From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935706Ab1KJDeJ (ORCPT ); Wed, 9 Nov 2011 22:34:09 -0500 Received: from cantor2.suse.de ([195.135.220.15]:43227 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935691Ab1KJDeA (ORCPT ); Wed, 9 Nov 2011 22:34:00 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Nov 9 13:27:22 2011 Message-Id: <20111109212722.306152701@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 09 Nov 2011 13:28:58 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Bart Van Assche , James Bottomley Subject: [216/262] [SCSI] Make scsi_free_queue() kill pending SCSI commands In-Reply-To: <20111109212847.GA20838@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bart Van Assche commit 3308511c93e6ad0d3c58984ecd6e5e57f96b12c8 upstream. Make sure that SCSI device removal via scsi_remove_host() does finish all pending SCSI commands. Currently that's not the case and hence removal of a SCSI host during I/O can cause a deadlock. See also "blkdev_issue_discard() hangs forever if underlying storage device is removed" (http://bugzilla.kernel.org/show_bug.cgi?id=40472). See also http://lkml.org/lkml/2011/8/27/6. Signed-off-by: Bart Van Assche Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/hosts.c | 9 ++++++--- drivers/scsi/scsi_lib.c | 9 +++++++++ 2 files changed, 15 insertions(+), 3 deletions(-) --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -286,6 +286,7 @@ static void scsi_host_dev_release(struct { struct Scsi_Host *shost = dev_to_shost(dev); struct device *parent = dev->parent; + struct request_queue *q; scsi_proc_hostdir_rm(shost->hostt); @@ -293,9 +294,11 @@ static void scsi_host_dev_release(struct kthread_stop(shost->ehandler); if (shost->work_q) destroy_workqueue(shost->work_q); - if (shost->uspace_req_q) { - kfree(shost->uspace_req_q->queuedata); - scsi_free_queue(shost->uspace_req_q); + q = shost->uspace_req_q; + if (q) { + kfree(q->queuedata); + q->queuedata = NULL; + scsi_free_queue(q); } scsi_destroy_command_freelist(shost); --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1697,6 +1697,15 @@ struct request_queue *scsi_alloc_queue(s void scsi_free_queue(struct request_queue *q) { + unsigned long flags; + + WARN_ON(q->queuedata); + + /* cause scsi_request_fn() to kill all non-finished requests */ + spin_lock_irqsave(q->queue_lock, flags); + q->request_fn(q); + spin_unlock_irqrestore(q->queue_lock, flags); + blk_cleanup_queue(q); }