diff --git a/Docs/Tasks.md b/Docs/Tasks.md
index e5a21cd..aec4361 100644
--- a/Docs/Tasks.md
+++ b/Docs/Tasks.md
@@ -37,6 +37,8 @@ If the runtime DB creation fails (e.g., path does not exist, permission denied)
 
 ### Task 2 — Fix log_service.preview_log: stale run_blocking call site
 
+**Status:** Completed
+
 **Severity:** Bug
 
 **Where:**
diff --git a/backend/app/services/action_config_service.py b/backend/app/services/action_config_service.py
index f9c9bb0..ef9b9c4 100644
--- a/backend/app/services/action_config_service.py
+++ b/backend/app/services/action_config_service.py
@@ -981,9 +981,7 @@ async def assign_action_to_jail(
     else:
         action_entry = req.action_name
 
-    await run_blocking(
-        None,
-        _append_jail_action_sync,
+    await run_blocking(_append_jail_action_sync,
         Path(config_dir),
         jail_name,
         action_entry,
@@ -1043,9 +1041,7 @@ async def remove_action_from_jail(
     if jail_name not in all_jails:
         raise JailNotFoundInConfigError(jail_name)
 
-    await run_blocking(
-        None,
-        _remove_jail_action_sync,
+    await run_blocking(_remove_jail_action_sync,
         Path(config_dir),
         jail_name,
         action_name,
diff --git a/backend/app/services/config_file_service.py b/backend/app/services/config_file_service.py
index 3e42e2b..eacf4a2 100644
--- a/backend/app/services/config_file_service.py
+++ b/backend/app/services/config_file_service.py
@@ -1099,8 +1099,7 @@ async def list_inactive_jails(
         inactive jails.
     """
     loop = asyncio.get_event_loop()
-    parsed_result: tuple[dict[str, dict[str, str]], dict[str, str]] = await run_blocking(
-        None, _parse_jails_sync, Path(config_dir)
+    parsed_result: tuple[dict[str, dict[str, str]], dict[str, str]] = await run_blocking(_parse_jails_sync, Path(config_dir)
     )
     all_jails, source_files = parsed_result
     active_names: set[str] = await _get_active_jail_names(socket_path)
@@ -1169,8 +1168,7 @@ async def activate_jail(
     # ---------------------------------------------------------------------- #
     # Pre-activation validation — collect warnings but do not block           #
     # ---------------------------------------------------------------------- #
-    validation_result: JailValidationResult = await run_blocking(
-        None, _validate_jail_config_sync, Path(config_dir), name
+    validation_result: JailValidationResult = await run_blocking(_validate_jail_config_sync, Path(config_dir), name
     )
     warnings: list[str] = [f"{i.field}: {i.message}" for i in validation_result.issues]
     if warnings:
@@ -1209,14 +1207,10 @@ async def activate_jail(
     # we can restore it if activation fails.                                   #
     # ---------------------------------------------------------------------- #
     local_path = Path(config_dir) / "jail.d" / f"{name}.local"
-    original_content: bytes | None = await run_blocking(
-        None,
-        lambda: local_path.read_bytes() if local_path.exists() else None,
+    original_content: bytes | None = await run_blocking(lambda: local_path.read_bytes() if local_path.exists() else None,
     )
 
-    await run_blocking(
-        None,
-        _write_local_override_sync,
+    await run_blocking(_write_local_override_sync,
         Path(config_dir),
         name,
         True,
@@ -1427,9 +1421,7 @@ async def deactivate_jail(
     if name not in active_names:
         raise JailAlreadyInactiveError(name)
 
-    await run_blocking(
-        None,
-        _write_local_override_sync,
+    await run_blocking(_write_local_override_sync,
         Path(config_dir),
         name,
         False,
@@ -1516,9 +1508,7 @@ async def validate_jail_config(
     """
     _safe_jail_name(name)
     loop = asyncio.get_event_loop()
-    return await run_blocking(
-        None,
-        _validate_jail_config_sync,
+    return await run_blocking(_validate_jail_config_sync,
         Path(config_dir),
         name,
     )
@@ -1555,9 +1545,7 @@ async def rollback_jail(
     loop = asyncio.get_event_loop()
 
     # Write enabled=false — this must succeed even when fail2ban is down.
-    await run_blocking(
-        None,
-        _write_local_override_sync,
+    await run_blocking(_write_local_override_sync,
         Path(config_dir),
         name,
         False,
@@ -2184,9 +2172,7 @@ async def assign_filter_to_jail(
 
     await run_blocking( _check_filter)
 
-    await run_blocking(
-        None,
-        _set_jail_local_key_sync,
+    await run_blocking(_set_jail_local_key_sync,
         Path(config_dir),
         jail_name,
         "filter",
@@ -3037,9 +3023,7 @@ async def assign_action_to_jail(
     else:
         action_entry = req.action_name
 
