From: Lijun Pan <hidden> Date: 2021-01-19 19:36:34
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, and rely on the flush_work and flush_delayed_work
to complete the pending resets, and 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.
[1] https://lore.kernel.org/linuxppc-dev/20210117101242.dpwayq6wdgfdzirl@pengutronix.de/T/#m48f5befd96bc9842ece2a3ad14f4c27747206a53
Reported-by: Uwe Kleine-König <redacted>
Fixes: 7d7195a026ba ("ibmvnic: Do not process device remove during device reset")
Signed-off-by: Lijun Pan <redacted>
---
drivers/net/ethernet/ibm/ibmvnic.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
On Tue, Jan 19, 2021 at 01:33:13PM -0600, Lijun Pan wrote:
quoted hunk
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, and rely on the flush_work and flush_delayed_work
to complete the pending resets, and 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.
[1] https://lore.kernel.org/linuxppc-dev/20210117101242.dpwayq6wdgfdzirl@pengutronix.de/T/#m48f5befd96bc9842ece2a3ad14f4c27747206a53
Reported-by: Uwe Kleine-König <redacted>
Fixes: 7d7195a026ba ("ibmvnic: Do not process device remove during device reset")
Signed-off-by: Lijun Pan <redacted>
---
drivers/net/ethernet/ibm/ibmvnic.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
I think you need to keep the check for VNIC_REMOVING. Otherwise you
don't prevent that a new reset being queued after ibmvnic_remove() set
the state to VNIC_REMOVING. Am I missing something?
From: Lijun Pan <hidden> Date: 2021-01-19 20:10:16
On Tue, Jan 19, 2021 at 1:56 PM Uwe Kleine-König
[off-list ref] wrote:
On Tue, Jan 19, 2021 at 01:33:13PM -0600, Lijun Pan wrote:
quoted
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, and rely on the flush_work and flush_delayed_work
to complete the pending resets, and 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.
[1] https://lore.kernel.org/linuxppc-dev/20210117101242.dpwayq6wdgfdzirl@pengutronix.de/T/#m48f5befd96bc9842ece2a3ad14f4c27747206a53
Reported-by: Uwe Kleine-König <redacted>
Fixes: 7d7195a026ba ("ibmvnic: Do not process device remove during device reset")
Signed-off-by: Lijun Pan <redacted>
---
drivers/net/ethernet/ibm/ibmvnic.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
I think you need to keep the check for VNIC_REMOVING. Otherwise you
don't prevent that a new reset being queued after ibmvnic_remove() set
the state to VNIC_REMOVING. Am I missing something?
I leave the checking for REMOVING there in ibmvnic_reset, which is the
function to schedule/queue up the resets.
Here I delete the REMOVING in __ibmvnic_reset to let it run and finish.
Otherwise flush_work will not do anything if __ibmvnic_reset() just return
doing nothing.
I can explain it in the commit message.