freebsd-dev/sys/kern/vfs_conf.c
Julian Elischer b40ce4165d KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after:    ha ha ha ha
2001-09-12 08:38:13 +00:00

382 lines
8.7 KiB
C

/*-
* Copyright (c) 1999 Michael Smith
* All rights reserved.
* Copyright (c) 1999 Poul-Henning Kamp
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/*
* Locate and mount the root filesystem.
*
* The root filesystem is detailed in the kernel environment variable
* vfs.root.mountfrom, which is expected to be in the general format
*
* <vfsname>:[<path>]
* vfsname := the name of a VFS known to the kernel and capable
* of being mounted as root
* path := disk device name or other data used by the filesystem
* to locate its physical store
*
*/
#include "opt_rootdevname.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/reboot.h>
#include <sys/diskslice.h>
#include <sys/disklabel.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/proc.h>
#include "opt_ddb.h"
#ifdef DDB
#include <ddb/ddb.h>
#endif
#include <paths.h>
MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
#define ROOTNAME "root_device"
struct vnode *rootvnode;
/*
* The root specifiers we will try if RB_CDROM is specified.
*/
static char *cdrom_rootdevnames[] = {
"cd9660:cd0a",
"cd9660:acd0a",
"cd9660:wcd0a",
NULL
};
static void vfs_mountroot(void *junk);
static int vfs_mountroot_try(char *mountfrom);
static int vfs_mountroot_ask(void);
static void gets(char *cp);
/* legacy find-root code */
char *rootdevnames[2] = {NULL, NULL};
static int setrootbyname(char *name);
SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL);
/*
* Find and mount the root filesystem
*/
static void
vfs_mountroot(void *junk)
{
int i;
/*
* The root filesystem information is compiled in, and we are
* booted with instructions to use it.
*/
#ifdef ROOTDEVNAME
if ((boothowto & RB_DFLTROOT) &&
!vfs_mountroot_try(ROOTDEVNAME))
return;
#endif
/*
* We are booted with instructions to prompt for the root filesystem,
* or to use the compiled-in default when it doesn't exist.
*/
if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) {
if (!vfs_mountroot_ask())
return;
}
/*
* We've been given the generic "use CDROM as root" flag. This is
* necessary because one media may be used in many different
* devices, so we need to search for them.
*/
if (boothowto & RB_CDROM) {
for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
return;
}
}
/*
* Try to use the value read by the loader from /etc/fstab, or
* supplied via some other means. This is the preferred
* mechanism.
*/
if (!vfs_mountroot_try(getenv("vfs.root.mountfrom")))
return;
/*
* Try values that may have been computed by the machine-dependant
* legacy code.
*/
if (!vfs_mountroot_try(rootdevnames[0]))
return;
if (!vfs_mountroot_try(rootdevnames[1]))
return;
/*
* If we have a compiled-in default, and haven't already tried it, try
* it now.
*/
#ifdef ROOTDEVNAME
if (!(boothowto & RB_DFLTROOT))
if (!vfs_mountroot_try(ROOTDEVNAME))
return;
#endif
/*
* Everything so far has failed, prompt on the console if we haven't
* already tried that.
*/
if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask())
return;
panic("Root mount failed, startup aborted.");
}
/*
* Mount (mountfrom) as the root filesystem.
