* PageDirty _after_ making sure that the page is freeable and
* not in use by anybody. (pagecache + us == 2)
*/
- if (page_count(page) != 2 || PageDirty(page)) {
- write_unlock_irq(&mapping->tree_lock);
- goto keep_locked;
- }
+ if (unlikely(page_count(page) != 2))
+ goto cannot_free;
+ smp_rmb();
+ if (unlikely(PageDirty(page)))
+ goto cannot_free;
#ifdef CONFIG_SWAP
if (PageSwapCache(page)) {
__pagevec_release_nonlru(&freed_pvec);
continue;
+cannot_free:
+ write_unlock_irq(&mapping->tree_lock);
+ goto keep_locked;
+
activate_locked:
SetPageActive(page);
pgactivate++;