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
Git-commit: a8f688ec437dc2045cc8f0c89fe877d5803850da
Patch-mainline: v4.18-rc1
References: git-fixes

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>
Acked-by: NeilBrown <neilb@suse.com>

---
 net/sunrpc/xprtrdma/rpc_rdma.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -234,7 +234,7 @@ rpcrdma_convert_iovs(struct rpcrdma_xprt
 			 */
 			*ppages = alloc_page(GFP_ATOMIC);
 			if (!*ppages)
-				return -EAGAIN;
+				return -ENOBUFS;
 		}
 		seg->mr_page = *ppages;
 		seg->mr_offset = (char *)page_base;