From: Andrea Parri <andrea.parri@amarulasolutions.com>
To: linux-kernel@vger.kernel.org
Cc: Andrea Parri <andrea.parri@amarulasolutions.com>,
stable@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
Ming Lei <ming.lei@redhat.com>,
linux-block@vger.kernel.org,
"Paul E. McKenney" <paulmck@linux.ibm.com>,
Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH 2/4] bio: fix improper use of smp_mb__before_atomic()
Date: Mon, 20 May 2019 19:23:56 +0200 [thread overview]
Message-ID: <1558373038-5611-3-git-send-email-andrea.parri@amarulasolutions.com> (raw)
In-Reply-To: <1558373038-5611-1-git-send-email-andrea.parri@amarulasolutions.com>
This barrier only applies to the read-modify-write operations; in
particular, it does not apply to the atomic_set() primitive.
Replace the barrier with an smp_mb().
Fixes: dac56212e8127 ("bio: skip atomic inc/dec of ->bi_cnt for most use cases")
Cc: stable@vger.kernel.org
Reported-by: "Paul E. McKenney" <paulmck@linux.ibm.com>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: linux-block@vger.kernel.org
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
---
include/linux/bio.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/bio.h b/include/linux/bio.h
index ea73df36529ad..0f23b56826403 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -210,7 +210,7 @@ static inline void bio_cnt_set(struct bio *bio, unsigned int count)
{
if (count != 1) {
bio->bi_flags |= (1 << BIO_REFFED);
- smp_mb__before_atomic();
+ smp_mb();
}
atomic_set(&bio->__bi_cnt, count);
}
--
2.7.4
next prev parent reply other threads:[~2019-05-20 17:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1558373038-5611-1-git-send-email-andrea.parri@amarulasolutions.com>
2019-05-20 17:23 ` [PATCH 1/4] drm/msm: Fix improper uses of smp_mb__{before,after}_atomic() Andrea Parri
2019-05-20 21:07 ` Jordan Crouse
2019-05-20 17:23 ` Andrea Parri [this message]
2019-05-20 17:23 ` [PATCH 3/4] sbitmap: fix improper use of smp_mb__before_atomic() Andrea Parri
2019-05-20 17:23 ` [PATCH 4/4] ceph: " Andrea Parri
2019-05-21 2:18 ` Yan, Zheng
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