From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 727C6433BC; Fri, 7 Nov 2025 13:59:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762523949; cv=none; b=M5a6VhZIK/yR+X7GI+jMZCoi1iLCFKYCoLo0iIuVYGDUrHaqKhwSFRLoRuwQLIuM5WDy4UCzLQ4S4yKmBIFXsjJr0wBeY8vSBBSrgzR6TJz/+h7O+gQUwjSf9TiRCXLQ0ltZAMkCjiD5HbtIFHc70ZVXsOEhSA6IYzSTl/Ft7Sc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762523949; c=relaxed/simple; bh=P6XUHOaJvjG29cBiZ2CB/0Yx4883pM3A3OrPUozDIX4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hZVCVMGwZn6YGKw/GNBtXcHKkfByKReuGdO4eAeMW5K7yv1kKCAgN3MFXUjhyvJIV1jp/r45tXAgtMHi7Q5gnDvqwFUD8esfFiXTqz3GreOn28MstLH3uKleamXliMot9u6v70X/01Q9ngcwJRhGc+8bJhVYu496jyHpCo0+TAs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=K10DaNeN; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="K10DaNeN" 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=7dUWbgfOqkVn7S/pp573YtAkvotd2+0fUGiwiV5AgqE=; b=K10DaNeN6/TEZ/6YgKnQ+Vbx3L 0aWGqAC12MgvdxL2ZfR0gB943XKed1B3yT1XIAf1qV6tx438EJSX2A1LvEFQ7kEAhfaOIHTkx6lHv 68BMhmkCWqCx47VmHtMOoyULtrQIPcRZAOQEMtR2diuHf5qndB+MOe+zaaEfKVbqO/S+vuG1o1PDC vm4ABhl3RlJlP4VAYSC8CnGQitHuaci6YT/6RjAPTZVFIh0FVSiuG3lPMB3trP7+t8LyZu/VL+Nwm VPqhc6iPJMZpXyqWJKH42hvwZy74YDG7z1v5aShuTmluQwgRO9cVzXFBx74aS6ag+A+0+AtGviax2 UhVbt6uA==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vHMzX-0000000HRec-3VPC; Fri, 07 Nov 2025 13:59:03 +0000 Date: Fri, 7 Nov 2025 05:59:03 -0800 From: Christoph Hellwig To: "Darrick J. Wong" Cc: Brian Foster , linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org Subject: Re: [PATCH 2/6] iomap, xfs: lift zero range hole mapping flush into xfs Message-ID: References: <20251016190303.53881-1-bfoster@redhat.com> <20251016190303.53881-3-bfoster@redhat.com> <20251105003114.GY196370@frogsfrogsfrogs> <20251105222350.GO196362@frogsfrogsfrogs> <20251106233208.GU196362@frogsfrogsfrogs> 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: <20251106233208.GU196362@frogsfrogsfrogs> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Thu, Nov 06, 2025 at 03:32:08PM -0800, Darrick J. Wong wrote: > A harder question is: what would filesystems put in write_map for a pure > read? They could leave it at the default (null mapping) and the kernel > wouldn't pay attention to it. Please make them entirely separate iomap_iters, and allowing nesting. That way no write map even exists for pure reads.