/****************************************************************************** * Create a degraded read DAG for RAID level 1 * * Hdr -> Nil -> R(p/s)d -> Commit -> Trm * * The "Rd" node reads data from the surviving disk in the mirror pair * Rpd - read of primary copy * Rsd - read of secondary copy * * Parameters: raidPtr - description of the physical array * asmap - logical & physical addresses for this access * bp - buffer ptr (for holding write data) * flags - general flags (e.g. disk locking) * allocList - list of memory allocated in DAG creation *****************************************************************************/