On 7/31/19 11:07 PM, Christoph Hellwig wrote:

On Tue, Jul 30, 2019 at 01:57:03PM -0700, john.hubbard@gmail.com wrote:

quoted

@@ -40,10 +40,7 @@
 static void __qib_release_user_pages(struct page **p, size_t num_pages,
 				     int dirty)
 {
-	if (dirty)
-		put_user_pages_dirty_lock(p, num_pages);
-	else
-		put_user_pages(p, num_pages);
+	put_user_pages_dirty_lock(p, num_pages, dirty);
 }

__qib_release_user_pages should be removed now as a direct call to
put_user_pages_dirty_lock is a lot more clear.

OK.

quoted

index 0b0237d41613..62e6ffa9ad78 100644

--- a/drivers/infiniband/hw/usnic/usnic_uiom.c
+++ b/drivers/infiniband/hw/usnic/usnic_uiom.c

@@ -75,10 +75,7 @@ static void usnic_uiom_put_pages(struct list_head *chunk_list, int dirty)
 		for_each_sg(chunk->page_list, sg, chunk->nents, i) {
 			page = sg_page(sg);
 			pa = sg_phys(sg);
-			if (dirty)
-				put_user_pages_dirty_lock(&page, 1);
-			else
-				put_user_page(page);
+			put_user_pages_dirty_lock(&page, 1, dirty);
 			usnic_dbg("pa: %pa\n", &pa);

There is a pre-existing bug here, as this needs to use the sg_page
iterator.  Probably worth throwing in a fix into your series while you
are at it.

The amount of scatterlist code I've written is approximately zero lines,
+/- a few lines. :)  I thought for_each_sg() *was* the sg_page iterator...

I'll be glad to post a fix, but I'm not yet actually spotting the bug! heh

quoted

@@ -63,15 +63,7 @@ struct siw_mem *siw_mem_id2obj(struct siw_device *sdev, int stag_index)
 static void siw_free_plist(struct siw_page_chunk *chunk, int num_pages,
 			   bool dirty)
 {
-	struct page **p = chunk->plist;
-
-	while (num_pages--) {
-		if (!PageDirty(*p) && dirty)
-			put_user_pages_dirty_lock(p, 1);
-		else
-			put_user_page(*p);
-		p++;
-	}
+	put_user_pages_dirty_lock(chunk->plist, num_pages, dirty);

siw_free_plist should just go away now.

OK, yes.

Otherwise this looks good to me.

Great, I'll make the above changes and post an updated series with your
Reviewed-by, and Bjorn's ACK for patch #3.

Next: I've just finished sweeping through a bunch of patches and applying this
where applicable, so now that this API seems acceptable, I'll post another
chunk of put_user_page*() conversions.

thanks,
-- 
John Hubbard
NVIDIA