From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Lijun Pan <ljp@linux.ibm.com>
Cc: netdev@vger.kernel.org, gregkh@linuxfoundation.org,
julietk@linux.vnet.ibm.com, mpe@ellerman.id.au, paulus@samba.org,
kernel@pengutronix.de, benh@kernel.crashing.org,
drt@linux.ibm.com, kuba@kernel.org, sukadev@linux.ibm.com,
linuxppc-dev@lists.ozlabs.org, davem@davemloft.net
Subject: Re: [PATCH net RFC] ibmvnic: device remove has higher precedence over reset
Date: Tue, 19 Jan 2021 20:49:59 +0100 [thread overview]
Message-ID: <20210119194959.a67nlfbngx4drvyz@pengutronix.de> (raw)
In-Reply-To: <20210119193313.43791-1-ljp@linux.ibm.com>
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On Tue, Jan 19, 2021 at 01:33:13PM -0600, 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, 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 <u.kleine-koenig@pengutronix.de>
> Fixes: 7d7195a026ba ("ibmvnic: Do not process device remove during device reset")
> Signed-off-by: Lijun Pan <ljp@linux.ibm.com>
> ---
> 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) {
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?
> 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);
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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next prev parent reply other threads:[~2021-01-19 19:55 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-19 19:33 [PATCH net RFC] ibmvnic: device remove has higher precedence over reset Lijun Pan
2021-01-19 19:49 ` Uwe Kleine-König [this message]
2021-01-19 20:08 ` Lijun Pan
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