net: Init NAPI dev_list on napi_del

The recent GRO patches introduced the NAPI removal of devices in
free_netdev.  For drivers that can change the number of queues during
driver operation, the NAPI infrastructure doesn't allow the freeing and
re-addition of NAPI entities without reloading the driver.

This change reinitializes the dev_list in each NAPI struct on delete,
instead of just deleting it (and assigning the list pointers to POISON).
Drivers that wish to remove/re-add NAPI will need to re-initialize the
netdev napi_list after removing all NAPI instances, before re-adding NAPI
devices again.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index daca72e6b37b12e7c8ea4d4ee5fa59e01cac1b59..536a8ac189c8a3016cb40a98d052aee875cf0ef8 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2548,7 +2548,7 @@ void netif_napi_del(struct napi_struct *napi)
 {
        struct sk_buff *skb, *next;
 
-       list_del(&napi->dev_list);
+       list_del_init(&napi->dev_list);
 
        for (skb = napi->gro_list; skb; skb = next) {
                next = skb->next;