diff options
| author | Wei Wang <weiwan@google.com> | 2017-06-17 19:42:28 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-06-18 04:53:59 +0200 |
| commit | 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 (patch) | |
| tree | 534f9011f830f5cea49311312b19a9f19a9f67f6 | |
| parent | net: introduce DST_NOGC in dst_release() to destroy dst based on refcnt (diff) | |
| download | linux-4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36.tar.xz linux-4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36.zip | |
net: introduce a new function dst_dev_put()
This function should be called when removing routes from fib tree after
the dst gc is no longer in use.
We first mark DST_OBSOLETE_DEAD on this dst to make sure next
dst_ops->check() fails and returns NULL.
Secondly, as we no longer keep the gc_list, we need to properly
release dst->dev right at the moment when the dst is removed from
the fib/fib6 tree.
It does the following:
1. change dst->input and output pointers to dst_discard/dst_dscard_out to
discard all packets
2. replace dst->dev with loopback interface
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/dst.h | 1 | ||||
| -rw-r--r-- | net/core/dst.c | 24 |
2 files changed, 25 insertions, 0 deletions
diff --git a/include/net/dst.h b/include/net/dst.h index 2735d5a1e774..11d779803c0d 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -428,6 +428,7 @@ void dst_init(struct dst_entry *dst, struct dst_ops *ops, unsigned short flags); void __dst_free(struct dst_entry *dst); struct dst_entry *dst_destroy(struct dst_entry *dst); +void dst_dev_put(struct dst_entry *dst); static inline void dst_free(struct dst_entry *dst) { diff --git a/net/core/dst.c b/net/core/dst.c index 551834c3363f..56998f69b84e 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -296,6 +296,30 @@ static void dst_destroy_rcu(struct rcu_head *head) __dst_free(dst); } +/* Operations to mark dst as DEAD and clean up the net device referenced + * by dst: + * 1. put the dst under loopback interface and discard all tx/rx packets + * on this route. + * 2. release the net_device + * This function should be called when removing routes from the fib tree + * in preparation for a NETDEV_DOWN/NETDEV_UNREGISTER event and also to + * make the next dst_ops->check() fail. + */ +void dst_dev_put(struct dst_entry *dst) +{ + struct net_device *dev = dst->dev; + + dst->obsolete = DST_OBSOLETE_DEAD; + if (dst->ops->ifdown) + dst->ops->ifdown(dst, dev, true); + dst->input = dst_discard; + dst->output = dst_discard_out; + dst->dev = dev_net(dst->dev)->loopback_dev; + dev_hold(dst->dev); + dev_put(dev); +} +EXPORT_SYMBOL(dst_dev_put); + void dst_release(struct dst_entry *dst) { if (dst) { |