diff --git a/fs/buffer.c b/fs/buffer.c
index c4e11390a44c52518539243d9767f95915e398d2..ec0aca8ba6bfdc79022563007207c5a70d23bd37 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2935,7 +2935,7 @@ static void guard_bh_eod(int rw, struct bio *bio, struct buffer_head *bh)
 	bio->bi_io_vec[0].bv_len = bytes;
 
 	/* ..and clear the end of the buffer for reads */
-	if (rw & READ) {
+	if ((rw & RW_MASK) == READ) {
 		void *kaddr = kmap_atomic(bh->b_page);
 		memset(kaddr + bh_offset(bh) + bytes, 0, bh->b_size - bytes);
 		kunmap_atomic(kaddr);