From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7661C47096 for ; Thu, 3 Jun 2021 16:57:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 94D2F61159 for ; Thu, 3 Jun 2021 16:57:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230330AbhFCQ7J (ORCPT ); Thu, 3 Jun 2021 12:59:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:38244 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229719AbhFCQ7I (ORCPT ); Thu, 3 Jun 2021 12:59:08 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 37CD661159; Thu, 3 Jun 2021 16:57:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622739443; bh=bKqrfNl7vm7fmziBgX9j/vDBDS8F59HQHS+Zgywygrs=; h=Subject:From:To:Date:In-Reply-To:References:From; b=jR+e9lrteVozr9qg0oNwLrKGcHEbhBkFzG0ODT+32WqHjtaN7C9lyFbmt58uKC6pR mJarTPfNDJuo52RG1MlmHmgvuPNgegnWbO3QHbVmxdxpRvDCMBY6g6EKUgNy8dA+nT FrMXMZ+CeYJAL9QseLo8WKooQbxpZdwgow0UwckRYweO0dTFAFXTMe10RoJNSEGEqp MOZm8NYkxkTPJ45aPy5p584IkAz0XSegN7Tpph9quPLjNGx4rUyS7OTgiOQF5WpVJ6 mE8bU/yGH4tDAfBwM647DVLOCRJEl5XI3kIk3jUDz0gUcM3L2d9E8uGGB7LQb8pCHj 5UGhtzkLH/MPA== Message-ID: <6cd5b19cbcee46474709a97b273c4270088fb241.camel@kernel.org> Subject: Re: [PATCH] ceph: ensure we flush delayed caps when unmounting From: Jeff Layton To: ceph-devel@vger.kernel.org, idryomov@gmail.com Date: Thu, 03 Jun 2021 12:57:22 -0400 In-Reply-To: <20210603134812.80276-1-jlayton@kernel.org> References: <20210603134812.80276-1-jlayton@kernel.org> Content-Type: text/plain; charset="ISO-8859-15" User-Agent: Evolution 3.40.1 (3.40.1-1.fc34) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org On Thu, 2021-06-03 at 09:48 -0400, Jeff Layton wrote: > I've seen some warnings when testing recently that indicate that there > are caps still delayed on the delayed list even after we've started > unmounting. > > When checking delayed caps, process the whole list if we're unmounting, > and check for delayed caps after setting the stopping var and flushing > dirty caps. > > Signed-off-by: Jeff Layton > --- > fs/ceph/caps.c | 3 ++- > fs/ceph/mds_client.c | 1 + > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c > index a5e93b185515..68b4c6dfe4db 100644 > --- a/fs/ceph/caps.c > +++ b/fs/ceph/caps.c > @@ -4236,7 +4236,8 @@ void ceph_check_delayed_caps(struct ceph_mds_client *mdsc) > ci = list_first_entry(&mdsc->cap_delay_list, > struct ceph_inode_info, > i_cap_delay_list); > - if ((ci->i_ceph_flags & CEPH_I_FLUSH) == 0 && > + if (!mdsc->stopping && > + (ci->i_ceph_flags & CEPH_I_FLUSH) == 0 && > time_before(jiffies, ci->i_hold_caps_max)) > break; > list_del_init(&ci->i_cap_delay_list); > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c > index e5af591d3bd4..916af5497829 100644 > --- a/fs/ceph/mds_client.c > +++ b/fs/ceph/mds_client.c > @@ -4691,6 +4691,7 @@ void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc) > > lock_unlock_sessions(mdsc); > ceph_flush_dirty_caps(mdsc); > + ceph_check_delayed_caps(mdsc); > wait_requests(mdsc); > > /* I'm going to self-NAK this patch for now. Initially this looked good in testing, but I think it's just papering over the real problem, which is that ceph_async_iput can queue a job to a workqueue after the point where we've flushed that workqueue on umount. I think the right approach is to look at how to ensure that calling iput doesn't end up taking these coarse-grained locks so we don't need to queue it in so many codepaths. -- Jeff Layton