Subject: Re: cp(1) vs. UVM/UBC
To: Matthias Scheler <tron@zhadum.de>
From: Ignatios Souvatzis <ignatios@theory.cs.uni-bonn.de>
List: tech-userlevel
Date: 07/19/2001 10:40:53
--SUOF0GtieIMvvwua
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Wed, Jul 18, 2001 at 06:37:54PM +0200, Matthias Scheler wrote:
> On Wed, Jul 18, 2001 at 09:05:01AM -0700, Jason R. Thorpe wrote:
> >  > So turning that option on would break "cp" on LFS. How fatal would t=
hat
> >  > be? Is LFS usable at the moment despite the mmap() problem?
> >=20
> > Somewhat usable, yes.  Let's wait to flip the switch until LFS
> > is fixed.
>=20
> I've submitted a change request in PR bin/13502 which says that it
> should be turned on after LFS and NTFS are fixed.

There are other file systems with potential problems, if I recall right...
e.g., the DOS\0 and DOS\1 variants of adosfs, which always have some=20
metadata in their datablocks, so for this case, data copying always
happens. (Chuck?)

Maybe we need to disable mmap()ing for such filesystems inside the kernel,
and make cp do the right thing if mmap fails? Is this possible?

	-is

--SUOF0GtieIMvvwua
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: 2.6.i

iQEVAgUBO1adETCn4om+4LhpAQECJgf+IFVVMdJHI9llhY/cGhqVlbmiYDo6PW1N
XWG9qDpaFEe53aHtU3rRUfnoi2lsdvfPP48PAMj/nY0rrcDGNQV7k4SQrZ6to/Ph
2W9yIIAF0ytoqFirIMAOgRBpkDH1p19A5ZJ23dJ8LMy0Ltzef5jGdwhYclkddM5x
pYbL5Wtuo/W1OglDg0B1m9CIwmEGM95Jkyc29FGZmcHdGqssLcbqJsb17qrcMwlY
3MhBWh2AlOHigEDVqrfnr8u6rHckDtUg/DFdxZIfcs2pKwDSUh68ewLv1gK2cY80
Ov9bq/aKjHhbjSpcu3ndmGJJH8B3Gpjrt6PQpwj8AtPTcXVt8jtwYA==
=5Nxs
-----END PGP SIGNATURE-----

--SUOF0GtieIMvvwua--