fix the linear path on backend

studio/backend/core/training/trainer.py

@@ -214,7 +214,13 @@ class UnslothTrainer:
                 return True
 
             # LoRA/QLoRA mode - apply PEFT
-            if target_modules is None or (isinstance(target_modules, list) and len(target_modules) == 0):
+            # "all-linear" is a PEFT keyword that targets every linear layer
+            if isinstance(target_modules, list) and "all-linear" in target_modules:
+                if len(target_modules) == 1:
+                    target_modules = "all-linear"
+                else:
+                    target_modules = [m for m in target_modules if m != "all-linear"]
+            elif target_modules is None or (isinstance(target_modules, list) and len(target_modules) == 0):
                 target_modules = ["q_proj", "k_proj", "v_proj", "o_proj",
                                 "gate_proj", "up_proj", "down_proj"]
 

studio/frontend/src/features/training/api/mappers.ts

@@ -46,9 +46,7 @@ export function buildTrainingStartPayload(
     lora_r: config.loraRank,
     lora_alpha: config.loraAlpha,
     lora_dropout: config.loraDropout,
-    target_modules: adapterMethod
-      ? config.targetModules.filter((m) => m !== "all-linear")
-      : [],
+    target_modules: adapterMethod ? config.targetModules : [],
     gradient_checkpointing: config.gradientCheckpointing,
     use_rslora: config.loraVariant === "rslora",
     use_loftq: config.loraVariant === "loftq",