Re: [PARPORT] Tape IOCTL (fsf) questions and HP 7/14 GB Report

Ian Soboroff (
23 Jul 1999 09:35:22 -0400

"Cary O'Brien" <cobrien@Radix.Net> writes:

> I was able to do this, but when I went to try "mt fsf" to skip past records,
> I found it wasn't supported. The only IOCTL in pt.c seems to be rewind.
> So, does anyone know what is necessary to add the IOCTLs to skip 'files'
> forward and backward on the tape? If someone even knew where I could find
> the protocols I'd be game to try and add them to the current
> code.

i asked about the other half of the problem - writing filemarks so you
have something to fsf to - and also hacked in a two-line patch to add
an ioctl to call the function for writing filemarks that is already in

however, (1) i really didn't have the time to poke at it and see if it
worked, and (2) when i talked about it here, i was basically told that
i hadn't thought through the issues very well (i assume that meant
"the issues of mtops in general", not just adding filemarks). and it
kind of fell through my cracks... much as i'd love to hack this stuff
i've got other full-time duties.

fsf is probably a matter of (a) making sure the drive can support it,
(b) adding the ATAPI call, and (c) making sure not to walk all over
some currently-happening operation like writing your backup.
ide-tape.c had some nice queue approaches for having all the mtops
play nice, but pt.c is much simpler...


Ian Soboroff                             
University of MD Baltimore County

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This archive was generated by hypermail 2.0b3 on Fri 23 Jul 1999 - 09:38:36 EDT