userland VFS (was Re: vinum?)

[Matthew Dillon]

:In the future, this userspace VFS will be a substitute for the in-kernel VFS,
:or a complement used only for the not important filesystems such as
:those named in your mail? Will it be possible to write filesystems in userspace
:without a significant performance/functionality loss?

    Generally speaking any kernel VFS we have now will be compileable
    for either in-kernel or in-user operation.  When I'm all through, in fact,
    I want to have a userland infrastructure capable of loading VFS filesystem
    kernel modules into a userland environment.

    In regards to performance... there will always be performance degredation
    simply due to the overhead of switching and copying data, but it will
    certainly never be any worse then, say, an NFS mount.  And I don't hear
    many complaints about NFS performance, do you?

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>