Commit c5ecd62c authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by David S. Miller
Browse files

[NET]: Move destructor from neigh->ops to neigh_params 



struct neigh_ops currently has a destructor field, which no in-kernel
drivers outside of infiniband use.  The infiniband/ulp/ipoib in-tree
driver stashes some info in the neighbour structure (the results of
the second-stage lookup from ARP results to real link-level path), and
it uses neigh->ops->destructor to get a callback so it can clean up
this extra info when a neighbour is freed.  We've run into problems
with this: since the destructor is in an ops field that is shared
between neighbours that may belong to different net devices, there's
no way to set/clear it safely.

The following patch moves this field to neigh_parms where it can be
safely set, together with its twin neigh_setup.  Two additional
patches in the patch series update ipoib to use this new interface.

Signed-off-by: default avatarMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 53dcb0e3

drivers/infiniband/ulp/ipoib/ipoib_main.c

+1 −15
Original line number Diff line number Diff line
@@ -247,7 +247,6 @@ static void path_free(struct net_device *dev, struct ipoib_path *path) 
		if (neigh->ah)

			ipoib_put_ah(neigh->ah);

		*to_ipoib_neigh(neigh->neighbour) = NULL;

		neigh->neighbour->ops->destructor = NULL;

		kfree(neigh);

	}
@@ -530,7 +529,6 @@ static void neigh_add_path(struct sk_buff *skb, struct net_device *dev) 
err:

	*to_ipoib_neigh(skb->dst->neighbour) = NULL;

	list_del(&neigh->list);

	neigh->neighbour->ops->destructor = NULL;

	kfree(neigh);



	++priv->stats.tx_dropped;
@@ -769,21 +767,9 @@ static void ipoib_neigh_destructor(struct neighbour *n) 
		ipoib_put_ah(ah);

}



static int ipoib_neigh_setup(struct neighbour *neigh)

{

	/*

	 * Is this kosher?  I can't find anybody in the kernel that

	 * sets neigh->destructor, so we should be able to set it here

	 * without trouble.

	 */

	neigh->ops->destructor = ipoib_neigh_destructor;



	return 0;

}



static int ipoib_neigh_setup_dev(struct net_device *dev, struct neigh_parms *parms)

{

	parms->neigh_setup = ipoib_neigh_setup;

	parms->neigh_destructor = ipoib_neigh_destructor;



	return 0;

}

include/net/neighbour.h

+1 −1
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ struct neigh_parms 
	struct net_device *dev;

	struct neigh_parms *next;

	int	(*neigh_setup)(struct neighbour *);

	void	(*neigh_destructor)(struct neighbour *);

	struct neigh_table *tbl;



	void	*sysctl_table;
@@ -145,7 +146,6 @@ struct neighbour 
struct neigh_ops

{

	int			family;

	void			(*destructor)(struct neighbour *);

	void			(*solicit)(struct neighbour *, struct sk_buff*);

	void			(*error_report)(struct neighbour *, struct sk_buff*);

	int			(*output)(struct sk_buff*);

net/core/neighbour.c

+2 −2
Original line number Diff line number Diff line
@@ -586,8 +586,8 @@ void neigh_destroy(struct neighbour *neigh) 
			kfree(hh);

	}



	if (neigh->ops && neigh->ops->destructor)

		(neigh->ops->destructor)(neigh);

	if (neigh->parms->neigh_destructor)

		(neigh->parms->neigh_destructor)(neigh);



	skb_queue_purge(&neigh->arp_queue);

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