bdev/null: Add metadata size option to construct_null_bdev RPC method

Signed-off-by: Evgeniy Kochetov <evgeniik@mellanox.com>
Signed-off-by: Sasha Kotchubievsky <sashakot@mellanox.com>
Signed-off-by: Alexey Marchuk <alexeymar@mellanox.com>
Change-Id: I31f40dd539a153a4f5ff1c3e78f49bd021154e39
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/464778
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Broadcom SPDK FC-NVMe CI <spdk-ci.pdl@broadcom.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>

CHANGELOG.md

@@ -43,6 +43,10 @@ can only be deleted.
 
 Metadata support has been added to Null bdev module.
 
+### rpc
+
+Added optional parameter '--md-size'to 'construct_null_bdev' RPC method.
+
 ## v19.07:
 
 ### ftl

doc/jsonrpc.md

@@ -1243,6 +1243,7 @@ name                    | Optional | string      | Bdev name to use
 block_size              | Required | number      | Block size in bytes
 num_blocks              | Required | number      | Number of blocks
 uuid                    | Optional | string      | UUID of new bdev
+md_size                 | Optional | number      | Metadata size in bytes
 
 ### Result
 
@@ -1255,10 +1256,11 @@ Example request:
 ~~~
 {
   "params": {
-    "block_size": 4096,
+    "block_size": 4104,
     "num_blocks": 16384,
     "name": "Null0",
-    "uuid": "2b6601ba-eada-44fb-9a83-a20eb9eb9e90"
+    "uuid": "2b6601ba-eada-44fb-9a83-a20eb9eb9e90",
+    "md_size": 8
   },
   "jsonrpc": "2.0",
   "method": "construct_null_bdev",

module/bdev/null/bdev_null.c

@@ -156,6 +156,7 @@ bdev_null_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *
 	spdk_json_write_named_string(w, "name", bdev->name);
 	spdk_json_write_named_uint64(w, "num_blocks", bdev->blockcnt);
 	spdk_json_write_named_uint32(w, "block_size", bdev->blocklen);
+	spdk_json_write_named_uint32(w, "md_size", bdev->md_len);
 	spdk_uuid_fmt_lower(uuid_str, sizeof(uuid_str), &bdev->uuid);
 	spdk_json_write_named_string(w, "uuid", uuid_str);
 	spdk_json_write_object_end(w);

module/bdev/null/bdev_null_rpc.c

@@ -44,6 +44,7 @@ struct rpc_construct_null {
 	char *uuid;
 	uint64_t num_blocks;
 	uint32_t block_size;
+	uint32_t md_size;
 };
 
 static void
@@ -58,6 +59,7 @@ static const struct spdk_json_object_decoder rpc_construct_null_decoders[] = {
 	{"uuid", offsetof(struct rpc_construct_null, uuid), spdk_json_decode_string, true},
 	{"num_blocks", offsetof(struct rpc_construct_null, num_blocks), spdk_json_decode_uint64},
 	{"block_size", offsetof(struct rpc_construct_null, block_size), spdk_json_decode_uint32},
+	{"md_size", offsetof(struct rpc_construct_null, md_size), spdk_json_decode_uint32, true},
 };
 
 static void
@@ -70,6 +72,7 @@ spdk_rpc_construct_null_bdev(struct spdk_jsonrpc_request *request,
 	struct spdk_uuid decoded_uuid;
 	struct spdk_bdev *bdev;
 	struct spdk_null_bdev_opts opts = {};
+	uint32_t data_block_size;
 	int rc = 0;
 
 	if (spdk_json_decode_object(params, rpc_construct_null_decoders,
@@ -81,9 +84,15 @@ spdk_rpc_construct_null_bdev(struct spdk_jsonrpc_request *request,
 		goto cleanup;
 	}
 
-	if (req.block_size % 512 != 0) {
+	if (req.block_size < req.md_size) {
 		spdk_jsonrpc_send_error_response_fmt(request, -EINVAL,
-						     "Block size %u is not a multiple of 512", req.block_size);
+						     "Interleaved metadata size can not be greater than block size");
+		goto cleanup;
+	}
+	data_block_size = req.block_size - req.md_size;
+	if (data_block_size % 512 != 0) {
+		spdk_jsonrpc_send_error_response_fmt(request, -EINVAL,
+						     "Data block size %u is not a multiple of 512", req.block_size);
 		goto cleanup;
 	}
 
@@ -106,6 +115,8 @@ spdk_rpc_construct_null_bdev(struct spdk_jsonrpc_request *request,
 	opts.uuid = uuid;
 	opts.num_blocks = req.num_blocks;
 	opts.block_size = req.block_size;
+	opts.md_size = req.md_size;
+	opts.md_interleave = true;
 	rc = create_null_bdev(&bdev, &opts);
 	if (rc) {
 		spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));

scripts/rpc.py

@@ -260,7 +260,8 @@ if __name__ == "__main__":
                                                 num_blocks=num_blocks,
                                                 block_size=args.block_size,
                                                 name=args.name,
-                                                uuid=args.uuid))
+                                                uuid=args.uuid,
+                                                md_size=args.md_size))
 
     p = subparsers.add_parser('construct_null_bdev',
                               help='Add a bdev with null backend')
@@ -269,6 +270,8 @@ if __name__ == "__main__":
     p.add_argument(
         'total_size', help='Size of null bdev in MB (int > 0)', type=int)
     p.add_argument('block_size', help='Block size for this bdev', type=int)
+    p.add_argument('-m', '--md-size', type=int,
+                   help='Metadata size for this bdev. Default 0')
     p.set_defaults(func=construct_null_bdev)
 
     def delete_null_bdev(args):

scripts/rpc/bdev.py

@@ -189,14 +189,15 @@ def delete_malloc_bdev(client, name):
     return client.call('delete_malloc_bdev', params)
 
 
-def construct_null_bdev(client, num_blocks, block_size, name, uuid=None):
+def construct_null_bdev(client, num_blocks, block_size, name, uuid=None, md_size=None):
     """Construct a null block device.
 
     Args:
         num_blocks: size of block device in blocks
-        block_size: block size of device; must be a power of 2 and at least 512
+        block_size: block size of device; data part size must be a power of 2 and at least 512
         name: name of block device
         uuid: UUID of block device (optional)
+        md_size: metadata size of device (optional)
 
     Returns:
         Name of created block device.
@@ -205,6 +206,8 @@ def construct_null_bdev(client, num_blocks, block_size, name, uuid=None):
               'block_size': block_size}
     if uuid:
         params['uuid'] = uuid
+    if md_size:
+        params['md_size'] = md_size
     return client.call('construct_null_bdev', params)