Multi-Initiator SAS

["Darrick J. Wong" <djwong@us.ibm.com>]

Hi everybody!

Alexis and I connected both a Adaptec 9410 and a LSI 1064E SAS initiator
to an expander.  Both machines saw the disks attached to the expander,
and both could send I/Os to the disks.  So far, so good.

We then connected a SATA disk to the expander.  libsas BUGd up in
sas_ex_discover_end_dev (sas_expander.c:636):

BUG_ON(sas_port_add(phy->port) != 0);

mptsas didn't seem to do anything with the SATA device at all, though
when we disconnected the SATA disk it recognized that a SATA device went
away.  We'll have a look at the libsas problem in a jiffy.

--D