src/plugins/job_submit/lua/job_submit_lua.c

/*****************************************************************************\
 *  job_submit_lua.c - Set defaults in job submit request specifications.
 *****************************************************************************
 *  Copyright (C) 2010 Lawrence Livermore National Security.
 *  Copyright (C) SchedMD LLC.
 *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
 *  Written by Danny Auble <da@llnl.gov>
 *  CODE-OCEC-09-009. All rights reserved.
 *
 *  This file is part of Slurm, a resource management program.
 *  For details, see <https://slurm.schedmd.com/>.
 *  Please also read the included file: DISCLAIMER.
 *
 *  Slurm is free software; you can redistribute it and/or modify it under
 *  the terms of the GNU General Public License as published by the Free
 *  Software Foundation; either version 2 of the License, or (at your option)
 *  any later version.
 *
 *  In addition, as a special exception, the copyright holders give permission
 *  to link the code of portions of this program with the OpenSSL library under
 *  certain conditions as described in each individual source file, and
 *  distribute linked combinations including the two. You must obey the GNU
 *  General Public License in all respects for all of the code used other than
 *  OpenSSL. If you modify file(s) with this exception, you may extend this
 *  exception to your version of the file(s), but you are not obligated to do
 *  so. If you do not wish to do so, delete this exception statement from your
 *  version.  If you delete this exception statement from all source files in
 *  the program, then also delete it here.
 *
 *  Slurm is distributed in the hope that it will be useful, but WITHOUT ANY
 *  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 *  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 *  details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with Slurm; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA.
\*****************************************************************************/

#include <dlfcn.h>
#include <inttypes.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>

#include "slurm/slurm.h"
#include "slurm/slurm_errno.h"

#include "src/common/slurm_xlator.h"
#include "src/common/assoc_mgr.h"
#include "src/interfaces/gres.h"
#include "src/common/uid.h"
#include "src/lua/slurm_lua.h"
#include "src/slurmctld/locks.h"
#include "src/slurmctld/slurmctld.h"
#include "src/slurmctld/reservation.h"

#define _DEBUG 0
#define MIN_ACCTG_FREQUENCY 30

/* Required Slurm plugin symbols: */
const char plugin_name[] = "Job submit lua plugin";
const char plugin_type[] = "job_submit/lua";
const uint32_t plugin_version = SLURM_VERSION_NUMBER;

static char *lua_script_path;
static time_t lua_script_last_loaded = (time_t) 0;
static lua_State *L = NULL;
static char *user_msg = NULL;
time_t last_lua_jobs_update = (time_t) 0;
time_t last_lua_resv_update = (time_t) 0;
static const char *req_fxns[] = {
	"slurm_job_submit",
	"slurm_job_modify",
	NULL
};
/*
 *  Mutex for protecting multi-threaded access to this plugin.
 *   (Only 1 thread at a time should be in here)
 */
static pthread_mutex_t lua_lock = PTHREAD_MUTEX_INITIALIZER;

typedef struct {
	uint32_t submit_uid;
	uint32_t user_id;
} foreach_part_list_args_t;

/*****************************************************************************\
 * We've provided a simple example of the type of things you can do with this
 * plugin. If you develop another plugin that may be of interest to others
 * please post it to slurm-dev@schedmd.com  Thanks!
\*****************************************************************************/

/* Get the default account for a user (or NULL if not present) */
static char *_get_default_account(uint32_t user_id)
{
	slurmdb_user_rec_t user;

	memset(&user, 0, sizeof(slurmdb_user_rec_t));
	user.uid = user_id;
	if (assoc_mgr_fill_in_user(acct_db_conn, &user, accounting_enforce,
				   NULL, false) == SLURM_SUCCESS) {
		return user.default_acct;
	} else {
		return NULL;
	}
}

static int _fill_assoc(uint32_t user_id, char *account, char *partition,
		       slurmdb_assoc_rec_t *assoc)
{
	xassert(assoc);

	memset(assoc, 0, sizeof(slurmdb_assoc_rec_t));
	assoc->uid = user_id;
	assoc->partition = partition;
	if (account) {
		assoc->acct = account;
	} else {
		assoc->acct = _get_default_account(user_id);
	}

	return assoc_mgr_fill_in_assoc(acct_db_conn, assoc, accounting_enforce,
				       NULL, false);
}

/* Get the default QOS for an association (or NULL if not present) */
static char *_get_default_qos(uint32_t user_id, char *account, char *partition)
{
	slurmdb_assoc_rec_t assoc;
	slurmdb_qos_rec_t qos;
	uint32_t qos_id = 0;

	if (_fill_assoc(user_id, account, partition, &assoc) == SLURM_SUCCESS)
		qos_id = assoc.def_qos_id;

	if (!qos_id)
		return NULL;

	memset(&qos, 0, sizeof(slurmdb_qos_rec_t));
	qos.id = qos_id;
	if (assoc_mgr_fill_in_qos(acct_db_conn, &qos, accounting_enforce, NULL,
				  false) == SLURM_SUCCESS) {
		return qos.name;
	} else {
		return NULL;
	}
}

static int _qos_id_to_qos_name(void *x, void *arg)
{
	char *qos_id = x;
	list_t *qos_name_list = arg;
	slurmdb_qos_rec_t qos = { 0 };

	qos.id = atoi(qos_id);

	if (assoc_mgr_fill_in_qos(acct_db_conn, &qos, accounting_enforce, NULL,
				  false) != SLURM_SUCCESS) {
		return 0;
	}

	slurm_addto_char_list(qos_name_list, qos.name);

	return 0;
}

/* Get all possible QOS for an association (or NULL if not present) */
static char *_get_assoc_qos(uint32_t user_id, char *account, char *partition)
{
	slurmdb_assoc_rec_t assoc;
	list_t *qos_name_list;
	char *qos_name_list_str;
	list_t *qos_list = NULL;

	if (_fill_assoc(user_id, account, partition, &assoc) == SLURM_SUCCESS)
		qos_list = assoc.qos_list;

	if (!qos_list)
		return NULL;

	qos_name_list = list_create(xfree_ptr);
	list_for_each_ro(qos_list, _qos_id_to_qos_name, qos_name_list);

	qos_name_list_str = slurm_char_list_to_xstr(qos_name_list);

	list_destroy(qos_name_list);

	return qos_name_list_str;
}

/* Get the comment for an association (or NULL if not present) */
static char *_get_assoc_comment(uint32_t user_id, char *account,
				char *partition)
{
	slurmdb_assoc_rec_t assoc;
	char *comment = NULL;

	if (_fill_assoc(user_id, account, partition, &assoc) == SLURM_SUCCESS)
		comment = assoc.comment;

	return comment;
}

/* Get fields in an existing slurmctld job_record */
static int _job_rec_field_index(lua_State *L)
{
	const char *name = luaL_checkstring(L, 2);
	job_record_t *job_ptr;

	lua_getmetatable(L, -2);
	lua_getfield(L, -1, "_job_rec_ptr");
	job_ptr = lua_touserdata(L, -1);

	return slurm_lua_job_record_field(L, job_ptr, name);
}

static int _foreach_update_jobs_global(void *x, void *arg)
{
	char job_id_buf[11]; /* Big enough for a uint32_t */
	job_record_t *job_ptr = x;
	lua_State *st = arg;

