cxgb3: Rework t3_l2t_get to take a dst_entry instead of a neighbour.

This way we consolidate the RCU locking down into the place where it
actually matters, and also we can make the code handle
dst_get_neighbour_noref() returning NULL properly.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/infiniband/hw/cxgb3/iwch_cm.c b/drivers/infiniband/hw/cxgb3/iwch_cm.c
index 23686df..740dcc0 100644 (file)
--- a/drivers/infiniband/hw/cxgb3/iwch_cm.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_cm.c
@@ -1338,7 +1338,6 @@ static int pass_accept_req(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
        struct iwch_ep *child_ep, *parent_ep = ctx;
        struct cpl_pass_accept_req *req = cplhdr(skb);
        unsigned int hwtid = GET_TID(req);
-       struct neighbour *neigh;
        struct dst_entry *dst;
        struct l2t_entry *l2t;
        struct rtable *rt;
@@ -1375,10 +1374,7 @@ static int pass_accept_req(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
                goto reject;
        }
        dst = &rt->dst;
-       rcu_read_lock();
-       neigh = dst_get_neighbour_noref(dst);
-       l2t = t3_l2t_get(tdev, neigh, neigh->dev);
-       rcu_read_unlock();
+       l2t = t3_l2t_get(tdev, dst, NULL);
        if (!l2t) {
                printk(KERN_ERR MOD "%s - failed to allocate l2t entry!\n",
                       __func__);
@@ -1889,7 +1885,6 @@ static int is_loopback_dst(struct iw_cm_id *cm_id)
 int iwch_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *conn_param)
 {
        struct iwch_dev *h = to_iwch_dev(cm_id->device);
-       struct neighbour *neigh;
        struct iwch_ep *ep;
        struct rtable *rt;
        int err = 0;
@@ -1947,13 +1942,7 @@ int iwch_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *conn_param)
                goto fail3;
        }
        ep->dst = &rt->dst;
-
-       rcu_read_lock();
-       neigh = dst_get_neighbour_noref(ep->dst);
-
-       /* get a l2t entry */
-       ep->l2t = t3_l2t_get(ep->com.tdev, neigh, neigh->dev);
-       rcu_read_unlock();
+       ep->l2t = t3_l2t_get(ep->com.tdev, ep->dst, NULL);
        if (!ep->l2t) {
                printk(KERN_ERR MOD "%s - cannot alloc l2e.\n", __func__);
                err = -ENOMEM;

diff --git a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c
index 6ed9f87..596cfe3 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c
+++ b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c
@@ -1132,7 +1132,7 @@ static void cxgb_redirect(struct dst_entry *old, struct dst_entry *new)
        }
 
        /* Add new L2T entry */
-       e = t3_l2t_get(tdev, dst_get_neighbour_noref(new), newdev);
+       e = t3_l2t_get(tdev, new, newdev);
        if (!e) {
                printk(KERN_ERR "%s: couldn't allocate new l2t entry!\n",
                       __func__);

diff --git a/drivers/net/ethernet/chelsio/cxgb3/l2t.c b/drivers/net/ethernet/chelsio/cxgb3/l2t.c
index 70fec8b..3fa3c88 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb3/l2t.c
+++ b/drivers/net/ethernet/chelsio/cxgb3/l2t.c
@@ -298,18 +298,31 @@ static inline void reuse_entry(struct l2t_entry *e, struct neighbour *neigh)
        spin_unlock(&e->lock);
 }
 
-struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct neighbour *neigh,
+struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct dst_entry *dst,
                             struct net_device *dev)
 {
        struct l2t_entry *e = NULL;
+       struct neighbour *neigh;
+       struct port_info *p;
        struct l2t_data *d;
        int hash;
-       u32 addr = *(u32 *) neigh->primary_key;
-       int ifidx = neigh->dev->ifindex;
-       struct port_info *p = netdev_priv(dev);
-       int smt_idx = p->port_id;
+       u32 addr;
+       int ifidx;
+       int smt_idx;
 
        rcu_read_lock();
+       neigh = dst_get_neighbour_noref(dst);
+       if (!neigh)
+               goto done_rcu;
+
+       addr = *(u32 *) neigh->primary_key;
+       ifidx = neigh->dev->ifindex;
+
+       if (!dev)
+               dev = neigh->dev;
+       p = netdev_priv(dev);
+       smt_idx = p->port_id;
+
        d = L2DATA(cdev);
        if (!d)
                goto done_rcu;
@@ -323,7 +336,7 @@ struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct neighbour *neigh,
                        l2t_hold(d, e);
                        if (atomic_read(&e->refcnt) == 1)
                                reuse_entry(e, neigh);
-                       goto done;
+                       goto done_unlock;
                }
 
        /* Need to allocate a new entry */
@@ -344,7 +357,7 @@ struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct neighbour *neigh,
                        e->vlan = VLAN_NONE;
                spin_unlock(&e->lock);
        }
-done:
+done_unlock:
        write_unlock_bh(&d->lock);
 done_rcu:
        rcu_read_unlock();

diff --git a/drivers/net/ethernet/chelsio/cxgb3/l2t.h b/drivers/net/ethernet/chelsio/cxgb3/l2t.h
index c5f5479..c4e8643 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb3/l2t.h
+++ b/drivers/net/ethernet/chelsio/cxgb3/l2t.h
@@ -109,7 +109,7 @@ static inline void set_arp_failure_handler(struct sk_buff *skb,
 
 void t3_l2e_free(struct l2t_data *d, struct l2t_entry *e);
 void t3_l2t_update(struct t3cdev *dev, struct neighbour *neigh);
-struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct neighbour *neigh,
+struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct dst_entry *dst,
                             struct net_device *dev);
 int t3_l2t_send_slow(struct t3cdev *dev, struct sk_buff *skb,
                     struct l2t_entry *e);

diff --git a/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c b/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
index 88902d3..36739da 100644 (file)
--- a/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
+++ b/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
@@ -966,7 +966,7 @@ static int init_act_open(struct cxgbi_sock *csk)
                csk->saddr.sin_addr.s_addr = chba->ipv4addr;
 
        csk->rss_qid = 0;
-       csk->l2t = t3_l2t_get(t3dev, dst_get_neighbour_noref(dst), ndev);
+       csk->l2t = t3_l2t_get(t3dev, dst, ndev);
        if (!csk->l2t) {
                pr_err("NO l2t available.\n");
                return -EINVAL;