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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5778C433EF for ; Tue, 25 Jan 2022 03:33:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1323363AbiAYD2G (ORCPT ); Mon, 24 Jan 2022 22:28:06 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:56964 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1445552AbiAXVEI (ORCPT ); Mon, 24 Jan 2022 16:04:08 -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 ams.source.kernel.org (Postfix) with ESMTPS id 513A1B81243; Mon, 24 Jan 2022 21:04:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74E73C340E8; Mon, 24 Jan 2022 21:04:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643058245; bh=m7RRE022Wc5gZPWYmXs4z6p4oQ3nEjAxUbiCzT3e58w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=djqVHgqkL5XuI95fPuMdbge2VlpkmtBHVp5d4gAtAbCh7Hl0rSAXYy1znEzh/l60L j9ege123Y4AMo/W01OGtOZmm8zXr5L3eV/dXa+puUaZhUUXk0WZOproR0W6uQ1kTOb OMlLccFSEOuJPgSjvoRpaKUHO3t0St7ELaOZWskY= 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 5.16 0225/1039] floppy: Fix hang in watchdog when disk is ejected Date: Mon, 24 Jan 2022 19:33:34 +0100 Message-Id: <20220124184132.892327683@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184125.121143506@linuxfoundation.org> References: <20220124184125.121143506@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 c4267da716fe6..02ba1db5b8046 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -1015,7 +1015,7 @@ 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); } -- 2.34.1