diff --git a/google/storage/v2/BUILD.bazel b/google/storage/v2/BUILD.bazel
index 4d6ae86d9..09b187f17 100644
--- a/google/storage/v2/BUILD.bazel
+++ b/google/storage/v2/BUILD.bazel
@@ -27,6 +27,7 @@ proto_library(
         "//google/api:client_proto",
         "//google/api:field_behavior_proto",
         "//google/api:resource_proto",
+        "//google/api:routing_proto",
         "//google/iam/v1:iam_policy_proto",
         "//google/iam/v1:policy_proto",
         "//google/type:date_proto",
diff --git a/google/storage/v2/storage.proto b/google/storage/v2/storage.proto
index 4b0fb49aa..577463db5 100644
--- a/google/storage/v2/storage.proto
+++ b/google/storage/v2/storage.proto
@@ -19,6 +19,7 @@ package google.storage.v2;
 import "google/api/client.proto";
 import "google/api/field_behavior.proto";
 import "google/api/resource.proto";
+import "google/api/routing.proto";
 import "google/iam/v1/iam_policy.proto";
 import "google/iam/v1/policy.proto";
 import "google/protobuf/empty.proto";
@@ -67,11 +68,23 @@ service Storage {
 
   // Permanently deletes an empty bucket.
   rpc DeleteBucket(DeleteBucketRequest) returns (google.protobuf.Empty) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "name"
+        path_template: "{bucket=**}"
+      }
+    };
     option (google.api.method_signature) = "name";
   }
 
   // Returns metadata for the specified bucket.
   rpc GetBucket(GetBucketRequest) returns (Bucket) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "name"
+        path_template: "{bucket=**}"
+      }
+    };
     option (google.api.method_signature) = "name";
   }
 
@@ -87,37 +100,91 @@ service Storage {
 
   // Locks retention policy on a bucket.
   rpc LockBucketRetentionPolicy(LockBucketRetentionPolicyRequest) returns (Bucket) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "bucket"
+        path_template: "{bucket=**}"
+      }
+    };
     option (google.api.method_signature) = "bucket";
   }
 
-  // Gets the IAM policy for a specified bucket.
+  // Gets the IAM policy for a specified bucket or object.
   rpc GetIamPolicy(google.iam.v1.GetIamPolicyRequest) returns (google.iam.v1.Policy) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "resource"
+        path_template: "{bucket=**}"
+      }
+      routing_parameters {
+        field: "resource"
+        path_template: "{bucket=projects/*/buckets/*}/objects/**"
+      }
+    };
     option (google.api.method_signature) = "resource";
   }
 
-  // Updates an IAM policy for the specified bucket.
+  // Updates an IAM policy for the specified bucket or object.
   rpc SetIamPolicy(google.iam.v1.SetIamPolicyRequest) returns (google.iam.v1.Policy) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "resource"
+        path_template: "{bucket=**}"
+      }
+      routing_parameters {
+        field: "resource"
+        path_template: "{bucket=projects/*/buckets/*}/objects/**"
+      }
+    };
     option (google.api.method_signature) = "resource,policy";
   }
 
-  // Tests a set of permissions on the given bucket to see which, if
+  // Tests a set of permissions on the given bucket or object to see which, if
   // any, are held by the caller.
   rpc TestIamPermissions(google.iam.v1.TestIamPermissionsRequest) returns (google.iam.v1.TestIamPermissionsResponse) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "resource"
+        path_template: "{bucket=**}"
+      }
+      routing_parameters {
+        field: "resource"
+        path_template: "{bucket=projects/*/buckets/*}/objects/**"
+      }
+    };
     option (google.api.method_signature) = "resource,permissions";
   }
 
   // Updates a bucket. Equivalent to JSON API's storage.buckets.patch method.
   rpc UpdateBucket(UpdateBucketRequest) returns (Bucket) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "bucket.name"
+        path_template: "{bucket=**}"
+      }
+    };
     option (google.api.method_signature) = "bucket,update_mask";
   }
 
