2 * Copyright (c) 1999 Michael Smith
4 * Copyright (c) 1999 Poul-Henning Kamp
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
28 * $FreeBSD: src/sys/kern/vfs_conf.c,v 1.49.2.5 2003/01/07 11:56:53 joerg Exp $
29 * $DragonFly: src/sys/kern/vfs_conf.c,v 1.4 2003/07/06 21:23:51 dillon Exp $
33 * Locate and mount the root filesystem.
35 * The root filesystem is detailed in the kernel environment variable
36 * vfs.root.mountfrom, which is expected to be in the general format
39 * vfsname := the name of a VFS known to the kernel and capable
40 * of being mounted as root
41 * path := disk device name or other data used by the filesystem
42 * to locate its physical store
46 #include "opt_rootdevname.h"
48 #include <sys/param.h>
49 #include <sys/kernel.h>
50 #include <sys/systm.h>
52 #include <sys/vnode.h>
53 #include <sys/mount.h>
54 #include <sys/malloc.h>
55 #include <sys/reboot.h>
56 #include <sys/diskslice.h>
57 #include <sys/disklabel.h>
67 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
69 #define ROOTNAME "root_device"
71 struct vnode *rootvnode;
74 * The root specifiers we will try if RB_CDROM is specified.
76 static char *cdrom_rootdevnames[] = {
83 static void vfs_mountroot(void *junk);
84 static int vfs_mountroot_try(char *mountfrom);
85 static int vfs_mountroot_ask(void);
86 static void gets(char *cp);
88 /* legacy find-root code */
89 char *rootdevnames[2] = {NULL, NULL};
90 static int setrootbyname(char *name);
92 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL);
95 * Find and mount the root filesystem
98 vfs_mountroot(void *junk)
103 * The root filesystem information is compiled in, and we are
104 * booted with instructions to use it.
107 if ((boothowto & RB_DFLTROOT) &&
108 !vfs_mountroot_try(ROOTDEVNAME))
112 * We are booted with instructions to prompt for the root filesystem,
113 * or to use the compiled-in default when it doesn't exist.
115 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) {
116 if (!vfs_mountroot_ask())
121 * We've been given the generic "use CDROM as root" flag. This is
122 * necessary because one media may be used in many different
123 * devices, so we need to search for them.
125 if (boothowto & RB_CDROM) {
126 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
127 if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
133 * Try to use the value read by the loader from /etc/fstab, or
134 * supplied via some other means. This is the preferred
137 if (!vfs_mountroot_try(getenv("vfs.root.mountfrom")))
141 * Try values that may have been computed by the machine-dependant
144 if (!vfs_mountroot_try(rootdevnames[0]))
146 if (!vfs_mountroot_try(rootdevnames[1]))
150 * If we have a compiled-in default, and haven't already tried it, try
154 if (!(boothowto & RB_DFLTROOT))
155 if (!vfs_mountroot_try(ROOTDEVNAME))
160 * Everything so far has failed, prompt on the console if we haven't
161 * already tried that.
163 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask())
165 panic("Root mount failed, startup aborted.");
169 * Mount (mountfrom) as the root filesystem.
172 vfs_mountroot_try(char *mountfrom)
174 struct thread *td = curthread;
176 char *vfsname, *path;
186 if (mountfrom == NULL)
187 return(error); /* don't complain */
189 s = splcam(); /* Overkill, but annoying without it */
190 printf("Mounting root from %s\n", mountfrom);
193 /* parse vfs name and path */
194 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
195 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK);
196 vfsname[0] = path[0] = 0;
197 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
198 if (sscanf(mountfrom, patt, vfsname, path) < 1)
201 /* allocate a root mount */
202 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME,
205 printf("Can't allocate root mount for filesystem '%s': %d\n",
209 mp->mnt_flag |= MNT_ROOTFS;
211 /* do our best to set rootdev */
212 if ((path[0] != 0) && setrootbyname(path))
213 printf("setrootbyname failed\n");
215 /* If the root device is a type "memory disk", mount RW */
216 if (rootdev != NODEV && devsw(rootdev) &&
217 (devsw(rootdev)->d_flags & D_MEMDISK))
218 mp->mnt_flag &= ~MNT_RDONLY;
220 error = VFS_MOUNT(mp, NULL, NULL, NULL, td);
224 free(vfsname, M_MOUNT);
232 printf("Root mount failed: %d\n", error);
235 /* register with list of mounted filesystems */
236 lwkt_gettoken(&mountlist_token);
237 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
238 lwkt_reltoken(&mountlist_token);
240 /* sanity check system clock against root fs timestamp */
241 inittodr(mp->mnt_time);
248 * Spin prompting on the console for a suitable root filesystem
251 vfs_mountroot_ask(void)
258 printf("\nManual root filesystem specification:\n");
259 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n");
260 printf(" eg. ufs:%sda0s1a\n", _PATH_DEV);
261 printf(" ? List valid disk boot devices\n");
262 printf(" <empty line> Abort manual input\n");
263 printf("\nmountroot> ");
267 if (name[0] == '?') {
268 printf("Possibly valid devices for 'ufs' root:\n");
269 for (i = 0; i < NUMCDEVSW; i++) {
271 if (devsw(dev) != NULL)
272 printf(" \"%s\"", devsw(dev)->d_name);
277 if (!vfs_mountroot_try(name))
290 printf("%c", c = cngetc() & 0177);
321 * Convert a given name to the dev_t of the disk-like device
325 getdiskbyname(char *name) {
327 int cd, unit, slice, part;
332 if (strncmp(name, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
333 name += sizeof(_PATH_DEV) - 1;
335 while (*cp != '\0' && (*cp < '0' || *cp > '9') && *cp != '/')
338 printf("missing device name\n");
341 if (*cp == '\0' || *cp == '/')
346 for (cd = 0; cd < NUMCDEVSW; cd++) {
347 dev = makedev(cd, 0);
348 if (devsw(dev) != NULL &&
349 strcmp(devsw(dev)->d_name, name) == 0)
352 printf("no such device '%s'\n", name);
355 if (devsw(dev)->d_maj == major(rootdev))
356 /* driver has already configured rootdev, e. g. vinum */
359 printf("missing unit number\n");
362 while (*cp >= '0' && *cp <= '9')
363 unit = 10 * unit + *cp++ - '0';
364 if (*cp == 's' && cp[1] >= '0' && cp[1] <= '9') {
365 slice = cp[1] - '0' + 1;
368 if (*cp >= 'a' && *cp <= 'h') {
373 printf("junk after name\n");
376 return (makedev(cd, dkmakeminor(unit, slice, part)));
380 * Set rootdev to match (name), given that we expect it to
381 * refer to a disk-like device.
384 setrootbyname(char *name)
388 diskdev = getdiskbyname(name);
389 if (diskdev != NODEV) {
398 DB_SHOW_COMMAND(disk, db_getdiskbyname)
402 if (modif[0] == '\0') {
403 db_error("usage: show disk/devicename");
406 dev = getdiskbyname(modif);
408 db_printf("dev_t = %p\n", dev);
410 db_printf("No disk device matched.\n");