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")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxx>
Reported-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Andrea Parri <andrea.parri@xxxxxxxxxxxxxxxxxxxx>
Cc: "Yan, Zheng" <zyan@xxxxxxxxxx>
Cc: Sage Weil <sage@xxxxxxxxxx>
Cc: Ilya Dryomov <idryomov@xxxxxxxxx>
Cc: ceph-devel@xxxxxxxxxxxxxxx
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
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 6edab9a750f8a..e02f4ff0be3f1 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -541,7 +541,12 @@ 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);
}
--
2.7.4
