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>

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index bd41df9..e86dbbd 100644 (file)
--- 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;
 }