From patchwork Thu Sep 5 04:28:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 11132075 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D42FE14DE for ; Thu, 5 Sep 2019 04:29:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B73AC208E4 for ; Thu, 5 Sep 2019 04:29:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="Q5tg4z5j" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731143AbfIEE3I (ORCPT ); Thu, 5 Sep 2019 00:29:08 -0400 Received: from esa1.hgst.iphmx.com ([68.232.141.245]:62199 "EHLO esa1.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731095AbfIEE3F (ORCPT ); Thu, 5 Sep 2019 00:29:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1567657745; x=1599193745; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=4es099Tzn+1lybmV19FyhcM0o6YKAGlTweyIXLI8G2M=; b=Q5tg4z5jfpwQcwbO5s0Tpg7LsZ5Y0dQOW3yElhxBazGRNlSr3Onl7aeP OvLcMR4s9nlvoM+3SjLC/UBpN1kH7sMEZxUbL9GxG45o2pPTknAnslAJP 76EZ5ssKD7DYY7hiYdSTc12IPDNLgxTP5asoNbsH/94Ng8CX2/XnmamDB TaLrtcogkSnziqLwLyxZomnp4EaJHl5Gsl4TsB/E3CUqGiX9kh0Bf+Wmd PnXOccr60hVd0LmDnPRMKy4v9JFxNH7YWOL8CUKv6qTryYVOpAwtSp1le 6m8oLbt7I47WAsB7v0klwDhmkimj31WfZogg3rjzQE7hSnLD3YgsrNivd g==; IronPort-SDR: mDlEBW6ucd9Nvjb9I8HynlO4pizPfyaGNvTxTEWc1DRahFp5wcQD9JBsjQJMm7jvvupApnVkox BeFqXpSb50af0CbIhTdNBEO2PHpz9hJjQ72uHL+o7JDwiGy1et3yOSo/02aqHfjT/iMW7uC7aa NXbbDBR5gvzjrHFbI/vz7sRR91LxEHGS6KCWpeQig+/Qlfjt/W9c29QVhpZ4JbmINzocEohqAv QwqY1qG1Hyj4oMFdCP9h3FeEu4DzoC9kKL1r3x8++FOaa22bj90mxQ0ze3mNndAb5P4Hkx9i9M t/o= X-IronPort-AV: E=Sophos;i="5.64,469,1559491200"; d="scan'208";a="224233073" Received: from uls-op-cesaip02.wdc.com (HELO uls-op-cesaep02.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 05 Sep 2019 12:29:04 +0800 IronPort-SDR: gnDPaI8zDUxDx/4zFnOgRWWF/i+XWPB0YNn1UNQDJ20c5NFJaKtxe0mIwBbqULFpphT7RTPYO4 p/PscSviE5qmHNzJvxQPIXF1998ThCcad84HcoWz6+R8bomJ2exDTSSjiaV69a5zBQwRzItWJp wfwZA0MCYHUB5raj8enk3hC+NTv/rbtM63GtJDdfkWbG0QmA7j3IP/QeT9Ccd7rFicGRa/h114 VTXIV9Fzl5OUGj8su686kqT78eIEqMrhxEXFU5hkBuqYmJ6FSwtfmnHFLlQuBdTusMw3CS6GIh rLo19urMWC7gqollPT4ZtY+G Received: from uls-op-cesaip01.wdc.com ([10.248.3.36]) by uls-op-cesaep02.wdc.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Sep 2019 21:26:01 -0700 IronPort-SDR: swWbFTikVbWqQ4x8Nafg6Dfmxd/Jl7AFEMMKNSU6536CyJS2tqFks9byp/SS90QypqA3a80V48 0VGP1FaTGC1qZuD4MWfvgtMsnZtYh7+t2L5GmRSuB8DKffVtQcpvQpk6q++uk8fq1cWy4U+Uss DqeUiiJQODiWaKo8aFbnzAhDOL0pRSpJD2O3/CE5B60n/6OzpTmmbsujZ23rOz3Zo5rYjWBADg qxeIPt8HUL88A2R5NcDTUvlHBFZVWpmxg+YjWpTu93agR4/xR7XbBl+oaHVuZf/UNH4hj+wfvY J3c= WDCIronportException: Internal Received: from washi.fujisawa.hgst.com ([10.149.53.254]) by uls-op-cesaip01.wdc.com with ESMTP; 04 Sep 2019 21:29:04 -0700 From: Damien Le Moal To: linux-block@vger.kernel.org, Jens Axboe , linux-scsi@vger.kernel.org, "Martin K . Petersen" Subject: [PATCH v4 2/7] block: Change elevator_init_mq() to always succeed Date: Thu, 5 Sep 2019 13:28:56 +0900 Message-Id: <20190905042901.5830-3-damien.lemoal@wdc.