4.20-stable review patch. If anyone has any objections, please let me know.
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From: Gao Xiang gaoxiang25@huawei.com
commit 948bbdb1818b7ad6e539dad4fbd2dd4650793ea9 upstream.
Just like other generic locks, insert a full barrier in case of memory reorder.
Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Gao Xiang gaoxiang25@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/staging/erofs/internal.h | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/staging/erofs/internal.h +++ b/drivers/staging/erofs/internal.h @@ -209,6 +209,11 @@ static inline bool erofs_workgroup_try_t 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(); }