From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Wed, 31 Aug 2016 22:17:49 +0000 (-0700)
Subject: dm: mark request_queue dead before destroying the DM device
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3b785fbcf81c3533772c52b717f77293099498d3;p=linux-beck.git

dm: mark request_queue dead before destroying the DM device

This avoids that new requests are queued while __dm_destroy() is in
progress.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
---

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index c0742129a9cb..0f2928b3136b 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1873,6 +1873,7 @@ EXPORT_SYMBOL_GPL(dm_device_name);
 
 static void __dm_destroy(struct mapped_device *md, bool wait)
 {
+	struct request_queue *q = dm_get_md_queue(md);
 	struct dm_table *map;
 	int srcu_idx;
 
@@ -1883,6 +1884,10 @@ static void __dm_destroy(struct mapped_device *md, bool wait)
 	set_bit(DMF_FREEING, &md->flags);
 	spin_unlock(&_minor_lock);
 
+	spin_lock_irq(q->queue_lock);
+	queue_flag_set(QUEUE_FLAG_DYING, q);
+	spin_unlock_irq(q->queue_lock);
+
 	if (dm_request_based(md) && md->kworker_task)
 		flush_kthread_worker(&md->kworker);