[Ocfs2-devel] [PATCH 1/2] Ocfs2: Add stuffs associated with ocfs2_info_request ioctls to ioctl.h

[Joel Becker <Joel.Becker@oracle.com>]

On Mon, Jan 04, 2010 at 10:36:15AM +0800, tristan wrote:
> Oh, I may misunderstand your words, Joel. Did you mean we only split the on-disk layout and ioctls into two parts(ocfs2_fs.h and ocfs2_ioctl.h) in ocfs2-tools for userspace,
> while kernel part still maintains one ocfs2_fs.h to cover both definitions for on-disk and ioctl strutures?

	No, I don't mean that.  I mean we have ocfs2_fs.h and
ocfs2_ioctl.h in both the kernel and the tools.

> If not, why we need maintain two ioctl headers in kernel part(ioctl.h and ocfs2_ioctl.h)?

	ioctl.h contains things that are only important inside the
kernel build; specifically, the declarations of the ioctl functions
called by file_operations.  No userspace program needs the declaration
of kernel code functions.   ocfs2_ioctl.h should contain the things a
userspace program needs to invoke the ioctls.  The IOC definitions and
any structures they use.
	Basically, anything ocfs2_*.h is a userspace header that can be
installed for userspace programs to use.  They get copied to ocfs2-tools
include/ocfs2-kernel.  All the other headers are kernel-only.

Joel


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Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127