From patchwork Mon Nov 16 03:04:57 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: 11907291 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 7ADFB17F7 for ; Mon, 16 Nov 2020 03:05:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BBBD20719 for ; Mon, 16 Nov 2020 03:05:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726774AbgKPDFZ (ORCPT ); Sun, 15 Nov 2020 22:05:25 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:33874 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726743AbgKPDFY (ORCPT ); Sun, 15 Nov 2020 22:05:24 -0500 Received: by mail-pf1-f193.google.com with SMTP id w6so12672556pfu.1; Sun, 15 Nov 2020 19:05:22 -0800 (PST) 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=vKZkkxQfIYClt1SKHZ26PtBNYxtwIWnYLF7YJcr9mjg=; b=BxNjK23Epd2g8j5gozpoFSQwmwNhlpNT6QNyNnx4X3qKy3Ur4tl+92GJKOQVeLNAW/ ZZSJXwHn3SYvG/BaaFXGh1XJWZyMhK6XClnJwkvOZD1IOZ1A78q0IaynrSMr4MvPQ0uC 670HhjOTXPkMTkoFlg5Bv7TQRU9GzDAQfbqF9a32UXSVlvEIR4lokDR9OLXwiVPqzSTt Le1dIYmP0lEctdymYrGnrzh8c9UzEfITMOmtDlMdwYK+hy/TUiznoxh2eRmmwXamGJLZ zO0otcD/GKKeS17k+ecbW1G5cmxNHXRWDvnX/+YEmkA9uNxo01MjNgmYWfhTtIvffPON jY7Q== X-Gm-Message-State: AOAM532SNGBiOrbLYX8e3B9/qhgYo3IJ0XdQ/jTIm+9dYaC+iirjAG+H JX4CXrbaG60xzKo7P9v2o+Y= X-Google-Smtp-Source: ABdhPJzvzXV5mUxuQncpW6jgEOWFv0l1I82M4eqly8gc09CF7mtUX4qnho6Pe9cY/7wmtro80GVfzw== X-Received: by 2002:a63:215f:: with SMTP id s31mr11439350pgm.258.1605495922026; Sun, 15 Nov 2020 19:05:22 -0800 (PST) Received: from asus.hsd1.ca.comcast.net (c-73-241-217-19.hsd1.ca.comcast.net. [73.241.217.19]) by smtp.gmail.com with ESMTPSA id r3sm17148131pjl.23.2020.11.15.19.05.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 15 Nov 2020 19:05:21 -0800 (PST) From: Bart Van Assche To: "Martin K . Petersen" Cc: "James E . J . Bottomley" , Jens Axboe , Christoph Hellwig , linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, Bart Van Assche , James Bottomley , Woody Suwalski , Alan Stern , Can Guo , Stanley Chu , Ming Lei , "Rafael J . Wysocki" , Stan Johnson Subject: [PATCH v2 7/9] scsi_transport_spi: Freeze request queues instead of quiescing Date: Sun, 15 Nov 2020 19:04:57 -0800 Message-Id: <20201116030459.13963-8-bvanassche@acm.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201116030459.13963-1-bvanassche@acm.org> References: <20201116030459.13963-1-bvanassche@acm.org> MIME-Version: 1.0 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 Reviewed-by: Alan Stern Cc: Can Guo Cc: Stanley Chu Cc: Ming Lei Cc: Rafael J. Wysocki Tested-by: Stan Johnson 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 ff480fa6261e..df1f22b32964 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1893,6 +1893,7 @@ 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) { @@ -2568,7 +2569,6 @@ 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. @@ -2597,30 +2597,30 @@ 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 180636d54982..3c64929291c5 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -96,6 +96,8 @@ 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 f47fdf9cf788..dc193d7f479a 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -423,10 +423,8 @@ 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);