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To: Warner Losh <imp@bsdimp.com>
cc: "Rodney W. Grimes" <rgrimes@freebsd.org>, Ian Lepore <ian@freebsd.org>,
 Maxim Sobolev <sobomax@freebsd.org>,
 src-committers <src-committers@freebsd.org>, svn-src-all@freebsd.org,
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Subject: Re: svn commit: r340187 - head/sys/geom
In-reply-to: <CANCZdfrK-7vBETkhfQ9KkM4usrvjVh8wS_OZJiDmH5336DTsqQ@mail.gmail.com>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
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Date: Wed, 07 Nov 2018 20:20:15 +0000
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--------
In message <CANCZdfrK-7vBETkhfQ9KkM4usrvjVh8wS_OZJiDmH5336DTsqQ@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=3D0,len=3D0) and (off=3Dend,len=3D0) but they were differe=
nt
from each other in some important aspect (Pawel?)

-- =

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@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=
.