qeth: improve ip_list administration after deregister failures

1. ip_list handling after deregister failure of multicast address:
   If error code "MC Address not found" is returned do not re-add
   multicast address to ip_list.
   For other error codes readd multicast address at the end of
   function qeth_delete_all_mc.
2. ip_list handling after deregister failure or normal ip address:
   If error code "IP Address not found" is returned do not re-add
   multicast address to ip list.
   This is especially important in IP address takeover scenarios,
   to enable re-takeover of a taken over IP address.

Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 21c439046b3c..1013a2a8ec00 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -401,8 +401,11 @@ static int __qeth_l3_ref_ip_on_card(struct qeth_card *card,
 static void __qeth_l3_delete_all_mc(struct qeth_card *card,
                                         unsigned long *flags)
 {
+        struct list_head fail_list;
         struct qeth_ipaddr *addr, *tmp;
         int rc;
+
+        INIT_LIST_HEAD(&fail_list);
 again:
         list_for_each_entry_safe(addr, tmp, &card->ip_list, entry) {
                 if (addr->is_multicast) {
@@ -410,13 +413,14 @@ again:
                         spin_unlock_irqrestore(&card->ip_lock, *flags);
                         rc = qeth_l3_deregister_addr_entry(card, addr);
                         spin_lock_irqsave(&card->ip_lock, *flags);
-                        if (!rc) {
+                        if (!rc || (rc == IPA_RC_MC_ADDR_NOT_FOUND))
                                 kfree(addr);
-                                goto again;
-                        } else
-                                list_add(&addr->entry, &card->ip_list);
+                        else
+                                list_add_tail(&addr->entry, &fail_list);
+                        goto again;
                 }
         }
+        list_splice(&fail_list, &card->ip_list);
 }
 
 static void qeth_l3_set_ip_addr_list(struct qeth_card *card)
@@ -467,7 +471,7 @@ static void qeth_l3_set_ip_addr_list(struct qeth_card *card)
                         spin_unlock_irqrestore(&card->ip_lock, flags);
                         rc = qeth_l3_deregister_addr_entry(card, addr);
                         spin_lock_irqsave(&card->ip_lock, flags);
-                        if (!rc)
+                        if (!rc || (rc == IPA_RC_PRIMARY_ALREADY_DEFINED))
                                 kfree(addr);
                         else
                                 list_add_tail(&addr->entry, &card->ip_list);