From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CFA0322ACCF for ; Thu, 16 Jan 2025 14:12:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737036755; cv=none; b=mgY7bOo1HsOYI3j1UGmm573dssfCKsKBX61XpcepDYBqpIOp3W0dbci8gwE1HQl4937HJBor7CU5rwpsjRZukXDAJ9vOQKjBzX+S7mq3tDDJB2N/nPBYCLBE2zzHd8KNTq3Ydrx9XJm8R3pX7jZ4mIBjIHbv/incE732H6HcEcQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737036755; c=relaxed/simple; bh=oRtFi8McpCxVVsyZleMs0GMtACqZkHAyjdFnsbDBZQk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=R4PEhQ+zZKWyTH3xVBx/m3AWrUdvln3aMJ6WiQE+MtyR76cY6ZZ8Qt4EXmS3hMP/VzF2V9Wp8y63nLRXneSpbwe1L8UL2163QPOUW44Bdhb71YtTy7i4uKrxKBm9Fr6dxck5zRZOAZjbCoNG0plyHX3fFMgMaW5bRqo/WBsbiz4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=H7e6xByO; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="H7e6xByO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1737036752; 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=dbWlw8NVg/axutqw+0j5popL7IrrTmwSvM9kB1WHeaI=; b=H7e6xByOHgtnYfVbk9NF4efTjlz2eyt+iI4ScCgZk1uItR5FnK1E3VC9HLnoBL2BZNBHxv XSrPAs6ZVf+n01njF+z/w/4jDlg44XfUhiDiffosKgSd2F9hMMh+9Nrxs8CFQN5nj1uuyQ DsHnJ7VkRlHJWFIZ+DqnGWP4ZrZ5H7A= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-631-fwybAtCwNFOwZ8zFI9-9hg-1; Thu, 16 Jan 2025 09:12:26 -0500 X-MC-Unique: fwybAtCwNFOwZ8zFI9-9hg-1 X-Mimecast-MFC-AGG-ID: fwybAtCwNFOwZ8zFI9-9hg Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3683F1910B28; Thu, 16 Jan 2025 14:12:17 +0000 (UTC) Received: from bfoster (unknown [10.22.80.118]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6C7341955F10; Thu, 16 Jan 2025 14:12:16 +0000 (UTC) Date: Thu, 16 Jan 2025 09:14:28 -0500 From: Brian Foster To: Christoph Hellwig Cc: linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org Subject: Re: [PATCH RFCv2 2/4] iomap: optional zero range dirty folio processing Message-ID: References: <20241213150528.1003662-1-bfoster@redhat.com> <20241213150528.1003662-3-bfoster@redhat.com> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On Tue, Jan 14, 2025 at 09:47:28PM -0800, Christoph Hellwig wrote: > On Mon, Jan 13, 2025 at 09:32:37AM -0500, Brian Foster wrote: > > In turn, this means that extending write zero range would have either > > physically zeroed delalloc extents or skipped unwritten blocks, > > depending on the situation. Personally, I don't think it really matters > > which as there is no real guarantee that "all blocks not previously > > written to are unwritten," for example, but rather just that "all blocks > > not written to return zeroes on read." > > Yes. > > > For that reason, I'm _hoping_ > > that we can keep this simple and just deal with some potential spurious > > zeroing on folios that are already dirty, but I'm open to arguments > > against that. > > I can't see one. But we really should fine a way to write all this > including the arguments for an again down. > Indeed. If the first non-rfc pass ultimately makes this tradeoff, I'll plan to document the behavior in the code and the reasoning and tradeoffs in the commit log so it can be reviewed. Brian