2009/12/16 Charles Manning <manningc2@actrix.gen.nz>:
> On Wednesday 16 December 2009 16:36:02 JiSheng Zhang wrote:
>> 2009/12/16 JiSheng Zhang <jszhang3@gmail.com>:
>> > Hi list,
>> >
>> > First mount an empty partition, then cp some files to the mnt dir then
>> > run "df", and then delete all the files, then run "df" again. df
>> > report this time is wrong. It seems that the chunks occupied by
>> > unlinked files aren't recycled until needed.
>> >
>> > Is this a bug or characteristic?
>
> I don't see that problem.
>
> root@linux-dual-head:/opt/y/cvs/yaffs2# mount -t yaffs2 /dev/mtdblock0 /mnt
> root@linux-dual-head:/opt/y/cvs/yaffs2# df
> Filesystem           1K-blocks      Used Available Use% Mounted on
> /dev/mtdblock0           65536      1152     64384   2% /mnt
> root@linux-dual-head:/opt/y/cvs/yaffs2# cp * /mnt
> root@linux-dual-head:/opt/y/cvs/yaffs2# df
> Filesystem           1K-blocks      Used Available Use% Mounted on
> /dev/mtdblock0           65536      5860     59676   9% /mnt
> root@linux-dual-head:/opt/y/cvs/yaffs2# rm /mnt/*
> root@linux-dual-head:/opt/y/cvs/yaffs2# df
> Filesystem           1K-blocks      Used Available Use% Mounted on
> /dev/mtdblock0           65536      1156     64380   2% /mnt
>
> If you can make a test case then I would like to see it please.
>

I made a mistake. I redo the test steps, found that there's no problem
with df on yaffs2.
>>
>> I think I found where the problem was. in revision 1.62 of
>> yaffs_guts.c yaffs_ResizeFile(in, 0); is added at the beginning of
>> function yaffs_DeleteFile(). Could someone give an explanation?
>
> The Resize was done because this removed the need for SoftDelete. Doing it
> this way makes the garbage collection faster.
>
Thanks for you explanation.

Best Regard,
Jisheng