From d09960b0032174eb493c4c13be5b9c9ef36dc9a7 Mon Sep 17 00:00:00 2001 From: Tahsin Erdogan Date: Mon, 10 Oct 2016 05:35:19 -0700 Subject: [PATCH] dm: free io_barrier after blk_cleanup_queue call dm_old_request_fn() has paths that access md->io_barrier. The party destroying io_barrier should ensure that no future execution of dm_old_request_fn() is possible. Move io_barrier destruction to below blk_cleanup_queue() to ensure this and avoid a NULL pointer crash during request-based DM device shutdown. Cc: stable@vger.kernel.org # 4.3+ Signed-off-by: Tahsin Erdogan Signed-off-by: Mike Snitzer --- drivers/md/dm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index be35258324c1..ec513ee864f2 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1423,8 +1423,6 @@ static void cleanup_mapped_device(struct mapped_device *md) if (md->bs) bioset_free(md->bs); - cleanup_srcu_struct(&md->io_barrier); - if (md->disk) { spin_lock(&_minor_lock); md->disk->private_data = NULL; @@ -1436,6 +1434,8 @@ static void cleanup_mapped_device(struct mapped_device *md) if (md->queue) blk_cleanup_queue(md->queue); + cleanup_srcu_struct(&md->io_barrier); + if (md->bdev) { bdput(md->bdev); md->bdev = NULL; -- 2.20.1