linux-kernel - Re: Kernel BUG at fs/mpage.c:489

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <200802132039.26169.nickpiggin@yahoo.com.au>
Date:	Wed, 13 Feb 2008 20:39:25 +1100
From:	Nick Piggin <nickpiggin@...oo.com.au>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Bart Dopheide <dopheide@....nl>,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	linux-kernel@...r.kernel.org,
	OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>,
	Jens Axboe <jens.axboe@...cle.com>,
	Bartlomiej Zolnierkiewicz <mzolnier@...il.com>
Subject: Re: Kernel BUG at fs/mpage.c:489

On Wednesday 13 February 2008 20:32, Andrew Morton wrote:
> On Wed, 13 Feb 2008 20:24:03 +1100 Nick Piggin <nickpiggin@...oo.com.au> 
wrote:
> > BTW is it really true that the buffer can never be locked by
> > anything else at this point?
>
> It has been for the past five or six years.  With the page locked, nobody
> else can get at that page.

Hmm OK.


> > What about fsync_buffers_list?
>
> They're metadata buffers, not regular file data.  Things might get ugly if
> IO to /dev/sda went via that path, but it doesn't.

Yeah right... so the BUG_ON is basically because you want to avoid
the overhead of locking the buffer (which would presumably allow it
to work in situations where someone else might lock the buffer without
locking the page?). OK, makes sense.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/