[GIT PULL] Namespace file descriptors for 2.6.40

[Eric W. Biederman]

Ingo Molnar <mingo at elte.hu> writes:

> I agree with Linus's notion in this thread though, a core kernel change should 
> generally not worry about hooking up rare-arch system calls (concentrate on the 
> architectures that get tested most) - those are better enabled gradually 
> anyway.

The way I read it he was complaining about my having parisc bits and
asking for my branch to be merged before the parisc bits had been
merged.  Which I credit as a fair complaint.  If I am going to depend on
other peoples trees I should wait.

At the same time when I am busy looking for every possible source of
trouble and putting code into net-next to detect pending conflicts,
and when maintainers complain when I ask for review that my patches
conflict with their patches.  Being a contentious developer I am
inclined to do something.

Now that the reality has sunk in that it means waiting for other peoples
code to be merged before I request for my changes to be merged I don't
think I will structure a tree that way again while I remember.

> Also, system call table conflicts are trivial to resolve. Merging in net-next 
> to avoid such a conflict is like cracking a nut with a sledgehammer.

Well I still have trauma from how nasty it was to test with syscall
numbers continuing to change when I was working on the kexec_load system
call.

As far as I can tell any one system call conflict on any one
architecture is easy to resolve.  Resolving a conflict on all
architectures would amount to at least 50 files that need to be resolved
that feels a bit more than trivial.

My gut feel says we should really implement an
include/asm-generic/unistd-common.h to include all new system calls.

That way there would be only one file to touch instead of 50.
Certainly it works for include/asm-generic/unistd.h for the
architectures that use it.  And all we really need is just a little
abstraction on that concept.

Eric