list_for_each_rcu must die: networking

All uses of list_for_each_rcu() can be profitably replaced by the
easier-to-use list_for_each_entry_rcu().  This patch makes this change for
networking, in preparation for removing the list_for_each_rcu() API
entirely.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/net/802/psnap.c b/net/802/psnap.c
index ea46439..b3cfe5a 100644 (file)
--- a/net/802/psnap.c
+++ b/net/802/psnap.c
@@ -31,11 +31,9 @@ static struct llc_sap *snap_sap;
  */
 static struct datalink_proto *find_snap_client(unsigned char *desc)
 {
-       struct list_head *entry;
        struct datalink_proto *proto = NULL, *p;
 
-       list_for_each_rcu(entry, &snap_list) {
-               p = list_entry(entry, struct datalink_proto, node);
+       list_for_each_entry_rcu(p, &snap_list, node) {
                if (!memcmp(p->type, desc, 5)) {
                        proto = p;
                        break;

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index dd919d8..f440a9f 100644 (file)
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -264,7 +264,6 @@ static inline int inet_netns_ok(struct net *net, int protocol)
 static int inet_create(struct net *net, struct socket *sock, int protocol)
 {
        struct sock *sk;
-       struct list_head *p;
        struct inet_protosw *answer;
        struct inet_sock *inet;
        struct proto *answer_prot;
@@ -281,13 +280,12 @@ static int inet_create(struct net *net, struct socket *sock, int protocol)
        sock->state = SS_UNCONNECTED;
 
        /* Look for the requested type/protocol pair. */
-       answer = NULL;
 lookup_protocol:
        err = -ESOCKTNOSUPPORT;
        rcu_read_lock();
-       list_for_each_rcu(p, &inetsw[sock->type]) {
-               answer = list_entry(p, struct inet_protosw, list);
+       list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
 
+               err = 0;
                /* Check the non-wild match. */
                if (protocol == answer->protocol) {
                        if (protocol != IPPROTO_IP)
@@ -302,10 +300,9 @@ lookup_protocol:
                                break;
                }
                err = -EPROTONOSUPPORT;
-               answer = NULL;
        }
 
-       if (unlikely(answer == NULL)) {
+       if (unlikely(err)) {
                if (try_loading_module < 2) {
                        rcu_read_unlock();
                        /*

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 3d828bc..60461ad 100644 (file)
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -83,7 +83,6 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol)
        struct inet_sock *inet;
        struct ipv6_pinfo *np;
        struct sock *sk;
-       struct list_head *p;
        struct inet_protosw *answer;
        struct proto *answer_prot;
        unsigned char answer_flags;
@@ -97,13 +96,12 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol)
                build_ehash_secret();
 
        /* Look for the requested type/protocol pair. */
-       answer = NULL;
 lookup_protocol:
        err = -ESOCKTNOSUPPORT;
        rcu_read_lock();
-       list_for_each_rcu(p, &inetsw6[sock->type]) {
-               answer = list_entry(p, struct inet_protosw, list);
+       list_for_each_entry_rcu(answer, &inetsw6[sock->type], list) {
 
+               err = 0;
                /* Check the non-wild match. */
                if (protocol == answer->protocol) {
                        if (protocol != IPPROTO_IP)
@@ -118,10 +116,9 @@ lookup_protocol:
                                break;
                }
                err = -EPROTONOSUPPORT;
-               answer = NULL;
        }
 
-       if (!answer) {
+       if (err) {
                if (try_loading_module < 2) {
                        rcu_read_unlock();
                        /*