bdev/ftl: Examine config support

Bdev FTL is dependent on base bdev and cache
bdev. Allow for examine config if dependent
bdevs are not ready during bdev FTL creation.

Change-Id: I917994d7015f3b74a29ccd066f0c6989ad3c1c4e
Signed-off-by: Wojciech Malikowski <wojciech.malikowski@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/471375
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Broadcom SPDK FC-NVMe CI <spdk-ci.pdl@broadcom.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Konrad Sztyber <konrad.sztyber@intel.com>

module/bdev/ftl/bdev_ftl.c

@@ -90,8 +90,11 @@ struct ftl_deferred_init {
 	LIST_ENTRY(ftl_deferred_init)	entry;
 };
 
+static LIST_HEAD(, ftl_deferred_init)	g_deferred_init = LIST_HEAD_INITIALIZER(g_deferred_init);
+
 static int bdev_ftl_initialize(void);
 static void bdev_ftl_finish(void);
+static void bdev_ftl_examine(struct spdk_bdev *bdev);
 
 static int
 bdev_ftl_get_ctx_size(void)
@@ -103,6 +106,7 @@ static struct spdk_bdev_module g_ftl_if = {
 	.name		= "ftl",
 	.module_init	= bdev_ftl_initialize,
 	.module_fini	= bdev_ftl_finish,
+	.examine_disk	= bdev_ftl_examine,
 	.get_ctx_size	= bdev_ftl_get_ctx_size,
 };
 
@@ -527,6 +531,58 @@ error_dev:
 	init_cb(NULL, init_arg, rc);
 }
 
+static void
+bdev_ftl_defer_free(struct ftl_deferred_init *init)
+{
+	free((char *)init->opts.name);
+	free((char *)init->opts.base_bdev);
+	free((char *)init->opts.cache_bdev);
+	free(init);
+}
+
+static int
+bdev_ftl_defer_init(const struct ftl_bdev_init_opts *opts)
+{
+	struct ftl_deferred_init *init;
+
+	init = calloc(1, sizeof(*init));
+	if (!init) {
+		return -ENOMEM;
+	}
+
+	init->opts.mode = opts->mode;
+	init->opts.uuid = opts->uuid;
+	init->opts.ftl_conf = opts->ftl_conf;
+
+	init->opts.name = strdup(opts->name);
+	if (!init->opts.name) {
+		SPDK_ERRLOG("Could not allocate bdev name\n");
+		goto error;
+	}
+
+	init->opts.base_bdev = strdup(opts->base_bdev);
+	if (!init->opts.base_bdev) {
+		SPDK_ERRLOG("Could not allocate base bdev name\n");
+		goto error;
+	}
+
+	if (opts->cache_bdev) {
+		init->opts.cache_bdev = strdup(opts->cache_bdev);
+		if (!init->opts.cache_bdev) {
+			SPDK_ERRLOG("Could not allocate cache bdev name\n");
+			goto error;
+		}
+	}
+
+	LIST_INSERT_HEAD(&g_deferred_init, init, entry);
+
+	return 0;
+
+error:
+	bdev_ftl_defer_free(init);
+	return -ENOMEM;
+}
+
 static int
 bdev_ftl_init_dependent_bdev(struct ftl_bdev *ftl_bdev, const char *bdev_name,
 			     struct spdk_bdev_desc **bdev_desc)
@@ -574,6 +630,15 @@ bdev_ftl_create_bdev(const struct ftl_bdev_init_opts *bdev_opts,
 		goto error_bdev;
 	}
 
+	if (spdk_bdev_get_by_name(bdev_opts->base_bdev) == NULL ||
+	    (bdev_opts->cache_bdev && spdk_bdev_get_by_name(bdev_opts->cache_bdev) == NULL)) {
+		rc = bdev_ftl_defer_init(bdev_opts);
+		if (rc == 0) {
+			rc = -ENODEV;
+		}
+		goto error_name;
+	}
+
 	rc = bdev_ftl_init_dependent_bdev(ftl_bdev, bdev_opts->base_bdev,
 					  &ftl_bdev->base_bdev_desc);
 	if (rc) {
@@ -654,4 +719,46 @@ bdev_ftl_finish(void)
 {
 }
 
