[PATCH 0/5] scsi: Allow fast io fail without waiting through timeout

[Ren Mingxin <renmx@cn.fujitsu.com>]

When there is a scsi command timed-out or failed, the scsi eh
tries a thorugh recovery, which is necessary for non-redundant
systems. However, the thorugh recovery usually takes much time,
which is not acceptable for misson critical systems. To improve
this latency, if we are working on a redundant system, we should
avoid the scsi eh for its long time failing recovery, and quick
failover to another path.

This set of patches is trying to implement above.

NOTE: the userland tools need to eusure the environment
restriction, which will be implemented later.

Thanks,
Ren

Ren Mingxin (5):
  scsi: rename return code FAST_IO_FAIL to FAST_IO
  FC transport: Add interface to specify fast io level for timed-out cmds
  SAS transport: Add interface to specify fast io level for timed-out cmds
  lpfc: Allow fast timed-out io recovery
  mptfusion: Allow fast timed-out io recovery

 drivers/message/fusion/mptscsih.c   |   29 ++++++++-
 drivers/scsi/lpfc/lpfc_scsi.c       |   34 ++++++++++
 drivers/scsi/scsi_error.c           |   18 ++---
 drivers/scsi/scsi_sas_internal.h    |    4 -
 drivers/scsi/scsi_transport_fc.c    |  112 ++++++++++++++++++++++++++++++++++--
 drivers/scsi/scsi_transport_iscsi.c |    6 -
 drivers/scsi/scsi_transport_sas.c   |  103 ++++++++++++++++++++++++++++++++-
 include/scsi/scsi.h                 |    2 
 include/scsi/scsi_transport_fc.h    |   11 +++
 include/scsi/scsi_transport_sas.h   |    8 ++
 10 files changed, 303 insertions(+), 24 deletions(-)