From: Hans-Joachim Picht <hpicht@redhat.com>
Date: Thu, 26 Feb 2009 18:01:06 +0100
Subject: [s390] dasd: fix waitqueue for sleep_on_immediatly
Message-id: 20090226170106.GC17830@redhat.com
O-Subject: Re: [RHEL5 U4 PATCH 1/1] s390 - dasd: fix waitqueue for sleep_on_immediatly
Bugzilla: 480161
RH-Acked-by: Pete Zaitcev <zaitcev@redhat.com>

Description
============

Description: dasd fix waitqueue for sleep_on_immediatly

Currently tools like tunedasd -S will hang
The problem is caused by the fact that the callback_data
for dasd_sleep_on_immediatly contains the wrong waitqueue

Chaining the waitqueue to generic_waitqueue fixes the problem.

Bugzilla
=========

BZ 480161
https://bugzilla.redhat.com/show_bug.cgi?id=480161

Upstream status of the patch:
=============================

The fix is upstream as of git commit
c80ee724966a8ce9a68020d9095233fb1c6f57e8

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=c80ee724966a8ce9a68020d9095233fb1c6f57e8

Test status:
============

The patch has been tested and fixes the problem.
The fix has been verified by the IBM test department.

Please ACK.

With best regards,

        --Hans

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 72d837f..6414a4c 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -1656,7 +1656,6 @@ _dasd_term_running_cqr(struct dasd_device *device)
 int
 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
 {
-	wait_queue_head_t wait_q;
 	struct dasd_device *device;
 	int rc;
 
@@ -1668,9 +1667,8 @@ dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
 		return rc;
 	}
 
-	init_waitqueue_head (&wait_q);
 	cqr->callback = dasd_wakeup_cb;
-	cqr->callback_data = (void *) &wait_q;
+	cqr->callback_data = (void *) &generic_waitq;
 	cqr->status = DASD_CQR_QUEUED;
 	list_add(&cqr->list, &device->ccw_queue);