Merge branch 'master' into for-2.6.35

Conflicts:
	fs/ext3/fsync.c

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

7 files changed, 336 insertions, 189 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index acf222f91f5..0e86247d791 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -37,6 +37,9 @@
  */
 #define DASD_CHANQ_MAX_SIZE 4
 
+#define DASD_SLEEPON_START_TAG	(void *) 1
+#define DASD_SLEEPON_END_TAG	(void *) 2
+
 /*
  * SECTION: exported variables of dasd.c
  */
@@ -62,6 +65,7 @@ static void dasd_device_tasklet(struct dasd_device *);
 static void dasd_block_tasklet(struct dasd_block *);
 static void do_kick_device(struct work_struct *);
 static void do_restore_device(struct work_struct *);
+static void do_reload_device(struct work_struct *);
 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
 static void dasd_device_timeout(unsigned long);
 static void dasd_block_timeout(unsigned long);
@@ -112,6 +116,7 @@ struct dasd_device *dasd_alloc_device(void)
 	device->timer.data = (unsigned long) device;
 	INIT_WORK(&device->kick_work, do_kick_device);
 	INIT_WORK(&device->restore_device, do_restore_device);
+	INIT_WORK(&device->reload_device, do_reload_device);
 	device->state = DASD_STATE_NEW;
 	device->target = DASD_STATE_NEW;
 	mutex_init(&device->state_mutex);
@@ -518,6 +523,26 @@ void dasd_kick_device(struct dasd_device *device)
 }
 
 /*
+ * dasd_reload_device will schedule a call do do_reload_device to the kernel
+ * event daemon.
+ */
+static void do_reload_device(struct work_struct *work)
+{
+	struct dasd_device *device = container_of(work, struct dasd_device,
+						  reload_device);
+	device->discipline->reload(device);
+	dasd_put_device(device);
+}
+
+void dasd_reload_device(struct dasd_device *device)
+{
+	dasd_get_device(device);
+	/* queue call to dasd_reload_device to the kernel event daemon. */
+	schedule_work(&device->reload_device);
+}
+EXPORT_SYMBOL(dasd_reload_device);
+
+/*
  * dasd_restore_device will schedule a call do do_restore_device to the kernel
  * event daemon.
  */
@@ -1472,7 +1497,10 @@ void dasd_add_request_tail(struct dasd_ccw_req *cqr)
  */
 static void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
 {
-	wake_up((wait_queue_head_t *) data);
+	spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
+	cqr->callback_data = DASD_SLEEPON_END_TAG;
+	spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
+	wake_up(&generic_waitq);
 }
 
 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
@@ -1482,10 +1510,7 @@ static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
 
 	device = cqr->startdev;
 	spin_lock_irq(get_ccwdev_lock(device->cdev));
-	rc = ((cqr->status == DASD_CQR_DONE ||
-	       cqr->status == DASD_CQR_NEED_ERP ||
-	       cqr->status == DASD_CQR_TERMINATED) &&
-	      list_empty(&cqr->devlist));
+	rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
 	return rc;
 }
@@ -1573,7 +1598,7 @@ static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
 			wait_event(generic_waitq, !(device->stopped));
 
 		cqr->callback = dasd_wakeup_cb;
-		cqr->callback_data = (void *) &generic_waitq;
+		cqr->callback_data = DASD_SLEEPON_START_TAG;
 		dasd_add_request_tail(cqr);
 		if (interruptible) {
 			rc = wait_event_interruptible(
@@ -1652,7 +1677,7 @@ int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
 	}
 
 	cqr->callback = dasd_wakeup_cb;
-	cqr->callback_data = (void *) &generic_waitq;
+	cqr->callback_data = DASD_SLEEPON_START_TAG;
 	cqr->status = DASD_CQR_QUEUED;
 	list_add(&cqr->devlist, &device->ccw_queue);
 
diff --git a/drivers/s390/block/dasd_3990_erp.c b/drivers/s390/block/dasd_3990_erp.c
index 6632649dd6a..85bfd879485 100644
--- a/drivers/s390/block/dasd_3990_erp.c
+++ b/drivers/s390/block/dasd_3990_erp.c
@@ -1418,9 +1418,29 @@ static struct dasd_ccw_req *dasd_3990_erp_inspect_alias(
 						struct dasd_ccw_req *erp)
 {
 	struct dasd_ccw_req *cqr = erp->refers;
+	char *sense;
 
