The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a8f688ec437dc2045cc8f0c89fe877d5803850da Mon Sep 17 00:00:00 2001
From: Chuck Lever chuck.lever@oracle.com Date: Fri, 4 May 2018 15:35:46 -0400 Subject: [PATCH] xprtrdma: Return -ENOBUFS when no pages are available
The use of -EAGAIN in rpcrdma_convert_iovs() is a latent bug: the transport never calls xprt_write_space() when more pages become available. -ENOBUFS will trigger the correct "delay briefly and call again" logic.
Fixes: 7a89f9c626e3 ("xprtrdma: Honor ->send_request API contract") Signed-off-by: Chuck Lever chuck.lever@oracle.com Cc: stable@vger.kernel.org # 4.8+ Signed-off-by: Anna Schumaker Anna.Schumaker@Netapp.com
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index d676106295ff..1d7857919d3d 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -231,7 +231,7 @@ rpcrdma_convert_iovs(struct rpcrdma_xprt *r_xprt, struct xdr_buf *xdrbuf, */ *ppages = alloc_page(GFP_ATOMIC); if (!*ppages) - return -EAGAIN; + return -ENOBUFS; } seg->mr_page = *ppages; seg->mr_offset = (char *)page_base;