[ 3.5.y.z extended stable ] Patch "s390/cio: fix pgid reserved check" has been added to staging queue

[Herton Ronaldo Krzesinski]

This is a note to let you know that I have just added a patch titled

    s390/cio: fix pgid reserved check

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From 39bb56d1e283b99947d2e4ad5c25e5ae4acb7998 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott at linux.vnet.ibm.com>
Date: Fri, 30 Nov 2012 16:48:59 +0100
Subject: [PATCH] s390/cio: fix pgid reserved check

commit d99e79ec5574fc556c988f613ed6175f6de66f4a upstream.

The check to whom a device is reserved is done by checking the path
state of the affected channel paths. If it turns out that one path is
flagged as reserved by someone else the whole device is marked as such.

However the meaning of the RESVD_ELSE bit is that the addressed device
is reserved to a different pathgroup (and not reserved to a different
LPAR). If we do this test on a path which is currently not a member of
the pathgroup we could erroneously mark the device as reserved to
someone else.

To fix this collect the reserved state for all potential members of the
pathgroup and only mark the device as reserved if all of those potential
members have the RESVD_ELSE bit set.

Acked-by: Peter Oberparleiter <peter.oberparleiter at de.ibm.com>
Signed-off-by: Sebastian Ott <sebott at linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky at de.ibm.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 drivers/s390/cio/device_pgid.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 07a4fd2..daa6b90 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -234,7 +234,7 @@ static int pgid_cmp(struct pgid *p1, struct pgid *p2)
  * Determine pathgroup state from PGID data.
  */
 static void pgid_analyze(struct ccw_device *cdev, struct pgid **p,
-			 int *mismatch, int *reserved, u8 *reset)
+			 int *mismatch, u8 *reserved, u8 *reset)
 {
 	struct pgid *pgid = &cdev->private->pgid[0];
 	struct pgid *first = NULL;
@@ -248,7 +248,7 @@ static void pgid_analyze(struct ccw_device *cdev, struct pgid **p,
 		if ((cdev->private->pgid_valid_mask & lpm) == 0)
 			continue;
 		if (pgid->inf.ps.state2 == SNID_STATE2_RESVD_ELSE)
-			*reserved = 1;
+			*reserved |= lpm;
 		if (pgid_is_reset(pgid)) {
 			*reset |= lpm;
 			continue;
@@ -316,14 +316,14 @@ static void snid_done(struct ccw_device *cdev, int rc)
 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
 	struct pgid *pgid;
 	int mismatch = 0;
-	int reserved = 0;
+	u8 reserved = 0;
 	u8 reset = 0;
 	u8 donepm;

 	if (rc)
 		goto out;
 	pgid_analyze(cdev, &pgid, &mismatch, &reserved, &reset);
-	if (reserved)
+	if (reserved == cdev->private->pgid_valid_mask)
 		rc = -EUSERS;
 	else if (mismatch)
 		rc = -EOPNOTSUPP;
@@ -336,7 +336,7 @@ static void snid_done(struct ccw_device *cdev, int rc)
 	}
 out:
 	CIO_MSG_EVENT(2, "snid: device 0.%x.%04x: rc=%d pvm=%02x vpm=%02x "
-		      "todo=%02x mism=%d rsvd=%d reset=%02x\n", id->ssid,
+		      "todo=%02x mism=%d rsvd=%02x reset=%02x\n", id->ssid,
 		      id->devno, rc, cdev->private->pgid_valid_mask, sch->vpm,
 		      cdev->private->pgid_todo_mask, mismatch, reserved, reset);
 	switch (rc) {
--
1.7.9.5