5056 ZFS deadlock on db_mtx and dn_holds
Reviewed by: Will Andrews <willa@spectralogic.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>

@@ -559,11 +559,11 @@
 
         if (spa_version(dmu_objset_spa(dp->dp_meta_objset)) <
             SPA_VERSION_DELEGATED_PERMS)
                 return (SET_ERROR(EPERM));
 
-        if (dsl_dataset_is_snapshot(ds)) {
+        if (ds->ds_is_snapshot) {
                 /*
                  * Snapshots are treated as descendents only,
                  * local permissions do not apply.
                  */
                 checkflag = ZFS_DELEG_DESCENDENT;