959          * It's possible that the best uberblock was discovered on a label
 960          * that has a configuration which was written in a future txg.
 961          * Search all labels on this vdev to find the configuration that
 962          * matches the txg for our uberblock.
 963          */
 964         if (cb.ubl_vd != NULL)
 965                 *config = vdev_label_read_config(cb.ubl_vd, ub->ub_txg);
 966         spa_config_exit(spa, SCL_ALL, FTAG);
 967 }
 968 
 969 /*
 970  * On success, increment root zio's count of good writes.
 971  * We only get credit for writes to known-visible vdevs; see spa_vdev_add().
 972  */
 973 static void
 974 vdev_uberblock_sync_done(zio_t *zio)
 975 {
 976         uint64_t *good_writes = zio->io_private;
 977 
 978         if (zio->io_error == 0 && zio->io_vd->vdev_top->vdev_ms_array != 0)
 979                 atomic_add_64(good_writes, 1);
 980 }
 981 
 982 /*
 983  * Write the uberblock to all labels of all leaves of the specified vdev.
 984  */
 985 static void
 986 vdev_uberblock_sync(zio_t *zio, uberblock_t *ub, vdev_t *vd, int flags)
 987 {
 988         uberblock_t *ubbuf;
 989         int n;
 990 
 991         for (int c = 0; c < vd->vdev_children; c++)
 992                 vdev_uberblock_sync(zio, ub, vd->vdev_child[c], flags);
 993 
 994         if (!vd->vdev_ops->vdev_op_leaf)
 995                 return;
 996 
 997         if (!vdev_writeable(vd))
 998                 return;
 999 

1034          */
1035         zio = zio_root(spa, NULL, NULL, flags);
1036 
1037         for (int v = 0; v < svdcount; v++)
1038                 zio_flush(zio, svd[v]);
1039 
1040         (void) zio_wait(zio);
1041 
1042         return (good_writes >= 1 ? 0 : EIO);
1043 }
1044 
1045 /*
1046  * On success, increment the count of good writes for our top-level vdev.
1047  */
1048 static void
1049 vdev_label_sync_done(zio_t *zio)
1050 {
1051         uint64_t *good_writes = zio->io_private;
1052 
1053         if (zio->io_error == 0)
1054                 atomic_add_64(good_writes, 1);
1055 }
1056 
1057 /*
1058  * If there weren't enough good writes, indicate failure to the parent.
1059  */
1060 static void
1061 vdev_label_sync_top_done(zio_t *zio)
1062 {
1063         uint64_t *good_writes = zio->io_private;
1064 
1065         if (*good_writes == 0)
1066                 zio->io_error = SET_ERROR(EIO);
1067 
1068         kmem_free(good_writes, sizeof (uint64_t));
1069 }
1070 
1071 /*
1072  * We ignore errors for log and cache devices, simply free the private data.
1073  */
1074 static void

 959          * It's possible that the best uberblock was discovered on a label
 960          * that has a configuration which was written in a future txg.
 961          * Search all labels on this vdev to find the configuration that
 962          * matches the txg for our uberblock.
 963          */
 964         if (cb.ubl_vd != NULL)
 965                 *config = vdev_label_read_config(cb.ubl_vd, ub->ub_txg);
 966         spa_config_exit(spa, SCL_ALL, FTAG);
 967 }
 968 
 969 /*
 970  * On success, increment root zio's count of good writes.
 971  * We only get credit for writes to known-visible vdevs; see spa_vdev_add().
 972  */
 973 static void
 974 vdev_uberblock_sync_done(zio_t *zio)
 975 {
 976         uint64_t *good_writes = zio->io_private;
 977 
 978         if (zio->io_error == 0 && zio->io_vd->vdev_top->vdev_ms_array != 0)
 979                 atomic_inc_64(good_writes);
 980 }
 981 
 982 /*
 983  * Write the uberblock to all labels of all leaves of the specified vdev.
 984  */
 985 static void
 986 vdev_uberblock_sync(zio_t *zio, uberblock_t *ub, vdev_t *vd, int flags)
 987 {
 988         uberblock_t *ubbuf;
 989         int n;
 990 
 991         for (int c = 0; c < vd->vdev_children; c++)
 992                 vdev_uberblock_sync(zio, ub, vd->vdev_child[c], flags);
 993 
 994         if (!vd->vdev_ops->vdev_op_leaf)
 995                 return;
 996 
 997         if (!vdev_writeable(vd))
 998                 return;
 999 

1034          */
1035         zio = zio_root(spa, NULL, NULL, flags);
1036 
1037         for (int v = 0; v < svdcount; v++)
1038                 zio_flush(zio, svd[v]);
1039 
1040         (void) zio_wait(zio);
1041 
1042         return (good_writes >= 1 ? 0 : EIO);
1043 }
1044 
1045 /*
1046  * On success, increment the count of good writes for our top-level vdev.
1047  */
1048 static void
1049 vdev_label_sync_done(zio_t *zio)
1050 {
1051         uint64_t *good_writes = zio->io_private;
1052 
1053         if (zio->io_error == 0)
1054                 atomic_inc_64(good_writes);
1055 }
1056 
1057 /*
1058  * If there weren't enough good writes, indicate failure to the parent.
1059  */
1060 static void
1061 vdev_label_sync_top_done(zio_t *zio)
1062 {
1063         uint64_t *good_writes = zio->io_private;
1064 
1065         if (*good_writes == 0)
1066                 zio->io_error = SET_ERROR(EIO);
1067 
1068         kmem_free(good_writes, sizeof (uint64_t));
1069 }
1070 
1071 /*
1072  * We ignore errors for log and cache devices, simply free the private data.
1073  */
1074 static void