Date: Wed, 05 Dec 2001 06:02:49 +1000 From: Greg Black <gjb@gbch.net> To: Matthew Dillon <dillon@apollo.backplane.com> Cc: Ian Dowse <iedowse@maths.tcd.ie>, Bernd Walter <ticso@cicely8.cicely.de>, cjclark@alum.mit.edu, Mark Hannon <markhannon@optushome.com.au>, bugs-followup@FreeBSD.ORG, hackers@FreeBSD.ORG Subject: Re: bin/32261: dump creates a dump file much larger than sum of dumped files Message-ID: <nospam-1007496169.54760@bambi.gbch.net> In-Reply-To: <200112041957.fB4Jv1j20226@apollo.backplane.com> of Tue, 04 Dec 2001 11:57:01 PST References: <200112041339.aa05506@salmon.maths.tcd.ie> <200112041957.fB4Jv1j20226@apollo.backplane.com>
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Matthew Dillon wrote: | :In message <20011204135626.A75212@cicely8.cicely.de>, Bernd Walter writes: | :>> Is there any reason we don't want to truncate the file? Does O_TRUNC | :>> not work well of the file is a tape device or something? | :> | :>I don't expect O_TRUNK to work on devices such tapes and disks. | : | :Well, it won't achieve anything on tapes or disk devices, but it | :should be completely harmless to add the O_TRUNC flag. The current | :behaviour is likely to be unexpected and cause confusion so it | :might as well be changed. I'll commit this later unless someone | :can think of a good reason not to. | : | :Ian | | Woa! That sounds like a bad idea to me. If you want to do it right | then open(), fstat(), and only if the stat says it is a regular file | do you then ftruncate(). Passing O_TRUNC to a tape device may be ignored | by us, but it's not a valid flag to pass to a tape device and we shouldn't | do it. I haven't used any of them for a while, but there are certainly Unix systems that treat O_TRUNC as a signal to rewind a tape device before writing to it. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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