af_iucv: change net_device handling for HS transport

This patch saves the net_device in the iucv_sock structure during
bind in order to fasten skb sending.
In addition some other small improvements are made for HS transport:
   - error checking when sending skbs
   - locking changes in afiucv_hs_callback_txnotify
   - skb freeing in afiucv_hs_callback_txnotify
And finally it contains code cleanup to get rid of iucv_skb_queue_purge.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 63 insertions, 57 deletions

diff --git a/include/net/iucv/af_iucv.h b/include/net/iucv/af_iucv.h
index 0954ec95915..a1517887aea 100644
--- a/include/net/iucv/af_iucv.h
+++ b/include/net/iucv/af_iucv.h
@@ -113,6 +113,7 @@ struct iucv_sock {
         spinlock_t              accept_q_lock;
         struct sock             *parent;
         struct iucv_path        *path;
+        struct net_device       *hs_dev;
         struct sk_buff_head     send_skb_q;
         struct sk_buff_head     backlog_skb_q;
         struct sock_msg_q       message_q;
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index ef6ab71921f..fbce4a3126d 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -131,17 +131,6 @@ static inline void low_nmcpy(unsigned char *dst, char *src)
        memcpy(&dst[8], src, 8);
 }
 
-static void iucv_skb_queue_purge(struct sk_buff_head *list)
-{
-        struct sk_buff *skb;
-
-        while ((skb = skb_dequeue(list)) != NULL) {
-                if (skb->dev)
-                        dev_put(skb->dev);
-                kfree_skb(skb);
-        }
-}
-
 static int afiucv_pm_prepare(struct device *dev)
 {
 #ifdef CONFIG_PM_DEBUG
@@ -176,7 +165,7 @@ static int afiucv_pm_freeze(struct device *dev)
         read_lock(&iucv_sk_list.lock);
         sk_for_each(sk, node, &iucv_sk_list.head) {
                 iucv = iucv_sk(sk);
-                iucv_skb_queue_purge(&iucv->send_skb_q);
+                skb_queue_purge(&iucv->send_skb_q);
                 skb_queue_purge(&iucv->backlog_skb_q);
                 switch (sk->sk_state) {
                 case IUCV_DISCONN:
@@ -337,7 +326,6 @@ static void iucv_sock_wake_msglim(struct sock *sk)
 static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
                    struct sk_buff *skb, u8 flags)
 {
-        struct net *net = sock_net(sock);
         struct iucv_sock *iucv = iucv_sk(sock);
         struct af_iucv_trans_hdr *phs_hdr;
         struct sk_buff *nskb;
@@ -374,10 +362,10 @@ static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
         if (imsg)
                 memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));
 
-        skb->dev = dev_get_by_index(net, sock->sk_bound_dev_if);
+        skb->dev = iucv->hs_dev;
         if (!skb->dev)
                 return -ENODEV;
-        if (!(skb->dev->flags & IFF_UP))
+        if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev))
                 return -ENETDOWN;
         if (skb->len > skb->dev->mtu) {
                 if (sock->sk_type == SOCK_SEQPACKET)
@@ -392,15 +380,14 @@ static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
                 return -ENOMEM;
         skb_queue_tail(&iucv->send_skb_q, nskb);
         err = dev_queue_xmit(skb);
-        if (err) {
+        if (net_xmit_eval(err)) {
                 skb_unlink(nskb, &iucv->send_skb_q);
-                dev_put(nskb->dev);
                 kfree_skb(nskb);
         } else {
                 atomic_sub(confirm_recv, &iucv->msg_recv);
                 WARN_ON(atomic_read(&iucv->msg_recv) < 0);
         }
-        return err;
+        return net_xmit_eval(err);
 }
 
 static struct sock *__iucv_get_sock_by_name(char *nm)
@@ -471,7 +458,8 @@ static void iucv_sock_close(struct sock *sk)
 {
         struct iucv_sock *iucv = iucv_sk(sk);
         unsigned long timeo;
-        int err, blen;
+        int err = 0;
+        int blen;
         struct sk_buff *skb;
 
         lock_sock(sk);
@@ -498,7 +486,7 @@ static void iucv_sock_close(struct sock *sk)
                 sk->sk_state = IUCV_CLOSING;
                 sk->sk_state_change(sk);
 
-                if (!skb_queue_empty(&iucv->send_skb_q)) {
+                if (!err && !skb_queue_empty(&iucv->send_skb_q)) {
                         if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
                                 timeo = sk->sk_lingertime;
                         else
@@ -515,13 +503,19 @@ static void iucv_sock_close(struct sock *sk)
                 sk->sk_err = ECONNRESET;
                 sk->sk_state_change(sk);
 
-                iucv_skb_queue_purge(&iucv->send_skb_q);
+                skb_queue_purge(&iucv->send_skb_q);
                 skb_queue_purge(&iucv->backlog_skb_q);
 
         default:   /* fall through */
                 iucv_sever_path(sk, 1);
         }
 
+        if (iucv->hs_dev) {
+                dev_put(iucv->hs_dev);
+                iucv->hs_dev = NULL;
+                sk->sk_bound_dev_if = 0;
+        }
+
         /* mark socket for deletion by iucv_sock_kill() */
         sock_set_flag(sk, SOCK_ZAPPED);
 
@@ -713,7 +707,6 @@ static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
                 goto done_unlock;
 
         /* Bind the socket */
-
         if (pr_iucv)
                 if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
                         goto vm_bind; /* VM IUCV transport */
@@ -727,6 +720,8 @@ static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
                         memcpy(iucv->src_name, sa->siucv_name, 8);
                         memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
                         sk->sk_bound_dev_if = dev->ifindex;
+                        iucv->hs_dev = dev;
+                        dev_hold(dev);
                         sk->sk_state = IUCV_BOUND;
                         iucv->transport = AF_IUCV_TRANS_HIPER;
                         if (!iucv->msglimit)
@@ -1128,8 +1123,10 @@ static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
                         noblock, &err);
         else
                 skb = sock_alloc_send_skb(sk, len, noblock, &err);
-        if (!skb)
+        if (!skb) {
+                err = -ENOMEM;
                 goto out;
+        }
         if (iucv->transport == AF_IUCV_TRANS_HIPER)
                 skb_reserve(skb, sizeof(struct af_iucv_trans_hdr) + ETH_HLEN);
         if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
@@ -1152,6 +1149,7 @@ static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
         /* increment and save iucv message tag for msg_completion cbk */
         txmsg.tag = iucv->send_tag++;
         memcpy(CB_TAG(skb), &txmsg.tag, CB_TAG_LEN);
+
         if (iucv->transport == AF_IUCV_TRANS_HIPER) {
                 atomic_inc(&iucv->msg_sent);
                 err = afiucv_hs_send(&txmsg, sk, skb, 0);
@@ -1206,8 +1204,6 @@ release:
         return len;
 
 fail:
-        if (skb->dev)
-                dev_put(skb->dev);
         kfree_skb(skb);
 out:
         release_sock(sk);
@@ -1400,7 +1396,14 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
                 }