[PATCH 4.9 004/111] net/mlx5: Fix debugfs cleanup in the device init/remove flow

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jack Morgenstein <jackm@xxxxxxxxxxxxxxxxxx>

[ Upstream commit 5df816e7f43f1297c40021ef17ec6e722b45c82f ]

When initializing the device (procedure init_one), the driver
calls mlx5_pci_init to perform pci initialization. As part of this
initialization, mlx5_pci_init creates a debugfs directory.
If this creation fails, init_one aborts, returning failure to
the caller (which is the probe method caller).

The main reason for such a failure to occur is if the debugfs
directory already exists. This can happen if the last time
mlx5_pci_close was called, debugfs_remove (silently) failed due
to the debugfs directory not being empty.

Guarantee that such a debugfs_remove failure will not occur by
instead calling debugfs_remove_recursive in procedure mlx5_pci_close.

Fixes: 59211bd3b632 ("net/mlx5: Split the load/unload flow into hardware and software flows")
Signed-off-by: Jack Morgenstein <jackm@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Daniel Jurgens <danielj@xxxxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx5/core/main.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c
@@ -787,8 +787,10 @@ static int mlx5_pci_init(struct mlx5_cor
 	priv->numa_node = dev_to_node(&dev->pdev->dev);
 
 	priv->dbg_root = debugfs_create_dir(dev_name(&pdev->dev), mlx5_debugfs_root);
-	if (!priv->dbg_root)
+	if (!priv->dbg_root) {
+		dev_err(&pdev->dev, "Cannot create debugfs dir, aborting\n");
 		return -ENOMEM;
+	}
 
 	err = mlx5_pci_enable_device(dev);
 	if (err) {
@@ -837,7 +839,7 @@ static void mlx5_pci_close(struct mlx5_c
 	pci_clear_master(dev->pdev);
 	release_bar(dev->pdev);
 	mlx5_pci_disable_device(dev);
-	debugfs_remove(priv->dbg_root);
+	debugfs_remove_recursive(priv->dbg_root);
 }
 
 static int mlx5_init_once(struct mlx5_core_dev *dev, struct mlx5_priv *priv)