From patchwork Mon Jun 12 15:03:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Wilck X-Patchwork-Id: 692527 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 704A8C88CB8 for ; Mon, 12 Jun 2023 15:03:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239023AbjFLPDe (ORCPT ); Mon, 12 Jun 2023 11:03:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239196AbjFLPDZ (ORCPT ); Mon, 12 Jun 2023 11:03:25 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07D49CC; Mon, 12 Jun 2023 08:03:24 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 93D4F20080; Mon, 12 Jun 2023 15:03:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1686582202; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=LKSm99PcW1erU7LuoqWkdem5Qff98IIubG8yENUJKHU=; b=OE0B8rOHy3+Drz/ghRVOHiT3ylfAMOJTTOPc6t9Kc+lTyanhj2WjvQU1A+ix844sysUZJD 0qmD+n2o4njbVErBTH+5acvlX3ZQYiFto7pyir8y/nbJRFd1YZsa4J/9gRaLRZZe0d2U/d 9t5xE2j1POvFj2R/c9o5ta3UozdB9ew= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 393A9138EC; Mon, 12 Jun 2023 15:03:22 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id eEESDLozh2RMMAAAMHmgww (envelope-from ); Mon, 12 Jun 2023 15:03:22 +0000 From: mwilck@suse.com To: "Martin K. Petersen" , Christoph Hellwig , Ming Lei , Bart Van Assche Cc: James Bottomley , linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, Hannes Reinecke , Martin Wilck Subject: [PATCH v4 5/6] scsi: don't wait for quiesce in scsi_device_block() Date: Mon, 12 Jun 2023 17:03:08 +0200 Message-Id: <20230612150309.18103-6-mwilck@suse.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230612150309.18103-1-mwilck@suse.com> References: <20230612150309.18103-1-mwilck@suse.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Martin Wilck scsi_device_block() is only called from scsi_target_block(), which calls it repeatedly for every child device. For targets with many devices, waiting for every queue to quiesce may cause a substantial delay (we measured more than 100s delay for blocking a FC rport with 2048 LUNs). Just call blk_mq_wait_quiesce_done() once from scsi_target_block() after stopping all queues. Signed-off-by: Martin Wilck --- drivers/scsi/scsi_lib.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index b4cc1501dc36..183f29705af7 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2777,8 +2777,8 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); * @sdev: device to block * @data: dummy argument, ignored * - * Pause SCSI command processing on the specified device and wait until all - * ongoing scsi_queue_rq() calls have finished. May sleep. + * Pause SCSI command processing on the specified device. Callers must wait until all + * ongoing scsi_queue_rq() calls have finished after this function returns. * * Note: * This routine transitions the device to the SDEV_BLOCK state (which must be @@ -2792,17 +2792,15 @@ static void scsi_device_block(struct scsi_device *sdev, void *data) mutex_lock(&sdev->state_mutex); err = __scsi_internal_device_block_nowait(sdev); - if (err == 0) { + if (err == 0) /* * scsi_stop_queue() must be called with the state_mutex * held. Otherwise a simultaneous scsi_start_queue() call * might unquiesce the queue before we quiesce it. */ scsi_stop_queue(sdev); - mutex_unlock(&sdev->state_mutex); - blk_mq_wait_quiesce_done(sdev->request_queue->tag_set); - } else - mutex_unlock(&sdev->state_mutex); + + mutex_unlock(&sdev->state_mutex); WARN_ONCE(err, "__scsi_internal_device_block_nowait(%s) failed: err = %d\n", dev_name(&sdev->sdev_gendev), err); @@ -2900,11 +2898,15 @@ target_block(struct device *dev, void *data) void scsi_target_block(struct device *dev) { + struct Scsi_Host *shost = dev_to_shost(dev); + if (scsi_is_target_device(dev)) starget_for_each_device(to_scsi_target(dev), NULL, scsi_device_block); else device_for_each_child(dev, NULL, target_block); + + blk_mq_wait_quiesce_done(&shost->tag_set); } EXPORT_SYMBOL_GPL(scsi_target_block);