svn commit: r340187 - head/sys/geom

[Poul-Henning Kamp]

--------
In message <CANCZdfrK-7vBETkhfQ9KkM4usrvjVh8wS_OZJiDmH5336DTsqQ at mail.gmail.com>
, Warner Losh writes:

>BIO_FLUSH is primarily done to force ordering points, 

Originally BIO_FLUSH was defined the way it is, to make it possible
to flush an isolated specified range on providers which support that
so that fsync(2) could be implemented that way.

I can't remember the exact semantics of the two "magic" flush
operations (off=0,len=0) and (off=end,len=0) but they were different
from each other in some important aspect (Pawel?)

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.