[PATCH 5.4 030/203] hsr: add hsr root debugfs directory

Greg Kroah-Hartman
2020-01-16T23:47:48Z

From: Taehee Yoo <ap420073@gmail.com>

commit c6c4ccd7f96993e106dfea7ef18127f972f2db5e upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/hsr/hsr_debugfs.c | 23 ++++++++++++++++++++---
net/hsr/hsr_main.c | 1 +
net/hsr/hsr_main.h | 6 ++++++
net/hsr/hsr_netlink.c | 1 +
4 files changed, 28 insertions(+), 3 deletions(-)

--- 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 *p
{
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 *p
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);
+}
--- a/net/hsr/hsr_main.c
+++ b/net/hsr/hsr_main.c
@@ -123,6 +123,7 @@ static void __exit hsr_exit(void)
{
unregister_netdevice_notifier(&hsr_nb);
hsr_netlink_exit();
+ hsr_debugfs_remove_root();
}

module_init(hsr_init);
--- a/net/hsr/hsr_main.h
+++ b/net/hsr/hsr_main.h
@@ -187,12 +187,18 @@ static inline u16 hsr_get_skb_sequence_n
#if IS_ENABLED(CONFIG_DEBUG_FS)
void hsr_debugfs_init(struct hsr_priv *priv, struct net_device *hsr_dev);
void hsr_debugfs_term(struct hsr_priv *priv);
+void hsr_debugfs_create_root(void);
+void hsr_debugfs_remove_root(void);
#else
static inline void hsr_debugfs_init(struct hsr_priv *priv,
struct net_device *hsr_dev)
{}
static inline void hsr_debugfs_term(struct hsr_priv *priv)
{}
+static inline void hsr_debugfs_create_root(void)
+{}
+static inline void hsr_debugfs_remove_root(void)
+{}
#endif

#endif /* __HSR_PRIVATE_H */
--- a/net/hsr/hsr_netlink.c
+++ b/net/hsr/hsr_netlink.c
@@ -476,6 +476,7 @@ int __init hsr_netlink_init(void)
if (rc)
goto fail_genl_register_family;

+ hsr_debugfs_create_root();
return 0;