tree ebc33843fee8087c2dc69fafe3aa7c58378e270c
parent aad1b688c996b4a247c4a8fd1bd6c5c563963ddb
author Stefan Haberland <stefan.haberland@de.ibm.com> 1438946343 +0200
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1439147261 +0200

s390/dasd: fix failing path verification

DASD path verification requires the usage of sleep_on_immediatly to
ensure that no other I/O request is blocking the recovery of
disconnected devices. But two concurrent path verification workers for
the same device may kill each others requests due to the usage of the
immediate sleep_on function. This may lead to unsuccessful path
verifications.

Prevent that two parallel path verification workers conflict with
each other by implementing a device flag signalling a already running
worker.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>