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:
[ 32.862645] WARNING: possible recursive locking detected
[ 32.863304] 5.3.0+ #3 Not tainted
[ 32.863700] --------------------------------------------
[ 32.864358] ip/647 is trying to acquire lock:
[ 32.864968] ffff8880666a6ad8 (&dev_addr_list_lock_key/1){+...}, at: dev_uc_sync_multiple+0xfa/0x1a0
[ 32.866047]
[ 32.866047] but task is already holding lock:
[ 32.866744] ffff888067402558 (&dev_addr_list_lock_key/1){+...}, at: dev_uc_unsync+0x10c/0x1b0
[ 32.867774]
[ 32.867774] other info that might help us debug this:
[ 32.868513] Possible unsafe locking scenario:
[ 32.868513]
[ 32.869180] CPU0
[ 32.872973] ----
[ 32.876717] lock(&dev_addr_list_lock_key/1);
[ 32.877130] lock(&dev_addr_list_lock_key/1);
[ 32.877621]
[ 32.877621] *** DEADLOCK ***
[ 32.877621]
[ 32.878284] May be due to missing lock nesting notation
[ 32.878284]
[ 32.878999] 5 locks held by ip/647:
[ 32.879382] #0: ffffffff8fec7a30 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0
[ 32.880110] #1: ffff888068d5e300 (&team->lock){+.+.}, at: team_uninit+0x3a/0x1a0 [team]
[ 32.880889] #2: ffff888068d5d978 (&dev_addr_list_lock_key){+...}, at: dev_uc_unsync+0x98/0x1b0
[ 32.881660] #3: ffff888067402558 (&dev_addr_list_lock_key/1){+...}, at: dev_uc_unsync+0x10c/0x1b0
[ 32.882451] #4: ffffffff8fb22780 (rcu_read_lock){....}, at: team_set_rx_mode+0x5/0x1d0 [team]
[ 32.883209]
[ 32.883209] stack backtrace:
[ 32.883605] CPU: 0 PID: 647 Comm: ip Not tainted 5.3.0+ #3
[ 32.884144] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 32.884926] Call Trace:
[ 32.885151] dump_stack+0x7c/0xbb
[ 32.885460] __lock_acquire+0x26a9/0x3df0
[ 32.885964] ? register_lock_class+0x14d0/0x14d0
[ 32.886522] ? register_lock_class+0x14d0/0x14d0
[ 32.887114] lock_acquire+0x164/0x3b0
[ 32.887578] ? dev_uc_sync_multiple+0xfa/0x1a0
[ 32.888130] _raw_spin_lock_nested+0x2e/0x60
[ 32.888725] ? dev_uc_sync_multiple+0xfa/0x1a0
[ 32.889264] dev_uc_sync_multiple+0xfa/0x1a0
[ 32.889779] team_set_rx_mode+0xa9/0x1d0 [team]
[ 32.892841] dev_uc_unsync+0x151/0x1b0
[ ... ]
Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device")
Signed-off-by: Taehee Yoo <ap420073@xxxxxxxxx>
---
v1 -> v4 :
- This patch is not changed
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
