Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 28 Oct 2010 01:01:53 -0700
From:      perryh@pluto.rain.com
To:        ivoras@freebsd.org
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: fsync(2) manual and hdd write caching
Message-ID:  <4cc92df1.Z0CRaJOCdvd/ZJSL%perryh@pluto.rain.com>
In-Reply-To: <ia8u9l$46j$1@dough.gmane.org>
References:  <20101026213618.GA3013@freebsd.org> <ia7nln$piv$1@dough.gmane.org> <4cc7ea44.ApOaxS8Xr4Sxu%2B0x%perryh@pluto.rain.com> <20101027111124.00007450@unknown> <ia8u9l$46j$1@dough.gmane.org>

next in thread | previous in thread | raw e-mail | index | archive | help
Ivan Voras <ivoras@freebsd.org> wrote:

> ... The problem is actually pretty hard - since AFAIK SoftUpdates
> doesn't have "checkpoints" in the sense that it groups writes and
> all data "before" can guaranteed to be on-disk, the problem is
> *when* to issue BIO_FLUSH requests.

Seems to me the originally-stated problem -- making fsync(2)
do what it claims to do -- is not hard at all.  Just issue a
BIO_FLUSH request as the final step in handling fsync(2).

While we're at it, perhaps do the same in close(2).
I _hope_ we are already doing it in unmount(2).



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4cc92df1.Z0CRaJOCdvd/ZJSL%perryh>