The TC_SETUP_QDISC_MQPRIO path of ice_setup_tc() takes the auxiliary
device lock to test whether the RDMA driver is bound, and ndo_setup_tc()
runs with the RTNL lock held. This closes the same cycle against the
RDMA auxiliary probe as the two preceding patches.
Use device_trylock() and report the device as busy when it fails. When
the qdisc is added, userspace gets -EBUSY and can retry. When it is
deleted, mqprio_disable_offload() ignores the return value, so the
hardware traffic classes and the channel VSIs stay in place until a
later qdisc teardown gets through, the same as the existing -EBUSY for
a bound RDMA driver. The message is a netdev_warn() because of that
second case, nothing else reports it.
Fixes: 4b31fd4d77ff ("ice: Fix RDMA VSI removal during queue rebuild")
Signed-off-by: Petr Oros <[email protected]>
---
v2:
- rebased on the new patches 1 and 2
- netdev_warn() instead of netdev_dbg(), the qdisc teardown cannot
retry and ignores the return value
v1: https://lore.kernel.org/all/[email protected]/
---
drivers/net/ethernet/intel/ice/ice_main.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c
b/drivers/net/ethernet/intel/ice/ice_main.c
index 9de375f5c4deb5..7eb653a7ebacd5 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -9451,7 +9451,12 @@ ice_setup_tc(struct net_device *netdev, enum
tc_setup_type type,
mutex_lock(&pf->adev_mutex);
adev = cdev->adev;
if (adev) {
- device_lock(&adev->dev);
+ if (!device_trylock(&adev->dev)) {
+ mutex_unlock(&pf->adev_mutex);
+ netdev_warn(netdev, "RDMA auxiliary
device is busy, qdisc not changed\n");
+ err = -EBUSY;
+ goto tc_unlock;
+ }
locked = true;
if (adev->dev.driver) {
netdev_err(netdev, "Cannot change qdisc
when RDMA is active\n");
@@ -9471,6 +9476,7 @@ ice_setup_tc(struct net_device *netdev, enum
tc_setup_type type,
device_unlock(&adev->dev);
mutex_unlock(&pf->adev_mutex);
}
+tc_unlock:
mutex_unlock(&pf->tc_mutex);
return err;
case TC_SETUP_QDISC_ETF:
--
2.56.0
