From patchwork Mon Jun 8 17:01:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 11593729 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 1CC3F92A for ; Mon, 8 Jun 2020 17:02:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EBDC920810 for ; Mon, 8 Jun 2020 17:02:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591635739; bh=GFDS5ZeXJWKepPtGtYd1p8VC4NzatXMF4WFN56n95Xc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xqFw7Ta+HSgtVJRQ18agwA3oZsbIXsyvY4JmANN2gDf0h6guaOoS+oCykAPQWQcV/ 3au0qabkdmG6f+RAYeGo6k1lts69OR3oeLhWmf61mFeaqEfj9WR4j0V2BpzHU4u+N0 oyPA4mOPBW5wj7Q1qxkVXuAq6sDJARrb2RjqEPj8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387504AbgFHRCC (ORCPT ); Mon, 8 Jun 2020 13:02:02 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:33115 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730726AbgFHRBj (ORCPT ); Mon, 8 Jun 2020 13:01:39 -0400 Received: by mail-pf1-f196.google.com with SMTP id b201so8822009pfb.0; Mon, 08 Jun 2020 10:01:37 -0700 (PDT) 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=f88bEORI++QIsnJdKm2ca64CmhxGUzC3g+SSrwClYUg=; b=fFY9lOlx1tsbi3CWNCs5HITSv6HGFSS6uQzU2SDIeXdrSs9JSC0cGIGAUKMcznY3uM ZXLpFFlhw+Tjvs56UTnnFK1JykEDSVXDQ3MatEDJ7aTGn7GljYVGtOrNgJxZARHZVi3O dWCa5bI8l/IHKozet5oo9FqZB8sF3hUX650r5yRvyHFRfXknw2SX9WARPjMDiq1RuGfX TsiwrJe1qPx1/J0S9yp7gygBdcZCrPoU2OC71PBpE/ZLWLC91o7/kreIhHwxjzW8aV/0 JggYnb4B1GohPdV8pa0ONRUTBAMrED/pgubAQfp34+SRtJkLgYM43VCWuKmWLA4/RKmO YNUw== X-Gm-Message-State: AOAM5320Ph1jDP87dX0Cxdx510UX79yeV9sGxJ/uASUotrxq8vIe/Maj 1Jf9Dzv1nAt3p/MZtAg8BR4= X-Google-Smtp-Source: ABdhPJwmTcpNrr37VElfNpqehHSBvOJFHFFfHrHovcAKxDpg8BeyMYMNILKDT4r2RmVxa1x2U8XKog== X-Received: by 2002:a63:f14a:: with SMTP id o10mr21710759pgk.216.1591635696982; Mon, 08 Jun 2020 10:01:36 -0700 (PDT) Received: from 42.do-not-panic.com (42.do-not-panic.com. [157.230.128.187]) by smtp.gmail.com with ESMTPSA id iq3sm103489pjb.6.2020.06.08.10.01.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Jun 2020 10:01:32 -0700 (PDT) Received: by 42.do-not-panic.com (Postfix, from userid 1000) id 9045A41DD1; Mon, 8 Jun 2020 17:01:28 +0000 (UTC) From: Luis Chamberlain To: axboe@kernel.dk, viro@zeniv.linux.org.uk, bvanassche@acm.org, gregkh@linuxfoundation.org, rostedt@goodmis.org, mingo@redhat.com, jack@suse.cz, ming.lei@redhat.com, nstange@suse.de, akpm@linux-foundation.org Cc: mhocko@suse.com, yukuai3@huawei.com, martin.petersen@oracle.com, jejb@linux.ibm.com, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Luis Chamberlain , Christoph Hellwig Subject: [PATCH v6 5/6] loop: be paranoid on exit and prevent new additions / removals Date: Mon, 8 Jun 2020 17:01:25 +0000 Message-Id: <20200608170127.20419-6-mcgrof@kernel.org> X-Mailer: git-send-email 2.23.0.rc1 In-Reply-To: <20200608170127.20419-1-mcgrof@kernel.org> References: <20200608170127.20419-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Be pedantic on removal as well and hold the mutex. This should prevent uses of addition while we exit. Reviewed-by: Ming Lei Reviewed-by: Christoph Hellwig Signed-off-by: Luis Chamberlain --- drivers/block/loop.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index c33bbbfd1bd9..d55e1b52f076 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -2402,6 +2402,8 @@ 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); @@ -2409,6 +2411,8 @@ static void __exit loop_exit(void) unregister_blkdev(LOOP_MAJOR, "loop"); misc_deregister(&loop_misc); + + mutex_unlock(&loop_ctl_mutex); } module_init(loop_init);