Okay... this patch against the linux-2.5.72 nbd driver I think will be 
to a lot more peoples liking. This patch makes NBD work with the new 
linux 2.5 block layer design. Specifically, it fixes memory corruption 
that results from module removal and possible memory corruption from 
sending or receiving disk data from the server. This patch  essentially 
rolls together the changes from two of the last patchlets that I 
emailed: the fix for module removal & the fix for incorrect struct bio 
usage. I believe it's wisest to roll these both together into this one 
patch since they both deal with making NBD work better with the 2.5 
linux block layer design and without either of which, it's possible that 
NBD will corrupt memory. Other changes I'd like to see introduced (like 
in the earlier jumbo patch) meanwhile are feature enhancements so they 
can wait. This patch also should address all the very helpful concerns 
that have been raised so far. Particularly:

1. that the very first submitted NBD patch was broken down [Andrew]
2. that only 1 spinlock is used for all the NBD request_queue structures 
used [Jens,Al]
3. that kmap() is used in case of highmem pages [Jens]
4. that the allocation of request_queue is dynamic and seperate from 
other allocated objects [Al]

If no one has any problems with this patch, would someone be so kind as 
to put it into the next distribution?