On Tue, 2018-05-22 at 16:00 +0200, Evgenii Smirnov wrote:
> In unicast_arp_send function there is an inconsistency in error handling
> of path_rec_start call. If path_rec_start is called because of an absent
> ah field, skb will be dropped. But if it is called on a creation of a new path,
> or if the path is invalid, skb will be added to the tail of path queue.
> In case of a new path it will be dropped on path_free, but in case
> of invalid path it can stay in the queue forever.
>
> This patch unifies the behavior, dropping skb in all cases
> of path_rec_start failure.
>
> Signed-off-by: Evgenii Smirnov <evgenii.smirnov@xxxxxxxxxxxxxxxx>
>
Your patch wouldn't apply (would have needed to be rebased on top of my
final patch). So, I hand applied your patch, and simplified things even
a little further in the process (if we allocate a new path, just add it
right away and greatly simplify the code path, allowing us to entirely
eliminate the new_path variable and unwind sequences). Here it is for
review:
commit 5755dd0e647eecaf3c32af858e9ef69db199b0a7 (HEAD -> k.o/wip/dl-for-next)
Author: Evgenii Smirnov <evgenii.smirnov@xxxxxxxxxxxxxxxx>
Date: Tue May 22 16:00:47 2018 +0200
RDMA/ipoib: drop skb on path record lookup failure
In unicast_arp_send function there is an inconsistency in error handling
of path_rec_start call. If path_rec_start is called because of an absent
ah field, skb will be dropped. But if it is called on a creation of a
new path, or if the path is invalid, skb will be added to the tail of
path queue. In case of a new path it will be dropped on path_free, but
in case of invalid path it can stay in the queue forever.
This patch unifies the behavior, dropping skb in all cases
of path_rec_start failure.
Signed-off-by: Evgenii Smirnov <evgenii.smirnov@xxxxxxxxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 788bb9573f1f..b84f9e8f881d 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -1054,62 +1054,36 @@ static void unicast_arp_send(struct sk_buff *skb, struct net_device *dev,
path = __path_find(dev, phdr->hwaddr + 4);
if (!path || !path->ah || !path->ah->valid) {
- int new_path = 0;
-
if (!path) {
path = path_rec_create(dev, phdr->hwaddr + 4);
- new_path = 1;
+ if (!path)
+ goto drop_and_unlock;
+ __path_add(dev, path);
+ }
+ if (!path->query && path_rec_start(dev, path)) {
+ goto drop_and_unlock;
}
- if (path) {
- if (!new_path)
- /* make sure there is no changes in the existing path record */
- init_path_rec(priv, path, phdr->hwaddr + 4);
-
- if (skb_queue_len(&path->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
- push_pseudo_header(skb, phdr->hwaddr);
- __skb_queue_tail(&path->queue, skb);
- } else {
- ++dev->stats.tx_dropped;
- dev_kfree_skb_any(skb);
- }
- if (!path->query && path_rec_start(dev, path)) {
- spin_unlock_irqrestore(&priv->lock, flags);
- if (new_path)
- path_free(dev, path);
- return;
- } else
- __path_add(dev, path);
+ if (skb_queue_len(&path->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
+ push_pseudo_header(skb, phdr->hwaddr);
+ __skb_queue_tail(&path->queue, skb);
+ goto unlock;
} else {
goto drop_and_unlock;
}
-
- spin_unlock_irqrestore(&priv->lock, flags);
- return;
- }
-
- if (path->ah && path->ah->valid) {
- ipoib_dbg(priv, "Send unicast ARP to %08x\n",
- be32_to_cpu(sa_path_get_dlid(&path->pathrec)));
-
- spin_unlock_irqrestore(&priv->lock, flags);
- path->ah->last_send = rn->send(dev, skb, path->ah->ah,
- IPOIB_QPN(phdr->hwaddr));
- return;
- } else if ((path->query || !path_rec_start(dev, path)) &&
- skb_queue_len(&path->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
- push_pseudo_header(skb, phdr->hwaddr);
- __skb_queue_tail(&path->queue, skb);
- } else {
- goto drop_and_unlock;
}
spin_unlock_irqrestore(&priv->lock, flags);
+ ipoib_dbg(priv, "Send unicast ARP to %08x\n",
+ be32_to_cpu(sa_path_get_dlid(&path->pathrec)));
+ path->ah->last_send = rn->send(dev, skb, path->ah->ah,
+ IPOIB_QPN(phdr->hwaddr));
return;
drop_and_unlock:
++dev->stats.tx_dropped;
dev_kfree_skb_any(skb);
+unlock:
spin_unlock_irqrestore(&priv->lock, flags);
}
--
Doug Ledford <dledford@xxxxxxxxxx>
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