s390/dasd: channel path aware error recovery
authorStefan Haberland <sth@linux.vnet.ibm.com>
Mon, 8 Aug 2016 13:56:54 +0000 (15:56 +0200)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Mon, 12 Dec 2016 11:05:03 +0000 (12:05 +0100)
commita521b048bc8c5d3c57a468c2cba70eb60e873616
treed84e42b5653a1761a5cf7307ab4fef0e884f1c07
parentc93461515a1a16486f4e483cb34170366fa73ea1
s390/dasd: channel path aware error recovery

With this feature, the DASD device driver more robustly handles DASDs
that are attached via multiple channel paths and are subject to
constant Interface-Control-Checks (IFCCs) and Channel-Control-Checks
(CCCs) or loss of High-Performance-FICON (HPF) functionality on one or
more of these paths.

If a channel path does not work correctly, it is removed from normal
operation as long as other channel paths are available. All extended
error recovery states can be queried and reset via user space
interfaces.

Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/include/asm/scsw.h
drivers/s390/block/dasd.c
drivers/s390/block/dasd_3990_erp.c
drivers/s390/block/dasd_devmap.c
drivers/s390/block/dasd_eckd.c
drivers/s390/block/dasd_eckd.h
drivers/s390/block/dasd_int.h