	/*
	 * Create an empty table, with a metatable that looks up the
	 * data for the individual job.
	 */
	lua_newtable(st);

	lua_newtable(st);
	lua_pushcfunction(st, _job_rec_field_index);
	lua_setfield(st, -2, "__index");
	/*
	 * Store the job_record in the metatable, so the index
	 * function knows which job it's getting data for.
	 */
	lua_pushlightuserdata(st, job_ptr);
	lua_setfield(st, -2, "_job_rec_ptr");
	lua_setmetatable(st, -2);

	/* Lua copies passed strings, so we can reuse the buffer. */
	snprintf(job_id_buf, sizeof(job_id_buf), "%d", job_ptr->job_id);
	lua_setfield(st, -2, job_id_buf);

	return 0;
}

/* Get the list of existing slurmctld job records. */
static void _update_jobs_global(lua_State *st)
{
	if (last_lua_jobs_update >= last_job_update) {
		return;
	}

	lua_getglobal(st, "slurm");
	lua_newtable(st);

	list_for_each(job_list, _foreach_update_jobs_global, st);
	last_lua_jobs_update = last_job_update;

	lua_setfield(st, -2, "jobs");
	lua_pop(st, 1);
}

static int _resv_field(const slurmctld_resv_t *resv_ptr,
                       const char *name)
{
	if (resv_ptr == NULL) {
		error("_resv_field: resv_ptr is NULL");
		lua_pushnil(L);
	} else if (!xstrcmp(name, "accounts")) {
		lua_pushstring(L, resv_ptr->accounts);
	} else if (!xstrcmp(name, "assoc_list")) {
		lua_pushstring(L, resv_ptr->assoc_list);
	} else if (!xstrcmp(name, "duration")) {
		lua_pushnumber(L, resv_ptr->duration);
	} else if (!xstrcmp(name, "end_time")) {
		lua_pushnumber(L, resv_ptr->end_time);
	} else if (!xstrcmp(name, "features")) {
		lua_pushstring(L, resv_ptr->features);
	} else if (!xstrcmp(name, "flags")) {
		lua_pushnumber(L, resv_ptr->flags);
	} else if (!xstrcmp(name, "full_nodes")) {
		lua_pushboolean(L,
				(resv_ptr->ctld_flags & RESV_CTLD_FULL_NODE) ?
				true : false);
	} else if (!xstrcmp(name, "flags_set_node")) {
		lua_pushboolean(L,
				(resv_ptr->ctld_flags &
				 RESV_CTLD_NODE_FLAGS_SET) ? true : false);
	} else if (!xstrcmp(name, "licenses")) {
		lua_pushstring(L, resv_ptr->licenses);
	} else if (!xstrcmp(name, "node_cnt")) {
		lua_pushnumber(L, resv_ptr->node_cnt);
	} else if (!xstrcmp(name, "node_list")) {
		lua_pushstring(L, resv_ptr->node_list);
	} else if (!xstrcmp(name, "partition")) {
		lua_pushstring(L, resv_ptr->partition);
	} else if (!xstrcmp(name, "start_time")) {
		lua_pushnumber(L, resv_ptr->start_time);
	} else if (!xstrcmp(name, "users")) {
		lua_pushstring(L, resv_ptr->users);
	} else {
		lua_pushnil(L);
	}

	return 1;
}

/* Get fields in an existing slurmctld reservation record */
static int _resv_field_index(lua_State *L)
{
	const char *name = luaL_checkstring(L, 2);
	slurmctld_resv_t *resv_ptr;

	lua_getmetatable(L, -2);
	lua_getfield(L, -1, "_resv_ptr");
	resv_ptr = lua_touserdata(L, -1);

	return _resv_field(resv_ptr, name);
}

static int _foreach_update_resvs_global(void *x, void *arg)
{
	slurmctld_resv_t *resv_ptr = x;
	lua_State *st = arg;

	/*
	 * Create an empty table, with a metatable that looks up the
	 * data for the individual reservation.
	 */
	lua_newtable(st);

	lua_newtable(st);
	lua_pushcfunction(st, _resv_field_index);
	lua_setfield(st, -2, "__index");
	/*
	 * Store the slurmctld_resv_t in the metatable, so the index
	 * function knows which reservation it's getting data for.
	 */
	lua_pushlightuserdata(st, resv_ptr);
	lua_setfield(st, -2, "_resv_ptr");
	lua_setmetatable(st, -2);

	lua_setfield(st, -2, resv_ptr->name);

	return 0;
}

/* Get the list of existing slurmctld reservation records. */
static void _update_resvs_global(lua_State *st)
{
	if (last_lua_resv_update >= last_resv_update) {
		return;
	}

	lua_getglobal(st, "slurm");
	lua_newtable(st);

	list_for_each(resv_list, _foreach_update_resvs_global, st);
	last_lua_resv_update = last_resv_update;

	lua_setfield(st, -2, "reservations");
	lua_pop(st, 1);
}

/* Set fields in the job request structure on job submit or modify */
static int _set_job_env_field(lua_State *L)
{
	const char *name, *value_str;
	job_desc_msg_t *job_desc;
	char *name_eq = NULL;
	int i, j, name_len;

	name = luaL_checkstring(L, 2);
	name_eq = xstrdup(name);
	xstrcat(name_eq, "=");
	name_len = strlen(name_eq);
	lua_getmetatable(L, -3);
	lua_getfield(L, -1, "_job_desc");
	job_desc = lua_touserdata(L, -1);
	if (job_desc == NULL) {
		error("%s: job_desc is NULL", __func__);
	} else if (job_desc->environment == NULL) {
		if (job_desc->script)
			error("%s: %s: job_desc->environment is NULL.",
			      plugin_type, __func__);
		else
			info("job_desc->environment only accessible for batch jobs. ");
		lua_pushnil(L);
	} else {
		value_str = luaL_checkstring(L, 3);
		for (i = 0; job_desc->environment[i]; i++) {
			if (!xstrncmp(job_desc->environment[i], name_eq,
				      name_len)) {
				job_desc->environment[i][name_len] = '\0';
				xstrcat(job_desc->environment[i], value_str);
				break;
			}
		}
		if (!job_desc->environment[i]) {
			job_desc->environment = xrealloc(job_desc->environment,
							 sizeof(char*) * (i+2));
			for (j = i; j >= 1; j--) {
				job_desc->environment[j] =
					job_desc->environment[j-1];
			}
			job_desc->environment[0] = xstrdup(name_eq);
			xstrcat(job_desc->environment[0], value_str);
			job_desc->env_size++;
		}
	}
	xfree(name_eq);

	return 0;
}

static int _job_env_field(const job_desc_msg_t *job_desc, const char *name)
{
	char *name_eq = "";
	int i, name_len;

	name_eq = xstrdup(name);
	xstrcat(name_eq, "=");
	name_len = strlen(name_eq);
	if (job_desc == NULL) {
		error("%s: job_desc is NULL", __func__);
		lua_pushnil(L);
	} else if (job_desc->environment == NULL) {
		if (job_desc->script)
			error("%s: %s: job_desc->environment is NULL.",
			      plugin_type, __func__);
		else
			info("job_desc->environment only accessible for batch jobs.");
		lua_pushnil(L);
	} else {
		for (i = 0; job_desc->environment[i]; i++) {
			if (!xstrncmp(job_desc->environment[i], name_eq,
				      name_len)) {
				lua_pushstring(L, job_desc->environment[i] +
					       name_len);
				break;
			}
		}
		if (!job_desc->environment[i])
			lua_pushnil(L);
	}
	xfree(name_eq);

	return 1;
}

/* Get fields in the job request record on job submit or modify */
static int _get_job_env_field_name(lua_State *L)
{
	const job_desc_msg_t *job_desc = lua_touserdata(L, 1);
	const char *name = luaL_checkstring(L, 2);
	return _job_env_field(job_desc, name);
}

