can now be developed in userspace using puffs for development
(I hate emulators, they are annoyingly clumsy).
To e.g. mount psshfs using puffs-on-puffs, run fs/bin/syspuffs/syspuffs
with the regular mount_psshfs command line as an argument:
golem> ./syspuffs /usr/sbin/mount_psshfs ftp.netbsd.org:/pub /puffs
This will make the mount appear as usual, with the exception that the
requests will be passed through puffs both in the kernel and userspace:
ftp.netbsd.org:/pub on /puffs type puffs|p2k|puffs|psshfs
the "disk driver" (rumpuser) call biodone() to indicate the completion
of I/O. Support for B_ASYNC is coming at some point, but I need
more locking support in the emulated vm for that.
locking and makes it possible to run file systems which create
threads. It also makes rump file system behaviour better match
file system behaviour in the kernel.
file system safe, but less performant as the kernel, as it syncs
*all* outstanding dirty buffers. However, we don't have much choice
in userspace currently.
accessors for:
* struct mount & VFS ops
* struct uio
* struct vnode
* struct vattr
and some namespace games for:
* namei flags
* VOPs
* enum vtype
Also, split rump services into two categories: library private and public
(rump_private.h and rump.h, respectively).
As a result, it is now possible to compile and use the NetBSD kernel
file systems on Linux (and probably other systems too with very
little work), although the makefiles need a bit of work to make it
a pleasureable experience.
/sys/rump contains programs which run unmodified kernel code in an
emulated userspace environment. The kernel environment is provided
by librump. Currently supported are a number of file systems,
which by using puffs integrate seamlessly into the system and
provide a similar user experience to if the code was running as
part of the kernel. Potential future rumpification targets include
for example parts of the networking stack and some device drivers.
This work was supported by Google Summer of Code 2007.
pooka