ext4: use non-racy method for proc entries creation

Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/ext4/mballoc.c

@@ -2449,17 +2449,10 @@ static void ext4_mb_history_init(struct super_block *sb)
 	int i;
 
 	if (sbi->s_mb_proc != NULL) {
-		struct proc_dir_entry *p;
-		p = create_proc_entry("mb_history", S_IRUGO, sbi->s_mb_proc);
-		if (p) {
-			p->proc_fops = &ext4_mb_seq_history_fops;
-			p->data = sb;
-		}
-		p = create_proc_entry("mb_groups", S_IRUGO, sbi->s_mb_proc);
-		if (p) {
-			p->proc_fops = &ext4_mb_seq_groups_fops;
-			p->data = sb;
-		}
+		proc_create_data("mb_history", S_IRUGO, sbi->s_mb_proc,
+				 &ext4_mb_seq_history_fops, sb);
+		proc_create_data("mb_groups", S_IRUGO, sbi->s_mb_proc,
+				 &ext4_mb_seq_groups_fops, sb);
 	}
 
 	sbi->s_mb_history_max = 1000;