R0dn3yS/android_kernel_xiaomi_sm7250
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

bio: fix improper use of smp_mb__before_atomic()

Browse Source 
commit f381c6a4bd0ae0fde2d6340f1b9bb0f58d915de6 upstream.

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: dac56212e8 ("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>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andrea Parri 2019-05-20 19:23:56 +02:00 committed by Greg Kroah-Hartman
parent 432ec4fa6c
commit b78255d6cf
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/bio.h
View File

@ -257,7 +257,7 @@ 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);
}