On Wed, Jan 20, 2016 at 06:48:30PM +0100, Andrew Lunn wrote:
[...]
+static DEFINE_MUTEX(batadv_debugfs_ns_mutex);
[...]
+static void batadv_debugfs_ns_put(struct net *net) +{
- struct batadv_debugfs_ns_entry *ns_entry;
- mutex_lock(&batadv_debugfs_ns_mutex);
- list_for_each_entry(ns_entry, &batadv_debugfs_ns, link) {
if (ns_entry->net == net) {kref_put(&ns_entry->refcount, batadv_ns_entry_release);break;}- }
- mutex_unlock(&batadv_debugfs_ns_mutex);
+}
Andrew, is there any particular reason why in this case we use a mutex instead of a spinlock + RCU ? I imagine it is something related to debugfs..or just to make the code simpler as we don't really require a full-blown RCU strategy ?
int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface) {
- char *name = hard_iface->net_dev->name;
- struct net *net = dev_net(hard_iface->net_dev);
here we should respect David's inverted Christmas tree rule :)
struct batadv_debuginfo **bat_debug;
struct dentry *debugfs_ns_dir; struct dentry *file;
if (!batadv_debugfs) goto out;
- hard_iface->debug_dir = debugfs_create_dir(hard_iface->net_dev->name,
batadv_debugfs);
how about:
debugfs_ns_dir = batadv_debugfs;
- if (net != &init_net) {
debugfs_ns_dir = batadv_debugfs_ns_get(net);if (!debugfs_ns_dir)goto out;
}
hard_iface->debug_dir = debugfs_create_dir(name, debugfs_ns_dir);
isn't it nicer? :)
if (!hard_iface->debug_dir) goto out;
[...]
- bat_priv->debug_dir = debugfs_create_dir(dev->name, batadv_debugfs);
- if (net != &init_net) {
debugfs_ns_dir = batadv_debugfs_ns_get(net);if (!debugfs_ns_dir)goto out;bat_priv->debug_dir = debugfs_create_dir(dev->name,debugfs_ns_dir);- } else {
bat_priv->debug_dir = debugfs_create_dir(dev->name,batadv_debugfs);- }
same as above
- if (!bat_priv->debug_dir) goto out;