From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Mon, 4 Nov 2019 08:38:07 +0100
Subject: IB: mlx5: no need to check return value of debugfs_create functions
Patch-mainline: v5.5-rc1
Git-commit: 09b0965ee8cced20a4791ff54506f1a6600996fe
References: jsc#SLE-8446

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Leon Romanovsky <leon@kernel.org>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-rdma@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/mlx5/main.c    |   62 ++++++++---------------------------
 drivers/infiniband/hw/mlx5/mlx5_ib.h |    9 -----
 2 files changed, 16 insertions(+), 55 deletions(-)

--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -5701,11 +5701,10 @@ static int mlx5_ib_rn_get_params(struct
 
 static void delay_drop_debugfs_cleanup(struct mlx5_ib_dev *dev)
 {
-	if (!dev->delay_drop.dbg)
+	if (!dev->delay_drop.dir_debugfs)
 		return;
-	debugfs_remove_recursive(dev->delay_drop.dbg->dir_debugfs);
-	kfree(dev->delay_drop.dbg);
-	dev->delay_drop.dbg = NULL;
+	debugfs_remove_recursive(dev->delay_drop.dir_debugfs);
+	dev->delay_drop.dir_debugfs = NULL;
 }
 
 static void cancel_delay_drop(struct mlx5_ib_dev *dev)
@@ -5756,52 +5755,22 @@ static const struct file_operations fops
 	.read	= delay_drop_timeout_read,
 };
 
-static int delay_drop_debugfs_init(struct mlx5_ib_dev *dev)
+static void delay_drop_debugfs_init(struct mlx5_ib_dev *dev)
 {
-	struct mlx5_ib_dbg_delay_drop *dbg;
+	struct dentry *root;
 
 	if (!mlx5_debugfs_root)
-		return 0;
-
-	dbg = kzalloc(sizeof(*dbg), GFP_KERNEL);
-	if (!dbg)
-		return -ENOMEM;
-
-	dev->delay_drop.dbg = dbg;
-
-	dbg->dir_debugfs =
-		debugfs_create_dir("delay_drop",
-				   dev->mdev->priv.dbg_root);
-	if (!dbg->dir_debugfs)
-		goto out_debugfs;
-
-	dbg->events_cnt_debugfs =
-		debugfs_create_atomic_t("num_timeout_events", 0400,
-					dbg->dir_debugfs,
-					&dev->delay_drop.events_cnt);
-	if (!dbg->events_cnt_debugfs)
-		goto out_debugfs;
-
-	dbg->rqs_cnt_debugfs =
-		debugfs_create_atomic_t("num_rqs", 0400,
-					dbg->dir_debugfs,
-					&dev->delay_drop.rqs_cnt);
-	if (!dbg->rqs_cnt_debugfs)
-		goto out_debugfs;
-
-	dbg->timeout_debugfs =
-		debugfs_create_file("timeout", 0600,
-				    dbg->dir_debugfs,
-				    &dev->delay_drop,
-				    &fops_delay_drop_timeout);
-	if (!dbg->timeout_debugfs)
-		goto out_debugfs;
+		return;
 
-	return 0;
+	root = debugfs_create_dir("delay_drop", dev->mdev->priv.dbg_root);
+	dev->delay_drop.dir_debugfs = root;
 
-out_debugfs:
-	delay_drop_debugfs_cleanup(dev);
-	return -ENOMEM;
+	debugfs_create_atomic_t("num_timeout_events", 0400, root,
+				&dev->delay_drop.events_cnt);
+	debugfs_create_atomic_t("num_rqs", 0400, root,
+				&dev->delay_drop.rqs_cnt);
+	debugfs_create_file("timeout", 0600, root, &dev->delay_drop,
+			    &fops_delay_drop_timeout);
 }
 
 static void init_delay_drop(struct mlx5_ib_dev *dev)
@@ -5817,8 +5786,7 @@ static void init_delay_drop(struct mlx5_
 	atomic_set(&dev->delay_drop.rqs_cnt, 0);
 	atomic_set(&dev->delay_drop.events_cnt, 0);
 
-	if (delay_drop_debugfs_init(dev))
-		mlx5_ib_warn(dev, "Failed to init delay drop debugfs\n");
+	delay_drop_debugfs_init(dev);
 }
 
 static void mlx5_ib_unbind_slave_port(struct mlx5_ib_dev *ibdev,
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -799,13 +799,6 @@ enum {
 	MLX5_MAX_DELAY_DROP_TIMEOUT_MS = 100,
 };
 
-struct mlx5_ib_dbg_delay_drop {
-	struct dentry		*dir_debugfs;
-	struct dentry		*rqs_cnt_debugfs;
-	struct dentry		*events_cnt_debugfs;
-	struct dentry		*timeout_debugfs;
-};
-
 struct mlx5_ib_delay_drop {
 	struct mlx5_ib_dev     *dev;
 	struct work_struct	delay_drop_work;
@@ -815,7 +808,7 @@ struct mlx5_ib_delay_drop {
 	bool			activate;
 	atomic_t		events_cnt;
 	atomic_t		rqs_cnt;
-	struct mlx5_ib_dbg_delay_drop *dbg;
+	struct dentry		*dir_debugfs;
 };
 
 enum mlx5_ib_stages {