Re: [PATCH v7 04/25] RDMA/rtrs: core: lib functions shared between client and server modules

[Jinpu Wang <jinpu.wang@cloud.ionos.com>]

On Sun, Jan 19, 2020 at 3:48 PM Leon Romanovsky <leon@kernel.org> wrote:
>
> On Thu, Jan 16, 2020 at 01:58:54PM +0100, Jack Wang wrote:
> > From: Jack Wang <jinpu.wang@cloud.ionos.com>
> >
> > This is a set of library functions existing as a rtrs-core module,
> > used by client and server modules.
> >
> > Mainly these functions wrap IB and RDMA calls and provide a bit higher
> > abstraction for implementing of RTRS protocol on client or server
> > sides.
> >
> > Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
> > Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
> > ---
> >  drivers/infiniband/ulp/rtrs/rtrs.c | 597 +++++++++++++++++++++++++++++
> >  1 file changed, 597 insertions(+)
> >  create mode 100644 drivers/infiniband/ulp/rtrs/rtrs.c
> >
> > diff --git a/drivers/infiniband/ulp/rtrs/rtrs.c b/drivers/infiniband/ulp/rtrs/rtrs.c
> > new file mode 100644
> > index 000000000000..7b84d76e2a67
> > --- /dev/null
> > +++ b/drivers/infiniband/ulp/rtrs/rtrs.c
> > @@ -0,0 +1,597 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * RDMA Transport Layer
> > + *
> > + * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
> > + *
> > + * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
> > + *
> > + * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
> > + */
> > +#undef pr_fmt
> > +#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
> > +
> > +#include <linux/module.h>
> > +#include <linux/inet.h>
> > +
> > +#include "rtrs-pri.h"
> > +#include "rtrs-log.h"
> > +
> > +MODULE_DESCRIPTION("RDMA Transport Core");
> > +MODULE_LICENSE("GPL");
> > +
> > +struct rtrs_iu *rtrs_iu_alloc(u32 queue_size, size_t size, gfp_t gfp_mask,
> > +                           struct ib_device *dma_dev,
> > +                           enum dma_data_direction dir,
> > +                           void (*done)(struct ib_cq *cq, struct ib_wc *wc))
> > +{
> > +     struct rtrs_iu *ius, *iu;
> > +     int i;
> > +
> > +     WARN_ON(!queue_size);
> > +     ius = kcalloc(queue_size, sizeof(*ius), gfp_mask);
> > +     if (unlikely(!ius))
> > +             return NULL;
>
> Let's do not add useless WARN_ON() and unlikely to every error path.
I can remove the WARN_ON, but the unlikey for error case seems normal to use,
small size memory allocation is unlikely to fail.

> > +int rtrs_iu_post_recv(struct rtrs_con *con, struct rtrs_iu *iu)
> > +{
> > +     struct rtrs_sess *sess = con->sess;
> > +     struct ib_recv_wr wr;
> > +     struct ib_sge list;
> > +
> > +     list.addr   = iu->dma_addr;
> > +     list.length = iu->size;
> > +     list.lkey   = sess->dev->ib_pd->local_dma_lkey;
> > +
> > +     if (WARN_ON(list.length == 0)) {
> > +             rtrs_wrn(con->sess,
> > +                       "Posting receive work request failed, sg list is empty\n");
>
> Both WARN_ON and warning message?
Will remove the WARN_ON.

Thanks Leon.