diff options
| author | Thomas Graf <tgraf@infradead.org> | 2011-06-21 03:11:20 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-07-01 15:39:53 -0700 |
| commit | 4e985adaa504c1c1a05c8e013777ea0791a17b4d (patch) | |
| tree | d2eedf47256577ebfc67f0356c9b348590b560d3 /net/core | |
| parent | e77aeb71f04ed236fffe5f347e208c8b0e92d48a (diff) | |
rtnl: provide link dump consistency info
This patch adds a change sequence counter to each net namespace
which is bumped whenever a netdevice is added or removed from
the list. If such a change occurred while a link dump took place,
the dump will have the NLM_F_DUMP_INTR flag set in the first
message which has been interrupted and in all subsequent messages
of the same dump.
Note that links may still be modified or renamed while a dump is
taking place but we can guarantee for userspace to receive a
complete list of links and not miss any.
Testing:
I have added 500 VLAN netdevices to make sure the dump is split
over multiple messages. Then while continuously dumping links in
one process I also continuously deleted and re-added a dummy
netdevice in another process. Multiple dumps per seconds have
had the NLM_F_DUMP_INTR flag set.
I guess we can wait for Johannes patch to hit net-next via the
wireless tree. I just wanted to give this some testing right away.
Signed-off-by: Thomas Graf <tgraf@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/dev.c | 10 | ||||
| -rw-r--r-- | net/core/net_namespace.c | 1 | ||||
| -rw-r--r-- | net/core/rtnetlink.c | 4 |
3 files changed, 15 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 6b6ef14b42f..4577e6711ec 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -199,6 +199,11 @@ static struct list_head ptype_all __read_mostly; /* Taps */ DEFINE_RWLOCK(dev_base_lock); EXPORT_SYMBOL(dev_base_lock); +static inline void dev_base_seq_inc(struct net *net) +{ + while (++net->dev_base_seq == 0); +} + static inline struct hlist_head *dev_name_hash(struct net *net, const char *name) { unsigned hash = full_name_hash(name, strnlen(name, IFNAMSIZ)); @@ -237,6 +242,9 @@ static int list_netdevice(struct net_device *dev) hlist_add_head_rcu(&dev->index_hlist, dev_index_hash(net, dev->ifindex)); write_unlock_bh(&dev_base_lock); + + dev_base_seq_inc(net); + return 0; } @@ -253,6 +261,8 @@ static void unlist_netdevice(struct net_device *dev) hlist_del_rcu(&dev->name_hlist); hlist_del_rcu(&dev->index_hlist); write_unlock_bh(&dev_base_lock); + + dev_base_seq_inc(dev_net(dev)); } /* diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index ea489db1bc2..5bbdbf0d366 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -129,6 +129,7 @@ static __net_init int setup_net(struct net *net) atomic_set(&net->count, 1); atomic_set(&net->passive, 1); + net->dev_base_seq = 1; #ifdef NETNS_REFCNT_DEBUG atomic_set(&net->use_count, 0); diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index a798fc6f2aa..99d9e953fe3 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1032,6 +1032,8 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) s_idx = cb->args[1]; rcu_read_lock(); + cb->seq = net->dev_base_seq; + for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { idx = 0; head = &net->dev_index_head[h]; @@ -1043,6 +1045,8 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0) goto out; + + nl_dump_check_consistent(cb, nlmsg_hdr(skb)); cont: idx++; } |