drm/bochs: Don't grab dev->struct_mutex for in mmap offset ioctl

Since David Herrmann's mmap vma manager rework we don't need to grab
dev->struct_mutex any more to prevent races when looking up the mmap
offset. Drop it and instead don't forget to use the unref_unlocked
variant (since the drm core still cares).

Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

diff --git a/drivers/gpu/drm/bochs/bochs_mm.c b/drivers/gpu/drm/bochs/bochs_mm.c
index 66286ff518d4be28e8b71b2b8ebf0d0b2ada6496..f69e6bf9bb0e3cd295285f3fbf5ad72c49a3ed93 100644 (file)
--- a/drivers/gpu/drm/bochs/bochs_mm.c
+++ b/drivers/gpu/drm/bochs/bochs_mm.c
@@ -454,25 +454,17 @@ int bochs_dumb_mmap_offset(struct drm_file *file, struct drm_device *dev,
                           uint32_t handle, uint64_t *offset)
 {
        struct drm_gem_object *obj;
-       int ret;
        struct bochs_bo *bo;
 
-       mutex_lock(&dev->struct_mutex);
        obj = drm_gem_object_lookup(dev, file, handle);
-       if (obj == NULL) {
-               ret = -ENOENT;
-               goto out_unlock;
-       }
+       if (obj == NULL)
+               return -ENOENT;
 
        bo = gem_to_bochs_bo(obj);
        *offset = bochs_bo_mmap_offset(bo);
 
-       drm_gem_object_unreference(obj);
-       ret = 0;
-out_unlock:
-       mutex_unlock(&dev->struct_mutex);
-       return ret;
-
+       drm_gem_object_unreference_unlocked(obj);
+       return 0;
 }
 
 /* ---------------------------------------------------------------------- */