#include <linux/memcontrol.h>
#include <linux/mmu_notifier.h>
#include <linux/migrate.h>
+#include <linux/hugetlb.h>
#include <asm/tlbflush.h>
*/
struct anon_vma *page_lock_anon_vma(struct page *page)
{
- struct anon_vma *anon_vma;
+ struct anon_vma *anon_vma, *root_anon_vma;
unsigned long anon_mapping;
rcu_read_lock();
goto out;
anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);
- anon_vma_lock(anon_vma);
- return anon_vma;
+ root_anon_vma = ACCESS_ONCE(anon_vma->root);
+ spin_lock(&root_anon_vma->lock);
+
+ /*
+ * If this page is still mapped, then its anon_vma cannot have been
+ * freed. But if it has been unmapped, we have no security against
+ * the anon_vma structure being freed and reused (for another anon_vma:
+ * SLAB_DESTROY_BY_RCU guarantees that - so the spin_lock above cannot
+ * corrupt): with anon_vma_prepare() or anon_vma_fork() redirecting
+ * anon_vma->root before page_unlock_anon_vma() is called to unlock.
+ */
+ if (page_mapped(page))
+ return anon_vma;
+
+ spin_unlock(&root_anon_vma->lock);
out:
rcu_read_unlock();
return NULL;
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
unsigned long address;
+ if (unlikely(is_vm_hugetlb_page(vma)))
+ pgoff = page->index << huge_page_order(page_hstate(page));
address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
if (unlikely(address < vma->vm_start || address >= vma->vm_end)) {
/* page should be within @vma mapping range */
pte_t *pte;
spinlock_t *ptl;
+ if (unlikely(PageHuge(page))) {
+ pte = huge_pte_offset(mm, address);
+ ptl = &mm->page_table_lock;
+ goto check;
+ }
+
pgd = pgd_offset(mm, address);
if (!pgd_present(*pgd))
return NULL;
}
ptl = pte_lockptr(mm, pmd);
+check:
spin_lock(ptl);
if (pte_present(*pte) && page_to_pfn(page) == pte_pfn(*pte)) {
*ptlp = ptl;
page_clear_dirty(page);
set_page_dirty(page);
}
+ /*
+ * Hugepages are not counted in NR_ANON_PAGES nor NR_FILE_MAPPED
+ * and not charged by memcg for now.
+ */
+ if (unlikely(PageHuge(page)))
+ return;
if (PageAnon(page)) {
mem_cgroup_uncharge_page(page);
__dec_zone_page_state(page, NR_ANON_PAGES);
return rmap_walk_file(page, rmap_one, arg);
}
#endif /* CONFIG_MIGRATION */
+
+#ifdef CONFIG_HUGETLB_PAGE
+/*
+ * The following three functions are for anonymous (private mapped) hugepages.
+ * Unlike common anonymous pages, anonymous hugepages have no accounting code
+ * and no lru code, because we handle hugepages differently from common pages.
+ */
+static void __hugepage_set_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address, int exclusive)
+{
+ struct anon_vma *anon_vma = vma->anon_vma;
+
+ BUG_ON(!anon_vma);
+
+ if (PageAnon(page))
+ return;
+ if (!exclusive)
+ anon_vma = anon_vma->root;
+
+ anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
+ page->mapping = (struct address_space *) anon_vma;
+ page->index = linear_page_index(vma, address);
+}
+
+void hugepage_add_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ struct anon_vma *anon_vma = vma->anon_vma;
+ int first;
+ BUG_ON(!anon_vma);
+ BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+ first = atomic_inc_and_test(&page->_mapcount);
+ if (first)
+ __hugepage_set_anon_rmap(page, vma, address, 0);
+}
+
+void hugepage_add_new_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+ atomic_set(&page->_mapcount, 0);
+ __hugepage_set_anon_rmap(page, vma, address, 1);
+}
+#endif /* CONFIG_HUGETLB_PAGE */