This is a note to let you know that I've just added the patch titled
ibmvnic: Properly dispose of all skbs during a failover.
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ibmvnic-properly-dispose-of-all-skbs-during-a-failov.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 65c56af6bcc95373b50345db2601be158054e6ef
Author: Rick Lindsley <ricklind@xxxxxxxxxx>
Date: Sat Jul 2 03:37:12 2022 -0700
ibmvnic: Properly dispose of all skbs during a failover.
[ Upstream commit 1b18f09d31cfa7148df15a7d5c5e0e86f105f7d1 ]
During a reset, there may have been transmits in flight that are no
longer valid and cannot be fulfilled. Resetting and clearing the
queues is insufficient; each skb also needs to be explicitly freed
so that upper levels are not left waiting for confirmation of a
transmit that will never happen. If this happens frequently enough,
the apparent backlog will cause TCP to begin "congestion control"
unnecessarily, culminating in permanently decreased throughput.
Fixes: d7c0ef36bde03 ("ibmvnic: Free and re-allocate scrqs when tx/rx scrqs change")
Tested-by: Nick Child <nnac123@xxxxxxxxxxxxx>
Reviewed-by: Brian King <brking@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Rick Lindsley <ricklind@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 5c5931dba51d..c4221f89ab18 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -5774,6 +5774,15 @@ static int ibmvnic_reset_init(struct ibmvnic_adapter *adapter, bool reset)
release_sub_crqs(adapter, 0);
rc = init_sub_crqs(adapter);
} else {
+ /* no need to reinitialize completely, but we do
+ * need to clean up transmits that were in flight
+ * when we processed the reset. Failure to do so
+ * will confound the upper layer, usually TCP, by
+ * creating the illusion of transmits that are
+ * awaiting completion.
+ */
+ clean_tx_pools(adapter);
+
rc = reset_sub_crq_queues(adapter);
}
} else {
