From mboxrd@z Thu Jan 1 00:00:00 1970 From: Milosz Tanski Subject: [PATCH 0/3] FS-Cache: Bug fixes for bugs that happen under vma pressure Date: Tue, 22 Jul 2014 11:49:47 -0400 Message-ID: <53CE881B.3070402@adfin.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "David Howells" , "NeilBrown" , "Shantanu Goel" To: linux-cachefs@redhat.com Return-path: Received: from mail-qa0-f45.google.com ([209.85.216.45]:47066 "EHLO mail-qa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755791AbaGVPtt (ORCPT ); Tue, 22 Jul 2014 11:49:49 -0400 Received: by mail-qa0-f45.google.com with SMTP id cm18so6705869qab.32 for ; Tue, 22 Jul 2014 08:49:48 -0700 (PDT) Sender: linux-fsdevel-owner@vger.kernel.org List-ID: FS-Cache has a few bugs generally only get tried in error mode / under VMA preassure. The problem is exhasterbated when majority of the IO is cacheable netfs IO. At that point there are few pages that are evictalbe due to GPF_NOFS allocation strategies. The first bug is a recursive hang caused by fscache write out to ext4 which in turn needs to allocate pages and ends up calling releasepages() on the netfs. The second two bugs are cookie ref count bugs that happen when in the error cases (mostly from related memory alloc failures). Milosz Tanski (3): FS-Cache: Timeout for releasepage() FS-Cache: Reduce cookie ref count if submit fails. FS-Cache: refcount becomes corrupt under vma pressure. fs/fscache/object.c | 4 ++++ fs/fscache/page.c | 22 ++++++++++++++++++---- 2 files changed, 22 insertions(+), 4 deletions(-) -- 1.7.9.5