Hi Andrew, I found the problem with O_DIRECT memory leak. The problem is, when we are doing DIO read and crossed the end of file - we don't release referencess on all the pages we got from get_user_pages(). (since it is a sucess case). The fix is to call dio_cleanup() even for sucess cases. Can you please review this ? I tested the patch with fsstress and there are no memory leak problems now. Thanks, Badari