Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 31739139 authored by Alex Elder's avatar Alex Elder
Browse files

libceph: use kernel_sendpage() for sending zeroes 



If a message queued for send gets revoked, zeroes are sent over the
wire instead of any unsent data.  This is done by constructing a
message and passing it to kernel_sendmsg() via ceph_tcp_sendmsg().

Since we are already working with a page in this case we can use
the sendpage interface instead.  Create a new ceph_tcp_sendpage()
helper that sets up flags to match the way ceph_tcp_sendmsg()
does now.

Signed-off-by: default avatarAlex Elder <elder@dreamhost.com>
Reviewed-by: default avatarSage Weil <sage@newdream.net>
parent 37675b0f

net/ceph/messenger.c

+15 −5
Original line number Diff line number Diff line
@@ -321,6 +321,19 @@ static int ceph_tcp_sendmsg(struct socket *sock, struct kvec *iov, 
	return r;

}



static int ceph_tcp_sendpage(struct socket *sock, struct page *page,

		     int offset, size_t size, int more)

{

	int flags = MSG_DONTWAIT | MSG_NOSIGNAL | (more ? MSG_MORE : MSG_EOR);

	int ret;



	ret = kernel_sendpage(sock, page, offset, size, flags);

	if (ret == -EAGAIN)

		ret = 0;



	return ret;

}





/*

 * Shutdown/close the socket for the given connection.
@@ -944,12 +957,9 @@ static int write_partial_skip(struct ceph_connection *con) 
	int ret;



	while (con->out_skip > 0) {

		struct kvec iov = {

			.iov_base = zero_page_address,

			.iov_len = min(con->out_skip, (int)PAGE_CACHE_SIZE)

		};

		size_t size = min(con->out_skip, (int) PAGE_CACHE_SIZE);



		ret = ceph_tcp_sendmsg(con->sock, &iov, 1, iov.iov_len, 1);

		ret = ceph_tcp_sendpage(con->sock, zero_page, 0, size, 1);

		if (ret <= 0)

			goto out;

		con->out_skip -= ret;