net/ceph: Only clear SOCK_NOSPACE when there is sufficient space in the socket buffer

The Ceph messenger would sometimes queue multiple work items to write
data to a socket when the socket buffer was full.

Fix this problem by making ceph_write_space() use SOCK_NOSPACE in the
same way that net/core/stream.c:sk_stream_write_space() does, i.e.,
clearing it only when sufficient space is available in the socket buffer.

Signed-off-by: Jim Schutt <jaschut@sandia.gov>
Reviewed-by: Alex Elder <elder@dreamhost.com>
This commit is contained in:
Jim Schutt 2012-02-29 08:30:58 -07:00 committed by Alex Elder
parent c16fa4f2ad
commit 182fac2689
1 changed files with 12 additions and 6 deletions

View File

@ -143,16 +143,22 @@ static void ceph_write_space(struct sock *sk)
struct ceph_connection *con =
(struct ceph_connection *)sk->sk_user_data;
/* only queue to workqueue if there is data we want to write. */
/* only queue to workqueue if there is data we want to write,
* and there is sufficient space in the socket buffer to accept
* more data. clear SOCK_NOSPACE so that ceph_write_space()
* doesn't get called again until try_write() fills the socket
* buffer. See net/ipv4/tcp_input.c:tcp_check_space()
* and net/core/stream.c:sk_stream_write_space().
*/
if (test_bit(WRITE_PENDING, &con->state)) {
dout("ceph_write_space %p queueing write work\n", con);
queue_con(con);
if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
dout("ceph_write_space %p queueing write work\n", con);
clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
queue_con(con);
}
} else {
dout("ceph_write_space %p nothing to write\n", con);
}
/* since we have our own write_space, clear the SOCK_NOSPACE flag */
clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
}
/* socket's state has changed */