when stopping torrents, only abort hash jobs from a full check. Those jobs are likely to have deep queues and to benefit from being cancelled. Other hash jobs from downloading pieces cannot be restarted and should not be cancelled

src/disk_io_thread.cpp

@@ -1896,6 +1896,11 @@ constexpr disk_job_flags_t disk_interface::cache_hit;
 		{
 			disk_io_job *j = i.get();
 			if (j->storage != st) continue;
+			// only cancel volatile-read jobs. This means only full checking
+			// jobs. These jobs are likely to have a pretty deep queue and
+			// really gain from being cancelled. They can also be restarted
+			// easily.
+			if (!(j->flags & disk_interface::volatile_read)) continue;
 			j->flags |= disk_io_job::aborted;
 		}
 	}