RDMA/mlx5: Fix mkey cache WQ flush

The cited patch tries to ensure no pending works on the mkey cache
workqueue by disabling adding new works and call flush_workqueue().
But this workqueue also has delayed works which might still be pending
the delay time to be queued.

Add cancel_delayed_work() for the delayed works which waits to be queued
and then the flush_workqueue() will flush all works which are already
queued and running.

Fixes: 374012b00457 ("RDMA/mlx5: Fix mkey cache possible deadlock on cleanup")
Link: https://lore.kernel.org/r/b8722f14e7ed81452f791764a26d2ed4cfa11478.1698256179.git.leon@kernel.org
Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index 1d6c54a53df629f9742fd16e3432caa11aee3b5e..18e459b55746e4e86da57a236973d2751aabc392 100644 (file)
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1000,11 +1000,13 @@ void mlx5_mkey_cache_cleanup(struct mlx5_ib_dev *dev)
                return;
 
        mutex_lock(&dev->cache.rb_lock);
+       cancel_delayed_work(&dev->cache.remove_ent_dwork);
        for (node = rb_first(root); node; node = rb_next(node)) {
                ent = rb_entry(node, struct mlx5_cache_ent, node);
                spin_lock_irq(&ent->mkeys_queue.lock);
                ent->disabled = true;
                spin_unlock_irq(&ent->mkeys_queue.lock);
+               cancel_delayed_work(&ent->dwork);
        }
        mutex_unlock(&dev->cache.rb_lock);