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From: j@uriah.heep.sax.de (J Wunsch)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: tar cMvf /dev/fd0
Date: 22 Oct 1996 23:23:31 GMT
Organization: Private BSD site, Dresden
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Message-ID: <54jl1j$k3o@uriah.heep.sax.de>
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<slrn56ks4p.3d7.hdm@dishmop.noc.demon.net>
Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch)
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hdm@demon.net (Dominic Mitchell) wrote:
> | Probably because there's a bug in the fd driver...
> |
> | Try -L1440, or better yet, fix the bug and send me the fix. <:)
>
> Hmmm... I experienced this bug under NetBSD, too. Probably means that
> it's a gnu tar bug, or it's a piece of code which has remained common
> for some time!
Inherited bugs from the 386BSD floppy disk driver.
I think the error is inside fdstrategy() about here:
/*
* Set up block calculations.
*/
blknum = (unsigned long) bp->b_blkno * DEV_BSIZE/fdblk;
nblocks = fd->ft->size;
if (blknum + (bp->b_bcount / fdblk) > nblocks) {
if (blknum == nblocks) {
bp->b_resid = bp->b_bcount;
} else {
bp->b_error = ENOSPC;
bp->b_flags |= B_ERROR;
}
goto bad;
}
The ENOSPC itself is already bogus, but i seem to remember that Bruce
Evans once pointed out to me that the entire error is wrong. I think
it should return EINVAL for an attempt to start a transfer beyond the
limit of the disk, but should return a short read (or write) of length
0 but no error if the fence has just been hit only.
> If you want more details, mail me and I will try to help.
The only more detail i need is a bugfix. :-)
I can reproduce the bug fine if i want... so no, i don't need any more
data _on this_.
--
cheers, J"org
joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)