Date: Wed, 10 Apr 2013 22:01:10 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: Matthew Rezny <mrezny@hexaneinc.com> Cc: freebsd-standards@FreeBSD.org Subject: Re: standards/177742: conflict of dd's bs= option with use of conv=sparse Message-ID: <20130410190110.GM2930@kib.kiev.ua> In-Reply-To: <201304101410.r3AEA1vH044880@freefall.freebsd.org> References: <201304101410.r3AEA1vH044880@freefall.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--bZ2MuwyI/0uB8yuJ
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
On Wed, Apr 10, 2013 at 02:10:01PM +0000, Matthew Rezny wrote:
> The following reply was made to PR standards/177742; it has been noted by=
GNATS.
>=20
> From: Matthew Rezny <mrezny@hexaneinc.com>
> To: bug-followup@FreeBSD.org
> Cc: =20
> Subject: Re: standards/177742: conflict of dd's bs=3D option with use of
> conv=3Dsparse
> Date: Wed, 10 Apr 2013 15:31:08 +0200
>=20
> The patch I suggested got a little messed up by the web form, and it
> also contained a typo. Further, I had neglected to consider the
> C_BS flag itself should be present after masking off the few allowed
> flags, so the patch should be amended as such follows.
> =20
> if (ddflags & C_BS) {
> out.dbcnt =3D in.dbcnt;
> - dd_out(1);
> + dd_out((ddflags & !(C_NOERROR | C_NOTRUNC | C_SYNC)) =3D=3D C_BS);
> in.dbcnt =3D 0;
> continue;
> }
> =20
> This patch has been tested to confirm conv=3Dsparse now works as expected
> with bs=3D set. No other conversions have been checked with the bs=3D
> option and from reading the code I don't think they will.
I somehow followed what you wrote.
Still, I think your patch is not correct. Its result is always using the
block coalescing mode there. The issue is that the '!' operator result
is defined to be either 0 or 1, which mask and-ed with ddflags never could
be equal to the C_BS =3D=3D 4. You probably mean '~' ?
In fact, the test in the containing if () means that C_BS is guaranteed
to be set there.
So my question is, do you want to explicitely check that no other flags
are set, except noerror, notrunc, sync and bs ? Or is it yet another bug ?
--bZ2MuwyI/0uB8yuJ
Content-Type: application/pgp-signature
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (FreeBSD)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=OIM8
-----END PGP SIGNATURE-----
--bZ2MuwyI/0uB8yuJ--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20130410190110.GM2930>