Make it possible to reload configuration without stopping and restarting

istgt, which could distrub e.g. Xen clients when they are actively doing I/O. The patch that implements the underlying functionality was written by Kun Huang, sponsored by Applied Operations, LLC. PR: ports/165844 Approved by: maintainer timeout Feature safe: yes
svn path=/head/; revision=293699
2025-07-18 09:49:18 -04:00 · 2012-03-23 00:03:54 +00:00 · 2012-03-23 00:03:54 +00:00 · fd249f572a · 2021-03-31 03:12:20 +00:00
commit fd249f572a
parent 10d2d4fa88
6 changed files with 928 additions and 0 deletions
--- a/net/istgt/Makefile
+++ b/net/istgt/Makefile
@ -7,6 +7,7 @@

 PORTNAME=	istgt
 PORTVERSION=	20111008
+PORTREVISION=	1
 CATEGORIES=	net
 MASTER_SITES=	http://www.peach.ne.jp/archives/istgt/

--- a/net/istgt/files/patch-istgt-rc
+++ b/net/istgt/files/patch-istgt-rc
@ -0,0 +1,25 @@
+--- etc/istgt.sh.in.orig	2011-08-31 11:53:08.000000000 -0700
+++ etc/istgt.sh.in	2012-03-07 17:12:49.615160257 -0800
+@@ -9,6 +9,7 @@
+ 
+ name="istgt"
+ rcvar=`set_rcvar`
+reload_cmd="istgt_reload"
+ extra_commands="reload"
+ 
+ load_rc_config $name
+@@ -18,6 +19,14 @@
+ : ${istgt_pidfile="/var/run/istgt.pid"}
+ : ${istgt_flags=""}
+ 
+#
+# Refresh configuration
+#
+istgt_reload()
+{
+	%%BINDIR%%/istgtcontrol refresh
+}
+
+ required_files="${istgt_config}"
+ pidfile="${istgt_pidfile}"
+ command="%%BINDIR%%/istgt"
--- a/net/istgt/files/patch-istgt-reload
+++ b/net/istgt/files/patch-istgt-reload
@ -0,0 +1,438 @@
+diff --git src/istgt.c src/istgt.c
+index e62de97..8fd509e 100644
+--- src/istgt.c
+++ src/istgt.c
+@@ -71,6 +71,7 @@
+ #define PORTNUMLEN 32
+ 
+ ISTGT g_istgt;
+const char  *g_config_file;
+ 
+ #if 0
+ void
+@@ -1598,6 +1599,7 @@ main(int argc, char **argv)
+ 
+ 	/* read config files */
+ 	config = istgt_allocate_config();
+	g_config_file = config_file;
+ 	rc = istgt_read_config(config, config_file);
+ 	if (rc < 0) {
+ 		fprintf(stderr, "config error\n");
+@@ -1662,7 +1664,7 @@ main(int argc, char **argv)
+ 		istgt_free_config(config);
+ 		exit(EXIT_FAILURE);
+ 	}
+-	rc = istgt_lu_init(istgt);
+	rc = istgt_lu_init(istgt, 0);
+ 	if (rc < 0) {
+ 		ISTGT_ERRLOG("istgt_lu_init() failed\n");
+ 		goto initialize_error;
+@@ -1772,7 +1774,7 @@ main(int argc, char **argv)
+ #endif
+ 
+ 	/* create LUN threads for command queuing */
+-	rc = istgt_lu_create_threads(istgt);
+	rc = istgt_lu_create_threads(istgt, 0);
+ 	if (rc < 0) {
+ 		ISTGT_ERRLOG("lu_create_threads() failed\n");
+ 		goto initialize_error;
+@@ -1809,7 +1811,7 @@ main(int argc, char **argv)
+ 		istgt_close_portal(istgt);
+ 		istgt_close_uctl_portal(istgt);
+ 		istgt_iscsi_shutdown(istgt);
+-		istgt_lu_shutdown(istgt);
+		istgt_lu_shutdown(istgt, 0);
+ 		istgt_destory_initiator_group_array(istgt);
+ 		istgt_destroy_portal_array(istgt);
+ 		istgt_destroy_uctl_portal(istgt);
+@@ -1837,7 +1839,7 @@ main(int argc, char **argv)
+ 	istgt_close_portal(istgt);
+ 	istgt_close_uctl_portal(istgt);
+ 	istgt_iscsi_shutdown(istgt);
+-	istgt_lu_shutdown(istgt);
+	istgt_lu_shutdown(istgt, 0);
+ 	istgt_destory_initiator_group_array(istgt);
+ 	istgt_destroy_portal_array(istgt);
+ 	istgt_destroy_uctl_portal(istgt);
+diff --git src/istgt_lu.c src/istgt_lu.c
+index 783f809..c0c4f31 100644
+--- src/istgt_lu.c
+++ src/istgt_lu.c
+@@ -1202,7 +1202,7 @@ istgt_lu_set_local_settings(ISTGT_Ptr istgt, CF_SECTION *sp, ISTGT_LU_Ptr lu)
+ }
+ 
+ static int
+-istgt_lu_add_unit(ISTGT_Ptr istgt, CF_SECTION *sp)
+istgt_lu_add_unit(ISTGT_Ptr istgt, CF_SECTION *sp, int ignore_dup)
+ {
+ 	char buf[MAX_TMPBUF], buf2[MAX_TMPBUF];
