1 files changed, 10 insertions, 0 deletions
diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c
index 1136e1d70..72fce35c5 100644
--- a/module/zfs/dmu.c
+++ b/module/zfs/dmu.c
@@ -672,6 +672,16 @@ dmu_free_long_range(objset_t *os, uint64_t object,
 	if (err != 0)
 		return (err);
 	err = dmu_free_long_range_impl(os, dn, offset, length);
+
+	/*
+	 * It is important to zero out the maxblkid when freeing the entire
+	 * file, so that (a) subsequent calls to dmu_free_long_range_impl()
+	 * will take the fast path, and (b) dnode_reallocate() can verify
+	 * that the entire file has been freed.
+	 */
+	if (offset == 0 && length == DMU_OBJECT_END)
+		dn->dn_maxblkid = 0;
+
 	dnode_rele(dn, FTAG);
 	return (err);
 }