4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steffen Maier <maier@xxxxxxxxxxxxx> commit d70aab55924b44f213fec2b900b095430b33eec6 upstream. For problem determination we always want to see when we were invoked on the terminate_rport_io callback whether we perform something or not. Temporal event sequence of interest with a long fast_io_fail_tmo of 27 sec: loose remote port t workqueue [s] zfcp_q_<dev> IRQ zfcperp<dev> === ================== =================== ============================ 0 recv RSCN q p.test_link_work block rport start fast_io_fail_tmo send ADISC ELS 4 recv ADISC fail block zfcp_port port forced reopen send open port 12 recv open port fail q p.gid_pn_work zfcp_erp_wakeup (zfcp_erp_wait would return) GID_PN fail Before this point, we got a SCSI trace with tag "sctrpi1" on fast_io_fail, e.g. with the typical 5 sec setting. port.status |= ERP_FAILED If fast_io_fail_tmo triggers after this point, we missed a SCSI trace. workqueue fc_dl_<host> ================== 27 fc_timeout_fail_rport_io fc_terminate_rport_io zfcp_scsi_terminate_rport_io zfcp_erp_port_forced_reopen _zfcp_erp_port_forced_reopen if (port.status & ERP_FAILED) return; Therefore, write a trace before above early return. Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : REC Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 ZFCP_DBF_REC_TRIG Tag : sctrpi1 SCSI terminate rport I/O LUN : 0xffffffffffffffff none (invalid) WWPN : 0x<wwpn> D_ID : 0x<n_port_id> Adapter status : 0x... Port status : 0x... LUN status : 0x00000000 none (invalid) Ready count : 0x... Running count : 0x... ERP want : 0x03 ZFCP_ERP_ACTION_REOPEN_PORT_FORCED ERP need : 0xe0 ZFCP_ERP_ACTION_FAILED Signed-off-by: Steffen Maier <maier@xxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> #2.6.38+ Reviewed-by: Benjamin Block <bblock@xxxxxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/s390/scsi/zfcp_erp.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/drivers/s390/scsi/zfcp_erp.c +++ b/drivers/s390/scsi/zfcp_erp.c @@ -41,9 +41,13 @@ enum zfcp_erp_steps { * @ZFCP_ERP_ACTION_REOPEN_PORT_FORCED: Forced port recovery. * @ZFCP_ERP_ACTION_REOPEN_ADAPTER: Adapter recovery. * @ZFCP_ERP_ACTION_NONE: Eyecatcher pseudo flag to bitwise or-combine with - * either of the other enum values. + * either of the first four enum values. * Used to indicate that an ERP action could not be * set up despite a detected need for some recovery. + * @ZFCP_ERP_ACTION_FAILED: Eyecatcher pseudo flag to bitwise or-combine with + * either of the first four enum values. + * Used to indicate that ERP not needed because + * the object has ZFCP_STATUS_COMMON_ERP_FAILED. */ enum zfcp_erp_act_type { ZFCP_ERP_ACTION_REOPEN_LUN = 1, @@ -51,6 +55,7 @@ enum zfcp_erp_act_type { ZFCP_ERP_ACTION_REOPEN_PORT_FORCED = 3, ZFCP_ERP_ACTION_REOPEN_ADAPTER = 4, ZFCP_ERP_ACTION_NONE = 0xc0, + ZFCP_ERP_ACTION_FAILED = 0xe0, }; enum zfcp_erp_act_state { @@ -378,8 +383,12 @@ static void _zfcp_erp_port_forced_reopen zfcp_erp_port_block(port, clear); zfcp_scsi_schedule_rport_block(port); - if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) + if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) { + zfcp_dbf_rec_trig(id, port->adapter, port, NULL, + ZFCP_ERP_ACTION_REOPEN_PORT_FORCED, + ZFCP_ERP_ACTION_FAILED); return; + } zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT_FORCED, port->adapter, port, NULL, id, 0);