Re: Some nilfs comments

[Chris Mason <chris.mason-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>]

On Mon, 2008-12-22 at 18:07 +0900, Ryusuke Konishi wrote:
> > I haven't dug too deeply in yet, but if there are parts you're most
> > interested in comments on, please let me know.
> 
> Well, I feel that the following two matters are particularlly
> questionable and need to be checked:
> 

> - ioctl:
>   Ioctl interface (routines and structures) were implemented in an
>   own way.  These seems to be checked whether to comply with the rules
>   of ioctl design.
> 

It took me far too long to look at this, I'm sorry.  But, looking
through the ioctl code I think you'll have a few (easy to fix) problems.

struct nilfs_argv {
        void *v_base;
        size_t v_nmembs;        /* number of members */
        size_t v_size;          /* size of members */
        int v_index;
        int v_flags;
};

The structs that get passed from userland to kernel should use fixed
sized types.

I get around this by using u64s (and __u64s) everywhere.  It looks like
you have compat ioctls to fix this too, I find it easier to use the
fixed types.

Otherwise the ioctl code looks pretty reasonable.

-chris