In the current code, all team devices have same static lockdep key
and team devices could be nested so that it makes unnecessary
lockdep warning.
Test commands:
ip link add team0 type team
for i in {1..7}
do
let A=$i-1
ip link add team$i type team
ip link set team$i master team$A
done
ip link del team0
Splat looks like:
[ 137.406730] ============================================
[ 137.412685] WARNING: possible recursive locking detected
[ 137.418642] 5.3.0-rc7+ #322 Not tainted
[ 137.422941] --------------------------------------------
[ 137.428886] ip/1383 is trying to acquire lock:
[ 137.433869] 0000000089571080 (&dev_addr_list_lock_key/1){+...}, at:
dev_uc_sync_multiple+0xfa/0x1a0
[ 137.444034]
[ 137.444034] but task is already holding lock:
[ 137.450572] 00000000d9597252 (&dev_addr_list_lock_key/1){+...}, at:
dev_uc_unsync+0x10c/0x1b0
[ 137.460142]
[ 137.460142] other info that might help us debug this:
[ 137.467458] Possible unsafe locking scenario:
[ 137.467458]
[ 137.474096] CPU0
[ 137.476828] ----
[ 137.479569] lock(&dev_addr_list_lock_key/1);
[ 137.484554] lock(&dev_addr_list_lock_key/1);
[ 137.489539]
[ 137.489539] *** DEADLOCK ***
[ 137.489539]
[ 137.496178] May be due to missing lock nesting notation
[ 137.496178]
[ 137.503789] 5 locks held by ip/1383:
[ 137.507797] #0: 00000000d497f415 (rtnl_mutex){+.+.}, at:
rtnetlink_rcv_msg+0x466/0x8a0
[ 137.516786] #1: 000000008e4b4656 (&team->lock){+.+.}, at:
team_uninit+0x3a/0x1a0 [team]
[ 137.525882] #2: 000000005cf248d1 (&dev_addr_list_lock_key){+...}, at:
dev_uc_unsync+0x98/0x1b0
[ 137.535649] #3: 00000000d9597252 (&dev_addr_list_lock_key/1){+...}, at:
dev_uc_unsync+0x10c/0x1b0
[ 137.545709] #4: 00000000bec134c3 (rcu_read_lock){....}, at:
team_set_rx_mode+0x5/0x1d0 [team]
[ 137.555384]
[ 137.555384] stack backtrace:
[ 137.560277] CPU: 0 PID: 1383 Comm: ip Not tainted 5.3.0-rc7+ #322
[ 137.577826] Call Trace:
[ 137.580586] dump_stack+0x7c/0xbb
[ 137.584307] __lock_acquire+0x26a9/0x3de0
[ 137.588820] ? register_lock_class+0x14d0/0x14d0
[ 137.594008] ? register_lock_class+0x14d0/0x14d0
[ 137.599194] lock_acquire+0x164/0x3b0
[ 137.603310] ? dev_uc_sync_multiple+0xfa/0x1a0
[ 137.608307] _raw_spin_lock_nested+0x2e/0x60
[ 137.613105] ? dev_uc_sync_multiple+0xfa/0x1a0
[ 137.618095] dev_uc_sync_multiple+0xfa/0x1a0
[ 137.622900] team_set_rx_mode+0xa9/0x1d0 [team]
[ 137.627993] dev_uc_unsync+0x151/0x1b0
[ 137.632205] team_port_del+0x304/0x790 [team]
[ 137.637110] team_uninit+0xb0/0x1a0 [team]
[ 137.641717] rollback_registered_many+0x728/0xda0
[ 137.647005] ? generic_xdp_install+0x310/0x310
[ 137.651994] ? __set_pages_p+0xf4/0x150
[ 137.656306] ? check_chain_key+0x236/0x5d0
[ 137.660914] ? __nla_validate_parse+0x98/0x1ad0
[ 137.666006] unregister_netdevice_many.part.120+0x13/0x1b0
[ 137.672167] rtnl_delete_link+0xbc/0x100
[ 137.676575] ? rtnl_af_register+0xc0/0xc0
[ 137.681084] rtnl_dellink+0x2e7/0x870
[ 137.685204] ? find_held_lock+0x39/0x1d0
[ ... ]
Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device")
Signed-off-by: Taehee Yoo <ap420...@gmail.com>
---
drivers/net/team/team.c | 61 ++++++++++++++++++++++++++++++++++++++---
include/linux/if_team.h | 5 ++++
2 files changed, 62 insertions(+), 4 deletions(-)
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index e8089def5a46..bfcd6ed57493 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -1607,6 +1607,34 @@ static const struct team_option team_options[] = {
