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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F839C433FE for ; Thu, 20 Jan 2022 08:46:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2F5A16B0072; Thu, 20 Jan 2022 03:46:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 27E6C6B00AB; Thu, 20 Jan 2022 03:46:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 11F8A6B00AC; Thu, 20 Jan 2022 03:46:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0154.hostedemail.com [216.40.44.154]) by kanga.kvack.org (Postfix) with ESMTP id F35F46B0072 for ; Thu, 20 Jan 2022 03:46:26 -0500 (EST) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id B37738249980 for ; Thu, 20 Jan 2022 08:46:26 +0000 (UTC) X-FDA: 79050033972.09.C9FEBA5 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf14.hostedemail.com (Postfix) with ESMTP id C4712100007 for ; Thu, 20 Jan 2022 08:46:25 +0000 (UTC) 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 X-Rspamd-Queue-Id: C4712100007 X-Stat-Signature: m5oz71d6ephbjkk3uwkmnk3jduzg6btk Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=zvTVKUKQ; dmarc=none; spf=none (imf14.hostedemail.com: domain of BATV+0328028a7a74e2859a11+6724+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+0328028a7a74e2859a11+6724+infradead.org+hch@bombadil.srs.infradead.org X-Rspamd-Server: rspam03 X-HE-Tag: 1642668385-781838 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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)