From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 558FB8F70 for ; Sun, 16 Jul 2023 19:53:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9066C433C8; Sun, 16 Jul 2023 19:53:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689537209; bh=z/ZsT1jcYwNb7ax/VtNUfQkxQ/eId54uF8d1+B3/YiM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EkmnAHHy9gPPenOOO98/VuxA7u//WYQLTXKfUJmuXRxPNGAsGCIldUUqTaNRSelrE ixaYYCo00JfYaHUiSs/wrTUYc4tl5MjWwvyqOVp/SEf3556nw/ux1OTYqmL/psfNfx 8T0fZxHovSc+rB/PqkGF8tbcQ5elk62pWGO+A7S4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Guangwu Zhang , Ming Lei , Christoph Hellwig , Jens Axboe , Sasha Levin , Yu Kuai Subject: [PATCH 6.4 015/800] blk-mq: dont queue plugged passthrough requests into scheduler Date: Sun, 16 Jul 2023 21:37:48 +0200 Message-ID: <20230716194949.458921693@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230716194949.099592437@linuxfoundation.org> References: <20230716194949.099592437@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ming Lei [ Upstream commit d97217e7f024bbe9aa62aea070771234c2879358 ] Passthrough requests should never be queued to the I/O scheduler, as scheduling these opaque requests doesn't make sense, and I/O schedulers might require req->bio to be always valid. We never let passthrough requests insert into the scheduler before commit 1c2d2fff6dc0 ("block: wire-up support for passthrough plugging"), restore this behavior even for passthrough requests issued under a plug. [hch: use blk_mq_insert_requests for passthrough requests, fix up the commit message and comments] Reported-by: Guangwu Zhang Closes: https://lore.kernel.org/linux-block/CAGS2=YosaYaUTEMU3uaf+y=8MqSrhL7sYsJn8EwbaM=76p_4Qg@mail.gmail.com/ Investigated-by: Yu Kuai Fixes: 1c2d2fff6dc0 ("block: wire-up support for passthrough plugging") Signed-off-by: Ming Lei Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230518053101.760632-2-hch@lst.de Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-mq.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 850bfb844ed2f..c763f0bc66371 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2711,6 +2711,7 @@ static void blk_mq_dispatch_plug_list(struct blk_plug *plug, bool from_sched) struct request *requeue_list = NULL; struct request **requeue_lastp = &requeue_list; unsigned int depth = 0; + bool is_passthrough = false; LIST_HEAD(list); do { @@ -2719,7 +2720,9 @@ static void blk_mq_dispatch_plug_list(struct blk_plug *plug, bool from_sched) if (!this_hctx) { this_hctx = rq->mq_hctx; this_ctx = rq->mq_ctx; - } else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx) { + is_passthrough = blk_rq_is_passthrough(rq); + } else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx || + is_passthrough != blk_rq_is_passthrough(rq)) { rq_list_add_tail(&requeue_lastp, rq); continue; } @@ -2731,7 +2734,8 @@ static void blk_mq_dispatch_plug_list(struct blk_plug *plug, bool from_sched) trace_block_unplug(this_hctx->queue, depth, !from_sched); percpu_ref_get(&this_hctx->queue->q_usage_counter); - if (this_hctx->queue->elevator) { + /* passthrough requests should never be issued to the I/O scheduler */ + if (this_hctx->queue->elevator && !is_passthrough) { this_hctx->queue->elevator->type->ops.insert_requests(this_hctx, &list, 0); blk_mq_run_hw_queue(this_hctx, from_sched); -- 2.39.2