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authorThomas Graf <tgraf@infradead.org>2011-06-21 03:11:20 +0000
committerDavid S. Miller <davem@davemloft.net>2011-07-01 15:39:53 -0700
commit4e985adaa504c1c1a05c8e013777ea0791a17b4d (patch)
treed2eedf47256577ebfc67f0356c9b348590b560d3 /net/core/rtnetlink.c
parente77aeb71f04ed236fffe5f347e208c8b0e92d48a (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/rtnetlink.c')
-rw-r--r--net/core/rtnetlink.c4
1 files changed, 4 insertions, 0 deletions
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++;
}