f2fs: introduce __try_update_largest_extent

This patch adds a new helper __try_update_largest_extent for cleanup.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/extent_cache.c

@@ -351,8 +351,7 @@ static struct extent_node *__try_merge_extent_node(struct f2fs_sb_info *sbi,
 	}
 
 	if (en) {
-		if (en->ei.len > et->largest.len)
-			et->largest = en->ei;
+		__try_update_largest_extent(et, en);
 		et->cached_en = en;
 	}
 	return en;
@@ -389,8 +388,7 @@ static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
 	if (!en)
 		return NULL;
 
-	if (en->ei.len > et->largest.len)
-		et->largest = en->ei;
+	__try_update_largest_extent(et, en);
 	et->cached_en = en;
 	return en;
 }
@@ -476,12 +474,10 @@ static unsigned int f2fs_update_extent_tree_range(struct inode *inode,
 				: NULL;
 		}
 
-		if (parts) {
-			if (en->ei.len > et->largest.len)
-				et->largest = en->ei;
-		} else {
+		if (parts)
+			__try_update_largest_extent(et, en);
+		else
 			__detach_extent_node(sbi, et, en);
-		}
 
 		/*
 		 * if original extent is split into zero or two parts, extent

fs/f2fs/f2fs.h

@@ -492,6 +492,13 @@ static inline bool __is_front_mergeable(struct extent_info *cur,
 	return __is_extent_mergeable(cur, front);
 }
 
+static inline void __try_update_largest_extent(struct extent_tree *et,
+						struct extent_node *en)
+{
+	if (en->ei.len > et->largest.len)
+		et->largest = en->ei;
+}
+
 struct f2fs_nm_info {
 	block_t nat_blkaddr;		/* base disk address of NAT */
 	nid_t max_nid;			/* maximum possible node ids */