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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 DF052C433E2 for ; Fri, 11 Sep 2020 11:50:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 86210221E7 for ; Fri, 11 Sep 2020 11:50:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599825006; bh=iHOEuqY2IISIowcVjExJxn/MeIDiEYvblEe/lfZwOvs=; h=Subject:From:To:Cc:Date:In-Reply-To:References:List-ID:From; b=hNyLT1Jcnw7Cyo/Qd86+ewMTq+q8XRWeSXEj0H8bVyt8XQeTZRraFfUmbqTjouGN6 q0laa4N/vg4KOg0IOqe0F52lkqYQDARzMm0WVbqbnQU0MNwBA/t+GTwTYG6iYjim1o ZfIl6IT7cp9IrF+3dDjUa/aEMQuNmqjoi5wFO1X8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725869AbgIKLti (ORCPT ); Fri, 11 Sep 2020 07:49:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:54906 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725863AbgIKLtT (ORCPT ); Fri, 11 Sep 2020 07:49:19 -0400 Received: from tleilax.poochiereds.net (68-20-15-154.lightspeed.rlghnc.sbcglobal.net [68.20.15.154]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id ED6D8221E7; Fri, 11 Sep 2020 11:49:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599824958; bh=iHOEuqY2IISIowcVjExJxn/MeIDiEYvblEe/lfZwOvs=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=0QK1ej+AM/3twvbQQ/q27JJVckLUo5EUO6Fh+rABImMr3EbHCLMUsC817OGCimv/k FkpQgf/BeAXpHCBa637vVu1NiatUXW3UkLyEZu59bNJhBvFDddpaMXTKnuWcKb5lcV YNySgZA2mxy8/PxQCSwZ0Jm1R5XjwH1V6wzCd6D4= Message-ID: Subject: Re: [PATCH v5 0/2] ceph: metrics for opened files, pinned caps and opened inodes From: Jeff Layton To: Xiubo Li , Ilya Dryomov Cc: "Yan, Zheng" , Patrick Donnelly , Ceph Development Date: Fri, 11 Sep 2020 07:49:16 -0400 In-Reply-To: <9a5c5d2f-d105-21c4-327e-5ad18bf49518@redhat.com> References: <20200903130140.799392-1-xiubli@redhat.com> <449a56624f3dd4e2a4a4cf95cd24d69c53700b6d.camel@kernel.org> <9a5c5d2f-d105-21c4-327e-5ad18bf49518@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-1.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org On Fri, 2020-09-11 at 11:43 +0800, Xiubo Li wrote: > On 2020/9/10 20:13, Jeff Layton wrote: > > On Thu, 2020-09-10 at 08:00 +0200, Ilya Dryomov wrote: > > > On Thu, Sep 10, 2020 at 2:59 AM Xiubo Li wrote: > > > > On 2020/9/10 4:34, Ilya Dryomov wrote: > > > > > On Thu, Sep 3, 2020 at 4:22 PM Xiubo Li wrote: > > > > > > On 2020/9/3 22:18, Jeff Layton wrote: > > > > > > > On Thu, 2020-09-03 at 09:01 -0400, xiubli@redhat.com wrote: > > > > > > > > From: Xiubo Li > > > > > > > > > > > > > > > > Changed in V5: > > > > > > > > - Remove mdsc parsing helpers except the ceph_sb_to_mdsc() > > > > > > > > - Remove the is_opened member. > > > > > > > > > > > > > > > > Changed in V4: > > > > > > > > - A small fix about the total_inodes. > > > > > > > > > > > > > > > > Changed in V3: > > > > > > > > - Resend for V2 just forgot one patch, which is adding some helpers > > > > > > > > support to simplify the code. > > > > > > > > > > > > > > > > Changed in V2: > > > > > > > > - Add number of inodes that have opened files. > > > > > > > > - Remove the dir metrics and fold into files. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Xiubo Li (2): > > > > > > > > ceph: add ceph_sb_to_mdsc helper support to parse the mdsc > > > > > > > > ceph: metrics for opened files, pinned caps and opened inodes > > > > > > > > > > > > > > > > fs/ceph/caps.c | 41 +++++++++++++++++++++++++++++++++++++---- > > > > > > > > fs/ceph/debugfs.c | 11 +++++++++++ > > > > > > > > fs/ceph/dir.c | 20 +++++++------------- > > > > > > > > fs/ceph/file.c | 13 ++++++------- > > > > > > > > fs/ceph/inode.c | 11 ++++++++--- > > > > > > > > fs/ceph/locks.c | 2 +- > > > > > > > > fs/ceph/metric.c | 14 ++++++++++++++ > > > > > > > > fs/ceph/metric.h | 7 +++++++ > > > > > > > > fs/ceph/quota.c | 10 +++++----- > > > > > > > > fs/ceph/snap.c | 2 +- > > > > > > > > fs/ceph/super.h | 6 ++++++ > > > > > > > > 11 files changed, 103 insertions(+), 34 deletions(-) > > > > > > > > > > > > > > > Looks good. I went ahead and merge this into testing. > > > > > > > > > > > > > > Small merge conflict in quota.c, which I guess is probably due to not > > > > > > > basing this on testing branch. I also dropped what looks like an > > > > > > > unrelated hunk in the second patch. > > > > > > > > > > > > > > In the future, if you can be sure that patches you post apply cleanly to > > > > > > > testing branch then that would make things easier. > > > > > > Okay, will do it. > > > > > Hi Xiubo, > > > > > > > > > > There is a problem with lifetimes here. mdsc isn't guaranteed to exist > > > > > when ->free_inode() is called. This can lead to crashes on a NULL mdsc > > > > > in ceph_free_inode() in case of e.g. "umount -f". I know it was Jeff's > > > > > suggestion to move the decrement of total_inodes into ceph_free_inode(), > > > > > but it doesn't look like it can be easily deferred past ->evict_inode(). > > > > Okay, I will take a look. > > > Given that it's just a counter which we don't care about if the > > > mount is going away, some form of "if (mdsc)" check might do, but > > > need to make sure that it covers possible races, if any. > > > > > Good catch, Ilya. > > > > What may be best is to move the increment out of ceph_alloc_inode and > > instead put it in ceph_set_ino_cb. Then the decrement can go back into > > ceph_evict_inode. > > Hi Jeff, Ilya > > Checked the code, it seems in the ceph_evict_inode() we will also hit > the same issue . > > With the '-f' options when umounting, it will skip the inodes whose > i_count ref > 0. And then free the fsc/mdsc in ceph. And later the > iput_final() will call the ceph_evict_inode() and then ceph_free_inode(). > > Could we just check if !!(sb->s_flags & SB_ACTIVE) is false will we skip > the counting ? > Note that umount -f (MNT_FORCE) just means that ceph_umount_begin is called before unmounting. If what you're saying it true, then we have bigger problems. ceph_evict_inode does this today when ci->i_snap_realm is set: struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; ...and then goes on to use that mdsc pointer. I wonder if we ought to be moving move some of the operations in ceph_kill_sb into ceph_put_super... particularly the call to destroy_fs_client()? -- Jeff Layton