Date: Tue, 21 Dec 1999 10:34:48 -0800 (PST) From: "Rodney W. Grimes" <freebsd@gndrsh.dnsmgr.net> To: bde@zeta.org.au (Bruce Evans) Cc: mjacob@feral.com (Matthew Jacob), freebsd-arch@freebsd.org, syssgm@detir.qld.gov.au (Stephen McKay), grog@lemis.com (Greg Lehey), rb@gid.co.uk (Bob Bishop), rivers@dignus.com (Thomas David Rivers), joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch), hf@Melog.DE (Hauke Fath) Subject: Re: filemarks? Message-ID: <199912211834.KAA46534@gndrsh.dnsmgr.net> In-Reply-To: <Pine.BSF.4.10.9912211946160.11122-100000@alphplex.bde.org> from Bruce Evans at "Dec 21, 1999 08:34:32 pm"
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...
> > > We seem to have 3 cases when Early Warning is detected:
> > > ...
>
> > > b) The write(2) was not completed, some bytes did make it to the tape.
> > > If _some_ bytes made it we should return how many did and set the
> > > Early Warning flag as in a). If no bytes made it we return 0, which
> > > is a degenerative case, no quite covered by the definition of
> > > RETURN VALUE but in wide usage.
>
> This is in narrow or nonexistent usage. POSIX requires returning -1/ENOSPC
> if "there is no space on the device". The only reasonable interpretation
> of a return value of 0 is that there is some space, but not this time.
AHhh... BSD dump is probably the #1 consumer of the write(2) call with
respect to tape drives and:
if (wrote == 0)
eot_count++;
And if I recall my read of the amanda tape driver code it does the
exact same thing.
I would say that is not ``narrow or nonexistent''.
--
Rod Grimes - KD7CAX @ CN85sl - (RWG25) rgrimes@gndrsh.dnsmgr.net
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