6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nick Child nnac123@linux.ibm.com
[ Upstream commit 5cb431dcf8048572e9ffc6c30cdbd8832cbe502d ]
In ibmvnic_xmit() if ibmvnic_tx_scrq_flush() returns H_CLOSED then it will inform upper level networking functions to disable tx queues. H_CLOSED signals that the connection with the vnic server is down and a transport event is expected to recover the device.
Previously, ibmvnic_tx_scrq_flush() was hard-coded to return success. Therefore, the queues would remain active until ibmvnic_cleanup() is called within do_reset().
The problem is that do_reset() depends on the RTNL lock. If several ibmvnic devices are resetting then there can be a long wait time until the last device can grab the lock. During this time the tx/rx queues still appear active to upper level functions.
FYI, we do make a call to netif_carrier_off() outside the RTNL lock but its calls to dev_deactivate() are also dependent on the RTNL lock.
As a result, large amounts of retransmissions were observed in a short period of time, eventually leading to ETIMEOUT. This was specifically seen with HNV devices, likely because of even more RTNL dependencies.
Therefore, ensure the return code of ibmvnic_tx_scrq_flush() is propagated to the xmit function to allow for an earlier (and lock-less) response to a transport event.
Signed-off-by: Nick Child nnac123@linux.ibm.com Link: https://lore.kernel.org/r/20240416164128.387920-1-nnac123@linux.ibm.com Signed-off-by: Paolo Abeni pabeni@redhat.com Stable-dep-of: bdf5d13aa05e ("ibmvnic: Don't reference skb after sending to VIOS") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/ibm/ibmvnic.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 6d17738c1c536..7fe1fefef9934 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -2181,7 +2181,7 @@ static int ibmvnic_tx_scrq_flush(struct ibmvnic_adapter *adapter, ibmvnic_tx_scrq_clean_buffer(adapter, tx_scrq); else ind_bufp->index = 0; - return 0; + return rc; }
static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) @@ -2234,7 +2234,9 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) tx_dropped++; tx_send_failed++; ret = NETDEV_TX_OK; - ibmvnic_tx_scrq_flush(adapter, tx_scrq); + lpar_rc = ibmvnic_tx_scrq_flush(adapter, tx_scrq); + if (lpar_rc != H_SUCCESS) + goto tx_err; goto out; }
@@ -2249,8 +2251,10 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) dev_kfree_skb_any(skb); tx_send_failed++; tx_dropped++; - ibmvnic_tx_scrq_flush(adapter, tx_scrq); ret = NETDEV_TX_OK; + lpar_rc = ibmvnic_tx_scrq_flush(adapter, tx_scrq); + if (lpar_rc != H_SUCCESS) + goto tx_err; goto out; }