[Yaffs] Can not see file after write yaffs2 image on NAND

Hi everybody,
I have got a big big problem :(
I use mkyaffs2image, then use nandwrite command but i can not see any file after mounting NAND flash.. Here is what i have done:

# mkyaffs2image source/ yaffs2.img
# flash_eraseall /dev/mtd3
# nandwrite -a -o /dev/mtd3 yaffs2.img
# mount -t yaffs2 /dev/mtdlock3 /mnt
# ls /mnt
lost+found

There is only lost+found.

Best regard. :)

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