[PATCH 2/4] proc: Simplify proc_get_sb.

[ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman)]

The idle_thread now has a struct pid, so we can always find out know
the pid of the child_reaper before we mount proc.

Therefore we can remove the special cases for getting the pid of the
child_reaper from proc_get_sb.

Signed-off-by: Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
---
 fs/proc/root.c |   17 +----------------
 1 files changed, 1 insertions(+), 16 deletions(-)

diff --git a/fs/proc/root.c b/fs/proc/root.c
index 81f99e6..f442967 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -46,17 +46,6 @@ static int proc_get_sb(struct file_system_type *fs_type,
 	struct pid_namespace *ns;
 	struct proc_inode *ei;
 
-	if (proc_mnt) {
-		/* Seed the root directory with a pid so it doesn't need
-		 * to be special in base.c.  I would do this earlier but
-		 * the only task alive when /proc is mounted the first time
-		 * is the init_task and it doesn't have any pids.
-		 */
-		ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode);
-		if (!ei->pid)
-			ei->pid = find_get_pid(1);
-	}
-
 	if (flags & MS_KERNMOUNT)
 		ns = (struct pid_namespace *)data;
 	else
@@ -76,11 +65,7 @@ static int proc_get_sb(struct file_system_type *fs_type,
 		}
 
 		ei = PROC_I(sb->s_root->d_inode);
-		if (!ei->pid) {
-			rcu_read_lock();
-			ei->pid = get_pid(find_pid_ns(1, ns));
-			rcu_read_unlock();
-		}
+		ei->pid = get_pid(ns->child_reaper);
 
 		sb->s_flags |= MS_ACTIVE;
 		ns->proc_mnt = mnt;
-- 
1.5.3.rc6.17.g1911