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authorDenis V. Lunev <den@openvz.org>2007-10-10 21:15:29 -0700
committerDavid S. Miller <davem@davemloft.net>2007-10-10 21:15:29 -0700
commitcd40b7d3983c708aabe3d3008ec64ffce56d33b0 (patch)
tree0d6fe9cfd2f03fdeee126e317d4bfb145afc458d /net/decnet
parentaed815601f3f95281ab3a01f7e2cbe1bd54285a0 (diff)
downloadlwn-cd40b7d3983c708aabe3d3008ec64ffce56d33b0.tar.gz
lwn-cd40b7d3983c708aabe3d3008ec64ffce56d33b0.zip
[NET]: make netlink user -> kernel interface synchronious
This patch make processing netlink user -> kernel messages synchronious. This change was inspired by the talk with Alexey Kuznetsov about current netlink messages processing. He says that he was badly wrong when introduced asynchronious user -> kernel communication. The call netlink_unicast is the only path to send message to the kernel netlink socket. But, unfortunately, it is also used to send data to the user. Before this change the user message has been attached to the socket queue and sk->sk_data_ready was called. The process has been blocked until all pending messages were processed. The bad thing is that this processing may occur in the arbitrary process context. This patch changes nlk->data_ready callback to get 1 skb and force packet processing right in the netlink_unicast. Kernel -> user path in netlink_unicast remains untouched. EINTR processing for in netlink_run_queue was changed. It forces rtnl_lock drop, but the process remains in the cycle until the message will be fully processed. So, there is no need to use this kludges now. Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/decnet')
-rw-r--r--net/decnet/netfilter/dn_rtmsg.c14
1 files changed, 2 insertions, 12 deletions
diff --git a/net/decnet/netfilter/dn_rtmsg.c b/net/decnet/netfilter/dn_rtmsg.c
index ebb38feb4df3..f7fba7721e63 100644
--- a/net/decnet/netfilter/dn_rtmsg.c
+++ b/net/decnet/netfilter/dn_rtmsg.c
@@ -115,17 +115,6 @@ static inline void dnrmg_receive_user_skb(struct sk_buff *skb)
RCV_SKB_FAIL(-EINVAL);
}
-static void dnrmg_receive_user_sk(struct sock *sk, int len)
-{
- struct sk_buff *skb;
- unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
-
- for (; qlen && (skb = skb_dequeue(&sk->sk_receive_queue)); qlen--) {
- dnrmg_receive_user_skb(skb);
- kfree_skb(skb);
- }
-}
-
static struct nf_hook_ops dnrmg_ops = {
.hook = dnrmg_hook,
.pf = PF_DECnet,
@@ -139,7 +128,8 @@ static int __init dn_rtmsg_init(void)
dnrmg = netlink_kernel_create(&init_net,
NETLINK_DNRTMSG, DNRNG_NLGRP_MAX,
- dnrmg_receive_user_sk, NULL, THIS_MODULE);
+ dnrmg_receive_user_skb,
+ NULL, THIS_MODULE);
if (dnrmg == NULL) {
printk(KERN_ERR "dn_rtmsg: Cannot create netlink socket");
return -ENOMEM;