On 8/13/20 3:31 PM, Christoph Hellwig wrote:
On Thu, Aug 13, 2020 at 10:44:38AM +0800, Jacob Wen wrote:
wake_up_bit() uses waitqueue_active() that needs the explicit smp_mb().
Sounds like the barrier should go into wake_up_bit then..
wake_up_bit() doesn't know which one to chose: smp_mb__after_atomic() or
smp_mb().
Signed-off-by: Jacob Wen <jian.w.wen@xxxxxxxxxx>
---
fs/block_dev.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 0ae656e022fd..e74980848a2a 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1175,6 +1175,7 @@ static void bd_clear_claiming(struct block_device *whole, void *holder)
/* tell others that we're done */
BUG_ON(whole->bd_claiming != holder);
whole->bd_claiming = NULL;
+ smp_mb();
wake_up_bit(&whole->bd_claiming, 0);
}
--
2.17.1
---end quoted text---
