Re: regression in fs/ext2.c

[Pavel Roskin <proski@gnu.org>]

On Thu, 2008-06-05 at 00:12 +0200, Robert Millan wrote:
> The following commit:
> 
> 2008-05-20  Bean  <bean123ch@gmail.com>
> 
> introduced a regression in fs/ext2.c.  The effect is that when attempting
> to access an ext2 filesystem from grub-emu (and AFAICT only from grub-emu),
> it will spend a lot of time (a minute or so) in a loop that calls lseek()
> repeatedly (with increasingly higher offsets).
> 
> I'm sorry, I spent a while looking into this, but haven't been able to
> find the source of the problem.

Actually I noticed that grub won't work in qemu anymore.  I would
normally do this:

qemu -hda /dev/sda

and that would show the menu.  Sometimes the menu would be old, but
running "grub-install /dev/sda" would synchronize the cache.

In the recent days, grub would simply hang or report "out of partition".
I was installing Fedora 9 around that time, so I blamed it on qemu
changes.  But now I did a bisect in git, and sure enough, it pointed
exactly to that change from May 20.

It looks like grub has problems accessing mounted filesystem.  That's a
problem because the OS can reboot suddenly, leaving the filesystem in a
state that grub cannot grok.

I'm using ext3 everywhere, so I suspect that the problem may have to do
with the journal support implemented in that commit.

-- 
Regards,
Pavel Roskin