On 11/30/2018 2:18 PM, Jason Gunthorpe wrote: > On Fri, Nov 30, 2018 at 02:18:00PM -0600, Steve Wise wrote: >> >> On 11/30/2018 2:12 PM, Jason Gunthorpe wrote: >>> On Fri, Nov 30, 2018 at 02:07:52PM -0600, Steve Wise wrote: >>> >>>> So perhaps nldev_dellink() should just lookup the ib_device by index >>>> using ib_device_get_by_index(), note the device name (copy it >>>> locally) >>> That just creates races with rename. >>> >>> The API to the driver should be pointer based and has to hold only the >>> kref not the refcnt >>> >>> Jason >> What kref? I don't see any kref in struct ib_device. /me confused... > It is inside the embedded struct device > > Jason How's this look? + device = ib_device_get_by_index(index); + if (!device) + return -EINVAL; + + ops = device->link_ops; + + /* + * Deref the ib_device before deleting it. Otherwise we + * deadlock unregistering the device. Hold a ref on the + * underlying dma_device though to keep the memory around + * until we're done. + */ + dma_device = get_device(device->dma_device); + ib_device_put(device); + err = ops ? ops->dellink(device) : -ENODEV; + put_device(dma_device); + + return err;
