* anon_vma->lock
* mm->page_table_lock
* zone->lru_lock (in mark_page_accessed)
- * swap_list_lock (in swap_free etc's swap_info_get)
+ * swap_lock (in swap_duplicate, swap_info_get)
* mmlist_lock (in mmput, drain_mmlist and others)
- * swap_device_lock (in swap_duplicate, swap_info_get)
* mapping->private_lock (in __set_page_dirty_buffers)
* inode_lock (in set_page_dirty's __mark_inode_dirty)
* sb_lock (within inode_lock in fs/fs-writeback.c)
*
* On success returns with mapped pte and locked mm->page_table_lock.
*/
-static pte_t *page_check_address(struct page *page, struct mm_struct *mm,
- unsigned long address)
+pte_t *page_check_address(struct page *page, struct mm_struct *mm,
+ unsigned long address)
{
pgd_t *pgd;
pud_t *pud;
pte_t *pte;
int referenced = 0;
- if (!get_mm_counter(mm, rss))
- goto out;
address = vma_address(page, vma);
if (address == -EFAULT)
goto out;
void page_add_anon_rmap(struct page *page,
struct vm_area_struct *vma, unsigned long address)
{
- struct anon_vma *anon_vma = vma->anon_vma;
- pgoff_t index;
-
BUG_ON(PageReserved(page));
- BUG_ON(!anon_vma);
inc_mm_counter(vma->vm_mm, anon_rss);
- anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
- index = (address - vma->vm_start) >> PAGE_SHIFT;
- index += vma->vm_pgoff;
- index >>= PAGE_CACHE_SHIFT - PAGE_SHIFT;
-
if (atomic_inc_and_test(&page->_mapcount)) {
- page->index = index;
+ struct anon_vma *anon_vma = vma->anon_vma;
+
+ BUG_ON(!anon_vma);
+ anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
page->mapping = (struct address_space *) anon_vma;
+
+ page->index = linear_page_index(vma, address);
+
inc_page_state(nr_mapped);
}
/* else checking page index and mapping is racy */
pte_t pteval;
int ret = SWAP_AGAIN;
- if (!get_mm_counter(mm, rss))
- goto out;
address = vma_address(page, vma);
if (address == -EFAULT)
goto out;
* If the page is mlock()d, we cannot swap it out.
* If it's recently referenced (perhaps page_referenced
* skipped over this mm) then we should reactivate it.
+ *
+ * Pages belonging to VM_RESERVED regions should not happen here.
*/
if ((vma->vm_flags & (VM_LOCKED|VM_RESERVED)) ||
ptep_clear_flush_young(vma, address, pte)) {
goto out_unmap;
}
- /*
- * Don't pull an anonymous page out from under get_user_pages.
- * GUP carefully breaks COW and raises page count (while holding
- * page_table_lock, as we have here) to make sure that the page
- * cannot be freed. If we unmap that page here, a user write
- * access to the virtual address will bring back the page, but
- * its raised count will (ironically) be taken to mean it's not
- * an exclusive swap page, do_wp_page will replace it by a copy
- * page, and the user never get to see the data GUP was holding
- * the original page for.
- *
- * This test is also useful for when swapoff (unuse_process) has
- * to drop page lock: its reference to the page stops existing
- * ptes from being unmapped, so swapoff can make progress.
- */
- if (PageSwapCache(page) &&
- page_count(page) != page_mapcount(page) + 2) {
- ret = SWAP_FAIL;
- goto out_unmap;
- }
-
/* Nuke the page table entry. */
flush_cache_page(vma, address, page_to_pfn(page));
pteval = ptep_clear_flush(vma, address, pte);
if (vma->vm_flags & (VM_LOCKED|VM_RESERVED))
continue;
cursor = (unsigned long) vma->vm_private_data;
- while (get_mm_counter(vma->vm_mm, rss) &&
- cursor < max_nl_cursor &&
+ while ( cursor < max_nl_cursor &&
cursor < vma->vm_end - vma->vm_start) {
try_to_unmap_cluster(cursor, &mapcount, vma);
cursor += CLUSTER_SIZE;