get rid of the second argument of acct_kill()

Replace the old ns->bacct only with NULL and only if it still points
to acct.  And assign the new value to it *before* calling acct_kill()
in acct_on().  That way we don't need to pass the new acct to acct_kill().

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

1 files changed, 7 insertions, 10 deletions

diff --git a/kernel/acct.c b/kernel/acct.c
index b8fbefb8678f..cf6588ab517b 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -168,8 +168,7 @@ static void close_work(struct work_struct *work)
         complete(&acct->done);
 }
 
-static void acct_kill(struct bsd_acct_struct *acct,
-                      struct bsd_acct_struct *new)
+static void acct_kill(struct bsd_acct_struct *acct)
 {
         if (acct) {
                 struct pid_namespace *ns = acct->ns;
@@ -179,7 +178,7 @@ static void acct_kill(struct bsd_acct_struct *acct,
                 schedule_work(&acct->work);
                 wait_for_completion(&acct->done);
                 pin_remove(&acct->pin);
-                ns->bacct = new;
+                cmpxchg(&ns->bacct, acct, NULL);
                 acct->ns = NULL;
                 atomic_long_dec(&acct->count);
                 mutex_unlock(&acct->lock);
@@ -203,7 +202,7 @@ static void acct_pin_kill(struct fs_pin *pin)
                 acct_put(acct);
                 acct = NULL;
         }
-        acct_kill(acct, NULL);
+        acct_kill(acct);
 }
 
 static int acct_on(struct filename *pathname)
@@ -262,10 +261,8 @@ static int acct_on(struct filename *pathname)
         pin_insert(&acct->pin, mnt);
 
         old = acct_get(ns);
-        if (old)
-                acct_kill(old, acct);
-        else
-                ns->bacct = acct;
+        ns->bacct = acct;
+        acct_kill(old);
         mutex_unlock(&acct->lock);
         mnt_drop_write(mnt);
         mntput(mnt);
@@ -302,7 +299,7 @@ SYSCALL_DEFINE1(acct, const char __user *, name)
                 mutex_unlock(&acct_on_mutex);
                 putname(tmp);
         } else {
-                acct_kill(acct_get(task_active_pid_ns(current)), NULL);
+                acct_kill(acct_get(task_active_pid_ns(current)));
         }
 
         return error;
@@ -310,7 +307,7 @@ SYSCALL_DEFINE1(acct, const char __user *, name)
 
 void acct_exit_ns(struct pid_namespace *ns)
 {
-        acct_kill(acct_get(ns), NULL);
+        acct_kill(acct_get(ns));
 }
 
 /*