From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Fri, 28 Apr 2006 01:40:02 +0000 (-0700)
Subject: [PATCH] s390: fix I/O termination race in cio
X-Git-Tag: v2.6.17-rc4~124
X-Git-Url: https://bbs.cooldavid.org/git/?a=commitdiff_plain;h=329b785bcee5d001f97a33bdb80de014bb5020b0;p=net-next-2.6.git

[PATCH] s390: fix I/O termination race in cio

Fix a race condition in the I/O termination logic.  The race can cause I/O to
a dasd device to fail with no retry left after turning one channel path to the
device off and on multiple times.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 6412b2c3edd..daedb00a434 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -242,28 +242,10 @@ s390_subchannel_remove_chpid(struct device *dev, void *data)
 	if (sch->vpm == mask)
 		goto out_unreg;
 
-	if ((sch->schib.scsw.actl & (SCSW_ACTL_CLEAR_PEND |
-				     SCSW_ACTL_HALT_PEND |
-				     SCSW_ACTL_START_PEND |
-				     SCSW_ACTL_RESUME_PEND)) &&
-	    (sch->schib.pmcw.lpum == mask)) {
-		int cc = cio_cancel(sch);
-		
-		if (cc == -ENODEV)
-			goto out_unreg;
-
-		if (cc == -EINVAL) {
-			cc = cio_clear(sch);
-			if (cc == -ENODEV)
-				goto out_unreg;
-			/* Call handler. */
-			if (sch->driver && sch->driver->termination)
-				sch->driver->termination(&sch->dev);
-			goto out_unlock;
-		}
-	} else if ((sch->schib.scsw.actl & SCSW_ACTL_DEVACT) &&
-		   (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
-		   (sch->schib.pmcw.lpum == mask)) {
+	if ((sch->schib.scsw.actl & SCSW_ACTL_DEVACT) &&
+	    (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
+	    (sch->schib.pmcw.lpum == mask) &&
+	    (sch->vpm == 0)) {
 		int cc;
 
 		cc = cio_clear(sch);