In message <199911162046.PAA04133@Twig.Rodents.Montreal.QC.CA>, der Mouse write
s:
>How do you avoid an inode write for the mtime/ctime on the parent of
>the created (and later deleted) directory?  (And its contents, for ffs,
>since creating and deleting a subdirectory does modify the (containing)
>directory's contents.)

You declare that it was folded into some other inode write that woulda
happened anyway.  Don't ask so many relevant questions.  ;-)

Anyway, you can avoid writing to the contents of the parent directory, as long
as you know that the result is "nothing got created".  The entire creation of
the directory, modulo mtime, can be thrown out, since Nothing Happened.

I'll give you a concrete example.  This is from a BSD/OS system, but it's
similar FFS code.  I use MH.  It used to be, 'refile 1-10000 +foo-arch' would
take about 5 minutes.  Now it takes about 15 seconds.

:)

-s