Merge branch 'slurm-2.2'

NEWS

@@ -204,6 +204,9 @@ documents those changes that are of interest to users and admins.
 ========================
  -- Eliminate zombie process created if salloc exits with stopped child
     process. Patch from Gerrit Renker, CSCS.
+ -- With default configuration on non-Cray systems, enable salloc to be
+    spawned as a background process. Based upon work by Don Albert (Bull) and
+    Gerrit Renker (CSCS).
 
 * Changes in SLURM 2.2.6
 ========================

src/salloc/salloc.c

@@ -219,6 +219,7 @@ int main(int argc, char *argv[])
 	 * a) input is from a terminal (stdin has valid termios attributes),
 	 * b) controlling terminal exists (non-negative tpgid),
 	 * c) salloc is not run in allocation-only (--no-shell) mode,
+	 * NOTE: d and e below are configuration dependent
 	 * d) salloc runs in its own process group (true in interactive
 	 *    shells that support job control),
 	 * e) salloc has been configured at compile-time to support background
@@ -234,10 +235,10 @@ int main(int argc, char *argv[])
 			error("no controlling terminal: please set --no-shell");
 			exit(error_exit);
 		}
+#ifdef SALLOC_RUN_FOREGROUND
 	} else if ((!opt.no_shell) && (pid == getpgrp())) {
 		if (tpgid == pid)
 			is_interactive = true;
-#ifdef SALLOC_RUN_FOREGROUND
 		while (tcgetpgrp(STDIN_FILENO) != pid) {
 			if (!is_interactive) {
 				error("Waiting for program to be placed in "
@@ -246,8 +247,12 @@ int main(int argc, char *argv[])
 			}
 			killpg(pid, SIGTTIN);
 		}
-#endif
 	}
+#else
+	} else if (!opt.no_shell) {
+		is_interactive = true;
+	}
+#endif
 	/*
 	 * Reset saved tty attributes at exit, in case a child
 	 * process died before properly resetting terminal.