[S390] dasd: remove uid from devmap

Remove the duplicate of the DASD uid from the devmap structure.
Use the uid from the device private structure instead.
This also removes a lockdep warning complaining about a possible
SOFTIRQ-safe -> SOFTIRQ-unsafe lock order.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 75 insertions, 42 deletions

diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
index a564b9941114..4155805dcdff 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;
         }
@@ -638,7 +659,8 @@ 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;
 }
 
@@ -748,19 +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);
         }