From 943d045a6d796175e5d08f9973953b1d2c07d797 Mon Sep 17 00:00:00 2001 From: Siddharth Kawar Date: Mon, 20 Mar 2023 20:37:40 +0000 Subject: SUNRPC: fix shutdown of NFS TCP client socket NFS server Duplicate Request Cache (DRC) algorithms rely on NFS clients reconnecting using the same local TCP port. Unique NFS operations are identified by the per-TCP connection set of XIDs. This prevents file corruption when non-idempotent NFS operations are retried. Currently, NFS client TCP connections are using different local TCP ports when reconnecting to NFS servers. After an NFS server initiates shutdown of the TCP connection, the NFS client's TCP socket is set to NULL after the socket state has reached TCP_LAST_ACK(9). When reconnecting, the new socket attempts to reuse the same local port but fails with EADDRNOTAVAIL (99). This forces the socket to use a different local TCP port to reconnect to the remote NFS server. State Transition and Events: TCP_CLOSE_WAIT(8) TCP_LAST_ACK(9) connect(fail EADDRNOTAVAIL(99)) TCP_CLOSE(7) bind on new port connect success dmesg excerpts showing reconnect switching from TCP local port of 926 to 763 after commit 7c81e6a9d75b: [13354.947854] NFS call mkdir testW ... [13405.654781] RPC: xs_tcp_state_change client 00000000037d0f03... [13405.654813] RPC: state 8 conn 1 dead 0 zapped 1 sk_shutdown 1 [13405.654826] RPC: xs_data_ready... [13405.654892] RPC: xs_tcp_state_change client 00000000037d0f03... [13405.654895] RPC: state 9 conn 0 dead 0 zapped 1 sk_shutdown 3 [13405.654899] RPC: xs_tcp_state_change client 00000000037d0f03... [13405.654900] RPC: state 9 conn 0 dead 0 zapped 1 sk_shutdown 3 [13405.654950] RPC: xs_connect scheduled xprt 00000000037d0f03 [13405.654975] RPC: xs_bind 0.0.0.0:926: ok (0) [13405.654980] RPC: worker connecting xprt 00000000037d0f03 via tcp to 10.101.6.228 (port 2049) [13405.654991] RPC: 00000000037d0f03 connect status 99 connected 0 sock state 7 [13405.655001] RPC: xs_tcp_state_change client 00000000037d0f03... [13405.655002] RPC: state 7 conn 0 dead 0 zapped 1 sk_shutdown 3 [13405.655024] RPC: xs_connect scheduled xprt 00000000037d0f03 [13405.655038] RPC: xs_bind 0.0.0.0:763: ok (0) [13405.655041] RPC: worker connecting xprt 00000000037d0f03 via tcp to 10.101.6.228 (port 2049) [13405.655065] RPC: 00000000037d0f03 connect status 115 connected 0 sock state 2 State Transition and Events with patch applied: TCP_CLOSE_WAIT(8) TCP_LAST_ACK(9) TCP_CLOSE(7) connect(reuse of port succeeds) dmesg excerpts showing reconnect on same TCP local port of 936 with patch applied: [ 257.139935] NFS: mkdir(0:59/560857152), testQ [ 257.139937] NFS call mkdir testQ ... [ 307.822702] RPC: state 8 conn 1 dead 0 zapped 1 sk_shutdown 1 [ 307.822714] RPC: xs_data_ready... [ 307.822817] RPC: xs_tcp_state_change client 00000000ce702f14... [ 307.822821] RPC: state 9 conn 0 dead 0 zapped 1 sk_shutdown 3 [ 307.822825] RPC: xs_tcp_state_change client 00000000ce702f14... [ 307.822826] RPC: state 9 conn 0 dead 0 zapped 1 sk_shutdown 3 [ 307.823606] RPC: xs_tcp_state_change client 00000000ce702f14... [ 307.823609] RPC: state 7 conn 0 dead 0 zapped 1 sk_shutdown 3 [ 307.823629] RPC: xs_tcp_state_change client 00000000ce702f14... [ 307.823632] RPC: state 7 conn 0 dead 0 zapped 1 sk_shutdown 3 [ 307.823676] RPC: xs_connect scheduled xprt 00000000ce702f14 [ 307.823704] RPC: xs_bind 0.0.0.0:936: ok (0) [ 307.823709] RPC: worker connecting xprt 00000000ce702f14 via tcp to 10.101.1.30 (port 2049) [ 307.823748] RPC: 00000000ce702f14 connect status 115 connected 0 sock state 2 ... [ 314.916193] RPC: state 7 conn 0 dead 0 zapped 1 sk_shutdown 3 [ 314.916251] RPC: xs_connect scheduled xprt 00000000ce702f14 [ 314.916282] RPC: xs_bind 0.0.0.0:936: ok (0) [ 314.916292] RPC: worker connecting xprt 00000000ce702f14 via tcp to 10.101.1.30 (port 2049) [ 314.916342] RPC: 00000000ce702f14 connect status 115 connected 0 sock state 2 Fixes: 7c81e6a9d75b ("SUNRPC: Tweak TCP socket shutdown in the RPC client") Signed-off-by: Siddharth Rajendra Kawar Signed-off-by: Anna Schumaker --- net/sunrpc/xprtsock.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/sunrpc/xprtsock.c') diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index adcbedc244d6..6cacd70a15ff 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2158,6 +2158,7 @@ static void xs_tcp_shutdown(struct rpc_xprt *xprt) switch (skst) { case TCP_FIN_WAIT1: case TCP_FIN_WAIT2: + case TCP_LAST_ACK: break; case TCP_ESTABLISHED: case TCP_CLOSE_WAIT: -- cgit v1.2.3 From c946cb69f238b2bd3e42790b8450f76b62b491f4 Mon Sep 17 00:00:00 2001 From: Luis Chamberlain Date: Sat, 11 Mar 2023 15:39:42 -0800 Subject: sunrpc: simplify one-level sysctl registration for xs_tunables_table There is no need to declare an extra tables to just create directory, this can be easily be done with a prefix path with register_sysctl(). Simplify this registration. Signed-off-by: Luis Chamberlain Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker --- net/sunrpc/xprtsock.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) (limited to 'net/sunrpc/xprtsock.c') diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 6cacd70a15ff..5f9030b81c9e 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -78,7 +78,7 @@ static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO; /* * We can register our own files under /proc/sys/sunrpc by - * calling register_sysctl_table() again. The files in that + * calling register_sysctl() again. The files in that * directory become the union of all files registered there. * * We simply need to make sure that we don't collide with @@ -158,15 +158,6 @@ static struct ctl_table xs_tunables_table[] = { { }, }; -static struct ctl_table sunrpc_table[] = { - { - .procname = "sunrpc", - .mode = 0555, - .child = xs_tunables_table - }, - { }, -}; - /* * Wait duration for a reply from the RPC portmapper. */ @@ -3178,7 +3169,7 @@ static struct xprt_class xs_bc_tcp_transport = { int init_socket_xprt(void) { if (!sunrpc_table_header) - sunrpc_table_header = register_sysctl_table(sunrpc_table); + sunrpc_table_header = register_sysctl("sunrpc", xs_tunables_table); xprt_register_transport(&xs_local_transport); xprt_register_transport(&xs_udp_transport); -- cgit v1.2.3