Re: [RFC PATCH] bcache: enable big endian support for IBM s390x

+static void swap_cache_sb_from_cpu(struct cache_sb *sb,
+				   struct cache_sb *out)
+{
+	int i;
+
+	out->offset		= cpu_to_le64(sb->offset);
+	out->flags		= cpu_to_le64(sb->flags);
+	out->seq		= cpu_to_le64(sb->seq);

This looks completely bogus and sparse will complain loudly about it.
Please make sure you have proper endianess annotations in place.