nvmf: spdk_nvmf_tgt_init is now spdk_nvmf_tgt_create

This new function returns a reference to the target
object. This sets the library up to support multiple
targets in the future.

Change-Id: Id803dbcbb166eca33d8d5c381d9db97628606f3e
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/374877
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

app/nvmf_tgt/conf.c

@@ -181,10 +181,10 @@ spdk_nvmf_parse_nvmf_tgt(void)
 	}
 	g_spdk_nvmf_tgt_conf.acceptor_poll_rate = acceptor_poll_rate;
 
-	rc = spdk_nvmf_tgt_init(&opts);
+	g_tgt = spdk_nvmf_tgt_create(&opts);
-	if (rc != 0) {
+	if (!g_tgt) {
-		SPDK_ERRLOG("spdk_nvmf_tgt_init() failed\n");
+		SPDK_ERRLOG("spdk_nvmf_tgt_create() failed\n");
-		return rc;
+		return -1;
 	}
 
 	rc = spdk_add_nvmf_discovery_subsystem();

app/nvmf_tgt/nvmf_tgt.c

@@ -40,6 +40,8 @@
 #include "spdk/log.h"
 #include "spdk/nvme.h"
 
+struct spdk_nvmf_tgt *g_tgt = NULL;
+
 static struct spdk_poller *g_acceptor_poller = NULL;
 
 static TAILQ_HEAD(, nvmf_tgt_subsystem) g_subsystems = TAILQ_HEAD_INITIALIZER(g_subsystems);
@@ -63,7 +65,7 @@ subsystem_delete_event(void *arg1, void *arg2)
 	spdk_nvmf_delete_subsystem(subsystem);
 
 	if (g_subsystems_shutdown && TAILQ_EMPTY(&g_subsystems)) {
-		spdk_nvmf_tgt_fini();
+		spdk_nvmf_tgt_destroy(g_tgt);
 		/* Finished shutting down all subsystems - continue the shutdown process. */
 		shutdown_complete();
 	}

app/nvmf_tgt/nvmf_tgt.h

@@ -63,6 +63,8 @@ struct nvmf_tgt_subsystem {
 
 extern struct spdk_nvmf_tgt_conf g_spdk_nvmf_tgt_conf;
 
+extern struct spdk_nvmf_tgt *g_tgt;
+
 struct nvmf_tgt_subsystem *
 nvmf_tgt_subsystem_first(void);
 

include/spdk/nvmf.h

@@ -48,6 +48,8 @@
 #define MAX_VIRTUAL_NAMESPACE 16
 #define MAX_SN_LEN 20
 
+struct spdk_nvmf_tgt;
+
 struct spdk_nvmf_tgt_opts {
 	uint16_t max_queue_depth;
 	uint16_t max_qpairs_per_ctrlr;
@@ -57,9 +59,20 @@ struct spdk_nvmf_tgt_opts {
 
 void spdk_nvmf_tgt_opts_init(struct spdk_nvmf_tgt_opts *opts);
 
-int spdk_nvmf_tgt_init(struct spdk_nvmf_tgt_opts *opts);
+/**
+ * Construct an NVMe-oF target
+ *
+ * \param opts Options
+ * \return An spdk_nvmf_tgt on success, NULL on failure.
+ */
+struct spdk_nvmf_tgt *spdk_nvmf_tgt_create(struct spdk_nvmf_tgt_opts *opts);
 
-int spdk_nvmf_tgt_fini(void);
+/**
+ * Destroy an NVMe-oF target
+ *
+ * \param tgt The target to destroy. This releases all resources.
+ */
+void spdk_nvmf_tgt_destroy(struct spdk_nvmf_tgt *tgt);
 
 int spdk_nvmf_check_pools(void);
 

lib/nvmf/nvmf.c

@@ -62,52 +62,54 @@ spdk_nvmf_tgt_opts_init(struct spdk_nvmf_tgt_opts *opts)
 	opts->max_io_size = SPDK_NVMF_DEFAULT_MAX_IO_SIZE;
 }
 
