linux/drivers/s390/scsi
Steffen Maier 2190168aae scsi: zfcp: fix reaction on bit error threshold notification
On excessive bit errors for the FCP channel ingress fibre path, the channel
notifies us.  Previously, we only emitted a kernel message and a trace
record.  Since performance can become suboptimal with I/O timeouts due to
bit errors, we now stop using an FCP device by default on channel
notification so multipath on top can timely failover to other paths.  A new
module parameter zfcp.ber_stop can be used to get zfcp old behavior.

User explanation of new kernel message:

 * Description:
 * The FCP channel reported that its bit error threshold has been exceeded.
 * These errors might result from a problem with the physical components
 * of the local fibre link into the FCP channel.
 * The problem might be damage or malfunction of the cable or
 * cable connection between the FCP channel and
 * the adjacent fabric switch port or the point-to-point peer.
 * Find details about the errors in the HBA trace for the FCP device.
 * The zfcp device driver closed down the FCP device
 * to limit the performance impact from possible I/O command timeouts.
 * User action:
 * Check for problems on the local fibre link, ensure that fibre optics are
 * clean and functional, and all cables are properly plugged.
 * After the repair action, you can manually recover the FCP device by
 * writing "0" into its "failed" sysfs attribute.
 * If recovery through sysfs is not possible, set the CHPID of the device
 * offline and back online on the service element.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: <stable@vger.kernel.org> #2.6.30+
Link: https://lore.kernel.org/r/20191001104949.42810-1-maier@linux.ibm.com
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-10-03 21:45:53 -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 GCC compiler warning emitted with -Wmaybe-uninitialized 2019-07-11 21:04:23 -04:00
zfcp_ext.h scsi: zfcp: fix to prevent port_remove with pure auto scan LUNs (only sdevs) 2019-05-29 21:52:31 -04:00
zfcp_fc.c scsi: s390: zfcp_fc: use sg helper to iterate over scatterlist 2019-06-20 15:21:33 -04:00
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: fix reaction on bit error threshold notification 2019-10-03 21:45:53 -04:00
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 to prevent port_remove with pure auto scan LUNs (only sdevs) 2019-05-29 21:52:31 -04:00
zfcp_sysfs.c scsi: zfcp: fix to prevent port_remove with pure auto scan LUNs (only sdevs) 2019-05-29 21:52:31 -04:00
zfcp_unit.c scsi: zfcp: fix to prevent port_remove with pure auto scan LUNs (only sdevs) 2019-05-29 21:52:31 -04:00