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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AB60C43334 for ; Mon, 27 Jun 2022 11:26:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235057AbiF0L0W (ORCPT ); Mon, 27 Jun 2022 07:26:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45606 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234949AbiF0LZh (ORCPT ); Mon, 27 Jun 2022 07:25:37 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7545659D; Mon, 27 Jun 2022 04:25:19 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 257EC61459; Mon, 27 Jun 2022 11:25:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 284EDC341C7; Mon, 27 Jun 2022 11:25:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656329118; bh=Xs774V0mF+K9kaKGqJ0IKq9qDk6UomBqM7x0sPzgZWQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JlKsdM20MQzMKjXLsgjmSvmpp9mZcwmfrFc2HhqNq5kWzbl6F1hCKF/Ip1f5BZQqt GHSSaacJEmu2qqHXx1LXrSOnwG86jA7uESNGGclzzg3nQZlgwiofOfMo1CQyX+iTwe hGS2IWJD8bp9LtYlEPe0roZPOgwP1irKtq730SXM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chaitanya Kulkarni , Christoph Hellwig , Sasha Levin Subject: [PATCH 5.10 057/102] nvme: dont check nvme_req flags for new req Date: Mon, 27 Jun 2022 13:21:08 +0200 Message-Id: <20220627111935.162378464@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220627111933.455024953@linuxfoundation.org> References: <20220627111933.455024953@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chaitanya Kulkarni [ Upstream commit c03fd85de293a4f65fcb94a795bf4c12a432bb6c ] nvme_clear_request() has a check for flag REQ_DONTPREP and it is called from nvme_init_request() and nvme_setuo_cmd(). The function nvme_init_request() is called from nvme_alloc_request() and nvme_alloc_request_qid(). From these two callers new request is allocated everytime. For newly allocated request RQF_DONTPREP is never set. Since after getting a tag, block layer sets the req->rq_flags == 0 and never sets the REQ_DONTPREP when returning the request :- nvme_alloc_request() blk_mq_alloc_request() blk_mq_rq_ctx_init() rq->rq_flags = 0 <---- nvme_alloc_request_qid() blk_mq_alloc_request_hctx() blk_mq_rq_ctx_init() rq->rq_flags = 0 <---- The block layer does set req->rq_flags but REQ_DONTPREP is not one of them and that is set by the driver. That means we can unconditinally set the REQ_DONTPREP value to the rq->rq_flags when nvme_init_request()->nvme_clear_request() is called from above two callers. Move the check for REQ_DONTPREP from nvme_clear_nvme_request() into nvme_setup_cmd(). This is needed since nvme_alloc_request() now gets called from fast path when NVMeOF target is configured with passthru backend to avoid unnecessary checks in the fast path. Signed-off-by: Chaitanya Kulkarni Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- drivers/nvme/host/core.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index d81b0cff15e0..c42ad0b8247b 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -531,11 +531,9 @@ EXPORT_SYMBOL_NS_GPL(nvme_put_ns, NVME_TARGET_PASSTHRU); static inline void nvme_clear_nvme_request(struct request *req) { - if (!(req->rq_flags & RQF_DONTPREP)) { - nvme_req(req)->retries = 0; - nvme_req(req)->flags = 0; - req->rq_flags |= RQF_DONTPREP; - } + nvme_req(req)->retries = 0; + nvme_req(req)->flags = 0; + req->rq_flags |= RQF_DONTPREP; } static inline unsigned int nvme_req_op(struct nvme_command *cmd) @@ -854,7 +852,8 @@ blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req, struct nvme_ctrl *ctrl = nvme_req(req)->ctrl; blk_status_t ret = BLK_STS_OK; - nvme_clear_nvme_request(req); + if (!(req->rq_flags & RQF_DONTPREP)) + nvme_clear_nvme_request(req); memset(cmd, 0, sizeof(*cmd)); switch (req_op(req)) { -- 2.35.1