From patchwork Sun Sep 6 01:22:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 257730 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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 39170C2D0A8 for ; Sun, 6 Sep 2020 01:22:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 053AE2078D for ; Sun, 6 Sep 2020 01:22:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728880AbgIFBWl (ORCPT ); Sat, 5 Sep 2020 21:22:41 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:38087 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728850AbgIFBWi (ORCPT ); Sat, 5 Sep 2020 21:22:38 -0400 Received: by mail-pg1-f193.google.com with SMTP id l191so6282403pgd.5; Sat, 05 Sep 2020 18:22:38 -0700 (PDT) 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:mime-version:content-transfer-encoding; bh=i3+83kwUl5p6aC78eMCGt1VVVPamG+eHtGnBI8drvj0=; b=ZrrpOHIumjEVIINnohGfxvp0WoZaCRzLL1o61O+xXL/NyI0+R0povvsht5XAeZIUa4 aHAe95yFioni+SSyiR4YTFSsODw3kj2o1CJEmityQWZfr20veXcXYWskd7iiOrT6XzyL mQkSu8lsJr73+BiUUqdm1lfkPePepJTl0cKni98GqG+bAWtFV/Sb84xHQCgCx9YOtLfe 4z+rIMirW0A3epYct2niZofM/RjH1W+2pJ7IDWsgFmaiZoY4Tm3T23HDAf/ZBmroYAH0 Jy4QMt5aWdCuxkjMeYdGaSW8VdNdphMMN3sa8aurk8fJc820wm+nXKEhSwItA5oE2K/r SGIg== X-Gm-Message-State: AOAM532NMA9ILC9BGIBgmJ7h+a7XD+MSRQTE3iaVrzlK+MzWpHyej+m1 tlSzTkF/hr9OMfcpPequdFQ= X-Google-Smtp-Source: ABdhPJzJ0iLHo6bLBqQHqNWyfop11rMuomOL3K8hOjyz6jeFWrVD1tcPRZLWP4OLuC24tKE8ZQPH/g== X-Received: by 2002:a63:ba5e:: with SMTP id l30mr12218966pgu.425.1599355357583; Sat, 05 Sep 2020 18:22:37 -0700 (PDT) Received: from asus.hsd1.ca.comcast.net ([2601:647:4000:d7:cd46:435a:ac98:84de]) by smtp.gmail.com with ESMTPSA id 25sm3585165pjh.57.2020.09.05.18.22.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 05 Sep 2020 18:22:36 -0700 (PDT) From: Bart Van Assche To: Jens Axboe , "Martin K . Petersen" , "James E . J . Bottomley" Cc: linux-block@vger.kernel.org, Christoph Hellwig , linux-scsi@vger.kernel.org, Alan Stern , Bart Van Assche , James Bottomley , Woody Suwalski , Can Guo , Stanley Chu , Ming Lei , "Rafael J . Wysocki" Subject: [PATCH 7/9] scsi_transport_spi: Freeze request queues instead of quiescing Date: Sat, 5 Sep 2020 18:22:17 -0700 Message-Id: <20200906012219.17893-8-bvanassche@acm.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200906012219.17893-1-bvanassche@acm.org> References: <20200906012219.17893-1-bvanassche@acm.org> MIME-Version: 1.0 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Instead of quiescing the request queues involved in domain validation, freeze these. As a result, the struct request_queue pm_only member is no longer set during domain validation. That will allow to modify scsi_execute() such that it stops setting the BLK_MQ_REQ_PREEMPT flag. Three additional changes in this patch are that scsi_mq_alloc_queue() is exported, that scsi_device_quiesce() is no longer exported and that scsi_target_{quiesce,resume}() have been changed into scsi_target_{freeze,unfreeze}(). Cc: James Bottomley Cc: Martin K. Petersen Cc: Woody Suwalski Cc: Alan Stern Cc: Can Guo Cc: Stanley Chu Cc: Ming Lei Cc: Rafael J. Wysocki Signed-off-by: Bart Van Assche --- drivers/scsi/scsi_lib.c | 22 +++++----- drivers/scsi/scsi_priv.h | 2 + drivers/scsi/scsi_transport_spi.c | 72 ++++++++++++++++++++----------- include/scsi/scsi_device.h | 6 +-- 4 files changed, 61 insertions(+), 41 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 9e3c2930ce40..0b0cb727e699 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1864,6 +1864,7 @@ struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev) blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, q); return q; } +EXPORT_SYMBOL_GPL(scsi_mq_alloc_queue); int scsi_mq_setup_tags(struct Scsi_Host *shost) { @@ -2538,7 +2539,6 @@ scsi_device_quiesce(struct scsi_device *sdev) return err; } -EXPORT_SYMBOL(scsi_device_quiesce); /** * scsi_device_resume - Restart user issued commands to a quiesced device. @@ -2567,30 +2567,30 @@ void scsi_device_resume(struct scsi_device *sdev) EXPORT_SYMBOL(scsi_device_resume); static void -device_quiesce_fn(struct scsi_device *sdev, void *data) +device_freeze_fn(struct scsi_device *sdev, void *data) { - scsi_device_quiesce(sdev); + blk_mq_freeze_queue(sdev->request_queue); } void -scsi_target_quiesce(struct scsi_target *starget) +scsi_target_freeze(struct scsi_target *starget) { - starget_for_each_device(starget, NULL, device_quiesce_fn); + starget_for_each_device(starget, NULL, device_freeze_fn); } -EXPORT_SYMBOL(scsi_target_quiesce); +EXPORT_SYMBOL(scsi_target_freeze); static void -device_resume_fn(struct scsi_device *sdev, void *data) +device_unfreeze_fn(struct scsi_device *sdev, void *data) { - scsi_device_resume(sdev); + blk_mq_unfreeze_queue(sdev->request_queue); } void -scsi_target_resume(struct scsi_target *starget) +scsi_target_unfreeze(struct scsi_target *starget) { - starget_for_each_device(starget, NULL, device_resume_fn); + starget_for_each_device(starget, NULL, device_unfreeze_fn); } -EXPORT_SYMBOL(scsi_target_resume); +EXPORT_SYMBOL(scsi_target_unfreeze); /** * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index d12ada035961..6b9203df84c8 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -95,6 +95,8 @@ extern int scsi_mq_setup_tags(struct Scsi_Host *shost); extern void scsi_mq_destroy_tags(struct Scsi_Host *shost); extern void scsi_exit_queue(void); extern void scsi_evt_thread(struct work_struct *work); +extern int scsi_device_quiesce(struct scsi_device *sdev); +extern void scsi_device_resume(struct scsi_device *sdev); struct request_queue; struct request; diff --git a/drivers/scsi/scsi_transport_spi.c b/drivers/scsi/scsi_transport_spi.c index 959990f66865..f0ef9ab008c5 100644 --- a/drivers/scsi/scsi_transport_spi.c +++ b/drivers/scsi/scsi_transport_spi.c @@ -997,59 +997,79 @@ void spi_dv_device(struct scsi_device *sdev) { struct scsi_target *starget = sdev->sdev_target; + struct request_queue *q2; u8 *buffer; const int len = SPI_MAX_ECHO_BUFFER_SIZE*2; /* - * Because this function and the power management code both call - * scsi_device_quiesce(), it is not safe to perform domain validation - * while suspend or resume is in progress. Hence the - * lock/unlock_system_sleep() calls. + * Because this function creates a new request queue that is not + * visible to the rest of the system, this function must be serialized + * against suspend, resume and runtime power management. Hence the + * lock/unlock_system_sleep() and scsi_autopm_{get,put}_device() + * calls. */ lock_system_sleep(); + if (scsi_autopm_get_device(sdev)) + goto unlock_system_sleep; + if (unlikely(spi_dv_in_progress(starget))) - goto unlock; + goto put_autopm; if (unlikely(scsi_device_get(sdev))) - goto unlock; - - spi_dv_in_progress(starget) = 1; + goto put_autopm; buffer = kzalloc(len, GFP_KERNEL); if (unlikely(!buffer)) - goto out_put; - - /* We need to verify that the actual device will quiesce; the - * later target quiesce is just a nice to have */ - if (unlikely(scsi_device_quiesce(sdev))) - goto out_free; - - scsi_target_quiesce(starget); + goto put_sdev; spi_dv_pending(starget) = 1; + mutex_lock(&spi_dv_mutex(starget)); + if (unlikely(spi_dv_in_progress(starget))) + goto clear_pending; + + spi_dv_in_progress(starget) = 1; starget_printk(KERN_INFO, starget, "Beginning Domain Validation\n"); - spi_dv_device_internal(sdev, sdev->request_queue, buffer); + q2 = scsi_mq_alloc_queue(sdev); + + if (q2) { + /* + * Freeze the target such that no other subsystem can submit + * SCSI commands to 'sdev'. Submitting SCSI commands through + * q2 may trigger the SCSI error handler. The SCSI error + * handler must be able to handle a frozen sdev->request_queue + * and must also use blk_mq_rq_from_pdu(q2)->q instead of + * sdev->request_queue if it would be necessary to access q2 + * directly. + */ + scsi_target_freeze(starget); + spi_dv_device_internal(sdev, q2, buffer); + blk_cleanup_queue(q2); + scsi_target_unfreeze(starget); + } starget_printk(KERN_INFO, starget, "Ending Domain Validation\n"); - mutex_unlock(&spi_dv_mutex(starget)); - spi_dv_pending(starget) = 0; - - scsi_target_resume(starget); - spi_initial_dv(starget) = 1; + spi_dv_in_progress(starget) = 0; + +clear_pending: + spi_dv_pending(starget) = 0; + mutex_unlock(&spi_dv_mutex(starget)); - out_free: kfree(buffer); - out_put: - spi_dv_in_progress(starget) = 0; + +put_sdev: scsi_device_put(sdev); -unlock: + +put_autopm: + scsi_autopm_put_device(sdev); + +unlock_system_sleep: unlock_system_sleep(); } EXPORT_SYMBOL(spi_dv_device); diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 48c80793915e..891ffebadebe 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -422,10 +422,8 @@ extern struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, extern void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt); extern void sdev_evt_send_simple(struct scsi_device *sdev, enum scsi_device_event evt_type, gfp_t gfpflags); -extern int scsi_device_quiesce(struct scsi_device *sdev); -extern void scsi_device_resume(struct scsi_device *sdev); -extern void scsi_target_quiesce(struct scsi_target *); -extern void scsi_target_resume(struct scsi_target *); +extern void scsi_target_freeze(struct scsi_target *); +extern void scsi_target_unfreeze(struct scsi_target *); extern void scsi_scan_target(struct device *parent, unsigned int channel, unsigned int id, u64 lun, enum scsi_scan_mode rescan);