/* Get fields in an existing slurmctld job_descriptor record */
static int _job_env_field_index(lua_State *L)
{
	const char *name;
	job_desc_msg_t *job_desc;

	name = luaL_checkstring(L, 2);
	lua_getmetatable(L, -2);
	lua_getfield(L, -1, "_job_desc");
	job_desc = lua_touserdata(L, -1);
	return _job_env_field(job_desc, name);
}

static void _push_job_env(job_desc_msg_t *job_desc)
{
	lua_newtable(L);

	lua_newtable(L);
	lua_pushcfunction(L, _job_env_field_index);
	lua_setfield(L, -2, "__index");
	lua_pushcfunction(L, _set_job_env_field);
	lua_setfield(L, -2, "__newindex");
	/* Store the job descriptor in the metatable, so the index
	 * function knows which struct it's getting data for.
	 */
	lua_pushlightuserdata(L, job_desc);
	lua_setfield(L, -2, "_job_desc");
	lua_setmetatable(L, -2);
}

static int _get_job_req_field(const job_desc_msg_t *job_desc, const char *name)
{
	int i;

	if (job_desc == NULL) {
		error("%s: job_desc is NULL", __func__);
		lua_pushnil(L);
	} else if (!xstrcmp(name, "account")) {
		lua_pushstring(L, job_desc->account);
	} else if (!xstrcmp(name, "acctg_freq")) {
		lua_pushstring(L, job_desc->acctg_freq);
	} else if (!xstrcmp(name, "admin_comment")) {
		lua_pushstring(L, job_desc->admin_comment);
	} else if (!xstrcmp(name, "alloc_node")) {
		lua_pushstring(L, job_desc->alloc_node);
	} else if (!xstrcmp(name, "argc")) {
		lua_pushnumber(L, job_desc->argc);
	} else if (!xstrcmp(name, "argv")) {
		if ((job_desc->argc == 0) ||
		    (job_desc->argv == NULL)) {
			lua_pushnil(L);
		} else {
			lua_newtable(L);
			for (i = 0; i < job_desc->argc; i++) {
				if (job_desc->argv[i] != NULL) {
					lua_pushnumber(L, i);
					lua_pushstring(L, job_desc->argv[i]);
					lua_settable(L, -3);
				}
			}
		}
	} else if (!xstrcmp(name, "array_inx")) {
		lua_pushstring(L, job_desc->array_inx);
	} else if (!xstrcmp(name, "assoc_comment")) {
		lua_pushstring(L, _get_assoc_comment(job_desc->target_user.uid,
						     job_desc->account,
						     job_desc->partition));
	} else if (!xstrcmp(name, "assoc_qos")) {
		char *assoc_qos_str =
			_get_assoc_qos(job_desc->target_user.uid,
				       job_desc->account, job_desc->partition);
		lua_pushstring(L, assoc_qos_str);
		xfree(assoc_qos_str);
	} else if (!xstrcmp(name, "batch_features")) {
		lua_pushstring(L, job_desc->batch_features);
	} else if (!xstrcmp(name, "begin_time")) {
		lua_pushnumber(L, job_desc->begin_time);
	} else if (!xstrcmp(name, "bitflags")) {
		lua_pushnumber(L, job_desc->bitflags);
	} else if (!xstrcmp(name, "boards_per_node")) {
		lua_pushnumber(L, job_desc->boards_per_node);
	} else if (!xstrcmp(name, "burst_buffer")) {
		lua_pushstring(L, job_desc->burst_buffer);
	} else if (!xstrcmp(name, "clusters")) {
		lua_pushstring(L, job_desc->clusters);
	} else if (!xstrcmp(name, "comment")) {
		lua_pushstring(L, job_desc->comment);
	} else if (!xstrcmp(name, "container")) {
		lua_pushstring(L, job_desc->container);
	} else if (!xstrcmp(name, "contiguous")) {
		lua_pushnumber(L, job_desc->contiguous);
	} else if (!xstrcmp(name, "core_spec") &&
		   (job_desc->core_spec != NO_VAL16) &&
		   !(job_desc->core_spec & CORE_SPEC_THREAD)) {
		lua_pushnumber(L, job_desc->core_spec);
	} else if (!xstrcmp(name, "cores_per_socket")) {
		lua_pushnumber(L, job_desc->cores_per_socket);
	} else if (!xstrcmp(name, "cpu_freq_min")) {
		lua_pushnumber(L, job_desc->cpu_freq_min);
	} else if (!xstrcmp(name, "cpu_freq_max")) {
		lua_pushnumber(L, job_desc->cpu_freq_max);
	} else if (!xstrcmp(name, "cpu_freq_gov")) {
		lua_pushnumber(L, job_desc->cpu_freq_gov);
	} else if (!xstrcmp(name, "cpus_per_task")) {
		lua_pushnumber(L, job_desc->cpus_per_task);
	} else if (!xstrcmp(name, "cpus_per_tres")) {
		lua_pushstring(L, job_desc->cpus_per_tres);
	} else if (!xstrcmp(name, "cron_job")) {
		lua_pushboolean(L, job_desc->bitflags & CRON_JOB);
	} else if (!xstrcmp(name, "default_account")) {
		lua_pushstring(L,
			       _get_default_account(job_desc->target_user.uid));
	} else if (!xstrcmp(name, "default_qos")) {
		lua_pushstring(L, _get_default_qos(job_desc->target_user.uid,
						   job_desc->account,
						   job_desc->partition));
	} else if (!xstrcmp(name, "delay_boot")) {
		lua_pushnumber(L, job_desc->delay_boot);
	} else if (!xstrcmp(name, "dependency")) {
		lua_pushstring(L, job_desc->dependency);
	} else if (!xstrcmp(name, "end_time")) {
		lua_pushnumber(L, job_desc->end_time);
	} else if (!xstrcmp(name, "environment")) {
		_push_job_env((job_desc_msg_t *) job_desc); // No const
	} else if (!xstrcmp(name, "exc_nodes")) {
		lua_pushstring(L, job_desc->exc_nodes);
	} else if (!xstrcmp(name, "extra")) {
		lua_pushstring(L, job_desc->extra);
	} else if (!xstrcmp(name, "features")) {
		lua_pushstring(L, job_desc->features);
	} else if (!xstrcmp(name, "gres")) {
		/* "gres" replaced by "tres_per_node" in v18.08 */
		lua_pushstring(L, job_desc->tres_per_node);
	} else if (!xstrcmp(name, "group_id")) {
		lua_pushnumber(L, job_desc->target_user.gid);
	} else if (!xstrcmp(name, "immediate")) {
		lua_pushnumber(L, job_desc->immediate);
	} else if (!xstrcmp(name, "layout")) {
		lua_pushstring(L, job_desc->layout);
	} else if (!xstrcmp(name, "licenses")) {
		lua_pushstring(L, job_desc->licenses);
	} else if (!xstrcmp(name, "mail_type")) {
		lua_pushnumber(L, job_desc->mail_type);
	} else if (!xstrcmp(name, "mail_user")) {
		lua_pushstring(L, job_desc->mail_user);
	} else if (!xstrcmp(name, "max_cpus")) {
		lua_pushnumber(L, job_desc->max_cpus);
	} else if (!xstrcmp(name, "max_nodes")) {
		lua_pushnumber(L, job_desc->max_nodes);
	} else if (!xstrcmp(name, "max_npids")) {
		lua_pushnumber(L, job_desc->max_npids);
	} else if (!xstrcmp(name, "mcs_label")) {
		lua_pushstring(L, job_desc->mcs_label);
	} else if (!xstrcmp(name, "mem_per_tres")) {
		lua_pushstring(L, job_desc->mem_per_tres);
	} else if (!xstrcmp(name, "min_cpus")) {
		lua_pushnumber(L, job_desc->min_cpus);
	} else if (!xstrcmp(name, "min_mem_per_node") &&
		   (job_desc->pn_min_memory != NO_VAL64) &&
		   !(job_desc->pn_min_memory & MEM_PER_CPU)) {
		lua_pushnumber(L, job_desc->pn_min_memory);
