Re: [PATCH] alternative API for raw devices

From: H. Peter Anvin (hpa@zytor.com)
Date: Wed May 01 2002 - 17:52:25 EST


Followup to: <Pine.GSO.4.21.0205011555450.12640-100000@weyl.math.psu.edu>
By author: Alexander Viro <viro@math.psu.edu>
In newsgroup: linux.dev.kernel
>
> * it's _not_ a character device - stat() will give you S_IFREG.
> To check that <foo> is a new-style raw device call statfs(2) and
> compare .f_type with rawfs magic (0x726177). It doesn't conflict
> with existing check for raw devices (stat(), check that it's
> a character device and compare major with RAW_MAJOR), so existing
> software can be taught to check for raw devices in
> backwards-compatible way.
>

I really don't know if it's a good idea for this to be S_IFREG, which
software has a reasonable expecation to behave like a normal file,
which a raw device *definitely* doesn't.

I would really like things like this as well as a lot of the
zero-length magic files in /proc to be S_ISCHR with i_rdev ==
MK_DEV(0,0) (the latter to let user space know that this isn't a
standard device node.)

        -hpa

-- 
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
http://www.zytor.com/~hpa/puzzle.txt	<amsp@zytor.com>
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Tue May 07 2002 - 22:00:11 EST