[Devel] [patch 18/20] [Network namespace] For debug purpose only. Show ref count for current namespace and level of isolation.

[dlezcano at fr.ibm.com]

Signed-off-by: Daniel Lezcano <dlezcano at fr.ibm.com>

---

 fs/debugfs/net_ns.c |   72 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 71 insertions(+), 1 deletion(-)

Index: 2.6.19-rc6-mm2/fs/debugfs/net_ns.c
===================================================================
--- 2.6.19-rc6-mm2.orig/fs/debugfs/net_ns.c
+++ 2.6.19-rc6-mm2/fs/debugfs/net_ns.c
@@ -21,6 +21,7 @@
 static struct dentry *net_ns_dentry;
 static struct dentry *net_ns_dentry_dev;
 static struct dentry *net_ns_dentry_start;
+static struct dentry *net_ns_dentry_info;
 
 static ssize_t net_ns_dev_read_file(struct file *file, char __user *user_buf,
 				    size_t count, loff_t *ppos)
@@ -109,6 +110,63 @@ static ssize_t net_ns_start_write_file(s
 	return count;
 }
 
+static int net_ns_info_open_file(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+static ssize_t net_ns_info_read_file(struct file *file, char __user *user_buf,
+				     size_t count, loff_t *ppos)
+{
+	const unsigned int length = 256;
+	size_t len;
+	char buff[length];
+	char *level;
+	struct net_namespace *net_ns = current_net_ns;
+
+	if (*ppos < 0)
+		return -EINVAL;
+	if (*ppos >= count)
+		return 0;
+	if (!count)
+		return 0;
+
+	switch (net_ns->level) {
+	case NET_NS_LEVEL2:
+		level = "layer 2";
+		break;
+	case NET_NS_LEVEL3:
+		level = "layer 3";
+		break;
+	default:
+		level = "unknown";
+		break;
+	}
+
+	sprintf(buff,"refcnt: %d\nlevel: %s\n",
+		atomic_read(&net_ns->kref.refcount), level);
+
+	len = strlen(buff);
+	if (len > count)
+		len = count;
+
+	if (copy_to_user(user_buf, buff, len))
+		return -EINVAL;
+
+	*ppos += count;
+
+	return count;
+}
+
+static ssize_t net_ns_info_write_file(struct file *file,
+				      const char __user *user_buf,
+				      size_t count, loff_t *ppos)
+{
+
+	return -EPERM;
+}
+
+
 static struct file_operations net_ns_dev_fops = {
        .read =         net_ns_dev_read_file,
        .write =        net_ns_dev_write_file,
@@ -121,11 +179,17 @@ static struct file_operations net_ns_sta
        .open =         net_ns_start_open_file,
 };
 
+static struct file_operations net_ns_info_fops = {
+       .read =         net_ns_info_read_file,
+       .write =        net_ns_info_write_file,
+       .open =         net_ns_info_open_file,
+};
+
 static int __init net_ns_init(void)
 {
 	net_ns_dentry = debugfs_create_dir("net_ns", NULL);
 
-	net_ns_dentry_dev = debugfs_create_file("dev", 0666,
+	net_ns_dentry_dev = debugfs_create_file("dev", 0444,
 						net_ns_dentry,
 						NULL,
 						&net_ns_dev_fops);
@@ -135,11 +199,17 @@ static int __init net_ns_init(void)
 						  NULL,
 						  &net_ns_start_fops);
 
+	net_ns_dentry_info = debugfs_create_file("info", 0444,
+						 net_ns_dentry,
+						 NULL,
+						 &net_ns_info_fops);
+
 	return 0;
 }
 
 static void __exit net_ns_exit(void)
 {
+	debugfs_remove(net_ns_dentry_info);
 	debugfs_remove(net_ns_dentry_start);
 	debugfs_remove(net_ns_dentry_dev);
 	debugfs_remove(net_ns_dentry);

-- 
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