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>
This commit is contained in:
Stefan Haberland 2015-08-07 13:19:03 +02:00 committed by Martin Schwidefsky
parent aad1b688c9
commit 1eb38023dd
2 changed files with 7 additions and 2 deletions

View file

@ -1259,7 +1259,11 @@ static void do_path_verification_work(struct work_struct *work)
schedule_work(work);
return;
}
/* check if path verification already running and delay if so */
if (test_and_set_bit(DASD_FLAG_PATH_VERIFY, &device->flags)) {
schedule_work(work);
return;
}
opm = 0;
npm = 0;
ppm = 0;
@ -1402,7 +1406,7 @@ static void do_path_verification_work(struct work_struct *work)
device->path_data.hpfpm |= hpfpm;
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}
clear_bit(DASD_FLAG_PATH_VERIFY, &device->flags);
dasd_put_device(device);
if (data->isglobal)
mutex_unlock(&dasd_path_verification_mutex);

View file

@ -534,6 +534,7 @@ struct dasd_attention_data {
#define DASD_FLAG_SAFE_OFFLINE 10 /* safe offline processing requested*/
#define DASD_FLAG_SAFE_OFFLINE_RUNNING 11 /* safe offline running */
#define DASD_FLAG_ABORTALL 12 /* Abort all noretry requests */
#define DASD_FLAG_PATH_VERIFY 13 /* Path verification worker running */
#define DASD_SLEEPON_START_TAG ((void *) 1)
#define DASD_SLEEPON_END_TAG ((void *) 2)