp = cp;
550 for (;;) {
7f12a969
MD
551 c = cngetc();
552
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MD
553 switch (c) {
554 case -1:
cee92776 555 return(-1);
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MD
556 case '\n':
557 case '\r':
7f12a969 558 kprintf("\n");
984263bc 559 *lp++ = '\0';
cee92776 560 return(0);
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MD
561 case '\b':
562 case '\177':
563 if (lp > cp) {
7f12a969 564 kprintf("\b \b");
984263bc 565 lp--;
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MD
566 } else {
567 kprintf("%c", 7);
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MD
568 }
569 continue;
570 case '#':
7f12a969 571 kprintf("#");
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572 lp--;
573 if (lp < cp)
574 lp = cp;
575 continue;
576 case '@':
577 case 'u' & 037:
578 lp = cp;
6ea70f76 579 kprintf("%c", '\n');
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580 continue;
581 default:
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MD
582 if (lp - cp >= limit - 1) {
583 kprintf("%c", 7);
584 } else {
7f12a969 585 kprintf("%c", c);
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MD
586 *lp++ = c;
587 }
588 continue;
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MD
589 }
590 }
591}
592
593/*
b13267a5 594 * Convert a given name to the cdev_t of the disk-like device
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595 * it refers to.
596 */
b13267a5 597cdev_t
bc01a404 598kgetdiskbyname(const char *name)
e4c9c0c8 599{
b13267a5 600 cdev_t rdev;
984263bc 601
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MD
602 /*
603 * Get the base name of the device
604 */
1f2de5d4
MD
605 if (strncmp(name, __SYS_PATH_DEV, sizeof(__SYS_PATH_DEV) - 1) == 0)
606 name += sizeof(__SYS_PATH_DEV) - 1;
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MD
607
608 /*
609 * Locate the device
610 */
a7a95662 611 rdev = devfs_find_device_by_name("%s", name);
cd29885a 612 if (rdev == NULL) {
1a8913f1 613 kprintf("no disk named '%s'\n", name);
6b98993e 614 }
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615 /*
616 * FOUND DEVICE
617 */
e4c9c0c8 618 return(rdev);
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619}
620
621/*
622 * Set rootdev to match (name), given that we expect it to
623 * refer to a disk-like device.
624 */
625static int
626setrootbyname(char *name)
627{
b13267a5 628 cdev_t diskdev;
984263bc 629
bc01a404 630 diskdev = kgetdiskbyname(name);
028066b1 631 if (diskdev != NULL) {
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632 rootdev = diskdev;
633 return (0);
634 }
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635 /* set to NULL if kgetdiskbyname() fails so that if the first rootdev is
636 * found by fails to mount and the second one isn't found, mountroot_try
637 * doesn't try again with the first one
638 */
639 rootdev = NULL;
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640 return (1);
641}
642
643#ifdef DDB
644DB_SHOW_COMMAND(disk, db_getdiskbyname)
645{
b13267a5 646 cdev_t dev;
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647
648 if (modif[0] == '\0') {
649 db_error("usage: show disk/devicename");
650 return;
651 }
bc01a404 652 dev = kgetdiskbyname(modif);
028066b1 653 if (dev != NULL)
b13267a5 654 db_printf("cdev_t = %p\n", dev);
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655 else
656 db_printf("No disk device matched.\n");
657}
658#endif
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659
660static int
661vfs_sysctl_real_root(SYSCTL_HANDLER_ARGS)
662{
663 char *real_root;
664 size_t len;
665 int error;
666
667 real_root = kgetenv("vfs.root.realroot");
668
669 if (real_root == NULL)
670 real_root = "";
671
672 len = strlen(real_root) + 1;
673
674 error = sysctl_handle_string(oidp, real_root, len, req);
675
676 return error;
677}
678
679SYSCTL_PROC(_vfs, OID_AUTO, real_root,
680 CTLTYPE_STRING | CTLFLAG_RD, 0, 0, vfs_sysctl_real_root,
681 "A", "Real root mount string");