3.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Trond Myklebust <trond.mykleb...@primarydata.com> commit 06ea0bfe6e6043cb56a78935a19f6f8ebc636226 upstream. When a send failure occurs due to the socket being out of buffer space, we call xs_nospace() in order to have the RPC task wait until the socket has drained enough to make it worth while trying again. The current patch fixes a race in which the socket is drained before we get round to setting up the machinery in xs_nospace(), and which is reported to cause hangs. Link: http://lkml.kernel.org/r/20140210170315.33dfc621@notabene.brown Fixes: a9a6b52ee1ba (SUNRPC: Don't start the retransmission timer...) Reported-by: Neil Brown <ne...@suse.com> Signed-off-by: Trond Myklebust <trond.mykleb...@primarydata.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- net/sunrpc/xprtsock.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -501,6 +501,7 @@ static int xs_nospace(struct rpc_task *t struct rpc_rqst *req = task->tk_rqstp; struct rpc_xprt *xprt = req->rq_xprt; struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt); + struct sock *sk = transport->inet; int ret = -EAGAIN; dprintk("RPC: %5u xmit incomplete (%u left of %u)\n", @@ -518,7 +519,7 @@ static int xs_nospace(struct rpc_task *t * window size */ set_bit(SOCK_NOSPACE, &transport->sock->flags); - transport->inet->sk_write_pending++; + sk->sk_write_pending++; /* ...and wait for more buffer space */ xprt_wait_for_buffer_space(task, xs_nospace_callback); } @@ -528,6 +529,9 @@ static int xs_nospace(struct rpc_task *t } spin_unlock_bh(&xprt->transport_lock); + + /* Race breaker in case memory is freed before above code is called */ + sk->sk_write_space(sk); return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
