From 60ce4b5297971e089a69e103c606d83eb52a8f1e Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Fri, 23 Nov 2018 01:16:03 +0800 Subject: [PATCH] staging: erofs: add a full barrier in erofs_workgroup_unfreeze commit 948bbdb1818b7ad6e539dad4fbd2dd4650793ea9 upstream. Just like other generic locks, insert a full barrier in case of memory reorder. Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Signed-off-by: Greg Kroah-Hartman --- drivers/staging/erofs/internal.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h index 771a84e3077d..9f44ed8f0023 100644 --- a/drivers/staging/erofs/internal.h +++ b/drivers/staging/erofs/internal.h @@ -199,6 +199,11 @@ static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp, static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp, int orig_val) { + /* + * other observers should notice all modifications + * in the freezing period. + */ + smp_mb(); atomic_set(&grp->refcount, orig_val); preempt_enable(); } -- 2.17.1