[PATCH 3.18 53/90] dm: remove duplicate dm_get_live_table() in __dm_destroy()

From: Greg Kroah-Hartman
Date: Mon Nov 19 2018 - 12:05:12 EST


3.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Corey Wright <undefined@xxxxxxxxx>

[3.18.y only, to fix a previous patch]

__dm_destroy() takes io_barrier SRCU lock (dm_get_live_table) twice
which leads to a deadlock. Remove taking lock before holding
suspend_lock to prevent a different potential deadlock.

Signed-off-by: Corey Wright <undefined@xxxxxxxxx>
Fixes: e1db66a5fdcc ("dm: fix AB-BA deadlock in __dm_destroy()")
Cc: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/md/dm.c | 1 -
1 file changed, 1 deletion(-)

--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2589,7 +2589,6 @@ static void __dm_destroy(struct mapped_d
might_sleep();

spin_lock(&_minor_lock);
- map = dm_get_live_table(md, &srcu_idx);
idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
set_bit(DMF_FREEING, &md->flags);
spin_unlock(&_minor_lock);