SUNRPC: Fix suspicious enobufs issues.
The current test is racy when dealing with fast NICs.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 646170d..6b3efeb 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -642,6 +642,7 @@
struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
struct xdr_buf *xdr = &req->rq_snd_buf;
bool zerocopy = true;
+ bool vm_wait = false;
int status;
int sent;
@@ -677,15 +678,33 @@
return 0;
}
+ WARN_ON_ONCE(sent == 0 && status == 0);
+
+ if (status == -EAGAIN ) {
+ /*
+ * Return EAGAIN if we're sure we're hitting the
+ * socket send buffer limits.
+ */
+ if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
+ break;
+ /*
+ * Did we hit a memory allocation failure?
+ */
+ if (sent == 0) {
+ status = -ENOBUFS;
+ if (vm_wait)
+ break;
+ /* Retry, knowing now that we're below the
+ * socket send buffer limit
+ */
+ vm_wait = true;
+ }
+ continue;
+ }
if (status < 0)
break;
- if (sent == 0) {
- status = -EAGAIN;
- break;
- }
+ vm_wait = false;
}
- if (status == -EAGAIN && sk_stream_is_writeable(transport->inet))
- status = -ENOBUFS;
switch (status) {
case -ENOTSOCK: