[PATCH 2.5.69] IPV4 should use dev_hold

[Stephen Hemminger <shemminger@xxxxxxxx>]

David,

While debugging possible changes to dev refcounting, discovered
a couple of places in IPV4 that were directly incrementing rather
than using the inline dev_hold.  Let's hide the implementation of
net device ref counting so  future module ref count fixes will be easier.

diff -urN -X dontdiff linux-2.5/net/ipv4/fib_frontend.c 
linux-2.5-dev/net/ipv4/fib_frontend.c
--- linux-2.5/net/ipv4/fib_frontend.c   2003-04-14 13:32:26.000000000 -0700
+++ linux-2.5-dev/net/ipv4/fib_frontend.c       2003-05-06 15:16:03.000000000 
-0700
@@ -115,9 +115,9 @@
        if (res.type != RTN_LOCAL)
                goto out;
        dev = FIB_RES_DEV(res);
-       if (dev)
-               atomic_inc(&dev->refcnt);
 
+       if (dev)
+               dev_hold(dev);
 out:
        fib_res_put(&res);
        return dev;
diff -urN -X dontdiff linux-2.5/net/ipv4/fib_semantics.c 
linux-2.5-dev/net/ipv4/fib_semantics.c
--- linux-2.5/net/ipv4/fib_semantics.c  2003-04-29 09:57:41.000000000 -0700
+++ linux-2.5-dev/net/ipv4/fib_semantics.c      2003-05-06 15:10:40.000000000 
-0700
@@ -406,7 +406,7 @@
                        if (!(dev->flags&IFF_UP))
                                return -ENETDOWN;
                        nh->nh_dev = dev;
-                       atomic_inc(&dev->refcnt);
+                       dev_hold(dev);
                        nh->nh_scope = RT_SCOPE_LINK;
                        return 0;
                }
@@ -429,7 +429,7 @@
                nh->nh_oif = FIB_RES_OIF(res);
                if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL)
                        goto out;
-               atomic_inc(&nh->nh_dev->refcnt);
+               dev_hold(nh->nh_dev);
                err = -ENETDOWN;
                if (!(nh->nh_dev->flags & IFF_UP))
                        goto out;
@@ -451,7 +451,7 @@
                        return -ENETDOWN;
                }
                nh->nh_dev = in_dev->dev;
-               atomic_inc(&nh->nh_dev->refcnt);
+               dev_hold(nh->nh_dev);
                nh->nh_scope = RT_SCOPE_HOST;
                in_dev_put(in_dev);
        }