From patchwork Mon Jul 18 06:34:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 12920791 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 9027ACCA482 for ; Mon, 18 Jul 2022 06:34:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233582AbiGRGe5 (ORCPT ); Mon, 18 Jul 2022 02:34:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233571AbiGRGes (ORCPT ); Mon, 18 Jul 2022 02:34:48 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F972165BA; Sun, 17 Jul 2022 23:34:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=9V0aQoOiMRI4EkpKNbU8q4SwaJx+xMRw4Ry7O21tYGc=; b=H7U/qCa26Vm+TRVvjCm0Rs813B XsJuoEn5X0HNXReXZSXyBKl6rpp9fz2ka1SW2AjHePI/xvY4FVAYzGZVkAxO2t4vdi962mPjxpSgS a/6ELgWEla1VJyZcbvNw1RCQxgmLBP+AlpgR0yn6DYb926xmrgdjQLqAxhTBU1E/TGWCvS0RrDNqI JBu+SLvDmcF3hSiii672ygGyuurFvzWe3mJjXQsyEkhQswsfCRVYNLSb123Jbo1EQZ42PMy+gugy4 VbYizhr6y3zi4SquaD6j7FO4F0e5iauOmifzKRi995gCuwIdHoMJyqX6z6Ao8o1tsNqIX+PuK0/6Z 8x13NC6w==; Received: from 089144198117.atnat0007.highway.a1.net ([89.144.198.117] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1oDKL7-00BEia-Ht; Mon, 18 Jul 2022 06:34:46 +0000 From: Christoph Hellwig To: Song Liu Cc: Logan Gunthorpe , linux-raid@vger.kernel.org, linux-block@vger.kernel.org Subject: [PATCH 10/10] md: simplify md_open Date: Mon, 18 Jul 2022 08:34:10 +0200 Message-Id: <20220718063410.338626-11-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220718063410.338626-1-hch@lst.de> References: <20220718063410.338626-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Now that devices are on the all_mddevs list until the gendisk is freed, there can't be any duplicates. Remove the global list lookup and just grab a reference. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke --- drivers/md/md.c | 42 +++++++++++++++--------------------------- 1 file changed, 15 insertions(+), 27 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 08cf21ad4c2d7..9b1e61b4bac8b 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7785,45 +7785,33 @@ static int md_set_read_only(struct block_device *bdev, bool ro) static int md_open(struct block_device *bdev, fmode_t mode) { - /* - * Succeed if we can lock the mddev, which confirms that - * it isn't being stopped right now. - */ - struct mddev *mddev = mddev_find(bdev->bd_dev); + struct mddev *mddev; int err; + spin_lock(&all_mddevs_lock); + mddev = mddev_get(bdev->bd_disk->private_data); + spin_unlock(&all_mddevs_lock); if (!mddev) return -ENODEV; - if (mddev->gendisk != bdev->bd_disk) { - /* we are racing with mddev_put which is discarding this - * bd_disk. - */ - mddev_put(mddev); - /* Wait until bdev->bd_disk is definitely gone */ - if (work_pending(&mddev->del_work)) - flush_workqueue(md_misc_wq); - return -EBUSY; - } - BUG_ON(mddev != bdev->bd_disk->private_data); - - if ((err = mutex_lock_interruptible(&mddev->open_mutex))) + err = mutex_lock_interruptible(&mddev->open_mutex); + if (err) goto out; - if (test_bit(MD_CLOSING, &mddev->flags)) { - mutex_unlock(&mddev->open_mutex); - err = -ENODEV; - goto out; - } + err = -ENODEV; + if (test_bit(MD_CLOSING, &mddev->flags)) + goto out_unlock; - err = 0; atomic_inc(&mddev->openers); mutex_unlock(&mddev->open_mutex); bdev_check_media_change(bdev); - out: - if (err) - mddev_put(mddev); + return 0; + +out_unlock: + mutex_unlock(&mddev->open_mutex); +out: + mddev_put(mddev); return err; }