[PATCH opensm] Add support for synchronizing in memory files with storage

[Hal Rosenstock <hal-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>]

OpenSM produces certain in memory files critical to high availability
operation. These include guid2lid, guid2mkey, and neighbors as well 
as the SA registration database (opensm-sa.dump).

These in memory files can be synchronized with storage immediately
rather than waiting for pdflush daemon to do this.

This is done based on new fsync_high_avail_files option which defaults to true.
In some embedded systems with flash based storage, this option might
be set to false as a tradeoff not to unduly affect OpenSM operation due to
possible long delay to flash storage.

Pointed-out-by: Bart Van Assche <bvanassche-HInyCGIudOg@public.gmane.org> in thread on
"[PATCH opensm] Implement atomic update operation for sa_db_file"
http://marc.info/?l=linux-rdma&m=138436562629008&w=2

Signed-off-by: Hal Rosenstock <hal-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
diff --git a/include/opensm/osm_db.h b/include/opensm/osm_db.h
index 05332c0..e8860f3 100644
--- a/include/opensm/osm_db.h
+++ b/include/opensm/osm_db.h
@@ -288,7 +288,8 @@ int osm_db_clear(IN osm_db_domain_t * p_domain);
 *
 * SYNOPSIS
 */
-int osm_db_store(IN osm_db_domain_t * p_domain);
+int osm_db_store(IN osm_db_domain_t * p_domain,
+		 IN boolean_t fsync_high_avail_files);
 /*
 * PARAMETERS
 *
@@ -296,6 +297,10 @@ int osm_db_store(IN osm_db_domain_t * p_domain);
 *		[in] Pointer to the database domain object to restore from
 *		     persistent db
 *
+*	fsync_high_avail_files
+*		[in] Boolean that indicates whether or not to synchronize
+*		     in-memory high availability files with storage
+*
 * RETURN VALUES
 *	0 if successful 1 otherwize
 *
diff --git a/include/opensm/osm_subnet.h b/include/opensm/osm_subnet.h
index 19f2079..606c63e 100644
--- a/include/opensm/osm_subnet.h
+++ b/include/opensm/osm_subnet.h
@@ -328,6 +328,7 @@ typedef struct osm_subn_opt {
 	boolean_t babbling_port_policy;
 	boolean_t drop_event_subscriptions;
 	boolean_t use_optimized_slvl;
+	boolean_t fsync_high_avail_files;
 	osm_qos_options_t qos_options;
 	osm_qos_options_t qos_ca_options;
 	osm_qos_options_t qos_sw0_options;
@@ -604,6 +605,10 @@ typedef struct osm_subn_opt {
 *		Use optimized SLtoVLMappingTable programming if
 *		device indicates it supports this.
 *
+*	fsync_high_avail_files
+*		Synchronize high availability in memory files
+*		with storage.
+*
 *	perfmgr
 *		Enable or disable the performance manager
 *
diff --git a/opensm/osm_db_files.c b/opensm/osm_db_files.c
index cab7170..9eaba8e 100644
--- a/opensm/osm_db_files.c
+++ b/opensm/osm_db_files.c
@@ -48,6 +48,7 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 #include <opensm/osm_file_ids.h>
 #define FILE_ID OSM_FILE_DB_FILES_C
 #include <opensm/st.h>
@@ -461,12 +462,13 @@ static int dump_tbl_entry(st_data_t key, st_data_t val, st_data_t arg)
 	return ST_CONTINUE;
 }
 
-int osm_db_store(IN osm_db_domain_t * p_domain)
+int osm_db_store(IN osm_db_domain_t * p_domain,
+		 IN boolean_t fsync_high_avail_files)
 {
 	osm_log_t *p_log = p_domain->p_db->p_log;
 	osm_db_domain_imp_t *p_domain_imp;
 	FILE *p_file = NULL;
-	int status = 0;
+	int fd, status = 0;
 	char *p_tmp_file_name = NULL;
 
 	OSM_LOG_ENTER(p_log);
@@ -494,6 +496,21 @@ int osm_db_store(IN osm_db_domain_t * p_domain)
 	}
 
 	st_foreach(p_domain_imp->p_hash, dump_tbl_entry, (st_data_t) p_file);
+
+	if (fsync_high_avail_files) {
+		fd = fileno(p_file);
+		if (fd != -1) {
+			if (fsync(fd) == -1)
+				OSM_LOG(p_log, OSM_LOG_ERROR, "ERR 6110: "
+					"fsync failed (%s) for %s\n",
+					strerror(errno),
+					p_domain_imp->file_name);
+		} else
+			OSM_LOG(p_log, OSM_LOG_ERROR, "ERR 6111: "
+				"fileno() failed for %s\n",
+				p_domain_imp->file_name);
+	}
+
 	fclose(p_file);
 
 	status = rename(p_tmp_file_name, p_domain_imp->file_name);
@@ -734,7 +751,7 @@ int main(int argc, char **argv)
 			printf("key = %s val = %s\n", p_key, p_val);
 		}
 	}
-	if (osm_db_store(p_dbd))
+	if (osm_db_store(p_dbd, FALSE))
 		printf("failed to store\n");
 
 	osm_db_destroy(&db);
diff --git a/opensm/osm_lid_mgr.c b/opensm/osm_lid_mgr.c
index f8a3739..3ba1a79 100644
--- a/opensm/osm_lid_mgr.c
+++ b/opensm/osm_lid_mgr.c
@@ -1233,7 +1233,7 @@ int osm_lid_mgr_process_subnet(IN osm_lid_mgr_t * p_mgr)
 	}			/* all ports */
 
