path: root/net
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authorTrond Myklebust <trond.myklebust@primarydata.com>2014-02-11 09:15:54 -0500
committerTrond Myklebust <trond.myklebust@primarydata.com>2014-02-11 09:34:30 -0500
commit06ea0bfe6e6043cb56a78935a19f6f8ebc636226 (patch)
treefac441e73156f1cdef93f3907aa69fdf2ca6c9d2 /net
parenta699d65ec4ff82245d2c4fdfb8ed1d64776d756e (diff)
SUNRPC: Fix races in xs_nospace()
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 <neilb@suse.com> Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'net')
1 files changed, 5 insertions, 1 deletions
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 817a1e523969..0addefca8e77 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -510,6 +510,7 @@ static int xs_nospace(struct rpc_task *task)
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",
@@ -527,7 +528,7 @@ static int xs_nospace(struct rpc_task *task)
* 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);
@@ -537,6 +538,9 @@ static int xs_nospace(struct rpc_task *task)
+ /* Race breaker in case memory is freed before above code is called */
+ sk->sk_write_space(sk);
return ret;

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