From patchwork Mon Jan 24 18:42:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 536326 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 6A380C4332F for ; Mon, 24 Jan 2022 19:07:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234038AbiAXTG7 (ORCPT ); Mon, 24 Jan 2022 14:06:59 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:34980 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345897AbiAXTEn (ORCPT ); Mon, 24 Jan 2022 14:04:43 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id ACD0460B88; Mon, 24 Jan 2022 19:04:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73926C340E5; Mon, 24 Jan 2022 19:04:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643051082; bh=DNwXRQqJ2zdm78xxZBfZY5HB4Qqc18c8IshS3hzlm+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kqU/+ORPfz6FGfshyo0SEFZsw2a2ZKaXyLZweF5BInvcuq9Ayf3v6vNPEkR/yFN10 oQvbBMbLVgE5TQKFsuslYRnQ0jkR0GjBxFCODWiUU4Mzew41fcOmOh0KWyZLMeIOd4 iH1LhG4Apo8inFGvr9abflzrMEzod7TkY+Vn4h4k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tasos Sahanidis , Denis Efremov , Jens Axboe , Sasha Levin Subject: [PATCH 4.14 049/186] floppy: Fix hang in watchdog when disk is ejected Date: Mon, 24 Jan 2022 19:42:04 +0100 Message-Id: <20220124183938.707913060@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183937.101330125@linuxfoundation.org> References: <20220124183937.101330125@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tasos Sahanidis [ Upstream commit fb48febce7e30baed94dd791e19521abd2c3fd83 ] When the watchdog detects a disk change, it calls cancel_activity(), which in turn tries to cancel the fd_timer delayed work. In the above scenario, fd_timer_fn is set to fd_watchdog(), meaning it is trying to cancel its own work. This results in a hang as cancel_delayed_work_sync() is waiting for the watchdog (itself) to return, which never happens. This can be reproduced relatively consistently by attempting to read a broken floppy, and ejecting it while IO is being attempted and retried. To resolve this, this patch calls cancel_delayed_work() instead, which cancels the work without waiting for the watchdog to return and finish. Before this regression was introduced, the code in this section used del_timer(), and not del_timer_sync() to delete the watchdog timer. Link: https://lore.kernel.org/r/399e486c-6540-db27-76aa-7a271b061f76@tasossah.com Fixes: 070ad7e793dc ("floppy: convert to delayed work and single-thread wq") Signed-off-by: Tasos Sahanidis Signed-off-by: Denis Efremov Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/floppy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index cbf74731cfce6..b6c99cf1ce745 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -994,7 +994,7 @@ static DECLARE_DELAYED_WORK(fd_timer, fd_timer_workfn); static void cancel_activity(void) { do_floppy = NULL; - cancel_delayed_work_sync(&fd_timer); + cancel_delayed_work(&fd_timer); cancel_work_sync(&floppy_work); }