From 8a7f752125a930a83f4d8dfe37fa5a081ab19d31 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 19 Jul 2006 17:44:37 +0300 Subject: [PATCH] IB/ipoib: Fix packet loss after hardware address update The neighbour ha field may get updated without destroying the neighbour. In this case, the ha field gets out of sync with the address handle stored in ipoib_neigh->ah, with the result that the ah field would point to an incorrect path, resulting in all packets being lost. Signed-off-by: Michael S. Tsirkin Signed-off-by: Roland Dreier --- drivers/infiniband/ulp/ipoib/ipoib.h | 1 + drivers/infiniband/ulp/ipoib/ipoib_main.c | 23 +++++++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h index 3f89f5e19036..474aa214ab57 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib.h +++ b/drivers/infiniband/ulp/ipoib/ipoib.h @@ -212,6 +212,7 @@ struct ipoib_path { struct ipoib_neigh { struct ipoib_ah *ah; + union ib_gid dgid; struct sk_buff_head queue; struct neighbour *neighbour; diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c index 1c6ea1c682a5..cf71d2a5515c 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_main.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c @@ -404,6 +404,8 @@ static void path_rec_completion(int status, list_for_each_entry(neigh, &path->neigh_list, list) { kref_get(&path->ah->ref); neigh->ah = path->ah; + memcpy(&neigh->dgid.raw, &path->pathrec.dgid.raw, + sizeof(union ib_gid)); while ((skb = __skb_dequeue(&neigh->queue))) __skb_queue_tail(&skqueue, skb); @@ -510,6 +512,8 @@ static void neigh_add_path(struct sk_buff *skb, struct net_device *dev) if (path->ah) { kref_get(&path->ah->ref); neigh->ah = path->ah; + memcpy(&neigh->dgid.raw, &path->pathrec.dgid.raw, + sizeof(union ib_gid)); ipoib_send(dev, skb, path->ah, be32_to_cpup((__be32 *) skb->dst->neighbour->ha)); @@ -633,6 +637,25 @@ static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev) neigh = *to_ipoib_neigh(skb->dst->neighbour); if (likely(neigh->ah)) { + if (unlikely(memcmp(&neigh->dgid.raw, + skb->dst->neighbour->ha + 4, + sizeof(union ib_gid)))) { + spin_lock(&priv->lock); + /* + * It's safe to call ipoib_put_ah() inside + * priv->lock here, because we know that + * path->ah will always hold one more reference, + * so ipoib_put_ah() will never do more than + * decrement the ref count. + */ + ipoib_put_ah(neigh->ah); + list_del(&neigh->list); + ipoib_neigh_free(neigh); + spin_unlock(&priv->lock); + ipoib_path_lookup(skb, dev); + goto out; + } + ipoib_send(dev, skb, neigh->ah, be32_to_cpup((__be32 *) skb->dst->neighbour->ha)); goto out; -- 2.20.1