> > > Log Message:
> > > Note the fact that buffer cache takes block numbers in
> > > units of DEV_BSIZE, even if the device's device size is
> > > larger. Update date.
> > 
> > it's plainly wrong.
> 
> How is it plainly wrong?

the unit is filesystem specific.  normally it's a filesystem block size.
in the case of specfs, it's the same as what DEV_STRATEGY takes.
(ie. DEV_BSIZE, as you say.)

> I am very confused. As all the code I looked at actually works the way I
> describe in the change, I fail to see how it is "plainly wrong."
> Confusing, yes! Non-intuitive, yes! But that's what the code is doing now.

i guess you are mixing b_lblkno and b_blkno.

> However the units used for block numbers in the buffer cache really seems 
> to me to be appropriate for "man 9 buffercache". This behavior doesn't 
> seem to me to be at all specfs-specific, so it seems fine to document it 
> here; what specfs-level code does is also what buffer cache code has to 
> work with.

see above.
these interfaces are not dedicated to specfs.
if you want to document it here, you should write
"in the case of specfs", at least.

i guess what you really want is specfs(9),
deviceio(9) or something like them.

YAMAMOTO Takashi