• Petr Machata's avatar
    mlxsw: spectrum_switchdev: Fix port_vlan refcounting · 9e25826f
    Petr Machata authored
    Switchdev notifications for addition of SWITCHDEV_OBJ_ID_PORT_VLAN are
    distributed not only on clean addition, but also when flags on an
    existing VLAN are changed. mlxsw_sp_bridge_port_vlan_add() calls
    mlxsw_sp_port_vlan_get() to get at the port_vlan in question, which
    implicitly references the object. This then leads to discrepancies in
    reference counting when the VLAN is removed. spectrum.c warns about the
    problem when the module is removed:
    
    [13578.493090] WARNING: CPU: 0 PID: 2454 at drivers/net/ethernet/mellanox/mlxsw/spectrum.c:2973 mlxsw_sp_port_remove+0xfd/0x110 [mlxsw_spectrum]
    [...]
    [13578.627106] Call Trace:
    [13578.629617]  mlxsw_sp_fini+0x2a/0xe0 [mlxsw_spectrum]
    [13578.634748]  mlxsw_core_bus_device_unregister+0x3e/0x130 [mlxsw_core]
    [13578.641290]  mlxsw_pci_remove+0x13/0x40 [mlxsw_pci]
    [13578.646238]  pci_device_remove+0x31/0xb0
    [13578.650244]  device_release_driver_internal+0x14f/0x220
    [13578.655562]  driver_detach+0x32/0x70
    [13578.659183]  bus_remove_driver+0x47/0xa0
    [13578.663134]  pci_unregister_driver+0x1e/0x80
    [13578.667486]  mlxsw_sp_module_exit+0xc/0x3fa [mlxsw_spectrum]
    [13578.673207]  __x64_sys_delete_module+0x13b/0x1e0
    [13578.677888]  ? exit_to_usermode_loop+0x78/0x80
    [13578.682374]  do_syscall_64+0x39/0xe0
    [13578.685976]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
    
    Fix by putting the port_vlan when mlxsw_sp_port_vlan_bridge_join()
    determines it's a flag-only change.
    
    Fixes: b3529af6 ("spectrum: Reference count VLAN entries")
    Signed-off-by: default avatarPetr Machata <[email protected]>
    Acked-by: default avatarJiri Pirko <[email protected]>
    Signed-off-by: default avatarIdo Schimmel <[email protected]>
    Signed-off-by: default avatarDavid S. Miller <[email protected]>
    9e25826f
spectrum_switchdev.c 66.4 KB