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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 0975DC3F2D2 for ; Fri, 28 Feb 2020 14:05:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B63572051A for ; Fri, 28 Feb 2020 14:05:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="mtQ9sSvz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726810AbgB1OFO (ORCPT ); Fri, 28 Feb 2020 09:05:14 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:56250 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725892AbgB1OFO (ORCPT ); Fri, 28 Feb 2020 09:05:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; 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=l/9vD4kWJ5DgSyvKhFv1tb5oLOTsgXLSNIzvAAdRX2o=; b=mtQ9sSvzCTY3BgpfOC5D6cHQFZ Ixh2Tv/4gk5gFcBys/QcmXPiA5puZzBqBTeFRuaSaH9QNSl0CfAglRw6bNLx6AhO7qlQlH957/HD6 HM0yj+eoyohvvRCiPJYQqJWZABZeaoIgzGoT8oK1uBJSrUjBGRXGgJDcuyyxFISQGu0lsQukeM5/4 GLt4ahZoIPPu7FbZqDZ12B/QLmJAxu3kS6CLYe1V0/Shv7FP6vb8SJfCGT0WrmWMLoe5Cd1+J4lcY UAGcWqH+e1nEcznk5WKgMdVW6DkCturcBrWQ1BrsKa7ai3BQXloxASvhwdD8ZZkDDocxBjmYONzzP 80DEcfqw==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j7gGK-00048K-IE; Fri, 28 Feb 2020 14:05:08 +0000 Date: Fri, 28 Feb 2020 06:05:08 -0800 From: Christoph Hellwig To: Dan Williams Cc: Dave Chinner , Vivek Goyal , Jeff Moyer , linux-fsdevel , linux-nvdimm , Christoph Hellwig , device-mapper development Subject: Re: [PATCH v5 2/8] drivers/pmem: Allow pmem_clear_poison() to accept arbitrary offset and len Message-ID: <20200228140508.GA2987@infradead.org> References: <20200220215707.GC10816@redhat.com> <20200221201759.GF25974@redhat.com> <20200223230330.GE10737@dread.disaster.area> <20200224153844.GB14651@redhat.com> <20200227030248.GG10737@dread.disaster.area> <20200228013054.GO10737@dread.disaster.area> 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 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, Feb 27, 2020 at 07:28:41PM -0800, Dan Williams wrote: > "don't perform generic memory-error-handling, there's an fs that owns > this daxdev and wants to disposition errors". The fs/dax.c > infrastructure that sets up ->index and ->mapping would still need to > be there for ext4 until its ready to take on the same responsibility. > Last I checked the ext4 reverse mapping implementation was not as > capable as XFS. This goes back to why the initial design avoided > relying on not universally available / stable reverse-mapping > facilities and opted for extending the generic mm/memory-failure.c > implementation. The important but is that we stop using ->index and ->mapping when XFS is used as that enables using DAX+reflinks, which actually is the most requested DAX feature on XFS (way more than silly runtime flag switches for example).