safe remove old lora backend 👋

.github/workflows/pr_tests.yml

@@ -34,11 +34,6 @@ jobs:
             runner: docker-cpu
             image: diffusers/diffusers-pytorch-cpu
             report: torch_cpu_models_schedulers
-          - name: LoRA
-            framework: lora
-            runner: docker-cpu
-            image: diffusers/diffusers-pytorch-cpu
-            report: torch_cpu_lora
           - name: Fast Flax CPU tests
             framework: flax
             runner: docker-cpu
@@ -94,14 +89,6 @@ jobs:
           --make-reports=tests_${{ matrix.config.report }} \
           tests/models tests/schedulers tests/others
 
-    - name: Run fast PyTorch LoRA CPU tests
-      if: ${{ matrix.config.framework == 'lora' }}
-      run: |
-        python -m pytest -n 2 --max-worker-restart=0 --dist=loadfile \
-          -s -v -k "not Flax and not Onnx and not Dependency" \
-          --make-reports=tests_${{ matrix.config.report }} \
-          tests/lora
-
     - name: Run fast Flax TPU tests
       if: ${{ matrix.config.framework == 'flax' }}
       run: |

src/diffusers/loaders/lora.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 import inspect
 import os
-from contextlib import nullcontext
 from pathlib import Path
 from typing import Callable, Dict, List, Optional, Union
 
@@ -26,7 +25,7 @@ from packaging import version
 from torch import nn
 
 from .. import __version__
-from ..models.modeling_utils import _LOW_CPU_MEM_USAGE_DEFAULT, load_model_dict_into_meta
+from ..models.modeling_utils import _LOW_CPU_MEM_USAGE_DEFAULT
 from ..utils import (
     USE_PEFT_BACKEND,
     _get_model_file,
@@ -34,7 +33,6 @@ from ..utils import (
     convert_state_dict_to_peft,
     convert_unet_state_dict_to_peft,
     delete_adapter_layers,
-    deprecate,
     get_adapter_name,
     get_peft_kwargs,
     is_accelerate_available,
@@ -51,10 +49,9 @@ from .lora_conversion_utils import _convert_kohya_lora_to_diffusers, _maybe_map_
 if is_transformers_available():
     from transformers import PreTrainedModel
 
-    from ..models.lora import PatchedLoraProjection, text_encoder_attn_modules, text_encoder_mlp_modules
+    from ..models.lora import text_encoder_attn_modules, text_encoder_mlp_modules
 
 if is_accelerate_available():
-    from accelerate import init_empty_weights
     from accelerate.hooks import AlignDevicesHook, CpuOffload, remove_hook_from_module
 
 logger = logging.get_logger(__name__)
@@ -106,6 +103,9 @@ class LoraLoaderMixin:
                 Adapter name to be used for referencing the loaded adapter model. If not specified, it will use
                 `default_{i}` where i is the total number of adapters being loaded.
         """
+        if not USE_PEFT_BACKEND:
+            raise ValueError("PEFT backend is required for this method.")
+
         # First, ensure that the checkpoint is a compatible one and can be successfully loaded.
         state_dict, network_alphas = self.lora_state_dict(pretrained_model_name_or_path_or_dict, **kwargs)
 
@@ -397,16 +397,17 @@ class LoraLoaderMixin:
                 Adapter name to be used for referencing the loaded adapter model. If not specified, it will use
                 `default_{i}` where i is the total number of adapters being loaded.
         """
+        if not USE_PEFT_BACKEND:
+            raise ValueError("PEFT backend is required for this method.")
+
+        from peft import LoraConfig, inject_adapter_in_model, set_peft_model_state_dict
+
         low_cpu_mem_usage = low_cpu_mem_usage if low_cpu_mem_usage is not None else _LOW_CPU_MEM_USAGE_DEFAULT
         # If the serialization format is new (introduced in https://github.com/huggingface/diffusers/pull/2918),
         # then the `state_dict` keys should have `cls.unet_name` and/or `cls.text_encoder_name` as
         # their prefixes.
         keys = list(state_dict.keys())
 
