Description of Problem:
If DMA is enabled for an IDE Tape device filesystem corruption can occur

Version-Release number of selected component (if applicable):
errata kernel 2.4.9-13.i586

How Reproducible:
Leave ide settings at Red Hat default i.e. hdparm says tape drive is DMA 
capable.

Steps to Reproduce:
1. Fresh install - dual UDMA/33 drives - RAID-1 mirrored - ext3
2. Perform e2fsck -f -n /dev/md[0-4]; echo $?
3. Execute a full backup with afbackup
4. Perform e2fsck -f -n /dev/md[0-4]; echo $?

Actual Results:
Directories are hit returning errors like "invalid fs type" or attempting 
to ls -l their contents returns "unable to stat ..." or permissions 
damaged e.g. "?--------x"

Expected Results:
None of the above is expected

Additional Information:
This took some tracking down. I had to watch several fresh installs 
through the RAID-1 creation process (bad block check enabled and 
formatted to ext3) then did readonly e2fscks of the partitions before and 
after the full backup.
On three separate occasions filesystem damage occurred with DMA enabled 
for the IDE Tape Drive and does not occur with DMA disabled.
I don't mind doing some testing for you on this but I'm getting a little 
bored with doing fresh installs :-)