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Date: Sun, 28 Oct 2018 13:34:47 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>,
        Bart Van Assche <bvanassche@acm.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
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        Johannes Berg <johannes.berg@intel.com>,
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Subject: Re: [PATCH RFC] kernel/locking, fs/direct-io: Introduce and use
 down_write_nolockdep()
Message-ID: <20181028203447.GA9330@infradead.org>
References: <20181026164905.214474-1-bvanassche@acm.org>
 <20181027053745.GI6311@dastard>
 <20181028175840.GA744@hirez.programming.kicks-ass.net>
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On Sun, Oct 28, 2018 at 06:58:40PM +0100, Peter Zijlstra wrote:
> Also, from a quick look, this has been broken for donkeys years,
> right? That comment:
> 
> 	/* will be released by direct_io_worker */
> 
> has been there since 2009. Back then of course it was a mutex, and the
> curious thing is, mutexes have _never_ supported this release from
> another context thing.

direct_io_worker back then was just a helper called by
__blockdev_direct_IO in the same context.  But yes, this comment
is horribly out of date.