 	if (cqr->block &&
 	    (cqr->block->base != cqr->startdev)) {
+
+		sense = dasd_get_sense(&erp->refers->irb);
+		/*
+		 * dynamic pav may have changed base alias mapping
+		 */
+		if (!test_bit(DASD_FLAG_OFFLINE, &cqr->startdev->flags) && sense
+		    && (sense[0] == 0x10) && (sense[7] == 0x0F)
+		    && (sense[8] == 0x67)) {
+			/*
+			 * remove device from alias handling to prevent new
+			 * requests from being scheduled on the
+			 * wrong alias device
+			 */
+			dasd_alias_remove_device(cqr->startdev);
+
+			/* schedule worker to reload device */
+			dasd_reload_device(cqr->startdev);
+		}
+
 		if (cqr->startdev->features & DASD_FEATURE_ERPLOG) {
 			DBF_DEV_EVENT(DBF_ERR, cqr->startdev,
 				    "ERP on alias device for request %p,"
diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
index 8c4814258e9..4155805dcdf 100644
--- a/drivers/s390/block/dasd_alias.c
+++ b/drivers/s390/block/dasd_alias.c
@@ -190,20 +190,21 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
 	struct alias_server *server, *newserver;
 	struct alias_lcu *lcu, *newlcu;
 	int is_lcu_known;
-	struct dasd_uid *uid;
+	struct dasd_uid uid;
 
 	private = (struct dasd_eckd_private *) device->private;
-	uid = &private->uid;
+
+	device->discipline->get_uid(device, &uid);
 	spin_lock_irqsave(&aliastree.lock, flags);
 	is_lcu_known = 1;
-	server = _find_server(uid);
+	server = _find_server(&uid);
 	if (!server) {
 		spin_unlock_irqrestore(&aliastree.lock, flags);
-		newserver = _allocate_server(uid);
+		newserver = _allocate_server(&uid);
 		if (IS_ERR(newserver))
 			return PTR_ERR(newserver);
 		spin_lock_irqsave(&aliastree.lock, flags);
-		server = _find_server(uid);
+		server = _find_server(&uid);
 		if (!server) {
 			list_add(&newserver->server, &aliastree.serverlist);
 			server = newserver;
@@ -214,14 +215,14 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
 		}
 	}
 
-	lcu = _find_lcu(server, uid);
+	lcu = _find_lcu(server, &uid);
 	if (!lcu) {
 		spin_unlock_irqrestore(&aliastree.lock, flags);
-		newlcu = _allocate_lcu(uid);
+		newlcu = _allocate_lcu(&uid);
 		if (IS_ERR(newlcu))
 			return PTR_ERR(newlcu);
 		spin_lock_irqsave(&aliastree.lock, flags);
-		lcu = _find_lcu(server, uid);
+		lcu = _find_lcu(server, &uid);
 		if (!lcu) {
 			list_add(&newlcu->lcu, &server->lculist);
 			lcu = newlcu;
@@ -256,20 +257,20 @@ void dasd_alias_lcu_setup_complete(struct dasd_device *device)
 	unsigned long flags;
 	struct alias_server *server;
 	struct alias_lcu *lcu;
-	struct dasd_uid *uid;
+	struct dasd_uid uid;
 
 	private = (struct dasd_eckd_private *) device->private;
-	uid = &private->uid;
+	device->discipline->get_uid(device, &uid);
 	lcu = NULL;
 	spin_lock_irqsave(&aliastree.lock, flags);
-	server = _find_server(uid);
+	server = _find_server(&uid);
 	if (server)
-		lcu = _find_lcu(server, uid);
+		lcu = _find_lcu(server, &uid);
 	spin_unlock_irqrestore(&aliastree.lock, flags);
 	if (!lcu) {
 		DBF_EVENT_DEVID(DBF_ERR, device->cdev,
 				"could not find lcu for %04x %02x",
-				uid->ssid, uid->real_unit_addr);
+				uid.ssid, uid.real_unit_addr);
 		WARN_ON(1);
 		return;
 	}
@@ -282,20 +283,20 @@ void dasd_alias_wait_for_lcu_setup(struct dasd_device *device)
 	unsigned long flags;
 	struct alias_server *server;
 	struct alias_lcu *lcu;
-	struct dasd_uid *uid;
+	struct dasd_uid uid;
 
 	private = (struct dasd_eckd_private *) device->private;
-	uid = &private->uid;
+	device->discipline->get_uid(device, &uid);
 	lcu = NULL;
 	spin_lock_irqsave(&aliastree.lock, flags);
-	server = _find_server(uid);
+	server = _find_server(&uid);
 	if (server)
-		lcu = _find_lcu(server, uid);
+		lcu = _find_lcu(server, &uid);
 	spin_unlock_irqrestore(&aliastree.lock, flags);
 	if (!lcu) {
 		DBF_EVENT_DEVID(DBF_ERR, device->cdev,
 				"could not find lcu for %04x %02x",
-				uid->ssid, uid->real_unit_addr);
+				uid.ssid, uid.real_unit_addr);
 		WARN_ON(1);
 		return;
 	}
@@ -314,9 +315,11 @@ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device)
 	struct alias_lcu *lcu;
 	struct alias_server *server;
 	int was_pending;
+	struct dasd_uid uid;
 
