[PATCH] mm/swap: Fix release_pages() when releasing devmap pages

From: ira.weiny@intel.com
To: Andrew Morton <akpm@linux-foundation.org>
Cc: "Michal Hocko" <mhocko@suse.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	"John Hubbard" <jhubbard@nvidia.com>,
	"Ira Weiny" <ira.weiny@intel.com>,
	"Jérôme Glisse" <jglisse@redhat.com>,
	"Dan Williams" <dan.j.williams@intel.com>
Subject: [PATCH] mm/swap: Fix release_pages() when releasing devmap pages
Date: Thu, 23 May 2019 15:37:46 -0700	[thread overview]
Message-ID: <20190523223746.4982-1-ira.weiny@intel.com> (raw)

From: Ira Weiny <ira.weiny@intel.com>

Device pages can be more than type MEMORY_DEVICE_PUBLIC.

Handle all device pages within release_pages()

This was found via code inspection while determining if release_pages()
and the new put_user_pages() could be interchangeable.

Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 mm/swap.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/swap.c b/mm/swap.c
index 3a75722e68a9..d1e8122568d0 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -739,15 +739,14 @@ void release_pages(struct page **pages, int nr)
 		if (is_huge_zero_page(page))
 			continue;
 
-		/* Device public page can not be huge page */
-		if (is_device_public_page(page)) {
+		if (is_zone_device_page(page)) {
 			if (locked_pgdat) {
 				spin_unlock_irqrestore(&locked_pgdat->lru_lock,
 						       flags);
 				locked_pgdat = NULL;
 			}
-			put_devmap_managed_page(page);
-			continue;
+			if (put_devmap_managed_page(page))
+				continue;
 		}
 
 		page = compound_head(page);
-- 
2.20.1