+ 	ISTGT_LU_Ptr lu;
+@@ -1222,21 +1222,40 @@ istgt_lu_add_unit(ISTGT_Ptr istgt, CF_SECTION *sp)
+ 	int i, j, k;
+ 	int rc;
+ 
+-	ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "add unit %d\n", sp->num);
+	ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "add unit %d (ignore dup = %d)\n", sp->num, ignore_dup);
+ 
+ 	if (sp->num >= MAX_LOGICAL_UNIT) {
+ 		ISTGT_ERRLOG("LU%d: over maximum unit number\n", sp->num);
+ 		return -1;
+ 	}
+-	if (istgt->logical_unit[sp->num] != NULL) {
+	if (istgt->logical_unit[sp->num] != NULL && !ignore_dup) {
+ 		ISTGT_ERRLOG("LU%d: duplicate unit\n", sp->num);
+ 		return -1;
+ 	}
+	/* existing LUNs */
+	if (istgt->logical_unit[sp->num] != NULL && ignore_dup) {
+		istgt->logical_unit[sp->num]->to_add = 0;
+		istgt->logical_unit[sp->num]->to_remove = 0;
+		ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "skip existing unit %d\n", sp->num);
+		return 0;
+	}
+
+	/* new LUNs */
+	if (istgt->logical_unit[sp->num] == NULL && ignore_dup) {
+		ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "add NEW unit %d\n", sp->num);
+	}
+ 
+ 	lu = xmalloc(sizeof *lu);
+ 	memset(lu, 0, sizeof *lu);
+ 	lu->num = sp->num;
+ 	lu->istgt = istgt;
+
+	/* tag new LUNs */
+	if (ignore_dup) {
+		lu->to_add = 1;
+		lu->to_remove = 0;
+	}
+
+ 	istgt_lu_set_state(lu, ISTGT_STATE_INVALID);
+ 	nbs64 = istgt_lu_get_nbserial(istgt->nodebase);
+ #if 0
+@@ -1944,12 +1963,15 @@ istgt_lu_del_unit(ISTGT_Ptr istgt, ISTGT_LU_Ptr lu)
+ static void *luworker(void *arg);
+ 
+ int
+-istgt_lu_init(ISTGT_Ptr istgt)
+istgt_lu_init(ISTGT_Ptr istgt, int ignore_dup)
+ {
+ 	ISTGT_LU_Ptr lu;
+ 	CF_SECTION *sp;
+ 	int rc;
+ 	int i;
+	int lun_map[MAX_LOGICAL_UNIT];
+
+	memset(lun_map, 0, sizeof(int) * MAX_LOGICAL_UNIT);
+ 
+ 	ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "istgt_lu_init\n");
+ 	sp = istgt_find_cf_section(istgt->config, "Global");
+@@ -1969,11 +1991,12 @@ istgt_lu_init(ISTGT_Ptr istgt)
+ 				ISTGT_ERRLOG("tag %d is invalid\n", sp->num);
+ 				return -1;
+ 			}
+-			rc = istgt_lu_add_unit(istgt, sp);
+			rc = istgt_lu_add_unit(istgt, sp, ignore_dup);
+ 			if (rc < 0) {
+ 				ISTGT_ERRLOG("lu_add_unit() failed\n");
+ 				return -1;
+ 			}
+			lun_map[sp->num] = 1; /* in new LUN list */
+ 		}
+ 		sp = sp->next;
+ 	}
+@@ -1982,6 +2005,22 @@ istgt_lu_init(ISTGT_Ptr istgt)
+ 		lu = istgt->logical_unit[i];
+ 		if (lu == NULL)
+ 			continue;
+		/* tag to be removed LUNs */
+		if (lun_map[i] == 0) {
+			istgt->logical_unit[i]->to_add = 0;
+			istgt->logical_unit[i]->to_remove = 1;
+			continue;
+		}
+		/* only process newly added LUNs here beyond in loop */
+		if (ignore_dup &&
+		    (istgt->logical_unit[i]->to_add == 1 &&
+		     istgt->logical_unit[i]->to_remove == 0)) {
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "adding unit %d\n", i);
+		} else if (ignore_dup &&
+		    !(istgt->logical_unit[i]->to_add == 1 &&
+		      istgt->logical_unit[i]->to_remove == 0)) {
+			continue;
+		}
+ 
+ 		rc = pthread_mutex_init(&lu->mutex, NULL);
+ 		if (rc != 0) {
+@@ -2069,7 +2108,7 @@ istgt_lu_set_all_state(ISTGT_Ptr istgt, ISTGT_STATE state)
+ }
+ 
+ int
+-istgt_lu_create_threads(ISTGT_Ptr istgt)
+istgt_lu_create_threads(ISTGT_Ptr istgt, int new_only)
+ {
+ #ifdef HAVE_PTHREAD_SET_NAME_NP
+ 	char buf[MAX_TMPBUF];
+@@ -2084,6 +2123,10 @@ istgt_lu_create_threads(ISTGT_Ptr istgt)
+ 		lu = istgt->logical_unit[i];
+ 		if (lu == NULL)
+ 			continue;
+		if (new_only && !lu->to_add) {
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "skip existing LUN %d\n", i);
+			continue;
+		}
+ 
+ 		if (lu->queue_depth != 0) {
