Serious mapping problem with 2.9

[Dave borman]

One interesting thing to note about the fix for the mapping problem is
that you wind up saving the map when you don't need to, but that's better
than not saving it when you need to.  The KA5 descriptor will have the
modified bit clear when it is saved at boot time.  Then, anytime you
touch anything in KA5 the modified savemap macro will force the save,
even though it isn't needed.

Depending on how far into KA5 your data extends, I've been considering
just getting rid of the macro since you'll wind up saveing it most
of the time anyway. Any thoughts on this?

Speaking of 2.9, has anyone out there had trouble with mount/unmount?
When running with RX50 floppies and several hundred buffers, I would
have problems with kernel cancelling write request before all the
buffers got written out.  This caused me a few headaches and several
re-writes of the unmount system call to make sure that 1) all the
delayed writes got queued up to be written, and 2) not return from the
mount until they are all done.

I suppose most people aren't mounting and unmounting file systems a lot.

		-Dave Borman, Digital UNIX Engineering Group
		decvax!borman