[PATCH v5 4/5] mm: Use is_cow_mapping() across tree where proper

[Peter Xu]

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-maintai...@vmware.com>
Cc: Roland Scheidegger <srol...@vmware.com>
Cc: David Airlie <airl...@linux.ie>
Cc: Daniel Vetter <dan...@ffwll.ch>
Cc: Mike Kravetz <mike.krav...@oracle.com>
Cc: Alexey Dobriyan <adobri...@gmail.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Reviewed-by: Jason Gunthorpe <j...@ziepe.ca>
Signed-off-by: Peter Xu <pet...@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 0a900afc66ff..45c9c6a7f1d6 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 3cec6fbef725..e862cab69583 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 2ba4ea4ab46e..8379224e1d43 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3731,15 +3731,13 @@ 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;
        unsigned long addr;
-       int cow;
+       bool 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