DragonFly kernel List (threaded) for 2006-01
Re: cowloop technology
:I'm more concerned about the concept than the perfomance. Im against
:the automatic creation and removal of files in /dev. Im sure the
:problems devfs tries to address is solvable in a much cleaner
:If Im not mistaken there was a similar thread here at these lists a
:year ago where Matt stated his own ideas for major / minor removal
There are a bunch of ways that /dev can be cleaned up, but it isn't
really a priority because while the current dev methodology is
sometimes inconvenient it still works just fine.
One method that would work would be to have a specially tagged directory
and then have the system parse device names in that directory. So
instead of having to create 37 /dev/ad0* files we would only have to
create one "/dev/ad0" and lookups of things like "/dev/ad0s1h" would
automatically be converted to "/dev/ad" with the "0s1h" part parsed
out and passed to the device code for further interpretation.
Instead of having major/minor numbers, the devices would be looked up
by name. so e.g. /dev/ad would locate ANY "ad" device.
One could even theoretically do away with the contents of /dev entirely
and simply parse the entire file name as a device. So one would then
only need a specially tagged, empty /dev directory and all accesses within
that directory would be parsed as devices. We could also allow specific
devices needing different permissions to be specified, such as
"/dev/ad0s1h", and "dev/ad" would still deal with all the loose ends.
The directory tagging could be implemented outside the filesystem
code using nullfs or something similar.
I do feel that it is important that devices still be integrated into
the filesystem namespace in some manner so permissions and ownership
can still be assigned, access and modification times updated, and so