From ee04bbccdeb11bdbc54015be8dca30a0deeca5e4 Mon Sep 17 00:00:00 2001
From: Cornelia Huck <cornelia.huck@de.ibm.com>
Date: Mon, 5 Mar 2007 23:35:56 +0100
Subject: [S390] cio: Fix locking when calling notify function.

Make sure we hold the device lock when we modify the ccw device
structure but always call the notify function without the lock held.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device_fsm.c | 67 ++++++++++++++++++++++++++++++-------------
 1 file changed, 47 insertions(+), 20 deletions(-)

(limited to 'drivers/s390/cio')

diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index 51238e7555b..8baa9cd3794 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -334,20 +334,29 @@ ccw_device_oper_notify(struct work_struct *work)
 	struct ccw_device *cdev;
 	struct subchannel *sch;
 	int ret;
+	unsigned long flags;
 
 	priv = container_of(work, struct ccw_device_private, kick_work);
 	cdev = priv->cdev;
+	spin_lock_irqsave(cdev->ccwlock, flags);
 	sch = to_subchannel(cdev->dev.parent);
-	ret = (sch->driver && sch->driver->notify) ?
-		sch->driver->notify(&sch->dev, CIO_OPER) : 0;
-	if (!ret)
-		/* Driver doesn't want device back. */
-		ccw_device_do_unreg_rereg(work);
-	else {
+	if (sch->driver && sch->driver->notify) {
+		spin_unlock_irqrestore(cdev->ccwlock, flags);
+		ret = sch->driver->notify(&sch->dev, CIO_OPER);
+		spin_lock_irqsave(cdev->ccwlock, flags);
+	} else
+		ret = 0;
+	if (ret) {
 		/* Reenable channel measurements, if needed. */
+		spin_unlock_irqrestore(cdev->ccwlock, flags);
 		cmf_reenable(cdev);
+		spin_lock_irqsave(cdev->ccwlock, flags);
 		wake_up(&cdev->private->wait_q);
 	}
+	spin_unlock_irqrestore(cdev->ccwlock, flags);
+	if (!ret)
+		/* Driver doesn't want device back. */
+		ccw_device_do_unreg_rereg(work);
 }
 
 /*
@@ -534,15 +543,21 @@ ccw_device_nopath_notify(struct work_struct *work)
 	struct ccw_device *cdev;
 	struct subchannel *sch;
 	int ret;
+	unsigned long flags;
 
 	priv = container_of(work, struct ccw_device_private, kick_work);
 	cdev = priv->cdev;
+	spin_lock_irqsave(cdev->ccwlock, flags);
 	sch = to_subchannel(cdev->dev.parent);
 	/* Extra sanity. */
 	if (sch->lpm)
-		return;
-	ret = (sch->driver && sch->driver->notify) ?
-		sch->driver->notify(&sch->dev, CIO_NO_PATH) : 0;
+		goto out_unlock;
+	if (sch->driver && sch->driver->notify) {
+		spin_unlock_irqrestore(cdev->ccwlock, flags);
+		ret = sch->driver->notify(&sch->dev, CIO_NO_PATH);
+		spin_lock_irqsave(cdev->ccwlock, flags);
+	} else
+		ret = 0;
 	if (!ret) {
 		if (get_device(&sch->dev)) {
 			/* Driver doesn't want to keep device. */
@@ -562,6 +577,8 @@ ccw_device_nopath_notify(struct work_struct *work)
 		cdev->private->state = DEV_STATE_DISCONNECTED;
 		wake_up(&cdev->private->wait_q);
 	}
+out_unlock:
+	spin_unlock_irqrestore(cdev->ccwlock, flags);
 }
 
 void
@@ -607,10 +624,13 @@ ccw_device_verify_done(struct ccw_device *cdev, int err)
 	default:
 		/* Reset oper notify indication after verify error. */
 		cdev->private->flags.donotify = 0;
-		PREPARE_WORK(&cdev->private->kick_work,
-			     ccw_device_nopath_notify);
-		queue_work(ccw_device_notify_work, &cdev->private->kick_work);
-		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
+		if (cdev->online) {
+			PREPARE_WORK(&cdev->private->kick_work,
+				     ccw_device_nopath_notify);
+			queue_work(ccw_device_notify_work,
+				   &cdev->private->kick_work);
+		} else
+			ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 		break;
 	}
 }
@@ -756,15 +776,22 @@ static void
 ccw_device_online_notoper(struct ccw_device *cdev, enum dev_event dev_event)
 {
 	struct subchannel *sch;
+	int ret;
 
 	sch = to_subchannel(cdev->dev.parent);
-	if (sch->driver->notify &&
-	    sch->driver->notify(&sch->dev, sch->lpm ? CIO_GONE : CIO_NO_PATH)) {
-			ccw_device_set_timeout(cdev, 0);
-			cdev->private->flags.fake_irb = 0;
-			cdev->private->state = DEV_STATE_DISCONNECTED;
-			wake_up(&cdev->private->wait_q);
-			return;
+	if (sch->driver->notify) {
+		spin_unlock_irq(cdev->ccwlock);
+		ret = sch->driver->notify(&sch->dev,
+					  sch->lpm ? CIO_GONE : CIO_NO_PATH);
+		spin_lock_irq(cdev->ccwlock);
+	} else
+		ret = 0;
+	if (ret) {
+		ccw_device_set_timeout(cdev, 0);
+		cdev->private->flags.fake_irb = 0;
+		cdev->private->state = DEV_STATE_DISCONNECTED;
+		wake_up(&cdev->private->wait_q);
+		return;
 	}
 	cdev->private->state = DEV_STATE_NOT_OPER;
 	cio_disable_subchannel(sch);
-- 
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