[training] show how metadata stuff should be incorporated in training scripts.

examples/dreambooth/test_dreambooth_lora_flux.py

@@ -13,13 +13,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import json
 import logging
 import os
 import sys
 import tempfile
 
 import safetensors
 
+from diffusers.loaders.lora_base import LORA_ADAPTER_METADATA_KEY
+
 
 sys.path.append("..")
 from test_examples_utils import ExamplesTestsAccelerate, run_command  # noqa: E402
@@ -234,3 +237,45 @@ def test_dreambooth_lora_flux_checkpointing_checkpoints_total_limit_removes_mult
             run_command(self._launch_args + resume_run_args)
 
             self.assertEqual({x for x in os.listdir(tmpdir) if "checkpoint" in x}, {"checkpoint-6", "checkpoint-8"})
+
+    def test_dreambooth_lora_with_metadata(self):
+        # Use a `lora_alpha` that is different from `rank`.
+        lora_alpha = 8
+        rank = 4
+        with tempfile.TemporaryDirectory() as tmpdir:
+            test_args = f"""
+                {self.script_path}
+                --pretrained_model_name_or_path {self.pretrained_model_name_or_path}
+                --instance_data_dir {self.instance_data_dir}
+                --instance_prompt {self.instance_prompt}
+                --resolution 64
+                --train_batch_size 1
+                --gradient_accumulation_steps 1
+                --max_train_steps 2
+                --lora_alpha={lora_alpha}
+                --rank={rank}
+                --learning_rate 5.0e-04
+                --scale_lr
+                --lr_scheduler constant
+                --lr_warmup_steps 0
+                --output_dir {tmpdir}
+                """.split()
+
+            run_command(self._launch_args + test_args)
+            # save_pretrained smoke test
+            state_dict_file = os.path.join(tmpdir, "pytorch_lora_weights.safetensors")
+            self.assertTrue(os.path.isfile(state_dict_file))
+
+            # Check if the metadata was properly serialized.
+            with safetensors.torch.safe_open(state_dict_file, framework="pt", device="cpu") as f:
+                metadata = f.metadata() or {}
+
+            metadata.pop("format", None)
+            raw = metadata.get(LORA_ADAPTER_METADATA_KEY)
+            if raw:
+                raw = json.loads(raw)
+
+            loaded_lora_alpha = raw["transformer.lora_alpha"]
+            self.assertTrue(loaded_lora_alpha == lora_alpha)
+            loaded_lora_rank = raw["transformer.r"]
+            self.assertTrue(loaded_lora_rank == rank)

examples/dreambooth/train_dreambooth_lora_flux.py

@@ -27,7 +27,6 @@
 
 import numpy as np
 import torch
-import torch.utils.checkpoint
 import transformers
 from accelerate import Accelerator
 from accelerate.logging import get_logger
@@ -53,6 +52,7 @@
 )
 from diffusers.optimization import get_scheduler
 from diffusers.training_utils import (
+    _collate_lora_metadata,
     _set_state_dict_into_text_encoder,
     cast_training_params,
     compute_density_for_timestep_sampling,
@@ -358,7 +358,12 @@ def parse_args(input_args=None):
         default=4,
         help=("The dimension of the LoRA update matrices."),
     )
-
+    parser.add_argument(
+        "--lora_alpha",
+        type=int,
+        default=4,
+        help="LoRA alpha to be used for additional scaling.",
+    )
     parser.add_argument("--lora_dropout", type=float, default=0.0, help="Dropout probability for LoRA layers")
 
     parser.add_argument(
@@ -1238,7 +1243,7 @@ def main(args):
     # now we will add new LoRA weights the transformer layers
     transformer_lora_config = LoraConfig(
         r=args.rank,
-        lora_alpha=args.rank,
+        lora_alpha=args.lora_alpha,
         lora_dropout=args.lora_dropout,
         init_lora_weights="gaussian",
         target_modules=target_modules,
@@ -1247,7 +1252,7 @@ def main(args):
     if args.train_text_encoder:
         text_lora_config = LoraConfig(
             r=args.rank,
-            lora_alpha=args.rank,
+            lora_alpha=args.lora_alpha,
             lora_dropout=args.lora_dropout,
             init_lora_weights="gaussian",
             target_modules=["q_proj", "k_proj", "v_proj", "out_proj"],
@@ -1264,12 +1269,14 @@ def save_model_hook(models, weights, output_dir):
         if accelerator.is_main_process:
             transformer_lora_layers_to_save = None
             text_encoder_one_lora_layers_to_save = None
-
+            modules_to_save = {}
             for model in models:
                 if isinstance(model, type(unwrap_model(transformer))):
                     transformer_lora_layers_to_save = get_peft_model_state_dict(model)
+                    modules_to_save["transformer"] = model
                 elif isinstance(model, type(unwrap_model(text_encoder_one))):
                     text_encoder_one_lora_layers_to_save = get_peft_model_state_dict(model)
+                    modules_to_save["text_encoder"] = model
                 else:
                     raise ValueError(f"unexpected save model: {model.__class__}")
 
@@ -1280,6 +1287,7 @@ def save_model_hook(models, weights, output_dir):
                 output_dir,
                 transformer_lora_layers=transformer_lora_layers_to_save,
                 text_encoder_lora_layers=text_encoder_one_lora_layers_to_save,
+                **_collate_lora_metadata(modules_to_save),
             )
 
     def load_model_hook(models, input_dir):
@@ -1889,23 +1897,27 @@ def get_sigmas(timesteps, n_dim=4, dtype=torch.float32):
     # Save the lora layers
     accelerator.wait_for_everyone()
     if accelerator.is_main_process:
+        modules_to_save = {}
         transformer = unwrap_model(transformer)
         if args.upcast_before_saving:
             transformer.to(torch.float32)
         else:
             transformer = transformer.to(weight_dtype)
         transformer_lora_layers = get_peft_model_state_dict(transformer)
+        modules_to_save["transformer"] = transformer
 
         if args.train_text_encoder:
             text_encoder_one = unwrap_model(text_encoder_one)
             text_encoder_lora_layers = get_peft_model_state_dict(text_encoder_one.to(torch.float32))
+            modules_to_save["text_encoder"] = text_encoder_one
         else:
             text_encoder_lora_layers = None
 
         FluxPipeline.save_lora_weights(
             save_directory=args.output_dir,
             transformer_lora_layers=transformer_lora_layers,
             text_encoder_lora_layers=text_encoder_lora_layers,
+            **_collate_lora_metadata(modules_to_save),
         )
 
         # Final inference

src/diffusers/training_utils.py

@@ -247,6 +247,14 @@ def _set_state_dict_into_text_encoder(
     set_peft_model_state_dict(text_encoder, text_encoder_state_dict, adapter_name="default")
 
 
+def _collate_lora_metadata(modules_to_save: Dict[str, torch.nn.Module]) -> Dict[str, Any]:
+    metadatas = {}
+    for module_name, module in modules_to_save.items():
+        if module is not None:
+            metadatas[f"{module_name}_lora_adapter_metadata"] = module.peft_config["default"].to_dict()
+    return metadatas
+
+
 def compute_density_for_timestep_sampling(
     weighting_scheme: str,
     batch_size: int,