-        if all(key.startswith("unet.unet") for key in keys):
-            deprecation_message = "Keys starting with 'unet.unet' are deprecated."
-            deprecate("unet.unet keys", "0.27", deprecation_message)
-
         if all(key.startswith(cls.unet_name) or key.startswith(cls.text_encoder_name) for key in keys):
             # Load the layers corresponding to UNet.
             logger.info(f"Loading {cls.unet_name}.")
@@ -427,9 +428,7 @@ class LoraLoaderMixin:
                 warn_message = "You have saved the LoRA weights using the old format. To convert the old LoRA weights to the new format, you can first load them in a dictionary and then create a new dictionary like the following: `new_state_dict = {f'unet.{module_name}': params for module_name, params in old_state_dict.items()}`."
                 logger.warn(warn_message)
 
-        if USE_PEFT_BACKEND and len(state_dict.keys()) > 0:
-            from peft import LoraConfig, inject_adapter_in_model, set_peft_model_state_dict
-
+        if len(state_dict.keys()) > 0:
             if adapter_name in getattr(unet, "peft_config", {}):
                 raise ValueError(
                     f"Adapter name {adapter_name} already in use in the Unet - please select a new adapter name."
@@ -518,6 +517,11 @@ class LoraLoaderMixin:
                 Adapter name to be used for referencing the loaded adapter model. If not specified, it will use
                 `default_{i}` where i is the total number of adapters being loaded.
         """
+        if not USE_PEFT_BACKEND:
+            raise ValueError("PEFT backend is required for this method.")
+
+        from peft import LoraConfig
+
         low_cpu_mem_usage = low_cpu_mem_usage if low_cpu_mem_usage is not None else _LOW_CPU_MEM_USAGE_DEFAULT
 
         # If the serialization format is new (introduced in https://github.com/huggingface/diffusers/pull/2918),
@@ -539,34 +543,21 @@ class LoraLoaderMixin:
                 rank = {}
                 text_encoder_lora_state_dict = convert_state_dict_to_diffusers(text_encoder_lora_state_dict)
 
-                if USE_PEFT_BACKEND:
-                    # convert state dict
-                    text_encoder_lora_state_dict = convert_state_dict_to_peft(text_encoder_lora_state_dict)
+                # convert state dict
+                text_encoder_lora_state_dict = convert_state_dict_to_peft(text_encoder_lora_state_dict)
 
-                    for name, _ in text_encoder_attn_modules(text_encoder):
-                        rank_key = f"{name}.out_proj.lora_B.weight"
-                        rank[rank_key] = text_encoder_lora_state_dict[rank_key].shape[1]
+                for name, _ in text_encoder_attn_modules(text_encoder):
+                    rank_key = f"{name}.out_proj.lora_B.weight"
+                    rank[rank_key] = text_encoder_lora_state_dict[rank_key].shape[1]
 
-                    patch_mlp = any(".mlp." in key for key in text_encoder_lora_state_dict.keys())
-                    if patch_mlp:
-                        for name, _ in text_encoder_mlp_modules(text_encoder):
-                            rank_key_fc1 = f"{name}.fc1.lora_B.weight"
-                            rank_key_fc2 = f"{name}.fc2.lora_B.weight"
+                patch_mlp = any(".mlp." in key for key in text_encoder_lora_state_dict.keys())
+                if patch_mlp:
+                    for name, _ in text_encoder_mlp_modules(text_encoder):
+                        rank_key_fc1 = f"{name}.fc1.lora_B.weight"
+                        rank_key_fc2 = f"{name}.fc2.lora_B.weight"
 
-                            rank[rank_key_fc1] = text_encoder_lora_state_dict[rank_key_fc1].shape[1]
-                            rank[rank_key_fc2] = text_encoder_lora_state_dict[rank_key_fc2].shape[1]
-                else:
-                    for name, _ in text_encoder_attn_modules(text_encoder):
-                        rank_key = f"{name}.out_proj.lora_linear_layer.up.weight"
-                        rank.update({rank_key: text_encoder_lora_state_dict[rank_key].shape[1]})
-
-                    patch_mlp = any(".mlp." in key for key in text_encoder_lora_state_dict.keys())
-                    if patch_mlp:
-                        for name, _ in text_encoder_mlp_modules(text_encoder):
-                            rank_key_fc1 = f"{name}.fc1.lora_linear_layer.up.weight"
-                            rank_key_fc2 = f"{name}.fc2.lora_linear_layer.up.weight"
-                            rank[rank_key_fc1] = text_encoder_lora_state_dict[rank_key_fc1].shape[1]
-                            rank[rank_key_fc2] = text_encoder_lora_state_dict[rank_key_fc2].shape[1]
+                        rank[rank_key_fc1] = text_encoder_lora_state_dict[rank_key_fc1].shape[1]
+                        rank[rank_key_fc2] = text_encoder_lora_state_dict[rank_key_fc2].shape[1]
 
