Ext3 users - Nov 2001 - [andrea@suse.de: Re: VFS bug in 2.4.10+ which applies ulimits to block devices]

I had sent email to Andrea asking him if his blkdev-in-pagecache might
cause the recent reports about ulimits being applied to block devices.
This is his response which he asked me to forward to ext3-users since he
can't post being a non-subscriber

BTW, Redhat should whitelist various kernel hackers email address on
their mailserver so that they can post freely to various lists

Regards, Yusuf

----- Forwarded message from Andrea Arcangeli <andrea@suse.de> -----

Date: Mon, 26 Nov 2001 15:26:17 +0100
From: Andrea Arcangeli <andrea@suse.de>
To: Yusuf Goolamabbas <yusufg@outblaze.com>
Cc: ext3-users@redhat.com
Subject: Re: VFS bug in 2.4.10+ which applies ulimits to block devices
Message-ID: <20011126152617.F14196@athlon.random>

On Mon, Nov 26, 2001 at 10:00:39PM +0800, Yusuf Goolamabbas
wrote:
> Hi Andrea, The following is a thread on ext3-users in which sct mentions
> that this is due to a core VFS bug introduced in 2.4.10 which applies
> ulimits to block devices. Maybe this could be due to some interaction
> with your blockdevice in pagecache
> 
> I don't know if you already have a fix in your tree. Maybe sct can
> provide you with more info
You need to upgrade glibc to something recent like 2.2.1, so that the
ulimit will be correctly set to ~0UL. We could also fix this problem in
the kernel but even if we do you will still run into troubles with LFS
with the mounted filesystems.

Or maybe you run really play with the blkdev with file limits not set to
unlimited? I think it's insane to set file limits for root during boot,
the only problem I know of were because of the old userspace that
doesn't handle correctly the new ulimited defines ~0UL instead of
~0UL>>1.

We can provide total backwards compatibility with a simple IS_BLK check
in generic_file_* in filemap.c, but I'm not sure if it really worth to
add a branch there just for this.

Andrea


----- End forwarded message -----

-- 
Yusuf Goolamabbas
yusufg@outblaze.com