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authorTrond Myklebust <trond.myklebust@primarydata.com>2016-07-26 09:51:19 -0400
committerJ. Bruce Fields <bfields@redhat.com>2016-08-01 17:53:41 -0400
commitb2f21f7d85758309f94eafd502fe555e8e5a7f06 (patch)
tree55262bcba32ed561db0953883f1f73090925f413 /net/sunrpc
parent8a4c3926889e7bf226e9f0254e7eface1f85f312 (diff)
SUNRPC: accept() may return sockets that are still in SYN_RECV
We're seeing traces of the following form: [10952.396347] svc: transport ffff88042ba4a 000 dequeued, inuse=2 [10952.396351] svc: tcp_accept ffff88042ba4 a000 sock ffff88042a6e4c80 [10952.396362] nfsd: connect from 10.2.6.1, port=187 [10952.396364] svc: svc_setup_socket ffff8800b99bcf00 [10952.396368] setting up TCP socket for reading [10952.396370] svc: svc_setup_socket created ffff8803eb10a000 (inet ffff88042b75b800) [10952.396373] svc: transport ffff8803eb10a000 put into queue [10952.396375] svc: transport ffff88042ba4a000 put into queue [10952.396377] svc: server ffff8800bb0ec000 waiting for data (to = 3600000) [10952.396380] svc: transport ffff8803eb10a000 dequeued, inuse=2 [10952.396381] svc_recv: found XPT_CLOSE [10952.396397] svc: svc_delete_xprt(ffff8803eb10a000) [10952.396398] svc: svc_tcp_sock_detach(ffff8803eb10a000) [10952.396399] svc: svc_sock_detach(ffff8803eb10a000) [10952.396412] svc: svc_sock_free(ffff8803eb10a000) i.e. an immediate close of the socket after initialisation. The culprit appears to be the test at the end of svc_tcp_init, which checks if the newly created socket is in the TCP_ESTABLISHED state, and immediately closes it if not. The evidence appears to suggest that the socket might still be in the SYN_RECV state at this time. The fix is to check for both states, and then to add a check in svc_tcp_state_change() to ensure we don't close the socket when it transitions into TCP_ESTABLISHED. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'net/sunrpc')
-rw-r--r--net/sunrpc/svcsock.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index bc3ef0734f2f..a11ddc8975c3 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -763,8 +763,10 @@ static void svc_tcp_state_change(struct sock *sk)
printk("svc: socket %p: no user data\n", sk);
else {
svsk->sk_ostate(sk);
- set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
- svc_xprt_enqueue(&svsk->sk_xprt);
+ if (sk->sk_state != TCP_ESTABLISHED) {
+ set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
+ svc_xprt_enqueue(&svsk->sk_xprt);
+ }
}
}
@@ -1290,8 +1292,13 @@ static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
- if (sk->sk_state != TCP_ESTABLISHED)
+ switch (sk->sk_state) {
+ case TCP_SYN_RECV:
+ case TCP_ESTABLISHED:
+ break;
+ default:
set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
+ }
}
}