On Tue, May 10, 2022 at 07:33:23PM -0700, Meena Shanmugam wrote:
> From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> Date: Wed, 16 Mar 2022 19:10:43 -0400
> Subject: [PATCH] SUNRPC: Don't call connect() more than once on a TCP socket
>
> commit 89f42494f92f448747bd8a7ab1ae8b5d5520577d upstream.
>
> Avoid socket state races due to repeated calls to ->connect() using the
> same socket. If connect() returns 0 due to the connection having
> completed, but we are in fact in a closing state, then we may leave the
> XPRT_CONNECTING flag set on the transport.
>
> Reported-by: Enrico Scholz <enrico.scholz@xxxxxxxxxxxxxxxxx>
> Fixes: 3be232f11a3c ("SUNRPC: Prevent immediate close+reconnect")
> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> [meenashanmugam: Backported to 5.10: Fixed merge conflict in
> xs_tcp_setup_socket]
> Signed-off-by: Meena Shanmugam <meena.shanmugam@xxxxxxxxxx>
> ---
> include/linux/sunrpc/xprtsock.h | 1 +
> net/sunrpc/xprtsock.c | 21 +++++++++++----------
> 2 files changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/include/linux/sunrpc/xprtsock.h b/include/linux/sunrpc/xprtsock.h
> index 8c2a712cb242..689062afdd61 100644
> --- a/include/linux/sunrpc/xprtsock.h
> +++ b/include/linux/sunrpc/xprtsock.h
> @@ -89,5 +89,6 @@ struct sock_xprt {
> #define XPRT_SOCK_WAKE_WRITE (5)
> #define XPRT_SOCK_WAKE_PENDING (6)
> #define XPRT_SOCK_WAKE_DISCONNECT (7)
> +#define XPRT_SOCK_CONNECT_SENT (8)
>
> #endif /* _LINUX_SUNRPC_XPRTSOCK_H */
> diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
> index 60c58eb9a456..33a81f9703b1 100644
> --- a/net/sunrpc/xprtsock.c
> +++ b/net/sunrpc/xprtsock.c
> @@ -2260,10 +2260,14 @@ static void xs_tcp_setup_socket(struct
> work_struct *work)
> struct rpc_xprt *xprt = &transport->xprt;
> int status = -EIO;
>
> - if (!sock) {
> - sock = xs_create_sock(xprt, transport,
> - xs_addr(xprt)->sa_family, SOCK_STREAM,
> - IPPROTO_TCP, true);
> + if (xprt_connected(xprt))
> + goto out;
> + if (test_and_clear_bit(XPRT_SOCK_CONNECT_SENT,
> + &transport->sock_state) ||
> + !sock) {
> + xs_reset_transport(transport);
> + sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family,
> + SOCK_STREAM, IPPROTO_TCP, true);
> if (IS_ERR(sock)) {
> status = PTR_ERR(sock);
> goto out;
> @@ -2294,6 +2298,7 @@ static void xs_tcp_setup_socket(struct work_struct *work)
> break;
> case 0:
> case -EINPROGRESS:
> + set_bit(XPRT_SOCK_CONNECT_SENT, &transport->sock_state);
> case -EALREADY:
> xprt_unlock_connect(xprt, transport);
> return;
> @@ -2345,13 +2350,9 @@ static void xs_connect(struct rpc_xprt *xprt,
> struct rpc_task *task)
>
> WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
>
> - if (transport->sock != NULL && !xprt_connecting(xprt)) {
> + if (transport->sock != NULL) {
> dprintk("RPC: xs_connect delayed xprt %p for %lu "
> - "seconds\n",
> - xprt, xprt->reestablish_timeout / HZ);
> -
> - /* Start by resetting any existing state */
> - xs_reset_transport(transport);
> + "seconds\n", xprt, xprt->reestablish_timeout / HZ);
>
> delay = xprt_reconnect_delay(xprt);
> xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
> --
> 2.36.0.512.ge40c2bad7a-goog
Hi Meena,
The backport above didn't apply due to whitespace mangling (maybe your
mailer?). So I had to manually apply it.
