Subject: Re: nfs vs pagedaemon
To: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
From: Chuck Silvers <chuq@chuq.com>
List: tech-kern
Date: 04/18/2003 09:21:51
On Tue, Apr 15, 2003 at 11:08:31PM +0900, YAMAMOTO Takashi wrote:
> > the change you checked in isn't quite correct, though.
> > if someone does a physio write (via vnd) to an NFS file from a mapping of
> > the same file at a different offset, you'd set PG_NEEDCOMMMIT on the
> > pages from the mapping instead of the pages for the range being modified
> > (which might not even exist on the client).
> 
> i see.  so, adding check of pg->offset is enough?

it looks like that would take care of it, yea.
(and on second thought, physio would take a different path and avoid
any problem here, but writes via a vnd block device would still need this.)

it would be easier to tell that the nfs_strategy() code is correct if it were
told more explicitly when it's ok to use the commit mechanism, though.

-Chuck