Re: [PATCH] lazy umount (1/4)

[Mike Fedyk <mfedyk@matchmail.com>]

On Sat, Sep 15, 2001 at 08:32:36AM -0400, jlnance@intrex.net wrote:
> On Fri, Sep 14, 2001 at 03:01:26PM -0400, Alexander Viro wrote:
> 
> > convenient when you are doing fs hacking ;-)  Actually I've got into
> > a habit of using that instead of normal umount in all cases except
> > the shutdown scripts - works just fine (for obvious reasons in case
> > of shutdown non-lazy behaviour is precisely what we want).
> 
> Why not shutdown?  This is the place I think it would help me the most.
> 
> Thanks,
> 
> Jim

If you have a FS with a process stuck in D state, and you shutdown with an
umount that *always* does lazy unmounting you get the same affect, because
you'd want the kernel to pause the shutdown until the FS was properly
unmounted.

Either way, you'd have a system you can't reboot without hardware reset if
you have a process stuck in D state on a rw FS.

I have a system with badblocks and shutdown stuck in D state.  Kernel is
2.2.19 on PPC with the freeswan1.9 patch.

It has been stuck for about two weeks, but operating normally otherwise.
I'm going to have to sync; sync; and power off, as I need to update the
kernel anyway.

I too would like to see a way to force umount, but I don't see a safe way.
OTOH, I'm also not a kernel hacker.  Does anyone see a solution?

Mike