| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 11/42] ceph: fix improper use of smp_mb__before_atomic() | Date | Mon, 5 Aug 2019 15:02:37 +0200 |
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[ Upstream commit 749607731e26dfb2558118038c40e9c0c80d23b5 ]
This barrier only applies to the read-modify-write operations; in particular, it does not apply to the atomic64_set() primitive.
Replace the barrier with an smp_mb().
Fixes: fdd4e15838e59 ("ceph: rework dcache readdir") 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: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- fs/ceph/super.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/fs/ceph/super.h b/fs/ceph/super.h index 622d5dd9f6169..9bd0d928057b7 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -476,7 +476,12 @@ static inline void __ceph_dir_set_complete(struct ceph_inode_info *ci, long long release_count, long long ordered_count) { - smp_mb__before_atomic(); + /* + * Makes sure operations that setup readdir cache (update page + * cache and i_size) are strongly ordered w.r.t. the following + * atomic64_set() operations. + */ + smp_mb(); atomic64_set(&ci->i_complete_seq[0], release_count); atomic64_set(&ci->i_complete_seq[1], ordered_count); } -- 2.20.1
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