The barrier provided by smp_store_release() is before the store, while
wake_up_var() needs a full barrier *after* the store.

The new store_release_wake_up() interface encodes all the barriers
making this sort of bug harder to write.

Signed-off-by: NeilBrown <redacted>
---
 fs/nfs/dir.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 492cffd9d3d8..ded86facef8f 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c

@@ -1837,9 +1837,7 @@ static void block_revalidate(struct dentry *dentry)
 
 static void unblock_revalidate(struct dentry *dentry)
 {
-	/* store_release ensures wait_var_event() sees the update */
-	smp_store_release(&dentry->d_fsdata, NULL);
-	wake_up_var(&dentry->d_fsdata);
+	store_release_wake_up(&dentry->d_fsdata, NULL);
 }
 
 /*

-- 
2.47.0