-int
+struct spdk_nvmf_tgt *
-spdk_nvmf_tgt_init(struct spdk_nvmf_tgt_opts *opts)
+spdk_nvmf_tgt_create(struct spdk_nvmf_tgt_opts *opts)
 {
+	struct spdk_nvmf_tgt *tgt;
+
+	tgt = &g_nvmf_tgt;
+
 	if (!opts) {
-		spdk_nvmf_tgt_opts_init(&g_nvmf_tgt.opts);
+		spdk_nvmf_tgt_opts_init(&tgt->opts);
 	} else {
-		g_nvmf_tgt.opts = *opts;
+		tgt->opts = *opts;
 	}
 
-	g_nvmf_tgt.discovery_genctr = 0;
+	tgt->discovery_genctr = 0;
-	g_nvmf_tgt.discovery_log_page = NULL;
+	tgt->discovery_log_page = NULL;
-	g_nvmf_tgt.discovery_log_page_size = 0;
+	tgt->discovery_log_page_size = 0;
-	g_nvmf_tgt.current_subsystem_id = 0;
+	tgt->current_subsystem_id = 0;
-	TAILQ_INIT(&g_nvmf_tgt.subsystems);
+	TAILQ_INIT(&tgt->subsystems);
-	TAILQ_INIT(&g_nvmf_tgt.listen_addrs);
+	TAILQ_INIT(&tgt->listen_addrs);
-	TAILQ_INIT(&g_nvmf_tgt.transports);
+	TAILQ_INIT(&tgt->transports);
 
 	SPDK_TRACELOG(SPDK_TRACE_NVMF, "Max Queue Pairs Per Controller: %d\n",
-		      g_nvmf_tgt.opts.max_qpairs_per_ctrlr);
+		      tgt->opts.max_qpairs_per_ctrlr);
-	SPDK_TRACELOG(SPDK_TRACE_NVMF, "Max Queue Depth: %d\n", g_nvmf_tgt.opts.max_queue_depth);
+	SPDK_TRACELOG(SPDK_TRACE_NVMF, "Max Queue Depth: %d\n", tgt->opts.max_queue_depth);
 	SPDK_TRACELOG(SPDK_TRACE_NVMF, "Max In Capsule Data: %d bytes\n",
-		      g_nvmf_tgt.opts.in_capsule_data_size);
+		      tgt->opts.in_capsule_data_size);
-	SPDK_TRACELOG(SPDK_TRACE_NVMF, "Max I/O Size: %d bytes\n", g_nvmf_tgt.opts.max_io_size);
+	SPDK_TRACELOG(SPDK_TRACE_NVMF, "Max I/O Size: %d bytes\n", tgt->opts.max_io_size);
 
-	return 0;
+	return tgt;
 }
 
-int
+void
-spdk_nvmf_tgt_fini(void)
+spdk_nvmf_tgt_destroy(struct spdk_nvmf_tgt *tgt)
 {
 	struct spdk_nvmf_listen_addr *listen_addr, *listen_addr_tmp;
 	struct spdk_nvmf_transport *transport, *transport_tmp;
 
-	TAILQ_FOREACH_SAFE(listen_addr, &g_nvmf_tgt.listen_addrs, link, listen_addr_tmp) {
+	TAILQ_FOREACH_SAFE(listen_addr, &tgt->listen_addrs, link, listen_addr_tmp) {
-		TAILQ_REMOVE(&g_nvmf_tgt.listen_addrs, listen_addr, link);
+		TAILQ_REMOVE(&tgt->listen_addrs, listen_addr, link);
-		g_nvmf_tgt.discovery_genctr++;
+		tgt->discovery_genctr++;
 
 		spdk_nvmf_listen_addr_destroy(listen_addr);
 	}
 
-	TAILQ_FOREACH_SAFE(transport, &g_nvmf_tgt.transports, link, transport_tmp) {
+	TAILQ_FOREACH_SAFE(transport, &tgt->transports, link, transport_tmp) {
-		TAILQ_REMOVE(&g_nvmf_tgt.transports, transport, link);
+		TAILQ_REMOVE(&tgt->transports, transport, link);
 		spdk_nvmf_transport_destroy(transport);
 	}
-
-	return 0;
 }
 
 struct spdk_nvmf_transport *