diff options
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index 296e0bbf7836..510f0039b000 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -401,8 +401,6 @@ void free_swap_and_cache(swp_entry_t entry) * No need to decide whether this PTE shares the swap entry with others, * just let do_wp_page work it out if a write is requested later - to * force COW, vm_page_prot omits write permission from any private vma. - * - * vma->vm_mm->page_table_lock is held. */ static void unuse_pte(struct vm_area_struct *vma, pte_t *pte, unsigned long addr, swp_entry_t entry, struct page *page) @@ -424,23 +422,25 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, swp_entry_t entry, struct page *page) { - pte_t *pte; pte_t swp_pte = swp_entry_to_pte(entry); + pte_t *pte; + spinlock_t *ptl; + int found = 0; - pte = pte_offset_map(pmd, addr); + pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); do { /* * swapoff spends a _lot_ of time in this loop! * Test inline before going to call unuse_pte. */ if (unlikely(pte_same(*pte, swp_pte))) { - unuse_pte(vma, pte, addr, entry, page); - pte_unmap(pte); - return 1; + unuse_pte(vma, pte++, addr, entry, page); + found = 1; + break; } } while (pte++, addr += PAGE_SIZE, addr != end); - pte_unmap(pte - 1); - return 0; + pte_unmap_unlock(pte - 1, ptl); + return found; } static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud, @@ -522,12 +522,10 @@ static int unuse_mm(struct mm_struct *mm, down_read(&mm->mmap_sem); lock_page(page); } - spin_lock(&mm->page_table_lock); for (vma = mm->mmap; vma; vma = vma->vm_next) { if (vma->anon_vma && unuse_vma(vma, entry, page)) break; } - spin_unlock(&mm->page_table_lock); up_read(&mm->mmap_sem); /* * Currently unuse_mm cannot fail, but leave error handling |