                 if network_alphas is not None:
                     alpha_keys = [
@@ -576,84 +567,25 @@ class LoraLoaderMixin:
                         k.replace(f"{prefix}.", ""): v for k, v in network_alphas.items() if k in alpha_keys
                     }
 
-                if USE_PEFT_BACKEND:
-                    from peft import LoraConfig
+                lora_config_kwargs = get_peft_kwargs(rank, network_alphas, text_encoder_lora_state_dict, is_unet=False)
+                lora_config = LoraConfig(**lora_config_kwargs)
 
-                    lora_config_kwargs = get_peft_kwargs(
-                        rank, network_alphas, text_encoder_lora_state_dict, is_unet=False
-                    )
-                    lora_config = LoraConfig(**lora_config_kwargs)
+                # adapter_name
+                if adapter_name is None:
+                    adapter_name = get_adapter_name(text_encoder)
 
-                    # adapter_name
-                    if adapter_name is None:
-                        adapter_name = get_adapter_name(text_encoder)
+                is_model_cpu_offload, is_sequential_cpu_offload = cls._optionally_disable_offloading(_pipeline)
 
-                    is_model_cpu_offload, is_sequential_cpu_offload = cls._optionally_disable_offloading(_pipeline)
+                # inject LoRA layers and load the state dict
+                # in transformers we automatically check whether the adapter name is already in use or not
+                text_encoder.load_adapter(
+                    adapter_name=adapter_name,
+                    adapter_state_dict=text_encoder_lora_state_dict,
+                    peft_config=lora_config,
+                )
 
-                    # inject LoRA layers and load the state dict
-                    # in transformers we automatically check whether the adapter name is already in use or not
-                    text_encoder.load_adapter(
-                        adapter_name=adapter_name,
-                        adapter_state_dict=text_encoder_lora_state_dict,
-                        peft_config=lora_config,
-                    )
-
-                    # scale LoRA layers with `lora_scale`
-                    scale_lora_layers(text_encoder, weight=lora_scale)
-                else:
-                    cls._modify_text_encoder(
-                        text_encoder,
-                        lora_scale,
-                        network_alphas,
-                        rank=rank,
-                        patch_mlp=patch_mlp,
-                        low_cpu_mem_usage=low_cpu_mem_usage,
-                    )
-
-                    is_pipeline_offloaded = _pipeline is not None and any(
-                        isinstance(c, torch.nn.Module) and hasattr(c, "_hf_hook")
-                        for c in _pipeline.components.values()
-                    )
-                    if is_pipeline_offloaded and low_cpu_mem_usage:
-                        low_cpu_mem_usage = True
-                        logger.info(
-                            f"Pipeline {_pipeline.__class__} is offloaded. Therefore low cpu mem usage loading is forced."
-                        )
-
-                    if low_cpu_mem_usage:
-                        device = next(iter(text_encoder_lora_state_dict.values())).device
-                        dtype = next(iter(text_encoder_lora_state_dict.values())).dtype
-                        unexpected_keys = load_model_dict_into_meta(
-                            text_encoder, text_encoder_lora_state_dict, device=device, dtype=dtype
-                        )
-                    else:
-                        load_state_dict_results = text_encoder.load_state_dict(
-                            text_encoder_lora_state_dict, strict=False
-                        )
-                        unexpected_keys = load_state_dict_results.unexpected_keys
-
-                    if len(unexpected_keys) != 0:
-                        raise ValueError(
-                            f"failed to load text encoder state dict, unexpected keys: {load_state_dict_results.unexpected_keys}"
-                        )
-
-                    # <Unsafe code
-                    # We can be sure that the following works as all we do is change the dtype and device of the text encoder
-                    # Now we remove any existing hooks to
-                    is_model_cpu_offload = False
-                    is_sequential_cpu_offload = False
-                    if _pipeline is not None:
-                        for _, component in _pipeline.components.items():
-                            if isinstance(component, torch.nn.Module):
-                                if hasattr(component, "_hf_hook"):
-                                    is_model_cpu_offload = isinstance(getattr(component, "_hf_hook"), CpuOffload)
-                                    is_sequential_cpu_offload = isinstance(
-                                        getattr(component, "_hf_hook"), AlignDevicesHook
-                                    )
-                                    logger.info(
-                                        "Accelerate hooks detected. Since you have called `load_lora_weights()`, the previous hooks will be first removed. Then the LoRA parameters will be loaded and the hooks will be applied again."
-                                    )
-                                    remove_hook_from_module(component, recurse=is_sequential_cpu_offload)
+                # scale LoRA layers with `lora_scale`
+                scale_lora_layers(text_encoder, weight=lora_scale)
 
