aio: add aio bdev rescan feature

Signed-off-by: shuochen0311 <shuo.chen@databricks.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/11084 (master)

(cherry picked from commit b635d19a26)
Change-Id: I7f2788640a56d1e1bc8b7b311622628e8a6be56e
Signed-off-by: Krzysztof Karas <krzysztof.karas@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/11275
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: <shuo.chen@databricks.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>

CHANGELOG.md

@@ -19,6 +19,10 @@ is fabric or not.
 API `spdk_nvme_poll_group_remove` was limited to be available only for a
 disconnected qpair in the group.
 
+### bdev_aio
+
+Added `bdev_aio_rescan` RPC to allow rescaning the size of aio bdev
+
 ### bdev
 
 The NVMe bdev module supports multipath and improved I/O error resiliency.

doc/jsonrpc.md

@@ -2813,6 +2813,41 @@ Example response:
 }
 ~~~
 
+### bdev_aio_rescan {#rpc_bdev_aio_rescan}
+
+Rescan the size of @ref bdev_config_aio.
+
+#### Parameters
+
+Name                    | Optional | Type        | Description
+----------------------- | -------- | ----------- | -----------
+name                    | Required | string      | Bdev name
+
+#### Example
+
+Example request:
+
+~~json
+{
+  "params": {
+    "name": "Aio0"
+  },
+  "jsonrpc": "2.0",
+  "method": "bdev_aio_rescan",
+  "id": 1
+}
+~~
+
+Example response:
+
+~~json
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "result": true
+}
+~~
+
 ### bdev_aio_delete {#rpc_bdev_aio_delete}
 
 Delete @ref bdev_config_aio.

module/bdev/aio/bdev_aio.c

@@ -820,6 +820,38 @@ error_return:
 	return rc;
 }
 
+int
+bdev_aio_rescan(struct spdk_bdev *bdev)
+{
+	struct file_disk *fdisk;
+	uint64_t disk_size, blockcnt;
+	int rc;
+
+	if (!bdev || bdev->module != &aio_if) {
+		return -ENODEV;
+	}
+
+	fdisk = SPDK_CONTAINEROF(bdev, struct file_disk, disk);
+	disk_size = spdk_fd_get_size(fdisk->fd);
+	blockcnt = disk_size / fdisk->disk.blocklen;
+
+	if (fdisk->disk.blockcnt != blockcnt) {
+		SPDK_NOTICELOG("AIO device is resized: bdev name %s, old block count %" PRIu64 ", new block count %"
+			       PRIu64 "\n",
+			       fdisk->filename,
+			       fdisk->disk.blockcnt,
+			       blockcnt);
+		rc = spdk_bdev_notify_blockcnt_change(&fdisk->disk, blockcnt);
+		if (rc != 0) {
+			SPDK_ERRLOG("Could not change num blocks for aio bdev: name %s, errno: %d.\n",
+				    fdisk->filename, rc);
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
 struct delete_aio_bdev_ctx {
 	delete_aio_bdev_complete cb_fn;
 	void *cb_arg;

module/bdev/aio/bdev_aio.h

@@ -41,6 +41,7 @@ typedef void (*delete_aio_bdev_complete)(void *cb_arg, int bdeverrno);
 
 int create_aio_bdev(const char *name, const char *filename, uint32_t block_size);
 
+int bdev_aio_rescan(struct spdk_bdev *bdev);
 void bdev_aio_delete(struct spdk_bdev *bdev, delete_aio_bdev_complete cb_fn, void *cb_arg);
 
 #endif /* SPDK_BDEV_AIO_H */

module/bdev/aio/bdev_aio_rpc.c

@@ -111,6 +111,44 @@ rpc_bdev_aio_create(struct spdk_jsonrpc_request *request,
 SPDK_RPC_REGISTER("bdev_aio_create", rpc_bdev_aio_create, SPDK_RPC_RUNTIME)
 SPDK_RPC_REGISTER_ALIAS_DEPRECATED(bdev_aio_create, construct_aio_bdev)
 
+struct rpc_rescan_aio {
+	char *name;
+};
+
+static const struct spdk_json_object_decoder rpc_rescan_aio_decoders[] = {
+	{"name", offsetof(struct rpc_rescan_aio, name), spdk_json_decode_string},
+};
+
+static void
+rpc_bdev_aio_rescan(struct spdk_jsonrpc_request *request,
+		    const struct spdk_json_val *params)
+{
+	struct rpc_rescan_aio req = {NULL};
+	struct spdk_bdev *bdev;
+	int bdeverrno;
+
+	if (spdk_json_decode_object(params, rpc_rescan_aio_decoders,
+				    SPDK_COUNTOF(rpc_rescan_aio_decoders),
+				    &req)) {
+		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
+						 "spdk_json_decode_object failed");
+		goto cleanup;
+	}
+
+	bdev = spdk_bdev_get_by_name(req.name);
+	if (bdev == NULL) {
+		spdk_jsonrpc_send_error_response(request, -ENODEV, spdk_strerror(ENODEV));
+		goto cleanup;
+	}
+
+	bdeverrno = bdev_aio_rescan(bdev);
+	spdk_jsonrpc_send_bool_response(request, bdeverrno);
+
+cleanup:
+	free(req.name);
+}
+SPDK_RPC_REGISTER("bdev_aio_rescan", rpc_bdev_aio_rescan, SPDK_RPC_RUNTIME)
+
 struct rpc_delete_aio {
 	char *name;
 };

scripts/rpc.py

@@ -426,6 +426,14 @@ if __name__ == "__main__":
     p.add_argument('block_size', help='Block size for this bdev', type=int, nargs='?', default=0)
     p.set_defaults(func=bdev_aio_create)
 
+    def bdev_aio_rescan(args):
+        print_json(rpc.bdev.bdev_aio_rescan(args.client,
+                                            name=args.name))
+
+    p = subparsers.add_parser('bdev_aio_rescan', help='Rescan a bdev size with aio backend')
+    p.add_argument('name', help='Block device name')
+    p.set_defaults(func=bdev_aio_rescan)
+
     def bdev_aio_delete(args):
         rpc.bdev.bdev_aio_delete(args.client,
                                  name=args.name)

scripts/rpc/bdev.py

@@ -386,6 +386,16 @@ def bdev_aio_create(client, filename, name, block_size=None):
     return client.call('bdev_aio_create', params)
 
 
+def bdev_aio_rescan(client, name):
+    """Rescan a Linux AIO block device.
+
+    Args:
+        bdev_name: name of aio bdev to delete
+    """
+    params = {'name': name}
+    return client.call('bdev_aio_rescan', params)
+
+
 @deprecated_alias('delete_aio_bdev')
 def bdev_aio_delete(client, name):
     """Remove aio bdev from the system.