5882 Temporary pool names
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>

@@ -4581,35 +4581,50 @@
         uint64_t txg = TXG_INITIAL;
         nvlist_t **spares, **l2cache;
         uint_t nspares, nl2cache;
         uint64_t version, obj;
         boolean_t has_features;
+        char *poolname;
+        nvlist_t *nvl;
 
+        if (nvlist_lookup_string(props,
+            zpool_prop_to_name(ZPOOL_PROP_TNAME), &poolname) != 0)
+                poolname = (char *)pool;
+
         /*
          * If this pool already exists, return failure.
          */
         mutex_enter(&spa_namespace_lock);
-        if (spa_lookup(pool) != NULL) {
+        if (spa_lookup(poolname) != NULL) {
                 mutex_exit(&spa_namespace_lock);
                 return (SET_ERROR(EEXIST));
         }
 
         /*
          * Allocate a new spa_t structure.
          */
+        nvl = fnvlist_alloc();
+        fnvlist_add_string(nvl, ZPOOL_CONFIG_POOL_NAME, pool);
         (void) nvlist_lookup_string(props,
             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
-        spa = spa_add(pool, NULL, altroot);
+        spa = spa_add(poolname, nvl, altroot);
+        fnvlist_free(nvl);
         spa_activate(spa, spa_mode_global);
 
         if (props && (error = spa_prop_validate(spa, props))) {
                 spa_deactivate(spa);
                 spa_remove(spa);
                 mutex_exit(&spa_namespace_lock);
                 return (error);
         }
 
+        /*
+         * Temporary pool names should never be written to disk.
+         */
+        if (poolname != pool)
+                spa->spa_import_flags |= ZFS_IMPORT_TEMP_NAME;
+
         has_features = B_FALSE;
         for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
             elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
                 if (zpool_prop_feature(nvpair_name(elem)))
                         has_features = B_TRUE;