wifi: mac80211: remove debugfs dir for virtual monitor

Don't call ieee80211_debugfs_recreate_netdev() for virtual monitor
interface when deleting it.

The virtual monitor interface shouldn't have debugfs entries and trying
to update them will *create* them on deletion.

And when the virtual monitor interface is created/destroyed multiple
times we'll get warnings about debugfs name conflicts.

Signed-off-by: Alexander Wetzel <Alexander@wetzel-home.de>
Link: https://patch.msgid.link/20250204164240.370153-1-Alexander@wetzel-home.de
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Author: alexw65500

net/mac80211/driver-ops.c

@@ -116,8 +116,14 @@ void drv_remove_interface(struct ieee80211_local *local,
 
 	sdata->flags &= ~IEEE80211_SDATA_IN_DRIVER;
 
-	/* Remove driver debugfs entries */
-	ieee80211_debugfs_recreate_netdev(sdata, sdata->vif.valid_links);
+	/*
+	 * Remove driver debugfs entries.
+	 * The virtual monitor interface doesn't get a debugfs
+	 * entry, so it's exempt here.
+	 */
+	if (sdata != local->monitor_sdata)
+		ieee80211_debugfs_recreate_netdev(sdata,
+						  sdata->vif.valid_links);
 
 	trace_drv_remove_interface(local, sdata);
 	local->ops->remove_interface(&local->hw, &sdata->vif);

net/mac80211/iface.c

@@ -1206,16 +1206,17 @@ void ieee80211_del_virtual_monitor(struct ieee80211_local *local)
 		return;
 	}
 
-	RCU_INIT_POINTER(local->monitor_sdata, NULL);
-	mutex_unlock(&local->iflist_mtx);
-
-	synchronize_net();
-
+	clear_bit(SDATA_STATE_RUNNING, &sdata->state);
 	ieee80211_link_release_channel(&sdata->deflink);
 
 	if (ieee80211_hw_check(&local->hw, WANT_MONITOR_VIF))
 		drv_remove_interface(local, sdata);
 
+	RCU_INIT_POINTER(local->monitor_sdata, NULL);
+	mutex_unlock(&local->iflist_mtx);
+
+	synchronize_net();
+
 	kfree(sdata);
 }