[RFC] breakage in sysfs_readdir() and s_instances abuse in sysfs

[Linus Torvalds]

On Sun, Jun 12, 2011 at 12:15 AM, Eric W. Biederman
<ebiederm at xmission.com> wrote:
>
> I honestly hate the pattern that is being used here.  Holding a
> reference count because we can't be bothered to free things reliably
> when we actually stop using them.

WHAT?

That's what a reference count *is*. It's all about "free things
reliably when we actually stop using them".

Your comment makes zero sense.

EVERY SINGLE kernel data structure should be reference counted. Read
Documentation/CodingStyle, or look at any of the good code in the
kernel (ie core process or VFS code). A non-refcounted data structure
that is used by more than one entity IS A BUG!

Quite frankly, your objection sounds moronic. If there is more than
one user, then a reference count is _always_ the right thing. Nothing
else ever works, and trust me, people have tried. They've tried
locking, they've tried luck, they've tried crazy things. Nothing but
refcounts works.

                           Linus