--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -789,6 +789,8 @@ static void __update_extent_tree_range(struct inode *inode,
 	BUG_ON(type != EX_READ);
 
 	if (tei->blk) {
+		struct extent_tree_info *eti = &sbi->extent_tree[et->type];
+		mutex_lock(&eti->extent_tree_lock);
 		__set_extent_info(&ei, fofs, len, tei->blk, false,
 				  0, 0, EX_READ);
 		if (!__try_merge_extent_node(sbi, et, &ei, prev_en, next_en))
@@ -803,6 +805,7 @@ static void __update_extent_tree_range(struct inode *inode,
 			et->largest_updated = true;
 			set_inode_flag(inode, FI_NO_EXTENT);
 		}
+		mutex_unlock(&eti->extent_tree_lock);
 	}
 
 	if (is_inode_flag_set(inode, FI_NO_EXTENT))