From mboxrd@z Thu Jan  1 00:00:00 1970
From: Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: [PATCH v2] fs: Fix hang with BSD accounting on frozen filesystem
Date: Sat, 4 May 2013 19:58:57 +0100
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Cc: linux-fsdevel@vger.kernel.org,
	Nikola Ciprich <nikola.ciprich@linuxbox.cz>,
	LKML <linux-kernel@vger.kernel.org>
To: Jan Kara <jack@suse.cz>
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On Sat, May 04, 2013 at 12:11:23AM +0200, Jan Kara wrote:
> When BSD process accounting is enabled and logs information to a
> filesystem which gets frozen, system easily becomes unusable because
> each attempt to account process information blocks. Thus e.g. every task
> gets blocked in exit.
> 
> It seems better to drop accounting information (which can already happen
> when filesystem is running out of space) instead of locking system up.
> So we just skip the write if the filesystem is frozen.

Applied, with one modification - file_start_write_trylock() added and
used instead of sb_start_write_trylock()