From mboxrd@z Thu Jan 1 00:00:00 1970 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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 B6F59C4338F for ; Fri, 20 Aug 2021 15:08:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9481F60FDA for ; Fri, 20 Aug 2021 15:08:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240958AbhHTPIs (ORCPT ); Fri, 20 Aug 2021 11:08:48 -0400 Received: from verein.lst.de ([213.95.11.211]:41320 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238570AbhHTPIo (ORCPT ); Fri, 20 Aug 2021 11:08:44 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 20D2D6736F; Fri, 20 Aug 2021 17:08:04 +0200 (CEST) Date: Fri, 20 Aug 2021 17:08:03 +0200 From: Christoph Hellwig To: Guenter Roeck Cc: Christoph Hellwig , Jens Axboe , Mike Snitzer , linux-block@vger.kernel.org, dm-devel@redhat.com Subject: Re: [dm-devel] [PATCH 4/8] block: support delayed holder registration Message-ID: <20210820150803.GA490@lst.de> References: <20210804094147.459763-1-hch@lst.de> <20210804094147.459763-5-hch@lst.de> <20210814211309.GA616511@roeck-us.net> <20210815070724.GA23276@lst.de> <20210816072158.GA27147@lst.de> <20210816141702.GA3449320@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210816141702.GA3449320@roeck-us.net> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Please try the patch below: --- >From 7609266da56160d211662cd2fbe26570aad11b15 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 20 Aug 2021 17:00:11 +0200 Subject: mtd_blkdevs: don't hold del_mtd_blktrans_dev in blktrans_{open,release} There is nothing that this protects against except for slightly reducing the window when new opens can appear just before calling del_gendisk. Signed-off-by: Christoph Hellwig --- drivers/mtd/mtd_blkdevs.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c index 44bea3f65060..6b81a1c9ccbe 100644 --- a/drivers/mtd/mtd_blkdevs.c +++ b/drivers/mtd/mtd_blkdevs.c @@ -207,7 +207,6 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode) if (!dev) return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/ - mutex_lock(&mtd_table_mutex); mutex_lock(&dev->lock); if (dev->open) @@ -233,7 +232,6 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode) unlock: dev->open++; mutex_unlock(&dev->lock); - mutex_unlock(&mtd_table_mutex); blktrans_dev_put(dev); return ret; @@ -244,7 +242,6 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode) module_put(dev->tr->owner); kref_put(&dev->ref, blktrans_dev_release); mutex_unlock(&dev->lock); - mutex_unlock(&mtd_table_mutex); blktrans_dev_put(dev); return ret; } @@ -256,7 +253,6 @@ static void blktrans_release(struct gendisk *disk, fmode_t mode) if (!dev) return; - mutex_lock(&mtd_table_mutex); mutex_lock(&dev->lock); if (--dev->open) @@ -272,7 +268,6 @@ static void blktrans_release(struct gendisk *disk, fmode_t mode) } unlock: mutex_unlock(&dev->lock); - mutex_unlock(&mtd_table_mutex); blktrans_dev_put(dev); } -- 2.30.2