diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6ddaeba..f130d02 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3757,6 +3757,9 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pavail,
 	unsigned long file_pages;
 
 	*pdirty = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+	WARN(*pdirty > (1<<30), "%s() huge dirty: %ld\n", __func__, *pdirty);
+	if (*pdirty > (1<<30))
+		*pdirty = 0;
 
 	/* this should eventually include NR_UNSTABLE_NFS */
 	*pwriteback = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_WRITEBACK);
@@ -4607,6 +4610,8 @@ static int mem_cgroup_move_account(struct page *page,
 				       nr_pages);
 			__this_cpu_add(to->stat->count[MEM_CGROUP_STAT_DIRTY],
 				       nr_pages);
+			WARN_ONCE(__this_cpu_read(from->stat->count[MEM_CGROUP_STAT_DIRTY]) > (1UL<<30), "MEM_CGROUP_STAT_DIRTY bogus");
+			WARN_ONCE(__this_cpu_read(  to->stat->count[MEM_CGROUP_STAT_DIRTY]) > (1UL<<30), "MEM_CGROUP_STAT_DIRTY bogus");
 		}
 	}
 
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 0a931cd..9dfd8fa 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1546,6 +1546,7 @@ static void balance_dirty_pages(struct address_space *mapping,
 					global_page_state(NR_UNSTABLE_NFS);
 		gdtc->avail = global_dirtyable_memory();
 		gdtc->dirty = nr_reclaimable + global_page_state(NR_WRITEBACK);
+		WARN(gdtc->dirty > (1<<30), "%s() huge dirty: %ld\n", __func__, gdtc->dirty);
 
 		domain_dirty_limits(gdtc);
 
@@ -1570,6 +1571,7 @@ static void balance_dirty_pages(struct address_space *mapping,
 			 */
 			mem_cgroup_wb_stats(wb, &mdtc->avail, &mdtc->dirty,
 					    &writeback);
+			WARN(mdtc->dirty > (1<<30), "%s() huge dirty: %ld\n", __func__, mdtc->dirty);
 			mdtc_cap_avail(mdtc);
 			mdtc->dirty += writeback;
 
@@ -1884,6 +1886,7 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb)
 	gdtc->avail = global_dirtyable_memory();
 	gdtc->dirty = global_page_state(NR_FILE_DIRTY) +
 		      global_page_state(NR_UNSTABLE_NFS);
+	WARN(gdtc->dirty > (1<<30), "%s() huge dirty: %ld\n", __func__, gdtc->dirty);
 	domain_dirty_limits(gdtc);
 
 	if (gdtc->dirty > gdtc->bg_thresh)
@@ -1896,6 +1899,7 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb)
 		unsigned long writeback;
 
 		mem_cgroup_wb_stats(wb, &mdtc->avail, &mdtc->dirty, &writeback);
+		WARN(mdtc->dirty > (1<<30), "%s() huge dirty: %ld\n", __func__, mdtc->dirty);
 		mdtc_cap_avail(mdtc);
 		domain_dirty_limits(mdtc);	/* ditto, ignore writeback */
 
@@ -2404,7 +2408,9 @@ void account_page_dirtied(struct page *page, struct address_space *mapping,
 		inode_attach_wb(inode, page);
 		wb = inode_to_wb(inode);
 
+		WARN_ONCE(__this_cpu_read(memcg->stat->count[MEM_CGROUP_STAT_DIRTY]) > (1UL<<30), "MEM_CGROUP_STAT_DIRTY bogus");
 		mem_cgroup_inc_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+		WARN_ONCE(__this_cpu_read(memcg->stat->count[MEM_CGROUP_STAT_DIRTY]) > (1UL<<30), "MEM_CGROUP_STAT_DIRTY bogus");
 		__inc_zone_page_state(page, NR_FILE_DIRTY);
 		__inc_zone_page_state(page, NR_DIRTIED);
 		__inc_wb_stat(wb, WB_RECLAIMABLE);
@@ -2426,6 +2432,7 @@ void account_page_cleaned(struct page *page, struct address_space *mapping,
 {
 	if (mapping_cap_account_dirty(mapping)) {
 		mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+		WARN_ONCE(__this_cpu_read(memcg->stat->count[MEM_CGROUP_STAT_DIRTY]) > (1UL<<30), "MEM_CGROUP_STAT_DIRTY bogus");
 		dec_zone_page_state(page, NR_FILE_DIRTY);
 		dec_wb_stat(wb, WB_RECLAIMABLE);
 		task_io_account_cancelled_write(PAGE_CACHE_SIZE);
@@ -2686,6 +2693,7 @@ int clear_page_dirty_for_io(struct page *page)
 		wb = unlocked_inode_to_wb_begin(inode, &locked);
 		if (TestClearPageDirty(page)) {
 			mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+			WARN_ONCE(__this_cpu_read(memcg->stat->count[MEM_CGROUP_STAT_DIRTY]) > (1UL<<30), "MEM_CGROUP_STAT_DIRTY bogus");
 			dec_zone_page_state(page, NR_FILE_DIRTY);
 			dec_wb_stat(wb, WB_RECLAIMABLE);
 			ret = 1;