nvmf: Correctly unregister nvmf tgt as an I/O device

Change-Id: I9552354d620986c2a3d6b071f32b587e9e683198
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/413861
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>

CHANGELOG.md

@@ -20,6 +20,11 @@ The spdk_mem_map_translate() function now takes a size parameter to indicate the
 the memory region.  This can be used by environment implementations to validate the
 requested translation.
 
+### NVMe Over Fabrics
+
+The spdk_nvmf_tgt_destroy() function is now asynchronous and takes a callback
+as a parameter.
+
 ### git pre-commit and pre-push hooks
 
 The pre-commit hook will run `scripts/check_format.sh` and verify there are no formating

include/spdk/nvmf.h

@@ -85,12 +85,16 @@ void spdk_nvmf_tgt_opts_init(struct spdk_nvmf_tgt_opts *opts);
  */
 struct spdk_nvmf_tgt *spdk_nvmf_tgt_create(struct spdk_nvmf_tgt_opts *opts);
 
+typedef void (spdk_nvmf_tgt_destroy_done_fn)(void *ctx, int status);
+
 /**
  * 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);
+void spdk_nvmf_tgt_destroy(struct spdk_nvmf_tgt *tgt,
+			   spdk_nvmf_tgt_destroy_done_fn cb_fn,
+			   void *cb_arg);
 
 /**
  * Function to be called once the target is listening.

lib/event/subsystems/nvmf/nvmf_tgt.c

@@ -216,6 +216,13 @@ nvmf_tgt_subsystem_stopped(struct spdk_nvmf_subsystem *subsystem,
 	nvmf_tgt_advance_state();
 }
 
+static void
+nvmf_tgt_destroy_done(void *ctx, int status)
+{
+	g_tgt_state = NVMF_TGT_STOPPED;
+	nvmf_tgt_advance_state();
+}
+
 static void
 nvmf_tgt_advance_state(void)
 {
@@ -303,8 +310,7 @@ nvmf_tgt_advance_state(void)
 					     nvmf_tgt_destroy_poll_group_done);
 			break;
 		case NVMF_TGT_FINI_FREE_RESOURCES:
-			spdk_nvmf_tgt_destroy(g_spdk_nvmf_tgt);
+			spdk_nvmf_tgt_destroy(g_spdk_nvmf_tgt, nvmf_tgt_destroy_done, NULL);
-			g_tgt_state = NVMF_TGT_STOPPED;
 			break;
 		case NVMF_TGT_STOPPED:
 			spdk_subsystem_fini_next();

lib/nvmf/nvmf.c

@@ -202,10 +202,13 @@ spdk_nvmf_tgt_create(struct spdk_nvmf_tgt_opts *opts)
 	return tgt;
 }
 
-void
+static void
-spdk_nvmf_tgt_destroy(struct spdk_nvmf_tgt *tgt)
+spdk_nvmf_tgt_destroy_cb(void *io_device)
 {
+	struct spdk_nvmf_tgt *tgt = io_device;
 	struct spdk_nvmf_transport *transport, *transport_tmp;
+	spdk_nvmf_tgt_destroy_done_fn		*destroy_cb_fn;
+	void					*destroy_cb_arg;
 	uint32_t i;
 
 	if (tgt->discovery_log_page) {
@@ -226,7 +229,25 @@ spdk_nvmf_tgt_destroy(struct spdk_nvmf_tgt *tgt)
 		spdk_nvmf_transport_destroy(transport);
 	}
 
+	destroy_cb_fn = tgt->destroy_cb_fn;
+	destroy_cb_arg = tgt->destroy_cb_arg;
+
 	free(tgt);
+
+	if (destroy_cb_fn) {
+		destroy_cb_fn(destroy_cb_arg, 0);
+	}
+}
+
+void
+spdk_nvmf_tgt_destroy(struct spdk_nvmf_tgt *tgt,
+		      spdk_nvmf_tgt_destroy_done_fn cb_fn,
+		      void *cb_arg)
+{
+	tgt->destroy_cb_fn = cb_fn;
+	tgt->destroy_cb_arg = cb_arg;
+
+	spdk_io_device_unregister(tgt, spdk_nvmf_tgt_destroy_cb);
 }
 
 struct spdk_nvmf_tgt_listen_ctx {

lib/nvmf/nvmf_internal.h

@@ -75,6 +75,9 @@ struct spdk_nvmf_tgt {
 	struct spdk_nvmf_discovery_log_page	*discovery_log_page;
 	size_t					discovery_log_page_size;
 	TAILQ_HEAD(, spdk_nvmf_transport)	transports;
+
+	spdk_nvmf_tgt_destroy_done_fn		*destroy_cb_fn;
+	void					*destroy_cb_arg;
 };
 
 struct spdk_nvmf_host {