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>

1 files changed, 62 insertions, 57 deletions

diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index ef6ab71921fc..fbce4a3126de 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,
                 }
 
                 kfree_skb(skb);
-                atomic_inc(&iucv->msg_recv);
+                if (iucv->transport == AF_IUCV_TRANS_HIPER) {
+                        atomic_inc(&iucv->msg_recv);
+                        if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
+                                WARN_ON(1);
+                                iucv_sock_close(sk);
+                                return -EFAULT;
+                        }
+                }
 
                 /* Queue backlog skbs */
                 spin_lock_bh(&iucv->message_q.lock);
@@ -1957,6 +1960,8 @@ static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
         memcpy(niucv->src_name, iucv->src_name, 8);
         memcpy(niucv->src_user_id, iucv->src_user_id, 8);
         nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
+        niucv->hs_dev = iucv->hs_dev;
+        dev_hold(niucv->hs_dev);
         afiucv_swap_src_dest(skb);
         trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
         trans_hdr->window = niucv->msglimit;
@@ -2025,12 +2030,15 @@ static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
         struct iucv_sock *iucv = iucv_sk(sk);
 
         /* other end of connection closed */
-        if (iucv) {
-                bh_lock_sock(sk);
+        if (!iucv)
+                goto out;
+        bh_lock_sock(sk);
+        if (sk->sk_state == IUCV_CONNECTED) {
                 sk->sk_state = IUCV_DISCONN;
                 sk->sk_state_change(sk);
-                bh_unlock_sock(sk);
         }
+        bh_unlock_sock(sk);
+out:
         kfree_skb(skb);
         return NET_RX_SUCCESS;
 }
@@ -2175,11 +2183,11 @@ static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
                 break;
         case (AF_IUCV_FLAG_WIN):
                 err = afiucv_hs_callback_win(sk, skb);
-                if (skb->len > sizeof(struct af_iucv_trans_hdr))
-                        err = afiucv_hs_callback_rx(sk, skb);
-                else
-                        kfree(skb);
-                break;
+                if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
+                        kfree_skb(skb);
+                        break;
+                }
+                /* fall through */
         case 0:
                 /* plain data frame */
                 memcpy(CB_TRGCLS(skb), &trans_hdr->iucv_hdr.class,
@@ -2205,65 +2213,64 @@ static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
         struct iucv_sock *iucv = NULL;
         struct sk_buff_head *list;
         struct sk_buff *list_skb;
-        struct sk_buff *this = NULL;
+        struct sk_buff *nskb;
         unsigned long flags;
         struct hlist_node *node;
 
-        read_lock(&iucv_sk_list.lock);
+        read_lock_irqsave(&iucv_sk_list.lock, flags);
         sk_for_each(sk, node, &iucv_sk_list.head)
                 if (sk == isk) {
                         iucv = iucv_sk(sk);
                         break;
                 }
-        read_unlock(&iucv_sk_list.lock);
+        read_unlock_irqrestore(&iucv_sk_list.lock, flags);
 
-        if (!iucv)
+        if (!iucv || sock_flag(sk, SOCK_ZAPPED))
                 return;
 
-        bh_lock_sock(sk);
         list = &iucv->send_skb_q;
-        list_skb = list->next;
+        spin_lock_irqsave(&list->lock, flags);
         if (skb_queue_empty(list))
                 goto out_unlock;
-
-        spin_lock_irqsave(&list->lock, flags);
+        list_skb = list->next;
+        nskb = list_skb->next;
         while (list_skb != (struct sk_buff *)list) {
                 if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
-                        this = list_skb;
                         switch (n) {
                         case TX_NOTIFY_OK:
-                                __skb_unlink(this, list);
+                                __skb_unlink(list_skb, list);
+                                kfree_skb(list_skb);
                                 iucv_sock_wake_msglim(sk);
-                                dev_put(this->dev);
-                                kfree_skb(this);
                                 break;
                         case TX_NOTIFY_PENDING:
                                 atomic_inc(&iucv->pendings);
                                 break;
                         case TX_NOTIFY_DELAYED_OK:
-                                __skb_unlink(this, list);
+                                __skb_unlink(list_skb, list);
                                 atomic_dec(&iucv->pendings);
                                 if (atomic_read(&iucv->pendings) <= 0)
                                         iucv_sock_wake_msglim(sk);
-                                dev_put(this->dev);
-                                kfree_skb(this);
+                                kfree_skb(list_skb);
                                 break;
                         case TX_NOTIFY_UNREACHABLE:
                         case TX_NOTIFY_DELAYED_UNREACHABLE:
                         case TX_NOTIFY_TPQFULL: /* not yet used */
                         case TX_NOTIFY_GENERALERROR:
                         case TX_NOTIFY_DELAYED_GENERALERROR:
-                                __skb_unlink(this, list);
-                                dev_put(this->dev);
-                                kfree_skb(this);
-                                sk->sk_state = IUCV_DISCONN;
-                                sk->sk_state_change(sk);
+                                __skb_unlink(list_skb, list);
+                                kfree_skb(list_skb);
+                                if (sk->sk_state == IUCV_CONNECTED) {
+                                        sk->sk_state = IUCV_DISCONN;
+                                        sk->sk_state_change(sk);
+                                }
                                 break;
                         }
                         break;
                 }
-                list_skb = list_skb->next;
+                list_skb = nskb;
+                nskb = nskb->next;
         }
+out_unlock:
         spin_unlock_irqrestore(&list->lock, flags);
 
         if (sk->sk_state == IUCV_CLOSING) {
@@ -2273,8 +2280,6 @@ static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
                 }
         }
 
-out_unlock:
-        bh_unlock_sock(sk);
 }
 static const struct proto_ops iucv_sock_ops = {
         .family         = PF_IUCV,