Subject: Re: CVS commit: syssrc
To: Lennart Augustsson <lennart@augustsson.net>
From: Bill Studenmund <wrstuden@nas.nasa.gov>
List: tech-kern
Date: 06/30/1999 09:58:25
On Wed, 30 Jun 1999, Lennart Augustsson wrote:

> Bill Studenmund wrote:
> 
> > Module Name:    syssrc
> > Committed By:   wrstuden
> > Date:           Tue Jun 29 22:15:32 UTC 1999
> >
> > Modified Files:
> >         syssrc/sys/kern: syscalls.master
> >
> > Log Message:
> > Add fhopen, fhstat, fhstatfs.
> 
> I thought I read just about all NetBSD mailing list, but here, out of the blue,
> appears three new system calls.  I can't remember seeing any discussion
> about them, anywhere.  But maybe my memory is failing.

Well, we discussed them back in February or March. :-)

> I presume they are "necessary", because don't we all dislike bloat?
> Could someone explain to me what they do, and why we need them.

As Jason mentioned, they permit programs to open a file w/o knowing the
path to the file. They require you to be root.

The main applications I see are in new filesystems where userland daemons
help the kernel out. Like for the data migration system I'm working on,
where a daemon needs to load a file in from tape. By the time the fs gets
all the calls, it has no clue of the path to the file. But with these
calls, userland can be told how to find an daccess the file.

Take care,

Bill