From patchwork Mon Nov 19 03:51:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 10688195 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B6A1A17D2 for ; Mon, 19 Nov 2018 03:52:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A37B529AC4 for ; Mon, 19 Nov 2018 03:52:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9877329ACA; Mon, 19 Nov 2018 03:52:04 +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=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham 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 3F83C29AC4 for ; Mon, 19 Nov 2018 03:52:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728281AbeKSOOT (ORCPT ); Mon, 19 Nov 2018 09:14:19 -0500 Received: from esa6.hgst.iphmx.com ([216.71.154.45]:62746 "EHLO esa6.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726903AbeKSOOR (ORCPT ); Mon, 19 Nov 2018 09:14:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1542599521; x=1574135521; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=0Xnqma5d37U1rxyzamL4z6UnYEUN6VPkgOpnFiZGCoA=; b=eenaSNxEhz1ZvQhwtXTiIw71spRoU3YDFv5ckm5x7o6MDuPng/AxifcA U01s0Cx1q+1oLhtVgklv6WDRyO8tYbyF5zGa4tClf+SZpKqHMmk4j9dcE KORPtjdjZKtrCKU98+493zMg0jKR5yCPQBV167x+UON0Nn5rikq3gRIw5 ZRVNoUn5QvCd/frCbPts2+Azx6mANImJsGasSQ5nF9xfaFf2T1/ViVZwM n8a9Sje5UVG3N11FRcatWUBedL7G1hKKOpNzn3OLNNvQcbpDOaVq9V4Xa FZavbTL6sAL9iB71Y8Ovr69DU9JEHGL+NArUGJkPjTxRsKXWaRC9pRdDJ Q==; X-IronPort-AV: E=Sophos;i="5.56,250,1539619200"; d="scan'208";a="96272470" Received: from uls-op-cesaip01.wdc.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 19 Nov 2018 11:51:52 +0800 Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP; 18 Nov 2018 19:34:50 -0800 Received: from washi.fujisawa.hgst.com ([10.149.53.254]) by uls-op-cesaip02.wdc.com with ESMTP; 18 Nov 2018 19:51:50 -0800 From: Damien Le Moal To: linux-block@vger.kernel.org, Jens Axboe Cc: Adam Manzanares , Alexander Viro , linux-fsdevel@vger.kernel.org Subject: [PATCH 7/7] block: Initialize BIO I/O priority early Date: Mon, 19 Nov 2018 12:51:31 +0900 Message-Id: <20181119035131.11255-8-damien.lemoal@wdc.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181119035131.11255-1-damien.lemoal@wdc.com> References: <20181119035131.11255-1-damien.lemoal@wdc.com> MIME-Version: 1.0 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 For the synchronous I/O path case (read(), write() etc system calls), a BIO I/O priority is not initialized until the execution of blk_init_request_from_bio() when the BIO is submitted and a request initialized for the BIO execution. This is due to the ki_ioprio field of the struct kiocb defined on stack being always initialized to IOPRIO_CLASS_NONE, regardless of the calling process I/O context ioprio value set with ioprio_set(). This late initialization can result in the BIO being merged to pending requests even when the I/O priorities differ. Fix this by initializing the ki_iopriority field of on stack struct kiocb using the get_current_ioprio() helper, ensuring that all BIOs allocated and submitted for the system call execution see the correct intended I/O priority early. With this, since a BIO I/O priority is always set to the intended effective value for both the sync and async path, blk_init_request_from_bio() can be simplified. Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Adam Manzanares --- block/blk-core.c | 5 +---- include/linux/fs.h | 2 +- 2 files changed, 2 insertions(+), 5 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index dde30b08aa14..04f5be473638 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -814,10 +814,7 @@ void blk_init_request_from_bio(struct request *req, struct bio *bio) req->cmd_flags |= REQ_FAILFAST_MASK; req->__sector = bio->bi_iter.bi_sector; - if (ioprio_valid(bio_prio(bio))) - req->ioprio = bio_prio(bio); - else - req->ioprio = get_current_ioprio(); + req->ioprio = bio_prio(bio); req->write_hint = bio->bi_write_hint; blk_rq_bio_prep(req->q, req, bio); } diff --git a/include/linux/fs.h b/include/linux/fs.h index c95c0807471f..a1ab233e6469 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2021,7 +2021,7 @@ static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) .ki_filp = filp, .ki_flags = iocb_flags(filp), .ki_hint = ki_hint_validate(file_write_hint(filp)), - .ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0), + .ki_ioprio = get_current_ioprio(), }; }