SUNRPC: Ensure we flush any closed sockets before xs_xprt_free()

From: Trond Myklebust <trond.myklebust@hammerspace.com>

commit f00432063d upstream.

We must ensure that all sockets are closed before we call xprt_free()
and release the reference to the net namespace. The problem is that
calling fput() will defer closing the socket until delayed_fput() gets
called.
Let's fix the situation by allowing rpciod and the transport teardown
code (which runs on the system wq) to call __fput_sync(), and directly
close the socket.

Reported-by: Felix Fu <foyjog@gmail.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: a73881c96d ("SUNRPC: Fix an Oops in udp_poll()")
Cc: stable@vger.kernel.org # 5.1.x: 3be232f11a3c: SUNRPC: Prevent immediate close+reconnect
Cc: stable@vger.kernel.org # 5.1.x: 89f42494f92f: SUNRPC: Don't call connect() more than once on a TCP socket
Cc: stable@vger.kernel.org # 5.1.x
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
[meenashanmugam: Fix merge conflict in xprt_connect]
Signed-off-by: Meena Shanmugam <meenashanmugam@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Meena Shanmugam 2022-05-18 18:40:11 +00:00 committed by Jianping Liu
parent e5af1e10fe
commit 0ba47fb306
3 changed files with 15 additions and 7 deletions

View File

@ -375,6 +375,7 @@ void __fput_sync(struct file *file)
}
EXPORT_SYMBOL(fput);
EXPORT_SYMBOL(__fput_sync);
void __init files_init(void)
{

View File

@ -861,10 +861,7 @@ void xprt_connect(struct rpc_task *task)
if (!xprt_lock_write(xprt, task))
return;
if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state))
xprt->ops->close(xprt);
if (!xprt_connected(xprt)) {
if (!xprt_connected(xprt) && !test_bit(XPRT_CLOSE_WAIT, &xprt->state)) {
task->tk_rqstp->rq_connect_cookie = xprt->connect_cookie;
rpc_sleep_on_timeout(&xprt->pending, task, NULL,
xprt_request_timeout(task->tk_rqstp));

View File

@ -965,7 +965,7 @@ static int xs_local_send_request(struct rpc_rqst *req)
/* Close the stream if the previous transmission was incomplete */
if (xs_send_request_was_aborted(transport, req)) {
xs_close(xprt);
xprt_force_disconnect(xprt);
return -ENOTCONN;
}
@ -1003,7 +1003,7 @@ static int xs_local_send_request(struct rpc_rqst *req)
-status);
/* fall through */
case -EPIPE:
xs_close(xprt);
xprt_force_disconnect(xprt);
status = -ENOTCONN;
}
@ -1279,6 +1279,16 @@ static void xs_reset_transport(struct sock_xprt *transport)
if (sk == NULL)
return;
/*
* Make sure we're calling this in a context from which it is safe
* to call __fput_sync(). In practice that means rpciod and the
* system workqueue.
*/
if (!(current->flags & PF_WQ_WORKER)) {
WARN_ON_ONCE(1);
set_bit(XPRT_CLOSE_WAIT, &xprt->state);
return;
}
if (atomic_read(&transport->xprt.swapper))
sk_clear_memalloc(sk);
@ -1302,7 +1312,7 @@ static void xs_reset_transport(struct sock_xprt *transport)
mutex_unlock(&transport->recv_mutex);
trace_rpc_socket_close(xprt, sock);
fput(filp);
__fput_sync(filp);
xprt_disconnect_done(xprt);
}