Re: VFS + path walktrough

[Miklos Szeredi]

> > > This is still wrong.  We not just pass the pathname to filesystem (note
> > > that you still need to deal with symlinks),
> > 
> > Symlinks are easy: filesystem just needs to *stop* the resolution the
> > moment it finds one.
> 
> That assumes you see types of objects as you do multi-step walk...

Umm, OK.  The 9P server does see the type of objects, so it should be
able to do that.

> > >  Take a look at 9P walk - it does *not* give
> > > you anything resembling stat, you just get qids of intermediates.
> > 
> > Which is exactly what's needed to populate the dentry tree, no?
> 
> No - you need inodes as well (i.e. as the absolute least you want
> mode and ownership).  Which is to say, you need to issue stat on
> each component in such situation anyway.  Not a win...

You're right.  It doesn't sound too good, although it all depends on
the how permission checking is done.  If it's done in the server, then
neither the mode nor the ownership is needed for lookup.  The file
type *is* known for all but the last component, and doing a stat for
that one is not a big issue.  All this is modulo the symlink issue of
course.

Miklos
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/