[Stgt-devel] User-mode iSER

[Ming Zhang]

On Wed, 2006-08-02 at 07:21 +0900, FUJITA Tomonori wrote:
> From: Tom Tucker <tom at opengridcomputing.com>
> Subject: Re: [Stgt-devel] User-mode iSER
> Date: Tue, 01 Aug 2006 15:43:09 -0500
> 
> > > and it will be better if kernel/user space line is marked. so people
> > > know your intention and can comment in that if need. otherwise, i saw no
> > > difference from stgt or scst.
> > 
> > Attaches is a new picture with kernel/user boundaries. I think the
> > boundary is somewhat fuzzy at the top and bottom due to the fact that
> > the API is different for each target type and for each network provider
> > type. 
> > 
> > For example, the sd driver will use open /dev/sdN and submit ioctl to
> > read/write the disk, whereas the file target will
> > open("/home/thisandthat", ...) and submit lseek/read/write to read/write
> > the file.
> > 
> > On the network side, the TCP provider would use socket, listen, accept,
> > send, recv (at least initially), the RMDA provider would use
> > rdma_resolve_addr, rdma_resolve_route, rdma_listen, rdma_accept,
> > rdma_create_qp, rdma_post_send, etc....
> > 
> > My only point is that the kernel/user interface is not a straight line
> > since some of these interfaces are higher level than others.
> 
> Yes. Most of the tgt drivers (except for iSCSI tcp and iSER drivers)
> need their own in-kernel part. Oh, iSCSI hardware drivers (like
> qla4xxx) need the in-kernel part too.

can we say that u want the parts that need to handle interrupt and
registers in kernel and then hand to a common user-space scsi target
layer?



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