From: Brian Behlendorf <behlendorf1@llnl.gov>
Subject: [PATCH] linux-kernel-device

This branch contains the majority of the changes required to cleanly
intergrate with Linux style special devices (/dev/zfs).  Mainly this
means dropping all the Solaris style callbacks and replacing them
with the Linux equivilants.  Additionally, this means slightly
expanding the zfs_ioc_* functions to include a 'struct file *' to
allow the tracking of private data for each open file descriptor.
This is very helpful when you need to maintain a little information
about the open file between ioctls().

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>