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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 <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
Kirill A. Shutemov 2017-02-24 14:58:04 -08:00 committed by Linus Torvalds
parent c7ab0d2fdc
commit 36eaff3364
1 changed files with 18 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
mm/ksm.c
View File

@ -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: