* R <[EMAIL PROTECTED]> [071114 13:19]: > On Nov 14, 2007 1:44 PM, Iruata Souza <[EMAIL PROTECTED]> wrote: > > On 11/14/07, R <[EMAIL PROTECTED]> wrote: > > > OpenBSD already has filesystems in userland. Look for mount_xfs > > > (nothing to do with the SGI/linux thing). It is used by their afs client > > > implementation. > > > > > > > if you talking about /sbin/mount_xfs, it's just a mounter for the xfs > > filesystem. if you take a look at /sys/xfs you'll see what have to be > > done in the kernel. > > No, you're wrong ! > > You can write a new filesystem as a userland daemon - and have > it communicate with the kernel via a /dev/xfs* device. > There's no need for extra code in the kernel. > > In fact, that's exactly how afsd (the Andrew Filesystem client, part > of the standard distribution) is working.
You are both right. The AFS daemon runs in userspace. There has to be a kernel interface to get it into the systems namespace facility (here it is called VFS). For AFS this interface is very application specific (/dev/xfs) but Iru's approach would allow to write drivers in userspace and communicate with the kernel through an application independent interface. This is what 9p is all about... -- You may use my gpg key for replies: pub 1024D/47F79788 2005/02/02 Christian Kellermann (C-Keen)
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