md/md-bitmap: fix dm-raid max_write_behind setting

[ Upstream commit 2afe17794cfed5f80295b1b9facd66e6f65e5002 ]

It's supposed to be COUNTER_MAX / 2, not COUNTER_MAX.

Link: https://lore.kernel.org/linux-raid/[email protected]
Signed-off-by: Yu Kuai <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
(cherry picked from commit 8ddce5eab6c364cdbfadf87164627c3ab7e63a76)
Signed-off-by: Vijayendra Suman <[email protected]>

Author: YuKuai-huawei

drivers/md/md-bitmap.c

@@ -546,7 +546,7 @@ static int md_bitmap_new_disk_sb(struct bitmap *bitmap)
 	 * is a good choice?  We choose COUNTER_MAX / 2 arbitrarily.
 	 */
 	write_behind = bitmap->mddev->bitmap_info.max_write_behind;
-	if (write_behind > COUNTER_MAX)
+	if (write_behind > COUNTER_MAX / 2)
 		write_behind = COUNTER_MAX / 2;
 	sb->write_behind = cpu_to_le32(write_behind);
 	bitmap->mddev->bitmap_info.max_write_behind = write_behind;