IB/mlx5: Flush cache workqueue before destroying it

Destroying the workqueue without flushing it first can lead to a case
in which the kernel tries to push a delayed work to the workqueue
which does not exist anymore.

Signed-off-by: Moshe Lazer <moshel@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index bd41df95b6f0..e86dbbdb3836 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -415,6 +415,7 @@ static void clean_keys(struct mlx5_ib_dev *dev, int c)
         int size;
         int err;
 
+        cancel_delayed_work(&ent->dwork);
         while (1) {
                 spin_lock(&ent->lock);
                 if (list_empty(&ent->head)) {
@@ -540,13 +541,15 @@ int mlx5_mr_cache_cleanup(struct mlx5_ib_dev *dev)
         int i;
 
         dev->cache.stopped = 1;
-        destroy_workqueue(dev->cache.wq);
+        flush_workqueue(dev->cache.wq);
 
         mlx5_mr_cache_debugfs_cleanup(dev);
 
         for (i = 0; i < MAX_MR_CACHE_ENTRIES; i++)
                 clean_keys(dev, i);
 
+        destroy_workqueue(dev->cache.wq);
+
         return 0;
 }