[PATCH v2] net/mlx4_core: Fix error handling in mlx4_init_port_info.

[PATCH v2] net/mlx4_core: Fix error handling in mlx4_init_port_info.

[Tarick Bedeir]

Avoid exiting the function with a lingering sysfs file (if the first
call to device_create_file() fails while the second succeeds), and avoid
calling devlink_port_unregister() twice.

In other words, either mlx4_init_port_info() succeeds and returns zero, or
it fails, returns non-zero, and requires no cleanup.

Fixes: 096335b3f983 ("mlx4_core: Allow dynamic MTU configuration for IB
ports")
Signed-off-by: Tarick Bedeir <tarick@google.com>
---
v1 -> v2: Added "Fixes" tag.
---
 drivers/net/ethernet/mellanox/mlx4/main.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index 4d84cab77105..e8a3a45d0b53 100644
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -3007,6 +3007,7 @@ static int mlx4_init_port_info(struct mlx4_dev *dev, int port)
 		mlx4_err(dev, "Failed to create file for port %d\n", port);
 		devlink_port_unregister(&info->devlink_port);
 		info->port = -1;
+		return err;
 	}
 
 	sprintf(info->dev_mtu_name, "mlx4_port%d_mtu", port);
@@ -3028,9 +3029,10 @@ static int mlx4_init_port_info(struct mlx4_dev *dev, int port)
 				   &info->port_attr);
 		devlink_port_unregister(&info->devlink_port);
 		info->port = -1;
+		return err;
 	}
 
-	return err;
+	return 0;
 }
 
 static void mlx4_cleanup_port_info(struct mlx4_port_info *info)
-- 
2.17.0.441.gb46fe60e1d-goog

Re: [PATCH v2] net/mlx4_core: Fix error handling in mlx4_init_port_info.

[Leon Romanovsky]

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On Sun, May 13, 2018 at 04:38:45PM -0700, Tarick Bedeir wrote:
> Avoid exiting the function with a lingering sysfs file (if the first
> call to device_create_file() fails while the second succeeds), and avoid
> calling devlink_port_unregister() twice.
>
> In other words, either mlx4_init_port_info() succeeds and returns zero, or
> it fails, returns non-zero, and requires no cleanup.
>
> Fixes: 096335b3f983 ("mlx4_core: Allow dynamic MTU configuration for IB
> ports")

Please don't break "Fixes" lines, it complicates "grep".

IMHO, general cleanup exit point is needed in this function (goto ...),
but your fix is good enough too. Thanks for doing it.

Reviewed-by: Leon Romanovsky <leonro@mellanox.com>

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Re: [PATCH v2] net/mlx4_core: Fix error handling in mlx4_init_port_info.

[Tariq Toukan]

On 14/05/2018 2:38 AM, Tarick Bedeir wrote:
> Avoid exiting the function with a lingering sysfs file (if the first
> call to device_create_file() fails while the second succeeds), and avoid
> calling devlink_port_unregister() twice.
> 
> In other words, either mlx4_init_port_info() succeeds and returns zero, or
> it fails, returns non-zero, and requires no cleanup.
> 
> Fixes: 096335b3f983 ("mlx4_core: Allow dynamic MTU configuration for IB
> ports")
> Signed-off-by: Tarick Bedeir <tarick@google.com>
> ---
> v1 -> v2: Added "Fixes" tag.
> ---
>   drivers/net/ethernet/mellanox/mlx4/main.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
> index 4d84cab77105..e8a3a45d0b53 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/main.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/main.c
> @@ -3007,6 +3007,7 @@ static int mlx4_init_port_info(struct mlx4_dev *dev, int port)
>   		mlx4_err(dev, "Failed to create file for port %d\n", port);
>   		devlink_port_unregister(&info->devlink_port);
>   		info->port = -1;
> +		return err;
>   	}
>   
>   	sprintf(info->dev_mtu_name, "mlx4_port%d_mtu", port);
> @@ -3028,9 +3029,10 @@ static int mlx4_init_port_info(struct mlx4_dev *dev, int port)
>   				   &info->port_attr);
>   		devlink_port_unregister(&info->devlink_port);
>   		info->port = -1;
> +		return err;
>   	}
>   
> -	return err;
> +	return 0;
>   }
>   
>   static void mlx4_cleanup_port_info(struct mlx4_port_info *info)
> 

Thanks for you patch.
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>

Dave, please queue for -stable.

Best,
Tariq

Re: [PATCH v2] net/mlx4_core: Fix error handling in mlx4_init_port_info.

[David Miller]

From: Tarick Bedeir <tarick@google.com>
Date: Sun, 13 May 2018 16:38:45 -0700

> Avoid exiting the function with a lingering sysfs file (if the first
> call to device_create_file() fails while the second succeeds), and avoid
> calling devlink_port_unregister() twice.
> 
> In other words, either mlx4_init_port_info() succeeds and returns zero, or
> it fails, returns non-zero, and requires no cleanup.
> 
> Fixes: 096335b3f983 ("mlx4_core: Allow dynamic MTU configuration for IB
> ports")
> Signed-off-by: Tarick Bedeir <tarick@google.com>
> ---
> v1 -> v2: Added "Fixes" tag.

Applied and queued up for -stable.