From patchwork Wed Oct 31 17:59:01 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10663061 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 27AF01751 for ; Wed, 31 Oct 2018 17:59:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 142822B4D3 for ; Wed, 31 Oct 2018 17:59:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 074DE2B4E0; Wed, 31 Oct 2018 17:59:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DDC952B4D3 for ; Wed, 31 Oct 2018 17:59:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730161AbeKAC6v (ORCPT ); Wed, 31 Oct 2018 22:58:51 -0400 Received: from mail-it1-f194.google.com ([209.85.166.194]:54178 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730032AbeKAC6v (ORCPT ); Wed, 31 Oct 2018 22:58:51 -0400 Received: by mail-it1-f194.google.com with SMTP id y73-v6so2906561itc.3 for ; Wed, 31 Oct 2018 10:59:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=umexRBJ2m6/LpigGLTbifbGEjJRhvi3w7FZPm6s4psk=; b=Kd5AUSH3ABkpx+0uqOeomeHcrCFdAGyy0cAlZspIZEv4WuHeWnrg5Q6B8UnQYWAK+H glpPt5jVruWptjpZh1KhjaqR5GJiHWX0AtSln27083uIorZ2Q3kSEq2aDaJioUz1nVDB il6mxvHpTUEZic8k4XWKnYexklTJxoR6jtRwR4PRq3co7GP53+f1weMbJjCEy3w+mYDf 8MHctWlSPT4QLWqL20n+2zq50RgCiV5iDQbPBjIa8DGEmM8PLB2hekkENh0fUgM2lVFE Vl0IMCscXlrrK69sDKvk1VpSiaHC00VtGrMF5NBkaNNa8ZIoUoubq8Wr8/ZwiuRQIktu 0u9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=umexRBJ2m6/LpigGLTbifbGEjJRhvi3w7FZPm6s4psk=; b=EoAPx5IK34WClkN7JsqW3fvIAPqoNy0DL0lA8GDsQnKFR9RYxzbDLv0oBs/BVX4Pr5 Lkc8dQI86NY7ngqBsOCOIo4NaszOV2F/G/gBO2Lg/Ym7fqUZI1BFHUzqmOQUX5WP2a81 D+fCRnmbpEdrNMf/PMNl/PGmNFzXplij4uGmbGe4yyo1mDZxW+j7ikga4kvsc/e8N8c/ aLH0ps8C4EV492G3Aq0eBNSkSsnHKku+IFzRgfLWtleT6nym6V61pokJKRjvLDRgbtqE jESBntYptA5nsOHxU4xEuHOM/bnylYceOmC6vZlxtNcLCZkviHxAnspVhKUnw4s7tmND UhEw== X-Gm-Message-State: AGRZ1gJIuR+Ref/dc0WpyxBFMSChbk09dxxHFF/Lhk+fvxlwji9vHJ1f rJk1wrPlL19tT10HVKwsQDykBw== X-Google-Smtp-Source: AJdET5eNJmWnvjcgSTb3Bz0hLMZK7yRjoAMDoqvRusfHSYOabp7a7tCiWGoY43sT6XcSw39UwVSvDw== X-Received: by 2002:a24:fc02:: with SMTP id b2-v6mr2764275ith.45.1541008784847; Wed, 31 Oct 2018 10:59:44 -0700 (PDT) Received: from localhost.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id 197-v6sm10982947iou.87.2018.10.31.10.59.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 31 Oct 2018 10:59:43 -0700 (PDT) From: Jens Axboe To: linux-block@vger.kernel.org, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org Cc: Jens Axboe Subject: [PATCH 09/30] scsi: kill off the legacy IO path Date: Wed, 31 Oct 2018 11:59:01 -0600 Message-Id: <20181031175922.8849-10-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181031175922.8849-1-axboe@kernel.dk> References: <20181031175922.8849-1-axboe@kernel.dk> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Cc: linux-scsi@vger.kernel.org Acked-by: Himanshu Madhani Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe Reviewed-by: Omar Sandoval Acked-by: Martin K. Petersen --- Documentation/scsi/scsi-parameters.txt | 5 - drivers/scsi/Kconfig | 12 - drivers/scsi/cxlflash/main.c | 6 - drivers/scsi/hosts.c | 29 +- drivers/scsi/lpfc/lpfc_scsi.c | 2 +- drivers/scsi/qedi/qedi_main.c | 3 +- drivers/scsi/qla2xxx/qla_os.c | 30 +- drivers/scsi/scsi.c | 5 +- drivers/scsi/scsi_debug.c | 3 +- drivers/scsi/scsi_error.c | 2 +- drivers/scsi/scsi_lib.c | 603 ++----------------------- drivers/scsi/scsi_priv.h | 1 - drivers/scsi/scsi_scan.c | 10 +- drivers/scsi/scsi_sysfs.c | 8 +- drivers/scsi/ufs/ufshcd.c | 6 - include/scsi/scsi_host.h | 18 +- include/scsi/scsi_tcq.h | 14 +- 17 files changed, 77 insertions(+), 680 deletions(-) diff --git a/Documentation/scsi/scsi-parameters.txt b/Documentation/scsi/scsi-parameters.txt index 92999d4e0cb8..25a4b4cf04a6 100644 --- a/Documentation/scsi/scsi-parameters.txt +++ b/Documentation/scsi/scsi-parameters.txt @@ -97,11 +97,6 @@ parameters may be changed at runtime by the command allowing boot to proceed. none ignores them, expecting user space to do the scan. - scsi_mod.use_blk_mq= - [SCSI] use blk-mq I/O path by default - See SCSI_MQ_DEFAULT in drivers/scsi/Kconfig. - Format: - sim710= [SCSI,HW] See header of drivers/scsi/sim710.c. diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig index 70988c381268..ff5a569fdbcb 100644 --- a/drivers/scsi/Kconfig +++ b/drivers/scsi/Kconfig @@ -50,18 +50,6 @@ config SCSI_NETLINK default n depends on NET -config SCSI_MQ_DEFAULT - bool "SCSI: use blk-mq I/O path by default" - default y - depends on SCSI - ---help--- - This option enables the blk-mq based I/O path for SCSI devices by - default. With this option the scsi_mod.use_blk_mq module/boot - option defaults to Y, without it to N, but it can still be - overridden either way. - - If unsure say Y. - config SCSI_PROC_FS bool "legacy /proc/scsi/ support" depends on SCSI && PROC_FS diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index 6637116529aa..abdc9eac4173 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -3088,12 +3088,6 @@ static ssize_t hwq_mode_store(struct device *dev, return -EINVAL; } - if ((mode == HWQ_MODE_TAG) && !shost_use_blk_mq(shost)) { - dev_info(cfgdev, "SCSI-MQ is not enabled, use a different " - "HWQ steering mode.