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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 75F2CC2D0EC for ; Fri, 27 Mar 2020 14:01:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C21B206F1 for ; Fri, 27 Mar 2020 14:01:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Q4Y6MQ8M" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727354AbgC0OBa (ORCPT ); Fri, 27 Mar 2020 10:01:30 -0400 Received: from us-smtp-delivery-74.mimecast.com ([63.128.21.74]:54732 "EHLO us-smtp-delivery-74.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726900AbgC0OB3 (ORCPT ); Fri, 27 Mar 2020 10:01:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585317689; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=nmGn2iu/6hb//kS/DiygB1sR/c0YTQN3IceTCMDHJQI=; b=Q4Y6MQ8MtI0Dc3KPYFS70IytyzW90zN8cPLRhQvUpNiPSGhOVgXoAYwnsXoTX/s/JmFrX6 4Q3xCR58wuBX42kAV15IcW6K16WwAS/pPveOC8JqY45R33ZjJ+lDmJbOKSitYGVPpNWoO0 PhPtXdIUlCn+HL+idUAvFn1awmwFlIQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-30-IhFdegswPqOnvQl_xs_QBQ-1; Fri, 27 Mar 2020 10:01:25 -0400 X-MC-Unique: IhFdegswPqOnvQl_xs_QBQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 331DC8018AB; Fri, 27 Mar 2020 14:01:24 +0000 (UTC) Received: from horse.redhat.com (ovpn-117-99.rdu2.redhat.com [10.10.117.99]) by smtp.corp.redhat.com (Postfix) with ESMTP id 05F425DA81; Fri, 27 Mar 2020 14:01:14 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 3255B222D9D; Fri, 27 Mar 2020 10:01:14 -0400 (EDT) Date: Fri, 27 Mar 2020 10:01:14 -0400 From: Vivek Goyal To: Liu Bo Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, virtio-fs@redhat.com, miklos@szeredi.hu, stefanha@redhat.com, dgilbert@redhat.com, mst@redhat.com Subject: Re: [PATCH 20/20] fuse,virtiofs: Add logic to free up a memory range Message-ID: <20200327140114.GB32717@redhat.com> References: <20200304165845.3081-1-vgoyal@redhat.com> <20200304165845.3081-21-vgoyal@redhat.com> <20200326000904.GA34937@rsjd01523.et2sqa> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200326000904.GA34937@rsjd01523.et2sqa> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 26, 2020 at 08:09:05AM +0800, Liu Bo wrote: [..] > > +/* > > + * Find first mapping in the tree and free it and return it. Do not add > > + * it back to free pool. If fault == true, this function should be called > > + * with fi->i_mmap_sem held. > > + */ > > +static struct fuse_dax_mapping *inode_reclaim_one_dmap(struct fuse_conn *fc, > > + struct inode *inode, > > + bool fault) > > +{ > > + struct fuse_inode *fi = get_fuse_inode(inode); > > + struct fuse_dax_mapping *dmap; > > + int ret; > > + > > + if (!fault) > > + down_write(&fi->i_mmap_sem); > > + > > + /* > > + * Make sure there are no references to inode pages using > > + * get_user_pages() > > + */ > > + ret = fuse_break_dax_layouts(inode, 0, 0); > > Hi Vivek, > > This patch is enabling inline reclaim for fault path, but fault path > has already holds a locked exceptional entry which I believe the above > fuse_break_dax_layouts() needs to wait for, can you please elaborate > on how this can be avoided? > Hi Liubo, Can you please point to the exact lock you are referring to. I will check it out. Once we got rid of needing to take inode lock in reclaim path, that opended the door to do inline reclaim in fault path as well. But I was not aware of this exceptional entry lock. Vivek