tree 80737a2703a9f4d09cee2410342aeccb281413ae
parent 626350b63ef2cd447023d3dc2a34eaa7ca01bfff
author Stefan Weinhuber <wein@de.ibm.com> 1260186711 +0100
committer Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> 1260186694 +0100

[S390] dasd: improve error recovery for internal I/O

Most of the error conditions reported by a FICON storage server
indicate situations which can be recovered. Sometimes the host just
needs to retry an I/O request, but sometimes the recovery
is more complex and requires the device driver to wait, choose
a different path, etc.

The DASD device driver has a fully featured error recovery
for normal block layer I/O, but not for internal I/O request which
are for example used during the device bring up.
This can lead to situations where the IPL of a system fails because
DASD devices are not properly recognized.
This patch will extend the internal I/O handling to use the existing
error recovery procedures.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>