From: John Hubbard <jhubbard@nvidia.com>
Date: Mon, 4 Mar 2019 19:46:45 +0000 (-0800)
Subject: RDMA/umem: minor bug fix in error handling path
X-Git-Tag: v5.1-rc1~86^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=75a3e6a3c129cddcc683538d8702c6ef998ec589;p=thirdparty%2Fkernel%2Flinux.git

RDMA/umem: minor bug fix in error handling path

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.

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---

diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c
index 6013cf0b8f4fd..577f1b12bff4d 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>
@@ -685,9 +686,11 @@ 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;
 		}
 	}