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To: Jens Axboe <jens.axboe@oracle.com>
Cc: "Vladimir V. Saveliev" <vs@namesys.com>,
       Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org,
       linux-aio@kvack.org, reiserfs-dev@namesys.com, linux-mm@kvack.org
Subject: Re: dio_get_page() lockdep complaints
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From: Roland Dreier <rdreier@cisco.com>
Date: Thu, 19 Apr 2007 06:53:55 -0700
In-Reply-To: <20070419125236.GF11780@kernel.dk> (Jens Axboe's message of "Thu, 19 Apr 2007 14:52:36 +0200")
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 > As I mentioned, the rootfs is on reiser. So something in the boot up
 > scripts may trigger something that gets reiser to run through that path
 > with the wrong locking order. After the box is done booting, the dmesg
 > is clean. I then mount the ext3 fs and run the fio test, the lockdep
 > trace shows up immediately.

Maybe you could add some hack really early on (say at the beginning of
the reiserfs mount code) that took instances of the locks in the
correct order, so you would get a lockdep trace of where the ordering
is violated when it first happens?

 - R.