                 text_encoder.to(device=text_encoder.device, dtype=text_encoder.dtype)
 
@@ -689,6 +621,8 @@ class LoraLoaderMixin:
                 Adapter name to be used for referencing the loaded adapter model. If not specified, it will use
                 `default_{i}` where i is the total number of adapters being loaded.
         """
+        from peft import LoraConfig, inject_adapter_in_model, set_peft_model_state_dict
+
         low_cpu_mem_usage = low_cpu_mem_usage if low_cpu_mem_usage is not None else _LOW_CPU_MEM_USAGE_DEFAULT
 
         keys = list(state_dict.keys())
@@ -705,8 +639,6 @@ class LoraLoaderMixin:
             }
 
         if len(state_dict.keys()) > 0:
-            from peft import LoraConfig, inject_adapter_in_model, set_peft_model_state_dict
-
             if adapter_name in getattr(transformer, "peft_config", {}):
                 raise ValueError(
                     f"Adapter name {adapter_name} already in use in the transformer - please select a new adapter name."
@@ -754,118 +686,20 @@ class LoraLoaderMixin:
         return self._lora_scale if hasattr(self, "_lora_scale") else 1.0
 
     def _remove_text_encoder_monkey_patch(self):
-        if USE_PEFT_BACKEND:
-            remove_method = recurse_remove_peft_layers
-        else:
-            remove_method = self._remove_text_encoder_monkey_patch_classmethod
-
+        remove_method = recurse_remove_peft_layers
         if hasattr(self, "text_encoder"):
             remove_method(self.text_encoder)
-
             # In case text encoder have no Lora attached
-            if USE_PEFT_BACKEND and getattr(self.text_encoder, "peft_config", None) is not None:
+            if getattr(self.text_encoder, "peft_config", None) is not None:
                 del self.text_encoder.peft_config
                 self.text_encoder._hf_peft_config_loaded = None
+
         if hasattr(self, "text_encoder_2"):
             remove_method(self.text_encoder_2)
-            if USE_PEFT_BACKEND:
+            if getattr(self.text_encoder_2, "peft_config", None) is not None:
                 del self.text_encoder_2.peft_config
                 self.text_encoder_2._hf_peft_config_loaded = None
 
