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Date:   Wed, 21 Jul 2021 10:06:06 +0300
From:   Leon Romanovsky <leon@kernel.org>
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Doug Ledford <dledford@redhat.com>,
        Jason Gunthorpe <jgg@nvidia.com>, linux-kernel@vger.kernel.org,
        linux-rdma@vger.kernel.org, Mark Zhang <markz@mellanox.com>
Subject: Re: [PATCH rdma-next 7/7] RDMA/core: Create clean QP creations
 interface for uverbs
Message-ID: <YPfHXpFtB1RJ4yjU@unreal>
References: <cover.1626846795.git.leonro@nvidia.com>
 <8eaf125d3bfb463e1641b6f2794203cc93d76c90.1626846795.git.leonro@nvidia.com>
 <YPfDUN6CaOdGZLPS@infradead.org>
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On Wed, Jul 21, 2021 at 07:48:48AM +0100, Christoph Hellwig wrote:
> > +struct ib_qp *ib_create_qp_user(struct ib_device *dev, struct ib_pd *pd,
> > +				struct ib_qp_init_attr *attr,
> > +				struct ib_udata *udata,
> > +				struct ib_uqp_object *uobj, const char *caller);
> > +static inline struct ib_qp *ib_create_qp_uverbs(struct ib_device *dev,
> > +						struct ib_pd *pd,
> > +						struct ib_qp_init_attr *attr,
> > +						struct ib_udata *udata,
> > +						struct ib_uqp_object *uobj)
> > +{
> > +	if (attr->qp_type == IB_QPT_XRC_TGT)
> > +		return ib_create_qp_user(dev, pd, attr, NULL, uobj,
> > +					 KBUILD_MODNAME);
> > +
> > +	return ib_create_qp_user(dev, pd, attr, udata, uobj, NULL);
> 
> Why not always pass along the udata and caller and just not use them
> in the low-level code?

You will need to add some sort of "if qp tpye" for ib_create_qp_uverbs() callers,
because they always provide udata != NULL. 

After this series, the callers look like this:

 1438         qp = ib_create_qp_uverbs(device, pd, &attr, &attrs->driver_udata, obj);
                                                          ^^^^^^^^^ not NULL

So instead of bothering callers, I implemented it here with one "if".

Thanks