+ 			/* create LU thread */
+@@ -2114,18 +2157,22 @@ istgt_lu_create_threads(ISTGT_Ptr istgt)
+ }
+ 
+ int
+-istgt_lu_shutdown(ISTGT_Ptr istgt)
+istgt_lu_shutdown(ISTGT_Ptr istgt, int removed_only)
+ {
+ 	ISTGT_LU_Ptr lu;
+ 	int rc;
+ 	int i;
+ 
+-	ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "istgt_lu_shutdown\n");
+	ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "istgt_lu_shutdown (removed_only = %d\n", removed_only);
+ 
+ 	for (i = 0; i < MAX_LOGICAL_UNIT; i++) {
+ 		lu = istgt->logical_unit[i];
+ 		if (lu == NULL)
+ 			continue;
+		if (removed_only && !lu->to_remove) {
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "skip existing LUNs %d\n", i);
+			continue;
+		}
+ 		istgt_lu_set_state(lu, ISTGT_STATE_SHUTDOWN);
+ 
+ 		switch (lu->type) {
+diff --git src/istgt_lu.h src/istgt_lu.h
+index 72c5a6c..9484266 100644
+--- src/istgt_lu.h
+++ src/istgt_lu.h
+@@ -236,6 +236,9 @@ typedef struct istgt_lu_t {
+ 	ISTGT_LU_TSIH tsih[MAX_LU_TSIH];
+ 	int maxmap;
+ 	ISTGT_LU_MAP map[MAX_LU_MAP];
+
+	int to_add;
+	int to_remove;
+ } ISTGT_LU;
+ typedef ISTGT_LU *ISTGT_LU_Ptr;
+ 
+diff --git src/istgt_lu_ctl.c src/istgt_lu_ctl.c
+index 70c93e1..47e2fd3 100644
+--- src/istgt_lu_ctl.c
+++ src/istgt_lu_ctl.c
+@@ -965,6 +965,113 @@ istgt_uctl_cmd_change(UCTL_Ptr uctl)
+ 	return UCTL_CMD_OK;
+ }
+ 
+extern const char *g_config_file;
+extern ISTGT g_istgt;
+
+static int
+istgt_uctl_cmd_refresh(UCTL_Ptr uctl)
+{
+	char *arg;
+	int rc, i, j;
+	CONFIG *config;
+	ISTGT_Ptr istgt;
+
+	arg = uctl->arg;
+	istgt = &g_istgt;
+
+	/* reload config, might add/remove LUNs */
+	/* step 1: re-read config files */
+	config = istgt_allocate_config();
+	rc = istgt_read_config(config, g_config_file);
+	if (rc < 0) {
+		fprintf(stderr, "refresh config error\n");
+		return UCTL_CMD_ERR;
+	}
+	if (config->section == NULL) {
+		fprintf(stderr, "empty config\n");
+		istgt_free_config(config);
+		return UCTL_CMD_ERR;
+	}
+	istgt_free_config(istgt->config);
+	istgt->config = config;
+
+	/* step 2: add new units, init new LUNs, tag to-add/remove LUNs */
+	rc = istgt_lu_init(istgt, 1);
+	if (rc < 0) {
+		ISTGT_ERRLOG("istgt_lu_init() failed\n");
+		istgt_free_config(config);
+		return UCTL_CMD_ERR;
+	}
+
+	for (i = 0; i < MAX_LOGICAL_UNIT; i++) {
+		ISTGT_LU_Ptr lu = istgt->logical_unit[i];
+		if (lu == NULL)
+			continue;
+		if (lu->to_add)
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "newly added LUN %s\n", lu->name);
+		if (lu->to_remove)
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "newly removed LUN %s\n", lu->name);
+	}
+
+	/* creat new threads for new LUNs, do work in luworker() */
+	/* create LUN threads for command queuing */
+	rc = istgt_lu_create_threads(istgt, 1);
+	if (rc < 0) {
+		ISTGT_ERRLOG("lu_create_threads() failed\n");
+		istgt_free_config(config);
+		return UCTL_CMD_ERR;
+	}
+	/* start taking IOs */
+	for (i = 0; i < MAX_LOGICAL_UNIT; i++) {
+		ISTGT_LU_Ptr lu = istgt->logical_unit[i];
+		if (lu == NULL)
+			continue;
+		if (lu->to_add) {
+			istgt_lu_set_state(lu, ISTGT_STATE_RUNNING);
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "set newly added LUN as running %s\n", lu->name);
+		}
+	}
+
+	/* step 3: shutdown removed LUNs */
+	/* clear outstanding IOs */
+	for (i = 0; i < MAX_LOGICAL_UNIT; i++) {
+		ISTGT_LU_Ptr lu = istgt->logical_unit[i];
+		if (lu == NULL)
+			continue;
+		if (lu->to_remove) {
+			for (j = 0; j<lu->maxlun; j++)
+				istgt_lu_clear_all_task(lu, j);
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "clear newly removed LUN queue %s\n", lu
+->name);
+		}
+	}
+