   // Permanently deletes a notification subscription.
   rpc DeleteNotification(DeleteNotificationRequest) returns (google.protobuf.Empty) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "name"
+        path_template: "{bucket=projects/*/buckets/*}/**"
+      }
+    };
     option (google.api.method_signature) = "name";
   }
 
   // View a notification config.
   rpc GetNotification(GetNotificationRequest) returns (Notification) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "name"
+        path_template: "{bucket=projects/*/buckets/*}/**"
+      }
+    };
     option (google.api.method_signature) = "name";
   }
 
@@ -126,35 +193,81 @@ service Storage {
   // Pub/Sub topics.
   // See https://cloud.google.com/storage/docs/pubsub-notifications.
   rpc CreateNotification(CreateNotificationRequest) returns (Notification) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "parent"
+        path_template: "{bucket=**}"
+      }
+    };
     option (google.api.method_signature) = "parent,notification";
   }
 
   // Retrieves a list of notification subscriptions for a given bucket.
   rpc ListNotifications(ListNotificationsRequest) returns (ListNotificationsResponse) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "parent"
+        path_template: "{bucket=**}"
+      }
+    };
     option (google.api.method_signature) = "parent";
   }
 
   // Concatenates a list of existing objects into a new object in the same
   // bucket.
   rpc ComposeObject(ComposeObjectRequest) returns (Object) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "destination.bucket"
+        path_template: "{bucket=**}"
+      }
+    };
   }
 
   // Deletes an object and its metadata. Deletions are permanent if versioning
-  // is not enabled for the bucket, or if the `generation` parameter
-  // is used.
+  // is not enabled for the bucket, or if the `generation` parameter is used.
   rpc DeleteObject(DeleteObjectRequest) returns (google.protobuf.Empty) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "bucket"
+        path_template: "{bucket=**}"
+      }
+    };
     option (google.api.method_signature) = "bucket,object";
     option (google.api.method_signature) = "bucket,object,generation";
   }
 
+  // Cancels an in-progress resumable upload.
+  rpc CancelResumableWrite(CancelResumableWriteRequest) returns (CancelResumableWriteResponse) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "upload_id"
+        path_template: "{bucket=projects/*/buckets/*}/**"
+      }
+    };
+    option (google.api.method_signature) = "upload_id";
+  }
+
   // Retrieves an object's metadata.
   rpc GetObject(GetObjectRequest) returns (Object) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "bucket"
+        path_template: "{bucket=**}"
+      }
+    };
     option (google.api.method_signature) = "bucket,object";
     option (google.api.method_signature) = "bucket,object,generation";
   }
 
   // Reads an object's data.
   rpc ReadObject(ReadObjectRequest) returns (stream ReadObjectResponse) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "bucket"
+        path_template: "{bucket=**}"
+      }
+    };
     option (google.api.method_signature) = "bucket,object";
     option (google.api.method_signature) = "bucket,object,generation";
   }
@@ -162,6 +275,12 @@ service Storage {
   // Updates an object's metadata.
   // Equivalent to JSON API's storage.objects.patch.
   rpc UpdateObject(UpdateObjectRequest) returns (Object) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "object.bucket"
+        path_template: "{bucket=**}"
+      }
+    };
     option (google.api.method_signature) = "object,update_mask";
   }
 
@@ -218,22 +337,53 @@ service Storage {
   // status, with a WriteObjectResponse containing the finalized object's
   // metadata.
   rpc WriteObject(stream WriteObjectRequest) returns (WriteObjectResponse) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "write_object_spec.resource.bucket"
+        path_template: "{bucket=**}"
+      }
+      routing_parameters {
+        field: "upload_id"
+        path_template: "{bucket=projects/*/buckets/*}/**"
+      }
+    };
   }
 
