From: Jason Gunthorpe <jgg@xxxxxxxxxxxx> Work must hold a kref on the ib_device otherwise the dev pointer can become free before the work runs. Remove the bogus use of 'reg_state': - While in uverbs the reg_state is guaranteed to always be REGISTERED - Testing reg_state with no locking is bogus. Use ib_device_try_get() to get back into a region that prevents unregistration. Fixes: 813e90b1aeaa ("IB/mlx5: Add advise_mr() support") Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx> --- drivers/infiniband/hw/mlx5/odp.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c index 8d46b1dc56580f..a241a65834d4ca 100644 --- a/drivers/infiniband/hw/mlx5/odp.c +++ b/drivers/infiniband/hw/mlx5/odp.c @@ -1595,10 +1595,12 @@ static void mlx5_ib_prefetch_mr_work(struct work_struct *work) struct prefetch_mr_work *w = container_of(work, struct prefetch_mr_work, work); - if (w->dev->ib_dev.reg_state == IB_DEV_REGISTERED) + if (ib_device_try_get(&w->dev->ib_dev)) { mlx5_ib_prefetch_sg_list(w->dev, w->pf_flags, w->sg_list, w->num_sge); - + ib_device_put(&w->dev->ib_dev); + } + put_device(&w->dev->ib_dev.dev); kfree(w); } @@ -1617,15 +1619,13 @@ int mlx5_ib_advise_mr_prefetch(struct ib_pd *pd, return mlx5_ib_prefetch_sg_list(dev, pf_flags, sg_list, num_sge); - if (dev->ib_dev.reg_state != IB_DEV_REGISTERED) - return -ENODEV; - work = kvzalloc(struct_size(work, sg_list, num_sge), GFP_KERNEL); if (!work) return -ENOMEM; memcpy(work->sg_list, sg_list, num_sge * sizeof(struct ib_sge)); + get_device(&dev->ib_dev.dev); work->dev = dev; work->pf_flags = pf_flags; work->num_sge = num_sge; -- 2.20.1