hsr: add hsr root debugfs directory

In current hsr code, when hsr interface is created, it creates debugfs
directory /sys/kernel/debug/<interface name>.
If there is same directory or file name in there, it fails.
In order to reduce possibility of failure of creation of debugfs,
this patch adds root directory.

Test commands:
    ip link add dummy0 type dummy
    ip link add dummy1 type dummy
    ip link add hsr0 type hsr slave1 dummy0 slave2 dummy1

Before this patch:
    /sys/kernel/debug/hsr0/node_table

After this patch:
    /sys/kernel/debug/hsr/hsr0/node_table

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 3 deletions

diff --git a/net/hsr/hsr_debugfs.c b/net/hsr/hsr_debugfs.c
index 6618a9d8e58e..a7462a718e7b 100644
--- a/net/hsr/hsr_debugfs.c
+++ b/net/hsr/hsr_debugfs.c
@@ -20,6 +20,8 @@
 #include "hsr_main.h"
 #include "hsr_framereg.h"
 
+static struct dentry *hsr_debugfs_root_dir;
+
 static void print_mac_address(struct seq_file *sfp, unsigned char *mac)
 {
 	seq_printf(sfp, "%02x:%02x:%02x:%02x:%02x:%02x:",
@@ -81,9 +83,9 @@ void hsr_debugfs_init(struct hsr_priv *priv, struct net_device *hsr_dev)
 {
 	struct dentry *de = NULL;
 
-	de = debugfs_create_dir(hsr_dev->name, NULL);
+	de = debugfs_create_dir(hsr_dev->name, hsr_debugfs_root_dir);
 	if (IS_ERR(de)) {
-		pr_err("Cannot create hsr debugfs root\n");
+		pr_err("Cannot create hsr debugfs directory\n");
 		return;
 	}
 
@@ -93,7 +95,7 @@ void hsr_debugfs_init(struct hsr_priv *priv, struct net_device *hsr_dev)
 				 priv->node_tbl_root, priv,
 				 &hsr_fops);
 	if (IS_ERR(de)) {
-		pr_err("Cannot create hsr node_table directory\n");
+		pr_err("Cannot create hsr node_table file\n");
 		debugfs_remove(priv->node_tbl_root);
 		priv->node_tbl_root = NULL;
 		return;
@@ -115,3 +117,18 @@ hsr_debugfs_term(struct hsr_priv *priv)
 	debugfs_remove(priv->node_tbl_root);
 	priv->node_tbl_root = NULL;
 }
+
+void hsr_debugfs_create_root(void)
+{
+	hsr_debugfs_root_dir = debugfs_create_dir("hsr", NULL);
+	if (IS_ERR(hsr_debugfs_root_dir)) {
+		pr_err("Cannot create hsr debugfs root directory\n");
+		hsr_debugfs_root_dir = NULL;
+	}
+}
+
+void hsr_debugfs_remove_root(void)
+{
+	/* debugfs_remove() internally checks NULL and ERROR */
+	debugfs_remove(hsr_debugfs_root_dir);
+}