Kernel 2.6 : shutdown now impossible

[Stephane Bortzmeyer <bortzmeyer@nic.fr>]

I just upgraded an UltraSparc 10 from kernel 2.4 to 2.6, using the
Debian package in sarge:

myriam:~ % dpkg -s kernel-image-2.6.8-1-sparc64
Package: kernel-image-2.6.8-1-sparc64
Status: install ok installed
Priority: optional
Section: base
Installed-Size: 21560
Maintainer: Debian Kernel Team <debian-kernel@lists.debian.org>
Architecture: sparc
Source: kernel-image-2.6.8-sparc
Version: 2.6.8-2

Now, I can no longer shutdown (it worked before): there is no error
message, shutdown backgrounds itself and then is stopped in Disk Wait
(I tried several times, hence the three shutdowns in ps' output).

myriam:~ % ps auxwww|grep D
USER       PID %CPU %MEM   VSZ  RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.2  1632  704 ?        D    Oct18   0:12 init [2]  
root      2744  0.0  0.3  2064  872 ?        D    10:31   0:00 shutdown -r 0 w
root      2775  0.0  0.3  2064  872 ?        D    10:42   0:00 shutdown -r 0 w
root      2777  0.0  0.3  2064  872 ?        D    10:42   0:00 shutdown -r 0 w