From patchwork Sun Sep 24 07:02:40 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 9967809 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1D20A6037F for ; Sun, 24 Sep 2017 07:03:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 10F7521C9A for ; Sun, 24 Sep 2017 07:03:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 05FCF27F81; Sun, 24 Sep 2017 07:03:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B10B021C9A for ; Sun, 24 Sep 2017 07:03:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751908AbdIXHDU (ORCPT ); Sun, 24 Sep 2017 03:03:20 -0400 Received: from esa1.hgst.iphmx.com ([68.232.141.245]:22595 "EHLO esa1.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751813AbdIXHDD (ORCPT ); Sun, 24 Sep 2017 03:03:03 -0400 X-IronPort-AV: E=Sophos;i="5.42,431,1500912000"; d="scan'208";a="156248362" Received: from sjappemgw12.hgst.com (HELO sjappemgw11.hgst.com) ([199.255.44.66]) by ob1.hgst.iphmx.com with ESMTP; 24 Sep 2017 15:03:02 +0800 Received: from washi.fujisawa.hgst.com ([10.149.53.254]) by sjappemgw11.hgst.com with ESMTP; 24 Sep 2017 00:03:02 -0700 From: Damien Le Moal To: linux-scsi@vger.kernel.org, "Martin K . Petersen" , linux-block@vger.kernel.org, Jens Axboe Cc: Christoph Hellwig , Bart Van Assche Subject: [PATCH V4 09/16] scsi: sd_zbc: Disable zone write locking with scsi-mq Date: Sun, 24 Sep 2017 16:02:40 +0900 Message-Id: <20170924070247.25560-10-damien.lemoal@wdc.com> X-Mailer: git-send-email 2.13.5 In-Reply-To: <20170924070247.25560-1-damien.lemoal@wdc.com> References: <20170924070247.25560-1-damien.lemoal@wdc.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In the case of a ZBC disk used with scsi-mq, zone write locking does not prevent write reordering in sequential zones. Unlike the legacy case, zone locking is done after the command request is removed from the scheduler dispatch queue. That is, at the time of zone locking, the write command may already be out of order, making locking ineffective. Write order guarantees can only be provided by an adapted I/O scheduler. Disable zone write locking in sd_zbc_write_lock_zone() if the disk is used with scsi-mq. As the disk zones_wlock bitmap is not necessry, do not allocate it. Signed-off-by: Damien Le Moal Reviewed-by: Bart Van Assche Reviewed-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig --- drivers/scsi/sd_zbc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c index 9bc0bde596e3..34576fb31f3a 100644 --- a/drivers/scsi/sd_zbc.c +++ b/drivers/scsi/sd_zbc.c @@ -314,6 +314,10 @@ int sd_zbc_write_lock_zone(struct scsi_cmnd *cmd) (sector & (zone_sectors - 1)) + blk_rq_sectors(rq) > zone_sectors) return BLKPREP_KILL; + /* No write locking with scsi-mq */ + if (q->mq_ops) + return BLKPREP_OK; + /* * There is no write constraints on conventional zones. So any write * command can be sent. But do not issue more than one write command @@ -713,7 +717,8 @@ static int sd_zbc_setup(struct scsi_disk *sdkp) if (sdkp->first_scan) return 0; - if (!sdkp->zones_wlock || q->nr_zones != sdkp->nr_zones) { + if (!q->mq_ops && + (!sdkp->zones_wlock || q->nr_zones != sdkp->nr_zones)) { kfree(sdkp->zones_wlock); sdkp->zones_wlock = sd_zbc_alloc_zone_bitmap(sdkp); if (!sdkp->zones_wlock)