SUNRPC: Fix an RPC/RDMA performance regression

Use the standard gfp mask instead of using GFP_NOWAIT. The latter causes
issues when under memory pressure.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

net/sunrpc/auth_gss/auth_gss.c

@@ -1340,14 +1340,11 @@ gss_hash_cred(struct auth_cred *acred, unsigned int hashbits)
 /*
  * Lookup RPCSEC_GSS cred for the current process
  */
-static struct rpc_cred *
-gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
+static struct rpc_cred *gss_lookup_cred(struct rpc_auth *auth,
+					struct auth_cred *acred, int flags)
 {
-	gfp_t gfp = GFP_KERNEL;
-
-	if (flags & RPCAUTH_LOOKUP_ASYNC)
-		gfp = GFP_NOWAIT | __GFP_NOWARN;
-	return rpcauth_lookup_credcache(auth, acred, flags, gfp);
+	return rpcauth_lookup_credcache(auth, acred, flags,
+					rpc_task_gfp_mask());
 }
 
 static struct rpc_cred *

net/sunrpc/sched.c

@@ -63,6 +63,7 @@ gfp_t rpc_task_gfp_mask(void)
 		return GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN;
 	return GFP_KERNEL;
 }
+EXPORT_SYMBOL_GPL(rpc_task_gfp_mask);
 
 unsigned long
 rpc_task_timeout(const struct rpc_task *task)

net/sunrpc/xprtrdma/transport.c

@@ -571,11 +571,7 @@ xprt_rdma_allocate(struct rpc_task *task)
 	struct rpc_rqst *rqst = task->tk_rqstp;
 	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 	struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
-	gfp_t flags;
-
-	flags = RPCRDMA_DEF_GFP;
-	if (RPC_IS_ASYNC(task))
-		flags = GFP_NOWAIT | __GFP_NOWARN;
+	gfp_t flags = rpc_task_gfp_mask();
 
 	if (!rpcrdma_check_regbuf(r_xprt, req->rl_sendbuf, rqst->rq_callsize,
 				  flags))