[Yaffs] Lost blocks

[Charles Manning]

On Friday 16 December 2005 04:39, John M Cavallo wrote:
> I am having problems with portions of a flash becoming increasingly
> unavailable during usage. After a few cycles of filling and emptying the
> flash, with occasional reboots/remounts thrown in (see the script at the
> end of this message), the majority of the flash will become lost. For
> example, I had two partitions on one device, with 160 Mbytes on each,
> one was stressed, otherwise they are identical. When I get the disk
> usage of the two, there is approximately the same amount of information
> on both:

Hi John

Could you please provide a /proc/yaffs from from before and after running the 
test.

>
> # du -sk /nand /nand1
> 22544   /nand
> 22560   /nand1
>
> However, when I look at the available space on the two, none is left on
> the one that had been stressed.
>
> # df /nand /nand1
> Filesystem           1k-blocks      Used Available Use% Mounted on
> /dev/mtdblock/5         163840     24856    138984  16% /nand
> /dev/mtdblock/4         163840    163840         0 100% /nand1
>
> This effect is repeatable. We haven't been able to track down the exact
> cause of the problem, but it looks like it is connected to the initial
> scan not properly disposing of remnants of files that have been deleted.
>
> -------------------------
>
> This is a stripped down version of the script that we used to stress
> tests a partition mounted at /nand1.
>
> tar -cf /nand1/usr.tar /usr
>
> dirnum=1
>
> while true
>   # fill and empty 5 times
>   for i in 1 2 3 4 5
>   do
>     # create a sub directory and try filling it
>     mkdir -p /nand1/test/$dirnum
>     while cp -a /nand1/usr.tar /usr /nand1/test/$dirnum
>     do
>       dirnum=`expr $dirnum + 1`
>       mkdir -p /nand1/test/$dirnum
>     done
>     # the copy failed, so remove the test directory
>     rm -r /nand1/test
>   done
>   # unmount and remount. Could also reboot at this point,
>   # but that requires more than a single script.
>   umount /nand1
>   mount /nand1
> done