Patch "aacraid: Fix for aac_command_thread hang" has been added to the 4.6-stable tree

Patch "aacraid: Fix for aac_command_thread hang" has been added to the 4.6-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    aacraid: Fix for aac_command_thread hang

to the 4.6-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:
     aacraid-fix-for-aac_command_thread-hang.patch
and it can be found in the queue-4.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From fc4bf75ea300a5e62a2419f89dd0e22189dd7ab7 Mon Sep 17 00:00:00 2001
From: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>
Date: Mon, 25 Apr 2016 23:31:57 -0700
Subject: aacraid: Fix for aac_command_thread hang

From: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>

commit fc4bf75ea300a5e62a2419f89dd0e22189dd7ab7 upstream.

Typically under error conditions, it is possible for aac_command_thread()
to miss the wakeup from kthread_stop() and go back to sleep, causing it
to hang aac_shutdown.

In the observed scenario, the adapter is not functioning correctly and so
aac_fib_send() never completes (or time-outs depending on how it was
called). Shortly after aac_command_thread() starts it performs
aac_fib_send(SendHostTime) which hangs. When aac_probe_one
/aac_get_adapter_info send time outs, kthread_stop is called which breaks
the command thread out of it's hang.

The code will still go back to sleep in schedule_timeout() without
checking kthread_should_stop() so it causes aac_probe_one to hang until
the schedule_timeout() which is 30 minutes.

Fixed by: Adding another kthread_should_stop() before schedule_timeout()
Signed-off-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/scsi/aacraid/commsup.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/scsi/aacraid/commsup.c
+++ b/drivers/scsi/aacraid/commsup.c
@@ -1996,6 +1996,10 @@ int aac_command_thread(void *data)
 		if (difference <= 0)
 			difference = 1;
 		set_current_state(TASK_INTERRUPTIBLE);
+
+		if (kthread_should_stop())
+			break;
+
 		schedule_timeout(difference);
 
 		if (kthread_should_stop())


Patches currently in stable-queue which might be from RaghavaAditya.Renukunta@microsemi.com are

queue-4.6/aacraid-fix-for-kdump-driver-hang.patch
queue-4.6/aacraid-start-adapter-after-updating-number-of-msix-vectors.patch
queue-4.6/aacraid-fix-for-aac_command_thread-hang.patch
queue-4.6/aacraid-relinquish-cpu-during-timeout-wait.patch