Hi all,

I'm using yaffs in several mobile platform, and using mmap interface to
read/write contents of file in yaffs. it works well in normal situation,
but it losts data when I turn off its power without unmount.

Please look at the attached sample code, and the following is its result.

# ./a.out
# ls -l
-rwxr-xr-x 1 0 0 1024 Apr 7 14:37 mmap_test
...
# sync

... power off without unmount, and power-on

# ls -l
-rwxr-xr-x 1 0 0 0 Apr 7 14:37 mmap_test

I also waited for about 10 seconds before power off, but data was lost also.

The above problem is not happened if I read mmap_test file before
power-off(I used cat). and it's not happened if I unmount before. I also
have tested the above problem with write api instead of mmap, it was not
happened in this case.

Regards,
Louis JANG