Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932533AbbLHBRT (ORCPT ); Mon, 7 Dec 2015 20:17:19 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:46953 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932146AbbLHBRR (ORCPT ); Mon, 7 Dec 2015 20:17:17 -0500 To: "Darrick J. Wong" Cc: Jens Axboe , Christoph Hellwig , "Seymour\, Shane M" , "linux-kernel\@vger.kernel.org" , "linux-fsdevel\@vger.kernel.org" , "linux-api\@vger.kernel.org" , Jeff Layton , "J. Bruce Fields" , "martin.petersen\@oracle.com" Subject: Re: [PATCH v4] block: create ioctl to discard-or-zeroout a range of blocks From: "Martin K. Petersen" Organization: Oracle Corporation References: <20151113220143.GE2217@birch.djwong.org> Date: Mon, 07 Dec 2015 20:16:37 -0500 In-Reply-To: <20151113220143.GE2217@birch.djwong.org> (Darrick J. Wong's message of "Fri, 13 Nov 2015 14:01:43 -0800") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1118 Lines: 24 >>>>> "Darrick" == Darrick J Wong writes: Darrick> Create a new ioctl to expose the block layer's newfound ability Darrick> to issue either a zeroing discard, a WRITE SAME with a zero Darrick> page, or a regular write with the zero page. This BLKZEROOUT2 Darrick> ioctl takes {start, length, flags} as parameters. So far, the Darrick> only flag available is to enable the zeroing discard part -- Darrick> without it, the call invokes the old BLKZEROOUT behavior. Darrick> start and length have the same meaning as in BLKZEROOUT. Darrick> Furthermore, because BLKZEROOUT2 issues commands directly to Darrick> the storage device, we must invalidate the page cache (as a Darrick> regular O_DIRECT write would do) to avoid returning stale cache Darrick> contents at a later time. Jens? Christoph? -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/