Re: kernel BUG at /usr/src/linux/include/linux/nfs_fs.h:167! -reproducible

M.H.VanLeeuwen
2000-12-20T03:50:26Z

Alexander Viro wrote:
>
> On Mon, 18 Dec 2000, Neil Brown wrote:
>
> > On Monday December 18, trond.myklebust@fys.uio.no wrote:
> > > >>>>> " " == M H VanLeeuwen <vanl@megsinet.net> writes:
> > >
> > > > Trond, Neil I don't know if this is a loopback bug or an NFS
> > > > bug but since nfs_fs.h was implicated so I thought one of you
> > > > may be interested.
> > >
> > > > Could you let me know if you know this problem has already been
> > > > fixed or if you need more info.
> > >
> > > Hi,
> > >
> > > As far as I'm concerned, it's a loopback bug.
> >
> > I read it the same way.
> > Actually, I cannot see the point of copying the "struct file"! Why
> > not just take a reference to it? The comment tries to justify it, but
> > I don't buy it.
>
> Wish I remembered who had complained when I proposed to kill that copying...
> It was introduced back in 2.1.110 and back then comment looked so:
>
> + /* Backed by a regular file - we need to hold onto
> + a file structure for this file. We'll use it to
> + write to blocks that are not already present in
> + a sparse file. We create a new file structure
> + based on the one passed to us via 'arg'. This is
> + to avoid changing the file structure that the
> + caller is using */
> +
>
> I would be happy to get rid of that crap - it was the only reason why I
> had to add the sodding file_moveto() and world would be better without it.
> If we can kill it off - let's do it and let's take fs/file_table:file_moveto()
> along.
>
> IOW, I also think that copying the struct file is wrong. IIRC, complaints were
> bogus - losetup requires enough priviliges to make worrying about security
> implications somewhat pointless.

Ok, I've was able to cause 2 BUG's yesterday in a couple of hours, ( it was easier
to lock the machine solid than to get the BUG;-)), since loading test12 w/patch I
haven't seen a single BUG in the last 24 hours. Any chance we can get this change
to Linus for test13?

Any specific tests you want me to run?