bonding: add the debugfs facility to the bonding driver

This patch provides the debugfs facility to the bonding driver.
The "bonding" directory is created in the debugfs root and directories of
each bonding interface (like bond0, bond1...) are created in that.

 # mount -t debugfs none /sys/kernel/debug

 # ls /sys/kernel/debug/bonding
 bond0  bond1

Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 96 insertions, 0 deletions

diff --git a/drivers/net/bonding/bond_debugfs.c b/drivers/net/bonding/bond_debugfs.c
new file mode 100644
index 000000000000..ae1eb2fc3a47
--- /dev/null
+++ b/drivers/net/bonding/bond_debugfs.c
@@ -0,0 +1,96 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/netdevice.h>
+
+#include "bonding.h"
+
+#ifdef CONFIG_DEBUG_FS
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+static struct dentry *bonding_debug_root;
+
+void bond_debug_register(struct bonding *bond)
+{
+	if (!bonding_debug_root)
+		return;
+
+	bond->debug_dir =
+		debugfs_create_dir(bond->dev->name, bonding_debug_root);
+
+	if (!bond->debug_dir) {
+		pr_warning("%s: Warning: failed to register to debugfs\n",
+			bond->dev->name);
+		return;
+	}
+}
+
+void bond_debug_unregister(struct bonding *bond)
+{
+	if (!bonding_debug_root)
+		return;
+
+	debugfs_remove_recursive(bond->debug_dir);
+}
+
+void bond_debug_reregister(struct bonding *bond)
+{
+	struct dentry *d;
+
+	if (!bonding_debug_root)
+		return;
+
+	d = debugfs_rename(bonding_debug_root, bond->debug_dir,
+			   bonding_debug_root, bond->dev->name);
+	if (d) {
+		bond->debug_dir = d;
+	} else {
+		pr_warning("%s: Warning: failed to reregister, "
+				"so just unregister old one\n",
+				bond->dev->name);
+		bond_debug_unregister(bond);
+	}
+}
+
+void bond_create_debugfs(void)
+{
+	bonding_debug_root = debugfs_create_dir("bonding", NULL);
+
+	if (!bonding_debug_root) {
+		pr_warning("Warning: Cannot create bonding directory"
+				" in debugfs\n");
+	}
+}
+
+void bond_destroy_debugfs(void)
+{
+	debugfs_remove_recursive(bonding_debug_root);
+	bonding_debug_root = NULL;
+}
+
+
+#else /* !CONFIG_DEBUG_FS */
+
+void bond_debug_register(struct bonding *bond)
+{
+}
+
+void bond_debug_unregister(struct bonding *bond)
+{
+}
+
+void bond_debug_reregister(struct bonding *bond)
+{
+}
+
+void bond_create_debugfs(void)
+{
+}
+
+void bond_destroy_debugfs(void)
+{
+}
+
+#endif /* CONFIG_DEBUG_FS */