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: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 589b768..9207a8c 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -321,6 +321,19 @@
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 @@
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;