 	private = (struct dasd_eckd_private *) device->private;
 	lcu = private->lcu;
+	device->discipline->get_uid(device, &uid);
 	spin_lock_irqsave(&lcu->lock, flags);
 	list_del_init(&device->alias_list);
 	/* make sure that the workers don't use this device */
@@ -353,7 +356,7 @@ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device)
 			_schedule_lcu_update(lcu, NULL);
 		spin_unlock(&lcu->lock);
 	}
-	server = _find_server(&private->uid);
+	server = _find_server(&uid);
 	if (server && list_empty(&server->lculist)) {
 		list_del(&server->server);
 		_free_server(server);
@@ -366,19 +369,30 @@ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device)
  * in the lcu is up to date and will update the device uid before
  * adding it to a pav group.
  */
+
 static int _add_device_to_lcu(struct alias_lcu *lcu,
-			      struct dasd_device *device)
+			      struct dasd_device *device,
+			      struct dasd_device *pos)
 {
 
 	struct dasd_eckd_private *private;
 	struct alias_pav_group *group;
-	struct dasd_uid *uid;
+	struct dasd_uid uid;
+	unsigned long flags;
 
 	private = (struct dasd_eckd_private *) device->private;
-	uid = &private->uid;
-	uid->type = lcu->uac->unit[uid->real_unit_addr].ua_type;
-	uid->base_unit_addr = lcu->uac->unit[uid->real_unit_addr].base_ua;
-	dasd_set_uid(device->cdev, &private->uid);
+
+	/* only lock if not already locked */
+	if (device != pos)
+		spin_lock_irqsave_nested(get_ccwdev_lock(device->cdev), flags,
+					 CDEV_NESTED_SECOND);
+	private->uid.type = lcu->uac->unit[private->uid.real_unit_addr].ua_type;
+	private->uid.base_unit_addr =
+		lcu->uac->unit[private->uid.real_unit_addr].base_ua;
+	uid = private->uid;
+
+	if (device != pos)
+		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 
 	/* if we have no PAV anyway, we don't need to bother with PAV groups */
 	if (lcu->pav == NO_PAV) {
@@ -386,25 +400,25 @@ static int _add_device_to_lcu(struct alias_lcu *lcu,
 		return 0;
 	}
 
-	group = _find_group(lcu, uid);
+	group = _find_group(lcu, &uid);
 	if (!group) {
 		group = kzalloc(sizeof(*group), GFP_ATOMIC);
 		if (!group)
 			return -ENOMEM;
-		memcpy(group->uid.vendor, uid->vendor, sizeof(uid->vendor));
-		memcpy(group->uid.serial, uid->serial, sizeof(uid->serial));
-		group->uid.ssid = uid->ssid;
-		if (uid->type == UA_BASE_DEVICE)
-			group->uid.base_unit_addr = uid->real_unit_addr;
+		memcpy(group->uid.vendor, uid.vendor, sizeof(uid.vendor));
+		memcpy(group->uid.serial, uid.serial, sizeof(uid.serial));
+		group->uid.ssid = uid.ssid;
+		if (uid.type == UA_BASE_DEVICE)
+			group->uid.base_unit_addr = uid.real_unit_addr;
 		else
-			group->uid.base_unit_addr = uid->base_unit_addr;
-		memcpy(group->uid.vduit, uid->vduit, sizeof(uid->vduit));
+			group->uid.base_unit_addr = uid.base_unit_addr;
+		memcpy(group->uid.vduit, uid.vduit, sizeof(uid.vduit));
 		INIT_LIST_HEAD(&group->group);
 		INIT_LIST_HEAD(&group->baselist);
 		INIT_LIST_HEAD(&group->aliaslist);
 		list_add(&group->group, &lcu->grouplist);
 	}
-	if (uid->type == UA_BASE_DEVICE)
+	if (uid.type == UA_BASE_DEVICE)
 		list_move(&device->alias_list, &group->baselist);
 	else
 		list_move(&device->alias_list, &group->aliaslist);
@@ -525,7 +539,10 @@ static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu)
 	if (rc)
 		return rc;
 
