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

Christoph Hellwig
2018-05-16T05:47:41Z

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

Signed-off-by: Christoph Hellwig <hch@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