Re: [PATCH 0/5] scsi: Allow fast io fail without waiting throughtimeout

From: James Smart
Date: Mon May 20 2013 - 11:54:08 EST


Based on the discussion recently held at LSF 2013, we are reworking the error recovery path to address all the issues you are mentioning. That work contradicts these patches. So for now, these should be held off.

-- james s

On 5/20/2013 3:14 AM, Ren Mingxin wrote:
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.


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(-)

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