-	spin_lock_irqsave(&lcu->lock, flags);
+	/* need to take cdev lock before lcu lock */
+	spin_lock_irqsave_nested(get_ccwdev_lock(refdev->cdev), flags,
+				 CDEV_NESTED_FIRST);
+	spin_lock(&lcu->lock);
 	lcu->pav = NO_PAV;
 	for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) {
 		switch (lcu->uac->unit[i].ua_type) {
@@ -542,9 +559,10 @@ static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu)
 
 	list_for_each_entry_safe(device, tempdev, &lcu->active_devices,
 				 alias_list) {
-		_add_device_to_lcu(lcu, device);
+		_add_device_to_lcu(lcu, device, refdev);
 	}
-	spin_unlock_irqrestore(&lcu->lock, flags);
+	spin_unlock(&lcu->lock);
+	spin_unlock_irqrestore(get_ccwdev_lock(refdev->cdev), flags);
 	return 0;
 }
 
@@ -628,9 +646,12 @@ int dasd_alias_add_device(struct dasd_device *device)
 	private = (struct dasd_eckd_private *) device->private;
 	lcu = private->lcu;
 	rc = 0;
-	spin_lock_irqsave(&lcu->lock, flags);
+
+	/* need to take cdev lock before lcu lock */
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	spin_lock(&lcu->lock);
 	if (!(lcu->flags & UPDATE_PENDING)) {
-		rc = _add_device_to_lcu(lcu, device);
+		rc = _add_device_to_lcu(lcu, device, device);
 		if (rc)
 			lcu->flags |= UPDATE_PENDING;
 	}
@@ -638,10 +659,19 @@ int dasd_alias_add_device(struct dasd_device *device)
 		list_move(&device->alias_list, &lcu->active_devices);
 		_schedule_lcu_update(lcu, device);
 	}
-	spin_unlock_irqrestore(&lcu->lock, flags);
+	spin_unlock(&lcu->lock);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 	return rc;
 }
 
+int dasd_alias_update_add_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private;
+	private = (struct dasd_eckd_private *) device->private;
+	private->lcu->flags |= UPDATE_PENDING;
+	return dasd_alias_add_device(device);
+}
+
 int dasd_alias_remove_device(struct dasd_device *device)
 {
 	struct dasd_eckd_private *private;
@@ -740,19 +770,30 @@ static void _restart_all_base_devices_on_lcu(struct alias_lcu *lcu)
 	struct alias_pav_group *pavgroup;
 	struct dasd_device *device;
 	struct dasd_eckd_private *private;
+	unsigned long flags;
 
 	/* active and inactive list can contain alias as well as base devices */
 	list_for_each_entry(device, &lcu->active_devices, alias_list) {
 		private = (struct dasd_eckd_private *) device->private;
-		if (private->uid.type != UA_BASE_DEVICE)
+		spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+		if (private->uid.type != UA_BASE_DEVICE) {
+			spin_unlock_irqrestore(get_ccwdev_lock(device->cdev),
+					       flags);
 			continue;
+		}
+		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 		dasd_schedule_block_bh(device->block);
 		dasd_schedule_device_bh(device);
 	}
 	list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
 		private = (struct dasd_eckd_private *) device->private;
-		if (private->uid.type != UA_BASE_DEVICE)
+		spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+		if (private->uid.type != UA_BASE_DEVICE) {
+			spin_unlock_irqrestore(get_ccwdev_lock(device->cdev),
+					       flags);
 			continue;
+		}
+		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 		dasd_schedule_block_bh(device->block);
 		dasd_schedule_device_bh(device);
 	}
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index eff9c812c5c..34d51dd4c53 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -49,7 +49,6 @@ struct dasd_devmap {
         unsigned int devindex;
         unsigned short features;
 	struct dasd_device *device;
-	struct dasd_uid uid;
 };
 
 /*
@@ -936,42 +935,46 @@ dasd_device_status_show(struct device *dev, struct device_attribute *attr,
 
 static DEVICE_ATTR(status, 0444, dasd_device_status_show, NULL);
 
-static ssize_t
-dasd_alias_show(struct device *dev, struct device_attribute *attr, char *buf)
+static ssize_t dasd_alias_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
 {
-	struct dasd_devmap *devmap;
-	int alias;
+	struct dasd_device *device;
+	struct dasd_uid uid;
 
-	devmap = dasd_find_busid(dev_name(dev));
-	spin_lock(&dasd_devmap_lock);
-	if (IS_ERR(devmap) || strlen(devmap->uid.vendor) == 0) {
-		spin_unlock(&dasd_devmap_lock);
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
 		return sprintf(buf, "0\n");
+
+	if (device->discipline && device->discipline->get_uid &&
+	    !device->discipline->get_uid(device, &uid)) {
+		if (uid.type == UA_BASE_PAV_ALIAS ||
+		    uid.type == UA_HYPER_PAV_ALIAS)
+			return sprintf(buf, "1\n");
 	}
-	if (devmap->uid.type == UA_BASE_PAV_ALIAS ||
-	    devmap->uid.type == UA_HYPER_PAV_ALIAS)
-		alias = 1;
-	else
-		alias = 0;
-	spin_unlock(&dasd_devmap_lock);
-	return sprintf(buf, alias ? "1\n" : "0\n");
+	dasd_put_device(device);
+
+	return sprintf(buf, "0\n");
 }
 
 static DEVICE_ATTR(alias, 0444, dasd_alias_show, NULL);
 