-    @classmethod
-    def _remove_text_encoder_monkey_patch_classmethod(cls, text_encoder):
-        deprecate("_remove_text_encoder_monkey_patch_classmethod", "0.27", LORA_DEPRECATION_MESSAGE)
-
-        for _, attn_module in text_encoder_attn_modules(text_encoder):
-            if isinstance(attn_module.q_proj, PatchedLoraProjection):
-                attn_module.q_proj.lora_linear_layer = None
-                attn_module.k_proj.lora_linear_layer = None
-                attn_module.v_proj.lora_linear_layer = None
-                attn_module.out_proj.lora_linear_layer = None
-
-        for _, mlp_module in text_encoder_mlp_modules(text_encoder):
-            if isinstance(mlp_module.fc1, PatchedLoraProjection):
-                mlp_module.fc1.lora_linear_layer = None
-                mlp_module.fc2.lora_linear_layer = None
-
-    @classmethod
-    def _modify_text_encoder(
-        cls,
-        text_encoder,
-        lora_scale=1,
-        network_alphas=None,
-        rank: Union[Dict[str, int], int] = 4,
-        dtype=None,
-        patch_mlp=False,
-        low_cpu_mem_usage=False,
-    ):
-        r"""
-        Monkey-patches the forward passes of attention modules of the text encoder.
-        """
-        deprecate("_modify_text_encoder", "0.27", LORA_DEPRECATION_MESSAGE)
-
-        def create_patched_linear_lora(model, network_alpha, rank, dtype, lora_parameters):
-            linear_layer = model.regular_linear_layer if isinstance(model, PatchedLoraProjection) else model
-            ctx = init_empty_weights if low_cpu_mem_usage else nullcontext
-            with ctx():
-                model = PatchedLoraProjection(linear_layer, lora_scale, network_alpha, rank, dtype=dtype)
-
-            lora_parameters.extend(model.lora_linear_layer.parameters())
-            return model
-
-        # First, remove any monkey-patch that might have been applied before
-        cls._remove_text_encoder_monkey_patch_classmethod(text_encoder)
-
-        lora_parameters = []
-        network_alphas = {} if network_alphas is None else network_alphas
-        is_network_alphas_populated = len(network_alphas) > 0
-
-        for name, attn_module in text_encoder_attn_modules(text_encoder):
-            query_alpha = network_alphas.pop(name + ".to_q_lora.down.weight.alpha", None)
-            key_alpha = network_alphas.pop(name + ".to_k_lora.down.weight.alpha", None)
-            value_alpha = network_alphas.pop(name + ".to_v_lora.down.weight.alpha", None)
-            out_alpha = network_alphas.pop(name + ".to_out_lora.down.weight.alpha", None)
-
-            if isinstance(rank, dict):
-                current_rank = rank.pop(f"{name}.out_proj.lora_linear_layer.up.weight")
-            else:
-                current_rank = rank
-
-            attn_module.q_proj = create_patched_linear_lora(
-                attn_module.q_proj, query_alpha, current_rank, dtype, lora_parameters
-            )
-            attn_module.k_proj = create_patched_linear_lora(
-                attn_module.k_proj, key_alpha, current_rank, dtype, lora_parameters
-            )
-            attn_module.v_proj = create_patched_linear_lora(
-                attn_module.v_proj, value_alpha, current_rank, dtype, lora_parameters
-            )
-            attn_module.out_proj = create_patched_linear_lora(
-                attn_module.out_proj, out_alpha, current_rank, dtype, lora_parameters
-            )
-
-        if patch_mlp:
-            for name, mlp_module in text_encoder_mlp_modules(text_encoder):
-                fc1_alpha = network_alphas.pop(name + ".fc1.lora_linear_layer.down.weight.alpha", None)
-                fc2_alpha = network_alphas.pop(name + ".fc2.lora_linear_layer.down.weight.alpha", None)
-
-                current_rank_fc1 = rank.pop(f"{name}.fc1.lora_linear_layer.up.weight")
-                current_rank_fc2 = rank.pop(f"{name}.fc2.lora_linear_layer.up.weight")
-
-                mlp_module.fc1 = create_patched_linear_lora(
-                    mlp_module.fc1, fc1_alpha, current_rank_fc1, dtype, lora_parameters
-                )
-                mlp_module.fc2 = create_patched_linear_lora(
-                    mlp_module.fc2, fc2_alpha, current_rank_fc2, dtype, lora_parameters
-                )
-
-        if is_network_alphas_populated and len(network_alphas) > 0:
-            raise ValueError(
-                f"The `network_alphas` has to be empty at this point but has the following keys \n\n {', '.join(network_alphas.keys())}"
-            )
-
-        return lora_parameters
-
     @classmethod
     def save_lora_weights(
         cls,
@@ -1039,6 +873,8 @@ class LoraLoaderMixin:
         pipeline.fuse_lora(lora_scale=0.7)
         ```
         """
+        from peft.tuners.tuners_utils import BaseTunerLayer
+
         if fuse_unet or fuse_text_encoder:
             self.num_fused_loras += 1
             if self.num_fused_loras > 1:
@@ -1050,52 +886,26 @@ class LoraLoaderMixin:
             unet = getattr(self, self.unet_name) if not hasattr(self, "unet") else self.unet
             unet.fuse_lora(lora_scale, safe_fusing=safe_fusing, adapter_names=adapter_names)
 
-        if USE_PEFT_BACKEND:
-            from peft.tuners.tuners_utils import BaseTunerLayer
+        def fuse_text_encoder_lora(text_encoder, lora_scale=1.0, safe_fusing=False, adapter_names=None):
+            merge_kwargs = {"safe_merge": safe_fusing}
 
