Hi David, On Wed, Oct 17, 2018 at 03:23:38PM +0100, David Howells wrote: > From: kiran.modukuri <kiran.modukuri@xxxxxxxxx> > > The code in fscache_retrieval_complete is using atomic_sub followed by an > atomic_read: > > atomic_sub(n_pages, &op->n_pages); > if (atomic_read(&op->n_pages) <= 0) > fscache_op_complete(&op->op, true); > > This causes two threads doing a decrement of n_pages to race with each > other seeing the op->refcount 0 at same time - and they end up calling > fscache_op_complete() in both the threads leading to an assertion failure. > > Fix this by using atomic_sub_return() instead of two calls. Seems a case for atomic_sub_return_relaxed()... why not? Andrea
