This is a note to let you know that I've just added the patch titled
scsi: mpt3sas: Fix deadlock while cancelling the running firmware event
to the 5.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
scsi-mpt3sas-fix-deadlock-while-cancelling-the-runni.patch
and it can be found in the queue-5.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 87e13bed51473214dd34fe2632da5e62ba4f3f7b
Author: Suganath Prabu S <suganath-prabu.subramani@xxxxxxxxxxxx>
Date: Tue May 18 10:46:23 2021 +0530
scsi: mpt3sas: Fix deadlock while cancelling the running firmware event
[ Upstream commit e2fac6c44ae06e58ac02181b048af31195883c31 ]
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@xxxxxxxxxxxx
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@xxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index a5f70f0e0287..b48f10f7cf31 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -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
