[RFC PATCH net-next 05/20] net: bridge: switchdev: make br_fdb_replay offer sleepable context to consumers
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: 2021-08-18 12:05:32
Subsystem:
ethernet bridge, networking [general], the rest · Maintainers:
Nikolay Aleksandrov, Ido Schimmel, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Now that the SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE events are notified on
the blocking chain, it would be nice if we could also drop the
rcu_read_lock() atomic context from br_fdb_replay() so that drivers can
actually benefit from the blocking context and simplify their logic.
Do something similar to what is done in br_mdb_queue_one/br_mdb_replay_one,
except the fact that FDB entries are held in a hash list.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
net/bridge/br_fdb.c | 38 ++++++++++++++++++++++++++++++++++----
1 file changed, 34 insertions(+), 4 deletions(-)
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 0bdbcfc53914..36f4e3b8d21b 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c@@ -752,12 +752,28 @@ static int br_fdb_replay_one(struct net_bridge *br, struct notifier_block *nb, return notifier_to_errno(err); } +static int br_fdb_queue_one(struct hlist_head *fdb_list, + const struct net_bridge_fdb_entry *fdb) +{ + struct net_bridge_fdb_entry *fdb_new; + + fdb_new = kmemdup(fdb, sizeof(*fdb), GFP_ATOMIC); + if (!fdb_new) + return -ENOMEM; + + hlist_add_head_rcu(&fdb_new->fdb_node, fdb_list); + + return 0; +} + int br_fdb_replay(const struct net_device *br_dev, const void *ctx, bool adding, struct notifier_block *nb) { struct net_bridge_fdb_entry *fdb; + struct hlist_node *tmp; struct net_bridge *br; unsigned long action; + HLIST_HEAD(fdb_list); int err = 0; if (!nb)
@@ -770,20 +786,34 @@ int br_fdb_replay(const struct net_device *br_dev, const void *ctx, bool adding, br = netdev_priv(br_dev); + rcu_read_lock(); + + hlist_for_each_entry_rcu(fdb, &br->fdb_list, fdb_node) { + err = br_fdb_queue_one(&fdb_list, fdb); + if (err) { + rcu_read_unlock(); + goto out_free_fdb; + } + } + + rcu_read_unlock(); + if (adding) action = SWITCHDEV_FDB_ADD_TO_DEVICE; else action = SWITCHDEV_FDB_DEL_TO_DEVICE; - rcu_read_lock(); - - hlist_for_each_entry_rcu(fdb, &br->fdb_list, fdb_node) { + hlist_for_each_entry(fdb, &fdb_list, fdb_node) { err = br_fdb_replay_one(br, nb, fdb, action, ctx); if (err) break; } - rcu_read_unlock(); +out_free_fdb: + hlist_for_each_entry_safe(fdb, tmp, &fdb_list, fdb_node) { + hlist_del_rcu(&fdb->fdb_node); + kfree(fdb); + } return err; }
--
2.25.1