diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c
index 12666668a80e..489a5935202c 100644
--- a/fs/ntfs/mft.c
+++ b/fs/ntfs/mft.c
@@ -1352,6 +1352,10 @@ static int ntfs_mft_bitmap_extend_allocation_nolock(struct ntfs_volume *vol)
 	size_t new_rl_count;
 
 	ntfs_debug("Extending mft bitmap allocation.");
+	/* The initial bitmap scan must finish before we lock or change a folio. */
+	if (!NVolFreeClusterKnown(vol))
+		wait_event(vol->free_waitq, NVolFreeClusterKnown(vol));
+
 	mft_ni = NTFS_I(vol->mft_ino);
 	mftbmp_ni = NTFS_I(vol->mftbmp_ino);
 	/*