[PATCH 1/4] null_blk: use memcpy_page() in copy_to_nullb()

[Chaitanya Kulkarni <kch@nvidia.com>]

Use library helper memcpy_page() to copy source page into destination
instead of having duplicate code. This also removes deprecated API
kmap_atomic() from :include/linux/highmem.h:
"kmap_atomic - Atomically map a page for temporary usage - Deprecated!"

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
---
 drivers/block/null_blk/main.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 9e6b032c8ecc..947bba174e1e 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1112,7 +1112,6 @@ static int copy_to_nullb(struct nullb *nullb, struct page *source,
 	size_t temp, count = 0;
 	unsigned int offset;
 	struct nullb_page *t_page;
-	void *dst, *src;
 
 	while (count < n) {
 		temp = min_t(size_t, nullb->dev->blocksize, n - count);
@@ -1126,11 +1125,7 @@ static int copy_to_nullb(struct nullb *nullb, struct page *source,
 		if (!t_page)
 			return -ENOSPC;
 
-		src = kmap_atomic(source);
-		dst = kmap_atomic(t_page->page);
-		memcpy(dst + offset, src + off + count, temp);
-		kunmap_atomic(dst);
-		kunmap_atomic(src);
+		memcpy_page(t_page->page, offset, source, off + count, temp);
 
 		__set_bit(sector & SECTOR_MASK, t_page->bitmap);
 
-- 
2.29.0