From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F082C4338F for ; Thu, 29 Jul 2021 03:42:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46AE36103B for ; Thu, 29 Jul 2021 03:42:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233540AbhG2Dmf (ORCPT ); Wed, 28 Jul 2021 23:42:35 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:39810 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233485AbhG2Dme (ORCPT ); Wed, 28 Jul 2021 23:42:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627530152; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Cc/YzqRrbTx5UWbIoPFZIBO+WNHdOLY69/3c+ld8y+M=; b=V6h0Pu59QKyGGjY5FFhTFRDlNFJz4Jxfd0iGgl4WNhPHFvZvrOI+LovEj71pxgJ7JahMni APVgvsx94WVZdwYfJUOpOAe0sJevxaDzuKWNAcJw02ffC9fSsf3LJQWhvk1ngFMu7uTvAq vN7hpeoIcrVPZgkh6Fg1TSQmwwZm3qE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-468-izmmeIMYMsmRbDJ6mzFGSw-1; Wed, 28 Jul 2021 23:42:30 -0400 X-MC-Unique: izmmeIMYMsmRbDJ6mzFGSw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7427B107ACF5; Thu, 29 Jul 2021 03:42:29 +0000 (UTC) Received: from localhost (ovpn-13-29.pek2.redhat.com [10.72.13.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id B62CF26DC7; Thu, 29 Jul 2021 03:42:24 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Ming Lei , Oleksandr Natalenko Subject: [PATCH] block: return ELEVATOR_DISCARD_MERGE if possible Date: Thu, 29 Jul 2021 11:42:26 +0800 Message-Id: <20210729034226.1591070-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org When merging one bio to request, if they are discard IO and the queue supports multi-range discard, we need to return ELEVATOR_DISCARD_MERGE because both block core and related drivers(nvme, virtio-blk) doesn't handle mixed discard io merge(traditional IO merge together with discard merge) well. Fix the issue by returning ELEVATOR_DISCARD_MERGE in this situation, so both blk-mq and drivers just need to handle multi-range discard. Reported-by: Oleksandr Natalenko Signed-off-by: Ming Lei --- block/bfq-iosched.c | 3 +++ block/blk-merge.c | 16 ---------------- block/elevator.c | 3 +++ block/mq-deadline-main.c | 2 ++ include/linux/blkdev.h | 16 ++++++++++++++++ 5 files changed, 24 insertions(+), 16 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 727955918563..673a634eadd9 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2361,6 +2361,9 @@ static int bfq_request_merge(struct request_queue *q, struct request **req, __rq = bfq_find_rq_fmerge(bfqd, bio, q); if (__rq && elv_bio_merge_ok(__rq, bio)) { *req = __rq; + + if (blk_discard_mergable(__rq)) + return ELEVATOR_DISCARD_MERGE; return ELEVATOR_FRONT_MERGE; } diff --git a/block/blk-merge.c b/block/blk-merge.c index a11b3b53717e..f8707ff7e2fc 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -705,22 +705,6 @@ static void blk_account_io_merge_request(struct request *req) } } -/* - * Two cases of handling DISCARD merge: - * If max_discard_segments > 1, the driver takes every bio - * as a range and send them to controller together. The ranges - * needn't to be contiguous. - * Otherwise, the bios/requests will be handled as same as - * others which should be contiguous. - */ -static inline bool blk_discard_mergable(struct request *req) -{ - if (req_op(req) == REQ_OP_DISCARD && - queue_max_discard_segments(req->q) > 1) - return true; - return false; -} - static enum elv_merge blk_try_req_merge(struct request *req, struct request *next) { diff --git a/block/elevator.c b/block/elevator.c index 52ada14cfe45..a5fe2615ec0f 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -336,6 +336,9 @@ enum elv_merge elv_merge(struct request_queue *q, struct request **req, __rq = elv_rqhash_find(q, bio->bi_iter.bi_sector); if (__rq && elv_bio_merge_ok(__rq, bio)) { *req = __rq; + + if (blk_discard_mergable(__rq)) + return ELEVATOR_DISCARD_MERGE; return ELEVATOR_BACK_MERGE; } diff --git a/block/mq-deadline-main.c b/block/mq-deadline-main.c index 6f612e6dc82b..294be0c0db65 100644 --- a/block/mq-deadline-main.c +++ b/block/mq-deadline-main.c @@ -677,6 +677,8 @@ static int dd_request_merge(struct request_queue *q, struct request **rq, if (elv_bio_merge_ok(__rq, bio)) { *rq = __rq; + if (blk_discard_mergable(__rq)) + return ELEVATOR_DISCARD_MERGE; return ELEVATOR_FRONT_MERGE; } } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3177181c4326..87f00292fd7a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1521,6 +1521,22 @@ static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector return offset << SECTOR_SHIFT; } +/* + * Two cases of handling DISCARD merge: + * If max_discard_segments > 1, the driver takes every bio + * as a range and send them to controller together. The ranges + * needn't to be contiguous. + * Otherwise, the bios/requests will be handled as same as + * others which should be contiguous. + */ +static inline bool blk_discard_mergable(struct request *req) +{ + if (req_op(req) == REQ_OP_DISCARD && + queue_max_discard_segments(req->q) > 1) + return true; + return false; +} + static inline int bdev_discard_alignment(struct block_device *bdev) { struct request_queue *q = bdev_get_queue(bdev); -- 2.31.1