Bug in 1.3? - floppy buffers getting corrupted

Bernd Schmidt (crux@pool.informatik.rwth-aachen.de)
Mon, 9 Oct 1995 11:29:45 +0100 (MEZ)


Yesterday, I encountered a (possible) problem with the 1.3 kernels.
What I did was this: I had two VCs, on one I used mtools to copy files to/from
an MS-DOS floppy, on the other VC I did some compiles. Suddenly, after
compiling a file, the disk was no longer readable, mdir said "Probable
non-MSDOS disk". Removing the disk from the drive and re-inserting caused the
disk to be readable again.
I did some more experiments and found that I can reproduce this problem on
kernels 1.3.20, 1.3.29 and 1.3.31, with or without net/IDE/SCSI/CDROM drivers,
and on two different machines (both of which run flawlessly without any strange
crashes otherwise).
The problem does not only affect mtools, I used dd to transfer a disk image
to a file before and after the disk became unreadable, and the files differ.
I also tried 1.2.11, and I could not reproduce the problem. It seems that
mdir always accesses the floppy on 1.2.11, and this does not always happen with
the 1.3 kernels.

Am I doing something stupid, or can anyone else reproduce this behaviour?


Bernd Schmidt