linux/drivers/s390/scsi
Steffen Maier 242ec14551 scsi: zfcp: fix scsi_eh host reset with port_forced ERP for non-NPIV FCP devices
Suppose more than one non-NPIV FCP device is active on the same channel.
Send I/O to storage and have some of the pending I/O run into a SCSI
command timeout, e.g. due to bit errors on the fibre. Now the error
situation stops. However, we saw FCP requests continue to timeout in the
channel. The abort will be successful, but the subsequent TUR fails.
Scsi_eh starts. The LUN reset fails. The target reset fails.  The host
reset only did an FCP device recovery. However, for non-NPIV FCP devices,
this does not close and reopen ports on the SAN-side if other non-NPIV FCP
device(s) share the same open ports.

In order to resolve the continuing FCP request timeouts, we need to
explicitly close and reopen ports on the SAN-side.

This was missing since the beginning of zfcp in v2.6.0 history commit
ea127f975424 ("[PATCH] s390 (7/7): zfcp host adapter.").

Note: The FSF requests for forced port reopen could run into FSF request
timeouts due to other reasons. This would trigger an internal FCP device
recovery. Pending forced port reopen recoveries would get dismissed. So
some ports might not get fully reopened during this host reset handler.
However, subsequent I/O would trigger the above described escalation and
eventually all ports would be forced reopen to resolve any continuing FCP
request timeouts due to earlier bit errors.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: <stable@vger.kernel.org> #3.0+
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-03-27 21:26:12 -04:00
..
Makefile s390: add a few more SPDX identifiers 2017-12-05 07:51:09 +01:00
zfcp_aux.c scsi: zfcp: fix sysfs block queue limit output for max_segment_size 2019-01-29 01:14:59 -05:00
zfcp_ccw.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
zfcp_dbf.c scsi: zfcp: silence all W=1 build warnings for existing kdoc 2018-11-15 15:01:18 -05:00
zfcp_dbf.h scsi: zfcp: silence remaining kdoc warnings in header files 2018-11-15 15:01:18 -05:00
zfcp_def.h scsi: zfcp: use enum zfcp_erp_steps for struct zfcp_erp_action.step 2018-11-15 15:01:18 -05:00
zfcp_erp.c scsi: zfcp: fix scsi_eh host reset with port_forced ERP for non-NPIV FCP devices 2019-03-27 21:26:12 -04:00
zfcp_ext.h scsi: zfcp: fix scsi_eh host reset with port_forced ERP for non-NPIV FCP devices 2019-03-27 21:26:12 -04:00
zfcp_fc.c scsi: zfcp: silence all W=1 build warnings for existing kdoc 2018-11-15 15:01:18 -05:00
zfcp_fc.h scsi: zfcp: silence remaining kdoc warnings in header files 2018-11-15 15:01:18 -05:00
zfcp_fsf.c scsi: zfcp: silence all W=1 build warnings for existing kdoc 2018-11-15 15:01:18 -05:00
zfcp_fsf.h scsi: zfcp: silence remaining kdoc warnings in header files 2018-11-15 15:01:18 -05:00
zfcp_qdio.c s390/qdio: make SBAL address array type-safe 2019-02-07 11:57:07 +01:00
zfcp_qdio.h scsi: zfcp: silence remaining kdoc warnings in header files 2018-11-15 15:01:18 -05:00
zfcp_reqlist.h scsi: zfcp: silence remaining kdoc warnings in header files 2018-11-15 15:01:18 -05:00
zfcp_scsi.c scsi: zfcp: fix scsi_eh host reset with port_forced ERP for non-NPIV FCP devices 2019-03-27 21:26:12 -04:00
zfcp_sysfs.c scsi: zfcp: support SCSI_ADAPTER_RESET via scsi_host sysfs attribute host_reset 2018-05-18 11:28:15 -04:00
zfcp_unit.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00