Re: [PATCH] add a stub by which a module can bind to the AFS syscall

[Christoph Hellwig <hch@infradead.org>]

On Wed, Apr 30, 2003 at 11:13:23AM -0400, chas williams wrote:
> at the time afs was written it wasnt a mistake.

Oh yes, it was.  The same mistake as the even earlier SysV IPC mess.

> syscall was the only
> (easy) way into the kernel from user space.  adding multiple syscalls
> would have just been completely painful.  as for examples, pioctl() --
> the user space of the afs syscall -- is a bit like syssgi() i am afraid:
> 
> venus/fs.c:     code = pioctl(0, VIOC_GETCELLSTATUS, &blob, 1);
> venus/fs.c:    code = pioctl(0, VIOC_SETRXKCRYPT, &blob, 1);
> vlserver/sascnvldb.c:   code = pioctl(ti->data, VIOCGETVOLSTAT, &blob, 1);
> auth/ktc_nt.c:  code = pioctl(0, VIOCNEWGETTOK, &iob, 0);
> auth/ktc_nt.c:  code = pioctl(0, VIOCDELTOK, &iob, 0);
> package/package.c:  code = pioctl(0, VIOC_AFS_SYSNAME, &data, 1);
> venus/up.c:          code = pioctl(file1, _VICEIOCTL(2), &blob, 1);
> 
> in reality, very few things other than afs are going to want to use
> the afs syscall (arla might be a possible user).

So fix the AFS code up to use a routine for each subcall that
can still map to pioctl for !linux.  After that we can continue the
discussion on how these calls are best implemented on linux.