On Mon, Dec 02, 2013 at 04:33:20PM +0000, Christoph Lameter wrote:

On Wed, 27 Nov 2013, Greg KH wrote:

quoted

Just make the kobject "dynamic" instead of embedded in struct kmem_cache
and all will be fine.  I can't believe this code has been broken for
this long.

The slub code is was designed to use an embedded structure since we
only get the kobj  pointer passed to us from sysfs. If kobj is not
embedded then how can we get from the sysfs object to the kmem_cache
structure from the sysfs callbacks? Sysfs was designed to have embedded
objects as far as I can recall.

Yes, it's designed to have embedded objects, so then use it that way and
clean up the structure when the kobject goes away.  Don't use a
different reference count for your structure than the one in the kobject
and think that all will be fine.

greg k-h