* note that interfaces provided by <puffsdump.h> are not stable and
are to be used only for debug builds
* remove a few unimplemented/used dump interfaces
interacts with the userspace file server:
* since the kernel-user communication is not purely request-response
anymore (hasn't been since 2006), try to rename some "request" to
"message". more similar mangling will take place in the future.
* completely rework how messages are allocated. previously most of
them were borrowed from the stack (originally *all* of them),
but now always allocate dynamically. this makes the structure
of the code much cleaner. also makes it possible to fix a
locking order violation. it enables plenty of future enhancements.
* start generalizing the transport interface to be independent of puffs
* move transport interface to read/write instead of ioctl. the
old one had legacy design problems, and besides, ioctl's suck.
implement a very generic version for now; this will be
worked on later hopefully some day reaching "highly optimized".
* implement libpuffs support behind existing library request
interfaces. this will change eventually (I hate those interfaces)
This work was initially started and completed for Google SoC 2005
and tweaked to work a bit better in the past few weeks. While
being far from complete, it is functional enough to be able and
stable to host a fairly general-purpose in-memory file system in
userspace. Even so, puffs should be considered experimental and
no binary compatibility for interfaces or crash-freedom or zero
security implications should be relied upon just yet.
The GSoC project was mentored by William Studenmund and the final
review for the code was done by Christos.