   // Retrieves a list of objects matching the criteria.
   rpc ListObjects(ListObjectsRequest) returns (ListObjectsResponse) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "parent"
+        path_template: "{bucket=**}"
+      }
+    };
     option (google.api.method_signature) = "parent";
   }
 
   // Rewrites a source object to a destination object. Optionally overrides
   // metadata.
   rpc RewriteObject(RewriteObjectRequest) returns (RewriteResponse) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "source_bucket"
+      }
+      routing_parameters {
+        field: "destination_bucket"
+        path_template: "{bucket=**}"
+      }
+    };
   }
 
   // Starts a resumable write. How long the write operation remains valid, and
   // what happens when the write operation becomes invalid, are
   // service-dependent.
   rpc StartResumableWrite(StartResumableWriteRequest) returns (StartResumableWriteResponse) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "write_object_spec.resource.bucket"
+        path_template: "{bucket=**}"
+      }
+    };
   }
 
   // Determines the `persisted_size` for an object that is being written, which
@@ -250,6 +400,12 @@ service Storage {
   // object name, the sequence of returned `persisted_size` values will be
   // non-decreasing.
   rpc QueryWriteStatus(QueryWriteStatusRequest) returns (QueryWriteStatusResponse) {
+    option (google.api.routing) = {
+      routing_parameters {
+        field: "upload_id"
+        path_template: "{bucket=projects/*/buckets/*}/**"
+      }
+    };
     option (google.api.method_signature) = "upload_id";
   }
 
@@ -578,7 +734,7 @@ message ComposeObjectRequest {
 }
 
 // Message for deleting an object.
-// Either `bucket` and `object` *or* `upload_id` **must** be set (but not both).
+// `bucket` and `object` **must** be set.
 message DeleteObjectRequest {
   // Required. Name of the bucket in which the object resides.
   string bucket = 1 [(google.api.field_behavior) = REQUIRED];
@@ -586,11 +742,6 @@ message DeleteObjectRequest {
   // Required. The name of the object to delete (when not using a resumable write).
   string object = 2 [(google.api.field_behavior) = REQUIRED];
 
-  // The resumable upload_id of the object to delete (when deleting an
-  // in-progress resumable write). This should be copied from the `upload_id`
-  // field of `StartResumableWriteResponse`.
-  string upload_id = 3;
-
   // If present, permanently deletes a specific revision of this object (as
   // opposed to the latest version, the default).
   int64 generation = 4;
@@ -618,6 +769,20 @@ message DeleteObjectRequest {
   CommonObjectRequestParams common_object_request_params = 10;
 }
 
+// Message for canceling an in-progress resumable upload.
+// `upload_id` **must** be set.
+message CancelResumableWriteRequest {
+  // Required. The upload_id of the resumable upload to cancel. This should be copied
+  // from the `upload_id` field of `StartResumableWriteResponse`.
+  string upload_id = 1 [(google.api.field_behavior) = REQUIRED];
+}
+
+// Empty response message for canceling an in-progress resumable upload, will be
+// extended as needed.
+message CancelResumableWriteResponse {
+
+}
+
 // Request message for ReadObject.
 message ReadObjectRequest {
   // The name of the bucket containing the object to read.
@@ -772,6 +937,17 @@ message WriteObjectSpec {
   // Makes the operation conditional on whether the object's current
   // metageneration does not match the given value.
   optional int64 if_metageneration_not_match = 6;
+
+  // The expected final object size being uploaded.
+  // If this value is set, closing the stream after writing fewer or more than
+  // `object_size` bytes will result in an OUT_OF_RANGE error.
+  //
+  // This situation is considered a client error, and if such an error occurs
+  // you must start the upload over from scratch, this time sending the correct
+  // number of bytes.
+  //
+  // The `object_size` value is ignored for one-shot (non-resumable) writes.
+  optional int64 object_size = 8;
 }
 
