From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964860AbcHNLBy (ORCPT ); Sun, 14 Aug 2016 07:01:54 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51960 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964835AbcHNLBu (ORCPT ); Sun, 14 Aug 2016 07:01:50 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Raghava Aditya Renukunta" , "Johannes Thumshirn" , "Martin K. Petersen" Date: Sat, 13 Aug 2016 18:42:51 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 033/305] aacraid: Fix for aac_command_thread hang In-Reply-To: X-SA-Exim-Connect-IP: 92.40.249.202 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.37-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Raghava Aditya Renukunta 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 Reviewed-by: Johannes Thumshirn Signed-off-by: Martin K. Petersen Signed-off-by: Ben Hutchings --- drivers/scsi/aacraid/commsup.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/scsi/aacraid/commsup.c +++ b/drivers/scsi/aacraid/commsup.c @@ -1921,6 +1921,10 @@ 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())