Re: [PATCH net] net/smc: Fix lookup of netdev by using ib_device_get_netdev()

[Zhu Yanjun <yanjun.zhu@linux.dev>]

在 2024/10/25 9:23, Wenjia Zhang 写道:
> Commit c2261dd76b54 ("RDMA/device: Add ib_device_set_netdev() as an
> alternative to get_netdev") introduced an API ib_device_get_netdev.
> The SMC-R variant of the SMC protocol continued to use the old API
> ib_device_ops.get_netdev() to lookup netdev. As this commit 8d159eb2117b
> ("RDMA/mlx5: Use IB set_netdev and get_netdev functions") removed the
> get_netdev callback from mlx5_ib_dev_common_roce_ops, calling

Thanks a lot.

Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>

Because the commit 8d159eb2117b ("RDMA/mlx5: Use IB set_netdev and 
get_netdev functions") removes the get_netdev callback from 
mlx5_ib_dev_common_roce_ops, in mlx4, get_netdev is still in 
mlx4_ib_dev_ops. So the following commit will follow mlx5 to remove 
get_netdev from mlx4 driver.

 From a59f2e01428640a332a51b8d910ec166704aa441 Mon Sep 17 00:00:00 2001
From: Zhu Yanjun <yanjun.zhu@linux.dev>
Date: Sun, 27 Oct 2024 20:21:27 +0100
Subject: [PATCH 1/1] RDMA/mlx4: Use IB get_netdev functions and remove
  get_netdev callback

In the commit 8d159eb2117b ("RDMA/mlx5: Use IB set_netdev and get_netdev
functions") removed the get_netdev callback from
mlx5_ib_dev_common_roce_ops, in mlx4, get_netdev callback should also
be removed.

Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
---
compile successfully only
---
  drivers/infiniband/hw/mlx4/main.c | 35 -------------------------------
  1 file changed, 35 deletions(-)

diff --git a/drivers/infiniband/hw/mlx4/main.c 
b/drivers/infiniband/hw/mlx4/main.c
index 529db874d67c..cf34d92de7b1 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -123,40 +123,6 @@ static int num_ib_ports(struct mlx4_dev *dev)
         return ib_ports;
  }

-static struct net_device *mlx4_ib_get_netdev(struct ib_device *device,
-                                            u32 port_num)
-{
-       struct mlx4_ib_dev *ibdev = to_mdev(device);
-       struct net_device *dev, *ret = NULL;
-
-       rcu_read_lock();
-       for_each_netdev_rcu(&init_net, dev) {
-               if (dev->dev.parent != ibdev->ib_dev.dev.parent ||
-                   dev->dev_port + 1 != port_num)
-                       continue;
-
-               if (mlx4_is_bonded(ibdev->dev)) {
-                       struct net_device *upper;
-
-                       upper = netdev_master_upper_dev_get_rcu(dev);
-                       if (upper) {
-                               struct net_device *active;
-
-                               active = 
bond_option_active_slave_get_rcu(netdev_priv(upper));
-                               if (active)
-                                       dev = active;
-                       }
-               }
-
-               dev_hold(dev);
-               ret = dev;
-               break;
-       }
-
-       rcu_read_unlock();
-       return ret;
-}
-
  static int mlx4_ib_update_gids_v1(struct gid_entry *gids,
                                   struct mlx4_ib_dev *ibdev,
                                   u32 port_num)
@@ -2544,7 +2510,6 @@ static const struct ib_device_ops mlx4_ib_dev_ops = {
         .get_dev_fw_str = get_fw_ver_str,
         .get_dma_mr = mlx4_ib_get_dma_mr,
         .get_link_layer = mlx4_ib_port_link_layer,
-       .get_netdev = mlx4_ib_get_netdev,
         .get_port_immutable = mlx4_port_immutable,
         .map_mr_sg = mlx4_ib_map_mr_sg,
         .mmap = mlx4_ib_mmap,
--
2.34.1

Zhu Yanjun

> ib_device_ops.get_netdev didn't work any more at least by using a mlx5
> device driver. Thus, using ib_device_set_netdev() now became mandatory.
> 
> Replace ib_device_ops.get_netdev() with ib_device_get_netdev().
> 
> Fixes: 54903572c23c ("net/smc: allow pnetid-less configuration")
> Fixes: 8d159eb2117b ("RDMA/mlx5: Use IB set_netdev and get_netdev functions")
> Reported-by: Aswin K <aswin@linux.ibm.com>
> Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
> Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
> ---
>   net/smc/smc_ib.c   | 8 ++------
>   net/smc/smc_pnet.c | 4 +---
>   2 files changed, 3 insertions(+), 9 deletions(-)
> 
> diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
> index 9297dc20bfe2..9c563cdbea90 100644
> --- a/net/smc/smc_ib.c
> +++ b/net/smc/smc_ib.c
> @@ -899,9 +899,7 @@ static void smc_copy_netdev_ifindex(struct smc_ib_device *smcibdev, int port)
>   	struct ib_device *ibdev = smcibdev->ibdev;
>   	struct net_device *ndev;
>   
> -	if (!ibdev->ops.get_netdev)
> -		return;
> -	ndev = ibdev->ops.get_netdev(ibdev, port + 1);
> +	ndev = ib_device_get_netdev(ibdev, port + 1);
>   	if (ndev) {
>   		smcibdev->ndev_ifidx[port] = ndev->ifindex;
>   		dev_put(ndev);
> @@ -921,9 +919,7 @@ void smc_ib_ndev_change(struct net_device *ndev, unsigned long event)
>   		port_cnt = smcibdev->ibdev->phys_port_cnt;
>   		for (i = 0; i < min_t(size_t, port_cnt, SMC_MAX_PORTS); i++) {
>   			libdev = smcibdev->ibdev;
> -			if (!libdev->ops.get_netdev)
> -				continue;
> -			lndev = libdev->ops.get_netdev(libdev, i + 1);
> +			lndev = ib_device_get_netdev(libdev, i + 1);
>   			dev_put(lndev);
>   			if (lndev != ndev)
>   				continue;
> diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
> index 1dd362326c0a..8566937c8903 100644
> --- a/net/smc/smc_pnet.c
> +++ b/net/smc/smc_pnet.c
> @@ -1054,9 +1054,7 @@ static void smc_pnet_find_rdma_dev(struct net_device *netdev,
>   		for (i = 1; i <= SMC_MAX_PORTS; i++) {
>   			if (!rdma_is_port_valid(ibdev->ibdev, i))
>   				continue;
> -			if (!ibdev->ibdev->ops.get_netdev)
> -				continue;
> -			ndev = ibdev->ibdev->ops.get_netdev(ibdev->ibdev, i);
> +			ndev = ib_device_get_netdev(ibdev->ibdev, i);
>   			if (!ndev)
>   				continue;
>   			dev_put(ndev);