-            def fuse_text_encoder_lora(text_encoder, lora_scale=1.0, safe_fusing=False, adapter_names=None):
-                merge_kwargs = {"safe_merge": safe_fusing}
+            for module in text_encoder.modules():
+                if isinstance(module, BaseTunerLayer):
+                    if lora_scale != 1.0:
+                        module.scale_layer(lora_scale)
 
-                for module in text_encoder.modules():
-                    if isinstance(module, BaseTunerLayer):
-                        if lora_scale != 1.0:
-                            module.scale_layer(lora_scale)
+                    # For BC with previous PEFT versions, we need to check the signature
+                    # of the `merge` method to see if it supports the `adapter_names` argument.
+                    supported_merge_kwargs = list(inspect.signature(module.merge).parameters)
+                    if "adapter_names" in supported_merge_kwargs:
+                        merge_kwargs["adapter_names"] = adapter_names
+                    elif "adapter_names" not in supported_merge_kwargs and adapter_names is not None:
+                        raise ValueError(
+                            "The `adapter_names` argument is not supported with your PEFT version. "
+                            "Please upgrade to the latest version of PEFT. `pip install -U peft`"
+                        )
 
-                        # For BC with previous PEFT versions, we need to check the signature
-                        # of the `merge` method to see if it supports the `adapter_names` argument.
-                        supported_merge_kwargs = list(inspect.signature(module.merge).parameters)
-                        if "adapter_names" in supported_merge_kwargs:
-                            merge_kwargs["adapter_names"] = adapter_names
-                        elif "adapter_names" not in supported_merge_kwargs and adapter_names is not None:
-                            raise ValueError(
-                                "The `adapter_names` argument is not supported with your PEFT version. "
-                                "Please upgrade to the latest version of PEFT. `pip install -U peft`"
-                            )
-
-                        module.merge(**merge_kwargs)
-
-        else:
-            deprecate("fuse_text_encoder_lora", "0.27", LORA_DEPRECATION_MESSAGE)
-
-            def fuse_text_encoder_lora(text_encoder, lora_scale=1.0, safe_fusing=False, **kwargs):
-                if "adapter_names" in kwargs and kwargs["adapter_names"] is not None:
-                    raise ValueError(
-                        "The `adapter_names` argument is not supported in your environment. Please switch to PEFT "
-                        "backend to use this argument by installing latest PEFT and transformers."
-                        " `pip install -U peft transformers`"
-                    )
-
-                for _, attn_module in text_encoder_attn_modules(text_encoder):
-                    if isinstance(attn_module.q_proj, PatchedLoraProjection):
-                        attn_module.q_proj._fuse_lora(lora_scale, safe_fusing)
-                        attn_module.k_proj._fuse_lora(lora_scale, safe_fusing)
-                        attn_module.v_proj._fuse_lora(lora_scale, safe_fusing)
-                        attn_module.out_proj._fuse_lora(lora_scale, safe_fusing)
-
-                for _, mlp_module in text_encoder_mlp_modules(text_encoder):
-                    if isinstance(mlp_module.fc1, PatchedLoraProjection):
-                        mlp_module.fc1._fuse_lora(lora_scale, safe_fusing)
-                        mlp_module.fc2._fuse_lora(lora_scale, safe_fusing)
+                    module.merge(**merge_kwargs)
 
         if fuse_text_encoder:
             if hasattr(self, "text_encoder"):
@@ -1120,40 +930,18 @@ class LoraLoaderMixin:
                 Whether to unfuse the text encoder LoRA parameters. If the text encoder wasn't monkey-patched with the
                 LoRA parameters then it won't have any effect.
         """
+        from peft.tuners.tuners_utils import BaseTunerLayer
+
         unet = getattr(self, self.unet_name) if not hasattr(self, "unet") else self.unet
         if unfuse_unet:
-            if not USE_PEFT_BACKEND:
-                unet.unfuse_lora()
-            else:
-                from peft.tuners.tuners_utils import BaseTunerLayer
+            for module in unet.modules():
+                if isinstance(module, BaseTunerLayer):
+                    module.unmerge()
 