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190905042901.5830-1-damien.lemoal@wdc.com> References: <20190905042901.5830-1-damien.lemoal@wdc.com> MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org If the default elevator chosen is mq-deadline, elevator_init_mq() may return an error if mq-deadline initialization fails, leading to blk_mq_init_allocated_queue() returning an error, which in turn will cause the block device initialization to fail and the device not being exposed. Instead of taking such extreme measure, handle mq-deadline initialization failures in the same manner as when mq-deadline is not available (no module to load), that is, default to the "none" scheduler. With this change, elevator_init_mq() return type can be changed to void. Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig --- block/blk-mq.c | 8 +------- block/blk.h | 2 +- block/elevator.c | 23 ++++++++++++----------- 3 files changed, 14 insertions(+), 19 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 13923630e00a..ee4caf0c0807 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2842,8 +2842,6 @@ static unsigned int nr_hw_queues(struct blk_mq_tag_set *set) struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, struct request_queue *q) { - int ret = -ENOMEM; - /* mark the queue as mq asap */ q->mq_ops = set->ops; @@ -2904,14 +2902,10 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, blk_mq_add_queue_tag_set(set, q); blk_mq_map_swqueue(q); - ret = elevator_init_mq(q); - if (ret) - goto err_tag_set; + elevator_init_mq(q); return q; -err_tag_set: - blk_mq_del_queue_tag_set(q); err_hctxs: kfree(q->queue_hw_ctx); q->nr_hw_queues = 0; diff --git a/block/blk.h b/block/blk.h index e4619fc5c99a..ed347f7a97b1 100644 --- a/block/blk.h +++ b/block/blk.h @@ -184,7 +184,7 @@ void blk_account_io_done(struct request *req, u64 now); void blk_insert_flush(struct request *rq); -int elevator_init_mq(struct request_queue *q); +void elevator_init_mq(struct request_queue *q); int elevator_switch_mq(struct request_queue *q, struct elevator_type *new_e); void __elevator_exit(struct request_queue *, struct elevator_queue *); diff --git a/block/elevator.c b/block/elevator.c index 4721834815bb..2944c129760c 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -628,34 +628,35 @@ static inline bool elv_support_iosched(struct request_queue *q) /* * For blk-mq devices supporting IO scheduling, we default to using mq-deadline, - * if available, for single queue devices. If deadline isn't available OR we - * have multiple queues, default to "none". + * if available, for single queue devices. If deadline isn't available OR + * deadline initialization fails OR we have multiple queues, default to "none". */ -int elevator_init_mq(struct request_queue *q) +void elevator_init_mq(struct request_queue *q) { struct elevator_type *e; - int err = 0; + int err; if (!elv_support_iosched(q)) - return 0; + return; if (q->nr_hw_queues != 1) - return 0; + return; WARN_ON_ONCE(test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags)); if (unlikely(q->elevator)) - goto out; + return; e = elevator_get(q, "mq-deadline", false); if (!e) - goto out; + return; err = blk_mq_init_sched(q, e); - if (err) + if (err) { + pr_warn("\"%s\" elevator initialization failed, " + "falling back to \"none\"\n", e->elevator_name); elevator_put(e); -out: - return err; + } }