Re: [PATCH v6 03/25] rtrs: private headers with rtrs protocol structs and helpers

From: Jinpu Wang <jinpu.wang@cloud.ionos.com>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Bart Van Assche <bvanassche@acm.org>,
	Jack Wang <jinpuwang@gmail.com>,
	linux-block@vger.kernel.org, linux-rdma@vger.kernel.org,
	Jens Axboe <axboe@kernel.dk>,
	Christoph Hellwig <hch@infradead.org>,
	Sagi Grimberg <sagi@grimberg.me>,
	Leon Romanovsky <leon@kernel.org>,
	Doug Ledford <dledford@redhat.com>,
	Danil Kipnis <danil.kipnis@cloud.ionos.com>,
	rpenyaev@suse.de
Subject: Re: [PATCH v6 03/25] rtrs: private headers with rtrs protocol structs and helpers
Date: Fri, 3 Jan 2020 13:31:08 +0100	[thread overview]
Message-ID: <CAMGffEmwcVU7OTKGbGWiuDV2wmZy6jZyffFyGC9cT=yVF3ky_Q@mail.gmail.com> (raw)
In-Reply-To: <20200102182653.GE9282@ziepe.ca>

On Thu, Jan 2, 2020 at 7:26 PM Jason Gunthorpe <jgg@ziepe.ca> wrote:
>
> On Thu, Jan 02, 2020 at 09:00:53AM -0800, Bart Van Assche wrote:
>
> > > > > +/**
> > > > > + * struct rtrs_msg_conn_req - Client connection request to the server
> > > > > + * @magic:      RTRS magic
> > > > > + * @version:    RTRS protocol version
> > > > > + * @cid:        Current connection id
> > > > > + * @cid_num:    Number of connections per session
> > > > > + * @recon_cnt:          Reconnections counter
> > > > > + * @sess_uuid:          UUID of a session (path)
> > > > > + * @paths_uuid:         UUID of a group of sessions (paths)
> > > > > + *
> > > > > + * NOTE: max size 56 bytes, see man rdma_connect().
> > > > > + */
> > > > > +struct rtrs_msg_conn_req {
> > > > > +     u8              __cma_version; /* Is set to 0 by cma.c in case of
> > > > > +                                     * AF_IB, do not touch that.
> > > > > +                                     */
> > > > > +     u8              __ip_version;  /* On sender side that should be
> > > > > +                                     * set to 0, or cma_save_ip_info()
> > > > > +                                     * extract garbage and will fail.
> > > > > +                                     */
> > > >
> > > > The above two fields and the comments next to it look suspicious to me.
> > > > Does RTRS perhaps try to generate CMA-formatted messages without using
> > > > the CMA to format these messages?
> > > The problem is in cma_format_hdr over-writes the first byte for AF_IB
> > > https://www.spinics.net/lists/linux-rdma/msg22397.html
> > >
> > > No one fixes the problem since then.
> >
> > How about adding that URL to the comment block above struct
> > rtrs_msg_conn_req?
>
> Or just fixing whatever the problem is..
>
> Jason
I can do another try if no one else fix the problem, but I have plenty of to-do.

Thanks