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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 68806C54FCB for ; Thu, 23 Apr 2020 22:57:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 48B4C20CC7 for ; Thu, 23 Apr 2020 22:57:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728049AbgDWW5l (ORCPT ); Thu, 23 Apr 2020 18:57:41 -0400 Received: from mail104.syd.optusnet.com.au ([211.29.132.246]:48863 "EHLO mail104.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727021AbgDWW5k (ORCPT ); Thu, 23 Apr 2020 18:57:40 -0400 Received: from dread.disaster.area (pa49-180-0-232.pa.nsw.optusnet.com.au [49.180.0.232]) by mail104.syd.optusnet.com.au (Postfix) with ESMTPS id CA3A8820564; Fri, 24 Apr 2020 08:57:35 +1000 (AEST) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1jRkmk-0006uC-DD; Fri, 24 Apr 2020 08:57:34 +1000 Date: Fri, 24 Apr 2020 08:57:34 +1000 From: Dave Chinner To: ira.weiny@intel.com Cc: linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, "Darrick J. Wong" , Al Viro , Jan Kara , Dan Williams , Christoph Hellwig , "Theodore Y. Ts'o" , Jeff Moyer , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org Subject: Re: [PATCH V10 10/11] fs: Introduce DCACHE_DONTCACHE Message-ID: <20200423225734.GY27860@dread.disaster.area> References: <20200422212102.3757660-1-ira.weiny@intel.com> <20200422212102.3757660-11-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200422212102.3757660-11-ira.weiny@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=QIgWuTDL c=1 sm=1 tr=0 a=XYjVcjsg+1UI/cdbgX7I7g==:117 a=XYjVcjsg+1UI/cdbgX7I7g==:17 a=kj9zAlcOel0A:10 a=cl8xLZFz6L8A:10 a=QyXUC8HyAAAA:8 a=drOt6m5kAAAA:8 a=7-415B0cAAAA:8 a=y1ryl40uyaZQ8-5qDf4A:9 a=CjuIK1q_8ugA:10 a=RMMjzBEyIzXRtoq5n5K6:22 a=biEYGPWJfzWAr4FL6Ov7:22 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Apr 22, 2020 at 02:21:01PM -0700, ira.weiny@intel.com wrote: > From: Ira Weiny > > DCACHE_DONTCACHE indicates a dentry should not be cached on final > dput(). > > Also add a helper function to mark DCACHE_DONTCACHE on all dentries > pointing to a specific inode when that inode is being set I_DONTCACHE. > > This facilitates dropping dentry references to inodes sooner which > require eviction to swap S_DAX mode. > > Cc: Al Viro > Signed-off-by: Ira Weiny Code looks fine.... > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -1526,6 +1526,21 @@ int generic_delete_inode(struct inode *inode) > } > EXPORT_SYMBOL(generic_delete_inode); > > +void mark_inode_dontcache(struct inode *inode) > +{ > + struct dentry *de; > + > + spin_lock(&inode->i_lock); > + hlist_for_each_entry(de, &inode->i_dentry, d_u.d_alias) { > + spin_lock(&de->d_lock); > + de->d_flags |= DCACHE_DONTCACHE; > + spin_unlock(&de->d_lock); > + } > + inode->i_state |= I_DONTCACHE; > + spin_unlock(&inode->i_lock); > +} > +EXPORT_SYMBOL(mark_inode_dontcache); Though I suspect that this should be in fs/dcache.c and not fs/inode.c. i.e. nothing in fs/inode.c does dentry list walks, but there are several cases in the dcache code where inode dentry walks are done under the inode lock (e.g. d_find_alias(inode)). So perhaps this should be d_mark_dontcache(inode), which also marks the inode as I_DONTCACHE so that everything is evicted on last reference... Cheers, Dave. -- Dave Chinner david@fromorbit.com