\n"); - return -EINVAL; - } - afu->hwq_mode = mode; return count; diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index ea4b0bb0c1cd..cc71136ba300 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -222,18 +222,9 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, if (error) goto fail; - if (shost_use_blk_mq(shost)) { - error = scsi_mq_setup_tags(shost); - if (error) - goto fail; - } else { - shost->bqt = blk_init_tags(shost->can_queue, - shost->hostt->tag_alloc_policy); - if (!shost->bqt) { - error = -ENOMEM; - goto fail; - } - } + error = scsi_mq_setup_tags(shost); + if (error) + goto fail; if (!shost->shost_gendev.parent) shost->shost_gendev.parent = dev ? dev : &platform_bus; @@ -309,8 +300,7 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, pm_runtime_disable(&shost->shost_gendev); pm_runtime_set_suspended(&shost->shost_gendev); pm_runtime_put_noidle(&shost->shost_gendev); - if (shost_use_blk_mq(shost)) - scsi_mq_destroy_tags(shost); + scsi_mq_destroy_tags(shost); fail: return error; } @@ -344,13 +334,8 @@ static void scsi_host_dev_release(struct device *dev) kfree(dev_name(&shost->shost_dev)); } - if (shost_use_blk_mq(shost)) { - if (shost->tag_set.tags) - scsi_mq_destroy_tags(shost); - } else { - if (shost->bqt) - blk_free_tags(shost->bqt); - } + if (shost->tag_set.tags) + scsi_mq_destroy_tags(shost); kfree(shost->shost_data); @@ -472,8 +457,6 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) else shost->dma_boundary = 0xffffffff; - shost->use_blk_mq = scsi_use_blk_mq || shost->hostt->force_blk_mq; - device_initialize(&shost->shost_gendev); dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); shost->shost_gendev.bus = &scsi_bus_type; diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c index 4fa6703a9ec9..baed2b891efb 100644 --- a/drivers/scsi/lpfc/lpfc_scsi.c +++ b/drivers/scsi/lpfc/lpfc_scsi.c @@ -3914,7 +3914,7 @@ int lpfc_sli4_scmd_to_wqidx_distr(struct lpfc_hba *phba, uint32_t tag; uint16_t hwq; - if (cmnd && shost_use_blk_mq(cmnd->device->host)) { + if (cmnd) { tag = blk_mq_unique_tag(cmnd->request); hwq = blk_mq_unique_tag_to_hwq(tag); diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c index 105b0e4d7818..311eb22068e1 100644 --- a/drivers/scsi/qedi/qedi_main.c +++ b/drivers/scsi/qedi/qedi_main.c @@ -644,8 +644,7 @@ static struct qedi_ctx *qedi_host_alloc(struct pci_dev *pdev) qedi->max_active_conns = ISCSI_MAX_SESS_PER_HBA; qedi->max_sqes = QEDI_SQ_SIZE; - if (shost_use_blk_mq(shost)) - shost->nr_hw_queues = MIN_NUM_CPUS_MSIX(qedi); + shost->nr_hw_queues = MIN_NUM_CPUS_MSIX(qedi); pci_set_drvdata(pdev, qedi); diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c index 8794e54f43a9..3e2665c66bc4 100644 --- a/drivers/scsi/qla2xxx/qla_os.c +++ b/drivers/scsi/qla2xxx/qla_os.c @@ -857,13 +857,9 @@ qla2xxx_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) } if (ha->mqenable) { - if (shost_use_blk_mq(vha->host)) { - tag = blk_mq_unique_tag(cmd->request); - hwq = blk_mq_unique_tag_to_hwq(tag); - qpair = ha->queue_pair_map[hwq]; - } else if (vha->vp_idx && vha->qpair) { - qpair = vha->qpair; - } + tag = blk_mq_unique_tag(cmd->request); + hwq = blk_mq_unique_tag_to_hwq(tag); + qpair = ha->queue_pair_map[hwq]; if (qpair) return qla2xxx_mqueuecommand(host, cmd, qpair); @@ -3153,7 +3149,7 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id) goto probe_failed; } - if (ha->mqenable && shost_use_blk_mq(host)) { + if (ha->mqenable) { /* number of hardware queues supported by blk/scsi-mq*/ host->nr_hw_queues = ha->max_qpairs; @@ -3265,25 +3261,17 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id) base_vha->mgmt_svr_loop_id, host->sg_tablesize); if (ha->mqenable) { - bool mq = false; bool startit = false; - if (QLA_TGT_MODE_ENABLED()) { - mq = true; + if (QLA_TGT_MODE_ENABLED()) startit = false; - } - if ((ql2x_ini_mode == QLA2XXX_INI_MODE_ENABLED) && - shost_use_blk_mq(host)) { - mq = true; + if (ql2x_ini_mode == QLA2XXX_INI_MODE_ENABLED) startit = true; - } - if (mq) { - /* Create start of day qpairs for Block MQ */ - for (i = 0; i < ha->max_qpairs; i++) - qla2xxx_create_qpair(base_vha, 5, 0, startit); - } + /* Create start of day qpairs for Block MQ */ + for (i = 0; i < ha->max_qpairs; i++) + qla2xxx_create_qpair(base_vha, 5, 0, startit); } if (ha->flags.running_gold_fw) diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index fc1356d101b0..99db3f4316b5 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -780,11 +780,8 @@ MODULE_LICENSE("GPL"); module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); -#ifdef CONFIG_SCSI_MQ_DEFAULT +/* Kill module parameter */ bool scsi_use_blk_mq = true; -#else -bool scsi_use_blk_mq = false; -#endif module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO); static int __init init_scsi(void) diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 60bcc6df97a9..4740f1e9dd17 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -5881,8 +5881,7 @@ static int sdebug_driver_probe(struct device *dev) } /* Decide whether to tell scsi subsystem that we want mq */ /* Following should give the same answer for each host */ - if (shost_use_blk_mq(hpnt)) - hpnt->nr_hw_queues = submit_queues; + hpnt->nr_hw_queues = submit_queues; sdbg_host->shost = hpnt; *((struct sdebug_host_info **)hpnt->hostdata) = sdbg_host; diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index c736d61b1648..fff128aa9ec2 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -308,7 +308,7 @@ enum blk_eh_timer_return scsi_times_out(struct request *req) * error handler. In that case we can return immediately as no * further action is required. */ - if (req->q->mq_ops && !blk_mq_mark_complete(req)) + if (!blk_mq_mark_complete(req)) return rtn; if (scsi_abort_command(scmd) != SUCCESS) { set_host_byte(scmd, DID_TIME_OUT); diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 8b0345924a92..651be30ba96a 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -168,8 +168,6 @@ static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd) static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy) { struct scsi_device *device = cmd->device; - struct request_queue *q = device->request_queue; - unsigned long flags; SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd, "Inserting command %p into mlqueue\n", cmd)); @@ -190,26 +188,20 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy) * before blk_cleanup_queue() finishes. */ cmd->result = 0; - if (q->mq_ops) { - /* - * Before a SCSI command is dispatched, - * get_device(&sdev->sdev_gendev) is called and the host, - * target and device busy counters are increased. Since - * requeuing a request causes these actions to be repeated and - * since scsi_device_unbusy() has already been called, - * put_device(&device->sdev_gendev) must still be called. Call - * put_device() after blk_mq_requeue_request() to avoid that - * removal of the SCSI device can start before requeueing has - * happened. - */ - blk_mq_requeue_request(cmd->request, true); - put_device(&device->sdev_gendev); - return; - } - spin_lock_irqsave(q->queue_lock, flags); - blk_requeue_request(q, cmd->request); - kblockd_schedule_work(&device->requeue_work); - spin_unlock_irqrestore(q->queue_lock, flags); + + /* + * Before a SCSI command is dispatched, + * get_device(&sdev->sdev_gendev) is called and the host, + * target and device busy counters are increased. Since + * requeuing a request causes these actions to be repeated and + * since scsi_device_unbusy() has already been called, + * put_device(&device->sdev_gendev) must still be called. Call + * put_device() after blk_mq_requeue_request() to avoid that + * removal of the SCSI device can start before requeueing has + * happened. + */ + blk_mq_requeue_request(cmd->request, true); + put_device(&device->sdev_gendev); } /* @@ -370,10 +362,7 @@ void scsi_device_unbusy(struct scsi_device *sdev) static void scsi_kick_queue(struct request_queue *q) { - if (q->mq_ops) - blk_mq_run_hw_queues(q, false); - else - blk_run_queue(q); + blk_mq_run_hw_queues(q, false); } /* @@ -534,10 +523,7 @@ static void scsi_run_queue(struct request_queue *q) if (!list_empty(&sdev->host->starved_list)) scsi_starved_list_run(sdev->host); - if (q->mq_ops) - blk_mq_run_hw_queues(q, false); - else - blk_run_queue(q); + blk_mq_run_hw_queues(q, false); } void scsi_requeue_run_queue(struct work_struct *work) @@ -550,42 +536,6 @@ void scsi_requeue_run_queue(struct work_struct *work) scsi_run_queue(q); } -/* - * Function: scsi_requeue_command() - * - * Purpose: Handle post-processing of completed commands. - * - * Arguments: q - queue to operate on - * cmd - command that may need to be requeued. - * - * Returns: Nothing - * - * Notes: After command completion, there may be blocks left - * over which weren't finished by the previous command - * this can be for a number of reasons - the main one is - * I/O errors in the middle of the