Re: 2.6.20-mm1 - Oops using Minix 3 file system

["Cédric Augonnet" <cedric.augonnet@gmail.com>]

2007/2/17, Daniel Aragonés <danarag@gmail.com>:
>  Well, a glance at your dmesg doesn' show that a minix partition was
> recognized. Otherwise it would sow it. So you have not such a
> partition within your drives.
>
> You are using an emulator to run minix. You will have the same problem
> if you run minix2 or minix3 through an emulator and not from a real
> minix2 or minix3 partition.
>
> Regards,
>
> Daniel
>

Indeed the only line of dmesg showing i mounted the partition is
   loop: loaded (max 8 devices)

Still I actually mount an image : i can add files, edit and so on. If
i use the emulator and mount the partition, this partition works
perfectly and even the df commands works.

Now i tried to understand what is going on and traced the program :

It appears that the trouble is in  the count_free of file
fs/minix/bitmap.c . This procedure is actually called twice when we
issue a df command.
The point where things start to get strange is
        i = ((numbits - (numblocks-1) * bh->b_size * 8) / 16) * 2; at line 36

In the first call to that procedure i have
       i = 3506
       bh->b_data = 0xd4e79000

Whereas in the second call i have something much different :
       i = 536838736
       bh->b_data = d4e78000

Tt really seems to me that this value should not be so large.
Unfortunately, i cannot get any deeper in tracing the problem since
even if i tried to read the code, it not documented, so i can't be
sure I understand everything you're doing in count_free ...

Regards,
Cédric