Remove ua sense in recovery session #70
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When Initiator ping(noop out) failed, linux kernel will call stop_conn and recover session. Tgt will rebuild session info(in it_nexus_create) and add the ua sense(ASC_POWERON_RESET) to pending_ua_sense_list. But, tgt Set ASC_POWERON_RESET ua sense will make scsi command fast failed, after session recovery.
After recovery, first scmd request will get the ASC_POWERON_RESET(ua sense) and response with SAM_STAT_CHECK_CONDITION status. SCSI module will return IO-error to upper layer without retry, because of
expecting_cc_ua = 0in struct scsi_device(in kernel scsi module).According to linux kernel code
scsi_done --> scsi_complete --> scsi_decide_disposition --> scsi_check_sense, if expecting_cc_ua = 0, scmd response with ASC_POWERON_RESET(ua sense) do not NEEDS_RETRY. It make scmd fast failed, although lun(session)has recovered to normal.In addition, tgt has setted ASC_POWERON_RESET ua sense for LOGICAL_UNIT_RESET and CLEAR_TASK_SET device reset operation (in target_mgmt_request funtion).