request, in which case - * we need to request the blocks that come after the bad - * sector. - * Notes: Upon return, cmd is a stale pointer. - */ -static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) -{ - struct scsi_device *sdev = cmd->device; - struct request *req = cmd->request; - unsigned long flags; - - spin_lock_irqsave(q->queue_lock, flags); - blk_unprep_request(req); - req->special = NULL; - scsi_put_command(cmd); - blk_requeue_request(q, req); - spin_unlock_irqrestore(q->queue_lock, flags); - - scsi_run_queue(q); - - put_device(&sdev->sdev_gendev); -} - void scsi_run_host_queues(struct Scsi_Host *shost) { struct scsi_device *sdev; @@ -626,42 +576,6 @@ static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) scsi_del_cmd_from_list(cmd); } -/* - * Function: scsi_release_buffers() - * - * Purpose: Free resources allocate for a scsi_command. - * - * Arguments: cmd - command that we are bailing. - * - * Lock status: Assumed that no lock is held upon entry. - * - * Returns: Nothing - * - * Notes: In the event that an upper level driver rejects a - * command, we must release resources allocated during - * the __init_io() function. Primarily this would involve - * the scatter-gather table. - */ -static void scsi_release_buffers(struct scsi_cmnd *cmd) -{ - if (cmd->sdb.table.nents) - sg_free_table_chained(&cmd->sdb.table, false); - - memset(&cmd->sdb, 0, sizeof(cmd->sdb)); - - if (scsi_prot_sg_count(cmd)) - sg_free_table_chained(&cmd->prot_sdb->table, false); -} - -static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd) -{ - struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special; - - sg_free_table_chained(&bidi_sdb->table, false); - kmem_cache_free(scsi_sdb_cache, bidi_sdb); - cmd->request->next_rq->special = NULL; -} - /* Returns false when no more bytes to process, true if there are more */ static bool scsi_end_request(struct request *req, blk_status_t error, unsigned int bytes, unsigned int bidi_bytes) @@ -687,37 +601,22 @@ static bool scsi_end_request(struct request *req, blk_status_t error, destroy_rcu_head(&cmd->rcu); } - if (req->mq_ctx) { - /* - * In the MQ case the command gets freed by __blk_mq_end_request, - * so we have to do all cleanup that depends on it earlier. - * - * We also can't kick the queues from irq context, so we - * will have to defer it to a workqueue. - */ - scsi_mq_uninit_cmd(cmd); - - __blk_mq_end_request(req, error); - - if (scsi_target(sdev)->single_lun || - !list_empty(&sdev->host->starved_list)) - kblockd_schedule_work(&sdev->requeue_work); - else - blk_mq_run_hw_queues(q, true); - } else { - unsigned long flags; - - if (bidi_bytes) - scsi_release_bidi_buffers(cmd); - scsi_release_buffers(cmd); - scsi_put_command(cmd); + /* + * In the MQ case the command gets freed by __blk_mq_end_request, + * so we have to do all cleanup that depends on it earlier. + * + * We also can't kick the queues from irq context, so we + * will have to defer it to a workqueue. + */ + scsi_mq_uninit_cmd(cmd); - spin_lock_irqsave(q->queue_lock, flags); - blk_finish_request(req, error); - spin_unlock_irqrestore(q->queue_lock, flags); + __blk_mq_end_request(req, error); - scsi_run_queue(q); - } + if (scsi_target(sdev)->single_lun || + !list_empty(&sdev->host->starved_list)) + kblockd_schedule_work(&sdev->requeue_work); + else + blk_mq_run_hw_queues(q, true); put_device(&sdev->sdev_gendev); return false; @@ -766,13 +665,7 @@ static void scsi_io_completion_reprep(struct scsi_cmnd *cmd, struct request_queue *q) { /* A new command will be prepared and issued. */ - if (q->mq_ops) { - scsi_mq_requeue_cmd(cmd); - } else { - /* Unprep request and put it back at head of the queue. */ - scsi_release_buffers(cmd); - scsi_requeue_command(q, cmd); - } + scsi_mq_requeue_cmd(cmd); } /* Helper for scsi_io_completion() when special action required. */ @@ -1147,9 +1040,7 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb) */ int scsi_init_io(struct scsi_cmnd *cmd) { - struct scsi_device *sdev = cmd->device; struct request *rq = cmd->request; - bool is_mq = (rq->mq_ctx != NULL); int error = BLKPREP_KILL; if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq))) @@ -1160,17 +1051,6 @@ int scsi_init_io(struct scsi_cmnd *cmd) goto err_exit; if (blk_bidi_rq(rq)) { - if (!rq->q->mq_ops) { - struct scsi_data_buffer *bidi_sdb = - kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC); - if (!bidi_sdb) { - error = BLKPREP_DEFER; - goto err_exit; - } - - rq->next_rq->special = bidi_sdb; - } - error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special); if (error) goto err_exit; @@ -1210,14 +1090,7 @@ int scsi_init_io(struct scsi_cmnd *cmd) return BLKPREP_OK; err_exit: - if (is_mq) { - scsi_mq_free_sgtables(cmd); - } else { - scsi_release_buffers(cmd); - cmd->request->special = NULL; - scsi_put_command(cmd); - put_device(&sdev->sdev_gendev); - } + scsi_mq_free_sgtables(cmd); return error; } EXPORT_SYMBOL(scsi_init_io); @@ -1423,75 +1296,6 @@ scsi_prep_state_check(struct scsi_device *sdev, struct request *req) return ret; } -static int -scsi_prep_return(struct request_queue *q, struct request *req, int ret) -{ - struct scsi_device *sdev = q->queuedata; - - switch (ret) { - case BLKPREP_KILL: - case BLKPREP_INVALID: - scsi_req(req)->result = DID_NO_CONNECT << 16; - /* release the command and kill it */ - if (req->special) { - struct scsi_cmnd *cmd = req->special; - scsi_release_buffers(cmd); - scsi_put_command(cmd); - put_device(&sdev->sdev_gendev); - req->special = NULL; - } - break; - case BLKPREP_DEFER: - /* - * If we defer, the blk_peek_request() returns NULL, but the - * queue must be restarted, so we schedule a callback to happen - * shortly. - */ - if (atomic_read(&sdev->device_busy) == 0) - blk_delay_queue(q, SCSI_QUEUE_DELAY); - break; - default: - req->rq_flags |= RQF_DONTPREP; - } - - return ret; -} - -static int scsi_prep_fn(struct request_queue *q, struct request *req) -{ - struct scsi_device *sdev = q->queuedata; - struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); - int ret; - - ret = scsi_prep_state_check(sdev, req); - if (ret != BLKPREP_OK) - goto out; - - if (!req->special) { - /* Bail if we can't get a reference to the device */ - if (unlikely(!get_device(&sdev->sdev_gendev))) { - ret = BLKPREP_DEFER; - goto out; - } - - scsi_init_command(sdev, cmd); - req->special = cmd; - } - - cmd->tag = req->tag; - cmd->request = req; - cmd->prot_op = SCSI_PROT_NORMAL; - - ret = scsi_setup_cmnd(sdev, req); -out: - return scsi_prep_return(q, req, ret); -} - -static void scsi_unprep_fn(struct request_queue *q, struct request *req) -{ - scsi_uninit_cmd(blk_mq_rq_to_pdu(req)); -} - /* * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else * return 0. @@ -1511,14 +1315,8 @@ static inline int scsi_dev_queue_ready(struct request_queue *q, /* * unblock after device_blocked iterates to zero */ - if (atomic_dec_return(&sdev->device_blocked) > 0) { - /* - * For the MQ case we take care of this in the caller. - */ - if (!q->mq_ops) - blk_delay_queue(q, SCSI_QUEUE_DELAY); + if (atomic_dec_return(&sdev->device_blocked) > 0) goto out_dec; - } SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, "unblocking device at zero depth\n")); } @@ -1653,13 +1451,13 @@ static inline int scsi_host_queue_ready(struct request_queue *q, * needs to return 'not busy'. Otherwise, request stacking drivers * may hold requests forever. */ -static int scsi_lld_busy(struct request_queue *q) +static bool scsi_mq_lld_busy(struct request_queue *q) { struct scsi_device *sdev = q->queuedata; struct Scsi_Host *shost; if (blk_queue_dying(q)) - return 0; + return false; shost = sdev->host; @@ -1670,48 +1468,9 @@ static int scsi_lld_busy(struct request_queue *q) * in SCSI layer. */ if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) - return 1; - - return 0; -} - -static bool scsi_mq_lld_busy(struct request_queue *q) -{ - return scsi_lld_busy(q); -} - -/* - * Kill a request for a dead device - */ -static void scsi_kill_request(struct request *req, struct request_queue *q) -{ - struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); - struct scsi_device *sdev; - struct scsi_target *starget; - struct Scsi_Host *shost; - - blk_start_request(req); - - scmd_printk(KERN_INFO, cmd, "killing request\n"); - - sdev = cmd->device; - starget = scsi_target(sdev); - shost = sdev->host; - scsi_init_cmd_errh(cmd); - cmd->result = DID_NO_CONNECT << 16; - atomic_inc(&cmd->device->iorequest_cnt); - - /* - * SCSI request completion path will do scsi_device_unbusy(), - * bump busy counts. To bump the counters, we need to dance - * with the locks as normal issue path does. - */ - atomic_inc(&sdev->device_busy); - atomic_inc(&shost->host_busy); - if (starget->can_queue > 0) - atomic_inc(&starget->target_busy); + return true; - blk_complete_request(req); + return false; } static void scsi_softirq_done(struct request *rq) @@ -1834,158 +1593,6 @@ static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) return 0; } -/** - * scsi_done - Invoke completion on finished SCSI command. - * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives - * ownership back to SCSI Core -- i.e. the LLDD has finished with it. - * - * Description: This function is the mid-level's (SCSI Core) interrupt routine, - * which regains ownership of the SCSI command (de facto) from a LLDD, and - * calls