As noticed by Alan Cox:

"It doesn't work now so it clearly isnt being used 8). We hold the lock
because its a proc function and we then replace the proc functions in the
attach method -> deadlock. It is also incredibly hard to fix without a
major rewrite."

The same is true for HDIO_SET_IDE_SCSI ioctl.

Both were broken 18 months ago in 2.5.63 as a side-effect of locking fixes.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>