Re: CVS commit: src/sys/kern

["Steven M. Bellovin" <smb%cs.columbia.edu@localhost>]

On Wed, 24 Sep 2008 13:46:34 -0400
Thor Lancelot Simon <tls%rek.tjls.com@localhost> wrote:

> On Wed, Sep 24, 2008 at 07:38:20PM +0700, Robert Elz wrote:
> >     Date:        Wed, 24 Sep 2008 10:07:19 +0000 (UTC)
> >     From:        Andrew Doran <ad%NetBSD.org@localhost>
> >     Message-ID:  <20080924100719.D78AE175D0%cvs.netbsd.org@localhost>
> > 
> >   | Prevent r/w to r/o downgrade until such time as someone has
> > verified all | the relevant file system code.
> > 
> > Please don't do that - I do rw -> ro "down"grades (I'd call it an
> > upgrade...) all the time.   As long as you know what's up (that is,
> > to make sure there is no possibility of stale data) it is fine, and
> > causes no problems.
> 
> This also breaks products which run from flash with their filesystems
> mounted read-only most of the time, but remount them read-write in
> order to write back configuration data when it changes.  That is not
> an uncommon model AFAIK and it poses a fairly major problem for me.

Indeed, I do precisely that.


                --Steve Bellovin, http://www.cs.columbia.edu/~smb