Create a cache of devices that are seen in a system. This will avoid
the unnecessary traversal of the device list in the scsi_dh when there
are multiple luns of a same type.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>