Re: [PATCH 06/25] mtd: move ioctl32 code to mtdchar.c

Jörn Engel
2005-11-08T18:33:38Z

On Tue, 8 November 2005 11:10:27 -0700, Eric W. Biederman wrote:
> Jörn Engel <joern@wohnheim.fh-wedel.de> writes:
>
> > Moving crap over to mtdchar.c is a good thing. Complete removal of
> > mtdchar.c might be even better, but at least the crap is relatively
> > self-contained now.
>
> Agreed moving the compat_ioctl to mtdchar now that it is possible
> sounds good.
>
> I can see that argument with respect to mtdblock. But why would
> removal of mtdchar be a good thing? It is a simple raw access
> interface. For those whose flash parts are too small for a filesystem
> or when you are doing things that you can't do with a filesystem
> like making or checking it you need something like mtd char. For
> embedded folks who don't care you can just compile it out.

mtdchar.c is one of the worst drivers inside the kernel. The concept
of having a simple char device driver for flash may have its charm,
but the actual implementation is horrible. And things like the
read-only devices are even unfixable.

mtdblock.c, while being quite a bit more complicated, does not require
a ton of ioctls, will not confuse users with minor number 7 actually
being device number 3 and magically being read-only despite unix
permissions and hardware properties. Plus, it is just a file.

Can you name a few examples, where mtdchar.c makes sense? I've found
it to be quite useless.

Jörn

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