From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <axboe@kernel.dk>
Subject: Re: [PATCH 1/1] bcache: use llist_for_each_entry_safe() in
 __closure_wake_up()
To: Michael Lyle <mlyle@lyle.org>
Cc: Coly Li <i@coly.li>, linux-bcache@vger.kernel.org,
 linux-block@vger.kernel.org
References: <20170926095412.74028-1-colyli@suse.de>
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 <4c14e77e-577f-b7b7-d63a-b4b3a4d9e757@coly.li>
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 <CAJ+L6qeQu0A17gGb1RVu8g_JvzcvJ2uSDj+9vC-hsUEFqM-fAw@mail.gmail.com>
From: Jens Axboe <axboe@kernel.dk>
Message-ID: <90e74638-c396-a04f-da5c-72ae387f677d@kernel.dk>
Date: Wed, 27 Sep 2017 22:52:27 +0200
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On 09/27/2017 10:48 PM, Michael Lyle wrote:
> Jens--
> 
> I think it's a race condition-- the individual closures remain valid.
> It's just that the list element has different meanings-- it's either a
> list actively being used to wake, or a linkage on one of several lists
> that is being used to await wake.  If a closure goes back to wait very
> quickly after being woken, it can end up connecting its new wait-list
> with the being-woken list.

Reading it a second time, looks like you are right. OK, then let's just
queue it up as-is, I'll add the Fixes line this time.

-- 
Jens Axboe