From 36eaff3364e8cd35552a77ee426a8170f4f5fde9 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 24 Feb 2017 14:58:04 -0800 Subject: [PATCH] mm, ksm: convert write_protect_page() to use page_vma_mapped_walk() For consistency, it worth converting all page_check_address() to page_vma_mapped_walk(), so we could drop the former. Link: http://lkml.kernel.org/r/20170129173858.45174-9-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Cc: Andrea Arcangeli Cc: Hillf Danton Cc: Hugh Dickins Cc: Johannes Weiner Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rik van Riel Cc: Srikar Dronamraju Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/ksm.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) diff --git a/mm/ksm.c b/mm/ksm.c index 28bc5ab2b979..8960f6ecbc12 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -856,33 +856,35 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page, pte_t *orig_pte) { struct mm_struct *mm = vma->vm_mm; - unsigned long addr; - pte_t *ptep; - spinlock_t *ptl; + struct page_vma_mapped_walk pvmw = { + .page = page, + .vma = vma, + }; int swapped; int err = -EFAULT; unsigned long mmun_start; /* For mmu_notifiers */ unsigned long mmun_end; /* For mmu_notifiers */ - addr = page_address_in_vma(page, vma); - if (addr == -EFAULT) + pvmw.address = page_address_in_vma(page, vma); + if (pvmw.address == -EFAULT) goto out; BUG_ON(PageTransCompound(page)); - mmun_start = addr; - mmun_end = addr + PAGE_SIZE; + mmun_start = pvmw.address; + mmun_end = pvmw.address + PAGE_SIZE; mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); - ptep = page_check_address(page, mm, addr, &ptl, 0); - if (!ptep) + if (!page_vma_mapped_walk(&pvmw)) goto out_mn; + if (WARN_ONCE(!pvmw.pte, "Unexpected PMD mapping?")) + goto out_unlock; - if (pte_write(*ptep) || pte_dirty(*ptep)) { + if (pte_write(*pvmw.pte) || pte_dirty(*pvmw.pte)) { pte_t entry; swapped = PageSwapCache(page); - flush_cache_page(vma, addr, page_to_pfn(page)); + flush_cache_page(vma, pvmw.address, page_to_pfn(page)); /* * Ok this is tricky, when get_user_pages_fast() run it doesn't * take any lock, therefore the check that we are going to make @@ -892,25 +894,25 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page, * this assure us that no O_DIRECT can happen after the check * or in the middle of the check. */ - entry = ptep_clear_flush_notify(vma, addr, ptep); + entry = ptep_clear_flush_notify(vma, pvmw.address, pvmw.pte); /* * Check that no O_DIRECT or similar I/O is in progress on the * page */ if (page_mapcount(page) + 1 + swapped != page_count(page)) { - set_pte_at(mm, addr, ptep, entry); + set_pte_at(mm, pvmw.address, pvmw.pte, entry); goto out_unlock; } if (pte_dirty(entry)) set_page_dirty(page); entry = pte_mkclean(pte_wrprotect(entry)); - set_pte_at_notify(mm, addr, ptep, entry); + set_pte_at_notify(mm, pvmw.address, pvmw.pte, entry); } - *orig_pte = *ptep; + *orig_pte = *pvmw.pte; err = 0; out_unlock: - pte_unmap_unlock(ptep, ptl); + page_vma_mapped_walk_done(&pvmw); out_mn: mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); out: -- 2.20.1