 // Request message for WriteObject.
@@ -937,16 +1113,16 @@ message QueryWriteStatusResponse {
 // encryption_key_sha256_bytes fields of the
 // common_object_request_params.customer_encryption field.
 message RewriteObjectRequest {
-  // Immutable. The name of the destination object. Nearly any sequence of unicode
-  // characters is valid. See
-  // [Guidelines](https://cloud.google.com/storage/docs/naming-objects).
+  // Immutable. The name of the destination object.
+  // See the
+  // [Naming Guidelines](https://cloud.google.com/storage/docs/naming-objects).
   // Example: `test.txt`
   // The `name` field by itself does not uniquely identify a Cloud Storage
   // object. A Cloud Storage object is uniquely identified by the tuple of
   // (bucket, object, generation).
   string destination_name = 24 [(google.api.field_behavior) = IMMUTABLE];
 
-  // Immutable. The name of the bucket containing The name of the destination object.
+  // Immutable. The name of the bucket containing the destination object.
   string destination_bucket = 25 [
     (google.api.field_behavior) = IMMUTABLE,
     (google.api.resource_reference) = {
@@ -1147,7 +1323,8 @@ message UpdateObjectRequest {
 
 // Request message for GetServiceAccount.
 message GetServiceAccountRequest {
-  // Required. Project ID.
+  // Required. Project ID, in the format of "projects/<projectIdentifier>".
+  // <projectIdentifier> can be the project ID or project number.
   string project = 1 [
     (google.api.field_behavior) = REQUIRED,
     (google.api.resource_reference) = {
@@ -1158,7 +1335,9 @@ message GetServiceAccountRequest {
 
 // Request message for CreateHmacKey.
 message CreateHmacKeyRequest {
-  // Required. The project that the HMAC-owning service account lives in.
+  // Required. The project that the HMAC-owning service account lives in, in the format of
+  // "projects/<projectIdentifier>".
+  // <projectIdentifier> can be the project ID or project number.
   string project = 1 [
     (google.api.field_behavior) = REQUIRED,
     (google.api.resource_reference) = {
@@ -1185,7 +1364,9 @@ message DeleteHmacKeyRequest {
   // Required. The identifying key for the HMAC to delete.
   string access_id = 1 [(google.api.field_behavior) = REQUIRED];
 
-  // Required. The project id the HMAC key lies in.
+  // Required. The project that owns the HMAC key, in the format of
+  // "projects/<projectIdentifier>".
+  // <projectIdentifier> can be the project ID or project number.
   string project = 2 [
     (google.api.field_behavior) = REQUIRED,
     (google.api.resource_reference) = {
@@ -1199,7 +1380,9 @@ message GetHmacKeyRequest {
   // Required. The identifying key for the HMAC to delete.
   string access_id = 1 [(google.api.field_behavior) = REQUIRED];
 
-  // Required. The project id the HMAC key lies in.
+  // Required. The project the HMAC key lies in, in the format of
+  // "projects/<projectIdentifier>".
+  // <projectIdentifier> can be the project ID or project number.
   string project = 2 [
     (google.api.field_behavior) = REQUIRED,
     (google.api.resource_reference) = {
@@ -1210,7 +1393,9 @@ message GetHmacKeyRequest {
 
 // Request to fetch a list of HMAC keys under a given project.
 message ListHmacKeysRequest {
-  // Required. The project id to list HMAC keys for.
+  // Required. The project to list HMAC keys for, in the format of
+  // "projects/<projectIdentifier>".
+  // <projectIdentifier> can be the project ID or project number.
   string project = 1 [
     (google.api.field_behavior) = REQUIRED,
     (google.api.resource_reference) = {
@@ -1242,6 +1427,9 @@ message ListHmacKeysResponse {
 }
 
 // Request object to update an HMAC key state.
+// HmacKeyMetadata.state is required and the only writable field in
+// UpdateHmacKey operation. Specifying fields other than state will result in an
+// error.
 message UpdateHmacKeyRequest {
   // Required. The HMAC key to update.
   // If present, the hmac_key's `id` field will be used to identify the key.
@@ -1250,6 +1438,8 @@ message UpdateHmacKeyRequest {
   HmacKeyMetadata hmac_key = 1 [(google.api.field_behavior) = REQUIRED];
 