+	/* sync and close LUNs */
+	istgt_lu_shutdown(istgt, 1);
+
+	/* clear tag of to_add/to_remove, get ready for next refresh */
+	for (i = 0; i < MAX_LOGICAL_UNIT; i++) {
+		ISTGT_LU_Ptr lu = istgt->logical_unit[i];
+		if (lu == NULL)
+			continue;
+		if (lu->to_add)
+			lu->to_add = 0;
+		if (lu->to_remove)
+			lu->to_remove = 0;
+	}
+
+	/* logging event */
+	ISTGT_NOTICELOG("Configuration refresh requested from %s\n",
+	    uctl->caddr);
+
+	/* refresh succeeded */
+	istgt_uctl_snprintf(uctl, "OK %s\n", uctl->cmd);
+	rc = istgt_uctl_writeline(uctl);
+	if (rc != UCTL_CMD_OK)
+		return rc;
+	return UCTL_CMD_OK;
+}
+
+ static int
+ istgt_uctl_cmd_reset(UCTL_Ptr uctl)
+ {
+@@ -1183,6 +1290,7 @@ static ISTGT_UCTL_CMD_TABLE istgt_uctl_cmd_table[] =
+ 	{ "UNLOAD",  istgt_uctl_cmd_unload },
+ 	{ "LOAD",    istgt_uctl_cmd_load },
+ 	{ "CHANGE",  istgt_uctl_cmd_change },
+	{ "REFRESH", istgt_uctl_cmd_refresh },
+ 	{ "RESET",   istgt_uctl_cmd_reset },
+ 	{ "INFO",    istgt_uctl_cmd_info },
+ 	{ NULL,      NULL },
+diff --git src/istgt_lu_disk.c src/istgt_lu_disk.c
+index 84eff07..40c9402 100644
+--- src/istgt_lu_disk.c
+++ src/istgt_lu_disk.c
+@@ -794,6 +794,7 @@ istgt_lu_disk_shutdown(ISTGT_Ptr istgt, ISTGT_LU_Ptr lu)
+ 		xfree(spec);
+ 		lu->lun[i].spec = NULL;
+ 	}
+	lu->maxlun = 0;
+ 
+ 	return 0;
+ }
+diff --git src/istgt_proto.h src/istgt_proto.h
+index 8318f64..9bc842a 100644
+--- src/istgt_proto.h
+++ src/istgt_proto.h
+@@ -85,10 +85,10 @@ int istgt_lu_parse_media_flags(const char *flags);
+ uint64_t istgt_lu_parse_media_size(const char *file, const char *size, int *flags);
+ PORTAL *istgt_lu_find_portalgroup(ISTGT_Ptr istgt, int tag);
+ INITIATOR_GROUP *istgt_lu_find_initiatorgroup(ISTGT_Ptr istgt, int tag);
+-int istgt_lu_init(ISTGT_Ptr istgt);
+int istgt_lu_init(ISTGT_Ptr istgt, int ignore_dup);
+ int istgt_lu_set_all_state(ISTGT_Ptr istgt, ISTGT_STATE state);
+-int istgt_lu_create_threads(ISTGT_Ptr istgt);
+-int istgt_lu_shutdown(ISTGT_Ptr istgt);
+int istgt_lu_create_threads(ISTGT_Ptr istgt, int new_only);
+int istgt_lu_shutdown(ISTGT_Ptr istgt, int removed_only);
+ int istgt_lu_islun2lun(uint64_t islun);
+ uint64_t istgt_lu_lun2islun(int lun, int maxlun);
+ int istgt_lu_reset(ISTGT_LU_Ptr lu, uint64_t lun);
+diff --git src/istgtcontrol.c src/istgtcontrol.c
+index 46d6e98..489691d 100644
+--- src/istgtcontrol.c
+++ src/istgtcontrol.c
+@@ -494,6 +494,36 @@ exec_change(UCTL_Ptr uctl)
+ }
+ 
+ static int
+exec_refresh(UCTL_Ptr uctl)
+{
+	const char *delim = ARGS_DELIM;
+	char *arg;
+	char *result;
+	int rc;
+
+	/* send command */
+	uctl_snprintf(uctl, "REFRESH \n");
+	rc = uctl_writeline(uctl);
+	if (rc != UCTL_CMD_OK)
+		return rc;
+
+	/* receive result */
+	rc = uctl_readline(uctl);
+	if (rc != UCTL_CMD_OK)
+		return rc;
+	arg = trim_string(uctl->recvbuf);
+	result = strsepq(&arg, delim);
+	strupr(result);
+	if (strcmp(result, "OK") != 0) {
+		if (is_err_req_auth(uctl, arg))
+			return UCTL_CMD_REQAUTH;
+		fprintf(stderr, "ERROR %s\n", arg);
+		return UCTL_CMD_ERR;
+	}
+	return UCTL_CMD_OK;
+}
+
+static int
+ exec_reset(UCTL_Ptr uctl)
+ {
+ 	const char *delim = ARGS_DELIM;
+@@ -591,6 +621,7 @@ static EXEC_TABLE exec_table[] =
+ 	{ "UNLOAD",  exec_unload,   0, 1 },
+ 	{ "LOAD",    exec_load,     0, 1 },
+ 	{ "CHANGE",  exec_change,   1, 1 },
+	{ "REFRESH", exec_refresh,  0, 0 },
+ 	{ "RESET",   exec_reset,    0, 1 },
+ 	{ "INFO",    exec_info,     0, 0 },
+ 	{ NULL,      NULL,          0, 0 },
+@@ -1054,6 +1085,7 @@ usage(void)
+ 	printf(" load       load media to specified unit\n");
+ 	printf(" unload     unload media from specified unit\n");
