[LoRA] parse metadata from LoRA and save metadata (#11324)

* feat: parse metadata from lora state dicts.

* tests

* fix tests

* key renaming

* fix

* smol update

* smol updates

* load metadata.

* automatically save metadata in save_lora_adapter.

* propagate changes.

* changes

* add test to models too.

* tigher tests.

* updates

* fixes

* rename tests.

* sorted.

* Update src/diffusers/loaders/lora_base.py

Co-authored-by: Benjamin Bossan <BenjaminBossan@users.noreply.github.com>

* review suggestions.

* removeprefix.

* propagate changes.

* fix-copies

* sd

* docs.

* fixes

* get review ready.

* one more test to catch error.

* change to a different approach.

* fix-copies.

* todo

* sd3

* update

* revert changes in get_peft_kwargs.

* update

* fixes

* fixes

* simplify _load_sft_state_dict_metadata

* update

* style fix

* uipdate

* update

* update

* empty commit

* _pack_dict_with_prefix

* update

* TODO 1.

* todo: 2.

* todo: 3.

* update

* update

* Apply suggestions from code review

Co-authored-by: Benjamin Bossan <BenjaminBossan@users.noreply.github.com>

* reraise.

* move argument.

---------

Co-authored-by: Benjamin Bossan <BenjaminBossan@users.noreply.github.com>
Co-authored-by: Linoy Tsaban <57615435+linoytsaban@users.noreply.github.com>

Author: 3 people

examples/community/ip_adapter_face_id.py

@@ -282,10 +282,7 @@ def load_ip_adapter_face_id(self, pretrained_model_name_or_path_or_dict, weight_
         revision = kwargs.pop("revision", None)
         subfolder = kwargs.pop("subfolder", None)
 
-        user_agent = {
-            "file_type": "attn_procs_weights",
-            "framework": "pytorch",
-        }
+        user_agent = {"file_type": "attn_procs_weights", "framework": "pytorch"}
         model_file = _get_model_file(
             pretrained_model_name_or_path_or_dict,
             weights_name=weight_name,

src/diffusers/loaders/ip_adapter.py

@@ -159,10 +159,7 @@ def load_ip_adapter(
                 " `low_cpu_mem_usage=False`."
             )
 
-        user_agent = {
-            "file_type": "attn_procs_weights",
-            "framework": "pytorch",
-        }
+        user_agent = {"file_type": "attn_procs_weights", "framework": "pytorch"}
         state_dicts = []
         for pretrained_model_name_or_path_or_dict, weight_name, subfolder in zip(
             pretrained_model_name_or_path_or_dict, weight_name, subfolder
@@ -465,10 +462,7 @@ def load_ip_adapter(
                 " `low_cpu_mem_usage=False`."
             )
 
-        user_agent = {
-            "file_type": "attn_procs_weights",
-            "framework": "pytorch",
-        }
+        user_agent = {"file_type": "attn_procs_weights", "framework": "pytorch"}
         state_dicts = []
         for pretrained_model_name_or_path_or_dict, weight_name, subfolder in zip(
             pretrained_model_name_or_path_or_dict, weight_name, subfolder
@@ -750,10 +744,7 @@ def load_ip_adapter(
                 " `low_cpu_mem_usage=False`."
             )
 
-        user_agent = {
-            "file_type": "attn_procs_weights",
-            "framework": "pytorch",
-        }
+        user_agent = {"file_type": "attn_procs_weights", "framework": "pytorch"}
 
         if not isinstance(pretrained_model_name_or_path_or_dict, dict):
             model_file = _get_model_file(

src/diffusers/loaders/lora_base.py

@@ -14,6 +14,7 @@
 
 import copy
 import inspect
+import json
 import os
 from pathlib import Path
 from typing import Callable, Dict, List, Optional, Union
@@ -45,6 +46,7 @@
     set_adapter_layers,
     set_weights_and_activate_adapters,
 )
+from ..utils.state_dict_utils import _load_sft_state_dict_metadata
 
 
 if is_transformers_available():
@@ -62,6 +64,7 @@
 
 LORA_WEIGHT_NAME = "pytorch_lora_weights.bin"
 LORA_WEIGHT_NAME_SAFE = "pytorch_lora_weights.safetensors"
+LORA_ADAPTER_METADATA_KEY = "lora_adapter_metadata"
 
 
 def fuse_text_encoder_lora(text_encoder, lora_scale=1.0, safe_fusing=False, adapter_names=None):
@@ -206,6 +209,7 @@ def _fetch_state_dict(
     subfolder,
     user_agent,
     allow_pickle,
+    metadata=None,
 ):
     model_file = None
     if not isinstance(pretrained_model_name_or_path_or_dict, dict):
@@ -236,11 +240,14 @@ def _fetch_state_dict(
                     user_agent=user_agent,
                 )
                 state_dict = safetensors.torch.load_file(model_file, device="cpu")
+                metadata = _load_sft_state_dict_metadata(model_file)
+
             except (IOError, safetensors.SafetensorError) as e:
                 if not allow_pickle:
                     raise e
                 # try loading non-safetensors weights
                 model_file = None
+                metadata = None
                 pass
 
         if model_file is None:
@@ -261,10 +268,11 @@ def _fetch_state_dict(
                 user_agent=user_agent,
             )
             state_dict = load_state_dict(model_file)
+            metadata = None
     else:
         state_dict = pretrained_model_name_or_path_or_dict
 
