names_cache memory leak in unionfs module

[Mathieu Lafon]

There is a kernel memory leak in the unionfs 1 module which can leak names_cache entries (slab allocated). After a long time, this can lead to a general OOM situation as they will never be freed.

Fix is available since a long time but is not included in hardy.

See:
  http://comments.gmane.org/gmane.comp.file-systems.unionfs.general/2447

$ grep names_cache /proc/slabinfo
names_cache 144557 144558 4096 2 2 : tunables 0 0 0 : slabdata 72279 72279 0
( = 564 MB )

Patch for linux-ubuntu-modules included.