	} else if (!xstrcmp(name, "min_mem_per_cpu") &&
		   (job_desc->pn_min_memory != NO_VAL64) &&
		   (job_desc->pn_min_memory & MEM_PER_CPU)) {
		lua_pushnumber(L, (job_desc->pn_min_memory & (~MEM_PER_CPU)));
	} else if (!xstrcmp(name, "min_nodes")) {
		lua_pushnumber(L, job_desc->min_nodes);
	} else if (!xstrcmp(name, "name")) {
		lua_pushstring(L, job_desc->name);
	} else if (!xstrcmp(name, "network")) {
		lua_pushstring(L, job_desc->network);
	} else if (!xstrcmp(name, "nice")) {
		/*
		 * nice will be NO_VAL when unset or offset by NICE_OFFSET.
		 * Decrement nice by NICE_OFFSET in job_submit.lua if the value
		 * needs to be human readable.
		 */
		lua_pushnumber(L, job_desc->nice);
	} else if (!xstrcmp(name, "ntasks_per_board")) {
		lua_pushnumber(L, job_desc->ntasks_per_board);
	} else if (!xstrcmp(name, "ntasks_per_core")) {
		lua_pushnumber(L, job_desc->ntasks_per_core);
	} else if (!xstrcmp(name, "ntasks_per_gpu")) {
		lua_pushnumber(L, job_desc->ntasks_per_tres);
	} else if (!xstrcmp(name, "ntasks_per_node")) {
		lua_pushnumber(L, job_desc->ntasks_per_node);
	} else if (!xstrcmp(name, "ntasks_per_socket")) {
		lua_pushnumber(L, job_desc->ntasks_per_socket);
	} else if (!xstrcmp(name, "ntasks_per_tres")) {
		lua_pushnumber(L, job_desc->ntasks_per_tres);
	} else if (!xstrcmp(name, "num_tasks")) {
		lua_pushnumber(L, job_desc->num_tasks);
		/* Continue support for old hetjob terminology. */
	} else if (!xstrcmp(name, "pack_job_offset") ||
		   !xstrcmp(name, "het_job_offset")) {
		lua_pushnumber(L, job_desc->het_job_offset);
	} else if (!xstrcmp(name, "partition")) {
		lua_pushstring(L, job_desc->partition);
	} else if (!xstrcmp(name, "prefer")) {
		lua_pushstring(L, job_desc->prefer);
	} else if (!xstrcmp(name, "pn_min_cpus")) {
		lua_pushnumber(L, job_desc->pn_min_cpus);
	} else if (!xstrcmp(name, "pn_min_memory")) {
		/*
		 * FIXME: Remove this in the future, lua can't handle 64bit
		 * numbers!!!.  Use min_mem_per_node|cpu instead.
		 */
		lua_pushnumber(L, job_desc->pn_min_memory);
	} else if (!xstrcmp(name, "pn_min_tmp_disk")) {
		lua_pushnumber(L, job_desc->pn_min_tmp_disk);
	} else if (!xstrcmp(name, "priority")) {
		lua_pushnumber(L, job_desc->priority);
	} else if (!xstrcmp(name, "qos")) {
		lua_pushstring(L, job_desc->qos);
	} else if (!xstrcmp(name, "reboot")) {
		lua_pushnumber(L, job_desc->reboot);
	} else if (!xstrcmp(name, "relay_io")) {
		lua_pushnumber(L, job_desc->relay_io);
	} else if (!xstrcmp(name, "req_context")) {
		lua_pushstring(L, job_desc->req_context);
	} else if (!xstrcmp(name, "req_nodes")) {
		lua_pushstring(L, job_desc->req_nodes);
	} else if (!xstrcmp(name, "req_switch")) {
		lua_pushnumber(L, job_desc->req_switch);
	} else if (!xstrcmp(name, "requeue")) {
		lua_pushnumber(L, job_desc->requeue);
	} else if (!xstrcmp(name, "reservation")) {
		lua_pushstring(L, job_desc->reservation);
	} else if (!xstrcmp(name, "script")) {
		lua_pushstring(L, job_desc->script);
	} else if (!xstrcmp(name, "segment_size")) {
		lua_pushnumber(L, job_desc->segment_size);
	} else if (!xstrcmp(name, "shared") ||
		   !xstrcmp(name, "oversubscribe")) {
		lua_pushnumber(L, job_desc->shared);
	} else if (!xstrcmp(name, "selinux_context")) {
		lua_pushstring(L, job_desc->selinux_context);
	} else if (!xstrcmp(name, "site_factor")) {
		if (job_desc->site_factor == NO_VAL)
			lua_pushnumber(L, job_desc->site_factor);
		else
			lua_pushnumber(L,
				       (((int64_t)job_desc->site_factor)
					- NICE_OFFSET));
	} else if (!xstrcmp(name, "sockets_per_board")) {
		lua_pushnumber(L, job_desc->sockets_per_board);
	} else if (!xstrcmp(name, "sockets_per_node")) {
		lua_pushnumber(L, job_desc->sockets_per_node);
	} else if (!xstrcmp(name, "spank_job_env")) {
		if ((job_desc->spank_job_env_size == 0) ||
		    (job_desc->spank_job_env == NULL)) {
			lua_pushnil(L);
		} else {
			lua_newtable(L);
			for (i = 0; i < job_desc->spank_job_env_size; i++) {
				if (job_desc->spank_job_env[i] != NULL) {
					lua_pushnumber(L, i);
					lua_pushstring(
						L, job_desc->spank_job_env[i]);
					lua_settable(L, -3);
				}
			}
		}
	} else if (!xstrcmp(name, "spank_job_env_size")) {
		lua_pushnumber(L, job_desc->spank_job_env_size);
	} else if (!xstrcmp(name, "std_err")) {
		lua_pushstring(L, job_desc->std_err);
	} else if (!xstrcmp(name, "std_in")) {
		lua_pushstring(L, job_desc->std_in);
	} else if (!xstrcmp(name, "std_out")) {
		lua_pushstring(L, job_desc->std_out);
	} else if (!xstrcmp(name, "thread_spec") &&
		   (job_desc->core_spec != NO_VAL16) &&
		   (job_desc->core_spec & CORE_SPEC_THREAD)) {
		lua_pushnumber(L, (job_desc->core_spec & ~CORE_SPEC_THREAD));
	} else if (!xstrcmp(name, "threads_per_core")) {
		lua_pushnumber(L, job_desc->threads_per_core);
	} else if (!xstrcmp(name, "time_limit")) {
		lua_pushnumber(L, job_desc->time_limit);
	} else if (!xstrcmp(name, "time_min")) {
		lua_pushnumber(L, job_desc->time_min);
	} else if (!xstrcmp(name, "tres_bind")) {
		lua_pushstring(L, job_desc->tres_bind);
	} else if (!xstrcmp(name, "tres_freq")) {
		lua_pushstring(L, job_desc->tres_freq);
	} else if (!xstrcmp(name, "tres_per_job")) {
		lua_pushstring(L, job_desc->tres_per_job);
	} else if (!xstrcmp(name, "tres_per_node")) {
		lua_pushstring(L, job_desc->tres_per_node);
	} else if (!xstrcmp(name, "tres_per_socket")) {
		lua_pushstring(L, job_desc->tres_per_socket);
	} else if (!xstrcmp(name, "tres_per_task")) {
		lua_pushstring(L, job_desc->tres_per_task);
	} else if (!xstrcmp(name, "user_id")) {
		lua_pushnumber(L, job_desc->target_user.uid);
	} else if (!xstrcmp(name, "user_name")) {
		if (job_desc->id) {
			identity_t *id = job_desc->id;
			lua_pushstring(L, id->pw_name);
		} else {
			char *username =
				uid_to_string_or_null(job_desc->target_user
							      .uid);
			lua_pushstring(L, username);
			xfree(username);
		}
	} else if (!xstrcmp(name, "wait4switch")) {
		lua_pushnumber(L, job_desc->wait4switch);
	} else if (!xstrcmp(name, "work_dir")) {
		lua_pushstring(L, job_desc->work_dir);
	} else if (!xstrcmp(name, "wckey")) {
		lua_pushstring(L, job_desc->wckey);
	} else {
		lua_pushnil(L);
	}

