- * bit 3 -- synchronous I/O hint: the block layer will unplug immediately
- * Note that this does NOT indicate that the IO itself is sync, just
- * that the block layer will not postpone issue of this IO by plugging.
- * bit 4 -- metadata request
+ * bit 3 -- synchronous I/O hint.
+ * bit 4 -- Unplug the device immediately after submitting this bio.
+ * bit 5 -- metadata request