From patchwork Tue Jun 11 11:09:00 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 2701921 Return-Path: X-Original-To: patchwork-ceph-devel@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id ECCF53FD4E for ; Tue, 11 Jun 2013 11:15:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754631Ab3FKLJq (ORCPT ); Tue, 11 Jun 2013 07:09:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:20124 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753552Ab3FKLJn (ORCPT ); Tue, 11 Jun 2013 07:09:43 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r5BB9IQu030916 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 11 Jun 2013 07:09:18 -0400 Received: from sikun.lab.eng.rdu2.redhat.com (sikun.lab.eng.rdu2.redhat.com [10.8.0.43]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r5BB99Nb008419; Tue, 11 Jun 2013 07:09:17 -0400 From: Jeff Layton To: viro@zeniv.linux.org.uk, matthew@wil.cx, bfields@fieldses.org Cc: dhowells@redhat.com, sage@inktank.com, smfrench@gmail.com, swhiteho@redhat.com, Trond.Myklebust@netapp.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-afs@lists.infradead.org, ceph-devel@vger.kernel.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, cluster-devel@redhat.com, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, piastryyy@gmail.com Subject: [PATCH v2 06/14] locks: don't walk inode->i_flock list in locks_show Date: Tue, 11 Jun 2013 07:09:00 -0400 Message-Id: <1370948948-31784-7-git-send-email-jlayton@redhat.com> In-Reply-To: <1370948948-31784-1-git-send-email-jlayton@redhat.com> References: <1370948948-31784-1-git-send-email-jlayton@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.25 Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org When we convert over to using the i_lock to protect the i_flock list, that will introduce a potential lock inversion problem in locks_show. When we want to walk the i_flock list, we'll need to take the i_lock. Rather than do that, just walk the global blocked_locks list and print out any that are blocked on the given lock. Signed-off-by: Jeff Layton --- fs/locks.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index e451d18..3fd27f0 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2249,8 +2249,10 @@ static int locks_show(struct seq_file *f, void *v) lock_get_status(f, fl, *((loff_t *)f->private), ""); - list_for_each_entry(bfl, &fl->fl_block, fl_block) - lock_get_status(f, bfl, *((loff_t *)f->private), " ->"); + list_for_each_entry(bfl, &blocked_list, fl_link) { + if (bfl->fl_next == fl) + lock_get_status(f, bfl, *((loff_t *)f->private), " ->"); + } return 0; }