[User-mode-linux-devel] 2.4.0-test8-final and 2.4.0-test8-pre6 as a host - echo or fork problems?

[William S. <wst...@po...>]

Good day, Jeff and all,
	I'm having trouble running uml's under 2.4.0-test8 (both final and
pre6).  The uml kernel(*) boots up partway but seems to get stuck in
rc.sysinit:

...
devfs: v0.102 (20000622) Richard Gooch (rg...@at...)
devfs: devfs_debug: 0x0
devfs: boot_options: 0x0
VFS: Mounted root (ext2 filesystem) readonly.
Mounted devfs on /dev
Child 967 exited with signal 11

	Booting up with devfs=nomount only changes to:
devfs: v0.102 (20000622) Richard Gooch (rg...@at...)
devfs: devfs_debug: 0x0
devfs: boot_options: 0x2
VFS: Mounted root (ext2 filesystem) readonly.
Child 1013 exited with signal 11

	rc.sysinit is from redhat pinstripe, I think; the only functional
change near the top is that it includes the "run devfsd" test:

#!/bin/sh
#
# /etc/rc.sysinit - run once at boot time
#
# Taken in part from Miquel van Smoorenburg's bcheckrc.
#

# Rerun ourselves through initlog
if [ -z "$IN_INITLOG" ]; then
 [ -f /sbin/initlog ] && exec /sbin/initlog $INITLOG_ARGS -r /etc/rc.sysinit
fi

# If we're using devfs, start devfsd now - we need the old device names
[ -e /dev/.devfsd -a -x /sbin/devfsd ] && /sbin/devfsd /dev

# Set the path
PATH=/bin:/sbin:/usr/bin:/usr/sbin
export PATH
...

	The uml boot has worked so far at least up to
2.4.0-test7-pre4.  I'm aware that sig 11's can indicate hardware failures,
but it seems a little strange that changing the host kernel would stop the
uml kernel to stop booting, and always at exactly the same point.
	I tried putting "echo a", "echo b" type debug statements in
rc.sysinit to see exactly which line fails, but echo doesn't seem to
actually put anything on the screen.  I've tried straight "echo a", "echo
a >/dev/console", "echo a >/dev/ttys/0", "echo a >/dev/tty0", and "echo a
>/dev/stderr" with no output at all.  :-(
	When I backed down to 2.4.0-test7 final, the debug statments
actually started to do something.  "echo a >/dev/tty0" just gave me
permission denied, but "echo a >/dev/console" actually spit out an
"a".  All 17 debugs actually showed up, and rc.sysinit actually seemed to
run, but the boot bagged out on checking the root filesystem:

Enabling swap space [  OK  ]
INIT: Entering runlevel: 3
Entering non-interactive startup
a
b
a
d
Error setting event mask        Device or resource busy
e
f
g
h
k
l
m
                        Welcome to Red Hat Linux
n
o
                Press 'I' to enter interactive startup.
p
q
Mounting proc filesystem [  OK  ]
Configuring kernel parameters [  OK  ]
Setting clock : Mon Sep 11 12:20:43 EDT 2000 [  OK  ]
Activating swap partitions [  OK  ]
Setting hostname lab21.ists.dartmouth.edu [  OK  ]
Checking root filesystem
/dev/ubd/0 is mounted.  Cannot continue, aborting.
[/sbin/fsck.ext2 -- /] fsck.ext2 -a /dev/ubd/0
[FAILED]
*** An error occurred during the file system check.
*** Dropping you to a shell; the system will reboot
*** when you leave the shell.
Give root password for maintenance
(or type Control-D for normal startup):

	What's "Error setting event mask, Device or resource
busy"?  Between "d" and "e" there's only the devfsd call:

[ -e /dev/.devfsd -a -x /sbin/devfsd ] && /sbin/devfsd /dev

	Same "/dev/ubd/0 is mounted." problem with devfs=mount and/or
"ro" on the command line.  Using devfs=nomount gives the expected:

Checking root filesystem
(null):
The superblock could not be read or does not describe a correct ext2
filesystem.  If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
    e2fsck -b 8193 <device>

[/sbin/fsck.ext2 -- /] fsck.ext2 -a /dev/ubd/0
fsck.ext2: No such file or directory while trying to open /dev/ubd/0
[FAILED]

*** An error occurred during the file system check.
*** Dropping you to a shell; the system will reboot
*** when you leave the shell.

	Summary:
2.4.0-test8 (pre6 and final) host: can't seem to echo, uml boot dies near
the beginning of rc.sysinit.

2.4.0-test7 final host: can see debug echos in rc.sysinit, but can't do
root fs check.

2.4.0-test7-pre4: boots fine.

	Cheers,
	- Bill 'probably found another red herring' Stearns

* (Linux version 2.4.0-test7-1um
(jd...@cc...) (gcc version egcs-2.91.66 19990314/Linux
(egcs-1.1.2 release)) #2 Thu Aug 24 12:51:12 EST 2000 in this case)

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