	return 1;
}

/* Get fields in the job request record on job submit or modify */
static int _get_job_req_field_name(lua_State *L)
{
	const job_desc_msg_t *job_desc = lua_touserdata(L, 1);
	const char *name = luaL_checkstring(L, 2);

	return _get_job_req_field(job_desc, name);
}

/* Get fields in an existing slurmctld job_descriptor record */
static int _get_job_req_field_index(lua_State *L)
{
	const char *name;
	job_desc_msg_t *job_desc;

	name = luaL_checkstring(L, 2);
	lua_getmetatable(L, -2);
	lua_getfield(L, -1, "_job_desc");
	job_desc = lua_touserdata(L, -1);

	return _get_job_req_field(job_desc, name);
}

/* Set fields in the job request structure on job submit or modify */
/*
 * Assign a job_desc string field from the Lua value at stack slot 3.
 * When (clearable) is true, an empty string is preserved on the modify
 * path (is_modify) so the controller's clear-on-empty branch fires;
 * otherwise an empty string drops the field to NULL. Relies on the
 * value_str, job_desc, is_modify and L locals of _set_job_req_field().
 */
#define SET_JOB_STRING(field, clearable) \
	do { \
		value_str = luaL_checkstring(L, 3); \
		xfree(job_desc->field); \
		if (((clearable) && is_modify) || strlen(value_str)) \
			job_desc->field = xstrdup(value_str); \
	} while (0)

static int _set_job_req_field(lua_State *L)
{
	const char *name, *value_str;
	job_desc_msg_t *job_desc;
	bool is_modify = false;

	name = luaL_checkstring(L, 2);
	lua_getmetatable(L, -3);
	lua_getfield(L, -1, "_job_desc");
	job_desc = lua_touserdata(L, -1);
	lua_pop(L, 1);
	lua_getfield(L, -1, "_is_modify");
	is_modify = lua_toboolean(L, -1);
	lua_pop(L, 1);
	if (job_desc == NULL) {
		error("%s: job_desc is NULL", __func__);
	} else if (!xstrcmp(name, "account")) {
		SET_JOB_STRING(account, false);
	} else if (!xstrcmp(name, "acctg_freq")) {
		SET_JOB_STRING(acctg_freq, false);
	} else if (!xstrcmp(name, "admin_comment")) {
		SET_JOB_STRING(admin_comment, true);
	} else if (!xstrcmp(name, "array_inx")) {
		SET_JOB_STRING(array_inx, false);
	} else if (!xstrcmp(name, "batch_features")) {
		SET_JOB_STRING(batch_features, false);
	} else if (!xstrcmp(name, "begin_time")) {
		job_desc->begin_time = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "bitflags")) {
		job_desc->bitflags = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "burst_buffer")) {
		SET_JOB_STRING(burst_buffer, false);
	} else if (!xstrcmp(name, "clusters")) {
		SET_JOB_STRING(clusters, false);
	} else if (!xstrcmp(name, "comment")) {
		SET_JOB_STRING(comment, true);
	} else if (!xstrcmp(name, "container")) {
		SET_JOB_STRING(container, false);
	} else if (!xstrcmp(name, "contiguous")) {
		job_desc->contiguous = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "core_spec")) {
		job_desc->core_spec = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "cores_per_socket")) {
		job_desc->cores_per_socket = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "cpu_freq_min")) {
		job_desc->cpu_freq_min = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "cpu_freq_max")) {
		job_desc->cpu_freq_max = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "cpu_freq_gov")) {
		job_desc->cpu_freq_gov = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "cpus_per_task")) {
		job_desc->cpus_per_task = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "cpus_per_tres")) {
		SET_JOB_STRING(cpus_per_tres, true);
	} else if (!xstrcmp(name, "dependency")) {
		SET_JOB_STRING(dependency, true);
	} else if (!xstrcmp(name, "delay_boot")) {
		job_desc->delay_boot = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "end_time")) {
		job_desc->end_time = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "extra")) {
		SET_JOB_STRING(extra, true);
	} else if (!xstrcmp(name, "exc_nodes")) {
		SET_JOB_STRING(exc_nodes, true);
	} else if (!xstrcmp(name, "features")) {
		SET_JOB_STRING(features, true);
	} else if (!xstrcmp(name, "gres")) {
		/* "gres" replaced by "tres_per_node" in v18.08 */
		value_str = luaL_checkstring(L, 3);
		xfree(job_desc->tres_per_node);
		if (strlen(value_str))
			job_desc->tres_per_node =
				gres_prepend_tres_type(value_str);
		else if (is_modify)
			/*
			 * On modify, propagate "" so the controller clears
			 * tres_per_node. Bypass gres_prepend_tres_type("")
			 * which would emit a malformed TRES string.
			 */
			job_desc->tres_per_node = xstrdup("");
	} else if (!xstrcmp(name, "immediate")) {
		job_desc->immediate = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "layout")) {
		SET_JOB_STRING(layout, true);
	} else if (!xstrcmp(name, "licenses")) {
		SET_JOB_STRING(licenses, true);
	} else if (!xstrcmp(name, "mail_type")) {
		job_desc->mail_type = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "mail_user")) {
		SET_JOB_STRING(mail_user, false);
	} else if (!xstrcmp(name, "max_cpus")) {
		job_desc->max_cpus = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "max_nodes")) {
		job_desc->max_nodes = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "max_npids")) {
		job_desc->max_npids = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "mcs_label")) {
		SET_JOB_STRING(mcs_label, false);
	} else if (!xstrcmp(name, "mem_per_tres")) {
		SET_JOB_STRING(mem_per_tres, true);
	} else if (!xstrcmp(name, "min_cpus")) {
		job_desc->min_cpus = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "min_mem_per_cpu")) {
		job_desc->pn_min_memory = luaL_checknumber(L, 3);
		job_desc->pn_min_memory |= MEM_PER_CPU;
	} else if (!xstrcmp(name, "min_mem_per_node")) {
		job_desc->pn_min_memory = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "min_nodes")) {
		job_desc->min_nodes = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "name")) {
		SET_JOB_STRING(name, false);
	} else if (!xstrcmp(name, "network")) {
		SET_JOB_STRING(network, true);
	} else if (!xstrcmp(name, "nice")) {
		/*
		 * nice should be NO_VAL when unset or incremented by
		 * NICE_OFFSET by the job_submit.lua script.
		 */
		job_desc->nice = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "ntasks_per_gpu")) {
		job_desc->ntasks_per_tres = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "ntasks_per_node")) {
		job_desc->ntasks_per_node = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "ntasks_per_socket")) {
		job_desc->ntasks_per_socket = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "ntasks_per_tres")) {
		job_desc->ntasks_per_tres = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "num_tasks")) {
		job_desc->num_tasks = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "partition")) {
		SET_JOB_STRING(partition, false);
	} else if (!xstrcmp(name, "prefer")) {
		SET_JOB_STRING(prefer, true);
	} else if (!xstrcmp(name, "pn_min_cpus")) {
		job_desc->pn_min_cpus = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "pn_min_memory")) {
		/*
		 * FIXME: Remove this in the future, lua can't handle 64bit
		 * numbers!!!.  Use min_mem_per_node|cpu instead.
		 */
		job_desc->pn_min_memory = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "pn_min_tmp_disk")) {
		job_desc->pn_min_tmp_disk = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "priority")) {
		job_desc->priority = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "qos")) {
		SET_JOB_STRING(qos, false);
	} else if (!xstrcmp(name, "reboot")) {
		job_desc->reboot = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "relay_io")) {
		/*
		 * Prevent overflowing relay_io since it is a uint16_t and a
		 * lua number is not. A NaN fails both tests and means on.
		 */
		lua_Number relay_io = luaL_checknumber(L, 3);

