split the slow path in acct_process() off

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 28 insertions, 22 deletions

diff --git a/kernel/acct.c b/kernel/acct.c
index efa891beeaa3..51188603b258 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -599,34 +599,35 @@ void acct_collect(long exitcode, int group_dead)
         spin_unlock_irq(&current->sighand->siglock);
 }
 
-static void acct_process_in_ns(struct pid_namespace *ns)
+static void slow_acct_process(struct pid_namespace *ns)
 {
-        struct file *file = NULL;
-        struct bsd_acct_struct *acct;
+        for ( ; ns; ns = ns->parent) {
+                struct file *file = NULL;
+                struct bsd_acct_struct *acct;
 
-        acct = ns->bacct;
-        /*
-         * accelerate the common fastpath:
-         */
-        if (!acct || !acct->file)
-                return;
+                acct = ns->bacct;
+                /*
+                 * accelerate the common fastpath:
+                 */
+                if (!acct || !acct->file)
+                        continue;
 
-        spin_lock(&acct_lock);
-        file = acct->file;
-        if (unlikely(!file)) {
+                spin_lock(&acct_lock);
+                file = acct->file;
+                if (unlikely(!file)) {
+                        spin_unlock(&acct_lock);
+                        continue;
+                }
+                get_file(file);
                 spin_unlock(&acct_lock);
-                return;
-        }
-        get_file(file);
-        spin_unlock(&acct_lock);
 
-        do_acct_process(acct, ns, file);
-        fput(file);
+                do_acct_process(acct, ns, file);
+                fput(file);
+        }
 }
 
 /**
- * acct_process - now just a wrapper around acct_process_in_ns,
- * which in turn is a wrapper around do_acct_process.
+ * acct_process
  *
  * handles process accounting for an exiting task
  */
@@ -639,6 +640,11 @@ void acct_process(void)
          * 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);
+        for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent) {
+                struct bsd_acct_struct *acct = ns->bacct;
+                if (acct && acct->file)
+                        break;
+        }
+        if (unlikely(ns))
+                slow_acct_process(ns);
 }