int test_clear_page_writeback(struct page *page)
{
struct address_space *mapping = page_mapping(page);
+ struct mem_cgroup *memcg;
+ struct lruvec *lruvec;
int ret;
- lock_page_memcg(page);
+ memcg = lock_page_memcg(page);
+ lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page));
if (mapping && mapping_use_writeback_tags(mapping)) {
struct inode *inode = mapping->host;
struct backing_dev_info *bdi = inode_to_bdi(inode);
} else {
ret = TestClearPageWriteback(page);
}
+ /*
+ * NOTE: Page might be free now! Writeback doesn't hold a page
+ * reference on its own, it relies on truncation to wait for
+ * the clearing of PG_writeback. The below can only access
+ * page state that is static across allocation cycles.
+ */
if (ret) {
- dec_lruvec_page_state(page, NR_WRITEBACK);
+ dec_lruvec_state(lruvec, NR_WRITEBACK);
dec_zone_page_state(page, NR_ZONE_WRITE_PENDING);
inc_node_page_state(page, NR_WRITTEN);
}
- unlock_page_memcg(page);
+ __unlock_page_memcg(memcg);
return ret;
}