-                for module in unet.modules():
-                    if isinstance(module, BaseTunerLayer):
-                        module.unmerge()
-
-        if USE_PEFT_BACKEND:
-            from peft.tuners.tuners_utils import BaseTunerLayer
-
-            def unfuse_text_encoder_lora(text_encoder):
-                for module in text_encoder.modules():
-                    if isinstance(module, BaseTunerLayer):
-                        module.unmerge()
-
-        else:
-            deprecate("unfuse_text_encoder_lora", "0.27", LORA_DEPRECATION_MESSAGE)
-
-            def unfuse_text_encoder_lora(text_encoder):
-                for _, attn_module in text_encoder_attn_modules(text_encoder):
-                    if isinstance(attn_module.q_proj, PatchedLoraProjection):
-                        attn_module.q_proj._unfuse_lora()
-                        attn_module.k_proj._unfuse_lora()
-                        attn_module.v_proj._unfuse_lora()
-                        attn_module.out_proj._unfuse_lora()
-
-                for _, mlp_module in text_encoder_mlp_modules(text_encoder):
-                    if isinstance(mlp_module.fc1, PatchedLoraProjection):
-                        mlp_module.fc1._unfuse_lora()
-                        mlp_module.fc2._unfuse_lora()
+        def unfuse_text_encoder_lora(text_encoder):
+            for module in text_encoder.modules():
+                if isinstance(module, BaseTunerLayer):
+                    module.unmerge()
 
         if unfuse_text_encoder:
             if hasattr(self, "text_encoder"):
@@ -1434,6 +1222,9 @@ class StableDiffusionXLLoraLoaderMixin(LoraLoaderMixin):
             kwargs (`dict`, *optional*):
                 See [`~loaders.LoraLoaderMixin.lora_state_dict`].
         """
+        if not USE_PEFT_BACKEND:
+            raise ValueError("PEFT backend is required for this method.")
+
         # We could have accessed the unet config from `lora_state_dict()` too. We pass
         # it here explicitly to be able to tell that it's coming from an SDXL
         # pipeline.
@@ -1538,17 +1329,13 @@ class StableDiffusionXLLoraLoaderMixin(LoraLoaderMixin):
         )
 
     def _remove_text_encoder_monkey_patch(self):
-        if USE_PEFT_BACKEND:
-            recurse_remove_peft_layers(self.text_encoder)
-            # TODO: @younesbelkada handle this in transformers side
-            if getattr(self.text_encoder, "peft_config", None) is not None:
-                del self.text_encoder.peft_config
-                self.text_encoder._hf_peft_config_loaded = None
+        recurse_remove_peft_layers(self.text_encoder)
+        # TODO: @younesbelkada handle this in transformers side
+        if getattr(self.text_encoder, "peft_config", None) is not None:
+            del self.text_encoder.peft_config
+            self.text_encoder._hf_peft_config_loaded = None
 
-            recurse_remove_peft_layers(self.text_encoder_2)
-            if getattr(self.text_encoder_2, "peft_config", None) is not None:
-                del self.text_encoder_2.peft_config
-                self.text_encoder_2._hf_peft_config_loaded = None
-        else:
-            self._remove_text_encoder_monkey_patch_classmethod(self.text_encoder)
-            self._remove_text_encoder_monkey_patch_classmethod(self.text_encoder_2)
+        recurse_remove_peft_layers(self.text_encoder_2)
+        if getattr(self.text_encoder_2, "peft_config", None) is not None:
+            del self.text_encoder_2.peft_config
+            self.text_encoder_2._hf_peft_config_loaded = None

src/diffusers/models/lora.py

@@ -27,7 +27,7 @@ import torch
 import torch.nn.functional as F
 from torch import nn
 
-from ..utils import logging
+from ..utils import deprecate, logging
 from ..utils.import_utils import is_transformers_available
 
 
@@ -82,6 +82,9 @@ def adjust_lora_scale_text_encoder(text_encoder, lora_scale: float = 1.0):
 
 class PatchedLoraProjection(torch.nn.Module):
     def __init__(self, regular_linear_layer, lora_scale=1, network_alpha=None, rank=4, dtype=None):
+        deprecation_message = "Use of `PatchedLoraProjection` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("PatchedLoraProjection", "1.0.0", deprecation_message)
+
         super().__init__()
         from ..models.lora import LoRALinearLayer
 
