[PATCH v2 5/4] mm: Use is_cow_mapping() across tree where proper

Peter Xu
2021-02-04T20:24:07Z

After is_cow_mapping() is exported in mm.h, replace some manual checks
elsewhere throughout the tree but start to use the new helper.

Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Roland Scheidegger <sroland@vmware.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c | 4 +---
drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c | 2 +-
fs/proc/task_mmu.c | 2 --
mm/hugetlb.c | 4 +---
4 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c
index 0b76b3d17d4c..22c4a0e9d250 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c
@@ -500,8 +500,6 @@ vm_fault_t vmw_bo_vm_huge_fault(struct vm_fault *vmf,
vm_fault_t ret;
pgoff_t fault_page_size;
bool write = vmf->flags & FAULT_FLAG_WRITE;
- bool is_cow_mapping =
- (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;

switch (pe_size) {
case PE_SIZE_PMD:
@@ -518,7 +516,7 @@ vm_fault_t vmw_bo_vm_huge_fault(struct vm_fault *vmf,
}

/* Always do write dirty-tracking and COW on PTE level. */
- if (write && (READ_ONCE(vbo->dirty) || is_cow_mapping))
+ if (write && (READ_ONCE(vbo->dirty) || is_cow_mapping(vma->vm_flags)))
return VM_FAULT_FALLBACK;

ret = ttm_bo_vm_reserve(bo, vmf);
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
index 3c03b1746661..cb9975889e2f 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
@@ -49,7 +49,7 @@ int vmw_mmap(struct file *filp, struct vm_area_struct *vma)
vma->vm_ops = &vmw_vm_ops;

/* Use VM_PFNMAP rather than VM_MIXEDMAP if not a COW mapping */
- if ((vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) != VM_MAYWRITE)
+ if (!is_cow_mapping(vma->vm_flags))
vma->vm_flags = (vma->vm_flags & ~VM_MIXEDMAP) | VM_PFNMAP;

return 0;
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 602e3a52884d..96c1682025f9 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1036,8 +1036,6 @@ struct clear_refs_private {

#ifdef CONFIG_MEM_SOFT_DIRTY

-#define is_cow_mapping(flags) (((flags) & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE)
-
static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
{
struct page *page;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 5793936e00ef..684d91b68b60 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3756,15 +3756,13 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
pte_t *src_pte, *dst_pte, entry, dst_entry;
struct page *ptepage, *prealloc = NULL;
unsigned long addr;
- int cow;
+ int cow = is_cow_mapping(vma->vm_flags);
struct hstate *h = hstate_vma(vma);
unsigned long sz = huge_page_size(h);
struct address_space *mapping = vma->vm_file->f_mapping;
struct mmu_notifier_range range;
int ret = 0;

- cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
-
if (cow) {
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, src,
vma->vm_start,
--
2.26.2