Re: [PATCH net-next] xsk: Return -EINVAL instead of -EBUSY after xsk_get_pool_from_qid() fails

[wanghai (M)]

Sorry, I misunderstood here, this is a faulty patch and no changes are 
needed here. Please ignore this patch

在 2021/6/2 16:29, Magnus Karlsson 写道:
> On Wed, Jun 2, 2021 at 6:02 AM Wang Hai <wanghai38@xxxxxxxxxx> wrote:
> > xsk_get_pool_from_qid() fails not because the device's queues are busy,
> > but because the queue_id exceeds the current number of queues.
> > So when it fails, it is better to return -EINVAL instead of -EBUSY.
> >
> > Signed-off-by: Wang Hai <wanghai38@xxxxxxxxxx>
> > ---
> >   net/xdp/xsk_buff_pool.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
> > index 8de01aaac4a0..30ece117117a 100644
> > --- a/net/xdp/xsk_buff_pool.c
> > +++ b/net/xdp/xsk_buff_pool.c
> > @@ -135,7 +135,7 @@ int xp_assign_dev(struct xsk_buff_pool *pool,
> >                  return -EINVAL;
> >
> >          if (xsk_get_pool_from_qid(netdev, queue_id))
> > -               return -EBUSY;
> > +               return -EINVAL;
> I guess your intent here is to return -EINVAL only when the queue_id
> is larger than the number of active queues.

Yes, I just confirmed that this has been implemented in xp_assign_dev().

int xp_assign_dev()

{

...

    err = xsk_reg_pool_at_qid(netdev, pool, queue_id);

    if (err)

        return err;     //return -EINVAL;

...

}

> But this patch also
> changes the return code when the queue id is already in use and in
> that case we should continue to return -EBUSY. As this function is
> used by a number of drivers, the easiest way to accomplish this is to
> introduce a test for queue_id out of bounds before this if-statement
> and return -EINVAL there.
>
> >          pool->netdev = netdev;
> >          pool->queue_id = queue_id;
> > --
> > 2.17.1
> .