On Mon, Mar 04, 2019 at 11:46:45AM -0800, john.hubb...@gmail.com wrote:
> From: John Hubbard <jhubb...@nvidia.com>
>
> 1. Bug fix: fix an off by one error in the code that
> cleans up if it fails to dma-map a page, after having
> done a get_user_pages_remote() on a range of pages.
>
> 2. Refinement: for that same cleanup code, release_pages()
> is better than put_page() in a loop.
>
> Cc: Leon Romanovsky <l...@kernel.org>
> Cc: Ira Weiny <ira.we...@intel.com>
> Cc: Jason Gunthorpe <j...@ziepe.ca>
> Cc: Andrew Morton <a...@linux-foundation.org>
> Cc: Doug Ledford <dledf...@redhat.com>
> Cc: linux-r...@vger.kernel.org
> Cc: linux...@kvack.org
> Signed-off-by: John Hubbard <jhubb...@nvidia.com>
Signed-off-by: Ira Weiny <ira.we...@intel.com>
> ---
> drivers/infiniband/core/umem_odp.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/infiniband/core/umem_odp.c
> b/drivers/infiniband/core/umem_odp.c
> index acb882f279cb..d45735b02e07 100644
> --- a/drivers/infiniband/core/umem_odp.c
> +++ b/drivers/infiniband/core/umem_odp.c
> @@ -40,6 +40,7 @@
> #include <linux/vmalloc.h>
> #include <linux/hugetlb.h>
> #include <linux/interval_tree_generic.h>
> +#include <linux/pagemap.h>
>
> #include <rdma/ib_verbs.h>
> #include <rdma/ib_umem.h>
> @@ -684,9 +685,11 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp
> *umem_odp, u64 user_virt,
> mutex_unlock(&umem_odp->umem_mutex);
>
> if (ret < 0) {
> - /* Release left over pages when handling errors. */
> - for (++j; j < npages; ++j)
> - put_page(local_page_list[j]);
> + /*
> + * Release pages, starting at the the first page
> + * that experienced an error.
> + */
> + release_pages(&local_page_list[j], npages - j);
> break;
> }
> }
> --
> 2.21.0
>