+ 	printf(" change     change media with <file> at specified unit\n");
+	printf(" refresh    refresh to reload target and lun configuration\n");
+ 	printf(" reset      reset specified lun of target\n");
+ 	printf(" info       show connections of target\n");
+ }
--- a/net/openistgt/Makefile
+++ b/net/openistgt/Makefile
@ -7,6 +7,7 @@

 PORTNAME=	istgt
 PORTVERSION=	20111008
+PORTREVISION=	1
 CATEGORIES=	net
 MASTER_SITES=	http://www.peach.ne.jp/archives/istgt/

--- a/net/openistgt/files/patch-istgt-rc
+++ b/net/openistgt/files/patch-istgt-rc
@ -0,0 +1,25 @@
+--- etc/istgt.sh.in.orig	2011-08-31 11:53:08.000000000 -0700
+++ etc/istgt.sh.in	2012-03-07 17:12:49.615160257 -0800
+@@ -9,6 +9,7 @@
+ 
+ name="istgt"
+ rcvar=`set_rcvar`
+reload_cmd="istgt_reload"
+ extra_commands="reload"
+ 
+ load_rc_config $name
+@@ -18,6 +19,14 @@
+ : ${istgt_pidfile="/var/run/istgt.pid"}
+ : ${istgt_flags=""}
+ 
+#
+# Refresh configuration
+#
+istgt_reload()
+{
+	%%BINDIR%%/istgtcontrol refresh
+}
+
+ required_files="${istgt_config}"
+ pidfile="${istgt_pidfile}"
+ command="%%BINDIR%%/istgt"
--- a/net/openistgt/files/patch-istgt-reload
+++ b/net/openistgt/files/patch-istgt-reload
@ -0,0 +1,438 @@
+diff --git src/istgt.c src/istgt.c
+index e62de97..8fd509e 100644
+--- src/istgt.c
+++ src/istgt.c
+@@ -71,6 +71,7 @@
+ #define PORTNUMLEN 32
+ 
+ ISTGT g_istgt;
+const char  *g_config_file;
+ 
+ #if 0
+ void
+@@ -1598,6 +1599,7 @@ main(int argc, char **argv)
+ 
+ 	/* read config files */
+ 	config = istgt_allocate_config();
+	g_config_file = config_file;
+ 	rc = istgt_read_config(config, config_file);
+ 	if (rc < 0) {
+ 		fprintf(stderr, "config error\n");
+@@ -1662,7 +1664,7 @@ main(int argc, char **argv)
+ 		istgt_free_config(config);
+ 		exit(EXIT_FAILURE);
+ 	}
+-	rc = istgt_lu_init(istgt);
+	rc = istgt_lu_init(istgt, 0);
+ 	if (rc < 0) {
+ 		ISTGT_ERRLOG("istgt_lu_init() failed\n");
+ 		goto initialize_error;
+@@ -1772,7 +1774,7 @@ main(int argc, char **argv)
+ #endif
+ 
+ 	/* create LUN threads for command queuing */
+-	rc = istgt_lu_create_threads(istgt);
+	rc = istgt_lu_create_threads(istgt, 0);
+ 	if (rc < 0) {
+ 		ISTGT_ERRLOG("lu_create_threads() failed\n");
+ 		goto initialize_error;
+@@ -1809,7 +1811,7 @@ main(int argc, char **argv)
+ 		istgt_close_portal(istgt);
+ 		istgt_close_uctl_portal(istgt);
+ 		istgt_iscsi_shutdown(istgt);
+-		istgt_lu_shutdown(istgt);
+		istgt_lu_shutdown(istgt, 0);
+ 		istgt_destory_initiator_group_array(istgt);
+ 		istgt_destroy_portal_array(istgt);
+ 		istgt_destroy_uctl_portal(istgt);
+@@ -1837,7 +1839,7 @@ main(int argc, char **argv)
+ 	istgt_close_portal(istgt);
+ 	istgt_close_uctl_portal(istgt);
+ 	istgt_iscsi_shutdown(istgt);
+-	istgt_lu_shutdown(istgt);
+	istgt_lu_shutdown(istgt, 0);
+ 	istgt_destory_initiator_group_array(istgt);
+ 	istgt_destroy_portal_array(istgt);
+ 	istgt_destroy_uctl_portal(istgt);
+diff --git src/istgt_lu.c src/istgt_lu.c
+index 783f809..c0c4f31 100644
+--- src/istgt_lu.c
+++ src/istgt_lu.c
+@@ -1202,7 +1202,7 @@ istgt_lu_set_local_settings(ISTGT_Ptr istgt, CF_SECTION *sp, ISTGT_LU_Ptr lu)
+ }
+ 
+ static int
+-istgt_lu_add_unit(ISTGT_Ptr istgt, CF_SECTION *sp)
+istgt_lu_add_unit(ISTGT_Ptr istgt, CF_SECTION *sp, int ignore_dup)
+ {
+ 	char buf[MAX_TMPBUF], buf2[MAX_TMPBUF];
+ 	ISTGT_LU_Ptr lu;
+@@ -1222,21 +1222,40 @@ istgt_lu_add_unit(ISTGT_Ptr istgt, CF_SECTION *sp)
+ 	int i, j, k;
+ 	int rc;
+ 
+-	ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "add unit %d\n", sp->num);
+	ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "add unit %d (ignore dup = %d)\n", sp->num, ignore_dup);
