From patchwork Mon Jul 20 17:01:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleg Nesterov X-Patchwork-Id: 6829451 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 568B6C05AC for ; Mon, 20 Jul 2015 17:03:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8D34120603 for ; Mon, 20 Jul 2015 17:03:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B17720601 for ; Mon, 20 Jul 2015 17:03:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753024AbbGTRDb (ORCPT ); Mon, 20 Jul 2015 13:03:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57893 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756584AbbGTRCz (ORCPT ); Mon, 20 Jul 2015 13:02:55 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id AADDBB6E92; Mon, 20 Jul 2015 17:02:55 +0000 (UTC) Received: from tranklukator.brq.redhat.com (dhcp-1-208.brq.redhat.com [10.34.1.208]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id t6KH2raN015500; Mon, 20 Jul 2015 13:02:54 -0400 Received: by tranklukator.brq.redhat.com (nbSMTP-1.00) for uid 500 oleg@redhat.com; Mon, 20 Jul 2015 19:01:08 +0200 (CEST) Date: Mon, 20 Jul 2015 19:01:06 +0200 From: Oleg Nesterov To: Al Viro , Dave Chinner , Dave Hansen , Jan Kara Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/4] move rwsem_release() from sb_wait_write() to freeze_super() Message-ID: <20150720170106.GA3906@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20150720170044.GA3868@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-8.1 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Move the "fool the lockdep" code from sb_wait_write() into the new simple helper, sb_lockdep_release(), called once before return from freeze_super(). This is preparation, but imo this makes sense in any case. This way we do not hide from lockdep the "write" locks we hold when we call s_op->freeze_fs(sb). Signed-off-by: Oleg Nesterov Reviewed-by: Jan Kara --- fs/super.c | 16 ++++++++++------ 1 files changed, 10 insertions(+), 6 deletions(-) diff --git a/fs/super.c b/fs/super.c index d0fdd49..e7ea9f1 100644 --- a/fs/super.c +++ b/fs/super.c @@ -1236,16 +1236,10 @@ static void sb_wait_write(struct super_block *sb, int level) { s64 writers; - /* - * We just cycle-through lockdep here so that it does not complain - * about returning with lock to userspace - */ rwsem_acquire(&sb->s_writers.lock_map[level-1], 0, 0, _THIS_IP_); - rwsem_release(&sb->s_writers.lock_map[level-1], 1, _THIS_IP_); do { DEFINE_WAIT(wait); - /* * We use a barrier in prepare_to_wait() to separate setting * of frozen and checking of the counter @@ -1261,6 +1255,14 @@ static void sb_wait_write(struct super_block *sb, int level) } while (writers); } +static void sb_freeze_release(struct super_block *sb) +{ + int level; + /* Avoid the warning from lockdep_sys_exit() */ + for (level = 0; level < SB_FREEZE_LEVELS; ++level) + rwsem_release(sb->s_writers.lock_map + level, 1, _THIS_IP_); +} + /** * freeze_super - lock the filesystem and force it into a consistent state * @sb: the super to lock @@ -1349,6 +1351,7 @@ int freeze_super(struct super_block *sb) sb->s_writers.frozen = SB_UNFROZEN; smp_wmb(); wake_up(&sb->s_writers.wait_unfrozen); + sb_freeze_release(sb); deactivate_locked_super(sb); return ret; } @@ -1358,6 +1361,7 @@ int freeze_super(struct super_block *sb) * sees write activity when frozen is set to SB_FREEZE_COMPLETE. */ sb->s_writers.frozen = SB_FREEZE_COMPLETE; + sb_freeze_release(sb); up_write(&sb->s_umount); return 0; }