-static ssize_t
-dasd_vendor_show(struct device *dev, struct device_attribute *attr, char *buf)
+static ssize_t dasd_vendor_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
 {
-	struct dasd_devmap *devmap;
+	struct dasd_device *device;
+	struct dasd_uid uid;
 	char *vendor;
 
-	devmap = dasd_find_busid(dev_name(dev));
-	spin_lock(&dasd_devmap_lock);
-	if (!IS_ERR(devmap) && strlen(devmap->uid.vendor) > 0)
-		vendor = devmap->uid.vendor;
-	else
-		vendor = "";
-	spin_unlock(&dasd_devmap_lock);
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	vendor = "";
+	if (IS_ERR(device))
+		return snprintf(buf, PAGE_SIZE, "%s\n", vendor);
+
+	if (device->discipline && device->discipline->get_uid &&
+	    !device->discipline->get_uid(device, &uid))
+			vendor = uid.vendor;
+
+	dasd_put_device(device);
 
 	return snprintf(buf, PAGE_SIZE, "%s\n", vendor);
 }
@@ -985,48 +988,51 @@ static DEVICE_ATTR(vendor, 0444, dasd_vendor_show, NULL);
 static ssize_t
 dasd_uid_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	struct dasd_devmap *devmap;
+	struct dasd_device *device;
+	struct dasd_uid uid;
 	char uid_string[UID_STRLEN];
 	char ua_string[3];
-	struct dasd_uid *uid;
 
-	devmap = dasd_find_busid(dev_name(dev));
-	spin_lock(&dasd_devmap_lock);
-	if (IS_ERR(devmap) || strlen(devmap->uid.vendor) == 0) {
-		spin_unlock(&dasd_devmap_lock);
-		return sprintf(buf, "\n");
-	}
-	uid = &devmap->uid;
-	switch (uid->type) {
-	case UA_BASE_DEVICE:
-		sprintf(ua_string, "%02x", uid->real_unit_addr);
-		break;
-	case UA_BASE_PAV_ALIAS:
-		sprintf(ua_string, "%02x", uid->base_unit_addr);
-		break;
-	case UA_HYPER_PAV_ALIAS:
-		sprintf(ua_string, "xx");
-		break;
-	default:
-		/* should not happen, treat like base device */
-		sprintf(ua_string, "%02x", uid->real_unit_addr);
-		break;
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	uid_string[0] = 0;
+	if (IS_ERR(device))
+		return snprintf(buf, PAGE_SIZE, "%s\n", uid_string);
+
+	if (device->discipline && device->discipline->get_uid &&
+	    !device->discipline->get_uid(device, &uid)) {
+		switch (uid.type) {
+		case UA_BASE_DEVICE:
+			snprintf(ua_string, sizeof(ua_string), "%02x",
+				 uid.real_unit_addr);
+			break;
+		case UA_BASE_PAV_ALIAS:
+			snprintf(ua_string, sizeof(ua_string), "%02x",
+				 uid.base_unit_addr);
+			break;
+		case UA_HYPER_PAV_ALIAS:
+			snprintf(ua_string, sizeof(ua_string), "xx");
+			break;
+		default:
+			/* should not happen, treat like base device */
+			snprintf(ua_string, sizeof(ua_string), "%02x",
+				 uid.real_unit_addr);
+			break;
+		}
+
+		if (strlen(uid.vduit) > 0)
+			snprintf(uid_string, sizeof(uid_string),
+				 "%s.%s.%04x.%s.%s",
+				 uid.vendor, uid.serial, uid.ssid, ua_string,
+				 uid.vduit);
+		else
+			snprintf(uid_string, sizeof(uid_string),
+				 "%s.%s.%04x.%s",
+				 uid.vendor, uid.serial, uid.ssid, ua_string);
 	}
-	if (strlen(uid->vduit) > 0)
-		snprintf(uid_string, sizeof(uid_string),
-			 "%s.%s.%04x.%s.%s",
-			 uid->vendor, uid->serial,
-			 uid->ssid, ua_string,
-			 uid->vduit);
-	else
-		snprintf(uid_string, sizeof(uid_string),
-			 "%s.%s.%04x.%s",
-			 uid->vendor, uid->serial,
-			 uid->ssid, ua_string);
-	spin_unlock(&dasd_devmap_lock);
+	dasd_put_device(device);
+
 	return snprintf(buf, PAGE_SIZE, "%s\n", uid_string);
 }
-
 static DEVICE_ATTR(uid, 0444, dasd_uid_show, NULL);
 