+ 
+ 	if (sp->num >= MAX_LOGICAL_UNIT) {
+ 		ISTGT_ERRLOG("LU%d: over maximum unit number\n", sp->num);
+ 		return -1;
+ 	}
+-	if (istgt->logical_unit[sp->num] != NULL) {
+	if (istgt->logical_unit[sp->num] != NULL && !ignore_dup) {
+ 		ISTGT_ERRLOG("LU%d: duplicate unit\n", sp->num);
+ 		return -1;
+ 	}
+	/* existing LUNs */
+	if (istgt->logical_unit[sp->num] != NULL && ignore_dup) {
+		istgt->logical_unit[sp->num]->to_add = 0;
+		istgt->logical_unit[sp->num]->to_remove = 0;
+		ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "skip existing unit %d\n", sp->num);
+		return 0;
+	}
+
+	/* new LUNs */
+	if (istgt->logical_unit[sp->num] == NULL && ignore_dup) {
+		ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "add NEW unit %d\n", sp->num);
+	}
+ 
+ 	lu = xmalloc(sizeof *lu);
+ 	memset(lu, 0, sizeof *lu);
+ 	lu->num = sp->num;
+ 	lu->istgt = istgt;
+
+	/* tag new LUNs */
+	if (ignore_dup) {
+		lu->to_add = 1;
+		lu->to_remove = 0;
+	}
+
+ 	istgt_lu_set_state(lu, ISTGT_STATE_INVALID);
+ 	nbs64 = istgt_lu_get_nbserial(istgt->nodebase);
+ #if 0
+@@ -1944,12 +1963,15 @@ istgt_lu_del_unit(ISTGT_Ptr istgt, ISTGT_LU_Ptr lu)
+ static void *luworker(void *arg);
+ 
+ int
+-istgt_lu_init(ISTGT_Ptr istgt)
+istgt_lu_init(ISTGT_Ptr istgt, int ignore_dup)
+ {
+ 	ISTGT_LU_Ptr lu;
+ 	CF_SECTION *sp;
+ 	int rc;
+ 	int i;
+	int lun_map[MAX_LOGICAL_UNIT];
+
+	memset(lun_map, 0, sizeof(int) * MAX_LOGICAL_UNIT);
+ 
+ 	ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "istgt_lu_init\n");
+ 	sp = istgt_find_cf_section(istgt->config, "Global");
+@@ -1969,11 +1991,12 @@ istgt_lu_init(ISTGT_Ptr istgt)
+ 				ISTGT_ERRLOG("tag %d is invalid\n", sp->num);
+ 				return -1;
+ 			}
+-			rc = istgt_lu_add_unit(istgt, sp);
+			rc = istgt_lu_add_unit(istgt, sp, ignore_dup);
+ 			if (rc < 0) {
+ 				ISTGT_ERRLOG("lu_add_unit() failed\n");
+ 				return -1;
+ 			}
+			lun_map[sp->num] = 1; /* in new LUN list */
+ 		}
+ 		sp = sp->next;
+ 	}
+@@ -1982,6 +2005,22 @@ istgt_lu_init(ISTGT_Ptr istgt)
+ 		lu = istgt->logical_unit[i];
+ 		if (lu == NULL)
+ 			continue;
+		/* tag to be removed LUNs */
+		if (lun_map[i] == 0) {
+			istgt->logical_unit[i]->to_add = 0;
+			istgt->logical_unit[i]->to_remove = 1;
+			continue;
+		}
+		/* only process newly added LUNs here beyond in loop */
+		if (ignore_dup &&
+		    (istgt->logical_unit[i]->to_add == 1 &&
+		     istgt->logical_unit[i]->to_remove == 0)) {
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "adding unit %d\n", i);
+		} else if (ignore_dup &&
+		    !(istgt->logical_unit[i]->to_add == 1 &&
+		      istgt->logical_unit[i]->to_remove == 0)) {
+			continue;
+		}
+ 
+ 		rc = pthread_mutex_init(&lu->mutex, NULL);
+ 		if (rc != 0) {
+@@ -2069,7 +2108,7 @@ istgt_lu_set_all_state(ISTGT_Ptr istgt, ISTGT_STATE state)
+ }
+ 
+ int
+-istgt_lu_create_threads(ISTGT_Ptr istgt)
+istgt_lu_create_threads(ISTGT_Ptr istgt, int new_only)
+ {
+ #ifdef HAVE_PTHREAD_SET_NAME_NP
+ 	char buf[MAX_TMPBUF];
+@@ -2084,6 +2123,10 @@ istgt_lu_create_threads(ISTGT_Ptr istgt)
+ 		lu = istgt->logical_unit[i];
+ 		if (lu == NULL)
+ 			continue;
+		if (new_only && !lu->to_add) {
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "skip existing LUN %d\n", i);
+			continue;
+		}
+ 
+ 		if (lu->queue_depth != 0) {
+ 			/* create LU thread */
+@@ -2114,18 +2157,22 @@ istgt_lu_create_threads(ISTGT_Ptr istgt)
+ }
+ 
+ int
+-istgt_lu_shutdown(ISTGT_Ptr istgt)
+istgt_lu_shutdown(ISTGT_Ptr istgt, int removed_only)
+ {
+ 	ISTGT_LU_Ptr lu;
+ 	int rc;
+ 	int i;
+ 
