drbd: code cleanup by using sendpage_ok() to check page for kernel_sendpage()

In _drbd_send_page() a page is checked by following code before sending
it by kernel_sendpage(),
        (page_count(page) < 1) || PageSlab(page)
If the check is true, this page won't be send by kernel_sendpage() and
handled by sock_no_sendpage().

This kind of check is exactly what macro sendpage_ok() does, which is
introduced into include/linux/net.h to solve a similar send page issue
in nvme-tcp code.

This patch uses macro sendpage_ok() to replace the open coded checks to
page type and refcount in _drbd_send_page(), as a code cleanup.

Signed-off-by: Coly Li <colyli@suse.de>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 04b6bde..573dbf6 100644 (file)
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1553,7 +1553,7 @@ static int _drbd_send_page(struct drbd_peer_device *peer_device, struct page *pa
         * put_page(); and would cause either a VM_BUG directly, or
         * __page_cache_release a page that would actually still be referenced
         * by someone, leading to some obscure delayed Oops somewhere else. */
-       if (drbd_disable_sendpage || (page_count(page) < 1) || PageSlab(page))
+       if (drbd_disable_sendpage || !sendpage_ok(page))
                return _drbd_no_send_page(peer_device, page, offset, size, msg_flags);
 
        msg_flags |= MSG_NOSIGNAL;