 /*
@@ -1094,50 +1100,6 @@ static struct attribute_group dasd_attr_group = {
 };
 
 /*
- * Return copy of the device unique identifier.
- */
-int
-dasd_get_uid(struct ccw_device *cdev, struct dasd_uid *uid)
-{
-	struct dasd_devmap *devmap;
-
-	devmap = dasd_find_busid(dev_name(&cdev->dev));
-	if (IS_ERR(devmap))
-		return PTR_ERR(devmap);
-	spin_lock(&dasd_devmap_lock);
-	*uid = devmap->uid;
-	spin_unlock(&dasd_devmap_lock);
-	return 0;
-}
-EXPORT_SYMBOL_GPL(dasd_get_uid);
-
-/*
- * Register the given device unique identifier into devmap struct.
- * In addition check if the related storage server subsystem ID is already
- * contained in the dasd_server_ssid_list. If subsystem ID is not contained,
- * create new entry.
- * Return 0 if server was already in serverlist,
- *	  1 if the server was added successful
- *	 <0 in case of error.
- */
-int
-dasd_set_uid(struct ccw_device *cdev, struct dasd_uid *uid)
-{
-	struct dasd_devmap *devmap;
-
-	devmap = dasd_find_busid(dev_name(&cdev->dev));
-	if (IS_ERR(devmap))
-		return PTR_ERR(devmap);
-
-	spin_lock(&dasd_devmap_lock);
-	devmap->uid = *uid;
-	spin_unlock(&dasd_devmap_lock);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(dasd_set_uid);
-
-/*
  * Return value of the specified feature.
  */
 int
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 0cb23311685..5b1cd8d6e97 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -692,18 +692,20 @@ dasd_eckd_cdl_reclen(int recid)
 /*
  * Generate device unique id that specifies the physical device.
  */
-static int dasd_eckd_generate_uid(struct dasd_device *device,
-				  struct dasd_uid *uid)
+static int dasd_eckd_generate_uid(struct dasd_device *device)
 {
 	struct dasd_eckd_private *private;
+	struct dasd_uid *uid;
 	int count;
+	unsigned long flags;
 
 	private = (struct dasd_eckd_private *) device->private;
 	if (!private)
 		return -ENODEV;
 	if (!private->ned || !private->gneq)
 		return -ENODEV;
-
+	uid = &private->uid;
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 	memset(uid, 0, sizeof(struct dasd_uid));
 	memcpy(uid->vendor, private->ned->HDA_manufacturer,
 	       sizeof(uid->vendor) - 1);
@@ -726,9 +728,25 @@ static int dasd_eckd_generate_uid(struct dasd_device *device,
 				private->vdsneq->uit[count]);
 		}
 	}
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 	return 0;
 }
 
+static int dasd_eckd_get_uid(struct dasd_device *device, struct dasd_uid *uid)
+{
+	struct dasd_eckd_private *private;
+	unsigned long flags;
+
+	if (device->private) {
+		private = (struct dasd_eckd_private *)device->private;
+		spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+		*uid = private->uid;
+		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+		return 0;
+	}
+	return -EINVAL;
+}
+
 static struct dasd_ccw_req *dasd_eckd_build_rcd_lpm(struct dasd_device *device,
 						    void *rcd_buffer,
 						    struct ciw *ciw, __u8 lpm)
@@ -1088,6 +1106,7 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
 {
 	struct dasd_eckd_private *private;
 	struct dasd_block *block;
+	struct dasd_uid temp_uid;
 	int is_known, rc;
 	int readonly;
 
@@ -1124,13 +1143,13 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
 	if (rc)
 		goto out_err1;
 
-	/* Generate device unique id and register in devmap */
-	rc = dasd_eckd_generate_uid(device, &private->uid);
+	/* Generate device unique id */
+	rc = dasd_eckd_generate_uid(device);
 	if (rc)
 		goto out_err1;
-	dasd_set_uid(device->cdev, &private->uid);
 
-	if (private->uid.type == UA_BASE_DEVICE) {
+	dasd_eckd_get_uid(device, &temp_uid);
+	if (temp_uid.type == UA_BASE_DEVICE) {
 		block = dasd_alloc_block();
 		if (IS_ERR(block)) {
 			DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
@@ -1451,6 +1470,7 @@ static int dasd_eckd_ready_to_online(struct dasd_device *device)
 
 static int dasd_eckd_online_to_ready(struct dasd_device *device)
 {
+	cancel_work_sync(&device->reload_device);
 	return dasd_alias_remove_device(device);
 };
 
