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,URIBL_BLOCKED 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 AC67AC0044C for ; Sun, 11 Nov 2018 19:58:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7BE1C20871 for ; Sun, 11 Nov 2018 19:58:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7BE1C20871 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730378AbeKLFsS (ORCPT ); Mon, 12 Nov 2018 00:48:18 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:50182 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730285AbeKLFsQ (ORCPT ); Mon, 12 Nov 2018 00:48:16 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gLvsc-0000oJ-EK; Sun, 11 Nov 2018 19:58:46 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gLvsY-0001or-Ux; Sun, 11 Nov 2018 19:58:42 +0000 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, "Alan Stern" , "Bart Van Assche" , "Johannes Thumshirn" , "Martin K. Petersen" , "Maurizio Lombardi" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 308/366] scsi: sr: Avoid that opening a CD-ROM hangs with runtime power management enabled In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 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 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Bart Van Assche commit 1214fd7b497400d200e3f4e64e2338b303a20949 upstream. Surround scsi_execute() calls with scsi_autopm_get_device() and scsi_autopm_put_device(). Note: removing sr_mutex protection from the scsi_cd_get() and scsi_cd_put() calls is safe because the purpose of sr_mutex is to serialize cdrom_*() calls. This patch avoids that complaints similar to the following appear in the kernel log if runtime power management is enabled: INFO: task systemd-udevd:650 blocked for more than 120 seconds. Not tainted 4.18.0-rc7-dbg+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D28176 650 513 0x00000104 Call Trace: __schedule+0x444/0xfe0 schedule+0x4e/0xe0 schedule_preempt_disabled+0x18/0x30 __mutex_lock+0x41c/0xc70 mutex_lock_nested+0x1b/0x20 __blkdev_get+0x106/0x970 blkdev_get+0x22c/0x5a0 blkdev_open+0xe9/0x100 do_dentry_open.isra.19+0x33e/0x570 vfs_open+0x7c/0xd0 path_openat+0x6e3/0x1120 do_filp_open+0x11c/0x1c0 do_sys_open+0x208/0x2d0 __x64_sys_openat+0x59/0x70 do_syscall_64+0x77/0x230 entry_SYSCALL_64_after_hwframe+0x49/0xbe Signed-off-by: Bart Van Assche Cc: Maurizio Lombardi Cc: Johannes Thumshirn Cc: Alan Stern Tested-by: Johannes Thumshirn Reviewed-by: Johannes Thumshirn Signed-off-by: Martin K. Petersen [bwh: Backported to 3.16: - Update one extra "goto out" in sr_block_ioctl() and delete the unused label - Adjust context] Signed-off-by: Ben Hutchings --- --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -521,16 +521,25 @@ static int sr_init_command(struct scsi_c static int sr_block_open(struct block_device *bdev, fmode_t mode) { struct scsi_cd *cd; + struct scsi_device *sdev; int ret = -ENXIO; - mutex_lock(&sr_mutex); cd = scsi_cd_get(bdev->bd_disk); - if (cd) { - ret = cdrom_open(&cd->cdi, bdev, mode); - if (ret) - scsi_cd_put(cd); - } + if (!cd) + goto out; + + sdev = cd->device; + scsi_autopm_get_device(sdev); + + mutex_lock(&sr_mutex); + ret = cdrom_open(&cd->cdi, bdev, mode); mutex_unlock(&sr_mutex); + + scsi_autopm_put_device(sdev); + if (ret) + scsi_cd_put(cd); + +out: return ret; } @@ -553,6 +562,8 @@ static int sr_block_ioctl(struct block_d mutex_lock(&sr_mutex); + scsi_autopm_get_device(sdev); + /* * Send SCSI addressing ioctls directly to mid level, send other * ioctls to cdrom/block level. @@ -561,12 +572,12 @@ static int sr_block_ioctl(struct block_d case SCSI_IOCTL_GET_IDLUN: case SCSI_IOCTL_GET_BUS_NUMBER: ret = scsi_ioctl(sdev, cmd, argp); - goto out; + goto put; } ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg); if (ret != -ENOSYS) - goto out; + goto put; /* * ENODEV means that we didn't recognise the ioctl, or that we @@ -577,10 +588,12 @@ static int sr_block_ioctl(struct block_d ret = scsi_nonblockable_ioctl(sdev, cmd, argp, (mode & FMODE_NDELAY) != 0); if (ret != -ENODEV) - goto out; + goto put; ret = scsi_ioctl(sdev, cmd, argp); -out: +put: + scsi_autopm_put_device(sdev); + mutex_unlock(&sr_mutex); return ret; }