LP #1287098: Double fil_system->mutex exit in fil_extend_space_to_desired_size if posix_fallocate is used

**Reported in Launchpad by Raghavendra D Prabhu last update 04-03-2014 13:05:21

Here:

/* At this point it is safe to release fil_system mutex. No
other thread can rename, delete or close the file because
we have set the node->being_extended flag. */
mutex_exit(&fil_system->mutex);

start_page_no = space->size;
file_start_page_no = space->size - node->size;

#ifdef HAVE_POSIX_FALLOCATE
if (srv_use_posix_fallocate) {

mutex_exit(&fil_system->mutex);
success = os_file_set_size(node->name, node->handle,
(size_after_extend

• file_start_page_no) * page_size);
  mutex_enter(&fil_system->mutex);
  if (success) {
  node->size += (size_after_extend - start_page_no);
  space->size += (size_after_extend - start_page_no);
  os_has_said_disk_full = FALSE;
  }
  node->being_extended = FALSE;
  fil_node_complete_io(node, fil_system, OS_FILE_READ);
  goto complete_io;
  }
  #endif

the mutex_exit and mutex_enter are reversed. (may be a merge regression etc.)