@@ -1709,10 +1729,27 @@ static void dasd_eckd_handle_unsolicited_interrupt(struct dasd_device *device,
 {
 	char mask;
 	char *sense = NULL;
+	struct dasd_eckd_private *private;
 
+	private = (struct dasd_eckd_private *) device->private;
 	/* first of all check for state change pending interrupt */
 	mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
 	if ((scsw_dstat(&irb->scsw) & mask) == mask) {
+		/* for alias only and not in offline processing*/
+		if (!device->block && private->lcu &&
+		    !test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
+			/*
+			 * the state change could be caused by an alias
+			 * reassignment remove device from alias handling
+			 * to prevent new requests from being scheduled on
+			 * the wrong alias device
+			 */
+			dasd_alias_remove_device(device);
+
+			/* schedule worker to reload device */
+			dasd_reload_device(device);
+		}
+
 		dasd_generic_handle_state_change(device);
 		return;
 	}
@@ -3259,7 +3296,7 @@ static void dasd_eckd_dump_sense(struct dasd_device *device,
 		dasd_eckd_dump_sense_ccw(device, req, irb);
 }
 
-int dasd_eckd_pm_freeze(struct dasd_device *device)
+static int dasd_eckd_pm_freeze(struct dasd_device *device)
 {
 	/*
 	 * the device should be disconnected from our LCU structure
@@ -3272,7 +3309,7 @@ int dasd_eckd_pm_freeze(struct dasd_device *device)
 	return 0;
 }
 
-int dasd_eckd_restore_device(struct dasd_device *device)
+static int dasd_eckd_restore_device(struct dasd_device *device)
 {
 	struct dasd_eckd_private *private;
 	struct dasd_eckd_characteristics temp_rdc_data;
@@ -3287,15 +3324,16 @@ int dasd_eckd_restore_device(struct dasd_device *device)
 	if (rc)
 		goto out_err;
 
-	/* Generate device unique id and register in devmap */
-	rc = dasd_eckd_generate_uid(device, &private->uid);
-	dasd_get_uid(device->cdev, &temp_uid);
+	dasd_eckd_get_uid(device, &temp_uid);
+	/* Generate device unique id */
+	rc = dasd_eckd_generate_uid(device);
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 	if (memcmp(&private->uid, &temp_uid, sizeof(struct dasd_uid)) != 0)
 		dev_err(&device->cdev->dev, "The UID of the DASD has "
 			"changed\n");
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 	if (rc)
 		goto out_err;
-	dasd_set_uid(device->cdev, &private->uid);
 
 	/* register lcu with alias handling, enable PAV if this is a new lcu */
 	is_known = dasd_alias_make_device_known_to_lcu(device);
@@ -3336,6 +3374,56 @@ out_err:
 	return -1;
 }
 
+static int dasd_eckd_reload_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private;
+	int rc, old_base;
+	char print_uid[60];
+	struct dasd_uid uid;
+	unsigned long flags;
+
+	private = (struct dasd_eckd_private *) device->private;
+
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	old_base = private->uid.base_unit_addr;
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+
+	/* Read Configuration Data */
+	rc = dasd_eckd_read_conf(device);
+	if (rc)
+		goto out_err;
+
+	rc = dasd_eckd_generate_uid(device);
+	if (rc)
+		goto out_err;
+	/*
+	 * update unit address configuration and
+	 * add device to alias management
+	 */
+	dasd_alias_update_add_device(device);
+
+	dasd_eckd_get_uid(device, &uid);
+
+	if (old_base != uid.base_unit_addr) {
+		if (strlen(uid.vduit) > 0)
+			snprintf(print_uid, sizeof(print_uid),
+				 "%s.%s.%04x.%02x.%s", uid.vendor, uid.serial,
+				 uid.ssid, uid.base_unit_addr, uid.vduit);
+		else
+			snprintf(print_uid, sizeof(print_uid),
+				 "%s.%s.%04x.%02x", uid.vendor, uid.serial,
+				 uid.ssid, uid.base_unit_addr);
+
+		dev_info(&device->cdev->dev,
+			 "An Alias device was reassigned to a new base device "
+			 "with UID: %s\n", print_uid);
+	}
+	return 0;
+
+out_err:
+	return -1;
+}
+
 static struct ccw_driver dasd_eckd_driver = {
 	.name	     = "dasd-eckd",
 	.owner	     = THIS_MODULE,
@@ -3389,6 +3477,8 @@ static struct dasd_discipline dasd_eckd_discipline = {
 	.ioctl = dasd_eckd_ioctl,
 	.freeze = dasd_eckd_pm_freeze,
 	.restore = dasd_eckd_restore_device,
+	.reload = dasd_eckd_reload_device,
+	.get_uid = dasd_eckd_get_uid,
 };
 
 static int __init
diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h
index 864d53c0420..dd6385a5af1 100644
--- a/drivers/s390/block/dasd_eckd.h
+++ b/drivers/s390/block/dasd_eckd.h
@@ -426,7 +426,6 @@ struct alias_pav_group {
 	struct dasd_device *next;
 };
 
