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>

@@ -118,11 +118,11 @@
         dsl_dataset_t *bmark_fs;
         char *shortname;
         int error;
         zfs_bookmark_phys_t bmark_phys;
 
-        if (!dsl_dataset_is_snapshot(snapds))
+        if (!snapds->ds_is_snapshot)
                 return (SET_ERROR(EINVAL));
 
         error = dsl_bookmark_hold_ds(dp, bookmark_name,
             &bmark_fs, FTAG, &shortname);
         if (error != 0)