From owner-freebsd-current  Fri Jun 16  5:34: 6 2000
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To: Luoqi Chen <luoqi@watermarkgroup.com>
Cc: current@FreeBSD.ORG
Subject: Re: HEADSUP: bioops patch. 
In-reply-to: Your message of "Fri, 16 Jun 2000 08:27:28 EDT."
             <200006161227.e5GCRSd01893@lor.watermarkgroup.com> 
Date: Fri, 16 Jun 2000 14:33:46 +0200
Message-ID: <27867.961158826@critter.freebsd.dk>
From: Poul-Henning Kamp <phk@critter.freebsd.dk>
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In message <200006161227.e5GCRSd01893@lor.watermarkgroup.com>, Luoqi Chen write
s:
>> Background:

>> Ideally struct buf should have had a real OO like operations vector
>> like vnodes have it, and struct bioops is the first step towards that.
>> 
>struct buf will eventually become merely an iocmd structure, so why do
>we want to complicate things here?

No, struct buf will remain the cache-handle. the iocmd is called
struct bio.

>We already have an OO method for bwrite: VOP_BWRITE(), the problem
>is most of the code are still calling bwrite() directly. Will it
>solve your problem if we change every bwrite() into a VOP_BWRITE()?

Well, I'm not sure it is correct to go the detour around Vnodes,
if we do, we need to add VOP_BAWRITE, VOP_BDWRITE and all those
other operations as well.

But what vnode would you use for a buffer associated with a freeblock
bitmap ?

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


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