-    return state_dict
+    return state_dict, metadata
 
 
 def _best_guess_weight_name(
@@ -306,6 +314,11 @@ def _best_guess_weight_name(
     return weight_name
 
 
+def _pack_dict_with_prefix(state_dict, prefix):
+    sd_with_prefix = {f"{prefix}.{key}": value for key, value in state_dict.items()}
+    return sd_with_prefix
+
+
 def _load_lora_into_text_encoder(
     state_dict,
     network_alphas,
@@ -317,10 +330,14 @@ def _load_lora_into_text_encoder(
     _pipeline=None,
     low_cpu_mem_usage=False,
     hotswap: bool = False,
+    metadata=None,
 ):
     if not USE_PEFT_BACKEND:
         raise ValueError("PEFT backend is required for this method.")
 
+    if network_alphas and metadata:
+        raise ValueError("`network_alphas` and `metadata` cannot be specified both at the same time.")
+
     peft_kwargs = {}
     if low_cpu_mem_usage:
         if not is_peft_version(">=", "0.13.1"):
@@ -349,6 +366,8 @@ def _load_lora_into_text_encoder(
     # Load the layers corresponding to text encoder and make necessary adjustments.
     if prefix is not None:
         state_dict = {k.removeprefix(f"{prefix}."): v for k, v in state_dict.items() if k.startswith(f"{prefix}.")}
+        if metadata is not None:
+            metadata = {k.removeprefix(f"{prefix}."): v for k, v in metadata.items() if k.startswith(f"{prefix}.")}
 
     if len(state_dict) > 0:
         logger.info(f"Loading {prefix}.")
@@ -376,7 +395,10 @@ def _load_lora_into_text_encoder(
             alpha_keys = [k for k in network_alphas.keys() if k.startswith(prefix) and k.split(".")[0] == prefix]
             network_alphas = {k.removeprefix(f"{prefix}."): v for k, v in network_alphas.items() if k in alpha_keys}
 
-        lora_config_kwargs = get_peft_kwargs(rank, network_alphas, state_dict, is_unet=False)
+        if metadata is not None:
+            lora_config_kwargs = metadata
+        else:
+            lora_config_kwargs = get_peft_kwargs(rank, network_alphas, state_dict, is_unet=False)
 
         if "use_dora" in lora_config_kwargs:
             if lora_config_kwargs["use_dora"]:
@@ -398,7 +420,10 @@ def _load_lora_into_text_encoder(
                 if is_peft_version("<=", "0.13.2"):
                     lora_config_kwargs.pop("lora_bias")
 
-        lora_config = LoraConfig(**lora_config_kwargs)
+            try:
+                lora_config = LoraConfig(**lora_config_kwargs)
+            except TypeError as e:
+                raise TypeError("`LoraConfig` class could not be instantiated.") from e
 
         # adapter_name
         if adapter_name is None:
@@ -889,8 +914,7 @@ def set_lora_device(self, adapter_names: List[str], device: Union[torch.device,
     @staticmethod
     def pack_weights(layers, prefix):
         layers_weights = layers.state_dict() if isinstance(layers, torch.nn.Module) else layers
-        layers_state_dict = {f"{prefix}.{module_name}": param for module_name, param in layers_weights.items()}
-        return layers_state_dict
+        return _pack_dict_with_prefix(layers_weights, prefix)
 
     @staticmethod
     def write_lora_layers(
@@ -900,16 +924,32 @@ def write_lora_layers(
         weight_name: str,
         save_function: Callable,
         safe_serialization: bool,
+        lora_adapter_metadata: Optional[dict] = None,
     ):
         if os.path.isfile(save_directory):
             logger.error(f"Provided path ({save_directory}) should be a directory, not a file")
             return
 
+        if lora_adapter_metadata and not safe_serialization:
+            raise ValueError("`lora_adapter_metadata` cannot be specified when not using `safe_serialization`.")
+        if lora_adapter_metadata and not isinstance(lora_adapter_metadata, dict):
+            raise TypeError("`lora_adapter_metadata` must be of type `dict`.")
+
         if save_function is None:
             if safe_serialization:
 
                 def save_function(weights, filename):
-                    return safetensors.torch.save_file(weights, filename, metadata={"format": "pt"})
+                    # Inject framework format.
+                    metadata = {"format": "pt"}
+                    if lora_adapter_metadata:
+                        for key, value in lora_adapter_metadata.items():
+                            if isinstance(value, set):
+                                lora_adapter_metadata[key] = list(value)
+                        metadata[LORA_ADAPTER_METADATA_KEY] = json.dumps(
+                            lora_adapter_metadata, indent=2, sort_keys=True
+                        )
+
+                    return safetensors.torch.save_file(weights, filename, metadata=metadata)
 
             else:
                 save_function = torch.save