From patchwork Wed Jan 18 10:31:42 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thadeu Lima de Souza Cascardo X-Patchwork-Id: 716580 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 3v3NZ55N0Gz9t0C; Wed, 18 Jan 2017 21:31:57 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1cTnWz-00072x-5a; Wed, 18 Jan 2017 10:31:53 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1cTnWv-00071j-B4 for kernel-team@lists.ubuntu.com; Wed, 18 Jan 2017 10:31:49 +0000 Received: from 1.general.cascardo.us.vpn ([10.172.70.58] helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1cTnWu-0000fO-Hu for kernel-team@lists.ubuntu.com; Wed, 18 Jan 2017 10:31:48 +0000 From: Thadeu Lima de Souza Cascardo To: kernel-team@lists.ubuntu.com Subject: [Xenial] blk-mq: really fix plug list flushing for nomerge queues Date: Wed, 18 Jan 2017 08:31:42 -0200 Message-Id: <20170118103142.24265-1-cascardo@canonical.com> X-Mailer: git-send-email 2.9.3 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com From: Omar Sandoval BugLink: https://bugs.launchpad.net/bugs/1657281 Commit 0809e3ac6231 ("block: fix plug list flushing for nomerge queues") updated blk_mq_make_request() to set request_count even when blk_queue_nomerges() returns true. However, blk_mq_make_request() only does limited plugging and doesn't use request_count; blk_sq_make_request() is the one that should have been fixed. Do that and get rid of the unnecessary work in the mq version. Fixes: 0809e3ac6231 ("block: fix plug list flushing for nomerge queues") Signed-off-by: Omar Sandoval Reviewed-by: Ming Lei Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe (cherry picked from commit 87c279e613f848c691111b29d49de8df3f4f56da) Signed-off-by: Thadeu Lima de Souza Cascardo Acked-by: Luis Henriques --- block/blk-mq.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index ec732f5..1b7a905 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1304,12 +1304,9 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) blk_queue_split(q, &bio, q->bio_split); - if (!is_flush_fua && !blk_queue_nomerges(q)) { - if (blk_attempt_plug_merge(q, bio, &request_count, - &same_queue_rq)) - return BLK_QC_T_NONE; - } else - request_count = blk_plug_queued_count(q); + if (!is_flush_fua && !blk_queue_nomerges(q) && + blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq)) + return BLK_QC_T_NONE; rq = blk_mq_map_request(q, bio, &data); if (unlikely(!rq)) @@ -1400,9 +1397,11 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) blk_queue_split(q, &bio, q->bio_split); - if (!is_flush_fua && !blk_queue_nomerges(q) && - blk_attempt_plug_merge(q, bio, &request_count, NULL)) - return BLK_QC_T_NONE; + if (!is_flush_fua && !blk_queue_nomerges(q)) { + if (blk_attempt_plug_merge(q, bio, &request_count, NULL)) + return BLK_QC_T_NONE; + } else + request_count = blk_plug_queued_count(q); rq = blk_mq_map_request(q, bio, &data); if (unlikely(!rq))