pidns: rewrite copy_pid_ns()

copy_pid_ns() is a perfect example of a case where unwinding leads to more
code and makes it less clear.  Watch the diffstat.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 15 deletions

diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 495d5dea22b2..821722ae58a7 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -116,23 +116,11 @@ static void destroy_pid_namespace(struct pid_namespace *ns)
 
 struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old_ns)
 {
-        struct pid_namespace *new_ns;
-
-        BUG_ON(!old_ns);
-        new_ns = get_pid_ns(old_ns);
         if (!(flags & CLONE_NEWPID))
-                goto out;
-
-        new_ns = ERR_PTR(-EINVAL);
+                return get_pid_ns(old_ns);
         if (flags & CLONE_THREAD)
-                goto out_put;
-
-        new_ns = create_pid_namespace(old_ns);
-
-out_put:
-        put_pid_ns(old_ns);
-out:
-        return new_ns;
+                return ERR_PTR(-EINVAL);
+        return create_pid_namespace(old_ns);
 }
 
 void free_pid_ns(struct kref *kref)