diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 089c9ad..df518c4 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -138,6 +138,17 @@ BUFFER_FNS(Defer_Completion, defer_completion)
 static __always_inline void set_buffer_uptodate(struct buffer_head *bh)
 {
 	/*
+	 * If somebody else already set this uptodate, they will
+	 * have done the memory barrier, and a reader will thus
+	 * see *some* valid buffer state.
+	 *
+	 * Any other serialization (with IO errors or whatever that
+	 * might clear the bit) has to come from other state (eg BH_Lock).
+	 */
+	if (test_bit(BH_Uptodate, &bh->b_state))
+		return;
+
+	/*
 	 * make it consistent with folio_mark_uptodate
 	 * pairs with smp_load_acquire in buffer_uptodate
 	 */