Commit e2fac6c4 authored by Suganath Prabu S's avatar Suganath Prabu S Committed by Martin K. Petersen
Browse files

scsi: mpt3sas: Fix deadlock while cancelling the running firmware event 

Do not cancel current running firmware event work if the event type is
different from MPT3SAS_REMOVE_UNRESPONDING_DEVICES.  Otherwise a deadlock
can be observed while cancelling the current firmware event work if a hard
reset operation is called as part of processing the current event.

Link: https://lore.kernel.org/r/20210518051625.1596742-2-suganath-prabu.subramani@broadcom.com


Signed-off-by: default avatarSuganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent ea2f0f77

drivers/scsi/mpt3sas/mpt3sas_scsih.c

+22 −0
Original line number Diff line number Diff line
@@ -3697,6 +3697,28 @@ _scsih_fw_event_cleanup_queue(struct MPT3SAS_ADAPTER *ioc) 
	ioc->fw_events_cleanup = 1;

	while ((fw_event = dequeue_next_fw_event(ioc)) ||

	     (fw_event = ioc->current_event)) {



		/*

		 * Don't call cancel_work_sync() for current_event

		 * other than MPT3SAS_REMOVE_UNRESPONDING_DEVICES;

		 * otherwise we may observe deadlock if current

		 * hard reset issued as part of processing the current_event.

		 *

		 * Orginal logic of cleaning the current_event is added

		 * for handling the back to back host reset issued by the user.

		 * i.e. during back to back host reset, driver use to process

		 * the two instances of MPT3SAS_REMOVE_UNRESPONDING_DEVICES

		 * event back to back and this made the drives to unregister

		 * the devices from SML.

		 */



		if (fw_event == ioc->current_event &&

		    ioc->current_event->event !=

		    MPT3SAS_REMOVE_UNRESPONDING_DEVICES) {

			ioc->current_event = NULL;

			continue;

		}



		/*

		 * Wait on the fw_event to complete. If this returns 1, then

		 * the event was never executed, and we need a put for the