From: Jiri Pirko <jiri@mellanox.com>
Date: Mon, 30 Sep 2019 11:48:15 +0200
Subject: net: introduce name_node struct to be used in hashlist
Patch-mainline: v5.5-rc1
Git-commit: ff92741270bf8b6e78aa885f166b68c7a67ab13a
References: bsc#1154353
Introduce name_node structure to hold name of device and put it into
hashlist instead of putting there struct net_device directly. Add a
necessary infrastructure to manipulate the hashlist. This prepares
the code to use the same hashlist for alternative names introduced
later in this set.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
include/linux/netdevice.h | 10 +++-
net/core/dev.c | 97 +++++++++++++++++++++++++++++++++++++---------
2 files changed, 87 insertions(+), 20 deletions(-)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -926,6 +926,12 @@ struct devlink;
struct tlsdev_ops;
+struct netdev_name_node {
+ struct hlist_node hlist;
+ struct net_device *dev;
+ const char *name;
+};
+
/*
* This structure defines the management hooks for network devices.
* The following hooks can be defined; unless noted otherwise, they are
@@ -1564,7 +1570,7 @@ enum netdev_priv_flags {
* (i.e. as seen by users in the "Space.c" file). It is the name
* of the interface.
*
- * @name_hlist: Device name hash chain, please keep it close to name[]
+ * @name_node: Name hashlist node
* @ifalias: SNMP alias
* @mem_end: Shared memory end
* @mem_start: Shared memory start
@@ -1780,7 +1786,7 @@ enum netdev_priv_flags {
struct net_device {
char name[IFNAMSIZ];
- struct hlist_node name_hlist;
+ struct netdev_name_node *name_node;
struct dev_ifalias __rcu *ifalias;
/*
* I/O specific fields
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -229,6 +229,67 @@ static inline void rps_unlock(struct sof
#endif
}
+static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
+ const char *name)
+{
+ struct netdev_name_node *name_node;
+
+ name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
+ if (!name_node)
+ return NULL;
+ INIT_HLIST_NODE(&name_node->hlist);
+ name_node->dev = dev;
+ name_node->name = name;
+ return name_node;
+}
+
+static struct netdev_name_node *
+netdev_name_node_head_alloc(struct net_device *dev)
+{
+ return netdev_name_node_alloc(dev, dev->name);
+}
+
+static void netdev_name_node_free(struct netdev_name_node *name_node)
+{
+ kfree(name_node);
+}
+
+static void netdev_name_node_add(struct net *net,
+ struct netdev_name_node *name_node)
+{
+ hlist_add_head_rcu(&name_node->hlist,
+ dev_name_hash(net, name_node->name));
+}
+
+static void netdev_name_node_del(struct netdev_name_node *name_node)
+{
+ hlist_del_rcu(&name_node->hlist);
+}
+
+static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
+ const char *name)
+{
+ struct hlist_head *head = dev_name_hash(net, name);
+ struct netdev_name_node *name_node;
+
+ hlist_for_each_entry(name_node, head, hlist)
+ if (!strcmp(name_node->name, name))
+ return name_node;
+ return NULL;
+}
+
+static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
+ const char *name)
+{
+ struct hlist_head *head = dev_name_hash(net, name);
+ struct netdev_name_node *name_node;
+
+ hlist_for_each_entry_rcu(name_node, head, hlist)
+ if (!strcmp(name_node->name, name))
+ return name_node;
+ return NULL;
+}
+
/* Device list insertion */
static void list_netdevice(struct net_device *dev)
{
@@ -238,7 +299,7 @@ static void list_netdevice(struct net_de
write_lock_bh(&dev_base_lock);
list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
- hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
+ netdev_name_node_add(net, dev->name_node);
hlist_add_head_rcu(&dev->index_hlist,
dev_index_hash(net, dev->ifindex));
write_unlock_bh(&dev_base_lock);
@@ -256,7 +317,7 @@ static void unlist_netdevice(struct net_
/* Unlink dev from the device chain */
write_lock_bh(&dev_base_lock);
list_del_rcu(&dev->dev_list);
- hlist_del_rcu(&dev->name_hlist);
+ netdev_name_node_del(dev->name_node);
hlist_del_rcu(&dev->index_hlist);
write_unlock_bh(&dev_base_lock);
@@ -652,14 +713,10 @@ EXPORT_SYMBOL_GPL(dev_fill_metadata_dst)
struct net_device *__dev_get_by_name(struct net *net, const char *name)
{
- struct net_device *dev;
- struct hlist_head *head = dev_name_hash(net, name);
+ struct netdev_name_node *node_name;
- hlist_for_each_entry(dev, head, name_hlist)
- if (!strncmp(dev->name, name, IFNAMSIZ))
- return dev;
-
- return NULL;
+ node_name = netdev_name_node_lookup(net, name);
+ return node_name ? node_name->dev : NULL;
}
EXPORT_SYMBOL(__dev_get_by_name);
@@ -677,14 +734,10 @@ EXPORT_SYMBOL(__dev_get_by_name);
struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
{
- struct net_device *dev;
- struct hlist_head *head = dev_name_hash(net, name);
-
- hlist_for_each_entry_rcu(dev, head, name_hlist)
- if (!strncmp(dev->name, name, IFNAMSIZ))
- return dev;
+ struct netdev_name_node *node_name;
- return NULL;
+ node_name = netdev_name_node_lookup_rcu(net, name);
+ return node_name ? node_name->dev : NULL;
}
EXPORT_SYMBOL(dev_get_by_name_rcu);
@@ -1151,13 +1204,13 @@ rollback:
netdev_adjacent_rename_links(dev, oldname);
write_lock_bh(&dev_base_lock);
- hlist_del_rcu(&dev->name_hlist);
+ netdev_name_node_del(dev->name_node);
write_unlock_bh(&dev_base_lock);
synchronize_rcu();
write_lock_bh(&dev_base_lock);
- hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
+ netdev_name_node_add(net, dev->name_node);
write_unlock_bh(&dev_base_lock);
ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
@@ -8532,6 +8585,8 @@ static void rollback_registered_many(str
dev_uc_flush(dev);
dev_mc_flush(dev);
+ netdev_name_node_free(dev->name_node);
+
if (dev->netdev_ops->ndo_uninit)
dev->netdev_ops->ndo_uninit(dev);
@@ -9011,6 +9066,10 @@ int register_netdevice(struct net_device
if (ret < 0)
goto out;
+ dev->name_node = netdev_name_node_head_alloc(dev);
+ if (!dev->name_node)
+ goto out;
+
/* Init, if this function is available */
if (dev->netdev_ops->ndo_init) {
ret = dev->netdev_ops->ndo_init(dev);
@@ -9132,6 +9191,8 @@ out:
return ret;
err_uninit:
+ if (dev->name_node)
+ netdev_name_node_free(dev->name_node);
if (dev->netdev_ops->ndo_uninit)
dev->netdev_ops->ndo_uninit(dev);
if (dev->priv_destructor)