+static void
+bdev_ftl_create_defered_cb(const struct ftl_bdev_info *info, void *ctx, int status)
+{
+	struct ftl_deferred_init *opts = ctx;
+
+	if (status) {
+		SPDK_ERRLOG("Failed to initialize FTL bdev '%s'\n", opts->opts.name);
+	}
+
+	bdev_ftl_defer_free(opts);
+
+	spdk_bdev_module_examine_done(&g_ftl_if);
+}
+
+static void
+bdev_ftl_examine(struct spdk_bdev *bdev)
+{
+	struct ftl_deferred_init *opts;
+
+	LIST_FOREACH(opts, &g_deferred_init, entry) {
+		if (spdk_bdev_get_by_name(opts->opts.base_bdev) == NULL) {
+			continue;
+		}
+
+		if (opts->opts.cache_bdev && spdk_bdev_get_by_name(opts->opts.base_bdev) == NULL) {
+			continue;
+		}
+
+		LIST_REMOVE(opts, entry);
+
+		/* spdk_bdev_module_examine_done will be called by bdev_ftl_create_defered_cb */
+		if (bdev_ftl_create_bdev(&opts->opts, bdev_ftl_create_defered_cb, opts)) {
+			SPDK_ERRLOG("Failed to initialize FTL bdev '%s'\n", opts->opts.name);
+			bdev_ftl_defer_free(opts);
+			break;
+		}
+		return;
+	}
+
+	spdk_bdev_module_examine_done(&g_ftl_if);
+}
+
 SPDK_LOG_REGISTER_COMPONENT("bdev_ftl", SPDK_LOG_BDEV_FTL)

module/bdev/ftl/bdev_ftl_rpc.c

@@ -148,6 +148,7 @@ spdk_rpc_bdev_ftl_create(struct spdk_jsonrpc_request *request,
 {
 	struct rpc_bdev_ftl_create req = {};
 	struct ftl_bdev_init_opts opts = {};
+	struct spdk_json_write_ctx *w;
 	int rc;
 
 	spdk_ftl_conf_init_defaults(&req.ftl_conf);
@@ -187,9 +188,15 @@ spdk_rpc_bdev_ftl_create(struct spdk_jsonrpc_request *request,
 
 	rc = bdev_ftl_create_bdev(&opts, _spdk_rpc_bdev_ftl_create_cb, request);
 	if (rc) {
+		if (rc == -ENODEV) {
+			w = spdk_jsonrpc_begin_result(request);
+			spdk_json_write_string_fmt(w, "FTL bdev: %s creation deferred", req.name);
+			spdk_jsonrpc_end_result(request, w);
+		} else {
 			spdk_jsonrpc_send_error_response_fmt(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
 							     "Failed to create FTL bdev: %s",
 							     spdk_strerror(-rc));
+		}
 		goto invalid;
 	}
 

test/ftl/json.sh

@@ -20,9 +20,12 @@ $rootdir/app/spdk_tgt/spdk_tgt & svcpid=$!
 waitforlisten $svcpid
 
 # Create new bdev from json configuration
-$rootdir/scripts/gen_ftl.sh -j -a $device -n nvme0 | $rpc_py load_subsystem_config
+$rootdir/scripts/gen_ftl.sh -n ftl0 -d nvme0n1 | $rpc_py load_subsystem_config
+$rpc_py bdev_nvme_attach_controller -b nvme0 -a $device -t pcie
+$rpc_py bdev_ocssd_create -c nvme0 -b nvme0n1 -n 1
 
-uuid=$($rpc_py bdev_get_bdevs | jq -r '.[0].uuid')
+waitforbdev ftl0
+uuid=$($rpc_py bdev_get_bdevs | jq -r ".[] | select(.name==\"ftl0\").uuid")
 
 $rpc_py bdev_ftl_delete -b nvme0