From patchwork Wed Nov 14 16:02:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 10682815 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 9E7A613BF for ; Wed, 14 Nov 2018 16:02:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 90C302BB01 for ; Wed, 14 Nov 2018 16:02:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 851592BB10; Wed, 14 Nov 2018 16:02:28 +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 1129C2BB01 for ; Wed, 14 Nov 2018 16:02:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732906AbeKOCGQ (ORCPT ); Wed, 14 Nov 2018 21:06:16 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:41644 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726295AbeKOCGP (ORCPT ); Wed, 14 Nov 2018 21:06:15 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=GgkbLm4aj778i58LRBJCVM4tY1mReXiv/WOPYxzOVg4=; b=NqhQBVZ2+7ojq4QXLc59+oI3oa pl94huKOlRGmfSX5XnuqVsZc3wQ3N3bLoWtBRSLDg6BVChunn2qTSThuhfBdqu9DRED2ezhhWXMG3 mj+KsMtjPwVUh/rp88ouv1nKZI/CkGNBYtMeQggBUuc8oRnH7YUmrzm9i/0BKuveAqO8YHCGv+eHl YnRxjPzi67ztT26pVanV/JN3E+o4H1r7k+9NXNUqvroSAvigjvyLdOEKQVOvSI3kUHuPqPiw+jled xQr/s7DuvCWMoCchBo4VRUPbPmP9/wJkTULVyT8A97MLaui244GXAIS3j6A5Ev70YZeGk3klDvgd7 rQjX3lqA==; Received: from 089144211136.atnat0020.highway.a1.net ([89.144.211.136] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gMxcY-00068R-Me; Wed, 14 Nov 2018 16:02:27 +0000 From: Christoph Hellwig To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-mmc@vger.kernel.org, drbd-dev@lists.linbit.com Subject: [PATCH 02/16] block: remove deadline __deadline manipulation helpers Date: Wed, 14 Nov 2018 17:02:05 +0100 Message-Id: <20181114160219.28328-3-hch@lst.de> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181114160219.28328-1-hch@lst.de> References: <20181114160219.28328-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html 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 No users left since the removal of the legacy request interface, we can remove all the magic bit stealing now and make it a normal field. But use WRITE_ONCE/READ_ONCE on the new deadline field, given that we don't seem to have any mechanism to guarantee a new value actually gets seen by other threads. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke --- block/blk-mq.c | 4 ++-- block/blk-timeout.c | 8 +++++--- block/blk.h | 35 ----------------------------------- include/linux/blkdev.h | 4 +--- 4 files changed, 8 insertions(+), 43 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 411be60d0cb6..4c82b4b4fa3e 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -325,7 +325,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, rq->special = NULL; /* tag was already set */ rq->extra_len = 0; - rq->__deadline = 0; + WRITE_ONCE(rq->deadline, 0); rq->timeout = 0; @@ -839,7 +839,7 @@ static bool blk_mq_req_expired(struct request *rq, unsigned long *next) if (rq->rq_flags & RQF_TIMED_OUT) return false; - deadline = blk_rq_deadline(rq); + deadline = READ_ONCE(rq->deadline); if (time_after_eq(jiffies, deadline)) return true; diff --git a/block/blk-timeout.c b/block/blk-timeout.c index 006cff4390c0..3b0179fbdd6a 100644 --- a/block/blk-timeout.c +++ b/block/blk-timeout.c @@ -84,7 +84,7 @@ void blk_abort_request(struct request *req) * immediately and that scan sees the new timeout value. * No need for fancy synchronizations. */ - blk_rq_set_deadline(req, jiffies); + WRITE_ONCE(req->deadline, jiffies); kblockd_schedule_work(&req->q->timeout_work); } EXPORT_SYMBOL_GPL(blk_abort_request); @@ -121,14 +121,16 @@ void blk_add_timer(struct request *req) req->timeout = q->rq_timeout; req->rq_flags &= ~RQF_TIMED_OUT; - blk_rq_set_deadline(req, jiffies + req->timeout); + + expiry = jiffies + req->timeout; + WRITE_ONCE(req->deadline, expiry); /* * If the timer isn't already pending or this timeout is earlier * than an existing one, modify the timer. Round up to next nearest * second. */ - expiry = blk_rq_timeout(round_jiffies_up(blk_rq_deadline(req))); + expiry = blk_rq_timeout(round_jiffies_up(expiry)); if (!timer_pending(&q->timeout) || time_before(expiry, q->timeout.expires)) { diff --git a/block/blk.h b/block/blk.h index 41b64e6e101b..08a5845b03ba 100644 --- a/block/blk.h +++ b/block/blk.h @@ -238,26 +238,6 @@ void blk_account_io_start(struct request *req, bool new_io); void blk_account_io_completion(struct request *req, unsigned int bytes); void blk_account_io_done(struct request *req, u64 now); -/* - * EH timer and IO completion will both attempt to 'grab' the request, make - * sure that only one of them succeeds. Steal the bottom bit of the - * __deadline field for this. - */ -static inline int blk_mark_rq_complete(struct request *rq) -{ - return test_and_set_bit(0, &rq->__deadline); -} - -static inline void blk_clear_rq_complete(struct request *rq) -{ - clear_bit(0, &rq->__deadline); -} - -static inline bool blk_rq_is_complete(struct request *rq) -{ - return test_bit(0, &rq->__deadline); -} - /* * Internal elevator interface */ @@ -322,21 +302,6 @@ static inline void req_set_nomerge(struct request_queue *q, struct request *req) q->last_merge = NULL; } -/* - * Steal a bit from this field for legacy IO path atomic IO marking. Note that - * setting the deadline clears the bottom bit, potentially clearing the - * completed bit. The user has to be OK with this (current ones are fine). - */ -static inline void blk_rq_set_deadline(struct request *rq, unsigned long time) -{ - rq->__deadline = time & ~0x1UL; -} - -static inline unsigned long blk_rq_deadline(struct request *rq) -{ - return rq->__deadline & ~0x1UL; -} - /* * Internal io_context interface */ diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index c92aafcde0b8..1aa94759d219 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -224,9 +224,7 @@ struct request { refcount_t ref; unsigned int timeout; - - /* access through blk_rq_set_deadline, blk_rq_deadline */ - unsigned long __deadline; + unsigned long deadline; union { struct __call_single_data csd;