f2fs: add remap_pages as generic_file_remap_pages

This was added for all the file systems before.

See the following commit.

commit id: 0b173bc4

[PATCH] mm: kill vma flag VM_CAN_NONLINEAR

This patch moves actual ptes filling for non-linear file mappings
into special vma operation: ->remap_pages().

File system must implement this method to get non-linear mappings support,
if it uses filemap_fault() then generic_file_remap_pages() can be used.

Now device drivers can implement this method and obtain nonlinear vma support."
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

fs/f2fs/file.c

@@ -96,8 +96,9 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
 }
 
 static const struct vm_operations_struct f2fs_file_vm_ops = {
-	.fault        = filemap_fault,
-	.page_mkwrite = f2fs_vm_page_mkwrite,
+	.fault		= filemap_fault,
+	.page_mkwrite	= f2fs_vm_page_mkwrite,
+	.remap_pages	= generic_file_remap_pages,
 };
 
 static int need_to_sync_dir(struct f2fs_sb_info *sbi, struct inode *inode)