blk_complete_request() for further processing. - * - * This function is interrupt context safe. - */ -static void scsi_done(struct scsi_cmnd *cmd) -{ - trace_scsi_dispatch_cmd_done(cmd); - blk_complete_request(cmd->request); -} - -/* - * Function: scsi_request_fn() - * - * Purpose: Main strategy routine for SCSI. - * - * Arguments: q - Pointer to actual queue. - * - * Returns: Nothing - * - * Lock status: request queue lock assumed to be held when called. - * - * Note: See sd_zbc.c sd_zbc_write_lock_zone() for write order - * protection for ZBC disks. - */ -static void scsi_request_fn(struct request_queue *q) - __releases(q->queue_lock) - __acquires(q->queue_lock) -{ - struct scsi_device *sdev = q->queuedata; - struct Scsi_Host *shost; - struct scsi_cmnd *cmd; - struct request *req; - - /* - * To start with, we keep looping until the queue is empty, or until - * the host is no longer able to accept any more requests. - */ - shost = sdev->host; - for (;;) { - int rtn; - /* - * get next queueable request. We do this early to make sure - * that the request is fully prepared even if we cannot - * accept it. - */ - req = blk_peek_request(q); - if (!req) - break; - - if (unlikely(!scsi_device_online(sdev))) { - sdev_printk(KERN_ERR, sdev, - "rejecting I/O to offline device\n"); - scsi_kill_request(req, q); - continue; - } - - if (!scsi_dev_queue_ready(q, sdev)) - break; - - /* - * Remove the request from the request list. - */ - if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) - blk_start_request(req); - - spin_unlock_irq(q->queue_lock); - cmd = blk_mq_rq_to_pdu(req); - if (cmd != req->special) { - printk(KERN_CRIT "impossible request in %s.\n" - "please mail a stack trace to " - "linux-scsi@vger.kernel.org\n", - __func__); - blk_dump_rq_flags(req, "foo"); - BUG(); - } - - /* - * We hit this when the driver is using a host wide - * tag map. For device level tag maps the queue_depth check - * in the device ready fn would prevent us from trying - * to allocate a tag. Since the map is a shared host resource - * we add the dev to the starved list so it eventually gets - * a run when a tag is freed. - */ - if (blk_queue_tagged(q) && !(req->rq_flags & RQF_QUEUED)) { - spin_lock_irq(shost->host_lock); - if (list_empty(&sdev->starved_entry)) - list_add_tail(&sdev->starved_entry, - &shost->starved_list); - spin_unlock_irq(shost->host_lock); - goto not_ready; - } - - if (!scsi_target_queue_ready(shost, sdev)) - goto not_ready; - - if (!scsi_host_queue_ready(q, shost, sdev)) - goto host_not_ready; - - if (sdev->simple_tags) - cmd->flags |= SCMD_TAGGED; - else - cmd->flags &= ~SCMD_TAGGED; - - /* - * Finally, initialize any error handling parameters, and set up - * the timers for timeouts. - */ - scsi_init_cmd_errh(cmd); - - /* - * Dispatch the command to the low-level driver. - */ - cmd->scsi_done = scsi_done; - rtn = scsi_dispatch_cmd(cmd); - if (rtn) { - scsi_queue_insert(cmd, rtn); - spin_lock_irq(q->queue_lock); - goto out_delay; - } - spin_lock_irq(q->queue_lock); - } - - return; - - host_not_ready: - if (scsi_target(sdev)->can_queue > 0) - atomic_dec(&scsi_target(sdev)->target_busy); - not_ready: - /* - * lock q, handle tag, requeue req, and decrement device_busy. We - * must return with queue_lock held. - * - * Decrementing device_busy without checking it is OK, as all such - * cases (host limits or settings) should run the queue at some - * later time. - */ - spin_lock_irq(q->queue_lock); - blk_requeue_request(q, req); - atomic_dec(&sdev->device_busy); -out_delay: - if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev)) - blk_delay_queue(q, SCSI_QUEUE_DELAY); -} - static inline blk_status_t prep_to_mq(int ret) { switch (ret) { @@ -2248,77 +1855,6 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) } EXPORT_SYMBOL_GPL(__scsi_init_queue); -static int scsi_old_init_rq(struct request_queue *q, struct request *rq, - gfp_t gfp) -{ - struct Scsi_Host *shost = q->rq_alloc_data; - const bool unchecked_isa_dma = shost->unchecked_isa_dma; - struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); - - memset(cmd, 0, sizeof(*cmd)); - - if (unchecked_isa_dma) - cmd->flags |= SCMD_UNCHECKED_ISA_DMA; - cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma, gfp, - NUMA_NO_NODE); - if (!cmd->sense_buffer) - goto fail; - cmd->req.sense = cmd->sense_buffer; - - if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) { - cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp); - if (!cmd->prot_sdb) - goto fail_free_sense; - } - - return 0; - -fail_free_sense: - scsi_free_sense_buffer(unchecked_isa_dma, cmd->sense_buffer); -fail: - return -ENOMEM; -} - -static void scsi_old_exit_rq(struct