From 146693471f1df44115cf4aaf13c33618619ad855 Mon Sep 17 00:00:00 2001
From: Geliang Tang <geliangtang@163.com>
Date: Thu, 14 Jan 2016 15:19:32 -0800
Subject: [PATCH] mm, thp: use list_first_entry_or_null()

Simplify the code with list_first_entry_or_null().

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/pgtable-generic.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 7d3db0247983..4c681baff363 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -176,13 +176,10 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
 
 	/* FIFO */
 	pgtable = pmd_huge_pte(mm, pmdp);
-	if (list_empty(&pgtable->lru))
-		pmd_huge_pte(mm, pmdp) = NULL;
-	else {
-		pmd_huge_pte(mm, pmdp) = list_entry(pgtable->lru.next,
-					      struct page, lru);
+	pmd_huge_pte(mm, pmdp) = list_first_entry_or_null(&pgtable->lru,
+							  struct page, lru);
+	if (pmd_huge_pte(mm, pmdp))
 		list_del(&pgtable->lru);
-	}
 	return pgtable;
 }
 #endif