ctcm rollback in case of errors

Group device now cleanly reacts to failures during channel start and
implements a clean rollback.

Signed-off-by: Einar Lueck <elelueck@de.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 42 insertions, 17 deletions

diff --git a/drivers/s390/net/ctcm_main.c b/drivers/s390/net/ctcm_main.c
index c5b83874500..db054ed1a8c 100644
--- a/drivers/s390/net/ctcm_main.c
+++ b/drivers/s390/net/ctcm_main.c
@@ -1530,11 +1530,16 @@ static int ctcm_new_device(struct ccwgroup_device *cgdev)
         struct net_device *dev;
         struct ccw_device *cdev0;
         struct ccw_device *cdev1;
+        struct channel *readc;
+        struct channel *writec;
         int ret;
+        int result;
 
         priv = dev_get_drvdata(&cgdev->dev);
-        if (!priv)
-                return -ENODEV;
+        if (!priv) {
+                result = -ENODEV;
+                goto out_err_result;
+        }
 
         cdev0 = cgdev->cdev[0];
         cdev1 = cgdev->cdev[1];
@@ -1545,31 +1550,40 @@ static int ctcm_new_device(struct ccwgroup_device *cgdev)
         snprintf(write_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev1->dev));
 
         ret = add_channel(cdev0, type, priv);
-        if (ret)
-                return ret;
+        if (ret) {
+                result = ret;
+                goto out_err_result;
+        }
         ret = add_channel(cdev1, type, priv);
-        if (ret)
-                return ret;
+        if (ret) {
+                result = ret;
+                goto out_remove_channel1;
+        }
 
         ret = ccw_device_set_online(cdev0);
         if (ret != 0) {
-                /* may be ok to fail now - can be done later */
                 CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
                         "%s(%s) set_online rc=%d",
                                 CTCM_FUNTAIL, read_id, ret);
+                result = -EIO;
+                goto out_remove_channel2;
         }
 
         ret = ccw_device_set_online(cdev1);
         if (ret != 0) {
-                /* may be ok to fail now - can be done later */
                 CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
                         "%s(%s) set_online rc=%d",
                                 CTCM_FUNTAIL, write_id, ret);
+
+                result = -EIO;
+                goto out_ccw1;
         }
 
         dev = ctcm_init_netdevice(priv);
-        if (dev == NULL)
-                        goto out;
+        if (dev == NULL) {
+                result = -ENODEV;
+                goto out_ccw2;
+        }
 
         for (direction = READ; direction <= WRITE; direction++) {
                 priv->channel[direction] =
@@ -1587,12 +1601,14 @@ static int ctcm_new_device(struct ccwgroup_device *cgdev)
         /* sysfs magic */
         SET_NETDEV_DEV(dev, &cgdev->dev);
 
-        if (register_netdev(dev))
-                        goto out_dev;
+        if (register_netdev(dev)) {
+                result = -ENODEV;
+                goto out_dev;
+        }
 
         if (ctcm_add_attributes(&cgdev->dev)) {
-                unregister_netdev(dev);
-                        goto out_dev;
+                result = -ENODEV;
+                goto out_unregister;
         }
 
         strlcpy(priv->fsm->name, dev->name, sizeof(priv->fsm->name));
@@ -1608,13 +1624,22 @@ static int ctcm_new_device(struct ccwgroup_device *cgdev)
                         priv->channel[WRITE]->id, priv->protocol);
 
         return 0;
+out_unregister:
+        unregister_netdev(dev);
 out_dev:
         ctcm_free_netdevice(dev);
-out:
+out_ccw2:
         ccw_device_set_offline(cgdev->cdev[1]);
+out_ccw1:
         ccw_device_set_offline(cgdev->cdev[0]);
-
-        return -ENODEV;
+out_remove_channel2:
+        readc = channel_get(type, read_id, READ);
+        channel_remove(readc);
+out_remove_channel1:
+        writec = channel_get(type, write_id, WRITE);
+        channel_remove(writec);
+out_err_result:
+        return result;
 }
 
 /**