Re: [PATCH v2 2/2] ibmvnic: fix race with multiple open/close

On Wed, 3 Feb 2021 12:56:52 -0800 Sukadev Bhattiprolu wrote:

Willem de Bruijn [willemdebruijn.kernel@gmail.com] wrote:

quoted

On Wed, Feb 3, 2021 at 12:10 AM Sukadev Bhattiprolu
[off-list ref] wrote:  

quoted

If two or more instances of 'ip link set' commands race and first one
already brings the interface up (or down), the subsequent instances
can simply return without redoing the up/down operation.

Fixes: ed651a10875f ("ibmvnic: Updated reset handling")
Reported-by: Abdul Haleem <redacted>
Tested-by: Abdul Haleem <redacted>
Signed-off-by: Sukadev Bhattiprolu <redacted>

---
Changelog[v2] For consistency with ibmvnic_open() use "goto out" and return
              from end of function.  

Did you find the code path that triggers this?  

Not yet. I need to find time on the system to repro/debug that

quoted

In v1 we discussed how the usual ip link path should not call the
driver twice based on IFF_UP.  

Yes, we can hold this patch for now if necessary. Hopefully Patch 1/2 is
ok.

Patch 1 does not apply to net as is. Please rebase and fix up the
comments the way I fixed them for

 "ibmvnic: Clear failover_pending if unable to schedule"

Thanks!