Use sendmsg() conditionally with MSG_SPLICE_PAGES in _drbd_send_page()
rather than calling sendpage() or _drbd_no_send_page().
Signed-off-by: David Howells <[email protected]>
cc: Philipp Reisner <[email protected]>
cc: Lars Ellenberg <[email protected]>
cc: "Christoph Böhmwalder" <[email protected]>
cc: Jens Axboe <[email protected]>
cc: "David S. Miller" <[email protected]>
cc: Eric Dumazet <[email protected]>
cc: Jakub Kicinski <[email protected]>
cc: Paolo Abeni <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
Notes:
ver #4)
- Don't look at msg.msg_iter after calling sendmsg. There's no guarantee
it has changed.
ver #2)
- Wrap lines at 80.
drivers/block/drbd/drbd_main.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 83987e7a5ef2..ea82d6733313 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1540,6 +1540,8 @@ static int _drbd_send_page(struct drbd_peer_device *peer_device, struct page *pa
int offset, size_t size, unsigned msg_flags)
{
struct socket *socket = peer_device->connection->data.socket;
+ struct msghdr msg = { .msg_flags = msg_flags, };
+ struct bio_vec bvec;
int len = size;
int err = -EIO;
@@ -1549,15 +1551,17 @@ 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 || !sendpage_ok(page))
- return _drbd_no_send_page(peer_device, page, offset, size, msg_flags);
+ if (!drbd_disable_sendpage && sendpage_ok(page))
+ msg.msg_flags |= MSG_NOSIGNAL | MSG_SPLICE_PAGES;
- msg_flags |= MSG_NOSIGNAL;
drbd_update_congested(peer_device->connection);
do {
int sent;
- sent = socket->ops->sendpage(socket, page, offset, len, msg_flags);
+ bvec_set_page(&bvec, page, offset, len);
+ iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, len);
+
+ sent = sock_sendmsg(socket, &msg);
if (sent <= 0) {
if (sent == -EAGAIN) {
if (we_should_drop_the_connection(peer_device->connection, socket))