[PATCH 10/14] vgem: separate errno from VM_FAULT_* values

[Christoph Hellwig]

And streamline the code in vgem_fault with early returns so that it is
a little bit more readable.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 drivers/gpu/drm/vgem/vgem_drv.c | 51 +++++++++++++++------------------
 1 file changed, 23 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
index 2524ff116f00..a261e0aab83a 100644
--- a/drivers/gpu/drm/vgem/vgem_drv.c
+++ b/drivers/gpu/drm/vgem/vgem_drv.c
@@ -61,12 +61,13 @@ static void vgem_gem_free_object(struct drm_gem_object *obj)
        kfree(vgem_obj);
 }
 
-static int vgem_gem_fault(struct vm_fault *vmf)
+static vm_fault_t vgem_gem_fault(struct vm_fault *vmf)
 {
        struct vm_area_struct *vma = vmf->vma;
        struct drm_vgem_gem_object *obj = vma->vm_private_data;
        /* We don't use vmf->pgoff since that has the fake offset */
        unsigned long vaddr = vmf->address;
+       struct page *page;
        int ret;
        loff_t num_pages;
        pgoff_t page_offset;
@@ -85,35 +86,29 @@ static int vgem_gem_fault(struct vm_fault *vmf)
                ret = 0;
        }
        mutex_unlock(&obj->pages_lock);
-       if (ret) {
-               struct page *page;
-
-               page = shmem_read_mapping_page(
-                                       file_inode(obj->base.filp)->i_mapping,
-                                       page_offset);
-               if (!IS_ERR(page)) {
-                       vmf->page = page;
-                       ret = 0;
-               } else switch (PTR_ERR(page)) {
-                       case -ENOSPC:
-                       case -ENOMEM:
-                               ret = VM_FAULT_OOM;
-                               break;
-                       case -EBUSY:
-                               ret = VM_FAULT_RETRY;
-                               break;
-                       case -EFAULT:
-                       case -EINVAL:
-                               ret = VM_FAULT_SIGBUS;
-                               break;
-                       default:
-                               WARN_ON(PTR_ERR(page));
-                               ret = VM_FAULT_SIGBUS;
-                               break;
-               }
+       if (!ret)
+               return 0;
+
+       page = shmem_read_mapping_page(file_inode(obj->base.filp)->i_mapping,
+                       page_offset);
+       if (!IS_ERR(page)) {
+               vmf->page = page;
+               return 0;
+       }
 
+       switch (PTR_ERR(page)) {
+       case -ENOSPC:
+       case -ENOMEM:
+               return VM_FAULT_OOM;
+       case -EBUSY:
+               return VM_FAULT_RETRY;
+       case -EFAULT:
+       case -EINVAL:
+               return VM_FAULT_SIGBUS;
+       default:
+               WARN_ON(PTR_ERR(page));
+               return VM_FAULT_SIGBUS;
        }
-       return ret;
 }
 
 static const struct vm_operations_struct vgem_gem_vm_ops = {
-- 
2.17.0

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