		if ((relay_io >= 0) && (relay_io <= UINT16_MAX))
			job_desc->relay_io = relay_io;
		else
			job_desc->relay_io = 1;
	} else if (!xstrcmp(name, "req_nodes")) {
		SET_JOB_STRING(req_nodes, true);
	} else if (!xstrcmp(name, "req_switch")) {
		job_desc->req_switch = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "requeue")) {
		job_desc->requeue = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "reservation")) {
		SET_JOB_STRING(reservation, true);
	} else if (!xstrcmp(name, "script")) {
		SET_JOB_STRING(script, false);
	} else if (!xstrcmp(name, "segment_size")) {
		job_desc->segment_size = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "selinux_context")) {
		SET_JOB_STRING(selinux_context, false);
	} else if (!xstrcmp(name, "shared") ||
		   !xstrcmp(name, "oversubscribe")) {
		job_desc->shared = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "site_factor")) {
		job_desc->site_factor = luaL_checknumber(L, 3);
		if (job_desc->site_factor != NO_VAL)
			job_desc->site_factor =
				NICE_OFFSET + job_desc->site_factor;
	} else if (!xstrcmp(name, "sockets_per_node")) {
		job_desc->sockets_per_node = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "std_err")) {
		SET_JOB_STRING(std_err, false);
	} else if (!xstrcmp(name, "std_in")) {
		SET_JOB_STRING(std_in, false);
	} else if (!xstrcmp(name, "std_out")) {
		SET_JOB_STRING(std_out, false);
	} else if (!xstrcmp(name, "thread_spec")) {
		job_desc->core_spec = luaL_checknumber(L, 3);
		job_desc->core_spec |= CORE_SPEC_THREAD;
	} else if (!xstrcmp(name, "threads_per_core")) {
		job_desc->threads_per_core = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "time_limit")) {
		job_desc->time_limit = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "time_min")) {
		job_desc->time_min = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "tres_bind")) {
		SET_JOB_STRING(tres_bind, true);
	} else if (!xstrcmp(name, "tres_freq")) {
		SET_JOB_STRING(tres_freq, true);
	} else if (!xstrcmp(name, "tres_per_job")) {
		SET_JOB_STRING(tres_per_job, true);
	} else if (!xstrcmp(name, "tres_per_node")) {
		SET_JOB_STRING(tres_per_node, true);
	} else if (!xstrcmp(name, "tres_per_socket")) {
		SET_JOB_STRING(tres_per_socket, true);
	} else if (!xstrcmp(name, "tres_per_task")) {
		SET_JOB_STRING(tres_per_task, true);
	} else if (!xstrcmp(name, "wait4switch")) {
		job_desc->wait4switch = luaL_checknumber(L, 3);
	} else if (!xstrcmp(name, "wckey")) {
		SET_JOB_STRING(wckey, true);
	} else if (!xstrcmp(name, "work_dir")) {
		SET_JOB_STRING(work_dir, false);
	} else {
		error("_set_job_field: unrecognized field: %s", name);
	}

	return 0;
}

#undef SET_JOB_STRING

static void _push_job_desc(job_desc_msg_t *job_desc, bool is_modify)
{
	lua_newtable(L);

	lua_newtable(L);
	lua_pushcfunction(L, _get_job_req_field_index);
	lua_setfield(L, -2, "__index");
	lua_pushcfunction(L, _set_job_req_field);
	lua_setfield(L, -2, "__newindex");
	/* Store the job descriptor in the metatable, so the index
	 * function knows which struct it's getting data for.
	 */
	lua_pushlightuserdata(L, job_desc);
	lua_setfield(L, -2, "_job_desc");
	/* Mark modify so setters can let "" clear string fields. */
	lua_pushboolean(L, is_modify);
	lua_setfield(L, -2, "_is_modify");
	lua_setmetatable(L, -2);
}

static void _push_job_rec(job_record_t *job_ptr)
{
	lua_newtable(L);

	lua_newtable(L);
	lua_pushcfunction(L, _job_rec_field_index);
	lua_setfield(L, -2, "__index");
	/* Store the job_ptr in the metatable, so the index
	 * function knows which struct it's getting data for.
	 */
	lua_pushlightuserdata(L, job_ptr);
	lua_setfield(L, -2, "_job_rec_ptr");
	lua_setmetatable(L, -2);
}

