dax: don't use set_huge_zero_page()

[mirror_ubuntu-bionic-kernel.git] / fs / dax.c

diff --git a/fs/dax.c b/fs/dax.c
index 9593f4bee32774e06fa5c8be7d1b24634cb8d0c0..d778e5f1a01cf3ff76e4f222f43bed90bf5d2774 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -572,18 +572,24 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
                unmap_mapping_range(mapping, pgoff << PAGE_SHIFT, PMD_SIZE, 0);
 
        if (!write && !buffer_mapped(&bh) && buffer_uptodate(&bh)) {
-               bool set;
                spinlock_t *ptl;
-               struct mm_struct *mm = vma->vm_mm;
+               pmd_t entry;
                struct page *zero_page = get_huge_zero_page();
+
                if (unlikely(!zero_page))
                        goto fallback;
 
-               ptl = pmd_lock(mm, pmd);
-               set = set_huge_zero_page(NULL, mm, vma, pmd_addr, pmd,
-                                                               zero_page);
-               spin_unlock(ptl);
+               ptl = pmd_lock(vma->vm_mm, pmd);
+               if (!pmd_none(*pmd)) {
+                       spin_unlock(ptl);
+                       goto fallback;
+               }
+
+               entry = mk_pmd(zero_page, vma->vm_page_prot);
+               entry = pmd_mkhuge(entry);
+               set_pmd_at(vma->vm_mm, pmd_addr, pmd, entry);
                result = VM_FAULT_NOPAGE;
+               spin_unlock(ptl);
        } else {
                sector = bh.b_blocknr << (blkbits - 9);
                length = bdev_direct_access(bh.b_bdev, sector, &kaddr, &pfn,