request_queue *q, struct request *rq) -{ - struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); - - if (cmd->prot_sdb) - kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb); - scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA, - cmd->sense_buffer); -} - -struct request_queue *scsi_old_alloc_queue(struct scsi_device *sdev) -{ - struct Scsi_Host *shost = sdev->host; - struct request_queue *q; - - q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE, NULL); - if (!q) - return NULL; - q->cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; - q->rq_alloc_data = shost; - q->request_fn = scsi_request_fn; - q->init_rq_fn = scsi_old_init_rq; - q->exit_rq_fn = scsi_old_exit_rq; - q->initialize_rq_fn = scsi_initialize_rq; - - if (blk_init_allocated_queue(q) < 0) { - blk_cleanup_queue(q); - return NULL; - } - - __scsi_init_queue(shost, q); - blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, q); - blk_queue_prep_rq(q, scsi_prep_fn); - blk_queue_unprep_rq(q, scsi_unprep_fn); - blk_queue_softirq_done(q, scsi_softirq_done); - blk_queue_rq_timed_out(q, scsi_times_out); - blk_queue_lld_busy(q, scsi_lld_busy); - return q; -} - static const struct blk_mq_ops scsi_mq_ops = { .get_budget = scsi_mq_get_budget, .put_budget = scsi_mq_put_budget, @@ -2386,10 +1922,7 @@ struct scsi_device *scsi_device_from_queue(struct request_queue *q) { struct scsi_device *sdev = NULL; - if (q->mq_ops) { - if (q->mq_ops == &scsi_mq_ops) - sdev = q->queuedata; - } else if (q->request_fn == scsi_request_fn) + if (q->mq_ops == &scsi_mq_ops) sdev = q->queuedata; if (!sdev || !get_device(&sdev->sdev_gendev)) sdev = NULL; @@ -2992,39 +2525,6 @@ void sdev_evt_send_simple(struct scsi_device *sdev, } EXPORT_SYMBOL_GPL(sdev_evt_send_simple); -/** - * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn() - * @sdev: SCSI device to count the number of scsi_request_fn() callers for. - */ -static int scsi_request_fn_active(struct scsi_device *sdev) -{ - struct request_queue *q = sdev->request_queue; - int request_fn_active; - - WARN_ON_ONCE(sdev->host->use_blk_mq); - - spin_lock_irq(q->queue_lock); - request_fn_active = q->request_fn_active; - spin_unlock_irq(q->queue_lock); - - return request_fn_active; -} - -/** - * scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls - * @sdev: SCSI device pointer. - * - * Wait until the ongoing shost->hostt->queuecommand() calls that are - * invoked from scsi_request_fn() have finished. - */ -static void scsi_wait_for_queuecommand(struct scsi_device *sdev) -{ - WARN_ON_ONCE(sdev->host->use_blk_mq); - - while (scsi_request_fn_active(sdev)) - msleep(20); -} - /** * scsi_device_quiesce - Block user issued commands. * @sdev: scsi device to quiesce. @@ -3148,7 +2648,6 @@ EXPORT_SYMBOL(scsi_target_resume); int scsi_internal_device_block_nowait(struct scsi_device *sdev) { struct request_queue *q = sdev->request_queue; - unsigned long flags; int err = 0; err = scsi_device_set_state(sdev, SDEV_BLOCK); @@ -3164,14 +2663,7 @@ int scsi_internal_device_block_nowait(struct scsi_device *sdev) * block layer from calling the midlayer with this device's * request queue. */ - if (q->mq_ops) { - blk_mq_quiesce_queue_nowait(q); - } else { - spin_lock_irqsave(q->queue_lock, flags); - blk_stop_queue(q); - spin_unlock_irqrestore(q->queue_lock, flags); - } - + blk_mq_quiesce_queue_nowait(q); return 0; } EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); @@ -3202,12 +2694,8 @@ static int scsi_internal_device_block(struct scsi_device *sdev) mutex_lock(&sdev->state_mutex); err = scsi_internal_device_block_nowait(sdev); - if (err == 0) { - if (q->mq_ops) - blk_mq_quiesce_queue(q); - else - scsi_wait_for_queuecommand(sdev); - } + if (err == 0) + blk_mq_quiesce_queue(q); mutex_unlock(&sdev->state_mutex); return err; @@ -3216,15 +2704,8 @@ static int scsi_internal_device_block(struct scsi_device *sdev) void scsi_start_queue(struct scsi_device *sdev) { struct request_queue *q = sdev->request_queue; - unsigned long flags; - if (q->mq_ops) { - blk_mq_unquiesce_queue(q); - } else { - spin_lock_irqsave(q->queue_lock, flags); - blk_start_queue(q); - spin_unlock_irqrestore(q->queue_lock, flags); - } + blk_mq_unquiesce_queue(q); } /** diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 99f1db5e467e..5f21547b2ad2 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -92,7 +92,6 @@ extern void scsi_queue_insert(struct scsi_cmnd *cmd, int reason); extern void scsi_io_completion(struct scsi_cmnd *, unsigned int); extern void scsi_run_host_queues(struct Scsi_Host *shost); extern void scsi_requeue_run_queue(struct work_struct *work); -extern struct request_queue *scsi_old_alloc_queue(struct scsi_device *sdev); extern struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev); extern void scsi_start_queue(struct scsi_device *sdev); extern int scsi_mq_setup_tags(struct Scsi_Host *shost); diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 78ca63dfba4a..dd0d516f65e2 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -266,10 +266,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, */ sdev->borken = 1; - if (shost_use_blk_mq(shost)) - sdev->request_queue = scsi_mq_alloc_queue(sdev); - else - sdev->request_queue = scsi_old_alloc_queue(sdev); + sdev->request_queue = scsi_mq_alloc_queue(sdev); if (!sdev->request_queue) { /* release fn is set up in scsi_sysfs_device_initialise, so * have to free and put manually here */ @@ -280,11 +277,6 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, WARN_ON_ONCE(!blk_get_queue(sdev->request_queue)); sdev->request_queue->queuedata = sdev; - if (!shost_use_blk_mq(sdev->host)) { - blk_queue_init_tags(sdev->request_queue, - sdev->host->cmd_per_lun, shost->bqt, - shost->hostt->tag_alloc_policy); - } scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun ? sdev->host->cmd_per_lun : 1); diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 3aee9464a7bf..12e2c2829df2 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -367,7 +367,6 @@ store_shost_eh_deadline(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR(eh_deadline, S_IRUGO | S_IWUSR, show_shost_eh_deadline, store_shost_eh_deadline); -shost_rd_attr(use_blk_mq, "%d\n"); shost_rd_attr(unique_id, "%u\n"); shost_rd_attr(cmd_per_lun, "%hd\n"); shost_rd_attr(can_queue, "%hd\n"); @@ -386,6 +385,13 @@ show_host_busy(struct device *dev, struct device_attribute *attr, char *buf) } static DEVICE_ATTR(host_busy, S_IRUGO, show_host_busy, NULL); +static ssize_t +show_use_blk_mq(struct device *dev, struct device_attribute *attr, char *buf) +{ + return snprintf(buf, 20, "1\n"); +} +static DEVICE_ATTR(use_blk_mq, S_IRUGO, show_use_blk_mq, NULL); + static struct attribute *scsi_sysfs_shost_attrs[] = { &dev_attr_use_blk_mq.attr, &dev_attr_unique_id.attr, diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 23d7cca36ff0..fb308ea8e9a5 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -8100,12 +8100,6 @@ int ufshcd_alloc_host(struct device *dev, struct ufs_hba **hba_handle) goto out_error; } - /* - * Do not use blk-mq at this time because blk-mq does not support - * runtime pm. - */ - host->use_blk_mq = false; - hba = shost_priv(host); hba->host = host; hba->dev = dev; diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 5ea06d310a25..aa760df8c6b3 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -11,7 +11,6 @@ #include #include -struct request_queue; struct block_device; struct completion; struct module; @@ -22,7 +21,6 @@ struct scsi_target; struct Scsi_Host; struct scsi_host_cmd_pool; struct scsi_transport_template; -struct blk_queue_tags; /* @@ -547,14 +545,8 @@ struct Scsi_Host { struct scsi_host_template *hostt; struct scsi_transport_template *transportt; - /* - * Area to keep a shared tag map (if needed, will be - * NULL if not). - */ - union { - struct blk_queue_tag *bqt; - struct blk_mq_tag_set tag_set; - }; + /* Area to keep a shared tag map */ + struct blk_mq_tag_set tag_set; atomic_t host_busy; /* commands actually active on low-level */ atomic_t host_blocked; @@ -648,7 +640,6 @@ struct Scsi_Host { /* The controller does not support WRITE SAME */ unsigned no_write_same:1; - unsigned use_blk_mq:1; unsigned use_cmd_list:1; /* Host responded with short (<36 bytes) INQUIRY result */ @@ -742,11 +733,6 @@ static inline int scsi_host_in_recovery(struct Scsi_Host *shost) shost->tmf_in_progress; } -static inline bool shost_use_blk_mq(struct Scsi_Host *shost) -{ - return shost->use_blk_mq; -} - extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *); extern void scsi_flush_work(struct Scsi_Host *); diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h index e192a0caa850..6053d46e794e 100644 --- a/include/scsi/scsi_tcq.h +++ b/include/scsi/scsi_tcq.h @@ -23,19 +23,15 @@ static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost, int tag) { struct request *req = NULL; + u16 hwq; if (tag == SCSI_NO_TAG) return NULL; - if (shost_use_blk_mq(shost)) { - u16 hwq = blk_mq_unique_tag_to_hwq(tag); - - if (hwq < shost->tag_set.nr_hw_queues) { - req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq], - blk_mq_unique_tag_to_tag(tag)); - } - } else { - req = blk_map_queue_find_tag(shost->bqt, tag); + hwq = blk_mq_unique_tag_to_hwq(tag); + if (hwq < shost->tag_set.nr_hw_queues) { + req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq], + blk_mq_unique_tag_to_tag(tag)); } if (!req)