NFSv4/pnfs: Layoutreturn on close must handle fatal networking errors

If we have a fatal ENETDOWN or ENETUNREACH error, then the layoutreturn
on close code should also handle that as fatal, and free the layouts.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

fs/nfs/pnfs.c

@@ -1661,6 +1661,18 @@ int pnfs_roc_done(struct rpc_task *task, struct nfs4_layoutreturn_args **argpp,
 		/* Was there an RPC level error? If not, retry */
 		if (task->tk_rpc_status == 0)
 			break;
+		/*
+		 * Is there a fatal network level error?
+		 * If so release the layout, but flag the error.
+		 */
+		if ((task->tk_rpc_status == -ENETDOWN ||
+		     task->tk_rpc_status == -ENETUNREACH) &&
+		    task->tk_flags & RPC_TASK_NETUNREACH_FATAL) {
+			*ret = 0;
+			(*respp)->lrs_present = 0;
+			retval = -EIO;
+			break;
+		}
 		/* If the call was not sent, let caller handle it */
 		if (!RPC_WAS_SENT(task))
 			return 0;