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Date: Thu, 20 Nov 2014 18:11:46 +0000
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Will Deacon <will.deacon@arm.com>
Cc: Andrey Konovalov <andreyknvl@google.com>, Ingo Molnar <mingo@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
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        Dmitry Vyukov <dvyukov@google.com>, Kostya Serebryany <kcc@google.com>,
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Subject: Re: Potential data race in dput and __d_lookup
Message-ID: <20141120181145.GO7996@ZenIV.linux.org.uk>
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 <20141120174101.GT19126@arm.com>
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On Thu, Nov 20, 2014 at 05:41:01PM +0000, Will Deacon wrote:

> I think it should be fine. d_lock is #defined as d_lockref.lock, and the
> whole way the lockref works is that you can either cmpxchg the lock and the
> counter

... both by a single operation, that is.