SLUB: Fix memory leak by not reusing cpu_slab

SLUB: Fix memory leak by not reusing cpu_slab

backport of 05aa345034de6ae9c77fb93f6a796013641d57d5 from Linus's tree.

SLUB: Fix memory leak by not reusing cpu_slab

Fix the memory leak that may occur when we attempt to reuse a cpu_slab
that was allocated while we reenabled interrupts in order to be able to
grow a slab cache. The per cpu freelist may contain objects and in that
situation we may overwrite the per cpu freelist pointer loosing objects.
This only occurs if we find that the concurrently allocated slab fits
our allocation needs.

If we simply always deactivate the slab then the freelist will be properly
reintegrated and the memory leak will go away.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>