__f2fs_add_link() 4096 4096 3
page = get_new_data_page (page->index = 1 by NEW_ADDR)
add a dentry to the page successfully
f2fs_rmdir()
f2fs_empty_dir() 4096 4096 3
f2fs_unlink() goes, since there is no valid dentry due to i_size = 4096.
But, still there is one dentry in page->index = 1.
So this patch moves the code to write dir->i_size into on-disk i_size in order
to sync dir's i_size, on-disk i_size, and its i_blocks.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>