Re: New device filesystems

[M. R. B. <mr...@0x...>]

* James Simmons <jsi...@tr...> on Sun, Oct 07, 2001:

> 
>    A few commits about the code entered into CVS. I really like to create
> a directory devfs2 and place gfxfs in their. The reason is I like to write
> the inputfs as well. Plus in time we probable will add more device
> classes like sound to this directory. I just like to keep the fs directory
> clean.

I don't think creating a new directory is a good idea.  What's wrong with
keeping gfxfs where it is in fs/gfxfs?  What isn't clean about that?
That's the standard spot for all vfs drivers and it's self-contained.  Also
(and Paul can explain this better than I can), gfxfs is just a vfs layer
for the fb, it isn't devfs.  You seem to think they're related, when gfxfs
is intended to perform a different role.  When describing this, please keep
devfs and gfxfs seperate to reduce confusion.

IMO, inputfs should go into fs/inputfs as well.

>    The second thing is you have 
> 
> struct file_operations gfxfs_file_ops = {
>         mmap:           generic_file_mmap,
>         llseek:         generic_file_llseek,
> };
> 
> For this filesystem to be truly network transparent we also need to remove
> mmap support as well as ioctl support. Read and write only. 

Er, these would still be needed for /dev/gfx/0/fb, since they'll be
translated into the fb_mmap() call (I'm not so sure what llseek would be
used for, but it would probably be useful in other gfxfs files).

M. R.