On Tue, May 10, 2022 at 07:33:23PM -0700, Meena Shanmugam wrote:
From: Trond Myklebust trond.myklebust@hammerspace.com 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@sigma-chemnitz.de Fixes: 3be232f11a3c ("SUNRPC: Prevent immediate close+reconnect") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com [meenashanmugam: Backported to 5.10: Fixed merge conflict in xs_tcp_setup_socket] Signed-off-by: Meena Shanmugam meena.shanmugam@google.com
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);@@ -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@gmail.com 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@hammerspace.com
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@sigma-chemnitz.de Fixes: 3be232f11a3cc9 ("SUNRPC: Prevent immediate close+reconnect") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com [meenashanmugam: Backported to 5.10: Fixed merge conflict in xs_tcp_setup_socket] Signed-off-by: Meena Shanmugam meena.shanmugam@google.com [Bagas: Fix patch corruption by manually applying the backport] Signed-off-by: Bagas Sanjaya bagasdotme@gmail.com --- 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);