FreeBSD commit message:

FreeBSD commit message:
 After a rmdir()ed directory has been truncated, force an update of
 the directory's inode after queuing the dirrem that will decrement
 the parent directory's link count.  This will force the update of
 the parent directory's actual link to actually be scheduled.  Without
 this change the parent directory's actual link count would not be
 updated until ufs_inactive() cleared the inode of the newly removed
 directory, which might be deferred indefinitely.  ufs_inactive()
 will not be called as long as any process holds a reference to the
 removed directory, and ufs_inactive() will not clear the inode if
 the link count is non-zero, which could be the result of an earlier
 system crash.

 This change has the fortunate side effect of more quickly cleaning
 up the large number dirrem structures that linger for an extended
 time after the removal of a large directory tree.  It also fixes a
 potential problem with the shutdown of the syncer thread timing out
 if the system is rebooted immediately after removing a large directory
 tree.

Taken-from: FreeBSD/1.185
Submitted-by: tegge