[RFC PATCH net-next 07/20] net: switchdev: don't assume RCU context in switchdev_handle_fdb_{add,del}_to_device
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STALE1895d
SUPERSEDED
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: 2021-08-18 12:03:25
Subsystem:
networking [dsa], networking [general], switchdev, the rest · Maintainers:
Andrew Lunn, Vladimir Oltean, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jiri Pirko, Ivan Vecera, Linus Torvalds
Status: Superseded by v2 (posted 2022-02-25). [go to v2]
Revision rfc (2 revisions archived).
Revisions (2)
- rfc current
- v2 [diff against previous]
Now that the SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE events are blocking, it
would be nice if callers of the fan-out helper functions (i.e. DSA)
could benefit from that blocking context.
But at the moment, switchdev_handle_fdb_{add,del}_to_device use some
netdev adjacency list checking functions that assume RCU protection.
Switch over to their rtnl_mutex equivalents, since we are also running
with that taken, and drop the surrounding rcu_read_lock from the callers.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
net/dsa/slave.c | 4 ----
net/switchdev/switchdev.c | 10 +++++++---
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 249303ac3c3c..b6a94861cddd 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c@@ -2484,22 +2484,18 @@ static int dsa_slave_switchdev_blocking_event(struct notifier_block *unused, dsa_slave_port_attr_set); return notifier_from_errno(err); case SWITCHDEV_FDB_ADD_TO_DEVICE: - rcu_read_lock(); err = switchdev_handle_fdb_add_to_device(dev, ptr, dsa_slave_dev_check, dsa_foreign_dev_check, dsa_slave_fdb_add_to_device, NULL); - rcu_read_unlock(); return notifier_from_errno(err); case SWITCHDEV_FDB_DEL_TO_DEVICE: - rcu_read_lock(); err = switchdev_handle_fdb_del_to_device(dev, ptr, dsa_slave_dev_check, dsa_foreign_dev_check, dsa_slave_fdb_del_to_device, NULL); - rcu_read_unlock(); return notifier_from_errno(err); }
diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
index d09e8e9df5b6..fdbb73439f37 100644
--- a/net/switchdev/switchdev.c
+++ b/net/switchdev/switchdev.c@@ -470,7 +470,7 @@ switchdev_lower_dev_find(struct net_device *dev, .data = &switchdev_priv, }; - netdev_walk_all_lower_dev_rcu(dev, switchdev_lower_dev_walk, &priv); + netdev_walk_all_lower_dev(dev, switchdev_lower_dev_walk, &priv); return switchdev_priv.lower_dev; }
@@ -543,7 +543,7 @@ static int __switchdev_handle_fdb_add_to_device(struct net_device *dev, /* Event is neither on a bridge nor a LAG. Check whether it is on an * interface that is in a bridge with us. */ - br = netdev_master_upper_dev_get_rcu(dev); + br = netdev_master_upper_dev_get(dev); if (!br || !netif_is_bridge_master(br)) return 0;
@@ -569,6 +569,8 @@ int switchdev_handle_fdb_add_to_device(struct net_device *dev, { int err; + ASSERT_RTNL(); + err = __switchdev_handle_fdb_add_to_device(dev, dev, fdb_info, check_cb, foreign_dev_check_cb,
@@ -648,7 +650,7 @@ static int __switchdev_handle_fdb_del_to_device(struct net_device *dev, /* Event is neither on a bridge nor a LAG. Check whether it is on an * interface that is in a bridge with us. */ - br = netdev_master_upper_dev_get_rcu(dev); + br = netdev_master_upper_dev_get(dev); if (!br || !netif_is_bridge_master(br)) return 0;
@@ -674,6 +676,8 @@ int switchdev_handle_fdb_del_to_device(struct net_device *dev, { int err; + ASSERT_RTNL(); + err = __switchdev_handle_fdb_del_to_device(dev, dev, fdb_info, check_cb, foreign_dev_check_cb,
--
2.25.1