From mboxrd@z Thu Jan  1 00:00:00 1970
From: Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: panic in do_last()
Date: Fri, 18 Apr 2014 03:42:23 +0100
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Cc: David Howells <dhowells@redhat.com>, linux-fsdevel@vger.kernel.org,
	Hugh Dickins <hughd@google.com>
To: Lin Ming <minggr@gmail.com>
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On Thu, Apr 17, 2014 at 07:35:14PM -0700, Lin Ming wrote:
> Added a barrier(), but still panic.

Wrong kind of barrier ;-)  This one just says the compiler that it
shouldn't reorder; it doesn't help other CPUs at all.

Read Documentation/memory-barriers.txt for details, but I seriously
wonder if we _want_ to mess with barriers in the first place...