bsdacct: fix and add comments around acct_process()

Fix the one describing what this function is and add one more - about locking absence around pid namespaces loop. Signed-off-by: Pavel Emelyanov <[email protected]> Cc: Randy Dunlap <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
mrcsosa · Jul 25, 2008 · 0c18d7a · 0c18d7a
1 parent 7d1e135
commit 0c18d7a
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/kernel/acct.c b/kernel/acct.c
@@ -657,14 +657,20 @@ static void acct_process_in_ns(struct pid_namespace *ns)
 }
 
 /**
- * acct_process - now just a wrapper around do_acct_process
+ * acct_process - now just a wrapper around acct_process_in_ns,
+ * which in turn is a wrapper around do_acct_process.
  *
  * handles process accounting for an exiting task
  */
 void acct_process(void)
 {
 	struct pid_namespace *ns;
 
+	/*
+	 * This loop is safe lockless, since current is still
+	 * alive and holds its namespace, which in turn holds
+	 * its parent.
+	 */
 	for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent)
 		acct_process_in_ns(ns);
 }