if_cloners list is poulated at system boot only

[Alexandr Nedvedicky]

Hello,

while poking around 'XXXSMP' comments in net/if.c, I've noticed
the 'if_cloners_lock' can be removed. The thing is the list of
cloners gets populated/modified at system boot only, while kernel
attaches device drivers.

And because cloners are never removed, the if_clone_detach()
function can go, no one calls it.

OK ?

thanks and
regards
sashan

--------8<---------------8<---------------8<------------------8<--------
diff --git a/sys/net/if.c b/sys/net/if.c
index 7097eb278ef..93def034a9e 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -219,8 +219,6 @@ void        if_idxmap_remove(struct ifnet *);
 
 TAILQ_HEAD(, ifg_group) ifg_head = TAILQ_HEAD_INITIALIZER(ifg_head);
 
-/* Serialize access to &if_cloners and if_cloners_count */
-struct rwlock if_cloners_lock = RWLOCK_INITIALIZER("ifclonerslk");
 LIST_HEAD(, if_clone) if_cloners = LIST_HEAD_INITIALIZER(if_cloners);
 int if_cloners_count;
 
@@ -1252,13 +1250,11 @@ if_clone_lookup(const char *name, int *unitp)
        if (cp - name < IFNAMSIZ-1 && *cp == '0' && cp[1] != '\0')
                return (NULL);  /* unit number 0 padded */
 
-       rw_enter_read(&if_cloners_lock);
        LIST_FOREACH(ifc, &if_cloners, ifc_list) {
                if (strlen(ifc->ifc_name) == cp - name &&
                    !strncmp(name, ifc->ifc_name, cp - name))
                        break;
        }
-       rw_exit_read(&if_cloners_lock);
 
        if (ifc == NULL)
                return (NULL);
@@ -1284,22 +1280,8 @@ if_clone_lookup(const char *name, int *unitp)
 void
 if_clone_attach(struct if_clone *ifc)
 {
-       rw_enter_write(&if_cloners_lock);
        LIST_INSERT_HEAD(&if_cloners, ifc, ifc_list);
        if_cloners_count++;
-       rw_exit_write(&if_cloners_lock);
-}
-
-/*
- * Unregister a network interface cloner.
- */
-void
-if_clone_detach(struct if_clone *ifc)
-{
-       rw_enter_write(&if_cloners_lock);
-       LIST_REMOVE(ifc, ifc_list);
-       if_cloners_count--;
-       rw_exit_write(&if_cloners_lock);
 }
 
 /*
@@ -1314,17 +1296,13 @@ if_clone_list(struct if_clonereq *ifcr)
 
        if ((dst = ifcr->ifcr_buffer) == NULL) {
                /* Just asking how many there are. */
-               rw_enter_read(&if_cloners_lock);
                ifcr->ifcr_total = if_cloners_count;
-               rw_exit_read(&if_cloners_lock);
                return (0);
        }
 
        if (ifcr->ifcr_count < 0)
                return (EINVAL);
 
-       rw_enter_read(&if_cloners_lock);
-
        ifcr->ifcr_total = if_cloners_count;
        count = MIN(if_cloners_count, ifcr->ifcr_count);
 
@@ -1340,7 +1318,6 @@ if_clone_list(struct if_clonereq *ifcr)
                dst += IFNAMSIZ;
        }
 
-       rw_exit_read(&if_cloners_lock);
        return (error);
 }
 
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index e9f69c964cb..e59f3ba9701 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -328,7 +328,6 @@ void        ifafree(struct ifaddr *);
 int    if_isconnected(const struct ifnet *, unsigned int);
 
 void   if_clone_attach(struct if_clone *);
-void   if_clone_detach(struct if_clone *);
 
 int    if_clone_create(const char *, int);
 int    if_clone_destroy(const char *);