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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 B5C48C433E7 for ; Mon, 31 Aug 2020 17:13:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8590C20658 for ; Mon, 31 Aug 2020 17:13:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729016AbgHaRND (ORCPT ); Mon, 31 Aug 2020 13:13:03 -0400 Received: from mga05.intel.com ([192.55.52.43]:45914 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727044AbgHaRNC (ORCPT ); Mon, 31 Aug 2020 13:13:02 -0400 IronPort-SDR: dfkRCZWL5j641E5QWBkEgOypzc5Y+42uo89zke1iEls5xve07dGl+G9A9fLqA8P4R6H7/FPUMe UX1BaYxfmtBg== X-IronPort-AV: E=McAfee;i="6000,8403,9730"; a="241838518" X-IronPort-AV: E=Sophos;i="5.76,376,1592895600"; d="scan'208";a="241838518" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2020 10:12:59 -0700 IronPort-SDR: Y41XvCv6aivpF6BcwaaJivkQ0Jd2PyWIKbmvWPSvEAOkXy+DJxzAzfn8LfU6MWpD59gSRgXXqf uvR5w9wPR7IQ== X-IronPort-AV: E=Sophos;i="5.76,376,1592895600"; d="scan'208";a="301118539" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2020 10:12:58 -0700 Date: Mon, 31 Aug 2020 10:12:57 -0700 From: Ira Weiny To: Hao Li Cc: viro@zeniv.linux.org.uk, david@fromorbit.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, y-goto@fujitsu.com Subject: Re: [PATCH] fs: Handle I_DONTCACHE in iput_final() instead of generic_drop_inode() Message-ID: <20200831171257.GF1422350@iweiny-DESK2.sc.intel.com> References: <20200831101313.168889-1-lihao2018.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200831101313.168889-1-lihao2018.fnst@cn.fujitsu.com> User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 31, 2020 at 06:13:13PM +0800, Hao Li wrote: > If generic_drop_inode() returns true, it means iput_final() can evict > this inode regardless of whether it is dirty or not. If we check > I_DONTCACHE in generic_drop_inode(), any inode with this bit set will be > evicted unconditionally. This is not the desired behavior because > I_DONTCACHE only means the inode shouldn't be cached on the LRU list. > As for whether we need to evict this inode, this is what > generic_drop_inode() should do. This patch corrects the usage of > I_DONTCACHE. > > This patch was proposed in [1]. > > [1]: https://lore.kernel.org/linux-fsdevel/20200831003407.GE12096@dread.disaster.area/ > > Signed-off-by: Hao Li Thanks! I think this looks good, but shouldn't we add? It seems like this is a bug right? Fixes: dae2f8ed7992 ("fs: Lift XFS_IDONTCACHE to the VFS layer") Reviewed-by: Ira Weiny > --- > fs/inode.c | 3 ++- > include/linux/fs.h | 3 +-- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/fs/inode.c b/fs/inode.c > index 72c4c347afb7..4e45d5ea3d0f 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -1625,7 +1625,8 @@ static void iput_final(struct inode *inode) > else > drop = generic_drop_inode(inode); > > - if (!drop && (sb->s_flags & SB_ACTIVE)) { > + if (!drop && !(inode->i_state & I_DONTCACHE) && > + (sb->s_flags & SB_ACTIVE)) { > inode_add_lru(inode); > spin_unlock(&inode->i_lock); > return; > diff --git a/include/linux/fs.h b/include/linux/fs.h > index e019ea2f1347..93caee80ce47 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -2922,8 +2922,7 @@ extern int inode_needs_sync(struct inode *inode); > extern int generic_delete_inode(struct inode *inode); > static inline int generic_drop_inode(struct inode *inode) > { > - return !inode->i_nlink || inode_unhashed(inode) || > - (inode->i_state & I_DONTCACHE); > + return !inode->i_nlink || inode_unhashed(inode); > } > extern void d_mark_dontcache(struct inode *inode); > > -- > 2.28.0 > > >