Subject: [PATCH] xen-netback: no need to check return value of debugfs_create functions

From: Greg Kroah-Hartman <[email-masked]>
Date: Sat, 10 Aug 2019 12:31:08 +0200

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: Wei Liu <[email-masked]>
Cc: Paul Durrant <[email-masked]>
Cc: [email-masked]
Cc: [email-masked]
Signed-off-by: Greg Kroah-Hartman <[email-masked]>
---
 drivers/net/xen-netback/netback.c |  3 --
 drivers/net/xen-netback/xenbus.c  | 46 ++++++++-----------------------
 2 files changed, 11 insertions(+), 38 deletions(-)

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 1d9940d4e8c7..e018932abf49 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1653,9 +1653,6 @@ static int __init netback_init(void)
 
 #ifdef CONFIG_DEBUG_FS
 	xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);
-	if (IS_ERR_OR_NULL(xen_netback_dbg_root))
-		pr_warn("Init of debugfs returned %ld!\n",
-			PTR_ERR(xen_netback_dbg_root));
 #endif /* CONFIG_DEBUG_FS */
 
 	return 0;
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 41034264bd34..f533b7372d59 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -170,50 +170,26 @@ DEFINE_SHOW_ATTRIBUTE(xenvif_ctrl);
 
 static void xenvif_debugfs_addif(struct xenvif *vif)
 {
-	struct dentry *pfile;
 	int i;
 
-	if (IS_ERR_OR_NULL(xen_netback_dbg_root))
-		return;
-
 	vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
 						  xen_netback_dbg_root);
-	if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
-		for (i = 0; i < vif->num_queues; ++i) {
-			char filename[sizeof("io_ring_q") + 4];
-
-			snprintf(filename, sizeof(filename), "io_ring_q%d", i);
-			pfile = debugfs_create_file(filename,
-						    0600,
-						    vif->xenvif_dbg_root,
-						    &vif->queues[i],
-						    &xenvif_dbg_io_ring_ops_fops);
-			if (IS_ERR_OR_NULL(pfile))
-				pr_warn("Creation of io_ring file returned %ld!\n",
-					PTR_ERR(pfile));
-		}
+	for (i = 0; i < vif->num_queues; ++i) {
+		char filename[sizeof("io_ring_q") + 4];
 
-		if (vif->ctrl_irq) {
-			pfile = debugfs_create_file("ctrl",
-						    0400,
-						    vif->xenvif_dbg_root,
-						    vif,
-						    &xenvif_ctrl_fops);
-			if (IS_ERR_OR_NULL(pfile))
-				pr_warn("Creation of ctrl file returned %ld!\n",
-					PTR_ERR(pfile));
-		}
-	} else
-		netdev_warn(vif->dev,
-			    "Creation of vif debugfs dir returned %ld!\n",
-			    PTR_ERR(vif->xenvif_dbg_root));
+		snprintf(filename, sizeof(filename), "io_ring_q%d", i);
+		debugfs_create_file(filename, 0600, vif->xenvif_dbg_root,
+				    &vif->queues[i],
+				    &xenvif_dbg_io_ring_ops_fops);
+	}
+
+	if (vif->ctrl_irq)
+		debugfs_create_file("ctrl", 0400, vif->xenvif_dbg_root, vif,
+				    &xenvif_ctrl_fops);
 }
 
 static void xenvif_debugfs_delif(struct xenvif *vif)
 {
-	if (IS_ERR_OR_NULL(xen_netback_dbg_root))
-		return;
-
 	debugfs_remove_recursive(vif->xenvif_dbg_root);
 	vif->xenvif_dbg_root = NULL;
 }
-- 
2.22.0