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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 1FA99C433E0 for ; Mon, 10 Aug 2020 19:13:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D362322BEB for ; Mon, 10 Aug 2020 19:13:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597086794; bh=cVwW3JpkPI2yvj2GLbXy1z9Bl6AxSIj5FTixz3QA3ms=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=2XeR+mUBDquXFMn3Hji2G7PklxZ7gbFZukt/6+321h9R/lOoi6AHS/H/dVoP83x9R gMaXeJVF9OvMqg1gFQbxohL2bhWZoxgbSrMTD1g93u455jpKIlqz69niTdIfSs8NmZ d1K5uLSb8zzkmL2IdHUgTx50qEUncXz8AFhIuG4g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729714AbgHJTNN (ORCPT ); Mon, 10 Aug 2020 15:13:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:43636 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729692AbgHJTNG (ORCPT ); Mon, 10 Aug 2020 15:13:06 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EB0252224D; Mon, 10 Aug 2020 19:13:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597086785; bh=cVwW3JpkPI2yvj2GLbXy1z9Bl6AxSIj5FTixz3QA3ms=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L1WhpnkTm+mmNhEYdv2/RdldDSJ5wdTjV0eDGEvPv6805vnkg8rqonA6cMSBIsZAQ zVdC1hsWgZyIVXzSogUkzuLafKoQqXEjMZT7Wd8TezxRNUi5fSRhvkYVLtA/l/uF86 Njms0PQR0jyD+m8jHDLjYsRU8JOZtjK2wGsIRYSk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Luis Chamberlain , Ming Lei , Christoph Hellwig , Jens Axboe , Sasha Levin , linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 04/31] loop: be paranoid on exit and prevent new additions / removals Date: Mon, 10 Aug 2020 15:12:32 -0400 Message-Id: <20200810191259.3794858-4-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200810191259.3794858-1-sashal@kernel.org> References: <20200810191259.3794858-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Luis Chamberlain [ Upstream commit 200f93377220504c5e56754823e7adfea6037f1a ] Be pedantic on removal as well and hold the mutex. This should prevent uses of addition while we exit. Signed-off-by: Luis Chamberlain Reviewed-by: Ming Lei Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/loop.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 728681a20b7f4..da68c42aed682 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -2279,6 +2279,8 @@ static void __exit loop_exit(void) range = max_loop ? max_loop << part_shift : 1UL << MINORBITS; + mutex_lock(&loop_ctl_mutex); + idr_for_each(&loop_index_idr, &loop_exit_cb, NULL); idr_destroy(&loop_index_idr); @@ -2286,6 +2288,8 @@ static void __exit loop_exit(void) unregister_blkdev(LOOP_MAJOR, "loop"); misc_deregister(&loop_misc); + + mutex_unlock(&loop_ctl_mutex); } module_init(loop_init); -- 2.25.1