f0947d0d21
Function __team_compute_features() is protected by team->lock
mutex when it is called from team_compute_features() used when
features of an underlying device is changed. This causes
a deadlock when NETDEV_FEAT_CHANGE notifier for underlying device
is fired due to change propagated from team driver (e.g. MTU
change). It's because callbacks like team_change_mtu() or
team_vlan_rx_{add,del}_vid() protect their port list traversal
by team->lock mutex.
Example (r8169 case where this driver disables TSO for certain MTU
values):
...
[ 6391.348202] __mutex_lock.isra.6+0x2d0/0x4a0
[ 6391.358602] team_device_event+0x9d/0x160 [team]
[ 6391.363756] notifier_call_chain+0x47/0x70
[ 6391.368329] netdev_update_features+0x56/0x60
[ 6391.373207] rtl8169_change_mtu+0x14/0x50 [r8169]
[ 6391.378457] dev_set_mtu_ext+0xe1/0x1d0
[ 6391.387022] dev_set_mtu+0x52/0x90
[ 6391.390820] team_change_mtu+0x64/0xf0 [team]
[ 6391.395683] dev_set_mtu_ext+0xe1/0x1d0
[ 6391.399963] do_setlink+0x231/0xf50
...
In fact team_compute_features() called from team_device_event()
does not need to be protected by team->lock mutex and rcu_read_lock()
is sufficient there for port list traversal.
Fixes:
|
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| team.c | ||
| team_mode_activebackup.c | ||
| team_mode_broadcast.c | ||
| team_mode_loadbalance.c | ||
| team_mode_random.c | ||
| team_mode_roundrobin.c | ||