tree 4ed2e3b56ebdcf5976c5427c8de1539c211e5826
parent 835ee624c99d0b63797babf25abe208182bb88bf
author Bart Van Assche <bart.vanassche@sandisk.com> 1463075435 -0700
committer Doug Ledford <dledford@redhat.com> 1463161611 -0400

IB/srp: Prevent mapping failures

If both max_sectors and the queue_depth are high enough it can
happen that the MR pool is depleted temporarily. This causes
the SRP initiator to report mapping failures. Although the SRP
initiator recovers from such mapping failures, prevent that
this can happen by allocating more memory regions.

Additionally, only enable memory registration if at least two
pages can be registered per memory region.

Reported-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>