RE: [PATCH rdma] IB/cache: Restore compatibility for ib_query_gid

[Parav Pandit]

> -----Original Message-----
> From: Jason Gunthorpe
> Sent: Friday, July 27, 2018 10:54 AM
> To: linux-rdma@xxxxxxxxxxxxxxx; Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> Cc: David Miller <davem@xxxxxxxxxxxxx>; Networking
> <netdev@xxxxxxxxxxxxxxx>; Doug Ledford <dledford@xxxxxxxxxx>; Linux-Next
> Mailing List <linux-next@xxxxxxxxxxxxxxx>; Linux Kernel Mailing List <linux-
> kernel@xxxxxxxxxxxxxxx>; Parav Pandit <parav@xxxxxxxxxxxx>; Ursula Braun
> <ubraun@xxxxxxxxxxxxx>; Leon Romanovsky <leonro@xxxxxxxxxxxx>; linux-
> rdma@xxxxxxxxxxxxxxx
> Subject: [PATCH rdma] IB/cache: Restore compatibility for ib_query_gid
> 
> Code changes in smc have become so complicated this cycle that the RDMA
> patches to remove ib_query_gid in smc create too complex merge conflicts.
> Allow those conflicts to be resolved by using the net/smc hunks by providing a
> compatibility wrapper. During the second phase of the merge window this
> wrapper will be deleted and smc updated to use the new API.
> 
> Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
> ---
>  include/rdma/ib_cache.h | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> The resolution Stephen had to make is too complicated, I think we should go this
> way instead. Parav can send a patch to DaveM during the 2nd half of the merge
> window to safely update SMC and delete this wrapper.
> 
Last night Stephen send the changes, if Ursula can test it, its preferred but if that is not possible, 
I am with below approach too.

> Parav, can you check this?
> 
> Ursula, this is only for SMC, are you able to test SMC with it? You will need to
> apply it to the RDMA tree here:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git/log/?h=for-next
> 
> Thanks,
> Jason
> 
> diff --git a/include/rdma/ib_cache.h b/include/rdma/ib_cache.h index
> 1108d422027696..c7e9b42b96e5b8 100644
> --- a/include/rdma/ib_cache.h
> +++ b/include/rdma/ib_cache.h
> @@ -132,4 +132,28 @@ const struct ib_gid_attr *rdma_get_gid_attr(struct
> ib_device *device,
>  					    u8 port_num, int index);
>  void rdma_put_gid_attr(const struct ib_gid_attr *attr);  void
> rdma_hold_gid_attr(const struct ib_gid_attr *attr);
> +
> +/*
> + * This is to be removed. It only exists to make merging rdma and smc simpler.
> + */
> +static inline __deprecated int ib_query_gid(struct ib_device *device,
> +					    u8 port_num, int index,
> +					    union ib_gid *gid,
> +					    struct ib_gid_attr *attr_out)
> +{
> +	const struct ib_gid_attr *attr;
> +
> +	attr = rdma_get_gid_attr(device,port_num,index);
White space after each variable is needed to avoid warnings.

> +	if (IS_ERR(attr))
> +		return PTR_ERR(attr);
> +
> +	if (attr->ndev)
> +		dev_hold(attr->ndev);
> +	*attr_out = *attr;
> +
> +	rdma_put_gid_attr(attr);
> +
> +	return 0;
> +}
> +
>  #endif /* _IB_CACHE_H */

Rest looks fine.
RB: parav@xxxxxxxxxxxx