Commit c4ed5253 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'drop_monitor-Various-improvements-and-cleanups' 

Ido Schimmel says:

====================
drop_monitor: Various improvements and cleanups

This patchset performs various improvements and cleanups in drop monitor
with no functional changes intended. There are no changes in these
patches relative to the RFC I sent two weeks ago [1].

A followup patchset will extend drop monitor with a packet alert mode in
which the dropped packet is notified to user space instead of just a
summary of recent drops. Subsequent patchsets will add the ability to
monitor hardware originated drops via drop monitor.

[1] https://patchwork.ozlabs.org/cover/1135226/


====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 267df70f b19d9550

net/core/drop_monitor.c

+38 −20
Original line number Diff line number Diff line
@@ -43,10 +43,16 @@ 
 * netlink alerts

 */

static int trace_state = TRACE_OFF;

static DEFINE_MUTEX(trace_state_mutex);



/* net_dm_mutex

 *

 * An overall lock guarding every operation coming from userspace.

 * It also guards the global 'hw_stats_list' list.

 */

static DEFINE_MUTEX(net_dm_mutex);



struct per_cpu_dm_data {

	spinlock_t		lock;

	spinlock_t		lock;	/* Protects 'skb' and 'send_timer' */

	struct sk_buff		*skb;

	struct work_struct	dm_alert_work;

	struct timer_list	send_timer;
@@ -235,22 +241,21 @@ static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi, 
	rcu_read_unlock();

}



static int set_all_monitor_traces(int state)

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;



	mutex_lock(&trace_state_mutex);



	if (state == trace_state) {

		rc = -EAGAIN;

		goto out_unlock;

		NL_SET_ERR_MSG_MOD(extack, "Trace state already set to requested state");

		return -EAGAIN;

	}



	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;

		}
@@ -288,17 +293,15 @@ static int set_all_monitor_traces(int state) 
	else

		rc = -EINPROGRESS;



out_unlock:

	mutex_unlock(&trace_state_mutex);



	return rc;

}





static int net_dm_cmd_config(struct sk_buff *skb,

			struct genl_info *info)

{

	return -ENOTSUPP;

	NL_SET_ERR_MSG_MOD(info->extack, "Command not supported");



	return -EOPNOTSUPP;

}



static int net_dm_cmd_trace(struct sk_buff *skb,
@@ -306,12 +309,12 @@ static int net_dm_cmd_trace(struct sk_buff *skb, 
{

	switch (info->genlhdr->cmd) {

	case NET_DM_CMD_START:

		return set_all_monitor_traces(TRACE_ON);

		return set_all_monitor_traces(TRACE_ON, info->extack);

	case NET_DM_CMD_STOP:

		return set_all_monitor_traces(TRACE_OFF);

		return set_all_monitor_traces(TRACE_OFF, info->extack);

	}



	return -ENOTSUPP;

	return -EOPNOTSUPP;

}



static int dropmon_net_event(struct notifier_block *ev_block,
@@ -330,12 +333,12 @@ static int dropmon_net_event(struct notifier_block *ev_block, 


		new_stat->dev = dev;

		new_stat->last_rx = jiffies;

		mutex_lock(&trace_state_mutex);

		mutex_lock(&net_dm_mutex);

		list_add_rcu(&new_stat->list, &hw_stats_list);

		mutex_unlock(&trace_state_mutex);

		mutex_unlock(&net_dm_mutex);

		break;

	case NETDEV_UNREGISTER:

		mutex_lock(&trace_state_mutex);

		mutex_lock(&net_dm_mutex);

		list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) {

			if (new_stat->dev == dev) {

				new_stat->dev = NULL;
@@ -346,7 +349,7 @@ static int dropmon_net_event(struct notifier_block *ev_block, 
				}

			}

		}

		mutex_unlock(&trace_state_mutex);

		mutex_unlock(&net_dm_mutex);

		break;

	}

out:
@@ -371,10 +374,26 @@ static const struct genl_ops dropmon_ops[] = { 
	},

};



static int net_dm_nl_pre_doit(const struct genl_ops *ops,

			      struct sk_buff *skb, struct genl_info *info)

{

	mutex_lock(&net_dm_mutex);



	return 0;

}



static void net_dm_nl_post_doit(const struct genl_ops *ops,

				struct sk_buff *skb, struct genl_info *info)

{

	mutex_unlock(&net_dm_mutex);

}



static struct genl_family net_drop_monitor_family __ro_after_init = {

	.hdrsize        = 0,

	.name           = "NET_DM",

	.version        = 2,

	.pre_doit	= net_dm_nl_pre_doit,

	.post_doit	= net_dm_nl_post_doit,

	.module		= THIS_MODULE,

	.ops		= dropmon_ops,

	.n_ops		= ARRAY_SIZE(dropmon_ops),
@@ -421,7 +440,6 @@ static int __init init_net_drop_monitor(void) 
		reset_per_cpu_data(data);

	}





	goto out;



out_unreg:

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