 	/* store the guid to lid table in persistent db */
-	osm_db_store(p_mgr->p_g2l);
+	osm_db_store(p_mgr->p_g2l, p_mgr->p_subn->opt.fsync_high_avail_files);
 
 	CL_PLOCK_RELEASE(p_mgr->p_lock);
 
diff --git a/opensm/osm_sa.c b/opensm/osm_sa.c
index 4b15d39..2b8f01c 100644
--- a/opensm/osm_sa.c
+++ b/opensm/osm_sa.c
@@ -49,6 +49,7 @@
 #include <ctype.h>
 #include <errno.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <complib/cl_qmap.h>
@@ -508,7 +509,7 @@ opensm_dump_to_file(osm_opensm_t * p_osm, const char *file_name,
 	char path[1024];
 	char path_tmp[1032];
 	FILE *file;
-	int status = 0;
+	int fd, status = 0;
 
 	snprintf(path, sizeof(path), "%s/%s",
 		 p_osm->subn.opt.dump_files_dir, file_name);
@@ -527,6 +528,18 @@ opensm_dump_to_file(osm_opensm_t * p_osm, const char *file_name,
 
 	dump_func(p_osm, file);
 
+	if (p_osm->subn.opt.fsync_high_avail_files) {
+		fd = fileno(file);
+		if (fd != -1) {
+			if (fsync(fd) == -1)
+				OSM_LOG(&p_osm->log, OSM_LOG_ERROR, "ERR 4C09: "
+					"fsync failed (%s) for %s\n",
+					strerror(errno), path_tmp);
+		} else
+			OSM_LOG(&p_osm->log, OSM_LOG_ERROR, "ERR 4C0A: "
+				"fileno() failed for %s\n", path_tmp);
+	}
+
 	fclose(file);
 
 	status = rename(path_tmp, path);
diff --git a/opensm/osm_state_mgr.c b/opensm/osm_state_mgr.c
index 10ae17a..85b233d 100644
--- a/opensm/osm_state_mgr.c
+++ b/opensm/osm_state_mgr.c
@@ -1493,8 +1493,9 @@ repeat_discovery:
 		osm_sm_signal(sm, OSM_SIGNAL_SWEEP);
 
 	/* Write a new copy of our persistent guid2mkey database */
-	osm_db_store(sm->p_subn->p_g2m);
-	osm_db_store(sm->p_subn->p_neighbor);
+	osm_db_store(sm->p_subn->p_g2m, sm->p_subn->opt.fsync_high_avail_files);
+	osm_db_store(sm->p_subn->p_neighbor,
+		     sm->p_subn->opt.fsync_high_avail_files);
 }
 
 static void do_process_mgrp_queue(osm_sm_t * sm)
diff --git a/opensm/osm_subnet.c b/opensm/osm_subnet.c
index f7b6942..b69b54e 100644
--- a/opensm/osm_subnet.c
+++ b/opensm/osm_subnet.c
@@ -778,6 +778,7 @@ static const opt_rec_t opt_tbl[] = {
 	{ "babbling_port_policy", OPT_OFFSET(babbling_port_policy), opts_parse_boolean, NULL, 1 },
 	{ "drop_event_subscriptions", OPT_OFFSET(drop_event_subscriptions), opts_parse_boolean, NULL, 1 },
 	{ "use_optimized_slvl", OPT_OFFSET(use_optimized_slvl), opts_parse_boolean, NULL, 1 },
+	{ "fsync_high_avail_files", OPT_OFFSET(fsync_high_avail_files), opts_parse_boolean, NULL, 1 },
 #ifdef ENABLE_OSM_PERF_MGR
 	{ "perfmgr", OPT_OFFSET(perfmgr), opts_parse_boolean, NULL, 0 },
 	{ "perfmgr_redir", OPT_OFFSET(perfmgr_redir), opts_parse_boolean, NULL, 0 },
@@ -1483,6 +1484,7 @@ void osm_subn_set_default_opt(IN osm_subn_opt_t * p_opt)
 	p_opt->babbling_port_policy = FALSE;
 	p_opt->drop_event_subscriptions = FALSE;
 	p_opt->use_optimized_slvl = FALSE;
+	p_opt->fsync_high_avail_files = TRUE;
 #ifdef ENABLE_OSM_PERF_MGR
 	p_opt->perfmgr = FALSE;
 	p_opt->perfmgr_redir = TRUE;
@@ -2538,12 +2540,15 @@ int osm_subn_output_conf(FILE *out, IN osm_subn_opt_t * p_opts)
 		"# Drop event subscriptions (InformInfo) if the port goes away\n"
 		"drop_event_subscriptions %s\n\n"
 		"# Use Optimized SLtoVLMapping programming if supported by device\n"
-		"use_optimized_slvl %s\n\n",
+		"use_optimized_slvl %s\n\n"
+		"# Sync in memory files used for high availability with storage\n"
+		"fsync_high_avail_files %s\n\n",
 		p_opts->daemon ? "TRUE" : "FALSE",
 		p_opts->sm_inactive ? "TRUE" : "FALSE",
 		p_opts->babbling_port_policy ? "TRUE" : "FALSE",
 		p_opts->drop_event_subscriptions ? "TRUE" : "FALSE",
-		p_opts->use_optimized_slvl ? "TRUE" : "FALSE");
+		p_opts->use_optimized_slvl ? "TRUE" : "FALSE",
+		p_opts->fsync_high_avail_files ? "TRUE" : "FALSE");
 
 #ifdef ENABLE_OSM_PERF_MGR
 	fprintf(out,
--
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