+/*
+ * Vanilla kernels before 4.0 do not implement inode_to_bdi
+ * RHEL kernels before 3.10.0-327.10.1 do not implement inode_to_bdi
+ * RHEL kernel 3.10.0-327.10.1 has inode_to_bdi
+ * RHEL kernel 3.10.0-327.13.1 includes a partial merge of upstream
+ * commit a212b105b07d75b48b1a166378282e8a77fbf53d which inlines
+ * inode_to_bdi but not sb_is_blkdev_sb making it unusable by modules.
+ */