test(robot): refactor block device size assertion to use retry-based helper

- Add `wait_for_block_device_size_in_pod` method in workload_keywords.py
  that polls until block device size matches expected value, with retry logic
- Replace inline `blockdev --getsize64` one-time check in deployment.resource
  with the new `wait_for_block_device_size_in_pod` helper call
- Remove `BLOCK_DEVICE_NAME/DIR/PATH` variables from variables.resource
  in favor of `BLOCK_PVC_VOLUME_DEVICE_PATH` constant

Signed-off-by: Roger Yao <roger.yao@suse.com>

Author: roger-ryao

e2e/keywords/deployment.resource

@@ -7,7 +7,6 @@ Library    ../libs/keywords/deployment_keywords.py
 Library    ../libs/keywords/node_keywords.py
 Library    ../libs/keywords/workload_keywords.py
 Library    ../libs/keywords/volume_keywords.py
-Resource    variables.resource
 
 *** Keywords ***
 Create deployment ${deployment_id} with persistentvolumeclaim ${claim_id}
@@ -137,7 +136,4 @@ Assert block device size in deployment pod for deployment ${deployment_id} is ${
     ${expected_bytes} =    convert_size_to_bytes    ${size}    to_str=True
     ${deployment_name} =    generate_name_with_suffix    deployment    ${deployment_id}
     ${pod_name} =    get_workload_pod_name    ${deployment_name}
-    ${cmd} =    Set Variable    blockdev --getsize64 ${BLOCK_DEVICE_PATH}
-    ${result} =    pod_exec    ${pod_name}    default    ${cmd}
-    Should Be Equal As Integers    ${result.strip()}    ${expected_bytes}
-    ...    msg=Block device size in pod ${pod_name}: expected ${expected_bytes} B, got ${result.strip()} B
+    wait_for_block_device_size_in_pod    ${pod_name}    ${expected_bytes}

e2e/keywords/sharemanager.resource

@@ -49,7 +49,6 @@ Wait for sharemanager pod of ${workload_kind} ${workload_id} deleted
 
 Assert disk size in sharemanager pod for ${workload_kind} ${workload_id} is ${size}
     ${expected_size_byte} =    convert_size_to_bytes    ${size}    to_str=True
-
     ${workload_name}=    generate_name_with_suffix    ${workload_kind}    ${workload_id}
     ${volume_name}=    get_workload_volume_name    ${workload_name}
     ${share_manager_pod}=    Set Variable    share-manager-${volume_name}

e2e/keywords/variables.resource

@@ -12,11 +12,6 @@ ${VOLUME_STATE_CHECK_TIMEOUT}    120
 ${LONGHORN_NAMESPACE}    longhorn-system
 ${DEFAULT_BLOCK_DISK_NAME}    block-disk
 
-# Block volume device path (volumeMode=Block)
-${BLOCK_DEVICE_NAME}    longhorn-testblk
-${BLOCK_DEVICE_DIR}    /dev/longhorn
-${BLOCK_DEVICE_PATH}    ${BLOCK_DEVICE_DIR}/${BLOCK_DEVICE_NAME}
-
 @{powered_off_nodes}=
 
 &{volume_checksums}=

e2e/libs/keywords/workload_keywords.py

@@ -47,6 +47,7 @@
 from utility.constant import ANNOT_CHECKSUM
 from utility.constant import ANNOT_EXPANDED_SIZE
 from utility.constant import LABEL_LONGHORN_COMPONENT
+from utility.constant import BLOCK_PVC_VOLUME_DEVICE_PATH
 import utility.constant as constant
 from utility.utility import convert_size_to_bytes
 from utility.utility import logging
@@ -485,3 +486,20 @@ def verify_fio_data_integrity_in_workload(self, workload_name, namespace="defaul
             raise AssertionError(f"FIO verification failed with errors: {resp}")
 
         logging(f"FIO data integrity verification passed")
+
+    def wait_for_block_device_size_in_pod(self, pod_name, expected_size, namespace="default"):
+        for i in range(self.retry_count):
+            logging(f"Waiting for block device size in pod {pod_name} to be {expected_size} ... ({i})")
+            time.sleep(self.retry_interval)
+            cmd = f"blockdev --getsize64 {BLOCK_PVC_VOLUME_DEVICE_PATH}"
+            try:
+                result = pod_exec(pod_name, namespace, cmd)
+                actual_size = result.strip()
+                logging(f"Current block device size in pod {pod_name}: {actual_size}, expected: {expected_size}")
+                if actual_size == expected_size:
+                    return
+            except Exception as e:
+                logging(f"Error checking block device size in pod {pod_name}: {e}")
+                continue
+
+        assert False, f"Block device size in pod {pod_name} is not {expected_size}"