From: Al Viro <viro@ZenIV.linux.org.uk>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: Ingo Molnar <mingo@kernel.org>, Will Deacon <will.deacon@arm.com>,
Peter Zijlstra <peterz@infradead.org>,
Davidlohr Bueso <davidlohr@hp.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
Dmitry Vyukov <dvyukov@google.com>,
Kostya Serebryany <kcc@google.com>,
ktsan@googlegroups.com
Subject: Re: Potential data race in dput and __d_lookup
Date: Thu, 20 Nov 2014 18:05:03 +0000 [thread overview]
Message-ID: <20141120180503.GN7996@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAAeHK+zQZ=sJYQA=BKLS2i7hu8NyXn6GXngvDqG9WD96yd9acg@mail.gmail.com>
On Thu, Nov 20, 2014 at 09:20:14PM +0400, Andrey Konovalov wrote:
> It seems that one thread increments 'dentry->d_lockref.count', while
> other does 'lockref_put_or_lock(&dentry->d_lockref)' without any
> synchronization.
>
> Could you confirm if this is a real race?
I can not. Increment in __d_lookup() is under ->d_lockref.lock (aka
->d_lock) and lockref_put_or_lock() is atomic wrt that.
prev parent reply other threads:[~2014-11-20 18:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-20 17:20 Andrey Konovalov
2014-11-20 17:41 ` Will Deacon
2014-11-20 18:11 ` Al Viro
2014-11-20 18:05 ` Al Viro [this message]
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