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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6BB10C4332F for ; Thu, 20 Jan 2022 08:46:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359349AbiATIq1 (ORCPT ); Thu, 20 Jan 2022 03:46:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359357AbiATIqX (ORCPT ); Thu, 20 Jan 2022 03:46:23 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A2D3C06173F; Thu, 20 Jan 2022 00:46:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Fc144p+00WPTTP0zDhiznn2Saihska6K3bXQ86DJDN8=; b=zvTVKUKQd9PEBeP/epohTKoS+l or0ElzDA6K1hJ+W7u12fMmcQpP7gHqMjL3UzuuGFGloW2ww1X/tKQiBNw7gj+Fj7abYWevriIOS6H 1GzCib8DXwF5Hr1I6wLxqUm6hPlDb58oR7iQ5ohv5nmbRvA7GXelUVCdaF4HjMlyS7E+/ZxcG9XH0 09qYIkZ//VSEouo9f4Uy3qffJOfHEiW1mS8AfmNQpZTvyqZPB4iNotwURjoiG8xOk9mM4ndDLy1sp z3qtmtboIzdqQc863Ssh+x57Dn1FKDdh26S8CkLMnfMD5neyvmq3y7BR5cJwcJb9R0BU973hNaXU2 r6+tKmWg==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nAT5I-009tD3-5C; Thu, 20 Jan 2022 08:46:20 +0000 Date: Thu, 20 Jan 2022 00:46:20 -0800 From: Christoph Hellwig To: Dan Williams Cc: "Darrick J. Wong" , Shiyang Ruan , Linux Kernel Mailing List , linux-xfs , Linux NVDIMM , Linux MM , linux-fsdevel , david , Christoph Hellwig , Jane Chu Subject: Re: [PATCH v9 02/10] dax: Introduce holder for dax_device Message-ID: References: <20211226143439.3985960-1-ruansy.fnst@fujitsu.com> <20211226143439.3985960-3-ruansy.fnst@fujitsu.com> <20220105181230.GC398655@magnolia> <20220105185626.GE398655@magnolia> <20220105224727.GG398655@magnolia> <20220105235407.GN656707@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 05, 2022 at 04:12:04PM -0800, Dan Williams wrote: > We ended up with explicit callbacks after hch balked at a notifier > call-chain, but I think we're back to that now. The partition mistake > might be unfixable, but at least bdev_dax_pgoff() is dead. Notifier > call chains have their own locking so, Ruan, this still does not need > to touch dax_read_lock(). I think we have a few options here: (1) don't allow error notifications on partitions. And error return from the holder registration with proper error handling in the file system would give us that (2) extent the holder mechanism to cover a range (3) bite the bullet and create a new stacked dax_device for each partition I think (1) is the best option for now. If people really do need partitions we'll have to go for (3)