},
};
+static void team_dev_set_lockdep_one(struct net_device *dev,
+ struct netdev_queue *txq,
+ void *_unused)
+{
+ struct team *team = netdev_priv(dev);
+
+ lockdep_set_class(&txq->_xmit_lock, &team->xmit_lock_key);
+}
+
+static struct lock_class_key qdisc_tx_busylock_key;
+static struct lock_class_key qdisc_running_key;
+
+static void team_dev_set_lockdep_class(struct net_device *dev)
+{
+ struct team *team = netdev_priv(dev);
+
+ dev->qdisc_tx_busylock = &qdisc_tx_busylock_key;
+ dev->qdisc_running_key = &qdisc_running_key;
+
+ lockdep_register_key(&team->team_lock_key);
+ __mutex_init(&team->lock, "team->team_lock_key", &team->team_lock_key);
+
+ lockdep_register_key(&team->addr_lock_key);
+ lockdep_set_class(&dev->addr_list_lock, &team->addr_lock_key);
+
+ lockdep_register_key(&team->xmit_lock_key);
+ netdev_for_each_tx_queue(dev, team_dev_set_lockdep_one, NULL);
+}
static int team_init(struct net_device *dev)
{
@@ -1615,7 +1643,6 @@ static int team_init(struct net_device *dev)
int err;
team->dev = dev;
- mutex_init(&team->lock);
team_set_no_mode(team);
team->pcpu_stats = netdev_alloc_pcpu_stats(struct team_pcpu_stats);
@@ -1642,7 +1669,7 @@ static int team_init(struct net_device *dev)
goto err_options_register;
netif_carrier_off(dev);
- netdev_lockdep_set_classes(dev);
+ team_dev_set_lockdep_class(dev);
return 0;
@@ -1673,6 +1700,11 @@ static void team_uninit(struct net_device *dev)
team_queue_override_fini(team);
mutex_unlock(&team->lock);
netdev_change_features(dev);
+
+ lockdep_unregister_key(&team->team_lock_key);
+ lockdep_unregister_key(&team->addr_lock_key);
+ lockdep_unregister_key(&team->xmit_lock_key);
+
}
static void team_destructor(struct net_device *dev)
@@ -1967,6 +1999,23 @@ static int team_add_slave(struct net_device *dev, struct
net_device *port_dev,
return err;
}
+static void team_update_lock_key(struct net_device *dev)
+{
+ struct team *team = netdev_priv(dev);
+
+ lockdep_unregister_key(&team->team_lock_key);
+ lockdep_unregister_key(&team->addr_lock_key);
+ lockdep_unregister_key(&team->xmit_lock_key);
+
+ lockdep_register_key(&team->team_lock_key);
+ lockdep_register_key(&team->addr_lock_key);
+ lockdep_register_key(&team->xmit_lock_key);
+
+ lockdep_set_class(&team->lock, &team->team_lock_key);
+ lockdep_set_class(&dev->addr_list_lock, &team->addr_lock_key);
+ netdev_for_each_tx_queue(dev, team_dev_set_lockdep_one, NULL);
+}
+
static int team_del_slave(struct net_device *dev, struct net_device *port_dev)
{
struct team *team = netdev_priv(dev);
@@ -1976,8 +2025,12 @@ static int team_del_slave(struct net_device *dev, struct
net_device *port_dev)
err = team_port_del(team, port_dev);
mutex_unlock(&team->lock);
- if (!err)
- netdev_change_features(dev);
+ if (err)
+ return err;
+
+ if (netif_is_team_master(port_dev))
+ team_update_lock_key(port_dev);
+ netdev_change_features(dev);
return err;
}
diff --git a/include/linux/if_team.h b/include/linux/if_team.h
index 06faa066496f..9c97bb19ed34 100644
--- a/include/linux/if_team.h
+++ b/include/linux/if_team.h
@@ -223,6 +223,11 @@ struct team {
atomic_t count_pending;
struct delayed_work dw;
} mcast_rejoin;
+
+ struct lock_class_key team_lock_key;
+ struct lock_class_key xmit_lock_key;
+ struct lock_class_key addr_lock_key;
+
long mode_priv[TEAM_MODE_PRIV_LONGS];
};
--
2.17.1
