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>

*** 183,193 ****
  }
  
  static int
  vdev_file_io_start(zio_t *zio)
  {
-         spa_t *spa = zio->io_spa;
          vdev_t *vd = zio->io_vd;
          vdev_file_t *vf = vd->vdev_tsd;
          vdev_buf_t *vb;
          buf_t *bp;
  
--- 183,192 ----
*** 222,233 ****
          bp->b_lblkno = lbtodb(zio->io_offset);
          bp->b_bufsize = zio->io_size;
          bp->b_private = vf->vf_vnode;
          bp->b_iodone = (int (*)())vdev_file_io_intr;
  
!         spa_taskq_dispatch_ent(spa, ZIO_TYPE_FREE, ZIO_TASKQ_ISSUE,
!             vdev_file_io_strategy, bp, 0, &zio->io_tqent);
  
          return (ZIO_PIPELINE_STOP);
  }
  
  /* ARGSUSED */
--- 221,232 ----
          bp->b_lblkno = lbtodb(zio->io_offset);
          bp->b_bufsize = zio->io_size;
          bp->b_private = vf->vf_vnode;
          bp->b_iodone = (int (*)())vdev_file_io_intr;
  
!         VERIFY3U(taskq_dispatch(system_taskq, vdev_file_io_strategy, bp,
!             TQ_SLEEP), !=, 0);
  
          return (ZIO_PIPELINE_STOP);
  }
  
  /* ARGSUSED */