linux-kernel - [v2.6.34-stable 121/165] [SCSI] Make scsi_free

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1345060109-9187-122-git-send-email-paul.gortmaker@windriver.com>
Date:	Wed, 15 Aug 2012 15:47:45 -0400
From:	Paul Gortmaker <paul.gortmaker@...driver.com>
To:	<stable@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC:	Bart Van Assche <bvanassche@....org>,
	James Bottomley <JBottomley@...allels.com>,
	Paul Gortmaker <paul.gortmaker@...driver.com>
Subject: [v2.6.34-stable 121/165] [SCSI] Make scsi_free_queue() kill pending SCSI commands

From: Bart Van Assche <bvanassche@....org>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
    If you see a problem with using this for longterm, please comment.
                   -------------------

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 <bvanassche@....org>
Signed-off-by: James Bottomley <JBottomley@...allels.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@...driver.com>
---
 drivers/scsi/hosts.c    | 9 ++++++---
 drivers/scsi/scsi_lib.c | 9 +++++++++
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 6660fa9..cdd904d 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -280,6 +280,7 @@ static void scsi_host_dev_release(struct device *dev)
 {
 	struct Scsi_Host *shost = dev_to_shost(dev);
 	struct device *parent = dev->parent;
+	struct request_queue *q;
 
 	scsi_proc_hostdir_rm(shost->hostt);
 
@@ -287,9 +288,11 @@ static void scsi_host_dev_release(struct device *dev)
 		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);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 725f3cd..9f240f4 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1676,6 +1676,15 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
 
 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);
 }
 
-- 
1.7.12.rc2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/