+-	ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "istgt_lu_shutdown\n");
+	ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "istgt_lu_shutdown (removed_only = %d\n", removed_only);
+ 
+ 	for (i = 0; i < MAX_LOGICAL_UNIT; i++) {
+ 		lu = istgt->logical_unit[i];
+ 		if (lu == NULL)
+ 			continue;
+		if (removed_only && !lu->to_remove) {
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "skip existing LUNs %d\n", i);
+			continue;
+		}
+ 		istgt_lu_set_state(lu, ISTGT_STATE_SHUTDOWN);
+ 
+ 		switch (lu->type) {
+diff --git src/istgt_lu.h src/istgt_lu.h
+index 72c5a6c..9484266 100644
+--- src/istgt_lu.h
+++ src/istgt_lu.h
+@@ -236,6 +236,9 @@ typedef struct istgt_lu_t {
+ 	ISTGT_LU_TSIH tsih[MAX_LU_TSIH];
+ 	int maxmap;
+ 	ISTGT_LU_MAP map[MAX_LU_MAP];
+
+	int to_add;
+	int to_remove;
+ } ISTGT_LU;
+ typedef ISTGT_LU *ISTGT_LU_Ptr;
+ 
+diff --git src/istgt_lu_ctl.c src/istgt_lu_ctl.c
+index 70c93e1..47e2fd3 100644
+--- src/istgt_lu_ctl.c
+++ src/istgt_lu_ctl.c
+@@ -965,6 +965,113 @@ istgt_uctl_cmd_change(UCTL_Ptr uctl)
+ 	return UCTL_CMD_OK;
+ }
+ 
+extern const char *g_config_file;
+extern ISTGT g_istgt;
+
+static int
+istgt_uctl_cmd_refresh(UCTL_Ptr uctl)
+{
+	char *arg;
+	int rc, i, j;
+	CONFIG *config;
+	ISTGT_Ptr istgt;
+
+	arg = uctl->arg;
+	istgt = &g_istgt;
+
+	/* reload config, might add/remove LUNs */
+	/* step 1: re-read config files */
+	config = istgt_allocate_config();
+	rc = istgt_read_config(config, g_config_file);
+	if (rc < 0) {
+		fprintf(stderr, "refresh config error\n");
+		return UCTL_CMD_ERR;
+	}
+	if (config->section == NULL) {
+		fprintf(stderr, "empty config\n");
+		istgt_free_config(config);
+		return UCTL_CMD_ERR;
+	}
+	istgt_free_config(istgt->config);
+	istgt->config = config;
+
+	/* step 2: add new units, init new LUNs, tag to-add/remove LUNs */
+	rc = istgt_lu_init(istgt, 1);
+	if (rc < 0) {
+		ISTGT_ERRLOG("istgt_lu_init() failed\n");
+		istgt_free_config(config);
+		return UCTL_CMD_ERR;
+	}
+
+	for (i = 0; i < MAX_LOGICAL_UNIT; i++) {
+		ISTGT_LU_Ptr lu = istgt->logical_unit[i];
+		if (lu == NULL)
+			continue;
+		if (lu->to_add)
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "newly added LUN %s\n", lu->name);
+		if (lu->to_remove)
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "newly removed LUN %s\n", lu->name);
+	}
+
+	/* creat new threads for new LUNs, do work in luworker() */
+	/* create LUN threads for command queuing */
+	rc = istgt_lu_create_threads(istgt, 1);
+	if (rc < 0) {
+		ISTGT_ERRLOG("lu_create_threads() failed\n");
+		istgt_free_config(config);
+		return UCTL_CMD_ERR;
+	}
+	/* start taking IOs */
+	for (i = 0; i < MAX_LOGICAL_UNIT; i++) {
+		ISTGT_LU_Ptr lu = istgt->logical_unit[i];
+		if (lu == NULL)
+			continue;
+		if (lu->to_add) {
+			istgt_lu_set_state(lu, ISTGT_STATE_RUNNING);
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "set newly added LUN as running %s\n", lu->name);
+		}
+	}
+
+	/* step 3: shutdown removed LUNs */
+	/* clear outstanding IOs */
+	for (i = 0; i < MAX_LOGICAL_UNIT; i++) {
+		ISTGT_LU_Ptr lu = istgt->logical_unit[i];
+		if (lu == NULL)
+			continue;
+		if (lu->to_remove) {
+			for (j = 0; j<lu->maxlun; j++)
+				istgt_lu_clear_all_task(lu, j);
+			ISTGT_TRACELOG(ISTGT_TRACE_DEBUG, "clear newly removed LUN queue %s\n", lu
+->name);
+		}
+	}
+
+	/* sync and close LUNs */
+	istgt_lu_shutdown(istgt, 1);
+
+	/* clear tag of to_add/to_remove, get ready for next refresh */
+	for (i = 0; i < MAX_LOGICAL_UNIT; i++) {
+		ISTGT_LU_Ptr lu = istgt->logical_unit[i];
+		if (lu == NULL)
+			continue;
+		if (lu->to_add)
+			lu->to_add = 0;
