3949 ztest fault injection should avoid resilvering devices
3950 ztest: deadman fires when we're doing a scan
3951 ztest hang when running dedup test
3952 ztest: ztest_reguid test and ztest_fault_inject don't place nice together
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>

*** 62,66 ****
--- 62,67 ----
  #include <sys/dsl_userhold.h>
  
  extern uint64_t metaslab_gang_bang;
  extern uint64_t metaslab_df_alloc_threshold;
  extern boolean_t zfeature_checks_disable;
+ extern uint64_t zfs_deadman_synctime;