Subject: Re: code to store the path of the executable in struct proc...
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Jason Thorpe <>
List: tech-kern
Date: 09/25/2007 13:03:50
On Sep 23, 2007, at 10:05 PM, der Mouse wrote:

>>>> Because arranging that files always have a path, and, what's  
>>>> more, have
> a "the path", is a very fundamental change to filesystem semantics,

Oh get a clue.  Unnecessarily dwelling on the semantics of my casual  
wording of a sentence is just silly.  I'm not completely stupid, you  
know... I do file systems for a living and totally get the whole "hard  
links" thing.

> one
> that as far as I can see is incompatible with FFS on disk.  Regardless
> of the means by which this end is achieved.  (He can't possibly create
> the ability to "always get the path for a file" without, at the very
> least, breaking the ability to have files with no paths naming them,  
> no
> matter what he is or isn't hacking on.)

If there are no paths that name a file, then that file is removed.  If  
all the links to a file go away while the vnode is open, then the  
names are removed from the name cache and the new code would  
gracefully fail.

C'mon, it's not really that hard to grasp this.

> Well, I'm sorry, then you want something that is not very much like
> Unix.  Unix simply does not support that operation, and never has; it
> has always been possible to have files that have no paths at all that
> name them.

What you're talking about has nothing inherently to do with "Unix",  
but rather your idea of a particular implementation.  There are other  
Unix systems out there that support what we're talking about.

-- thorpej