Re: dst_ifdown breaks infiniband?

From: Alexey Kuznetsov
Date: Mon Mar 19 2007 - 19:21:19 EST


Hello!

> This might work. Could you post a patch to better show what you mean to do?

Here it is.

->neigh_destructor() is killed (not used), replaced with ->neigh_cleanup(),
which is called when neighbor entry goes to dead state. At this point
everything is still valid: neigh->dev, neigh->parms etc.

The device should guarantee that dead neighbor entries (neigh->dead != 0)
do not get private part initialized, otherwise nobody will cleanup it.

I think this is enough for ipoib which is the only user of this thing.
Initialization private part of neighbor entries happens in ipib
start_xmit routine, which is not reached when device is down.
But it would be better to add explicit test for neigh->dead
in any case.


diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index f9dbc6f..2b5c297 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -814,7 +814,7 @@ static void ipoib_set_mcast_list(struct
queue_work(ipoib_workqueue, &priv->restart_task);
}

-static void ipoib_neigh_destructor(struct neighbour *n)
+static void ipoib_neigh_cleanup(struct neighbour *n)
{
struct ipoib_neigh *neigh;
struct ipoib_dev_priv *priv = netdev_priv(n->dev);
@@ -822,7 +822,7 @@ static void ipoib_neigh_destructor(struc
struct ipoib_ah *ah = NULL;

ipoib_dbg(priv,
- "neigh_destructor for %06x " IPOIB_GID_FMT "\n",
+ "neigh_cleanup for %06x " IPOIB_GID_FMT "\n",
IPOIB_QPN(n->ha),
IPOIB_GID_RAW_ARG(n->ha + 4));

@@ -874,7 +874,7 @@ void ipoib_neigh_free(struct net_device

static int ipoib_neigh_setup_dev(struct net_device *dev, struct neigh_parms *parms)
{
- parms->neigh_destructor = ipoib_neigh_destructor;
+ parms->neigh_cleanup = ipoib_neigh_cleanup;

return 0;
}
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 3725b93..ad7fe11 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -36,7 +36,7 @@ struct neigh_parms
struct net_device *dev;
struct neigh_parms *next;
int (*neigh_setup)(struct neighbour *);
- void (*neigh_destructor)(struct neighbour *);
+ void (*neigh_cleanup)(struct neighbour *);
struct neigh_table *tbl;

void *sysctl_table;
diff --git a/net/atm/clip.c b/net/atm/clip.c
index ebb5d0c..8c38258 100644
--- a/net/atm/clip.c
+++ b/net/atm/clip.c
@@ -261,14 +261,6 @@ static void clip_pop(struct atm_vcc *vcc
spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
}

-static void clip_neigh_destroy(struct neighbour *neigh)
-{
- DPRINTK("clip_neigh_destroy (neigh %p)\n", neigh);
- if (NEIGH2ENTRY(neigh)->vccs)
- printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n");
- NEIGH2ENTRY(neigh)->vccs = (void *) NEIGHBOR_DEAD;
-}
-
static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
{
DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n", neigh, skb);
@@ -342,7 +334,6 @@ static struct neigh_table clip_tbl = {
/* parameters are copied from ARP ... */
.parms = {
.tbl = &clip_tbl,
- .neigh_destructor = clip_neigh_destroy,
.base_reachable_time = 30 * HZ,
.retrans_time = 1 * HZ,
.gc_staletime = 60 * HZ,
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 3183142..cfc6001 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -140,6 +140,8 @@ static int neigh_forced_gc(struct neigh_
n->dead = 1;
shrunk = 1;
write_unlock(&n->lock);
+ if (n->parms->neigh_cleanup)
+ n->parms->neigh_cleanup(n);
neigh_release(n);
continue;
}
@@ -211,6 +213,8 @@ static void neigh_flush_dev(struct neigh
NEIGH_PRINTK2("neigh %p is stray.\n", n);
}
write_unlock(&n->lock);
+ if (n->parms->neigh_cleanup)
+ n->parms->neigh_cleanup(n);
neigh_release(n);
}
}
@@ -582,9 +586,6 @@ void neigh_destroy(struct neighbour *nei
kfree(hh);
}

- if (neigh->parms->neigh_destructor)
- (neigh->parms->neigh_destructor)(neigh);
-
skb_queue_purge(&neigh->arp_queue);

dev_put(neigh->dev);
@@ -675,6 +676,8 @@ static void neigh_periodic_timer(unsigne
*np = n->next;
n->dead = 1;
write_unlock(&n->lock);
+ if (n->parms->neigh_cleanup)
+ n->parms->neigh_cleanup(n);
neigh_release(n);
continue;
}
@@ -2088,8 +2091,11 @@ void __neigh_for_each_release(struct nei
} else
np = &n->next;
write_unlock(&n->lock);
- if (release)
+ if (release) {
+ if (n->parms->neigh_cleanup)
+ n->parms->neigh_cleanup(n);
neigh_release(n);
+ }
}
}
}
-
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