[PATCH net v2] net/smc: Fix lookup of netdev by using ib_device_get_netdev()

[PATCH net v2] net/smc: Fix lookup of netdev by using ib_device_get_netdev()

[Wenjia Zhang]

The SMC-R variant of the SMC protocol used direct call to function
ib_device_ops.get_netdev() to lookup netdev. As we used mlx5 device
driver to run SMC-R, it failed to find a device, because in mlx5_ib the
internal net device management for retrieving net devices was replaced
by a common interface ib_device_get_netdev() in commit 8d159eb2117b
("RDMA/mlx5: Use IB set_netdev and get_netdev functions").

Since such direct accesses to the internal net device management is not
recommended at all, update the SMC-R code to use proper API
ib_device_get_netdev().

Fixes: 54903572c23c ("net/smc: allow pnetid-less configuration")
Reported-by: Aswin K <aswin@linux.ibm.com>
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.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 a04aa0e882f8..716808f374a8 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);
-- 
2.43.0

Re: [PATCH net v2] net/smc: Fix lookup of netdev by using ib_device_get_netdev()

[Leon Romanovsky]

On Wed, Nov 06, 2024 at 09:26:12AM +0100, Wenjia Zhang wrote:
> The SMC-R variant of the SMC protocol used direct call to function
> ib_device_ops.get_netdev() to lookup netdev. As we used mlx5 device
> driver to run SMC-R, it failed to find a device, because in mlx5_ib the
> internal net device management for retrieving net devices was replaced
> by a common interface ib_device_get_netdev() in commit 8d159eb2117b
> ("RDMA/mlx5: Use IB set_netdev and get_netdev functions").
> 
> Since such direct accesses to the internal net device management is not
> recommended at all, update the SMC-R code to use proper API
> ib_device_get_netdev().
> 
> Fixes: 54903572c23c ("net/smc: allow pnetid-less configuration")
> Reported-by: Aswin K <aswin@linux.ibm.com>
> Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
> Reviewed-by: Simon Horman <horms@kernel.org>
> Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
> Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
> Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
> Reviewed-by: D. Wythe <alibuda@linux.alibaba.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(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

Re: [PATCH net v2] net/smc: Fix lookup of netdev by using ib_device_get_netdev()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Wed,  6 Nov 2024 09:26:12 +0100 you wrote:
> The SMC-R variant of the SMC protocol used direct call to function
> ib_device_ops.get_netdev() to lookup netdev. As we used mlx5 device
> driver to run SMC-R, it failed to find a device, because in mlx5_ib the
> internal net device management for retrieving net devices was replaced
> by a common interface ib_device_get_netdev() in commit 8d159eb2117b
> ("RDMA/mlx5: Use IB set_netdev and get_netdev functions").
> 
> [...]

Here is the summary with links:
  - [net,v2] net/smc: Fix lookup of netdev by using ib_device_get_netdev()
    https://git.kernel.org/netdev/net/c/de88df01796b

You are awesome, thank you!
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