From owner-freebsd-bugs  Tue Jul 28 03:57:18 1998
Return-Path: <owner-freebsd-bugs@FreeBSD.ORG>
Received: (from majordom@localhost)
          by hub.freebsd.org (8.8.8/8.8.8) id DAA18384
          for freebsd-bugs-outgoing; Tue, 28 Jul 1998 03:57:18 -0700 (PDT)
          (envelope-from owner-freebsd-bugs@FreeBSD.ORG)
Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.15.68.22])
          by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id DAA18374;
          Tue, 28 Jul 1998 03:57:11 -0700 (PDT)
          (envelope-from bde@godzilla.zeta.org.au)
Received: (from bde@localhost)
	by godzilla.zeta.org.au (8.8.7/8.8.7) id UAA30494;
	Tue, 28 Jul 1998 20:56:37 +1000
Date: Tue, 28 Jul 1998 20:56:37 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199807281056.UAA30494@godzilla.zeta.org.au>
To: freebsd-bugs@FreeBSD.ORG, luoqi@chen.ml.org, phk@FreeBSD.ORG
Subject: Re: kern/7415
Sender: owner-freebsd-bugs@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.org

>it sounds to me like the simple solution would be to either:
>A) have ufs clear the vmio flag agan
>B) have msdosfs (and other similar fs) clear the flag before they start.

Simple and wrong.  File systems know nothing of the vmio flag.  Either
vm should clear it and be more careful about setting it (it only works
now for ufs because ufs never requests a misaligned block), or it should
always be set for block devices and fixes like the ones in the patch
should be applied.

>Could you explain what your patch does ?

It attempts to make misaligned buffers (ones whose size and file offsets
are multiples of PAGE_SIZE) actually work.  It isn't clear whether they
were intended to work, but they will need to work if the buffer cache
and vm are ever fully merged.

Bruce

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-bugs" in the body of the message