From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Horman Subject: [PATCH] drop_monitor: convert to modular building Date: Wed, 16 May 2012 10:27:06 -0400 Message-ID: <1337178426-2470-1-git-send-email-nhorman@tuxdriver.com> Cc: Neil Horman , "David S. Miller" To: netdev@vger.kernel.org Return-path: Received: from charlotte.tuxdriver.com ([70.61.120.58]:47968 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752089Ab2EPO1b (ORCPT ); Wed, 16 May 2012 10:27:31 -0400 Sender: netdev-owner@vger.kernel.org List-ID: When I first wrote drop monitor I wrote it to just build monolithically. There is no reason it can't be built modularly as well, so lets give it that flexibiity. I've tested this by building it as both a module and monolithically, and it seems to work quite well Signed-off-by: Neil Horman CC: "David S. Miller" --- net/Kconfig | 2 +- net/core/drop_monitor.c | 46 +++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 46 insertions(+), 2 deletions(-) diff --git a/net/Kconfig b/net/Kconfig index e07272d..76ad6fa 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -295,7 +295,7 @@ config NET_TCPPROBE module will be called tcp_probe. config NET_DROP_MONITOR - boolean "Network packet drop alerting service" + tristate "Network packet drop alerting service" depends on INET && EXPERIMENTAL && TRACEPOINTS ---help--- This feature provides an alerting service to userspace in the diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index 5c3c81a..145f399 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -223,9 +224,15 @@ static int set_all_monitor_traces(int state) switch (state) { case TRACE_ON: + if (!try_module_get(THIS_MODULE)) { + rc = -EINVAL; + break; + } + rc |= register_trace_kfree_skb(trace_kfree_skb_hit, NULL); rc |= register_trace_napi_poll(trace_napi_poll_hit, NULL); break; + case TRACE_OFF: rc |= unregister_trace_kfree_skb(trace_kfree_skb_hit, NULL); rc |= unregister_trace_napi_poll(trace_napi_poll_hit, NULL); @@ -241,6 +248,9 @@ static int set_all_monitor_traces(int state) kfree_rcu(new_stat, rcu); } } + + module_put(THIS_MODULE); + break; default: rc = 1; @@ -383,4 +393,38 @@ out: return rc; } -late_initcall(init_net_drop_monitor); +static void exit_net_drop_monitor(void) +{ + struct per_cpu_dm_data *data; + int cpu; + + if (unregister_netdevice_notifier(&dropmon_net_notifier)) + printk(KERN_WARNING "Unable to unregiser dropmon notifer\n"); + + /* + * Because of the module_get/put we do in the trace state change path + * we are guarnateed not to have any current users when we get here + * all we need to do is make sure that we don't have any running timers + * or pending schedule calls + */ + + for_each_present_cpu(cpu) { + data = &per_cpu(dm_cpu_data, cpu); + del_timer(&data->send_timer); + cancel_work_sync(&data->dm_alert_work); + /* + * At this point, we should have exclusive access + * to this struct and can free the skb inside it + */ + kfree_skb(data->skb); + } + + if (genl_unregister_family(&net_drop_monitor_family)) + printk(KERN_WARNING "Unable to unregister drop monitor socket family\n"); +} + +module_init(init_net_drop_monitor); +module_exit(exit_net_drop_monitor); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Neil Horman "); -- 1.7.7.6