From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753449Ab2IQAuO (ORCPT ); Sun, 16 Sep 2012 20:50:14 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33317 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752924Ab2IQAtX (ORCPT ); Sun, 16 Sep 2012 20:49:23 -0400 Message-Id: <20120917003627.321569181@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 17 Sep 2012 01:36:33 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, "sreekanth.reddy@lsi.com" , James Bottomley Subject: [ 008/135] [SCSI] mpt2sas: Fix for Driver oops, when loading driver with max_queue_depth command line option to a very small value In-Reply-To: <20120917003625.784119135@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 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 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: "sreekanth.reddy@lsi.com" commit 338b131a3269881c7431234855c93c219b0979b6 upstream. If the specified max_queue_depth setting is less than the expected number of internal commands, then driver will calculate the queue depth size to a negitive number. This negitive number is actually a very large number because variable is unsigned 16bit integer. So, the driver will ask for a very large amount of memory for message frames and resulting into oops as memory allocation routines will not able to handle such a large request. So, in order to limit this kind of oops, The driver need to set the max_queue_depth to a scsi mid layer's can_queue value. Then the overall message frames required for IO is minimum of either (max_queue_depth plus internal commands) or the IOC global credits. Signed-off-by: Sreekanth Reddy Signed-off-by: James Bottomley Signed-off-by: Ben Hutchings --- drivers/scsi/mpt2sas/mpt2sas_base.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c index 9d46fcb..b25757d 100644 --- a/drivers/scsi/mpt2sas/mpt2sas_base.c +++ b/drivers/scsi/mpt2sas/mpt2sas_base.c @@ -2424,10 +2424,13 @@ _base_allocate_memory_pools(struct MPT2SAS_ADAPTER *ioc, int sleep_flag) } /* command line tunables for max controller queue depth */ - if (max_queue_depth != -1) - max_request_credit = (max_queue_depth < facts->RequestCredit) - ? max_queue_depth : facts->RequestCredit; - else + if (max_queue_depth != -1 && max_queue_depth != 0) { + max_request_credit = min_t(u16, max_queue_depth + + ioc->hi_priority_depth + ioc->internal_depth, + facts->RequestCredit); + if (max_request_credit > MAX_HBA_QUEUE_DEPTH) + max_request_credit = MAX_HBA_QUEUE_DEPTH; + } else max_request_credit = min_t(u16, facts->RequestCredit, MAX_HBA_QUEUE_DEPTH); @@ -2502,7 +2505,7 @@ _base_allocate_memory_pools(struct MPT2SAS_ADAPTER *ioc, int sleep_flag) /* set the scsi host can_queue depth * with some internal commands that could be outstanding */ - ioc->shost->can_queue = ioc->scsiio_depth - (2); + ioc->shost->can_queue = ioc->scsiio_depth; dinitprintk(ioc, printk(MPT2SAS_INFO_FMT "scsi host: " "can_queue depth (%d)\n", ioc->name, ioc->shost->can_queue));