diff options
| author | Ido Schimmel <idosch@mellanox.com> | 2016-12-03 16:45:06 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-12-03 19:29:35 -0500 |
| commit | cacaad11f43aefbbe5fca00af3b9c16e6aee1ba4 (patch) | |
| tree | ca7600f9e865f6bfef8ce60a9c1d1ddd34acba96 | |
| parent | d3f706f68e2fd93f1172fe7fd6f16ba70cc52b31 (diff) | |
ipv4: fib: Allow for consistent FIB dumping
The next patch will enable listeners of the FIB notification chain to
request a dump of the FIB tables. However, since RTNL isn't taken during
the dump, it's possible for the FIB tables to change mid-dump, which
will result in inconsistency between the listener's table and the
kernel's.
Allow listeners to know about changes that occurred mid-dump, by adding
a change sequence counter to each net namespace. The counter is
incremented just before a notification is sent in the FIB chain.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/netns/ipv4.h | 3 | ||||
| -rw-r--r-- | net/ipv4/fib_frontend.c | 2 | ||||
| -rw-r--r-- | net/ipv4/fib_trie.c | 1 |
3 files changed, 6 insertions, 0 deletions
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 7adf4386ac8f..f0cf5a1b777e 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -135,6 +135,9 @@ struct netns_ipv4 { #ifdef CONFIG_IP_ROUTE_MULTIPATH int sysctl_fib_multipath_use_neigh; #endif + + unsigned int fib_seq; /* protected by rtnl_mutex */ + atomic_t rt_genid; }; #endif diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 121384bbb40b..dbad5a1c161a 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -1219,6 +1219,8 @@ static int __net_init ip_fib_net_init(struct net *net) int err; size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; + net->ipv4.fib_seq = 0; + /* Avoid false sharing : Use at least a full cache line */ size = max_t(size_t, size, L1_CACHE_BYTES); diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 9bfce0df20dc..28913563e7cd 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -101,6 +101,7 @@ EXPORT_SYMBOL(unregister_fib_notifier); int call_fib_notifiers(struct net *net, enum fib_event_type event_type, struct fib_notifier_info *info) { + net->ipv4.fib_seq++; info->net = net; return atomic_notifier_call_chain(&fib_chain, event_type, info); } |