diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 0a5bb3e8a8a3..d4a06afbeda4 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1352,6 +1352,16 @@ static void collapse_shmem(struct mm_struct *mm,
 	radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
 		int n = min(iter.index, end) - index;
 
+		/*
+		 * Stop if extent has been hole-punched, and is now completely
+		 * empty (the more obvious i_size_read() check would take an
+		 * irq-unsafe seqlock on 32-bit).
+		 */
+		if (n >= HPAGE_PMD_NR) {
+			result = SCAN_TRUNCATED;
+			goto tree_locked;
+		}
+
 		/*
 		 * Handle holes in the radix tree: charge it from shmem and
 		 * insert relevant subpage of new_page into the radix-tree.
@@ -1463,6 +1473,11 @@ out_unlock:
 	if (result == SCAN_SUCCEED && index < end) {
 		int n = end - index;
 
+		/* Stop if extent has been truncated, and is now empty */
+		if (n >= HPAGE_PMD_NR) {
+			result = SCAN_TRUNCATED;
+			goto tree_locked;
+		}
 		if (!shmem_charge(mapping->host, n)) {
 			result = SCAN_FAIL;
 			goto tree_locked;