Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938005AbdCJOh4 (ORCPT ); Fri, 10 Mar 2017 09:37:56 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:35938 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933058AbdCJJOE (ORCPT ); Fri, 10 Mar 2017 04:14:04 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hannes Reinecke , "Ewan D. Milne" , Bart Van Assche , "Martin K. Petersen" , Jinpu Wang Subject: [PATCH 4.4 39/91] sd: get disk reference in sd_check_events() Date: Fri, 10 Mar 2017 10:08:38 +0100 Message-Id: <20170310083902.729353444@linuxfoundation.org> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170310083900.730556986@linuxfoundation.org> References: <20170310083900.730556986@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1523 Lines: 53 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hannes Reinecke commit eb72d0bb84eee5d0dc3044fd17b75e7101dabb57 upstream. sd_check_events() is called asynchronously, and might race with device removal. So always take a disk reference when processing the event to avoid the device being removed while the event is processed. Signed-off-by: Hannes Reinecke Reviewed-by: Ewan D. Milne Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen Cc: Jinpu Wang Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/sd.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1398,11 +1398,15 @@ static int media_not_present(struct scsi **/ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing) { - struct scsi_disk *sdkp = scsi_disk(disk); - struct scsi_device *sdp = sdkp->device; + struct scsi_disk *sdkp = scsi_disk_get(disk); + struct scsi_device *sdp; struct scsi_sense_hdr *sshdr = NULL; int retval; + if (!sdkp) + return 0; + + sdp = sdkp->device; SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_check_events\n")); /* @@ -1459,6 +1463,7 @@ out: kfree(sshdr); retval = sdp->changed ? DISK_EVENT_MEDIA_CHANGE : 0; sdp->changed = 0; + scsi_disk_put(sdkp); return retval; }