[10/34] genwqe: convert put_page() to put_user_page*()
diff mbox series

Message ID 20190802022005.5117-11-jhubbard@nvidia.com
State New
Headers show
Series
  • put_user_pages(): miscellaneous call sites
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Commit Message

john.hubbard@gmail.com Aug. 2, 2019, 2:19 a.m. UTC
From: John Hubbard <jhubbard@nvidia.com>

For pages that were retained via get_user_pages*(), release those pages
via the new put_user_page*() routines, instead of via put_page() or
release_pages().

This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
("mm: introduce put_user_page*(), placeholder versions").

This changes the release code slightly, because each page slot in the
page_list[] array is no longer checked for NULL. However, that check
was wrong anyway, because the get_user_pages() pattern of usage here
never allowed for NULL entries within a range of pinned pages.

Cc: Frank Haverkamp <haver@linux.vnet.ibm.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 drivers/misc/genwqe/card_utils.c | 17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

Comments

Greg Kroah-Hartman Aug. 3, 2019, 7:06 a.m. UTC | #1
On Thu, Aug 01, 2019 at 07:19:41PM -0700, john.hubbard@gmail.com wrote:
> From: John Hubbard <jhubbard@nvidia.com>
> 
> For pages that were retained via get_user_pages*(), release those pages
> via the new put_user_page*() routines, instead of via put_page() or
> release_pages().
> 
> This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
> ("mm: introduce put_user_page*(), placeholder versions").
> 
> This changes the release code slightly, because each page slot in the
> page_list[] array is no longer checked for NULL. However, that check
> was wrong anyway, because the get_user_pages() pattern of usage here
> never allowed for NULL entries within a range of pinned pages.
> 
> Cc: Frank Haverkamp <haver@linux.vnet.ibm.com>
> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> ---
>  drivers/misc/genwqe/card_utils.c | 17 +++--------------
>  1 file changed, 3 insertions(+), 14 deletions(-)

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Patch
diff mbox series

diff --git a/drivers/misc/genwqe/card_utils.c b/drivers/misc/genwqe/card_utils.c
index 2e1c4d2905e8..2a888f31d2c5 100644
--- a/drivers/misc/genwqe/card_utils.c
+++ b/drivers/misc/genwqe/card_utils.c
@@ -517,24 +517,13 @@  int genwqe_free_sync_sgl(struct genwqe_dev *cd, struct genwqe_sgl *sgl)
 /**
  * genwqe_free_user_pages() - Give pinned pages back
  *
- * Documentation of get_user_pages is in mm/gup.c:
- *
- * If the page is written to, set_page_dirty (or set_page_dirty_lock,
- * as appropriate) must be called after the page is finished with, and
- * before put_page is called.
+ * The pages may have been written to, so we call put_user_pages_dirty_lock(),
+ * rather than put_user_pages().
  */
 static int genwqe_free_user_pages(struct page **page_list,
 			unsigned int nr_pages, int dirty)
 {
-	unsigned int i;
-
-	for (i = 0; i < nr_pages; i++) {
-		if (page_list[i] != NULL) {
-			if (dirty)
-				set_page_dirty_lock(page_list[i]);
-			put_page(page_list[i]);
-		}
-	}
+	put_user_pages_dirty_lock(page_list, nr_pages, dirty);
 	return 0;
 }