blob: ce0f2c3c3ad2ebae91e67892e738cc253974db35 [file] [log] [blame]
From foo@baz Thu May 19 04:26:41 PM CEST 2022
From: Meena Shanmugam <meenashanmugam@google.com>
Date: Wed, 18 May 2022 18:40:11 +0000
Subject: SUNRPC: Ensure we flush any closed sockets before xs_xprt_free()
To: stable@vger.kernel.org
Cc: gregkh@linuxfoundation.org, trond.myklebust@hammerspace.com, Felix Fu <foyjog@gmail.com>, Al Viro <viro@zeniv.linux.org.uk>, Meena Shanmugam <meenashanmugam@google.com>
Message-ID: <20220518184011.789699-5-meenashanmugam@google.com>
From: Meena Shanmugam <meenashanmugam@google.com>
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>
[meenashanmugam: Fix merge conflict in xprt_connect]
Signed-off-by: Meena Shanmugam <meenashanmugam@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/file_table.c | 1 +
net/sunrpc/xprt.c | 5 +----
net/sunrpc/xprtsock.c | 16 +++++++++++++---
3 files changed, 15 insertions(+), 7 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/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -868,10 +868,7 @@ 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));
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -989,7 +989,7 @@ 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;
}
@@ -1027,7 +1027,7 @@ static int xs_local_send_request(struct
-status);
/* fall through */
case -EPIPE:
- xs_close(xprt);
+ xprt_force_disconnect(xprt);
status = -ENOTCONN;
}
@@ -1303,6 +1303,16 @@ 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);
@@ -1326,7 +1336,7 @@ 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);
}