+		if (lu->to_remove)
+			lu->to_remove = 0;
+	}
+
+	/* logging event */
+	ISTGT_NOTICELOG("Configuration refresh requested from %s\n",
+	    uctl->caddr);
+
+	/* refresh succeeded */
+	istgt_uctl_snprintf(uctl, "OK %s\n", uctl->cmd);
+	rc = istgt_uctl_writeline(uctl);
+	if (rc != UCTL_CMD_OK)
+		return rc;
+	return UCTL_CMD_OK;
+}
+
+ static int
+ istgt_uctl_cmd_reset(UCTL_Ptr uctl)
+ {
+@@ -1183,6 +1290,7 @@ static ISTGT_UCTL_CMD_TABLE istgt_uctl_cmd_table[] =
+ 	{ "UNLOAD",  istgt_uctl_cmd_unload },
+ 	{ "LOAD",    istgt_uctl_cmd_load },
+ 	{ "CHANGE",  istgt_uctl_cmd_change },
+	{ "REFRESH", istgt_uctl_cmd_refresh },
+ 	{ "RESET",   istgt_uctl_cmd_reset },
+ 	{ "INFO",    istgt_uctl_cmd_info },
+ 	{ NULL,      NULL },
+diff --git src/istgt_lu_disk.c src/istgt_lu_disk.c
+index 84eff07..40c9402 100644
+--- src/istgt_lu_disk.c
+++ src/istgt_lu_disk.c
+@@ -794,6 +794,7 @@ istgt_lu_disk_shutdown(ISTGT_Ptr istgt, ISTGT_LU_Ptr lu)
+ 		xfree(spec);
+ 		lu->lun[i].spec = NULL;
+ 	}
+	lu->maxlun = 0;
+ 
+ 	return 0;
+ }
+diff --git src/istgt_proto.h src/istgt_proto.h
+index 8318f64..9bc842a 100644
+--- src/istgt_proto.h
+++ src/istgt_proto.h
+@@ -85,10 +85,10 @@ int istgt_lu_parse_media_flags(const char *flags);
+ uint64_t istgt_lu_parse_media_size(const char *file, const char *size, int *flags);
+ PORTAL *istgt_lu_find_portalgroup(ISTGT_Ptr istgt, int tag);
+ INITIATOR_GROUP *istgt_lu_find_initiatorgroup(ISTGT_Ptr istgt, int tag);
+-int istgt_lu_init(ISTGT_Ptr istgt);
+int istgt_lu_init(ISTGT_Ptr istgt, int ignore_dup);
+ int istgt_lu_set_all_state(ISTGT_Ptr istgt, ISTGT_STATE state);
+-int istgt_lu_create_threads(ISTGT_Ptr istgt);
+-int istgt_lu_shutdown(ISTGT_Ptr istgt);
+int istgt_lu_create_threads(ISTGT_Ptr istgt, int new_only);
+int istgt_lu_shutdown(ISTGT_Ptr istgt, int removed_only);
+ int istgt_lu_islun2lun(uint64_t islun);
+ uint64_t istgt_lu_lun2islun(int lun, int maxlun);
+ int istgt_lu_reset(ISTGT_LU_Ptr lu, uint64_t lun);
+diff --git src/istgtcontrol.c src/istgtcontrol.c
+index 46d6e98..489691d 100644
+--- src/istgtcontrol.c
+++ src/istgtcontrol.c
+@@ -494,6 +494,36 @@ exec_change(UCTL_Ptr uctl)
+ }
+ 
+ static int
+exec_refresh(UCTL_Ptr uctl)
+{
+	const char *delim = ARGS_DELIM;
+	char *arg;
+	char *result;
+	int rc;
+
+	/* send command */
+	uctl_snprintf(uctl, "REFRESH \n");
+	rc = uctl_writeline(uctl);
+	if (rc != UCTL_CMD_OK)
+		return rc;
+
+	/* receive result */
+	rc = uctl_readline(uctl);
+	if (rc != UCTL_CMD_OK)
+		return rc;
+	arg = trim_string(uctl->recvbuf);
+	result = strsepq(&arg, delim);
+	strupr(result);
+	if (strcmp(result, "OK") != 0) {
+		if (is_err_req_auth(uctl, arg))
+			return UCTL_CMD_REQAUTH;
+		fprintf(stderr, "ERROR %s\n", arg);
+		return UCTL_CMD_ERR;
+	}
+	return UCTL_CMD_OK;
+}
+
+static int
+ exec_reset(UCTL_Ptr uctl)
+ {
+ 	const char *delim = ARGS_DELIM;
+@@ -591,6 +621,7 @@ static EXEC_TABLE exec_table[] =
+ 	{ "UNLOAD",  exec_unload,   0, 1 },
+ 	{ "LOAD",    exec_load,     0, 1 },
+ 	{ "CHANGE",  exec_change,   1, 1 },
+	{ "REFRESH", exec_refresh,  0, 0 },
+ 	{ "RESET",   exec_reset,    0, 1 },
+ 	{ "INFO",    exec_info,     0, 0 },
+ 	{ NULL,      NULL,          0, 0 },
+@@ -1054,6 +1085,7 @@ usage(void)
+ 	printf(" load       load media to specified unit\n");
+ 	printf(" unload     unload media from specified unit\n");
+ 	printf(" change     change media with <file> at specified unit\n");
+	printf(" refresh    refresh to reload target and lun configuration\n");
+ 	printf(" reset      reset specified lun of target\n");
+ 	printf(" info       show connections of target\n");
+ }