On Thu, Jan 21, 2021 at 12:42 PM Dany Madden <d...@linux.ibm.com> wrote: > > On 2021-01-20 22:20, Lijun Pan wrote: > > Returning -EBUSY in ibmvnic_remove() does not actually hold the > > removal procedure since driver core doesn't care for the return > > value (see __device_release_driver() in drivers/base/dd.c > > calling dev->bus->remove()) though vio_bus_remove > > (in arch/powerpc/platforms/pseries/vio.c) records the > > return value and passes it on. [1] > > > > During the device removal precedure, we should not schedule > > any new reset (ibmvnic_reset check for REMOVING and exit), > > and should rely on the flush_work and flush_delayed_work > > to complete the pending resets, specifically we need to > > let __ibmvnic_reset() keep running while in REMOVING state since > > flush_work and flush_delayed_work shall call __ibmvnic_reset finally. > > So we skip the checking for REMOVING in __ibmvnic_reset. > > > > [1] > > https://lore.kernel.org/linuxppc-dev/20210117101242.dpwayq6wdgfdz...@pengutronix.de/T/#m48f5befd96bc9842ece2a3ad14f4c27747206a53 > > Reported-by: Uwe Kleine-König <u.kleine-koe...@pengutronix.de> > > Fixes: 7d7195a026ba ("ibmvnic: Do not process device remove during > > device reset") > > Signed-off-by: Lijun Pan <l...@linux.ibm.com> > > --- > > v1 versus RFC: > > 1/ articulate why remove the REMOVING checking in __ibmvnic_reset > > and why keep the current checking for REMOVING in ibmvnic_reset. > > 2/ The locking issue mentioned by Uwe are being addressed separately > > by https://lists.openwall.net/netdev/2021/01/08/89 > > 3/ This patch does not have merge conflict with 2/ > > > > drivers/net/ethernet/ibm/ibmvnic.c | 8 +------- > > 1 file changed, 1 insertion(+), 7 deletions(-) > > > > diff --git a/drivers/net/ethernet/ibm/ibmvnic.c > > b/drivers/net/ethernet/ibm/ibmvnic.c > > index aed985e08e8a..11f28fd03057 100644 > > --- a/drivers/net/ethernet/ibm/ibmvnic.c > > +++ b/drivers/net/ethernet/ibm/ibmvnic.c > > @@ -2235,8 +2235,7 @@ static void __ibmvnic_reset(struct work_struct > > *work) > > while (rwi) { > > spin_lock_irqsave(&adapter->state_lock, flags); > > > > - if (adapter->state == VNIC_REMOVING || > > - adapter->state == VNIC_REMOVED) { > > + if (adapter->state == VNIC_REMOVED) { > > If we do get here, we would crash because ibmvnic_remove() happened. It > frees the adapter struct already.
Not exactly. viodev is gone; netdev is done; ibmvnic_adapter is still there. Lijun > > > spin_unlock_irqrestore(&adapter->state_lock, flags); > > kfree(rwi); > > rc = EBUSY; > > @@ -5372,11 +5371,6 @@ static int ibmvnic_remove(struct vio_dev *dev) > > unsigned long flags; > > > > spin_lock_irqsave(&adapter->state_lock, flags); > > - if (test_bit(0, &adapter->resetting)) { > > - spin_unlock_irqrestore(&adapter->state_lock, flags); > > - return -EBUSY; > > - } > > - > > adapter->state = VNIC_REMOVING; > > spin_unlock_irqrestore(&adapter->state_lock, flags);