From 7c747838a55818fd0cdbe48afd98fba726aa898d Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Sun, 11 Aug 2019 10:35:46 +0300 Subject: [PATCH] drop_monitor: Split tracing enable / disable to different functions Subsequent patches will need to enable / disable tracing based on the configured alerting mode. Reduce the nesting level and prepare for the introduction of this functionality by splitting the tracing enable / disable operations into two different functions. Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller --- net/core/drop_monitor.c | 79 ++++++++++++++++++++++++++--------------- 1 file changed, 51 insertions(+), 28 deletions(-) diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index 4deb86f990f1..8b9b0b899ebc 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -241,11 +241,58 @@ static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi, rcu_read_unlock(); } +static int net_dm_trace_on_set(struct netlink_ext_ack *extack) +{ + int rc; + + if (!try_module_get(THIS_MODULE)) { + NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module"); + return -ENODEV; + } + + rc = register_trace_kfree_skb(trace_kfree_skb_hit, NULL); + if (rc) { + NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to kfree_skb() tracepoint"); + goto err_module_put; + } + + rc = register_trace_napi_poll(trace_napi_poll_hit, NULL); + if (rc) { + NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to napi_poll() tracepoint"); + goto err_unregister_trace; + } + + return 0; + +err_unregister_trace: + unregister_trace_kfree_skb(trace_kfree_skb_hit, NULL); +err_module_put: + module_put(THIS_MODULE); + return rc; +} + +static void net_dm_trace_off_set(void) +{ + struct dm_hw_stat_delta *new_stat, *temp; + + unregister_trace_napi_poll(trace_napi_poll_hit, NULL); + unregister_trace_kfree_skb(trace_kfree_skb_hit, NULL); + + tracepoint_synchronize_unregister(); + + list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) { + if (new_stat->dev == NULL) { + list_del_rcu(&new_stat->list); + kfree_rcu(new_stat, rcu); + } + } + + module_put(THIS_MODULE); +} + static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack) { int rc = 0; - struct dm_hw_stat_delta *new_stat = NULL; - struct dm_hw_stat_delta *temp; if (state == trace_state) { NL_SET_ERR_MSG_MOD(extack, "Trace state already set to requested state"); @@ -254,34 +301,10 @@ static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack) switch (state) { case TRACE_ON: - if (!try_module_get(THIS_MODULE)) { - NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module"); - rc = -ENODEV; - break; - } - - rc |= register_trace_kfree_skb(trace_kfree_skb_hit, NULL); - rc |= register_trace_napi_poll(trace_napi_poll_hit, NULL); + rc = net_dm_trace_on_set(extack); break; - case TRACE_OFF: - rc |= unregister_trace_kfree_skb(trace_kfree_skb_hit, NULL); - rc |= unregister_trace_napi_poll(trace_napi_poll_hit, NULL); - - tracepoint_synchronize_unregister(); - - /* - * Clean the device list - */ - list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) { - if (new_stat->dev == NULL) { - list_del_rcu(&new_stat->list); - kfree_rcu(new_stat, rcu); - } - } - - module_put(THIS_MODULE); - + net_dm_trace_off_set(); break; default: rc = 1; -- 2.30.2