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 EF88B7346F; Thu, 16 Jan 2025 05:42:29 +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=1737006151; cv=none; b=FCbwqljE4EJv121h7HarpXMB1Sd49haVQrJ8ofrk8X5T343rG0baOcD3UN5keK1FoEWo5XcIK8jS5GDE+/PSDWsXXUSSM4ZaQ39bZxfKj9PtCDPQ8FccLHvk3Bvas55aMwXWe2zvBFDH9FgZFED4VLWheUPKZG5/+rCxqKNnc48= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737006151; c=relaxed/simple; bh=qBtIqKbPYLQDzRLYEL+GnEA4r0PMl400HhRevUspdqQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hRRftLjdztCCNjI5n3JcQmaWPHtyK1V+tDU2daKUZo029Zz8EwtvvAUvLQuljYh1P7+mz5yshwFHgxrCIrQwNGCOmW+fs46kOCFH4eoy1DeTD/MDwznZ1Wy59aEC7Fpq7PFRxvTyWH1AMTqLtsdf0sS6jKp5OSBl1OHOcpFvBGg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=tNVlfNOG; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (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="tNVlfNOG" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Transfer-Encoding :Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=oq12XYVIy0vKReS7B9XEMqCqZJpn3crY8ZLl/z7O9oQ=; b=tNVlfNOG8A7NCs5Sn+R3RSzibx +440KJlre66dy38PFNq+PZLV+39uq6ASK+KxOmF5w/vAP5RrLoUf9JzPuRFJ1l0bSr7didGcpFdOd 52ymXzxFgciQS4OM1T5x+V+2RCnWR79F3q7JP6Sp15FLmq3oevtSYUJautd3nDOE1aORAdf+PNHs/ RUSx51HIObTfSxiuQvWlCUD0NRrnIxbWouZmUe/GnWy9T3KBnJnQKbOkbvS1aFh3x9B4JbB8T58RF LSf8Ubnitec6VMqJmmL3bIlpoobaroq4ONIImCIOFqOLr9b3lSIh+6j8QYobBCryuCOKjF2UEtR5J iVTR4Q7g==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tYIeD-0000000Dtl7-1Um9; Thu, 16 Jan 2025 05:42:29 +0000 Date: Wed, 15 Jan 2025 21:42:29 -0800 From: Christoph Hellwig To: Dave Chinner Cc: Anna Schumaker , lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, Linux NFS Mailing List Subject: Re: [LSF/MM/BPF TOPIC] Implementing the NFS v4.2 WRITE_SAME operation: VFS or NFS ioctl() ? Message-ID: References: Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Wed, Jan 15, 2025 at 10:14:56AM +1100, Dave Chinner wrote: > How closely does this match to the block device WRITE_SAME > (SCSI/NVMe) commands? I note there is a reference to this in the > RFC, but there are no details given. There is no write same in NVMe. In one of the few wiѕe choices in NVMe the protocol only does a write zeroes for zeroing instead of the overly complex write zeroes. And no one has complained about that so far.