freebsd-nq/sys/coda
Poul-Henning Kamp bfbb9ce670 Divorce "dev_t" from the "major|minor" bitmap, which is now called
udev_t in the kernel but still called dev_t in userland.

Provide functions to manipulate both types:
        major()         umajor()
        minor()         uminor()
        makedev()       umakedev()
        dev2udev()      udev2dev()

For now they're functions, they will become in-line functions
after one of the next two steps in this process.

Return major/minor/makedev to macro-hood for userland.

Register a name in cdevsw[] for the "filedescriptor" driver.

In the kernel the udev_t appears in places where we have the
major/minor number combination, (ie: a potential device: we
may not have the driver nor the device), like in inodes, vattr,
cdevsw registration and so on, whereas the dev_t appears where
we carry around a reference to a actual device.

In the future the cdevsw and the aliased-from vnode will be hung
directly from the dev_t, along with up to two softc pointers for
the device driver and a few houskeeping bits.  This will essentially
replace the current "alias" check code (same buck, bigger bang).

A little stunt has been provided to try to catch places where the
wrong type is being used (dev_t vs udev_t), if you see something
not working, #undef DEVT_FASCIST in kern/kern_conf.c and see if
it makes a difference.  If it does, please try to track it down
(many hands make light work) or at least try to reproduce it
as simply as possible, and describe how to do that.

Without DEVT_FASCIST I belive this patch is a no-op.

Stylistic/posixoid comments about the userland view of the <sys/*.h>
files welcome now, from userland they now contain the end result.

Next planned step: make all dev_t's refer to the same devsw[] which
means convert BLK's to CHR's at the perimeter of the vnodes and
other places where they enter the game (bootdev, mknod, sysctl).
1999-05-11 19:55:07 +00:00
..
00READ Update 1998-10-28 19:39:12 +00:00
cnode.h coda_lookup now passes up an extra flag. But old veni will 1998-11-11 20:32:20 +00:00
coda_fbsd.c Fix warnings in preparation for adding -Wall -Wcast-qual to the 1999-01-28 00:57:57 +00:00
coda_io.h
coda_kernel.h
coda_namecache.c Venus must be passed O_CREAT flag on VOP_OPEN iff this is 1998-10-28 19:33:50 +00:00
coda_namecache.h
coda_opstats.h
coda_pioctl.h
coda_psdev.c Missed a stray LKM #ifdef 1999-01-17 21:04:53 +00:00
coda_psdev.h
coda_subr.c Clean up the KLD/LKM goop a bit. 1999-01-17 20:25:22 +00:00
coda_subr.h
coda_venus.c Divorce "dev_t" from the "major|minor" bitmap, which is now called 1999-05-11 19:55:07 +00:00
coda_venus.h
coda_vfsops.c remove cast from dev_t to dev_t. 1999-05-09 13:11:37 +00:00
coda_vfsops.h
coda_vnops.c Removed a bogus cast to c_caddr_t. This is part of terminating 1999-01-29 07:23:53 +00:00
coda_vnops.h
coda.h Divorce "dev_t" from the "major|minor" bitmap, which is now called 1999-05-11 19:55:07 +00:00
README
TODO

                Announcing the Availability of the
                        Coda Distributed
                           Filesystem
                              for
                         BSD Unix Systems

        Coda is a distributed file system like NFS and AFS.  It is
freely available, like NFS.  But it functions much like AFS in being a
"stateful" file system.  Coda and AFS cache files on your local
machine to improve performance.  But Coda goes a step further than AFS
by letting you access the cached files when there is no available
network, viz. disconnected laptops and network outages.  In Coda, both
the client and server are outside the kernel which makes them easier
to experiment with.

To get more information on Coda, I would like to refer people to
        http://www.coda.cs.cmu.edu
There is a wealth of documents, papers, and theses there.  There is
also a good introduction to the Coda File System in
        http://www.coda.cs.cmu.edu/ljpaper/lj.html

Coda was originally developed as an academic prototype/testbed.  It is
being polished and rewritten where necessary.  Coda is a work in
progress and does have bugs.  It is, though, very usable.  Our
interest is in making Coda available to as many people as possible and
to have Coda evolve and flourish.

The bulk of the Coda file system code supports the Coda client
program, the Coda server program and the utilities needed by both.
All these programs are unix programs and can run equally well on any
Unix platform.  Our main development thrust is improving these
programs.  There is a small part of Coda that deals with the kernel to
file system interface.  This code is OS specific (but should not be
platform specific).

Coda is currently available for several OS's and platforms:
        Freebsd-2.2.5: i386
        Freebsd-2.2.6: i386
	Freebsd -current: i386
        linux 2.0: i386 & sparc
        linux 2.1: i386 & sparc
        NetBSD 1.3: i386
	NetBSD -current: i386
The relevant sources, binaries, and docs can be found in
        ftp://ftp.coda.cs.cmu.edu/pub/coda/

We intend to come out with new Coda releases often, not daily.  We
don't want to slight any OS/platform not mentioned above.  We are just
limited in our resources as to what we can support internally.  We
will be happy to integrate OpenBSD support as well as other OS
support.  Also, adding platform support should be relatively easy and
we can discuss this.  The only difficulty is that Coda has a light weight
process package.  It does some manipulations in assembler which would
have to be redone for a different platform.

There are several mailing lists @coda.cs.cmu.edu that discuss coda:
coda-announce and linux-coda.  We are going to revise linux-coda to be
OS neutral, since it is mainly Coda we want to discuss.  We appreciate
comments, feedback, bug reports, bug fixes, enhancements, etc.