-
 struct dasd_eckd_private {
 	struct dasd_eckd_characteristics rdc_data;
 	u8 *conf_data;
@@ -463,4 +462,5 @@ void dasd_alias_handle_summary_unit_check(struct dasd_device *, struct irb *);
 void dasd_eckd_reset_ccw_to_base_io(struct dasd_ccw_req *);
 void dasd_alias_lcu_setup_complete(struct dasd_device *);
 void dasd_alias_wait_for_lcu_setup(struct dasd_device *);
+int dasd_alias_update_add_device(struct dasd_device *);
 #endif				/* DASD_ECKD_H */
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index a91d4a97d4f..32fac186ba3 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -81,6 +81,10 @@ struct dasd_block;
 #define DASD_SIM_MSG_TO_OP 0x03
 #define DASD_SIM_LOG 0x0C
 
+/* lock class for nested cdev lock */
+#define CDEV_NESTED_FIRST 1
+#define CDEV_NESTED_SECOND 2
+
 /*
  * SECTION: MACROs for klogd and s390 debug feature (dbf)
  */
@@ -229,6 +233,24 @@ struct dasd_ccw_req {
 typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);
 
 /*
+ * Unique identifier for dasd device.
+ */
+#define UA_NOT_CONFIGURED  0x00
+#define UA_BASE_DEVICE	   0x01
+#define UA_BASE_PAV_ALIAS  0x02
+#define UA_HYPER_PAV_ALIAS 0x03
+
+struct dasd_uid {
+	__u8 type;
+	char vendor[4];
+	char serial[15];
+	__u16 ssid;
+	__u8 real_unit_addr;
+	__u8 base_unit_addr;
+	char vduit[33];
+};
+
+/*
  * the struct dasd_discipline is
  * sth like a table of virtual functions, if you think of dasd_eckd
  * inheriting dasd...
@@ -312,28 +334,15 @@ struct dasd_discipline {
 	/* suspend/resume functions */
 	int (*freeze) (struct dasd_device *);
 	int (*restore) (struct dasd_device *);
-};
 
-extern struct dasd_discipline *dasd_diag_discipline_pointer;
-
-/*
- * Unique identifier for dasd device.
- */
-#define UA_NOT_CONFIGURED  0x00
-#define UA_BASE_DEVICE	   0x01
-#define UA_BASE_PAV_ALIAS  0x02
-#define UA_HYPER_PAV_ALIAS 0x03
+	/* reload device after state change */
+	int (*reload) (struct dasd_device *);
 
-struct dasd_uid {
-	__u8 type;
-	char vendor[4];
-	char serial[15];
-	__u16 ssid;
-	__u8 real_unit_addr;
-	__u8 base_unit_addr;
-	char vduit[33];
+	int (*get_uid) (struct dasd_device *, struct dasd_uid *);
 };
 
+extern struct dasd_discipline *dasd_diag_discipline_pointer;
+
 /*
  * Notification numbers for extended error reporting notifications:
  * The DASD_EER_DISABLE notification is sent before a dasd_device (and it's
@@ -386,6 +395,7 @@ struct dasd_device {
         struct tasklet_struct tasklet;
 	struct work_struct kick_work;
 	struct work_struct restore_device;
+	struct work_struct reload_device;
 	struct timer_list timer;
 
 	debug_info_t *debug_area;
@@ -582,6 +592,7 @@ void dasd_enable_device(struct dasd_device *);
 void dasd_set_target_state(struct dasd_device *, int);
 void dasd_kick_device(struct dasd_device *);
 void dasd_restore_device(struct dasd_device *);
+void dasd_reload_device(struct dasd_device *);
 
 void dasd_add_request_head(struct dasd_ccw_req *);
 void dasd_add_request_tail(struct dasd_ccw_req *);
@@ -629,8 +640,6 @@ void dasd_devmap_exit(void);
 struct dasd_device *dasd_create_device(struct ccw_device *);
 void dasd_delete_device(struct dasd_device *);
 
-int dasd_get_uid(struct ccw_device *, struct dasd_uid *);
-int dasd_set_uid(struct ccw_device *, struct dasd_uid *);
 int dasd_get_feature(struct ccw_device *, int);
 int dasd_set_feature(struct ccw_device *, int, int);