   // Update mask for hmac_key.
+  // Not specifying any fields will mean only the `state` field is updated to
+  // the value specified in `hmac_key`.
   google.protobuf.FieldMask update_mask = 3;
 }
 
@@ -1595,7 +1785,9 @@ message Bucket {
   // only be performed if the etag matches that of the bucket.
   string etag = 29;
 
-  // Immutable. The project which owns this bucket.
+  // Immutable. The project which owns this bucket, in the format of
+  // "projects/<projectIdentifier>".
+  // <projectIdentifier> can be the project ID or project number.
   string project = 3 [
     (google.api.field_behavior) = IMMUTABLE,
     (google.api.resource_reference) = {
@@ -1803,28 +1995,36 @@ message ObjectChecksums {
 
 // Hmac Key Metadata, which includes all information other than the secret.
 message HmacKeyMetadata {
-  // Resource name ID of the key in the format <projectId>/<accessId>.
-  string id = 1;
+  // Immutable. Resource name ID of the key in the format
+  // <projectIdentifier>/<accessId>.
+  // <projectIdentifier> can be the project ID or project number.
+  string id = 1 [(google.api.field_behavior) = IMMUTABLE];
 
-  // Globally unique id for keys.
-  string access_id = 2;
+  // Immutable. Globally unique id for keys.
+  string access_id = 2 [(google.api.field_behavior) = IMMUTABLE];
 
-  // The project ID that the hmac key is contained in.
-  string project = 3 [(google.api.resource_reference) = {
-                        type: "cloudresourcemanager.googleapis.com/Project"
-                      }];
+  // Immutable. Identifies the project that owns the service account of the specified HMAC
+  // key, in the format "projects/<projectIdentifier>". <projectIdentifier> can
+  // be the project ID or project number.
+  string project = 3 [
+    (google.api.field_behavior) = IMMUTABLE,
+    (google.api.resource_reference) = {
+      type: "cloudresourcemanager.googleapis.com/Project"
+    }
+  ];
 
-  // Email of the service account the key authenticates as.
-  string service_account_email = 4;
+  // Output only. Email of the service account the key authenticates as.
+  string service_account_email = 4 [(google.api.field_behavior) = OUTPUT_ONLY];
 
   // State of the key. One of ACTIVE, INACTIVE, or DELETED.
+  // Writable, can be updated by UpdateHmacKey operation.
   string state = 5;
 
-  // The creation time of the HMAC key.
-  google.protobuf.Timestamp create_time = 6;
+  // Output only. The creation time of the HMAC key.
+  google.protobuf.Timestamp create_time = 6 [(google.api.field_behavior) = OUTPUT_ONLY];
 
-  // The last modification time of the HMAC key metadata.
-  google.protobuf.Timestamp update_time = 7;
+  // Output only. The last modification time of the HMAC key metadata.
+  google.protobuf.Timestamp update_time = 7 [(google.api.field_behavior) = OUTPUT_ONLY];
 
   // The etag of the HMAC key.
   string etag = 8;
@@ -1976,6 +2176,11 @@ message Object {
   ObjectChecksums checksums = 16 [(google.api.field_behavior) = OUTPUT_ONLY];
 
   // Output only. The modification time of the object metadata.
+  // Set initially to object creation time and then updated whenever any
+  // metadata of the object changes. This includes changes made by a requester,
+  // such as modifying custom metadata, as well as changes made by Cloud Storage
+  // on behalf of a requester, such as changing the storage class based on an
+  // Object Lifecycle Configuration.
   // Attempting to set or update this field will result in a
   // [FieldViolation][google.rpc.BadRequest.FieldViolation].
   google.protobuf.Timestamp update_time = 17 [(google.api.field_behavior) = OUTPUT_ONLY];