#define DF_EMULATED_VPD_UNIT_SERIAL 0x00000004
#define DF_USING_UDEV_PATH 0x00000008
#define DF_USING_ALIAS 0x00000010
+#define DF_READ_ONLY 0x00000020
/* Physical device queue depth */
u32 queue_depth;
/* Used for SPC-2 reservations enforce of ISIDs */