Re: [PATCH RFC iproute2-next 1/2] rdma: add 'link add/delete' commands

[Jason Gunthorpe <jgg@ziepe.ca>]

On Wed, Nov 28, 2018 at 02:18:55PM -0600, Steve Wise wrote:
> 
> 
> On 11/28/2018 2:13 PM, Leon Romanovsky wrote:
> > On Wed, Nov 28, 2018 at 02:07:29PM -0600, Steve Wise wrote:
> >>
> >> On 11/28/2018 2:04 PM, Leon Romanovsky wrote:
> >>> On Wed, Nov 28, 2018 at 01:08:05PM -0600, Steve Wise wrote:
> >>>> On 11/28/2018 12:26 PM, Leon Romanovsky wrote:
> >>>>> On Thu, Sep 13, 2018 at 10:19:21AM -0700, Steve Wise wrote:
> >>>>>> Add new 'link' subcommand 'add' and 'delete' to allow binding a soft-rdma
> >>>>>> device to a netdev interface.
> >>>>>>
> >>>>>> EG:
> >>>>>>
> >>>>>> rdma link add rxe_eth0 type rxe dev eth0
> >>>>>> rdma link delete rxe_eth0
> >>>>>>
> >>>>>> Signed-off-by: Steve Wise <swise@opengridcomputing.com>
> >>>>>>  rdma/link.c  | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>>>>>  rdma/rdma.h  |   1 +
> >>>>>>  rdma/utils.c |   2 +-
> >>>>>>  3 files changed, 108 insertions(+), 1 deletion(-)
> >>>>>>
> >>>>>> diff --git a/rdma/link.c b/rdma/link.c
> >>>>>> index 7a6d4b7e356d..d4f76b0ce11f 100644
> >>>>>> +++ b/rdma/link.c
> >>>>>> @@ -14,6 +14,8 @@
> >>>>>>  static int link_help(struct rd *rd)
> >>>>>>  {
> >>>>>>  	pr_out("Usage: %s link show [DEV/PORT_INDEX]\n", rd->filename);
> >>>>>> +	pr_out("Usage: %s link add NAME type TYPE dev DEV\n", rd->filename);
> >>>>> I suggest to rename "dev" to be "netdev", because we are using "dev" for
> >>>>> ib devices.
> >>>> Yea ok.
> >>>>
> >>>>>> +	pr_out("Usage: %s link delete NAME type TYPE\n", rd->filename);
> >>>>> Why do you need "type" for "delete" command?
> >>>> Because the type is used in the kernel to find the appropriate link
> >>>> ops.  I could change the kernel side to search all types for the device
> >>>> name to delete? 
> >>> I would say, yes.
> >>> It makes "delete" operation more natural.
> >>>
> >>> Thanks
> >> Perhaps.
> >>
> >> Note: 'ip link delete' takes a type as well...
> > According to man section, yes.
> > According to various guides, no.
> > https://docs.fedoraproject.org/en-US/Fedora/20/html/Networking_Guide/sec-Configure_802_1Q_VLAN_Tagging_ip_Commands.html
> >
> > Thanks
> 
> It does make sense to not require type.  The name must be unique so that
> should be enough.  I'll have to respin the kernel side though...

The delete_link really should be an operation on the ib_device, not
the link_ops thing. 

That directly prevents mis-matching function callbacks..

Jason