From: Trond Myklebust trond.myklebust@hammerspace.com
commit f00432063db1a0db484e85193eccc6845435b80e 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: a73881c96d73 ("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 Cc: Meena Shanmugam meenashanmugam@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/file_table.c | 1 + include/trace/events/sunrpc.h | 1 - net/sunrpc/xprt.c | 7 +------ net/sunrpc/xprtsock.c | 16 +++++++++++++--- 4 files changed, 15 insertions(+), 10 deletions(-)
--- a/fs/file_table.c +++ b/fs/file_table.c @@ -375,6 +375,7 @@ void __fput_sync(struct file *file) }
EXPORT_SYMBOL(fput); +EXPORT_SYMBOL(__fput_sync);
void __init files_init(void) { --- a/include/trace/events/sunrpc.h +++ b/include/trace/events/sunrpc.h @@ -976,7 +976,6 @@ DEFINE_RPC_XPRT_LIFETIME_EVENT(connect); DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_auto); DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_done); DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_force); -DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_cleanup); DEFINE_RPC_XPRT_LIFETIME_EVENT(destroy);
DECLARE_EVENT_CLASS(rpc_xprt_event, --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -929,12 +929,7 @@ void xprt_connect(struct rpc_task *task) if (!xprt_lock_write(xprt, task)) return;
- if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state)) { - trace_xprt_disconnect_cleanup(xprt); - 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)); --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -880,7 +880,7 @@ static int xs_local_send_request(struct
/* 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; }
@@ -918,7 +918,7 @@ static int xs_local_send_request(struct -status); fallthrough; case -EPIPE: - xs_close(xprt); + xprt_force_disconnect(xprt); status = -ENOTCONN; }
@@ -1205,6 +1205,16 @@ static void xs_reset_transport(struct so
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); @@ -1228,7 +1238,7 @@ static void xs_reset_transport(struct so mutex_unlock(&transport->recv_mutex);
trace_rpc_socket_close(xprt, sock); - fput(filp); + __fput_sync(filp);
xprt_disconnect_done(xprt); }