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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 F0367C10F00 for ; Tue, 2 Apr 2019 13:42:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C721F2133D for ; Tue, 2 Apr 2019 13:42:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731842AbfDBNmf (ORCPT ); Tue, 2 Apr 2019 09:42:35 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43732 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731541AbfDBNkM (ORCPT ); Tue, 2 Apr 2019 09:40:12 -0400 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hBJe4-0002p6-4f; Tue, 02 Apr 2019 14:40:08 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hBJdy-0004xt-2s; Tue, 02 Apr 2019 14:40:02 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , linuxppc-dev@lists.ozlabs.org, "Finn Thain" , "Jens Axboe" Date: Tue, 02 Apr 2019 14:38:28 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 92/99] block/swim3: Fix -EBUSY error when re-opening device after unmount In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.65-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Finn Thain commit 296dcc40f2f2e402facf7cd26cf3f2c8f4b17d47 upstream. When the block device is opened with FMODE_EXCL, ref_count is set to -1. This value doesn't get reset when the device is closed which means the device cannot be opened again. Fix this by checking for refcount <= 0 in the release method. Reported-and-tested-by: Stan Johnson Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Finn Thain Signed-off-by: Jens Axboe Signed-off-by: Ben Hutchings --- drivers/block/swim3.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/block/swim3.c +++ b/drivers/block/swim3.c @@ -1027,7 +1027,11 @@ static void floppy_release(struct gendis struct swim3 __iomem *sw = fs->swim3; mutex_lock(&swim3_mutex); - if (fs->ref_count > 0 && --fs->ref_count == 0) { + if (fs->ref_count > 0) + --fs->ref_count; + else if (fs->ref_count == -1) + fs->ref_count = 0; + if (fs->ref_count == 0) { swim3_action(fs, MOTOR_OFF); out_8(&sw->control_bic, 0xff); swim3_select(fs, RELAX);