-    await run_blocking(
-        None,
-        _append_jail_action_sync,
+    await run_blocking(_append_jail_action_sync,
         Path(config_dir),
         jail_name,
         action_entry,
@@ -3099,9 +3083,7 @@ async def remove_action_from_jail(
     if jail_name not in all_jails:
         raise JailNotFoundInConfigError(jail_name)
 
-    await run_blocking(
-        None,
-        _remove_jail_action_sync,
+    await run_blocking(_remove_jail_action_sync,
         Path(config_dir),
         jail_name,
         action_name,
diff --git a/backend/app/services/filter_config_service.py b/backend/app/services/filter_config_service.py
index 7bd9f2f..d20c6a4 100644
--- a/backend/app/services/filter_config_service.py
+++ b/backend/app/services/filter_config_service.py
@@ -899,9 +899,7 @@ async def assign_filter_to_jail(
 
     await run_blocking( _check_filter)
 
-    await run_blocking(
-        None,
-        _set_jail_local_key_sync,
+    await run_blocking(_set_jail_local_key_sync,
         Path(config_dir),
         jail_name,
         "filter",
diff --git a/backend/app/services/jail_config_service.py b/backend/app/services/jail_config_service.py
index b6daef4..3380b43 100644
--- a/backend/app/services/jail_config_service.py
+++ b/backend/app/services/jail_config_service.py
@@ -503,8 +503,7 @@ async def list_inactive_jails(
         inactive jails.
     """
     loop = asyncio.get_event_loop()
-    parsed_result: tuple[dict[str, dict[str, str]], dict[str, str]] = await run_blocking(
-        None, _parse_jails_sync, Path(config_dir)
+    parsed_result: tuple[dict[str, dict[str, str]], dict[str, str]] = await run_blocking(_parse_jails_sync, Path(config_dir)
     )
     all_jails, source_files = parsed_result
     active_names: set[str] = await _get_active_jail_names(socket_path)
@@ -601,8 +600,7 @@ async def _activate_jail(
     # ---------------------------------------------------------------------- #
     # Pre-activation validation — collect warnings but do not block           #
     # ---------------------------------------------------------------------- #
-    validation_result: JailValidationResult = await run_blocking(
-        None, _validate_jail_config_sync, Path(config_dir), name
+    validation_result: JailValidationResult = await run_blocking(_validate_jail_config_sync, Path(config_dir), name
     )
     warnings: list[str] = [f"{i.field}: {i.message}" for i in validation_result.issues]
     if warnings:
@@ -641,14 +639,10 @@ async def _activate_jail(
     # we can restore it if activation fails.                                   #
     # ---------------------------------------------------------------------- #
     local_path = Path(config_dir) / "jail.d" / f"{name}.local"
-    original_content: bytes | None = await run_blocking(
-        None,
-        lambda: local_path.read_bytes() if local_path.exists() else None,
+    original_content: bytes | None = await run_blocking(lambda: local_path.read_bytes() if local_path.exists() else None,
     )
 
-    await run_blocking(
-        None,
-        _write_local_override_sync,
+    await run_blocking(_write_local_override_sync,
         Path(config_dir),
         name,
         True,
@@ -876,9 +870,7 @@ async def _deactivate_jail(
     if name not in active_names:
         raise JailAlreadyInactiveError(name)
 
-    await run_blocking(
-        None,
-        _write_local_override_sync,
+    await run_blocking(_write_local_override_sync,
         Path(config_dir),
         name,
         False,
@@ -965,9 +957,7 @@ async def validate_jail_config(
     """
     _safe_jail_name(name)
     loop = asyncio.get_event_loop()
-    return await run_blocking(
-        None,
-        _validate_jail_config_sync,
+    return await run_blocking(_validate_jail_config_sync,
         Path(config_dir),
         name,
     )
@@ -1021,9 +1011,7 @@ async def _rollback_jail(
     loop = asyncio.get_event_loop()
 
     # Write enabled=false — this must succeed even when fail2ban is down.
-    await run_blocking(
-        None,
-        _write_local_override_sync,
+    await run_blocking(_write_local_override_sync,
         Path(config_dir),
         name,
         False,
diff --git a/backend/app/services/log_service.py b/backend/app/services/log_service.py
index 2829b6e..74a7720 100644
--- a/backend/app/services/log_service.py
+++ b/backend/app/services/log_service.py
@@ -72,7 +72,6 @@ async def preview_log(req: LogPreviewRequest) -> LogPreviewResponse:
 
     try:
         raw_lines = await run_blocking(
-            None,
             _read_tail_lines,
             str(path),
             req.num_lines,