Here's the proper backport:
-- >8 --
>From 2ec4a7d1668a53a1f46d3413bdec6ff9cc0458a3 Mon Sep 17 00:00:00 2001
From: Bagas Sanjaya <bagasdotme@xxxxxxxxx>
Date: Thu, 12 May 2022 12:53:07 +0700
Subject: [PATCH] SUNRPC: Don't call connect() more than once on a TCP socket
From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
commit 89f42494f92f448747bd8a7ab1ae8b5d5520577d upstream.
Avoid socket state races due to repeated calls to ->connect() using the
same socket. If connect() returns 0 due to the connection having
completed, but we are in fact in a closing state, then we may leave the
XPRT_CONNECTING flag set on the transport.
Reported-by: Enrico Scholz <enrico.scholz@xxxxxxxxxxxxxxxxx>
Fixes: 3be232f11a3cc9 ("SUNRPC: Prevent immediate close+reconnect")
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
[meenashanmugam: Backported to 5.10: Fixed merge conflict in
xs_tcp_setup_socket]
Signed-off-by: Meena Shanmugam <meena.shanmugam@xxxxxxxxxx>
[Bagas: Fix patch corruption by manually applying the backport]
Signed-off-by: Bagas Sanjaya <bagasdotme@xxxxxxxxx>
---
include/linux/sunrpc/xprtsock.h | 1 +
net/sunrpc/xprtsock.c | 22 ++++++++++++----------
2 files changed, 13 insertions(+), 10 deletions(-)
diff --git a/include/linux/sunrpc/xprtsock.h b/include/linux/sunrpc/xprtsock.h
index 8c2a712cb24202..689062afdd610d 100644
--- a/include/linux/sunrpc/xprtsock.h
+++ b/include/linux/sunrpc/xprtsock.h
@@ -89,5 +89,6 @@ struct sock_xprt {
#define XPRT_SOCK_WAKE_WRITE (5)
#define XPRT_SOCK_WAKE_PENDING (6)
#define XPRT_SOCK_WAKE_DISCONNECT (7)
+#define XPRT_SOCK_CONNECT_SENT (8)
#endif /* _LINUX_SUNRPC_XPRTSOCK_H */
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 60c58eb9a456f1..c9975a5c769be9 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2260,10 +2260,15 @@ static void xs_tcp_setup_socket(struct work_struct *work)
struct rpc_xprt *xprt = &transport->xprt;
int status = -EIO;
- if (!sock) {
- sock = xs_create_sock(xprt, transport,
- xs_addr(xprt)->sa_family, SOCK_STREAM,
- IPPROTO_TCP, true);
+ if (xprt_connected(xprt))
+ goto out;
+
+ if (test_and_clear_bit(XPRT_SOCK_CONNECT_SENT),
+ &transport->sock_state || !sock) {
+ xs_reset_transport(transport);
+ sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family,
+ SOCK_STREAM, IPPROTO_TCP, true);
+
if (IS_ERR(sock)) {
status = PTR_ERR(sock);
goto out;
@@ -2294,6 +2299,7 @@ static void xs_tcp_setup_socket(struct work_struct *work)
break;
case 0:
case -EINPROGRESS:
+ set_bit(XPRT_SOCK_CONNECT_SENT, &transport->sock_state);
case -EALREADY:
xprt_unlock_connect(xprt, transport);
return;
@@ -2345,13 +2351,9 @@ static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
- if (transport->sock != NULL && !xprt_connecting(xprt)) {
+ if (transport->sock != NULL) {
dprintk("RPC: xs_connect delayed xprt %p for %lu "
- "seconds\n",
- xprt, xprt->reestablish_timeout / HZ);
-
- /* Start by resetting any existing state */
- xs_reset_transport(transport);
+ "seconds\n", xprt, xprt->reestablish_timeout / HZ);
delay = xprt_reconnect_delay(xprt);
xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
--
An old man doll... just what I always wanted! - Clara
Next time, configure your mailer/MUA to not mangle whitespaces. For sending
patches, it is preferred to use git-send-email(1).
FYI, CC Dexter Rivera since he's also requesting the backport [1].
[1]: https://lore.kernel.org/stable/CAG5dfppH0s-ujBjXyJJ62mGiJRiKz1NOYBPYOx3A1550Z8X7Mg@xxxxxxxxxxxxxx/
--
An old man doll... just what I always wanted! - Clara
