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thp: fix zap_huge_pmd() for DAX 

The original DAX code assumed that pgtable_t was a pointer, which isn't
true on all architectures.  Restructure the code to not rely on that
assumption.

[willy@linux.intel.com: further fixes integrated into this patch]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kirill A. Shutemov 2015-09-08 14:59:31 -07:00 committed by Linus Torvalds
parent 5b701b846a
commit da14676900
1 changed files with 31 additions and 40 deletions
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71
mm/huge_memory.c
View File

@ -1456,50 +1456,41 @@ out:
int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
pmd_t *pmd, unsigned long addr)
{
pmd_t orig_pmd;
spinlock_t *ptl;
int ret = 0;
if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
pgtable_t pgtable;
pmd_t orig_pmd;
/*
* For architectures like ppc64 we look at deposited pgtable
* when calling pmdp_huge_get_and_clear. So do the
* pgtable_trans_huge_withdraw after finishing pmdp related
* operations.
*/
orig_pmd = pmdp_huge_get_and_clear_full(tlb->mm, addr, pmd,
tlb->fullmm);
tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
if (vma_is_dax(vma)) {
if (is_huge_zero_pmd(orig_pmd)) {
pgtable = NULL;
} else {
spin_unlock(ptl);
return 1;
}
} else {
pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
}
if (is_huge_zero_pmd(orig_pmd)) {
atomic_long_dec(&tlb->mm->nr_ptes);
spin_unlock(ptl);
if (__pmd_trans_huge_lock(pmd, vma, &ptl) != 1)
return 0;
/*
* For architectures like ppc64 we look at deposited pgtable
* when calling pmdp_huge_get_and_clear. So do the
* pgtable_trans_huge_withdraw after finishing pmdp related
* operations.
*/
orig_pmd = pmdp_huge_get_and_clear_full(tlb->mm, addr, pmd,
tlb->fullmm);
tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
if (vma_is_dax(vma)) {
spin_unlock(ptl);
if (is_huge_zero_pmd(orig_pmd))
put_huge_zero_page();
} else {
struct page *page = pmd_page(orig_pmd);
page_remove_rmap(page);
VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);
add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
VM_BUG_ON_PAGE(!PageHead(page), page);
atomic_long_dec(&tlb->mm->nr_ptes);
spin_unlock(ptl);
tlb_remove_page(tlb, page);
}
if (pgtable)
pte_free(tlb->mm, pgtable);
ret = 1;
} else if (is_huge_zero_pmd(orig_pmd)) {
pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd));
atomic_long_dec(&tlb->mm->nr_ptes);
spin_unlock(ptl);
put_huge_zero_page();
} else {
struct page *page = pmd_page(orig_pmd);
page_remove_rmap(page);
VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);
add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
VM_BUG_ON_PAGE(!PageHead(page), page);
pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd));
atomic_long_dec(&tlb->mm->nr_ptes);
spin_unlock(ptl);
tlb_remove_page(tlb, page);
}
return ret;
return 1;
}
int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,