Add example job_modify support for job_submit/defaults plugin

src/plugins/job_submit/defaults/job_submit_defaults.c

@@ -107,7 +107,8 @@ const uint32_t min_plug_version = 100;
 extern int job_submit(struct job_descriptor *job_desc)
 {
 	if (job_desc->acctg_freq < MIN_ACCTG_FREQUENCY) {
-		info("Changing accounting frequency of submitted from %u to %u",
+		info("Changing accounting frequency of submitted job "
+		     "from %u to %u",
 		     job_desc->acctg_freq, MIN_ACCTG_FREQUENCY);
 		job_desc->acctg_freq = MIN_ACCTG_FREQUENCY;
 	}
@@ -121,9 +122,24 @@ extern int job_submit(struct job_descriptor *job_desc)
 }
 
 /* This example code will prevent users from setting an accounting frequency
- * of less than 30 seconds in order to insure more precise accounting. */
+ * of less than 30 seconds in order to insure more precise accounting.
+ * Also remove any QOS value set by the user in order to use the default value
+ * from the database. */
 extern int job_modify(struct job_descriptor *job_desc, 
 		      struct job_record *job_ptr)
 {
+	if (job_desc->acctg_freq < MIN_ACCTG_FREQUENCY) {
+		info("Changing accounting frequency of modify job %u "
+		     "from %u to %u", job_ptr->job_id,
+		     job_desc->acctg_freq, MIN_ACCTG_FREQUENCY);
+		job_desc->acctg_freq = MIN_ACCTG_FREQUENCY;
+	}
+
+	if (job_desc->qos) {
+		info("Clearing QOS (%s) from modify of job %u", 
+		     job_desc->qos, job_ptr->job_id);
+		xfree(job_desc->qos);
+	}
+
 	return SLURM_SUCCESS;
 }