[PATCH 1/1] ibmvnic: Clear failover_pending if unable to schedule

[PATCH 1/1] ibmvnic: Clear failover_pending if unable to schedule

[Sukadev Bhattiprolu]

Normally we clear the failover_pending flag when processing the reset.
But if we are unable to schedule a failover reset we must clear the
flag ourselves. We could fail to schedule the reset if we are in PROBING
state (eg: when booting via kexec) or because we could not allocate memory.

Thanks to Cris Forno for helping isolate the problem and for testing.

Fixes: 1d8504937478 ("powerpc/vnic: Extend "failover pending" window")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Tested-by: Cristobal Forno <cforno12@linux.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index df1b4884b4e8..58108e1a1d2e 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -4907,7 +4907,23 @@ static void ibmvnic_handle_crq(union ibmvnic_crq *crq,
 				complete(&adapter->init_done);
 				adapter->init_done_rc = -EIO;
 			}
-			ibmvnic_reset(adapter, VNIC_RESET_FAILOVER);
+			rc = ibmvnic_reset(adapter, VNIC_RESET_FAILOVER);
+			if (rc && rc != -EBUSY) {
+				/**
+				 * We were unable to schedule the failover
+				 * reset either because the adapter was still
+				 * probing (eg: during kexec) or we could not
+				 * allocate memory. Clear the failover_pending
+				 * flag since no one else will. We ignore
+				 * EBUSY because it means either FAILOVER reset
+				 * is already scheduled or the adapter is
+				 * being removed.
+				 */
+				netdev_err(netdev,
+					   "Error %ld scheduling failover reset\n",
+					   rc);
+				adapter->failover_pending = false;
+			}
 			break;
 		case IBMVNIC_CRQ_INIT_COMPLETE:
 			dev_info(dev, "Partner initialization complete\n");
-- 
2.26.2

Re: [PATCH 1/1] ibmvnic: Clear failover_pending if unable to schedule

[Jakub Kicinski]

On Tue,  2 Feb 2021 21:08:02 -0800 Sukadev Bhattiprolu wrote:
> Normally we clear the failover_pending flag when processing the reset.
> But if we are unable to schedule a failover reset we must clear the
> flag ourselves. We could fail to schedule the reset if we are in PROBING
> state (eg: when booting via kexec) or because we could not allocate memory.
> 
> Thanks to Cris Forno for helping isolate the problem and for testing.
> 
> Fixes: 1d8504937478 ("powerpc/vnic: Extend "failover pending" window")
> Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
> Tested-by: Cristobal Forno <cforno12@linux.ibm.com>

Applied, thanks.

> diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
> index df1b4884b4e8..58108e1a1d2e 100644
> --- a/drivers/net/ethernet/ibm/ibmvnic.c
> +++ b/drivers/net/ethernet/ibm/ibmvnic.c
> @@ -4907,7 +4907,23 @@ static void ibmvnic_handle_crq(union ibmvnic_crq *crq,
>  				complete(&adapter->init_done);
>  				adapter->init_done_rc = -EIO;
>  			}
> -			ibmvnic_reset(adapter, VNIC_RESET_FAILOVER);
> +			rc = ibmvnic_reset(adapter, VNIC_RESET_FAILOVER);
> +			if (rc && rc != -EBUSY) {
> +				/**

I fixed this comment up for you - /** (double star) is reserved for
kdoc comments, normal comments should start with /*. And in networking
the first line of the multi-line comment is not empty.

> +				 * We were unable to schedule the failover