Patch "s390/dasd: prevent prefix I/O error" has been added to the 4.4-stable tree

Patch "s390/dasd: prevent prefix I/O error" has been added to the 4.4-stable tree

[gregkh]

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

    s390/dasd: prevent prefix I/O error

to the 4.4-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:
     s390-dasd-prevent-prefix-i-o-error.patch
and it can be found in the queue-4.4 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 foo@baz Fri Feb 23 11:58:50 CET 2018
From: Stefan Haberland <sth@linux.vnet.ibm.com>
Date: Thu, 26 Oct 2017 14:37:35 +0200
Subject: s390/dasd: prevent prefix I/O error

From: Stefan Haberland <sth@linux.vnet.ibm.com>


[ Upstream commit da340f921d3454f1521671c7a5a43ad3331fbe50 ]

Prevent that a prefix flag is set based on invalid configuration data.
The validity.verify_base flag should only be set for alias devices.
Usually the unit address type is either one of base, PAV alias or
HyperPAV alias. But in cases where the unit address type is not set or
any other value the validity.verify_base flag might be set as well.
This would lead to follow on errors.
Explicitly check for alias devices and set the validity flag only for
them.

Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/s390/block/dasd_eckd.c |   16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -518,10 +518,12 @@ static int prefix_LRE(struct ccw1 *ccw,
 	pfxdata->validity.define_extent = 1;
 
 	/* private uid is kept up to date, conf_data may be outdated */
-	if (startpriv->uid.type != UA_BASE_DEVICE) {
+	if (startpriv->uid.type == UA_BASE_PAV_ALIAS)
 		pfxdata->validity.verify_base = 1;
-		if (startpriv->uid.type == UA_HYPER_PAV_ALIAS)
-			pfxdata->validity.hyper_pav = 1;
+
+	if (startpriv->uid.type == UA_HYPER_PAV_ALIAS) {
+		pfxdata->validity.verify_base = 1;
+		pfxdata->validity.hyper_pav = 1;
 	}
 
 	/* define extend data (mostly)*/
@@ -3002,10 +3004,12 @@ static int prepare_itcw(struct itcw *itc
 	pfxdata.validity.define_extent = 1;
 
 	/* private uid is kept up to date, conf_data may be outdated */
-	if (startpriv->uid.type != UA_BASE_DEVICE) {
+	if (startpriv->uid.type == UA_BASE_PAV_ALIAS)
+		pfxdata.validity.verify_base = 1;
+
+	if (startpriv->uid.type == UA_HYPER_PAV_ALIAS) {
 		pfxdata.validity.verify_base = 1;
-		if (startpriv->uid.type == UA_HYPER_PAV_ALIAS)
-			pfxdata.validity.hyper_pav = 1;
+		pfxdata.validity.hyper_pav = 1;
 	}
 
 	switch (cmd) {


Patches currently in stable-queue which might be from sth@linux.vnet.ibm.com are

queue-4.4/s390-dasd-prevent-prefix-i-o-error.patch