Patch "megaraid_sas: Do not use PAGE_SIZE for max_sectors" has been added to the 3.10-stable tree

Patch "megaraid_sas: Do not use PAGE_SIZE for max_sectors" has been added to the 3.10-stable tree

[gregkh]

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

    megaraid_sas: Do not use PAGE_SIZE for max_sectors

to the 3.10-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:
     megaraid_sas-do-not-use-page_size-for-max_sectors.patch
and it can be found in the queue-3.10 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 357ae967ad66e357f78b5cfb5ab6ca07fb4a7758 Mon Sep 17 00:00:00 2001
From: "sumit.saxena@avagotech.com" <sumit.saxena@avagotech.com>
Date: Thu, 15 Oct 2015 13:40:04 +0530
Subject: megaraid_sas: Do not use PAGE_SIZE for max_sectors

From: sumit.saxena@avagotech.com <sumit.saxena@avagotech.com>

commit 357ae967ad66e357f78b5cfb5ab6ca07fb4a7758 upstream.

Do not use PAGE_SIZE marco to calculate max_sectors per I/O
request. Driver code assumes PAGE_SIZE will be always 4096 which can
lead to wrongly calculated value if PAGE_SIZE is not 4096. This issue
was reported in Ubuntu Bugzilla Bug #1475166.

Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/scsi/megaraid/megaraid_sas.h      |    2 ++
 drivers/scsi/megaraid/megaraid_sas_base.c |    2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -300,6 +300,8 @@ enum MR_EVT_ARGS {
 	MR_EVT_ARGS_GENERIC,
 };
 
+
+#define SGE_BUFFER_SIZE	4096
 /*
  * define constants for device list query options
  */
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -3602,7 +3602,7 @@ static int megasas_init_fw(struct megasa
 	}
 
 	instance->max_sectors_per_req = instance->max_num_sge *
-						PAGE_SIZE / 512;
+						SGE_BUFFER_SIZE / 512;
 	if (tmp_sectors && (instance->max_sectors_per_req > tmp_sectors))
 		instance->max_sectors_per_req = tmp_sectors;
 


Patches currently in stable-queue which might be from sumit.saxena@avagotech.com are

queue-3.10/megaraid_sas-smap-restriction-do-not-access-user-memory-from-ioctl-code.patch
queue-3.10/megaraid_sas-do-not-use-page_size-for-max_sectors.patch