提交 31739139 编写于 作者: A Alex Elder

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: NAlex Elder <elder@dreamhost.com>
Reviewed-by: NSage Weil <sage@newdream.net>
上级 37675b0f
...@@ -321,6 +321,19 @@ static int ceph_tcp_sendmsg(struct socket *sock, struct kvec *iov, ...@@ -321,6 +321,19 @@ static int ceph_tcp_sendmsg(struct socket *sock, struct kvec *iov,
return r; 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. * Shutdown/close the socket for the given connection.
...@@ -944,12 +957,9 @@ static int write_partial_skip(struct ceph_connection *con) ...@@ -944,12 +957,9 @@ static int write_partial_skip(struct ceph_connection *con)
int ret; int ret;
while (con->out_skip > 0) { while (con->out_skip > 0) {
struct kvec iov = { size_t size = min(con->out_skip, (int) PAGE_CACHE_SIZE);
.iov_base = zero_page_address,
.iov_len = 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) if (ret <= 0)
goto out; goto out;
con->out_skip -= ret; con->out_skip -= ret;
......
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