*/
static int
vfs_mountroot_try(char *mountfrom)
{
struct mount *mp;
char *vfsname, *path;
int error;
char patt[32];
int s;
vfsname = NULL;
path = NULL;
mp = NULL;
error = EINVAL;
if (mountfrom == NULL)
return(error); /* don't complain */
s = splcam(); /* Overkill, but annoying without it */
printf("Mounting root from %s\n", mountfrom);
splx(s);
/* parse vfs name and path */
vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
path = malloc(MNAMELEN, M_MOUNT, M_WAITOK);
vfsname[0] = path[0] = 0;
sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
if (sscanf(mountfrom, patt, vfsname, path) < 1)
goto done;
/* allocate a root mount */
error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME,
&mp);
if (error != 0) {
printf("Can't allocate root mount for filesystem '%s': %d\n",
vfsname, error);
goto done;
}
mp->mnt_flag |= MNT_ROOTFS;
/* do our best to set rootdev */
if ((path[0] != 0) && setrootbyname(path))
printf("setrootbyname failed\n");
/* If the root device is a type "memory disk", mount RW */
if (rootdev != NODEV && devsw(rootdev) &&
(devsw(rootdev)->d_flags & D_MEMDISK))
mp->mnt_flag &= ~MNT_RDONLY;
/*
* Set the mount path to be something useful, because the
* filesystem code isn't responsible now for initialising
* f_mntonname unless they want to override the default
* (which is `path'.)
*/
strncpy(mp->mnt_stat.f_mntonname, "/", MNAMELEN);
error = VFS_MOUNT(mp, NULL, NULL, NULL, curthread);
done:
if (vfsname != NULL)
free(vfsname, M_MOUNT);
if (path != NULL)
free(path, M_MOUNT);
if (error != 0) {
if (mp != NULL) {
vfs_unbusy(mp, curthread);
free(mp, M_MOUNT);
}
printf("Root mount failed: %d\n", error);
} else {
/* register with list of mounted filesystems */
mtx_lock(&mountlist_mtx);
TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
/* sanity check system clock against root filesystem timestamp */
inittodr(mp->mnt_time);
vfs_unbusy(mp, curthread);
}
return(error);
}
/*
* Spin prompting on the console for a suitable root filesystem
*/
static int
vfs_mountroot_ask(void)
{
char name[128];
int i;
dev_t dev;
for(;;) {
printf("\nManual root filesystem specification:\n");
printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n");
printf(" eg. ufs:%sda0s1a\n", _PATH_DEV);
printf(" ? List valid disk boot devices\n");
printf(" <empty line> Abort manual input\n");
printf("\nmountroot> ");
gets(name);
if (name[0] == 0)
return(1);
if (name[0] == '?') {
printf("Possibly valid devices for 'ufs' root:\n");
for (i = 0; i < NUMCDEVSW; i++) {
dev = makedev(i, 0);
if (devsw(dev) != NULL)
printf(" \"%s\"", devsw(dev)->d_name);
}
printf("\n");
continue;
}
if (!vfs_mountroot_try(name))
return(0);
}
}
static void
gets(char *cp)
{
char *lp;
int c;
lp = cp;
for (;;) {
printf("%c", c = cngetc() & 0177);
switch (c) {
case -1:
case '\n':
case '\r':
*lp++ = '\0';
return;
case '\b':
case '\177':
if (lp > cp) {
printf(" \b");
lp--;
}
continue;
case '#':
lp--;
if (lp < cp)
lp = cp;
continue;
case '@':
case 'u' & 037:
lp = cp;
printf("%c", '\n');
continue;
default:
*lp++ = c;
}
}
}
/*
* Convert a given name to the dev_t of the disk-like device
* it refers to.
*/
dev_t
getdiskbyname(char *name) {
char *cp;
dev_t dev;
cp = name;
if (!bcmp(cp, "/dev/", 5))
cp += 5;
dev = NODEV;
EVENTHANDLER_INVOKE(dev_clone, cp, strlen(cp), &dev);
return (dev);
}
/*
* Set rootdev to match (name), given that we expect it to
* refer to a disk-like device.
*/
static int
setrootbyname(char *name)
{
dev_t diskdev;
diskdev = getdiskbyname(name);
if (diskdev != NODEV) {
rootdev = diskdev;
return (0);
}
return (1);
}
#ifdef DDB
DB_SHOW_COMMAND(disk, db_getdiskbyname)
{
dev_t dev;
if (modif[0] == '\0') {
db_error("usage: show disk/devicename");
return;
}
dev = getdiskbyname(modif);
if (dev != NODEV)
db_printf("dev_t = %p\n", dev);
else
db_printf("No disk device matched.\n");
}
#endif