bdev/rpc: add driver-specific data to get_bdevs

Change-Id: Ieb37c9fdb55b36b62adcb421ab1d0426052d23a4
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>

include/spdk/bdev.h

@@ -56,6 +56,7 @@
 
 struct spdk_bdev_io;
 struct spdk_bdev_fn_table;
+struct spdk_json_write_ctx;
 
 /**
  * \brief SPDK block device.
@@ -286,6 +287,8 @@ struct spdk_bdev *spdk_bdev_next(struct spdk_bdev *prev);
 
 bool spdk_bdev_io_type_supported(struct spdk_bdev *bdev, enum spdk_bdev_io_type io_type);
 
+int spdk_bdev_dump_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w);
+
 struct spdk_bdev_io *spdk_bdev_read(struct spdk_bdev *bdev, struct spdk_io_channel *ch,
 				    void *buf, uint64_t offset, uint64_t nbytes,
 				    spdk_bdev_io_completion_cb cb, void *cb_arg);

lib/bdev/bdev.c

@@ -511,6 +511,16 @@ spdk_bdev_io_type_supported(struct spdk_bdev *bdev, enum spdk_bdev_io_type io_ty
 	return bdev->fn_table->io_type_supported(bdev, io_type);
 }
 
+int
+spdk_bdev_dump_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
+{
+	if (bdev->fn_table->dump_config_json) {
+		return bdev->fn_table->dump_config_json(bdev, w);
+	}
+
+	return 0;
+}
+
 struct spdk_io_channel *
 spdk_bdev_get_io_channel(struct spdk_bdev *bdev, uint32_t priority)
 {

lib/bdev/bdev_module.h

@@ -139,6 +139,15 @@ struct spdk_bdev_fn_table {
 
 	/** Get an I/O channel for the specific bdev for the calling thread. */
 	struct spdk_io_channel *(*get_io_channel)(struct spdk_bdev *bdev, uint32_t priority);
+
+	/**
+	 * Output driver-specific configuration to a JSON stream. Optional - may be NULL.
+	 *
+	 * The JSON write context will be initialized with an open object, so the bdev
+	 * driver should write a name (based on the driver name) followed by a JSON value
+	 * (most likely another nested object).
+	 */
+	int (*dump_config_json)(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w);
 };
 
 void spdk_bdev_register(struct spdk_bdev *bdev);

lib/bdev/nvme/blockdev_nvme.c

@@ -45,6 +45,7 @@
 #include "spdk/conf.h"
 #include "spdk/endian.h"
 #include "spdk/bdev.h"
+#include "spdk/json.h"
 #include "spdk/nvme.h"
 #include "spdk/io_channel.h"
 
@@ -332,11 +333,28 @@ blockdev_nvme_get_io_channel(struct spdk_bdev *bdev, uint32_t priority)
 	return spdk_get_io_channel(nvme_bdev->ctrlr, priority, false, NULL);
 }
 
+static int
+blockdev_nvme_dump_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
+{
+	struct nvme_blockdev *nvme_bdev = (struct nvme_blockdev *)bdev;
+
+	spdk_json_write_name(w, "nvme");
+	spdk_json_write_object_begin(w);
+
+	spdk_json_write_name(w, "nsid");
+	spdk_json_write_uint32(w, spdk_nvme_ns_get_id(nvme_bdev->ns));
+
+	spdk_json_write_object_end(w);
+
+	return 0;
+}
+
 static const struct spdk_bdev_fn_table nvmelib_fn_table = {
 	.destruct		= blockdev_nvme_destruct,
 	.submit_request		= blockdev_nvme_submit_request,
 	.io_type_supported	= blockdev_nvme_io_type_supported,
 	.get_io_channel		= blockdev_nvme_get_io_channel,
+	.dump_config_json	= blockdev_nvme_dump_config_json,
 };
 
 static bool

lib/bdev/rpc/bdev_rpc.c

@@ -74,6 +74,11 @@ spdk_rpc_get_bdevs(struct spdk_jsonrpc_server_conn *conn,
 		spdk_json_write_name(w, "claimed");
 		spdk_json_write_bool(w, bdev->claimed);
 
+		spdk_json_write_name(w, "driver_specific");
+		spdk_json_write_object_begin(w);
+		spdk_bdev_dump_config_json(bdev, w);
+		spdk_json_write_object_end(w);
+
 		spdk_json_write_object_end(w);
 	}
 	spdk_json_write_array_end(w);

test/iscsi_tgt/rpc_config/rpc_config.sh

@@ -40,6 +40,8 @@ echo "iscsi_tgt is listening. Running tests..."
 
 $rpc_config_py $rpc_py
 
+$rpc_py get_bdevs
+
 trap - SIGINT SIGTERM EXIT
 
 iscsicleanup