/* Get fields in an existing slurmctld partition record
 *
 * This is an incomplete list of partition record fields. Add more as needed
 * and send patches to slurm-dev@schedmd.com
 */
static int _part_rec_field(const part_record_t *part_ptr, const char *name)
{
	if (part_ptr == NULL) {
		error("_get_part_field: part_ptr is NULL");
		lua_pushnil(L);
	} else if (!xstrcmp(name, "allow_accounts")) {
		lua_pushstring(L, part_ptr->allow_accounts);
	} else if (!xstrcmp(name, "allow_alloc_nodes")) {
		lua_pushstring(L, part_ptr->allow_alloc_nodes);
	} else if (!xstrcmp(name, "allow_groups")) {
		lua_pushstring(L, part_ptr->allow_groups);
	} else if (!xstrcmp(name, "allow_qos")) {
		lua_pushstring(L, part_ptr->allow_qos);
	} else if (!xstrcmp(name, "alternate")) {
		lua_pushstring(L, part_ptr->alternate);
	} else if (!xstrcmp(name, "billing_weights_str")) {
		lua_pushstring(L, part_ptr->billing_weights_str);
	} else if (!xstrcmp(name, "default_time")) {
		lua_pushnumber(L, part_ptr->default_time);
	} else if (!xstrcmp(name, "def_mem_per_cpu") &&
		   (part_ptr->def_mem_per_cpu != NO_VAL64) &&
		   (part_ptr->def_mem_per_cpu & MEM_PER_CPU)) {
		lua_pushnumber(L, part_ptr->def_mem_per_cpu & (~MEM_PER_CPU));
	} else if (!xstrcmp(name, "def_mem_per_node") &&
		   (part_ptr->def_mem_per_cpu != NO_VAL64) &&
		   !(part_ptr->def_mem_per_cpu & MEM_PER_CPU)) {
		lua_pushnumber(L, part_ptr->def_mem_per_cpu);
	} else if (!xstrcmp(name, "deny_accounts")) {
		lua_pushstring(L, part_ptr->deny_accounts);
	} else if (!xstrcmp(name, "deny_qos")) {
		lua_pushstring(L, part_ptr->deny_qos);
	} else if (!xstrcmp(name, "flag_default")) {
		int is_default = 0;
		if (part_ptr->flags & PART_FLAG_DEFAULT)
			is_default = 1;
		lua_pushnumber(L, is_default);
	} else if (!xstrcmp(name, "flags")) {
		lua_pushnumber(L, part_ptr->flags);
	} else if (!xstrcmp(name, "max_cpus_per_node")) {
		lua_pushnumber(L, part_ptr->max_cpus_per_node);
	} else if (!xstrcmp(name, "max_cpus_per_socket")) {
		lua_pushnumber(L, part_ptr->max_cpus_per_socket);
	} else if (!xstrcmp(name, "max_mem_per_cpu") &&
		   (part_ptr->max_mem_per_cpu != NO_VAL64) &&
		   (part_ptr->max_mem_per_cpu & MEM_PER_CPU)) {
		lua_pushnumber(L, part_ptr->max_mem_per_cpu & (~MEM_PER_CPU));
	} else if (!xstrcmp(name, "max_mem_per_node") &&
		   (part_ptr->max_mem_per_cpu != NO_VAL64) &&
		   !(part_ptr->max_mem_per_cpu & MEM_PER_CPU)) {
		lua_pushnumber(L, part_ptr->max_mem_per_cpu);
	} else if (!xstrcmp(name, "max_nodes")) {
		lua_pushnumber(L, part_ptr->max_nodes);
	} else if (!xstrcmp(name, "max_nodes_orig")) {
		lua_pushnumber(L, part_ptr->max_nodes);
	} else if (!xstrcmp(name, "max_share") ||
		   !xstrcmp(name, "max_oversubscribe")) {
		lua_pushnumber(L, part_ptr->max_share);
	} else if (!xstrcmp(name, "max_time")) {
		lua_pushnumber(L, part_ptr->max_time);
	} else if (!xstrcmp(name, "min_nodes")) {
		lua_pushnumber(L, part_ptr->min_nodes);
	} else if (!xstrcmp(name, "min_nodes_orig")) {
		lua_pushnumber(L, part_ptr->min_nodes);
	} else if (!xstrcmp(name, "name")) {
		lua_pushstring(L, part_ptr->name);
	} else if (!xstrcmp(name, "nodes")) {
		lua_pushstring(L, part_ptr->nodes);
	} else if (!xstrcmp(name, "priority_job_factor")) {
		lua_pushnumber(L, part_ptr->priority_job_factor);
	} else if (!xstrcmp(name, "priority_tier")) {
		lua_pushnumber(L, part_ptr->priority_tier);
	} else if (!xstrcmp(name, "qos")) {
		lua_pushstring(L, part_ptr->qos_char);
	} else if (!xstrcmp(name, "state_up")) {
		lua_pushnumber(L, part_ptr->state_up);
	} else if (!xstrcmp(name, "total_cpus")) {
		lua_pushnumber(L, part_ptr->total_cpus);
	} else if (!xstrcmp(name, "total_nodes")) {
		lua_pushnumber(L, part_ptr->total_nodes);
	} else {
		lua_pushnil(L);
	}

	return 1;
}

static int _get_part_rec_field (lua_State *L)
{
	const part_record_t *part_ptr = lua_touserdata(L, 1);
	const char *name = luaL_checkstring(L, 2);

	return _part_rec_field(part_ptr, name);
}

static int _part_rec_field_index(lua_State *L)
{
	const char *name = luaL_checkstring(L, 2);
	part_record_t *part_ptr;

	lua_getmetatable(L, -2);
	lua_getfield(L, -1, "_part_rec_ptr");
	part_ptr = lua_touserdata(L, -1);

	return _part_rec_field(part_ptr, name);
}

static bool _user_can_use_part(uint32_t user_id, uint32_t submit_uid,
			       part_record_t *part_ptr)
{
	if (user_id == 0) {
		if (part_ptr->flags & PART_FLAG_NO_ROOT)
			return false;
		return true;
	}

	if ((part_ptr->flags & PART_FLAG_ROOT_ONLY) && (submit_uid != 0))
		return false;

	if (!part_ptr->allow_uids_cnt)
		return true;	/* No user ID filters */

	for (int i = 0; i < part_ptr->allow_uids_cnt; i++) {
		if (user_id == part_ptr->allow_uids[i])
			return true;
	}
	return false;
}

static int _foreach_push_partition_list(void *x, void *arg)
{
	part_record_t *part_ptr = x;
	foreach_part_list_args_t *args = arg;

	if (!_user_can_use_part(args->user_id, args->submit_uid, part_ptr))
		return 0;