@@ -293,10 +296,16 @@ class LoRACompatibleConv(nn.Conv2d):
     """
 
     def __init__(self, *args, lora_layer: Optional[LoRAConv2dLayer] = None, **kwargs):
+        deprecation_message = "Use of `LoRACompatibleConv` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("LoRACompatibleConv", "1.0.0", deprecation_message)
+
         super().__init__(*args, **kwargs)
         self.lora_layer = lora_layer
 
     def set_lora_layer(self, lora_layer: Optional[LoRAConv2dLayer]):
+        deprecation_message = "Use of `set_lora_layer()` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("set_lora_layer", "1.0.0", deprecation_message)
+
         self.lora_layer = lora_layer
 
     def _fuse_lora(self, lora_scale: float = 1.0, safe_fusing: bool = False):
@@ -371,10 +380,15 @@ class LoRACompatibleLinear(nn.Linear):
     """
 
     def __init__(self, *args, lora_layer: Optional[LoRALinearLayer] = None, **kwargs):
+        deprecation_message = "Use of `LoRACompatibleLinear` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("LoRACompatibleLinear", "1.0.0", deprecation_message)
+
         super().__init__(*args, **kwargs)
         self.lora_layer = lora_layer
 
     def set_lora_layer(self, lora_layer: Optional[LoRALinearLayer]):
+        deprecation_message = "Use of `set_lora_layer()` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("set_lora_layer", "1.0.0", deprecation_message)
         self.lora_layer = lora_layer
 
     def _fuse_lora(self, lora_scale: float = 1.0, safe_fusing: bool = False):

tests/lora/test_peft_lora_in_non_peft.py

@@ -1,64 +0,0 @@
-# coding=utf-8
-# Copyright 2024 HuggingFace Inc.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-import unittest
-
-import numpy as np
-import torch
-
-from diffusers import DiffusionPipeline
-from diffusers.utils.testing_utils import torch_device
-
-
-class PEFTLoRALoading(unittest.TestCase):
-    def get_dummy_inputs(self):
-        pipeline_inputs = {
-            "prompt": "A painting of a squirrel eating a burger",
-            "num_inference_steps": 2,
-            "guidance_scale": 6.0,
-            "output_type": "np",
-            "generator": torch.manual_seed(0),
-        }
-        return pipeline_inputs
-
-    def test_stable_diffusion_peft_lora_loading_in_non_peft(self):
-        sd_pipe = DiffusionPipeline.from_pretrained("hf-internal-testing/tiny-sd-pipe").to(torch_device)
-        # This LoRA was obtained using similarly as how it's done in the training scripts.
-        # For details on how the LoRA was obtained, refer to:
-        # https://hf.co/datasets/diffusers/notebooks/blob/main/check_logits_with_serialization_peft_lora.py
-        sd_pipe.load_lora_weights("hf-internal-testing/tiny-sd-lora-peft")
-
-        inputs = self.get_dummy_inputs()
-        outputs = sd_pipe(**inputs).images
-
-        predicted_slice = outputs[0, -3:, -3:, -1].flatten()
-        expected_slice = np.array([0.5396, 0.5707, 0.477, 0.4665, 0.5419, 0.4594, 0.4857, 0.4741, 0.4804])
-
-        self.assertTrue(outputs.shape == (1, 64, 64, 3))
-        assert np.allclose(expected_slice, predicted_slice, atol=1e-3, rtol=1e-3)
-
-    def test_stable_diffusion_xl_peft_lora_loading_in_non_peft(self):
-        sd_pipe = DiffusionPipeline.from_pretrained("hf-internal-testing/tiny-sdxl-pipe").to(torch_device)
-        # This LoRA was obtained using similarly as how it's done in the training scripts.
-        sd_pipe.load_lora_weights("hf-internal-testing/tiny-sdxl-lora-peft")
-
-        inputs = self.get_dummy_inputs()
-        outputs = sd_pipe(**inputs).images
-
-        predicted_slice = outputs[0, -3:, -3:, -1].flatten()
-        expected_slice = np.array([0.613, 0.5566, 0.54, 0.4162, 0.4042, 0.4596, 0.5374, 0.5286, 0.5038])
-
-        self.assertTrue(outputs.shape == (1, 64, 64, 3))
-        assert np.allclose(expected_slice, predicted_slice, atol=1e-3, rtol=1e-3)