why the emulated block driver by gluebi.c can't be used by FAT32

[rednoah]

Hi all:
    According to the documentations of mtd,the gluebi of ubi is used to
emulate block driver on the top of ubi,for jffs2 or other mtd-oriented
software using.Since the ubi is capable of wear leveling and bad
block,why we can't build FAT32 filesystem on the emulated block
device?
    I tried building a FAT32 on a ubi volume using the emulated block
node generated by gluebi.c.It seem ok when I transfer files between
this
partition and SD card.
B/r