diff --unified --recursive --text archlinux-linux/drivers/md/raid1.c archlinux-linux-diff/drivers/md/raid1.c
--- archlinux-linux/drivers/md/raid1.c	2021-09-24 14:37:15.347771866 +0200
+++ archlinux-linux-diff/drivers/md/raid1.c	2021-09-24 14:40:02.443978319 +0200
@@ -1501,7 +1501,7 @@
 			 * Not if there are too many, or cannot
 			 * allocate memory, or a reader on WriteMostly
 			 * is waiting for behind writes to flush */
-			if (bitmap &&
+			if (bitmap && write_behind &&
 			    (atomic_read(&bitmap->behind_writes)
 			     < mddev->bitmap_info.max_write_behind) &&
 			    !waitqueue_active(&bitmap->behind_wait)) {
diff --unified --recursive --text archlinux-linux/drivers/md/raid1.c archlinux-linux-changed/drivers/md/raid1.c
--- archlinux-linux/drivers/md/raid1.c	2021-09-24 15:43:22.842680119 +0200
+++ archlinux-linux-changed/drivers/md/raid1.c	2021-09-24 15:43:59.426142955 +0200
@@ -1329,7 +1329,6 @@
 	struct raid1_plug_cb *plug = NULL;
 	int first_clone;
 	int max_sectors;
-	bool write_behind = false;
 
 	if (mddev_is_clustered(mddev) &&
 	     md_cluster_ops->area_resyncing(mddev, WRITE,
@@ -1383,14 +1382,6 @@
 	for (i = 0;  i < disks; i++) {
 		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
 
-		/*
-		 * The write-behind io is only attempted on drives marked as
-		 * write-mostly, which means we could allocate write behind
-		 * bio later.
-		 */
-		if (rdev && test_bit(WriteMostly, &rdev->flags))
-			write_behind = true;
-
 		if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
 			atomic_inc(&rdev->nr_pending);
 			blocked_rdev = rdev;
@@ -1470,7 +1461,7 @@
 	 * at a time and thus needs a new bio that can fit the whole payload
 	 * this bio in page sized chunks.
 	 */
-	if (write_behind && bitmap)
+	if (bitmap)
 		max_sectors = min_t(int, max_sectors,
 				    BIO_MAX_VECS * (PAGE_SIZE >> 9));
 	if (max_sectors < bio_sectors(bio)) {
@@ -1501,7 +1492,7 @@
 			 * Not if there are too many, or cannot
 			 * allocate memory, or a reader on WriteMostly
 			 * is waiting for behind writes to flush */
-			if (bitmap &&
+			if (bitmap && 
 			    (atomic_read(&bitmap->behind_writes)
 			     < mddev->bitmap_info.max_write_behind) &&
 			    !waitqueue_active(&bitmap->behind_wait)) {