	/*
	 * Create an empty table, with a metatable that looks up the
	 * data for the partition.
	 */
	lua_newtable(L);

	lua_newtable(L);
	lua_pushcfunction(L, _part_rec_field_index);
	lua_setfield(L, -2, "__index");
	/*
	 * Store the part_record in the metatable, so the index
	 * function knows which job it's getting data for.
	 */
	lua_pushlightuserdata(L, part_ptr);
	lua_setfield(L, -2, "_part_rec_ptr");
	lua_setmetatable(L, -2);

	lua_setfield(L, -2, part_ptr->name);

	return 0;
}

static void _push_partition_list(uint32_t user_id, uint32_t submit_uid)
{
	foreach_part_list_args_t args = {
		.submit_uid = submit_uid,
		.user_id = user_id,
	};

	lua_newtable(L);

	list_for_each(part_list, _foreach_push_partition_list, &args);
}


static int _log_lua_user_msg (lua_State *L)
{
	const char *msg = lua_tostring(L, -1);
	char *tmp = NULL;

	if (user_msg) {
		xstrfmtcat(tmp, "%s\n%s", user_msg, msg);
		xfree(user_msg);
		user_msg = tmp;
		tmp = NULL;
	} else {
		user_msg = xstrdup(msg);
	}

	return (0);
}

static const struct luaL_Reg slurm_functions [] = {
	{ "user_msg",   _log_lua_user_msg },
	{ NULL,         NULL        }
};


static void _register_local_output_functions(lua_State *L)
{
	slurm_lua_table_register(L, NULL, slurm_functions);

	/* Must be always done after we register the slurm_functions */
	lua_setglobal(L, "slurm");

	last_lua_jobs_update = 0;
	_update_jobs_global(L);
	last_lua_resv_update = 0;
	_update_resvs_global(L);
}

static void _register_lua_slurm_struct_functions(lua_State *st)
{
	lua_pushcfunction(st, _get_job_env_field_name);
	lua_setglobal(st, "_get_job_env_field_name");
	lua_pushcfunction(st, _get_job_req_field_name);
	lua_setglobal(st, "_get_job_req_field_name");
	lua_pushcfunction(st, _set_job_env_field);
	lua_setglobal(st, "_set_job_env_field");
	lua_pushcfunction(st, _set_job_req_field);
	lua_setglobal(st, "_set_job_req_field");
	lua_pushcfunction(st, _get_part_rec_field);
	lua_setglobal(st, "_get_part_rec_field");
}

static void _loadscript_extra(lua_State *st)
{
	/* local setup */
	_register_local_output_functions(st);
	_register_lua_slurm_struct_functions(st);
}

/*
 *  NOTE: The init callback should never be called multiple times,
 *   let alone called from multiple threads. Therefore, locking
 *   is unnecessary here.
 */
extern int init(void)
{
	int rc = SLURM_SUCCESS;

	if ((rc = slurm_lua_init()) != SLURM_SUCCESS)
		return rc;
	lua_script_path = get_extra_conf_path("job_submit.lua");

	return slurm_lua_loadscript(&L, "job_submit/lua",
				    lua_script_path, req_fxns,
				    &lua_script_last_loaded,
				    _loadscript_extra, NULL);
}

extern void fini(void)
{
	if (L) {
		debug3("%s: Unloading Lua script", __func__);
		lua_close(L);
		L = NULL;
		lua_script_last_loaded = 0;
	}
	xfree(lua_script_path);

	slurm_lua_fini();
}


/* Lua script hook called for "submit job" event. */
extern int job_submit(slurm_msg_t *msg, job_desc_msg_t *job_desc,
		      char **err_msg)
{
	int rc;
	char *err_str = NULL;

	slurm_mutex_lock (&lua_lock);

	rc = slurm_lua_loadscript(&L, "job_submit/lua",
				  lua_script_path, req_fxns,
				  &lua_script_last_loaded, _loadscript_extra,
				  NULL);

	if (rc != SLURM_SUCCESS)
		goto out;

	/*
	 *  All lua script functions should have been verified during
	 *   initialization:
	 */
	lua_getglobal(L, "slurm_job_submit");
	if (lua_isnil(L, -1))
		goto out;

	_update_jobs_global(L);
	_update_resvs_global(L);

	_push_job_desc(job_desc, false);
	_push_partition_list(job_desc->target_user.uid, msg->auth.uid);
	lua_pushnumber(L, msg->auth.uid);
	slurm_lua_stack_dump(
		"job_submit/lua", "job_submit, before lua_pcall", L);
	if ((rc = slurm_lua_pcall(L, 3, 1, &err_str, __func__))) {
		if (!err_str)
			err_str = xstrdup_printf("Lua %s failed: %s",
						 lua_script_path,
						 slurm_strerror(rc));

		error("%s/lua: %s: %s",
		      __func__, lua_script_path, err_str);

		/* Replace user_msg as err_msg with Lua error */
		xfree(user_msg);
		SWAP(*err_msg, err_str);
	} else {
		if (lua_isnumber(L, -1)) {
			rc = lua_tonumber(L, -1);
		} else {
			info("%s/lua: %s: non-numeric return code",
			     __func__, lua_script_path);
			rc = SLURM_SUCCESS;
		}
		lua_pop(L, 1);
	}
	slurm_lua_stack_dump(
		"job_submit/lua", "job_submit, after lua_pcall", L);
	if (user_msg) {
		*err_msg = user_msg;
		user_msg = NULL;
	}

out:	slurm_mutex_unlock (&lua_lock);

	xfree(err_str);
	return rc;
}

/* Lua script hook called for "modify job" event. */
extern int job_modify(slurm_msg_t *msg, job_desc_msg_t *job_desc,
		      job_record_t *job_ptr, char **err_msg)
{
	int rc;
	char *err_str = NULL;

	slurm_mutex_lock (&lua_lock);

	rc = slurm_lua_loadscript(&L, "job_submit/lua",
				  lua_script_path, req_fxns,
				  &lua_script_last_loaded, _loadscript_extra,
				  NULL);

	if (rc != SLURM_SUCCESS)
		goto out;

	/*
	 *  All lua script functions should have been verified during
	 *   initialization:
	 */
	lua_getglobal(L, "slurm_job_modify");
	if (lua_isnil(L, -1))
		goto out;

	_update_jobs_global(L);
	_update_resvs_global(L);

	_push_job_desc(job_desc, true);
	_push_job_rec(job_ptr);
	_push_partition_list(job_ptr->user_id, msg->auth.uid);
	lua_pushnumber(L, msg->auth.uid);
	slurm_lua_stack_dump(
		"job_submit/lua", "job_modify, before lua_pcall", L);
	if ((rc = slurm_lua_pcall(L, 4, 1, &err_str, __func__))) {
		if (!err_str)
			err_str = xstrdup_printf("Lua %s failed: %s",
						 lua_script_path,
						 slurm_strerror(rc));

		error("%s/lua: %s: %s",
		      __func__, lua_script_path, err_str);

		/* Replace user_msg as err_msg with Lua error */
		xfree(user_msg);
		SWAP(*err_msg, err_str);
	} else {
		if (lua_isnumber(L, -1)) {
			rc = lua_tonumber(L, -1);
		} else {
			info("%s/lua: %s: non-numeric return code",
			     __func__, lua_script_path);
			rc = SLURM_SUCCESS;
		}
		lua_pop(L, 1);
	}
	slurm_lua_stack_dump(
		"job_submit/lua", "job_modify, after lua_pcall", L);
	if (user_msg) {
		*err_msg = user_msg;
		user_msg = NULL;
	}

out:	slurm_mutex_unlock (&lua_lock);

	xfree(err_str);
	return rc;
}